nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 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(expression) == 0;
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(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
2538         if (token.type == T___attribute__) {
2539                 parse_attributes(NULL);
2540         }
2541
2542         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2543         if (token.type == T_IDENTIFIER) {
2544                 /* the compound has a name, check if we have seen it already */
2545                 symbol = token.v.symbol;
2546                 next_token();
2547
2548                 entity_t *entity = get_tag(symbol, kind);
2549                 if (entity != NULL) {
2550                         compound = &entity->compound;
2551                         if (compound->base.parent_scope != current_scope &&
2552                             (token.type == '{' || token.type == ';')) {
2553                                 /* we're in an inner scope and have a definition. Shadow
2554                                  * existing definition in outer scope */
2555                                 compound = NULL;
2556                         } else if (compound->complete && token.type == '{') {
2557                                 assert(symbol != NULL);
2558                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2559                                        is_struct ? "struct" : "union", symbol,
2560                                        &compound->base.source_position);
2561                                 /* clear members in the hope to avoid further errors */
2562                                 compound->members.entities = NULL;
2563                         }
2564                 }
2565         } else if (token.type != '{') {
2566                 if (is_struct) {
2567                         parse_error_expected("while parsing struct type specifier",
2568                                              T_IDENTIFIER, '{', NULL);
2569                 } else {
2570                         parse_error_expected("while parsing union type specifier",
2571                                              T_IDENTIFIER, '{', NULL);
2572                 }
2573
2574                 return NULL;
2575         }
2576
2577         if (compound == NULL) {
2578                 entity_t *entity = allocate_entity_zero(kind);
2579                 compound         = &entity->compound;
2580
2581                 compound->base.namespc         = NAMESPACE_TAG;
2582                 compound->base.source_position = token.source_position;
2583                 compound->base.symbol          = symbol;
2584                 compound->base.parent_scope    = current_scope;
2585                 if (symbol != NULL) {
2586                         environment_push(entity);
2587                 }
2588                 append_entity(current_scope, entity);
2589         }
2590
2591         if (token.type == '{') {
2592                 parse_compound_type_entries(compound);
2593                 parse_attributes(NULL);
2594
2595                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2596                 if (symbol == NULL) {
2597                         assert(anonymous_entity == NULL);
2598                         anonymous_entity = (entity_t*)compound;
2599                 }
2600         }
2601
2602         return compound;
2603 }
2604
2605 static void parse_enum_entries(type_t *const enum_type)
2606 {
2607         eat('{');
2608
2609         if (token.type == '}') {
2610                 errorf(HERE, "empty enum not allowed");
2611                 next_token();
2612                 return;
2613         }
2614
2615         add_anchor_token('}');
2616         do {
2617                 if (token.type != T_IDENTIFIER) {
2618                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2619                         eat_block();
2620                         rem_anchor_token('}');
2621                         return;
2622                 }
2623
2624                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
2625                 entity->enum_value.enum_type = enum_type;
2626                 entity->base.symbol          = token.v.symbol;
2627                 entity->base.source_position = token.source_position;
2628                 next_token();
2629
2630                 if (token.type == '=') {
2631                         next_token();
2632                         expression_t *value = parse_constant_expression();
2633
2634                         value = create_implicit_cast(value, enum_type);
2635                         entity->enum_value.value = value;
2636
2637                         /* TODO semantic */
2638                 }
2639
2640                 record_entity(entity, false);
2641
2642                 if (token.type != ',')
2643                         break;
2644                 next_token();
2645         } while (token.type != '}');
2646         rem_anchor_token('}');
2647
2648         expect('}', end_error);
2649
2650 end_error:
2651         ;
2652 }
2653
2654 static type_t *parse_enum_specifier(void)
2655 {
2656         entity_t        *entity;
2657         symbol_t        *symbol;
2658
2659         eat(T_enum);
2660         if (token.type == T_IDENTIFIER) {
2661                 symbol = token.v.symbol;
2662                 next_token();
2663
2664                 entity = get_tag(symbol, ENTITY_ENUM);
2665                 if (entity != NULL) {
2666                         if (entity->base.parent_scope != current_scope &&
2667                                         (token.type == '{' || token.type == ';')) {
2668                                 /* we're in an inner scope and have a definition. Shadow
2669                                  * existing definition in outer scope */
2670                                 entity = NULL;
2671                         } else if (entity->enume.complete && token.type == '{') {
2672                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
2673                                                 symbol, &entity->base.source_position);
2674                         }
2675                 }
2676         } else if (token.type != '{') {
2677                 parse_error_expected("while parsing enum type specifier",
2678                                      T_IDENTIFIER, '{', NULL);
2679                 return NULL;
2680         } else {
2681                 entity  = NULL;
2682                 symbol  = NULL;
2683         }
2684
2685         if (entity == NULL) {
2686                 entity                       = allocate_entity_zero(ENTITY_ENUM);
2687                 entity->base.namespc         = NAMESPACE_TAG;
2688                 entity->base.source_position = token.source_position;
2689                 entity->base.symbol          = symbol;
2690                 entity->base.parent_scope    = current_scope;
2691         }
2692
2693         type_t *const type = allocate_type_zero(TYPE_ENUM);
2694         type->enumt.enume  = &entity->enume;
2695         type->enumt.akind  = ATOMIC_TYPE_INT;
2696
2697         if (token.type == '{') {
2698                 if (symbol != NULL) {
2699                         environment_push(entity);
2700                 }
2701                 append_entity(current_scope, entity);
2702                 entity->enume.complete = true;
2703
2704                 parse_enum_entries(type);
2705                 parse_attributes(NULL);
2706
2707                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2708                 if (symbol == NULL) {
2709                         assert(anonymous_entity == NULL);
2710                         anonymous_entity = entity;
2711                 }
2712         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2713                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
2714                        symbol);
2715         }
2716
2717         return type;
2718 }
2719
2720 /**
2721  * if a symbol is a typedef to another type, return true
2722  */
2723 static bool is_typedef_symbol(symbol_t *symbol)
2724 {
2725         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2726         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2727 }
2728
2729 static type_t *parse_typeof(void)
2730 {
2731         eat(T___typeof__);
2732
2733         type_t *type;
2734
2735         expect('(', end_error);
2736         add_anchor_token(')');
2737
2738         expression_t *expression  = NULL;
2739
2740         bool old_type_prop     = in_type_prop;
2741         bool old_gcc_extension = in_gcc_extension;
2742         in_type_prop           = true;
2743
2744         while (token.type == T___extension__) {
2745                 /* This can be a prefix to a typename or an expression. */
2746                 next_token();
2747                 in_gcc_extension = true;
2748         }
2749         switch (token.type) {
2750         case T_IDENTIFIER:
2751                 if (is_typedef_symbol(token.v.symbol)) {
2752                         type = parse_typename();
2753                 } else {
2754                         expression = parse_expression();
2755                         type       = revert_automatic_type_conversion(expression);
2756                 }
2757                 break;
2758
2759         TYPENAME_START
2760                 type = parse_typename();
2761                 break;
2762
2763         default:
2764                 expression = parse_expression();
2765                 type       = expression->base.type;
2766                 break;
2767         }
2768         in_type_prop     = old_type_prop;
2769         in_gcc_extension = old_gcc_extension;
2770
2771         rem_anchor_token(')');
2772         expect(')', end_error);
2773
2774         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2775         typeof_type->typeoft.expression  = expression;
2776         typeof_type->typeoft.typeof_type = type;
2777
2778         return typeof_type;
2779 end_error:
2780         return NULL;
2781 }
2782
2783 typedef enum specifiers_t {
2784         SPECIFIER_SIGNED    = 1 << 0,
2785         SPECIFIER_UNSIGNED  = 1 << 1,
2786         SPECIFIER_LONG      = 1 << 2,
2787         SPECIFIER_INT       = 1 << 3,
2788         SPECIFIER_DOUBLE    = 1 << 4,
2789         SPECIFIER_CHAR      = 1 << 5,
2790         SPECIFIER_WCHAR_T   = 1 << 6,
2791         SPECIFIER_SHORT     = 1 << 7,
2792         SPECIFIER_LONG_LONG = 1 << 8,
2793         SPECIFIER_FLOAT     = 1 << 9,
2794         SPECIFIER_BOOL      = 1 << 10,
2795         SPECIFIER_VOID      = 1 << 11,
2796         SPECIFIER_INT8      = 1 << 12,
2797         SPECIFIER_INT16     = 1 << 13,
2798         SPECIFIER_INT32     = 1 << 14,
2799         SPECIFIER_INT64     = 1 << 15,
2800         SPECIFIER_INT128    = 1 << 16,
2801         SPECIFIER_COMPLEX   = 1 << 17,
2802         SPECIFIER_IMAGINARY = 1 << 18,
2803 } specifiers_t;
2804
2805 static type_t *create_builtin_type(symbol_t *const symbol,
2806                                    type_t *const real_type)
2807 {
2808         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
2809         type->builtin.symbol    = symbol;
2810         type->builtin.real_type = real_type;
2811         return identify_new_type(type);
2812 }
2813
2814 static type_t *get_typedef_type(symbol_t *symbol)
2815 {
2816         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2817         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2818                 return NULL;
2819
2820         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2821         type->typedeft.typedefe = &entity->typedefe;
2822
2823         return type;
2824 }
2825
2826 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2827 {
2828         expect('(', end_error);
2829
2830         attribute_property_argument_t *property
2831                 = allocate_ast_zero(sizeof(*property));
2832
2833         while (true) {
2834                 if (token.type != T_IDENTIFIER) {
2835                         parse_error_expected("while parsing property declspec",
2836                                              T_IDENTIFIER, NULL);
2837                         goto end_error;
2838                 }
2839
2840                 bool is_put;
2841                 symbol_t *symbol = token.v.symbol;
2842                 next_token();
2843                 if (strcmp(symbol->string, "put") == 0) {
2844                         is_put = true;
2845                 } else if (strcmp(symbol->string, "get") == 0) {
2846                         is_put = false;
2847                 } else {
2848                         errorf(HERE, "expected put or get in property declspec");
2849                         goto end_error;
2850                 }
2851                 expect('=', end_error);
2852                 if (token.type != T_IDENTIFIER) {
2853                         parse_error_expected("while parsing property declspec",
2854                                              T_IDENTIFIER, NULL);
2855                         goto end_error;
2856                 }
2857                 if (is_put) {
2858                         property->put_symbol = token.v.symbol;
2859                 } else {
2860                         property->get_symbol = token.v.symbol;
2861                 }
2862                 next_token();
2863                 if (token.type == ')')
2864                         break;
2865                 expect(',', end_error);
2866         }
2867
2868         attribute->a.property = property;
2869
2870         expect(')', end_error);
2871
2872 end_error:
2873         return attribute;
2874 }
2875
2876 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2877 {
2878         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2879         if (token.type == T_restrict) {
2880                 kind = ATTRIBUTE_MS_RESTRICT;
2881                 next_token();
2882         } else if (token.type == T_IDENTIFIER) {
2883                 const char *name = token.v.symbol->string;
2884                 next_token();
2885                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2886                      ++k) {
2887                         const char *attribute_name = get_attribute_name(k);
2888                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2889                                 kind = k;
2890                                 break;
2891                         }
2892                 }
2893
2894                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2895                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2896                 }
2897         } else {
2898                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2899                 return NULL;
2900         }
2901
2902         attribute_t *attribute = allocate_attribute_zero(kind);
2903
2904         if (kind == ATTRIBUTE_MS_PROPERTY) {
2905                 return parse_attribute_ms_property(attribute);
2906         }
2907
2908         /* parse arguments */
2909         if (token.type == '(') {
2910                 next_token();
2911                 attribute->a.arguments = parse_attribute_arguments();
2912         }
2913
2914         return attribute;
2915 }
2916
2917 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2918 {
2919         eat(T__declspec);
2920
2921         expect('(', end_error);
2922
2923         if (token.type == ')') {
2924                 next_token();
2925                 return NULL;
2926         }
2927
2928         add_anchor_token(')');
2929
2930         attribute_t *last = first;
2931         while (true) {
2932                 if (last != NULL) {
2933                         while (last->next != NULL)
2934                                 last = last->next;
2935                 }
2936
2937                 attribute_t *attribute
2938                         = parse_microsoft_extended_decl_modifier_single();
2939                 if (attribute == NULL)
2940                         goto end_error;
2941
2942                 if (last == NULL) {
2943                         first = attribute;
2944                 } else {
2945                         last->next = attribute;
2946                 }
2947                 last = attribute;
2948
2949                 if (token.type == ')') {
2950                         break;
2951                 }
2952                 expect(',', end_error);
2953         }
2954
2955         rem_anchor_token(')');
2956         expect(')', end_error);
2957         return first;
2958
2959 end_error:
2960         rem_anchor_token(')');
2961         return first;
2962 }
2963
2964 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2965 {
2966         entity_t *entity             = allocate_entity_zero(kind);
2967         entity->base.source_position = *HERE;
2968         entity->base.symbol          = symbol;
2969         if (is_declaration(entity)) {
2970                 entity->declaration.type     = type_error_type;
2971                 entity->declaration.implicit = true;
2972         } else if (kind == ENTITY_TYPEDEF) {
2973                 entity->typedefe.type    = type_error_type;
2974                 entity->typedefe.builtin = true;
2975         }
2976         if (kind != ENTITY_COMPOUND_MEMBER)
2977                 record_entity(entity, false);
2978         return entity;
2979 }
2980
2981 /**
2982  * Finish the construction of a struct type by calculating its size, offsets,
2983  * alignment.
2984  */
2985 static void finish_struct_type(compound_type_t *type)
2986 {
2987         assert(type->compound != NULL);
2988
2989         compound_t *compound = type->compound;
2990         if (!compound->complete)
2991                 return;
2992
2993         il_size_t      size = 0;
2994         il_size_t      offset;
2995         il_alignment_t alignment = compound->alignment;
2996         bool           need_pad  = false;
2997
2998         entity_t *entry = compound->members.entities;
2999         for (; entry != NULL; entry = entry->base.next) {
3000                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3001                         continue;
3002
3003                 type_t *m_type = entry->declaration.type;
3004                 if (! is_type_valid(skip_typeref(m_type))) {
3005                         /* simply ignore errors here */
3006                         continue;
3007                 }
3008                 il_alignment_t m_alignment = get_type_alignment(m_type);
3009                 if (m_alignment > alignment)
3010                         alignment = m_alignment;
3011
3012                 offset = (size + m_alignment - 1) & -m_alignment;
3013
3014                 if (offset > size)
3015                         need_pad = true;
3016                 entry->compound_member.offset = offset;
3017                 size = offset + get_type_size(m_type);
3018         }
3019
3020         offset = (size + alignment - 1) & -alignment;
3021         if (offset > size)
3022                 need_pad = true;
3023
3024         if (need_pad) {
3025                 if (warning.padded) {
3026                         warningf(&compound->base.source_position, "'%T' needs padding",
3027                                  type);
3028                 }
3029         } else if (compound->packed && warning.packed) {
3030                 warningf(&compound->base.source_position,
3031                          "superfluous packed attribute on '%T'", type);
3032         }
3033
3034         compound->size      = offset;
3035         compound->alignment = alignment;
3036 }
3037
3038 /**
3039  * Finish the construction of an union type by calculating
3040  * its size and alignment.
3041  */
3042 static void finish_union_type(compound_type_t *type)
3043 {
3044         assert(type->compound != NULL);
3045
3046         compound_t *compound = type->compound;
3047         if (! compound->complete)
3048                 return;
3049
3050         il_size_t      size      = 0;
3051         il_alignment_t alignment = compound->alignment;
3052
3053         entity_t *entry = compound->members.entities;
3054         for (; entry != NULL; entry = entry->base.next) {
3055                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3056                         continue;
3057
3058                 type_t *m_type = entry->declaration.type;
3059                 if (! is_type_valid(skip_typeref(m_type)))
3060                         continue;
3061
3062                 entry->compound_member.offset = 0;
3063                 il_size_t m_size = get_type_size(m_type);
3064                 if (m_size > size)
3065                         size = m_size;
3066                 il_alignment_t m_alignment = get_type_alignment(m_type);
3067                 if (m_alignment > alignment)
3068                         alignment = m_alignment;
3069         }
3070         size = (size + alignment - 1) & -alignment;
3071
3072         compound->size      = size;
3073         compound->alignment = alignment;
3074 }
3075
3076 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3077 {
3078         type_t            *type              = NULL;
3079         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3080         unsigned           type_specifiers   = 0;
3081         bool               newtype           = false;
3082         bool               saw_error         = false;
3083         bool               old_gcc_extension = in_gcc_extension;
3084
3085         specifiers->source_position = token.source_position;
3086
3087         while (true) {
3088                 specifiers->attributes = parse_attributes(specifiers->attributes);
3089
3090                 switch (token.type) {
3091                 /* storage class */
3092 #define MATCH_STORAGE_CLASS(token, class)                                  \
3093                 case token:                                                        \
3094                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3095                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3096                         }                                                              \
3097                         specifiers->storage_class = class;                             \
3098                         if (specifiers->thread_local)                                  \
3099                                 goto check_thread_storage_class;                           \
3100                         next_token();                                                  \
3101                         break;
3102
3103                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3104                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3105                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3106                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3107                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3108
3109                 case T__declspec:
3110                         specifiers->attributes
3111                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
3112                         break;
3113
3114                 case T___thread:
3115                         if (specifiers->thread_local) {
3116                                 errorf(HERE, "duplicate '__thread'");
3117                         } else {
3118                                 specifiers->thread_local = true;
3119 check_thread_storage_class:
3120                                 switch (specifiers->storage_class) {
3121                                         case STORAGE_CLASS_EXTERN:
3122                                         case STORAGE_CLASS_NONE:
3123                                         case STORAGE_CLASS_STATIC:
3124                                                 break;
3125
3126                                                 char const* wrong;
3127                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3128                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3129                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3130 wrong_thread_stoarge_class:
3131                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3132                                                 break;
3133                                 }
3134                         }
3135                         next_token();
3136                         break;
3137
3138                 /* type qualifiers */
3139 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3140                 case token:                                                     \
3141                         qualifiers |= qualifier;                                    \
3142                         next_token();                                               \
3143                         break
3144
3145                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3146                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3147                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3148                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3149                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3150                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3151                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3152                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3153
3154                 case T___extension__:
3155                         next_token();
3156                         in_gcc_extension = true;
3157                         break;
3158
3159                 /* type specifiers */
3160 #define MATCH_SPECIFIER(token, specifier, name)                         \
3161                 case token:                                                     \
3162                         if (type_specifiers & specifier) {                           \
3163                                 errorf(HERE, "multiple " name " type specifiers given"); \
3164                         } else {                                                    \
3165                                 type_specifiers |= specifier;                           \
3166                         }                                                           \
3167                         next_token();                                               \
3168                         break
3169
3170                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3171                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3172                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3173                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3174                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3175                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3176                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3177                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3178                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3179                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3180                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3181                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3182                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3183                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3184                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3185                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3186                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3187                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3188
3189                 case T_inline:
3190                         next_token();
3191                         specifiers->is_inline = true;
3192                         break;
3193
3194 #if 0
3195                 case T__forceinline:
3196                         next_token();
3197                         specifiers->modifiers |= DM_FORCEINLINE;
3198                         break;
3199 #endif
3200
3201                 case T_long:
3202                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3203                                 errorf(HERE, "multiple type specifiers given");
3204                         } else if (type_specifiers & SPECIFIER_LONG) {
3205                                 type_specifiers |= SPECIFIER_LONG_LONG;
3206                         } else {
3207                                 type_specifiers |= SPECIFIER_LONG;
3208                         }
3209                         next_token();
3210                         break;
3211
3212 #define CHECK_DOUBLE_TYPE()        \
3213                         if ( type != NULL)     \
3214                                 errorf(HERE, "multiple data types in declaration specifiers");
3215
3216                 case T_struct:
3217                         CHECK_DOUBLE_TYPE();
3218                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3219
3220                         type->compound.compound = parse_compound_type_specifier(true);
3221                         finish_struct_type(&type->compound);
3222                         break;
3223                 case T_union:
3224                         CHECK_DOUBLE_TYPE();
3225                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3226                         type->compound.compound = parse_compound_type_specifier(false);
3227                         finish_union_type(&type->compound);
3228                         break;
3229                 case T_enum:
3230                         CHECK_DOUBLE_TYPE();
3231                         type = parse_enum_specifier();
3232                         break;
3233                 case T___typeof__:
3234                         CHECK_DOUBLE_TYPE();
3235                         type = parse_typeof();
3236                         break;
3237                 case T___builtin_va_list:
3238                         CHECK_DOUBLE_TYPE();
3239                         type = duplicate_type(type_valist);
3240                         next_token();
3241                         break;
3242
3243                 case T_IDENTIFIER: {
3244                         /* only parse identifier if we haven't found a type yet */
3245                         if (type != NULL || type_specifiers != 0) {
3246                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3247                                  * declaration, so it doesn't generate errors about expecting '(' or
3248                                  * '{' later on. */
3249                                 switch (look_ahead(1)->type) {
3250                                         STORAGE_CLASSES
3251                                         TYPE_SPECIFIERS
3252                                         case T_const:
3253                                         case T_restrict:
3254                                         case T_volatile:
3255                                         case T_inline:
3256                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3257                                         case T_IDENTIFIER:
3258                                         case '&':
3259                                         case '*':
3260                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3261                                                 next_token();
3262                                                 continue;
3263
3264                                         default:
3265                                                 goto finish_specifiers;
3266                                 }
3267                         }
3268
3269                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3270                         if (typedef_type == NULL) {
3271                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3272                                  * declaration, so it doesn't generate 'implicit int' followed by more
3273                                  * errors later on. */
3274                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3275                                 switch (la1_type) {
3276                                         DECLARATION_START
3277                                         case T_IDENTIFIER:
3278                                         case '&':
3279                                         case '*': {
3280                                                 errorf(HERE, "%K does not name a type", &token);
3281
3282                                                 entity_t *entity =
3283                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3284
3285                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3286                                                 type->typedeft.typedefe = &entity->typedefe;
3287
3288                                                 next_token();
3289                                                 saw_error = true;
3290                                                 if (la1_type == '&' || la1_type == '*')
3291                                                         goto finish_specifiers;
3292                                                 continue;
3293                                         }
3294
3295                                         default:
3296                                                 goto finish_specifiers;
3297                                 }
3298                         }
3299
3300                         next_token();
3301                         type = typedef_type;
3302                         break;
3303                 }
3304
3305                 /* function specifier */
3306                 default:
3307                         goto finish_specifiers;
3308                 }
3309         }
3310
3311 finish_specifiers:
3312         specifiers->attributes = parse_attributes(specifiers->attributes);
3313
3314         in_gcc_extension = old_gcc_extension;
3315
3316         if (type == NULL || (saw_error && type_specifiers != 0)) {
3317                 atomic_type_kind_t atomic_type;
3318
3319                 /* match valid basic types */
3320                 switch (type_specifiers) {
3321                 case SPECIFIER_VOID:
3322                         atomic_type = ATOMIC_TYPE_VOID;
3323                         break;
3324                 case SPECIFIER_WCHAR_T:
3325                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3326                         break;
3327                 case SPECIFIER_CHAR:
3328                         atomic_type = ATOMIC_TYPE_CHAR;
3329                         break;
3330                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3331                         atomic_type = ATOMIC_TYPE_SCHAR;
3332                         break;
3333                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3334                         atomic_type = ATOMIC_TYPE_UCHAR;
3335                         break;
3336                 case SPECIFIER_SHORT:
3337                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3338                 case SPECIFIER_SHORT | SPECIFIER_INT:
3339                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3340                         atomic_type = ATOMIC_TYPE_SHORT;
3341                         break;
3342                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3343                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3344                         atomic_type = ATOMIC_TYPE_USHORT;
3345                         break;
3346                 case SPECIFIER_INT:
3347                 case SPECIFIER_SIGNED:
3348                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3349                         atomic_type = ATOMIC_TYPE_INT;
3350                         break;
3351                 case SPECIFIER_UNSIGNED:
3352                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3353                         atomic_type = ATOMIC_TYPE_UINT;
3354                         break;
3355                 case SPECIFIER_LONG:
3356                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3357                 case SPECIFIER_LONG | SPECIFIER_INT:
3358                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3359                         atomic_type = ATOMIC_TYPE_LONG;
3360                         break;
3361                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3362                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3363                         atomic_type = ATOMIC_TYPE_ULONG;
3364                         break;
3365
3366                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3367                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3368                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3369                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3370                         | SPECIFIER_INT:
3371                         atomic_type = ATOMIC_TYPE_LONGLONG;
3372                         goto warn_about_long_long;
3373
3374                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3375                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3376                         | SPECIFIER_INT:
3377                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3378 warn_about_long_long:
3379                         if (warning.long_long) {
3380                                 warningf(&specifiers->source_position,
3381                                          "ISO C90 does not support 'long long'");
3382                         }
3383                         break;
3384
3385                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3386                         atomic_type = unsigned_int8_type_kind;
3387                         break;
3388
3389                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3390                         atomic_type = unsigned_int16_type_kind;
3391                         break;
3392
3393                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3394                         atomic_type = unsigned_int32_type_kind;
3395                         break;
3396
3397                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3398                         atomic_type = unsigned_int64_type_kind;
3399                         break;
3400
3401                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3402                         atomic_type = unsigned_int128_type_kind;
3403                         break;
3404
3405                 case SPECIFIER_INT8:
3406                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3407                         atomic_type = int8_type_kind;
3408                         break;
3409
3410                 case SPECIFIER_INT16:
3411                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3412                         atomic_type = int16_type_kind;
3413                         break;
3414
3415                 case SPECIFIER_INT32:
3416                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3417                         atomic_type = int32_type_kind;
3418                         break;
3419
3420                 case SPECIFIER_INT64:
3421                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3422                         atomic_type = int64_type_kind;
3423                         break;
3424
3425                 case SPECIFIER_INT128:
3426                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3427                         atomic_type = int128_type_kind;
3428                         break;
3429
3430                 case SPECIFIER_FLOAT:
3431                         atomic_type = ATOMIC_TYPE_FLOAT;
3432                         break;
3433                 case SPECIFIER_DOUBLE:
3434                         atomic_type = ATOMIC_TYPE_DOUBLE;
3435                         break;
3436                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3437                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3438                         break;
3439                 case SPECIFIER_BOOL:
3440                         atomic_type = ATOMIC_TYPE_BOOL;
3441                         break;
3442                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3443                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3444                         atomic_type = ATOMIC_TYPE_FLOAT;
3445                         break;
3446                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3447                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3448                         atomic_type = ATOMIC_TYPE_DOUBLE;
3449                         break;
3450                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3451                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3452                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3453                         break;
3454                 default:
3455                         /* invalid specifier combination, give an error message */
3456                         if (type_specifiers == 0) {
3457                                 if (saw_error)
3458                                         goto end_error;
3459
3460                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3461                                 if (!(c_mode & _CXX) && !strict_mode) {
3462                                         if (warning.implicit_int) {
3463                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3464                                         }
3465                                         atomic_type = ATOMIC_TYPE_INT;
3466                                         break;
3467                                 } else {
3468                                         errorf(HERE, "no type specifiers given in declaration");
3469                                 }
3470                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3471                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3472                                 errorf(HERE, "signed and unsigned specifiers given");
3473                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3474                                 errorf(HERE, "only integer types can be signed or unsigned");
3475                         } else {
3476                                 errorf(HERE, "multiple datatypes in declaration");
3477                         }
3478                         goto end_error;
3479                 }
3480
3481                 if (type_specifiers & SPECIFIER_COMPLEX) {
3482                         type                = allocate_type_zero(TYPE_COMPLEX);
3483                         type->complex.akind = atomic_type;
3484                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3485                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3486                         type->imaginary.akind = atomic_type;
3487                 } else {
3488                         type                 = allocate_type_zero(TYPE_ATOMIC);
3489                         type->atomic.akind   = atomic_type;
3490                 }
3491                 newtype = true;
3492         } else if (type_specifiers != 0) {
3493                 errorf(HERE, "multiple datatypes in declaration");
3494         }
3495
3496         /* FIXME: check type qualifiers here */
3497         type->base.qualifiers = qualifiers;
3498
3499         if (newtype) {
3500                 type = identify_new_type(type);
3501         } else {
3502                 type = typehash_insert(type);
3503         }
3504
3505         if (specifiers->attributes != NULL)
3506                 type = handle_type_attributes(specifiers->attributes, type);
3507         specifiers->type = type;
3508         return;
3509
3510 end_error:
3511         specifiers->type = type_error_type;
3512         return;
3513 }
3514
3515 static type_qualifiers_t parse_type_qualifiers(void)
3516 {
3517         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3518
3519         while (true) {
3520                 switch (token.type) {
3521                 /* type qualifiers */
3522                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3523                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3524                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3525                 /* microsoft extended type modifiers */
3526                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3527                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3528                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3529                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3530                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3531
3532                 default:
3533                         return qualifiers;
3534                 }
3535         }
3536 }
3537
3538 /**
3539  * Parses an K&R identifier list
3540  */
3541 static void parse_identifier_list(scope_t *scope)
3542 {
3543         do {
3544                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
3545                 entity->base.source_position = token.source_position;
3546                 entity->base.namespc         = NAMESPACE_NORMAL;
3547                 entity->base.symbol          = token.v.symbol;
3548                 /* a K&R parameter has no type, yet */
3549                 next_token();
3550
3551                 if (scope != NULL)
3552                         append_entity(scope, entity);
3553
3554                 if (token.type != ',') {
3555                         break;
3556                 }
3557                 next_token();
3558         } while (token.type == T_IDENTIFIER);
3559 }
3560
3561 static entity_t *parse_parameter(void)
3562 {
3563         declaration_specifiers_t specifiers;
3564         memset(&specifiers, 0, sizeof(specifiers));
3565
3566         parse_declaration_specifiers(&specifiers);
3567
3568         entity_t *entity = parse_declarator(&specifiers,
3569                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3570         anonymous_entity = NULL;
3571         return entity;
3572 }
3573
3574 static void semantic_parameter_incomplete(const entity_t *entity)
3575 {
3576         assert(entity->kind == ENTITY_PARAMETER);
3577
3578         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3579          *             list in a function declarator that is part of a
3580          *             definition of that function shall not have
3581          *             incomplete type. */
3582         type_t *type = skip_typeref(entity->declaration.type);
3583         if (is_type_incomplete(type)) {
3584                 errorf(&entity->base.source_position,
3585                                 "parameter '%#T' has incomplete type",
3586                                 entity->declaration.type, entity->base.symbol);
3587         }
3588 }
3589
3590 static bool has_parameters(void)
3591 {
3592         /* func(void) is not a parameter */
3593         if (token.type == T_IDENTIFIER) {
3594                 entity_t const *const entity = get_entity(token.v.symbol, NAMESPACE_NORMAL);
3595                 if (entity == NULL)
3596                         return true;
3597                 if (entity->kind != ENTITY_TYPEDEF)
3598                         return true;
3599                 if (skip_typeref(entity->typedefe.type) != type_void)
3600                         return true;
3601         } else if (token.type != T_void) {
3602                 return true;
3603         }
3604         if (look_ahead(1)->type != ')')
3605                 return true;
3606         next_token();
3607         return false;
3608 }
3609
3610 /**
3611  * Parses function type parameters (and optionally creates variable_t entities
3612  * for them in a scope)
3613  */
3614 static void parse_parameters(function_type_t *type, scope_t *scope)
3615 {
3616         eat('(');
3617         add_anchor_token(')');
3618         int saved_comma_state = save_and_reset_anchor_state(',');
3619
3620         if (token.type == T_IDENTIFIER &&
3621             !is_typedef_symbol(token.v.symbol)) {
3622                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3623                 if (la1_type == ',' || la1_type == ')') {
3624                         type->kr_style_parameters    = true;
3625                         type->unspecified_parameters = true;
3626                         parse_identifier_list(scope);
3627                         goto parameters_finished;
3628                 }
3629         }
3630
3631         if (token.type == ')') {
3632                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3633                 if (!(c_mode & _CXX))
3634                         type->unspecified_parameters = true;
3635                 goto parameters_finished;
3636         }
3637
3638         if (has_parameters()) {
3639                 function_parameter_t **anchor = &type->parameters;
3640                 for (;;) {
3641                         switch (token.type) {
3642                         case T_DOTDOTDOT:
3643                                 next_token();
3644                                 type->variadic = true;
3645                                 goto parameters_finished;
3646
3647                         case T_IDENTIFIER:
3648                         case T___extension__:
3649                         DECLARATION_START
3650                         {
3651                                 entity_t *entity = parse_parameter();
3652                                 if (entity->kind == ENTITY_TYPEDEF) {
3653                                         errorf(&entity->base.source_position,
3654                                                         "typedef not allowed as function parameter");
3655                                         break;
3656                                 }
3657                                 assert(is_declaration(entity));
3658
3659                                 semantic_parameter_incomplete(entity);
3660
3661                                 function_parameter_t *const parameter =
3662                                         allocate_parameter(entity->declaration.type);
3663
3664                                 if (scope != NULL) {
3665                                         append_entity(scope, entity);
3666                                 }
3667
3668                                 *anchor = parameter;
3669                                 anchor  = &parameter->next;
3670                                 break;
3671                         }
3672
3673                         default:
3674                                 goto parameters_finished;
3675                         }
3676                         if (token.type != ',') {
3677                                 goto parameters_finished;
3678                         }
3679                         next_token();
3680                 }
3681         }
3682
3683
3684 parameters_finished:
3685         rem_anchor_token(')');
3686         expect(')', end_error);
3687
3688 end_error:
3689         restore_anchor_state(',', saved_comma_state);
3690 }
3691
3692 typedef enum construct_type_kind_t {
3693         CONSTRUCT_INVALID,
3694         CONSTRUCT_POINTER,
3695         CONSTRUCT_REFERENCE,
3696         CONSTRUCT_FUNCTION,
3697         CONSTRUCT_ARRAY
3698 } construct_type_kind_t;
3699
3700 typedef union construct_type_t construct_type_t;
3701
3702 typedef struct construct_type_base_t {
3703         construct_type_kind_t  kind;
3704         construct_type_t      *next;
3705 } construct_type_base_t;
3706
3707 typedef struct parsed_pointer_t {
3708         construct_type_base_t  base;
3709         type_qualifiers_t      type_qualifiers;
3710         variable_t            *base_variable;  /**< MS __based extension. */
3711 } parsed_pointer_t;
3712
3713 typedef struct parsed_reference_t {
3714         construct_type_base_t base;
3715 } parsed_reference_t;
3716
3717 typedef struct construct_function_type_t {
3718         construct_type_base_t  base;
3719         type_t                *function_type;
3720 } construct_function_type_t;
3721
3722 typedef struct parsed_array_t {
3723         construct_type_base_t  base;
3724         type_qualifiers_t      type_qualifiers;
3725         bool                   is_static;
3726         bool                   is_variable;
3727         expression_t          *size;
3728 } parsed_array_t;
3729
3730 union construct_type_t {
3731         construct_type_kind_t     kind;
3732         construct_type_base_t     base;
3733         parsed_pointer_t          pointer;
3734         parsed_reference_t        reference;
3735         construct_function_type_t function;
3736         parsed_array_t            array;
3737 };
3738
3739 static construct_type_t *parse_pointer_declarator(void)
3740 {
3741         eat('*');
3742
3743         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
3744         memset(pointer, 0, sizeof(pointer[0]));
3745         pointer->base.kind       = CONSTRUCT_POINTER;
3746         pointer->type_qualifiers = parse_type_qualifiers();
3747         //pointer->base_variable       = base_variable;
3748
3749         return (construct_type_t*) pointer;
3750 }
3751
3752 static construct_type_t *parse_reference_declarator(void)
3753 {
3754         eat('&');
3755
3756         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
3757         parsed_reference_t *reference = &cons->reference;
3758         memset(reference, 0, sizeof(*reference));
3759         cons->kind = CONSTRUCT_REFERENCE;
3760
3761         return cons;
3762 }
3763
3764 static construct_type_t *parse_array_declarator(void)
3765 {
3766         eat('[');
3767         add_anchor_token(']');
3768
3769         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
3770         parsed_array_t   *array = &cons->array;
3771         memset(array, 0, sizeof(*array));
3772         cons->kind = CONSTRUCT_ARRAY;
3773
3774         if (token.type == T_static) {
3775                 array->is_static = true;
3776                 next_token();
3777         }
3778
3779         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3780         if (type_qualifiers != 0) {
3781                 if (token.type == T_static) {
3782                         array->is_static = true;
3783                         next_token();
3784                 }
3785         }
3786         array->type_qualifiers = type_qualifiers;
3787
3788         if (token.type == '*' && look_ahead(1)->type == ']') {
3789                 array->is_variable = true;
3790                 next_token();
3791         } else if (token.type != ']') {
3792                 expression_t *const size = parse_assignment_expression();
3793
3794                 /* §6.7.5.2:1  Array size must have integer type */
3795                 type_t *const orig_type = size->base.type;
3796                 type_t *const type      = skip_typeref(orig_type);
3797                 if (!is_type_integer(type) && is_type_valid(type)) {
3798                         errorf(&size->base.source_position,
3799                                "array size '%E' must have integer type but has type '%T'",
3800                                size, orig_type);
3801                 }
3802
3803                 array->size = size;
3804                 mark_vars_read(size, NULL);
3805         }
3806
3807         rem_anchor_token(']');
3808         expect(']', end_error);
3809
3810 end_error:
3811         return cons;
3812 }
3813
3814 static construct_type_t *parse_function_declarator(scope_t *scope)
3815 {
3816         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3817         function_type_t *ftype = &type->function;
3818
3819         ftype->linkage = current_linkage;
