nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "adt/bitfiddle.h"
  42 #include "adt/error.h"
  43 #include "adt/array.h"
  44
  45 //#define PRINT_TOKENS
  46 #define MAX_LOOKAHEAD 1
  47
  48 typedef struct {
  49         entity_t           *old_entity;
  50         symbol_t           *symbol;
  51         entity_namespace_t  namespc;
  52 } stack_entry_t;
  53
  54 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  55 struct declaration_specifiers_t {
  56         source_position_t  source_position;
  57         storage_class_t    storage_class;
  58         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  59         bool               is_inline    : 1;
  60         bool               thread_local : 1;  /**< GCC __thread */
  61         attribute_t       *attributes;        /**< list of attributes */
  62         type_t            *type;
  63 };
  64
  65 /**
  66  * An environment for parsing initializers (and compound literals).
  67  */
  68 typedef struct parse_initializer_env_t {
  69         type_t     *type;   /**< the type of the initializer. In case of an
  70                                  array type with unspecified size this gets
  71                                  adjusted to the actual size. */
  72         entity_t   *entity; /**< the variable that is initialized if any */
  73         bool        must_be_constant;
  74 } parse_initializer_env_t;
  75
  76 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  77
  78 /** The current token. */
  79 static token_t              token;
  80 /** The lookahead ring-buffer. */
  81 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  82 /** Position of the next token in the lookahead buffer. */
  83 static size_t               lookahead_bufpos;
  84 static stack_entry_t       *environment_stack = NULL;
  85 static stack_entry_t       *label_stack       = NULL;
  86 static scope_t             *file_scope        = NULL;
  87 static scope_t             *current_scope     = NULL;
  88 /** Point to the current function declaration if inside a function. */
  89 static function_t          *current_function  = NULL;
  90 static entity_t            *current_init_decl = NULL;
  91 static switch_statement_t  *current_switch    = NULL;
  92 static statement_t         *current_loop      = NULL;
  93 static statement_t         *current_parent    = NULL;
  94 static ms_try_statement_t  *current_try       = NULL;
  95 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  96 static goto_statement_t    *goto_first        = NULL;
  97 static goto_statement_t   **goto_anchor       = NULL;
  98 static label_statement_t   *label_first       = NULL;
  99 static label_statement_t  **label_anchor      = NULL;
 100 /** current translation unit. */
 101 static translation_unit_t  *unit              = NULL;
 102 /** true if we are in a type property context (evaluation only for type. */
 103 static bool                 in_type_prop      = false;
 104 /** true in we are in a __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109
 110
 111 #define PUSH_PARENT(stmt)                          \
 112         statement_t *const prev_parent = current_parent; \
 113         ((void)(current_parent = (stmt)))
 114 #define POP_PARENT ((void)(current_parent = prev_parent))
 115
 116 /** special symbol used for anonymous entities. */
 117 static const symbol_t *sym_anonymous = NULL;
 118
 119 /** The token anchor set */
 120 static unsigned char token_anchor_set[T_LAST_TOKEN];
 121
 122 /** The current source position. */
 123 #define HERE (&token.source_position)
 124
 125 /** true if we are in GCC mode. */
 126 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 127
 128 static statement_t *parse_compound_statement(bool inside_expression_statement);
 129 static statement_t *parse_statement(void);
 130
 131 static expression_t *parse_sub_expression(precedence_t);
 132 static expression_t *parse_expression(void);
 133 static type_t       *parse_typename(void);
 134 static void          parse_externals(void);
 135 static void          parse_external(void);
 136
 137 static void parse_compound_type_entries(compound_t *compound_declaration);
 138
 139 static void check_call_argument(type_t          *expected_type,
 140                                                                 call_argument_t *argument, unsigned pos);
 141
 142 typedef enum declarator_flags_t {
 143         DECL_FLAGS_NONE             = 0,
 144         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 145         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 146         DECL_IS_PARAMETER           = 1U << 2
 147 } declarator_flags_t;
 148
 149 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 150                                   declarator_flags_t flags);
 151
 152 static entity_t *record_entity(entity_t *entity, bool is_definition);
 153
 154 static void semantic_comparison(binary_expression_t *expression);
 155
 156 static void create_gnu_builtins(void);
 157 static void create_microsoft_intrinsics(void);
 158
 159 #define STORAGE_CLASSES       \
 160         STORAGE_CLASSES_NO_EXTERN \
 161         case T_extern:
 162
 163 #define STORAGE_CLASSES_NO_EXTERN \
 164         case T_typedef:         \
 165         case T_static:          \
 166         case T_auto:            \
 167         case T_register:        \
 168         case T___thread:
 169
 170 #define TYPE_QUALIFIERS     \
 171         case T_const:           \
 172         case T_restrict:        \
 173         case T_volatile:        \
 174         case T_inline:          \
 175         case T__forceinline:    \
 176         case T___attribute__:
 177
 178 #define COMPLEX_SPECIFIERS  \
 179         case T__Complex:
 180 #define IMAGINARY_SPECIFIERS \
 181         case T__Imaginary:
 182
 183 #define TYPE_SPECIFIERS       \
 184         case T__Bool:             \
 185         case T___builtin_va_list: \
 186         case T___typeof__:        \
 187         case T__declspec:         \
 188         case T_bool:              \
 189         case T_char:              \
 190         case T_double:            \
 191         case T_enum:              \
 192         case T_float:             \
 193         case T_int:               \
 194         case T_long:              \
 195         case T_short:             \
 196         case T_signed:            \
 197         case T_struct:            \
 198         case T_union:             \
 199         case T_unsigned:          \
 200         case T_void:              \
 201         case T_wchar_t:           \
 202         case T__int8:             \
 203         case T__int16:            \
 204         case T__int32:            \
 205         case T__int64:            \
 206         case T__int128:           \
 207         COMPLEX_SPECIFIERS        \
 208         IMAGINARY_SPECIFIERS
 209
 210 #define DECLARATION_START   \
 211         STORAGE_CLASSES         \
 212         TYPE_QUALIFIERS         \
 213         TYPE_SPECIFIERS
 214
 215 #define DECLARATION_START_NO_EXTERN \
 216         STORAGE_CLASSES_NO_EXTERN       \
 217         TYPE_QUALIFIERS                 \
 218         TYPE_SPECIFIERS
 219
 220 #define TYPENAME_START      \
 221         TYPE_QUALIFIERS         \
 222         TYPE_SPECIFIERS
 223
 224 #define EXPRESSION_START           \
 225         case '!':                        \
 226         case '&':                        \
 227         case '(':                        \
 228         case '*':                        \
 229         case '+':                        \
 230         case '-':                        \
 231         case '~':                        \
 232         case T_ANDAND:                   \
 233         case T_CHARACTER_CONSTANT:       \
 234         case T_FLOATINGPOINT:            \
 235         case T_INTEGER:                  \
 236         case T_MINUSMINUS:               \
 237         case T_PLUSPLUS:                 \
 238         case T_STRING_LITERAL:           \
 239         case T_WIDE_CHARACTER_CONSTANT:  \
 240         case T_WIDE_STRING_LITERAL:      \
 241         case T___FUNCDNAME__:            \
 242         case T___FUNCSIG__:              \
 243         case T___FUNCTION__:             \
 244         case T___PRETTY_FUNCTION__:      \
 245         case T___alignof__:              \
 246         case T___builtin_classify_type:  \
 247         case T___builtin_constant_p:     \
 248         case T___builtin_isgreater:      \
 249         case T___builtin_isgreaterequal: \
 250         case T___builtin_isless:         \
 251         case T___builtin_islessequal:    \
 252         case T___builtin_islessgreater:  \
 253         case T___builtin_isunordered:    \
 254         case T___builtin_offsetof:       \
 255         case T___builtin_va_arg:         \
 256         case T___builtin_va_start:       \
 257         case T___builtin_va_copy:        \
 258         case T___func__:                 \
 259         case T___noop:                   \
 260         case T__assume:                  \
 261         case T_delete:                   \
 262         case T_false:                    \
 263         case T_sizeof:                   \
 264         case T_throw:                    \
 265         case T_true:
 266
 267 /**
 268  * Allocate an AST node with given size and
 269  * initialize all fields with zero.
 270  */
 271 static void *allocate_ast_zero(size_t size)
 272 {
 273         void *res = allocate_ast(size);
 274         memset(res, 0, size);
 275         return res;
 276 }
 277
 278 /**
 279  * Returns the size of an entity node.
 280  *
 281  * @param kind  the entity kind
 282  */
 283 static size_t get_entity_struct_size(entity_kind_t kind)
 284 {
 285         static const size_t sizes[] = {
 286                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 287                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 288                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 289                 [ENTITY_FUNCTION]        = sizeof(function_t),
 290                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 291                 [ENTITY_STRUCT]          = sizeof(compound_t),
 292                 [ENTITY_UNION]           = sizeof(compound_t),
 293                 [ENTITY_ENUM]            = sizeof(enum_t),
 294                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 295                 [ENTITY_LABEL]           = sizeof(label_t),
 296                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 297                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 298         };
 299         assert(kind < lengthof(sizes));
 300         assert(sizes[kind] != 0);
 301         return sizes[kind];
 302 }
 303
 304 /**
 305  * Allocate an entity of given kind and initialize all
 306  * fields with zero.
 307  *
 308  * @param kind   the kind of the entity to allocate
 309  */
 310 static entity_t *allocate_entity_zero(entity_kind_t kind)
 311 {
 312         size_t    size   = get_entity_struct_size(kind);
 313         entity_t *entity = allocate_ast_zero(size);
 314         entity->kind     = kind;
 315         return entity;
 316 }
 317
 318 /**
 319  * Returns the size of a statement node.
 320  *
 321  * @param kind  the statement kind
 322  */
 323 static size_t get_statement_struct_size(statement_kind_t kind)
 324 {
 325         static const size_t sizes[] = {
 326                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 327                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 328                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 329                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 330                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 331                 [STATEMENT_IF]          = sizeof(if_statement_t),
 332                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 333                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 334                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 335                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 336                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 337                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 338                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 339                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 340                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 341                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 342                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 343                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 344                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 345         };
 346         assert(kind < lengthof(sizes));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 /**
 352  * Returns the size of an expression node.
 353  *
 354  * @param kind  the expression kind
 355  */
 356 static size_t get_expression_struct_size(expression_kind_t kind)
 357 {
 358         static const size_t sizes[] = {
 359                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 360                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 361                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 362                 [EXPR_CONST]                      = sizeof(const_expression_t),
 363                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 364                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 365                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 366                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 367                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 368                 [EXPR_CALL]                       = sizeof(call_expression_t),
 369                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 370                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 371                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 372                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 373                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 374                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 375                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 376                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 377                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 378                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 379                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 380                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 381                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 382                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 383                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 384                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 385                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 386         };
 387         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 388                 return sizes[EXPR_UNARY_FIRST];
 389         }
 390         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 391                 return sizes[EXPR_BINARY_FIRST];
 392         }
 393         assert(kind < lengthof(sizes));
 394         assert(sizes[kind] != 0);
 395         return sizes[kind];
 396 }
 397
 398 /**
 399  * Allocate a statement node of given kind and initialize all
 400  * fields with zero. Sets its source position to the position
 401  * of the current token.
 402  */
 403 static statement_t *allocate_statement_zero(statement_kind_t kind)
 404 {
 405         size_t       size = get_statement_struct_size(kind);
 406         statement_t *res  = allocate_ast_zero(size);
 407
 408         res->base.kind            = kind;
 409         res->base.parent          = current_parent;
 410         res->base.source_position = token.source_position;
 411         return res;
 412 }
 413
 414 /**
 415  * Allocate an expression node of given kind and initialize all
 416  * fields with zero.
 417  *
 418  * @param kind  the kind of the expression to allocate
 419  */
 420 static expression_t *allocate_expression_zero(expression_kind_t kind)
 421 {
 422         size_t        size = get_expression_struct_size(kind);
 423         expression_t *res  = allocate_ast_zero(size);
 424
 425         res->base.kind            = kind;
 426         res->base.type            = type_error_type;
 427         res->base.source_position = token.source_position;
 428         return res;
 429 }
 430
 431 /**
 432  * Creates a new invalid expression at the source position
 433  * of the current token.
 434  */
 435 static expression_t *create_invalid_expression(void)
 436 {
 437         return allocate_expression_zero(EXPR_INVALID);
 438 }
 439
 440 /**
 441  * Creates a new invalid statement.
 442  */
 443 static statement_t *create_invalid_statement(void)
 444 {
 445         return allocate_statement_zero(STATEMENT_INVALID);
 446 }
 447
 448 /**
 449  * Allocate a new empty statement.
 450  */
 451 static statement_t *create_empty_statement(void)
 452 {
 453         return allocate_statement_zero(STATEMENT_EMPTY);
 454 }
 455
 456 /**
 457  * Returns the size of a type node.
 458  *
 459  * @param kind  the type kind
 460  */
 461 static size_t get_type_struct_size(type_kind_t kind)
 462 {
 463         static const size_t sizes[] = {
 464                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 465                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 466                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 467                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 468                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 469                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 470                 [TYPE_ENUM]            = sizeof(enum_type_t),
 471                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 472                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 473                 [TYPE_ARRAY]           = sizeof(array_type_t),
 474                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 475                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 476                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 477         };
 478         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 479         assert(kind <= TYPE_TYPEOF);
 480         assert(sizes[kind] != 0);
 481         return sizes[kind];
 482 }
 483
 484 /**
 485  * Allocate a type node of given kind and initialize all
 486  * fields with zero.
 487  *
 488  * @param kind             type kind to allocate
 489  */
 490 static type_t *allocate_type_zero(type_kind_t kind)
 491 {
 492         size_t  size = get_type_struct_size(kind);
 493         type_t *res  = obstack_alloc(type_obst, size);
 494         memset(res, 0, size);
 495         res->base.kind = kind;
 496
 497         return res;
 498 }
 499
 500 static function_parameter_t *allocate_parameter(type_t *const type)
 501 {
 502         function_parameter_t *const param = obstack_alloc(type_obst, sizeof(*param));
 503         memset(param, 0, sizeof(*param));
 504         param->type = type;
 505         return param;
 506 }
 507
 508 /**
 509  * Returns the size of an initializer node.
 510  *
 511  * @param kind  the initializer kind
 512  */
 513 static size_t get_initializer_size(initializer_kind_t kind)
 514 {
 515         static const size_t sizes[] = {
 516                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 517                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 518                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 519                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 520                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 521         };
 522         assert(kind < lengthof(sizes));
 523         assert(sizes[kind] != 0);
 524         return sizes[kind];
 525 }
 526
 527 /**
 528  * Allocate an initializer node of given kind and initialize all
 529  * fields with zero.
 530  */
 531 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 532 {
 533         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 534         result->kind          = kind;
 535
 536         return result;
 537 }
 538
 539 /**
 540  * Returns the index of the top element of the environment stack.
 541  */
 542 static size_t environment_top(void)
 543 {
 544         return ARR_LEN(environment_stack);
 545 }
 546
 547 /**
 548  * Returns the index of the top element of the global label stack.
 549  */
 550 static size_t label_top(void)
 551 {
 552         return ARR_LEN(label_stack);
 553 }
 554
 555 /**
 556  * Return the next token.
 557  */
 558 static inline void next_token(void)
 559 {
 560         token                              = lookahead_buffer[lookahead_bufpos];
 561         lookahead_buffer[lookahead_bufpos] = lexer_token;
 562         lexer_next_token();
 563
 564         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 565
 566 #ifdef PRINT_TOKENS
 567         print_token(stderr, &token);
 568         fprintf(stderr, "\n");
 569 #endif
 570 }
 571
 572 /**
 573  * Return the next token with a given lookahead.
 574  */
 575 static inline const token_t *look_ahead(size_t num)
 576 {
 577         assert(0 < num && num <= MAX_LOOKAHEAD);
 578         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 579         return &lookahead_buffer[pos];
 580 }
 581
 582 /**
 583  * Adds a token type to the token type anchor set (a multi-set).
 584  */
 585 static void add_anchor_token(int token_type)
 586 {
 587         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 588         ++token_anchor_set[token_type];
 589 }
 590
 591 /**
 592  * Set the number of tokens types of the given type
 593  * to zero and return the old count.
 594  */
 595 static int save_and_reset_anchor_state(int token_type)
 596 {
 597         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 598         int count = token_anchor_set[token_type];
 599         token_anchor_set[token_type] = 0;
 600         return count;
 601 }
 602
 603 /**
 604  * Restore the number of token types to the given count.
 605  */
 606 static void restore_anchor_state(int token_type, int count)
 607 {
 608         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 609         token_anchor_set[token_type] = count;
 610 }
 611
 612 /**
 613  * Remove a token type from the token type anchor set (a multi-set).
 614  */
 615 static void rem_anchor_token(int token_type)
 616 {
 617         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 618         assert(token_anchor_set[token_type] != 0);
 619         --token_anchor_set[token_type];
 620 }
 621
 622 /**
 623  * Return true if the token type of the current token is
 624  * in the anchor set.
 625  */
 626 static bool at_anchor(void)
 627 {
 628         if (token.type < 0)
 629                 return false;
 630         return token_anchor_set[token.type];
 631 }
 632
 633 /**
 634  * Eat tokens until a matching token type is found.
 635  */
 636 static void eat_until_matching_token(int type)
 637 {
 638         int end_token;
 639         switch (type) {
 640                 case '(': end_token = ')';  break;
 641                 case '{': end_token = '}';  break;
 642                 case '[': end_token = ']';  break;
 643                 default:  end_token = type; break;
 644         }
 645
 646         unsigned parenthesis_count = 0;
 647         unsigned brace_count       = 0;
 648         unsigned bracket_count     = 0;
 649         while (token.type        != end_token ||
 650                parenthesis_count != 0         ||
 651                brace_count       != 0         ||
 652                bracket_count     != 0) {
 653                 switch (token.type) {
 654                 case T_EOF: return;
 655                 case '(': ++parenthesis_count; break;
 656                 case '{': ++brace_count;       break;
 657                 case '[': ++bracket_count;     break;
 658
 659                 case ')':
 660                         if (parenthesis_count > 0)
 661                                 --parenthesis_count;
 662                         goto check_stop;
 663
 664                 case '}':
 665                         if (brace_count > 0)
 666                                 --brace_count;
 667                         goto check_stop;
 668
 669                 case ']':
 670                         if (bracket_count > 0)
 671                                 --bracket_count;
 672 check_stop:
 673                         if (token.type        == end_token &&
 674                             parenthesis_count == 0         &&
 675                             brace_count       == 0         &&
 676                             bracket_count     == 0)
 677                                 return;
 678                         break;
 679
 680                 default:
 681                         break;
 682                 }
 683                 next_token();
 684         }
 685 }
 686
 687 /**
 688  * Eat input tokens until an anchor is found.
 689  */
 690 static void eat_until_anchor(void)
 691 {
 692         while (token_anchor_set[token.type] == 0) {
 693                 if (token.type == '(' || token.type == '{' || token.type == '[')
 694                         eat_until_matching_token(token.type);
 695                 next_token();
 696         }
 697 }
 698
 699 /**
 700  * Eat a whole block from input tokens.
 701  */
 702 static void eat_block(void)
 703 {
 704         eat_until_matching_token('{');
 705         if (token.type == '}')
 706                 next_token();
 707 }
 708
 709 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 710
 711 /**
 712  * Report a parse error because an expected token was not found.
 713  */
 714 static
 715 #if defined __GNUC__ && __GNUC__ >= 4
 716 __attribute__((sentinel))
 717 #endif
 718 void parse_error_expected(const char *message, ...)
 719 {
 720         if (message != NULL) {
 721                 errorf(HERE, "%s", message);
 722         }
 723         va_list ap;
 724         va_start(ap, message);
 725         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 726         va_end(ap);
 727 }
 728
 729 /**
 730  * Report an incompatible type.
 731  */
 732 static void type_error_incompatible(const char *msg,
 733                 const source_position_t *source_position, type_t *type1, type_t *type2)
 734 {
 735         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 736                msg, type1, type2);
 737 }
 738
 739 /**
 740  * Expect the current token is the expected token.
 741  * If not, generate an error, eat the current statement,
 742  * and goto the end_error label.
 743  */
 744 #define expect(expected, error_label)                     \
 745         do {                                                  \
 746                 if (UNLIKELY(token.type != (expected))) {         \
 747                         parse_error_expected(NULL, (expected), NULL); \
 748                         add_anchor_token(expected);                   \
 749                         eat_until_anchor();                           \
 750                         if (token.type == expected)                   \
 751                                 next_token();                             \
 752                         rem_anchor_token(expected);                   \
 753                         goto error_label;                             \
 754                 }                                                 \
 755                 next_token();                                     \
 756         } while (0)
 757
 758 /**
 759  * Push a given scope on the scope stack and make it the
 760  * current scope
 761  */
 762 static scope_t *scope_push(scope_t *new_scope)
 763 {
 764         if (current_scope != NULL) {
 765                 new_scope->depth = current_scope->depth + 1;
 766         }
 767
 768         scope_t *old_scope = current_scope;
 769         current_scope      = new_scope;
 770         return old_scope;
 771 }
 772
 773 /**
 774  * Pop the current scope from the scope stack.
 775  */
 776 static void scope_pop(scope_t *old_scope)
 777 {
 778         current_scope = old_scope;
 779 }
 780
 781 /**
 782  * Search an entity by its symbol in a given namespace.
 783  */
 784 static entity_t *get_entity(const symbol_t *const symbol,
 785                             namespace_tag_t namespc)
 786 {
 787         entity_t *entity = symbol->entity;
 788         for (; entity != NULL; entity = entity->base.symbol_next) {
 789                 if (entity->base.namespc == namespc)
 790                         return entity;
 791         }
 792
 793         return NULL;
 794 }
 795
 796 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 797  * possible. */
 798 static entity_t *get_tag(symbol_t const *const symbol,
 799                 entity_kind_tag_t const kind)
 800 {
 801         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 802         if (entity != NULL && entity->kind != kind) {
 803                 errorf(HERE,
 804                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 805                                 symbol, &entity->base.source_position);
 806                 entity = NULL;
 807         }
 808         return entity;
 809 }
 810
 811 /**
 812  * pushs an entity on the environment stack and links the corresponding symbol
 813  * it.
 814  */
 815 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 816 {
 817         symbol_t           *symbol  = entity->base.symbol;
 818         entity_namespace_t  namespc = entity->base.namespc;
 819         assert(namespc != NAMESPACE_INVALID);
 820
 821         /* replace/add entity into entity list of the symbol */
 822         entity_t **anchor;
 823         entity_t  *iter;
 824         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 825                 iter = *anchor;
 826                 if (iter == NULL)
 827                         break;
 828
 829                 /* replace an entry? */
 830                 if (iter->base.namespc == namespc) {
 831                         entity->base.symbol_next = iter->base.symbol_next;
 832                         break;
 833                 }
 834         }
 835         *anchor = entity;
 836
 837         /* remember old declaration */
 838         stack_entry_t entry;
 839         entry.symbol     = symbol;
 840         entry.old_entity = iter;
 841         entry.namespc    = namespc;
 842         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 843 }
 844
 845 /**
 846  * Push an entity on the environment stack.
 847  */
 848 static void environment_push(entity_t *entity)
 849 {
 850         assert(entity->base.source_position.input_name != NULL);
 851         assert(entity->base.parent_scope != NULL);
 852         stack_push(&environment_stack, entity);
 853 }
 854
 855 /**
 856  * Push a declaration on the global label stack.
 857  *
 858  * @param declaration  the declaration
 859  */
 860 static void label_push(entity_t *label)
 861 {
 862         /* we abuse the parameters scope as parent for the labels */
 863         label->base.parent_scope = &current_function->parameters;
 864         stack_push(&label_stack, label);
 865 }
 866
 867 /**
 868  * pops symbols from the environment stack until @p new_top is the top element
 869  */
 870 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 871 {
 872         stack_entry_t *stack = *stack_ptr;
 873         size_t         top   = ARR_LEN(stack);
 874         size_t         i;
 875
 876         assert(new_top <= top);
 877         if (new_top == top)
 878                 return;
 879
 880         for (i = top; i > new_top; --i) {
 881                 stack_entry_t *entry = &stack[i - 1];
 882
 883                 entity_t           *old_entity = entry->old_entity;
 884                 symbol_t           *symbol     = entry->symbol;
 885                 entity_namespace_t  namespc    = entry->namespc;
 886
 887                 /* replace with old_entity/remove */
 888                 entity_t **anchor;
 889                 entity_t  *iter;
 890                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 891                         iter = *anchor;
 892                         assert(iter != NULL);
 893                         /* replace an entry? */
 894                         if (iter->base.namespc == namespc)
 895                                 break;
 896                 }
 897
 898                 /* restore definition from outer scopes (if there was one) */
 899                 if (old_entity != NULL) {
 900                         old_entity->base.symbol_next = iter->base.symbol_next;
 901                         *anchor                      = old_entity;
 902                 } else {
 903                         /* remove entry from list */
 904                         *anchor = iter->base.symbol_next;
 905                 }
 906         }
 907
 908         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 909 }
 910
 911 /**
 912  * Pop all entries from the environment stack until the new_top
 913  * is reached.
 914  *
 915  * @param new_top  the new stack top
 916  */
 917 static void environment_pop_to(size_t new_top)
 918 {
 919         stack_pop_to(&environment_stack, new_top);
 920 }
 921
 922 /**
 923  * Pop all entries from the global label stack until the new_top
 924  * is reached.
 925  *
 926  * @param new_top  the new stack top
 927  */
 928 static void label_pop_to(size_t new_top)
 929 {
 930         stack_pop_to(&label_stack, new_top);
 931 }
 932
 933 static int get_akind_rank(atomic_type_kind_t akind)
 934 {
 935         return (int) akind;
 936 }
 937
 938 /**
 939  * Return the type rank for an atomic type.
 940  */
 941 static int get_rank(const type_t *type)
 942 {
 943         assert(!is_typeref(type));
 944         if (type->kind == TYPE_ENUM)
 945                 return get_akind_rank(type->enumt.akind);
 946
 947         assert(type->kind == TYPE_ATOMIC);
 948         return get_akind_rank(type->atomic.akind);
 949 }
 950
 951 /**
 952  * §6.3.1.1:2  Do integer promotion for a given type.
 953  *
 954  * @param type  the type to promote
 955  * @return the promoted type
 956  */
 957 static type_t *promote_integer(type_t *type)
 958 {
 959         if (type->kind == TYPE_BITFIELD)
 960                 type = type->bitfield.base_type;
 961
 962         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 963                 type = type_int;
 964
 965         return type;
 966 }
 967
 968 /**
 969  * Create a cast expression.
 970  *
 971  * @param expression  the expression to cast
 972  * @param dest_type   the destination type
 973  */
 974 static expression_t *create_cast_expression(expression_t *expression,
 975                                             type_t *dest_type)
 976 {
 977         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 978
 979         cast->unary.value = expression;
 980         cast->base.type   = dest_type;
 981
 982         return cast;
 983 }
 984
 985 /**
 986  * Check if a given expression represents a null pointer constant.
 987  *
 988  * @param expression  the expression to check
 989  */
 990 static bool is_null_pointer_constant(const expression_t *expression)
 991 {
 992         /* skip void* cast */
 993         if (expression->kind == EXPR_UNARY_CAST ||
 994                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 995                 type_t *const type = skip_typeref(expression->base.type);
 996                 if (types_compatible(type, type_void_ptr))
 997                         expression = expression->unary.value;
 998         }
 999
1000         type_t *const type = skip_typeref(expression->base.type);
1001         return
1002                 is_type_integer(type)              &&
1003                 is_constant_expression(expression) &&
1004                 !fold_constant_to_bool(expression);
1005 }
1006
1007 /**
1008  * Create an implicit cast expression.
1009  *
1010  * @param expression  the expression to cast
1011  * @param dest_type   the destination type
1012  */
1013 static expression_t *create_implicit_cast(expression_t *expression,
1014                                           type_t *dest_type)
1015 {
1016         type_t *const source_type = expression->base.type;
1017
1018         if (source_type == dest_type)
1019                 return expression;
1020
1021         return create_cast_expression(expression, dest_type);
1022 }
1023
1024 typedef enum assign_error_t {
1025         ASSIGN_SUCCESS,
1026         ASSIGN_ERROR_INCOMPATIBLE,
1027         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1028         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1029         ASSIGN_WARNING_POINTER_FROM_INT,
1030         ASSIGN_WARNING_INT_FROM_POINTER
1031 } assign_error_t;
1032
1033 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1034                                 const expression_t *const right,
1035                                 const char *context,
1036                                 const source_position_t *source_position)
1037 {
1038         type_t *const orig_type_right = right->base.type;
1039         type_t *const type_left       = skip_typeref(orig_type_left);
1040         type_t *const type_right      = skip_typeref(orig_type_right);
1041
1042         switch (error) {
1043         case ASSIGN_SUCCESS:
1044                 return;
1045         case ASSIGN_ERROR_INCOMPATIBLE:
1046                 errorf(source_position,
1047                        "destination type '%T' in %s is incompatible with type '%T'",
1048                        orig_type_left, context, orig_type_right);
1049                 return;
1050
1051         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1052                 if (warning.other) {
1053                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1054                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1055
1056                         /* the left type has all qualifiers from the right type */
1057                         unsigned missing_qualifiers
1058                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1059                         warningf(source_position,
1060                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1061                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1062                 }
1063                 return;
1064         }
1065
1066         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1067                 if (warning.other) {
1068                         warningf(source_position,
1069                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1070                                         orig_type_left, context, right, orig_type_right);
1071                 }
1072                 return;
1073
1074         case ASSIGN_WARNING_POINTER_FROM_INT:
1075                 if (warning.other) {
1076                         warningf(source_position,
1077                                         "%s makes pointer '%T' from integer '%T' without a cast",
1078                                         context, orig_type_left, orig_type_right);
1079                 }
1080                 return;
1081
1082         case ASSIGN_WARNING_INT_FROM_POINTER:
1083                 if (warning.other) {
1084                         warningf(source_position,
1085                                         "%s makes integer '%T' from pointer '%T' without a cast",
1086                                         context, orig_type_left, orig_type_right);
1087                 }
1088                 return;
1089
1090         default:
1091                 panic("invalid error value");
1092         }
1093 }
1094
1095 /** Implements the rules from §6.5.16.1 */
1096 static assign_error_t semantic_assign(type_t *orig_type_left,
1097                                       const expression_t *const right)
1098 {
1099         type_t *const orig_type_right = right->base.type;
1100         type_t *const type_left       = skip_typeref(orig_type_left);
1101         type_t *const type_right      = skip_typeref(orig_type_right);
1102
1103         if (is_type_pointer(type_left)) {
1104                 if (is_null_pointer_constant(right)) {
1105                         return ASSIGN_SUCCESS;
1106                 } else if (is_type_pointer(type_right)) {
1107                         type_t *points_to_left
1108                                 = skip_typeref(type_left->pointer.points_to);
1109                         type_t *points_to_right
1110                                 = skip_typeref(type_right->pointer.points_to);
1111                         assign_error_t res = ASSIGN_SUCCESS;
1112
1113                         /* the left type has all qualifiers from the right type */
1114                         unsigned missing_qualifiers
1115                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1116                         if (missing_qualifiers != 0) {
1117                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1118                         }
1119
1120                         points_to_left  = get_unqualified_type(points_to_left);
1121                         points_to_right = get_unqualified_type(points_to_right);
1122
1123                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1124                                 return res;
1125
1126                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1127                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1128                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1129                         }
1130
1131                         if (!types_compatible(points_to_left, points_to_right)) {
1132                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1133                         }
1134
1135                         return res;
1136                 } else if (is_type_integer(type_right)) {
1137                         return ASSIGN_WARNING_POINTER_FROM_INT;
1138                 }
1139         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1140             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1141                 && is_type_pointer(type_right))) {
1142                 return ASSIGN_SUCCESS;
1143         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1144                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1145                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1146                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1147                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1148                         return ASSIGN_SUCCESS;
1149                 }
1150         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1151                 return ASSIGN_WARNING_INT_FROM_POINTER;
1152         }
1153
1154         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1155                 return ASSIGN_SUCCESS;
1156
1157         return ASSIGN_ERROR_INCOMPATIBLE;
1158 }
1159
1160 static expression_t *parse_constant_expression(void)
1161 {
1162         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1163
1164         if (!is_constant_expression(result)) {
1165                 errorf(&result->base.source_position,
1166                        "expression '%E' is not constant", result);
1167         }
1168
1169         return result;
1170 }
1171
1172 static expression_t *parse_assignment_expression(void)
1173 {
1174         return parse_sub_expression(PREC_ASSIGNMENT);
1175 }
1176
1177 static string_t parse_string_literals(void)
1178 {
1179         assert(token.type == T_STRING_LITERAL);
1180         string_t result = token.v.string;
1181
1182         next_token();
1183
1184         while (token.type == T_STRING_LITERAL) {
1185                 result = concat_strings(&result, &token.v.string);
1186                 next_token();
1187         }
1188
1189         return result;
1190 }
1191
1192 /**
1193  * compare two string, ignoring double underscores on the second.
1194  */
1195 static int strcmp_underscore(const char *s1, const char *s2)
1196 {
1197         if (s2[0] == '_' && s2[1] == '_') {
1198                 size_t len2 = strlen(s2);
1199                 size_t len1 = strlen(s1);
1200                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1201                         return strncmp(s1, s2+2, len2-4);
1202                 }
1203         }
1204
1205         return strcmp(s1, s2);
1206 }
1207
1208 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1209 {
1210         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1211         attribute->kind        = kind;
1212         return attribute;
1213 }
1214
1215 /**
1216  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1217  *
1218  *  attribute:
1219  *    __attribute__ ( ( attribute-list ) )
1220  *
1221  *  attribute-list:
1222  *    attrib
1223  *    attribute_list , attrib
1224  *
1225  *  attrib:
1226  *    empty
1227  *    any-word
1228  *    any-word ( identifier )
1229  *    any-word ( identifier , nonempty-expr-list )
1230  *    any-word ( expr-list )
1231  *
1232  *  where the "identifier" must not be declared as a type, and
1233  *  "any-word" may be any identifier (including one declared as a
1234  *  type), a reserved word storage class specifier, type specifier or
1235  *  type qualifier.  ??? This still leaves out most reserved keywords
1236  *  (following the old parser), shouldn't we include them, and why not
1237  *  allow identifiers declared as types to start the arguments?
1238  *
1239  *  Matze: this all looks confusing and little systematic, so we're even less
1240  *  strict and parse any list of things which are identifiers or
1241  *  (assignment-)expressions.
1242  */
1243 static attribute_argument_t *parse_attribute_arguments(void)
1244 {
1245         if (token.type == ')')
1246                 return NULL;
1247
1248         attribute_argument_t *first = NULL;
1249         attribute_argument_t *last  = NULL;
1250         while (true) {
1251                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1252
1253                 /* is it an identifier */
1254                 if (token.type == T_IDENTIFIER
1255                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1256                         symbol_t *symbol   = token.v.symbol;
1257                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1258                         argument->v.symbol = symbol;
1259                         next_token();
1260                 } else {
1261                         /* must be an expression */
1262                         expression_t *expression = parse_assignment_expression();
1263
1264                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1265                         argument->v.expression = expression;
1266                 }
1267
1268                 /* append argument */
1269                 if (last == NULL) {
1270                         first = argument;
1271                 } else {
1272                         last->next = argument;
1273                 }
1274                 last = argument;
1275
1276                 if (token.type == ',') {
1277                         next_token();
1278                         continue;
1279                 }
1280                 expect(')', end_error);
1281                 break;
1282         }
1283
1284         return first;
1285
1286 end_error:
1287         /* TODO... */
1288         return first;
1289 }
1290
1291 static attribute_t *parse_attribute_asm(void)
1292 {
1293         eat(T_asm);
1294
1295         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1296
1297         expect('(', end_error);
1298         attribute->a.arguments = parse_attribute_arguments();
1299         return attribute;
1300
1301 end_error:
1302         return NULL;
1303 }
1304
1305 static symbol_t *get_symbol_from_token(void)
1306 {
1307         switch(token.type) {
1308         case T_IDENTIFIER:
1309                 return token.v.symbol;
1310         case T_auto:
1311         case T_char:
1312         case T_double:
1313         case T_enum:
1314         case T_extern:
1315         case T_float:
1316         case T_int:
1317         case T_long:
1318         case T_register:
1319         case T_short:
1320         case T_static:
1321         case T_struct:
1322         case T_union:
1323         case T_unsigned:
1324         case T_void:
1325         case T_bool:
1326         case T__Bool:
1327         case T_class:
1328         case T_explicit:
1329         case T_export:
1330         case T_wchar_t:
1331         case T_const:
1332         case T_signed:
1333         case T___real__:
1334         case T___imag__:
1335         case T_restrict:
1336         case T_volatile:
1337         case T_inline:
1338                 /* maybe we need more tokens ... add them on demand */
1339                 return get_token_symbol(&token);
1340         default:
1341                 return NULL;
1342         }
1343 }
1344
1345 static attribute_t *parse_attribute_gnu_single(void)
1346 {
1347         /* parse "any-word" */
1348         symbol_t *symbol = get_symbol_from_token();
1349         if (symbol == NULL) {
1350                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1351                 goto end_error;
1352         }
1353
1354         const char *name = symbol->string;
1355         next_token();
1356
1357         attribute_kind_t kind;
1358         for (kind = ATTRIBUTE_GNU_FIRST; kind <= ATTRIBUTE_GNU_LAST; ++kind) {
1359                 const char *attribute_name = get_attribute_name(kind);
1360                 if (attribute_name != NULL
1361                                 && strcmp_underscore(attribute_name, name) == 0)
1362                         break;
1363         }
1364
1365         if (kind >= ATTRIBUTE_GNU_LAST) {
1366                 if (warning.attribute) {
1367                         warningf(HERE, "unknown attribute '%s' ignored", name);
1368                 }
1369                 /* TODO: we should still save the attribute in the list... */
1370                 kind = ATTRIBUTE_UNKNOWN;
1371         }
1372
1373         attribute_t *attribute = allocate_attribute_zero(kind);
1374
1375         /* parse arguments */
1376         if (token.type == '(') {
1377                 next_token();
1378                 attribute->a.arguments = parse_attribute_arguments();
1379         }
1380
1381         return attribute;
1382
1383 end_error:
1384         return NULL;
1385 }
1386
1387 static attribute_t *parse_attribute_gnu(void)
1388 {
1389         attribute_t *first = NULL;
1390         attribute_t *last  = NULL;
1391
1392         eat(T___attribute__);
1393         expect('(', end_error);
1394         expect('(', end_error);
1395
1396         if (token.type == ')') {
1397                 next_token();
1398                 expect(')', end_error);
1399                 return first;
1400         }
1401
1402         while (true) {
1403                 attribute_t *attribute = parse_attribute_gnu_single();
1404                 if (attribute == NULL)
1405                         goto end_error;
1406
1407                 if (last == NULL) {
1408                         first = attribute;
1409                 } else {
1410                         last->next = attribute;
1411                 }
1412                 last = attribute;
1413
1414                 if (token.type == ')') {
1415                         next_token();
1416                         break;
1417                 }
1418                 expect(',', end_error);
1419         }
1420         expect(')', end_error);
1421
1422 end_error:
1423         return first;
1424 }
1425
1426 /** Parse attributes. */
1427 static attribute_t *parse_attributes(attribute_t *first)
1428 {
1429         attribute_t *last = first;
1430         while (true) {
1431                 if (last != NULL) {
1432                         while (last->next != NULL)
1433                                 last = last->next;
1434                 }
1435
1436                 attribute_t *attribute;
1437                 switch (token.type) {
1438                 case T___attribute__:
1439                         attribute = parse_attribute_gnu();
1440                         break;
1441
1442                 case T_asm:
1443                         attribute = parse_attribute_asm();
1444                         break;
1445
1446                 case T_cdecl:
1447                         next_token();
1448                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1449                         break;
1450
1451                 case T__fastcall:
1452                         next_token();
1453                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1454                         break;
1455
1456                 case T__forceinline:
1457                         next_token();
1458                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1459                         break;
1460
1461                 case T__stdcall:
1462                         next_token();
1463                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1464                         break;
1465
1466                 case T___thiscall:
1467                         next_token();
1468                         /* TODO record modifier */
1469                         if (warning.other)
1470                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1471                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1472                         break;
1473
1474                 default:
1475                         return first;
1476                 }
1477
1478                 if (last == NULL) {
1479                         first = attribute;
1480                 } else {
1481                         last->next = attribute;
1482                 }
1483                 last = attribute;
1484         }
1485 }
1486
1487 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1488
1489 static entity_t *determine_lhs_ent(expression_t *const expr,
1490                                    entity_t *lhs_ent)
1491 {
1492         switch (expr->kind) {
1493                 case EXPR_REFERENCE: {
1494                         entity_t *const entity = expr->reference.entity;
1495                         /* we should only find variables as lvalues... */
1496                         if (entity->base.kind != ENTITY_VARIABLE
1497                                         && entity->base.kind != ENTITY_PARAMETER)
1498                                 return NULL;
1499
1500                         return entity;
1501                 }
1502
1503                 case EXPR_ARRAY_ACCESS: {
1504                         expression_t *const ref = expr->array_access.array_ref;
1505                         entity_t     *      ent = NULL;
1506                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1507                                 ent     = determine_lhs_ent(ref, lhs_ent);
1508                                 lhs_ent = ent;
1509                         } else {
1510                                 mark_vars_read(expr->select.compound, lhs_ent);
1511                         }
1512                         mark_vars_read(expr->array_access.index, lhs_ent);
1513                         return ent;
1514                 }
1515
1516                 case EXPR_SELECT: {
1517                         if (is_type_compound(skip_typeref(expr->base.type))) {
1518                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1519                         } else {
1520                                 mark_vars_read(expr->select.compound, lhs_ent);
1521                                 return NULL;
1522                         }
1523                 }
1524
1525                 case EXPR_UNARY_DEREFERENCE: {
1526                         expression_t *const val = expr->unary.value;
1527                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1528                                 /* *&x is a NOP */
1529                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1530                         } else {
1531                                 mark_vars_read(val, NULL);
1532                                 return NULL;
1533                         }
1534                 }
1535
1536                 default:
1537                         mark_vars_read(expr, NULL);
1538                         return NULL;
1539         }
1540 }
1541
1542 #define ENT_ANY ((entity_t*)-1)
1543
1544 /**
1545  * Mark declarations, which are read.  This is used to detect variables, which
1546  * are never read.
