nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "adt/bitfiddle.h"
  42 #include "adt/error.h"
  43 #include "adt/array.h"
  44
  45 //#define PRINT_TOKENS
  46 #define MAX_LOOKAHEAD 1
  47
  48 typedef struct {
  49         entity_t           *old_entity;
  50         symbol_t           *symbol;
  51         entity_namespace_t  namespc;
  52 } stack_entry_t;
  53
  54 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  55 struct declaration_specifiers_t {
  56         source_position_t  source_position;
  57         storage_class_t    storage_class;
  58         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  59         bool               is_inline    : 1;
  60         bool               thread_local : 1;  /**< GCC __thread */
  61         attribute_t       *attributes;        /**< list of attributes */
  62         type_t            *type;
  63 };
  64
  65 /**
  66  * An environment for parsing initializers (and compound literals).
  67  */
  68 typedef struct parse_initializer_env_t {
  69         type_t     *type;   /**< the type of the initializer. In case of an
  70                                  array type with unspecified size this gets
  71                                  adjusted to the actual size. */
  72         entity_t   *entity; /**< the variable that is initialized if any */
  73         bool        must_be_constant;
  74 } parse_initializer_env_t;
  75
  76 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  77
  78 /** The current token. */
  79 static token_t              token;
  80 /** The lookahead ring-buffer. */
  81 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  82 /** Position of the next token in the lookahead buffer. */
  83 static size_t               lookahead_bufpos;
  84 static stack_entry_t       *environment_stack = NULL;
  85 static stack_entry_t       *label_stack       = NULL;
  86 static scope_t             *file_scope        = NULL;
  87 static scope_t             *current_scope     = NULL;
  88 /** Point to the current function declaration if inside a function. */
  89 static function_t          *current_function  = NULL;
  90 static entity_t            *current_init_decl = NULL;
  91 static switch_statement_t  *current_switch    = NULL;
  92 static statement_t         *current_loop      = NULL;
  93 static statement_t         *current_parent    = NULL;
  94 static ms_try_statement_t  *current_try       = NULL;
  95 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  96 static goto_statement_t    *goto_first        = NULL;
  97 static goto_statement_t   **goto_anchor       = NULL;
  98 static label_statement_t   *label_first       = NULL;
  99 static label_statement_t  **label_anchor      = NULL;
 100 /** current translation unit. */
 101 static translation_unit_t  *unit              = NULL;
 102 /** true if we are in a type property context (evaluation only for type. */
 103 static bool                 in_type_prop      = false;
 104 /** true in we are in a __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109
 110
 111 #define PUSH_PARENT(stmt)                          \
 112         statement_t *const prev_parent = current_parent; \
 113         ((void)(current_parent = (stmt)))
 114 #define POP_PARENT ((void)(current_parent = prev_parent))
 115
 116 /** special symbol used for anonymous entities. */
 117 static symbol_t *sym_anonymous = NULL;
 118
 119 /** The token anchor set */
 120 static unsigned char token_anchor_set[T_LAST_TOKEN];
 121
 122 /** The current source position. */
 123 #define HERE (&token.source_position)
 124
 125 /** true if we are in GCC mode. */
 126 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 127
 128 static statement_t *parse_compound_statement(bool inside_expression_statement);
 129 static statement_t *parse_statement(void);
 130
 131 static expression_t *parse_sub_expression(precedence_t);
 132 static expression_t *parse_expression(void);
 133 static type_t       *parse_typename(void);
 134 static void          parse_externals(void);
 135 static void          parse_external(void);
 136
 137 static void parse_compound_type_entries(compound_t *compound_declaration);
 138
 139 static void check_call_argument(type_t          *expected_type,
 140                                                                 call_argument_t *argument, unsigned pos);
 141
 142 typedef enum declarator_flags_t {
 143         DECL_FLAGS_NONE             = 0,
 144         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 145         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 146         DECL_IS_PARAMETER           = 1U << 2
 147 } declarator_flags_t;
 148
 149 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 150                                   declarator_flags_t flags);
 151
 152 static entity_t *record_entity(entity_t *entity, bool is_definition);
 153
 154 static void semantic_comparison(binary_expression_t *expression);
 155
 156 static void create_gnu_builtins(void);
 157 static void create_microsoft_intrinsics(void);
 158
 159 #define STORAGE_CLASSES       \
 160         STORAGE_CLASSES_NO_EXTERN \
 161         case T_extern:
 162
 163 #define STORAGE_CLASSES_NO_EXTERN \
 164         case T_typedef:         \
 165         case T_static:          \
 166         case T_auto:            \
 167         case T_register:        \
 168         case T___thread:
 169
 170 #define TYPE_QUALIFIERS     \
 171         case T_const:           \
 172         case T_restrict:        \
 173         case T_volatile:        \
 174         case T_inline:          \
 175         case T__forceinline:    \
 176         case T___attribute__:
 177
 178 #define COMPLEX_SPECIFIERS  \
 179         case T__Complex:
 180 #define IMAGINARY_SPECIFIERS \
 181         case T__Imaginary:
 182
 183 #define TYPE_SPECIFIERS       \
 184         case T__Bool:             \
 185         case T___builtin_va_list: \
 186         case T___typeof__:        \
 187         case T__declspec:         \
 188         case T_bool:              \
 189         case T_char:              \
 190         case T_double:            \
 191         case T_enum:              \
 192         case T_float:             \
 193         case T_int:               \
 194         case T_long:              \
 195         case T_short:             \
 196         case T_signed:            \
 197         case T_struct:            \
 198         case T_union:             \
 199         case T_unsigned:          \
 200         case T_void:              \
 201         case T_wchar_t:           \
 202         case T__int8:             \
 203         case T__int16:            \
 204         case T__int32:            \
 205         case T__int64:            \
 206         case T__int128:           \
 207         COMPLEX_SPECIFIERS        \
 208         IMAGINARY_SPECIFIERS
 209
 210 #define DECLARATION_START   \
 211         STORAGE_CLASSES         \
 212         TYPE_QUALIFIERS         \
 213         TYPE_SPECIFIERS
 214
 215 #define DECLARATION_START_NO_EXTERN \
 216         STORAGE_CLASSES_NO_EXTERN       \
 217         TYPE_QUALIFIERS                 \
 218         TYPE_SPECIFIERS
 219
 220 #define TYPENAME_START      \
 221         TYPE_QUALIFIERS         \
 222         TYPE_SPECIFIERS
 223
 224 #define EXPRESSION_START           \
 225         case '!':                        \
 226         case '&':                        \
 227         case '(':                        \
 228         case '*':                        \
 229         case '+':                        \
 230         case '-':                        \
 231         case '~':                        \
 232         case T_ANDAND:                   \
 233         case T_CHARACTER_CONSTANT:       \
 234         case T_FLOATINGPOINT:            \
 235         case T_INTEGER:                  \
 236         case T_MINUSMINUS:               \
 237         case T_PLUSPLUS:                 \
 238         case T_STRING_LITERAL:           \
 239         case T_WIDE_CHARACTER_CONSTANT:  \
 240         case T_WIDE_STRING_LITERAL:      \
 241         case T___FUNCDNAME__:            \
 242         case T___FUNCSIG__:              \
 243         case T___FUNCTION__:             \
 244         case T___PRETTY_FUNCTION__:      \
 245         case T___alignof__:              \
 246         case T___builtin_classify_type:  \
 247         case T___builtin_constant_p:     \
 248         case T___builtin_isgreater:      \
 249         case T___builtin_isgreaterequal: \
 250         case T___builtin_isless:         \
 251         case T___builtin_islessequal:    \
 252         case T___builtin_islessgreater:  \
 253         case T___builtin_isunordered:    \
 254         case T___builtin_offsetof:       \
 255         case T___builtin_va_arg:         \
 256         case T___builtin_va_start:       \
 257         case T___builtin_va_copy:        \
 258         case T___func__:                 \
 259         case T___noop:                   \
 260         case T__assume:                  \
 261         case T_delete:                   \
 262         case T_false:                    \
 263         case T_sizeof:                   \
 264         case T_throw:                    \
 265         case T_true:
 266
 267 /**
 268  * Allocate an AST node with given size and
 269  * initialize all fields with zero.
 270  */
 271 static void *allocate_ast_zero(size_t size)
 272 {
 273         void *res = allocate_ast(size);
 274         memset(res, 0, size);
 275         return res;
 276 }
 277
 278 /**
 279  * Returns the size of an entity node.
 280  *
 281  * @param kind  the entity kind
 282  */
 283 static size_t get_entity_struct_size(entity_kind_t kind)
 284 {
 285         static const size_t sizes[] = {
 286                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 287                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 288                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 289                 [ENTITY_FUNCTION]        = sizeof(function_t),
 290                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 291                 [ENTITY_STRUCT]          = sizeof(compound_t),
 292                 [ENTITY_UNION]           = sizeof(compound_t),
 293                 [ENTITY_ENUM]            = sizeof(enum_t),
 294                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 295                 [ENTITY_LABEL]           = sizeof(label_t),
 296                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 297                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 298         };
 299         assert(kind < lengthof(sizes));
 300         assert(sizes[kind] != 0);
 301         return sizes[kind];
 302 }
 303
 304 /**
 305  * Allocate an entity of given kind and initialize all
 306  * fields with zero.
 307  *
 308  * @param kind   the kind of the entity to allocate
 309  */
 310 static entity_t *allocate_entity_zero(entity_kind_t kind)
 311 {
 312         size_t    size   = get_entity_struct_size(kind);
 313         entity_t *entity = allocate_ast_zero(size);
 314         entity->kind     = kind;
 315         return entity;
 316 }
 317
 318 /**
 319  * Returns the size of a statement node.
 320  *
 321  * @param kind  the statement kind
 322  */
 323 static size_t get_statement_struct_size(statement_kind_t kind)
 324 {
 325         static const size_t sizes[] = {
 326                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 327                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 328                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 329                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 330                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 331                 [STATEMENT_IF]          = sizeof(if_statement_t),
 332                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 333                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 334                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 335                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 336                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 337                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 338                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 339                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 340                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 341                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 342                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 343                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 344                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 345         };
 346         assert(kind < lengthof(sizes));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 /**
 352  * Returns the size of an expression node.
 353  *
 354  * @param kind  the expression kind
 355  */
 356 static size_t get_expression_struct_size(expression_kind_t kind)
 357 {
 358         static const size_t sizes[] = {
 359                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 360                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 361                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 362                 [EXPR_CONST]                      = sizeof(const_expression_t),
 363                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 364                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 365                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 366                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 367                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 368                 [EXPR_CALL]                       = sizeof(call_expression_t),
 369                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 370                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 371                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 372                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 373                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 374                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 375                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 376                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 377                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 378                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 379                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 380                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 381                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 382                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 383                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 384                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 385                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 386         };
 387         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 388                 return sizes[EXPR_UNARY_FIRST];
 389         }
 390         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 391                 return sizes[EXPR_BINARY_FIRST];
 392         }
 393         assert(kind < lengthof(sizes));
 394         assert(sizes[kind] != 0);
 395         return sizes[kind];
 396 }
 397
 398 /**
 399  * Allocate a statement node of given kind and initialize all
 400  * fields with zero. Sets its source position to the position
 401  * of the current token.
 402  */
 403 static statement_t *allocate_statement_zero(statement_kind_t kind)
 404 {
 405         size_t       size = get_statement_struct_size(kind);
 406         statement_t *res  = allocate_ast_zero(size);
 407
 408         res->base.kind            = kind;
 409         res->base.parent          = current_parent;
 410         res->base.source_position = token.source_position;
 411         return res;
 412 }
 413
 414 /**
 415  * Allocate an expression node of given kind and initialize all
 416  * fields with zero.
 417  *
 418  * @param kind  the kind of the expression to allocate
 419  */
 420 static expression_t *allocate_expression_zero(expression_kind_t kind)
 421 {
 422         size_t        size = get_expression_struct_size(kind);
 423         expression_t *res  = allocate_ast_zero(size);
 424
 425         res->base.kind            = kind;
 426         res->base.type            = type_error_type;
 427         res->base.source_position = token.source_position;
 428         return res;
 429 }
 430
 431 /**
 432  * Creates a new invalid expression at the source position
 433  * of the current token.
 434  */
 435 static expression_t *create_invalid_expression(void)
 436 {
 437         return allocate_expression_zero(EXPR_INVALID);
 438 }
 439
 440 /**
 441  * Creates a new invalid statement.
 442  */
 443 static statement_t *create_invalid_statement(void)
 444 {
 445         return allocate_statement_zero(STATEMENT_INVALID);
 446 }
 447
 448 /**
 449  * Allocate a new empty statement.
 450  */
 451 static statement_t *create_empty_statement(void)
 452 {
 453         return allocate_statement_zero(STATEMENT_EMPTY);
 454 }
 455
 456 /**
 457  * Returns the size of a type node.
 458  *
 459  * @param kind  the type kind
 460  */
 461 static size_t get_type_struct_size(type_kind_t kind)
 462 {
 463         static const size_t sizes[] = {
 464                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 465                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 466                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 467                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 468                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 469                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 470                 [TYPE_ENUM]            = sizeof(enum_type_t),
 471                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 472                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 473                 [TYPE_ARRAY]           = sizeof(array_type_t),
 474                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 475                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 476                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 477         };
 478         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 479         assert(kind <= TYPE_TYPEOF);
 480         assert(sizes[kind] != 0);
 481         return sizes[kind];
 482 }
 483
 484 /**
 485  * Allocate a type node of given kind and initialize all
 486  * fields with zero.
 487  *
 488  * @param kind             type kind to allocate
 489  */
 490 static type_t *allocate_type_zero(type_kind_t kind)
 491 {
 492         size_t  size = get_type_struct_size(kind);
 493         type_t *res  = obstack_alloc(type_obst, size);
 494         memset(res, 0, size);
 495         res->base.kind = kind;
 496
 497         return res;
 498 }
 499
 500 static function_parameter_t *allocate_parameter(type_t *const type)
 501 {
 502         function_parameter_t *const param = obstack_alloc(type_obst, sizeof(*param));
 503         memset(param, 0, sizeof(*param));
 504         param->type = type;
 505         return param;
 506 }
 507
 508 /**
 509  * Returns the size of an initializer node.
 510  *
 511  * @param kind  the initializer kind
 512  */
 513 static size_t get_initializer_size(initializer_kind_t kind)
 514 {
 515         static const size_t sizes[] = {
 516                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 517                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 518                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 519                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 520                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 521         };
 522         assert(kind < lengthof(sizes));
 523         assert(sizes[kind] != 0);
 524         return sizes[kind];
 525 }
 526
 527 /**
 528  * Allocate an initializer node of given kind and initialize all
 529  * fields with zero.
 530  */
 531 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 532 {
 533         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 534         result->kind          = kind;
 535
 536         return result;
 537 }
 538
 539 /**
 540  * Returns the index of the top element of the environment stack.
 541  */
 542 static size_t environment_top(void)
 543 {
 544         return ARR_LEN(environment_stack);
 545 }
 546
 547 /**
 548  * Returns the index of the top element of the global label stack.
 549  */
 550 static size_t label_top(void)
 551 {
 552         return ARR_LEN(label_stack);
 553 }
 554
 555 /**
 556  * Return the next token.
 557  */
 558 static inline void next_token(void)
 559 {
 560         token                              = lookahead_buffer[lookahead_bufpos];
 561         lookahead_buffer[lookahead_bufpos] = lexer_token;
 562         lexer_next_token();
 563
 564         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 565
 566 #ifdef PRINT_TOKENS
 567         print_token(stderr, &token);
 568         fprintf(stderr, "\n");
 569 #endif
 570 }
 571
 572 /**
 573  * Return the next token with a given lookahead.
 574  */
 575 static inline const token_t *look_ahead(size_t num)
 576 {
 577         assert(0 < num && num <= MAX_LOOKAHEAD);
 578         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 579         return &lookahead_buffer[pos];
 580 }
 581
 582 /**
 583  * Adds a token type to the token type anchor set (a multi-set).
 584  */
 585 static void add_anchor_token(int token_type)
 586 {
 587         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 588         ++token_anchor_set[token_type];
 589 }
 590
 591 /**
 592  * Set the number of tokens types of the given type
 593  * to zero and return the old count.
 594  */
 595 static int save_and_reset_anchor_state(int token_type)
 596 {
 597         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 598         int count = token_anchor_set[token_type];
 599         token_anchor_set[token_type] = 0;
 600         return count;
 601 }
 602
 603 /**
 604  * Restore the number of token types to the given count.
 605  */
 606 static void restore_anchor_state(int token_type, int count)
 607 {
 608         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 609         token_anchor_set[token_type] = count;
 610 }
 611
 612 /**
 613  * Remove a token type from the token type anchor set (a multi-set).
 614  */
 615 static void rem_anchor_token(int token_type)
 616 {
 617         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 618         assert(token_anchor_set[token_type] != 0);
 619         --token_anchor_set[token_type];
 620 }
 621
 622 /**
 623  * Return true if the token type of the current token is
 624  * in the anchor set.
 625  */
 626 static bool at_anchor(void)
 627 {
 628         if (token.type < 0)
 629                 return false;
 630         return token_anchor_set[token.type];
 631 }
 632
 633 /**
 634  * Eat tokens until a matching token type is found.
 635  */
 636 static void eat_until_matching_token(int type)
 637 {
 638         int end_token;
 639         switch (type) {
 640                 case '(': end_token = ')';  break;
 641                 case '{': end_token = '}';  break;
 642                 case '[': end_token = ']';  break;
 643                 default:  end_token = type; break;
 644         }
 645
 646         unsigned parenthesis_count = 0;
 647         unsigned brace_count       = 0;
 648         unsigned bracket_count     = 0;
 649         while (token.type        != end_token ||
 650                parenthesis_count != 0         ||
 651                brace_count       != 0         ||
 652                bracket_count     != 0) {
 653                 switch (token.type) {
 654                 case T_EOF: return;
 655                 case '(': ++parenthesis_count; break;
 656                 case '{': ++brace_count;       break;
 657                 case '[': ++bracket_count;     break;
 658
 659                 case ')':
 660                         if (parenthesis_count > 0)
 661                                 --parenthesis_count;
 662                         goto check_stop;
 663
 664                 case '}':
 665                         if (brace_count > 0)
 666                                 --brace_count;
 667                         goto check_stop;
 668
 669                 case ']':
 670                         if (bracket_count > 0)
 671                                 --bracket_count;
 672 check_stop:
 673                         if (token.type        == end_token &&
 674                             parenthesis_count == 0         &&
 675                             brace_count       == 0         &&
 676                             bracket_count     == 0)
 677                                 return;
 678                         break;
 679
 680                 default:
 681                         break;
 682                 }
 683                 next_token();
 684         }
 685 }
 686
 687 /**
 688  * Eat input tokens until an anchor is found.
 689  */
 690 static void eat_until_anchor(void)
 691 {
 692         while (token_anchor_set[token.type] == 0) {
 693                 if (token.type == '(' || token.type == '{' || token.type == '[')
 694                         eat_until_matching_token(token.type);
 695                 next_token();
 696         }
 697 }
 698
 699 /**
 700  * Eat a whole block from input tokens.
 701  */
 702 static void eat_block(void)
 703 {
 704         eat_until_matching_token('{');
 705         if (token.type == '}')
 706                 next_token();
 707 }
 708
 709 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 710
 711 /**
 712  * Report a parse error because an expected token was not found.
 713  */
 714 static
 715 #if defined __GNUC__ && __GNUC__ >= 4
 716 __attribute__((sentinel))
 717 #endif
 718 void parse_error_expected(const char *message, ...)
 719 {
 720         if (message != NULL) {
 721                 errorf(HERE, "%s", message);
 722         }
 723         va_list ap;
 724         va_start(ap, message);
 725         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 726         va_end(ap);
 727 }
 728
 729 /**
 730  * Report an incompatible type.
 731  */
 732 static void type_error_incompatible(const char *msg,
 733                 const source_position_t *source_position, type_t *type1, type_t *type2)
 734 {
 735         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 736                msg, type1, type2);
 737 }
 738
 739 /**
 740  * Expect the current token is the expected token.
 741  * If not, generate an error, eat the current statement,
 742  * and goto the end_error label.