3820
3821 #if 0
3822         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
3823                 case DM_NONE:     break;
3824                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
3825                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
3826                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
3827                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
3828
3829                 default:
3830                         errorf(HERE, "multiple calling conventions in declaration");
3831                         break;
3832         }
3833 #endif
3834
3835         parse_parameters(ftype, scope);
3836
3837         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
3838         construct_function_type_t *function = &cons->function;
3839         memset(function, 0, sizeof(*function));
3840         cons->kind              = CONSTRUCT_FUNCTION;
3841         function->function_type = type;
3842
3843         return cons;
3844 }
3845
3846 typedef struct parse_declarator_env_t {
3847         bool               may_be_abstract : 1;
3848         bool               must_be_abstract : 1;
3849         decl_modifiers_t   modifiers;
3850         symbol_t          *symbol;
3851         source_position_t  source_position;
3852         scope_t            parameters;
3853         attribute_t       *attributes;
3854 } parse_declarator_env_t;
3855
3856 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3857 {
3858         /* construct a single linked list of construct_type_t's which describe
3859          * how to construct the final declarator type */
3860         construct_type_t  *first      = NULL;
3861         construct_type_t **anchor     = &first;
3862
3863         env->attributes = parse_attributes(env->attributes);
3864
3865         for (;;) {
3866                 construct_type_t *type;
3867                 //variable_t       *based = NULL; /* MS __based extension */
3868                 switch (token.type) {
3869                         case '&':
3870                                 if (!(c_mode & _CXX))
3871                                         errorf(HERE, "references are only available for C++");
3872                                 type = parse_reference_declarator();
3873                                 break;
3874
3875                         case T__based: {
3876 #if 0
3877                                 source_position_t const pos = *HERE;
3878                                 next_token();
3879                                 expect('(', end_error);
3880                                 add_anchor_token(')');
3881                                 based = parse_microsoft_based();
3882                                 rem_anchor_token(')');
3883                                 expect(')', end_error);
3884                                 if (token.type != '*') {
3885                                         if (token.type == T__based) {
3886                                                 errorf(&pos, "__based type modifier specified more than once");
3887                                         } else if (warning.other) {
3888                                                 warningf(&pos,
3889                                                                 "__based does not precede a pointer declarator, ignored");
3890                                         }
3891                                         continue;
3892                                 }
3893 #else
3894                                 panic("based currently disabled");
3895 #endif
3896                                 /* FALLTHROUGH */
3897                         }
3898
3899                         case '*':
3900                                 type = parse_pointer_declarator();
3901                                 break;
3902
3903                         default:
3904                                 goto ptr_operator_end;
3905                 }
3906
3907                 *anchor = type;
3908                 anchor  = &type->base.next;
3909
3910                 /* TODO: find out if this is correct */
3911                 env->attributes = parse_attributes(env->attributes);
3912         }
3913
3914 ptr_operator_end: ;
3915 #if 0
3916         modifiers      |= env->modifiers;
3917         env->modifiers  = modifiers;
3918 #endif
3919
3920         construct_type_t *inner_types = NULL;
3921
3922         switch (token.type) {
3923         case T_IDENTIFIER:
3924                 if (env->must_be_abstract) {
3925                         errorf(HERE, "no identifier expected in typename");
3926                 } else {
3927                         env->symbol          = token.v.symbol;
3928                         env->source_position = token.source_position;
3929                 }
3930                 next_token();
3931                 break;
3932         case '(':
3933                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3934                  * interpreted as ``function with no parameter specification'', rather
3935                  * than redundant parentheses around the omitted identifier. */
3936                 if (look_ahead(1)->type != ')') {
3937                         next_token();
3938                         add_anchor_token(')');
3939                         inner_types = parse_inner_declarator(env);
3940                         if (inner_types != NULL) {
3941                                 /* All later declarators only modify the return type */
3942                                 env->must_be_abstract = true;
3943                         }
3944                         rem_anchor_token(')');
3945                         expect(')', end_error);
3946                 }
3947                 break;
3948         default:
3949                 if (env->may_be_abstract)
3950                         break;
3951                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3952                 eat_until_anchor();
3953                 return NULL;
3954         }
3955
3956         construct_type_t **const p = anchor;
3957
3958         for (;;) {
3959                 construct_type_t *type;
3960                 switch (token.type) {
3961                 case '(': {
3962                         scope_t *scope = NULL;
3963                         if (!env->must_be_abstract) {
3964                                 scope = &env->parameters;
3965                         }
3966
3967                         type = parse_function_declarator(scope);
3968                         break;
3969                 }
3970                 case '[':
3971                         type = parse_array_declarator();
3972                         break;
3973                 default:
3974                         goto declarator_finished;
3975                 }
3976
3977                 /* insert in the middle of the list (at p) */
3978                 type->base.next = *p;
3979                 *p              = type;
3980                 if (anchor == p)
3981                         anchor = &type->base.next;
3982         }
3983
3984 declarator_finished:
3985         /* append inner_types at the end of the list, we don't to set anchor anymore
3986          * as it's not needed anymore */
3987         *anchor = inner_types;
3988
3989         return first;
3990 end_error:
3991         return NULL;
3992 }
3993
3994 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
3995 {
3996         construct_type_t *iter = construct_list;
3997         for (; iter != NULL; iter = iter->base.next) {
3998                 switch (iter->kind) {
3999                 case CONSTRUCT_INVALID:
4000                         break;
4001                 case CONSTRUCT_FUNCTION: {
4002                         construct_function_type_t *function      = &iter->function;
4003                         type_t                    *function_type = function->function_type;
4004
4005                         function_type->function.return_type = type;
4006
4007                         type_t *skipped_return_type = skip_typeref(type);
4008                         /* §6.7.5.3:1 */
4009                         if (is_type_function(skipped_return_type)) {
4010                                 errorf(HERE, "function returning function is not allowed");
4011                         } else if (is_type_array(skipped_return_type)) {
4012                                 errorf(HERE, "function returning array is not allowed");
4013                         } else {
4014                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4015                                         warningf(HERE,
4016                                                 "type qualifiers in return type of function type are meaningless");
4017                                 }
4018                         }
4019
4020                         /* The function type was constructed earlier.  Freeing it here will
4021                          * destroy other types. */
4022                         type = typehash_insert(function_type);
4023                         continue;
4024                 }
4025
4026                 case CONSTRUCT_POINTER: {
4027                         if (is_type_reference(skip_typeref(type)))
4028                                 errorf(HERE, "cannot declare a pointer to reference");
4029
4030                         parsed_pointer_t *pointer = &iter->pointer;
4031                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
4032                         continue;
4033                 }
4034
4035                 case CONSTRUCT_REFERENCE:
4036                         if (is_type_reference(skip_typeref(type)))
4037                                 errorf(HERE, "cannot declare a reference to reference");
4038
4039                         type = make_reference_type(type);
4040                         continue;
4041
4042                 case CONSTRUCT_ARRAY: {
4043                         if (is_type_reference(skip_typeref(type)))
4044                                 errorf(HERE, "cannot declare an array of references");
4045
4046                         parsed_array_t *array      = &iter->array;
4047                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
4048
4049                         expression_t *size_expression = array->size;
4050                         if (size_expression != NULL) {
4051                                 size_expression
4052                                         = create_implicit_cast(size_expression, type_size_t);
4053                         }
4054
4055                         array_type->base.qualifiers       = array->type_qualifiers;
4056                         array_type->array.element_type    = type;
4057                         array_type->array.is_static       = array->is_static;
4058                         array_type->array.is_variable     = array->is_variable;
4059                         array_type->array.size_expression = size_expression;
4060
4061                         if (size_expression != NULL) {
4062                                 if (is_constant_expression(size_expression)) {
4063                                         long const size                 = fold_constant(size_expression);
4064                                         array_type->array.size          = size;
4065                                         array_type->array.size_constant = true;
4066                                         /* §6.7.5.2:1  If the expression is a constant expression, it shall
4067                                          * have a value greater than zero. */
4068                                         if (size <= 0) {
4069                                                 if (size < 0 || !GNU_MODE) {
4070                                                         errorf(&size_expression->base.source_position,
4071                                                                         "size of array must be greater than zero");
4072                                                 } else if (warning.other) {
4073                                                         warningf(&size_expression->base.source_position,
4074                                                                         "zero length arrays are a GCC extension");
4075                                                 }
4076                                         }
4077                                 } else {
4078                                         array_type->array.is_vla = true;
4079                                 }
4080                         }
4081
4082                         type_t *skipped_type = skip_typeref(type);
4083                         /* §6.7.5.2:1 */
4084                         if (is_type_incomplete(skipped_type)) {
4085                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4086                         } else if (is_type_function(skipped_type)) {
4087                                 errorf(HERE, "array of functions is not allowed");
4088                         }
4089                         type = identify_new_type(array_type);
4090                         continue;
4091                 }
4092                 }
4093                 internal_errorf(HERE, "invalid type construction found");
4094         }
4095
4096         return type;
4097 }
4098
4099 static type_t *automatic_type_conversion(type_t *orig_type);
4100
4101 static type_t *semantic_parameter(const source_position_t *pos,
4102                                   type_t *type,
4103                                   const declaration_specifiers_t *specifiers,
4104                                   symbol_t *symbol)
4105 {
4106         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4107          *             shall be adjusted to ``qualified pointer to type'',
4108          *             [...]
4109          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4110          *             type'' shall be adjusted to ``pointer to function
4111          *             returning type'', as in 6.3.2.1. */
4112         type = automatic_type_conversion(type);
4113
4114         if (specifiers->is_inline && is_type_valid(type)) {
4115                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
4116         }
4117
4118         /* §6.9.1:6  The declarations in the declaration list shall contain
4119          *           no storage-class specifier other than register and no
4120          *           initializations. */
4121         if (specifiers->thread_local || (
4122                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4123                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4124            ) {
4125                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
4126         }
4127
4128         /* delay test for incomplete type, because we might have (void)
4129          * which is legal but incomplete... */
4130
4131         return type;
4132 }
4133
4134 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4135                                   declarator_flags_t flags)
4136 {
4137         parse_declarator_env_t env;
4138         memset(&env, 0, sizeof(env));
4139         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
4140
4141         construct_type_t *construct_type = parse_inner_declarator(&env);
4142         type_t           *orig_type      =
4143                 construct_declarator_type(construct_type, specifiers->type);
4144         type_t           *type           = skip_typeref(orig_type);
4145
4146         if (construct_type != NULL) {
4147                 obstack_free(&temp_obst, construct_type);
4148         }
4149
4150         attribute_t *attributes = parse_attributes(env.attributes);
4151         /* append (shared) specifier attribute behind attributes of this
4152            declarator */
4153         if (attributes != NULL) {
4154                 attribute_t *last = attributes;
4155                 while (last->next != NULL)
4156                         last = last->next;
4157                 last->next = specifiers->attributes;
4158         } else {
4159                 attributes = specifiers->attributes;
4160         }
4161
4162         entity_t *entity;
4163         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4164                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4165                 entity->base.symbol          = env.symbol;
4166                 entity->base.source_position = env.source_position;
4167                 entity->typedefe.type        = orig_type;
4168
4169                 if (anonymous_entity != NULL) {
4170                         if (is_type_compound(type)) {
4171                                 assert(anonymous_entity->compound.alias == NULL);
4172                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4173                                        anonymous_entity->kind == ENTITY_UNION);
4174                                 anonymous_entity->compound.alias = entity;
4175                                 anonymous_entity = NULL;
4176                         } else if (is_type_enum(type)) {
4177                                 assert(anonymous_entity->enume.alias == NULL);
4178                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4179                                 anonymous_entity->enume.alias = entity;
4180                                 anonymous_entity = NULL;
4181                         }
4182                 }
4183         } else {
4184                 /* create a declaration type entity */
4185                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4186                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4187
4188                         if (env.symbol != NULL) {
4189                                 if (specifiers->is_inline && is_type_valid(type)) {
4190                                         errorf(&env.source_position,
4191                                                         "compound member '%Y' declared 'inline'", env.symbol);
4192                                 }
4193
4194                                 if (specifiers->thread_local ||
4195                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4196                                         errorf(&env.source_position,
4197                                                         "compound member '%Y' must have no storage class",
4198                                                         env.symbol);
4199                                 }
4200                         }
4201                 } else if (flags & DECL_IS_PARAMETER) {
4202                         orig_type = semantic_parameter(&env.source_position, orig_type,
4203                                                        specifiers, env.symbol);
4204
4205                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4206                 } else if (is_type_function(type)) {
4207                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4208
4209                         entity->function.is_inline  = specifiers->is_inline;
4210                         entity->function.parameters = env.parameters;
4211
4212                         if (env.symbol != NULL) {
4213                                 /* this needs fixes for C++ */
4214                                 bool in_function_scope = current_function != NULL;
4215
4216                                 if (specifiers->thread_local || (
4217                                       specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4218                                           specifiers->storage_class != STORAGE_CLASS_NONE   &&
4219                                           (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
4220                                    )) {
4221                                         errorf(&env.source_position,
4222                                                         "invalid storage class for function '%Y'", env.symbol);
4223                                 }
4224                         }
4225                 } else {
4226                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4227
4228                         entity->variable.thread_local = specifiers->thread_local;
4229
4230                         if (env.symbol != NULL) {
4231                                 if (specifiers->is_inline && is_type_valid(type)) {
4232                                         errorf(&env.source_position,
4233                                                         "variable '%Y' declared 'inline'", env.symbol);
4234                                 }
4235
4236                                 bool invalid_storage_class = false;
4237                                 if (current_scope == file_scope) {
4238                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4239                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4240                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4241                                                 invalid_storage_class = true;
4242                                         }
4243                                 } else {
4244                                         if (specifiers->thread_local &&
4245                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4246                                                 invalid_storage_class = true;
4247                                         }
4248                                 }
4249                                 if (invalid_storage_class) {
4250                                         errorf(&env.source_position,
4251                                                         "invalid storage class for variable '%Y'", env.symbol);
4252                                 }
4253                         }
4254                 }
4255
4256                 if (env.symbol != NULL) {
4257                         entity->base.symbol          = env.symbol;
4258                         entity->base.source_position = env.source_position;
4259                 } else {
4260                         entity->base.source_position = specifiers->source_position;
4261                 }
4262                 entity->base.namespc           = NAMESPACE_NORMAL;
4263                 entity->declaration.type       = orig_type;
4264                 entity->declaration.alignment  = get_type_alignment(orig_type);
4265                 entity->declaration.modifiers  = env.modifiers;
4266                 entity->declaration.attributes = attributes;
4267
4268                 storage_class_t storage_class = specifiers->storage_class;
4269                 entity->declaration.declared_storage_class = storage_class;
4270
4271                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4272                         storage_class = STORAGE_CLASS_AUTO;
4273                 entity->declaration.storage_class = storage_class;
4274         }
4275
4276         if (attributes != NULL) {
4277                 handle_entity_attributes(attributes, entity);
4278         }
4279
4280         return entity;
4281 }
4282
4283 static type_t *parse_abstract_declarator(type_t *base_type)
4284 {
4285         parse_declarator_env_t env;
4286         memset(&env, 0, sizeof(env));
4287         env.may_be_abstract = true;
4288         env.must_be_abstract = true;
4289
4290         construct_type_t *construct_type = parse_inner_declarator(&env);
4291
4292         type_t *result = construct_declarator_type(construct_type, base_type);
4293         if (construct_type != NULL) {
4294                 obstack_free(&temp_obst, construct_type);
4295         }
4296         result = handle_type_attributes(env.attributes, result);
4297
4298         return result;
4299 }
4300
4301 /**
4302  * Check if the declaration of main is suspicious.  main should be a
4303  * function with external linkage, returning int, taking either zero
4304  * arguments, two, or three arguments of appropriate types, ie.
4305  *
4306  * int main([ int argc, char **argv [, char **env ] ]).
4307  *
4308  * @param decl    the declaration to check
4309  * @param type    the function type of the declaration
4310  */
4311 static void check_type_of_main(const entity_t *entity)
4312 {
4313         const source_position_t *pos = &entity->base.source_position;
4314         if (entity->kind != ENTITY_FUNCTION) {
4315                 warningf(pos, "'main' is not a function");
4316                 return;
4317         }
4318
4319         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4320                 warningf(pos, "'main' is normally a non-static function");
4321         }
4322
4323         type_t *type = skip_typeref(entity->declaration.type);
4324         assert(is_type_function(type));
4325
4326         function_type_t *func_type = &type->function;
4327         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4328                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4329                          func_type->return_type);
4330         }
4331         const function_parameter_t *parm = func_type->parameters;
4332         if (parm != NULL) {
4333                 type_t *const first_type = parm->type;
4334                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4335                         warningf(pos,
4336                                  "first argument of 'main' should be 'int', but is '%T'",
4337                                  first_type);
4338                 }
4339                 parm = parm->next;
4340                 if (parm != NULL) {
4341                         type_t *const second_type = parm->type;
4342                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4343                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4344                         }
4345                         parm = parm->next;
4346                         if (parm != NULL) {
4347                                 type_t *const third_type = parm->type;
4348                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4349                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4350                                 }
4351                                 parm = parm->next;
4352                                 if (parm != NULL)
4353                                         goto warn_arg_count;
4354                         }
4355                 } else {
4356 warn_arg_count:
4357                         warningf(pos, "'main' takes only zero, two or three arguments");
4358                 }
4359         }
4360 }
4361
4362 /**
4363  * Check if a symbol is the equal to "main".
4364  */
4365 static bool is_sym_main(const symbol_t *const sym)
4366 {
4367         return strcmp(sym->string, "main") == 0;
4368 }
4369
4370 static void error_redefined_as_different_kind(const source_position_t *pos,
4371                 const entity_t *old, entity_kind_t new_kind)
4372 {
4373         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4374                get_entity_kind_name(old->kind), old->base.symbol,
4375                get_entity_kind_name(new_kind), &old->base.source_position);
4376 }
4377
4378 static bool is_error_entity(entity_t *const ent)
4379 {
4380         if (is_declaration(ent)) {
4381                 return is_type_valid(skip_typeref(ent->declaration.type));
4382         } else if (ent->kind == ENTITY_TYPEDEF) {
4383                 return is_type_valid(skip_typeref(ent->typedefe.type));
4384         }
4385         return false;
4386 }
4387
4388 /**
4389  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4390  * for various problems that occur for multiple definitions
4391  */
4392 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4393 {
4394         const symbol_t *const    symbol  = entity->base.symbol;
4395         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4396         const source_position_t *pos     = &entity->base.source_position;
4397
4398         /* can happen in error cases */
4399         if (symbol == NULL)
4400                 return entity;
4401
4402         entity_t *const previous_entity = get_entity(symbol, namespc);
4403         /* pushing the same entity twice will break the stack structure */
4404         assert(previous_entity != entity);
4405
4406         if (entity->kind == ENTITY_FUNCTION) {
4407                 type_t *const orig_type = entity->declaration.type;
4408                 type_t *const type      = skip_typeref(orig_type);
4409
4410                 assert(is_type_function(type));
4411                 if (type->function.unspecified_parameters &&
4412                                 warning.strict_prototypes &&
4413                                 previous_entity == NULL) {
4414                         warningf(pos, "function declaration '%#T' is not a prototype",
4415                                          orig_type, symbol);
4416                 }
4417
4418                 if (warning.main && current_scope == file_scope
4419                                 && is_sym_main(symbol)) {
4420                         check_type_of_main(entity);
4421                 }
4422         }
4423
4424         if (is_declaration(entity) &&
4425                         warning.nested_externs &&
4426                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4427                         current_scope != file_scope) {
4428                 warningf(pos, "nested extern declaration of '%#T'",
4429                          entity->declaration.type, symbol);
4430         }
4431
4432         if (previous_entity != NULL) {
4433                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4434                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4435                         assert(previous_entity->kind == ENTITY_PARAMETER);
4436                         errorf(pos,
4437                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4438                                         entity->declaration.type, symbol,
4439                                         previous_entity->declaration.type, symbol,
4440                                         &previous_entity->base.source_position);
4441                         goto finish;
4442                 }
4443
4444                 if (previous_entity->base.parent_scope == current_scope) {
4445                         if (previous_entity->kind != entity->kind) {
4446                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
4447                                         error_redefined_as_different_kind(pos, previous_entity,
4448                                                         entity->kind);
4449                                 }
4450                                 goto finish;
4451                         }
4452                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4453                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4454                                                 symbol, &previous_entity->base.source_position);
4455                                 goto finish;
4456                         }
4457                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4458                                 /* TODO: C++ allows this for exactly the same type */
4459                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4460                                                 symbol, &previous_entity->base.source_position);
4461                                 goto finish;
4462                         }
4463
4464                         /* at this point we should have only VARIABLES or FUNCTIONS */
4465                         assert(is_declaration(previous_entity) && is_declaration(entity));
4466
4467                         declaration_t *const prev_decl = &previous_entity->declaration;
4468                         declaration_t *const decl      = &entity->declaration;
4469
4470                         /* can happen for K&R style declarations */
4471                         if (prev_decl->type       == NULL             &&
4472                                         previous_entity->kind == ENTITY_PARAMETER &&
4473                                         entity->kind          == ENTITY_PARAMETER) {
4474                                 prev_decl->type                   = decl->type;
4475                                 prev_decl->storage_class          = decl->storage_class;
4476                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4477                                 prev_decl->modifiers              = decl->modifiers;
4478                                 return previous_entity;
4479                         }
4480
4481                         type_t *const orig_type = decl->type;
4482                         assert(orig_type != NULL);
4483                         type_t *const type      = skip_typeref(orig_type);
4484                         type_t *const prev_type = skip_typeref(prev_decl->type);
4485
4486                         if (!types_compatible(type, prev_type)) {
4487                                 errorf(pos,
4488                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4489                                                 orig_type, symbol, prev_decl->type, symbol,
4490                                                 &previous_entity->base.source_position);
4491                         } else {
4492                                 unsigned old_storage_class = prev_decl->storage_class;
4493                                 if (warning.redundant_decls               &&
4494                                                 is_definition                     &&
4495                                                 !prev_decl->used                  &&
4496                                                 !(prev_decl->modifiers & DM_USED) &&
4497                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4498                                         warningf(&previous_entity->base.source_position,
4499                                                         "unnecessary static forward declaration for '%#T'",
4500                                                         prev_decl->type, symbol);
4501                                 }
4502
4503                                 storage_class_t new_storage_class = decl->storage_class;
4504
4505                                 /* pretend no storage class means extern for function
4506                                  * declarations (except if the previous declaration is neither
4507                                  * none nor extern) */
4508                                 if (entity->kind == ENTITY_FUNCTION) {
4509                                         /* the previous declaration could have unspecified parameters or
4510                                          * be a typedef, so use the new type */
4511                                         if (prev_type->function.unspecified_parameters || is_definition)
4512                                                 prev_decl->type = type;
4513
4514                                         switch (old_storage_class) {
4515                                                 case STORAGE_CLASS_NONE:
4516                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4517                                                         /* FALLTHROUGH */
4518
4519                                                 case STORAGE_CLASS_EXTERN:
4520                                                         if (is_definition) {
4521                                                                 if (warning.missing_prototypes &&
4522                                                                                 prev_type->function.unspecified_parameters &&
4523                                                                                 !is_sym_main(symbol)) {
4524                                                                         warningf(pos, "no previous prototype for '%#T'",
4525                                                                                         orig_type, symbol);
4526                                                                 }
4527                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4528                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4529                                                         }
4530                                                         break;
4531
4532                                                 default:
4533                                                         break;
4534                                         }
4535                                 } else if (is_type_incomplete(prev_type)) {
4536                                         prev_decl->type = type;
4537                                 }
4538
4539                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4540                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4541 warn_redundant_declaration:
4542                                         if (!is_definition           &&
4543                                                         warning.redundant_decls  &&
4544                                                         is_type_valid(prev_type) &&
4545                                                         strcmp(previous_entity->base.source_position.input_name,
4546                                                                 "<builtin>") != 0) {
4547                                                 warningf(pos,
4548                                                                 "redundant declaration for '%Y' (declared %P)",
4549                                                                 symbol, &previous_entity->base.source_position);
4550                                         }
4551                                 } else if (current_function == NULL) {
4552                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4553                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4554                                                 errorf(pos,
4555                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
4556                                                                 symbol, &previous_entity->base.source_position);
4557                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4558                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4559                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4560                                         } else {
4561                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4562                                                 if (c_mode & _CXX)
4563                                                         goto error_redeclaration;
4564                                                 goto warn_redundant_declaration;
4565                                         }
4566                                 } else if (is_type_valid(prev_type)) {
4567                                         if (old_storage_class == new_storage_class) {
4568 error_redeclaration:
4569                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4570                                                                 symbol, &previous_entity->base.source_position);
4571                                         } else {
4572                                                 errorf(pos,
4573                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4574                                                                 symbol, &previous_entity->base.source_position);
4575                                         }
4576                                 }
4577                         }
4578
4579                         prev_decl->modifiers |= decl->modifiers;
4580                         if (entity->kind == ENTITY_FUNCTION) {
4581                                 previous_entity->function.is_inline |= entity->function.is_inline;
4582                         }
4583                         return previous_entity;
4584                 }
4585
4586                 if (warning.shadow) {
4587                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4588                                         get_entity_kind_name(entity->kind), symbol,
4589                                         get_entity_kind_name(previous_entity->kind),
4590                                         &previous_entity->base.source_position);
4591                 }
4592         }
4593
4594         if (entity->kind == ENTITY_FUNCTION) {
4595                 if (is_definition &&
4596                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4597                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4598                                 warningf(pos, "no previous prototype for '%#T'",
4599                                          entity->declaration.type, symbol);
4600                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4601                                 warningf(pos, "no previous declaration for '%#T'",
4602                                          entity->declaration.type, symbol);
4603                         }
4604                 }
4605         } else if (warning.missing_declarations &&
4606                         entity->kind == ENTITY_VARIABLE &&
4607                         current_scope == file_scope) {
4608                 declaration_t *declaration = &entity->declaration;
4609                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4610                         warningf(pos, "no previous declaration for '%#T'",
4611                                  declaration->type, symbol);
4612                 }
4613         }
4614
4615 finish:
4616         assert(entity->base.parent_scope == NULL);
4617         assert(current_scope != NULL);
4618
4619         entity->base.parent_scope = current_scope;
4620         entity->base.namespc      = NAMESPACE_NORMAL;
4621         environment_push(entity);
4622         append_entity(current_scope, entity);
4623
4624         return entity;
4625 }
4626
4627 static void parser_error_multiple_definition(entity_t *entity,
4628                 const source_position_t *source_position)
4629 {
4630         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4631                entity->base.symbol, &entity->base.source_position);
4632 }
4633
4634 static bool is_declaration_specifier(const token_t *token,
4635                                      bool only_specifiers_qualifiers)
4636 {
4637         switch (token->type) {
4638                 TYPE_SPECIFIERS
4639                 TYPE_QUALIFIERS
4640                         return true;
4641                 case T_IDENTIFIER:
4642                         return is_typedef_symbol(token->v.symbol);
4643
4644                 case T___extension__:
4645                 STORAGE_CLASSES
4646                         return !only_specifiers_qualifiers;
4647
4648                 default:
4649                         return false;
4650         }
4651 }
4652
4653 static void parse_init_declarator_rest(entity_t *entity)
4654 {
4655         assert(is_declaration(entity));
4656         declaration_t *const declaration = &entity->declaration;
4657
4658         eat('=');
4659
4660         type_t *orig_type = declaration->type;
4661         type_t *type      = skip_typeref(orig_type);
4662
4663         if (entity->kind == ENTITY_VARIABLE
4664                         && entity->variable.initializer != NULL) {
4665                 parser_error_multiple_definition(entity, HERE);
4666         }
4667
4668         bool must_be_constant = false;
4669         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4670             entity->base.parent_scope  == file_scope) {
4671                 must_be_constant = true;
4672         }
4673
4674         if (is_type_function(type)) {
4675                 errorf(&entity->base.source_position,
4676                        "function '%#T' is initialized like a variable",
4677                        orig_type, entity->base.symbol);
4678                 orig_type = type_error_type;
4679         }
4680
4681         parse_initializer_env_t env;
4682         env.type             = orig_type;
4683         env.must_be_constant = must_be_constant;
4684         env.entity           = entity;
4685         current_init_decl    = entity;
4686
4687         initializer_t *initializer = parse_initializer(&env);
4688         current_init_decl = NULL;
4689
4690         if (entity->kind == ENTITY_VARIABLE) {
4691                 /* §6.7.5:22  array initializers for arrays with unknown size
4692                  * determine the array type size */
4693                 declaration->type            = env.type;
4694                 entity->variable.initializer = initializer;
4695         }
4696 }
4697
4698 /* parse rest of a declaration without any declarator */
4699 static void parse_anonymous_declaration_rest(
4700                 const declaration_specifiers_t *specifiers)
4701 {
4702         eat(';');
4703         anonymous_entity = NULL;
4704
4705         if (warning.other) {
4706                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4707                                 specifiers->thread_local) {
4708                         warningf(&specifiers->source_position,
4709                                  "useless storage class in empty declaration");
4710                 }
4711
4712                 type_t *type = specifiers->type;
4713                 switch (type->kind) {
4714                         case TYPE_COMPOUND_STRUCT:
4715                         case TYPE_COMPOUND_UNION: {
4716                                 if (type->compound.compound->base.symbol == NULL) {
4717                                         warningf(&specifiers->source_position,
4718                                                  "unnamed struct/union that defines no instances");
4719                                 }
4720                                 break;
4721                         }
4722
4723                         case TYPE_ENUM:
4724                                 break;
4725
4726                         default:
4727                                 warningf(&specifiers->source_position, "empty declaration");
4728                                 break;
4729                 }
4730         }
4731 }
4732
4733 static void check_variable_type_complete(entity_t *ent)
4734 {
4735         if (ent->kind != ENTITY_VARIABLE)
4736                 return;
4737
4738         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4739          *         type for the object shall be complete [...] */
4740         declaration_t *decl = &ent->declaration;
4741         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4742                         decl->storage_class == STORAGE_CLASS_STATIC)
4743                 return;
4744
4745         type_t *const orig_type = decl->type;
4746         type_t *const type      = skip_typeref(orig_type);
4747         if (!is_type_incomplete(type))
4748                 return;
4749
4750         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4751          * are given length one. */
4752         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4753                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4754                 return;
4755         }
4756
4757         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4758                         orig_type, ent->base.symbol);
4759 }
4760
4761
4762 static void parse_declaration_rest(entity_t *ndeclaration,
4763                 const declaration_specifiers_t *specifiers,
4764                 parsed_declaration_func         finished_declaration,
4765                 declarator_flags_t              flags)
4766 {
4767         add_anchor_token(';');
4768         add_anchor_token(',');
4769         while (true) {
4770                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4771
4772                 if (token.type == '=') {
4773                         parse_init_declarator_rest(entity);
4774                 } else if (entity->kind == ENTITY_VARIABLE) {
4775                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4776                          * [...] where the extern specifier is explicitly used. */
4777                         declaration_t *decl = &entity->declaration;
4778                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4779                                 type_t *type = decl->type;
4780                                 if (is_type_reference(skip_typeref(type))) {
4781                                         errorf(&entity->base.source_position,
4782                                                         "reference '%#T' must be initialized",
4783                                                         type, entity->base.symbol);
4784                                 }
4785                         }
4786                 }
4787
4788                 check_variable_type_complete(entity);
4789
4790                 if (token.type != ',')
4791                         break;
4792                 eat(',');
4793
4794                 add_anchor_token('=');
4795                 ndeclaration = parse_declarator(specifiers, flags);
4796                 rem_anchor_token('=');
4797         }
4798         expect(';', end_error);
4799
4800 end_error:
4801         anonymous_entity = NULL;
4802         rem_anchor_token(';');
4803         rem_anchor_token(',');
4804 }
4805
4806 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4807 {
4808         symbol_t *symbol = entity->base.symbol;
4809         if (symbol == NULL) {
4810                 errorf(HERE, "anonymous declaration not valid as function parameter");
4811                 return entity;
4812         }
4813
4814         assert(entity->base.namespc == NAMESPACE_NORMAL);
4815         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4816         if (previous_entity == NULL
4817                         || previous_entity->base.parent_scope != current_scope) {
4818                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
4819                        symbol);
4820                 return entity;
4821         }
4822
4823         if (is_definition) {
4824                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4825         }
4826
4827         return record_entity(entity, false);
4828 }
4829
4830 static void parse_declaration(parsed_declaration_func finished_declaration,
4831                               declarator_flags_t      flags)
4832 {
4833         declaration_specifiers_t specifiers;
4834         memset(&specifiers, 0, sizeof(specifiers));
4835
4836         add_anchor_token(';');
4837         parse_declaration_specifiers(&specifiers);
4838         rem_anchor_token(';');
4839
4840         if (token.type == ';') {
4841                 parse_anonymous_declaration_rest(&specifiers);
4842         } else {
4843                 entity_t *entity = parse_declarator(&specifiers, flags);
4844                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4845         }
4846 }
4847
4848 /* §6.5.2.2:6 */
4849 static type_t *get_default_promoted_type(type_t *orig_type)
4850 {
4851         type_t *result = orig_type;
4852
4853         type_t *type = skip_typeref(orig_type);
4854         if (is_type_integer(type)) {
4855                 result = promote_integer(type);
4856         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4857                 result = type_double;
4858         }
4859
4860         return result;
4861 }
4862
4863 static void parse_kr_declaration_list(entity_t *entity)
4864 {
4865         if (entity->kind != ENTITY_FUNCTION)
4866                 return;
4867
4868         type_t *type = skip_typeref(entity->declaration.type);
4869         assert(is_type_function(type));
4870         if (!type->function.kr_style_parameters)
4871                 return;
4872
4873
4874         add_anchor_token('{');
4875
4876         /* push function parameters */
4877         size_t const  top       = environment_top();
4878         scope_t      *old_scope = scope_push(&entity->function.parameters);
4879
4880         entity_t *parameter = entity->function.parameters.entities;
4881         for ( ; parameter != NULL; parameter = parameter->base.next) {
4882                 assert(parameter->base.parent_scope == NULL);
4883                 parameter->base.parent_scope = current_scope;
4884                 environment_push(parameter);
4885         }
4886
4887         /* parse declaration list */
4888         for (;;) {
4889                 switch (token.type) {
4890                         DECLARATION_START
4891                         case T___extension__:
4892                         /* This covers symbols, which are no type, too, and results in
4893                          * better error messages.  The typical cases are misspelled type
4894                          * names and missing includes. */
4895                         case T_IDENTIFIER:
4896                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4897                                 break;
4898                         default:
4899                                 goto decl_list_end;
4900                 }
4901         }
4902 decl_list_end:
4903
4904         /* pop function parameters */
4905         assert(current_scope == &entity->function.parameters);
4906         scope_pop(old_scope);
4907         environment_pop_to(top);
4908
4909         /* update function type */
4910         type_t *new_type = duplicate_type(type);
4911
4912         function_parameter_t  *parameters = NULL;
4913         function_parameter_t **anchor     = &parameters;
4914
4915         parameter = entity->function.parameters.entities;
4916         for (; parameter != NULL; parameter = parameter->base.next) {
4917                 if (parameter->kind != ENTITY_PARAMETER)
4918                         continue;
4919
4920                 type_t *parameter_type = parameter->declaration.type;
4921                 if (parameter_type == NULL) {
4922                         if (strict_mode) {
4923                                 errorf(HERE, "no type specified for function parameter '%Y'",
4924                                        parameter->base.symbol);
4925                                 parameter_type = type_error_type;
4926                         } else {
4927                                 if (warning.implicit_int) {
4928                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4929                                                  parameter->base.symbol);
4930                                 }
4931                                 parameter_type = type_int;
4932                         }
4933                         parameter->declaration.type = parameter_type;
4934                 }
4935
4936                 semantic_parameter_incomplete(parameter);
4937
4938                 /*
4939                  * we need the default promoted types for the function type
4940                  */
4941                 parameter_type = get_default_promoted_type(parameter_type);
4942
4943                 function_parameter_t *const parameter =
4944                         allocate_parameter(parameter_type);
4945
4946                 *anchor = parameter;
4947                 anchor  = &parameter->next;
4948         }
4949
4950         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4951          * prototype */
4952         new_type->function.parameters             = parameters;
4953         new_type->function.unspecified_parameters = true;
4954
4955         new_type = identify_new_type(new_type);
4956
4957         entity->declaration.type = new_type;
4958
4959         rem_anchor_token('{');
4960 }
4961
4962 static bool first_err = true;
4963
4964 /**
4965  * When called with first_err set, prints the name of the current function,
4966  * else does noting.