1547  * Example:
1548  * x = x + 1;
1549  *   x is not marked as "read", because it is only read to calculate its own new
1550  *   value.
1551  *
1552  * x += y; y += x;
1553  *   x and y are not detected as "not read", because multiple variables are
1554  *   involved.
1555  */
1556 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1557 {
1558         switch (expr->kind) {
1559                 case EXPR_REFERENCE: {
1560                         entity_t *const entity = expr->reference.entity;
1561                         if (entity->kind != ENTITY_VARIABLE
1562                                         && entity->kind != ENTITY_PARAMETER)
1563                                 return;
1564
1565                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1566                                 if (entity->kind == ENTITY_VARIABLE) {
1567                                         entity->variable.read = true;
1568                                 } else {
1569                                         entity->parameter.read = true;
1570                                 }
1571                         }
1572                         return;
1573                 }
1574
1575                 case EXPR_CALL:
1576                         // TODO respect pure/const
1577                         mark_vars_read(expr->call.function, NULL);
1578                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1579                                 mark_vars_read(arg->expression, NULL);
1580                         }
1581                         return;
1582
1583                 case EXPR_CONDITIONAL:
1584                         // TODO lhs_decl should depend on whether true/false have an effect
1585                         mark_vars_read(expr->conditional.condition, NULL);
1586                         if (expr->conditional.true_expression != NULL)
1587                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1588                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1589                         return;
1590
1591                 case EXPR_SELECT:
1592                         if (lhs_ent == ENT_ANY
1593                                         && !is_type_compound(skip_typeref(expr->base.type)))
1594                                 lhs_ent = NULL;
1595                         mark_vars_read(expr->select.compound, lhs_ent);
1596                         return;
1597
1598                 case EXPR_ARRAY_ACCESS: {
1599                         expression_t *const ref = expr->array_access.array_ref;
1600                         mark_vars_read(ref, lhs_ent);
1601                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1602                         mark_vars_read(expr->array_access.index, lhs_ent);
1603                         return;
1604                 }
1605
1606                 case EXPR_VA_ARG:
1607                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1608                         return;
1609
1610                 case EXPR_VA_COPY:
1611                         mark_vars_read(expr->va_copye.src, lhs_ent);
1612                         return;
1613
1614                 case EXPR_UNARY_CAST:
1615                         /* Special case: Use void cast to mark a variable as "read" */
1616                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1617                                 lhs_ent = NULL;
1618                         goto unary;
1619
1620
1621                 case EXPR_UNARY_THROW:
1622                         if (expr->unary.value == NULL)
1623                                 return;
1624                         /* FALLTHROUGH */
1625                 case EXPR_UNARY_DEREFERENCE:
1626                 case EXPR_UNARY_DELETE:
1627                 case EXPR_UNARY_DELETE_ARRAY:
1628                         if (lhs_ent == ENT_ANY)
1629                                 lhs_ent = NULL;
1630                         goto unary;
1631
1632                 case EXPR_UNARY_NEGATE:
1633                 case EXPR_UNARY_PLUS:
1634                 case EXPR_UNARY_BITWISE_NEGATE:
1635                 case EXPR_UNARY_NOT:
1636                 case EXPR_UNARY_TAKE_ADDRESS:
1637                 case EXPR_UNARY_POSTFIX_INCREMENT:
1638                 case EXPR_UNARY_POSTFIX_DECREMENT:
1639                 case EXPR_UNARY_PREFIX_INCREMENT:
1640                 case EXPR_UNARY_PREFIX_DECREMENT:
1641                 case EXPR_UNARY_CAST_IMPLICIT:
1642                 case EXPR_UNARY_ASSUME:
1643 unary:
1644                         mark_vars_read(expr->unary.value, lhs_ent);
1645                         return;
1646
1647                 case EXPR_BINARY_ADD:
1648                 case EXPR_BINARY_SUB:
1649                 case EXPR_BINARY_MUL:
1650                 case EXPR_BINARY_DIV:
1651                 case EXPR_BINARY_MOD:
1652                 case EXPR_BINARY_EQUAL:
1653                 case EXPR_BINARY_NOTEQUAL:
1654                 case EXPR_BINARY_LESS:
1655                 case EXPR_BINARY_LESSEQUAL:
1656                 case EXPR_BINARY_GREATER:
1657                 case EXPR_BINARY_GREATEREQUAL:
1658                 case EXPR_BINARY_BITWISE_AND:
1659                 case EXPR_BINARY_BITWISE_OR:
1660                 case EXPR_BINARY_BITWISE_XOR:
1661                 case EXPR_BINARY_LOGICAL_AND:
1662                 case EXPR_BINARY_LOGICAL_OR:
1663                 case EXPR_BINARY_SHIFTLEFT:
1664                 case EXPR_BINARY_SHIFTRIGHT:
1665                 case EXPR_BINARY_COMMA:
1666                 case EXPR_BINARY_ISGREATER:
1667                 case EXPR_BINARY_ISGREATEREQUAL:
1668                 case EXPR_BINARY_ISLESS:
1669                 case EXPR_BINARY_ISLESSEQUAL:
1670                 case EXPR_BINARY_ISLESSGREATER:
1671                 case EXPR_BINARY_ISUNORDERED:
1672                         mark_vars_read(expr->binary.left,  lhs_ent);
1673                         mark_vars_read(expr->binary.right, lhs_ent);
1674                         return;
1675
1676                 case EXPR_BINARY_ASSIGN:
1677                 case EXPR_BINARY_MUL_ASSIGN:
1678                 case EXPR_BINARY_DIV_ASSIGN:
1679                 case EXPR_BINARY_MOD_ASSIGN:
1680                 case EXPR_BINARY_ADD_ASSIGN:
1681                 case EXPR_BINARY_SUB_ASSIGN:
1682                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1683                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1684                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1685                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1686                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1687                         if (lhs_ent == ENT_ANY)
1688                                 lhs_ent = NULL;
1689                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1690                         mark_vars_read(expr->binary.right, lhs_ent);
1691                         return;
1692                 }
1693
1694                 case EXPR_VA_START:
1695                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1696                         return;
1697
1698                 case EXPR_UNKNOWN:
1699                 case EXPR_INVALID:
1700                 case EXPR_CONST:
1701                 case EXPR_CHARACTER_CONSTANT:
1702                 case EXPR_WIDE_CHARACTER_CONSTANT:
1703                 case EXPR_STRING_LITERAL:
1704                 case EXPR_WIDE_STRING_LITERAL:
1705                 case EXPR_COMPOUND_LITERAL: // TODO init?
1706                 case EXPR_SIZEOF:
1707                 case EXPR_CLASSIFY_TYPE:
1708                 case EXPR_ALIGNOF:
1709                 case EXPR_FUNCNAME:
1710                 case EXPR_BUILTIN_CONSTANT_P:
1711                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1712                 case EXPR_OFFSETOF:
1713                 case EXPR_STATEMENT: // TODO
1714                 case EXPR_LABEL_ADDRESS:
1715                 case EXPR_REFERENCE_ENUM_VALUE:
1716                         return;
1717         }
1718
1719         panic("unhandled expression");
1720 }
1721
1722 static designator_t *parse_designation(void)
1723 {
1724         designator_t *result = NULL;
1725         designator_t *last   = NULL;
1726
1727         while (true) {
1728                 designator_t *designator;
1729                 switch (token.type) {
1730                 case '[':
1731                         designator = allocate_ast_zero(sizeof(designator[0]));
1732                         designator->source_position = token.source_position;
1733                         next_token();
1734                         add_anchor_token(']');
1735                         designator->array_index = parse_constant_expression();
1736                         rem_anchor_token(']');
1737                         expect(']', end_error);
1738                         break;
1739                 case '.':
1740                         designator = allocate_ast_zero(sizeof(designator[0]));
1741                         designator->source_position = token.source_position;
1742                         next_token();
1743                         if (token.type != T_IDENTIFIER) {
1744                                 parse_error_expected("while parsing designator",
1745                                                      T_IDENTIFIER, NULL);
1746                                 return NULL;
1747                         }
1748                         designator->symbol = token.v.symbol;
1749                         next_token();
1750                         break;
1751                 default:
1752                         expect('=', end_error);
1753                         return result;
1754                 }
1755
1756                 assert(designator != NULL);
1757                 if (last != NULL) {
1758                         last->next = designator;
1759                 } else {
1760                         result = designator;
1761                 }
1762                 last = designator;
1763         }
1764 end_error:
1765         return NULL;
1766 }
1767
1768 static initializer_t *initializer_from_string(array_type_t *type,
1769                                               const string_t *const string)
1770 {
1771         /* TODO: check len vs. size of array type */
1772         (void) type;
1773
1774         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1775         initializer->string.string = *string;
1776
1777         return initializer;
1778 }
1779
1780 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1781                                                    wide_string_t *const string)
1782 {
1783         /* TODO: check len vs. size of array type */
1784         (void) type;
1785
1786         initializer_t *const initializer =
1787                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1788         initializer->wide_string.string = *string;
1789
1790         return initializer;
1791 }
1792
1793 /**
1794  * Build an initializer from a given expression.
1795  */
1796 static initializer_t *initializer_from_expression(type_t *orig_type,
1797                                                   expression_t *expression)
1798 {
1799         /* TODO check that expression is a constant expression */
1800
1801         /* §6.7.8.14/15 char array may be initialized by string literals */
1802         type_t *type           = skip_typeref(orig_type);
1803         type_t *expr_type_orig = expression->base.type;
1804         type_t *expr_type      = skip_typeref(expr_type_orig);
1805         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1806                 array_type_t *const array_type   = &type->array;
1807                 type_t       *const element_type = skip_typeref(array_type->element_type);
1808
1809                 if (element_type->kind == TYPE_ATOMIC) {
1810                         atomic_type_kind_t akind = element_type->atomic.akind;
1811                         switch (expression->kind) {
1812                                 case EXPR_STRING_LITERAL:
1813                                         if (akind == ATOMIC_TYPE_CHAR
1814                                                         || akind == ATOMIC_TYPE_SCHAR
1815                                                         || akind == ATOMIC_TYPE_UCHAR) {
1816                                                 return initializer_from_string(array_type,
1817                                                         &expression->string.value);
1818                                         }
1819                                         break;
1820
1821                                 case EXPR_WIDE_STRING_LITERAL: {
1822                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1823                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1824                                                 return initializer_from_wide_string(array_type,
1825                                                         &expression->wide_string.value);
1826                                         }
1827                                         break;
1828                                 }
1829
1830                                 default:
1831                                         break;
1832                         }
1833                 }
1834         }
1835
1836         assign_error_t error = semantic_assign(type, expression);
1837         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1838                 return NULL;
1839         report_assign_error(error, type, expression, "initializer",
1840                             &expression->base.source_position);
1841
1842         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1843 #if 0
1844         if (type->kind == TYPE_BITFIELD) {
1845                 type = type->bitfield.base_type;
1846         }
1847 #endif
1848         result->value.value = create_implicit_cast(expression, type);
1849
1850         return result;
1851 }
1852
1853 /**
1854  * Checks if a given expression can be used as an constant initializer.
1855  */
1856 static bool is_initializer_constant(const expression_t *expression)
1857 {
1858         return is_constant_expression(expression)
1859                 || is_address_constant(expression);
1860 }
1861
1862 /**
1863  * Parses an scalar initializer.
1864  *
1865  * §6.7.8.11; eat {} without warning
1866  */
1867 static initializer_t *parse_scalar_initializer(type_t *type,
1868                                                bool must_be_constant)
1869 {
1870         /* there might be extra {} hierarchies */
1871         int braces = 0;
1872         if (token.type == '{') {
1873                 if (warning.other)
1874                         warningf(HERE, "extra curly braces around scalar initializer");
1875                 do {
1876                         ++braces;
1877                         next_token();
1878                 } while (token.type == '{');
1879         }
1880
1881         expression_t *expression = parse_assignment_expression();
1882         mark_vars_read(expression, NULL);
1883         if (must_be_constant && !is_initializer_constant(expression)) {
1884                 errorf(&expression->base.source_position,
1885                        "Initialisation expression '%E' is not constant",
1886                        expression);
1887         }
1888
1889         initializer_t *initializer = initializer_from_expression(type, expression);
1890
1891         if (initializer == NULL) {
1892                 errorf(&expression->base.source_position,
1893                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1894                        expression, expression->base.type, type);
1895                 /* TODO */
1896                 return NULL;
1897         }
1898
1899         bool additional_warning_displayed = false;
1900         while (braces > 0) {
1901                 if (token.type == ',') {
1902                         next_token();
1903                 }
1904                 if (token.type != '}') {
1905                         if (!additional_warning_displayed && warning.other) {
1906                                 warningf(HERE, "additional elements in scalar initializer");
1907                                 additional_warning_displayed = true;
1908                         }
1909                 }
1910                 eat_block();
1911                 braces--;
1912         }
1913
1914         return initializer;
1915 }
1916
1917 /**
1918  * An entry in the type path.
1919  */
1920 typedef struct type_path_entry_t type_path_entry_t;
1921 struct type_path_entry_t {
1922         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1923         union {
1924                 size_t         index;          /**< For array types: the current index. */
1925                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1926         } v;
1927 };
1928
1929 /**
1930  * A type path expression a position inside compound or array types.
1931  */
1932 typedef struct type_path_t type_path_t;
1933 struct type_path_t {
1934         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1935         type_t            *top_type;     /**< type of the element the path points */
1936         size_t             max_index;    /**< largest index in outermost array */
1937 };
1938
1939 /**
1940  * Prints a type path for debugging.
1941  */
1942 static __attribute__((unused)) void debug_print_type_path(
1943                 const type_path_t *path)
1944 {
1945         size_t len = ARR_LEN(path->path);
1946
1947         for (size_t i = 0; i < len; ++i) {
1948                 const type_path_entry_t *entry = & path->path[i];
1949
1950                 type_t *type = skip_typeref(entry->type);
1951                 if (is_type_compound(type)) {
1952                         /* in gcc mode structs can have no members */
1953                         if (entry->v.compound_entry == NULL) {
1954                                 assert(i == len-1);
1955                                 continue;
1956                         }
1957                         fprintf(stderr, ".%s",
1958                                 entry->v.compound_entry->base.symbol->string);
1959                 } else if (is_type_array(type)) {
1960                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1961                 } else {
1962                         fprintf(stderr, "-INVALID-");
1963                 }
1964         }
1965         if (path->top_type != NULL) {
1966                 fprintf(stderr, "  (");
1967                 print_type(path->top_type);
1968                 fprintf(stderr, ")");
1969         }
1970 }
1971
1972 /**
1973  * Return the top type path entry, ie. in a path
1974  * (type).a.b returns the b.
1975  */
1976 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1977 {
1978         size_t len = ARR_LEN(path->path);
1979         assert(len > 0);
1980         return &path->path[len-1];
1981 }
1982
1983 /**
1984  * Enlarge the type path by an (empty) element.
1985  */
1986 static type_path_entry_t *append_to_type_path(type_path_t *path)
1987 {
1988         size_t len = ARR_LEN(path->path);
1989         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1990
1991         type_path_entry_t *result = & path->path[len];
1992         memset(result, 0, sizeof(result[0]));
1993         return result;
1994 }
1995
1996 /**
1997  * Descending into a sub-type. Enter the scope of the current top_type.
1998  */
1999 static void descend_into_subtype(type_path_t *path)
2000 {
2001         type_t *orig_top_type = path->top_type;
2002         type_t *top_type      = skip_typeref(orig_top_type);
2003
2004         type_path_entry_t *top = append_to_type_path(path);
2005         top->type              = top_type;
2006
2007         if (is_type_compound(top_type)) {
2008                 compound_t *compound  = top_type->compound.compound;
2009                 entity_t   *entry     = compound->members.entities;
2010
2011                 if (entry != NULL) {
2012                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2013                         top->v.compound_entry = &entry->declaration;
2014                         path->top_type = entry->declaration.type;
2015                 } else {
2016                         path->top_type = NULL;
2017                 }
2018         } else if (is_type_array(top_type)) {
2019                 top->v.index   = 0;
2020                 path->top_type = top_type->array.element_type;
2021         } else {
2022                 assert(!is_type_valid(top_type));
2023         }
2024 }
2025
2026 /**
2027  * Pop an entry from the given type path, ie. returning from
2028  * (type).a.b to (type).a
2029  */
2030 static void ascend_from_subtype(type_path_t *path)
2031 {
2032         type_path_entry_t *top = get_type_path_top(path);
2033
2034         path->top_type = top->type;
2035
2036         size_t len = ARR_LEN(path->path);
2037         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2038 }
2039
2040 /**
2041  * Pop entries from the given type path until the given
2042  * path level is reached.
2043  */
2044 static void ascend_to(type_path_t *path, size_t top_path_level)
2045 {
2046         size_t len = ARR_LEN(path->path);
2047
2048         while (len > top_path_level) {
2049                 ascend_from_subtype(path);
2050                 len = ARR_LEN(path->path);
2051         }
2052 }
2053
2054 static bool walk_designator(type_path_t *path, const designator_t *designator,
2055                             bool used_in_offsetof)
2056 {
2057         for (; designator != NULL; designator = designator->next) {
2058                 type_path_entry_t *top       = get_type_path_top(path);
2059                 type_t            *orig_type = top->type;
2060
2061                 type_t *type = skip_typeref(orig_type);
2062
2063                 if (designator->symbol != NULL) {
2064                         symbol_t *symbol = designator->symbol;
2065                         if (!is_type_compound(type)) {
2066                                 if (is_type_valid(type)) {
2067                                         errorf(&designator->source_position,
2068                                                "'.%Y' designator used for non-compound type '%T'",
2069                                                symbol, orig_type);
2070                                 }
2071
2072                                 top->type             = type_error_type;
2073                                 top->v.compound_entry = NULL;
2074                                 orig_type             = type_error_type;
2075                         } else {
2076                                 compound_t *compound = type->compound.compound;
2077                                 entity_t   *iter     = compound->members.entities;
2078                                 for (; iter != NULL; iter = iter->base.next) {
2079                                         if (iter->base.symbol == symbol) {
2080                                                 break;
2081                                         }
2082                                 }
2083                                 if (iter == NULL) {
2084                                         errorf(&designator->source_position,
2085                                                "'%T' has no member named '%Y'", orig_type, symbol);
2086                                         goto failed;
2087                                 }
2088                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2089                                 if (used_in_offsetof) {
2090                                         type_t *real_type = skip_typeref(iter->declaration.type);
2091                                         if (real_type->kind == TYPE_BITFIELD) {
2092                                                 errorf(&designator->source_position,
2093                                                        "offsetof designator '%Y' may not specify bitfield",
2094                                                        symbol);
2095                                                 goto failed;
2096                                         }
2097                                 }
2098
2099                                 top->type             = orig_type;
2100                                 top->v.compound_entry = &iter->declaration;
2101                                 orig_type             = iter->declaration.type;
2102                         }
2103                 } else {
2104                         expression_t *array_index = designator->array_index;
2105                         assert(designator->array_index != NULL);
2106
2107                         if (!is_type_array(type)) {
2108                                 if (is_type_valid(type)) {
2109                                         errorf(&designator->source_position,
2110                                                "[%E] designator used for non-array type '%T'",
2111                                                array_index, orig_type);
2112                                 }
2113                                 goto failed;
2114                         }
2115
2116                         long index = fold_constant_to_int(array_index);
2117                         if (!used_in_offsetof) {
2118                                 if (index < 0) {
2119                                         errorf(&designator->source_position,
2120                                                "array index [%E] must be positive", array_index);
2121                                 } else if (type->array.size_constant) {
2122                                         long array_size = type->array.size;
2123                                         if (index >= array_size) {
2124                                                 errorf(&designator->source_position,
2125                                                        "designator [%E] (%d) exceeds array size %d",
2126                                                        array_index, index, array_size);
2127                                         }
2128                                 }
2129                         }
2130
2131                         top->type    = orig_type;
2132                         top->v.index = (size_t) index;
2133                         orig_type    = type->array.element_type;
2134                 }
2135                 path->top_type = orig_type;
2136
2137                 if (designator->next != NULL) {
2138                         descend_into_subtype(path);
2139                 }
2140         }
2141         return true;
2142
2143 failed:
2144         return false;
2145 }
2146
2147 static void advance_current_object(type_path_t *path, size_t top_path_level)
2148 {
2149         type_path_entry_t *top = get_type_path_top(path);
2150
2151         type_t *type = skip_typeref(top->type);
2152         if (is_type_union(type)) {
2153                 /* in unions only the first element is initialized */
2154                 top->v.compound_entry = NULL;
2155         } else if (is_type_struct(type)) {
2156                 declaration_t *entry = top->v.compound_entry;
2157
2158                 entity_t *next_entity = entry->base.next;
2159                 if (next_entity != NULL) {
2160                         assert(is_declaration(next_entity));
2161                         entry = &next_entity->declaration;
2162                 } else {
2163                         entry = NULL;
2164                 }
2165
2166                 top->v.compound_entry = entry;
2167                 if (entry != NULL) {
2168                         path->top_type = entry->type;
2169                         return;
2170                 }
2171         } else if (is_type_array(type)) {
2172                 assert(is_type_array(type));
2173
2174                 top->v.index++;
2175
2176                 if (!type->array.size_constant || top->v.index < type->array.size) {
2177                         return;
2178                 }
2179         } else {
2180                 assert(!is_type_valid(type));
2181                 return;
2182         }
2183
2184         /* we're past the last member of the current sub-aggregate, try if we
2185          * can ascend in the type hierarchy and continue with another subobject */
2186         size_t len = ARR_LEN(path->path);
2187
2188         if (len > top_path_level) {
2189                 ascend_from_subtype(path);
2190                 advance_current_object(path, top_path_level);
2191         } else {
2192                 path->top_type = NULL;
2193         }
2194 }
2195
2196 /**
2197  * skip any {...} blocks until a closing bracket is reached.
2198  */
2199 static void skip_initializers(void)
2200 {
2201         if (token.type == '{')
2202                 next_token();
2203
2204         while (token.type != '}') {
2205                 if (token.type == T_EOF)
2206                         return;
2207                 if (token.type == '{') {
2208                         eat_block();
2209                         continue;
2210                 }
2211                 next_token();
2212         }
2213 }
2214
2215 static initializer_t *create_empty_initializer(void)
2216 {
2217         static initializer_t empty_initializer
2218                 = { .list = { { INITIALIZER_LIST }, 0 } };
2219         return &empty_initializer;
2220 }
2221
2222 /**
2223  * Parse a part of an initialiser for a struct or union,
2224  */
2225 static initializer_t *parse_sub_initializer(type_path_t *path,
2226                 type_t *outer_type, size_t top_path_level,
2227                 parse_initializer_env_t *env)
2228 {
2229         if (token.type == '}') {
2230                 /* empty initializer */
2231                 return create_empty_initializer();
2232         }
2233
2234         type_t *orig_type = path->top_type;
2235         type_t *type      = NULL;
2236
2237         if (orig_type == NULL) {
2238                 /* We are initializing an empty compound. */
2239         } else {
2240                 type = skip_typeref(orig_type);
2241         }
2242
2243         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2244
2245         while (true) {
2246                 designator_t *designator = NULL;
2247                 if (token.type == '.' || token.type == '[') {
2248                         designator = parse_designation();
2249                         goto finish_designator;
2250                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2251                         /* GNU-style designator ("identifier: value") */
2252                         designator = allocate_ast_zero(sizeof(designator[0]));
2253                         designator->source_position = token.source_position;
2254                         designator->symbol          = token.v.symbol;
2255                         eat(T_IDENTIFIER);
2256                         eat(':');
2257
2258 finish_designator:
2259                         /* reset path to toplevel, evaluate designator from there */
2260                         ascend_to(path, top_path_level);
2261                         if (!walk_designator(path, designator, false)) {
2262                                 /* can't continue after designation error */
2263                                 goto end_error;
2264                         }
2265
2266                         initializer_t *designator_initializer
2267                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2268                         designator_initializer->designator.designator = designator;
2269                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2270
2271                         orig_type = path->top_type;
2272                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2273                 }
2274
2275                 initializer_t *sub;
2276
2277                 if (token.type == '{') {
2278                         if (type != NULL && is_type_scalar(type)) {
2279                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2280                         } else {
2281                                 eat('{');
2282                                 if (type == NULL) {
2283                                         if (env->entity != NULL) {
2284                                                 errorf(HERE,
2285                                                      "extra brace group at end of initializer for '%Y'",
2286                                                      env->entity->base.symbol);
2287                                         } else {
2288                                                 errorf(HERE, "extra brace group at end of initializer");
2289                                         }
2290                                 } else
2291                                         descend_into_subtype(path);
2292
2293                                 add_anchor_token('}');
2294                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2295                                                             env);
2296                                 rem_anchor_token('}');
2297
2298                                 if (type != NULL) {
2299                                         ascend_from_subtype(path);
2300                                         expect('}', end_error);
2301                                 } else {
2302                                         expect('}', end_error);
2303                                         goto error_parse_next;
2304                                 }
2305                         }
2306                 } else {
2307                         /* must be an expression */
2308                         expression_t *expression = parse_assignment_expression();
2309                         mark_vars_read(expression, NULL);
2310
2311                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2312                                 errorf(&expression->base.source_position,
2313                                        "Initialisation expression '%E' is not constant",
2314                                        expression);
2315                         }
2316
2317                         if (type == NULL) {
2318                                 /* we are already outside, ... */
2319                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2320                                 if (is_type_compound(outer_type_skip) &&
2321                                     !outer_type_skip->compound.compound->complete) {
2322                                         goto error_parse_next;
2323                                 }
2324                                 goto error_excess;
2325                         }
2326
2327                         /* handle { "string" } special case */
2328                         if ((expression->kind == EXPR_STRING_LITERAL
2329                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2330                                         && outer_type != NULL) {
2331                                 sub = initializer_from_expression(outer_type, expression);
2332                                 if (sub != NULL) {
2333                                         if (token.type == ',') {
2334                                                 next_token();
2335                                         }
2336                                         if (token.type != '}' && warning.other) {
2337                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2338                                                                  orig_type);
2339                                         }
2340                                         /* TODO: eat , ... */
2341                                         return sub;
2342                                 }
2343                         }
2344
2345                         /* descend into subtypes until expression matches type */
2346                         while (true) {
2347                                 orig_type = path->top_type;
2348                                 type      = skip_typeref(orig_type);
2349
2350                                 sub = initializer_from_expression(orig_type, expression);
2351                                 if (sub != NULL) {
2352                                         break;
2353                                 }
2354                                 if (!is_type_valid(type)) {
2355                                         goto end_error;
2356                                 }
2357                                 if (is_type_scalar(type)) {
2358                                         errorf(&expression->base.source_position,
2359                                                         "expression '%E' doesn't match expected type '%T'",
2360                                                         expression, orig_type);
2361                                         goto end_error;
2362                                 }
2363
2364                                 descend_into_subtype(path);
2365                         }
2366                 }
2367
2368                 /* update largest index of top array */
2369                 const type_path_entry_t *first      = &path->path[0];
2370                 type_t                  *first_type = first->type;
2371                 first_type                          = skip_typeref(first_type);
2372                 if (is_type_array(first_type)) {
2373                         size_t index = first->v.index;
2374                         if (index > path->max_index)
2375                                 path->max_index = index;
2376                 }
2377
2378                 if (type != NULL) {
2379                         /* append to initializers list */
2380                         ARR_APP1(initializer_t*, initializers, sub);
2381                 } else {
2382 error_excess:
2383                         if (warning.other) {
2384                                 if (env->entity != NULL) {
2385                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2386                                            env->entity->base.symbol);
2387                                 } else {
2388                                         warningf(HERE, "excess elements in struct initializer");
2389                                 }
2390                         }
2391                 }
2392
2393 error_parse_next:
2394                 if (token.type == '}') {
2395                         break;
2396                 }
2397                 expect(',', end_error);
2398                 if (token.type == '}') {
2399                         break;
2400                 }
2401
2402                 if (type != NULL) {
2403                         /* advance to the next declaration if we are not at the end */
2404                         advance_current_object(path, top_path_level);
2405                         orig_type = path->top_type;
2406                         if (orig_type != NULL)
2407                                 type = skip_typeref(orig_type);
2408                         else
2409                                 type = NULL;
2410                 }
2411         }
2412
2413         size_t len  = ARR_LEN(initializers);
2414         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2415         initializer_t *result = allocate_ast_zero(size);
2416         result->kind          = INITIALIZER_LIST;
2417         result->list.len      = len;
2418         memcpy(&result->list.initializers, initializers,
2419                len * sizeof(initializers[0]));
2420
2421         DEL_ARR_F(initializers);
2422         ascend_to(path, top_path_level+1);
2423
2424         return result;
2425
2426 end_error:
2427         skip_initializers();
2428         DEL_ARR_F(initializers);
2429         ascend_to(path, top_path_level+1);
2430         return NULL;
2431 }
2432
2433 /**
2434  * Parses an initializer. Parsers either a compound literal
2435  * (env->declaration == NULL) or an initializer of a declaration.