 743  */
 744 #define expect(expected, error_label)                     \
 745         do {                                                  \
 746                 if (UNLIKELY(token.type != (expected))) {         \
 747                         parse_error_expected(NULL, (expected), NULL); \
 748                         add_anchor_token(expected);                   \
 749                         eat_until_anchor();                           \
 750                         if (token.type == expected)                   \
 751                                 next_token();                             \
 752                         rem_anchor_token(expected);                   \
 753                         goto error_label;                             \
 754                 }                                                 \
 755                 next_token();                                     \
 756         } while (0)
 757
 758 /**
 759  * Push a given scope on the scope stack and make it the
 760  * current scope
 761  */
 762 static scope_t *scope_push(scope_t *new_scope)
 763 {
 764         if (current_scope != NULL) {
 765                 new_scope->depth = current_scope->depth + 1;
 766         }
 767
 768         scope_t *old_scope = current_scope;
 769         current_scope      = new_scope;
 770         return old_scope;
 771 }
 772
 773 /**
 774  * Pop the current scope from the scope stack.
 775  */
 776 static void scope_pop(scope_t *old_scope)
 777 {
 778         current_scope = old_scope;
 779 }
 780
 781 /**
 782  * Search an entity by its symbol in a given namespace.
 783  */
 784 static entity_t *get_entity(const symbol_t *const symbol,
 785                             namespace_tag_t namespc)
 786 {
 787         entity_t *entity = symbol->entity;
 788         for (; entity != NULL; entity = entity->base.symbol_next) {
 789                 if (entity->base.namespc == namespc)
 790                         return entity;
 791         }
 792
 793         return NULL;
 794 }
 795
 796 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 797  * possible. */
 798 static entity_t *get_tag(symbol_t const *const symbol,
 799                          entity_kind_tag_t const kind)
 800 {
 801         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 802         if (entity != NULL && entity->kind != kind) {
 803                 errorf(HERE,
 804                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 805                                 symbol, &entity->base.source_position);
 806                 entity = NULL;
 807         }
 808         return entity;
 809 }
 810
 811 /**
 812  * pushs an entity on the environment stack and links the corresponding symbol
 813  * it.
 814  */
 815 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 816 {
 817         symbol_t           *symbol  = entity->base.symbol;
 818         entity_namespace_t  namespc = entity->base.namespc;
 819         assert(namespc != NAMESPACE_INVALID);
 820
 821         /* replace/add entity into entity list of the symbol */
 822         entity_t **anchor;
 823         entity_t  *iter;
 824         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 825                 iter = *anchor;
 826                 if (iter == NULL)
 827                         break;
 828
 829                 /* replace an entry? */
 830                 if (iter->base.namespc == namespc) {
 831                         entity->base.symbol_next = iter->base.symbol_next;
 832                         break;
 833                 }
 834         }
 835         *anchor = entity;
 836
 837         /* remember old declaration */
 838         stack_entry_t entry;
 839         entry.symbol     = symbol;
 840         entry.old_entity = iter;
 841         entry.namespc    = namespc;
 842         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 843 }
 844
 845 /**
 846  * Push an entity on the environment stack.
 847  */
 848 static void environment_push(entity_t *entity)
 849 {
 850         assert(entity->base.source_position.input_name != NULL);
 851         assert(entity->base.parent_scope != NULL);
 852         stack_push(&environment_stack, entity);
 853 }
 854
 855 /**
 856  * Push a declaration on the global label stack.
 857  *
 858  * @param declaration  the declaration
 859  */
 860 static void label_push(entity_t *label)
 861 {
 862         /* we abuse the parameters scope as parent for the labels */
 863         label->base.parent_scope = &current_function->parameters;
 864         stack_push(&label_stack, label);
 865 }
 866
 867 /**
 868  * pops symbols from the environment stack until @p new_top is the top element
 869  */
 870 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 871 {
 872         stack_entry_t *stack = *stack_ptr;
 873         size_t         top   = ARR_LEN(stack);
 874         size_t         i;
 875
 876         assert(new_top <= top);
 877         if (new_top == top)
 878                 return;
 879
 880         for (i = top; i > new_top; --i) {
 881                 stack_entry_t *entry = &stack[i - 1];
 882
 883                 entity_t           *old_entity = entry->old_entity;
 884                 symbol_t           *symbol     = entry->symbol;
 885                 entity_namespace_t  namespc    = entry->namespc;
 886
 887                 /* replace with old_entity/remove */
 888                 entity_t **anchor;
 889                 entity_t  *iter;
 890                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 891                         iter = *anchor;
 892                         assert(iter != NULL);
 893                         /* replace an entry? */
 894                         if (iter->base.namespc == namespc)
 895                                 break;
 896                 }
 897
 898                 /* restore definition from outer scopes (if there was one) */
 899                 if (old_entity != NULL) {
 900                         old_entity->base.symbol_next = iter->base.symbol_next;
 901                         *anchor                      = old_entity;
 902                 } else {
 903                         /* remove entry from list */
 904                         *anchor = iter->base.symbol_next;
 905                 }
 906         }
 907
 908         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 909 }
 910
 911 /**
 912  * Pop all entries from the environment stack until the new_top
 913  * is reached.
 914  *
 915  * @param new_top  the new stack top
 916  */
 917 static void environment_pop_to(size_t new_top)
 918 {
 919         stack_pop_to(&environment_stack, new_top);
 920 }
 921
 922 /**
 923  * Pop all entries from the global label stack until the new_top
 924  * is reached.
 925  *
 926  * @param new_top  the new stack top
 927  */
 928 static void label_pop_to(size_t new_top)
 929 {
 930         stack_pop_to(&label_stack, new_top);
 931 }
 932
 933 static int get_akind_rank(atomic_type_kind_t akind)
 934 {
 935         return (int) akind;
 936 }
 937
 938 /**
 939  * Return the type rank for an atomic type.
 940  */
 941 static int get_rank(const type_t *type)
 942 {
 943         assert(!is_typeref(type));
 944         if (type->kind == TYPE_ENUM)
 945                 return get_akind_rank(type->enumt.akind);
 946
 947         assert(type->kind == TYPE_ATOMIC);
 948         return get_akind_rank(type->atomic.akind);
 949 }
 950
 951 /**
 952  * §6.3.1.1:2  Do integer promotion for a given type.
 953  *
 954  * @param type  the type to promote
 955  * @return the promoted type
 956  */
 957 static type_t *promote_integer(type_t *type)
 958 {
 959         if (type->kind == TYPE_BITFIELD)
 960                 type = type->bitfield.base_type;
 961
 962         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 963                 type = type_int;
 964
 965         return type;
 966 }
 967
 968 /**
 969  * Create a cast expression.
 970  *
 971  * @param expression  the expression to cast
 972  * @param dest_type   the destination type
 973  */
 974 static expression_t *create_cast_expression(expression_t *expression,
 975                                             type_t *dest_type)
 976 {
 977         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 978
 979         cast->unary.value = expression;
 980         cast->base.type   = dest_type;
 981
 982         return cast;
 983 }
 984
 985 /**
 986  * Check if a given expression represents a null pointer constant.
 987  *
 988  * @param expression  the expression to check
 989  */
 990 static bool is_null_pointer_constant(const expression_t *expression)
 991 {
 992         /* skip void* cast */
 993         if (expression->kind == EXPR_UNARY_CAST ||
 994                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 995                 type_t *const type = skip_typeref(expression->base.type);
 996                 if (types_compatible(type, type_void_ptr))
 997                         expression = expression->unary.value;
 998         }
 999
1000         type_t *const type = skip_typeref(expression->base.type);
1001         return
1002                 is_type_integer(type)              &&
1003                 is_constant_expression(expression) &&
1004                 !fold_constant_to_bool(expression);
1005 }
1006
1007 /**
1008  * Create an implicit cast expression.
1009  *
1010  * @param expression  the expression to cast
1011  * @param dest_type   the destination type
1012  */
1013 static expression_t *create_implicit_cast(expression_t *expression,
1014                                           type_t *dest_type)
1015 {
1016         type_t *const source_type = expression->base.type;
1017
1018         if (source_type == dest_type)
1019                 return expression;
1020
1021         return create_cast_expression(expression, dest_type);
1022 }
1023
1024 typedef enum assign_error_t {
1025         ASSIGN_SUCCESS,
1026         ASSIGN_ERROR_INCOMPATIBLE,
1027         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1028         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1029         ASSIGN_WARNING_POINTER_FROM_INT,
1030         ASSIGN_WARNING_INT_FROM_POINTER
1031 } assign_error_t;
1032
1033 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1034                                 const expression_t *const right,
1035                                 const char *context,
1036                                 const source_position_t *source_position)
1037 {
1038         type_t *const orig_type_right = right->base.type;
1039         type_t *const type_left       = skip_typeref(orig_type_left);
1040         type_t *const type_right      = skip_typeref(orig_type_right);
1041
1042         switch (error) {
1043         case ASSIGN_SUCCESS:
1044                 return;
1045         case ASSIGN_ERROR_INCOMPATIBLE:
1046                 errorf(source_position,
1047                        "destination type '%T' in %s is incompatible with type '%T'",
1048                        orig_type_left, context, orig_type_right);
1049                 return;
1050
1051         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1052                 if (warning.other) {
1053                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1054                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1055
1056                         /* the left type has all qualifiers from the right type */
1057                         unsigned missing_qualifiers
1058                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1059                         warningf(source_position,
1060                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1061                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1062                 }
1063                 return;
1064         }
1065
1066         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1067                 if (warning.other) {
1068                         warningf(source_position,
1069                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1070                                         orig_type_left, context, right, orig_type_right);
1071                 }
1072                 return;
1073
1074         case ASSIGN_WARNING_POINTER_FROM_INT:
1075                 if (warning.other) {
1076                         warningf(source_position,
1077                                         "%s makes pointer '%T' from integer '%T' without a cast",
1078                                         context, orig_type_left, orig_type_right);
1079                 }
1080                 return;
1081
1082         case ASSIGN_WARNING_INT_FROM_POINTER:
1083                 if (warning.other) {
1084                         warningf(source_position,
1085                                         "%s makes integer '%T' from pointer '%T' without a cast",
1086                                         context, orig_type_left, orig_type_right);
1087                 }
1088                 return;
1089
1090         default:
1091                 panic("invalid error value");
1092         }
1093 }
1094
1095 /** Implements the rules from §6.5.16.1 */
1096 static assign_error_t semantic_assign(type_t *orig_type_left,
1097                                       const expression_t *const right)
1098 {
1099         type_t *const orig_type_right = right->base.type;
1100         type_t *const type_left       = skip_typeref(orig_type_left);
1101         type_t *const type_right      = skip_typeref(orig_type_right);
1102
1103         if (is_type_pointer(type_left)) {
1104                 if (is_null_pointer_constant(right)) {
1105                         return ASSIGN_SUCCESS;
1106                 } else if (is_type_pointer(type_right)) {
1107                         type_t *points_to_left
1108                                 = skip_typeref(type_left->pointer.points_to);
1109                         type_t *points_to_right
1110                                 = skip_typeref(type_right->pointer.points_to);
1111                         assign_error_t res = ASSIGN_SUCCESS;
1112
1113                         /* the left type has all qualifiers from the right type */
1114                         unsigned missing_qualifiers
1115                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1116                         if (missing_qualifiers != 0) {
1117                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1118                         }
1119
1120                         points_to_left  = get_unqualified_type(points_to_left);
1121                         points_to_right = get_unqualified_type(points_to_right);
1122
1123                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1124                                 return res;
1125
1126                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1127                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1128                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1129                         }
1130
1131                         if (!types_compatible(points_to_left, points_to_right)) {
1132                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1133                         }
1134
1135                         return res;
1136                 } else if (is_type_integer(type_right)) {
1137                         return ASSIGN_WARNING_POINTER_FROM_INT;
1138                 }
1139         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1140             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1141                 && is_type_pointer(type_right))) {
1142                 return ASSIGN_SUCCESS;
1143         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1144                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1145                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1146                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1147                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1148                         return ASSIGN_SUCCESS;
1149                 }
1150         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1151                 return ASSIGN_WARNING_INT_FROM_POINTER;
1152         }
1153
1154         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1155                 return ASSIGN_SUCCESS;
1156
1157         return ASSIGN_ERROR_INCOMPATIBLE;
1158 }
1159
1160 static expression_t *parse_constant_expression(void)
1161 {
1162         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1163
1164         if (!is_constant_expression(result)) {
1165                 errorf(&result->base.source_position,
1166                        "expression '%E' is not constant", result);
1167         }
1168
1169         return result;
1170 }
1171
1172 static expression_t *parse_assignment_expression(void)
1173 {
1174         return parse_sub_expression(PREC_ASSIGNMENT);
1175 }
1176
1177 static string_t parse_string_literals(void)
1178 {
1179         assert(token.type == T_STRING_LITERAL);
1180         string_t result = token.v.string;
1181
1182         next_token();
1183
1184         while (token.type == T_STRING_LITERAL) {
1185                 result = concat_strings(&result, &token.v.string);
1186                 next_token();
1187         }
1188
1189         return result;
1190 }
1191
1192 /**
1193  * compare two string, ignoring double underscores on the second.
1194  */
1195 static int strcmp_underscore(const char *s1, const char *s2)
1196 {
1197         if (s2[0] == '_' && s2[1] == '_') {
1198                 size_t len2 = strlen(s2);
1199                 size_t len1 = strlen(s1);
1200                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1201                         return strncmp(s1, s2+2, len2-4);
1202                 }
1203         }
1204
1205         return strcmp(s1, s2);
1206 }
1207
1208 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1209 {
1210         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1211         attribute->kind        = kind;
1212         return attribute;
1213 }
1214
1215 /**
1216  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1217  *
1218  *  attribute:
1219  *    __attribute__ ( ( attribute-list ) )
1220  *
1221  *  attribute-list:
1222  *    attrib
1223  *    attribute_list , attrib
1224  *
1225  *  attrib:
1226  *    empty
1227  *    any-word
1228  *    any-word ( identifier )
1229  *    any-word ( identifier , nonempty-expr-list )
1230  *    any-word ( expr-list )
1231  *
1232  *  where the "identifier" must not be declared as a type, and
1233  *  "any-word" may be any identifier (including one declared as a
1234  *  type), a reserved word storage class specifier, type specifier or
1235  *  type qualifier.  ??? This still leaves out most reserved keywords
1236  *  (following the old parser), shouldn't we include them, and why not
1237  *  allow identifiers declared as types to start the arguments?
1238  *
1239  *  Matze: this all looks confusing and little systematic, so we're even less
1240  *  strict and parse any list of things which are identifiers or
1241  *  (assignment-)expressions.
1242  */
1243 static attribute_argument_t *parse_attribute_arguments(void)
1244 {
1245         if (token.type == ')')
1246                 return NULL;
1247
1248         attribute_argument_t *first = NULL;
1249         attribute_argument_t *last  = NULL;
1250         while (true) {
1251                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1252
1253                 /* is it an identifier */
1254                 if (token.type == T_IDENTIFIER
1255                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1256                         symbol_t *symbol   = token.v.symbol;
1257                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1258                         argument->v.symbol = symbol;
1259                         next_token();
1260                 } else {
1261                         /* must be an expression */
1262                         expression_t *expression = parse_assignment_expression();
1263
1264                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1265                         argument->v.expression = expression;
1266                 }
1267
1268                 /* append argument */
1269                 if (last == NULL) {
1270                         first = argument;
1271                 } else {
1272                         last->next = argument;
1273                 }
1274                 last = argument;
1275
1276                 if (token.type == ',') {
1277                         next_token();
1278                         continue;
1279                 }
1280                 expect(')', end_error);
1281                 break;
1282         }
1283
1284         return first;
1285
1286 end_error:
1287         /* TODO... */
1288         return first;
1289 }
1290
1291 static attribute_t *parse_attribute_asm(void)
1292 {
1293         eat(T_asm);
1294
1295         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1296
1297         expect('(', end_error);
1298         attribute->a.arguments = parse_attribute_arguments();
1299         return attribute;
1300
1301 end_error:
1302         return NULL;
1303 }
1304
1305 static symbol_t *get_symbol_from_token(void)
1306 {
1307         switch(token.type) {
1308         case T_IDENTIFIER:
1309                 return token.v.symbol;
1310         case T_auto:
1311         case T_char:
1312         case T_double:
1313         case T_enum:
1314         case T_extern:
1315         case T_float:
1316         case T_int:
1317         case T_long:
1318         case T_register:
1319         case T_short:
1320         case T_static:
1321         case T_struct:
1322         case T_union:
1323         case T_unsigned:
1324         case T_void:
1325         case T_bool:
1326         case T__Bool:
1327         case T_class:
1328         case T_explicit:
1329         case T_export:
1330         case T_wchar_t:
1331         case T_const:
1332         case T_signed:
1333         case T___real__:
1334         case T___imag__:
1335         case T_restrict:
1336         case T_volatile:
1337         case T_inline:
1338                 /* maybe we need more tokens ... add them on demand */
1339                 return get_token_symbol(&token);
1340         default:
1341                 return NULL;
1342         }
1343 }
1344
1345 static attribute_t *parse_attribute_gnu_single(void)
1346 {
1347         /* parse "any-word" */
1348         symbol_t *symbol = get_symbol_from_token();
1349         if (symbol == NULL) {
1350                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1351                 goto end_error;
1352         }
1353
1354         const char *name = symbol->string;
1355         next_token();
1356
1357         attribute_kind_t kind;
1358         for (kind = ATTRIBUTE_GNU_FIRST; kind <= ATTRIBUTE_GNU_LAST; ++kind) {
1359                 const char *attribute_name = get_attribute_name(kind);
1360                 if (attribute_name != NULL
1361                                 && strcmp_underscore(attribute_name, name) == 0)
1362                         break;
1363         }
1364
1365         if (kind >= ATTRIBUTE_GNU_LAST) {
1366                 if (warning.attribute) {
1367                         warningf(HERE, "unknown attribute '%s' ignored", name);
1368                 }
1369                 /* TODO: we should still save the attribute in the list... */
1370                 kind = ATTRIBUTE_UNKNOWN;
1371         }
1372
1373         attribute_t *attribute = allocate_attribute_zero(kind);
1374
1375         /* parse arguments */
1376         if (token.type == '(') {
1377                 next_token();
1378                 attribute->a.arguments = parse_attribute_arguments();
1379         }
1380
1381         return attribute;
1382
1383 end_error:
1384         return NULL;
1385 }
1386
1387 static attribute_t *parse_attribute_gnu(void)
1388 {
1389         attribute_t *first = NULL;
1390         attribute_t *last  = NULL;
1391
1392         eat(T___attribute__);
1393         expect('(', end_error);
1394         expect('(', end_error);
1395
1396         if (token.type == ')') {
1397                 next_token();
1398                 expect(')', end_error);
1399                 return first;
1400         }
1401
1402         while (true) {
1403                 attribute_t *attribute = parse_attribute_gnu_single();
1404                 if (attribute == NULL)
1405                         goto end_error;
1406
1407                 if (last == NULL) {
1408                         first = attribute;
1409                 } else {
1410                         last->next = attribute;
1411                 }
1412                 last = attribute;
1413
1414                 if (token.type == ')') {
1415                         next_token();
1416                         break;
1417                 }
1418                 expect(',', end_error);
1419         }
1420         expect(')', end_error);
1421
1422 end_error:
1423         return first;
1424 }
1425
1426 /** Parse attributes. */
1427 static attribute_t *parse_attributes(attribute_t *first)
1428 {
1429         attribute_t *last = first;
1430         while (true) {
1431                 if (last != NULL) {
1432                         while (last->next != NULL)
1433                                 last = last->next;
1434                 }
1435
1436                 attribute_t *attribute;
1437                 switch (token.type) {
1438                 case T___attribute__:
1439                         attribute = parse_attribute_gnu();
1440                         break;
1441
1442                 case T_asm:
1443                         attribute = parse_attribute_asm();
1444                         break;
1445
1446                 case T_cdecl:
1447                         next_token();
1448                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1449                         break;
1450
1451                 case T__fastcall:
1452                         next_token();
1453                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1454                         break;
1455
1456                 case T__forceinline:
1457                         next_token();
1458                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1459                         break;
1460
1461                 case T__stdcall:
1462                         next_token();
1463                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1464                         break;
1465
1466                 case T___thiscall:
1467                         next_token();
1468                         /* TODO record modifier */
1469                         if (warning.other)
1470                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1471                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1472                         break;
1473
1474                 default:
1475                         return first;
1476                 }
1477
1478                 if (last == NULL) {
1479                         first = attribute;
1480                 } else {
1481                         last->next = attribute;
1482                 }
1483                 last = attribute;
1484         }
1485 }
1486
1487 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1488
1489 static entity_t *determine_lhs_ent(expression_t *const expr,
1490                                    entity_t *lhs_ent)
1491 {
1492         switch (expr->kind) {
1493                 case EXPR_REFERENCE: {
1494                         entity_t *const entity = expr->reference.entity;
1495                         /* we should only find variables as lvalues... */
1496                         if (entity->base.kind != ENTITY_VARIABLE
1497                                         && entity->base.kind != ENTITY_PARAMETER)
1498                                 return NULL;
1499
1500                         return entity;
1501                 }
1502
1503                 case EXPR_ARRAY_ACCESS: {
1504                         expression_t *const ref = expr->array_access.array_ref;
1505                         entity_t     *      ent = NULL;
1506                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1507                                 ent     = determine_lhs_ent(ref, lhs_ent);
1508                                 lhs_ent = ent;
1509                         } else {
1510                                 mark_vars_read(expr->select.compound, lhs_ent);
1511                         }
1512                         mark_vars_read(expr->array_access.index, lhs_ent);
1513                         return ent;
1514                 }
1515
1516                 case EXPR_SELECT: {
1517                         if (is_type_compound(skip_typeref(expr->base.type))) {
1518                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1519                         } else {
1520                                 mark_vars_read(expr->select.compound, lhs_ent);
1521                                 return NULL;
1522                         }
1523                 }
1524
1525                 case EXPR_UNARY_DEREFERENCE: {
1526                         expression_t *const val = expr->unary.value;
1527                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1528                                 /* *&x is a NOP */
1529                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1530                         } else {
1531                                 mark_vars_read(val, NULL);
1532                                 return NULL;
1533                         }
1534                 }
1535
1536                 default:
1537                         mark_vars_read(expr, NULL);
1538                         return NULL;
1539         }
1540 }
1541
1542 #define ENT_ANY ((entity_t*)-1)
1543
1544 /**
1545  * Mark declarations, which are read.  This is used to detect variables, which
1546  * are never read.