4967  */
4968 static void print_in_function(void)
4969 {
4970         if (first_err) {
4971                 first_err = false;
4972                 diagnosticf("%s: In function '%Y':\n",
4973                             current_function->base.base.source_position.input_name,
4974                             current_function->base.base.symbol);
4975         }
4976 }
4977
4978 /**
4979  * Check if all labels are defined in the current function.
4980  * Check if all labels are used in the current function.
4981  */
4982 static void check_labels(void)
4983 {
4984         for (const goto_statement_t *goto_statement = goto_first;
4985             goto_statement != NULL;
4986             goto_statement = goto_statement->next) {
4987                 /* skip computed gotos */
4988                 if (goto_statement->expression != NULL)
4989                         continue;
4990
4991                 label_t *label = goto_statement->label;
4992
4993                 label->used = true;
4994                 if (label->base.source_position.input_name == NULL) {
4995                         print_in_function();
4996                         errorf(&goto_statement->base.source_position,
4997                                "label '%Y' used but not defined", label->base.symbol);
4998                  }
4999         }
5000
5001         if (warning.unused_label) {
5002                 for (const label_statement_t *label_statement = label_first;
5003                          label_statement != NULL;
5004                          label_statement = label_statement->next) {
5005                         label_t *label = label_statement->label;
5006
5007                         if (! label->used) {
5008                                 print_in_function();
5009                                 warningf(&label_statement->base.source_position,
5010                                          "label '%Y' defined but not used", label->base.symbol);
5011                         }
5012                 }
5013         }
5014 }
5015
5016 static void warn_unused_entity(entity_t *entity, entity_t *last)
5017 {
5018         entity_t const *const end = last != NULL ? last->base.next : NULL;
5019         for (; entity != end; entity = entity->base.next) {
5020                 if (!is_declaration(entity))
5021                         continue;
5022
5023                 declaration_t *declaration = &entity->declaration;
5024                 if (declaration->implicit)
5025                         continue;
5026
5027                 if (!declaration->used) {
5028                         print_in_function();
5029                         const char *what = get_entity_kind_name(entity->kind);
5030                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5031                                  what, entity->base.symbol);
5032                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5033                         print_in_function();
5034                         const char *what = get_entity_kind_name(entity->kind);
5035                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5036                                  what, entity->base.symbol);
5037                 }
5038         }
5039 }
5040
5041 static void check_unused_variables(statement_t *const stmt, void *const env)
5042 {
5043         (void)env;
5044
5045         switch (stmt->kind) {
5046                 case STATEMENT_DECLARATION: {
5047                         declaration_statement_t const *const decls = &stmt->declaration;
5048                         warn_unused_entity(decls->declarations_begin,
5049                                            decls->declarations_end);
5050                         return;
5051                 }
5052
5053                 case STATEMENT_FOR:
5054                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5055                         return;
5056
5057                 default:
5058                         return;
5059         }
5060 }
5061
5062 /**
5063  * Check declarations of current_function for unused entities.
5064  */
5065 static void check_declarations(void)
5066 {
5067         if (warning.unused_parameter) {
5068                 const scope_t *scope = &current_function->parameters;
5069
5070                 /* do not issue unused warnings for main */
5071                 if (!is_sym_main(current_function->base.base.symbol)) {
5072                         warn_unused_entity(scope->entities, NULL);
5073                 }
5074         }
5075         if (warning.unused_variable) {
5076                 walk_statements(current_function->statement, check_unused_variables,
5077                                 NULL);
5078         }
5079 }
5080
5081 static int determine_truth(expression_t const* const cond)
5082 {
5083         return
5084                 !is_constant_expression(cond) ? 0 :
5085                 fold_constant(cond) != 0      ? 1 :
5086                 -1;
5087 }
5088
5089 static void check_reachable(statement_t *);
5090 static bool reaches_end;
5091
5092 static bool expression_returns(expression_t const *const expr)
5093 {
5094         switch (expr->kind) {
5095                 case EXPR_CALL: {
5096                         expression_t const *const func = expr->call.function;
5097                         if (func->kind == EXPR_REFERENCE) {
5098                                 entity_t *entity = func->reference.entity;
5099                                 if (entity->kind == ENTITY_FUNCTION
5100                                                 && entity->declaration.modifiers & DM_NORETURN)
5101                                         return false;
5102                         }
5103
5104                         if (!expression_returns(func))
5105                                 return false;
5106
5107                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5108                                 if (!expression_returns(arg->expression))
5109                                         return false;
5110                         }
5111
5112                         return true;
5113                 }
5114
5115                 case EXPR_REFERENCE:
5116                 case EXPR_REFERENCE_ENUM_VALUE:
5117                 case EXPR_CONST:
5118                 case EXPR_CHARACTER_CONSTANT:
5119                 case EXPR_WIDE_CHARACTER_CONSTANT:
5120                 case EXPR_STRING_LITERAL:
5121                 case EXPR_WIDE_STRING_LITERAL:
5122                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5123                 case EXPR_LABEL_ADDRESS:
5124                 case EXPR_CLASSIFY_TYPE:
5125                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5126                 case EXPR_ALIGNOF:
5127                 case EXPR_FUNCNAME:
5128                 case EXPR_BUILTIN_CONSTANT_P:
5129                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5130                 case EXPR_OFFSETOF:
5131                 case EXPR_INVALID:
5132                         return true;
5133
5134                 case EXPR_STATEMENT: {
5135                         bool old_reaches_end = reaches_end;
5136                         reaches_end = false;
5137                         check_reachable(expr->statement.statement);
5138                         bool returns = reaches_end;
5139                         reaches_end = old_reaches_end;
5140                         return returns;
5141                 }
5142
5143                 case EXPR_CONDITIONAL:
5144                         // TODO handle constant expression
5145
5146                         if (!expression_returns(expr->conditional.condition))
5147                                 return false;
5148
5149                         if (expr->conditional.true_expression != NULL
5150                                         && expression_returns(expr->conditional.true_expression))
5151                                 return true;
5152
5153                         return expression_returns(expr->conditional.false_expression);
5154
5155                 case EXPR_SELECT:
5156                         return expression_returns(expr->select.compound);
5157
5158                 case EXPR_ARRAY_ACCESS:
5159                         return
5160                                 expression_returns(expr->array_access.array_ref) &&
5161                                 expression_returns(expr->array_access.index);
5162
5163                 case EXPR_VA_START:
5164                         return expression_returns(expr->va_starte.ap);
5165
5166                 case EXPR_VA_ARG:
5167                         return expression_returns(expr->va_arge.ap);
5168
5169                 case EXPR_VA_COPY:
5170                         return expression_returns(expr->va_copye.src);
5171
5172                 EXPR_UNARY_CASES_MANDATORY
5173                         return expression_returns(expr->unary.value);
5174
5175                 case EXPR_UNARY_THROW:
5176                         return false;
5177
5178                 EXPR_BINARY_CASES
5179                         // TODO handle constant lhs of && and ||
5180                         return
5181                                 expression_returns(expr->binary.left) &&
5182                                 expression_returns(expr->binary.right);
5183
5184                 case EXPR_UNKNOWN:
5185                         break;
5186         }
5187
5188         panic("unhandled expression");
5189 }
5190
5191 static bool initializer_returns(initializer_t const *const init)
5192 {
5193         switch (init->kind) {
5194                 case INITIALIZER_VALUE:
5195                         return expression_returns(init->value.value);
5196
5197                 case INITIALIZER_LIST: {
5198                         initializer_t * const*       i       = init->list.initializers;
5199                         initializer_t * const* const end     = i + init->list.len;
5200                         bool                         returns = true;
5201                         for (; i != end; ++i) {
5202                                 if (!initializer_returns(*i))
5203                                         returns = false;
5204                         }
5205                         return returns;
5206                 }
5207
5208                 case INITIALIZER_STRING:
5209                 case INITIALIZER_WIDE_STRING:
5210                 case INITIALIZER_DESIGNATOR: // designators have no payload
5211                         return true;
5212         }
5213         panic("unhandled initializer");
5214 }
5215
5216 static bool noreturn_candidate;
5217
5218 static void check_reachable(statement_t *const stmt)
5219 {
5220         if (stmt->base.reachable)
5221                 return;
5222         if (stmt->kind != STATEMENT_DO_WHILE)
5223                 stmt->base.reachable = true;
5224
5225         statement_t *last = stmt;
5226         statement_t *next;
5227         switch (stmt->kind) {
5228                 case STATEMENT_INVALID:
5229                 case STATEMENT_EMPTY:
5230                 case STATEMENT_ASM:
5231                         next = stmt->base.next;
5232                         break;
5233
5234                 case STATEMENT_DECLARATION: {
5235                         declaration_statement_t const *const decl = &stmt->declaration;
5236                         entity_t                const *      ent  = decl->declarations_begin;
5237                         entity_t                const *const last = decl->declarations_end;
5238                         if (ent != NULL) {
5239                                 for (;; ent = ent->base.next) {
5240                                         if (ent->kind                 == ENTITY_VARIABLE &&
5241                                                         ent->variable.initializer != NULL            &&
5242                                                         !initializer_returns(ent->variable.initializer)) {
5243                                                 return;
5244                                         }
5245                                         if (ent == last)
5246                                                 break;
5247                                 }
5248                         }
5249                         next = stmt->base.next;
5250                         break;
5251                 }
5252
5253                 case STATEMENT_COMPOUND:
5254                         next = stmt->compound.statements;
5255                         if (next == NULL)
5256                                 next = stmt->base.next;
5257                         break;
5258
5259                 case STATEMENT_RETURN: {
5260                         expression_t const *const val = stmt->returns.value;
5261                         if (val == NULL || expression_returns(val))
5262                                 noreturn_candidate = false;
5263                         return;
5264                 }
5265
5266                 case STATEMENT_IF: {
5267                         if_statement_t const *const ifs  = &stmt->ifs;
5268                         expression_t   const *const cond = ifs->condition;
5269
5270                         if (!expression_returns(cond))
5271                                 return;
5272
5273                         int const val = determine_truth(cond);
5274
5275                         if (val >= 0)
5276                                 check_reachable(ifs->true_statement);
5277
5278                         if (val > 0)
5279                                 return;
5280
5281                         if (ifs->false_statement != NULL) {
5282                                 check_reachable(ifs->false_statement);
5283                                 return;
5284                         }
5285
5286                         next = stmt->base.next;
5287                         break;
5288                 }
5289
5290                 case STATEMENT_SWITCH: {
5291                         switch_statement_t const *const switchs = &stmt->switchs;
5292                         expression_t       const *const expr    = switchs->expression;
5293
5294                         if (!expression_returns(expr))
5295                                 return;
5296
5297                         if (is_constant_expression(expr)) {
5298                                 long                    const val      = fold_constant(expr);
5299                                 case_label_statement_t *      defaults = NULL;
5300                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5301                                         if (i->expression == NULL) {
5302                                                 defaults = i;
5303                                                 continue;
5304                                         }
5305
5306                                         if (i->first_case <= val && val <= i->last_case) {
5307                                                 check_reachable((statement_t*)i);
5308                                                 return;
5309                                         }
5310                                 }
5311
5312                                 if (defaults != NULL) {
5313                                         check_reachable((statement_t*)defaults);
5314                                         return;
5315                                 }
5316                         } else {
5317                                 bool has_default = false;
5318                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5319                                         if (i->expression == NULL)
5320                                                 has_default = true;
5321
5322                                         check_reachable((statement_t*)i);
5323                                 }
5324
5325                                 if (has_default)
5326                                         return;
5327                         }
5328
5329                         next = stmt->base.next;
5330                         break;
5331                 }
5332
5333                 case STATEMENT_EXPRESSION: {
5334                         /* Check for noreturn function call */
5335                         expression_t const *const expr = stmt->expression.expression;
5336                         if (!expression_returns(expr))
5337                                 return;
5338
5339                         next = stmt->base.next;
5340                         break;
5341                 }
5342
5343                 case STATEMENT_CONTINUE: {
5344                         statement_t *parent = stmt;
5345                         for (;;) {
5346                                 parent = parent->base.parent;
5347                                 if (parent == NULL) /* continue not within loop */
5348                                         return;
5349
5350                                 next = parent;
5351                                 switch (parent->kind) {
5352                                         case STATEMENT_WHILE:    goto continue_while;
5353                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5354                                         case STATEMENT_FOR:      goto continue_for;
5355
5356                                         default: break;
5357                                 }
5358                         }
5359                 }
5360
5361                 case STATEMENT_BREAK: {
5362                         statement_t *parent = stmt;
5363                         for (;;) {
5364                                 parent = parent->base.parent;
5365                                 if (parent == NULL) /* break not within loop/switch */
5366                                         return;
5367
5368                                 switch (parent->kind) {
5369                                         case STATEMENT_SWITCH:
5370                                         case STATEMENT_WHILE:
5371                                         case STATEMENT_DO_WHILE:
5372                                         case STATEMENT_FOR:
5373                                                 last = parent;
5374                                                 next = parent->base.next;
5375                                                 goto found_break_parent;
5376
5377                                         default: break;
5378                                 }
5379                         }
5380 found_break_parent:
5381                         break;
5382                 }
5383
5384                 case STATEMENT_GOTO:
5385                         if (stmt->gotos.expression) {
5386                                 if (!expression_returns(stmt->gotos.expression))
5387                                         return;
5388
5389                                 statement_t *parent = stmt->base.parent;
5390                                 if (parent == NULL) /* top level goto */
5391                                         return;
5392                                 next = parent;
5393                         } else {
5394                                 next = stmt->gotos.label->statement;
5395                                 if (next == NULL) /* missing label */
5396                                         return;
5397                         }
5398                         break;
5399
5400                 case STATEMENT_LABEL:
5401                         next = stmt->label.statement;
5402                         break;
5403
5404                 case STATEMENT_CASE_LABEL:
5405                         next = stmt->case_label.statement;
5406                         break;
5407
5408                 case STATEMENT_WHILE: {
5409                         while_statement_t const *const whiles = &stmt->whiles;
5410                         expression_t      const *const cond   = whiles->condition;
5411
5412                         if (!expression_returns(cond))
5413                                 return;
5414
5415                         int const val = determine_truth(cond);
5416
5417                         if (val >= 0)
5418                                 check_reachable(whiles->body);
5419
5420                         if (val > 0)
5421                                 return;
5422
5423                         next = stmt->base.next;
5424                         break;
5425                 }
5426
5427                 case STATEMENT_DO_WHILE:
5428                         next = stmt->do_while.body;
5429                         break;
5430
5431                 case STATEMENT_FOR: {
5432                         for_statement_t *const fors = &stmt->fors;
5433
5434                         if (fors->condition_reachable)
5435                                 return;
5436                         fors->condition_reachable = true;
5437
5438                         expression_t const *const cond = fors->condition;
5439
5440                         int val;
5441                         if (cond == NULL) {
5442                                 val = 1;
5443                         } else if (expression_returns(cond)) {
5444                                 val = determine_truth(cond);
5445                         } else {
5446                                 return;
5447                         }
5448
5449                         if (val >= 0)
5450                                 check_reachable(fors->body);
5451
5452                         if (val > 0)
5453                                 return;
5454
5455                         next = stmt->base.next;
5456                         break;
5457                 }
5458
5459                 case STATEMENT_MS_TRY: {
5460                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5461                         check_reachable(ms_try->try_statement);
5462                         next = ms_try->final_statement;
5463                         break;
5464                 }
5465
5466                 case STATEMENT_LEAVE: {
5467                         statement_t *parent = stmt;
5468                         for (;;) {
5469                                 parent = parent->base.parent;
5470                                 if (parent == NULL) /* __leave not within __try */
5471                                         return;
5472
5473                                 if (parent->kind == STATEMENT_MS_TRY) {
5474                                         last = parent;
5475                                         next = parent->ms_try.final_statement;
5476                                         break;
5477                                 }
5478                         }
5479                         break;
5480                 }
5481
5482                 default:
5483                         panic("invalid statement kind");
5484         }
5485
5486         while (next == NULL) {
5487                 next = last->base.parent;
5488                 if (next == NULL) {
5489                         noreturn_candidate = false;
5490
5491                         type_t *const type = skip_typeref(current_function->base.type);
5492                         assert(is_type_function(type));
5493                         type_t *const ret  = skip_typeref(type->function.return_type);
5494                         if (warning.return_type                    &&
5495                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5496                             is_type_valid(ret)                     &&
5497                             !is_sym_main(current_function->base.base.symbol)) {
5498                                 warningf(&stmt->base.source_position,
5499                                          "control reaches end of non-void function");
5500                         }
5501                         return;
5502                 }
5503
5504                 switch (next->kind) {
5505                         case STATEMENT_INVALID:
5506                         case STATEMENT_EMPTY:
5507                         case STATEMENT_DECLARATION:
5508                         case STATEMENT_EXPRESSION:
5509                         case STATEMENT_ASM:
5510                         case STATEMENT_RETURN:
5511                         case STATEMENT_CONTINUE:
5512                         case STATEMENT_BREAK:
5513                         case STATEMENT_GOTO:
5514                         case STATEMENT_LEAVE:
5515                                 panic("invalid control flow in function");
5516
5517                         case STATEMENT_COMPOUND:
5518                                 if (next->compound.stmt_expr) {
5519                                         reaches_end = true;
5520                                         return;
5521                                 }
5522                                 /* FALLTHROUGH */
5523                         case STATEMENT_IF:
5524                         case STATEMENT_SWITCH:
5525                         case STATEMENT_LABEL:
5526                         case STATEMENT_CASE_LABEL:
5527                                 last = next;
5528                                 next = next->base.next;
5529                                 break;
5530
5531                         case STATEMENT_WHILE: {
5532 continue_while:
5533                                 if (next->base.reachable)
5534                                         return;
5535                                 next->base.reachable = true;
5536
5537                                 while_statement_t const *const whiles = &next->whiles;
5538                                 expression_t      const *const cond   = whiles->condition;
5539
5540                                 if (!expression_returns(cond))
5541                                         return;
5542
5543                                 int const val = determine_truth(cond);
5544
5545                                 if (val >= 0)
5546                                         check_reachable(whiles->body);
5547
5548                                 if (val > 0)
5549                                         return;
5550
5551                                 last = next;
5552                                 next = next->base.next;
5553                                 break;
5554                         }
5555
5556                         case STATEMENT_DO_WHILE: {
5557 continue_do_while:
5558                                 if (next->base.reachable)
5559                                         return;
5560                                 next->base.reachable = true;
5561
5562                                 do_while_statement_t const *const dw   = &next->do_while;
5563                                 expression_t         const *const cond = dw->condition;
5564
5565                                 if (!expression_returns(cond))
5566                                         return;
5567
5568                                 int const val = determine_truth(cond);
5569
5570                                 if (val >= 0)
5571                                         check_reachable(dw->body);
5572
5573                                 if (val > 0)
5574                                         return;
5575
5576                                 last = next;
5577                                 next = next->base.next;
5578                                 break;
5579                         }
5580
5581                         case STATEMENT_FOR: {
5582 continue_for:;
5583                                 for_statement_t *const fors = &next->fors;
5584
5585                                 fors->step_reachable = true;
5586
5587                                 if (fors->condition_reachable)
5588                                         return;
5589                                 fors->condition_reachable = true;
5590
5591                                 expression_t const *const cond = fors->condition;
5592
5593                                 int val;
5594                                 if (cond == NULL) {
5595                                         val = 1;
5596                                 } else if (expression_returns(cond)) {
5597                                         val = determine_truth(cond);
5598                                 } else {
5599                                         return;
5600                                 }
5601
5602                                 if (val >= 0)
5603                                         check_reachable(fors->body);
5604
5605                                 if (val > 0)
5606                                         return;
5607
5608                                 last = next;
5609                                 next = next->base.next;
5610                                 break;
5611                         }
5612
5613                         case STATEMENT_MS_TRY:
5614                                 last = next;
5615                                 next = next->ms_try.final_statement;
5616                                 break;
5617                 }
5618         }
5619
5620         check_reachable(next);
5621 }
5622
5623 static void check_unreachable(statement_t* const stmt, void *const env)
5624 {
5625         (void)env;
5626
5627         switch (stmt->kind) {
5628                 case STATEMENT_DO_WHILE:
5629                         if (!stmt->base.reachable) {
5630                                 expression_t const *const cond = stmt->do_while.condition;
5631                                 if (determine_truth(cond) >= 0) {
5632                                         warningf(&cond->base.source_position,
5633                                                  "condition of do-while-loop is unreachable");
5634                                 }
5635                         }
5636                         return;
5637
5638                 case STATEMENT_FOR: {
5639                         for_statement_t const* const fors = &stmt->fors;
5640
5641                         // if init and step are unreachable, cond is unreachable, too
5642                         if (!stmt->base.reachable && !fors->step_reachable) {
5643                                 warningf(&stmt->base.source_position, "statement is unreachable");
5644                         } else {
5645                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5646                                         warningf(&fors->initialisation->base.source_position,
5647                                                  "initialisation of for-statement is unreachable");
5648                                 }
5649
5650                                 if (!fors->condition_reachable && fors->condition != NULL) {
5651                                         warningf(&fors->condition->base.source_position,
5652                                                  "condition of for-statement is unreachable");
5653                                 }
5654
5655                                 if (!fors->step_reachable && fors->step != NULL) {
5656                                         warningf(&fors->step->base.source_position,
5657                                                  "step of for-statement is unreachable");
5658                                 }
5659                         }
5660                         return;
5661                 }
5662
5663                 case STATEMENT_COMPOUND:
5664                         if (stmt->compound.statements != NULL)
5665                                 return;
5666                         goto warn_unreachable;
5667
5668                 case STATEMENT_DECLARATION: {
5669                         /* Only warn if there is at least one declarator with an initializer.