2436  */
2437 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2438 {
2439         type_t        *type      = skip_typeref(env->type);
2440         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2441         initializer_t *result;
2442
2443         if (is_type_scalar(type)) {
2444                 result = parse_scalar_initializer(type, env->must_be_constant);
2445         } else if (token.type == '{') {
2446                 eat('{');
2447
2448                 type_path_t path;
2449                 memset(&path, 0, sizeof(path));
2450                 path.top_type = env->type;
2451                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2452
2453                 descend_into_subtype(&path);
2454
2455                 add_anchor_token('}');
2456                 result = parse_sub_initializer(&path, env->type, 1, env);
2457                 rem_anchor_token('}');
2458
2459                 max_index = path.max_index;
2460                 DEL_ARR_F(path.path);
2461
2462                 expect('}', end_error);
2463         } else {
2464                 /* parse_scalar_initializer() also works in this case: we simply
2465                  * have an expression without {} around it */
2466                 result = parse_scalar_initializer(type, env->must_be_constant);
2467         }
2468
2469         /* §6.7.8:22 array initializers for arrays with unknown size determine
2470          * the array type size */
2471         if (is_type_array(type) && type->array.size_expression == NULL
2472                         && result != NULL) {
2473                 size_t size;
2474                 switch (result->kind) {
2475                 case INITIALIZER_LIST:
2476                         assert(max_index != 0xdeadbeaf);
2477                         size = max_index + 1;
2478                         break;
2479
2480                 case INITIALIZER_STRING:
2481                         size = result->string.string.size;
2482                         break;
2483
2484                 case INITIALIZER_WIDE_STRING:
2485                         size = result->wide_string.string.size;
2486                         break;
2487
2488                 case INITIALIZER_DESIGNATOR:
2489                 case INITIALIZER_VALUE:
2490                         /* can happen for parse errors */
2491                         size = 0;
2492                         break;
2493
2494                 default:
2495                         internal_errorf(HERE, "invalid initializer type");
2496                 }
2497
2498                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2499                 cnst->base.type          = type_size_t;
2500                 cnst->conste.v.int_value = size;
2501
2502                 type_t *new_type = duplicate_type(type);
2503
2504                 new_type->array.size_expression   = cnst;
2505                 new_type->array.size_constant     = true;
2506                 new_type->array.has_implicit_size = true;
2507                 new_type->array.size              = size;
2508                 env->type = new_type;
2509         }
2510
2511         return result;
2512 end_error:
2513         return NULL;
2514 }
2515
2516 static void append_entity(scope_t *scope, entity_t *entity)
2517 {
2518         if (scope->last_entity != NULL) {
2519                 scope->last_entity->base.next = entity;
2520         } else {
2521                 scope->entities = entity;
2522         }
2523         scope->last_entity = entity;
2524 }
2525
2526
2527 static compound_t *parse_compound_type_specifier(bool is_struct)
2528 {
2529         if (is_struct) {
2530                 eat(T_struct);
2531         } else {
2532                 eat(T_union);
2533         }
2534
2535         symbol_t    *symbol   = NULL;
2536         compound_t  *compound = NULL;
2537         attribute_t *attributes = NULL;
2538
2539         if (token.type == T___attribute__) {
2540                 attributes = parse_attributes(NULL);
2541         }
2542
2543         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2544         if (token.type == T_IDENTIFIER) {
2545                 /* the compound has a name, check if we have seen it already */
2546                 symbol = token.v.symbol;
2547                 next_token();
2548
2549                 entity_t *entity = get_tag(symbol, kind);
2550                 if (entity != NULL) {
2551                         compound = &entity->compound;
2552                         if (compound->base.parent_scope != current_scope &&
2553                             (token.type == '{' || token.type == ';')) {
2554                                 /* we're in an inner scope and have a definition. Shadow
2555                                  * existing definition in outer scope */
2556                                 compound = NULL;
2557                         } else if (compound->complete && token.type == '{') {
2558                                 assert(symbol != NULL);
2559                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2560                                        is_struct ? "struct" : "union", symbol,
2561                                        &compound->base.source_position);
2562                                 /* clear members in the hope to avoid further errors */
2563                                 compound->members.entities = NULL;
2564                         }
2565                 }
2566         } else if (token.type != '{') {
2567                 if (is_struct) {
2568                         parse_error_expected("while parsing struct type specifier",
2569                                              T_IDENTIFIER, '{', NULL);
2570                 } else {
2571                         parse_error_expected("while parsing union type specifier",
2572                                              T_IDENTIFIER, '{', NULL);
2573                 }
2574
2575                 return NULL;
2576         }
2577
2578         if (compound == NULL) {
2579                 entity_t *entity = allocate_entity_zero(kind);
2580                 compound         = &entity->compound;
2581
2582                 compound->alignment            = 1;
2583                 compound->base.namespc         = NAMESPACE_TAG;
2584                 compound->base.source_position = token.source_position;
2585                 compound->base.symbol          = symbol;
2586                 compound->base.parent_scope    = current_scope;
2587                 if (symbol != NULL) {
2588                         environment_push(entity);
2589                 }
2590                 append_entity(current_scope, entity);
2591         }
2592
2593         if (token.type == '{') {
2594                 parse_compound_type_entries(compound);
2595
2596                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2597                 if (symbol == NULL) {
2598                         assert(anonymous_entity == NULL);
2599                         anonymous_entity = (entity_t*)compound;
2600                 }
2601         }
2602
2603         if (attributes != NULL) {
2604                 handle_entity_attributes(attributes, (entity_t*) compound);
2605         }
2606
2607         return compound;
2608 }
2609
2610 static void parse_enum_entries(type_t *const enum_type)
2611 {
2612         eat('{');
2613
2614         if (token.type == '}') {
2615                 errorf(HERE, "empty enum not allowed");
2616                 next_token();
2617                 return;
2618         }
2619
2620         add_anchor_token('}');
2621         do {
2622                 if (token.type != T_IDENTIFIER) {
2623                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2624                         eat_block();
2625                         rem_anchor_token('}');
2626                         return;
2627                 }
2628
2629                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
2630                 entity->enum_value.enum_type = enum_type;
2631                 entity->base.symbol          = token.v.symbol;
2632                 entity->base.source_position = token.source_position;
2633                 next_token();
2634
2635                 if (token.type == '=') {
2636                         next_token();
2637                         expression_t *value = parse_constant_expression();
2638
2639                         value = create_implicit_cast(value, enum_type);
2640                         entity->enum_value.value = value;
2641
2642                         /* TODO semantic */
2643                 }
2644
2645                 record_entity(entity, false);
2646
2647                 if (token.type != ',')
2648                         break;
2649                 next_token();
2650         } while (token.type != '}');
2651         rem_anchor_token('}');
2652
2653         expect('}', end_error);
2654
2655 end_error:
2656         ;
2657 }
2658
2659 static type_t *parse_enum_specifier(void)
2660 {
2661         entity_t        *entity;
2662         symbol_t        *symbol;
2663
2664         eat(T_enum);
2665         if (token.type == T_IDENTIFIER) {
2666                 symbol = token.v.symbol;
2667                 next_token();
2668
2669                 entity = get_tag(symbol, ENTITY_ENUM);
2670                 if (entity != NULL) {
2671                         if (entity->base.parent_scope != current_scope &&
2672                                         (token.type == '{' || token.type == ';')) {
2673                                 /* we're in an inner scope and have a definition. Shadow
2674                                  * existing definition in outer scope */
2675                                 entity = NULL;
2676                         } else if (entity->enume.complete && token.type == '{') {
2677                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
2678                                                 symbol, &entity->base.source_position);
2679                         }
2680                 }
2681         } else if (token.type != '{') {
2682                 parse_error_expected("while parsing enum type specifier",
2683                                      T_IDENTIFIER, '{', NULL);
2684                 return NULL;
2685         } else {
2686                 entity  = NULL;
2687                 symbol  = NULL;
2688         }
2689
2690         if (entity == NULL) {
2691                 entity                       = allocate_entity_zero(ENTITY_ENUM);
2692                 entity->base.namespc         = NAMESPACE_TAG;
2693                 entity->base.source_position = token.source_position;
2694                 entity->base.symbol          = symbol;
2695                 entity->base.parent_scope    = current_scope;
2696         }
2697
2698         type_t *const type = allocate_type_zero(TYPE_ENUM);
2699         type->enumt.enume  = &entity->enume;
2700         type->enumt.akind  = ATOMIC_TYPE_INT;
2701
2702         if (token.type == '{') {
2703                 if (symbol != NULL) {
2704                         environment_push(entity);
2705                 }
2706                 append_entity(current_scope, entity);
2707                 entity->enume.complete = true;
2708
2709                 parse_enum_entries(type);
2710                 parse_attributes(NULL);
2711
2712                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2713                 if (symbol == NULL) {
2714                         assert(anonymous_entity == NULL);
2715                         anonymous_entity = entity;
2716                 }
2717         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2718                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
2719                        symbol);
2720         }
2721
2722         return type;
2723 }
2724
2725 /**
2726  * if a symbol is a typedef to another type, return true
2727  */
2728 static bool is_typedef_symbol(symbol_t *symbol)
2729 {
2730         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2731         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2732 }
2733
2734 static type_t *parse_typeof(void)
2735 {
2736         eat(T___typeof__);
2737
2738         type_t *type;
2739
2740         expect('(', end_error);
2741         add_anchor_token(')');
2742
2743         expression_t *expression  = NULL;
2744
2745         bool old_type_prop     = in_type_prop;
2746         bool old_gcc_extension = in_gcc_extension;
2747         in_type_prop           = true;
2748
2749         while (token.type == T___extension__) {
2750                 /* This can be a prefix to a typename or an expression. */
2751                 next_token();
2752                 in_gcc_extension = true;
2753         }
2754         switch (token.type) {
2755         case T_IDENTIFIER:
2756                 if (is_typedef_symbol(token.v.symbol)) {
2757                         type = parse_typename();
2758                 } else {
2759                         expression = parse_expression();
2760                         type       = revert_automatic_type_conversion(expression);
2761                 }
2762                 break;
2763
2764         TYPENAME_START
2765                 type = parse_typename();
2766                 break;
2767
2768         default:
2769                 expression = parse_expression();
2770                 type       = expression->base.type;
2771                 break;
2772         }
2773         in_type_prop     = old_type_prop;
2774         in_gcc_extension = old_gcc_extension;
2775
2776         rem_anchor_token(')');
2777         expect(')', end_error);
2778
2779         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2780         typeof_type->typeoft.expression  = expression;
2781         typeof_type->typeoft.typeof_type = type;
2782
2783         return typeof_type;
2784 end_error:
2785         return NULL;
2786 }
2787
2788 typedef enum specifiers_t {
2789         SPECIFIER_SIGNED    = 1 << 0,
2790         SPECIFIER_UNSIGNED  = 1 << 1,
2791         SPECIFIER_LONG      = 1 << 2,
2792         SPECIFIER_INT       = 1 << 3,
2793         SPECIFIER_DOUBLE    = 1 << 4,
2794         SPECIFIER_CHAR      = 1 << 5,
2795         SPECIFIER_WCHAR_T   = 1 << 6,
2796         SPECIFIER_SHORT     = 1 << 7,
2797         SPECIFIER_LONG_LONG = 1 << 8,
2798         SPECIFIER_FLOAT     = 1 << 9,
2799         SPECIFIER_BOOL      = 1 << 10,
2800         SPECIFIER_VOID      = 1 << 11,
2801         SPECIFIER_INT8      = 1 << 12,
2802         SPECIFIER_INT16     = 1 << 13,
2803         SPECIFIER_INT32     = 1 << 14,
2804         SPECIFIER_INT64     = 1 << 15,
2805         SPECIFIER_INT128    = 1 << 16,
2806         SPECIFIER_COMPLEX   = 1 << 17,
2807         SPECIFIER_IMAGINARY = 1 << 18,
2808 } specifiers_t;
2809
2810 static type_t *create_builtin_type(symbol_t *const symbol,
2811                                    type_t *const real_type)
2812 {
2813         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
2814         type->builtin.symbol    = symbol;
2815         type->builtin.real_type = real_type;
2816         return identify_new_type(type);
2817 }
2818
2819 static type_t *get_typedef_type(symbol_t *symbol)
2820 {
2821         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2822         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2823                 return NULL;
2824
2825         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2826         type->typedeft.typedefe = &entity->typedefe;
2827
2828         return type;
2829 }
2830
2831 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2832 {
2833         expect('(', end_error);
2834
2835         attribute_property_argument_t *property
2836                 = allocate_ast_zero(sizeof(*property));
2837
2838         while (true) {
2839                 if (token.type != T_IDENTIFIER) {
2840                         parse_error_expected("while parsing property declspec",
2841                                              T_IDENTIFIER, NULL);
2842                         goto end_error;
2843                 }
2844
2845                 bool is_put;
2846                 symbol_t *symbol = token.v.symbol;
2847                 next_token();
2848                 if (strcmp(symbol->string, "put") == 0) {
2849                         is_put = true;
2850                 } else if (strcmp(symbol->string, "get") == 0) {
2851                         is_put = false;
2852                 } else {
2853                         errorf(HERE, "expected put or get in property declspec");
2854                         goto end_error;
2855                 }
2856                 expect('=', end_error);
2857                 if (token.type != T_IDENTIFIER) {
2858                         parse_error_expected("while parsing property declspec",
2859                                              T_IDENTIFIER, NULL);
2860                         goto end_error;
2861                 }
2862                 if (is_put) {
2863                         property->put_symbol = token.v.symbol;
2864                 } else {
2865                         property->get_symbol = token.v.symbol;
2866                 }
2867                 next_token();
2868                 if (token.type == ')')
2869                         break;
2870                 expect(',', end_error);
2871         }
2872
2873         attribute->a.property = property;
2874
2875         expect(')', end_error);
2876
2877 end_error:
2878         return attribute;
2879 }
2880
2881 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2882 {
2883         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2884         if (token.type == T_restrict) {
2885                 kind = ATTRIBUTE_MS_RESTRICT;
2886                 next_token();
2887         } else if (token.type == T_IDENTIFIER) {
2888                 const char *name = token.v.symbol->string;
2889                 next_token();
2890                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2891                      ++k) {
2892                         const char *attribute_name = get_attribute_name(k);
2893                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2894                                 kind = k;
2895                                 break;
2896                         }
2897                 }
2898
2899                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2900                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2901                 }
2902         } else {
2903                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2904                 return NULL;
2905         }
2906
2907         attribute_t *attribute = allocate_attribute_zero(kind);
2908
2909         if (kind == ATTRIBUTE_MS_PROPERTY) {
2910                 return parse_attribute_ms_property(attribute);
2911         }
2912
2913         /* parse arguments */
2914         if (token.type == '(') {
2915                 next_token();
2916                 attribute->a.arguments = parse_attribute_arguments();
2917         }
2918
2919         return attribute;
2920 }
2921
2922 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2923 {
2924         eat(T__declspec);
2925
2926         expect('(', end_error);
2927
2928         if (token.type == ')') {
2929                 next_token();
2930                 return NULL;
2931         }
2932
2933         add_anchor_token(')');
2934
2935         attribute_t *last = first;
2936         while (true) {
2937                 if (last != NULL) {
2938                         while (last->next != NULL)
2939                                 last = last->next;
2940                 }
2941
2942                 attribute_t *attribute
2943                         = parse_microsoft_extended_decl_modifier_single();
2944                 if (attribute == NULL)
2945                         goto end_error;
2946
2947                 if (last == NULL) {
2948                         first = attribute;
2949                 } else {
2950                         last->next = attribute;
2951                 }
2952                 last = attribute;
2953
2954                 if (token.type == ')') {
2955                         break;
2956                 }
2957                 expect(',', end_error);
2958         }
2959
2960         rem_anchor_token(')');
2961         expect(')', end_error);
2962         return first;
2963
2964 end_error:
2965         rem_anchor_token(')');
2966         return first;
2967 }
2968
2969 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2970 {
2971         entity_t *entity             = allocate_entity_zero(kind);
2972         entity->base.source_position = *HERE;
2973         entity->base.symbol          = symbol;
2974         if (is_declaration(entity)) {
2975                 entity->declaration.type     = type_error_type;
2976                 entity->declaration.implicit = true;
2977         } else if (kind == ENTITY_TYPEDEF) {
2978                 entity->typedefe.type    = type_error_type;
2979                 entity->typedefe.builtin = true;
2980         }
2981         if (kind != ENTITY_COMPOUND_MEMBER)
2982                 record_entity(entity, false);
2983         return entity;
2984 }
2985
2986 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2987 {
2988         type_t            *type              = NULL;
2989         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2990         unsigned           type_specifiers   = 0;
2991         bool               newtype           = false;
2992         bool               saw_error         = false;
2993         bool               old_gcc_extension = in_gcc_extension;
2994
2995         specifiers->source_position = token.source_position;
2996
2997         while (true) {
2998                 specifiers->attributes = parse_attributes(specifiers->attributes);
2999
3000                 switch (token.type) {
3001                 /* storage class */
3002 #define MATCH_STORAGE_CLASS(token, class)                                  \
3003                 case token:                                                        \
3004                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3005                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3006                         }                                                              \
3007                         specifiers->storage_class = class;                             \
3008                         if (specifiers->thread_local)                                  \
3009                                 goto check_thread_storage_class;                           \
3010                         next_token();                                                  \
3011                         break;
3012
3013                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3014                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3015                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3016                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3017                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3018
3019                 case T__declspec:
3020                         specifiers->attributes
3021                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
3022                         break;
3023
3024                 case T___thread:
3025                         if (specifiers->thread_local) {
3026                                 errorf(HERE, "duplicate '__thread'");
3027                         } else {
3028                                 specifiers->thread_local = true;
3029 check_thread_storage_class:
3030                                 switch (specifiers->storage_class) {
3031                                         case STORAGE_CLASS_EXTERN:
3032                                         case STORAGE_CLASS_NONE:
3033                                         case STORAGE_CLASS_STATIC:
3034                                                 break;
3035
3036                                                 char const* wrong;
3037                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3038                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3039                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3040 wrong_thread_stoarge_class:
3041                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3042                                                 break;
3043                                 }
3044                         }
3045                         next_token();
3046                         break;
3047
3048                 /* type qualifiers */
3049 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3050                 case token:                                                     \
3051                         qualifiers |= qualifier;                                    \
3052                         next_token();                                               \
3053                         break
3054
3055                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3056                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3057                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3058                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3059                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3060                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3061                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3062                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3063
3064                 case T___extension__:
3065                         next_token();
3066                         in_gcc_extension = true;
3067                         break;
3068
3069                 /* type specifiers */
3070 #define MATCH_SPECIFIER(token, specifier, name)                         \
3071                 case token:                                                     \
3072                         if (type_specifiers & specifier) {                           \
3073                                 errorf(HERE, "multiple " name " type specifiers given"); \
3074                         } else {                                                    \
3075                                 type_specifiers |= specifier;                           \
3076                         }                                                           \
3077                         next_token();                                               \
3078                         break
3079
3080                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3081                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3082                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3083                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3084                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3085                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3086                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3087                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3088                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3089                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3090                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3091                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3092                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3093                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3094                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3095                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3096                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3097                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3098
3099                 case T_inline:
3100                         next_token();
3101                         specifiers->is_inline = true;
3102                         break;
3103
3104 #if 0
3105                 case T__forceinline:
3106                         next_token();
3107                         specifiers->modifiers |= DM_FORCEINLINE;
3108                         break;
3109 #endif
3110
3111                 case T_long:
3112                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3113                                 errorf(HERE, "multiple type specifiers given");
3114                         } else if (type_specifiers & SPECIFIER_LONG) {
3115                                 type_specifiers |= SPECIFIER_LONG_LONG;
3116                         } else {
3117                                 type_specifiers |= SPECIFIER_LONG;
3118                         }
3119                         next_token();
3120                         break;
3121
3122 #define CHECK_DOUBLE_TYPE()        \
3123                         if ( type != NULL)     \
3124                                 errorf(HERE, "multiple data types in declaration specifiers");
3125
3126                 case T_struct:
3127                         CHECK_DOUBLE_TYPE();
3128                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3129
3130                         type->compound.compound = parse_compound_type_specifier(true);
3131                         break;
3132                 case T_union:
3133                         CHECK_DOUBLE_TYPE();
3134                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3135                         type->compound.compound = parse_compound_type_specifier(false);
3136                         break;
3137                 case T_enum:
3138                         CHECK_DOUBLE_TYPE();
3139                         type = parse_enum_specifier();
3140                         break;
3141                 case T___typeof__:
3142                         CHECK_DOUBLE_TYPE();
3143                         type = parse_typeof();
3144                         break;
3145                 case T___builtin_va_list:
3146                         CHECK_DOUBLE_TYPE();
3147                         type = duplicate_type(type_valist);
3148                         next_token();
3149                         break;
3150
3151                 case T_IDENTIFIER: {
3152                         /* only parse identifier if we haven't found a type yet */
3153                         if (type != NULL || type_specifiers != 0) {
3154                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3155                                  * declaration, so it doesn't generate errors about expecting '(' or
3156                                  * '{' later on. */
3157                                 switch (look_ahead(1)->type) {
3158                                         STORAGE_CLASSES
3159                                         TYPE_SPECIFIERS
3160                                         case T_const:
3161                                         case T_restrict:
3162                                         case T_volatile:
3163                                         case T_inline:
3164                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3165                                         case T_IDENTIFIER:
3166                                         case '&':
3167                                         case '*':
3168                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3169                                                 next_token();
3170                                                 continue;
3171
3172                                         default:
3173                                                 goto finish_specifiers;
3174                                 }
3175                         }
3176
3177                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3178                         if (typedef_type == NULL) {
3179                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3180                                  * declaration, so it doesn't generate 'implicit int' followed by more
3181                                  * errors later on. */
3182                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3183                                 switch (la1_type) {
3184                                         DECLARATION_START
3185                                         case T_IDENTIFIER:
3186                                         case '&':
3187                                         case '*': {
3188                                                 errorf(HERE, "%K does not name a type", &token);
3189
3190                                                 entity_t *entity =
3191                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3192
3193                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3194                                                 type->typedeft.typedefe = &entity->typedefe;
3195
3196                                                 next_token();
3197                                                 saw_error = true;
3198                                                 if (la1_type == '&' || la1_type == '*')
3199                                                         goto finish_specifiers;
3200                                                 continue;
3201                                         }
3202
3203                                         default:
3204                                                 goto finish_specifiers;
3205                                 }
3206                         }
3207
3208                         next_token();
3209                         type = typedef_type;
3210                         break;
3211                 }
3212
3213                 /* function specifier */
3214                 default:
3215                         goto finish_specifiers;
3216                 }
3217         }
3218
3219 finish_specifiers:
3220         specifiers->attributes = parse_attributes(specifiers->attributes);
3221
3222         in_gcc_extension = old_gcc_extension;
3223
3224         if (type == NULL || (saw_error && type_specifiers != 0)) {
3225                 atomic_type_kind_t atomic_type;
3226
3227                 /* match valid basic types */
3228                 switch (type_specifiers) {
3229                 case SPECIFIER_VOID:
3230                         atomic_type = ATOMIC_TYPE_VOID;
3231                         break;
3232                 case SPECIFIER_WCHAR_T:
3233                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3234                         break;
3235                 case SPECIFIER_CHAR:
3236                         atomic_type = ATOMIC_TYPE_CHAR;
3237                         break;
3238                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3239                         atomic_type = ATOMIC_TYPE_SCHAR;
3240                         break;
3241                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3242                         atomic_type = ATOMIC_TYPE_UCHAR;
3243                         break;
3244                 case SPECIFIER_SHORT:
3245                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3246                 case SPECIFIER_SHORT | SPECIFIER_INT:
3247                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3248                         atomic_type = ATOMIC_TYPE_SHORT;
3249                         break;
3250                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3251                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3252                         atomic_type = ATOMIC_TYPE_USHORT;
3253                         break;
3254                 case SPECIFIER_INT:
3255                 case SPECIFIER_SIGNED:
3256                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3257                         atomic_type = ATOMIC_TYPE_INT;
3258                         break;
3259                 case SPECIFIER_UNSIGNED:
3260                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3261                         atomic_type = ATOMIC_TYPE_UINT;
3262                         break;
3263                 case SPECIFIER_LONG:
3264                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3265                 case SPECIFIER_LONG | SPECIFIER_INT:
3266                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3267                         atomic_type = ATOMIC_TYPE_LONG;
3268                         break;
3269                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3270                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3271                         atomic_type = ATOMIC_TYPE_ULONG;
3272                         break;
3273
3274                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3275                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3276                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3277                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3278                         | SPECIFIER_INT:
3279                         atomic_type = ATOMIC_TYPE_LONGLONG;
3280                         goto warn_about_long_long;
3281
3282                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3283                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3284                         | SPECIFIER_INT:
3285                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3286 warn_about_long_long:
3287                         if (warning.long_long) {
3288                                 warningf(&specifiers->source_position,
3289                                          "ISO C90 does not support 'long long'");
3290                         }
3291                         break;
3292
3293                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3294                         atomic_type = unsigned_int8_type_kind;
3295                         break;
3296
3297                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3298                         atomic_type = unsigned_int16_type_kind;
3299                         break;
3300
3301                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3302                         atomic_type = unsigned_int32_type_kind;
3303                         break;
3304
3305                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3306                         atomic_type = unsigned_int64_type_kind;
3307                         break;
3308
3309                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3310                         atomic_type = unsigned_int128_type_kind;
3311                         break;
3312
3313                 case SPECIFIER_INT8:
3314                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3315                         atomic_type = int8_type_kind;
3316                         break;
3317
3318                 case SPECIFIER_INT16:
3319                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3320                         atomic_type = int16_type_kind;
3321                         break;
3322
3323                 case SPECIFIER_INT32:
3324                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3325                         atomic_type = int32_type_kind;
3326                         break;
3327
3328                 case SPECIFIER_INT64:
3329                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3330                         atomic_type = int64_type_kind;
3331                         break;
3332
3333                 case SPECIFIER_INT128:
3334                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3335                         atomic_type = int128_type_kind;
3336                         break;
3337
3338                 case SPECIFIER_FLOAT:
3339                         atomic_type = ATOMIC_TYPE_FLOAT;
3340                         break;
3341                 case SPECIFIER_DOUBLE:
3342                         atomic_type = ATOMIC_TYPE_DOUBLE;
3343                         break;
3344                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3345                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3346                         break;
3347                 case SPECIFIER_BOOL:
3348                         atomic_type = ATOMIC_TYPE_BOOL;
3349                         break;
3350                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3351                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3352                         atomic_type = ATOMIC_TYPE_FLOAT;
3353                         break;
3354                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3355                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3356                         atomic_type = ATOMIC_TYPE_DOUBLE;
3357                         break;
3358                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3359                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3360                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3361                         break;
3362                 default:
3363                         /* invalid specifier combination, give an error message */
3364                         if (type_specifiers == 0) {
3365                                 if (saw_error)
3366                                         goto end_error;
3367
3368                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3369                                 if (!(c_mode & _CXX) && !strict_mode) {
3370                                         if (warning.implicit_int) {
3371                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3372                                         }
3373                                         atomic_type = ATOMIC_TYPE_INT;
3374                                         break;
3375                                 } else {
3376                                         errorf(HERE, "no type specifiers given in declaration");
3377                                 }
3378                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3379                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3380                                 errorf(HERE, "signed and unsigned specifiers given");
3381                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3382                                 errorf(HERE, "only integer types can be signed or unsigned");
3383                         } else {
3384                                 errorf(HERE, "multiple datatypes in declaration");
3385                         }
3386                         goto end_error;
3387                 }
3388
3389                 if (type_specifiers & SPECIFIER_COMPLEX) {
3390                         type                = allocate_type_zero(TYPE_COMPLEX);
3391                         type->complex.akind = atomic_type;
3392                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3393                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3394                         type->imaginary.akind = atomic_type;
3395                 } else {
3396                         type                 = allocate_type_zero(TYPE_ATOMIC);
3397                         type->atomic.akind   = atomic_type;
3398                 }
3399                 newtype = true;
3400         } else if (type_specifiers != 0) {
3401                 errorf(HERE, "multiple datatypes in declaration");
3402         }
3403
3404         /* FIXME: check type qualifiers here */
3405         type->base.qualifiers = qualifiers;
3406
3407         if (newtype) {
3408                 type = identify_new_type(type);
3409         } else {
3410                 type = typehash_insert(type);
3411         }
3412
3413         if (specifiers->attributes != NULL)
3414                 type = handle_type_attributes(specifiers->attributes, type);
3415         specifiers->type = type;
3416         return;
3417
3418 end_error:
3419         specifiers->type = type_error_type;
3420         return;
3421 }
3422
3423 static type_qualifiers_t parse_type_qualifiers(void)
3424 {
3425         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3426
3427         while (true) {
3428                 switch (token.type) {
3429                 /* type qualifiers */
3430                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3431                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3432                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3433                 /* microsoft extended type modifiers */
3434                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3435                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3436                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3437                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3438                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3439
3440                 default:
3441                         return qualifiers;
3442                 }
3443         }
3444 }
3445
3446 /**
3447  * Parses an K&R identifier list
3448  */
3449 static void parse_identifier_list(scope_t *scope)
3450 {
3451         do {
3452                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
3453                 entity->base.source_position = token.source_position;
3454                 entity->base.namespc         = NAMESPACE_NORMAL;
3455                 entity->base.symbol          = token.v.symbol;
3456                 /* a K&R parameter has no type, yet */
3457                 next_token();
3458
3459                 if (scope != NULL)
3460                         append_entity(scope, entity);
3461
3462                 if (token.type != ',') {
3463                         break;
3464                 }
3465                 next_token();
3466         } while (token.type == T_IDENTIFIER);
3467 }
3468
3469 static entity_t *parse_parameter(void)
3470 {
3471         declaration_specifiers_t specifiers;
3472         memset(&specifiers, 0, sizeof(specifiers));
3473
3474         parse_declaration_specifiers(&specifiers);
3475
3476         entity_t *entity = parse_declarator(&specifiers,
3477                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3478         anonymous_entity = NULL;
3479         return entity;
3480 }
3481
3482 static void semantic_parameter_incomplete(const entity_t *entity)
3483 {
3484         assert(entity->kind == ENTITY_PARAMETER);
3485
3486         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3487          *             list in a function declarator that is part of a
3488          *             definition of that function shall not have
3489          *             incomplete type. */
3490         type_t *type = skip_typeref(entity->declaration.type);
3491         if (is_type_incomplete(type)) {
3492                 errorf(&entity->base.source_position,
3493                                 "parameter '%#T' has incomplete type",
3494                                 entity->declaration.type, entity->base.symbol);
3495         }
3496 }
3497
3498 static bool has_parameters(void)
3499 {
3500         /* func(void) is not a parameter */
3501         if (token.type == T_IDENTIFIER) {
3502                 entity_t const *const entity = get_entity(token.v.symbol, NAMESPACE_NORMAL);
3503                 if (entity == NULL)
3504                         return true;
3505                 if (entity->kind != ENTITY_TYPEDEF)
3506                         return true;
3507                 if (skip_typeref(entity->typedefe.type) != type_void)
3508                         return true;
3509         } else if (token.type != T_void) {
3510                 return true;
3511         }
3512         if (look_ahead(1)->type != ')')
3513                 return true;
3514         next_token();
3515         return false;
3516 }
3517
3518 /**
3519  * Parses function type parameters (and optionally creates variable_t entities
3520  * for them in a scope)
3521  */
3522 static void parse_parameters(function_type_t *type, scope_t *scope)
3523 {
3524         eat('(');
3525         add_anchor_token(')');
3526         int saved_comma_state = save_and_reset_anchor_state(',');
3527
3528         if (token.type == T_IDENTIFIER &&
3529             !is_typedef_symbol(token.v.symbol)) {
3530                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3531                 if (la1_type == ',' || la1_type == ')') {
3532                         type->kr_style_parameters = true;
3533                         parse_identifier_list(scope);
3534                         goto parameters_finished;
3535                 }
3536         }
3537
3538         if (token.type == ')') {
3539                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3540                 if (!(c_mode & _CXX))
3541                         type->unspecified_parameters = true;
3542                 goto parameters_finished;
3543         }
3544
3545         if (has_parameters()) {
3546                 function_parameter_t **anchor = &type->parameters;
3547                 for (;;) {
3548                         switch (token.type) {
3549                         case T_DOTDOTDOT:
3550                                 next_token();
3551                                 type->variadic = true;
3552                                 goto parameters_finished;
3553
3554                         case T_IDENTIFIER:
3555                         case T___extension__:
3556                         DECLARATION_START
3557                         {
3558                                 entity_t *entity = parse_parameter();
3559                                 if (entity->kind == ENTITY_TYPEDEF) {
3560                                         errorf(&entity->base.source_position,
3561                                                         "typedef not allowed as function parameter");
3562                                         break;
3563                                 }
3564                                 assert(is_declaration(entity));
3565
3566                                 semantic_parameter_incomplete(entity);
3567
3568                                 function_parameter_t *const parameter =
3569                                         allocate_parameter(entity->declaration.type);
3570
3571                                 if (scope != NULL) {
3572                                         append_entity(scope, entity);
3573                                 }
3574
3575                                 *anchor = parameter;
3576                                 anchor  = &parameter->next;
3577                                 break;
3578                         }
3579
3580                         default:
3581                                 goto parameters_finished;
3582                         }
3583                         if (token.type != ',') {
3584                                 goto parameters_finished;
3585                         }
3586                         next_token();
3587                 }
3588         }
3589
3590
3591 parameters_finished:
3592         rem_anchor_token(')');
3593         expect(')', end_error);
3594
3595 end_error:
3596         restore_anchor_state(',', saved_comma_state);
3597 }
3598
3599 typedef enum construct_type_kind_t {
3600         CONSTRUCT_INVALID,
3601         CONSTRUCT_POINTER,
3602         CONSTRUCT_REFERENCE,
3603         CONSTRUCT_FUNCTION,
3604         CONSTRUCT_ARRAY
3605 } construct_type_kind_t;
3606
3607 typedef union construct_type_t construct_type_t;
3608
3609 typedef struct construct_type_base_t {
3610         construct_type_kind_t  kind;
3611         construct_type_t      *next;
3612 } construct_type_base_t;
3613
3614 typedef struct parsed_pointer_t {
3615         construct_type_base_t  base;
3616         type_qualifiers_t      type_qualifiers;
3617         variable_t            *base_variable;  /**< MS __based extension. */
3618 } parsed_pointer_t;
3619
3620 typedef struct parsed_reference_t {
3621         construct_type_base_t base;
3622 } parsed_reference_t;
3623
3624 typedef struct construct_function_type_t {
3625         construct_type_base_t  base;
3626         type_t                *function_type;
3627 } construct_function_type_t;
3628
3629 typedef struct parsed_array_t {
3630         construct_type_base_t  base;
3631         type_qualifiers_t      type_qualifiers;
3632         bool                   is_static;
3633         bool                   is_variable;
3634         expression_t          *size;
3635 } parsed_array_t;
3636
3637 union construct_type_t {
3638         construct_type_kind_t     kind;
3639         construct_type_base_t     base;
3640         parsed_pointer_t          pointer;
3641         parsed_reference_t        reference;
3642         construct_function_type_t function;
3643         parsed_array_t            array;
3644 };
3645
3646 static construct_type_t *parse_pointer_declarator(void)
3647 {
3648         eat('*');
3649
3650         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
3651         memset(pointer, 0, sizeof(pointer[0]));
3652         pointer->base.kind       = CONSTRUCT_POINTER;
3653         pointer->type_qualifiers = parse_type_qualifiers();
3654         //pointer->base_variable       = base_variable;
3655
3656         return (construct_type_t*) pointer;
3657 }
3658
3659 static construct_type_t *parse_reference_declarator(void)
3660 {
3661         eat('&');
3662
3663         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
3664         parsed_reference_t *reference = &cons->reference;
3665         memset(reference, 0, sizeof(*reference));
3666         cons->kind = CONSTRUCT_REFERENCE;
3667
3668         return cons;
3669 }
3670
3671 static construct_type_t *parse_array_declarator(void)
3672 {
3673         eat('[');
3674         add_anchor_token(']');
3675
3676         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
3677         parsed_array_t   *array = &cons->array;
3678         memset(array, 0, sizeof(*array));
3679         cons->kind = CONSTRUCT_ARRAY;
3680
3681         if (token.type == T_static) {
3682                 array->is_static = true;
3683                 next_token();
3684         }
3685
3686         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3687         if (type_qualifiers != 0) {
3688                 if (token.type == T_static) {
3689                         array->is_static = true;
3690                         next_token();
3691                 }
3692         }
3693         array->type_qualifiers = type_qualifiers;
3694
3695         if (token.type == '*' && look_ahead(1)->type == ']') {
3696                 array->is_variable = true;
3697                 next_token();
3698         } else if (token.type != ']') {
3699                 expression_t *const size = parse_assignment_expression();
3700
3701                 /* §6.7.5.2:1  Array size must have integer type */
3702                 type_t *const orig_type = size->base.type;
3703                 type_t *const type      = skip_typeref(orig_type);
3704                 if (!is_type_integer(type) && is_type_valid(type)) {
3705                         errorf(&size->base.source_position,
3706                                "array size '%E' must have integer type but has type '%T'",
3707                                size, orig_type);
3708                 }
3709
3710                 array->size = size;
3711                 mark_vars_read(size, NULL);
3712         }
3713
3714         rem_anchor_token(']');
3715         expect(']', end_error);
3716
3717 end_error:
3718         return cons;
3719 }
3720
3721 static construct_type_t *parse_function_declarator(scope_t *scope)
3722 {
3723         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3724         function_type_t *ftype = &type->function;
3725
3726         ftype->linkage            = current_linkage;
3727         ftype->calling_convention = CC_DEFAULT;
3728
3729         parse_parameters(ftype, scope);
3730
3731         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
3732         construct_function_type_t *function = &cons->function;
3733         memset(function, 0, sizeof(*function));
3734         cons->kind              = CONSTRUCT_FUNCTION;
3735         function->function_type = type;
3736
3737         return cons;
3738 }
3739
3740 typedef struct parse_declarator_env_t {
3741         bool               may_be_abstract : 1;
3742         bool               must_be_abstract : 1;
3743         decl_modifiers_t   modifiers;
3744         symbol_t          *symbol;
3745         source_position_t  source_position;
3746         scope_t            parameters;
3747         attribute_t       *attributes;
3748 } parse_declarator_env_t;
3749
3750 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3751 {
3752         /* construct a single linked list of construct_type_t's which describe
3753          * how to construct the final declarator type */
3754         construct_type_t  *first      = NULL;
3755         construct_type_t **anchor     = &first;
3756
3757         env->attributes = parse_attributes(env->attributes);
3758
3759         for (;;) {
3760                 construct_type_t *type;
3761                 //variable_t       *based = NULL; /* MS __based extension */
3762                 switch (token.type) {
3763                         case '&':
3764                                 if (!(c_mode & _CXX))
3765                                         errorf(HERE, "references are only available for C++");
3766                                 type = parse_reference_declarator();
3767                                 break;
3768
3769                         case T__based: {
3770 #if 0
3771                                 source_position_t const pos = *HERE;
3772                                 next_token();
3773                                 expect('(', end_error);
3774                                 add_anchor_token(')');
3775                                 based = parse_microsoft_based();
3776                                 rem_anchor_token(')');
3777                                 expect(')', end_error);
3778                                 if (token.type != '*') {
3779                                         if (token.type == T__based) {
3780                                                 errorf(&pos, "__based type modifier specified more than once");
3781                                         } else if (warning.other) {
3782                                                 warningf(&pos,
3783                                                                 "__based does not precede a pointer declarator, ignored");
3784                                         }
3785                                         continue;
3786                                 }
3787 #else
3788                                 panic("based currently disabled");
3789 #endif
3790                                 /* FALLTHROUGH */
3791                         }
3792
3793                         case '*':
3794                                 type = parse_pointer_declarator();
3795                                 break;
3796
3797                         default:
3798                                 goto ptr_operator_end;
3799                 }
3800
3801                 *anchor = type;
3802                 anchor  = &type->base.next;
3803
3804                 /* TODO: find out if this is correct */
3805                 env->attributes = parse_attributes(env->attributes);
3806         }
3807
3808 ptr_operator_end: ;
3809 #if 0
3810         modifiers      |= env->modifiers;
3811         env->modifiers  = modifiers;
3812 #endif
3813
3814         construct_type_t *inner_types = NULL;
3815
3816         switch (token.type) {
3817         case T_IDENTIFIER:
3818                 if (env->must_be_abstract) {
3819                         errorf(HERE, "no identifier expected in typename");
3820                 } else {
3821                         env->symbol          = token.v.symbol;
3822                         env->source_position = token.source_position;
3823                 }
3824                 next_token();
3825                 break;
3826         case '(':
3827                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3828                  * interpreted as ``function with no parameter specification'', rather
3829                  * than redundant parentheses around the omitted identifier. */
3830                 if (look_ahead(1)->type != ')') {
3831                         next_token();
3832                         add_anchor_token(')');
3833                         inner_types = parse_inner_declarator(env);
3834                         if (inner_types != NULL) {
3835                                 /* All later declarators only modify the return type */
3836                                 env->must_be_abstract = true;
3837                         }
3838                         rem_anchor_token(')');
3839                         expect(')', end_error);
3840                 }
3841                 break;
3842         default:
3843                 if (env->may_be_abstract)
3844                         break;
3845                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3846                 eat_until_anchor();
3847                 return NULL;
3848         }
3849
3850         construct_type_t **const p = anchor;
3851
3852         for (;;) {
3853                 construct_type_t *type;
3854                 switch (token.type) {
3855                 case '(': {
3856                         scope_t *scope = NULL;
3857                         if (!env->must_be_abstract) {
3858                                 scope = &env->parameters;
3859                         }
3860
3861                         type = parse_function_declarator(scope);
3862                         break;
3863                 }
3864                 case '[':
3865                         type = parse_array_declarator();
3866                         break;
3867                 default:
3868                         goto declarator_finished;
3869                 }
3870
3871                 /* insert in the middle of the list (at p) */
3872                 type->base.next = *p;
3873                 *p              = type;
3874                 if (anchor == p)
3875                         anchor = &type->base.next;
3876         }
3877
3878 declarator_finished:
3879         /* append inner_types at the end of the list, we don't to set anchor anymore
3880          * as it's not needed anymore */
3881         *anchor = inner_types;
3882
3883         return first;
3884 end_error:
3885         return NULL;
3886 }
3887
3888 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
3889 {
3890         construct_type_t *iter = construct_list;
3891         for (; iter != NULL; iter = iter->base.next) {
3892                 switch (iter->kind) {
3893                 case CONSTRUCT_INVALID:
3894                         break;
3895                 case CONSTRUCT_FUNCTION: {
3896                         construct_function_type_t *function      = &iter->function;
3897                         type_t                    *function_type = function->function_type;
3898
3899                         function_type->function.return_type = type;
3900
3901                         type_t *skipped_return_type = skip_typeref(type);
3902                         /* §6.7.5.3:1 */
3903                         if (is_type_function(skipped_return_type)) {
3904                                 errorf(HERE, "function returning function is not allowed");
3905                         } else if (is_type_array(skipped_return_type)) {
3906                                 errorf(HERE, "function returning array is not allowed");
3907                         } else {
3908                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3909                                         warningf(HERE,
3910                                                 "type qualifiers in return type of function type are meaningless");
3911                                 }
3912                         }
3913
3914                         /* The function type was constructed earlier.  Freeing it here will
3915                          * destroy other types. */
3916                         type = typehash_insert(function_type);
3917                         continue;
3918                 }
3919
3920                 case CONSTRUCT_POINTER: {
3921                         if (is_type_reference(skip_typeref(type)))
3922                                 errorf(HERE, "cannot declare a pointer to reference");
3923
3924                         parsed_pointer_t *pointer = &iter->pointer;
3925                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3926                         continue;
3927                 }
3928
3929                 case CONSTRUCT_REFERENCE:
3930                         if (is_type_reference(skip_typeref(type)))
3931                                 errorf(HERE, "cannot declare a reference to reference");
3932
3933                         type = make_reference_type(type);
3934                         continue;
3935
3936                 case CONSTRUCT_ARRAY: {
3937                         if (is_type_reference(skip_typeref(type)))
3938                                 errorf(HERE, "cannot declare an array of references");
3939
3940                         parsed_array_t *array      = &iter->array;
3941                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3942
3943                         expression_t *size_expression = array->size;
3944                         if (size_expression != NULL) {
3945                                 size_expression
3946                                         = create_implicit_cast(size_expression, type_size_t);
3947                         }
3948
3949                         array_type->base.qualifiers       = array->type_qualifiers;
3950                         array_type->array.element_type    = type;
3951                         array_type->array.is_static       = array->is_static;
3952                         array_type->array.is_variable     = array->is_variable;
3953                         array_type->array.size_expression = size_expression;
3954
3955                         if (size_expression != NULL) {
3956                                 if (is_constant_expression(size_expression)) {
3957                                         long const size
3958                                                 = fold_constant_to_int(size_expression);
3959                                         array_type->array.size          = size;
3960                                         array_type->array.size_constant = true;
3961                                         /* §6.7.5.2:1  If the expression is a constant expression, it shall
3962                                          * have a value greater than zero. */
3963                                         if (size <= 0) {
3964                                                 if (size < 0 || !GNU_MODE) {
3965                                                         errorf(&size_expression->base.source_position,
3966                                                                         "size of array must be greater than zero");
3967                                                 } else if (warning.other) {
3968                                                         warningf(&size_expression->base.source_position,
3969                                                                         "zero length arrays are a GCC extension");
3970                                                 }
3971                                         }
3972                                 } else {
3973                                         array_type->array.is_vla = true;
3974                                 }
3975                         }
3976
3977                         type_t *skipped_type = skip_typeref(type);
3978                         /* §6.7.5.2:1 */
3979                         if (is_type_incomplete(skipped_type)) {
3980                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
3981                         } else if (is_type_function(skipped_type)) {
3982                                 errorf(HERE, "array of functions is not allowed");
3983                         }
3984                         type = identify_new_type(array_type);
3985                         continue;
3986                 }
3987                 }
3988                 internal_errorf(HERE, "invalid type construction found");
3989         }
3990
3991         return type;
3992 }
3993
3994 static type_t *automatic_type_conversion(type_t *orig_type);
3995
3996 static type_t *semantic_parameter(const source_position_t *pos,
3997                                   type_t *type,
3998                                   const declaration_specifiers_t *specifiers,
3999                                   symbol_t *symbol)
4000 {
4001         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4002          *             shall be adjusted to ``qualified pointer to type'',
4003          *             [...]
4004          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4005          *             type'' shall be adjusted to ``pointer to function
4006          *             returning type'', as in 6.3.2.1. */
4007         type = automatic_type_conversion(type);
4008
4009         if (specifiers->is_inline && is_type_valid(type)) {
4010                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
4011         }
4012
4013         /* §6.9.1:6  The declarations in the declaration list shall contain
4014          *           no storage-class specifier other than register and no
4015          *           initializations. */
4016         if (specifiers->thread_local || (
4017                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4018                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4019            ) {
4020                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
4021         }
4022
4023         /* delay test for incomplete type, because we might have (void)
4024          * which is legal but incomplete... */
4025
4026         return type;
4027 }
4028
4029 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4030                                   declarator_flags_t flags)
4031 {
4032         parse_declarator_env_t env;
4033         memset(&env, 0, sizeof(env));
4034         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
4035
4036         construct_type_t *construct_type = parse_inner_declarator(&env);
4037         type_t           *orig_type      =
4038                 construct_declarator_type(construct_type, specifiers->type);
4039         type_t           *type           = skip_typeref(orig_type);
4040
4041         if (construct_type != NULL) {
4042                 obstack_free(&temp_obst, construct_type);
4043         }
4044
4045         attribute_t *attributes = parse_attributes(env.attributes);
4046         /* append (shared) specifier attribute behind attributes of this
4047            declarator */
4048         if (attributes != NULL) {
4049                 attribute_t *last = attributes;
4050                 while (last->next != NULL)
4051                         last = last->next;
4052                 last->next = specifiers->attributes;
4053         } else {
4054                 attributes = specifiers->attributes;
4055         }
4056
4057         entity_t *entity;
4058         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4059                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4060                 entity->base.symbol          = env.symbol;
4061                 entity->base.source_position = env.source_position;
4062                 entity->typedefe.type        = orig_type;
4063
4064                 if (anonymous_entity != NULL) {
4065                         if (is_type_compound(type)) {
4066                                 assert(anonymous_entity->compound.alias == NULL);
4067                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4068                                        anonymous_entity->kind == ENTITY_UNION);
4069                                 anonymous_entity->compound.alias = entity;
4070                                 anonymous_entity = NULL;
4071                         } else if (is_type_enum(type)) {
4072                                 assert(anonymous_entity->enume.alias == NULL);
4073                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4074                                 anonymous_entity->enume.alias = entity;
4075                                 anonymous_entity = NULL;
4076                         }
4077                 }
4078         } else {
4079                 /* create a declaration type entity */
4080                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4081                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4082
4083                         if (env.symbol != NULL) {
4084                                 if (specifiers->is_inline && is_type_valid(type)) {
4085                                         errorf(&env.source_position,
4086                                                         "compound member '%Y' declared 'inline'", env.symbol);
4087                                 }
4088
4089                                 if (specifiers->thread_local ||
4090                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4091                                         errorf(&env.source_position,
4092                                                         "compound member '%Y' must have no storage class",
4093                                                         env.symbol);
4094                                 }
4095                         }
4096                 } else if (flags & DECL_IS_PARAMETER) {
4097                         orig_type = semantic_parameter(&env.source_position, orig_type,
4098                                                        specifiers, env.symbol);
4099
4100                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4101                 } else if (is_type_function(type)) {
4102                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4103
4104                         entity->function.is_inline  = specifiers->is_inline;
4105                         entity->function.parameters = env.parameters;
4106
4107                         if (env.symbol != NULL) {
4108                                 /* this needs fixes for C++ */
4109                                 bool in_function_scope = current_function != NULL;
4110
4111                                 if (specifiers->thread_local || (
4112                                       specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4113                                           specifiers->storage_class != STORAGE_CLASS_NONE   &&
4114                                           (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
4115                                    )) {
4116                                         errorf(&env.source_position,
4117                                                         "invalid storage class for function '%Y'", env.symbol);
4118                                 }
4119                         }
4120                 } else {
4121                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4122
4123                         entity->variable.thread_local = specifiers->thread_local;
4124
4125                         if (env.symbol != NULL) {
4126                                 if (specifiers->is_inline && is_type_valid(type)) {
4127                                         errorf(&env.source_position,
4128                                                         "variable '%Y' declared 'inline'", env.symbol);
4129                                 }
4130
4131                                 bool invalid_storage_class = false;
4132                                 if (current_scope == file_scope) {
4133                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4134                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4135                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4136                                                 invalid_storage_class = true;
4137                                         }
4138                                 } else {
4139                                         if (specifiers->thread_local &&
4140                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4141                                                 invalid_storage_class = true;
4142                                         }
4143                                 }
4144                                 if (invalid_storage_class) {
4145                                         errorf(&env.source_position,
4146                                                         "invalid storage class for variable '%Y'", env.symbol);
4147                                 }
4148                         }
4149                 }
4150
4151                 if (env.symbol != NULL) {
4152                         entity->base.symbol          = env.symbol;
4153                         entity->base.source_position = env.source_position;
4154                 } else {
4155                         entity->base.source_position = specifiers->source_position;
4156                 }
4157                 entity->base.namespc           = NAMESPACE_NORMAL;
4158                 entity->declaration.type       = orig_type;
4159                 entity->declaration.alignment  = get_type_alignment(orig_type);
4160                 entity->declaration.modifiers  = env.modifiers;
4161                 entity->declaration.attributes = attributes;
4162
4163                 storage_class_t storage_class = specifiers->storage_class;
4164                 entity->declaration.declared_storage_class = storage_class;
4165
4166                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4167                         storage_class = STORAGE_CLASS_AUTO;
4168                 entity->declaration.storage_class = storage_class;
4169         }
4170
4171         if (attributes != NULL) {
4172                 handle_entity_attributes(attributes, entity);
4173         }
4174
4175         return entity;
4176 }
4177
4178 static type_t *parse_abstract_declarator(type_t *base_type)
4179 {
4180         parse_declarator_env_t env;
4181         memset(&env, 0, sizeof(env));
4182         env.may_be_abstract = true;
4183         env.must_be_abstract = true;
4184
4185         construct_type_t *construct_type = parse_inner_declarator(&env);
4186
4187         type_t *result = construct_declarator_type(construct_type, base_type);
4188         if (construct_type != NULL) {
4189                 obstack_free(&temp_obst, construct_type);
4190         }
4191         result = handle_type_attributes(env.attributes, result);
4192
4193         return result;
4194 }
4195
4196 /**
4197  * Check if the declaration of main is suspicious.  main should be a
4198  * function with external linkage, returning int, taking either zero
4199  * arguments, two, or three arguments of appropriate types, ie.
4200  *
4201  * int main([ int argc, char **argv [, char **env ] ]).
4202  *
4203  * @param decl    the declaration to check
4204  * @param type    the function type of the declaration
4205  */
4206 static void check_main(const entity_t *entity)
4207 {
4208         const source_position_t *pos = &entity->base.source_position;
4209         if (entity->kind != ENTITY_FUNCTION) {
4210                 warningf(pos, "'main' is not a function");
4211                 return;
4212         }
4213
4214         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4215                 warningf(pos, "'main' is normally a non-static function");
4216         }
4217
4218         type_t *type = skip_typeref(entity->declaration.type);
4219         assert(is_type_function(type));
4220
4221         function_type_t *func_type = &type->function;
4222         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4223                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4224                          func_type->return_type);
4225         }
4226         const function_parameter_t *parm = func_type->parameters;
4227         if (parm != NULL) {
4228                 type_t *const first_type = parm->type;
4229                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4230                         warningf(pos,
4231                                  "first argument of 'main' should be 'int', but is '%T'",
4232                                  first_type);
4233                 }
4234                 parm = parm->next;
4235                 if (parm != NULL) {
4236                         type_t *const second_type = parm->type;
4237                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4238                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4239                         }
4240                         parm = parm->next;
4241                         if (parm != NULL) {
4242                                 type_t *const third_type = parm->type;
4243                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4244                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4245                                 }
4246                                 parm = parm->next;
4247                                 if (parm != NULL)
4248                                         goto warn_arg_count;
4249                         }
4250                 } else {
4251 warn_arg_count:
4252                         warningf(pos, "'main' takes only zero, two or three arguments");
4253                 }
4254         }
4255 }
4256
4257 /**
4258  * Check if a symbol is the equal to "main".