1547  * Example:
1548  * x = x + 1;
1549  *   x is not marked as "read", because it is only read to calculate its own new
1550  *   value.
1551  *
1552  * x += y; y += x;
1553  *   x and y are not detected as "not read", because multiple variables are
1554  *   involved.
1555  */
1556 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1557 {
1558         switch (expr->kind) {
1559                 case EXPR_REFERENCE: {
1560                         entity_t *const entity = expr->reference.entity;
1561                         if (entity->kind != ENTITY_VARIABLE
1562                                         && entity->kind != ENTITY_PARAMETER)
1563                                 return;
1564
1565                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1566                                 if (entity->kind == ENTITY_VARIABLE) {
1567                                         entity->variable.read = true;
1568                                 } else {
1569                                         entity->parameter.read = true;
1570                                 }
1571                         }
1572                         return;
1573                 }
1574
1575                 case EXPR_CALL:
1576                         // TODO respect pure/const
1577                         mark_vars_read(expr->call.function, NULL);
1578                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1579                                 mark_vars_read(arg->expression, NULL);
1580                         }
1581                         return;
1582
1583                 case EXPR_CONDITIONAL:
1584                         // TODO lhs_decl should depend on whether true/false have an effect
1585                         mark_vars_read(expr->conditional.condition, NULL);
1586                         if (expr->conditional.true_expression != NULL)
1587                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1588                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1589                         return;
1590
1591                 case EXPR_SELECT:
1592                         if (lhs_ent == ENT_ANY
1593                                         && !is_type_compound(skip_typeref(expr->base.type)))
1594                                 lhs_ent = NULL;
1595                         mark_vars_read(expr->select.compound, lhs_ent);
1596                         return;
1597
1598                 case EXPR_ARRAY_ACCESS: {
1599                         expression_t *const ref = expr->array_access.array_ref;
1600                         mark_vars_read(ref, lhs_ent);
1601                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1602                         mark_vars_read(expr->array_access.index, lhs_ent);
1603                         return;
1604                 }
1605
1606                 case EXPR_VA_ARG:
1607                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1608                         return;
1609
1610                 case EXPR_VA_COPY:
1611                         mark_vars_read(expr->va_copye.src, lhs_ent);
1612                         return;
1613
1614                 case EXPR_UNARY_CAST:
1615                         /* Special case: Use void cast to mark a variable as "read" */
1616                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1617                                 lhs_ent = NULL;
1618                         goto unary;
1619
1620
1621                 case EXPR_UNARY_THROW:
1622                         if (expr->unary.value == NULL)
1623                                 return;
1624                         /* FALLTHROUGH */
1625                 case EXPR_UNARY_DEREFERENCE:
1626                 case EXPR_UNARY_DELETE:
1627                 case EXPR_UNARY_DELETE_ARRAY:
1628                         if (lhs_ent == ENT_ANY)
1629                                 lhs_ent = NULL;
1630                         goto unary;
1631
1632                 case EXPR_UNARY_NEGATE:
1633                 case EXPR_UNARY_PLUS:
1634                 case EXPR_UNARY_BITWISE_NEGATE:
1635                 case EXPR_UNARY_NOT:
1636                 case EXPR_UNARY_TAKE_ADDRESS:
1637                 case EXPR_UNARY_POSTFIX_INCREMENT:
1638                 case EXPR_UNARY_POSTFIX_DECREMENT:
1639                 case EXPR_UNARY_PREFIX_INCREMENT:
1640                 case EXPR_UNARY_PREFIX_DECREMENT:
1641                 case EXPR_UNARY_CAST_IMPLICIT:
1642                 case EXPR_UNARY_ASSUME:
1643 unary:
1644                         mark_vars_read(expr->unary.value, lhs_ent);
1645                         return;
1646
1647                 case EXPR_BINARY_ADD:
1648                 case EXPR_BINARY_SUB:
1649                 case EXPR_BINARY_MUL:
1650                 case EXPR_BINARY_DIV:
1651                 case EXPR_BINARY_MOD:
1652                 case EXPR_BINARY_EQUAL:
1653                 case EXPR_BINARY_NOTEQUAL:
1654                 case EXPR_BINARY_LESS:
1655                 case EXPR_BINARY_LESSEQUAL:
1656                 case EXPR_BINARY_GREATER:
1657                 case EXPR_BINARY_GREATEREQUAL:
1658                 case EXPR_BINARY_BITWISE_AND:
1659                 case EXPR_BINARY_BITWISE_OR:
1660                 case EXPR_BINARY_BITWISE_XOR:
1661                 case EXPR_BINARY_LOGICAL_AND:
1662                 case EXPR_BINARY_LOGICAL_OR:
1663                 case EXPR_BINARY_SHIFTLEFT:
1664                 case EXPR_BINARY_SHIFTRIGHT:
1665                 case EXPR_BINARY_COMMA:
1666                 case EXPR_BINARY_ISGREATER:
1667                 case EXPR_BINARY_ISGREATEREQUAL:
1668                 case EXPR_BINARY_ISLESS:
1669                 case EXPR_BINARY_ISLESSEQUAL:
1670                 case EXPR_BINARY_ISLESSGREATER:
1671                 case EXPR_BINARY_ISUNORDERED:
1672                         mark_vars_read(expr->binary.left,  lhs_ent);
1673                         mark_vars_read(expr->binary.right, lhs_ent);
1674                         return;
1675
1676                 case EXPR_BINARY_ASSIGN:
1677                 case EXPR_BINARY_MUL_ASSIGN:
1678                 case EXPR_BINARY_DIV_ASSIGN:
1679                 case EXPR_BINARY_MOD_ASSIGN:
1680                 case EXPR_BINARY_ADD_ASSIGN:
1681                 case EXPR_BINARY_SUB_ASSIGN:
1682                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1683                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1684                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1685                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1686                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1687                         if (lhs_ent == ENT_ANY)
1688                                 lhs_ent = NULL;
1689                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1690                         mark_vars_read(expr->binary.right, lhs_ent);
1691                         return;
1692                 }
1693
1694                 case EXPR_VA_START:
1695                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1696                         return;
1697
1698                 case EXPR_UNKNOWN:
1699                 case EXPR_INVALID:
1700                 case EXPR_CONST:
1701                 case EXPR_CHARACTER_CONSTANT:
1702                 case EXPR_WIDE_CHARACTER_CONSTANT:
1703                 case EXPR_STRING_LITERAL:
1704                 case EXPR_WIDE_STRING_LITERAL:
1705                 case EXPR_COMPOUND_LITERAL: // TODO init?
1706                 case EXPR_SIZEOF:
1707                 case EXPR_CLASSIFY_TYPE:
1708                 case EXPR_ALIGNOF:
1709                 case EXPR_FUNCNAME:
1710                 case EXPR_BUILTIN_CONSTANT_P:
1711                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1712                 case EXPR_OFFSETOF:
1713                 case EXPR_STATEMENT: // TODO
1714                 case EXPR_LABEL_ADDRESS:
1715                 case EXPR_REFERENCE_ENUM_VALUE:
1716                         return;
1717         }
1718
1719         panic("unhandled expression");
1720 }
1721
1722 static designator_t *parse_designation(void)
1723 {
1724         designator_t *result = NULL;
1725         designator_t *last   = NULL;
1726
1727         while (true) {
1728                 designator_t *designator;
1729                 switch (token.type) {
1730                 case '[':
1731                         designator = allocate_ast_zero(sizeof(designator[0]));
1732                         designator->source_position = token.source_position;
1733                         next_token();
1734                         add_anchor_token(']');
1735                         designator->array_index = parse_constant_expression();
1736                         rem_anchor_token(']');
1737                         expect(']', end_error);
1738                         break;
1739                 case '.':
1740                         designator = allocate_ast_zero(sizeof(designator[0]));
1741                         designator->source_position = token.source_position;
1742                         next_token();
1743                         if (token.type != T_IDENTIFIER) {
1744                                 parse_error_expected("while parsing designator",
1745                                                      T_IDENTIFIER, NULL);
1746                                 return NULL;
1747                         }
1748                         designator->symbol = token.v.symbol;
1749                         next_token();
1750                         break;
1751                 default:
1752                         expect('=', end_error);
1753                         return result;
1754                 }
1755
1756                 assert(designator != NULL);
1757                 if (last != NULL) {
1758                         last->next = designator;
1759                 } else {
1760                         result = designator;
1761                 }
1762                 last = designator;
1763         }
1764 end_error:
1765         return NULL;
1766 }
1767
1768 static initializer_t *initializer_from_string(array_type_t *type,
1769                                               const string_t *const string)
1770 {
1771         /* TODO: check len vs. size of array type */
1772         (void) type;
1773
1774         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1775         initializer->string.string = *string;
1776
1777         return initializer;
1778 }
1779
1780 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1781                                                    wide_string_t *const string)
1782 {
1783         /* TODO: check len vs. size of array type */
1784         (void) type;
1785
1786         initializer_t *const initializer =
1787                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1788         initializer->wide_string.string = *string;
1789
1790         return initializer;
1791 }
1792
1793 /**
1794  * Build an initializer from a given expression.
1795  */
1796 static initializer_t *initializer_from_expression(type_t *orig_type,
1797                                                   expression_t *expression)
1798 {
1799         /* TODO check that expression is a constant expression */
1800
1801         /* §6.7.8.14/15 char array may be initialized by string literals */
1802         type_t *type           = skip_typeref(orig_type);
1803         type_t *expr_type_orig = expression->base.type;
1804         type_t *expr_type      = skip_typeref(expr_type_orig);
1805         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1806                 array_type_t *const array_type   = &type->array;
1807                 type_t       *const element_type = skip_typeref(array_type->element_type);
1808
1809                 if (element_type->kind == TYPE_ATOMIC) {
1810                         atomic_type_kind_t akind = element_type->atomic.akind;
1811                         switch (expression->kind) {
1812                                 case EXPR_STRING_LITERAL:
1813                                         if (akind == ATOMIC_TYPE_CHAR
1814                                                         || akind == ATOMIC_TYPE_SCHAR
1815                                                         || akind == ATOMIC_TYPE_UCHAR) {
1816                                                 return initializer_from_string(array_type,
1817                                                         &expression->string.value);
1818                                         }
1819                                         break;
1820
1821                                 case EXPR_WIDE_STRING_LITERAL: {
1822                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1823                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1824                                                 return initializer_from_wide_string(array_type,
1825                                                         &expression->wide_string.value);
1826                                         }
1827                                         break;
1828                                 }
1829
1830                                 default:
1831                                         break;
1832                         }
1833                 }
1834         }
1835
1836         assign_error_t error = semantic_assign(type, expression);
1837         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1838                 return NULL;
1839         report_assign_error(error, type, expression, "initializer",
1840                             &expression->base.source_position);
1841
1842         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1843         result->value.value = create_implicit_cast(expression, type);
1844
1845         return result;
1846 }
1847
1848 /**
1849  * Checks if a given expression can be used as an constant initializer.
1850  */
1851 static bool is_initializer_constant(const expression_t *expression)
1852 {
1853         return is_constant_expression(expression)
1854                 || is_address_constant(expression);
1855 }
1856
1857 /**
1858  * Parses an scalar initializer.
1859  *
1860  * §6.7.8.11; eat {} without warning
1861  */
1862 static initializer_t *parse_scalar_initializer(type_t *type,
1863                                                bool must_be_constant)
1864 {
1865         /* there might be extra {} hierarchies */
1866         int braces = 0;
1867         if (token.type == '{') {
1868                 if (warning.other)
1869                         warningf(HERE, "extra curly braces around scalar initializer");
1870                 do {
1871                         ++braces;
1872                         next_token();
1873                 } while (token.type == '{');
1874         }
1875
1876         expression_t *expression = parse_assignment_expression();
1877         mark_vars_read(expression, NULL);
1878         if (must_be_constant && !is_initializer_constant(expression)) {
1879                 errorf(&expression->base.source_position,
1880                        "Initialisation expression '%E' is not constant",
1881                        expression);
1882         }
1883
1884         initializer_t *initializer = initializer_from_expression(type, expression);
1885
1886         if (initializer == NULL) {
1887                 errorf(&expression->base.source_position,
1888                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1889                        expression, expression->base.type, type);
1890                 /* TODO */
1891                 return NULL;
1892         }
1893
1894         bool additional_warning_displayed = false;
1895         while (braces > 0) {
1896                 if (token.type == ',') {
1897                         next_token();
1898                 }
1899                 if (token.type != '}') {
1900                         if (!additional_warning_displayed && warning.other) {
1901                                 warningf(HERE, "additional elements in scalar initializer");
1902                                 additional_warning_displayed = true;
1903                         }
1904                 }
1905                 eat_block();
1906                 braces--;
1907         }
1908
1909         return initializer;
1910 }
1911
1912 /**
1913  * An entry in the type path.
1914  */
1915 typedef struct type_path_entry_t type_path_entry_t;
1916 struct type_path_entry_t {
1917         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1918         union {
1919                 size_t         index;          /**< For array types: the current index. */
1920                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1921         } v;
1922 };
1923
1924 /**
1925  * A type path expression a position inside compound or array types.
1926  */
1927 typedef struct type_path_t type_path_t;
1928 struct type_path_t {
1929         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1930         type_t            *top_type;     /**< type of the element the path points */
1931         size_t             max_index;    /**< largest index in outermost array */
1932 };
1933
1934 /**
1935  * Prints a type path for debugging.
1936  */
1937 static __attribute__((unused)) void debug_print_type_path(
1938                 const type_path_t *path)
1939 {
1940         size_t len = ARR_LEN(path->path);
1941
1942         for (size_t i = 0; i < len; ++i) {
1943                 const type_path_entry_t *entry = & path->path[i];
1944
1945                 type_t *type = skip_typeref(entry->type);
1946                 if (is_type_compound(type)) {
1947                         /* in gcc mode structs can have no members */
1948                         if (entry->v.compound_entry == NULL) {
1949                                 assert(i == len-1);
1950                                 continue;
1951                         }
1952                         fprintf(stderr, ".%s",
1953                                 entry->v.compound_entry->base.symbol->string);
1954                 } else if (is_type_array(type)) {
1955                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1956                 } else {
1957                         fprintf(stderr, "-INVALID-");
1958                 }
1959         }
1960         if (path->top_type != NULL) {
1961                 fprintf(stderr, "  (");
1962                 print_type(path->top_type);
1963                 fprintf(stderr, ")");
1964         }
1965 }
1966
1967 /**
1968  * Return the top type path entry, ie. in a path
1969  * (type).a.b returns the b.
1970  */
1971 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1972 {
1973         size_t len = ARR_LEN(path->path);
1974         assert(len > 0);
1975         return &path->path[len-1];
1976 }
1977
1978 /**
1979  * Enlarge the type path by an (empty) element.
1980  */
1981 static type_path_entry_t *append_to_type_path(type_path_t *path)
1982 {
1983         size_t len = ARR_LEN(path->path);
1984         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1985
1986         type_path_entry_t *result = & path->path[len];
1987         memset(result, 0, sizeof(result[0]));
1988         return result;
1989 }
1990
1991 /**
1992  * Descending into a sub-type. Enter the scope of the current top_type.
1993  */
1994 static void descend_into_subtype(type_path_t *path)
1995 {
1996         type_t *orig_top_type = path->top_type;
1997         type_t *top_type      = skip_typeref(orig_top_type);
1998
1999         type_path_entry_t *top = append_to_type_path(path);
2000         top->type              = top_type;
2001
2002         if (is_type_compound(top_type)) {
2003                 compound_t *compound  = top_type->compound.compound;
2004                 entity_t   *entry     = compound->members.entities;
2005
2006                 if (entry != NULL) {
2007                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2008                         top->v.compound_entry = &entry->declaration;
2009                         path->top_type = entry->declaration.type;
2010                 } else {
2011                         path->top_type = NULL;
2012                 }
2013         } else if (is_type_array(top_type)) {
2014                 top->v.index   = 0;
2015                 path->top_type = top_type->array.element_type;
2016         } else {
2017                 assert(!is_type_valid(top_type));
2018         }
2019 }
2020
2021 /**
2022  * Pop an entry from the given type path, ie. returning from
2023  * (type).a.b to (type).a
2024  */
2025 static void ascend_from_subtype(type_path_t *path)
2026 {
2027         type_path_entry_t *top = get_type_path_top(path);
2028
2029         path->top_type = top->type;
2030
2031         size_t len = ARR_LEN(path->path);
2032         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2033 }
2034
2035 /**
2036  * Pop entries from the given type path until the given
2037  * path level is reached.