5670                          * This typically occurs in switch statements. */
5671                         declaration_statement_t const *const decl = &stmt->declaration;
5672                         entity_t                const *      ent  = decl->declarations_begin;
5673                         entity_t                const *const last = decl->declarations_end;
5674                         if (ent != NULL) {
5675                                 for (;; ent = ent->base.next) {
5676                                         if (ent->kind                 == ENTITY_VARIABLE &&
5677                                                         ent->variable.initializer != NULL) {
5678                                                 goto warn_unreachable;
5679                                         }
5680                                         if (ent == last)
5681                                                 return;
5682                                 }
5683                         }
5684                 }
5685
5686                 default:
5687 warn_unreachable:
5688                         if (!stmt->base.reachable)
5689                                 warningf(&stmt->base.source_position, "statement is unreachable");
5690                         return;
5691         }
5692 }
5693
5694 static void parse_external_declaration(void)
5695 {
5696         /* function-definitions and declarations both start with declaration
5697          * specifiers */
5698         declaration_specifiers_t specifiers;
5699         memset(&specifiers, 0, sizeof(specifiers));
5700
5701         add_anchor_token(';');
5702         parse_declaration_specifiers(&specifiers);
5703         rem_anchor_token(';');
5704
5705         /* must be a declaration */
5706         if (token.type == ';') {
5707                 parse_anonymous_declaration_rest(&specifiers);
5708                 return;
5709         }
5710
5711         add_anchor_token(',');
5712         add_anchor_token('=');
5713         add_anchor_token(';');
5714         add_anchor_token('{');
5715
5716         /* declarator is common to both function-definitions and declarations */
5717         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5718
5719         rem_anchor_token('{');
5720         rem_anchor_token(';');
5721         rem_anchor_token('=');
5722         rem_anchor_token(',');
5723
5724         /* must be a declaration */
5725         switch (token.type) {
5726                 case ',':
5727                 case ';':
5728                 case '=':
5729                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5730                                         DECL_FLAGS_NONE);
5731                         return;
5732         }
5733
5734         /* must be a function definition */
5735         parse_kr_declaration_list(ndeclaration);
5736
5737         if (token.type != '{') {
5738                 parse_error_expected("while parsing function definition", '{', NULL);
5739                 eat_until_matching_token(';');
5740                 return;
5741         }
5742
5743         assert(is_declaration(ndeclaration));
5744         type_t *const orig_type = ndeclaration->declaration.type;
5745         type_t *      type      = skip_typeref(orig_type);
5746
5747         if (!is_type_function(type)) {
5748                 if (is_type_valid(type)) {
5749                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5750                                type, ndeclaration->base.symbol);
5751                 }
5752                 eat_block();
5753                 return;
5754         } else if (is_typeref(orig_type)) {
5755                 /* §6.9.1:2 */
5756                 errorf(&ndeclaration->base.source_position,
5757                                 "type of function definition '%#T' is a typedef",
5758                                 orig_type, ndeclaration->base.symbol);
5759         }
5760
5761         if (warning.aggregate_return &&
5762             is_type_compound(skip_typeref(type->function.return_type))) {
5763                 warningf(HERE, "function '%Y' returns an aggregate",
5764                          ndeclaration->base.symbol);
5765         }
5766         if (warning.traditional && !type->function.unspecified_parameters) {
5767                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5768                         ndeclaration->base.symbol);
5769         }
5770         if (warning.old_style_definition && type->function.unspecified_parameters) {
5771                 warningf(HERE, "old-style function definition '%Y'",
5772                         ndeclaration->base.symbol);
5773         }
5774
5775         /* §6.7.5.3:14 a function definition with () means no
5776          * parameters (and not unspecified parameters) */
5777         if (type->function.unspecified_parameters &&
5778                         type->function.parameters == NULL     &&
5779                         !type->function.kr_style_parameters) {
5780                 type_t *copy                          = duplicate_type(type);
5781                 copy->function.unspecified_parameters = false;
5782                 type                                  = identify_new_type(copy);
5783
5784                 ndeclaration->declaration.type = type;
5785         }
5786
5787         entity_t *const entity = record_entity(ndeclaration, true);
5788         assert(entity->kind == ENTITY_FUNCTION);
5789         assert(ndeclaration->kind == ENTITY_FUNCTION);
5790
5791         function_t *function = &entity->function;
5792         if (ndeclaration != entity) {
5793                 function->parameters = ndeclaration->function.parameters;
5794         }
5795         assert(is_declaration(entity));
5796         type = skip_typeref(entity->declaration.type);
5797
5798         /* push function parameters and switch scope */
5799         size_t const  top       = environment_top();
5800         scope_t      *old_scope = scope_push(&function->parameters);
5801
5802         entity_t *parameter = function->parameters.entities;
5803         for (; parameter != NULL; parameter = parameter->base.next) {
5804                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5805                         parameter->base.parent_scope = current_scope;
5806                 }
5807                 assert(parameter->base.parent_scope == NULL
5808                                 || parameter->base.parent_scope == current_scope);
5809                 parameter->base.parent_scope = current_scope;
5810                 if (parameter->base.symbol == NULL) {
5811                         errorf(&parameter->base.source_position, "parameter name omitted");
5812                         continue;
5813                 }
5814                 environment_push(parameter);
5815         }
5816
5817         if (function->statement != NULL) {
5818                 parser_error_multiple_definition(entity, HERE);
5819                 eat_block();
5820         } else {
5821                 /* parse function body */
5822                 int         label_stack_top      = label_top();
5823                 function_t *old_current_function = current_function;
5824                 current_function                 = function;
5825                 current_parent                   = NULL;
5826
5827                 goto_first   = NULL;
5828                 goto_anchor  = &goto_first;
5829                 label_first  = NULL;
5830                 label_anchor = &label_first;
5831
5832                 statement_t *const body = parse_compound_statement(false);
5833                 function->statement = body;
5834                 first_err = true;
5835                 check_labels();
5836                 check_declarations();
5837                 if (warning.return_type      ||
5838                     warning.unreachable_code ||
5839                     (warning.missing_noreturn
5840                      && !(function->base.modifiers & DM_NORETURN))) {
5841                         noreturn_candidate = true;
5842                         check_reachable(body);
5843                         if (warning.unreachable_code)
5844                                 walk_statements(body, check_unreachable, NULL);
5845                         if (warning.missing_noreturn &&
5846                             noreturn_candidate       &&
5847                             !(function->base.modifiers & DM_NORETURN)) {
5848                                 warningf(&body->base.source_position,
5849                                          "function '%#T' is candidate for attribute 'noreturn'",
5850                                          type, entity->base.symbol);
5851                         }
5852                 }
5853
5854                 assert(current_parent   == NULL);
5855                 assert(current_function == function);
5856                 current_function = old_current_function;
5857                 label_pop_to(label_stack_top);
5858         }
5859
5860         assert(current_scope == &function->parameters);
5861         scope_pop(old_scope);
5862         environment_pop_to(top);
5863 }
5864
5865 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5866                                   source_position_t *source_position,
5867                                   const symbol_t *symbol)
5868 {
5869         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5870
5871         type->bitfield.base_type       = base_type;
5872         type->bitfield.size_expression = size;
5873
5874         il_size_t bit_size;
5875         type_t *skipped_type = skip_typeref(base_type);
5876         if (!is_type_integer(skipped_type)) {
5877                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5878                         base_type);
5879                 bit_size = 0;
5880         } else {
5881                 bit_size = get_type_size(base_type) * 8;
5882         }
5883
5884         if (is_constant_expression(size)) {
5885                 long v = fold_constant(size);
5886
5887                 if (v < 0) {
5888                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
5889                 } else if (v == 0) {
5890                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
5891                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5892                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
5893                 } else {
5894                         type->bitfield.bit_size = v;
5895                 }
5896         }
5897
5898         return type;
5899 }
5900
5901 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5902 {
5903         entity_t *iter = compound->members.entities;
5904         for (; iter != NULL; iter = iter->base.next) {
5905                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5906                         continue;
5907
5908                 if (iter->base.symbol == symbol) {
5909                         return iter;
5910                 } else if (iter->base.symbol == NULL) {
5911                         type_t *type = skip_typeref(iter->declaration.type);
5912                         if (is_type_compound(type)) {
5913                                 entity_t *result
5914                                         = find_compound_entry(type->compound.compound, symbol);
5915                                 if (result != NULL)
5916                                         return result;
5917                         }
5918                         continue;
5919                 }
5920         }
5921
5922         return NULL;
5923 }
5924
5925 static void parse_compound_declarators(compound_t *compound,
5926                 const declaration_specifiers_t *specifiers)
5927 {
5928         while (true) {
5929                 entity_t *entity;
5930
5931                 if (token.type == ':') {
5932                         source_position_t source_position = *HERE;
5933                         next_token();
5934
5935                         type_t *base_type = specifiers->type;
5936                         expression_t *size = parse_constant_expression();
5937
5938                         type_t *type = make_bitfield_type(base_type, size,
5939                                         &source_position, sym_anonymous);
5940
5941                         attribute_t *attributes = parse_attributes(NULL);
5942                         if (attributes != NULL) {
5943                                 attribute_t *last = attributes;
5944                                 while (last->next != NULL)
5945                                         last = last->next;
5946                                 last->next = specifiers->attributes;
5947                         } else {
5948                                 attributes = specifiers->attributes;
5949                         }
5950
5951                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
5952                         entity->base.namespc                       = NAMESPACE_NORMAL;
5953                         entity->base.source_position               = source_position;
5954                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5955                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5956                         entity->declaration.type                   = type;
5957                         entity->declaration.attributes             = attributes;
5958
5959                         if (attributes != NULL) {
5960                                 handle_entity_attributes(attributes, entity);
5961                         }
5962                         append_entity(&compound->members, entity);
5963                 } else {
5964                         entity = parse_declarator(specifiers,
5965                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5966                         if (entity->kind == ENTITY_TYPEDEF) {
5967                                 errorf(&entity->base.source_position,
5968                                                 "typedef not allowed as compound member");
5969                         } else {
5970                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5971
5972                                 /* make sure we don't define a symbol multiple times */
5973                                 symbol_t *symbol = entity->base.symbol;
5974                                 if (symbol != NULL) {
5975                                         entity_t *prev = find_compound_entry(compound, symbol);
5976                                         if (prev != NULL) {
5977                                                 errorf(&entity->base.source_position,
5978                                                                 "multiple declarations of symbol '%Y' (declared %P)",
5979                                                                 symbol, &prev->base.source_position);
5980                                         }
5981                                 }
5982
5983                                 if (token.type == ':') {
5984                                         source_position_t source_position = *HERE;
5985                                         next_token();
5986                                         expression_t *size = parse_constant_expression();
5987
5988                                         type_t *type          = entity->declaration.type;
5989                                         type_t *bitfield_type = make_bitfield_type(type, size,
5990                                                         &source_position, entity->base.symbol);
5991
5992                                         attribute_t *attributes = parse_attributes(NULL);
5993                                         entity->declaration.type = bitfield_type;
5994                                         handle_entity_attributes(attributes, entity);
5995                                 } else {
5996                                         type_t *orig_type = entity->declaration.type;
5997                                         type_t *type      = skip_typeref(orig_type);
5998                                         if (is_type_function(type)) {
5999                                                 errorf(&entity->base.source_position,
6000                                                                 "compound member '%Y' must not have function type '%T'",
6001                                                                 entity->base.symbol, orig_type);
6002                                         } else if (is_type_incomplete(type)) {
6003                                                 /* §6.7.2.1:16 flexible array member */
6004                                                 if (!is_type_array(type)       ||
6005                                                                 token.type          != ';' ||
6006                                                                 look_ahead(1)->type != '}') {
6007                                                         errorf(&entity->base.source_position,
6008                                                                         "compound member '%Y' has incomplete type '%T'",
6009                                                                         entity->base.symbol, orig_type);
6010                                                 }
6011                                         }
6012                                 }
6013
6014                                 append_entity(&compound->members, entity);
6015                         }
6016                 }
6017
6018                 if (token.type != ',')
6019                         break;
6020                 next_token();
6021         }
6022         expect(';', end_error);
6023
6024 end_error:
6025         anonymous_entity = NULL;
6026 }
6027
6028 static void parse_compound_type_entries(compound_t *compound)
6029 {
6030         eat('{');
6031         add_anchor_token('}');
6032
6033         while (token.type != '}') {
6034                 if (token.type == T_EOF) {
6035                         errorf(HERE, "EOF while parsing struct");
6036                         break;
6037                 }
6038                 declaration_specifiers_t specifiers;
6039                 memset(&specifiers, 0, sizeof(specifiers));
6040                 parse_declaration_specifiers(&specifiers);
6041
6042                 parse_compound_declarators(compound, &specifiers);
6043         }
6044         rem_anchor_token('}');
6045         next_token();
6046
6047         /* §6.7.2.1:7 */
6048         compound->complete = true;
6049 }
6050
6051 static type_t *parse_typename(void)
6052 {
6053         declaration_specifiers_t specifiers;
6054         memset(&specifiers, 0, sizeof(specifiers));
6055         parse_declaration_specifiers(&specifiers);
6056         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6057                         specifiers.thread_local) {
6058                 /* TODO: improve error message, user does probably not know what a
6059                  * storage class is...
6060                  */
6061                 errorf(HERE, "typename may not have a storage class");
6062         }
6063
6064         type_t *result = parse_abstract_declarator(specifiers.type);
6065
6066         return result;
6067 }
6068
6069
6070
6071
6072 typedef expression_t* (*parse_expression_function)(void);
6073 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6074
6075 typedef struct expression_parser_function_t expression_parser_function_t;
6076 struct expression_parser_function_t {
6077         parse_expression_function        parser;
6078         precedence_t                     infix_precedence;
6079         parse_expression_infix_function  infix_parser;
6080 };
6081
6082 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6083
6084 /**
6085  * Prints an error message if an expression was expected but not read
6086  */
6087 static expression_t *expected_expression_error(void)
6088 {
6089         /* skip the error message if the error token was read */
6090         if (token.type != T_ERROR) {
6091                 errorf(HERE, "expected expression, got token %K", &token);
6092         }
6093         next_token();
6094
6095         return create_invalid_expression();
6096 }
6097
6098 /**
6099  * Parse a string constant.
6100  */
6101 static expression_t *parse_string_const(void)
6102 {
6103         wide_string_t wres;
6104         if (token.type == T_STRING_LITERAL) {
6105                 string_t res = token.v.string;
6106                 next_token();
6107                 while (token.type == T_STRING_LITERAL) {
6108                         res = concat_strings(&res, &token.v.string);
6109                         next_token();
6110                 }
6111                 if (token.type != T_WIDE_STRING_LITERAL) {
6112                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6113                         /* note: that we use type_char_ptr here, which is already the
6114                          * automatic converted type. revert_automatic_type_conversion
6115                          * will construct the array type */
6116                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6117                         cnst->string.value = res;
6118                         return cnst;
6119                 }
6120
6121                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6122         } else {
6123                 wres = token.v.wide_string;
6124         }
6125         next_token();
6126
6127         for (;;) {
6128                 switch (token.type) {
6129                         case T_WIDE_STRING_LITERAL:
6130                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6131                                 break;
6132
6133                         case T_STRING_LITERAL:
6134                                 wres = concat_wide_string_string(&wres, &token.v.string);
6135                                 break;
6136
6137                         default: {
6138                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6139                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6140                                 cnst->wide_string.value = wres;
6141                                 return cnst;
6142                         }
6143                 }
6144                 next_token();
6145         }
6146 }
6147
6148 /**
6149  * Parse a boolean constant.
6150  */
6151 static expression_t *parse_bool_const(bool value)
6152 {
6153         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6154         cnst->base.type          = type_bool;
6155         cnst->conste.v.int_value = value;
6156
6157         next_token();
6158
6159         return cnst;
6160 }
6161
6162 /**
6163  * Parse an integer constant.
6164  */
6165 static expression_t *parse_int_const(void)
6166 {
6167         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6168         cnst->base.type          = token.datatype;
6169         cnst->conste.v.int_value = token.v.intvalue;
6170
6171         next_token();
6172
6173         return cnst;
6174 }
6175
6176 /**
6177  * Parse a character constant.
6178  */
6179 static expression_t *parse_character_constant(void)
6180 {
6181         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6182         cnst->base.type          = token.datatype;
6183         cnst->conste.v.character = token.v.string;
6184
6185         if (cnst->conste.v.character.size != 1) {
6186                 if (!GNU_MODE) {
6187                         errorf(HERE, "more than 1 character in character constant");
6188                 } else if (warning.multichar) {
6189                         warningf(HERE, "multi-character character constant");
6190                 }
6191         }
6192         next_token();
6193
6194         return cnst;
6195 }
6196
6197 /**
6198  * Parse a wide character constant.
6199  */
6200 static expression_t *parse_wide_character_constant(void)
6201 {
6202         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6203         cnst->base.type               = token.datatype;
6204         cnst->conste.v.wide_character = token.v.wide_string;
6205
6206         if (cnst->conste.v.wide_character.size != 1) {
6207                 if (!GNU_MODE) {
6208                         errorf(HERE, "more than 1 character in character constant");
6209                 } else if (warning.multichar) {
6210                         warningf(HERE, "multi-character character constant");
6211                 }
6212         }
6213         next_token();
6214
6215         return cnst;
6216 }
6217
6218 /**
6219  * Parse a float constant.
6220  */
6221 static expression_t *parse_float_const(void)
6222 {
6223         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6224         cnst->base.type            = token.datatype;
6225         cnst->conste.v.float_value = token.v.floatvalue;
6226
6227         next_token();
6228
6229         return cnst;
6230 }
6231
6232 static entity_t *create_implicit_function(symbol_t *symbol,
6233                 const source_position_t *source_position)
6234 {
6235         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6236         ntype->function.return_type            = type_int;
6237         ntype->function.unspecified_parameters = true;
6238         ntype->function.linkage                = LINKAGE_C;
6239         type_t *type                           = identify_new_type(ntype);
6240
6241         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6242         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6243         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6244         entity->declaration.type                   = type;
6245         entity->declaration.implicit               = true;
6246         entity->base.symbol                        = symbol;
6247         entity->base.source_position               = *source_position;
6248
6249         bool strict_prototypes_old = warning.strict_prototypes;
6250         warning.strict_prototypes  = false;
6251         record_entity(entity, false);
6252         warning.strict_prototypes = strict_prototypes_old;
6253
6254         return entity;
6255 }
6256
6257 /**
6258  * Creates a return_type (func)(argument_type) function type if not
6259  * already exists.
6260  */
6261 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6262                                     type_t *argument_type2)
6263 {
6264         function_parameter_t *const parameter2 = allocate_parameter(argument_type2);
6265         function_parameter_t *const parameter1 = allocate_parameter(argument_type1);
6266         parameter1->next = parameter2;
6267
6268         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6269         type->function.return_type = return_type;
6270         type->function.parameters  = parameter1;
6271
6272         return identify_new_type(type);
6273 }
6274
6275 /**
6276  * Creates a return_type (func)(argument_type) function type if not
6277  * already exists.
6278  *
6279  * @param return_type    the return type
6280  * @param argument_type  the argument type
6281  */
6282 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6283 {
6284         function_parameter_t *const parameter = allocate_parameter(argument_type);
6285
6286         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6287         type->function.return_type = return_type;
6288         type->function.parameters  = parameter;
6289
6290         return identify_new_type(type);
6291 }
6292
6293 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6294 {
6295         type_t *res = make_function_1_type(return_type, argument_type);
6296         res->function.variadic = 1;
6297         return res;
6298 }
6299
6300 /**
6301  * Creates a return_type (func)(void) function type if not
6302  * already exists.
6303  *
6304  * @param return_type    the return type
6305  */
6306 static type_t *make_function_0_type(type_t *return_type)
6307 {
6308         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6309         type->function.return_type = return_type;
6310         type->function.parameters  = NULL;
6311
6312         return identify_new_type(type);
6313 }
6314
6315 /**
6316  * Creates a NO_RETURN 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_noreturn(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         type->function.modifiers  |= DM_NORETURN;
6327         return identify_new_type(type);
6328 }
6329
6330 /**
6331  * Performs automatic type cast as described in §6.3.2.1.
6332  *
6333  * @param orig_type  the original type
6334  */
6335 static type_t *automatic_type_conversion(type_t *orig_type)
6336 {
6337         type_t *type = skip_typeref(orig_type);
6338         if (is_type_array(type)) {
6339                 array_type_t *array_type   = &type->array;
6340                 type_t       *element_type = array_type->element_type;
6341                 unsigned      qualifiers   = array_type->base.qualifiers;
6342
6343                 return make_pointer_type(element_type, qualifiers);
6344         }
6345
6346         if (is_type_function(type)) {
6347                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6348         }
6349
6350         return orig_type;
6351 }
6352
6353 /**
6354  * reverts the automatic casts of array to pointer types and function
6355  * to function-pointer types as defined §6.3.2.1
6356  */
6357 type_t *revert_automatic_type_conversion(const expression_t *expression)
6358 {
6359         switch (expression->kind) {
6360                 case EXPR_REFERENCE: {
6361                         entity_t *entity = expression->reference.entity;
6362                         if (is_declaration(entity)) {
6363                                 return entity->declaration.type;
6364                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6365                                 return entity->enum_value.enum_type;
6366                         } else {
6367                                 panic("no declaration or enum in reference");
6368                         }
6369                 }
6370
6371                 case EXPR_SELECT: {
6372                         entity_t *entity = expression->select.compound_entry;
6373                         assert(is_declaration(entity));
6374                         type_t   *type   = entity->declaration.type;
6375                         return get_qualified_type(type,
6376                                         expression->base.type->base.qualifiers);
6377                 }
6378
6379                 case EXPR_UNARY_DEREFERENCE: {
6380                         const expression_t *const value = expression->unary.value;
6381                         type_t             *const type  = skip_typeref(value->base.type);
6382                         if (!is_type_pointer(type))
6383                                 return type_error_type;
6384                         return type->pointer.points_to;
6385                 }
6386
6387                 case EXPR_ARRAY_ACCESS: {
6388                         const expression_t *array_ref = expression->array_access.array_ref;
6389                         type_t             *type_left = skip_typeref(array_ref->base.type);
6390                         if (!is_type_pointer(type_left))
6391                                 return type_error_type;
6392                         return type_left->pointer.points_to;
6393                 }
6394
6395                 case EXPR_STRING_LITERAL: {
6396                         size_t size = expression->string.value.size;
6397                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6398                 }
6399
6400                 case EXPR_WIDE_STRING_LITERAL: {
6401                         size_t size = expression->wide_string.value.size;
6402                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6403                 }
6404
6405                 case EXPR_COMPOUND_LITERAL:
6406                         return expression->compound_literal.type;
6407
6408                 default:
6409                         return expression->base.type;
6410         }
6411 }
6412
6413 static void check_deprecated(const source_position_t *source_position,
6414                              const entity_t *entity)
6415 {
6416         if (!warning.deprecated_declarations)
6417                 return;
6418         if (!is_declaration(entity))
6419                 return;
6420         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
6421                 return;
6422
6423         char const *const prefix = get_entity_kind_name(entity->kind);
6424         const char *deprecated_string
6425                         = get_deprecated_string(entity->declaration.attributes);
6426         if (deprecated_string != NULL) {
6427                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
6428                                  prefix, entity->base.symbol, &entity->base.source_position,
6429                                  deprecated_string);
6430         } else {
6431                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
6432                                  entity->base.symbol, &entity->base.source_position);
6433         }
6434 }
6435
6436 static expression_t *parse_reference(void)
6437 {
6438         symbol_t *const symbol = token.v.symbol;
6439
6440         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6441
6442         if (entity == NULL) {
6443                 if (!strict_mode && look_ahead(1)->type == '(') {
6444                         /* an implicitly declared function */
6445                         if (warning.error_implicit_function_declaration) {
6446                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
6447                         } else if (warning.implicit_function_declaration) {
6448                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
6449                         }
6450
6451                         entity = create_implicit_function(symbol, HERE);
6452                 } else {
6453                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
6454                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6455                 }
6456         }
6457
6458         type_t *orig_type;
6459
6460         if (is_declaration(entity)) {
6461                 orig_type = entity->declaration.type;
6462         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6463                 orig_type = entity->enum_value.enum_type;
6464         } else {
6465                 panic("expected declaration or enum value in reference");
6466         }
6467
6468         /* we always do the auto-type conversions; the & and sizeof parser contains
6469          * code to revert this! */
6470         type_t *type = automatic_type_conversion(orig_type);
6471
6472         expression_kind_t kind = EXPR_REFERENCE;
6473         if (entity->kind == ENTITY_ENUM_VALUE)
6474                 kind = EXPR_REFERENCE_ENUM_VALUE;
6475
6476         expression_t *expression     = allocate_expression_zero(kind);
6477         expression->reference.entity = entity;
6478         expression->base.type        = type;
6479
6480         /* this declaration is used */
6481         if (is_declaration(entity)) {
6482                 entity->declaration.used = true;
6483         }
6484
6485         if (entity->base.parent_scope != file_scope
6486                 && (current_function != NULL && entity->base.parent_scope->depth < current_function->parameters.depth)
6487                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6488                 if (entity->kind == ENTITY_VARIABLE) {
6489                         /* access of a variable from an outer function */
6490                         entity->variable.address_taken = true;
6491                 } else if (entity->kind == ENTITY_PARAMETER) {
6492                         entity->parameter.address_taken = true;
6493                 }
6494                 current_function->need_closure = true;
6495         }
6496
6497         check_deprecated(HERE, entity);
6498
6499         if (warning.init_self && entity == current_init_decl && !in_type_prop
6500             && entity->kind == ENTITY_VARIABLE) {
6501                 current_init_decl = NULL;
6502                 warningf(HERE, "variable '%#T' is initialized by itself",
6503                          entity->declaration.type, entity->base.symbol);
6504         }
6505
6506         next_token();
6507         return expression;
6508 }
6509
6510 static bool semantic_cast(expression_t *cast)
6511 {
6512         expression_t            *expression      = cast->unary.value;
6513         type_t                  *orig_dest_type  = cast->base.type;
6514         type_t                  *orig_type_right = expression->base.type;
6515         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6516         type_t            const *src_type        = skip_typeref(orig_type_right);
6517         source_position_t const *pos             = &cast->base.source_position;
6518
6519         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6520         if (dst_type == type_void)
6521                 return true;
6522
6523         /* only integer and pointer can be casted to pointer */
6524         if (is_type_pointer(dst_type)  &&
6525             !is_type_pointer(src_type) &&
6526             !is_type_integer(src_type) &&
6527             is_type_valid(src_type)) {
6528                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6529                 return false;
6530         }
6531
6532         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6533                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6534                 return false;
6535         }
6536
6537         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6538                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6539                 return false;
6540         }
6541
6542         if (warning.cast_qual &&
6543             is_type_pointer(src_type) &&
6544             is_type_pointer(dst_type)) {
6545                 type_t *src = skip_typeref(src_type->pointer.points_to);
6546                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6547                 unsigned missing_qualifiers =
6548                         src->base.qualifiers & ~dst->base.qualifiers;
6549                 if (missing_qualifiers != 0) {
6550                         warningf(pos,
6551                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6552                                  missing_qualifiers, orig_type_right);
6553                 }
6554         }
6555         return true;
6556 }
6557
6558 static expression_t *parse_compound_literal(type_t *type)
6559 {
6560         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6561
6562         parse_initializer_env_t env;
6563         env.type             = type;
6564         env.entity           = NULL;
6565         env.must_be_constant = false;
6566         initializer_t *initializer = parse_initializer(&env);
6567         type = env.type;
6568
6569         expression->compound_literal.initializer = initializer;
6570         expression->compound_literal.type        = type;
6571         expression->base.type                    = automatic_type_conversion(type);
6572
6573         return expression;
6574 }
6575
6576 /**
6577  * Parse a cast expression.
6578  */
6579 static expression_t *parse_cast(void)
6580 {
6581         add_anchor_token(')');
6582
6583         source_position_t source_position = token.source_position;
6584
6585         type_t *type = parse_typename();
6586
6587         rem_anchor_token(')');
6588         expect(')', end_error);
6589
6590         if (token.type == '{') {
6591                 return parse_compound_literal(type);
6592         }
6593
6594         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6595         cast->base.source_position = source_position;
6596
6597         expression_t *value = parse_sub_expression(PREC_CAST);
6598         cast->base.type   = type;
6599         cast->unary.value = value;
6600
6601         if (! semantic_cast(cast)) {
6602                 /* TODO: record the error in the AST. else it is impossible to detect it */
6603         }
6604
6605         return cast;
6606 end_error:
6607         return create_invalid_expression();
6608 }
6609
6610 /**
6611  * Parse a statement expression.
6612  */
6613 static expression_t *parse_statement_expression(void)
6614 {
6615         add_anchor_token(')');
6616
6617         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6618
6619         statement_t *statement          = parse_compound_statement(true);
6620         statement->compound.stmt_expr   = true;
6621         expression->statement.statement = statement;
6622
6623         /* find last statement and use its type */
6624         type_t *type = type_void;
6625         const statement_t *stmt = statement->compound.statements;
6626         if (stmt != NULL) {
6627                 while (stmt->base.next != NULL)
6628                         stmt = stmt->base.next;
6629
6630                 if (stmt->kind == STATEMENT_EXPRESSION) {
6631                         type = stmt->expression.expression->base.type;
6632                 }
6633         } else if (warning.other) {
6634                 warningf(&expression->base.source_position, "empty statement expression ({})");
6635         }
6636         expression->base.type = type;
6637
6638         rem_anchor_token(')');
6639         expect(')', end_error);
6640
6641 end_error:
6642         return expression;
6643 }
6644
6645 /**
6646  * Parse a parenthesized expression.
6647  */
6648 static expression_t *parse_parenthesized_expression(void)
6649 {
6650         eat('(');
6651
6652         switch (token.type) {
6653         case '{':
6654                 /* gcc extension: a statement expression */
6655                 return parse_statement_expression();
6656
6657         TYPE_QUALIFIERS
6658         TYPE_SPECIFIERS
6659                 return parse_cast();
6660         case T_IDENTIFIER:
6661                 if (is_typedef_symbol(token.v.symbol)) {
6662                         return parse_cast();
6663                 }
6664         }
6665
6666         add_anchor_token(')');
6667         expression_t *result = parse_expression();
6668         result->base.parenthesized = true;
6669         rem_anchor_token(')');
6670         expect(')', end_error);
6671
6672 end_error:
6673         return result;
6674 }
6675
6676 static expression_t *parse_function_keyword(void)
6677 {
6678         /* TODO */
6679
6680         if (current_function == NULL) {
6681                 errorf(HERE, "'__func__' used outside of a function");
6682         }
6683
6684         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6685         expression->base.type     = type_char_ptr;
6686         expression->funcname.kind = FUNCNAME_FUNCTION;
6687
6688         next_token();
6689
6690         return expression;
6691 }
6692
6693 static expression_t *parse_pretty_function_keyword(void)
6694 {
6695         if (current_function == NULL) {
6696                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6697         }
6698
6699         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6700         expression->base.type     = type_char_ptr;
6701         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6702
6703         eat(T___PRETTY_FUNCTION__);
6704
6705         return expression;
6706 }
6707
6708 static expression_t *parse_funcsig_keyword(void)
6709 {
6710         if (current_function == NULL) {
6711                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6712         }
6713
6714         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6715         expression->base.type     = type_char_ptr;
6716         expression->funcname.kind = FUNCNAME_FUNCSIG;
6717
6718         eat(T___FUNCSIG__);
6719
6720         return expression;
6721 }
6722
6723 static expression_t *parse_funcdname_keyword(void)
6724 {
6725         if (current_function == NULL) {
6726                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6727         }
6728
6729         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6730         expression->base.type     = type_char_ptr;
6731         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6732
6733         eat(T___FUNCDNAME__);
6734
6735         return expression;
6736 }
6737
6738 static designator_t *parse_designator(void)
6739 {
6740         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6741         result->source_position = *HERE;
6742
6743         if (token.type != T_IDENTIFIER) {
6744                 parse_error_expected("while parsing member designator",
6745                                      T_IDENTIFIER, NULL);
6746                 return NULL;
6747         }
6748         result->symbol = token.v.symbol;
6749         next_token();
6750
6751         designator_t *last_designator = result;
6752         while (true) {
6753                 if (token.type == '.') {
6754                         next_token();
6755                         if (token.type != T_IDENTIFIER) {
6756                                 parse_error_expected("while parsing member designator",
6757                                                      T_IDENTIFIER, NULL);
6758                                 return NULL;
6759                         }
6760                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6761                         designator->source_position = *HERE;
6762                         designator->symbol          = token.v.symbol;
6763                         next_token();
6764
6765                         last_designator->next = designator;
6766                         last_designator       = designator;
6767                         continue;
6768                 }
6769                 if (token.type == '[') {
6770                         next_token();
6771                         add_anchor_token(']');
6772                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6773                         designator->source_position = *HERE;
6774                         designator->array_index     = parse_expression();
6775                         rem_anchor_token(']');
6776                         expect(']', end_error);
6777                         if (designator->array_index == NULL) {
6778                                 return NULL;
6779                         }
6780
6781                         last_designator->next = designator;
6782                         last_designator       = designator;
6783                         continue;
6784                 }
6785                 break;
6786         }
6787
6788         return result;
6789 end_error:
6790         return NULL;
6791 }
6792
6793 /**
6794  * Parse the __builtin_offsetof() expression.