4259  */
4260 static bool is_sym_main(const symbol_t *const sym)
4261 {
4262         return strcmp(sym->string, "main") == 0;
4263 }
4264
4265 static void error_redefined_as_different_kind(const source_position_t *pos,
4266                 const entity_t *old, entity_kind_t new_kind)
4267 {
4268         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4269                get_entity_kind_name(old->kind), old->base.symbol,
4270                get_entity_kind_name(new_kind), &old->base.source_position);
4271 }
4272
4273 static bool is_error_entity(entity_t *const ent)
4274 {
4275         if (is_declaration(ent)) {
4276                 return is_type_valid(skip_typeref(ent->declaration.type));
4277         } else if (ent->kind == ENTITY_TYPEDEF) {
4278                 return is_type_valid(skip_typeref(ent->typedefe.type));
4279         }
4280         return false;
4281 }
4282
4283 /**
4284  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4285  * for various problems that occur for multiple definitions
4286  */
4287 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4288 {
4289         const symbol_t *const    symbol  = entity->base.symbol;
4290         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4291         const source_position_t *pos     = &entity->base.source_position;
4292
4293         /* can happen in error cases */
4294         if (symbol == NULL)
4295                 return entity;
4296
4297         entity_t *const previous_entity = get_entity(symbol, namespc);
4298         /* pushing the same entity twice will break the stack structure */
4299         assert(previous_entity != entity);
4300
4301         if (entity->kind == ENTITY_FUNCTION) {
4302                 type_t *const orig_type = entity->declaration.type;
4303                 type_t *const type      = skip_typeref(orig_type);
4304
4305                 assert(is_type_function(type));
4306                 if (type->function.unspecified_parameters &&
4307                                 warning.strict_prototypes &&
4308                                 previous_entity == NULL) {
4309                         warningf(pos, "function declaration '%#T' is not a prototype",
4310                                          orig_type, symbol);
4311                 }
4312
4313                 if (warning.main && current_scope == file_scope
4314                                 && is_sym_main(symbol)) {
4315                         check_main(entity);
4316                 }
4317         }
4318
4319         if (is_declaration(entity) &&
4320                         warning.nested_externs &&
4321                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4322                         current_scope != file_scope) {
4323                 warningf(pos, "nested extern declaration of '%#T'",
4324                          entity->declaration.type, symbol);
4325         }
4326
4327         if (previous_entity != NULL) {
4328                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4329                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4330                         assert(previous_entity->kind == ENTITY_PARAMETER);
4331                         errorf(pos,
4332                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4333                                         entity->declaration.type, symbol,
4334                                         previous_entity->declaration.type, symbol,
4335                                         &previous_entity->base.source_position);
4336                         goto finish;
4337                 }
4338
4339                 if (previous_entity->base.parent_scope == current_scope) {
4340                         if (previous_entity->kind != entity->kind) {
4341                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
4342                                         error_redefined_as_different_kind(pos, previous_entity,
4343                                                         entity->kind);
4344                                 }
4345                                 goto finish;
4346                         }
4347                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4348                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4349                                                 symbol, &previous_entity->base.source_position);
4350                                 goto finish;
4351                         }
4352                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4353                                 /* TODO: C++ allows this for exactly the same type */
4354                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4355                                                 symbol, &previous_entity->base.source_position);
4356                                 goto finish;
4357                         }
4358
4359                         /* at this point we should have only VARIABLES or FUNCTIONS */
4360                         assert(is_declaration(previous_entity) && is_declaration(entity));
4361
4362                         declaration_t *const prev_decl = &previous_entity->declaration;
4363                         declaration_t *const decl      = &entity->declaration;
4364
4365                         /* can happen for K&R style declarations */
4366                         if (prev_decl->type       == NULL             &&
4367                                         previous_entity->kind == ENTITY_PARAMETER &&
4368                                         entity->kind          == ENTITY_PARAMETER) {
4369                                 prev_decl->type                   = decl->type;
4370                                 prev_decl->storage_class          = decl->storage_class;
4371                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4372                                 prev_decl->modifiers              = decl->modifiers;
4373                                 return previous_entity;
4374                         }
4375
4376                         type_t *const orig_type = decl->type;
4377                         assert(orig_type != NULL);
4378                         type_t *const type      = skip_typeref(orig_type);
4379                         type_t *const prev_type = skip_typeref(prev_decl->type);
4380
4381                         if (!types_compatible(type, prev_type)) {
4382                                 errorf(pos,
4383                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4384                                                 orig_type, symbol, prev_decl->type, symbol,
4385                                                 &previous_entity->base.source_position);
4386                         } else {
4387                                 unsigned old_storage_class = prev_decl->storage_class;
4388
4389                                 if (warning.redundant_decls               &&
4390                                                 is_definition                     &&
4391                                                 !prev_decl->used                  &&
4392                                                 !(prev_decl->modifiers & DM_USED) &&
4393                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4394                                         warningf(&previous_entity->base.source_position,
4395                                                         "unnecessary static forward declaration for '%#T'",
4396                                                         prev_decl->type, symbol);
4397                                 }
4398
4399                                 storage_class_t new_storage_class = decl->storage_class;
4400
4401                                 /* pretend no storage class means extern for function
4402                                  * declarations (except if the previous declaration is neither
4403                                  * none nor extern) */
4404                                 if (entity->kind == ENTITY_FUNCTION) {
4405                                         /* the previous declaration could have unspecified parameters or
4406                                          * be a typedef, so use the new type */
4407                                         if (prev_type->function.unspecified_parameters || is_definition)
4408                                                 prev_decl->type = type;
4409
4410                                         switch (old_storage_class) {
4411                                                 case STORAGE_CLASS_NONE:
4412                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4413                                                         /* FALLTHROUGH */
4414
4415                                                 case STORAGE_CLASS_EXTERN:
4416                                                         if (is_definition) {
4417                                                                 if (warning.missing_prototypes &&
4418                                                                                 prev_type->function.unspecified_parameters &&
4419                                                                                 !is_sym_main(symbol)) {
4420                                                                         warningf(pos, "no previous prototype for '%#T'",
4421                                                                                         orig_type, symbol);
4422                                                                 }
4423                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4424                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4425                                                         }
4426                                                         break;
4427
4428                                                 default:
4429                                                         break;
4430                                         }
4431                                 } else if (is_type_incomplete(prev_type)) {
4432                                         prev_decl->type = type;
4433                                 }
4434
4435                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4436                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4437 warn_redundant_declaration:
4438                                         if (!is_definition           &&
4439                                                         warning.redundant_decls  &&
4440                                                         is_type_valid(prev_type) &&
4441                                                         strcmp(previous_entity->base.source_position.input_name,
4442                                                                 "<builtin>") != 0) {
4443                                                 warningf(pos,
4444                                                                 "redundant declaration for '%Y' (declared %P)",
4445                                                                 symbol, &previous_entity->base.source_position);
4446                                         }
4447                                 } else if (current_function == NULL) {
4448                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4449                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4450                                                 errorf(pos,
4451                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
4452                                                                 symbol, &previous_entity->base.source_position);
4453                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4454                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4455                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4456                                         } else {
4457                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4458                                                 if (c_mode & _CXX)
4459                                                         goto error_redeclaration;
4460                                                 goto warn_redundant_declaration;
4461                                         }
4462                                 } else if (is_type_valid(prev_type)) {
4463                                         if (old_storage_class == new_storage_class) {
4464 error_redeclaration:
4465                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4466                                                                 symbol, &previous_entity->base.source_position);
4467                                         } else {
4468                                                 errorf(pos,
4469                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4470                                                                 symbol, &previous_entity->base.source_position);
4471                                         }
4472                                 }
4473                         }
4474
4475                         prev_decl->modifiers |= decl->modifiers;
4476                         if (entity->kind == ENTITY_FUNCTION) {
4477                                 previous_entity->function.is_inline |= entity->function.is_inline;
4478                         }
4479                         return previous_entity;
4480                 }
4481
4482                 if (warning.shadow) {
4483                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4484                                         get_entity_kind_name(entity->kind), symbol,
4485                                         get_entity_kind_name(previous_entity->kind),
4486                                         &previous_entity->base.source_position);
4487                 }
4488         }
4489
4490         if (entity->kind == ENTITY_FUNCTION) {
4491                 if (is_definition &&
4492                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4493                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4494                                 warningf(pos, "no previous prototype for '%#T'",
4495                                          entity->declaration.type, symbol);
4496                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4497                                 warningf(pos, "no previous declaration for '%#T'",
4498                                          entity->declaration.type, symbol);
4499                         }
4500                 }
4501         } else if (warning.missing_declarations &&
4502                         entity->kind == ENTITY_VARIABLE &&
4503                         current_scope == file_scope) {
4504                 declaration_t *declaration = &entity->declaration;
4505                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4506                         warningf(pos, "no previous declaration for '%#T'",
4507                                  declaration->type, symbol);
4508                 }
4509         }
4510
4511 finish:
4512         assert(entity->base.parent_scope == NULL);
4513         assert(current_scope != NULL);
4514
4515         entity->base.parent_scope = current_scope;
4516         entity->base.namespc      = NAMESPACE_NORMAL;
4517         environment_push(entity);
4518         append_entity(current_scope, entity);
4519
4520         return entity;
4521 }
4522
4523 static void parser_error_multiple_definition(entity_t *entity,
4524                 const source_position_t *source_position)
4525 {
4526         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4527                entity->base.symbol, &entity->base.source_position);
4528 }
4529
4530 static bool is_declaration_specifier(const token_t *token,
4531                                      bool only_specifiers_qualifiers)
4532 {
4533         switch (token->type) {
4534                 TYPE_SPECIFIERS
4535                 TYPE_QUALIFIERS
4536                         return true;
4537                 case T_IDENTIFIER:
4538                         return is_typedef_symbol(token->v.symbol);
4539
4540                 case T___extension__:
4541                 STORAGE_CLASSES
4542                         return !only_specifiers_qualifiers;
4543
4544                 default:
4545                         return false;
4546         }
4547 }
4548
4549 static void parse_init_declarator_rest(entity_t *entity)
4550 {
4551         assert(is_declaration(entity));
4552         declaration_t *const declaration = &entity->declaration;
4553
4554         eat('=');
4555
4556         type_t *orig_type = declaration->type;
4557         type_t *type      = skip_typeref(orig_type);
4558
4559         if (entity->kind == ENTITY_VARIABLE
4560                         && entity->variable.initializer != NULL) {
4561                 parser_error_multiple_definition(entity, HERE);
4562         }
4563
4564         bool must_be_constant = false;
4565         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4566             entity->base.parent_scope  == file_scope) {
4567                 must_be_constant = true;
4568         }
4569
4570         if (is_type_function(type)) {
4571                 errorf(&entity->base.source_position,
4572                        "function '%#T' is initialized like a variable",
4573                        orig_type, entity->base.symbol);
4574                 orig_type = type_error_type;
4575         }
4576
4577         parse_initializer_env_t env;
4578         env.type             = orig_type;
4579         env.must_be_constant = must_be_constant;
4580         env.entity           = entity;
4581         current_init_decl    = entity;
4582
4583         initializer_t *initializer = parse_initializer(&env);
4584         current_init_decl = NULL;
4585
4586         if (entity->kind == ENTITY_VARIABLE) {
4587                 /* §6.7.5:22  array initializers for arrays with unknown size
4588                  * determine the array type size */
4589                 declaration->type            = env.type;
4590                 entity->variable.initializer = initializer;
4591         }
4592 }
4593
4594 /* parse rest of a declaration without any declarator */
4595 static void parse_anonymous_declaration_rest(
4596                 const declaration_specifiers_t *specifiers)
4597 {
4598         eat(';');
4599         anonymous_entity = NULL;
4600
4601         if (warning.other) {
4602                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4603                                 specifiers->thread_local) {
4604                         warningf(&specifiers->source_position,
4605                                  "useless storage class in empty declaration");
4606                 }
4607
4608                 type_t *type = specifiers->type;
4609                 switch (type->kind) {
4610                         case TYPE_COMPOUND_STRUCT:
4611                         case TYPE_COMPOUND_UNION: {
4612                                 if (type->compound.compound->base.symbol == NULL) {
4613                                         warningf(&specifiers->source_position,
4614                                                  "unnamed struct/union that defines no instances");
4615                                 }
4616                                 break;
4617                         }
4618
4619                         case TYPE_ENUM:
4620                                 break;
4621
4622                         default:
4623                                 warningf(&specifiers->source_position, "empty declaration");
4624                                 break;
4625                 }
4626         }
4627 }
4628
4629 static void check_variable_type_complete(entity_t *ent)
4630 {
4631         if (ent->kind != ENTITY_VARIABLE)
4632                 return;
4633
4634         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4635          *         type for the object shall be complete [...] */
4636         declaration_t *decl = &ent->declaration;
4637         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4638                         decl->storage_class == STORAGE_CLASS_STATIC)
4639                 return;
4640
4641         type_t *const orig_type = decl->type;
4642         type_t *const type      = skip_typeref(orig_type);
4643         if (!is_type_incomplete(type))
4644                 return;
4645
4646         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4647          * are given length one. */
4648         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4649                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4650                 return;
4651         }
4652
4653         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4654                         orig_type, ent->base.symbol);
4655 }
4656
4657
4658 static void parse_declaration_rest(entity_t *ndeclaration,
4659                 const declaration_specifiers_t *specifiers,
4660                 parsed_declaration_func         finished_declaration,
4661                 declarator_flags_t              flags)
4662 {
4663         add_anchor_token(';');
4664         add_anchor_token(',');
4665         while (true) {
4666                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4667
4668                 if (token.type == '=') {
4669                         parse_init_declarator_rest(entity);
4670                 } else if (entity->kind == ENTITY_VARIABLE) {
4671                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4672                          * [...] where the extern specifier is explicitly used. */
4673                         declaration_t *decl = &entity->declaration;
4674                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4675                                 type_t *type = decl->type;
4676                                 if (is_type_reference(skip_typeref(type))) {
4677                                         errorf(&entity->base.source_position,
4678                                                         "reference '%#T' must be initialized",
4679                                                         type, entity->base.symbol);
4680                                 }
4681                         }
4682                 }
4683
4684                 check_variable_type_complete(entity);
4685
4686                 if (token.type != ',')
4687                         break;
4688                 eat(',');
4689
4690                 add_anchor_token('=');
4691                 ndeclaration = parse_declarator(specifiers, flags);
4692                 rem_anchor_token('=');
4693         }
4694         expect(';', end_error);
4695
4696 end_error:
4697         anonymous_entity = NULL;
4698         rem_anchor_token(';');
4699         rem_anchor_token(',');
4700 }
4701
4702 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4703 {
4704         symbol_t *symbol = entity->base.symbol;
4705         if (symbol == NULL) {
4706                 errorf(HERE, "anonymous declaration not valid as function parameter");
4707                 return entity;
4708         }
4709
4710         assert(entity->base.namespc == NAMESPACE_NORMAL);
4711         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4712         if (previous_entity == NULL
4713                         || previous_entity->base.parent_scope != current_scope) {
4714                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
4715                        symbol);
4716                 return entity;
4717         }
4718
4719         if (is_definition) {
4720                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4721         }
4722
4723         return record_entity(entity, false);
4724 }
4725
4726 static void parse_declaration(parsed_declaration_func finished_declaration,
4727                               declarator_flags_t      flags)
4728 {
4729         declaration_specifiers_t specifiers;
4730         memset(&specifiers, 0, sizeof(specifiers));
4731
4732         add_anchor_token(';');
4733         parse_declaration_specifiers(&specifiers);
4734         rem_anchor_token(';');
4735
4736         if (token.type == ';') {
4737                 parse_anonymous_declaration_rest(&specifiers);
4738         } else {
4739                 entity_t *entity = parse_declarator(&specifiers, flags);
4740                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4741         }
4742 }
4743
4744 /* §6.5.2.2:6 */
4745 static type_t *get_default_promoted_type(type_t *orig_type)
4746 {
4747         type_t *result = orig_type;
4748
4749         type_t *type = skip_typeref(orig_type);
4750         if (is_type_integer(type)) {
4751                 result = promote_integer(type);
4752         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4753                 result = type_double;
4754         }
4755
4756         return result;
4757 }
4758
4759 static void parse_kr_declaration_list(entity_t *entity)
4760 {
4761         if (entity->kind != ENTITY_FUNCTION)
4762                 return;
4763
4764         type_t *type = skip_typeref(entity->declaration.type);
4765         assert(is_type_function(type));
4766         if (!type->function.kr_style_parameters)
4767                 return;
4768
4769         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4770         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4771                 proto_type = NULL;
4772
4773         add_anchor_token('{');
4774
4775         /* push function parameters */
4776         size_t const  top       = environment_top();
4777         scope_t      *old_scope = scope_push(&entity->function.parameters);
4778
4779         entity_t *parameter = entity->function.parameters.entities;
4780         for ( ; parameter != NULL; parameter = parameter->base.next) {
4781                 assert(parameter->base.parent_scope == NULL);
4782                 parameter->base.parent_scope = current_scope;
4783                 environment_push(parameter);
4784         }
4785
4786         /* parse declaration list */
4787         for (;;) {
4788                 switch (token.type) {
4789                         DECLARATION_START
4790                         case T___extension__:
4791                         /* This covers symbols, which are no type, too, and results in
4792                          * better error messages.  The typical cases are misspelled type
4793                          * names and missing includes. */
4794                         case T_IDENTIFIER:
4795                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4796                                 break;
4797                         default:
4798                                 goto decl_list_end;
4799                 }
4800         }
4801 decl_list_end:
4802
4803         /* pop function parameters */
4804         assert(current_scope == &entity->function.parameters);
4805         scope_pop(old_scope);
4806         environment_pop_to(top);
4807
4808         /* update function type */
4809         type_t *new_type = duplicate_type(type);
4810
4811         function_parameter_t  *parameters = NULL;
4812         function_parameter_t **anchor     = &parameters;
4813
4814         parameter = entity->function.parameters.entities;
4815         for (; parameter != NULL; parameter = parameter->base.next) {
4816                 if (parameter->kind != ENTITY_PARAMETER)
4817                         continue;
4818
4819                 type_t *parameter_type = parameter->declaration.type;
4820                 if (parameter_type == NULL) {
4821                         if (strict_mode) {
4822                                 errorf(HERE, "no type specified for function parameter '%Y'",
4823                                        parameter->base.symbol);
4824                                 parameter_type = type_error_type;
4825                         } else {
4826                                 if (warning.implicit_int) {
4827                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4828                                                  parameter->base.symbol);
4829                                 }
4830                                 parameter_type = type_int;
4831                         }
4832                         parameter->declaration.type = parameter_type;
4833                 }
4834
4835                 semantic_parameter_incomplete(parameter);
4836
4837                 /*
4838                  * we need the default promoted types for the function type
4839                  */
4840                 if (proto_type == NULL)
4841                         parameter_type = get_default_promoted_type(parameter_type);
4842
4843                 function_parameter_t *const parameter =
4844                         allocate_parameter(parameter_type);
4845
4846                 *anchor = parameter;
4847                 anchor  = &parameter->next;
4848         }
4849
4850         new_type->function.parameters = parameters;
4851         if (proto_type != NULL) {
4852                 /* compatibility with the prototype will be checked later ... */
4853                 new_type->function.prototyped = true;
4854         } else {
4855                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4856                  * prototype */
4857                 new_type->function.unspecified_parameters = true;
4858         }
4859
4860         new_type = identify_new_type(new_type);
4861
4862         entity->declaration.type = new_type;
4863
4864         rem_anchor_token('{');
4865 }
4866
4867 static bool first_err = true;
4868
4869 /**
4870  * When called with first_err set, prints the name of the current function,
4871  * else does noting.
4872  */
4873 static void print_in_function(void)
4874 {
4875         if (first_err) {
4876                 first_err = false;
4877                 diagnosticf("%s: In function '%Y':\n",
4878                             current_function->base.base.source_position.input_name,
4879                             current_function->base.base.symbol);
4880         }
4881 }
4882
4883 /**
4884  * Check if all labels are defined in the current function.
4885  * Check if all labels are used in the current function.
4886  */
4887 static void check_labels(void)
4888 {
4889         for (const goto_statement_t *goto_statement = goto_first;
4890             goto_statement != NULL;
4891             goto_statement = goto_statement->next) {
4892                 /* skip computed gotos */
4893                 if (goto_statement->expression != NULL)
4894                         continue;
4895
4896                 label_t *label = goto_statement->label;
4897
4898                 label->used = true;
4899                 if (label->base.source_position.input_name == NULL) {
4900                         print_in_function();
4901                         errorf(&goto_statement->base.source_position,
4902                                "label '%Y' used but not defined", label->base.symbol);
4903                  }
4904         }
4905
4906         if (warning.unused_label) {
4907                 for (const label_statement_t *label_statement = label_first;
4908                          label_statement != NULL;
4909                          label_statement = label_statement->next) {
4910                         label_t *label = label_statement->label;
4911
4912                         if (! label->used) {
4913                                 print_in_function();
4914                                 warningf(&label_statement->base.source_position,
4915                                          "label '%Y' defined but not used", label->base.symbol);
4916                         }
4917                 }
4918         }
4919 }
4920
4921 static void warn_unused_entity(entity_t *entity, entity_t *last)
4922 {
4923         entity_t const *const end = last != NULL ? last->base.next : NULL;
4924         for (; entity != end; entity = entity->base.next) {
4925                 if (!is_declaration(entity))
4926                         continue;
4927
4928                 declaration_t *declaration = &entity->declaration;
4929                 if (declaration->implicit)
4930                         continue;
4931
4932                 if (!declaration->used) {
4933                         print_in_function();
4934                         const char *what = get_entity_kind_name(entity->kind);
4935                         warningf(&entity->base.source_position, "%s '%Y' is unused",
4936                                  what, entity->base.symbol);
4937                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4938                         print_in_function();
4939                         const char *what = get_entity_kind_name(entity->kind);
4940                         warningf(&entity->base.source_position, "%s '%Y' is never read",
4941                                  what, entity->base.symbol);
4942                 }
4943         }
4944 }
4945
4946 static void check_unused_variables(statement_t *const stmt, void *const env)
4947 {
4948         (void)env;
4949
4950         switch (stmt->kind) {
4951                 case STATEMENT_DECLARATION: {
4952                         declaration_statement_t const *const decls = &stmt->declaration;
4953                         warn_unused_entity(decls->declarations_begin,
4954                                            decls->declarations_end);
4955                         return;
4956                 }
4957
4958                 case STATEMENT_FOR:
4959                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4960                         return;
4961
4962                 default:
4963                         return;
4964         }
4965 }
4966
4967 /**
4968  * Check declarations of current_function for unused entities.
4969  */
4970 static void check_declarations(void)
4971 {
4972         if (warning.unused_parameter) {
4973                 const scope_t *scope = &current_function->parameters;
4974
4975                 /* do not issue unused warnings for main */
4976                 if (!is_sym_main(current_function->base.base.symbol)) {
4977                         warn_unused_entity(scope->entities, NULL);
4978                 }
4979         }
4980         if (warning.unused_variable) {
4981                 walk_statements(current_function->statement, check_unused_variables,
4982                                 NULL);
4983         }
4984 }
4985
4986 static int determine_truth(expression_t const* const cond)
4987 {
4988         return
4989                 !is_constant_expression(cond) ? 0 :
4990                 fold_constant_to_bool(cond)   ? 1 :
4991                 -1;
4992 }
4993
4994 static void check_reachable(statement_t *);
4995 static bool reaches_end;
4996
4997 static bool expression_returns(expression_t const *const expr)
4998 {
4999         switch (expr->kind) {
5000                 case EXPR_CALL: {
5001                         expression_t const *const func = expr->call.function;
5002                         if (func->kind == EXPR_REFERENCE) {
5003                                 entity_t *entity = func->reference.entity;
5004                                 if (entity->kind == ENTITY_FUNCTION
5005                                                 && entity->declaration.modifiers & DM_NORETURN)
5006                                         return false;
5007                         }
5008
5009                         if (!expression_returns(func))
5010                                 return false;
5011
5012                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5013                                 if (!expression_returns(arg->expression))
5014                                         return false;
5015                         }
5016
5017                         return true;
5018                 }
5019
5020                 case EXPR_REFERENCE:
5021                 case EXPR_REFERENCE_ENUM_VALUE:
5022                 case EXPR_CONST:
5023                 case EXPR_CHARACTER_CONSTANT:
5024                 case EXPR_WIDE_CHARACTER_CONSTANT:
5025                 case EXPR_STRING_LITERAL:
5026                 case EXPR_WIDE_STRING_LITERAL:
5027                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5028                 case EXPR_LABEL_ADDRESS:
5029                 case EXPR_CLASSIFY_TYPE:
5030                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5031                 case EXPR_ALIGNOF:
5032                 case EXPR_FUNCNAME:
5033                 case EXPR_BUILTIN_CONSTANT_P:
5034                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5035                 case EXPR_OFFSETOF:
5036                 case EXPR_INVALID:
5037                         return true;
5038
5039                 case EXPR_STATEMENT: {
5040                         bool old_reaches_end = reaches_end;
5041                         reaches_end = false;
5042                         check_reachable(expr->statement.statement);
5043                         bool returns = reaches_end;
5044                         reaches_end = old_reaches_end;
5045                         return returns;
5046                 }
5047
5048                 case EXPR_CONDITIONAL:
5049                         // TODO handle constant expression
5050
5051                         if (!expression_returns(expr->conditional.condition))
5052                                 return false;
5053
5054                         if (expr->conditional.true_expression != NULL
5055                                         && expression_returns(expr->conditional.true_expression))
5056                                 return true;
5057
5058                         return expression_returns(expr->conditional.false_expression);
5059
5060                 case EXPR_SELECT:
5061                         return expression_returns(expr->select.compound);
5062
5063                 case EXPR_ARRAY_ACCESS:
5064                         return
5065                                 expression_returns(expr->array_access.array_ref) &&
5066                                 expression_returns(expr->array_access.index);
5067
5068                 case EXPR_VA_START:
5069                         return expression_returns(expr->va_starte.ap);
5070
5071                 case EXPR_VA_ARG:
5072                         return expression_returns(expr->va_arge.ap);
5073
5074                 case EXPR_VA_COPY:
5075                         return expression_returns(expr->va_copye.src);
5076
5077                 EXPR_UNARY_CASES_MANDATORY
5078                         return expression_returns(expr->unary.value);
5079
5080                 case EXPR_UNARY_THROW:
5081                         return false;
5082
5083                 EXPR_BINARY_CASES
5084                         // TODO handle constant lhs of && and ||
5085                         return
5086                                 expression_returns(expr->binary.left) &&
5087                                 expression_returns(expr->binary.right);
5088
5089                 case EXPR_UNKNOWN:
5090                         break;
5091         }
5092
5093         panic("unhandled expression");
5094 }
5095
5096 static bool initializer_returns(initializer_t const *const init)
5097 {
5098         switch (init->kind) {
5099                 case INITIALIZER_VALUE:
5100                         return expression_returns(init->value.value);
5101
5102                 case INITIALIZER_LIST: {
5103                         initializer_t * const*       i       = init->list.initializers;
5104                         initializer_t * const* const end     = i + init->list.len;
5105                         bool                         returns = true;
5106                         for (; i != end; ++i) {
5107                                 if (!initializer_returns(*i))
5108                                         returns = false;
5109                         }
5110                         return returns;
5111                 }
5112
5113                 case INITIALIZER_STRING:
5114                 case INITIALIZER_WIDE_STRING:
5115                 case INITIALIZER_DESIGNATOR: // designators have no payload
5116                         return true;
5117         }
5118         panic("unhandled initializer");
5119 }
5120
5121 static bool noreturn_candidate;
5122
5123 static void check_reachable(statement_t *const stmt)
5124 {
5125         if (stmt->base.reachable)
5126                 return;
5127         if (stmt->kind != STATEMENT_DO_WHILE)
5128                 stmt->base.reachable = true;
5129
5130         statement_t *last = stmt;
5131         statement_t *next;
5132         switch (stmt->kind) {
5133                 case STATEMENT_INVALID:
5134                 case STATEMENT_EMPTY:
5135                 case STATEMENT_ASM:
5136                         next = stmt->base.next;
5137                         break;
5138
5139                 case STATEMENT_DECLARATION: {
5140                         declaration_statement_t const *const decl = &stmt->declaration;
5141                         entity_t                const *      ent  = decl->declarations_begin;
5142                         entity_t                const *const last = decl->declarations_end;
5143                         if (ent != NULL) {
5144                                 for (;; ent = ent->base.next) {
5145                                         if (ent->kind                 == ENTITY_VARIABLE &&
5146                                                         ent->variable.initializer != NULL            &&
5147                                                         !initializer_returns(ent->variable.initializer)) {
5148                                                 return;
5149                                         }
5150                                         if (ent == last)
5151                                                 break;
5152                                 }
5153                         }
5154                         next = stmt->base.next;
5155                         break;
5156                 }
5157
5158                 case STATEMENT_COMPOUND:
5159                         next = stmt->compound.statements;
5160                         if (next == NULL)
5161                                 next = stmt->base.next;
5162                         break;
5163
5164                 case STATEMENT_RETURN: {
5165                         expression_t const *const val = stmt->returns.value;
5166                         if (val == NULL || expression_returns(val))
5167                                 noreturn_candidate = false;
5168                         return;
5169                 }
5170
5171                 case STATEMENT_IF: {
5172                         if_statement_t const *const ifs  = &stmt->ifs;
5173                         expression_t   const *const cond = ifs->condition;
5174
5175                         if (!expression_returns(cond))
5176                                 return;
5177
5178                         int const val = determine_truth(cond);
5179
5180                         if (val >= 0)
5181                                 check_reachable(ifs->true_statement);
5182
5183                         if (val > 0)
5184                                 return;
5185
5186                         if (ifs->false_statement != NULL) {
5187                                 check_reachable(ifs->false_statement);
5188                                 return;
5189                         }
5190
5191                         next = stmt->base.next;
5192                         break;
5193                 }
5194
5195                 case STATEMENT_SWITCH: {
5196                         switch_statement_t const *const switchs = &stmt->switchs;
5197                         expression_t       const *const expr    = switchs->expression;
5198
5199                         if (!expression_returns(expr))
5200                                 return;
5201
5202                         if (is_constant_expression(expr)) {
5203                                 long                    const val      = fold_constant_to_int(expr);
5204                                 case_label_statement_t *      defaults = NULL;
5205                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5206                                         if (i->expression == NULL) {
5207                                                 defaults = i;
5208                                                 continue;
5209                                         }
5210
5211                                         if (i->first_case <= val && val <= i->last_case) {
5212                                                 check_reachable((statement_t*)i);
5213                                                 return;
5214                                         }
5215                                 }
5216
5217                                 if (defaults != NULL) {
5218                                         check_reachable((statement_t*)defaults);
5219                                         return;
5220                                 }
5221                         } else {
5222                                 bool has_default = false;
5223                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5224                                         if (i->expression == NULL)
5225                                                 has_default = true;
5226
5227                                         check_reachable((statement_t*)i);
5228                                 }
5229
5230                                 if (has_default)
5231                                         return;
5232                         }
5233
5234                         next = stmt->base.next;
5235                         break;
5236                 }
5237
5238                 case STATEMENT_EXPRESSION: {
5239                         /* Check for noreturn function call */
5240                         expression_t const *const expr = stmt->expression.expression;
5241                         if (!expression_returns(expr))
5242                                 return;
5243
5244                         next = stmt->base.next;
5245                         break;
5246                 }
5247
5248                 case STATEMENT_CONTINUE: {
5249                         statement_t *parent = stmt;
5250                         for (;;) {
5251                                 parent = parent->base.parent;
5252                                 if (parent == NULL) /* continue not within loop */
5253                                         return;
5254
5255                                 next = parent;
5256                                 switch (parent->kind) {
5257                                         case STATEMENT_WHILE:    goto continue_while;
5258                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5259                                         case STATEMENT_FOR:      goto continue_for;
5260
5261                                         default: break;
5262                                 }
5263                         }
5264                 }
5265
5266                 case STATEMENT_BREAK: {
5267                         statement_t *parent = stmt;
5268                         for (;;) {
5269                                 parent = parent->base.parent;
5270                                 if (parent == NULL) /* break not within loop/switch */
5271                                         return;
5272
5273                                 switch (parent->kind) {
5274                                         case STATEMENT_SWITCH:
5275                                         case STATEMENT_WHILE:
5276                                         case STATEMENT_DO_WHILE:
5277                                         case STATEMENT_FOR:
5278                                                 last = parent;
5279                                                 next = parent->base.next;
5280                                                 goto found_break_parent;
5281
5282                                         default: break;
5283                                 }
5284                         }
5285 found_break_parent:
5286                         break;
5287                 }
5288
5289                 case STATEMENT_GOTO:
5290                         if (stmt->gotos.expression) {
5291                                 if (!expression_returns(stmt->gotos.expression))
5292                                         return;
5293
5294                                 statement_t *parent = stmt->base.parent;
5295                                 if (parent == NULL) /* top level goto */
5296                                         return;
5297                                 next = parent;
5298                         } else {
5299                                 next = stmt->gotos.label->statement;
5300                                 if (next == NULL) /* missing label */
5301                                         return;
5302                         }
5303                         break;
5304
5305                 case STATEMENT_LABEL:
5306                         next = stmt->label.statement;
5307                         break;
5308
5309                 case STATEMENT_CASE_LABEL:
5310                         next = stmt->case_label.statement;
5311                         break;
5312
5313                 case STATEMENT_WHILE: {
5314                         while_statement_t const *const whiles = &stmt->whiles;
5315                         expression_t      const *const cond   = whiles->condition;
5316
5317                         if (!expression_returns(cond))
5318                                 return;
5319
5320                         int const val = determine_truth(cond);
5321
5322                         if (val >= 0)
5323                                 check_reachable(whiles->body);
5324
5325                         if (val > 0)
5326                                 return;
5327
5328                         next = stmt->base.next;
5329                         break;
5330                 }
5331
5332                 case STATEMENT_DO_WHILE:
5333                         next = stmt->do_while.body;
5334                         break;
5335
5336                 case STATEMENT_FOR: {
5337                         for_statement_t *const fors = &stmt->fors;
5338
5339                         if (fors->condition_reachable)
5340                                 return;
5341                         fors->condition_reachable = true;
5342
5343                         expression_t const *const cond = fors->condition;
5344
5345                         int val;
5346                         if (cond == NULL) {
5347                                 val = 1;
5348                         } else if (expression_returns(cond)) {
5349                                 val = determine_truth(cond);
5350                         } else {
5351                                 return;
5352                         }
5353
5354                         if (val >= 0)
5355                                 check_reachable(fors->body);
5356
5357                         if (val > 0)
5358                                 return;
5359
5360                         next = stmt->base.next;
5361                         break;
5362                 }
5363
5364                 case STATEMENT_MS_TRY: {
5365                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5366                         check_reachable(ms_try->try_statement);
5367                         next = ms_try->final_statement;
5368                         break;
5369                 }
5370
5371                 case STATEMENT_LEAVE: {
5372                         statement_t *parent = stmt;
5373                         for (;;) {
5374                                 parent = parent->base.parent;
5375                                 if (parent == NULL) /* __leave not within __try */
5376                                         return;
5377
5378                                 if (parent->kind == STATEMENT_MS_TRY) {
5379                                         last = parent;
5380                                         next = parent->ms_try.final_statement;
5381                                         break;
5382                                 }
5383                         }
5384                         break;
5385                 }
5386
5387                 default:
5388                         panic("invalid statement kind");
5389         }
5390
5391         while (next == NULL) {
5392                 next = last->base.parent;
5393                 if (next == NULL) {
5394                         noreturn_candidate = false;
5395
5396                         type_t *const type = skip_typeref(current_function->base.type);
5397                         assert(is_type_function(type));
5398                         type_t *const ret  = skip_typeref(type->function.return_type);
5399                         if (warning.return_type                    &&
5400                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5401                             is_type_valid(ret)                     &&
5402                             !is_sym_main(current_function->base.base.symbol)) {
5403                                 warningf(&stmt->base.source_position,
5404                                          "control reaches end of non-void function");
5405                         }
5406                         return;
5407                 }
5408
5409                 switch (next->kind) {
5410                         case STATEMENT_INVALID:
5411                         case STATEMENT_EMPTY:
5412                         case STATEMENT_DECLARATION:
5413                         case STATEMENT_EXPRESSION:
5414                         case STATEMENT_ASM:
5415                         case STATEMENT_RETURN:
5416                         case STATEMENT_CONTINUE:
5417                         case STATEMENT_BREAK:
5418                         case STATEMENT_GOTO:
5419                         case STATEMENT_LEAVE:
5420                                 panic("invalid control flow in function");
5421
5422                         case STATEMENT_COMPOUND:
5423                                 if (next->compound.stmt_expr) {
5424                                         reaches_end = true;
5425                                         return;
5426                                 }
5427                                 /* FALLTHROUGH */
5428                         case STATEMENT_IF:
5429                         case STATEMENT_SWITCH:
5430                         case STATEMENT_LABEL:
5431                         case STATEMENT_CASE_LABEL:
5432                                 last = next;
5433                                 next = next->base.next;
5434                                 break;
5435
5436                         case STATEMENT_WHILE: {
5437 continue_while:
5438                                 if (next->base.reachable)
5439                                         return;
5440                                 next->base.reachable = true;
5441
5442                                 while_statement_t const *const whiles = &next->whiles;
5443                                 expression_t      const *const cond   = whiles->condition;
5444
5445                                 if (!expression_returns(cond))
5446                                         return;
5447
5448                                 int const val = determine_truth(cond);
5449
5450                                 if (val >= 0)
5451                                         check_reachable(whiles->body);
5452
5453                                 if (val > 0)
5454                                         return;
5455
5456                                 last = next;
5457                                 next = next->base.next;
5458                                 break;
5459                         }
5460
5461                         case STATEMENT_DO_WHILE: {
5462 continue_do_while:
5463                                 if (next->base.reachable)
5464                                         return;
5465                                 next->base.reachable = true;
5466
5467                                 do_while_statement_t const *const dw   = &next->do_while;
5468                                 expression_t         const *const cond = dw->condition;
5469
5470                                 if (!expression_returns(cond))
5471                                         return;
5472
5473                                 int const val = determine_truth(cond);
5474
5475                                 if (val >= 0)
5476                                         check_reachable(dw->body);
5477
5478                                 if (val > 0)
5479                                         return;
5480
5481                                 last = next;
5482                                 next = next->base.next;
5483                                 break;
5484                         }
5485
5486                         case STATEMENT_FOR: {
5487 continue_for:;
5488                                 for_statement_t *const fors = &next->fors;
5489
5490                                 fors->step_reachable = true;
5491
5492                                 if (fors->condition_reachable)
5493                                         return;
5494                                 fors->condition_reachable = true;
5495
5496                                 expression_t const *const cond = fors->condition;
5497
5498                                 int val;
5499                                 if (cond == NULL) {
5500                                         val = 1;
5501                                 } else if (expression_returns(cond)) {
5502                                         val = determine_truth(cond);
5503                                 } else {
5504                                         return;
5505                                 }
5506
5507                                 if (val >= 0)
5508                                         check_reachable(fors->body);
5509
5510                                 if (val > 0)
5511                                         return;
5512
5513                                 last = next;
5514                                 next = next->base.next;
5515                                 break;
5516                         }
5517
5518                         case STATEMENT_MS_TRY:
5519                                 last = next;
5520                                 next = next->ms_try.final_statement;
5521                                 break;
5522                 }
5523         }
5524
5525         check_reachable(next);
5526 }
5527
5528 static void check_unreachable(statement_t* const stmt, void *const env)
5529 {
5530         (void)env;
5531
5532         switch (stmt->kind) {
5533                 case STATEMENT_DO_WHILE:
5534                         if (!stmt->base.reachable) {
5535                                 expression_t const *const cond = stmt->do_while.condition;
5536                                 if (determine_truth(cond) >= 0) {
5537                                         warningf(&cond->base.source_position,
5538                                                  "condition of do-while-loop is unreachable");
5539                                 }
5540                         }
5541                         return;
5542
5543                 case STATEMENT_FOR: {
5544                         for_statement_t const* const fors = &stmt->fors;
5545
5546                         // if init and step are unreachable, cond is unreachable, too
5547                         if (!stmt->base.reachable && !fors->step_reachable) {
5548                                 warningf(&stmt->base.source_position, "statement is unreachable");
5549                         } else {
5550                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5551                                         warningf(&fors->initialisation->base.source_position,
5552                                                  "initialisation of for-statement is unreachable");
5553                                 }
5554
5555                                 if (!fors->condition_reachable && fors->condition != NULL) {
5556                                         warningf(&fors->condition->base.source_position,
5557                                                  "condition of for-statement is unreachable");
5558                                 }
5559
5560                                 if (!fors->step_reachable && fors->step != NULL) {
5561                                         warningf(&fors->step->base.source_position,
5562                                                  "step of for-statement is unreachable");
5563                                 }
5564                         }
5565                         return;
5566                 }
5567
5568                 case STATEMENT_COMPOUND:
5569                         if (stmt->compound.statements != NULL)
5570                                 return;
5571                         goto warn_unreachable;
5572
5573                 case STATEMENT_DECLARATION: {
5574                         /* Only warn if there is at least one declarator with an initializer.