2038  */
2039 static void ascend_to(type_path_t *path, size_t top_path_level)
2040 {
2041         size_t len = ARR_LEN(path->path);
2042
2043         while (len > top_path_level) {
2044                 ascend_from_subtype(path);
2045                 len = ARR_LEN(path->path);
2046         }
2047 }
2048
2049 static bool walk_designator(type_path_t *path, const designator_t *designator,
2050                             bool used_in_offsetof)
2051 {
2052         for (; designator != NULL; designator = designator->next) {
2053                 type_path_entry_t *top       = get_type_path_top(path);
2054                 type_t            *orig_type = top->type;
2055
2056                 type_t *type = skip_typeref(orig_type);
2057
2058                 if (designator->symbol != NULL) {
2059                         symbol_t *symbol = designator->symbol;
2060                         if (!is_type_compound(type)) {
2061                                 if (is_type_valid(type)) {
2062                                         errorf(&designator->source_position,
2063                                                "'.%Y' designator used for non-compound type '%T'",
2064                                                symbol, orig_type);
2065                                 }
2066
2067                                 top->type             = type_error_type;
2068                                 top->v.compound_entry = NULL;
2069                                 orig_type             = type_error_type;
2070                         } else {
2071                                 compound_t *compound = type->compound.compound;
2072                                 entity_t   *iter     = compound->members.entities;
2073                                 for (; iter != NULL; iter = iter->base.next) {
2074                                         if (iter->base.symbol == symbol) {
2075                                                 break;
2076                                         }
2077                                 }
2078                                 if (iter == NULL) {
2079                                         errorf(&designator->source_position,
2080                                                "'%T' has no member named '%Y'", orig_type, symbol);
2081                                         goto failed;
2082                                 }
2083                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2084                                 if (used_in_offsetof) {
2085                                         type_t *real_type = skip_typeref(iter->declaration.type);
2086                                         if (real_type->kind == TYPE_BITFIELD) {
2087                                                 errorf(&designator->source_position,
2088                                                        "offsetof designator '%Y' may not specify bitfield",
2089                                                        symbol);
2090                                                 goto failed;
2091                                         }
2092                                 }
2093
2094                                 top->type             = orig_type;
2095                                 top->v.compound_entry = &iter->declaration;
2096                                 orig_type             = iter->declaration.type;
2097                         }
2098                 } else {
2099                         expression_t *array_index = designator->array_index;
2100                         assert(designator->array_index != NULL);
2101
2102                         if (!is_type_array(type)) {
2103                                 if (is_type_valid(type)) {
2104                                         errorf(&designator->source_position,
2105                                                "[%E] designator used for non-array type '%T'",
2106                                                array_index, orig_type);
2107                                 }
2108                                 goto failed;
2109                         }
2110
2111                         long index = fold_constant_to_int(array_index);
2112                         if (!used_in_offsetof) {
2113                                 if (index < 0) {
2114                                         errorf(&designator->source_position,
2115                                                "array index [%E] must be positive", array_index);
2116                                 } else if (type->array.size_constant) {
2117                                         long array_size = type->array.size;
2118                                         if (index >= array_size) {
2119                                                 errorf(&designator->source_position,
2120                                                        "designator [%E] (%d) exceeds array size %d",
2121                                                        array_index, index, array_size);
2122                                         }
2123                                 }
2124                         }
2125
2126                         top->type    = orig_type;
2127                         top->v.index = (size_t) index;
2128                         orig_type    = type->array.element_type;
2129                 }
2130                 path->top_type = orig_type;
2131
2132                 if (designator->next != NULL) {
2133                         descend_into_subtype(path);
2134                 }
2135         }
2136         return true;
2137
2138 failed:
2139         return false;
2140 }
2141
2142 static void advance_current_object(type_path_t *path, size_t top_path_level)
2143 {
2144         type_path_entry_t *top = get_type_path_top(path);
2145
2146         type_t *type = skip_typeref(top->type);
2147         if (is_type_union(type)) {
2148                 /* in unions only the first element is initialized */
2149                 top->v.compound_entry = NULL;
2150         } else if (is_type_struct(type)) {
2151                 declaration_t *entry = top->v.compound_entry;
2152
2153                 entity_t *next_entity = entry->base.next;
2154                 if (next_entity != NULL) {
2155                         assert(is_declaration(next_entity));
2156                         entry = &next_entity->declaration;
2157                 } else {
2158                         entry = NULL;
2159                 }
2160
2161                 top->v.compound_entry = entry;
2162                 if (entry != NULL) {
2163                         path->top_type = entry->type;
2164                         return;
2165                 }
2166         } else if (is_type_array(type)) {
2167                 assert(is_type_array(type));
2168
2169                 top->v.index++;
2170
2171                 if (!type->array.size_constant || top->v.index < type->array.size) {
2172                         return;
2173                 }
2174         } else {
2175                 assert(!is_type_valid(type));
2176                 return;
2177         }
2178
2179         /* we're past the last member of the current sub-aggregate, try if we
2180          * can ascend in the type hierarchy and continue with another subobject */
2181         size_t len = ARR_LEN(path->path);
2182
2183         if (len > top_path_level) {
2184                 ascend_from_subtype(path);
2185                 advance_current_object(path, top_path_level);
2186         } else {
2187                 path->top_type = NULL;
2188         }
2189 }
2190
2191 /**
2192  * skip any {...} blocks until a closing bracket is reached.
2193  */
2194 static void skip_initializers(void)
2195 {
2196         if (token.type == '{')
2197                 next_token();
2198
2199         while (token.type != '}') {
2200                 if (token.type == T_EOF)
2201                         return;
2202                 if (token.type == '{') {
2203                         eat_block();
2204                         continue;
2205                 }
2206                 next_token();
2207         }
2208 }
2209
2210 static initializer_t *create_empty_initializer(void)
2211 {
2212         static initializer_t empty_initializer
2213                 = { .list = { { INITIALIZER_LIST }, 0 } };
2214         return &empty_initializer;
2215 }
2216
2217 /**
2218  * Parse a part of an initialiser for a struct or union,
2219  */
2220 static initializer_t *parse_sub_initializer(type_path_t *path,
2221                 type_t *outer_type, size_t top_path_level,
2222                 parse_initializer_env_t *env)
2223 {
2224         if (token.type == '}') {
2225                 /* empty initializer */
2226                 return create_empty_initializer();
2227         }
2228
2229         type_t *orig_type = path->top_type;
2230         type_t *type      = NULL;
2231
2232         if (orig_type == NULL) {
2233                 /* We are initializing an empty compound. */
2234         } else {
2235                 type = skip_typeref(orig_type);
2236         }
2237
2238         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2239
2240         while (true) {
2241                 designator_t *designator = NULL;
2242                 if (token.type == '.' || token.type == '[') {
2243                         designator = parse_designation();
2244                         goto finish_designator;
2245                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2246                         /* GNU-style designator ("identifier: value") */
2247                         designator = allocate_ast_zero(sizeof(designator[0]));
2248                         designator->source_position = token.source_position;
2249                         designator->symbol          = token.v.symbol;
2250                         eat(T_IDENTIFIER);
2251                         eat(':');
2252
2253 finish_designator:
2254                         /* reset path to toplevel, evaluate designator from there */
2255                         ascend_to(path, top_path_level);
2256                         if (!walk_designator(path, designator, false)) {
2257                                 /* can't continue after designation error */
2258                                 goto end_error;
2259                         }
2260
2261                         initializer_t *designator_initializer
2262                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2263                         designator_initializer->designator.designator = designator;
2264                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2265
2266                         orig_type = path->top_type;
2267                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2268                 }
2269
2270                 initializer_t *sub;
2271
2272                 if (token.type == '{') {
2273                         if (type != NULL && is_type_scalar(type)) {
2274                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2275                         } else {
2276                                 eat('{');
2277                                 if (type == NULL) {
2278                                         if (env->entity != NULL) {
2279                                                 errorf(HERE,
2280                                                      "extra brace group at end of initializer for '%Y'",
2281                                                      env->entity->base.symbol);
2282                                         } else {
2283                                                 errorf(HERE, "extra brace group at end of initializer");
2284                                         }
2285                                 } else
2286                                         descend_into_subtype(path);
2287
2288                                 add_anchor_token('}');
2289                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2290                                                             env);
2291                                 rem_anchor_token('}');
2292
2293                                 if (type != NULL) {
2294                                         ascend_from_subtype(path);
2295                                         expect('}', end_error);
2296                                 } else {
2297                                         expect('}', end_error);
2298                                         goto error_parse_next;
2299                                 }
2300                         }
2301                 } else {
2302                         /* must be an expression */
2303                         expression_t *expression = parse_assignment_expression();
2304                         mark_vars_read(expression, NULL);
2305
2306                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2307                                 errorf(&expression->base.source_position,
2308                                        "Initialisation expression '%E' is not constant",
2309                                        expression);
2310                         }
2311
2312                         if (type == NULL) {
2313                                 /* we are already outside, ... */
2314                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2315                                 if (is_type_compound(outer_type_skip) &&
2316                                     !outer_type_skip->compound.compound->complete) {
2317                                         goto error_parse_next;
2318                                 }
2319                                 goto error_excess;
2320                         }
2321
2322                         /* handle { "string" } special case */
2323                         if ((expression->kind == EXPR_STRING_LITERAL
2324                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2325                                         && outer_type != NULL) {
2326                                 sub = initializer_from_expression(outer_type, expression);
2327                                 if (sub != NULL) {
2328                                         if (token.type == ',') {
2329                                                 next_token();
2330                                         }
2331                                         if (token.type != '}' && warning.other) {
2332                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2333                                                                  orig_type);
2334                                         }
2335                                         /* TODO: eat , ... */
2336                                         return sub;
2337                                 }
2338                         }
2339
2340                         /* descend into subtypes until expression matches type */
2341                         while (true) {
2342                                 orig_type = path->top_type;
2343                                 type      = skip_typeref(orig_type);
2344
2345                                 sub = initializer_from_expression(orig_type, expression);
2346                                 if (sub != NULL) {
2347                                         break;
2348                                 }
2349                                 if (!is_type_valid(type)) {
2350                                         goto end_error;
2351                                 }
2352                                 if (is_type_scalar(type)) {
2353                                         errorf(&expression->base.source_position,
2354                                                         "expression '%E' doesn't match expected type '%T'",
2355                                                         expression, orig_type);
2356                                         goto end_error;
2357                                 }
2358
2359                                 descend_into_subtype(path);
2360                         }
2361                 }
2362
2363                 /* update largest index of top array */
2364                 const type_path_entry_t *first      = &path->path[0];
2365                 type_t                  *first_type = first->type;
2366                 first_type                          = skip_typeref(first_type);
2367                 if (is_type_array(first_type)) {
2368                         size_t index = first->v.index;
2369                         if (index > path->max_index)
2370                                 path->max_index = index;
2371                 }
2372
2373                 if (type != NULL) {
2374                         /* append to initializers list */
2375                         ARR_APP1(initializer_t*, initializers, sub);
2376                 } else {
2377 error_excess:
2378                         if (warning.other) {
2379                                 if (env->entity != NULL) {
2380                                         warningf(HERE, "excess elements in initializer for '%Y'",
2381                                                  env->entity->base.symbol);
2382                                 } else {
2383                                         warningf(HERE, "excess elements in initializer");
2384                                 }
2385                         }
2386                 }
2387
2388 error_parse_next:
2389                 if (token.type == '}') {
2390                         break;
2391                 }
2392                 expect(',', end_error);
2393                 if (token.type == '}') {
2394                         break;
2395                 }
2396
2397                 if (type != NULL) {
2398                         /* advance to the next declaration if we are not at the end */
2399                         advance_current_object(path, top_path_level);
2400                         orig_type = path->top_type;
2401                         if (orig_type != NULL)
2402                                 type = skip_typeref(orig_type);
2403                         else
2404                                 type = NULL;
2405                 }
2406         }
2407
2408         size_t len  = ARR_LEN(initializers);
2409         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2410         initializer_t *result = allocate_ast_zero(size);
2411         result->kind          = INITIALIZER_LIST;
2412         result->list.len      = len;
2413         memcpy(&result->list.initializers, initializers,
2414                len * sizeof(initializers[0]));
2415
2416         DEL_ARR_F(initializers);
2417         ascend_to(path, top_path_level+1);
2418
2419         return result;
2420
2421 end_error:
2422         skip_initializers();
2423         DEL_ARR_F(initializers);
2424         ascend_to(path, top_path_level+1);
2425         return NULL;
2426 }
2427
2428 /**
2429  * Parses an initializer. Parsers either a compound literal
2430  * (env->declaration == NULL) or an initializer of a declaration.
2431  */
2432 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2433 {
2434         type_t        *type      = skip_typeref(env->type);
2435         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2436         initializer_t *result;
2437
2438         if (is_type_scalar(type)) {
2439                 result = parse_scalar_initializer(type, env->must_be_constant);
2440         } else if (token.type == '{') {
2441                 eat('{');
2442
2443                 type_path_t path;
2444                 memset(&path, 0, sizeof(path));
2445                 path.top_type = env->type;
2446                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2447
2448                 descend_into_subtype(&path);
2449
2450                 add_anchor_token('}');
2451                 result = parse_sub_initializer(&path, env->type, 1, env);
2452                 rem_anchor_token('}');
2453
2454                 max_index = path.max_index;
2455                 DEL_ARR_F(path.path);
2456
2457                 expect('}', end_error);
2458         } else {
2459                 /* parse_scalar_initializer() also works in this case: we simply
2460                  * have an expression without {} around it */
2461                 result = parse_scalar_initializer(type, env->must_be_constant);
2462         }
2463
2464         /* §6.7.8:22 array initializers for arrays with unknown size determine
2465          * the array type size */
2466         if (is_type_array(type) && type->array.size_expression == NULL
2467                         && result != NULL) {
2468                 size_t size;
2469                 switch (result->kind) {
2470                 case INITIALIZER_LIST:
2471                         assert(max_index != 0xdeadbeaf);
2472                         size = max_index + 1;
2473                         break;
2474
2475                 case INITIALIZER_STRING:
2476                         size = result->string.string.size;
2477                         break;
2478
2479                 case INITIALIZER_WIDE_STRING:
2480                         size = result->wide_string.string.size;
2481                         break;
2482
2483                 case INITIALIZER_DESIGNATOR:
2484                 case INITIALIZER_VALUE:
2485                         /* can happen for parse errors */
2486                         size = 0;
2487                         break;
2488
2489                 default:
2490                         internal_errorf(HERE, "invalid initializer type");
2491                 }
2492
2493                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2494                 cnst->base.type          = type_size_t;
2495                 cnst->conste.v.int_value = size;
2496
2497                 type_t *new_type = duplicate_type(type);
2498
2499                 new_type->array.size_expression   = cnst;
2500                 new_type->array.size_constant     = true;
2501                 new_type->array.has_implicit_size = true;
2502                 new_type->array.size              = size;
2503                 env->type = new_type;
2504         }
2505
2506         return result;
2507 end_error:
2508         return NULL;
2509 }
2510
2511 static void append_entity(scope_t *scope, entity_t *entity)
2512 {
2513         if (scope->last_entity != NULL) {
2514                 scope->last_entity->base.next = entity;
2515         } else {
2516                 scope->entities = entity;
2517         }
2518         scope->last_entity = entity;
2519 }
2520
2521
2522 static compound_t *parse_compound_type_specifier(bool is_struct)
2523 {
2524         if (is_struct) {
2525                 eat(T_struct);
2526         } else {
2527                 eat(T_union);
2528         }
2529
2530         symbol_t    *symbol   = NULL;
2531         compound_t  *compound = NULL;
2532         attribute_t *attributes = NULL;
2533
2534         if (token.type == T___attribute__) {
2535                 attributes = parse_attributes(NULL);
2536         }
2537
2538         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2539         if (token.type == T_IDENTIFIER) {
2540                 /* the compound has a name, check if we have seen it already */
2541                 symbol = token.v.symbol;
2542                 next_token();
2543
2544                 entity_t *entity = get_tag(symbol, kind);
2545                 if (entity != NULL) {
2546                         compound = &entity->compound;
2547                         if (compound->base.parent_scope != current_scope &&
2548                             (token.type == '{' || token.type == ';')) {
2549                                 /* we're in an inner scope and have a definition. Shadow
2550                                  * existing definition in outer scope */
2551                                 compound = NULL;
2552                         } else if (compound->complete && token.type == '{') {
2553                                 assert(symbol != NULL);
2554                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2555                                        is_struct ? "struct" : "union", symbol,
2556                                        &compound->base.source_position);
2557                                 /* clear members in the hope to avoid further errors */
2558                                 compound->members.entities = NULL;
2559                         }
2560                 }
2561         } else if (token.type != '{') {
2562                 if (is_struct) {
2563                         parse_error_expected("while parsing struct type specifier",
2564                                              T_IDENTIFIER, '{', NULL);
2565                 } else {
2566                         parse_error_expected("while parsing union type specifier",
2567                                              T_IDENTIFIER, '{', NULL);
2568                 }
2569
2570                 return NULL;
2571         }
2572
2573         if (compound == NULL) {
2574                 entity_t *entity = allocate_entity_zero(kind);
2575                 compound         = &entity->compound;
2576
2577                 compound->alignment            = 1;
2578                 compound->base.namespc         = NAMESPACE_TAG;
2579                 compound->base.source_position = token.source_position;
2580                 compound->base.symbol          = symbol;
2581                 compound->base.parent_scope    = current_scope;
2582                 if (symbol != NULL) {
2583                         environment_push(entity);
2584                 }
2585                 append_entity(current_scope, entity);
2586         }
2587
2588         if (token.type == '{') {
2589                 parse_compound_type_entries(compound);
2590
2591                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2592                 if (symbol == NULL) {
2593                         assert(anonymous_entity == NULL);
2594                         anonymous_entity = (entity_t*)compound;
2595                 }
2596         }
2597
2598         if (attributes != NULL) {
2599                 handle_entity_attributes(attributes, (entity_t*) compound);
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 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2982 {
2983         type_t            *type              = NULL;
2984         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2985         unsigned           type_specifiers   = 0;
2986         bool               newtype           = false;
2987         bool               saw_error         = false;
2988         bool               old_gcc_extension = in_gcc_extension;
2989
2990         specifiers->source_position = token.source_position;
2991
2992         while (true) {
2993                 specifiers->attributes = parse_attributes(specifiers->attributes);
2994
2995                 switch (token.type) {
2996                 /* storage class */
2997 #define MATCH_STORAGE_CLASS(token, class)                                  \
2998                 case token:                                                        \
2999                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3000                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3001                         }                                                              \
3002                         specifiers->storage_class = class;                             \
3003                         if (specifiers->thread_local)                                  \
3004                                 goto check_thread_storage_class;                           \
3005                         next_token();                                                  \
3006                         break;
3007
3008                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3009                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3010                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3011                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3012                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3013
3014                 case T__declspec:
3015                         specifiers->attributes
3016                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
3017                         break;
3018
3019                 case T___thread:
3020                         if (specifiers->thread_local) {
3021                                 errorf(HERE, "duplicate '__thread'");
3022                         } else {
3023                                 specifiers->thread_local = true;
3024 check_thread_storage_class:
3025                                 switch (specifiers->storage_class) {
3026                                         case STORAGE_CLASS_EXTERN:
3027                                         case STORAGE_CLASS_NONE:
3028                                         case STORAGE_CLASS_STATIC:
3029                                                 break;
3030