6795  */
6796 static expression_t *parse_offsetof(void)
6797 {
6798         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6799         expression->base.type    = type_size_t;
6800
6801         eat(T___builtin_offsetof);
6802
6803         expect('(', end_error);
6804         add_anchor_token(',');
6805         type_t *type = parse_typename();
6806         rem_anchor_token(',');
6807         expect(',', end_error);
6808         add_anchor_token(')');
6809         designator_t *designator = parse_designator();
6810         rem_anchor_token(')');
6811         expect(')', end_error);
6812
6813         expression->offsetofe.type       = type;
6814         expression->offsetofe.designator = designator;
6815
6816         type_path_t path;
6817         memset(&path, 0, sizeof(path));
6818         path.top_type = type;
6819         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6820
6821         descend_into_subtype(&path);
6822
6823         if (!walk_designator(&path, designator, true)) {
6824                 return create_invalid_expression();
6825         }
6826
6827         DEL_ARR_F(path.path);
6828
6829         return expression;
6830 end_error:
6831         return create_invalid_expression();
6832 }
6833
6834 /**
6835  * Parses a _builtin_va_start() expression.
6836  */
6837 static expression_t *parse_va_start(void)
6838 {
6839         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6840
6841         eat(T___builtin_va_start);
6842
6843         expect('(', end_error);
6844         add_anchor_token(',');
6845         expression->va_starte.ap = parse_assignment_expression();
6846         rem_anchor_token(',');
6847         expect(',', end_error);
6848         expression_t *const expr = parse_assignment_expression();
6849         if (expr->kind == EXPR_REFERENCE) {
6850                 entity_t *const entity = expr->reference.entity;
6851                 if (entity->base.parent_scope != &current_function->parameters
6852                                 || entity->base.next != NULL
6853                                 || entity->kind != ENTITY_PARAMETER) {
6854                         errorf(&expr->base.source_position,
6855                                "second argument of 'va_start' must be last parameter of the current function");
6856                 } else {
6857                         expression->va_starte.parameter = &entity->variable;
6858                 }
6859                 expect(')', end_error);
6860                 return expression;
6861         }
6862         expect(')', end_error);
6863 end_error:
6864         return create_invalid_expression();
6865 }
6866
6867 /**
6868  * Parses a __builtin_va_arg() expression.
6869  */
6870 static expression_t *parse_va_arg(void)
6871 {
6872         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6873
6874         eat(T___builtin_va_arg);
6875
6876         expect('(', end_error);
6877         call_argument_t ap;
6878         ap.expression = parse_assignment_expression();
6879         expression->va_arge.ap = ap.expression;
6880         check_call_argument(type_valist, &ap, 1);
6881
6882         expect(',', end_error);
6883         expression->base.type = parse_typename();
6884         expect(')', end_error);
6885
6886         return expression;
6887 end_error:
6888         return create_invalid_expression();
6889 }
6890
6891 /**
6892  * Parses a __builtin_va_copy() expression.
6893  */
6894 static expression_t *parse_va_copy(void)
6895 {
6896         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6897
6898         eat(T___builtin_va_copy);
6899
6900         expect('(', end_error);
6901         expression_t *dst = parse_assignment_expression();
6902         assign_error_t error = semantic_assign(type_valist, dst);
6903         report_assign_error(error, type_valist, dst, "call argument 1",
6904                             &dst->base.source_position);
6905         expression->va_copye.dst = dst;
6906
6907         expect(',', end_error);
6908
6909         call_argument_t src;
6910         src.expression = parse_assignment_expression();
6911         check_call_argument(type_valist, &src, 2);
6912         expression->va_copye.src = src.expression;
6913         expect(')', end_error);
6914
6915         return expression;
6916 end_error:
6917         return create_invalid_expression();
6918 }
6919
6920 /**
6921  * Parses a __builtin_constant_p() expression.
6922  */
6923 static expression_t *parse_builtin_constant(void)
6924 {
6925         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6926
6927         eat(T___builtin_constant_p);
6928
6929         expect('(', end_error);
6930         add_anchor_token(')');
6931         expression->builtin_constant.value = parse_assignment_expression();
6932         rem_anchor_token(')');
6933         expect(')', end_error);
6934         expression->base.type = type_int;
6935
6936         return expression;
6937 end_error:
6938         return create_invalid_expression();
6939 }
6940
6941 /**
6942  * Parses a __builtin_types_compatible_p() expression.
6943  */
6944 static expression_t *parse_builtin_types_compatible(void)
6945 {
6946         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6947
6948         eat(T___builtin_types_compatible_p);
6949
6950         expect('(', end_error);
6951         add_anchor_token(')');
6952         add_anchor_token(',');
6953         expression->builtin_types_compatible.left = parse_typename();
6954         rem_anchor_token(',');
6955         expect(',', end_error);
6956         expression->builtin_types_compatible.right = parse_typename();
6957         rem_anchor_token(')');
6958         expect(')', end_error);
6959         expression->base.type = type_int;
6960
6961         return expression;
6962 end_error:
6963         return create_invalid_expression();
6964 }
6965
6966 /**
6967  * Parses a __builtin_is_*() compare expression.
6968  */
6969 static expression_t *parse_compare_builtin(void)
6970 {
6971         expression_t *expression;
6972
6973         switch (token.type) {
6974         case T___builtin_isgreater:
6975                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6976                 break;
6977         case T___builtin_isgreaterequal:
6978                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6979                 break;
6980         case T___builtin_isless:
6981                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6982                 break;
6983         case T___builtin_islessequal:
6984                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6985                 break;
6986         case T___builtin_islessgreater:
6987                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6988                 break;
6989         case T___builtin_isunordered:
6990                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6991                 break;
6992         default:
6993                 internal_errorf(HERE, "invalid compare builtin found");
6994         }
6995         expression->base.source_position = *HERE;
6996         next_token();
6997
6998         expect('(', end_error);
6999         expression->binary.left = parse_assignment_expression();
7000         expect(',', end_error);
7001         expression->binary.right = parse_assignment_expression();
7002         expect(')', end_error);
7003
7004         type_t *const orig_type_left  = expression->binary.left->base.type;
7005         type_t *const orig_type_right = expression->binary.right->base.type;
7006
7007         type_t *const type_left  = skip_typeref(orig_type_left);
7008         type_t *const type_right = skip_typeref(orig_type_right);
7009         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7010                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7011                         type_error_incompatible("invalid operands in comparison",
7012                                 &expression->base.source_position, orig_type_left, orig_type_right);
7013                 }
7014         } else {
7015                 semantic_comparison(&expression->binary);
7016         }
7017
7018         return expression;
7019 end_error:
7020         return create_invalid_expression();
7021 }
7022
7023 #if 0
7024 /**
7025  * Parses a __builtin_expect(, end_error) expression.
7026  */
7027 static expression_t *parse_builtin_expect(void, end_error)
7028 {
7029         expression_t *expression
7030                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7031
7032         eat(T___builtin_expect);
7033
7034         expect('(', end_error);
7035         expression->binary.left = parse_assignment_expression();
7036         expect(',', end_error);
7037         expression->binary.right = parse_constant_expression();
7038         expect(')', end_error);
7039
7040         expression->base.type = expression->binary.left->base.type;
7041
7042         return expression;
7043 end_error:
7044         return create_invalid_expression();
7045 }
7046 #endif
7047
7048 /**
7049  * Parses a MS assume() expression.
7050  */
7051 static expression_t *parse_assume(void)
7052 {
7053         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7054
7055         eat(T__assume);
7056
7057         expect('(', end_error);
7058         add_anchor_token(')');
7059         expression->unary.value = parse_assignment_expression();
7060         rem_anchor_token(')');
7061         expect(')', end_error);
7062
7063         expression->base.type = type_void;
7064         return expression;
7065 end_error:
7066         return create_invalid_expression();
7067 }
7068
7069 /**
7070  * Return the declaration for a given label symbol or create a new one.
7071  *
7072  * @param symbol  the symbol of the label
7073  */
7074 static label_t *get_label(symbol_t *symbol)
7075 {
7076         entity_t *label;
7077         assert(current_function != NULL);
7078
7079         label = get_entity(symbol, NAMESPACE_LABEL);
7080         /* if we found a local label, we already created the declaration */
7081         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7082                 if (label->base.parent_scope != current_scope) {
7083                         assert(label->base.parent_scope->depth < current_scope->depth);
7084                         current_function->goto_to_outer = true;
7085                 }
7086                 return &label->label;
7087         }
7088
7089         label = get_entity(symbol, NAMESPACE_LABEL);
7090         /* if we found a label in the same function, then we already created the
7091          * declaration */
7092         if (label != NULL
7093                         && label->base.parent_scope == &current_function->parameters) {
7094                 return &label->label;
7095         }
7096
7097         /* otherwise we need to create a new one */
7098         label               = allocate_entity_zero(ENTITY_LABEL);
7099         label->base.namespc = NAMESPACE_LABEL;
7100         label->base.symbol  = symbol;
7101
7102         label_push(label);
7103
7104         return &label->label;
7105 }
7106
7107 /**
7108  * Parses a GNU && label address expression.
7109  */
7110 static expression_t *parse_label_address(void)
7111 {
7112         source_position_t source_position = token.source_position;
7113         eat(T_ANDAND);
7114         if (token.type != T_IDENTIFIER) {
7115                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7116                 goto end_error;
7117         }
7118         symbol_t *symbol = token.v.symbol;
7119         next_token();
7120
7121         label_t *label       = get_label(symbol);
7122         label->used          = true;
7123         label->address_taken = true;
7124
7125         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7126         expression->base.source_position = source_position;
7127
7128         /* label address is threaten as a void pointer */
7129         expression->base.type           = type_void_ptr;
7130         expression->label_address.label = label;
7131         return expression;
7132 end_error:
7133         return create_invalid_expression();
7134 }
7135
7136 /**
7137  * Parse a microsoft __noop expression.
7138  */
7139 static expression_t *parse_noop_expression(void)
7140 {
7141         /* the result is a (int)0 */
7142         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7143         cnst->base.type            = type_int;
7144         cnst->conste.v.int_value   = 0;
7145         cnst->conste.is_ms_noop    = true;
7146
7147         eat(T___noop);
7148
7149         if (token.type == '(') {
7150                 /* parse arguments */
7151                 eat('(');
7152                 add_anchor_token(')');
7153                 add_anchor_token(',');
7154
7155                 if (token.type != ')') {
7156                         while (true) {
7157                                 (void)parse_assignment_expression();
7158                                 if (token.type != ',')
7159                                         break;
7160                                 next_token();
7161                         }
7162                 }
7163         }
7164         rem_anchor_token(',');
7165         rem_anchor_token(')');
7166         expect(')', end_error);
7167
7168 end_error:
7169         return cnst;
7170 }
7171
7172 /**
7173  * Parses a primary expression.
7174  */
7175 static expression_t *parse_primary_expression(void)
7176 {
7177         switch (token.type) {
7178                 case T_false:                        return parse_bool_const(false);
7179                 case T_true:                         return parse_bool_const(true);
7180                 case T_INTEGER:                      return parse_int_const();
7181                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7182                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7183                 case T_FLOATINGPOINT:                return parse_float_const();
7184                 case T_STRING_LITERAL:
7185                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7186                 case T___FUNCTION__:
7187                 case T___func__:                     return parse_function_keyword();
7188                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7189                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7190                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7191                 case T___builtin_offsetof:           return parse_offsetof();
7192                 case T___builtin_va_start:           return parse_va_start();
7193                 case T___builtin_va_arg:             return parse_va_arg();
7194                 case T___builtin_va_copy:            return parse_va_copy();
7195                 case T___builtin_isgreater:
7196                 case T___builtin_isgreaterequal:
7197                 case T___builtin_isless:
7198                 case T___builtin_islessequal:
7199                 case T___builtin_islessgreater:
7200                 case T___builtin_isunordered:        return parse_compare_builtin();
7201                 case T___builtin_constant_p:         return parse_builtin_constant();
7202                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7203                 case T__assume:                      return parse_assume();
7204                 case T_ANDAND:
7205                         if (GNU_MODE)
7206                                 return parse_label_address();
7207                         break;
7208
7209                 case '(':                            return parse_parenthesized_expression();
7210                 case T___noop:                       return parse_noop_expression();
7211
7212                 /* Gracefully handle type names while parsing expressions. */
7213                 case T_IDENTIFIER:
7214                         if (!is_typedef_symbol(token.v.symbol)) {
7215                                 return parse_reference();
7216                         }
7217                         /* FALLTHROUGH */
7218                 TYPENAME_START {
7219                         source_position_t  const pos  = *HERE;
7220                         type_t const      *const type = parse_typename();
7221                         errorf(&pos, "encountered type '%T' while parsing expression", type);
7222                         return create_invalid_expression();
7223                 }
7224         }
7225
7226         errorf(HERE, "unexpected token %K, expected an expression", &token);
7227         return create_invalid_expression();
7228 }
7229
7230 /**
7231  * Check if the expression has the character type and issue a warning then.
7232  */
7233 static void check_for_char_index_type(const expression_t *expression)
7234 {
7235         type_t       *const type      = expression->base.type;
7236         const type_t *const base_type = skip_typeref(type);
7237
7238         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7239                         warning.char_subscripts) {
7240                 warningf(&expression->base.source_position,
7241                          "array subscript has type '%T'", type);
7242         }
7243 }
7244
7245 static expression_t *parse_array_expression(expression_t *left)
7246 {
7247         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7248
7249         eat('[');
7250         add_anchor_token(']');
7251
7252         expression_t *inside = parse_expression();
7253
7254         type_t *const orig_type_left   = left->base.type;
7255         type_t *const orig_type_inside = inside->base.type;
7256
7257         type_t *const type_left   = skip_typeref(orig_type_left);
7258         type_t *const type_inside = skip_typeref(orig_type_inside);
7259
7260         type_t                    *return_type;
7261         array_access_expression_t *array_access = &expression->array_access;
7262         if (is_type_pointer(type_left)) {
7263                 return_type             = type_left->pointer.points_to;
7264                 array_access->array_ref = left;
7265                 array_access->index     = inside;
7266                 check_for_char_index_type(inside);
7267         } else if (is_type_pointer(type_inside)) {
7268                 return_type             = type_inside->pointer.points_to;
7269                 array_access->array_ref = inside;
7270                 array_access->index     = left;
7271                 array_access->flipped   = true;
7272                 check_for_char_index_type(left);
7273         } else {
7274                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7275                         errorf(HERE,
7276                                 "array access on object with non-pointer types '%T', '%T'",
7277                                 orig_type_left, orig_type_inside);
7278                 }
7279                 return_type             = type_error_type;
7280                 array_access->array_ref = left;
7281                 array_access->index     = inside;
7282         }
7283
7284         expression->base.type = automatic_type_conversion(return_type);
7285
7286         rem_anchor_token(']');
7287         expect(']', end_error);
7288 end_error:
7289         return expression;
7290 }
7291
7292 static expression_t *parse_typeprop(expression_kind_t const kind)
7293 {
7294         expression_t  *tp_expression = allocate_expression_zero(kind);
7295         tp_expression->base.type     = type_size_t;
7296
7297         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7298
7299         /* we only refer to a type property, mark this case */
7300         bool old     = in_type_prop;
7301         in_type_prop = true;
7302
7303         type_t       *orig_type;
7304         expression_t *expression;
7305         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7306                 next_token();
7307                 add_anchor_token(')');
7308                 orig_type = parse_typename();
7309                 rem_anchor_token(')');
7310                 expect(')', end_error);
7311
7312                 if (token.type == '{') {
7313                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7314                          * starting with a compound literal */
7315                         expression = parse_compound_literal(orig_type);
7316                         goto typeprop_expression;
7317                 }
7318         } else {
7319                 expression = parse_sub_expression(PREC_UNARY);
7320
7321 typeprop_expression:
7322                 tp_expression->typeprop.tp_expression = expression;
7323
7324                 orig_type = revert_automatic_type_conversion(expression);
7325                 expression->base.type = orig_type;
7326         }
7327
7328         tp_expression->typeprop.type   = orig_type;
7329         type_t const* const type       = skip_typeref(orig_type);
7330         char   const* const wrong_type =
7331                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7332                 is_type_incomplete(type)                           ? "incomplete"          :
7333                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7334                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7335                 NULL;
7336         if (wrong_type != NULL) {
7337                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7338                 errorf(&tp_expression->base.source_position,
7339                                 "operand of %s expression must not be of %s type '%T'",
7340                                 what, wrong_type, orig_type);
7341         }
7342
7343 end_error:
7344         in_type_prop = old;
7345         return tp_expression;
7346 }
7347
7348 static expression_t *parse_sizeof(void)
7349 {
7350         return parse_typeprop(EXPR_SIZEOF);
7351 }
7352
7353 static expression_t *parse_alignof(void)
7354 {
7355         return parse_typeprop(EXPR_ALIGNOF);
7356 }
7357
7358 static expression_t *parse_select_expression(expression_t *compound)
7359 {
7360         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7361         select->select.compound = compound;
7362
7363         assert(token.type == '.' || token.type == T_MINUSGREATER);
7364         bool is_pointer = (token.type == T_MINUSGREATER);
7365         next_token();
7366
7367         if (token.type != T_IDENTIFIER) {
7368                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7369                 return select;
7370         }
7371         symbol_t *symbol = token.v.symbol;
7372         next_token();
7373
7374         type_t *const orig_type = compound->base.type;
7375         type_t *const type      = skip_typeref(orig_type);
7376
7377         type_t *type_left;
7378         bool    saw_error = false;
7379         if (is_type_pointer(type)) {
7380                 if (!is_pointer) {
7381                         errorf(HERE,
7382                                "request for member '%Y' in something not a struct or union, but '%T'",
7383                                symbol, orig_type);
7384                         saw_error = true;
7385                 }
7386                 type_left = skip_typeref(type->pointer.points_to);
7387         } else {
7388                 if (is_pointer && is_type_valid(type)) {
7389                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7390                         saw_error = true;
7391                 }
7392                 type_left = type;
7393         }
7394
7395         entity_t *entry;
7396         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7397             type_left->kind == TYPE_COMPOUND_UNION) {
7398                 compound_t *compound = type_left->compound.compound;
7399
7400                 if (!compound->complete) {
7401                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7402                                symbol, type_left);
7403                         goto create_error_entry;
7404                 }
7405
7406                 entry = find_compound_entry(compound, symbol);
7407                 if (entry == NULL) {
7408                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7409                         goto create_error_entry;
7410                 }
7411         } else {
7412                 if (is_type_valid(type_left) && !saw_error) {
7413                         errorf(HERE,
7414                                "request for member '%Y' in something not a struct or union, but '%T'",
7415                                symbol, type_left);
7416                 }
7417 create_error_entry:
7418                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7419         }
7420
7421         assert(is_declaration(entry));
7422         select->select.compound_entry = entry;
7423
7424         check_deprecated(HERE, entry);
7425
7426         type_t *entry_type = entry->declaration.type;
7427         type_t *res_type
7428                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7429
7430         /* we always do the auto-type conversions; the & and sizeof parser contains
7431          * code to revert this! */
7432         select->base.type = automatic_type_conversion(res_type);
7433
7434         type_t *skipped = skip_typeref(res_type);
7435         if (skipped->kind == TYPE_BITFIELD) {
7436                 select->base.type = skipped->bitfield.base_type;
7437         }
7438
7439         return select;
7440 }
7441
7442 static void check_call_argument(type_t          *expected_type,
7443                                 call_argument_t *argument, unsigned pos)
7444 {
7445         type_t         *expected_type_skip = skip_typeref(expected_type);
7446         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7447         expression_t   *arg_expr           = argument->expression;
7448         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7449
7450         /* handle transparent union gnu extension */
7451         if (is_type_union(expected_type_skip)
7452                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7453                 compound_t *union_decl  = expected_type_skip->compound.compound;
7454                 type_t     *best_type   = NULL;
7455                 entity_t   *entry       = union_decl->members.entities;
7456                 for ( ; entry != NULL; entry = entry->base.next) {
7457                         assert(is_declaration(entry));
7458                         type_t *decl_type = entry->declaration.type;
7459                         error = semantic_assign(decl_type, arg_expr);
7460                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7461                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7462                                 continue;
7463
7464                         if (error == ASSIGN_SUCCESS) {
7465                                 best_type = decl_type;
7466                         } else if (best_type == NULL) {
7467                                 best_type = decl_type;
7468                         }
7469                 }
7470
7471                 if (best_type != NULL) {
7472                         expected_type = best_type;
7473                 }
7474         }
7475
7476         error                = semantic_assign(expected_type, arg_expr);
7477         argument->expression = create_implicit_cast(arg_expr, expected_type);
7478
7479         if (error != ASSIGN_SUCCESS) {
7480                 /* report exact scope in error messages (like "in argument 3") */
7481                 char buf[64];
7482                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7483                 report_assign_error(error, expected_type, arg_expr,     buf,
7484                                                         &arg_expr->base.source_position);
7485         } else if (warning.traditional || warning.conversion) {
7486                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7487                 if (!types_compatible(expected_type_skip, promoted_type) &&
7488                     !types_compatible(expected_type_skip, type_void_ptr) &&
7489                     !types_compatible(type_void_ptr,      promoted_type)) {
7490                         /* Deliberately show the skipped types in this warning */
7491                         warningf(&arg_expr->base.source_position,
7492                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7493                                 pos, expected_type_skip, promoted_type);
7494                 }
7495         }
7496 }
7497
7498 /**
7499  * Handle the semantic restrictions of builtin calls
7500  */
7501 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7502         switch (call->function->reference.entity->function.btk) {
7503                 case bk_gnu_builtin_return_address:
7504                 case bk_gnu_builtin_frame_address: {
7505                         /* argument must be constant */
7506                         call_argument_t *argument = call->arguments;
7507
7508                         if (! is_constant_expression(argument->expression)) {
7509                                 errorf(&call->base.source_position,
7510                                        "argument of '%Y' must be a constant expression",
7511                                        call->function->reference.entity->base.symbol);
7512                         }
7513                         break;
7514                 }
7515                 case bk_gnu_builtin_prefetch: {
7516                         /* second and third argument must be constant if existent */
7517                         call_argument_t *rw = call->arguments->next;
7518                         call_argument_t *locality = NULL;
7519
7520                         if (rw != NULL) {
7521                                 if (! is_constant_expression(rw->expression)) {
7522                                         errorf(&call->base.source_position,
7523                                                "second argument of '%Y' must be a constant expression",
7524                                                call->function->reference.entity->base.symbol);
7525                                 }
7526                                 locality = rw->next;
7527                         }
7528                         if (locality != NULL) {
7529                                 if (! is_constant_expression(locality->expression)) {
7530                                         errorf(&call->base.source_position,
7531                                                "third argument of '%Y' must be a constant expression",
7532                                                call->function->reference.entity->base.symbol);
7533                                 }
7534                                 locality = rw->next;
7535                         }
7536                         break;
7537                 }
7538                 default:
7539                         break;
7540         }
7541 }
7542
7543 /**
7544  * Parse a call expression, ie. expression '( ... )'.
7545  *
7546  * @param expression  the function address
7547  */
7548 static expression_t *parse_call_expression(expression_t *expression)
7549 {
7550         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7551         call_expression_t *call   = &result->call;
7552         call->function            = expression;
7553
7554         type_t *const orig_type = expression->base.type;
7555         type_t *const type      = skip_typeref(orig_type);
7556
7557         function_type_t *function_type = NULL;
7558         if (is_type_pointer(type)) {
7559                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7560
7561                 if (is_type_function(to_type)) {
7562                         function_type   = &to_type->function;
7563                         call->base.type = function_type->return_type;
7564                 }
7565         }
7566
7567         if (function_type == NULL && is_type_valid(type)) {
7568                 errorf(HERE,
7569                        "called object '%E' (type '%T') is not a pointer to a function",
7570                        expression, orig_type);
7571         }
7572
7573         /* parse arguments */
7574         eat('(');
7575         add_anchor_token(')');
7576         add_anchor_token(',');
7577
7578         if (token.type != ')') {
7579                 call_argument_t **anchor = &call->arguments;
7580                 for (;;) {
7581                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7582                         argument->expression = parse_assignment_expression();
7583
7584                         *anchor = argument;
7585                         anchor  = &argument->next;
7586
7587                         if (token.type != ',')
7588                                 break;
7589                         next_token();
7590                 }
7591         }
7592         rem_anchor_token(',');
7593         rem_anchor_token(')');
7594         expect(')', end_error);
7595
7596         if (function_type == NULL)
7597                 return result;
7598
7599         /* check type and count of call arguments */
7600         function_parameter_t *parameter = function_type->parameters;
7601         call_argument_t      *argument  = call->arguments;
7602         if (!function_type->unspecified_parameters) {
7603                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7604                                 parameter = parameter->next, argument = argument->next) {
7605                         check_call_argument(parameter->type, argument, ++pos);
7606                 }
7607
7608                 if (parameter != NULL) {
7609                         errorf(HERE, "too few arguments to function '%E'", expression);
7610                 } else if (argument != NULL && !function_type->variadic) {
7611                         errorf(HERE, "too many arguments to function '%E'", expression);
7612                 }
7613         }
7614
7615         /* do default promotion for other arguments */
7616         for (; argument != NULL; argument = argument->next) {
7617                 type_t *type = argument->expression->base.type;
7618
7619                 type = get_default_promoted_type(type);
7620
7621                 argument->expression
7622                         = create_implicit_cast(argument->expression, type);
7623         }
7624
7625         check_format(&result->call);
7626
7627         if (warning.aggregate_return &&
7628             is_type_compound(skip_typeref(function_type->return_type))) {
7629                 warningf(&result->base.source_position,
7630                          "function call has aggregate value");
7631         }
7632
7633         if (call->function->kind == EXPR_REFERENCE) {
7634                 reference_expression_t *reference = &call->function->reference;
7635                 if (reference->entity->kind == ENTITY_FUNCTION &&
7636                     reference->entity->function.btk != bk_none)
7637                         handle_builtin_argument_restrictions(call);
7638         }
7639
7640 end_error:
7641         return result;
7642 }
7643
7644 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7645
7646 static bool same_compound_type(const type_t *type1, const type_t *type2)
7647 {
7648         return
7649                 is_type_compound(type1) &&
7650                 type1->kind == type2->kind &&
7651                 type1->compound.compound == type2->compound.compound;
7652 }
7653
7654 static expression_t const *get_reference_address(expression_t const *expr)
7655 {
7656         bool regular_take_address = true;
7657         for (;;) {
7658                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7659                         expr = expr->unary.value;
7660                 } else {
7661                         regular_take_address = false;
7662                 }
7663
7664                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7665                         break;
7666
7667                 expr = expr->unary.value;
7668         }
7669
7670         if (expr->kind != EXPR_REFERENCE)
7671                 return NULL;
7672
7673         /* special case for functions which are automatically converted to a
7674          * pointer to function without an extra TAKE_ADDRESS operation */
7675         if (!regular_take_address &&
7676                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7677                 return NULL;
7678         }
7679
7680         return expr;
7681 }
7682
7683 static void warn_reference_address_as_bool(expression_t const* expr)
7684 {
7685         if (!warning.address)
7686                 return;
7687
7688         expr = get_reference_address(expr);
7689         if (expr != NULL) {
7690                 warningf(&expr->base.source_position,
7691                          "the address of '%Y' will always evaluate as 'true'",
7692                          expr->reference.entity->base.symbol);
7693         }
7694 }
7695
7696 static void warn_assignment_in_condition(const expression_t *const expr)
7697 {
7698         if (!warning.parentheses)
7699                 return;
7700         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7701                 return;
7702         if (expr->base.parenthesized)
7703                 return;
7704         warningf(&expr->base.source_position,
7705                         "suggest parentheses around assignment used as truth value");
7706 }
7707
7708 static void semantic_condition(expression_t const *const expr,
7709                                char const *const context)
7710 {
7711         type_t *const type = skip_typeref(expr->base.type);
7712         if (is_type_scalar(type)) {
7713                 warn_reference_address_as_bool(expr);
7714                 warn_assignment_in_condition(expr);
7715         } else if (is_type_valid(type)) {
7716                 errorf(&expr->base.source_position,
7717                                 "%s must have scalar type", context);
7718         }
7719 }
7720
7721 /**
7722  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7723  *
7724  * @param expression  the conditional expression
7725  */
7726 static expression_t *parse_conditional_expression(expression_t *expression)
7727 {
7728         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7729
7730         conditional_expression_t *conditional = &result->conditional;
7731         conditional->condition                = expression;
7732
7733         eat('?');
7734         add_anchor_token(':');
7735
7736         /* §6.5.15:2  The first operand shall have scalar type. */
7737         semantic_condition(expression, "condition of conditional operator");
7738
7739         expression_t *true_expression = expression;
7740         bool          gnu_cond = false;
7741         if (GNU_MODE && token.type == ':') {
7742                 gnu_cond = true;
7743         } else {
7744                 true_expression = parse_expression();
7745         }
7746         rem_anchor_token(':');
7747         expect(':', end_error);
7748 end_error:;
7749         expression_t *false_expression =
7750                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7751
7752         type_t *const orig_true_type  = true_expression->base.type;
7753         type_t *const orig_false_type = false_expression->base.type;
7754         type_t *const true_type       = skip_typeref(orig_true_type);
7755         type_t *const false_type      = skip_typeref(orig_false_type);
7756
7757         /* 6.5.15.3 */
7758         type_t *result_type;
7759         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7760                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7761                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7762                 if (true_expression->kind == EXPR_UNARY_THROW) {
7763                         result_type = false_type;
7764                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7765                         result_type = true_type;
7766                 } else {
7767                         if (warning.other && (
7768                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7769                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7770                                         )) {
7771                                 warningf(&conditional->base.source_position,
7772                                                 "ISO C forbids conditional expression with only one void side");
7773                         }
7774                         result_type = type_void;
7775                 }
7776         } else if (is_type_arithmetic(true_type)
7777                    && is_type_arithmetic(false_type)) {
7778                 result_type = semantic_arithmetic(true_type, false_type);
7779
7780                 true_expression  = create_implicit_cast(true_expression, result_type);
7781                 false_expression = create_implicit_cast(false_expression, result_type);
7782
7783                 conditional->true_expression  = true_expression;
7784                 conditional->false_expression = false_expression;
7785                 conditional->base.type        = result_type;
7786         } else if (same_compound_type(true_type, false_type)) {
7787                 /* just take 1 of the 2 types */
7788                 result_type = true_type;
7789         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7790                 type_t *pointer_type;
7791                 type_t *other_type;
7792                 expression_t *other_expression;
7793                 if (is_type_pointer(true_type) &&
7794                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7795                         pointer_type     = true_type;
7796                         other_type       = false_type;
7797                         other_expression = false_expression;
7798                 } else {
7799                         pointer_type     = false_type;
7800                         other_type       = true_type;
7801                         other_expression = true_expression;
7802                 }
7803
7804                 if (is_null_pointer_constant(other_expression)) {
7805                         result_type = pointer_type;
7806                 } else if (is_type_pointer(other_type)) {
7807                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7808                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7809
7810                         type_t *to;
7811                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7812                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7813                                 to = type_void;
7814                         } else if (types_compatible(get_unqualified_type(to1),
7815                                                     get_unqualified_type(to2))) {
7816                                 to = to1;
7817                         } else {
7818                                 if (warning.other) {
7819                                         warningf(&conditional->base.source_position,
7820                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7821                                                         true_type, false_type);
7822                                 }
7823                                 to = type_void;
7824                         }
7825
7826                         type_t *const type =
7827                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7828                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7829                 } else if (is_type_integer(other_type)) {
7830                         if (warning.other) {
7831                                 warningf(&conditional->base.source_position,
7832                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7833                         }
7834                         result_type = pointer_type;
7835                 } else {
7836                         if (is_type_valid(other_type)) {
7837                                 type_error_incompatible("while parsing conditional",
7838                                                 &expression->base.source_position, true_type, false_type);
7839                         }
7840                         result_type = type_error_type;
7841                 }
7842         } else {
7843                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7844                         type_error_incompatible("while parsing conditional",
7845                                                 &conditional->base.source_position, true_type,
7846                                                 false_type);
7847                 }
7848                 result_type = type_error_type;
7849         }
7850
7851         conditional->true_expression
7852                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7853         conditional->false_expression
7854                 = create_implicit_cast(false_expression, result_type);
7855         conditional->base.type = result_type;
7856         return result;
7857 }
7858
7859 /**
7860  * Parse an extension expression.
7861  */
7862 static expression_t *parse_extension(void)
7863 {
7864         eat(T___extension__);
7865
7866         bool old_gcc_extension   = in_gcc_extension;
7867         in_gcc_extension         = true;
7868         expression_t *expression = parse_sub_expression(PREC_UNARY);
7869         in_gcc_extension         = old_gcc_extension;
7870         return expression;
7871 }
7872
7873 /**
7874  * Parse a __builtin_classify_type() expression.