5575                          * This typically occurs in switch statements. */
5576                         declaration_statement_t const *const decl = &stmt->declaration;
5577                         entity_t                const *      ent  = decl->declarations_begin;
5578                         entity_t                const *const last = decl->declarations_end;
5579                         if (ent != NULL) {
5580                                 for (;; ent = ent->base.next) {
5581                                         if (ent->kind                 == ENTITY_VARIABLE &&
5582                                                         ent->variable.initializer != NULL) {
5583                                                 goto warn_unreachable;
5584                                         }
5585                                         if (ent == last)
5586                                                 return;
5587                                 }
5588                         }
5589                 }
5590
5591                 default:
5592 warn_unreachable:
5593                         if (!stmt->base.reachable)
5594                                 warningf(&stmt->base.source_position, "statement is unreachable");
5595                         return;
5596         }
5597 }
5598
5599 static void parse_external_declaration(void)
5600 {
5601         /* function-definitions and declarations both start with declaration
5602          * specifiers */
5603         declaration_specifiers_t specifiers;
5604         memset(&specifiers, 0, sizeof(specifiers));
5605
5606         add_anchor_token(';');
5607         parse_declaration_specifiers(&specifiers);
5608         rem_anchor_token(';');
5609
5610         /* must be a declaration */
5611         if (token.type == ';') {
5612                 parse_anonymous_declaration_rest(&specifiers);
5613                 return;
5614         }
5615
5616         add_anchor_token(',');
5617         add_anchor_token('=');
5618         add_anchor_token(';');
5619         add_anchor_token('{');
5620
5621         /* declarator is common to both function-definitions and declarations */
5622         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5623
5624         rem_anchor_token('{');
5625         rem_anchor_token(';');
5626         rem_anchor_token('=');
5627         rem_anchor_token(',');
5628
5629         /* must be a declaration */
5630         switch (token.type) {
5631                 case ',':
5632                 case ';':
5633                 case '=':
5634                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5635                                         DECL_FLAGS_NONE);
5636                         return;
5637         }
5638
5639         /* must be a function definition */
5640         parse_kr_declaration_list(ndeclaration);
5641
5642         if (token.type != '{') {
5643                 parse_error_expected("while parsing function definition", '{', NULL);
5644                 eat_until_matching_token(';');
5645                 return;
5646         }
5647
5648         assert(is_declaration(ndeclaration));
5649         type_t *const orig_type = ndeclaration->declaration.type;
5650         type_t *      type      = skip_typeref(orig_type);
5651
5652         if (!is_type_function(type)) {
5653                 if (is_type_valid(type)) {
5654                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5655                                type, ndeclaration->base.symbol);
5656                 }
5657                 eat_block();
5658                 return;
5659         } else if (is_typeref(orig_type)) {
5660                 /* §6.9.1:2 */
5661                 errorf(&ndeclaration->base.source_position,
5662                                 "type of function definition '%#T' is a typedef",
5663                                 orig_type, ndeclaration->base.symbol);
5664         }
5665
5666         if (warning.aggregate_return &&
5667             is_type_compound(skip_typeref(type->function.return_type))) {
5668                 warningf(HERE, "function '%Y' returns an aggregate",
5669                          ndeclaration->base.symbol);
5670         }
5671         if (warning.traditional && !type->function.unspecified_parameters) {
5672                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5673                         ndeclaration->base.symbol);
5674         }
5675         if (warning.old_style_definition && type->function.unspecified_parameters) {
5676                 warningf(HERE, "old-style function definition '%Y'",
5677                         ndeclaration->base.symbol);
5678         }
5679
5680         /* §6.7.5.3:14 a function definition with () means no
5681          * parameters (and not unspecified parameters) */
5682         if (type->function.unspecified_parameters &&
5683                         type->function.parameters == NULL     &&
5684                         !type->function.kr_style_parameters) {
5685                 type_t *copy                          = duplicate_type(type);
5686                 copy->function.unspecified_parameters = false;
5687                 type                                  = identify_new_type(copy);
5688
5689                 ndeclaration->declaration.type = type;
5690         }
5691
5692         entity_t *const entity = record_entity(ndeclaration, true);
5693         assert(entity->kind == ENTITY_FUNCTION);
5694         assert(ndeclaration->kind == ENTITY_FUNCTION);
5695
5696         function_t *function = &entity->function;
5697         if (ndeclaration != entity) {
5698                 function->parameters = ndeclaration->function.parameters;
5699         }
5700         assert(is_declaration(entity));
5701         type = skip_typeref(entity->declaration.type);
5702
5703         /* push function parameters and switch scope */
5704         size_t const  top       = environment_top();
5705         scope_t      *old_scope = scope_push(&function->parameters);
5706
5707         entity_t *parameter = function->parameters.entities;
5708         for (; parameter != NULL; parameter = parameter->base.next) {
5709                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5710                         parameter->base.parent_scope = current_scope;
5711                 }
5712                 assert(parameter->base.parent_scope == NULL
5713                                 || parameter->base.parent_scope == current_scope);
5714                 parameter->base.parent_scope = current_scope;
5715                 if (parameter->base.symbol == NULL) {
5716                         errorf(&parameter->base.source_position, "parameter name omitted");
5717                         continue;
5718                 }
5719                 environment_push(parameter);
5720         }
5721
5722         if (function->statement != NULL) {
5723                 parser_error_multiple_definition(entity, HERE);
5724                 eat_block();
5725         } else {
5726                 /* parse function body */
5727                 int         label_stack_top      = label_top();
5728                 function_t *old_current_function = current_function;
5729                 current_function                 = function;
5730                 current_parent                   = NULL;
5731
5732                 goto_first   = NULL;
5733                 goto_anchor  = &goto_first;
5734                 label_first  = NULL;
5735                 label_anchor = &label_first;
5736
5737                 statement_t *const body = parse_compound_statement(false);
5738                 function->statement = body;
5739                 first_err = true;
5740                 check_labels();
5741                 check_declarations();
5742                 if (warning.return_type      ||
5743                     warning.unreachable_code ||
5744                     (warning.missing_noreturn
5745                      && !(function->base.modifiers & DM_NORETURN))) {
5746                         noreturn_candidate = true;
5747                         check_reachable(body);
5748                         if (warning.unreachable_code)
5749                                 walk_statements(body, check_unreachable, NULL);
5750                         if (warning.missing_noreturn &&
5751                             noreturn_candidate       &&
5752                             !(function->base.modifiers & DM_NORETURN)) {
5753                                 warningf(&body->base.source_position,
5754                                          "function '%#T' is candidate for attribute 'noreturn'",
5755                                          type, entity->base.symbol);
5756                         }
5757                 }
5758
5759                 assert(current_parent   == NULL);
5760                 assert(current_function == function);
5761                 current_function = old_current_function;
5762                 label_pop_to(label_stack_top);
5763         }
5764
5765         assert(current_scope == &function->parameters);
5766         scope_pop(old_scope);
5767         environment_pop_to(top);
5768 }
5769
5770 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5771                                   source_position_t *source_position,
5772                                   const symbol_t *symbol)
5773 {
5774         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5775
5776         type->bitfield.base_type       = base_type;
5777         type->bitfield.size_expression = size;
5778
5779         il_size_t bit_size;
5780         type_t *skipped_type = skip_typeref(base_type);
5781         if (!is_type_integer(skipped_type)) {
5782                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5783                         base_type);
5784                 bit_size = 0;
5785         } else {
5786                 bit_size = get_type_size(base_type) * 8;
5787         }
5788
5789         if (is_constant_expression(size)) {
5790                 long v = fold_constant_to_int(size);
5791                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5792
5793                 if (v < 0) {
5794                         errorf(source_position, "negative width in bit-field '%Y'",
5795                                user_symbol);
5796                 } else if (v == 0 && symbol != NULL) {
5797                         errorf(source_position, "zero width for bit-field '%Y'",
5798                                user_symbol);
5799                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5800                         errorf(source_position, "width of '%Y' exceeds its type",
5801                                user_symbol);
5802                 } else {
5803                         type->bitfield.bit_size = v;
5804                 }
5805         }
5806
5807         return type;
5808 }
5809
5810 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5811 {
5812         entity_t *iter = compound->members.entities;
5813         for (; iter != NULL; iter = iter->base.next) {
5814                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5815                         continue;
5816
5817                 if (iter->base.symbol == symbol) {
5818                         return iter;
5819                 } else if (iter->base.symbol == NULL) {
5820                         /* search in anonymous structs and unions */
5821                         type_t *type = skip_typeref(iter->declaration.type);
5822                         if (is_type_compound(type)) {
5823                                 if (find_compound_entry(type->compound.compound, symbol)
5824                                                 != NULL)
5825                                         return iter;
5826                         }
5827                         continue;
5828                 }
5829         }
5830
5831         return NULL;
5832 }
5833
5834 static void check_deprecated(const source_position_t *source_position,
5835                              const entity_t *entity)
5836 {
5837         if (!warning.deprecated_declarations)
5838                 return;
5839         if (!is_declaration(entity))
5840                 return;
5841         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5842                 return;
5843
5844         char const *const prefix = get_entity_kind_name(entity->kind);
5845         const char *deprecated_string
5846                         = get_deprecated_string(entity->declaration.attributes);
5847         if (deprecated_string != NULL) {
5848                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
5849                                  prefix, entity->base.symbol, &entity->base.source_position,
5850                                  deprecated_string);
5851         } else {
5852                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
5853                                  entity->base.symbol, &entity->base.source_position);
5854         }
5855 }
5856
5857
5858 static expression_t *create_select(const source_position_t *pos,
5859                                    expression_t *addr,
5860                                    type_qualifiers_t qualifiers,
5861                                                                    entity_t *entry)
5862 {
5863         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5864
5865         check_deprecated(pos, entry);
5866
5867         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5868         select->select.compound       = addr;
5869         select->select.compound_entry = entry;
5870
5871         type_t *entry_type = entry->declaration.type;
5872         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5873
5874         /* we always do the auto-type conversions; the & and sizeof parser contains
5875          * code to revert this! */
5876         select->base.type = automatic_type_conversion(res_type);
5877         if (res_type->kind == TYPE_BITFIELD) {
5878                 select->base.type = res_type->bitfield.base_type;
5879         }
5880
5881         return select;
5882 }
5883
5884 /**
5885  * Find entry with symbol in compound. Search anonymous structs and unions and
5886  * creates implicit select expressions for them.
5887  * Returns the adress for the innermost compound.
5888  */
5889 static expression_t *find_create_select(const source_position_t *pos,
5890                                         expression_t *addr,
5891                                         type_qualifiers_t qualifiers,
5892                                         compound_t *compound, symbol_t *symbol)
5893 {
5894         entity_t *iter = compound->members.entities;
5895         for (; iter != NULL; iter = iter->base.next) {
5896                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5897                         continue;
5898
5899                 symbol_t *iter_symbol = iter->base.symbol;
5900                 if (iter_symbol == NULL) {
5901                         type_t *type = iter->declaration.type;
5902                         if (type->kind != TYPE_COMPOUND_STRUCT
5903                                         && type->kind != TYPE_COMPOUND_UNION)
5904                                 continue;
5905
5906                         compound_t *sub_compound = type->compound.compound;
5907
5908                         if (find_compound_entry(sub_compound, symbol) == NULL)
5909                                 continue;
5910
5911                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5912                         sub_addr->base.source_position = *pos;
5913                         sub_addr->select.implicit      = true;
5914                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5915                                                   symbol);
5916                 }
5917
5918                 if (iter_symbol == symbol) {
5919                         return create_select(pos, addr, qualifiers, iter);
5920                 }
5921         }
5922
5923         return NULL;
5924 }
5925
5926 static void parse_compound_declarators(compound_t *compound,
5927                 const declaration_specifiers_t *specifiers)
5928 {
5929         while (true) {
5930                 entity_t *entity;
5931
5932                 if (token.type == ':') {
5933                         source_position_t source_position = *HERE;
5934                         next_token();
5935
5936                         type_t *base_type = specifiers->type;
5937                         expression_t *size = parse_constant_expression();
5938
5939                         type_t *type = make_bitfield_type(base_type, size,
5940                                         &source_position, NULL);
5941
5942                         attribute_t *attributes = parse_attributes(NULL);
5943                         if (attributes != NULL) {
5944                                 attribute_t *last = attributes;
5945                                 while (last->next != NULL)
5946                                         last = last->next;
5947                                 last->next = specifiers->attributes;
5948                         } else {
5949                                 attributes = specifiers->attributes;
5950                         }
5951
5952                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
5953                         entity->base.namespc                       = NAMESPACE_NORMAL;
5954                         entity->base.source_position               = source_position;
5955                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5956                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5957                         entity->declaration.type                   = type;
5958                         entity->declaration.attributes             = attributes;
5959
5960                         if (attributes != NULL) {
5961                                 handle_entity_attributes(attributes, entity);
5962                         }
5963                         append_entity(&compound->members, entity);
5964                 } else {
5965                         entity = parse_declarator(specifiers,
5966                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5967                         if (entity->kind == ENTITY_TYPEDEF) {
5968                                 errorf(&entity->base.source_position,
5969                                                 "typedef not allowed as compound member");
5970                         } else {
5971                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5972
5973                                 /* make sure we don't define a symbol multiple times */
5974                                 symbol_t *symbol = entity->base.symbol;
5975                                 if (symbol != NULL) {
5976                                         entity_t *prev = find_compound_entry(compound, symbol);
5977                                         if (prev != NULL) {
5978                                                 errorf(&entity->base.source_position,
5979                                                                 "multiple declarations of symbol '%Y' (declared %P)",
5980                                                                 symbol, &prev->base.source_position);
5981                                         }
5982                                 }
5983
5984                                 if (token.type == ':') {
5985                                         source_position_t source_position = *HERE;
5986                                         next_token();
5987                                         expression_t *size = parse_constant_expression();
5988
5989                                         type_t *type          = entity->declaration.type;
5990                                         type_t *bitfield_type = make_bitfield_type(type, size,
5991                                                         &source_position, entity->base.symbol);
5992
5993                                         attribute_t *attributes = parse_attributes(NULL);
5994                                         entity->declaration.type = bitfield_type;
5995                                         handle_entity_attributes(attributes, entity);
5996                                 } else {
5997                                         type_t *orig_type = entity->declaration.type;
5998                                         type_t *type      = skip_typeref(orig_type);
5999                                         if (is_type_function(type)) {
6000                                                 errorf(&entity->base.source_position,
6001                                                                 "compound member '%Y' must not have function type '%T'",
6002                                                                 entity->base.symbol, orig_type);
6003                                         } else if (is_type_incomplete(type)) {
6004                                                 /* §6.7.2.1:16 flexible array member */
6005                                                 if (!is_type_array(type)       ||
6006                                                                 token.type          != ';' ||
6007                                                                 look_ahead(1)->type != '}') {
6008                                                         errorf(&entity->base.source_position,
6009                                                                         "compound member '%Y' has incomplete type '%T'",
6010                                                                         entity->base.symbol, orig_type);
6011                                                 }
6012                                         }
6013                                 }
6014
6015                                 append_entity(&compound->members, entity);
6016                         }
6017                 }
6018
6019                 if (token.type != ',')
6020                         break;
6021                 next_token();
6022         }
6023         expect(';', end_error);
6024
6025 end_error:
6026         anonymous_entity = NULL;
6027 }
6028
6029 static void parse_compound_type_entries(compound_t *compound)
6030 {
6031         eat('{');
6032         add_anchor_token('}');
6033
6034         while (token.type != '}') {
6035                 if (token.type == T_EOF) {
6036                         errorf(HERE, "EOF while parsing struct");
6037                         break;
6038                 }
6039                 declaration_specifiers_t specifiers;
6040                 memset(&specifiers, 0, sizeof(specifiers));
6041                 parse_declaration_specifiers(&specifiers);
6042
6043                 parse_compound_declarators(compound, &specifiers);
6044         }
6045         rem_anchor_token('}');
6046         next_token();
6047
6048         /* §6.7.2.1:7 */
6049         compound->complete = true;
6050 }
6051
6052 static type_t *parse_typename(void)
6053 {
6054         declaration_specifiers_t specifiers;
6055         memset(&specifiers, 0, sizeof(specifiers));
6056         parse_declaration_specifiers(&specifiers);
6057         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6058                         specifiers.thread_local) {
6059                 /* TODO: improve error message, user does probably not know what a
6060                  * storage class is...
6061                  */
6062                 errorf(HERE, "typename may not have a storage class");
6063         }
6064
6065         type_t *result = parse_abstract_declarator(specifiers.type);
6066
6067         return result;
6068 }
6069
6070
6071
6072
6073 typedef expression_t* (*parse_expression_function)(void);
6074 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6075
6076 typedef struct expression_parser_function_t expression_parser_function_t;
6077 struct expression_parser_function_t {
6078         parse_expression_function        parser;
6079         precedence_t                     infix_precedence;
6080         parse_expression_infix_function  infix_parser;
6081 };
6082
6083 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6084
6085 /**
6086  * Prints an error message if an expression was expected but not read
6087  */
6088 static expression_t *expected_expression_error(void)
6089 {
6090         /* skip the error message if the error token was read */
6091         if (token.type != T_ERROR) {
6092                 errorf(HERE, "expected expression, got token %K", &token);
6093         }
6094         next_token();
6095
6096         return create_invalid_expression();
6097 }
6098
6099 /**
6100  * Parse a string constant.
6101  */
6102 static expression_t *parse_string_const(void)
6103 {
6104         wide_string_t wres;
6105         if (token.type == T_STRING_LITERAL) {
6106                 string_t res = token.v.string;
6107                 next_token();
6108                 while (token.type == T_STRING_LITERAL) {
6109                         res = concat_strings(&res, &token.v.string);
6110                         next_token();
6111                 }
6112                 if (token.type != T_WIDE_STRING_LITERAL) {
6113                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6114                         /* note: that we use type_char_ptr here, which is already the
6115                          * automatic converted type. revert_automatic_type_conversion
6116                          * will construct the array type */
6117                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6118                         cnst->string.value = res;
6119                         return cnst;
6120                 }
6121
6122                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6123         } else {
6124                 wres = token.v.wide_string;
6125         }
6126         next_token();
6127
6128         for (;;) {
6129                 switch (token.type) {
6130                         case T_WIDE_STRING_LITERAL:
6131                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6132                                 break;
6133
6134                         case T_STRING_LITERAL:
6135                                 wres = concat_wide_string_string(&wres, &token.v.string);
6136                                 break;
6137
6138                         default: {
6139                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6140                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6141                                 cnst->wide_string.value = wres;
6142                                 return cnst;
6143                         }
6144                 }
6145                 next_token();
6146         }
6147 }
6148
6149 /**
6150  * Parse a boolean constant.
6151  */
6152 static expression_t *parse_bool_const(bool value)
6153 {
6154         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6155         cnst->base.type          = type_bool;
6156         cnst->conste.v.int_value = value;
6157
6158         next_token();
6159
6160         return cnst;
6161 }
6162
6163 /**
6164  * Parse an integer constant.
6165  */
6166 static expression_t *parse_int_const(void)
6167 {
6168         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6169         cnst->base.type          = token.datatype;
6170         cnst->conste.v.int_value = token.v.intvalue;
6171
6172         next_token();
6173
6174         return cnst;
6175 }
6176
6177 /**
6178  * Parse a character constant.
6179  */
6180 static expression_t *parse_character_constant(void)
6181 {
6182         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6183         cnst->base.type          = token.datatype;
6184         cnst->conste.v.character = token.v.string;
6185
6186         if (cnst->conste.v.character.size != 1) {
6187                 if (!GNU_MODE) {
6188                         errorf(HERE, "more than 1 character in character constant");
6189                 } else if (warning.multichar) {
6190                         warningf(HERE, "multi-character character constant");
6191                 }
6192         }
6193         next_token();
6194
6195         return cnst;
6196 }
6197
6198 /**
6199  * Parse a wide character constant.
6200  */
6201 static expression_t *parse_wide_character_constant(void)
6202 {
6203         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6204         cnst->base.type               = token.datatype;
6205         cnst->conste.v.wide_character = token.v.wide_string;
6206
6207         if (cnst->conste.v.wide_character.size != 1) {
6208                 if (!GNU_MODE) {
6209                         errorf(HERE, "more than 1 character in character constant");
6210                 } else if (warning.multichar) {
6211                         warningf(HERE, "multi-character character constant");
6212                 }
6213         }
6214         next_token();
6215
6216         return cnst;
6217 }
6218
6219 /**
6220  * Parse a float constant.
6221  */
6222 static expression_t *parse_float_const(void)
6223 {
6224         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6225         cnst->base.type            = token.datatype;
6226         cnst->conste.v.float_value = token.v.floatvalue;
6227
6228         next_token();
6229
6230         return cnst;
6231 }
6232
6233 static entity_t *create_implicit_function(symbol_t *symbol,
6234                 const source_position_t *source_position)
6235 {
6236         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6237         ntype->function.return_type            = type_int;
6238         ntype->function.unspecified_parameters = true;
6239         ntype->function.linkage                = LINKAGE_C;
6240         type_t *type                           = identify_new_type(ntype);
6241
6242         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6243         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6244         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6245         entity->declaration.type                   = type;
6246         entity->declaration.implicit               = true;
6247         entity->base.symbol                        = symbol;
6248         entity->base.source_position               = *source_position;
6249
6250         if (current_scope != NULL) {
6251                 bool strict_prototypes_old = warning.strict_prototypes;
6252                 warning.strict_prototypes  = false;
6253                 record_entity(entity, false);
6254                 warning.strict_prototypes = strict_prototypes_old;
6255         }
6256
6257         return entity;
6258 }
6259
6260 /**
6261  * Creates a return_type (func)(argument_type) function type if not
6262  * already exists.
6263  */
6264 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6265                                     type_t *argument_type2)
6266 {
6267         function_parameter_t *const parameter2 = allocate_parameter(argument_type2);
6268         function_parameter_t *const parameter1 = allocate_parameter(argument_type1);
6269         parameter1->next = parameter2;
6270
6271         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6272         type->function.return_type = return_type;
6273         type->function.parameters  = parameter1;
6274
6275         return identify_new_type(type);
6276 }
6277
6278 /**
6279  * Creates a return_type (func)(argument_type) function type if not
6280  * already exists.
6281  *
6282  * @param return_type    the return type
6283  * @param argument_type  the argument type
6284  */
6285 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6286 {
6287         function_parameter_t *const parameter = allocate_parameter(argument_type);
6288
6289         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6290         type->function.return_type = return_type;
6291         type->function.parameters  = parameter;
6292
6293         return identify_new_type(type);
6294 }
6295
6296 /**
6297  * Creates a return_type (func)(argument_type, ...) function type if not
6298  * already exists.
6299  *
6300  * @param return_type    the return type
6301  * @param argument_type  the argument type
6302  */
6303 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6304 {
6305         function_parameter_t *const parameter = allocate_parameter(argument_type);
6306
6307         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6308         type->function.return_type = return_type;
6309         type->function.parameters  = parameter;
6310         type->function.variadic    = true;
6311
6312         return identify_new_type(type);
6313 }
6314
6315 /**
6316  * Creates a return_type (func)(void) function type if not
6317  * already exists.
6318  *
6319  * @param return_type    the return type
6320  */
6321 static type_t *make_function_0_type(type_t *return_type)
6322 {
6323         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6324         type->function.return_type = return_type;
6325         type->function.parameters  = NULL;
6326
6327         return identify_new_type(type);
6328 }
6329
6330 /**
6331  * Creates a NO_RETURN return_type (func)(void) function type if not
6332  * already exists.
6333  *
6334  * @param return_type    the return type
6335  */
6336 static type_t *make_function_0_type_noreturn(type_t *return_type)
6337 {
6338         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6339         type->function.return_type = return_type;
6340         type->function.parameters  = NULL;
6341         type->function.modifiers  |= DM_NORETURN;
6342         return identify_new_type(type);
6343 }
6344
6345 /**
6346  * Performs automatic type cast as described in §6.3.2.1.
6347  *
6348  * @param orig_type  the original type
6349  */
6350 static type_t *automatic_type_conversion(type_t *orig_type)
6351 {
6352         type_t *type = skip_typeref(orig_type);
6353         if (is_type_array(type)) {
6354                 array_type_t *array_type   = &type->array;
6355                 type_t       *element_type = array_type->element_type;
6356                 unsigned      qualifiers   = array_type->base.qualifiers;
6357
6358                 return make_pointer_type(element_type, qualifiers);
6359         }
6360
6361         if (is_type_function(type)) {
6362                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6363         }
6364
6365         return orig_type;
6366 }
6367
6368 /**
6369  * reverts the automatic casts of array to pointer types and function
6370  * to function-pointer types as defined §6.3.2.1
6371  */
6372 type_t *revert_automatic_type_conversion(const expression_t *expression)
6373 {
6374         switch (expression->kind) {
6375                 case EXPR_REFERENCE: {
6376                         entity_t *entity = expression->reference.entity;
6377                         if (is_declaration(entity)) {
6378                                 return entity->declaration.type;
6379                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6380                                 return entity->enum_value.enum_type;
6381                         } else {
6382                                 panic("no declaration or enum in reference");
6383                         }
6384                 }
6385
6386                 case EXPR_SELECT: {
6387                         entity_t *entity = expression->select.compound_entry;
6388                         assert(is_declaration(entity));
6389                         type_t   *type   = entity->declaration.type;
6390                         return get_qualified_type(type,
6391                                         expression->base.type->base.qualifiers);
6392                 }
6393
6394                 case EXPR_UNARY_DEREFERENCE: {
6395                         const expression_t *const value = expression->unary.value;
6396                         type_t             *const type  = skip_typeref(value->base.type);
6397                         if (!is_type_pointer(type))
6398                                 return type_error_type;
6399                         return type->pointer.points_to;
6400                 }
6401
6402                 case EXPR_ARRAY_ACCESS: {
6403                         const expression_t *array_ref = expression->array_access.array_ref;
6404                         type_t             *type_left = skip_typeref(array_ref->base.type);
6405                         if (!is_type_pointer(type_left))
6406                                 return type_error_type;
6407                         return type_left->pointer.points_to;
6408                 }
6409
6410                 case EXPR_STRING_LITERAL: {
6411                         size_t size = expression->string.value.size;
6412                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6413                 }
6414
6415                 case EXPR_WIDE_STRING_LITERAL: {
6416                         size_t size = expression->wide_string.value.size;
6417                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6418                 }
6419
6420                 case EXPR_COMPOUND_LITERAL:
6421                         return expression->compound_literal.type;
6422
6423                 default:
6424                         return expression->base.type;
6425         }
6426 }
6427
6428 static expression_t *parse_reference(void)
6429 {
6430         symbol_t *const symbol = token.v.symbol;
6431
6432         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6433
6434         if (entity == NULL) {
6435                 if (!strict_mode && look_ahead(1)->type == '(') {
6436                         /* an implicitly declared function */
6437                         if (warning.error_implicit_function_declaration) {
6438                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
6439                         } else if (warning.implicit_function_declaration) {
6440                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
6441                         }
6442
6443                         entity = create_implicit_function(symbol, HERE);
6444                 } else {
6445                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
6446                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6447                 }
6448         }
6449
6450         type_t *orig_type;
6451
6452         if (is_declaration(entity)) {
6453                 orig_type = entity->declaration.type;
6454         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6455                 orig_type = entity->enum_value.enum_type;
6456         } else {
6457                 panic("expected declaration or enum value in reference");
6458         }
6459
6460         /* we always do the auto-type conversions; the & and sizeof parser contains
6461          * code to revert this! */
6462         type_t *type = automatic_type_conversion(orig_type);
6463
6464         expression_kind_t kind = EXPR_REFERENCE;
6465         if (entity->kind == ENTITY_ENUM_VALUE)
6466                 kind = EXPR_REFERENCE_ENUM_VALUE;
6467
6468         expression_t *expression     = allocate_expression_zero(kind);
6469         expression->reference.entity = entity;
6470         expression->base.type        = type;
6471
6472         /* this declaration is used */
6473         if (is_declaration(entity)) {
6474                 entity->declaration.used = true;
6475         }
6476
6477         if (entity->base.parent_scope != file_scope
6478                 && (current_function != NULL && entity->base.parent_scope->depth < current_function->parameters.depth)
6479                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6480                 if (entity->kind == ENTITY_VARIABLE) {
6481                         /* access of a variable from an outer function */
6482                         entity->variable.address_taken = true;
6483                 } else if (entity->kind == ENTITY_PARAMETER) {
6484                         entity->parameter.address_taken = true;
6485                 }
6486                 current_function->need_closure = true;
6487         }
6488
6489         check_deprecated(HERE, entity);
6490
6491         if (warning.init_self && entity == current_init_decl && !in_type_prop
6492             && entity->kind == ENTITY_VARIABLE) {
6493                 current_init_decl = NULL;
6494                 warningf(HERE, "variable '%#T' is initialized by itself",
6495                          entity->declaration.type, entity->base.symbol);
6496         }
6497
6498         next_token();
6499         return expression;
6500 }
6501
6502 static bool semantic_cast(expression_t *cast)
6503 {
6504         expression_t            *expression      = cast->unary.value;
6505         type_t                  *orig_dest_type  = cast->base.type;
6506         type_t                  *orig_type_right = expression->base.type;
6507         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6508         type_t            const *src_type        = skip_typeref(orig_type_right);
6509         source_position_t const *pos             = &cast->base.source_position;
6510
6511         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6512         if (dst_type == type_void)
6513                 return true;
6514
6515         /* only integer and pointer can be casted to pointer */
6516         if (is_type_pointer(dst_type)  &&
6517             !is_type_pointer(src_type) &&
6518             !is_type_integer(src_type) &&
6519             is_type_valid(src_type)) {
6520                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6521                 return false;
6522         }
6523
6524         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6525                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6526                 return false;
6527         }
6528
6529         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6530                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6531                 return false;
6532         }
6533
6534         if (warning.cast_qual &&
6535             is_type_pointer(src_type) &&
6536             is_type_pointer(dst_type)) {
6537                 type_t *src = skip_typeref(src_type->pointer.points_to);
6538                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6539                 unsigned missing_qualifiers =
6540                         src->base.qualifiers & ~dst->base.qualifiers;
6541                 if (missing_qualifiers != 0) {
6542                         warningf(pos,
6543                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6544                                  missing_qualifiers, orig_type_right);
6545                 }
6546         }
6547         return true;
6548 }
6549
6550 static expression_t *parse_compound_literal(type_t *type)
6551 {
6552         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6553
6554         parse_initializer_env_t env;
6555         env.type             = type;
6556         env.entity           = NULL;
6557         env.must_be_constant = false;
6558         initializer_t *initializer = parse_initializer(&env);
6559         type = env.type;
6560
6561         expression->compound_literal.initializer = initializer;
6562         expression->compound_literal.type        = type;
6563         expression->base.type                    = automatic_type_conversion(type);
6564
6565         return expression;
6566 }
6567
6568 /**
6569  * Parse a cast expression.
6570  */
6571 static expression_t *parse_cast(void)
6572 {
6573         add_anchor_token(')');
6574
6575         source_position_t source_position = token.source_position;
6576
6577         type_t *type = parse_typename();
6578
6579         rem_anchor_token(')');
6580         expect(')', end_error);
6581
6582         if (token.type == '{') {
6583                 return parse_compound_literal(type);
6584         }
6585
6586         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6587         cast->base.source_position = source_position;
6588
6589         expression_t *value = parse_sub_expression(PREC_CAST);
6590         cast->base.type   = type;
6591         cast->unary.value = value;
6592
6593         if (! semantic_cast(cast)) {
6594                 /* TODO: record the error in the AST. else it is impossible to detect it */
6595         }
6596
6597         return cast;
6598 end_error:
6599         return create_invalid_expression();
6600 }
6601
6602 /**
6603  * Parse a statement expression.
6604  */
6605 static expression_t *parse_statement_expression(void)
6606 {
6607         add_anchor_token(')');
6608
6609         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6610
6611         statement_t *statement          = parse_compound_statement(true);
6612         statement->compound.stmt_expr   = true;
6613         expression->statement.statement = statement;
6614
6615         /* find last statement and use its type */
6616         type_t *type = type_void;
6617         const statement_t *stmt = statement->compound.statements;
6618         if (stmt != NULL) {
6619                 while (stmt->base.next != NULL)
6620                         stmt = stmt->base.next;
6621
6622                 if (stmt->kind == STATEMENT_EXPRESSION) {
6623                         type = stmt->expression.expression->base.type;
6624                 }
6625         } else if (warning.other) {
6626                 warningf(&expression->base.source_position, "empty statement expression ({})");
6627         }
6628         expression->base.type = type;
6629
6630         rem_anchor_token(')');
6631         expect(')', end_error);
6632
6633 end_error:
6634         return expression;
6635 }
6636
6637 /**
6638  * Parse a parenthesized expression.
6639  */
6640 static expression_t *parse_parenthesized_expression(void)
6641 {
6642         eat('(');
6643
6644         switch (token.type) {
6645         case '{':
6646                 /* gcc extension: a statement expression */
6647                 return parse_statement_expression();
6648
6649         TYPE_QUALIFIERS
6650         TYPE_SPECIFIERS
6651                 return parse_cast();
6652         case T_IDENTIFIER:
6653                 if (is_typedef_symbol(token.v.symbol)) {
6654                         return parse_cast();
6655                 }
6656         }
6657
6658         add_anchor_token(')');
6659         expression_t *result = parse_expression();
6660         result->base.parenthesized = true;
6661         rem_anchor_token(')');
6662         expect(')', end_error);
6663
6664 end_error:
6665         return result;
6666 }
6667
6668 static expression_t *parse_function_keyword(void)
6669 {
6670         /* TODO */
6671
6672         if (current_function == NULL) {
6673                 errorf(HERE, "'__func__' used outside of a function");
6674         }
6675
6676         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6677         expression->base.type     = type_char_ptr;
6678         expression->funcname.kind = FUNCNAME_FUNCTION;
6679
6680         next_token();
6681
6682         return expression;
6683 }
6684
6685 static expression_t *parse_pretty_function_keyword(void)
6686 {
6687         if (current_function == NULL) {
6688                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6689         }
6690
6691         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6692         expression->base.type     = type_char_ptr;
6693         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6694
6695         eat(T___PRETTY_FUNCTION__);
6696
6697         return expression;
6698 }
6699
6700 static expression_t *parse_funcsig_keyword(void)
6701 {
6702         if (current_function == NULL) {
6703                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6704         }
6705
6706         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6707         expression->base.type     = type_char_ptr;
6708         expression->funcname.kind = FUNCNAME_FUNCSIG;
6709
6710         eat(T___FUNCSIG__);
6711
6712         return expression;
6713 }
6714
6715 static expression_t *parse_funcdname_keyword(void)
6716 {
6717         if (current_function == NULL) {
6718                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6719         }
6720
6721         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6722         expression->base.type     = type_char_ptr;
6723         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6724
6725         eat(T___FUNCDNAME__);
6726
6727         return expression;
6728 }
6729
6730 static designator_t *parse_designator(void)
6731 {
6732         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6733         result->source_position = *HERE;
6734
6735         if (token.type != T_IDENTIFIER) {
6736                 parse_error_expected("while parsing member designator",
6737                                      T_IDENTIFIER, NULL);
6738                 return NULL;
6739         }
6740         result->symbol = token.v.symbol;
6741         next_token();
6742
6743         designator_t *last_designator = result;
6744         while (true) {
6745                 if (token.type == '.') {
6746                         next_token();
6747                         if (token.type != T_IDENTIFIER) {
6748                                 parse_error_expected("while parsing member designator",
6749                                                      T_IDENTIFIER, NULL);
6750                                 return NULL;
6751                         }
6752                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6753                         designator->source_position = *HERE;
6754                         designator->symbol          = token.v.symbol;
6755                         next_token();
6756
6757                         last_designator->next = designator;
6758                         last_designator       = designator;
6759                         continue;
6760                 }
6761                 if (token.type == '[') {
6762                         next_token();
6763                         add_anchor_token(']');
6764                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6765                         designator->source_position = *HERE;
6766                         designator->array_index     = parse_expression();
6767                         rem_anchor_token(']');
6768                         expect(']', end_error);
6769                         if (designator->array_index == NULL) {
6770                                 return NULL;
6771                         }
6772
6773                         last_designator->next = designator;
6774                         last_designator       = designator;
6775                         continue;
6776                 }
6777                 break;
6778         }
6779
6780         return result;
6781 end_error:
6782         return NULL;
6783 }
6784
6785 /**
6786  * Parse the __builtin_offsetof() expression.
6787  */
6788 static expression_t *parse_offsetof(void)
6789 {
6790         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6791         expression->base.type    = type_size_t;
6792
6793         eat(T___builtin_offsetof);
6794
6795         expect('(', end_error);
6796         add_anchor_token(',');
6797         type_t *type = parse_typename();
6798         rem_anchor_token(',');
6799         expect(',', end_error);
6800         add_anchor_token(')');
6801         designator_t *designator = parse_designator();
6802         rem_anchor_token(')');
6803         expect(')', end_error);
6804
6805         expression->offsetofe.type       = type;
6806         expression->offsetofe.designator = designator;
6807
6808         type_path_t path;
6809         memset(&path, 0, sizeof(path));
6810         path.top_type = type;
6811         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6812
6813         descend_into_subtype(&path);
6814
6815         if (!walk_designator(&path, designator, true)) {
6816                 return create_invalid_expression();
6817         }
6818
6819         DEL_ARR_F(path.path);
6820
6821         return expression;
6822 end_error:
6823         return create_invalid_expression();
6824 }
6825
6826 /**
6827  * Parses a _builtin_va_start() expression.
6828  */
6829 static expression_t *parse_va_start(void)
6830 {
6831         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6832
6833         eat(T___builtin_va_start);
6834
6835         expect('(', end_error);
6836         add_anchor_token(',');
6837         expression->va_starte.ap = parse_assignment_expression();
6838         rem_anchor_token(',');
6839         expect(',', end_error);
6840         expression_t *const expr = parse_assignment_expression();
6841         if (expr->kind == EXPR_REFERENCE) {
6842                 entity_t *const entity = expr->reference.entity;
6843                 if (entity->base.parent_scope != &current_function->parameters
6844                                 || entity->base.next != NULL
6845                                 || entity->kind != ENTITY_PARAMETER) {
6846                         errorf(&expr->base.source_position,
6847                                "second argument of 'va_start' must be last parameter of the current function");
6848                 } else {
6849                         expression->va_starte.parameter = &entity->variable;
6850                 }
6851                 expect(')', end_error);
6852                 return expression;
6853         }
6854         expect(')', end_error);
6855 end_error:
6856         return create_invalid_expression();
6857 }
6858
6859 /**
6860  * Parses a __builtin_va_arg() expression.
6861  */
6862 static expression_t *parse_va_arg(void)
6863 {
6864         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6865
6866         eat(T___builtin_va_arg);
6867
6868         expect('(', end_error);
6869         call_argument_t ap;
6870         ap.expression = parse_assignment_expression();
6871         expression->va_arge.ap = ap.expression;
6872         check_call_argument(type_valist, &ap, 1);
6873
6874         expect(',', end_error);
6875         expression->base.type = parse_typename();
6876         expect(')', end_error);
6877
6878         return expression;
6879 end_error:
6880         return create_invalid_expression();
6881 }
6882
6883 /**
6884  * Parses a __builtin_va_copy() expression.
6885  */
6886 static expression_t *parse_va_copy(void)
6887 {
6888         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6889
6890         eat(T___builtin_va_copy);
6891
6892         expect('(', end_error);
6893         expression_t *dst = parse_assignment_expression();
6894         assign_error_t error = semantic_assign(type_valist, dst);
6895         report_assign_error(error, type_valist, dst, "call argument 1",
6896                             &dst->base.source_position);
6897         expression->va_copye.dst = dst;
6898
6899         expect(',', end_error);
6900
6901         call_argument_t src;
6902         src.expression = parse_assignment_expression();
6903         check_call_argument(type_valist, &src, 2);
6904         expression->va_copye.src = src.expression;
6905         expect(')', end_error);
6906
6907         return expression;
6908 end_error:
6909         return create_invalid_expression();
6910 }
6911
6912 /**
6913  * Parses a __builtin_constant_p() expression.
6914  */
6915 static expression_t *parse_builtin_constant(void)
6916 {
6917         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6918
6919         eat(T___builtin_constant_p);
6920
6921         expect('(', end_error);
6922         add_anchor_token(')');
6923         expression->builtin_constant.value = parse_assignment_expression();
6924         rem_anchor_token(')');
6925         expect(')', end_error);
6926         expression->base.type = type_int;
6927
6928         return expression;
6929 end_error:
6930         return create_invalid_expression();
6931 }
6932
6933 /**
6934  * Parses a __builtin_types_compatible_p() expression.
6935  */
6936 static expression_t *parse_builtin_types_compatible(void)
6937 {
6938         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6939
6940         eat(T___builtin_types_compatible_p);
6941
6942         expect('(', end_error);
6943         add_anchor_token(')');
6944         add_anchor_token(',');
6945         expression->builtin_types_compatible.left = parse_typename();
6946         rem_anchor_token(',');
6947         expect(',', end_error);
6948         expression->builtin_types_compatible.right = parse_typename();
6949         rem_anchor_token(')');
6950         expect(')', end_error);
6951         expression->base.type = type_int;
6952
6953         return expression;
6954 end_error:
6955         return create_invalid_expression();
6956 }
6957
6958 /**
6959  * Parses a __builtin_is_*() compare expression.