3031                                                 char const* wrong;
3032                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3033                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3034                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3035 wrong_thread_stoarge_class:
3036                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3037                                                 break;
3038                                 }
3039                         }
3040                         next_token();
3041                         break;
3042
3043                 /* type qualifiers */
3044 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3045                 case token:                                                     \
3046                         qualifiers |= qualifier;                                    \
3047                         next_token();                                               \
3048                         break
3049
3050                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3051                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3052                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3053                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3054                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3055                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3056                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3057                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3058
3059                 case T___extension__:
3060                         next_token();
3061                         in_gcc_extension = true;
3062                         break;
3063
3064                 /* type specifiers */
3065 #define MATCH_SPECIFIER(token, specifier, name)                         \
3066                 case token:                                                     \
3067                         if (type_specifiers & specifier) {                           \
3068                                 errorf(HERE, "multiple " name " type specifiers given"); \
3069                         } else {                                                    \
3070                                 type_specifiers |= specifier;                           \
3071                         }                                                           \
3072                         next_token();                                               \
3073                         break
3074
3075                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3076                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3077                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3078                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3079                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3080                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3081                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3082                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3083                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3084                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3085                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3086                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3087                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3088                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3089                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3090                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3091                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3092                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3093
3094                 case T_inline:
3095                         next_token();
3096                         specifiers->is_inline = true;
3097                         break;
3098
3099 #if 0
3100                 case T__forceinline:
3101                         next_token();
3102                         specifiers->modifiers |= DM_FORCEINLINE;
3103                         break;
3104 #endif
3105
3106                 case T_long:
3107                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3108                                 errorf(HERE, "multiple type specifiers given");
3109                         } else if (type_specifiers & SPECIFIER_LONG) {
3110                                 type_specifiers |= SPECIFIER_LONG_LONG;
3111                         } else {
3112                                 type_specifiers |= SPECIFIER_LONG;
3113                         }
3114                         next_token();
3115                         break;
3116
3117 #define CHECK_DOUBLE_TYPE()        \
3118                         if ( type != NULL)     \
3119                                 errorf(HERE, "multiple data types in declaration specifiers");
3120
3121                 case T_struct:
3122                         CHECK_DOUBLE_TYPE();
3123                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3124
3125                         type->compound.compound = parse_compound_type_specifier(true);
3126                         break;
3127                 case T_union:
3128                         CHECK_DOUBLE_TYPE();
3129                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3130                         type->compound.compound = parse_compound_type_specifier(false);
3131                         break;
3132                 case T_enum:
3133                         CHECK_DOUBLE_TYPE();
3134                         type = parse_enum_specifier();
3135                         break;
3136                 case T___typeof__:
3137                         CHECK_DOUBLE_TYPE();
3138                         type = parse_typeof();
3139                         break;
3140                 case T___builtin_va_list:
3141                         CHECK_DOUBLE_TYPE();
3142                         type = duplicate_type(type_valist);
3143                         next_token();
3144                         break;
3145
3146                 case T_IDENTIFIER: {
3147                         /* only parse identifier if we haven't found a type yet */
3148                         if (type != NULL || type_specifiers != 0) {
3149                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3150                                  * declaration, so it doesn't generate errors about expecting '(' or
3151                                  * '{' later on. */
3152                                 switch (look_ahead(1)->type) {
3153                                         STORAGE_CLASSES
3154                                         TYPE_SPECIFIERS
3155                                         case T_const:
3156                                         case T_restrict:
3157                                         case T_volatile:
3158                                         case T_inline:
3159                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3160                                         case T_IDENTIFIER:
3161                                         case '&':
3162                                         case '*':
3163                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3164                                                 next_token();
3165                                                 continue;
3166
3167                                         default:
3168                                                 goto finish_specifiers;
3169                                 }
3170                         }
3171
3172                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3173                         if (typedef_type == NULL) {
3174                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3175                                  * declaration, so it doesn't generate 'implicit int' followed by more
3176                                  * errors later on. */
3177                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3178                                 switch (la1_type) {
3179                                         DECLARATION_START
3180                                         case T_IDENTIFIER:
3181                                         case '&':
3182                                         case '*': {
3183                                                 errorf(HERE, "%K does not name a type", &token);
3184
3185                                                 entity_t *entity =
3186                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3187
3188                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3189                                                 type->typedeft.typedefe = &entity->typedefe;
3190
3191                                                 next_token();
3192                                                 saw_error = true;
3193                                                 if (la1_type == '&' || la1_type == '*')
3194                                                         goto finish_specifiers;
3195                                                 continue;
3196                                         }
3197
3198                                         default:
3199                                                 goto finish_specifiers;
3200                                 }
3201                         }
3202
3203                         next_token();
3204                         type = typedef_type;
3205                         break;
3206                 }
3207
3208                 /* function specifier */
3209                 default:
3210                         goto finish_specifiers;
3211                 }
3212         }
3213
3214 finish_specifiers:
3215         specifiers->attributes = parse_attributes(specifiers->attributes);
3216
3217         in_gcc_extension = old_gcc_extension;
3218
3219         if (type == NULL || (saw_error && type_specifiers != 0)) {
3220                 atomic_type_kind_t atomic_type;
3221
3222                 /* match valid basic types */
3223                 switch (type_specifiers) {
3224                 case SPECIFIER_VOID:
3225                         atomic_type = ATOMIC_TYPE_VOID;
3226                         break;
3227                 case SPECIFIER_WCHAR_T:
3228                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3229                         break;
3230                 case SPECIFIER_CHAR:
3231                         atomic_type = ATOMIC_TYPE_CHAR;
3232                         break;
3233                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3234                         atomic_type = ATOMIC_TYPE_SCHAR;
3235                         break;
3236                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3237                         atomic_type = ATOMIC_TYPE_UCHAR;
3238                         break;
3239                 case SPECIFIER_SHORT:
3240                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3241                 case SPECIFIER_SHORT | SPECIFIER_INT:
3242                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3243                         atomic_type = ATOMIC_TYPE_SHORT;
3244                         break;
3245                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3246                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3247                         atomic_type = ATOMIC_TYPE_USHORT;
3248                         break;
3249                 case SPECIFIER_INT:
3250                 case SPECIFIER_SIGNED:
3251                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3252                         atomic_type = ATOMIC_TYPE_INT;
3253                         break;
3254                 case SPECIFIER_UNSIGNED:
3255                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3256                         atomic_type = ATOMIC_TYPE_UINT;
3257                         break;
3258                 case SPECIFIER_LONG:
3259                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3260                 case SPECIFIER_LONG | SPECIFIER_INT:
3261                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3262                         atomic_type = ATOMIC_TYPE_LONG;
3263                         break;
3264                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3265                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3266                         atomic_type = ATOMIC_TYPE_ULONG;
3267                         break;
3268
3269                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3270                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3271                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3272                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3273                         | SPECIFIER_INT:
3274                         atomic_type = ATOMIC_TYPE_LONGLONG;
3275                         goto warn_about_long_long;
3276
3277                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3278                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3279                         | SPECIFIER_INT:
3280                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3281 warn_about_long_long:
3282                         if (warning.long_long) {
3283                                 warningf(&specifiers->source_position,
3284                                          "ISO C90 does not support 'long long'");
3285                         }
3286                         break;
3287
3288                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3289                         atomic_type = unsigned_int8_type_kind;
3290                         break;
3291
3292                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3293                         atomic_type = unsigned_int16_type_kind;
3294                         break;
3295
3296                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3297                         atomic_type = unsigned_int32_type_kind;
3298                         break;
3299
3300                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3301                         atomic_type = unsigned_int64_type_kind;
3302                         break;
3303
3304                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3305                         atomic_type = unsigned_int128_type_kind;
3306                         break;
3307
3308                 case SPECIFIER_INT8:
3309                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3310                         atomic_type = int8_type_kind;
3311                         break;
3312
3313                 case SPECIFIER_INT16:
3314                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3315                         atomic_type = int16_type_kind;
3316                         break;
3317
3318                 case SPECIFIER_INT32:
3319                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3320                         atomic_type = int32_type_kind;
3321                         break;
3322
3323                 case SPECIFIER_INT64:
3324                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3325                         atomic_type = int64_type_kind;
3326                         break;
3327
3328                 case SPECIFIER_INT128:
3329                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3330                         atomic_type = int128_type_kind;
3331                         break;
3332
3333                 case SPECIFIER_FLOAT:
3334                         atomic_type = ATOMIC_TYPE_FLOAT;
3335                         break;
3336                 case SPECIFIER_DOUBLE:
3337                         atomic_type = ATOMIC_TYPE_DOUBLE;
3338                         break;
3339                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3340                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3341                         break;
3342                 case SPECIFIER_BOOL:
3343                         atomic_type = ATOMIC_TYPE_BOOL;
3344                         break;
3345                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3346                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3347                         atomic_type = ATOMIC_TYPE_FLOAT;
3348                         break;
3349                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3350                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3351                         atomic_type = ATOMIC_TYPE_DOUBLE;
3352                         break;
3353                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3354                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3355                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3356                         break;
3357                 default:
3358                         /* invalid specifier combination, give an error message */
3359                         if (type_specifiers == 0) {
3360                                 if (saw_error)
3361                                         goto end_error;
3362
3363                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3364                                 if (!(c_mode & _CXX) && !strict_mode) {
3365                                         if (warning.implicit_int) {
3366                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3367                                         }
3368                                         atomic_type = ATOMIC_TYPE_INT;
3369                                         break;
3370                                 } else {
3371                                         errorf(HERE, "no type specifiers given in declaration");
3372                                 }
3373                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3374                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3375                                 errorf(HERE, "signed and unsigned specifiers given");
3376                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3377                                 errorf(HERE, "only integer types can be signed or unsigned");
3378                         } else {
3379                                 errorf(HERE, "multiple datatypes in declaration");
3380                         }
3381                         goto end_error;
3382                 }
3383
3384                 if (type_specifiers & SPECIFIER_COMPLEX) {
3385                         type                = allocate_type_zero(TYPE_COMPLEX);
3386                         type->complex.akind = atomic_type;
3387                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3388                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3389                         type->imaginary.akind = atomic_type;
3390                 } else {
3391                         type                 = allocate_type_zero(TYPE_ATOMIC);
3392                         type->atomic.akind   = atomic_type;
3393                 }
3394                 newtype = true;
3395         } else if (type_specifiers != 0) {
3396                 errorf(HERE, "multiple datatypes in declaration");
3397         }
3398
3399         /* FIXME: check type qualifiers here */
3400         type->base.qualifiers = qualifiers;
3401
3402         if (newtype) {
3403                 type = identify_new_type(type);
3404         } else {
3405                 type = typehash_insert(type);
3406         }
3407
3408         if (specifiers->attributes != NULL)
3409                 type = handle_type_attributes(specifiers->attributes, type);
3410         specifiers->type = type;
3411         return;
3412
3413 end_error:
3414         specifiers->type = type_error_type;
3415         return;
3416 }
3417
3418 static type_qualifiers_t parse_type_qualifiers(void)
3419 {
3420         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3421
3422         while (true) {
3423                 switch (token.type) {
3424                 /* type qualifiers */
3425                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3426                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3427                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3428                 /* microsoft extended type modifiers */
3429                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3430                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3431                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3432                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3433                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3434
3435                 default:
3436                         return qualifiers;
3437                 }
3438         }
3439 }
3440
3441 /**
3442  * Parses an K&R identifier list
3443  */
3444 static void parse_identifier_list(scope_t *scope)
3445 {
3446         do {
3447                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
3448                 entity->base.source_position = token.source_position;
3449                 entity->base.namespc         = NAMESPACE_NORMAL;
3450                 entity->base.symbol          = token.v.symbol;
3451                 /* a K&R parameter has no type, yet */
3452                 next_token();
3453
3454                 if (scope != NULL)
3455                         append_entity(scope, entity);
3456
3457                 if (token.type != ',') {
3458                         break;
3459                 }
3460                 next_token();
3461         } while (token.type == T_IDENTIFIER);
3462 }
3463
3464 static entity_t *parse_parameter(void)
3465 {
3466         declaration_specifiers_t specifiers;
3467         memset(&specifiers, 0, sizeof(specifiers));
3468
3469         parse_declaration_specifiers(&specifiers);
3470
3471         entity_t *entity = parse_declarator(&specifiers,
3472                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3473         anonymous_entity = NULL;
3474         return entity;
3475 }
3476
3477 static void semantic_parameter_incomplete(const entity_t *entity)
3478 {
3479         assert(entity->kind == ENTITY_PARAMETER);
3480
3481         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3482          *             list in a function declarator that is part of a
3483          *             definition of that function shall not have
3484          *             incomplete type. */
3485         type_t *type = skip_typeref(entity->declaration.type);
3486         if (is_type_incomplete(type)) {
3487                 errorf(&entity->base.source_position,
3488                                 "parameter '%#T' has incomplete type",
3489                                 entity->declaration.type, entity->base.symbol);
3490         }
3491 }
3492
3493 static bool has_parameters(void)
3494 {
3495         /* func(void) is not a parameter */
3496         if (token.type == T_IDENTIFIER) {
3497                 entity_t const *const entity = get_entity(token.v.symbol, NAMESPACE_NORMAL);
3498                 if (entity == NULL)
3499                         return true;
3500                 if (entity->kind != ENTITY_TYPEDEF)
3501                         return true;
3502                 if (skip_typeref(entity->typedefe.type) != type_void)
3503                         return true;
3504         } else if (token.type != T_void) {
3505                 return true;
3506         }
3507         if (look_ahead(1)->type != ')')
3508                 return true;
3509         next_token();
3510         return false;
3511 }
3512
3513 /**
3514  * Parses function type parameters (and optionally creates variable_t entities
3515  * for them in a scope)
3516  */
3517 static void parse_parameters(function_type_t *type, scope_t *scope)
3518 {
3519         eat('(');
3520         add_anchor_token(')');
3521         int saved_comma_state = save_and_reset_anchor_state(',');
3522
3523         if (token.type == T_IDENTIFIER &&
3524             !is_typedef_symbol(token.v.symbol)) {
3525                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3526                 if (la1_type == ',' || la1_type == ')') {
3527                         type->kr_style_parameters = true;
3528                         parse_identifier_list(scope);
3529                         goto parameters_finished;
3530                 }
3531         }
3532
3533         if (token.type == ')') {
3534                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3535                 if (!(c_mode & _CXX))
3536                         type->unspecified_parameters = true;
3537                 goto parameters_finished;
3538         }
3539
3540         if (has_parameters()) {
3541                 function_parameter_t **anchor = &type->parameters;
3542                 for (;;) {
3543                         switch (token.type) {
3544                         case T_DOTDOTDOT:
3545                                 next_token();
3546                                 type->variadic = true;
3547                                 goto parameters_finished;
3548
3549                         case T_IDENTIFIER:
3550                         case T___extension__:
3551                         DECLARATION_START
3552                         {
3553                                 entity_t *entity = parse_parameter();
3554                                 if (entity->kind == ENTITY_TYPEDEF) {
3555                                         errorf(&entity->base.source_position,
3556                                                         "typedef not allowed as function parameter");
3557                                         break;
3558                                 }
3559                                 assert(is_declaration(entity));
3560
3561                                 semantic_parameter_incomplete(entity);
3562
3563                                 function_parameter_t *const parameter =
3564                                         allocate_parameter(entity->declaration.type);
3565
3566                                 if (scope != NULL) {
3567                                         append_entity(scope, entity);
3568                                 }
3569
3570                                 *anchor = parameter;
3571                                 anchor  = &parameter->next;
3572                                 break;
3573                         }
3574
3575                         default:
3576                                 goto parameters_finished;
3577                         }
3578                         if (token.type != ',') {
3579                                 goto parameters_finished;
3580                         }
3581                         next_token();
3582                 }
3583         }
3584
3585
3586 parameters_finished:
3587         rem_anchor_token(')');
3588         expect(')', end_error);
3589
3590 end_error:
3591         restore_anchor_state(',', saved_comma_state);
3592 }
3593
3594 typedef enum construct_type_kind_t {
3595         CONSTRUCT_INVALID,
3596         CONSTRUCT_POINTER,
3597         CONSTRUCT_REFERENCE,
3598         CONSTRUCT_FUNCTION,
3599         CONSTRUCT_ARRAY
3600 } construct_type_kind_t;
3601
3602 typedef union construct_type_t construct_type_t;
3603
3604 typedef struct construct_type_base_t {
3605         construct_type_kind_t  kind;
3606         construct_type_t      *next;
3607 } construct_type_base_t;
3608
3609 typedef struct parsed_pointer_t {
3610         construct_type_base_t  base;
3611         type_qualifiers_t      type_qualifiers;
3612         variable_t            *base_variable;  /**< MS __based extension. */
3613 } parsed_pointer_t;
3614
3615 typedef struct parsed_reference_t {
3616         construct_type_base_t base;
3617 } parsed_reference_t;
3618
3619 typedef struct construct_function_type_t {
3620         construct_type_base_t  base;
3621         type_t                *function_type;
3622 } construct_function_type_t;
3623
3624 typedef struct parsed_array_t {
3625         construct_type_base_t  base;
3626         type_qualifiers_t      type_qualifiers;
3627         bool                   is_static;
3628         bool                   is_variable;
3629         expression_t          *size;
3630 } parsed_array_t;
3631
3632 union construct_type_t {
3633         construct_type_kind_t     kind;
3634         construct_type_base_t     base;
3635         parsed_pointer_t          pointer;
3636         parsed_reference_t        reference;
3637         construct_function_type_t function;
3638         parsed_array_t            array;
3639 };
3640
3641 static construct_type_t *parse_pointer_declarator(void)
3642 {