7875  */
7876 static expression_t *parse_builtin_classify_type(void)
7877 {
7878         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7879         result->base.type    = type_int;
7880
7881         eat(T___builtin_classify_type);
7882
7883         expect('(', end_error);
7884         add_anchor_token(')');
7885         expression_t *expression = parse_expression();
7886         rem_anchor_token(')');
7887         expect(')', end_error);
7888         result->classify_type.type_expression = expression;
7889
7890         return result;
7891 end_error:
7892         return create_invalid_expression();
7893 }
7894
7895 /**
7896  * Parse a delete expression
7897  * ISO/IEC 14882:1998(E) §5.3.5
7898  */
7899 static expression_t *parse_delete(void)
7900 {
7901         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7902         result->base.type          = type_void;
7903
7904         eat(T_delete);
7905
7906         if (token.type == '[') {
7907                 next_token();
7908                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7909                 expect(']', end_error);
7910 end_error:;
7911         }
7912
7913         expression_t *const value = parse_sub_expression(PREC_CAST);
7914         result->unary.value = value;
7915
7916         type_t *const type = skip_typeref(value->base.type);
7917         if (!is_type_pointer(type)) {
7918                 if (is_type_valid(type)) {
7919                         errorf(&value->base.source_position,
7920                                         "operand of delete must have pointer type");
7921                 }
7922         } else if (warning.other &&
7923                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7924                 warningf(&value->base.source_position,
7925                                 "deleting 'void*' is undefined");
7926         }
7927
7928         return result;
7929 }
7930
7931 /**
7932  * Parse a throw expression
7933  * ISO/IEC 14882:1998(E) §15:1
7934  */
7935 static expression_t *parse_throw(void)
7936 {
7937         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7938         result->base.type          = type_void;
7939
7940         eat(T_throw);
7941
7942         expression_t *value = NULL;
7943         switch (token.type) {
7944                 EXPRESSION_START {
7945                         value = parse_assignment_expression();
7946                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7947                         type_t *const orig_type = value->base.type;
7948                         type_t *const type      = skip_typeref(orig_type);
7949                         if (is_type_incomplete(type)) {
7950                                 errorf(&value->base.source_position,
7951                                                 "cannot throw object of incomplete type '%T'", orig_type);
7952                         } else if (is_type_pointer(type)) {
7953                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7954                                 if (is_type_incomplete(points_to) &&
7955                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7956                                         errorf(&value->base.source_position,
7957                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7958                                 }
7959                         }
7960                 }
7961
7962                 default:
7963                         break;
7964         }
7965         result->unary.value = value;
7966
7967         return result;
7968 }
7969
7970 static bool check_pointer_arithmetic(const source_position_t *source_position,
7971                                      type_t *pointer_type,
7972                                      type_t *orig_pointer_type)
7973 {
7974         type_t *points_to = pointer_type->pointer.points_to;
7975         points_to = skip_typeref(points_to);
7976
7977         if (is_type_incomplete(points_to)) {
7978                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7979                         errorf(source_position,
7980                                "arithmetic with pointer to incomplete type '%T' not allowed",
7981                                orig_pointer_type);
7982                         return false;
7983                 } else if (warning.pointer_arith) {
7984                         warningf(source_position,
7985                                  "pointer of type '%T' used in arithmetic",
7986                                  orig_pointer_type);
7987                 }
7988         } else if (is_type_function(points_to)) {
7989                 if (!GNU_MODE) {
7990                         errorf(source_position,
7991                                "arithmetic with pointer to function type '%T' not allowed",
7992                                orig_pointer_type);
7993                         return false;
7994                 } else if (warning.pointer_arith) {
7995                         warningf(source_position,
7996                                  "pointer to a function '%T' used in arithmetic",
7997                                  orig_pointer_type);
7998                 }
7999         }
8000         return true;
8001 }
8002
8003 static bool is_lvalue(const expression_t *expression)
8004 {
8005         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8006         switch (expression->kind) {
8007         case EXPR_ARRAY_ACCESS:
8008         case EXPR_COMPOUND_LITERAL:
8009         case EXPR_REFERENCE:
8010         case EXPR_SELECT:
8011         case EXPR_UNARY_DEREFERENCE:
8012                 return true;
8013
8014         default: {
8015           type_t *type = skip_typeref(expression->base.type);
8016           return
8017                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8018                 is_type_reference(type) ||
8019                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8020                  * error before, which maybe prevented properly recognizing it as
8021                  * lvalue. */
8022                 !is_type_valid(type);
8023         }
8024         }
8025 }
8026
8027 static void semantic_incdec(unary_expression_t *expression)
8028 {
8029         type_t *const orig_type = expression->value->base.type;
8030         type_t *const type      = skip_typeref(orig_type);
8031         if (is_type_pointer(type)) {
8032                 if (!check_pointer_arithmetic(&expression->base.source_position,
8033                                               type, orig_type)) {
8034                         return;
8035                 }
8036         } else if (!is_type_real(type) && is_type_valid(type)) {
8037                 /* TODO: improve error message */
8038                 errorf(&expression->base.source_position,
8039                        "operation needs an arithmetic or pointer type");
8040                 return;
8041         }
8042         if (!is_lvalue(expression->value)) {
8043                 /* TODO: improve error message */
8044                 errorf(&expression->base.source_position, "lvalue required as operand");
8045         }
8046         expression->base.type = orig_type;
8047 }
8048
8049 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8050 {
8051         type_t *const orig_type = expression->value->base.type;
8052         type_t *const type      = skip_typeref(orig_type);
8053         if (!is_type_arithmetic(type)) {
8054                 if (is_type_valid(type)) {
8055                         /* TODO: improve error message */
8056                         errorf(&expression->base.source_position,
8057                                 "operation needs an arithmetic type");
8058                 }
8059                 return;
8060         }
8061
8062         expression->base.type = orig_type;
8063 }
8064
8065 static void semantic_unexpr_plus(unary_expression_t *expression)
8066 {
8067         semantic_unexpr_arithmetic(expression);
8068         if (warning.traditional)
8069                 warningf(&expression->base.source_position,
8070                         "traditional C rejects the unary plus operator");
8071 }
8072
8073 static void semantic_not(unary_expression_t *expression)
8074 {
8075         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8076         semantic_condition(expression->value, "operand of !");
8077         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8078 }
8079
8080 static void semantic_unexpr_integer(unary_expression_t *expression)
8081 {
8082         type_t *const orig_type = expression->value->base.type;
8083         type_t *const type      = skip_typeref(orig_type);
8084         if (!is_type_integer(type)) {
8085                 if (is_type_valid(type)) {
8086                         errorf(&expression->base.source_position,
8087                                "operand of ~ must be of integer type");
8088                 }
8089                 return;
8090         }
8091
8092         expression->base.type = orig_type;
8093 }
8094
8095 static void semantic_dereference(unary_expression_t *expression)
8096 {
8097         type_t *const orig_type = expression->value->base.type;
8098         type_t *const type      = skip_typeref(orig_type);
8099         if (!is_type_pointer(type)) {
8100                 if (is_type_valid(type)) {
8101                         errorf(&expression->base.source_position,
8102                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8103                 }
8104                 return;
8105         }
8106
8107         type_t *result_type   = type->pointer.points_to;
8108         result_type           = automatic_type_conversion(result_type);
8109         expression->base.type = result_type;
8110 }
8111
8112 /**
8113  * Record that an address is taken (expression represents an lvalue).
8114  *
8115  * @param expression       the expression
8116  * @param may_be_register  if true, the expression might be an register
8117  */
8118 static void set_address_taken(expression_t *expression, bool may_be_register)
8119 {
8120         if (expression->kind != EXPR_REFERENCE)
8121                 return;
8122
8123         entity_t *const entity = expression->reference.entity;
8124
8125         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8126                 return;
8127
8128         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8129                         && !may_be_register) {
8130                 errorf(&expression->base.source_position,
8131                                 "address of register %s '%Y' requested",
8132                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8133         }
8134
8135         if (entity->kind == ENTITY_VARIABLE) {
8136                 entity->variable.address_taken = true;
8137         } else {
8138                 assert(entity->kind == ENTITY_PARAMETER);
8139                 entity->parameter.address_taken = true;
8140         }
8141 }
8142
8143 /**
8144  * Check the semantic of the address taken expression.
8145  */
8146 static void semantic_take_addr(unary_expression_t *expression)
8147 {
8148         expression_t *value = expression->value;
8149         value->base.type    = revert_automatic_type_conversion(value);
8150
8151         type_t *orig_type = value->base.type;
8152         type_t *type      = skip_typeref(orig_type);
8153         if (!is_type_valid(type))
8154                 return;
8155
8156         /* §6.5.3.2 */
8157         if (!is_lvalue(value)) {
8158                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8159         }
8160         if (type->kind == TYPE_BITFIELD) {
8161                 errorf(&expression->base.source_position,
8162                        "'&' not allowed on object with bitfield type '%T'",
8163                        type);
8164         }
8165
8166         set_address_taken(value, false);
8167
8168         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8169 }
8170
8171 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8172 static expression_t *parse_##unexpression_type(void)                         \
8173 {                                                                            \
8174         expression_t *unary_expression                                           \
8175                 = allocate_expression_zero(unexpression_type);                       \
8176         eat(token_type);                                                         \
8177         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8178                                                                                  \
8179         sfunc(&unary_expression->unary);                                         \
8180                                                                                  \
8181         return unary_expression;                                                 \
8182 }
8183
8184 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8185                                semantic_unexpr_arithmetic)
8186 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8187                                semantic_unexpr_plus)
8188 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8189                                semantic_not)
8190 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8191                                semantic_dereference)
8192 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8193                                semantic_take_addr)
8194 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8195                                semantic_unexpr_integer)
8196 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8197                                semantic_incdec)
8198 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8199                                semantic_incdec)
8200
8201 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8202                                                sfunc)                         \
8203 static expression_t *parse_##unexpression_type(expression_t *left)            \
8204 {                                                                             \
8205         expression_t *unary_expression                                            \
8206                 = allocate_expression_zero(unexpression_type);                        \
8207         eat(token_type);                                                          \
8208         unary_expression->unary.value = left;                                     \
8209                                                                                   \
8210         sfunc(&unary_expression->unary);                                          \
8211                                                                               \
8212         return unary_expression;                                                  \
8213 }
8214
8215 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8216                                        EXPR_UNARY_POSTFIX_INCREMENT,
8217                                        semantic_incdec)
8218 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8219                                        EXPR_UNARY_POSTFIX_DECREMENT,
8220                                        semantic_incdec)
8221
8222 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8223 {
8224         /* TODO: handle complex + imaginary types */
8225
8226         type_left  = get_unqualified_type(type_left);
8227         type_right = get_unqualified_type(type_right);
8228
8229         /* §6.3.1.8 Usual arithmetic conversions */
8230         if (type_left == type_long_double || type_right == type_long_double) {
8231                 return type_long_double;
8232         } else if (type_left == type_double || type_right == type_double) {
8233                 return type_double;
8234         } else if (type_left == type_float || type_right == type_float) {
8235                 return type_float;
8236         }
8237
8238         type_left  = promote_integer(type_left);
8239         type_right = promote_integer(type_right);
8240
8241         if (type_left == type_right)
8242                 return type_left;
8243
8244         bool const signed_left  = is_type_signed(type_left);
8245         bool const signed_right = is_type_signed(type_right);
8246         int const  rank_left    = get_rank(type_left);
8247         int const  rank_right   = get_rank(type_right);
8248
8249         if (signed_left == signed_right)
8250                 return rank_left >= rank_right ? type_left : type_right;
8251
8252         int     s_rank;
8253         int     u_rank;
8254         type_t *s_type;
8255         type_t *u_type;
8256         if (signed_left) {
8257                 s_rank = rank_left;
8258                 s_type = type_left;
8259                 u_rank = rank_right;
8260                 u_type = type_right;
8261         } else {
8262                 s_rank = rank_right;
8263                 s_type = type_right;
8264                 u_rank = rank_left;
8265                 u_type = type_left;
8266         }
8267
8268         if (u_rank >= s_rank)
8269                 return u_type;
8270
8271         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8272          * easier here... */
8273         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8274                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8275                 return s_type;
8276
8277         switch (s_rank) {
8278                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8279                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8280                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8281
8282                 default: panic("invalid atomic type");
8283         }
8284 }
8285
8286 /**
8287  * Check the semantic restrictions for a binary expression.
8288  */
8289 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8290 {
8291         expression_t *const left            = expression->left;
8292         expression_t *const right           = expression->right;
8293         type_t       *const orig_type_left  = left->base.type;
8294         type_t       *const orig_type_right = right->base.type;
8295         type_t       *const type_left       = skip_typeref(orig_type_left);
8296         type_t       *const type_right      = skip_typeref(orig_type_right);
8297
8298         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8299                 /* TODO: improve error message */
8300                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8301                         errorf(&expression->base.source_position,
8302                                "operation needs arithmetic types");
8303                 }
8304                 return;
8305         }
8306
8307         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8308         expression->left      = create_implicit_cast(left, arithmetic_type);
8309         expression->right     = create_implicit_cast(right, arithmetic_type);
8310         expression->base.type = arithmetic_type;
8311 }
8312
8313 static void warn_div_by_zero(binary_expression_t const *const expression)
8314 {
8315         if (!warning.div_by_zero ||
8316             !is_type_integer(expression->base.type))
8317                 return;
8318
8319         expression_t const *const right = expression->right;
8320         /* The type of the right operand can be different for /= */
8321         if (is_type_integer(right->base.type) &&
8322             is_constant_expression(right)     &&
8323             fold_constant(right) == 0) {
8324                 warningf(&expression->base.source_position, "division by zero");
8325         }
8326 }
8327
8328 /**
8329  * Check the semantic restrictions for a div/mod expression.
8330  */
8331 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8332 {
8333         semantic_binexpr_arithmetic(expression);
8334         warn_div_by_zero(expression);
8335 }
8336
8337 static void warn_addsub_in_shift(const expression_t *const expr)
8338 {
8339         if (expr->base.parenthesized)
8340                 return;
8341
8342         char op;
8343         switch (expr->kind) {
8344                 case EXPR_BINARY_ADD: op = '+'; break;
8345                 case EXPR_BINARY_SUB: op = '-'; break;
8346                 default:              return;
8347         }
8348
8349         warningf(&expr->base.source_position,
8350                         "suggest parentheses around '%c' inside shift", op);
8351 }
8352
8353 static bool semantic_shift(binary_expression_t *expression)
8354 {
8355         expression_t *const left            = expression->left;
8356         expression_t *const right           = expression->right;
8357         type_t       *const orig_type_left  = left->base.type;
8358         type_t       *const orig_type_right = right->base.type;
8359         type_t       *      type_left       = skip_typeref(orig_type_left);
8360         type_t       *      type_right      = skip_typeref(orig_type_right);
8361
8362         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8363                 /* TODO: improve error message */
8364                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8365                         errorf(&expression->base.source_position,
8366                                "operands of shift operation must have integer types");
8367                 }
8368                 return false;
8369         }
8370
8371         type_left = promote_integer(type_left);
8372
8373         if (is_constant_expression(right)) {
8374                 long count = fold_constant(right);
8375                 if (count < 0) {
8376                         warningf(&right->base.source_position,
8377                                         "shift count must be non-negative");
8378                 } else if ((unsigned long)count >=
8379                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8380                         warningf(&right->base.source_position,
8381                                         "shift count must be less than type width");
8382                 }
8383         }
8384
8385         type_right        = promote_integer(type_right);
8386         expression->right = create_implicit_cast(right, type_right);
8387
8388         return true;
8389 }
8390
8391 static void semantic_shift_op(binary_expression_t *expression)
8392 {
8393         expression_t *const left  = expression->left;
8394         expression_t *const right = expression->right;
8395
8396         if (!semantic_shift(expression))
8397                 return;
8398
8399         if (warning.parentheses) {
8400                 warn_addsub_in_shift(left);
8401                 warn_addsub_in_shift(right);
8402         }
8403
8404         type_t *const orig_type_left = left->base.type;
8405         type_t *      type_left      = skip_typeref(orig_type_left);
8406
8407         type_left             = promote_integer(type_left);
8408         expression->left      = create_implicit_cast(left, type_left);
8409         expression->base.type = type_left;
8410 }
8411
8412 static void semantic_add(binary_expression_t *expression)
8413 {
8414         expression_t *const left            = expression->left;
8415         expression_t *const right           = expression->right;
8416         type_t       *const orig_type_left  = left->base.type;
8417         type_t       *const orig_type_right = right->base.type;
8418         type_t       *const type_left       = skip_typeref(orig_type_left);
8419         type_t       *const type_right      = skip_typeref(orig_type_right);
8420
8421         /* §6.5.6 */
8422         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8423                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8424                 expression->left  = create_implicit_cast(left, arithmetic_type);
8425                 expression->right = create_implicit_cast(right, arithmetic_type);
8426                 expression->base.type = arithmetic_type;
8427         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8428                 check_pointer_arithmetic(&expression->base.source_position,
8429                                          type_left, orig_type_left);
8430                 expression->base.type = type_left;
8431         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8432                 check_pointer_arithmetic(&expression->base.source_position,
8433                                          type_right, orig_type_right);
8434                 expression->base.type = type_right;
8435         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8436                 errorf(&expression->base.source_position,
8437                        "invalid operands to binary + ('%T', '%T')",
8438                        orig_type_left, orig_type_right);
8439         }
8440 }
8441
8442 static void semantic_sub(binary_expression_t *expression)
8443 {
8444         expression_t            *const left            = expression->left;
8445         expression_t            *const right           = expression->right;
8446         type_t                  *const orig_type_left  = left->base.type;
8447         type_t                  *const orig_type_right = right->base.type;
8448         type_t                  *const type_left       = skip_typeref(orig_type_left);
8449         type_t                  *const type_right      = skip_typeref(orig_type_right);
8450         source_position_t const *const pos             = &expression->base.source_position;
8451
8452         /* §5.6.5 */
8453         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8454                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8455                 expression->left        = create_implicit_cast(left, arithmetic_type);
8456                 expression->right       = create_implicit_cast(right, arithmetic_type);
8457                 expression->base.type =  arithmetic_type;
8458         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8459                 check_pointer_arithmetic(&expression->base.source_position,
8460                                          type_left, orig_type_left);
8461                 expression->base.type = type_left;
8462         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8463                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8464                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8465                 if (!types_compatible(unqual_left, unqual_right)) {
8466                         errorf(pos,
8467                                "subtracting pointers to incompatible types '%T' and '%T'",
8468                                orig_type_left, orig_type_right);
8469                 } else if (!is_type_object(unqual_left)) {
8470                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8471                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8472                                        orig_type_left);
8473                         } else if (warning.other) {
8474                                 warningf(pos, "subtracting pointers to void");
8475                         }
8476                 }
8477                 expression->base.type = type_ptrdiff_t;
8478         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8479                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8480                        orig_type_left, orig_type_right);
8481         }
8482 }
8483
8484 static void warn_string_literal_address(expression_t const* expr)
8485 {
8486         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8487                 expr = expr->unary.value;
8488                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8489                         return;
8490                 expr = expr->unary.value;
8491         }
8492
8493         if (expr->kind == EXPR_STRING_LITERAL ||
8494             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8495                 warningf(&expr->base.source_position,
8496                         "comparison with string literal results in unspecified behaviour");
8497         }
8498 }
8499
8500 static void warn_comparison_in_comparison(const expression_t *const expr)
8501 {
8502         if (expr->base.parenthesized)
8503                 return;
8504         switch (expr->base.kind) {
8505                 case EXPR_BINARY_LESS:
8506                 case EXPR_BINARY_GREATER:
8507                 case EXPR_BINARY_LESSEQUAL:
8508                 case EXPR_BINARY_GREATEREQUAL:
8509                 case EXPR_BINARY_NOTEQUAL:
8510                 case EXPR_BINARY_EQUAL:
8511                         warningf(&expr->base.source_position,
8512                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8513                         break;
8514                 default:
8515                         break;
8516         }
8517 }
8518
8519 static bool maybe_negative(expression_t const *const expr)
8520 {
8521         return
8522                 !is_constant_expression(expr) ||
8523                 fold_constant(expr) < 0;
8524 }
8525
8526 /**
8527  * Check the semantics of comparison expressions.
8528  *
8529  * @param expression   The expression to check.
8530  */
8531 static void semantic_comparison(binary_expression_t *expression)
8532 {
8533         expression_t *left  = expression->left;
8534         expression_t *right = expression->right;
8535
8536         if (warning.address) {
8537                 warn_string_literal_address(left);
8538                 warn_string_literal_address(right);
8539
8540                 expression_t const* const func_left = get_reference_address(left);
8541                 if (func_left != NULL && is_null_pointer_constant(right)) {
8542                         warningf(&expression->base.source_position,
8543                                  "the address of '%Y' will never be NULL",
8544                                  func_left->reference.entity->base.symbol);
8545                 }
8546
8547                 expression_t const* const func_right = get_reference_address(right);
8548                 if (func_right != NULL && is_null_pointer_constant(right)) {
8549                         warningf(&expression->base.source_position,
8550                                  "the address of '%Y' will never be NULL",
8551                                  func_right->reference.entity->base.symbol);
8552                 }
8553         }
8554
8555         if (warning.parentheses) {
8556                 warn_comparison_in_comparison(left);
8557                 warn_comparison_in_comparison(right);
8558         }
8559
8560         type_t *orig_type_left  = left->base.type;
8561         type_t *orig_type_right = right->base.type;
8562         type_t *type_left       = skip_typeref(orig_type_left);
8563         type_t *type_right      = skip_typeref(orig_type_right);
8564
8565         /* TODO non-arithmetic types */
8566         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8567                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8568
8569                 /* test for signed vs unsigned compares */
8570                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8571                         bool const signed_left  = is_type_signed(type_left);
8572                         bool const signed_right = is_type_signed(type_right);
8573                         if (signed_left != signed_right) {
8574                                 /* FIXME long long needs better const folding magic */
8575                                 /* TODO check whether constant value can be represented by other type */
8576                                 if ((signed_left  && maybe_negative(left)) ||
8577                                                 (signed_right && maybe_negative(right))) {
8578                                         warningf(&expression->base.source_position,
8579                                                         "comparison between signed and unsigned");
8580                                 }
8581                         }
8582                 }
8583
8584                 expression->left        = create_implicit_cast(left, arithmetic_type);
8585                 expression->right       = create_implicit_cast(right, arithmetic_type);
8586                 expression->base.type   = arithmetic_type;
8587                 if (warning.float_equal &&
8588                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8589                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8590                     is_type_float(arithmetic_type)) {
8591                         warningf(&expression->base.source_position,
8592                                  "comparing floating point with == or != is unsafe");
8593                 }
8594         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8595                 /* TODO check compatibility */
8596         } else if (is_type_pointer(type_left)) {
8597                 expression->right = create_implicit_cast(right, type_left);
8598         } else if (is_type_pointer(type_right)) {
8599                 expression->left = create_implicit_cast(left, type_right);
8600         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8601                 type_error_incompatible("invalid operands in comparison",
8602                                         &expression->base.source_position,
8603                                         type_left, type_right);
8604         }
8605         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8606 }
8607
8608 /**
8609  * Checks if a compound type has constant fields.
8610  */
8611 static bool has_const_fields(const compound_type_t *type)
8612 {
8613         compound_t *compound = type->compound;
8614         entity_t   *entry    = compound->members.entities;
8615
8616         for (; entry != NULL; entry = entry->base.next) {
8617                 if (!is_declaration(entry))
8618                         continue;
8619
8620                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8621                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8622                         return true;
8623         }
8624
8625         return false;
8626 }
8627
8628 static bool is_valid_assignment_lhs(expression_t const* const left)
8629 {
8630         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8631         type_t *const type_left      = skip_typeref(orig_type_left);
8632
8633         if (!is_lvalue(left)) {
8634                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8635                        left);
8636                 return false;
8637         }
8638
8639         if (left->kind == EXPR_REFERENCE
8640                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8641                 errorf(HERE, "cannot assign to function '%E'", left);
8642                 return false;
8643         }
8644
8645         if (is_type_array(type_left)) {
8646                 errorf(HERE, "cannot assign to array '%E'", left);
8647                 return false;
8648         }
8649         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8650                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8651                        orig_type_left);
8652                 return false;
8653         }
8654         if (is_type_incomplete(type_left)) {
8655                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8656                        left, orig_type_left);
8657                 return false;
8658         }
8659         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8660                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8661                        left, orig_type_left);
8662                 return false;
8663         }
8664
8665         return true;
8666 }
8667
8668 static void semantic_arithmetic_assign(binary_expression_t *expression)
8669 {
8670         expression_t *left            = expression->left;
8671         expression_t *right           = expression->right;
8672         type_t       *orig_type_left  = left->base.type;
8673         type_t       *orig_type_right = right->base.type;
8674
8675         if (!is_valid_assignment_lhs(left))
8676                 return;
8677
8678         type_t *type_left  = skip_typeref(orig_type_left);
8679         type_t *type_right = skip_typeref(orig_type_right);
8680
8681         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8682                 /* TODO: improve error message */
8683                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8684                         errorf(&expression->base.source_position,
8685                                "operation needs arithmetic types");
8686                 }
8687                 return;
8688         }
8689
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 *arithmetic_type = semantic_arithmetic(type_left, type_right);
8695         expression->right       = create_implicit_cast(right, arithmetic_type);
8696         expression->base.type   = type_left;
8697 }
8698
8699 static void semantic_divmod_assign(binary_expression_t *expression)
8700 {
8701         semantic_arithmetic_assign(expression);
8702         warn_div_by_zero(expression);
8703 }
8704
8705 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8706 {
8707         expression_t *const left            = expression->left;
8708         expression_t *const right           = expression->right;
8709         type_t       *const orig_type_left  = left->base.type;
8710         type_t       *const orig_type_right = right->base.type;
8711         type_t       *const type_left       = skip_typeref(orig_type_left);
8712         type_t       *const type_right      = skip_typeref(orig_type_right);
8713
8714         if (!is_valid_assignment_lhs(left))
8715                 return;
8716
8717         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8718                 /* combined instructions are tricky. We can't create an implicit cast on
8719                  * the left side, because we need the uncasted form for the store.
8720                  * The ast2firm pass has to know that left_type must be right_type
8721                  * for the arithmetic operation and create a cast by itself */
8722                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8723                 expression->right     = create_implicit_cast(right, arithmetic_type);
8724                 expression->base.type = type_left;
8725         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8726                 check_pointer_arithmetic(&expression->base.source_position,
8727                                          type_left, orig_type_left);
8728                 expression->base.type = type_left;
8729         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8730                 errorf(&expression->base.source_position,
8731                        "incompatible types '%T' and '%T' in assignment",
8732                        orig_type_left, orig_type_right);
8733         }
8734 }
8735
8736 static void semantic_integer_assign(binary_expression_t *expression)
8737 {
8738         expression_t *left            = expression->left;
8739         expression_t *right           = expression->right;
8740         type_t       *orig_type_left  = left->base.type;
8741         type_t       *orig_type_right = right->base.type;
8742
8743         if (!is_valid_assignment_lhs(left))
8744                 return;
8745
8746         type_t *type_left  = skip_typeref(orig_type_left);
8747         type_t *type_right = skip_typeref(orig_type_right);
8748
8749         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8750                 /* TODO: improve error message */
8751                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8752                         errorf(&expression->base.source_position,
8753                                "operation needs integer types");
8754                 }
8755                 return;
8756         }
8757
8758         /* combined instructions are tricky. We can't create an implicit cast on
8759          * the left side, because we need the uncasted form for the store.
8760          * The ast2firm pass has to know that left_type must be right_type
8761          * for the arithmetic operation and create a cast by itself */
8762         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8763         expression->right       = create_implicit_cast(right, arithmetic_type);
8764         expression->base.type   = type_left;
8765 }
8766
8767 static void semantic_shift_assign(binary_expression_t *expression)
8768 {
8769         expression_t *left           = expression->left;
8770
8771         if (!is_valid_assignment_lhs(left))
8772                 return;
8773
8774         if (!semantic_shift(expression))
8775                 return;
8776
8777         expression->base.type = skip_typeref(left->base.type);
8778 }
8779
8780 static void warn_logical_and_within_or(const expression_t *const expr)
8781 {
8782         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8783                 return;
8784         if (expr->base.parenthesized)
8785                 return;
8786         warningf(&expr->base.source_position,
8787                         "suggest parentheses around && within ||");
8788 }
8789
8790 /**
8791  * Check the semantic restrictions of a logical expression.
8792  */
8793 static void semantic_logical_op(binary_expression_t *expression)
8794 {
8795         /* §6.5.13:2  Each of the operands shall have scalar type.
8796          * §6.5.14:2  Each of the operands shall have scalar type. */
8797         semantic_condition(expression->left,   "left operand of logical operator");
8798         semantic_condition(expression->right, "right operand of logical operator");
8799         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8800                         warning.parentheses) {
8801                 warn_logical_and_within_or(expression->left);
8802                 warn_logical_and_within_or(expression->right);
8803         }
8804         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8805 }
8806
8807 /**
8808  * Check the semantic restrictions of a binary assign expression.
8809  */
8810 static void semantic_binexpr_assign(binary_expression_t *expression)
8811 {
8812         expression_t *left           = expression->left;
8813         type_t       *orig_type_left = left->base.type;
8814
8815         if (!is_valid_assignment_lhs(left))
8816                 return;
8817
8818         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8819         report_assign_error(error, orig_type_left, expression->right,
8820                         "assignment", &left->base.source_position);
8821         expression->right = create_implicit_cast(expression->right, orig_type_left);
8822         expression->base.type = orig_type_left;
8823 }
8824
8825 /**
8826  * Determine if the outermost operation (or parts thereof) of the given
8827  * expression has no effect in order to generate a warning about this fact.
8828  * Therefore in some cases this only examines some of the operands of the
8829  * expression (see comments in the function and examples below).