6960  */
6961 static expression_t *parse_compare_builtin(void)
6962 {
6963         expression_t *expression;
6964
6965         switch (token.type) {
6966         case T___builtin_isgreater:
6967                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6968                 break;
6969         case T___builtin_isgreaterequal:
6970                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6971                 break;
6972         case T___builtin_isless:
6973                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6974                 break;
6975         case T___builtin_islessequal:
6976                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6977                 break;
6978         case T___builtin_islessgreater:
6979                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6980                 break;
6981         case T___builtin_isunordered:
6982                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6983                 break;
6984         default:
6985                 internal_errorf(HERE, "invalid compare builtin found");
6986         }
6987         expression->base.source_position = *HERE;
6988         next_token();
6989
6990         expect('(', end_error);
6991         expression->binary.left = parse_assignment_expression();
6992         expect(',', end_error);
6993         expression->binary.right = parse_assignment_expression();
6994         expect(')', end_error);
6995
6996         type_t *const orig_type_left  = expression->binary.left->base.type;
6997         type_t *const orig_type_right = expression->binary.right->base.type;
6998
6999         type_t *const type_left  = skip_typeref(orig_type_left);
7000         type_t *const type_right = skip_typeref(orig_type_right);
7001         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7002                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7003                         type_error_incompatible("invalid operands in comparison",
7004                                 &expression->base.source_position, orig_type_left, orig_type_right);
7005                 }
7006         } else {
7007                 semantic_comparison(&expression->binary);
7008         }
7009
7010         return expression;
7011 end_error:
7012         return create_invalid_expression();
7013 }
7014
7015 #if 0
7016 /**
7017  * Parses a __builtin_expect(, end_error) expression.
7018  */
7019 static expression_t *parse_builtin_expect(void, end_error)
7020 {
7021         expression_t *expression
7022                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7023
7024         eat(T___builtin_expect);
7025
7026         expect('(', end_error);
7027         expression->binary.left = parse_assignment_expression();
7028         expect(',', end_error);
7029         expression->binary.right = parse_constant_expression();
7030         expect(')', end_error);
7031
7032         expression->base.type = expression->binary.left->base.type;
7033
7034         return expression;
7035 end_error:
7036         return create_invalid_expression();
7037 }
7038 #endif
7039
7040 /**
7041  * Parses a MS assume() expression.
7042  */
7043 static expression_t *parse_assume(void)
7044 {
7045         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7046
7047         eat(T__assume);
7048
7049         expect('(', end_error);
7050         add_anchor_token(')');
7051         expression->unary.value = parse_assignment_expression();
7052         rem_anchor_token(')');
7053         expect(')', end_error);
7054
7055         expression->base.type = type_void;
7056         return expression;
7057 end_error:
7058         return create_invalid_expression();
7059 }
7060
7061 /**
7062  * Return the declaration for a given label symbol or create a new one.
7063  *
7064  * @param symbol  the symbol of the label
7065  */
7066 static label_t *get_label(symbol_t *symbol)
7067 {
7068         entity_t *label;
7069         assert(current_function != NULL);
7070
7071         label = get_entity(symbol, NAMESPACE_LABEL);
7072         /* if we found a local label, we already created the declaration */
7073         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7074                 if (label->base.parent_scope != current_scope) {
7075                         assert(label->base.parent_scope->depth < current_scope->depth);
7076                         current_function->goto_to_outer = true;
7077                 }
7078                 return &label->label;
7079         }
7080
7081         label = get_entity(symbol, NAMESPACE_LABEL);
7082         /* if we found a label in the same function, then we already created the
7083          * declaration */
7084         if (label != NULL
7085                         && label->base.parent_scope == &current_function->parameters) {
7086                 return &label->label;
7087         }
7088
7089         /* otherwise we need to create a new one */
7090         label               = allocate_entity_zero(ENTITY_LABEL);
7091         label->base.namespc = NAMESPACE_LABEL;
7092         label->base.symbol  = symbol;
7093
7094         label_push(label);
7095
7096         return &label->label;
7097 }
7098
7099 /**
7100  * Parses a GNU && label address expression.
7101  */
7102 static expression_t *parse_label_address(void)
7103 {
7104         source_position_t source_position = token.source_position;
7105         eat(T_ANDAND);
7106         if (token.type != T_IDENTIFIER) {
7107                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7108                 goto end_error;
7109         }
7110         symbol_t *symbol = token.v.symbol;
7111         next_token();
7112
7113         label_t *label       = get_label(symbol);
7114         label->used          = true;
7115         label->address_taken = true;
7116
7117         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7118         expression->base.source_position = source_position;
7119
7120         /* label address is threaten as a void pointer */
7121         expression->base.type           = type_void_ptr;
7122         expression->label_address.label = label;
7123         return expression;
7124 end_error:
7125         return create_invalid_expression();
7126 }
7127
7128 /**
7129  * Parse a microsoft __noop expression.
7130  */
7131 static expression_t *parse_noop_expression(void)
7132 {
7133         /* the result is a (int)0 */
7134         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7135         cnst->base.type            = type_int;
7136         cnst->conste.v.int_value   = 0;
7137         cnst->conste.is_ms_noop    = true;
7138
7139         eat(T___noop);
7140
7141         if (token.type == '(') {
7142                 /* parse arguments */
7143                 eat('(');
7144                 add_anchor_token(')');
7145                 add_anchor_token(',');
7146
7147                 if (token.type != ')') {
7148                         while (true) {
7149                                 (void)parse_assignment_expression();
7150                                 if (token.type != ',')
7151                                         break;
7152                                 next_token();
7153                         }
7154                 }
7155         }
7156         rem_anchor_token(',');
7157         rem_anchor_token(')');
7158         expect(')', end_error);
7159
7160 end_error:
7161         return cnst;
7162 }
7163
7164 /**
7165  * Parses a primary expression.
7166  */
7167 static expression_t *parse_primary_expression(void)
7168 {
7169         switch (token.type) {
7170                 case T_false:                        return parse_bool_const(false);
7171                 case T_true:                         return parse_bool_const(true);
7172                 case T_INTEGER:                      return parse_int_const();
7173                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7174                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7175                 case T_FLOATINGPOINT:                return parse_float_const();
7176                 case T_STRING_LITERAL:
7177                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7178                 case T___FUNCTION__:
7179                 case T___func__:                     return parse_function_keyword();
7180                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7181                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7182                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7183                 case T___builtin_offsetof:           return parse_offsetof();
7184                 case T___builtin_va_start:           return parse_va_start();
7185                 case T___builtin_va_arg:             return parse_va_arg();
7186                 case T___builtin_va_copy:            return parse_va_copy();
7187                 case T___builtin_isgreater:
7188                 case T___builtin_isgreaterequal:
7189                 case T___builtin_isless:
7190                 case T___builtin_islessequal:
7191                 case T___builtin_islessgreater:
7192                 case T___builtin_isunordered:        return parse_compare_builtin();
7193                 case T___builtin_constant_p:         return parse_builtin_constant();
7194                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7195                 case T__assume:                      return parse_assume();
7196                 case T_ANDAND:
7197                         if (GNU_MODE)
7198                                 return parse_label_address();
7199                         break;
7200
7201                 case '(':                            return parse_parenthesized_expression();
7202                 case T___noop:                       return parse_noop_expression();
7203
7204                 /* Gracefully handle type names while parsing expressions. */
7205                 case T_IDENTIFIER:
7206                         if (!is_typedef_symbol(token.v.symbol)) {
7207                                 return parse_reference();
7208                         }
7209                         /* FALLTHROUGH */
7210                 TYPENAME_START {
7211                         source_position_t  const pos  = *HERE;
7212                         type_t const      *const type = parse_typename();
7213                         errorf(&pos, "encountered type '%T' while parsing expression", type);
7214                         return create_invalid_expression();
7215                 }
7216         }
7217
7218         errorf(HERE, "unexpected token %K, expected an expression", &token);
7219         return create_invalid_expression();
7220 }
7221
7222 /**
7223  * Check if the expression has the character type and issue a warning then.
7224  */
7225 static void check_for_char_index_type(const expression_t *expression)
7226 {
7227         type_t       *const type      = expression->base.type;
7228         const type_t *const base_type = skip_typeref(type);
7229
7230         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7231                         warning.char_subscripts) {
7232                 warningf(&expression->base.source_position,
7233                          "array subscript has type '%T'", type);
7234         }
7235 }
7236
7237 static expression_t *parse_array_expression(expression_t *left)
7238 {
7239         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7240
7241         eat('[');
7242         add_anchor_token(']');
7243
7244         expression_t *inside = parse_expression();
7245
7246         type_t *const orig_type_left   = left->base.type;
7247         type_t *const orig_type_inside = inside->base.type;
7248
7249         type_t *const type_left   = skip_typeref(orig_type_left);
7250         type_t *const type_inside = skip_typeref(orig_type_inside);
7251
7252         type_t                    *return_type;
7253         array_access_expression_t *array_access = &expression->array_access;
7254         if (is_type_pointer(type_left)) {
7255                 return_type             = type_left->pointer.points_to;
7256                 array_access->array_ref = left;
7257                 array_access->index     = inside;
7258                 check_for_char_index_type(inside);
7259         } else if (is_type_pointer(type_inside)) {
7260                 return_type             = type_inside->pointer.points_to;
7261                 array_access->array_ref = inside;
7262                 array_access->index     = left;
7263                 array_access->flipped   = true;
7264                 check_for_char_index_type(left);
7265         } else {
7266                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7267                         errorf(HERE,
7268                                 "array access on object with non-pointer types '%T', '%T'",
7269                                 orig_type_left, orig_type_inside);
7270                 }
7271                 return_type             = type_error_type;
7272                 array_access->array_ref = left;
7273                 array_access->index     = inside;
7274         }
7275
7276         expression->base.type = automatic_type_conversion(return_type);
7277
7278         rem_anchor_token(']');
7279         expect(']', end_error);
7280 end_error:
7281         return expression;
7282 }
7283
7284 static expression_t *parse_typeprop(expression_kind_t const kind)
7285 {
7286         expression_t  *tp_expression = allocate_expression_zero(kind);
7287         tp_expression->base.type     = type_size_t;
7288
7289         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7290
7291         /* we only refer to a type property, mark this case */
7292         bool old     = in_type_prop;
7293         in_type_prop = true;
7294
7295         type_t       *orig_type;
7296         expression_t *expression;
7297         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7298                 next_token();
7299                 add_anchor_token(')');
7300                 orig_type = parse_typename();
7301                 rem_anchor_token(')');
7302                 expect(')', end_error);
7303
7304                 if (token.type == '{') {
7305                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7306                          * starting with a compound literal */
7307                         expression = parse_compound_literal(orig_type);
7308                         goto typeprop_expression;
7309                 }
7310         } else {
7311                 expression = parse_sub_expression(PREC_UNARY);
7312
7313 typeprop_expression:
7314                 tp_expression->typeprop.tp_expression = expression;
7315
7316                 orig_type = revert_automatic_type_conversion(expression);
7317                 expression->base.type = orig_type;
7318         }
7319
7320         tp_expression->typeprop.type   = orig_type;
7321         type_t const* const type       = skip_typeref(orig_type);
7322         char   const* const wrong_type =
7323                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7324                 is_type_incomplete(type)                           ? "incomplete"          :
7325                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7326                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7327                 NULL;
7328         if (wrong_type != NULL) {
7329                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7330                 errorf(&tp_expression->base.source_position,
7331                                 "operand of %s expression must not be of %s type '%T'",
7332                                 what, wrong_type, orig_type);
7333         }
7334
7335 end_error:
7336         in_type_prop = old;
7337         return tp_expression;
7338 }
7339
7340 static expression_t *parse_sizeof(void)
7341 {
7342         return parse_typeprop(EXPR_SIZEOF);
7343 }
7344
7345 static expression_t *parse_alignof(void)
7346 {
7347         return parse_typeprop(EXPR_ALIGNOF);
7348 }
7349
7350 static expression_t *parse_select_expression(expression_t *addr)
7351 {
7352         assert(token.type == '.' || token.type == T_MINUSGREATER);
7353         bool select_left_arrow = (token.type == T_MINUSGREATER);
7354         next_token();
7355
7356         if (token.type != T_IDENTIFIER) {
7357                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7358                 return create_invalid_expression();
7359         }
7360         symbol_t *symbol = token.v.symbol;
7361         next_token();
7362
7363         type_t *const orig_type = addr->base.type;
7364         type_t *const type      = skip_typeref(orig_type);
7365
7366         type_t *type_left;
7367         bool    saw_error = false;
7368         if (is_type_pointer(type)) {
7369                 if (!select_left_arrow) {
7370                         errorf(HERE,
7371                                "request for member '%Y' in something not a struct or union, but '%T'",
7372                                symbol, orig_type);
7373                         saw_error = true;
7374                 }
7375                 type_left = skip_typeref(type->pointer.points_to);
7376         } else {
7377                 if (select_left_arrow && is_type_valid(type)) {
7378                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7379                         saw_error = true;
7380                 }
7381                 type_left = type;
7382         }
7383
7384         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7385             type_left->kind != TYPE_COMPOUND_UNION) {
7386
7387                 if (is_type_valid(type_left) && !saw_error) {
7388                         errorf(HERE,
7389                                "request for member '%Y' in something not a struct or union, but '%T'",
7390                                symbol, type_left);
7391                 }
7392                 return create_invalid_expression();
7393         }
7394
7395         compound_t *compound = type_left->compound.compound;
7396         if (!compound->complete) {
7397                 errorf(HERE, "request for member '%Y' in incomplete type '%T'",
7398                        symbol, type_left);
7399                 return create_invalid_expression();
7400         }
7401
7402         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7403         expression_t      *result
7404                 = find_create_select(HERE, addr, qualifiers, compound, symbol);
7405
7406         if (result == NULL) {
7407                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7408                 return create_invalid_expression();
7409         }
7410
7411         return result;
7412 }
7413
7414 static void check_call_argument(type_t          *expected_type,
7415                                 call_argument_t *argument, unsigned pos)
7416 {
7417         type_t         *expected_type_skip = skip_typeref(expected_type);
7418         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7419         expression_t   *arg_expr           = argument->expression;
7420         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7421
7422         /* handle transparent union gnu extension */
7423         if (is_type_union(expected_type_skip)
7424                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7425                 compound_t *union_decl  = expected_type_skip->compound.compound;
7426                 type_t     *best_type   = NULL;
7427                 entity_t   *entry       = union_decl->members.entities;
7428                 for ( ; entry != NULL; entry = entry->base.next) {
7429                         assert(is_declaration(entry));
7430                         type_t *decl_type = entry->declaration.type;
7431                         error = semantic_assign(decl_type, arg_expr);
7432                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7433                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7434                                 continue;
7435
7436                         if (error == ASSIGN_SUCCESS) {
7437                                 best_type = decl_type;
7438                         } else if (best_type == NULL) {
7439                                 best_type = decl_type;
7440                         }
7441                 }
7442
7443                 if (best_type != NULL) {
7444                         expected_type = best_type;
7445                 }
7446         }
7447
7448         error                = semantic_assign(expected_type, arg_expr);
7449         argument->expression = create_implicit_cast(arg_expr, expected_type);
7450
7451         if (error != ASSIGN_SUCCESS) {
7452                 /* report exact scope in error messages (like "in argument 3") */
7453                 char buf[64];
7454                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7455                 report_assign_error(error, expected_type, arg_expr,     buf,
7456                                                         &arg_expr->base.source_position);
7457         } else if (warning.traditional || warning.conversion) {
7458                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7459                 if (!types_compatible(expected_type_skip, promoted_type) &&
7460                     !types_compatible(expected_type_skip, type_void_ptr) &&
7461                     !types_compatible(type_void_ptr,      promoted_type)) {
7462                         /* Deliberately show the skipped types in this warning */
7463                         warningf(&arg_expr->base.source_position,
7464                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7465                                 pos, expected_type_skip, promoted_type);
7466                 }
7467         }
7468 }
7469
7470 /**
7471  * Handle the semantic restrictions of builtin calls
7472  */
7473 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7474         switch (call->function->reference.entity->function.btk) {
7475                 case bk_gnu_builtin_return_address:
7476                 case bk_gnu_builtin_frame_address: {
7477                         /* argument must be constant */
7478                         call_argument_t *argument = call->arguments;
7479
7480                         if (! is_constant_expression(argument->expression)) {
7481                                 errorf(&call->base.source_position,
7482                                        "argument of '%Y' must be a constant expression",
7483                                        call->function->reference.entity->base.symbol);
7484                         }
7485                         break;
7486                 }
7487                 case bk_gnu_builtin_prefetch: {
7488                         /* second and third argument must be constant if existent */
7489                         call_argument_t *rw = call->arguments->next;
7490                         call_argument_t *locality = NULL;
7491
7492                         if (rw != NULL) {
7493                                 if (! is_constant_expression(rw->expression)) {
7494                                         errorf(&call->base.source_position,
7495                                                "second argument of '%Y' must be a constant expression",
7496                                                call->function->reference.entity->base.symbol);
7497                                 }
7498                                 locality = rw->next;
7499                         }
7500                         if (locality != NULL) {
7501                                 if (! is_constant_expression(locality->expression)) {
7502                                         errorf(&call->base.source_position,
7503                                                "third argument of '%Y' must be a constant expression",
7504                                                call->function->reference.entity->base.symbol);
7505                                 }
7506                                 locality = rw->next;
7507                         }
7508                         break;
7509                 }
7510                 default:
7511                         break;
7512         }
7513 }
7514
7515 /**
7516  * Parse a call expression, ie. expression '( ... )'.
7517  *
7518  * @param expression  the function address
7519  */
7520 static expression_t *parse_call_expression(expression_t *expression)
7521 {
7522         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7523         call_expression_t *call   = &result->call;
7524         call->function            = expression;
7525
7526         type_t *const orig_type = expression->base.type;
7527         type_t *const type      = skip_typeref(orig_type);
7528
7529         function_type_t *function_type = NULL;
7530         if (is_type_pointer(type)) {
7531                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7532
7533                 if (is_type_function(to_type)) {
7534                         function_type   = &to_type->function;
7535                         call->base.type = function_type->return_type;
7536                 }
7537         }
7538
7539         if (function_type == NULL && is_type_valid(type)) {
7540                 errorf(HERE,
7541                        "called object '%E' (type '%T') is not a pointer to a function",
7542                        expression, orig_type);
7543         }
7544
7545         /* parse arguments */
7546         eat('(');
7547         add_anchor_token(')');
7548         add_anchor_token(',');
7549
7550         if (token.type != ')') {
7551                 call_argument_t **anchor = &call->arguments;
7552                 for (;;) {
7553                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7554                         argument->expression = parse_assignment_expression();
7555
7556                         *anchor = argument;
7557                         anchor  = &argument->next;
7558
7559                         if (token.type != ',')
7560                                 break;
7561                         next_token();
7562                 }
7563         }
7564         rem_anchor_token(',');
7565         rem_anchor_token(')');
7566         expect(')', end_error);
7567
7568         if (function_type == NULL)
7569                 return result;
7570
7571         /* check type and count of call arguments */
7572         function_parameter_t *parameter = function_type->parameters;
7573         call_argument_t      *argument  = call->arguments;
7574         if (!function_type->unspecified_parameters) {
7575                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7576                                 parameter = parameter->next, argument = argument->next) {
7577                         check_call_argument(parameter->type, argument, ++pos);
7578                 }
7579
7580                 if (parameter != NULL) {
7581                         errorf(HERE, "too few arguments to function '%E'", expression);
7582                 } else if (argument != NULL && !function_type->variadic) {
7583                         errorf(HERE, "too many arguments to function '%E'", expression);
7584                 }
7585         }
7586
7587         /* do default promotion for other arguments */
7588         for (; argument != NULL; argument = argument->next) {
7589                 type_t *type = argument->expression->base.type;
7590
7591                 type = get_default_promoted_type(type);
7592
7593                 argument->expression
7594                         = create_implicit_cast(argument->expression, type);
7595         }
7596
7597         check_format(&result->call);
7598
7599         if (warning.aggregate_return &&
7600             is_type_compound(skip_typeref(function_type->return_type))) {
7601                 warningf(&result->base.source_position,
7602                          "function call has aggregate value");
7603         }
7604
7605         if (call->function->kind == EXPR_REFERENCE) {
7606                 reference_expression_t *reference = &call->function->reference;
7607                 if (reference->entity->kind == ENTITY_FUNCTION &&
7608                     reference->entity->function.btk != bk_none)
7609                         handle_builtin_argument_restrictions(call);
7610         }
7611
7612 end_error:
7613         return result;
7614 }
7615
7616 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7617
7618 static bool same_compound_type(const type_t *type1, const type_t *type2)
7619 {
7620         return
7621                 is_type_compound(type1) &&
7622                 type1->kind == type2->kind &&
7623                 type1->compound.compound == type2->compound.compound;
7624 }
7625
7626 static expression_t const *get_reference_address(expression_t const *expr)
7627 {
7628         bool regular_take_address = true;
7629         for (;;) {
7630                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7631                         expr = expr->unary.value;
7632                 } else {
7633                         regular_take_address = false;
7634                 }
7635
7636                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7637                         break;
7638
7639                 expr = expr->unary.value;
7640         }
7641
7642         if (expr->kind != EXPR_REFERENCE)
7643                 return NULL;
7644
7645         /* special case for functions which are automatically converted to a
7646          * pointer to function without an extra TAKE_ADDRESS operation */
7647         if (!regular_take_address &&
7648                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7649                 return NULL;
7650         }
7651
7652         return expr;
7653 }
7654
7655 static void warn_reference_address_as_bool(expression_t const* expr)
7656 {
7657         if (!warning.address)
7658                 return;
7659
7660         expr = get_reference_address(expr);
7661         if (expr != NULL) {
7662                 warningf(&expr->base.source_position,
7663                          "the address of '%Y' will always evaluate as 'true'",
7664                          expr->reference.entity->base.symbol);
7665         }
7666 }
7667
7668 static void warn_assignment_in_condition(const expression_t *const expr)
7669 {
7670         if (!warning.parentheses)
7671                 return;
7672         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7673                 return;
7674         if (expr->base.parenthesized)
7675                 return;
7676         warningf(&expr->base.source_position,
7677                         "suggest parentheses around assignment used as truth value");
7678 }
7679
7680 static void semantic_condition(expression_t const *const expr,
7681                                char const *const context)
7682 {
7683         type_t *const type = skip_typeref(expr->base.type);
7684         if (is_type_scalar(type)) {
7685                 warn_reference_address_as_bool(expr);
7686                 warn_assignment_in_condition(expr);
7687         } else if (is_type_valid(type)) {
7688                 errorf(&expr->base.source_position,
7689                                 "%s must have scalar type", context);
7690         }
7691 }
7692
7693 /**
7694  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7695  *
7696  * @param expression  the conditional expression
7697  */
7698 static expression_t *parse_conditional_expression(expression_t *expression)
7699 {
7700         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7701
7702         conditional_expression_t *conditional = &result->conditional;
7703         conditional->condition                = expression;
7704
7705         eat('?');
7706         add_anchor_token(':');
7707
7708         /* §6.5.15:2  The first operand shall have scalar type. */
7709         semantic_condition(expression, "condition of conditional operator");
7710
7711         expression_t *true_expression = expression;
7712         bool          gnu_cond = false;
7713         if (GNU_MODE && token.type == ':') {
7714                 gnu_cond = true;
7715         } else {
7716                 true_expression = parse_expression();
7717         }
7718         rem_anchor_token(':');
7719         expect(':', end_error);
7720 end_error:;
7721         expression_t *false_expression =
7722                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7723
7724         type_t *const orig_true_type  = true_expression->base.type;
7725         type_t *const orig_false_type = false_expression->base.type;
7726         type_t *const true_type       = skip_typeref(orig_true_type);
7727         type_t *const false_type      = skip_typeref(orig_false_type);
7728
7729         /* 6.5.15.3 */
7730         type_t *result_type;
7731         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7732                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7733                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7734                 if (true_expression->kind == EXPR_UNARY_THROW) {
7735                         result_type = false_type;
7736                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7737                         result_type = true_type;
7738                 } else {
7739                         if (warning.other && (
7740                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7741                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7742                                         )) {
7743                                 warningf(&conditional->base.source_position,
7744                                                 "ISO C forbids conditional expression with only one void side");
7745                         }
7746                         result_type = type_void;
7747                 }
7748         } else if (is_type_arithmetic(true_type)
7749                    && is_type_arithmetic(false_type)) {
7750                 result_type = semantic_arithmetic(true_type, false_type);
7751
7752                 true_expression  = create_implicit_cast(true_expression, result_type);
7753                 false_expression = create_implicit_cast(false_expression, result_type);
7754
7755                 conditional->true_expression  = true_expression;
7756                 conditional->false_expression = false_expression;
7757                 conditional->base.type        = result_type;
7758         } else if (same_compound_type(true_type, false_type)) {
7759                 /* just take 1 of the 2 types */
7760                 result_type = true_type;
7761         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7762                 type_t *pointer_type;
7763                 type_t *other_type;
7764                 expression_t *other_expression;
7765                 if (is_type_pointer(true_type) &&
7766                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7767                         pointer_type     = true_type;
7768                         other_type       = false_type;
7769                         other_expression = false_expression;
7770                 } else {
7771                         pointer_type     = false_type;
7772                         other_type       = true_type;
7773                         other_expression = true_expression;
7774                 }
7775
7776                 if (is_null_pointer_constant(other_expression)) {
7777                         result_type = pointer_type;
7778                 } else if (is_type_pointer(other_type)) {
7779                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7780                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7781
7782                         type_t *to;
7783                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7784                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7785                                 to = type_void;
7786                         } else if (types_compatible(get_unqualified_type(to1),
7787                                                     get_unqualified_type(to2))) {
7788                                 to = to1;
7789                         } else {
7790                                 if (warning.other) {
7791                                         warningf(&conditional->base.source_position,
7792                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7793                                                         true_type, false_type);
7794                                 }
7795                                 to = type_void;
7796                         }
7797
7798                         type_t *const type =
7799                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7800                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7801                 } else if (is_type_integer(other_type)) {
7802                         if (warning.other) {
7803                                 warningf(&conditional->base.source_position,
7804                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7805                         }
7806                         result_type = pointer_type;
7807                 } else {
7808                         if (is_type_valid(other_type)) {
7809                                 type_error_incompatible("while parsing conditional",
7810                                                 &expression->base.source_position, true_type, false_type);
7811                         }
7812                         result_type = type_error_type;
7813                 }
7814         } else {
7815                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7816                         type_error_incompatible("while parsing conditional",
7817                                                 &conditional->base.source_position, true_type,
7818                                                 false_type);
7819                 }
7820                 result_type = type_error_type;
7821         }
7822
7823         conditional->true_expression
7824                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7825         conditional->false_expression
7826                 = create_implicit_cast(false_expression, result_type);
7827         conditional->base.type = result_type;
7828         return result;
7829 }
7830
7831 /**
7832  * Parse an extension expression.
7833  */
7834 static expression_t *parse_extension(void)
7835 {
7836         eat(T___extension__);
7837
7838         bool old_gcc_extension   = in_gcc_extension;
7839         in_gcc_extension         = true;
7840         expression_t *expression = parse_sub_expression(PREC_UNARY);
7841         in_gcc_extension         = old_gcc_extension;
7842         return expression;
7843 }
7844
7845 /**
7846  * Parse a __builtin_classify_type() expression.
7847  */
7848 static expression_t *parse_builtin_classify_type(void)
7849 {
7850         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7851         result->base.type    = type_int;
7852
7853         eat(T___builtin_classify_type);
7854
7855         expect('(', end_error);
7856         add_anchor_token(')');
7857         expression_t *expression = parse_expression();
7858         rem_anchor_token(')');
7859         expect(')', end_error);
7860         result->classify_type.type_expression = expression;
7861
7862         return result;
7863 end_error:
7864         return create_invalid_expression();
7865 }
7866
7867 /**
7868  * Parse a delete expression
7869  * ISO/IEC 14882:1998(E) §5.3.5
7870  */
7871 static expression_t *parse_delete(void)
7872 {
7873         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7874         result->base.type          = type_void;
7875
7876         eat(T_delete);
7877
7878         if (token.type == '[') {
7879                 next_token();
7880                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7881                 expect(']', end_error);
7882 end_error:;
7883         }
7884
7885         expression_t *const value = parse_sub_expression(PREC_CAST);
7886         result->unary.value = value;
7887
7888         type_t *const type = skip_typeref(value->base.type);
7889         if (!is_type_pointer(type)) {
7890                 if (is_type_valid(type)) {
7891                         errorf(&value->base.source_position,
7892                                         "operand of delete must have pointer type");
7893                 }
7894         } else if (warning.other &&
7895                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7896                 warningf(&value->base.source_position,
7897                                 "deleting 'void*' is undefined");
7898         }
7899
7900         return result;
7901 }
7902
7903 /**
7904  * Parse a throw expression
7905  * ISO/IEC 14882:1998(E) §15:1
7906  */
7907 static expression_t *parse_throw(void)
7908 {
7909         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7910         result->base.type          = type_void;
7911
7912         eat(T_throw);
7913
7914         expression_t *value = NULL;
7915         switch (token.type) {
7916                 EXPRESSION_START {
7917                         value = parse_assignment_expression();
7918                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7919                         type_t *const orig_type = value->base.type;
7920                         type_t *const type      = skip_typeref(orig_type);
7921                         if (is_type_incomplete(type)) {
7922                                 errorf(&value->base.source_position,
7923                                                 "cannot throw object of incomplete type '%T'", orig_type);
7924                         } else if (is_type_pointer(type)) {
7925                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7926                                 if (is_type_incomplete(points_to) &&
7927                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7928                                         errorf(&value->base.source_position,
7929                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7930                                 }
7931                         }
7932                 }
7933
7934                 default:
7935                         break;
7936         }
7937         result->unary.value = value;
7938
7939         return result;
7940 }
7941
7942 static bool check_pointer_arithmetic(const source_position_t *source_position,
7943                                      type_t *pointer_type,
7944                                      type_t *orig_pointer_type)
7945 {
7946         type_t *points_to = pointer_type->pointer.points_to;
7947         points_to = skip_typeref(points_to);
7948
7949         if (is_type_incomplete(points_to)) {
7950                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7951                         errorf(source_position,
7952                                "arithmetic with pointer to incomplete type '%T' not allowed",
7953                                orig_pointer_type);
7954                         return false;
7955                 } else if (warning.pointer_arith) {
7956                         warningf(source_position,
7957                                  "pointer of type '%T' used in arithmetic",
7958                                  orig_pointer_type);
7959                 }
7960         } else if (is_type_function(points_to)) {
7961                 if (!GNU_MODE) {
7962                         errorf(source_position,
7963                                "arithmetic with pointer to function type '%T' not allowed",
7964                                orig_pointer_type);
7965                         return false;
7966                 } else if (warning.pointer_arith) {
7967                         warningf(source_position,
7968                                  "pointer to a function '%T' used in arithmetic",
7969                                  orig_pointer_type);
7970                 }
7971         }
7972         return true;
7973 }
7974
7975 static bool is_lvalue(const expression_t *expression)
7976 {
7977         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7978         switch (expression->kind) {
7979         case EXPR_ARRAY_ACCESS:
7980         case EXPR_COMPOUND_LITERAL:
7981         case EXPR_REFERENCE:
7982         case EXPR_SELECT:
7983         case EXPR_UNARY_DEREFERENCE:
7984                 return true;
7985
7986         default: {
7987           type_t *type = skip_typeref(expression->base.type);
7988           return
7989                 /* ISO/IEC 14882:1998(E) §3.10:3 */
7990                 is_type_reference(type) ||
7991                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
7992                  * error before, which maybe prevented properly recognizing it as
7993                  * lvalue. */
7994                 !is_type_valid(type);
7995         }
7996         }
7997 }
7998
7999 static void semantic_incdec(unary_expression_t *expression)
8000 {
8001         type_t *const orig_type = expression->value->base.type;
8002         type_t *const type      = skip_typeref(orig_type);
8003         if (is_type_pointer(type)) {
8004                 if (!check_pointer_arithmetic(&expression->base.source_position,
8005                                               type, orig_type)) {
8006                         return;
8007                 }
8008         } else if (!is_type_real(type) && is_type_valid(type)) {
8009                 /* TODO: improve error message */
8010                 errorf(&expression->base.source_position,
8011                        "operation needs an arithmetic or pointer type");
8012                 return;
8013         }
8014         if (!is_lvalue(expression->value)) {
8015                 /* TODO: improve error message */
8016                 errorf(&expression->base.source_position, "lvalue required as operand");
8017         }
8018         expression->base.type = orig_type;
8019 }
8020
8021 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8022 {
8023         type_t *const orig_type = expression->value->base.type;
8024         type_t *const type      = skip_typeref(orig_type);
8025         if (!is_type_arithmetic(type)) {
8026                 if (is_type_valid(type)) {
8027                         /* TODO: improve error message */
8028                         errorf(&expression->base.source_position,
8029                                 "operation needs an arithmetic type");
8030                 }
8031                 return;
8032         }
8033
8034         expression->base.type = orig_type;
8035 }
8036
8037 static void semantic_unexpr_plus(unary_expression_t *expression)
8038 {
8039         semantic_unexpr_arithmetic(expression);
8040         if (warning.traditional)
8041                 warningf(&expression->base.source_position,
8042                         "traditional C rejects the unary plus operator");
8043 }
8044
8045 static void semantic_not(unary_expression_t *expression)
8046 {
8047         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8048         semantic_condition(expression->value, "operand of !");
8049         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8050 }
8051
8052 static void semantic_unexpr_integer(unary_expression_t *expression)
8053 {
8054         type_t *const orig_type = expression->value->base.type;
8055         type_t *const type      = skip_typeref(orig_type);
8056         if (!is_type_integer(type)) {
8057                 if (is_type_valid(type)) {
8058                         errorf(&expression->base.source_position,
8059                                "operand of ~ must be of integer type");
8060                 }
8061                 return;
8062         }
8063
8064         expression->base.type = orig_type;
8065 }
8066
8067 static void semantic_dereference(unary_expression_t *expression)
8068 {
8069         type_t *const orig_type = expression->value->base.type;
8070         type_t *const type      = skip_typeref(orig_type);
8071         if (!is_type_pointer(type)) {
8072                 if (is_type_valid(type)) {
8073                         errorf(&expression->base.source_position,
8074                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8075                 }
8076                 return;
8077         }
8078
8079         type_t *result_type   = type->pointer.points_to;
8080         result_type           = automatic_type_conversion(result_type);
8081         expression->base.type = result_type;
8082 }
8083
8084 /**
8085  * Record that an address is taken (expression represents an lvalue).
8086  *
8087  * @param expression       the expression
8088  * @param may_be_register  if true, the expression might be an register
8089  */
8090 static void set_address_taken(expression_t *expression, bool may_be_register)
8091 {
8092         if (expression->kind != EXPR_REFERENCE)
8093                 return;
8094
8095         entity_t *const entity = expression->reference.entity;
8096
8097         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8098                 return;
8099
8100         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8101                         && !may_be_register) {
8102                 errorf(&expression->base.source_position,
8103                                 "address of register %s '%Y' requested",
8104                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8105         }
8106
8107         if (entity->kind == ENTITY_VARIABLE) {
8108                 entity->variable.address_taken = true;
8109         } else {
8110                 assert(entity->kind == ENTITY_PARAMETER);
8111                 entity->parameter.address_taken = true;
8112         }
8113 }
8114
8115 /**
8116  * Check the semantic of the address taken expression.
8117  */
8118 static void semantic_take_addr(unary_expression_t *expression)
8119 {
8120         expression_t *value = expression->value;
8121         value->base.type    = revert_automatic_type_conversion(value);
8122
8123         type_t *orig_type = value->base.type;
8124         type_t *type      = skip_typeref(orig_type);
8125         if (!is_type_valid(type))
8126                 return;
8127
8128         /* §6.5.3.2 */
8129         if (!is_lvalue(value)) {
8130                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8131         }
8132         if (type->kind == TYPE_BITFIELD) {
8133                 errorf(&expression->base.source_position,
8134                        "'&' not allowed on object with bitfield type '%T'",
8135                        type);
8136         }
8137
8138         set_address_taken(value, false);
8139
8140         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8141 }
8142
8143 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8144 static expression_t *parse_##unexpression_type(void)                         \
8145 {                                                                            \
8146         expression_t *unary_expression                                           \
8147                 = allocate_expression_zero(unexpression_type);                       \
8148         eat(token_type);                                                         \
8149         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8150                                                                                  \
8151         sfunc(&unary_expression->unary);                                         \
8152                                                                                  \
8153         return unary_expression;                                                 \
8154 }
8155
8156 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8157                                semantic_unexpr_arithmetic)
8158 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8159                                semantic_unexpr_plus)
8160 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8161                                semantic_not)
8162 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8163                                semantic_dereference)
8164 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8165                                semantic_take_addr)
8166 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8167                                semantic_unexpr_integer)
8168 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8169                                semantic_incdec)
8170 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8171                                semantic_incdec)
8172
8173 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8174                                                sfunc)                         \
8175 static expression_t *parse_##unexpression_type(expression_t *left)            \
8176 {                                                                             \
8177         expression_t *unary_expression                                            \
8178                 = allocate_expression_zero(unexpression_type);                        \
8179         eat(token_type);                                                          \
8180         unary_expression->unary.value = left;                                     \
8181                                                                                   \
8182         sfunc(&unary_expression->unary);                                          \
8183                                                                               \
8184         return unary_expression;                                                  \
8185 }
8186
8187 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8188                                        EXPR_UNARY_POSTFIX_INCREMENT,
8189                                        semantic_incdec)
8190 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8191                                        EXPR_UNARY_POSTFIX_DECREMENT,
8192                                        semantic_incdec)
8193
8194 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8195 {
8196         /* TODO: handle complex + imaginary types */
8197
8198         type_left  = get_unqualified_type(type_left);
8199         type_right = get_unqualified_type(type_right);
8200
8201         /* §6.3.1.8 Usual arithmetic conversions */
8202         if (type_left == type_long_double || type_right == type_long_double) {
8203                 return type_long_double;
8204         } else if (type_left == type_double || type_right == type_double) {
8205                 return type_double;
8206         } else if (type_left == type_float || type_right == type_float) {
8207                 return type_float;
8208         }
8209
8210         type_left  = promote_integer(type_left);
8211         type_right = promote_integer(type_right);
8212
8213         if (type_left == type_right)
8214                 return type_left;
8215
8216         bool const signed_left  = is_type_signed(type_left);
8217         bool const signed_right = is_type_signed(type_right);
8218         int const  rank_left    = get_rank(type_left);
8219         int const  rank_right   = get_rank(type_right);
8220
8221         if (signed_left == signed_right)
8222                 return rank_left >= rank_right ? type_left : type_right;
8223
8224         int     s_rank;
8225         int     u_rank;
8226         type_t *s_type;
8227         type_t *u_type;
8228         if (signed_left) {
8229                 s_rank = rank_left;
8230                 s_type = type_left;
8231                 u_rank = rank_right;
8232                 u_type = type_right;
8233         } else {
8234                 s_rank = rank_right;
8235                 s_type = type_right;
8236                 u_rank = rank_left;
8237                 u_type = type_left;
8238         }
8239
8240         if (u_rank >= s_rank)
8241                 return u_type;
8242
8243         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8244          * easier here... */
8245         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8246                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8247                 return s_type;
8248
8249         switch (s_rank) {
8250                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8251                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8252                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8253
8254                 default: panic("invalid atomic type");
8255         }
8256 }
8257
8258 /**
8259  * Check the semantic restrictions for a binary expression.
8260  */
8261 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8262 {
8263         expression_t *const left            = expression->left;
8264         expression_t *const right           = expression->right;
8265         type_t       *const orig_type_left  = left->base.type;
8266         type_t       *const orig_type_right = right->base.type;
8267         type_t       *const type_left       = skip_typeref(orig_type_left);
8268         type_t       *const type_right      = skip_typeref(orig_type_right);
8269
8270         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8271                 /* TODO: improve error message */
8272                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8273                         errorf(&expression->base.source_position,
8274                                "operation needs arithmetic types");
8275                 }
8276                 return;
8277         }
8278
8279         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8280         expression->left      = create_implicit_cast(left, arithmetic_type);
8281         expression->right     = create_implicit_cast(right, arithmetic_type);
8282         expression->base.type = arithmetic_type;
8283 }
8284
8285 static void warn_div_by_zero(binary_expression_t const *const expression)
8286 {
8287         if (!warning.div_by_zero ||
8288             !is_type_integer(expression->base.type))
8289                 return;
8290
8291         expression_t const *const right = expression->right;
8292         /* The type of the right operand can be different for /= */
8293         if (is_type_integer(right->base.type) &&
8294             is_constant_expression(right)     &&
8295             !fold_constant_to_bool(right)) {
8296                 warningf(&expression->base.source_position, "division by zero");
8297         }
8298 }
8299
8300 /**
8301  * Check the semantic restrictions for a div/mod expression.