3643         eat('*');
3644
3645         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
3646         memset(pointer, 0, sizeof(pointer[0]));
3647         pointer->base.kind       = CONSTRUCT_POINTER;
3648         pointer->type_qualifiers = parse_type_qualifiers();
3649         //pointer->base_variable       = base_variable;
3650
3651         return (construct_type_t*) pointer;
3652 }
3653
3654 static construct_type_t *parse_reference_declarator(void)
3655 {
3656         eat('&');
3657
3658         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
3659         parsed_reference_t *reference = &cons->reference;
3660         memset(reference, 0, sizeof(*reference));
3661         cons->kind = CONSTRUCT_REFERENCE;
3662
3663         return cons;
3664 }
3665
3666 static construct_type_t *parse_array_declarator(void)
3667 {
3668         eat('[');
3669         add_anchor_token(']');
3670
3671         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
3672         parsed_array_t   *array = &cons->array;
3673         memset(array, 0, sizeof(*array));
3674         cons->kind = CONSTRUCT_ARRAY;
3675
3676         if (token.type == T_static) {
3677                 array->is_static = true;
3678                 next_token();
3679         }
3680
3681         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3682         if (type_qualifiers != 0) {
3683                 if (token.type == T_static) {
3684                         array->is_static = true;
3685                         next_token();
3686                 }
3687         }
3688         array->type_qualifiers = type_qualifiers;
3689
3690         if (token.type == '*' && look_ahead(1)->type == ']') {
3691                 array->is_variable = true;
3692                 next_token();
3693         } else if (token.type != ']') {
3694                 expression_t *const size = parse_assignment_expression();
3695
3696                 /* §6.7.5.2:1  Array size must have integer type */
3697                 type_t *const orig_type = size->base.type;
3698                 type_t *const type      = skip_typeref(orig_type);
3699                 if (!is_type_integer(type) && is_type_valid(type)) {
3700                         errorf(&size->base.source_position,
3701                                "array size '%E' must have integer type but has type '%T'",
3702                                size, orig_type);
3703                 }
3704
3705                 array->size = size;
3706                 mark_vars_read(size, NULL);
3707         }
3708
3709         rem_anchor_token(']');
3710         expect(']', end_error);
3711
3712 end_error:
3713         return cons;
3714 }
3715
3716 static construct_type_t *parse_function_declarator(scope_t *scope)
3717 {
3718         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3719         function_type_t *ftype = &type->function;
3720
3721         ftype->linkage            = current_linkage;
3722         ftype->calling_convention = CC_DEFAULT;
3723
3724         parse_parameters(ftype, scope);
3725
3726         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
3727         construct_function_type_t *function = &cons->function;
3728         memset(function, 0, sizeof(*function));
3729         cons->kind              = CONSTRUCT_FUNCTION;
3730         function->function_type = type;
3731
3732         return cons;
3733 }
3734
3735 typedef struct parse_declarator_env_t {
3736         bool               may_be_abstract : 1;
3737         bool               must_be_abstract : 1;
3738         decl_modifiers_t   modifiers;
3739         symbol_t          *symbol;
3740         source_position_t  source_position;
3741         scope_t            parameters;
3742         attribute_t       *attributes;
3743 } parse_declarator_env_t;
3744
3745 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3746 {
3747         /* construct a single linked list of construct_type_t's which describe
3748          * how to construct the final declarator type */
3749         construct_type_t  *first      = NULL;
3750         construct_type_t **anchor     = &first;
3751
3752         env->attributes = parse_attributes(env->attributes);
3753
3754         for (;;) {
3755                 construct_type_t *type;
3756                 //variable_t       *based = NULL; /* MS __based extension */
3757                 switch (token.type) {
3758                         case '&':
3759                                 if (!(c_mode & _CXX))
3760                                         errorf(HERE, "references are only available for C++");
3761                                 type = parse_reference_declarator();
3762                                 break;
3763
3764                         case T__based: {
3765 #if 0
3766                                 source_position_t const pos = *HERE;
3767                                 next_token();
3768                                 expect('(', end_error);
3769                                 add_anchor_token(')');
3770                                 based = parse_microsoft_based();
3771                                 rem_anchor_token(')');
3772                                 expect(')', end_error);
3773                                 if (token.type != '*') {
3774                                         if (token.type == T__based) {
3775                                                 errorf(&pos, "__based type modifier specified more than once");
3776                                         } else if (warning.other) {
3777                                                 warningf(&pos,
3778                                                                 "__based does not precede a pointer declarator, ignored");
3779                                         }
3780                                         continue;
3781                                 }
3782 #else
3783                                 panic("based currently disabled");
3784 #endif
3785                                 /* FALLTHROUGH */
3786                         }
3787
3788                         case '*':
3789                                 type = parse_pointer_declarator();
3790                                 break;
3791
3792                         default:
3793                                 goto ptr_operator_end;
3794                 }
3795
3796                 *anchor = type;
3797                 anchor  = &type->base.next;
3798
3799                 /* TODO: find out if this is correct */
3800                 env->attributes = parse_attributes(env->attributes);
3801         }
3802
3803 ptr_operator_end: ;
3804 #if 0
3805         modifiers      |= env->modifiers;
3806         env->modifiers  = modifiers;
3807 #endif
3808
3809         construct_type_t *inner_types = NULL;
3810
3811         switch (token.type) {
3812         case T_IDENTIFIER:
3813                 if (env->must_be_abstract) {
3814                         errorf(HERE, "no identifier expected in typename");
3815                 } else {
3816                         env->symbol          = token.v.symbol;
3817                         env->source_position = token.source_position;
3818                 }
3819                 next_token();
3820                 break;
3821         case '(':
3822                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3823                  * interpreted as ``function with no parameter specification'', rather
3824                  * than redundant parentheses around the omitted identifier. */
3825                 if (look_ahead(1)->type != ')') {
3826                         next_token();
3827                         add_anchor_token(')');
3828                         inner_types = parse_inner_declarator(env);
3829                         if (inner_types != NULL) {
3830                                 /* All later declarators only modify the return type */
3831                                 env->must_be_abstract = true;
3832                         }
3833                         rem_anchor_token(')');
3834                         expect(')', end_error);
3835                 }
3836                 break;
3837         default:
3838                 if (env->may_be_abstract)
3839                         break;
3840                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3841                 eat_until_anchor();
3842                 return NULL;
3843         }
3844
3845         construct_type_t **const p = anchor;
3846
3847         for (;;) {
3848                 construct_type_t *type;
3849                 switch (token.type) {
3850                 case '(': {
3851                         scope_t *scope = NULL;
3852                         if (!env->must_be_abstract) {
3853                                 scope = &env->parameters;
3854                         }
3855
3856                         type = parse_function_declarator(scope);
3857                         break;
3858                 }
3859                 case '[':
3860                         type = parse_array_declarator();
3861                         break;
3862                 default:
3863                         goto declarator_finished;
3864                 }
3865
3866                 /* insert in the middle of the list (at p) */
3867                 type->base.next = *p;
3868                 *p              = type;
3869                 if (anchor == p)
3870                         anchor = &type->base.next;
3871         }
3872
3873 declarator_finished:
3874         /* append inner_types at the end of the list, we don't to set anchor anymore
3875          * as it's not needed anymore */
3876         *anchor = inner_types;
3877
3878         return first;
3879 end_error:
3880         return NULL;
3881 }
3882
3883 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
3884 {
3885         construct_type_t *iter = construct_list;
3886         for (; iter != NULL; iter = iter->base.next) {
3887                 switch (iter->kind) {
3888                 case CONSTRUCT_INVALID:
3889                         break;
3890                 case CONSTRUCT_FUNCTION: {
3891                         construct_function_type_t *function      = &iter->function;
3892                         type_t                    *function_type = function->function_type;
3893
3894                         function_type->function.return_type = type;
3895
3896                         type_t *skipped_return_type = skip_typeref(type);
3897                         /* §6.7.5.3:1 */
3898                         if (is_type_function(skipped_return_type)) {
3899                                 errorf(HERE, "function returning function is not allowed");
3900                         } else if (is_type_array(skipped_return_type)) {
3901                                 errorf(HERE, "function returning array is not allowed");
3902                         } else {
3903                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3904                                         warningf(HERE,
3905                                                 "type qualifiers in return type of function type are meaningless");
3906                                 }
3907                         }
3908
3909                         /* The function type was constructed earlier.  Freeing it here will
3910                          * destroy other types. */
3911                         type = typehash_insert(function_type);
3912                         continue;
3913                 }
3914
3915                 case CONSTRUCT_POINTER: {
3916                         if (is_type_reference(skip_typeref(type)))
3917                                 errorf(HERE, "cannot declare a pointer to reference");
3918
3919                         parsed_pointer_t *pointer = &iter->pointer;
3920                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3921                         continue;
3922                 }
3923
3924                 case CONSTRUCT_REFERENCE:
3925                         if (is_type_reference(skip_typeref(type)))
3926                                 errorf(HERE, "cannot declare a reference to reference");
3927
3928                         type = make_reference_type(type);
3929                         continue;
3930
3931                 case CONSTRUCT_ARRAY: {
3932                         if (is_type_reference(skip_typeref(type)))
3933                                 errorf(HERE, "cannot declare an array of references");
3934
3935                         parsed_array_t *array      = &iter->array;
3936                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3937
3938                         expression_t *size_expression = array->size;
3939                         if (size_expression != NULL) {
3940                                 size_expression
3941                                         = create_implicit_cast(size_expression, type_size_t);
3942                         }
3943
3944                         array_type->base.qualifiers       = array->type_qualifiers;
3945                         array_type->array.element_type    = type;
3946                         array_type->array.is_static       = array->is_static;
3947                         array_type->array.is_variable     = array->is_variable;
3948                         array_type->array.size_expression = size_expression;
3949
3950                         if (size_expression != NULL) {
3951                                 if (is_constant_expression(size_expression)) {
3952                                         long const size
3953                                                 = fold_constant_to_int(size_expression);
3954                                         array_type->array.size          = size;
3955                                         array_type->array.size_constant = true;
3956                                         /* §6.7.5.2:1  If the expression is a constant expression, it shall
3957                                          * have a value greater than zero. */
3958                                         if (size <= 0) {
3959                                                 if (size < 0 || !GNU_MODE) {
3960                                                         errorf(&size_expression->base.source_position,
3961                                                                         "size of array must be greater than zero");
3962                                                 } else if (warning.other) {
3963                                                         warningf(&size_expression->base.source_position,
3964                                                                         "zero length arrays are a GCC extension");
3965                                                 }
3966                                         }
3967                                 } else {
3968                                         array_type->array.is_vla = true;
3969                                 }
3970                         }
3971
3972                         type_t *skipped_type = skip_typeref(type);
3973                         /* §6.7.5.2:1 */
3974                         if (is_type_incomplete(skipped_type)) {
3975                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
3976                         } else if (is_type_function(skipped_type)) {
3977                                 errorf(HERE, "array of functions is not allowed");
3978                         }
3979                         type = identify_new_type(array_type);
3980                         continue;
3981                 }
3982                 }
3983                 internal_errorf(HERE, "invalid type construction found");
3984         }
3985
3986         return type;
3987 }
3988
3989 static type_t *automatic_type_conversion(type_t *orig_type);
3990
3991 static type_t *semantic_parameter(const source_position_t *pos,
3992                                   type_t *type,
3993                                   const declaration_specifiers_t *specifiers,
3994                                   symbol_t *symbol)
3995 {
3996         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3997          *             shall be adjusted to ``qualified pointer to type'',
3998          *             [...]
3999          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4000          *             type'' shall be adjusted to ``pointer to function
4001          *             returning type'', as in 6.3.2.1. */
4002         type = automatic_type_conversion(type);
4003
4004         if (specifiers->is_inline && is_type_valid(type)) {
4005                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
4006         }
4007
4008         /* §6.9.1:6  The declarations in the declaration list shall contain
4009          *           no storage-class specifier other than register and no
4010          *           initializations. */
4011         if (specifiers->thread_local || (
4012                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4013                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4014            ) {
4015                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
4016         }
4017
4018         /* delay test for incomplete type, because we might have (void)
4019          * which is legal but incomplete... */
4020
4021         return type;
4022 }
4023
4024 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4025                                   declarator_flags_t flags)
4026 {
4027         parse_declarator_env_t env;
4028         memset(&env, 0, sizeof(env));
4029         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
4030
4031         construct_type_t *construct_type = parse_inner_declarator(&env);
4032         type_t           *orig_type      =
4033                 construct_declarator_type(construct_type, specifiers->type);
4034         type_t           *type           = skip_typeref(orig_type);
4035
4036         if (construct_type != NULL) {
4037                 obstack_free(&temp_obst, construct_type);
4038         }
4039
4040         attribute_t *attributes = parse_attributes(env.attributes);
4041         /* append (shared) specifier attribute behind attributes of this
4042            declarator */
4043         if (attributes != NULL) {
4044                 attribute_t *last = attributes;
4045                 while (last->next != NULL)
4046                         last = last->next;
4047                 last->next = specifiers->attributes;
4048         } else {
4049                 attributes = specifiers->attributes;
4050         }
4051
4052         entity_t *entity;
4053         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4054                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4055                 entity->base.symbol          = env.symbol;
4056                 entity->base.source_position = env.source_position;
4057                 entity->typedefe.type        = orig_type;
4058
4059                 if (anonymous_entity != NULL) {
4060                         if (is_type_compound(type)) {
4061                                 assert(anonymous_entity->compound.alias == NULL);
4062                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4063                                        anonymous_entity->kind == ENTITY_UNION);
4064                                 anonymous_entity->compound.alias = entity;
4065                                 anonymous_entity = NULL;
4066                         } else if (is_type_enum(type)) {
4067                                 assert(anonymous_entity->enume.alias == NULL);
4068                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4069                                 anonymous_entity->enume.alias = entity;
4070                                 anonymous_entity = NULL;
4071                         }
4072                 }
4073         } else {
4074                 /* create a declaration type entity */
4075                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4076                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4077
4078                         if (env.symbol != NULL) {
4079                                 if (specifiers->is_inline && is_type_valid(type)) {
4080                                         errorf(&env.source_position,
4081                                                         "compound member '%Y' declared 'inline'", env.symbol);
4082                                 }
4083
4084                                 if (specifiers->thread_local ||
4085                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4086                                         errorf(&env.source_position,
4087                                                         "compound member '%Y' must have no storage class",
4088                                                         env.symbol);
4089                                 }
4090                         }
4091                 } else if (flags & DECL_IS_PARAMETER) {
4092                         orig_type = semantic_parameter(&env.source_position, orig_type,
4093                                                        specifiers, env.symbol);
4094
4095                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4096                 } else if (is_type_function(type)) {
4097                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4098
4099                         entity->function.is_inline  = specifiers->is_inline;
4100                         entity->function.parameters = env.parameters;
4101
4102                         if (env.symbol != NULL) {
4103                                 /* this needs fixes for C++ */
4104                                 bool in_function_scope = current_function != NULL;
4105
4106                                 if (specifiers->thread_local || (
4107                                       specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4108                                           specifiers->storage_class != STORAGE_CLASS_NONE   &&
4109                                           (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
4110                                    )) {
4111                                         errorf(&env.source_position,
4112                                                         "invalid storage class for function '%Y'", env.symbol);
4113                                 }
4114                         }
4115                 } else {
4116                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4117
4118                         entity->variable.thread_local = specifiers->thread_local;
4119
4120                         if (env.symbol != NULL) {
4121                                 if (specifiers->is_inline && is_type_valid(type)) {
4122                                         errorf(&env.source_position,
4123                                                         "variable '%Y' declared 'inline'", env.symbol);
4124                                 }
4125
4126                                 bool invalid_storage_class = false;
4127                                 if (current_scope == file_scope) {
4128                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4129                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4130                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4131                                                 invalid_storage_class = true;
4132                                         }
4133                                 } else {
4134                                         if (specifiers->thread_local &&
4135                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4136                                                 invalid_storage_class = true;
4137                                         }
4138                                 }
4139                                 if (invalid_storage_class) {
4140                                         errorf(&env.source_position,
4141                                                         "invalid storage class for variable '%Y'", env.symbol);
4142                                 }
4143                         }
4144                 }
4145
4146                 if (env.symbol != NULL) {
4147                         entity->base.symbol          = env.symbol;
4148                         entity->base.source_position = env.source_position;
4149                 } else {
4150                         entity->base.source_position = specifiers->source_position;
4151                 }
4152                 entity->base.namespc           = NAMESPACE_NORMAL;
4153                 entity->declaration.type       = orig_type;
4154                 entity->declaration.alignment  = get_type_alignment(orig_type);
4155                 entity->declaration.modifiers  = env.modifiers;
4156                 entity->declaration.attributes = attributes;
4157
4158                 storage_class_t storage_class = specifiers->storage_class;
4159                 entity->declaration.declared_storage_class = storage_class;
4160
4161                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
4162                         storage_class = STORAGE_CLASS_AUTO;
4163                 entity->declaration.storage_class = storage_class;
4164         }
4165
4166         if (attributes != NULL) {
4167                 handle_entity_attributes(attributes, entity);
4168         }
4169
4170         return entity;
4171 }
4172
4173 static type_t *parse_abstract_declarator(type_t *base_type)
4174 {
4175         parse_declarator_env_t env;
4176         memset(&env, 0, sizeof(env));
4177         env.may_be_abstract = true;
4178         env.must_be_abstract = true;
4179
4180         construct_type_t *construct_type = parse_inner_declarator(&env);
4181
4182         type_t *result = construct_declarator_type(construct_type, base_type);
4183         if (construct_type != NULL) {
4184                 obstack_free(&temp_obst, construct_type);
4185         }
4186         result = handle_type_attributes(env.attributes, result);
4187
4188         return result;
4189 }
4190
4191 /**
4192  * Check if the declaration of main is suspicious.  main should be a
4193  * function with external linkage, returning int, taking either zero
4194  * arguments, two, or three arguments of appropriate types, ie.
4195  *
4196  * int main([ int argc, char **argv [, char **env ] ]).
4197  *
4198  * @param decl    the declaration to check
4199  * @param type    the function type of the declaration
4200  */
4201 static void check_main(const entity_t *entity)
4202 {
4203         const source_position_t *pos = &entity->base.source_position;
4204         if (entity->kind != ENTITY_FUNCTION) {
4205                 warningf(pos, "'main' is not a function");
4206                 return;
4207         }
4208
4209         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4210                 warningf(pos, "'main' is normally a non-static function");
4211         }
4212
4213         type_t *type = skip_typeref(entity->declaration.type);
4214         assert(is_type_function(type));
4215
4216         function_type_t *func_type = &type->function;
4217         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4218                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4219                          func_type->return_type);
4220         }
4221         const function_parameter_t *parm = func_type->parameters;
4222         if (parm != NULL) {
4223                 type_t *const first_type = parm->type;
4224                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4225                         warningf(pos,
4226                                  "first argument of 'main' should be 'int', but is '%T'",
4227                                  first_type);
4228                 }
4229                 parm = parm->next;
4230                 if (parm != NULL) {
4231                         type_t *const second_type = parm->type;
4232                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4233                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4234                         }
4235                         parm = parm->next;
4236                         if (parm != NULL) {
4237                                 type_t *const third_type = parm->type;
4238                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4239                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4240                                 }
4241                                 parm = parm->next;
4242                                 if (parm != NULL)
4243                                         goto warn_arg_count;
4244                         }
4245                 } else {
4246 warn_arg_count:
4247                         warningf(pos, "'main' takes only zero, two or three arguments");
4248                 }
4249         }
4250 }
4251
4252 /**
4253  * Check if a symbol is the equal to "main".