8830  * Examples:
8831  *   f() + 23;    // warning, because + has no effect
8832  *   x || f();    // no warning, because x controls execution of f()
8833  *   x ? y : f(); // warning, because y has no effect
8834  *   (void)x;     // no warning to be able to suppress the warning
8835  * This function can NOT be used for an "expression has definitely no effect"-
8836  * analysis. */
8837 static bool expression_has_effect(const expression_t *const expr)
8838 {
8839         switch (expr->kind) {
8840                 case EXPR_UNKNOWN:                    break;
8841                 case EXPR_INVALID:                    return true; /* do NOT warn */
8842                 case EXPR_REFERENCE:                  return false;
8843                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8844                 /* suppress the warning for microsoft __noop operations */
8845                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
8846                 case EXPR_CHARACTER_CONSTANT:         return false;
8847                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
8848                 case EXPR_STRING_LITERAL:             return false;
8849                 case EXPR_WIDE_STRING_LITERAL:        return false;
8850                 case EXPR_LABEL_ADDRESS:              return false;
8851
8852                 case EXPR_CALL: {
8853                         const call_expression_t *const call = &expr->call;
8854                         if (call->function->kind != EXPR_REFERENCE)
8855                                 return true;
8856
8857                         switch (call->function->reference.entity->function.btk) {
8858                                 /* FIXME: which builtins have no effect? */
8859                                 default:                      return true;
8860                         }
8861                 }
8862
8863                 /* Generate the warning if either the left or right hand side of a
8864                  * conditional expression has no effect */
8865                 case EXPR_CONDITIONAL: {
8866                         conditional_expression_t const *const cond = &expr->conditional;
8867                         expression_t             const *const t    = cond->true_expression;
8868                         return
8869                                 (t == NULL || expression_has_effect(t)) &&
8870                                 expression_has_effect(cond->false_expression);
8871                 }
8872
8873                 case EXPR_SELECT:                     return false;
8874                 case EXPR_ARRAY_ACCESS:               return false;
8875                 case EXPR_SIZEOF:                     return false;
8876                 case EXPR_CLASSIFY_TYPE:              return false;
8877                 case EXPR_ALIGNOF:                    return false;
8878
8879                 case EXPR_FUNCNAME:                   return false;
8880                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8881                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8882                 case EXPR_OFFSETOF:                   return false;
8883                 case EXPR_VA_START:                   return true;
8884                 case EXPR_VA_ARG:                     return true;
8885                 case EXPR_VA_COPY:                    return true;
8886                 case EXPR_STATEMENT:                  return true; // TODO
8887                 case EXPR_COMPOUND_LITERAL:           return false;
8888
8889                 case EXPR_UNARY_NEGATE:               return false;
8890                 case EXPR_UNARY_PLUS:                 return false;
8891                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8892                 case EXPR_UNARY_NOT:                  return false;
8893                 case EXPR_UNARY_DEREFERENCE:          return false;
8894                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8895                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8896                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8897                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8898                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8899
8900                 /* Treat void casts as if they have an effect in order to being able to
8901                  * suppress the warning */
8902                 case EXPR_UNARY_CAST: {
8903                         type_t *const type = skip_typeref(expr->base.type);
8904                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8905                 }
8906
8907                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8908                 case EXPR_UNARY_ASSUME:               return true;
8909                 case EXPR_UNARY_DELETE:               return true;
8910                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8911                 case EXPR_UNARY_THROW:                return true;
8912
8913                 case EXPR_BINARY_ADD:                 return false;
8914                 case EXPR_BINARY_SUB:                 return false;
8915                 case EXPR_BINARY_MUL:                 return false;
8916                 case EXPR_BINARY_DIV:                 return false;
8917                 case EXPR_BINARY_MOD:                 return false;
8918                 case EXPR_BINARY_EQUAL:               return false;
8919                 case EXPR_BINARY_NOTEQUAL:            return false;
8920                 case EXPR_BINARY_LESS:                return false;
8921                 case EXPR_BINARY_LESSEQUAL:           return false;
8922                 case EXPR_BINARY_GREATER:             return false;
8923                 case EXPR_BINARY_GREATEREQUAL:        return false;
8924                 case EXPR_BINARY_BITWISE_AND:         return false;
8925                 case EXPR_BINARY_BITWISE_OR:          return false;
8926                 case EXPR_BINARY_BITWISE_XOR:         return false;
8927                 case EXPR_BINARY_SHIFTLEFT:           return false;
8928                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8929                 case EXPR_BINARY_ASSIGN:              return true;
8930                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8931                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8932                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8933                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8934                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8935                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8936                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8937                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8938                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8939                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8940
8941                 /* Only examine the right hand side of && and ||, because the left hand
8942                  * side already has the effect of controlling the execution of the right
8943                  * hand side */
8944                 case EXPR_BINARY_LOGICAL_AND:
8945                 case EXPR_BINARY_LOGICAL_OR:
8946                 /* Only examine the right hand side of a comma expression, because the left
8947                  * hand side has a separate warning */
8948                 case EXPR_BINARY_COMMA:
8949                         return expression_has_effect(expr->binary.right);
8950
8951                 case EXPR_BINARY_ISGREATER:           return false;
8952                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8953                 case EXPR_BINARY_ISLESS:              return false;
8954                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8955                 case EXPR_BINARY_ISLESSGREATER:       return false;
8956                 case EXPR_BINARY_ISUNORDERED:         return false;
8957         }
8958
8959         internal_errorf(HERE, "unexpected expression");
8960 }
8961
8962 static void semantic_comma(binary_expression_t *expression)
8963 {
8964         if (warning.unused_value) {
8965                 const expression_t *const left = expression->left;
8966                 if (!expression_has_effect(left)) {
8967                         warningf(&left->base.source_position,
8968                                  "left-hand operand of comma expression has no effect");
8969                 }
8970         }
8971         expression->base.type = expression->right->base.type;
8972 }
8973
8974 /**
8975  * @param prec_r precedence of the right operand
8976  */
8977 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8978 static expression_t *parse_##binexpression_type(expression_t *left)          \
8979 {                                                                            \
8980         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8981         binexpr->binary.left  = left;                                            \
8982         eat(token_type);                                                         \
8983                                                                              \
8984         expression_t *right = parse_sub_expression(prec_r);                      \
8985                                                                              \
8986         binexpr->binary.right = right;                                           \
8987         sfunc(&binexpr->binary);                                                 \
8988                                                                              \
8989         return binexpr;                                                          \
8990 }
8991
8992 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8993 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8994 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8995 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8996 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8997 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8998 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8999 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9000 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9001 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9002 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9003 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9004 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9005 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9006 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9007 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9008 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9009 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9010 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9011 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9012 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9013 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9014 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9015 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9016 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
9017 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
9018 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9019 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
9020 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9021 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9022
9023
9024 static expression_t *parse_sub_expression(precedence_t precedence)
9025 {
9026         if (token.type < 0) {
9027                 return expected_expression_error();
9028         }
9029
9030         expression_parser_function_t *parser
9031                 = &expression_parsers[token.type];
9032         source_position_t             source_position = token.source_position;
9033         expression_t                 *left;
9034
9035         if (parser->parser != NULL) {
9036                 left = parser->parser();
9037         } else {
9038                 left = parse_primary_expression();
9039         }
9040         assert(left != NULL);
9041         left->base.source_position = source_position;
9042
9043         while (true) {
9044                 if (token.type < 0) {
9045                         return expected_expression_error();
9046                 }
9047
9048                 parser = &expression_parsers[token.type];
9049                 if (parser->infix_parser == NULL)
9050                         break;
9051                 if (parser->infix_precedence < precedence)
9052                         break;
9053
9054                 left = parser->infix_parser(left);
9055
9056                 assert(left != NULL);
9057                 assert(left->kind != EXPR_UNKNOWN);
9058                 left->base.source_position = source_position;
9059         }
9060
9061         return left;
9062 }
9063
9064 /**
9065  * Parse an expression.
9066  */
9067 static expression_t *parse_expression(void)
9068 {
9069         return parse_sub_expression(PREC_EXPRESSION);
9070 }
9071
9072 /**
9073  * Register a parser for a prefix-like operator.
9074  *
9075  * @param parser      the parser function
9076  * @param token_type  the token type of the prefix token
9077  */
9078 static void register_expression_parser(parse_expression_function parser,
9079                                        int token_type)
9080 {
9081         expression_parser_function_t *entry = &expression_parsers[token_type];
9082
9083         if (entry->parser != NULL) {
9084                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9085                 panic("trying to register multiple expression parsers for a token");
9086         }
9087         entry->parser = parser;
9088 }
9089
9090 /**
9091  * Register a parser for an infix operator with given precedence.
9092  *
9093  * @param parser      the parser function
9094  * @param token_type  the token type of the infix operator
9095  * @param precedence  the precedence of the operator
9096  */
9097 static void register_infix_parser(parse_expression_infix_function parser,
9098                 int token_type, precedence_t precedence)
9099 {
9100         expression_parser_function_t *entry = &expression_parsers[token_type];
9101
9102         if (entry->infix_parser != NULL) {
9103                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9104                 panic("trying to register multiple infix expression parsers for a "
9105                       "token");
9106         }
9107         entry->infix_parser     = parser;
9108         entry->infix_precedence = precedence;
9109 }
9110
9111 /**
9112  * Initialize the expression parsers.
9113  */
9114 static void init_expression_parsers(void)
9115 {
9116         memset(&expression_parsers, 0, sizeof(expression_parsers));
9117
9118         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9119         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9120         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9121         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9122         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9123         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9124         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9125         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9126         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9127         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9128         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9129         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9130         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9131         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9132         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9133         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9134         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9135         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9136         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9137         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9138         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9139         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9140         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9141         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9142         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9143         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9144         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9145         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9146         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9147         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9148         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9149         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9150         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9151         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9152         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9153         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9154         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9155
9156         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9157         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9158         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9159         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9160         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9161         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9162         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9163         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9164         register_expression_parser(parse_sizeof,                      T_sizeof);
9165         register_expression_parser(parse_alignof,                     T___alignof__);
9166         register_expression_parser(parse_extension,                   T___extension__);
9167         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9168         register_expression_parser(parse_delete,                      T_delete);
9169         register_expression_parser(parse_throw,                       T_throw);
9170 }
9171
9172 /**
9173  * Parse a asm statement arguments specification.
9174  */
9175 static asm_argument_t *parse_asm_arguments(bool is_out)
9176 {
9177         asm_argument_t  *result = NULL;
9178         asm_argument_t **anchor = &result;
9179
9180         while (token.type == T_STRING_LITERAL || token.type == '[') {
9181                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9182                 memset(argument, 0, sizeof(argument[0]));
9183
9184                 if (token.type == '[') {
9185                         eat('[');
9186                         if (token.type != T_IDENTIFIER) {
9187                                 parse_error_expected("while parsing asm argument",
9188                                                      T_IDENTIFIER, NULL);
9189                                 return NULL;
9190                         }
9191                         argument->symbol = token.v.symbol;
9192
9193                         expect(']', end_error);
9194                 }
9195
9196                 argument->constraints = parse_string_literals();
9197                 expect('(', end_error);
9198                 add_anchor_token(')');
9199                 expression_t *expression = parse_expression();
9200                 rem_anchor_token(')');
9201                 if (is_out) {
9202                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9203                          * change size or type representation (e.g. int -> long is ok, but
9204                          * int -> float is not) */
9205                         if (expression->kind == EXPR_UNARY_CAST) {
9206                                 type_t      *const type = expression->base.type;
9207                                 type_kind_t  const kind = type->kind;
9208                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9209                                         unsigned flags;
9210                                         unsigned size;
9211                                         if (kind == TYPE_ATOMIC) {
9212                                                 atomic_type_kind_t const akind = type->atomic.akind;
9213                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9214                                                 size  = get_atomic_type_size(akind);
9215                                         } else {
9216                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9217                                                 size  = get_atomic_type_size(get_intptr_kind());
9218                                         }
9219
9220                                         do {
9221                                                 expression_t *const value      = expression->unary.value;
9222                                                 type_t       *const value_type = value->base.type;
9223                                                 type_kind_t   const value_kind = value_type->kind;
9224
9225                                                 unsigned value_flags;
9226                                                 unsigned value_size;
9227                                                 if (value_kind == TYPE_ATOMIC) {
9228                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9229                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9230                                                         value_size  = get_atomic_type_size(value_akind);
9231                                                 } else if (value_kind == TYPE_POINTER) {
9232                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9233                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9234                                                 } else {
9235                                                         break;
9236                                                 }
9237
9238                                                 if (value_flags != flags || value_size != size)
9239                                                         break;
9240
9241                                                 expression = value;
9242                                         } while (expression->kind == EXPR_UNARY_CAST);
9243                                 }
9244                         }
9245
9246                         if (!is_lvalue(expression)) {
9247                                 errorf(&expression->base.source_position,
9248                                        "asm output argument is not an lvalue");
9249                         }
9250
9251                         if (argument->constraints.begin[0] == '+')
9252                                 mark_vars_read(expression, NULL);
9253                 } else {
9254                         mark_vars_read(expression, NULL);
9255                 }
9256                 argument->expression = expression;
9257                 expect(')', end_error);
9258
9259                 set_address_taken(expression, true);
9260
9261                 *anchor = argument;
9262                 anchor  = &argument->next;
9263
9264                 if (token.type != ',')
9265                         break;
9266                 eat(',');
9267         }
9268
9269         return result;
9270 end_error:
9271         return NULL;
9272 }
9273
9274 /**
9275  * Parse a asm statement clobber specification.
9276  */
9277 static asm_clobber_t *parse_asm_clobbers(void)
9278 {
9279         asm_clobber_t *result = NULL;
9280         asm_clobber_t *last   = NULL;
9281
9282         while (token.type == T_STRING_LITERAL) {
9283                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9284                 clobber->clobber       = parse_string_literals();
9285
9286                 if (last != NULL) {
9287                         last->next = clobber;
9288                 } else {
9289                         result = clobber;
9290                 }
9291                 last = clobber;
9292
9293                 if (token.type != ',')
9294                         break;
9295                 eat(',');
9296         }
9297
9298         return result;
9299 }
9300
9301 /**
9302  * Parse an asm statement.
9303  */
9304 static statement_t *parse_asm_statement(void)
9305 {
9306         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9307         asm_statement_t *asm_statement = &statement->asms;
9308
9309         eat(T_asm);
9310
9311         if (token.type == T_volatile) {
9312                 next_token();
9313                 asm_statement->is_volatile = true;
9314         }
9315
9316         expect('(', end_error);
9317         add_anchor_token(')');
9318         add_anchor_token(':');
9319         asm_statement->asm_text = parse_string_literals();
9320
9321         if (token.type != ':') {
9322                 rem_anchor_token(':');
9323                 goto end_of_asm;
9324         }
9325         eat(':');
9326
9327         asm_statement->outputs = parse_asm_arguments(true);
9328         if (token.type != ':') {
9329                 rem_anchor_token(':');
9330                 goto end_of_asm;
9331         }
9332         eat(':');
9333
9334         asm_statement->inputs = parse_asm_arguments(false);
9335         if (token.type != ':') {
9336                 rem_anchor_token(':');
9337                 goto end_of_asm;
9338         }
9339         rem_anchor_token(':');
9340         eat(':');
9341
9342         asm_statement->clobbers = parse_asm_clobbers();
9343
9344 end_of_asm:
9345         rem_anchor_token(')');
9346         expect(')', end_error);
9347         expect(';', end_error);
9348
9349         if (asm_statement->outputs == NULL) {
9350                 /* GCC: An 'asm' instruction without any output operands will be treated
9351                  * identically to a volatile 'asm' instruction. */
9352                 asm_statement->is_volatile = true;
9353         }
9354
9355         return statement;
9356 end_error:
9357         return create_invalid_statement();
9358 }
9359
9360 /**
9361  * Parse a case statement.
9362  */
9363 static statement_t *parse_case_statement(void)
9364 {
9365         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9366         source_position_t *const pos       = &statement->base.source_position;
9367
9368         eat(T_case);
9369
9370         expression_t *const expression   = parse_expression();
9371         statement->case_label.expression = expression;
9372         if (!is_constant_expression(expression)) {
9373                 /* This check does not prevent the error message in all cases of an
9374                  * prior error while parsing the expression.  At least it catches the
9375                  * common case of a mistyped enum entry. */
9376                 if (is_type_valid(skip_typeref(expression->base.type))) {
9377                         errorf(pos, "case label does not reduce to an integer constant");
9378                 }
9379                 statement->case_label.is_bad = true;
9380         } else {
9381                 long const val = fold_constant(expression);
9382                 statement->case_label.first_case = val;
9383                 statement->case_label.last_case  = val;
9384         }
9385
9386         if (GNU_MODE) {
9387                 if (token.type == T_DOTDOTDOT) {
9388                         next_token();
9389                         expression_t *const end_range   = parse_expression();
9390                         statement->case_label.end_range = end_range;
9391                         if (!is_constant_expression(end_range)) {
9392                                 /* This check does not prevent the error message in all cases of an
9393                                  * prior error while parsing the expression.  At least it catches the
9394                                  * common case of a mistyped enum entry. */
9395                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9396                                         errorf(pos, "case range does not reduce to an integer constant");
9397                                 }
9398                                 statement->case_label.is_bad = true;
9399                         } else {
9400                                 long const val = fold_constant(end_range);
9401                                 statement->case_label.last_case = val;
9402
9403                                 if (warning.other && val < statement->case_label.first_case) {
9404                                         statement->case_label.is_empty_range = true;
9405                                         warningf(pos, "empty range specified");
9406                                 }
9407                         }
9408                 }
9409         }
9410
9411         PUSH_PARENT(statement);
9412
9413         expect(':', end_error);
9414 end_error:
9415
9416         if (current_switch != NULL) {
9417                 if (! statement->case_label.is_bad) {
9418                         /* Check for duplicate case values */
9419                         case_label_statement_t *c = &statement->case_label;
9420                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9421                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9422                                         continue;
9423
9424                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9425                                         continue;
9426
9427                                 errorf(pos, "duplicate case value (previously used %P)",
9428                                        &l->base.source_position);
9429                                 break;
9430                         }
9431                 }
9432                 /* link all cases into the switch statement */
9433                 if (current_switch->last_case == NULL) {
9434                         current_switch->first_case      = &statement->case_label;
9435                 } else {
9436                         current_switch->last_case->next = &statement->case_label;
9437                 }
9438                 current_switch->last_case = &statement->case_label;
9439         } else {
9440                 errorf(pos, "case label not within a switch statement");
9441         }
9442
9443         statement_t *const inner_stmt = parse_statement();
9444         statement->case_label.statement = inner_stmt;
9445         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9446                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9447         }
9448
9449         POP_PARENT;
9450         return statement;
9451 }
9452
9453 /**
9454  * Parse a default statement.
9455  */
9456 static statement_t *parse_default_statement(void)
9457 {
9458         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9459
9460         eat(T_default);
9461
9462         PUSH_PARENT(statement);
9463
9464         expect(':', end_error);
9465         if (current_switch != NULL) {
9466                 const case_label_statement_t *def_label = current_switch->default_label;
9467                 if (def_label != NULL) {
9468                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9469                                &def_label->base.source_position);
9470                 } else {
9471                         current_switch->default_label = &statement->case_label;
9472
9473                         /* link all cases into the switch statement */
9474                         if (current_switch->last_case == NULL) {
9475                                 current_switch->first_case      = &statement->case_label;
9476                         } else {
9477                                 current_switch->last_case->next = &statement->case_label;
9478                         }
9479                         current_switch->last_case = &statement->case_label;
9480                 }
9481         } else {
9482                 errorf(&statement->base.source_position,
9483                         "'default' label not within a switch statement");
9484         }
9485
9486         statement_t *const inner_stmt = parse_statement();
9487         statement->case_label.statement = inner_stmt;
9488         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9489                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9490         }
9491
9492         POP_PARENT;
9493         return statement;
9494 end_error:
9495         POP_PARENT;
9496         return create_invalid_statement();
9497 }
9498
9499 /**
9500  * Parse a label statement.
9501  */
9502 static statement_t *parse_label_statement(void)
9503 {
9504         assert(token.type == T_IDENTIFIER);
9505         symbol_t *symbol = token.v.symbol;
9506         label_t  *label  = get_label(symbol);
9507
9508         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9509         statement->label.label       = label;
9510
9511         next_token();
9512
9513         PUSH_PARENT(statement);
9514
9515         /* if statement is already set then the label is defined twice,
9516          * otherwise it was just mentioned in a goto/local label declaration so far
9517          */
9518         if (label->statement != NULL) {
9519                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9520                        symbol, &label->base.source_position);
9521         } else {
9522                 label->base.source_position = token.source_position;
9523                 label->statement            = statement;
9524         }
9525
9526         eat(':');
9527
9528         if (token.type == '}') {
9529                 /* TODO only warn? */
9530                 if (warning.other && false) {
9531                         warningf(HERE, "label at end of compound statement");
9532                         statement->label.statement = create_empty_statement();
9533                 } else {
9534                         errorf(HERE, "label at end of compound statement");
9535                         statement->label.statement = create_invalid_statement();
9536                 }
9537         } else if (token.type == ';') {
9538                 /* Eat an empty statement here, to avoid the warning about an empty
9539                  * statement after a label.  label:; is commonly used to have a label
9540                  * before a closing brace. */
9541                 statement->label.statement = create_empty_statement();
9542                 next_token();
9543         } else {
9544                 statement_t *const inner_stmt = parse_statement();
9545                 statement->label.statement = inner_stmt;
9546                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9547                         errorf(&inner_stmt->base.source_position, "declaration after label");
9548                 }
9549         }
9550
9551         /* remember the labels in a list for later checking */
9552         *label_anchor = &statement->label;
9553         label_anchor  = &statement->label.next;
9554
9555         POP_PARENT;
9556         return statement;
9557 }
9558
9559 /**
9560  * Parse an if statement.
9561  */
9562 static statement_t *parse_if(void)
9563 {
9564         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9565
9566         eat(T_if);
9567
9568         PUSH_PARENT(statement);
9569
9570         add_anchor_token('{');
9571
9572         expect('(', end_error);
9573         add_anchor_token(')');
9574         expression_t *const expr = parse_expression();
9575         statement->ifs.condition = expr;
9576         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9577          *             scalar type. */
9578         semantic_condition(expr, "condition of 'if'-statment");
9579         mark_vars_read(expr, NULL);
9580         rem_anchor_token(')');
9581         expect(')', end_error);
9582
9583 end_error:
9584         rem_anchor_token('{');
9585
9586         add_anchor_token(T_else);
9587         statement_t *const true_stmt = parse_statement();
9588         statement->ifs.true_statement = true_stmt;
9589         rem_anchor_token(T_else);
9590
9591         if (token.type == T_else) {
9592                 next_token();
9593                 statement->ifs.false_statement = parse_statement();
9594         } else if (warning.parentheses &&
9595                         true_stmt->kind == STATEMENT_IF &&
9596                         true_stmt->ifs.false_statement != NULL) {
9597                 warningf(&true_stmt->base.source_position,
9598                                 "suggest explicit braces to avoid ambiguous 'else'");
9599         }
9600
9601         POP_PARENT;
9602         return statement;
9603 }
9604
9605 /**
9606  * Check that all enums are handled in a switch.
9607  *
9608  * @param statement  the switch statement to check
9609  */
9610 static void check_enum_cases(const switch_statement_t *statement)
9611 {
9612         const type_t *type = skip_typeref(statement->expression->base.type);
9613         if (! is_type_enum(type))
9614                 return;
9615         const enum_type_t *enumt = &type->enumt;
9616
9617         /* if we have a default, no warnings */
9618         if (statement->default_label != NULL)
9619                 return;
9620
9621         /* FIXME: calculation of value should be done while parsing */
9622         /* TODO: quadratic algorithm here. Change to an n log n one */
9623         long            last_value = -1;
9624         const entity_t *entry      = enumt->enume->base.next;
9625         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9626              entry = entry->base.next) {
9627                 const expression_t *expression = entry->enum_value.value;
9628                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9629                 bool                found      = false;
9630                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9631                         if (l->expression == NULL)
9632                                 continue;
9633                         if (l->first_case <= value && value <= l->last_case) {
9634                                 found = true;
9635                                 break;
9636                         }
9637                 }
9638                 if (! found) {
9639                         warningf(&statement->base.source_position,
9640                                  "enumeration value '%Y' not handled in switch",
9641                                  entry->base.symbol);
9642                 }
9643                 last_value = value;
9644         }
9645 }
9646
9647 /**
9648  * Parse a switch statement.
9649  */
9650 static statement_t *parse_switch(void)
9651 {
9652         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9653
9654         eat(T_switch);
9655
9656         PUSH_PARENT(statement);
9657
9658         expect('(', end_error);
9659         add_anchor_token(')');
9660         expression_t *const expr = parse_expression();
9661         mark_vars_read(expr, NULL);
9662         type_t       *      type = skip_typeref(expr->base.type);
9663         if (is_type_integer(type)) {
9664                 type = promote_integer(type);
9665                 if (warning.traditional) {
9666                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9667                                 warningf(&expr->base.source_position,
9668                                         "'%T' switch expression not converted to '%T' in ISO C",
9669                                         type, type_int);
9670                         }
9671                 }
9672         } else if (is_type_valid(type)) {
9673                 errorf(&expr->base.source_position,
9674                        "switch quantity is not an integer, but '%T'", type);
9675                 type = type_error_type;
9676         }
9677         statement->switchs.expression = create_implicit_cast(expr, type);
9678         expect(')', end_error);
9679         rem_anchor_token(')');
9680
9681         switch_statement_t *rem = current_switch;
9682         current_switch          = &statement->switchs;
9683         statement->switchs.body = parse_statement();
9684         current_switch          = rem;
9685
9686         if (warning.switch_default &&
9687             statement->switchs.default_label == NULL) {
9688                 warningf(&statement->base.source_position, "switch has no default case");
9689         }
9690         if (warning.switch_enum)
9691                 check_enum_cases(&statement->switchs);
9692
9693         POP_PARENT;
9694         return statement;
9695 end_error:
9696         POP_PARENT;
9697         return create_invalid_statement();
9698 }
9699
9700 static statement_t *parse_loop_body(statement_t *const loop)
9701 {
9702         statement_t *const rem = current_loop;
9703         current_loop = loop;
9704
9705         statement_t *const body = parse_statement();
9706
9707         current_loop = rem;
9708         return body;
9709 }
9710
9711 /**
9712  * Parse a while statement.
9713  */
9714 static statement_t *parse_while(void)
9715 {
9716         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9717
9718         eat(T_while);
9719
9720         PUSH_PARENT(statement);
9721
9722         expect('(', end_error);
9723         add_anchor_token(')');
9724         expression_t *const cond = parse_expression();
9725         statement->whiles.condition = cond;
9726         /* §6.8.5:2    The controlling expression of an iteration statement shall
9727          *             have scalar type. */
9728         semantic_condition(cond, "condition of 'while'-statement");
9729         mark_vars_read(cond, NULL);
9730         rem_anchor_token(')');
9731         expect(')', end_error);
9732
9733         statement->whiles.body = parse_loop_body(statement);
9734
9735         POP_PARENT;
9736         return statement;
9737 end_error:
9738         POP_PARENT;
9739         return create_invalid_statement();
9740 }
9741
9742 /**
9743  * Parse a do statement.
9744  */
9745 static statement_t *parse_do(void)
9746 {
9747         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9748
9749         eat(T_do);
9750
9751         PUSH_PARENT(statement);
9752
9753         add_anchor_token(T_while);
9754         statement->do_while.body = parse_loop_body(statement);
9755         rem_anchor_token(T_while);
9756
9757         expect(T_while, end_error);
9758         expect('(', end_error);
9759         add_anchor_token(')');
9760         expression_t *const cond = parse_expression();
9761         statement->do_while.condition = cond;
9762         /* §6.8.5:2    The controlling expression of an iteration statement shall
9763          *             have scalar type. */
9764         semantic_condition(cond, "condition of 'do-while'-statement");
9765         mark_vars_read(cond, NULL);
9766         rem_anchor_token(')');
9767         expect(')', end_error);
9768         expect(';', end_error);
9769
9770         POP_PARENT;
9771         return statement;
9772 end_error:
9773         POP_PARENT;
9774         return create_invalid_statement();
9775 }
9776
9777 /**
9778  * Parse a for statement.
9779  */
9780 static statement_t *parse_for(void)
9781 {
9782         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9783
9784         eat(T_for);
9785
9786         expect('(', end_error1);
9787         add_anchor_token(')');
9788
9789         PUSH_PARENT(statement);
9790
9791         size_t const  top       = environment_top();
9792         scope_t      *old_scope = scope_push(&statement->fors.scope);
9793
9794         bool old_gcc_extension = in_gcc_extension;
9795         while (token.type == T___extension__) {
9796                 next_token();
9797                 in_gcc_extension = true;
9798         }
9799
9800         if (token.type == ';') {
9801                 next_token();
9802         } else if (is_declaration_specifier(&token, false)) {
9803                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9804         } else {
9805                 add_anchor_token(';');
9806                 expression_t *const init = parse_expression();
9807                 statement->fors.initialisation = init;
9808                 mark_vars_read(init, ENT_ANY);
9809                 if (warning.unused_value && !expression_has_effect(init)) {
9810                         warningf(&init->base.source_position,
9811                                         "initialisation of 'for'-statement has no effect");
9812                 }
9813                 rem_anchor_token(';');
9814                 expect(';', end_error2);
9815         }
9816         in_gcc_extension = old_gcc_extension;
9817
9818         if (token.type != ';') {
9819                 add_anchor_token(';');
9820                 expression_t *const cond = parse_expression();
9821                 statement->fors.condition = cond;
9822                 /* §6.8.5:2    The controlling expression of an iteration statement
9823                  *             shall have scalar type. */
9824                 semantic_condition(cond, "condition of 'for'-statement");
9825                 mark_vars_read(cond, NULL);
9826                 rem_anchor_token(';');
9827         }
9828         expect(';', end_error2);
9829         if (token.type != ')') {
9830                 expression_t *const step = parse_expression();
9831                 statement->fors.step = step;
9832                 mark_vars_read(step, ENT_ANY);
9833                 if (warning.unused_value && !expression_has_effect(step)) {
9834                         warningf(&step->base.source_position,
9835                                  "step of 'for'-statement has no effect");
9836                 }
9837         }
9838         expect(')', end_error2);
9839         rem_anchor_token(')');
9840         statement->fors.body = parse_loop_body(statement);
9841
9842         assert(current_scope == &statement->fors.scope);
9843         scope_pop(old_scope);
9844         environment_pop_to(top);
9845
9846         POP_PARENT;
9847         return statement;
9848
9849 end_error2:
9850         POP_PARENT;
9851         rem_anchor_token(')');
9852         assert(current_scope == &statement->fors.scope);
9853         scope_pop(old_scope);
9854         environment_pop_to(top);
9855         /* fallthrough */
9856
9857 end_error1:
9858         return create_invalid_statement();
9859 }
9860
9861 /**
9862  * Parse a goto statement.
9863  */
9864 static statement_t *parse_goto(void)
9865 {
9866         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9867         eat(T_goto);
9868
9869         if (GNU_MODE && token.type == '*') {
9870                 next_token();
9871                 expression_t *expression = parse_expression();
9872                 mark_vars_read(expression, NULL);
9873
9874                 /* Argh: although documentation says the expression must be of type void*,
9875                  * gcc accepts anything that can be casted into void* without error */
9876                 type_t *type = expression->base.type;
9877
9878                 if (type != type_error_type) {
9879                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9880                                 errorf(&expression->base.source_position,
9881                                         "cannot convert to a pointer type");
9882                         } else if (warning.other && type != type_void_ptr) {
9883                                 warningf(&expression->base.source_position,
9884                                         "type of computed goto expression should be 'void*' not '%T'", type);
9885                         }
9886                         expression = create_implicit_cast(expression, type_void_ptr);
9887                 }
9888
9889                 statement->gotos.expression = expression;
9890         } else if (token.type == T_IDENTIFIER) {
9891                 symbol_t *symbol = token.v.symbol;
9892                 next_token();
9893                 statement->gotos.label = get_label(symbol);
9894         } else {
9895                 if (GNU_MODE)
9896                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9897                 else
9898                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9899                 eat_until_anchor();
9900                 goto end_error;
9901         }
9902
9903         /* remember the goto's in a list for later checking */
9904         *goto_anchor = &statement->gotos;
9905         goto_anchor  = &statement->gotos.next;
9906
9907         expect(';', end_error);
9908
9909         return statement;
9910 end_error:
9911         return create_invalid_statement();
9912 }
9913
9914 /**
9915  * Parse a continue statement.
9916  */
9917 static statement_t *parse_continue(void)
9918 {
9919         if (current_loop == NULL) {
9920                 errorf(HERE, "continue statement not within loop");
9921         }
9922
9923         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9924
9925         eat(T_continue);
9926         expect(';', end_error);
9927
9928 end_error:
9929         return statement;
9930 }
9931
9932 /**
9933  * Parse a break statement.
9934  */
9935 static statement_t *parse_break(void)
9936 {
9937         if (current_switch == NULL && current_loop == NULL) {
9938                 errorf(HERE, "break statement not within loop or switch");
9939         }
9940
9941         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9942
9943         eat(T_break);
9944         expect(';', end_error);
9945
9946 end_error:
9947         return statement;
9948 }
9949
9950 /**
9951  * Parse a __leave statement.
9952  */
9953 static statement_t *parse_leave_statement(void)
9954 {
9955         if (current_try == NULL) {
9956                 errorf(HERE, "__leave statement not within __try");
9957         }
9958
9959         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9960
9961         eat(T___leave);
9962         expect(';', end_error);
9963
9964 end_error:
9965         return statement;
9966 }
9967
9968 /**
9969  * Check if a given entity represents a local variable.
9970  */
9971 static bool is_local_variable(const entity_t *entity)
9972 {
9973         if (entity->kind != ENTITY_VARIABLE)
9974                 return false;
9975
9976         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9977         case STORAGE_CLASS_AUTO:
9978         case STORAGE_CLASS_REGISTER: {
9979                 const type_t *type = skip_typeref(entity->declaration.type);
9980                 if (is_type_function(type)) {
9981                         return false;
9982                 } else {
9983                         return true;
9984                 }
9985         }
9986         default:
9987                 return false;
9988         }
9989 }
9990
9991 /**
9992  * Check if a given expression represents a local variable.
9993  */
9994 static bool expression_is_local_variable(const expression_t *expression)
9995 {
9996         if (expression->base.kind != EXPR_REFERENCE) {
9997                 return false;
9998         }
9999         const entity_t *entity = expression->reference.entity;
10000         return is_local_variable(entity);
10001 }
10002
10003 /**
10004  * Check if a given expression represents a local variable and
10005  * return its declaration then, else return NULL.
10006  */
10007 entity_t *expression_is_variable(const expression_t *expression)
10008 {
10009         if (expression->base.kind != EXPR_REFERENCE) {
10010                 return NULL;
10011         }
10012         entity_t *entity = expression->reference.entity;
10013         if (entity->kind != ENTITY_VARIABLE)
10014                 return NULL;
10015
10016         return entity;
10017 }
10018
10019 /**
10020  * Parse a return statement.