8302  */
8303 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8304 {
8305         semantic_binexpr_arithmetic(expression);
8306         warn_div_by_zero(expression);
8307 }
8308
8309 static void warn_addsub_in_shift(const expression_t *const expr)
8310 {
8311         if (expr->base.parenthesized)
8312                 return;
8313
8314         char op;
8315         switch (expr->kind) {
8316                 case EXPR_BINARY_ADD: op = '+'; break;
8317                 case EXPR_BINARY_SUB: op = '-'; break;
8318                 default:              return;
8319         }
8320
8321         warningf(&expr->base.source_position,
8322                         "suggest parentheses around '%c' inside shift", op);
8323 }
8324
8325 static bool semantic_shift(binary_expression_t *expression)
8326 {
8327         expression_t *const left            = expression->left;
8328         expression_t *const right           = expression->right;
8329         type_t       *const orig_type_left  = left->base.type;
8330         type_t       *const orig_type_right = right->base.type;
8331         type_t       *      type_left       = skip_typeref(orig_type_left);
8332         type_t       *      type_right      = skip_typeref(orig_type_right);
8333
8334         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8335                 /* TODO: improve error message */
8336                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8337                         errorf(&expression->base.source_position,
8338                                "operands of shift operation must have integer types");
8339                 }
8340                 return false;
8341         }
8342
8343         type_left = promote_integer(type_left);
8344
8345         if (is_constant_expression(right)) {
8346                 long count = fold_constant_to_int(right);
8347                 if (count < 0) {
8348                         warningf(&right->base.source_position,
8349                                         "shift count must be non-negative");
8350                 } else if ((unsigned long)count >=
8351                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8352                         warningf(&right->base.source_position,
8353                                         "shift count must be less than type width");
8354                 }
8355         }
8356
8357         type_right        = promote_integer(type_right);
8358         expression->right = create_implicit_cast(right, type_right);
8359
8360         return true;
8361 }
8362
8363 static void semantic_shift_op(binary_expression_t *expression)
8364 {
8365         expression_t *const left  = expression->left;
8366         expression_t *const right = expression->right;
8367
8368         if (!semantic_shift(expression))
8369                 return;
8370
8371         if (warning.parentheses) {
8372                 warn_addsub_in_shift(left);
8373                 warn_addsub_in_shift(right);
8374         }
8375
8376         type_t *const orig_type_left = left->base.type;
8377         type_t *      type_left      = skip_typeref(orig_type_left);
8378
8379         type_left             = promote_integer(type_left);
8380         expression->left      = create_implicit_cast(left, type_left);
8381         expression->base.type = type_left;
8382 }
8383
8384 static void semantic_add(binary_expression_t *expression)
8385 {
8386         expression_t *const left            = expression->left;
8387         expression_t *const right           = expression->right;
8388         type_t       *const orig_type_left  = left->base.type;
8389         type_t       *const orig_type_right = right->base.type;
8390         type_t       *const type_left       = skip_typeref(orig_type_left);
8391         type_t       *const type_right      = skip_typeref(orig_type_right);
8392
8393         /* §6.5.6 */
8394         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8395                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8396                 expression->left  = create_implicit_cast(left, arithmetic_type);
8397                 expression->right = create_implicit_cast(right, arithmetic_type);
8398                 expression->base.type = arithmetic_type;
8399         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8400                 check_pointer_arithmetic(&expression->base.source_position,
8401                                          type_left, orig_type_left);
8402                 expression->base.type = type_left;
8403         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8404                 check_pointer_arithmetic(&expression->base.source_position,
8405                                          type_right, orig_type_right);
8406                 expression->base.type = type_right;
8407         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8408                 errorf(&expression->base.source_position,
8409                        "invalid operands to binary + ('%T', '%T')",
8410                        orig_type_left, orig_type_right);
8411         }
8412 }
8413
8414 static void semantic_sub(binary_expression_t *expression)
8415 {
8416         expression_t            *const left            = expression->left;
8417         expression_t            *const right           = expression->right;
8418         type_t                  *const orig_type_left  = left->base.type;
8419         type_t                  *const orig_type_right = right->base.type;
8420         type_t                  *const type_left       = skip_typeref(orig_type_left);
8421         type_t                  *const type_right      = skip_typeref(orig_type_right);
8422         source_position_t const *const pos             = &expression->base.source_position;
8423
8424         /* §5.6.5 */
8425         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8426                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8427                 expression->left        = create_implicit_cast(left, arithmetic_type);
8428                 expression->right       = create_implicit_cast(right, arithmetic_type);
8429                 expression->base.type =  arithmetic_type;
8430         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8431                 check_pointer_arithmetic(&expression->base.source_position,
8432                                          type_left, orig_type_left);
8433                 expression->base.type = type_left;
8434         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8435                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8436                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8437                 if (!types_compatible(unqual_left, unqual_right)) {
8438                         errorf(pos,
8439                                "subtracting pointers to incompatible types '%T' and '%T'",
8440                                orig_type_left, orig_type_right);
8441                 } else if (!is_type_object(unqual_left)) {
8442                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8443                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8444                                        orig_type_left);
8445                         } else if (warning.other) {
8446                                 warningf(pos, "subtracting pointers to void");
8447                         }
8448                 }
8449                 expression->base.type = type_ptrdiff_t;
8450         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8451                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8452                        orig_type_left, orig_type_right);
8453         }
8454 }
8455
8456 static void warn_string_literal_address(expression_t const* expr)
8457 {
8458         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8459                 expr = expr->unary.value;
8460                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8461                         return;
8462                 expr = expr->unary.value;
8463         }
8464
8465         if (expr->kind == EXPR_STRING_LITERAL ||
8466             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8467                 warningf(&expr->base.source_position,
8468                         "comparison with string literal results in unspecified behaviour");
8469         }
8470 }
8471
8472 static void warn_comparison_in_comparison(const expression_t *const expr)
8473 {
8474         if (expr->base.parenthesized)
8475                 return;
8476         switch (expr->base.kind) {
8477                 case EXPR_BINARY_LESS:
8478                 case EXPR_BINARY_GREATER:
8479                 case EXPR_BINARY_LESSEQUAL:
8480                 case EXPR_BINARY_GREATEREQUAL:
8481                 case EXPR_BINARY_NOTEQUAL:
8482                 case EXPR_BINARY_EQUAL:
8483                         warningf(&expr->base.source_position,
8484                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8485                         break;
8486                 default:
8487                         break;
8488         }
8489 }
8490
8491 static bool maybe_negative(expression_t const *const expr)
8492 {
8493         return
8494                 !is_constant_expression(expr) ||
8495                 fold_constant_to_int(expr) < 0;
8496 }
8497
8498 /**
8499  * Check the semantics of comparison expressions.
8500  *
8501  * @param expression   The expression to check.
8502  */
8503 static void semantic_comparison(binary_expression_t *expression)
8504 {
8505         expression_t *left  = expression->left;
8506         expression_t *right = expression->right;
8507
8508         if (warning.address) {
8509                 warn_string_literal_address(left);
8510                 warn_string_literal_address(right);
8511
8512                 expression_t const* const func_left = get_reference_address(left);
8513                 if (func_left != NULL && is_null_pointer_constant(right)) {
8514                         warningf(&expression->base.source_position,
8515                                  "the address of '%Y' will never be NULL",
8516                                  func_left->reference.entity->base.symbol);
8517                 }
8518
8519                 expression_t const* const func_right = get_reference_address(right);
8520                 if (func_right != NULL && is_null_pointer_constant(right)) {
8521                         warningf(&expression->base.source_position,
8522                                  "the address of '%Y' will never be NULL",
8523                                  func_right->reference.entity->base.symbol);
8524                 }
8525         }
8526
8527         if (warning.parentheses) {
8528                 warn_comparison_in_comparison(left);
8529                 warn_comparison_in_comparison(right);
8530         }
8531
8532         type_t *orig_type_left  = left->base.type;
8533         type_t *orig_type_right = right->base.type;
8534         type_t *type_left       = skip_typeref(orig_type_left);
8535         type_t *type_right      = skip_typeref(orig_type_right);
8536
8537         /* TODO non-arithmetic types */
8538         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8539                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8540
8541                 /* test for signed vs unsigned compares */
8542                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8543                         bool const signed_left  = is_type_signed(type_left);
8544                         bool const signed_right = is_type_signed(type_right);
8545                         if (signed_left != signed_right) {
8546                                 /* FIXME long long needs better const folding magic */
8547                                 /* TODO check whether constant value can be represented by other type */
8548                                 if ((signed_left  && maybe_negative(left)) ||
8549                                                 (signed_right && maybe_negative(right))) {
8550                                         warningf(&expression->base.source_position,
8551                                                         "comparison between signed and unsigned");
8552                                 }
8553                         }
8554                 }
8555
8556                 expression->left        = create_implicit_cast(left, arithmetic_type);
8557                 expression->right       = create_implicit_cast(right, arithmetic_type);
8558                 expression->base.type   = arithmetic_type;
8559                 if (warning.float_equal &&
8560                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8561                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8562                     is_type_float(arithmetic_type)) {
8563                         warningf(&expression->base.source_position,
8564                                  "comparing floating point with == or != is unsafe");
8565                 }
8566         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8567                 /* TODO check compatibility */
8568         } else if (is_type_pointer(type_left)) {
8569                 expression->right = create_implicit_cast(right, type_left);
8570         } else if (is_type_pointer(type_right)) {
8571                 expression->left = create_implicit_cast(left, type_right);
8572         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8573                 type_error_incompatible("invalid operands in comparison",
8574                                         &expression->base.source_position,
8575                                         type_left, type_right);
8576         }
8577         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8578 }
8579
8580 /**
8581  * Checks if a compound type has constant fields.
8582  */
8583 static bool has_const_fields(const compound_type_t *type)
8584 {
8585         compound_t *compound = type->compound;
8586         entity_t   *entry    = compound->members.entities;
8587
8588         for (; entry != NULL; entry = entry->base.next) {
8589                 if (!is_declaration(entry))
8590                         continue;
8591
8592                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8593                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8594                         return true;
8595         }
8596
8597         return false;
8598 }
8599
8600 static bool is_valid_assignment_lhs(expression_t const* const left)
8601 {
8602         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8603         type_t *const type_left      = skip_typeref(orig_type_left);
8604
8605         if (!is_lvalue(left)) {
8606                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8607                        left);
8608                 return false;
8609         }
8610
8611         if (left->kind == EXPR_REFERENCE
8612                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8613                 errorf(HERE, "cannot assign to function '%E'", left);
8614                 return false;
8615         }
8616
8617         if (is_type_array(type_left)) {
8618                 errorf(HERE, "cannot assign to array '%E'", left);
8619                 return false;
8620         }
8621         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8622                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8623                        orig_type_left);
8624                 return false;
8625         }
8626         if (is_type_incomplete(type_left)) {
8627                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8628                        left, orig_type_left);
8629                 return false;
8630         }
8631         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8632                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8633                        left, orig_type_left);
8634                 return false;
8635         }
8636
8637         return true;
8638 }
8639
8640 static void semantic_arithmetic_assign(binary_expression_t *expression)
8641 {
8642         expression_t *left            = expression->left;
8643         expression_t *right           = expression->right;
8644         type_t       *orig_type_left  = left->base.type;
8645         type_t       *orig_type_right = right->base.type;
8646
8647         if (!is_valid_assignment_lhs(left))
8648                 return;
8649
8650         type_t *type_left  = skip_typeref(orig_type_left);
8651         type_t *type_right = skip_typeref(orig_type_right);
8652
8653         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8654                 /* TODO: improve error message */
8655                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8656                         errorf(&expression->base.source_position,
8657                                "operation needs arithmetic types");
8658                 }
8659                 return;
8660         }
8661
8662         /* combined instructions are tricky. We can't create an implicit cast on
8663          * the left side, because we need the uncasted form for the store.
8664          * The ast2firm pass has to know that left_type must be right_type
8665          * for the arithmetic operation and create a cast by itself */
8666         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8667         expression->right       = create_implicit_cast(right, arithmetic_type);
8668         expression->base.type   = type_left;
8669 }
8670
8671 static void semantic_divmod_assign(binary_expression_t *expression)
8672 {
8673         semantic_arithmetic_assign(expression);
8674         warn_div_by_zero(expression);
8675 }
8676
8677 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8678 {
8679         expression_t *const left            = expression->left;
8680         expression_t *const right           = expression->right;
8681         type_t       *const orig_type_left  = left->base.type;
8682         type_t       *const orig_type_right = right->base.type;
8683         type_t       *const type_left       = skip_typeref(orig_type_left);
8684         type_t       *const type_right      = skip_typeref(orig_type_right);
8685
8686         if (!is_valid_assignment_lhs(left))
8687                 return;
8688
8689         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8690                 /* combined instructions are tricky. We can't create an implicit cast on
8691                  * the left side, because we need the uncasted form for the store.
8692                  * The ast2firm pass has to know that left_type must be right_type
8693                  * for the arithmetic operation and create a cast by itself */
8694                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8695                 expression->right     = create_implicit_cast(right, arithmetic_type);
8696                 expression->base.type = type_left;
8697         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8698                 check_pointer_arithmetic(&expression->base.source_position,
8699                                          type_left, orig_type_left);
8700                 expression->base.type = type_left;
8701         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8702                 errorf(&expression->base.source_position,
8703                        "incompatible types '%T' and '%T' in assignment",
8704                        orig_type_left, orig_type_right);
8705         }
8706 }
8707
8708 static void semantic_integer_assign(binary_expression_t *expression)
8709 {
8710         expression_t *left            = expression->left;
8711         expression_t *right           = expression->right;
8712         type_t       *orig_type_left  = left->base.type;
8713         type_t       *orig_type_right = right->base.type;
8714
8715         if (!is_valid_assignment_lhs(left))
8716                 return;
8717
8718         type_t *type_left  = skip_typeref(orig_type_left);
8719         type_t *type_right = skip_typeref(orig_type_right);
8720
8721         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8722                 /* TODO: improve error message */
8723                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8724                         errorf(&expression->base.source_position,
8725                                "operation needs integer types");
8726                 }
8727                 return;
8728         }
8729
8730         /* combined instructions are tricky. We can't create an implicit cast on
8731          * the left side, because we need the uncasted form for the store.
8732          * The ast2firm pass has to know that left_type must be right_type
8733          * for the arithmetic operation and create a cast by itself */
8734         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8735         expression->right       = create_implicit_cast(right, arithmetic_type);
8736         expression->base.type   = type_left;
8737 }
8738
8739 static void semantic_shift_assign(binary_expression_t *expression)
8740 {
8741         expression_t *left           = expression->left;
8742
8743         if (!is_valid_assignment_lhs(left))
8744                 return;
8745
8746         if (!semantic_shift(expression))
8747                 return;
8748
8749         expression->base.type = skip_typeref(left->base.type);
8750 }
8751
8752 static void warn_logical_and_within_or(const expression_t *const expr)
8753 {
8754         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8755                 return;
8756         if (expr->base.parenthesized)
8757                 return;
8758         warningf(&expr->base.source_position,
8759                         "suggest parentheses around && within ||");
8760 }
8761
8762 /**
8763  * Check the semantic restrictions of a logical expression.
8764  */
8765 static void semantic_logical_op(binary_expression_t *expression)
8766 {
8767         /* §6.5.13:2  Each of the operands shall have scalar type.
8768          * §6.5.14:2  Each of the operands shall have scalar type. */
8769         semantic_condition(expression->left,   "left operand of logical operator");
8770         semantic_condition(expression->right, "right operand of logical operator");
8771         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8772                         warning.parentheses) {
8773                 warn_logical_and_within_or(expression->left);
8774                 warn_logical_and_within_or(expression->right);
8775         }
8776         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8777 }
8778
8779 /**
8780  * Check the semantic restrictions of a binary assign expression.
8781  */
8782 static void semantic_binexpr_assign(binary_expression_t *expression)
8783 {
8784         expression_t *left           = expression->left;
8785         type_t       *orig_type_left = left->base.type;
8786
8787         if (!is_valid_assignment_lhs(left))
8788                 return;
8789
8790         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8791         report_assign_error(error, orig_type_left, expression->right,
8792                         "assignment", &left->base.source_position);
8793         expression->right = create_implicit_cast(expression->right, orig_type_left);
8794         expression->base.type = orig_type_left;
8795 }
8796
8797 /**
8798  * Determine if the outermost operation (or parts thereof) of the given
8799  * expression has no effect in order to generate a warning about this fact.
8800  * Therefore in some cases this only examines some of the operands of the
8801  * expression (see comments in the function and examples below).
8802  * Examples:
8803  *   f() + 23;    // warning, because + has no effect
8804  *   x || f();    // no warning, because x controls execution of f()
8805  *   x ? y : f(); // warning, because y has no effect
8806  *   (void)x;     // no warning to be able to suppress the warning
8807  * This function can NOT be used for an "expression has definitely no effect"-
8808  * analysis. */
8809 static bool expression_has_effect(const expression_t *const expr)
8810 {
8811         switch (expr->kind) {
8812                 case EXPR_UNKNOWN:                    break;
8813                 case EXPR_INVALID:                    return true; /* do NOT warn */
8814                 case EXPR_REFERENCE:                  return false;
8815                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8816                 /* suppress the warning for microsoft __noop operations */
8817                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
8818                 case EXPR_CHARACTER_CONSTANT:         return false;
8819                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
8820                 case EXPR_STRING_LITERAL:             return false;
8821                 case EXPR_WIDE_STRING_LITERAL:        return false;
8822                 case EXPR_LABEL_ADDRESS:              return false;
8823
8824                 case EXPR_CALL: {
8825                         const call_expression_t *const call = &expr->call;
8826                         if (call->function->kind != EXPR_REFERENCE)
8827                                 return true;
8828
8829                         switch (call->function->reference.entity->function.btk) {
8830                                 /* FIXME: which builtins have no effect? */
8831                                 default:                      return true;
8832                         }
8833                 }
8834
8835                 /* Generate the warning if either the left or right hand side of a
8836                  * conditional expression has no effect */
8837                 case EXPR_CONDITIONAL: {
8838                         conditional_expression_t const *const cond = &expr->conditional;
8839                         expression_t             const *const t    = cond->true_expression;
8840                         return
8841                                 (t == NULL || expression_has_effect(t)) &&
8842                                 expression_has_effect(cond->false_expression);
8843                 }
8844
8845                 case EXPR_SELECT:                     return false;
8846                 case EXPR_ARRAY_ACCESS:               return false;
8847                 case EXPR_SIZEOF:                     return false;
8848                 case EXPR_CLASSIFY_TYPE:              return false;
8849                 case EXPR_ALIGNOF:                    return false;
8850
8851                 case EXPR_FUNCNAME:                   return false;
8852                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8853                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8854                 case EXPR_OFFSETOF:                   return false;
8855                 case EXPR_VA_START:                   return true;
8856                 case EXPR_VA_ARG:                     return true;
8857                 case EXPR_VA_COPY:                    return true;
8858                 case EXPR_STATEMENT:                  return true; // TODO
8859                 case EXPR_COMPOUND_LITERAL:           return false;
8860
8861                 case EXPR_UNARY_NEGATE:               return false;
8862                 case EXPR_UNARY_PLUS:                 return false;
8863                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8864                 case EXPR_UNARY_NOT:                  return false;
8865                 case EXPR_UNARY_DEREFERENCE:          return false;
8866                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8867                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8868                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8869                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8870                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8871
8872                 /* Treat void casts as if they have an effect in order to being able to
8873                  * suppress the warning */
8874                 case EXPR_UNARY_CAST: {
8875                         type_t *const type = skip_typeref(expr->base.type);
8876                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8877                 }
8878
8879                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8880                 case EXPR_UNARY_ASSUME:               return true;
8881                 case EXPR_UNARY_DELETE:               return true;
8882                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8883                 case EXPR_UNARY_THROW:                return true;
8884
8885                 case EXPR_BINARY_ADD:                 return false;
8886                 case EXPR_BINARY_SUB:                 return false;
8887                 case EXPR_BINARY_MUL:                 return false;
8888                 case EXPR_BINARY_DIV:                 return false;
8889                 case EXPR_BINARY_MOD:                 return false;
8890                 case EXPR_BINARY_EQUAL:               return false;
8891                 case EXPR_BINARY_NOTEQUAL:            return false;
8892                 case EXPR_BINARY_LESS:                return false;
8893                 case EXPR_BINARY_LESSEQUAL:           return false;
8894                 case EXPR_BINARY_GREATER:             return false;
8895                 case EXPR_BINARY_GREATEREQUAL:        return false;
8896                 case EXPR_BINARY_BITWISE_AND:         return false;
8897                 case EXPR_BINARY_BITWISE_OR:          return false;
8898                 case EXPR_BINARY_BITWISE_XOR:         return false;
8899                 case EXPR_BINARY_SHIFTLEFT:           return false;
8900                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8901                 case EXPR_BINARY_ASSIGN:              return true;
8902                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8903                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8904                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8905                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8906                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8907                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8908                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8909                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8910                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8911                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8912
8913                 /* Only examine the right hand side of && and ||, because the left hand
8914                  * side already has the effect of controlling the execution of the right
8915                  * hand side */
8916                 case EXPR_BINARY_LOGICAL_AND:
8917                 case EXPR_BINARY_LOGICAL_OR:
8918                 /* Only examine the right hand side of a comma expression, because the left
8919                  * hand side has a separate warning */
8920                 case EXPR_BINARY_COMMA:
8921                         return expression_has_effect(expr->binary.right);
8922
8923                 case EXPR_BINARY_ISGREATER:           return false;
8924                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8925                 case EXPR_BINARY_ISLESS:              return false;
8926                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8927                 case EXPR_BINARY_ISLESSGREATER:       return false;
8928                 case EXPR_BINARY_ISUNORDERED:         return false;
8929         }
8930
8931         internal_errorf(HERE, "unexpected expression");
8932 }
8933
8934 static void semantic_comma(binary_expression_t *expression)
8935 {
8936         if (warning.unused_value) {
8937                 const expression_t *const left = expression->left;
8938                 if (!expression_has_effect(left)) {
8939                         warningf(&left->base.source_position,
8940                                  "left-hand operand of comma expression has no effect");
8941                 }
8942         }
8943         expression->base.type = expression->right->base.type;
8944 }
8945
8946 /**
8947  * @param prec_r precedence of the right operand
8948  */
8949 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8950 static expression_t *parse_##binexpression_type(expression_t *left)          \
8951 {                                                                            \
8952         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8953         binexpr->binary.left  = left;                                            \
8954         eat(token_type);                                                         \
8955                                                                              \
8956         expression_t *right = parse_sub_expression(prec_r);                      \
8957                                                                              \
8958         binexpr->binary.right = right;                                           \
8959         sfunc(&binexpr->binary);                                                 \
8960                                                                              \
8961         return binexpr;                                                          \
8962 }
8963
8964 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8965 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8966 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8967 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8968 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8969 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8970 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8971 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8972 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8973 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8974 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8975 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8976 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8977 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
8978 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
8979 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
8980 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8981 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8982 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8983 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8984 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8985 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8986 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8987 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8988 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8989 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8990 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8991 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8992 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8993 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8994
8995
8996 static expression_t *parse_sub_expression(precedence_t precedence)
8997 {
8998         if (token.type < 0) {
8999                 return expected_expression_error();
9000         }
9001
9002         expression_parser_function_t *parser
9003                 = &expression_parsers[token.type];
9004         source_position_t             source_position = token.source_position;
9005         expression_t                 *left;
9006
9007         if (parser->parser != NULL) {
9008                 left = parser->parser();
9009         } else {
9010                 left = parse_primary_expression();
9011         }
9012         assert(left != NULL);
9013         left->base.source_position = source_position;
9014
9015         while (true) {
9016                 if (token.type < 0) {
9017                         return expected_expression_error();
9018                 }
9019
9020                 parser = &expression_parsers[token.type];
9021                 if (parser->infix_parser == NULL)
9022                         break;
9023                 if (parser->infix_precedence < precedence)
9024                         break;
9025
9026                 left = parser->infix_parser(left);
9027
9028                 assert(left != NULL);
9029                 assert(left->kind != EXPR_UNKNOWN);
9030                 left->base.source_position = source_position;
9031         }
9032
9033         return left;
9034 }
9035
9036 /**
9037  * Parse an expression.
9038  */
9039 static expression_t *parse_expression(void)
9040 {
9041         return parse_sub_expression(PREC_EXPRESSION);
9042 }
9043
9044 /**
9045  * Register a parser for a prefix-like operator.
9046  *
9047  * @param parser      the parser function
9048  * @param token_type  the token type of the prefix token
9049  */
9050 static void register_expression_parser(parse_expression_function parser,
9051                                        int token_type)
9052 {
9053         expression_parser_function_t *entry = &expression_parsers[token_type];
9054
9055         if (entry->parser != NULL) {
9056                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9057                 panic("trying to register multiple expression parsers for a token");
9058         }
9059         entry->parser = parser;
9060 }
9061
9062 /**
9063  * Register a parser for an infix operator with given precedence.
9064  *
9065  * @param parser      the parser function
9066  * @param token_type  the token type of the infix operator
9067  * @param precedence  the precedence of the operator
9068  */
9069 static void register_infix_parser(parse_expression_infix_function parser,
9070                 int token_type, precedence_t precedence)
9071 {
9072         expression_parser_function_t *entry = &expression_parsers[token_type];
9073
9074         if (entry->infix_parser != NULL) {
9075                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9076                 panic("trying to register multiple infix expression parsers for a "
9077                       "token");
9078         }
9079         entry->infix_parser     = parser;
9080         entry->infix_precedence = precedence;
9081 }
9082
9083 /**
9084  * Initialize the expression parsers.
9085  */
9086 static void init_expression_parsers(void)
9087 {
9088         memset(&expression_parsers, 0, sizeof(expression_parsers));
9089
9090         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9091         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9092         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9093         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9094         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9095         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9096         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9097         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9098         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9099         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9100         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9101         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9102         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9103         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9104         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9105         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9106         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9107         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9108         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9109         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9110         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9111         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9112         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9113         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9114         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9115         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9116         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9117         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9118         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9119         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9120         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9121         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9122         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9123         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9124         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9125         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9126         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9127
9128         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9129         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9130         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9131         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9132         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9133         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9134         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9135         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9136         register_expression_parser(parse_sizeof,                      T_sizeof);
9137         register_expression_parser(parse_alignof,                     T___alignof__);
9138         register_expression_parser(parse_extension,                   T___extension__);
9139         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9140         register_expression_parser(parse_delete,                      T_delete);
9141         register_expression_parser(parse_throw,                       T_throw);
9142 }
9143
9144 /**
9145  * Parse a asm statement arguments specification.
9146  */
9147 static asm_argument_t *parse_asm_arguments(bool is_out)
9148 {
9149         asm_argument_t  *result = NULL;
9150         asm_argument_t **anchor = &result;
9151
9152         while (token.type == T_STRING_LITERAL || token.type == '[') {
9153                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9154                 memset(argument, 0, sizeof(argument[0]));
9155
9156                 if (token.type == '[') {
9157                         eat('[');
9158                         if (token.type != T_IDENTIFIER) {
9159                                 parse_error_expected("while parsing asm argument",
9160                                                      T_IDENTIFIER, NULL);
9161                                 return NULL;
9162                         }
9163                         argument->symbol = token.v.symbol;
9164
9165                         expect(']', end_error);
9166                 }
9167
9168                 argument->constraints = parse_string_literals();
9169                 expect('(', end_error);
9170                 add_anchor_token(')');
9171                 expression_t *expression = parse_expression();
9172                 rem_anchor_token(')');
9173                 if (is_out) {
9174                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9175                          * change size or type representation (e.g. int -> long is ok, but
9176                          * int -> float is not) */
9177                         if (expression->kind == EXPR_UNARY_CAST) {
9178                                 type_t      *const type = expression->base.type;
9179                                 type_kind_t  const kind = type->kind;
9180                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9181                                         unsigned flags;
9182                                         unsigned size;
9183                                         if (kind == TYPE_ATOMIC) {
9184                                                 atomic_type_kind_t const akind = type->atomic.akind;
9185                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9186                                                 size  = get_atomic_type_size(akind);
9187                                         } else {
9188                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9189                                                 size  = get_atomic_type_size(get_intptr_kind());
9190                                         }
9191
9192                                         do {
9193                                                 expression_t *const value      = expression->unary.value;
9194                                                 type_t       *const value_type = value->base.type;
9195                                                 type_kind_t   const value_kind = value_type->kind;
9196
9197                                                 unsigned value_flags;
9198                                                 unsigned value_size;
9199                                                 if (value_kind == TYPE_ATOMIC) {
9200                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9201                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9202                                                         value_size  = get_atomic_type_size(value_akind);
9203                                                 } else if (value_kind == TYPE_POINTER) {
9204                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9205                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9206                                                 } else {
9207                                                         break;
9208                                                 }
9209
9210                                                 if (value_flags != flags || value_size != size)
9211                                                         break;
9212
9213                                                 expression = value;
9214                                         } while (expression->kind == EXPR_UNARY_CAST);
9215                                 }
9216                         }
9217
9218                         if (!is_lvalue(expression)) {
9219                                 errorf(&expression->base.source_position,
9220                                        "asm output argument is not an lvalue");
9221                         }
9222
9223                         if (argument->constraints.begin[0] == '+')
9224                                 mark_vars_read(expression, NULL);
9225                 } else {
9226                         mark_vars_read(expression, NULL);
9227                 }
9228                 argument->expression = expression;
9229                 expect(')', end_error);
9230
9231                 set_address_taken(expression, true);
9232
9233                 *anchor = argument;
9234                 anchor  = &argument->next;
9235
9236                 if (token.type != ',')
9237                         break;
9238                 eat(',');
9239         }
9240
9241         return result;
9242 end_error:
9243         return NULL;
9244 }
9245
9246 /**
9247  * Parse a asm statement clobber specification.
9248  */
9249 static asm_clobber_t *parse_asm_clobbers(void)
9250 {
9251         asm_clobber_t *result = NULL;
9252         asm_clobber_t *last   = NULL;
9253
9254         while (token.type == T_STRING_LITERAL) {
9255                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9256                 clobber->clobber       = parse_string_literals();
9257
9258                 if (last != NULL) {
9259                         last->next = clobber;
9260                 } else {
9261                         result = clobber;
9262                 }
9263                 last = clobber;
9264
9265                 if (token.type != ',')
9266                         break;
9267                 eat(',');
9268         }
9269
9270         return result;
9271 }
9272
9273 /**
9274  * Parse an asm statement.
9275  */
9276 static statement_t *parse_asm_statement(void)
9277 {
9278         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9279         asm_statement_t *asm_statement = &statement->asms;
9280
9281         eat(T_asm);
9282
9283         if (token.type == T_volatile) {
9284                 next_token();
9285                 asm_statement->is_volatile = true;
9286         }
9287
9288         expect('(', end_error);
9289         add_anchor_token(')');
9290         add_anchor_token(':');
9291         asm_statement->asm_text = parse_string_literals();
9292
9293         if (token.type != ':') {
9294                 rem_anchor_token(':');
9295                 goto end_of_asm;
9296         }
9297         eat(':');
9298
9299         asm_statement->outputs = parse_asm_arguments(true);
9300         if (token.type != ':') {
9301                 rem_anchor_token(':');
9302                 goto end_of_asm;
9303         }
9304         eat(':');
9305
9306         asm_statement->inputs = parse_asm_arguments(false);
9307         if (token.type != ':') {
9308                 rem_anchor_token(':');
9309                 goto end_of_asm;
9310         }
9311         rem_anchor_token(':');
9312         eat(':');
9313
9314         asm_statement->clobbers = parse_asm_clobbers();
9315
9316 end_of_asm:
9317         rem_anchor_token(')');
9318         expect(')', end_error);
9319         expect(';', end_error);
9320
9321         if (asm_statement->outputs == NULL) {
9322                 /* GCC: An 'asm' instruction without any output operands will be treated
9323                  * identically to a volatile 'asm' instruction. */
9324                 asm_statement->is_volatile = true;
9325         }
9326
9327         return statement;
9328 end_error:
9329         return create_invalid_statement();
9330 }
9331
9332 /**
9333  * Parse a case statement.
9334  */
9335 static statement_t *parse_case_statement(void)
9336 {
9337         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9338         source_position_t *const pos       = &statement->base.source_position;
9339
9340         eat(T_case);
9341
9342         expression_t *const expression   = parse_expression();
9343         statement->case_label.expression = expression;
9344         if (!is_constant_expression(expression)) {
9345                 /* This check does not prevent the error message in all cases of an
9346                  * prior error while parsing the expression.  At least it catches the
9347                  * common case of a mistyped enum entry. */
9348                 if (is_type_valid(skip_typeref(expression->base.type))) {
9349                         errorf(pos, "case label does not reduce to an integer constant");
9350                 }
9351                 statement->case_label.is_bad = true;
9352         } else {
9353                 long const val = fold_constant_to_int(expression);
9354                 statement->case_label.first_case = val;
9355                 statement->case_label.last_case  = val;
9356         }
9357
9358         if (GNU_MODE) {
9359                 if (token.type == T_DOTDOTDOT) {
9360                         next_token();
9361                         expression_t *const end_range   = parse_expression();
9362                         statement->case_label.end_range = end_range;
9363                         if (!is_constant_expression(end_range)) {
9364                                 /* This check does not prevent the error message in all cases of an
9365                                  * prior error while parsing the expression.  At least it catches the
9366                                  * common case of a mistyped enum entry. */
9367                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9368                                         errorf(pos, "case range does not reduce to an integer constant");
9369                                 }
9370                                 statement->case_label.is_bad = true;
9371                         } else {
9372                                 long const val = fold_constant_to_int(end_range);
9373                                 statement->case_label.last_case = val;
9374
9375                                 if (warning.other && val < statement->case_label.first_case) {
9376                                         statement->case_label.is_empty_range = true;
9377                                         warningf(pos, "empty range specified");
9378                                 }
9379                         }
9380                 }
9381         }
9382
9383         PUSH_PARENT(statement);
9384
9385         expect(':', end_error);
9386 end_error:
9387
9388         if (current_switch != NULL) {
9389                 if (! statement->case_label.is_bad) {
9390                         /* Check for duplicate case values */
9391                         case_label_statement_t *c = &statement->case_label;
9392                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9393                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9394                                         continue;
9395
9396                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9397                                         continue;
9398
9399                                 errorf(pos, "duplicate case value (previously used %P)",
9400                                        &l->base.source_position);
9401                                 break;
9402                         }
9403                 }
9404                 /* link all cases into the switch statement */
9405                 if (current_switch->last_case == NULL) {
9406                         current_switch->first_case      = &statement->case_label;
9407                 } else {
9408                         current_switch->last_case->next = &statement->case_label;
9409                 }
9410                 current_switch->last_case = &statement->case_label;
9411         } else {
9412                 errorf(pos, "case label not within a switch statement");
9413         }
9414
9415         statement_t *const inner_stmt = parse_statement();
9416         statement->case_label.statement = inner_stmt;
9417         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9418                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9419         }
9420
9421         POP_PARENT;
9422         return statement;
9423 }
9424
9425 /**
9426  * Parse a default statement.
9427  */
9428 static statement_t *parse_default_statement(void)
9429 {
9430         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9431
9432         eat(T_default);
9433
9434         PUSH_PARENT(statement);
9435
9436         expect(':', end_error);
9437         if (current_switch != NULL) {
9438                 const case_label_statement_t *def_label = current_switch->default_label;
9439                 if (def_label != NULL) {
9440                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9441                                &def_label->base.source_position);
9442                 } else {
9443                         current_switch->default_label = &statement->case_label;
9444
9445                         /* link all cases into the switch statement */
9446                         if (current_switch->last_case == NULL) {
9447                                 current_switch->first_case      = &statement->case_label;
9448                         } else {
9449                                 current_switch->last_case->next = &statement->case_label;
9450                         }
9451                         current_switch->last_case = &statement->case_label;
9452                 }
9453         } else {
9454                 errorf(&statement->base.source_position,
9455                         "'default' label not within a switch statement");
9456         }
9457
9458         statement_t *const inner_stmt = parse_statement();
9459         statement->case_label.statement = inner_stmt;
9460         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9461                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9462         }
9463
9464         POP_PARENT;
9465         return statement;
9466 end_error:
9467         POP_PARENT;
9468         return create_invalid_statement();
9469 }
9470
9471 /**
9472  * Parse a label statement.
9473  */
9474 static statement_t *parse_label_statement(void)
9475 {
9476         assert(token.type == T_IDENTIFIER);
9477         symbol_t *symbol = token.v.symbol;
9478         label_t  *label  = get_label(symbol);
9479
9480         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9481         statement->label.label       = label;
9482
9483         next_token();
9484
9485         PUSH_PARENT(statement);
9486
9487         /* if statement is already set then the label is defined twice,
9488          * otherwise it was just mentioned in a goto/local label declaration so far
9489          */
9490         if (label->statement != NULL) {
9491                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9492                        symbol, &label->base.source_position);
9493         } else {
9494                 label->base.source_position = token.source_position;
9495                 label->statement            = statement;
9496         }
9497
9498         eat(':');
9499
9500         if (token.type == '}') {
9501                 /* TODO only warn? */
9502                 if (warning.other && false) {
9503                         warningf(HERE, "label at end of compound statement");
9504                         statement->label.statement = create_empty_statement();
9505                 } else {
9506                         errorf(HERE, "label at end of compound statement");
9507                         statement->label.statement = create_invalid_statement();
9508                 }
9509         } else if (token.type == ';') {
9510                 /* Eat an empty statement here, to avoid the warning about an empty
9511                  * statement after a label.  label:; is commonly used to have a label
9512                  * before a closing brace. */
9513                 statement->label.statement = create_empty_statement();
9514                 next_token();
9515         } else {
9516                 statement_t *const inner_stmt = parse_statement();
9517                 statement->label.statement = inner_stmt;
9518                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9519                         errorf(&inner_stmt->base.source_position, "declaration after label");
9520                 }
9521         }
9522
9523         /* remember the labels in a list for later checking */
9524         *label_anchor = &statement->label;
9525         label_anchor  = &statement->label.next;
9526
9527         POP_PARENT;
9528         return statement;
9529 }
9530
9531 /**
9532  * Parse an if statement.
9533  */
9534 static statement_t *parse_if(void)
9535 {
9536         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9537
9538         eat(T_if);
9539
9540         PUSH_PARENT(statement);
9541
9542         add_anchor_token('{');
9543
9544         expect('(', end_error);
9545         add_anchor_token(')');
9546         expression_t *const expr = parse_expression();
9547         statement->ifs.condition = expr;
9548         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9549          *             scalar type. */
9550         semantic_condition(expr, "condition of 'if'-statment");
9551         mark_vars_read(expr, NULL);
9552         rem_anchor_token(')');
9553         expect(')', end_error);
9554
9555 end_error:
9556         rem_anchor_token('{');
9557
9558         add_anchor_token(T_else);
9559         statement_t *const true_stmt = parse_statement();
9560         statement->ifs.true_statement = true_stmt;
9561         rem_anchor_token(T_else);
9562
9563         if (token.type == T_else) {
9564                 next_token();
9565                 statement->ifs.false_statement = parse_statement();
9566         } else if (warning.parentheses &&
9567                         true_stmt->kind == STATEMENT_IF &&
9568                         true_stmt->ifs.false_statement != NULL) {
9569                 warningf(&true_stmt->base.source_position,
9570                                 "suggest explicit braces to avoid ambiguous 'else'");
9571         }
9572
9573         POP_PARENT;
9574         return statement;
9575 }
9576
9577 /**
9578  * Check that all enums are handled in a switch.
9579  *
9580  * @param statement  the switch statement to check
9581  */
9582 static void check_enum_cases(const switch_statement_t *statement)
9583 {
9584         const type_t *type = skip_typeref(statement->expression->base.type);
9585         if (! is_type_enum(type))
9586                 return;
9587         const enum_type_t *enumt = &type->enumt;
9588
9589         /* if we have a default, no warnings */
9590         if (statement->default_label != NULL)
9591                 return;
9592
9593         /* FIXME: calculation of value should be done while parsing */
9594         /* TODO: quadratic algorithm here. Change to an n log n one */
9595         long            last_value = -1;
9596         const entity_t *entry      = enumt->enume->base.next;
9597         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9598              entry = entry->base.next) {
9599                 const expression_t *expression = entry->enum_value.value;
9600                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9601                 bool                found      = false;
9602                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9603                         if (l->expression == NULL)
9604                                 continue;
9605                         if (l->first_case <= value && value <= l->last_case) {
9606                                 found = true;
9607                                 break;
9608                         }
9609                 }
9610                 if (! found) {
9611                         warningf(&statement->base.source_position,
9612                                  "enumeration value '%Y' not handled in switch",
9613                                  entry->base.symbol);
9614                 }
9615                 last_value = value;
9616         }
9617 }
9618
9619 /**
9620  * Parse a switch statement.
9621  */
9622 static statement_t *parse_switch(void)
9623 {
9624         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9625
9626         eat(T_switch);
9627
9628         PUSH_PARENT(statement);
9629
9630         expect('(', end_error);
9631         add_anchor_token(')');
9632         expression_t *const expr = parse_expression();
9633         mark_vars_read(expr, NULL);
9634         type_t       *      type = skip_typeref(expr->base.type);
9635         if (is_type_integer(type)) {
9636                 type = promote_integer(type);
9637                 if (warning.traditional) {
9638                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9639                                 warningf(&expr->base.source_position,
9640                                         "'%T' switch expression not converted to '%T' in ISO C",
9641                                         type, type_int);
9642                         }
9643                 }
9644         } else if (is_type_valid(type)) {
9645                 errorf(&expr->base.source_position,
9646                        "switch quantity is not an integer, but '%T'", type);
9647                 type = type_error_type;
9648         }
9649         statement->switchs.expression = create_implicit_cast(expr, type);
9650         expect(')', end_error);
9651         rem_anchor_token(')');
9652
9653         switch_statement_t *rem = current_switch;
9654         current_switch          = &statement->switchs;
9655         statement->switchs.body = parse_statement();
9656         current_switch          = rem;
9657
9658         if (warning.switch_default &&
9659             statement->switchs.default_label == NULL) {
9660                 warningf(&statement->base.source_position, "switch has no default case");
9661         }
9662         if (warning.switch_enum)
9663                 check_enum_cases(&statement->switchs);
9664
9665         POP_PARENT;
9666         return statement;
9667 end_error:
9668         POP_PARENT;
9669         return create_invalid_statement();
9670 }
9671
9672 static statement_t *parse_loop_body(statement_t *const loop)
9673 {
9674         statement_t *const rem = current_loop;
9675         current_loop = loop;
9676
9677         statement_t *const body = parse_statement();
9678
9679         current_loop = rem;
9680         return body;
9681 }
9682
9683 /**
9684  * Parse a while statement.