4254  */
4255 static bool is_sym_main(const symbol_t *const sym)
4256 {
4257         return strcmp(sym->string, "main") == 0;
4258 }
4259
4260 static void error_redefined_as_different_kind(const source_position_t *pos,
4261                 const entity_t *old, entity_kind_t new_kind)
4262 {
4263         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4264                get_entity_kind_name(old->kind), old->base.symbol,
4265                get_entity_kind_name(new_kind), &old->base.source_position);
4266 }
4267
4268 static bool is_error_entity(entity_t *const ent)
4269 {
4270         if (is_declaration(ent)) {
4271                 return is_type_valid(skip_typeref(ent->declaration.type));
4272         } else if (ent->kind == ENTITY_TYPEDEF) {
4273                 return is_type_valid(skip_typeref(ent->typedefe.type));
4274         }
4275         return false;
4276 }
4277
4278 /**
4279  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4280  * for various problems that occur for multiple definitions
4281  */
4282 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4283 {
4284         const symbol_t *const    symbol  = entity->base.symbol;
4285         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4286         const source_position_t *pos     = &entity->base.source_position;
4287
4288         /* can happen in error cases */
4289         if (symbol == NULL)
4290                 return entity;
4291
4292         entity_t *const previous_entity = get_entity(symbol, namespc);
4293         /* pushing the same entity twice will break the stack structure */
4294         assert(previous_entity != entity);
4295
4296         if (entity->kind == ENTITY_FUNCTION) {
4297                 type_t *const orig_type = entity->declaration.type;
4298                 type_t *const type      = skip_typeref(orig_type);
4299
4300                 assert(is_type_function(type));
4301                 if (type->function.unspecified_parameters &&
4302                                 warning.strict_prototypes &&
4303                                 previous_entity == NULL) {
4304                         warningf(pos, "function declaration '%#T' is not a prototype",
4305                                          orig_type, symbol);
4306                 }
4307
4308                 if (warning.main && current_scope == file_scope
4309                                 && is_sym_main(symbol)) {
4310                         check_main(entity);
4311                 }
4312         }
4313
4314         if (is_declaration(entity) &&
4315                         warning.nested_externs &&
4316                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4317                         current_scope != file_scope) {
4318                 warningf(pos, "nested extern declaration of '%#T'",
4319                          entity->declaration.type, symbol);
4320         }
4321
4322         if (previous_entity != NULL) {
4323                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4324                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4325                         assert(previous_entity->kind == ENTITY_PARAMETER);
4326                         errorf(pos,
4327                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4328                                         entity->declaration.type, symbol,
4329                                         previous_entity->declaration.type, symbol,
4330                                         &previous_entity->base.source_position);
4331                         goto finish;
4332                 }
4333
4334                 if (previous_entity->base.parent_scope == current_scope) {
4335                         if (previous_entity->kind != entity->kind) {
4336                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
4337                                         error_redefined_as_different_kind(pos, previous_entity,
4338                                                         entity->kind);
4339                                 }
4340                                 goto finish;
4341                         }
4342                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4343                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4344                                                 symbol, &previous_entity->base.source_position);
4345                                 goto finish;
4346                         }
4347                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4348                                 /* TODO: C++ allows this for exactly the same type */
4349                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4350                                                 symbol, &previous_entity->base.source_position);
4351                                 goto finish;
4352                         }
4353
4354                         /* at this point we should have only VARIABLES or FUNCTIONS */
4355                         assert(is_declaration(previous_entity) && is_declaration(entity));
4356
4357                         declaration_t *const prev_decl = &previous_entity->declaration;
4358                         declaration_t *const decl      = &entity->declaration;
4359
4360                         /* can happen for K&R style declarations */
4361                         if (prev_decl->type       == NULL             &&
4362                                         previous_entity->kind == ENTITY_PARAMETER &&
4363                                         entity->kind          == ENTITY_PARAMETER) {
4364                                 prev_decl->type                   = decl->type;
4365                                 prev_decl->storage_class          = decl->storage_class;
4366                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4367                                 prev_decl->modifiers              = decl->modifiers;
4368                                 return previous_entity;
4369                         }
4370
4371                         type_t *const orig_type = decl->type;
4372                         assert(orig_type != NULL);
4373                         type_t *const type      = skip_typeref(orig_type);
4374                         type_t *const prev_type = skip_typeref(prev_decl->type);
4375
4376                         if (!types_compatible(type, prev_type)) {
4377                                 errorf(pos,
4378                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4379                                                 orig_type, symbol, prev_decl->type, symbol,
4380                                                 &previous_entity->base.source_position);
4381                         } else {
4382                                 unsigned old_storage_class = prev_decl->storage_class;
4383
4384                                 if (warning.redundant_decls               &&
4385                                                 is_definition                     &&
4386                                                 !prev_decl->used                  &&
4387                                                 !(prev_decl->modifiers & DM_USED) &&
4388                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4389                                         warningf(&previous_entity->base.source_position,
4390                                                         "unnecessary static forward declaration for '%#T'",
4391                                                         prev_decl->type, symbol);
4392                                 }
4393
4394                                 storage_class_t new_storage_class = decl->storage_class;
4395
4396                                 /* pretend no storage class means extern for function
4397                                  * declarations (except if the previous declaration is neither
4398                                  * none nor extern) */
4399                                 if (entity->kind == ENTITY_FUNCTION) {
4400                                         /* the previous declaration could have unspecified parameters or
4401                                          * be a typedef, so use the new type */
4402                                         if (prev_type->function.unspecified_parameters || is_definition)
4403                                                 prev_decl->type = type;
4404
4405                                         switch (old_storage_class) {
4406                                                 case STORAGE_CLASS_NONE:
4407                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4408                                                         /* FALLTHROUGH */
4409
4410                                                 case STORAGE_CLASS_EXTERN:
4411                                                         if (is_definition) {
4412                                                                 if (warning.missing_prototypes &&
4413                                                                                 prev_type->function.unspecified_parameters &&
4414                                                                                 !is_sym_main(symbol)) {
4415                                                                         warningf(pos, "no previous prototype for '%#T'",
4416                                                                                         orig_type, symbol);
4417                                                                 }
4418                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4419                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4420                                                         }
4421                                                         break;
4422
4423                                                 default:
4424                                                         break;
4425                                         }
4426                                 } else if (is_type_incomplete(prev_type)) {
4427                                         prev_decl->type = type;
4428                                 }
4429
4430                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4431                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4432 warn_redundant_declaration:
4433                                         if (!is_definition           &&
4434                                                         warning.redundant_decls  &&
4435                                                         is_type_valid(prev_type) &&
4436                                                         strcmp(previous_entity->base.source_position.input_name,
4437                                                                 "<builtin>") != 0) {
4438                                                 warningf(pos,
4439                                                                 "redundant declaration for '%Y' (declared %P)",
4440                                                                 symbol, &previous_entity->base.source_position);
4441                                         }
4442                                 } else if (current_function == NULL) {
4443                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4444                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4445                                                 errorf(pos,
4446                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
4447                                                                 symbol, &previous_entity->base.source_position);
4448                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4449                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4450                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4451                                         } else {
4452                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4453                                                 if (c_mode & _CXX)
4454                                                         goto error_redeclaration;
4455                                                 goto warn_redundant_declaration;
4456                                         }
4457                                 } else if (is_type_valid(prev_type)) {
4458                                         if (old_storage_class == new_storage_class) {
4459 error_redeclaration:
4460                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4461                                                                 symbol, &previous_entity->base.source_position);
4462                                         } else {
4463                                                 errorf(pos,
4464                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4465                                                                 symbol, &previous_entity->base.source_position);
4466                                         }
4467                                 }
4468                         }
4469
4470                         prev_decl->modifiers |= decl->modifiers;
4471                         if (entity->kind == ENTITY_FUNCTION) {
4472                                 previous_entity->function.is_inline |= entity->function.is_inline;
4473                         }
4474                         return previous_entity;
4475                 }
4476
4477                 if (warning.shadow) {
4478                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4479                                         get_entity_kind_name(entity->kind), symbol,
4480                                         get_entity_kind_name(previous_entity->kind),
4481                                         &previous_entity->base.source_position);
4482                 }
4483         }
4484
4485         if (entity->kind == ENTITY_FUNCTION) {
4486                 if (is_definition &&
4487                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4488                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4489                                 warningf(pos, "no previous prototype for '%#T'",
4490                                          entity->declaration.type, symbol);
4491                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4492                                 warningf(pos, "no previous declaration for '%#T'",
4493                                          entity->declaration.type, symbol);
4494                         }
4495                 }
4496         } else if (warning.missing_declarations &&
4497                         entity->kind == ENTITY_VARIABLE &&
4498                         current_scope == file_scope) {
4499                 declaration_t *declaration = &entity->declaration;
4500                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4501                         warningf(pos, "no previous declaration for '%#T'",
4502                                  declaration->type, symbol);
4503                 }
4504         }
4505
4506 finish:
4507         assert(entity->base.parent_scope == NULL);
4508         assert(current_scope != NULL);
4509
4510         entity->base.parent_scope = current_scope;
4511         entity->base.namespc      = NAMESPACE_NORMAL;
4512         environment_push(entity);
4513         append_entity(current_scope, entity);
4514
4515         return entity;
4516 }
4517
4518 static void parser_error_multiple_definition(entity_t *entity,
4519                 const source_position_t *source_position)
4520 {
4521         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4522                entity->base.symbol, &entity->base.source_position);
4523 }
4524
4525 static bool is_declaration_specifier(const token_t *token,
4526                                      bool only_specifiers_qualifiers)
4527 {
4528         switch (token->type) {
4529                 TYPE_SPECIFIERS
4530                 TYPE_QUALIFIERS
4531                         return true;
4532                 case T_IDENTIFIER:
4533                         return is_typedef_symbol(token->v.symbol);
4534
4535                 case T___extension__:
4536                 STORAGE_CLASSES
4537                         return !only_specifiers_qualifiers;
4538
4539                 default:
4540                         return false;
4541         }
4542 }
4543
4544 static void parse_init_declarator_rest(entity_t *entity)
4545 {
4546         assert(is_declaration(entity));
4547         declaration_t *const declaration = &entity->declaration;
4548
4549         eat('=');
4550
4551         type_t *orig_type = declaration->type;
4552         type_t *type      = skip_typeref(orig_type);
4553
4554         if (entity->kind == ENTITY_VARIABLE
4555                         && entity->variable.initializer != NULL) {
4556                 parser_error_multiple_definition(entity, HERE);
4557         }
4558
4559         bool must_be_constant = false;
4560         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4561             entity->base.parent_scope  == file_scope) {
4562                 must_be_constant = true;
4563         }
4564
4565         if (is_type_function(type)) {
4566                 errorf(&entity->base.source_position,
4567                        "function '%#T' is initialized like a variable",
4568                        orig_type, entity->base.symbol);
4569                 orig_type = type_error_type;
4570         }
4571
4572         parse_initializer_env_t env;
4573         env.type             = orig_type;
4574         env.must_be_constant = must_be_constant;
4575         env.entity           = entity;
4576         current_init_decl    = entity;
4577
4578         initializer_t *initializer = parse_initializer(&env);
4579         current_init_decl = NULL;
4580
4581         if (entity->kind == ENTITY_VARIABLE) {
4582                 /* §6.7.5:22  array initializers for arrays with unknown size
4583                  * determine the array type size */
4584                 declaration->type            = env.type;
4585                 entity->variable.initializer = initializer;
4586         }
4587 }
4588
4589 /* parse rest of a declaration without any declarator */
4590 static void parse_anonymous_declaration_rest(
4591                 const declaration_specifiers_t *specifiers)
4592 {
4593         eat(';');
4594         anonymous_entity = NULL;
4595
4596         if (warning.other) {
4597                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4598                                 specifiers->thread_local) {
4599                         warningf(&specifiers->source_position,
4600                                  "useless storage class in empty declaration");
4601                 }
4602
4603                 type_t *type = specifiers->type;
4604                 switch (type->kind) {
4605                         case TYPE_COMPOUND_STRUCT:
4606                         case TYPE_COMPOUND_UNION: {
4607                                 if (type->compound.compound->base.symbol == NULL) {
4608                                         warningf(&specifiers->source_position,
4609                                                  "unnamed struct/union that defines no instances");
4610                                 }
4611                                 break;
4612                         }
4613
4614                         case TYPE_ENUM:
4615                                 break;
4616
4617                         default:
4618                                 warningf(&specifiers->source_position, "empty declaration");
4619                                 break;
4620                 }
4621         }
4622 }
4623
4624 static void check_variable_type_complete(entity_t *ent)
4625 {
4626         if (ent->kind != ENTITY_VARIABLE)
4627                 return;
4628
4629         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4630          *         type for the object shall be complete [...] */
4631         declaration_t *decl = &ent->declaration;
4632         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4633                         decl->storage_class == STORAGE_CLASS_STATIC)
4634                 return;
4635
4636         type_t *const orig_type = decl->type;
4637         type_t *const type      = skip_typeref(orig_type);
4638         if (!is_type_incomplete(type))
4639                 return;
4640
4641         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4642          * are given length one. */
4643         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4644                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4645                 return;
4646         }
4647
4648         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4649                         orig_type, ent->base.symbol);
4650 }
4651
4652
4653 static void parse_declaration_rest(entity_t *ndeclaration,
4654                 const declaration_specifiers_t *specifiers,
4655                 parsed_declaration_func         finished_declaration,
4656                 declarator_flags_t              flags)
4657 {
4658         add_anchor_token(';');
4659         add_anchor_token(',');
4660         while (true) {
4661                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4662
4663                 if (token.type == '=') {
4664                         parse_init_declarator_rest(entity);
4665                 } else if (entity->kind == ENTITY_VARIABLE) {
4666                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4667                          * [...] where the extern specifier is explicitly used. */
4668                         declaration_t *decl = &entity->declaration;
4669                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4670                                 type_t *type = decl->type;
4671                                 if (is_type_reference(skip_typeref(type))) {
4672                                         errorf(&entity->base.source_position,
4673                                                         "reference '%#T' must be initialized",
4674                                                         type, entity->base.symbol);
4675                                 }
4676                         }
4677                 }
4678
4679                 check_variable_type_complete(entity);
4680
4681                 if (token.type != ',')
4682                         break;
4683                 eat(',');
4684
4685                 add_anchor_token('=');
4686                 ndeclaration = parse_declarator(specifiers, flags);
4687                 rem_anchor_token('=');
4688         }
4689         expect(';', end_error);
4690
4691 end_error:
4692         anonymous_entity = NULL;
4693         rem_anchor_token(';');
4694         rem_anchor_token(',');
4695 }
4696
4697 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4698 {
4699         symbol_t *symbol = entity->base.symbol;
4700         if (symbol == NULL) {
4701                 errorf(HERE, "anonymous declaration not valid as function parameter");
4702                 return entity;
4703         }
4704
4705         assert(entity->base.namespc == NAMESPACE_NORMAL);
4706         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4707         if (previous_entity == NULL
4708                         || previous_entity->base.parent_scope != current_scope) {
4709                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
4710                        symbol);
4711                 return entity;
4712         }
4713
4714         if (is_definition) {
4715                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4716         }
4717
4718         return record_entity(entity, false);
4719 }
4720
4721 static void parse_declaration(parsed_declaration_func finished_declaration,
4722                               declarator_flags_t      flags)
4723 {
4724         declaration_specifiers_t specifiers;
4725         memset(&specifiers, 0, sizeof(specifiers));
4726
4727         add_anchor_token(';');
4728         parse_declaration_specifiers(&specifiers);
4729         rem_anchor_token(';');
4730
4731         if (token.type == ';') {
4732                 parse_anonymous_declaration_rest(&specifiers);
4733         } else {
4734                 entity_t *entity = parse_declarator(&specifiers, flags);
4735                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4736         }
4737 }
4738
4739 /* §6.5.2.2:6 */
4740 static type_t *get_default_promoted_type(type_t *orig_type)
4741 {
4742         type_t *result = orig_type;
4743
4744         type_t *type = skip_typeref(orig_type);
4745         if (is_type_integer(type)) {
4746                 result = promote_integer(type);
4747         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4748                 result = type_double;
4749         }
4750
4751         return result;
4752 }
4753
4754 static void parse_kr_declaration_list(entity_t *entity)
4755 {
4756         if (entity->kind != ENTITY_FUNCTION)
4757                 return;
4758
4759         type_t *type = skip_typeref(entity->declaration.type);
4760         assert(is_type_function(type));
4761         if (!type->function.kr_style_parameters)
4762                 return;
4763
4764         add_anchor_token('{');
4765
4766         /* push function parameters */
4767         size_t const  top       = environment_top();
4768         scope_t      *old_scope = scope_push(&entity->function.parameters);
4769
4770         entity_t *parameter = entity->function.parameters.entities;
4771         for ( ; parameter != NULL; parameter = parameter->base.next) {
4772                 assert(parameter->base.parent_scope == NULL);
4773                 parameter->base.parent_scope = current_scope;
4774                 environment_push(parameter);
4775         }
4776
4777         /* parse declaration list */
4778         for (;;) {
4779                 switch (token.type) {
4780                         DECLARATION_START
4781                         case T___extension__:
4782                         /* This covers symbols, which are no type, too, and results in
4783                          * better error messages.  The typical cases are misspelled type
4784                          * names and missing includes. */
4785                         case T_IDENTIFIER:
4786                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4787                                 break;
4788                         default:
4789                                 goto decl_list_end;
4790                 }
4791         }
4792 decl_list_end:
4793
4794         /* pop function parameters */
4795         assert(current_scope == &entity->function.parameters);
4796         scope_pop(old_scope);
4797         environment_pop_to(top);
4798
4799         /* update function type */
4800         type_t *new_type = duplicate_type(type);
4801
4802         function_parameter_t  *parameters = NULL;
4803         function_parameter_t **anchor     = &parameters;
4804
4805         /* did we have an earlier prototype? */
4806         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4807         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4808                 proto_type = NULL;
4809
4810         function_parameter_t *proto_parameter = NULL;
4811         if (proto_type != NULL) {
4812                 type_t *proto_type_type = proto_type->declaration.type;
4813                 proto_parameter         = proto_type_type->function.parameters;
4814                 /* If a K&R function definition has a variadic prototype earlier, then
4815                  * make the function definition variadic, too. This should conform to
4816                  * §6.7.5.3:15 and §6.9.1:8. */
4817                 new_type->function.variadic = proto_type_type->function.variadic;
4818         } else {
4819                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4820                  * prototype */
4821                 new_type->function.unspecified_parameters = true;
4822         }
4823
4824         bool need_incompatible_warning = false;
4825         parameter = entity->function.parameters.entities;
4826         for (; parameter != NULL; parameter = parameter->base.next,
4827                         proto_parameter =
4828                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4829                 if (parameter->kind != ENTITY_PARAMETER)
4830                         continue;
4831
4832                 type_t *parameter_type = parameter->declaration.type;
4833                 if (parameter_type == NULL) {
4834                         if (strict_mode) {
4835                                 errorf(HERE, "no type specified for function parameter '%Y'",
4836                                        parameter->base.symbol);
4837                                 parameter_type = type_error_type;
4838                         } else {
4839                                 if (warning.implicit_int) {
4840                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4841                                                  parameter->base.symbol);
4842                                 }
4843                                 parameter_type = type_int;
4844                         }
4845                         parameter->declaration.type = parameter_type;
4846                 }
4847
4848                 semantic_parameter_incomplete(parameter);
4849
4850                 /* we need the default promoted types for the function type */
4851                 type_t *not_promoted = parameter_type;
4852                 parameter_type       = get_default_promoted_type(parameter_type);
4853
4854                 /* gcc special: if the type of the prototype matches the unpromoted
4855                  * type don't promote */
4856                 if (!strict_mode && proto_parameter != NULL) {
4857                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4858                         type_t *promo_skip   = skip_typeref(parameter_type);
4859                         type_t *param_skip   = skip_typeref(not_promoted);
4860                         if (!types_compatible(proto_p_type, promo_skip)
4861                                 && types_compatible(proto_p_type, param_skip)) {
4862                                 /* don't promote */
4863                                 need_incompatible_warning = true;
4864                                 parameter_type = not_promoted;
4865                         }
4866                 }
4867                 function_parameter_t *const parameter
4868                         = allocate_parameter(parameter_type);
4869
4870                 *anchor = parameter;
4871                 anchor  = &parameter->next;
4872         }
4873
4874         new_type->function.parameters = parameters;
4875         new_type = identify_new_type(new_type);
4876
4877         if (warning.other && need_incompatible_warning) {
4878                 type_t *proto_type_type = proto_type->declaration.type;
4879                 warningf(HERE,
4880                          "declaration '%#T' is incompatible with '%#T' (declared %P)",
4881                          proto_type_type, proto_type->base.symbol,
4882                          new_type, entity->base.symbol,
4883                          &proto_type->base.source_position);
4884         }
4885
4886         entity->declaration.type = new_type;
4887
4888         rem_anchor_token('{');
4889 }
4890
4891 static bool first_err = true;
4892
4893 /**
4894  * When called with first_err set, prints the name of the current function,
4895  * else does noting.
4896  */
4897 static void print_in_function(void)
4898 {
4899         if (first_err) {
4900                 first_err = false;
4901                 diagnosticf("%s: In function '%Y':\n",
4902                             current_function->base.base.source_position.input_name,
4903                             current_function->base.base.symbol);
4904         }
4905 }
4906
4907 /**
4908  * Check if all labels are defined in the current function.
4909  * Check if all labels are used in the current function.
4910  */
4911 static void check_labels(void)
4912 {
4913         for (const goto_statement_t *goto_statement = goto_first;
4914             goto_statement != NULL;
4915             goto_statement = goto_statement->next) {
4916                 /* skip computed gotos */
4917                 if (goto_statement->expression != NULL)
4918                         continue;
4919
4920                 label_t *label = goto_statement->label;
4921
4922                 label->used = true;
4923                 if (label->base.source_position.input_name == NULL) {
4924                         print_in_function();
4925                         errorf(&goto_statement->base.source_position,
4926                                "label '%Y' used but not defined", label->base.symbol);
4927                  }
4928         }
4929
4930         if (warning.unused_label) {
4931                 for (const label_statement_t *label_statement = label_first;
4932                          label_statement != NULL;
4933                          label_statement = label_statement->next) {
4934                         label_t *label = label_statement->label;
4935
4936                         if (! label->used) {
4937                                 print_in_function();
4938                                 warningf(&label_statement->base.source_position,
4939                                          "label '%Y' defined but not used", label->base.symbol);
4940                         }
4941                 }
4942         }
4943 }
4944
4945 static void warn_unused_entity(entity_t *entity, entity_t *last)
4946 {
4947         entity_t const *const end = last != NULL ? last->base.next : NULL;
4948         for (; entity != end; entity = entity->base.next) {
4949                 if (!is_declaration(entity))
4950                         continue;
4951
4952                 declaration_t *declaration = &entity->declaration;
4953                 if (declaration->implicit)
4954                         continue;
4955
4956                 if (!declaration->used) {
4957                         print_in_function();
4958                         const char *what = get_entity_kind_name(entity->kind);
4959                         warningf(&entity->base.source_position, "%s '%Y' is unused",
4960                                  what, entity->base.symbol);
4961                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4962                         print_in_function();
4963                         const char *what = get_entity_kind_name(entity->kind);
4964                         warningf(&entity->base.source_position, "%s '%Y' is never read",
4965                                  what, entity->base.symbol);
4966                 }
4967         }
4968 }
4969
4970 static void check_unused_variables(statement_t *const stmt, void *const env)
4971 {
4972         (void)env;
4973
4974         switch (stmt->kind) {
4975                 case STATEMENT_DECLARATION: {
4976                         declaration_statement_t const *const decls = &stmt->declaration;
4977                         warn_unused_entity(decls->declarations_begin,
4978                                            decls->declarations_end);
4979                         return;
4980                 }
4981
4982                 case STATEMENT_FOR:
4983                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4984                         return;
4985
4986                 default:
4987                         return;
4988         }
4989 }
4990
4991 /**
4992  * Check declarations of current_function for unused entities.