10021  */
10022 static statement_t *parse_return(void)
10023 {
10024         eat(T_return);
10025
10026         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10027
10028         expression_t *return_value = NULL;
10029         if (token.type != ';') {
10030                 return_value = parse_expression();
10031                 mark_vars_read(return_value, NULL);
10032         }
10033
10034         const type_t *const func_type = skip_typeref(current_function->base.type);
10035         assert(is_type_function(func_type));
10036         type_t *const return_type = skip_typeref(func_type->function.return_type);
10037
10038         source_position_t const *const pos = &statement->base.source_position;
10039         if (return_value != NULL) {
10040                 type_t *return_value_type = skip_typeref(return_value->base.type);
10041
10042                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10043                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10044                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10045                                 /* Only warn in C mode, because GCC does the same */
10046                                 if (c_mode & _CXX || strict_mode) {
10047                                         errorf(pos,
10048                                                         "'return' with a value, in function returning 'void'");
10049                                 } else if (warning.other) {
10050                                         warningf(pos,
10051                                                         "'return' with a value, in function returning 'void'");
10052                                 }
10053                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10054                                 /* Only warn in C mode, because GCC does the same */
10055                                 if (strict_mode) {
10056                                         errorf(pos,
10057                                                         "'return' with expression in function returning 'void'");
10058                                 } else if (warning.other) {
10059                                         warningf(pos,
10060                                                         "'return' with expression in function returning 'void'");
10061                                 }
10062                         }
10063                 } else {
10064                         assign_error_t error = semantic_assign(return_type, return_value);
10065                         report_assign_error(error, return_type, return_value, "'return'",
10066                                         pos);
10067                 }
10068                 return_value = create_implicit_cast(return_value, return_type);
10069                 /* check for returning address of a local var */
10070                 if (warning.other && return_value != NULL
10071                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10072                         const expression_t *expression = return_value->unary.value;
10073                         if (expression_is_local_variable(expression)) {
10074                                 warningf(pos, "function returns address of local variable");
10075                         }
10076                 }
10077         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10078                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10079                 if (c_mode & _CXX || strict_mode) {
10080                         errorf(pos,
10081                                         "'return' without value, in function returning non-void");
10082                 } else {
10083                         warningf(pos,
10084                                         "'return' without value, in function returning non-void");
10085                 }
10086         }
10087         statement->returns.value = return_value;
10088
10089         expect(';', end_error);
10090
10091 end_error:
10092         return statement;
10093 }
10094
10095 /**
10096  * Parse a declaration statement.
10097  */
10098 static statement_t *parse_declaration_statement(void)
10099 {
10100         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10101
10102         entity_t *before = current_scope->last_entity;
10103         if (GNU_MODE) {
10104                 parse_external_declaration();
10105         } else {
10106                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10107         }
10108
10109         declaration_statement_t *const decl  = &statement->declaration;
10110         entity_t                *const begin =
10111                 before != NULL ? before->base.next : current_scope->entities;
10112         decl->declarations_begin = begin;
10113         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10114
10115         return statement;
10116 }
10117
10118 /**
10119  * Parse an expression statement, ie. expr ';'.
10120  */
10121 static statement_t *parse_expression_statement(void)
10122 {
10123         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10124
10125         expression_t *const expr         = parse_expression();
10126         statement->expression.expression = expr;
10127         mark_vars_read(expr, ENT_ANY);
10128
10129         expect(';', end_error);
10130
10131 end_error:
10132         return statement;
10133 }
10134
10135 /**
10136  * Parse a microsoft __try { } __finally { } or
10137  * __try{ } __except() { }
10138  */
10139 static statement_t *parse_ms_try_statment(void)
10140 {
10141         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10142         eat(T___try);
10143
10144         PUSH_PARENT(statement);
10145
10146         ms_try_statement_t *rem = current_try;
10147         current_try = &statement->ms_try;
10148         statement->ms_try.try_statement = parse_compound_statement(false);
10149         current_try = rem;
10150
10151         POP_PARENT;
10152
10153         if (token.type == T___except) {
10154                 eat(T___except);
10155                 expect('(', end_error);
10156                 add_anchor_token(')');
10157                 expression_t *const expr = parse_expression();
10158                 mark_vars_read(expr, NULL);
10159                 type_t       *      type = skip_typeref(expr->base.type);
10160                 if (is_type_integer(type)) {
10161                         type = promote_integer(type);
10162                 } else if (is_type_valid(type)) {
10163                         errorf(&expr->base.source_position,
10164                                "__expect expression is not an integer, but '%T'", type);
10165                         type = type_error_type;
10166                 }
10167                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10168                 rem_anchor_token(')');
10169                 expect(')', end_error);
10170                 statement->ms_try.final_statement = parse_compound_statement(false);
10171         } else if (token.type == T__finally) {
10172                 eat(T___finally);
10173                 statement->ms_try.final_statement = parse_compound_statement(false);
10174         } else {
10175                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10176                 return create_invalid_statement();
10177         }
10178         return statement;
10179 end_error:
10180         return create_invalid_statement();
10181 }
10182
10183 static statement_t *parse_empty_statement(void)
10184 {
10185         if (warning.empty_statement) {
10186                 warningf(HERE, "statement is empty");
10187         }
10188         statement_t *const statement = create_empty_statement();
10189         eat(';');
10190         return statement;
10191 }
10192
10193 static statement_t *parse_local_label_declaration(void)
10194 {
10195         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10196
10197         eat(T___label__);
10198
10199         entity_t *begin = NULL, *end = NULL;
10200
10201         while (true) {
10202                 if (token.type != T_IDENTIFIER) {
10203                         parse_error_expected("while parsing local label declaration",
10204                                 T_IDENTIFIER, NULL);
10205                         goto end_error;
10206                 }
10207                 symbol_t *symbol = token.v.symbol;
10208                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10209                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10210                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10211                                symbol, &entity->base.source_position);
10212                 } else {
10213                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10214
10215                         entity->base.parent_scope    = current_scope;
10216                         entity->base.namespc         = NAMESPACE_LABEL;
10217                         entity->base.source_position = token.source_position;
10218                         entity->base.symbol          = symbol;
10219
10220                         if (end != NULL)
10221                                 end->base.next = entity;
10222                         end = entity;
10223                         if (begin == NULL)
10224                                 begin = entity;
10225
10226                         environment_push(entity);
10227                 }
10228                 next_token();
10229
10230                 if (token.type != ',')
10231                         break;
10232                 next_token();
10233         }
10234         eat(';');
10235 end_error:
10236         statement->declaration.declarations_begin = begin;
10237         statement->declaration.declarations_end   = end;
10238         return statement;
10239 }
10240
10241 static void parse_namespace_definition(void)
10242 {
10243         eat(T_namespace);
10244
10245         entity_t *entity = NULL;
10246         symbol_t *symbol = NULL;
10247
10248         if (token.type == T_IDENTIFIER) {
10249                 symbol = token.v.symbol;
10250                 next_token();
10251
10252                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10253                 if (entity       != NULL             &&
10254                                 entity->kind != ENTITY_NAMESPACE &&
10255                                 entity->base.parent_scope == current_scope) {
10256                         if (!is_error_entity(entity)) {
10257                                 error_redefined_as_different_kind(&token.source_position,
10258                                                 entity, ENTITY_NAMESPACE);
10259                         }
10260                         entity = NULL;
10261                 }
10262         }
10263
10264         if (entity == NULL) {
10265                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10266                 entity->base.symbol          = symbol;
10267                 entity->base.source_position = token.source_position;
10268                 entity->base.namespc         = NAMESPACE_NORMAL;
10269                 entity->base.parent_scope    = current_scope;
10270         }
10271
10272         if (token.type == '=') {
10273                 /* TODO: parse namespace alias */
10274                 panic("namespace alias definition not supported yet");
10275         }
10276
10277         environment_push(entity);
10278         append_entity(current_scope, entity);
10279
10280         size_t const  top       = environment_top();
10281         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10282
10283         expect('{', end_error);
10284         parse_externals();
10285         expect('}', end_error);
10286
10287 end_error:
10288         assert(current_scope == &entity->namespacee.members);
10289         scope_pop(old_scope);
10290         environment_pop_to(top);
10291 }
10292
10293 /**
10294  * Parse a statement.
10295  * There's also parse_statement() which additionally checks for
10296  * "statement has no effect" warnings
10297  */
10298 static statement_t *intern_parse_statement(void)
10299 {
10300         statement_t *statement = NULL;
10301
10302         /* declaration or statement */
10303         add_anchor_token(';');
10304         switch (token.type) {
10305         case T_IDENTIFIER: {
10306                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10307                 if (la1_type == ':') {
10308                         statement = parse_label_statement();
10309                 } else if (is_typedef_symbol(token.v.symbol)) {
10310                         statement = parse_declaration_statement();
10311                 } else {
10312                         /* it's an identifier, the grammar says this must be an
10313                          * expression statement. However it is common that users mistype
10314                          * declaration types, so we guess a bit here to improve robustness
10315                          * for incorrect programs */
10316                         switch (la1_type) {
10317                         case '&':
10318                         case '*':
10319                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10320                                         goto expression_statment;
10321                                 /* FALLTHROUGH */
10322
10323                         DECLARATION_START
10324                         case T_IDENTIFIER:
10325                                 statement = parse_declaration_statement();
10326                                 break;
10327
10328                         default:
10329 expression_statment:
10330                                 statement = parse_expression_statement();
10331                                 break;
10332                         }
10333                 }
10334                 break;
10335         }
10336
10337         case T___extension__:
10338                 /* This can be a prefix to a declaration or an expression statement.
10339                  * We simply eat it now and parse the rest with tail recursion. */
10340                 do {
10341                         next_token();
10342                 } while (token.type == T___extension__);
10343                 bool old_gcc_extension = in_gcc_extension;
10344                 in_gcc_extension       = true;
10345                 statement = intern_parse_statement();
10346                 in_gcc_extension = old_gcc_extension;
10347                 break;
10348
10349         DECLARATION_START
10350                 statement = parse_declaration_statement();
10351                 break;
10352
10353         case T___label__:
10354                 statement = parse_local_label_declaration();
10355                 break;
10356
10357         case ';':         statement = parse_empty_statement();         break;
10358         case '{':         statement = parse_compound_statement(false); break;
10359         case T___leave:   statement = parse_leave_statement();         break;
10360         case T___try:     statement = parse_ms_try_statment();         break;
10361         case T_asm:       statement = parse_asm_statement();           break;
10362         case T_break:     statement = parse_break();                   break;
10363         case T_case:      statement = parse_case_statement();          break;
10364         case T_continue:  statement = parse_continue();                break;
10365         case T_default:   statement = parse_default_statement();       break;
10366         case T_do:        statement = parse_do();                      break;
10367         case T_for:       statement = parse_for();                     break;
10368         case T_goto:      statement = parse_goto();                    break;
10369         case T_if:        statement = parse_if();                      break;
10370         case T_return:    statement = parse_return();                  break;
10371         case T_switch:    statement = parse_switch();                  break;
10372         case T_while:     statement = parse_while();                   break;
10373
10374         EXPRESSION_START
10375                 statement = parse_expression_statement();
10376                 break;
10377
10378         default:
10379                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10380                 statement = create_invalid_statement();
10381                 if (!at_anchor())
10382                         next_token();
10383                 break;
10384         }
10385         rem_anchor_token(';');
10386
10387         assert(statement != NULL
10388                         && statement->base.source_position.input_name != NULL);
10389
10390         return statement;
10391 }
10392
10393 /**
10394  * parse a statement and emits "statement has no effect" warning if needed
10395  * (This is really a wrapper around intern_parse_statement with check for 1
10396  *  single warning. It is needed, because for statement expressions we have
10397  *  to avoid the warning on the last statement)
10398  */
10399 static statement_t *parse_statement(void)
10400 {
10401         statement_t *statement = intern_parse_statement();
10402
10403         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10404                 expression_t *expression = statement->expression.expression;
10405                 if (!expression_has_effect(expression)) {
10406                         warningf(&expression->base.source_position,
10407                                         "statement has no effect");
10408                 }
10409         }
10410
10411         return statement;
10412 }
10413
10414 /**
10415  * Parse a compound statement.
10416  */
10417 static statement_t *parse_compound_statement(bool inside_expression_statement)
10418 {
10419         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10420
10421         PUSH_PARENT(statement);
10422
10423         eat('{');
10424         add_anchor_token('}');
10425         /* tokens, which can start a statement */
10426         /* TODO MS, __builtin_FOO */
10427         add_anchor_token('!');
10428         add_anchor_token('&');
10429         add_anchor_token('(');
10430         add_anchor_token('*');
10431         add_anchor_token('+');
10432         add_anchor_token('-');
10433         add_anchor_token('{');
10434         add_anchor_token('~');
10435         add_anchor_token(T_CHARACTER_CONSTANT);
10436         add_anchor_token(T_COLONCOLON);
10437         add_anchor_token(T_FLOATINGPOINT);
10438         add_anchor_token(T_IDENTIFIER);
10439         add_anchor_token(T_INTEGER);
10440         add_anchor_token(T_MINUSMINUS);
10441         add_anchor_token(T_PLUSPLUS);
10442         add_anchor_token(T_STRING_LITERAL);
10443         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10444         add_anchor_token(T_WIDE_STRING_LITERAL);
10445         add_anchor_token(T__Bool);
10446         add_anchor_token(T__Complex);
10447         add_anchor_token(T__Imaginary);
10448         add_anchor_token(T___FUNCTION__);
10449         add_anchor_token(T___PRETTY_FUNCTION__);
10450         add_anchor_token(T___alignof__);
10451         add_anchor_token(T___attribute__);
10452         add_anchor_token(T___builtin_va_start);
10453         add_anchor_token(T___extension__);
10454         add_anchor_token(T___func__);
10455         add_anchor_token(T___imag__);
10456         add_anchor_token(T___label__);
10457         add_anchor_token(T___real__);
10458         add_anchor_token(T___thread);
10459         add_anchor_token(T_asm);
10460         add_anchor_token(T_auto);
10461         add_anchor_token(T_bool);
10462         add_anchor_token(T_break);
10463         add_anchor_token(T_case);
10464         add_anchor_token(T_char);
10465         add_anchor_token(T_class);
10466         add_anchor_token(T_const);
10467         add_anchor_token(T_const_cast);
10468         add_anchor_token(T_continue);
10469         add_anchor_token(T_default);
10470         add_anchor_token(T_delete);
10471         add_anchor_token(T_double);
10472         add_anchor_token(T_do);
10473         add_anchor_token(T_dynamic_cast);
10474         add_anchor_token(T_enum);
10475         add_anchor_token(T_extern);
10476         add_anchor_token(T_false);
10477         add_anchor_token(T_float);
10478         add_anchor_token(T_for);
10479         add_anchor_token(T_goto);
10480         add_anchor_token(T_if);
10481         add_anchor_token(T_inline);
10482         add_anchor_token(T_int);
10483         add_anchor_token(T_long);
10484         add_anchor_token(T_new);
10485         add_anchor_token(T_operator);
10486         add_anchor_token(T_register);
10487         add_anchor_token(T_reinterpret_cast);
10488         add_anchor_token(T_restrict);
10489         add_anchor_token(T_return);
10490         add_anchor_token(T_short);
10491         add_anchor_token(T_signed);
10492         add_anchor_token(T_sizeof);
10493         add_anchor_token(T_static);
10494         add_anchor_token(T_static_cast);
10495         add_anchor_token(T_struct);
10496         add_anchor_token(T_switch);
10497         add_anchor_token(T_template);
10498         add_anchor_token(T_this);
10499         add_anchor_token(T_throw);
10500         add_anchor_token(T_true);
10501         add_anchor_token(T_try);
10502         add_anchor_token(T_typedef);
10503         add_anchor_token(T_typeid);
10504         add_anchor_token(T_typename);
10505         add_anchor_token(T_typeof);
10506         add_anchor_token(T_union);
10507         add_anchor_token(T_unsigned);
10508         add_anchor_token(T_using);
10509         add_anchor_token(T_void);
10510         add_anchor_token(T_volatile);
10511         add_anchor_token(T_wchar_t);
10512         add_anchor_token(T_while);
10513
10514         size_t const  top       = environment_top();
10515         scope_t      *old_scope = scope_push(&statement->compound.scope);
10516
10517         statement_t **anchor            = &statement->compound.statements;
10518         bool          only_decls_so_far = true;
10519         while (token.type != '}') {
10520                 if (token.type == T_EOF) {
10521                         errorf(&statement->base.source_position,
10522                                "EOF while parsing compound statement");
10523                         break;
10524                 }
10525                 statement_t *sub_statement = intern_parse_statement();
10526                 if (is_invalid_statement(sub_statement)) {
10527                         /* an error occurred. if we are at an anchor, return */
10528                         if (at_anchor())
10529                                 goto end_error;
10530                         continue;
10531                 }
10532
10533                 if (warning.declaration_after_statement) {
10534                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10535                                 only_decls_so_far = false;
10536                         } else if (!only_decls_so_far) {
10537                                 warningf(&sub_statement->base.source_position,
10538                                          "ISO C90 forbids mixed declarations and code");
10539                         }
10540                 }
10541
10542                 *anchor = sub_statement;
10543
10544                 while (sub_statement->base.next != NULL)
10545                         sub_statement = sub_statement->base.next;
10546
10547                 anchor = &sub_statement->base.next;
10548         }
10549         next_token();
10550
10551         /* look over all statements again to produce no effect warnings */
10552         if (warning.unused_value) {
10553                 statement_t *sub_statement = statement->compound.statements;
10554                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10555                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10556                                 continue;
10557                         /* don't emit a warning for the last expression in an expression
10558                          * statement as it has always an effect */
10559                         if (inside_expression_statement && sub_statement->base.next == NULL)
10560                                 continue;
10561
10562                         expression_t *expression = sub_statement->expression.expression;
10563                         if (!expression_has_effect(expression)) {
10564                                 warningf(&expression->base.source_position,
10565                                          "statement has no effect");
10566                         }
10567                 }
10568         }
10569
10570 end_error:
10571         rem_anchor_token(T_while);
10572         rem_anchor_token(T_wchar_t);
10573         rem_anchor_token(T_volatile);
10574         rem_anchor_token(T_void);
10575         rem_anchor_token(T_using);
10576         rem_anchor_token(T_unsigned);
10577         rem_anchor_token(T_union);
10578         rem_anchor_token(T_typeof);
10579         rem_anchor_token(T_typename);
10580         rem_anchor_token(T_typeid);
10581         rem_anchor_token(T_typedef);
10582         rem_anchor_token(T_try);
10583         rem_anchor_token(T_true);
10584         rem_anchor_token(T_throw);
10585         rem_anchor_token(T_this);
10586         rem_anchor_token(T_template);
10587         rem_anchor_token(T_switch);
10588         rem_anchor_token(T_struct);
10589         rem_anchor_token(T_static_cast);
10590         rem_anchor_token(T_static);
10591         rem_anchor_token(T_sizeof);
10592         rem_anchor_token(T_signed);
10593         rem_anchor_token(T_short);
10594         rem_anchor_token(T_return);
10595         rem_anchor_token(T_restrict);
10596         rem_anchor_token(T_reinterpret_cast);
10597         rem_anchor_token(T_register);
10598         rem_anchor_token(T_operator);
10599         rem_anchor_token(T_new);
10600         rem_anchor_token(T_long);
10601         rem_anchor_token(T_int);
10602         rem_anchor_token(T_inline);
10603         rem_anchor_token(T_if);
10604         rem_anchor_token(T_goto);
10605         rem_anchor_token(T_for);
10606         rem_anchor_token(T_float);
10607         rem_anchor_token(T_false);
10608         rem_anchor_token(T_extern);
10609         rem_anchor_token(T_enum);
10610         rem_anchor_token(T_dynamic_cast);
10611         rem_anchor_token(T_do);
10612         rem_anchor_token(T_double);
10613         rem_anchor_token(T_delete);
10614         rem_anchor_token(T_default);
10615         rem_anchor_token(T_continue);
10616         rem_anchor_token(T_const_cast);
10617         rem_anchor_token(T_const);
10618         rem_anchor_token(T_class);
10619         rem_anchor_token(T_char);
10620         rem_anchor_token(T_case);
10621         rem_anchor_token(T_break);
10622         rem_anchor_token(T_bool);
10623         rem_anchor_token(T_auto);
10624         rem_anchor_token(T_asm);
10625         rem_anchor_token(T___thread);
10626         rem_anchor_token(T___real__);
10627         rem_anchor_token(T___label__);
10628         rem_anchor_token(T___imag__);
10629         rem_anchor_token(T___func__);
10630         rem_anchor_token(T___extension__);
10631         rem_anchor_token(T___builtin_va_start);
10632         rem_anchor_token(T___attribute__);
10633         rem_anchor_token(T___alignof__);
10634         rem_anchor_token(T___PRETTY_FUNCTION__);
10635         rem_anchor_token(T___FUNCTION__);
10636         rem_anchor_token(T__Imaginary);
10637         rem_anchor_token(T__Complex);
10638         rem_anchor_token(T__Bool);
10639         rem_anchor_token(T_WIDE_STRING_LITERAL);
10640         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10641         rem_anchor_token(T_STRING_LITERAL);
10642         rem_anchor_token(T_PLUSPLUS);
10643         rem_anchor_token(T_MINUSMINUS);
10644         rem_anchor_token(T_INTEGER);
10645         rem_anchor_token(T_IDENTIFIER);
10646         rem_anchor_token(T_FLOATINGPOINT);
10647         rem_anchor_token(T_COLONCOLON);
10648         rem_anchor_token(T_CHARACTER_CONSTANT);
10649         rem_anchor_token('~');
10650         rem_anchor_token('{');
10651         rem_anchor_token('-');
10652         rem_anchor_token('+');
10653         rem_anchor_token('*');
10654         rem_anchor_token('(');
10655         rem_anchor_token('&');
10656         rem_anchor_token('!');
10657         rem_anchor_token('}');
10658         assert(current_scope == &statement->compound.scope);
10659         scope_pop(old_scope);
10660         environment_pop_to(top);
10661
10662         POP_PARENT;
10663         return statement;
10664 }
10665
10666 /**
10667  * Check for unused global static functions and variables
10668  */
10669 static void check_unused_globals(void)
10670 {
10671         if (!warning.unused_function && !warning.unused_variable)
10672                 return;
10673
10674         for (const entity_t *entity = file_scope->entities; entity != NULL;
10675              entity = entity->base.next) {
10676                 if (!is_declaration(entity))
10677                         continue;
10678
10679                 const declaration_t *declaration = &entity->declaration;
10680                 if (declaration->used                  ||
10681                     declaration->modifiers & DM_UNUSED ||
10682                     declaration->modifiers & DM_USED   ||
10683                     declaration->storage_class != STORAGE_CLASS_STATIC)
10684                         continue;
10685
10686                 type_t *const type = declaration->type;
10687                 const char *s;
10688                 if (entity->kind == ENTITY_FUNCTION) {
10689                         /* inhibit warning for static inline functions */
10690                         if (entity->function.is_inline)
10691                                 continue;
10692
10693                         s = entity->function.statement != NULL ? "defined" : "declared";
10694                 } else {
10695                         s = "defined";
10696                 }
10697
10698                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10699                         type, declaration->base.symbol, s);
10700         }
10701 }
10702
10703 static void parse_global_asm(void)
10704 {
10705         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10706
10707         eat(T_asm);
10708         expect('(', end_error);
10709
10710         statement->asms.asm_text = parse_string_literals();
10711         statement->base.next     = unit->global_asm;
10712         unit->global_asm         = statement;
10713
10714         expect(')', end_error);
10715         expect(';', end_error);
10716
10717 end_error:;
10718 }
10719
10720 static void parse_linkage_specification(void)
10721 {
10722         eat(T_extern);
10723         assert(token.type == T_STRING_LITERAL);
10724
10725         const char *linkage = parse_string_literals().begin;
10726
10727         linkage_kind_t old_linkage = current_linkage;
10728         linkage_kind_t new_linkage;
10729         if (strcmp(linkage, "C") == 0) {
10730                 new_linkage = LINKAGE_C;
10731         } else if (strcmp(linkage, "C++") == 0) {
10732                 new_linkage = LINKAGE_CXX;
10733         } else {
10734                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10735                 new_linkage = LINKAGE_INVALID;
10736         }
10737         current_linkage = new_linkage;
10738
10739         if (token.type == '{') {
10740                 next_token();
10741                 parse_externals();
10742                 expect('}', end_error);
10743         } else {
10744                 parse_external();
10745         }
10746
10747 end_error:
10748         assert(current_linkage == new_linkage);
10749         current_linkage = old_linkage;
10750 }
10751
10752 static void parse_external(void)
10753 {
10754         switch (token.type) {
10755                 DECLARATION_START_NO_EXTERN
10756                 case T_IDENTIFIER:
10757                 case T___extension__:
10758                 /* tokens below are for implicit int */
10759                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10760                              implicit int) */
10761                 case '*': /* * x; -> int* x; */
10762                 case '(': /* (x); -> int (x); */
10763                         parse_external_declaration();
10764                         return;
10765
10766                 case T_extern:
10767                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10768                                 parse_linkage_specification();
10769                         } else {
10770                                 parse_external_declaration();
10771                         }
10772                         return;
10773
10774                 case T_asm:
10775                         parse_global_asm();
10776                         return;
10777
10778                 case T_namespace:
10779                         parse_namespace_definition();
10780                         return;
10781
10782                 case ';':
10783                         if (!strict_mode) {
10784                                 if (warning.other)
10785                                         warningf(HERE, "stray ';' outside of function");
10786                                 next_token();
10787                                 return;
10788                         }
10789                         /* FALLTHROUGH */
10790
10791                 default:
10792                         errorf(HERE, "stray %K outside of function", &token);
10793                         if (token.type == '(' || token.type == '{' || token.type == '[')
10794                                 eat_until_matching_token(token.type);
10795                         next_token();
10796                         return;
10797         }
10798 }
10799
10800 static void parse_externals(void)
10801 {
10802         add_anchor_token('}');
10803         add_anchor_token(T_EOF);
10804
10805 #ifndef NDEBUG
10806         unsigned char token_anchor_copy[T_LAST_TOKEN];
10807         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10808 #endif
10809
10810         while (token.type != T_EOF && token.type != '}') {
10811 #ifndef NDEBUG
10812                 bool anchor_leak = false;
10813                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10814                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10815                         if (count != 0) {
10816                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10817                                 anchor_leak = true;
10818                         }
10819                 }
10820                 if (in_gcc_extension) {
10821                         errorf(HERE, "Leaked __extension__");
10822                         anchor_leak = true;
10823                 }
10824
10825                 if (anchor_leak)
10826                         abort();
10827 #endif
10828
10829                 parse_external();
10830         }
10831
10832         rem_anchor_token(T_EOF);
10833         rem_anchor_token('}');
10834 }
10835
10836 /**
10837  * Parse a translation unit.
10838  */
10839 static void parse_translation_unit(void)
10840 {
10841         add_anchor_token(T_EOF);
10842
10843         while (true) {
10844                 parse_externals();
10845
10846                 if (token.type == T_EOF)
10847                         break;
10848
10849                 errorf(HERE, "stray %K outside of function", &token);
10850                 if (token.type == '(' || token.type == '{' || token.type == '[')
10851                         eat_until_matching_token(token.type);
10852                 next_token();
10853         }
10854 }
10855
10856 /**
10857  * Parse the input.
10858  *
10859  * @return  the translation unit or NULL if errors occurred.
10860  */
10861 void start_parsing(void)
10862 {
10863         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10864         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10865         diagnostic_count  = 0;
10866         error_count       = 0;
10867         warning_count     = 0;
10868
10869         type_set_output(stderr);
10870         ast_set_output(stderr);
10871
10872         assert(unit == NULL);
10873         unit = allocate_ast_zero(sizeof(unit[0]));
10874
10875         assert(file_scope == NULL);
10876         file_scope = &unit->scope;
10877
10878         assert(current_scope == NULL);
10879         scope_push(&unit->scope);
10880
10881         create_gnu_builtins();
10882         if (c_mode & _MS)
10883                 create_microsoft_intrinsics();
10884 }
10885
10886 translation_unit_t *finish_parsing(void)
10887 {
10888         assert(current_scope == &unit->scope);
10889         scope_pop(NULL);
10890
10891         assert(file_scope == &unit->scope);
10892         check_unused_globals();
10893         file_scope = NULL;
10894
10895         DEL_ARR_F(environment_stack);
10896         DEL_ARR_F(label_stack);
10897
10898         translation_unit_t *result = unit;
10899         unit = NULL;
10900         return result;
10901 }
10902
10903 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10904  * are given length one. */
10905 static void complete_incomplete_arrays(void)
10906 {
10907         size_t n = ARR_LEN(incomplete_arrays);
10908         for (size_t i = 0; i != n; ++i) {
10909                 declaration_t *const decl      = incomplete_arrays[i];
10910                 type_t        *const orig_type = decl->type;
10911                 type_t        *const type      = skip_typeref(orig_type);
10912
10913                 if (!is_type_incomplete(type))
10914                         continue;
10915
10916                 if (warning.other) {
10917                         warningf(&decl->base.source_position,
10918                                         "array '%#T' assumed to have one element",
10919                                         orig_type, decl->base.symbol);
10920                 }
10921
10922                 type_t *const new_type = duplicate_type(type);
10923                 new_type->array.size_constant     = true;
10924                 new_type->array.has_implicit_size = true;
10925                 new_type->array.size              = 1;
10926
10927                 type_t *const result = identify_new_type(new_type);
10928
10929                 decl->type = result;
10930         }
10931 }
10932
10933 void parse(void)
10934 {
10935         lookahead_bufpos = 0;
10936         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10937                 next_token();
10938         }
10939         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10940         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10941         parse_translation_unit();
10942         complete_incomplete_arrays();
10943         DEL_ARR_F(incomplete_arrays);
10944         incomplete_arrays = NULL;
10945 }
10946
10947 /**
10948  * create a builtin function.
10949  */
10950 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
10951 {
10952         symbol_t *symbol = symbol_table_insert(name);
10953         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
10954         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
10955         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
10956         entity->declaration.type                   = function_type;
10957         entity->declaration.implicit               = true;
10958         entity->base.symbol                        = symbol;
10959         entity->base.source_position               = builtin_source_position;
10960
10961         entity->function.btk                       = kind;
10962
10963         record_entity(entity, /*is_definition=*/false);
10964         return entity;
10965 }
10966
10967
10968 /**
10969  * Create predefined gnu builtins.
10970  */
10971 static void create_gnu_builtins(void)
10972 {
10973 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
10974
10975         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
10976         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
10977         GNU_BUILTIN(inf,            make_function_0_type(type_double));
10978         GNU_BUILTIN(inff,           make_function_0_type(type_float));
10979         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
10980         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
10981         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
10982         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
10983         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
10984         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
10985         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
10986         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
10987         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
10988         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
10989         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
10990         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
10991         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
10992         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
10993         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
10994
10995 #undef GNU_BUILTIN
10996 }
10997
10998 /**
10999  * Create predefined MS intrinsics.
11000  */
11001 static void create_microsoft_intrinsics(void)
11002 {
11003 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11004
11005         /* intrinsics for all architectures */
11006         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11007         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11008         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11009         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11010         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11011         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11012         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11013
11014         MS_BUILTIN(__debugbreak,            make_function_0_type(type_void));
11015         MS_BUILTIN(_ReturnAddress,          make_function_0_type(type_void_ptr));
11016         MS_BUILTIN(_AddressOfReturnAddress, make_function_0_type(type_void_ptr));
11017         MS_BUILTIN(__popcount,              make_function_1_type(type_unsigned_int, type_unsigned_int));
11018
11019         /* x86/x64 only */
11020         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11021         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11022         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11023         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11024         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11025         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11026         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11027         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11028         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11029         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11030         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11031         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11032         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11033
11034         if (machine_size <= 32) {
11035                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11036                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11037         } else {
11038                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11039                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11040         }
11041
11042 #undef MS_BUILTIN
11043 }
11044
11045 /**
11046  * Initialize the parser.
11047  */
11048 void init_parser(void)
11049 {
11050         sym_anonymous = symbol_table_insert("<anonymous>");
11051
11052         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11053
11054         init_expression_parsers();
11055         obstack_init(&temp_obst);
11056
11057         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11058         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11059 }
11060
11061 /**
11062  * Terminate the parser.
11063  */
11064 void exit_parser(void)
11065 {
11066         obstack_free(&temp_obst, NULL);
11067 }