9685  */
9686 static statement_t *parse_while(void)
9687 {
9688         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9689
9690         eat(T_while);
9691
9692         PUSH_PARENT(statement);
9693
9694         expect('(', end_error);
9695         add_anchor_token(')');
9696         expression_t *const cond = parse_expression();
9697         statement->whiles.condition = cond;
9698         /* §6.8.5:2    The controlling expression of an iteration statement shall
9699          *             have scalar type. */
9700         semantic_condition(cond, "condition of 'while'-statement");
9701         mark_vars_read(cond, NULL);
9702         rem_anchor_token(')');
9703         expect(')', end_error);
9704
9705         statement->whiles.body = parse_loop_body(statement);
9706
9707         POP_PARENT;
9708         return statement;
9709 end_error:
9710         POP_PARENT;
9711         return create_invalid_statement();
9712 }
9713
9714 /**
9715  * Parse a do statement.
9716  */
9717 static statement_t *parse_do(void)
9718 {
9719         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9720
9721         eat(T_do);
9722
9723         PUSH_PARENT(statement);
9724
9725         add_anchor_token(T_while);
9726         statement->do_while.body = parse_loop_body(statement);
9727         rem_anchor_token(T_while);
9728
9729         expect(T_while, end_error);
9730         expect('(', end_error);
9731         add_anchor_token(')');
9732         expression_t *const cond = parse_expression();
9733         statement->do_while.condition = cond;
9734         /* §6.8.5:2    The controlling expression of an iteration statement shall
9735          *             have scalar type. */
9736         semantic_condition(cond, "condition of 'do-while'-statement");
9737         mark_vars_read(cond, NULL);
9738         rem_anchor_token(')');
9739         expect(')', end_error);
9740         expect(';', end_error);
9741
9742         POP_PARENT;
9743         return statement;
9744 end_error:
9745         POP_PARENT;
9746         return create_invalid_statement();
9747 }
9748
9749 /**
9750  * Parse a for statement.
9751  */
9752 static statement_t *parse_for(void)
9753 {
9754         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9755
9756         eat(T_for);
9757
9758         expect('(', end_error1);
9759         add_anchor_token(')');
9760
9761         PUSH_PARENT(statement);
9762
9763         size_t const  top       = environment_top();
9764         scope_t      *old_scope = scope_push(&statement->fors.scope);
9765
9766         bool old_gcc_extension = in_gcc_extension;
9767         while (token.type == T___extension__) {
9768                 next_token();
9769                 in_gcc_extension = true;
9770         }
9771
9772         if (token.type == ';') {
9773                 next_token();
9774         } else if (is_declaration_specifier(&token, false)) {
9775                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9776         } else {
9777                 add_anchor_token(';');
9778                 expression_t *const init = parse_expression();
9779                 statement->fors.initialisation = init;
9780                 mark_vars_read(init, ENT_ANY);
9781                 if (warning.unused_value && !expression_has_effect(init)) {
9782                         warningf(&init->base.source_position,
9783                                         "initialisation of 'for'-statement has no effect");
9784                 }
9785                 rem_anchor_token(';');
9786                 expect(';', end_error2);
9787         }
9788         in_gcc_extension = old_gcc_extension;
9789
9790         if (token.type != ';') {
9791                 add_anchor_token(';');
9792                 expression_t *const cond = parse_expression();
9793                 statement->fors.condition = cond;
9794                 /* §6.8.5:2    The controlling expression of an iteration statement
9795                  *             shall have scalar type. */
9796                 semantic_condition(cond, "condition of 'for'-statement");
9797                 mark_vars_read(cond, NULL);
9798                 rem_anchor_token(';');
9799         }
9800         expect(';', end_error2);
9801         if (token.type != ')') {
9802                 expression_t *const step = parse_expression();
9803                 statement->fors.step = step;
9804                 mark_vars_read(step, ENT_ANY);
9805                 if (warning.unused_value && !expression_has_effect(step)) {
9806                         warningf(&step->base.source_position,
9807                                  "step of 'for'-statement has no effect");
9808                 }
9809         }
9810         expect(')', end_error2);
9811         rem_anchor_token(')');
9812         statement->fors.body = parse_loop_body(statement);
9813
9814         assert(current_scope == &statement->fors.scope);
9815         scope_pop(old_scope);
9816         environment_pop_to(top);
9817
9818         POP_PARENT;
9819         return statement;
9820
9821 end_error2:
9822         POP_PARENT;
9823         rem_anchor_token(')');
9824         assert(current_scope == &statement->fors.scope);
9825         scope_pop(old_scope);
9826         environment_pop_to(top);
9827         /* fallthrough */
9828
9829 end_error1:
9830         return create_invalid_statement();
9831 }
9832
9833 /**
9834  * Parse a goto statement.
9835  */
9836 static statement_t *parse_goto(void)
9837 {
9838         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9839         eat(T_goto);
9840
9841         if (GNU_MODE && token.type == '*') {
9842                 next_token();
9843                 expression_t *expression = parse_expression();
9844                 mark_vars_read(expression, NULL);
9845
9846                 /* Argh: although documentation says the expression must be of type void*,
9847                  * gcc accepts anything that can be casted into void* without error */
9848                 type_t *type = expression->base.type;
9849
9850                 if (type != type_error_type) {
9851                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9852                                 errorf(&expression->base.source_position,
9853                                         "cannot convert to a pointer type");
9854                         } else if (warning.other && type != type_void_ptr) {
9855                                 warningf(&expression->base.source_position,
9856                                         "type of computed goto expression should be 'void*' not '%T'", type);
9857                         }
9858                         expression = create_implicit_cast(expression, type_void_ptr);
9859                 }
9860
9861                 statement->gotos.expression = expression;
9862         } else if (token.type == T_IDENTIFIER) {
9863                 symbol_t *symbol = token.v.symbol;
9864                 next_token();
9865                 statement->gotos.label = get_label(symbol);
9866         } else {
9867                 if (GNU_MODE)
9868                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9869                 else
9870                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9871                 eat_until_anchor();
9872                 goto end_error;
9873         }
9874
9875         /* remember the goto's in a list for later checking */
9876         *goto_anchor = &statement->gotos;
9877         goto_anchor  = &statement->gotos.next;
9878
9879         expect(';', end_error);
9880
9881         return statement;
9882 end_error:
9883         return create_invalid_statement();
9884 }
9885
9886 /**
9887  * Parse a continue statement.
9888  */
9889 static statement_t *parse_continue(void)
9890 {
9891         if (current_loop == NULL) {
9892                 errorf(HERE, "continue statement not within loop");
9893         }
9894
9895         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9896
9897         eat(T_continue);
9898         expect(';', end_error);
9899
9900 end_error:
9901         return statement;
9902 }
9903
9904 /**
9905  * Parse a break statement.
9906  */
9907 static statement_t *parse_break(void)
9908 {
9909         if (current_switch == NULL && current_loop == NULL) {
9910                 errorf(HERE, "break statement not within loop or switch");
9911         }
9912
9913         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9914
9915         eat(T_break);
9916         expect(';', end_error);
9917
9918 end_error:
9919         return statement;
9920 }
9921
9922 /**
9923  * Parse a __leave statement.
9924  */
9925 static statement_t *parse_leave_statement(void)
9926 {
9927         if (current_try == NULL) {
9928                 errorf(HERE, "__leave statement not within __try");
9929         }
9930
9931         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9932
9933         eat(T___leave);
9934         expect(';', end_error);
9935
9936 end_error:
9937         return statement;
9938 }
9939
9940 /**
9941  * Check if a given entity represents a local variable.
9942  */
9943 static bool is_local_variable(const entity_t *entity)
9944 {
9945         if (entity->kind != ENTITY_VARIABLE)
9946                 return false;
9947
9948         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9949         case STORAGE_CLASS_AUTO:
9950         case STORAGE_CLASS_REGISTER: {
9951                 const type_t *type = skip_typeref(entity->declaration.type);
9952                 if (is_type_function(type)) {
9953                         return false;
9954                 } else {
9955                         return true;
9956                 }
9957         }
9958         default:
9959                 return false;
9960         }
9961 }
9962
9963 /**
9964  * Check if a given expression represents a local variable.
9965  */
9966 static bool expression_is_local_variable(const expression_t *expression)
9967 {
9968         if (expression->base.kind != EXPR_REFERENCE) {
9969                 return false;
9970         }
9971         const entity_t *entity = expression->reference.entity;
9972         return is_local_variable(entity);
9973 }
9974
9975 /**
9976  * Check if a given expression represents a local variable and
9977  * return its declaration then, else return NULL.
9978  */
9979 entity_t *expression_is_variable(const expression_t *expression)
9980 {
9981         if (expression->base.kind != EXPR_REFERENCE) {
9982                 return NULL;
9983         }
9984         entity_t *entity = expression->reference.entity;
9985         if (entity->kind != ENTITY_VARIABLE)
9986                 return NULL;
9987
9988         return entity;
9989 }
9990
9991 /**
9992  * Parse a return statement.
9993  */
9994 static statement_t *parse_return(void)
9995 {
9996         eat(T_return);
9997
9998         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9999
10000         expression_t *return_value = NULL;
10001         if (token.type != ';') {
10002                 return_value = parse_expression();
10003                 mark_vars_read(return_value, NULL);
10004         }
10005
10006         const type_t *const func_type = skip_typeref(current_function->base.type);
10007         assert(is_type_function(func_type));
10008         type_t *const return_type = skip_typeref(func_type->function.return_type);
10009
10010         source_position_t const *const pos = &statement->base.source_position;
10011         if (return_value != NULL) {
10012                 type_t *return_value_type = skip_typeref(return_value->base.type);
10013
10014                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10015                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10016                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10017                                 /* Only warn in C mode, because GCC does the same */
10018                                 if (c_mode & _CXX || strict_mode) {
10019                                         errorf(pos,
10020                                                         "'return' with a value, in function returning 'void'");
10021                                 } else if (warning.other) {
10022                                         warningf(pos,
10023                                                         "'return' with a value, in function returning 'void'");
10024                                 }
10025                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10026                                 /* Only warn in C mode, because GCC does the same */
10027                                 if (strict_mode) {
10028                                         errorf(pos,
10029                                                         "'return' with expression in function returning 'void'");
10030                                 } else if (warning.other) {
10031                                         warningf(pos,
10032                                                         "'return' with expression in function returning 'void'");
10033                                 }
10034                         }
10035                 } else {
10036                         assign_error_t error = semantic_assign(return_type, return_value);
10037                         report_assign_error(error, return_type, return_value, "'return'",
10038                                         pos);
10039                 }
10040                 return_value = create_implicit_cast(return_value, return_type);
10041                 /* check for returning address of a local var */
10042                 if (warning.other && return_value != NULL
10043                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10044                         const expression_t *expression = return_value->unary.value;
10045                         if (expression_is_local_variable(expression)) {
10046                                 warningf(pos, "function returns address of local variable");
10047                         }
10048                 }
10049         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10050                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10051                 if (c_mode & _CXX || strict_mode) {
10052                         errorf(pos,
10053                                         "'return' without value, in function returning non-void");
10054                 } else {
10055                         warningf(pos,
10056                                         "'return' without value, in function returning non-void");
10057                 }
10058         }
10059         statement->returns.value = return_value;
10060
10061         expect(';', end_error);
10062
10063 end_error:
10064         return statement;
10065 }
10066
10067 /**
10068  * Parse a declaration statement.
10069  */
10070 static statement_t *parse_declaration_statement(void)
10071 {
10072         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10073
10074         entity_t *before = current_scope->last_entity;
10075         if (GNU_MODE) {
10076                 parse_external_declaration();
10077         } else {
10078                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10079         }
10080
10081         declaration_statement_t *const decl  = &statement->declaration;
10082         entity_t                *const begin =
10083                 before != NULL ? before->base.next : current_scope->entities;
10084         decl->declarations_begin = begin;
10085         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10086
10087         return statement;
10088 }
10089
10090 /**
10091  * Parse an expression statement, ie. expr ';'.
10092  */
10093 static statement_t *parse_expression_statement(void)
10094 {
10095         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10096
10097         expression_t *const expr         = parse_expression();
10098         statement->expression.expression = expr;
10099         mark_vars_read(expr, ENT_ANY);
10100
10101         expect(';', end_error);
10102
10103 end_error:
10104         return statement;
10105 }
10106
10107 /**
10108  * Parse a microsoft __try { } __finally { } or
10109  * __try{ } __except() { }
10110  */
10111 static statement_t *parse_ms_try_statment(void)
10112 {
10113         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10114         eat(T___try);
10115
10116         PUSH_PARENT(statement);
10117
10118         ms_try_statement_t *rem = current_try;
10119         current_try = &statement->ms_try;
10120         statement->ms_try.try_statement = parse_compound_statement(false);
10121         current_try = rem;
10122
10123         POP_PARENT;
10124
10125         if (token.type == T___except) {
10126                 eat(T___except);
10127                 expect('(', end_error);
10128                 add_anchor_token(')');
10129                 expression_t *const expr = parse_expression();
10130                 mark_vars_read(expr, NULL);
10131                 type_t       *      type = skip_typeref(expr->base.type);
10132                 if (is_type_integer(type)) {
10133                         type = promote_integer(type);
10134                 } else if (is_type_valid(type)) {
10135                         errorf(&expr->base.source_position,
10136                                "__expect expression is not an integer, but '%T'", type);
10137                         type = type_error_type;
10138                 }
10139                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10140                 rem_anchor_token(')');
10141                 expect(')', end_error);
10142                 statement->ms_try.final_statement = parse_compound_statement(false);
10143         } else if (token.type == T__finally) {
10144                 eat(T___finally);
10145                 statement->ms_try.final_statement = parse_compound_statement(false);
10146         } else {
10147                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10148                 return create_invalid_statement();
10149         }
10150         return statement;
10151 end_error:
10152         return create_invalid_statement();
10153 }
10154
10155 static statement_t *parse_empty_statement(void)
10156 {
10157         if (warning.empty_statement) {
10158                 warningf(HERE, "statement is empty");
10159         }
10160         statement_t *const statement = create_empty_statement();
10161         eat(';');
10162         return statement;
10163 }
10164
10165 static statement_t *parse_local_label_declaration(void)
10166 {
10167         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10168
10169         eat(T___label__);
10170
10171         entity_t *begin = NULL, *end = NULL;
10172
10173         while (true) {
10174                 if (token.type != T_IDENTIFIER) {
10175                         parse_error_expected("while parsing local label declaration",
10176                                 T_IDENTIFIER, NULL);
10177                         goto end_error;
10178                 }
10179                 symbol_t *symbol = token.v.symbol;
10180                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10181                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10182                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10183                                symbol, &entity->base.source_position);
10184                 } else {
10185                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10186
10187                         entity->base.parent_scope    = current_scope;
10188                         entity->base.namespc         = NAMESPACE_LABEL;
10189                         entity->base.source_position = token.source_position;
10190                         entity->base.symbol          = symbol;
10191
10192                         if (end != NULL)
10193                                 end->base.next = entity;
10194                         end = entity;
10195                         if (begin == NULL)
10196                                 begin = entity;
10197
10198                         environment_push(entity);
10199                 }
10200                 next_token();
10201
10202                 if (token.type != ',')
10203                         break;
10204                 next_token();
10205         }
10206         eat(';');
10207 end_error:
10208         statement->declaration.declarations_begin = begin;
10209         statement->declaration.declarations_end   = end;
10210         return statement;
10211 }
10212
10213 static void parse_namespace_definition(void)
10214 {
10215         eat(T_namespace);
10216
10217         entity_t *entity = NULL;
10218         symbol_t *symbol = NULL;
10219
10220         if (token.type == T_IDENTIFIER) {
10221                 symbol = token.v.symbol;
10222                 next_token();
10223
10224                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10225                 if (entity       != NULL             &&
10226                                 entity->kind != ENTITY_NAMESPACE &&
10227                                 entity->base.parent_scope == current_scope) {
10228                         if (!is_error_entity(entity)) {
10229                                 error_redefined_as_different_kind(&token.source_position,
10230                                                 entity, ENTITY_NAMESPACE);
10231                         }
10232                         entity = NULL;
10233                 }
10234         }
10235
10236         if (entity == NULL) {
10237                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10238                 entity->base.symbol          = symbol;
10239                 entity->base.source_position = token.source_position;
10240                 entity->base.namespc         = NAMESPACE_NORMAL;
10241                 entity->base.parent_scope    = current_scope;
10242         }
10243
10244         if (token.type == '=') {
10245                 /* TODO: parse namespace alias */
10246                 panic("namespace alias definition not supported yet");
10247         }
10248
10249         environment_push(entity);
10250         append_entity(current_scope, entity);
10251
10252         size_t const  top       = environment_top();
10253         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10254
10255         expect('{', end_error);
10256         parse_externals();
10257         expect('}', end_error);
10258
10259 end_error:
10260         assert(current_scope == &entity->namespacee.members);
10261         scope_pop(old_scope);
10262         environment_pop_to(top);
10263 }
10264
10265 /**
10266  * Parse a statement.
10267  * There's also parse_statement() which additionally checks for
10268  * "statement has no effect" warnings
10269  */
10270 static statement_t *intern_parse_statement(void)
10271 {
10272         statement_t *statement = NULL;
10273
10274         /* declaration or statement */
10275         add_anchor_token(';');
10276         switch (token.type) {
10277         case T_IDENTIFIER: {
10278                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10279                 if (la1_type == ':') {
10280                         statement = parse_label_statement();
10281                 } else if (is_typedef_symbol(token.v.symbol)) {
10282                         statement = parse_declaration_statement();
10283                 } else {
10284                         /* it's an identifier, the grammar says this must be an
10285                          * expression statement. However it is common that users mistype
10286                          * declaration types, so we guess a bit here to improve robustness
10287                          * for incorrect programs */
10288                         switch (la1_type) {
10289                         case '&':
10290                         case '*':
10291                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10292                                         goto expression_statment;
10293                                 /* FALLTHROUGH */
10294
10295                         DECLARATION_START
10296                         case T_IDENTIFIER:
10297                                 statement = parse_declaration_statement();
10298                                 break;
10299
10300                         default:
10301 expression_statment:
10302                                 statement = parse_expression_statement();
10303                                 break;
10304                         }
10305                 }
10306                 break;
10307         }
10308
10309         case T___extension__:
10310                 /* This can be a prefix to a declaration or an expression statement.
10311                  * We simply eat it now and parse the rest with tail recursion. */
10312                 do {
10313                         next_token();
10314                 } while (token.type == T___extension__);
10315                 bool old_gcc_extension = in_gcc_extension;
10316                 in_gcc_extension       = true;
10317                 statement = intern_parse_statement();
10318                 in_gcc_extension = old_gcc_extension;
10319                 break;
10320
10321         DECLARATION_START
10322                 statement = parse_declaration_statement();
10323                 break;
10324
10325         case T___label__:
10326                 statement = parse_local_label_declaration();
10327                 break;
10328
10329         case ';':         statement = parse_empty_statement();         break;
10330         case '{':         statement = parse_compound_statement(false); break;
10331         case T___leave:   statement = parse_leave_statement();         break;
10332         case T___try:     statement = parse_ms_try_statment();         break;
10333         case T_asm:       statement = parse_asm_statement();           break;
10334         case T_break:     statement = parse_break();                   break;
10335         case T_case:      statement = parse_case_statement();          break;
10336         case T_continue:  statement = parse_continue();                break;
10337         case T_default:   statement = parse_default_statement();       break;
10338         case T_do:        statement = parse_do();                      break;
10339         case T_for:       statement = parse_for();                     break;
10340         case T_goto:      statement = parse_goto();                    break;
10341         case T_if:        statement = parse_if();                      break;
10342         case T_return:    statement = parse_return();                  break;
10343         case T_switch:    statement = parse_switch();                  break;
10344         case T_while:     statement = parse_while();                   break;
10345
10346         EXPRESSION_START
10347                 statement = parse_expression_statement();
10348                 break;
10349
10350         default:
10351                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10352                 statement = create_invalid_statement();
10353                 if (!at_anchor())
10354                         next_token();
10355                 break;
10356         }
10357         rem_anchor_token(';');
10358
10359         assert(statement != NULL
10360                         && statement->base.source_position.input_name != NULL);
10361
10362         return statement;
10363 }
10364
10365 /**
10366  * parse a statement and emits "statement has no effect" warning if needed
10367  * (This is really a wrapper around intern_parse_statement with check for 1
10368  *  single warning. It is needed, because for statement expressions we have
10369  *  to avoid the warning on the last statement)
10370  */
10371 static statement_t *parse_statement(void)
10372 {
10373         statement_t *statement = intern_parse_statement();
10374
10375         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10376                 expression_t *expression = statement->expression.expression;
10377                 if (!expression_has_effect(expression)) {
10378                         warningf(&expression->base.source_position,
10379                                         "statement has no effect");
10380                 }
10381         }
10382
10383         return statement;
10384 }
10385
10386 /**
10387  * Parse a compound statement.
10388  */
10389 static statement_t *parse_compound_statement(bool inside_expression_statement)
10390 {
10391         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10392
10393         PUSH_PARENT(statement);
10394
10395         eat('{');
10396         add_anchor_token('}');
10397         /* tokens, which can start a statement */
10398         /* TODO MS, __builtin_FOO */
10399         add_anchor_token('!');
10400         add_anchor_token('&');
10401         add_anchor_token('(');
10402         add_anchor_token('*');
10403         add_anchor_token('+');
10404         add_anchor_token('-');
10405         add_anchor_token('{');
10406         add_anchor_token('~');
10407         add_anchor_token(T_CHARACTER_CONSTANT);
10408         add_anchor_token(T_COLONCOLON);
10409         add_anchor_token(T_FLOATINGPOINT);
10410         add_anchor_token(T_IDENTIFIER);
10411         add_anchor_token(T_INTEGER);
10412         add_anchor_token(T_MINUSMINUS);
10413         add_anchor_token(T_PLUSPLUS);
10414         add_anchor_token(T_STRING_LITERAL);
10415         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10416         add_anchor_token(T_WIDE_STRING_LITERAL);
10417         add_anchor_token(T__Bool);
10418         add_anchor_token(T__Complex);
10419         add_anchor_token(T__Imaginary);
10420         add_anchor_token(T___FUNCTION__);
10421         add_anchor_token(T___PRETTY_FUNCTION__);
10422         add_anchor_token(T___alignof__);
10423         add_anchor_token(T___attribute__);
10424         add_anchor_token(T___builtin_va_start);
10425         add_anchor_token(T___extension__);
10426         add_anchor_token(T___func__);
10427         add_anchor_token(T___imag__);
10428         add_anchor_token(T___label__);
10429         add_anchor_token(T___real__);
10430         add_anchor_token(T___thread);
10431         add_anchor_token(T_asm);
10432         add_anchor_token(T_auto);
10433         add_anchor_token(T_bool);
10434         add_anchor_token(T_break);
10435         add_anchor_token(T_case);
10436         add_anchor_token(T_char);
10437         add_anchor_token(T_class);
10438         add_anchor_token(T_const);
10439         add_anchor_token(T_const_cast);
10440         add_anchor_token(T_continue);
10441         add_anchor_token(T_default);
10442         add_anchor_token(T_delete);
10443         add_anchor_token(T_double);
10444         add_anchor_token(T_do);
10445         add_anchor_token(T_dynamic_cast);
10446         add_anchor_token(T_enum);
10447         add_anchor_token(T_extern);
10448         add_anchor_token(T_false);
10449         add_anchor_token(T_float);
10450         add_anchor_token(T_for);
10451         add_anchor_token(T_goto);
10452         add_anchor_token(T_if);
10453         add_anchor_token(T_inline);
10454         add_anchor_token(T_int);
10455         add_anchor_token(T_long);
10456         add_anchor_token(T_new);
10457         add_anchor_token(T_operator);
10458         add_anchor_token(T_register);
10459         add_anchor_token(T_reinterpret_cast);
10460         add_anchor_token(T_restrict);
10461         add_anchor_token(T_return);
10462         add_anchor_token(T_short);
10463         add_anchor_token(T_signed);
10464         add_anchor_token(T_sizeof);
10465         add_anchor_token(T_static);
10466         add_anchor_token(T_static_cast);
10467         add_anchor_token(T_struct);
10468         add_anchor_token(T_switch);
10469         add_anchor_token(T_template);
10470         add_anchor_token(T_this);
10471         add_anchor_token(T_throw);
10472         add_anchor_token(T_true);
10473         add_anchor_token(T_try);
10474         add_anchor_token(T_typedef);
10475         add_anchor_token(T_typeid);
10476         add_anchor_token(T_typename);
10477         add_anchor_token(T_typeof);
10478         add_anchor_token(T_union);
10479         add_anchor_token(T_unsigned);
10480         add_anchor_token(T_using);
10481         add_anchor_token(T_void);
10482         add_anchor_token(T_volatile);
10483         add_anchor_token(T_wchar_t);
10484         add_anchor_token(T_while);
10485
10486         size_t const  top       = environment_top();
10487         scope_t      *old_scope = scope_push(&statement->compound.scope);
10488
10489         statement_t **anchor            = &statement->compound.statements;
10490         bool          only_decls_so_far = true;
10491         while (token.type != '}') {
10492                 if (token.type == T_EOF) {
10493                         errorf(&statement->base.source_position,
10494                                "EOF while parsing compound statement");
10495                         break;
10496                 }
10497                 statement_t *sub_statement = intern_parse_statement();
10498                 if (is_invalid_statement(sub_statement)) {
10499                         /* an error occurred. if we are at an anchor, return */
10500                         if (at_anchor())
10501                                 goto end_error;
10502                         continue;
10503                 }
10504
10505                 if (warning.declaration_after_statement) {
10506                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10507                                 only_decls_so_far = false;
10508                         } else if (!only_decls_so_far) {
10509                                 warningf(&sub_statement->base.source_position,
10510                                          "ISO C90 forbids mixed declarations and code");
10511                         }
10512                 }
10513
10514                 *anchor = sub_statement;
10515
10516                 while (sub_statement->base.next != NULL)
10517                         sub_statement = sub_statement->base.next;
10518
10519                 anchor = &sub_statement->base.next;
10520         }
10521         next_token();
10522
10523         /* look over all statements again to produce no effect warnings */
10524         if (warning.unused_value) {
10525                 statement_t *sub_statement = statement->compound.statements;
10526                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10527                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10528                                 continue;
10529                         /* don't emit a warning for the last expression in an expression
10530                          * statement as it has always an effect */
10531                         if (inside_expression_statement && sub_statement->base.next == NULL)
10532                                 continue;
10533
10534                         expression_t *expression = sub_statement->expression.expression;
10535                         if (!expression_has_effect(expression)) {
10536                                 warningf(&expression->base.source_position,
10537                                          "statement has no effect");
10538                         }
10539                 }
10540         }
10541
10542 end_error:
10543         rem_anchor_token(T_while);
10544         rem_anchor_token(T_wchar_t);
10545         rem_anchor_token(T_volatile);
10546         rem_anchor_token(T_void);
10547         rem_anchor_token(T_using);
10548         rem_anchor_token(T_unsigned);
10549         rem_anchor_token(T_union);
10550         rem_anchor_token(T_typeof);
10551         rem_anchor_token(T_typename);
10552         rem_anchor_token(T_typeid);
10553         rem_anchor_token(T_typedef);
10554         rem_anchor_token(T_try);
10555         rem_anchor_token(T_true);
10556         rem_anchor_token(T_throw);
10557         rem_anchor_token(T_this);
10558         rem_anchor_token(T_template);
10559         rem_anchor_token(T_switch);
10560         rem_anchor_token(T_struct);
10561         rem_anchor_token(T_static_cast);
10562         rem_anchor_token(T_static);
10563         rem_anchor_token(T_sizeof);
10564         rem_anchor_token(T_signed);
10565         rem_anchor_token(T_short);
10566         rem_anchor_token(T_return);
10567         rem_anchor_token(T_restrict);
10568         rem_anchor_token(T_reinterpret_cast);
10569         rem_anchor_token(T_register);
10570         rem_anchor_token(T_operator);
10571         rem_anchor_token(T_new);
10572         rem_anchor_token(T_long);
10573         rem_anchor_token(T_int);
10574         rem_anchor_token(T_inline);
10575         rem_anchor_token(T_if);
10576         rem_anchor_token(T_goto);
10577         rem_anchor_token(T_for);
10578         rem_anchor_token(T_float);
10579         rem_anchor_token(T_false);
10580         rem_anchor_token(T_extern);
10581         rem_anchor_token(T_enum);
10582         rem_anchor_token(T_dynamic_cast);
10583         rem_anchor_token(T_do);
10584         rem_anchor_token(T_double);
10585         rem_anchor_token(T_delete);
10586         rem_anchor_token(T_default);
10587         rem_anchor_token(T_continue);
10588         rem_anchor_token(T_const_cast);
10589         rem_anchor_token(T_const);
10590         rem_anchor_token(T_class);
10591         rem_anchor_token(T_char);
10592         rem_anchor_token(T_case);
10593         rem_anchor_token(T_break);
10594         rem_anchor_token(T_bool);
10595         rem_anchor_token(T_auto);
10596         rem_anchor_token(T_asm);
10597         rem_anchor_token(T___thread);
10598         rem_anchor_token(T___real__);
10599         rem_anchor_token(T___label__);
10600         rem_anchor_token(T___imag__);
10601         rem_anchor_token(T___func__);
10602         rem_anchor_token(T___extension__);
10603         rem_anchor_token(T___builtin_va_start);
10604         rem_anchor_token(T___attribute__);
10605         rem_anchor_token(T___alignof__);
10606         rem_anchor_token(T___PRETTY_FUNCTION__);
10607         rem_anchor_token(T___FUNCTION__);
10608         rem_anchor_token(T__Imaginary);
10609         rem_anchor_token(T__Complex);
10610         rem_anchor_token(T__Bool);
10611         rem_anchor_token(T_WIDE_STRING_LITERAL);
10612         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10613         rem_anchor_token(T_STRING_LITERAL);
10614         rem_anchor_token(T_PLUSPLUS);
10615         rem_anchor_token(T_MINUSMINUS);
10616         rem_anchor_token(T_INTEGER);
10617         rem_anchor_token(T_IDENTIFIER);
10618         rem_anchor_token(T_FLOATINGPOINT);
10619         rem_anchor_token(T_COLONCOLON);
10620         rem_anchor_token(T_CHARACTER_CONSTANT);
10621         rem_anchor_token('~');
10622         rem_anchor_token('{');
10623         rem_anchor_token('-');
10624         rem_anchor_token('+');
10625         rem_anchor_token('*');
10626         rem_anchor_token('(');
10627         rem_anchor_token('&');
10628         rem_anchor_token('!');
10629         rem_anchor_token('}');
10630         assert(current_scope == &statement->compound.scope);
10631         scope_pop(old_scope);
10632         environment_pop_to(top);
10633
10634         POP_PARENT;
10635         return statement;
10636 }
10637
10638 /**
10639  * Check for unused global static functions and variables
10640  */
10641 static void check_unused_globals(void)
10642 {
10643         if (!warning.unused_function && !warning.unused_variable)
10644                 return;
10645
10646         for (const entity_t *entity = file_scope->entities; entity != NULL;
10647              entity = entity->base.next) {
10648                 if (!is_declaration(entity))
10649                         continue;
10650
10651                 const declaration_t *declaration = &entity->declaration;
10652                 if (declaration->used                  ||
10653                     declaration->modifiers & DM_UNUSED ||
10654                     declaration->modifiers & DM_USED   ||
10655                     declaration->storage_class != STORAGE_CLASS_STATIC)
10656                         continue;
10657
10658                 type_t *const type = declaration->type;
10659                 const char *s;
10660                 if (entity->kind == ENTITY_FUNCTION) {
10661                         /* inhibit warning for static inline functions */
10662                         if (entity->function.is_inline)
10663                                 continue;
10664
10665                         s = entity->function.statement != NULL ? "defined" : "declared";
10666                 } else {
10667                         s = "defined";
10668                 }
10669
10670                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10671                         type, declaration->base.symbol, s);
10672         }
10673 }
10674
10675 static void parse_global_asm(void)
10676 {
10677         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10678
10679         eat(T_asm);
10680         expect('(', end_error);
10681
10682         statement->asms.asm_text = parse_string_literals();
10683         statement->base.next     = unit->global_asm;
10684         unit->global_asm         = statement;
10685
10686         expect(')', end_error);
10687         expect(';', end_error);
10688
10689 end_error:;
10690 }
10691
10692 static void parse_linkage_specification(void)
10693 {
10694         eat(T_extern);
10695         assert(token.type == T_STRING_LITERAL);
10696
10697         const char *linkage = parse_string_literals().begin;
10698
10699         linkage_kind_t old_linkage = current_linkage;
10700         linkage_kind_t new_linkage;
10701         if (strcmp(linkage, "C") == 0) {
10702                 new_linkage = LINKAGE_C;
10703         } else if (strcmp(linkage, "C++") == 0) {
10704                 new_linkage = LINKAGE_CXX;
10705         } else {
10706                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10707                 new_linkage = LINKAGE_INVALID;
10708         }
10709         current_linkage = new_linkage;
10710
10711         if (token.type == '{') {
10712                 next_token();
10713                 parse_externals();
10714                 expect('}', end_error);
10715         } else {
10716                 parse_external();
10717         }
10718
10719 end_error:
10720         assert(current_linkage == new_linkage);
10721         current_linkage = old_linkage;
10722 }
10723
10724 static void parse_external(void)
10725 {
10726         switch (token.type) {
10727                 DECLARATION_START_NO_EXTERN
10728                 case T_IDENTIFIER:
10729                 case T___extension__:
10730                 /* tokens below are for implicit int */
10731                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10732                              implicit int) */
10733                 case '*': /* * x; -> int* x; */
10734                 case '(': /* (x); -> int (x); */
10735                         parse_external_declaration();
10736                         return;
10737
10738                 case T_extern:
10739                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10740                                 parse_linkage_specification();
10741                         } else {
10742                                 parse_external_declaration();
10743                         }
10744                         return;
10745
10746                 case T_asm:
10747                         parse_global_asm();
10748                         return;
10749
10750                 case T_namespace:
10751                         parse_namespace_definition();
10752                         return;
10753
10754                 case ';':
10755                         if (!strict_mode) {
10756                                 if (warning.other)
10757                                         warningf(HERE, "stray ';' outside of function");
10758                                 next_token();
10759                                 return;
10760                         }
10761                         /* FALLTHROUGH */
10762
10763                 default:
10764                         errorf(HERE, "stray %K outside of function", &token);
10765                         if (token.type == '(' || token.type == '{' || token.type == '[')
10766                                 eat_until_matching_token(token.type);
10767                         next_token();
10768                         return;
10769         }
10770 }
10771
10772 static void parse_externals(void)
10773 {
10774         add_anchor_token('}');
10775         add_anchor_token(T_EOF);
10776
10777 #ifndef NDEBUG
10778         unsigned char token_anchor_copy[T_LAST_TOKEN];
10779         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10780 #endif
10781
10782         while (token.type != T_EOF && token.type != '}') {
10783 #ifndef NDEBUG
10784                 bool anchor_leak = false;
10785                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10786                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10787                         if (count != 0) {
10788                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10789                                 anchor_leak = true;
10790                         }
10791                 }
10792                 if (in_gcc_extension) {
10793                         errorf(HERE, "Leaked __extension__");
10794                         anchor_leak = true;
10795                 }
10796
10797                 if (anchor_leak)
10798                         abort();
10799 #endif
10800
10801                 parse_external();
10802         }
10803
10804         rem_anchor_token(T_EOF);
10805         rem_anchor_token('}');
10806 }
10807
10808 /**
10809  * Parse a translation unit.
10810  */
10811 static void parse_translation_unit(void)
10812 {
10813         add_anchor_token(T_EOF);
10814
10815         while (true) {
10816                 parse_externals();
10817
10818                 if (token.type == T_EOF)
10819                         break;
10820
10821                 errorf(HERE, "stray %K outside of function", &token);
10822                 if (token.type == '(' || token.type == '{' || token.type == '[')
10823                         eat_until_matching_token(token.type);
10824                 next_token();
10825         }
10826 }
10827
10828 /**
10829  * Parse the input.
10830  *
10831  * @return  the translation unit or NULL if errors occurred.
10832  */
10833 void start_parsing(void)
10834 {
10835         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10836         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10837         diagnostic_count  = 0;
10838         error_count       = 0;
10839         warning_count     = 0;
10840
10841         type_set_output(stderr);
10842         ast_set_output(stderr);
10843
10844         assert(unit == NULL);
10845         unit = allocate_ast_zero(sizeof(unit[0]));
10846
10847         assert(file_scope == NULL);
10848         file_scope = &unit->scope;
10849
10850         assert(current_scope == NULL);
10851         scope_push(&unit->scope);
10852
10853         create_gnu_builtins();
10854         if (c_mode & _MS)
10855                 create_microsoft_intrinsics();
10856 }
10857
10858 translation_unit_t *finish_parsing(void)
10859 {
10860         assert(current_scope == &unit->scope);
10861         scope_pop(NULL);
10862
10863         assert(file_scope == &unit->scope);
10864         check_unused_globals();
10865         file_scope = NULL;
10866
10867         DEL_ARR_F(environment_stack);
10868         DEL_ARR_F(label_stack);
10869
10870         translation_unit_t *result = unit;
10871         unit = NULL;
10872         return result;
10873 }
10874
10875 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10876  * are given length one. */
10877 static void complete_incomplete_arrays(void)
10878 {
10879         size_t n = ARR_LEN(incomplete_arrays);
10880         for (size_t i = 0; i != n; ++i) {
10881                 declaration_t *const decl      = incomplete_arrays[i];
10882                 type_t        *const orig_type = decl->type;
10883                 type_t        *const type      = skip_typeref(orig_type);
10884
10885                 if (!is_type_incomplete(type))
10886                         continue;
10887
10888                 if (warning.other) {
10889                         warningf(&decl->base.source_position,
10890                                         "array '%#T' assumed to have one element",
10891                                         orig_type, decl->base.symbol);
10892                 }
10893
10894                 type_t *const new_type = duplicate_type(type);
10895                 new_type->array.size_constant     = true;
10896                 new_type->array.has_implicit_size = true;
10897                 new_type->array.size              = 1;
10898
10899                 type_t *const result = identify_new_type(new_type);
10900
10901                 decl->type = result;
10902         }
10903 }
10904
10905 void prepare_main_collect2(entity_t *entity)
10906 {
10907         // create call to __main
10908         symbol_t *symbol         = symbol_table_insert("__main");
10909         entity_t *subsubmain_ent
10910                 = create_implicit_function(symbol, &builtin_source_position);
10911
10912         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10913         type_t       *ftype       = subsubmain_ent->declaration.type;
10914         ref->base.source_position = builtin_source_position;
10915         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10916         ref->reference.entity     = subsubmain_ent;
10917
10918         expression_t *call = allocate_expression_zero(EXPR_CALL);
10919         call->base.source_position = builtin_source_position;
10920         call->base.type            = type_void;
10921         call->call.function        = ref;
10922
10923         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10924         expr_statement->base.source_position  = builtin_source_position;
10925         expr_statement->expression.expression = call;
10926
10927         statement_t *statement = entity->function.statement;
10928         assert(statement->kind == STATEMENT_COMPOUND);
10929         compound_statement_t *compounds = &statement->compound;
10930
10931         expr_statement->base.next = compounds->statements;
10932         compounds->statements     = expr_statement;
10933 }
10934
10935 void parse(void)
10936 {
10937         lookahead_bufpos = 0;
10938         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10939                 next_token();
10940         }
10941         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10942         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10943         parse_translation_unit();
10944         complete_incomplete_arrays();
10945         DEL_ARR_F(incomplete_arrays);
10946         incomplete_arrays = NULL;
10947 }
10948
10949 /**
10950  * create a builtin function.
10951  */
10952 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
10953 {
10954         symbol_t *symbol = symbol_table_insert(name);
10955         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
10956         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
10957         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
10958         entity->declaration.type                   = function_type;
10959         entity->declaration.implicit               = true;
10960         entity->base.symbol                        = symbol;
10961         entity->base.source_position               = builtin_source_position;
10962
10963         entity->function.btk                       = kind;
10964
10965         record_entity(entity, /*is_definition=*/false);
10966         return entity;
10967 }
10968
10969
10970 /**
10971  * Create predefined gnu builtins.
10972  */
10973 static void create_gnu_builtins(void)
10974 {
10975 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
10976
10977         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
10978         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
10979         GNU_BUILTIN(inf,            make_function_0_type(type_double));
10980         GNU_BUILTIN(inff,           make_function_0_type(type_float));
10981         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
10982         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
10983         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
10984         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
10985         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
10986         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
10987         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
10988         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
10989         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
10990         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
10991         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
10992         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
10993         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
10994         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
10995         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
10996
10997 #undef GNU_BUILTIN
10998 }
10999
11000 /**
11001  * Create predefined MS intrinsics.
11002  */
11003 static void create_microsoft_intrinsics(void)
11004 {
11005 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11006
11007         /* intrinsics for all architectures */
11008         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11009         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11010         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11011         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11012         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11013         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11014         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11015
11016         MS_BUILTIN(__debugbreak,            make_function_0_type(type_void));
11017         MS_BUILTIN(_ReturnAddress,          make_function_0_type(type_void_ptr));
11018         MS_BUILTIN(_AddressOfReturnAddress, make_function_0_type(type_void_ptr));
11019         MS_BUILTIN(__popcount,              make_function_1_type(type_unsigned_int, type_unsigned_int));
11020
11021         /* x86/x64 only */
11022         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11023         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11024         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11025         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11026         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11027         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11028         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11029         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11030         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11031         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11032         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11033         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11034         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11035
11036         if (machine_size <= 32) {
11037                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11038                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11039         } else {
11040                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11041                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11042         }
11043
11044 #undef MS_BUILTIN
11045 }
11046
11047 /**
11048  * Initialize the parser.
11049  */
11050 void init_parser(void)
11051 {
11052         sym_anonymous = symbol_table_insert("<anonymous>");
11053
11054         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11055
11056         init_expression_parsers();
11057         obstack_init(&temp_obst);
11058
11059         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11060         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11061 }
11062
11063 /**
11064  * Terminate the parser.
11065  */
11066 void exit_parser(void)
11067 {
11068         obstack_free(&temp_obst, NULL);
11069 }