4993  */
4994 static void check_declarations(void)
4995 {
4996         if (warning.unused_parameter) {
4997                 const scope_t *scope = &current_function->parameters;
4998
4999                 /* do not issue unused warnings for main */
5000                 if (!is_sym_main(current_function->base.base.symbol)) {
5001                         warn_unused_entity(scope->entities, NULL);
5002                 }
5003         }
5004         if (warning.unused_variable) {
5005                 walk_statements(current_function->statement, check_unused_variables,
5006                                 NULL);
5007         }
5008 }
5009
5010 static int determine_truth(expression_t const* const cond)
5011 {
5012         return
5013                 !is_constant_expression(cond) ? 0 :
5014                 fold_constant_to_bool(cond)   ? 1 :
5015                 -1;
5016 }
5017
5018 static void check_reachable(statement_t *);
5019 static bool reaches_end;
5020
5021 static bool expression_returns(expression_t const *const expr)
5022 {
5023         switch (expr->kind) {
5024                 case EXPR_CALL: {
5025                         expression_t const *const func = expr->call.function;
5026                         if (func->kind == EXPR_REFERENCE) {
5027                                 entity_t *entity = func->reference.entity;
5028                                 if (entity->kind == ENTITY_FUNCTION
5029                                                 && entity->declaration.modifiers & DM_NORETURN)
5030                                         return false;
5031                         }
5032
5033                         if (!expression_returns(func))
5034                                 return false;
5035
5036                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5037                                 if (!expression_returns(arg->expression))
5038                                         return false;
5039                         }
5040
5041                         return true;
5042                 }
5043
5044                 case EXPR_REFERENCE:
5045                 case EXPR_REFERENCE_ENUM_VALUE:
5046                 case EXPR_CONST:
5047                 case EXPR_CHARACTER_CONSTANT:
5048                 case EXPR_WIDE_CHARACTER_CONSTANT:
5049                 case EXPR_STRING_LITERAL:
5050                 case EXPR_WIDE_STRING_LITERAL:
5051                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5052                 case EXPR_LABEL_ADDRESS:
5053                 case EXPR_CLASSIFY_TYPE:
5054                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5055                 case EXPR_ALIGNOF:
5056                 case EXPR_FUNCNAME:
5057                 case EXPR_BUILTIN_CONSTANT_P:
5058                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5059                 case EXPR_OFFSETOF:
5060                 case EXPR_INVALID:
5061                         return true;
5062
5063                 case EXPR_STATEMENT: {
5064                         bool old_reaches_end = reaches_end;
5065                         reaches_end = false;
5066                         check_reachable(expr->statement.statement);
5067                         bool returns = reaches_end;
5068                         reaches_end = old_reaches_end;
5069                         return returns;
5070                 }
5071
5072                 case EXPR_CONDITIONAL:
5073                         // TODO handle constant expression
5074
5075                         if (!expression_returns(expr->conditional.condition))
5076                                 return false;
5077
5078                         if (expr->conditional.true_expression != NULL
5079                                         && expression_returns(expr->conditional.true_expression))
5080                                 return true;
5081
5082                         return expression_returns(expr->conditional.false_expression);
5083
5084                 case EXPR_SELECT:
5085                         return expression_returns(expr->select.compound);
5086
5087                 case EXPR_ARRAY_ACCESS:
5088                         return
5089                                 expression_returns(expr->array_access.array_ref) &&
5090                                 expression_returns(expr->array_access.index);
5091
5092                 case EXPR_VA_START:
5093                         return expression_returns(expr->va_starte.ap);
5094
5095                 case EXPR_VA_ARG:
5096                         return expression_returns(expr->va_arge.ap);
5097
5098                 case EXPR_VA_COPY:
5099                         return expression_returns(expr->va_copye.src);
5100
5101                 EXPR_UNARY_CASES_MANDATORY
5102                         return expression_returns(expr->unary.value);
5103
5104                 case EXPR_UNARY_THROW:
5105                         return false;
5106
5107                 EXPR_BINARY_CASES
5108                         // TODO handle constant lhs of && and ||
5109                         return
5110                                 expression_returns(expr->binary.left) &&
5111                                 expression_returns(expr->binary.right);
5112
5113                 case EXPR_UNKNOWN:
5114                         break;
5115         }
5116
5117         panic("unhandled expression");
5118 }
5119
5120 static bool initializer_returns(initializer_t const *const init)
5121 {
5122         switch (init->kind) {
5123                 case INITIALIZER_VALUE:
5124                         return expression_returns(init->value.value);
5125
5126                 case INITIALIZER_LIST: {
5127                         initializer_t * const*       i       = init->list.initializers;
5128                         initializer_t * const* const end     = i + init->list.len;
5129                         bool                         returns = true;
5130                         for (; i != end; ++i) {
5131                                 if (!initializer_returns(*i))
5132                                         returns = false;
5133                         }
5134                         return returns;
5135                 }
5136
5137                 case INITIALIZER_STRING:
5138                 case INITIALIZER_WIDE_STRING:
5139                 case INITIALIZER_DESIGNATOR: // designators have no payload
5140                         return true;
5141         }
5142         panic("unhandled initializer");
5143 }
5144
5145 static bool noreturn_candidate;
5146
5147 static void check_reachable(statement_t *const stmt)
5148 {
5149         if (stmt->base.reachable)
5150                 return;
5151         if (stmt->kind != STATEMENT_DO_WHILE)
5152                 stmt->base.reachable = true;
5153
5154         statement_t *last = stmt;
5155         statement_t *next;
5156         switch (stmt->kind) {
5157                 case STATEMENT_INVALID:
5158                 case STATEMENT_EMPTY:
5159                 case STATEMENT_ASM:
5160                         next = stmt->base.next;
5161                         break;
5162
5163                 case STATEMENT_DECLARATION: {
5164                         declaration_statement_t const *const decl = &stmt->declaration;
5165                         entity_t                const *      ent  = decl->declarations_begin;
5166                         entity_t                const *const last = decl->declarations_end;
5167                         if (ent != NULL) {
5168                                 for (;; ent = ent->base.next) {
5169                                         if (ent->kind                 == ENTITY_VARIABLE &&
5170                                                         ent->variable.initializer != NULL            &&
5171                                                         !initializer_returns(ent->variable.initializer)) {
5172                                                 return;
5173                                         }
5174                                         if (ent == last)
5175                                                 break;
5176                                 }
5177                         }
5178                         next = stmt->base.next;
5179                         break;
5180                 }
5181
5182                 case STATEMENT_COMPOUND:
5183                         next = stmt->compound.statements;
5184                         if (next == NULL)
5185                                 next = stmt->base.next;
5186                         break;
5187
5188                 case STATEMENT_RETURN: {
5189                         expression_t const *const val = stmt->returns.value;
5190                         if (val == NULL || expression_returns(val))
5191                                 noreturn_candidate = false;
5192                         return;
5193                 }
5194
5195                 case STATEMENT_IF: {
5196                         if_statement_t const *const ifs  = &stmt->ifs;
5197                         expression_t   const *const cond = ifs->condition;
5198
5199                         if (!expression_returns(cond))
5200                                 return;
5201
5202                         int const val = determine_truth(cond);
5203
5204                         if (val >= 0)
5205                                 check_reachable(ifs->true_statement);
5206
5207                         if (val > 0)
5208                                 return;
5209
5210                         if (ifs->false_statement != NULL) {
5211                                 check_reachable(ifs->false_statement);
5212                                 return;
5213                         }
5214
5215                         next = stmt->base.next;
5216                         break;
5217                 }
5218
5219                 case STATEMENT_SWITCH: {
5220                         switch_statement_t const *const switchs = &stmt->switchs;
5221                         expression_t       const *const expr    = switchs->expression;
5222
5223                         if (!expression_returns(expr))
5224                                 return;
5225
5226                         if (is_constant_expression(expr)) {
5227                                 long                    const val      = fold_constant_to_int(expr);
5228                                 case_label_statement_t *      defaults = NULL;
5229                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5230                                         if (i->expression == NULL) {
5231                                                 defaults = i;
5232                                                 continue;
5233                                         }
5234
5235                                         if (i->first_case <= val && val <= i->last_case) {
5236                                                 check_reachable((statement_t*)i);
5237                                                 return;
5238                                         }
5239                                 }
5240
5241                                 if (defaults != NULL) {
5242                                         check_reachable((statement_t*)defaults);
5243                                         return;
5244                                 }
5245                         } else {
5246                                 bool has_default = false;
5247                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5248                                         if (i->expression == NULL)
5249                                                 has_default = true;
5250
5251                                         check_reachable((statement_t*)i);
5252                                 }
5253
5254                                 if (has_default)
5255                                         return;
5256                         }
5257
5258                         next = stmt->base.next;
5259                         break;
5260                 }
5261
5262                 case STATEMENT_EXPRESSION: {
5263                         /* Check for noreturn function call */
5264                         expression_t const *const expr = stmt->expression.expression;
5265                         if (!expression_returns(expr))
5266                                 return;
5267
5268                         next = stmt->base.next;
5269                         break;
5270                 }
5271
5272                 case STATEMENT_CONTINUE: {
5273                         statement_t *parent = stmt;
5274                         for (;;) {
5275                                 parent = parent->base.parent;
5276                                 if (parent == NULL) /* continue not within loop */
5277                                         return;
5278
5279                                 next = parent;
5280                                 switch (parent->kind) {
5281                                         case STATEMENT_WHILE:    goto continue_while;
5282                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5283                                         case STATEMENT_FOR:      goto continue_for;
5284
5285                                         default: break;
5286                                 }
5287                         }
5288                 }
5289
5290                 case STATEMENT_BREAK: {
5291                         statement_t *parent = stmt;
5292                         for (;;) {
5293                                 parent = parent->base.parent;
5294                                 if (parent == NULL) /* break not within loop/switch */
5295                                         return;
5296
5297                                 switch (parent->kind) {
5298                                         case STATEMENT_SWITCH:
5299                                         case STATEMENT_WHILE:
5300                                         case STATEMENT_DO_WHILE:
5301                                         case STATEMENT_FOR:
5302                                                 last = parent;
5303                                                 next = parent->base.next;
5304                                                 goto found_break_parent;
5305
5306                                         default: break;
5307                                 }
5308                         }
5309 found_break_parent:
5310                         break;
5311                 }
5312
5313                 case STATEMENT_GOTO:
5314                         if (stmt->gotos.expression) {
5315                                 if (!expression_returns(stmt->gotos.expression))
5316                                         return;
5317
5318                                 statement_t *parent = stmt->base.parent;
5319                                 if (parent == NULL) /* top level goto */
5320                                         return;
5321                                 next = parent;
5322                         } else {
5323                                 next = stmt->gotos.label->statement;
5324                                 if (next == NULL) /* missing label */
5325                                         return;
5326                         }
5327                         break;
5328
5329                 case STATEMENT_LABEL:
5330                         next = stmt->label.statement;
5331                         break;
5332
5333                 case STATEMENT_CASE_LABEL:
5334                         next = stmt->case_label.statement;
5335                         break;
5336
5337                 case STATEMENT_WHILE: {
5338                         while_statement_t const *const whiles = &stmt->whiles;
5339                         expression_t      const *const cond   = whiles->condition;
5340
5341                         if (!expression_returns(cond))
5342                                 return;
5343
5344                         int const val = determine_truth(cond);
5345
5346                         if (val >= 0)
5347                                 check_reachable(whiles->body);
5348
5349                         if (val > 0)
5350                                 return;
5351
5352                         next = stmt->base.next;
5353                         break;
5354                 }
5355
5356                 case STATEMENT_DO_WHILE:
5357                         next = stmt->do_while.body;
5358                         break;
5359
5360                 case STATEMENT_FOR: {
5361                         for_statement_t *const fors = &stmt->fors;
5362
5363                         if (fors->condition_reachable)
5364                                 return;
5365                         fors->condition_reachable = true;
5366
5367                         expression_t const *const cond = fors->condition;
5368
5369                         int val;
5370                         if (cond == NULL) {
5371                                 val = 1;
5372                         } else if (expression_returns(cond)) {
5373                                 val = determine_truth(cond);
5374                         } else {
5375                                 return;
5376                         }
5377
5378                         if (val >= 0)
5379                                 check_reachable(fors->body);
5380
5381                         if (val > 0)
5382                                 return;
5383
5384                         next = stmt->base.next;
5385                         break;
5386                 }
5387
5388                 case STATEMENT_MS_TRY: {
5389                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5390                         check_reachable(ms_try->try_statement);
5391                         next = ms_try->final_statement;
5392                         break;
5393                 }
5394
5395                 case STATEMENT_LEAVE: {
5396                         statement_t *parent = stmt;
5397                         for (;;) {
5398                                 parent = parent->base.parent;
5399                                 if (parent == NULL) /* __leave not within __try */
5400                                         return;
5401
5402                                 if (parent->kind == STATEMENT_MS_TRY) {
5403                                         last = parent;
5404                                         next = parent->ms_try.final_statement;
5405                                         break;
5406                                 }
5407                         }
5408                         break;
5409                 }
5410
5411                 default:
5412                         panic("invalid statement kind");
5413         }
5414
5415         while (next == NULL) {
5416                 next = last->base.parent;
5417                 if (next == NULL) {
5418                         noreturn_candidate = false;
5419
5420                         type_t *const type = skip_typeref(current_function->base.type);
5421                         assert(is_type_function(type));
5422                         type_t *const ret  = skip_typeref(type->function.return_type);
5423                         if (warning.return_type                    &&
5424                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5425                             is_type_valid(ret)                     &&
5426                             !is_sym_main(current_function->base.base.symbol)) {
5427                                 warningf(&stmt->base.source_position,
5428                                          "control reaches end of non-void function");
5429                         }
5430                         return;
5431                 }
5432
5433                 switch (next->kind) {
5434                         case STATEMENT_INVALID:
5435                         case STATEMENT_EMPTY:
5436                         case STATEMENT_DECLARATION:
5437                         case STATEMENT_EXPRESSION:
5438                         case STATEMENT_ASM:
5439                         case STATEMENT_RETURN:
5440                         case STATEMENT_CONTINUE:
5441                         case STATEMENT_BREAK:
5442                         case STATEMENT_GOTO:
5443                         case STATEMENT_LEAVE:
5444                                 panic("invalid control flow in function");
5445
5446                         case STATEMENT_COMPOUND:
5447                                 if (next->compound.stmt_expr) {
5448                                         reaches_end = true;
5449                                         return;
5450                                 }
5451                                 /* FALLTHROUGH */
5452                         case STATEMENT_IF:
5453                         case STATEMENT_SWITCH:
5454                         case STATEMENT_LABEL:
5455                         case STATEMENT_CASE_LABEL:
5456                                 last = next;
5457                                 next = next->base.next;
5458                                 break;
5459
5460                         case STATEMENT_WHILE: {
5461 continue_while:
5462                                 if (next->base.reachable)
5463                                         return;
5464                                 next->base.reachable = true;
5465
5466                                 while_statement_t const *const whiles = &next->whiles;
5467                                 expression_t      const *const cond   = whiles->condition;
5468
5469                                 if (!expression_returns(cond))
5470                                         return;
5471
5472                                 int const val = determine_truth(cond);
5473
5474                                 if (val >= 0)
5475                                         check_reachable(whiles->body);
5476
5477                                 if (val > 0)
5478                                         return;
5479
5480                                 last = next;
5481                                 next = next->base.next;
5482                                 break;
5483                         }
5484
5485                         case STATEMENT_DO_WHILE: {
5486 continue_do_while:
5487                                 if (next->base.reachable)
5488                                         return;
5489                                 next->base.reachable = true;
5490
5491                                 do_while_statement_t const *const dw   = &next->do_while;
5492                                 expression_t         const *const cond = dw->condition;
5493
5494                                 if (!expression_returns(cond))
5495                                         return;
5496
5497                                 int const val = determine_truth(cond);
5498
5499                                 if (val >= 0)
5500                                         check_reachable(dw->body);
5501
5502                                 if (val > 0)
5503                                         return;
5504
5505                                 last = next;
5506                                 next = next->base.next;
5507                                 break;
5508                         }
5509
5510                         case STATEMENT_FOR: {
5511 continue_for:;
5512                                 for_statement_t *const fors = &next->fors;
5513
5514                                 fors->step_reachable = true;
5515
5516                                 if (fors->condition_reachable)
5517                                         return;
5518                                 fors->condition_reachable = true;
5519
5520                                 expression_t const *const cond = fors->condition;
5521
5522                                 int val;
5523                                 if (cond == NULL) {
5524                                         val = 1;
5525                                 } else if (expression_returns(cond)) {
5526                                         val = determine_truth(cond);
5527                                 } else {
5528                                         return;
5529                                 }
5530
5531                                 if (val >= 0)
5532                                         check_reachable(fors->body);
5533
5534                                 if (val > 0)
5535                                         return;
5536
5537                                 last = next;
5538                                 next = next->base.next;
5539                                 break;
5540                         }
5541
5542                         case STATEMENT_MS_TRY:
5543                                 last = next;
5544                                 next = next->ms_try.final_statement;
5545                                 break;
5546                 }
5547         }
5548
5549         check_reachable(next);
5550 }
5551
5552 static void check_unreachable(statement_t* const stmt, void *const env)
5553 {
5554         (void)env;
5555
5556         switch (stmt->kind) {
5557                 case STATEMENT_DO_WHILE:
5558                         if (!stmt->base.reachable) {
5559                                 expression_t const *const cond = stmt->do_while.condition;
5560                                 if (determine_truth(cond) >= 0) {
5561                                         warningf(&cond->base.source_position,
5562                                                  "condition of do-while-loop is unreachable");
5563                                 }
5564                         }
5565                         return;
5566
5567                 case STATEMENT_FOR: {
5568                         for_statement_t const* const fors = &stmt->fors;
5569
5570                         // if init and step are unreachable, cond is unreachable, too
5571                         if (!stmt->base.reachable && !fors->step_reachable) {
5572                                 warningf(&stmt->base.source_position, "statement is unreachable");
5573                         } else {
5574                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5575                                         warningf(&fors->initialisation->base.source_position,
5576                                                  "initialisation of for-statement is unreachable");
5577                                 }
5578
5579                                 if (!fors->condition_reachable && fors->condition != NULL) {
5580                                         warningf(&fors->condition->base.source_position,
5581                                                  "condition of for-statement is unreachable");
5582                                 }
5583
5584                                 if (!fors->step_reachable && fors->step != NULL) {
5585                                         warningf(&fors->step->base.source_position,
5586                                                  "step of for-statement is unreachable");
5587                                 }
5588                         }
5589                         return;
5590                 }
5591
5592                 case STATEMENT_COMPOUND:
5593                         if (stmt->compound.statements != NULL)
5594                                 return;
5595                         goto warn_unreachable;
5596
5597                 case STATEMENT_DECLARATION: {
5598                         /* Only warn if there is at least one declarator with an initializer.
5599                          * This typically occurs in switch statements. */
5600                         declaration_statement_t const *const decl = &stmt->declaration;
5601                         entity_t                const *      ent  = decl->declarations_begin;
5602                         entity_t                const *const last = decl->declarations_end;
5603                         if (ent != NULL) {
5604                                 for (;; ent = ent->base.next) {
5605                                         if (ent->kind                 == ENTITY_VARIABLE &&
5606                                                         ent->variable.initializer != NULL) {
5607                                                 goto warn_unreachable;
5608                                         }
5609                                         if (ent == last)
5610                                                 return;
5611                                 }
5612                         }
5613                 }
5614
5615                 default:
5616 warn_unreachable:
5617                         if (!stmt->base.reachable)
5618                                 warningf(&stmt->base.source_position, "statement is unreachable");
5619                         return;
5620         }
5621 }
5622
5623 static void parse_external_declaration(void)
5624 {
5625         /* function-definitions and declarations both start with declaration
5626          * specifiers */
5627         declaration_specifiers_t specifiers;
5628         memset(&specifiers, 0, sizeof(specifiers));
5629
5630         add_anchor_token(';');
5631         parse_declaration_specifiers(&specifiers);
5632         rem_anchor_token(';');
5633
5634         /* must be a declaration */
5635         if (token.type == ';') {
5636                 parse_anonymous_declaration_rest(&specifiers);
5637                 return;
5638         }
5639
5640         add_anchor_token(',');
5641         add_anchor_token('=');
5642         add_anchor_token(';');
5643         add_anchor_token('{');
5644
5645         /* declarator is common to both function-definitions and declarations */
5646         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5647
5648         rem_anchor_token('{');
5649         rem_anchor_token(';');
5650         rem_anchor_token('=');
5651         rem_anchor_token(',');
5652
5653         /* must be a declaration */
5654         switch (token.type) {
5655                 case ',':
5656                 case ';':
5657                 case '=':
5658                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5659                                         DECL_FLAGS_NONE);
5660                         return;
5661         }
5662
5663         /* must be a function definition */
5664         parse_kr_declaration_list(ndeclaration);
5665
5666         if (token.type != '{') {
5667                 parse_error_expected("while parsing function definition", '{', NULL);
5668                 eat_until_matching_token(';');
5669                 return;
5670         }
5671
5672         assert(is_declaration(ndeclaration));
5673         type_t *const orig_type = ndeclaration->declaration.type;
5674         type_t *      type      = skip_typeref(orig_type);
5675
5676         if (!is_type_function(type)) {
5677                 if (is_type_valid(type)) {
5678                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5679                                type, ndeclaration->base.symbol);
5680                 }
5681                 eat_block();
5682                 return;
5683         } else if (is_typeref(orig_type)) {
5684                 /* §6.9.1:2 */
5685                 errorf(&ndeclaration->base.source_position,
5686                                 "type of function definition '%#T' is a typedef",
5687                                 orig_type, ndeclaration->base.symbol);
5688         }
5689
5690         if (warning.aggregate_return &&
5691             is_type_compound(skip_typeref(type->function.return_type))) {
5692                 warningf(HERE, "function '%Y' returns an aggregate",
5693                          ndeclaration->base.symbol);
5694         }
5695         if (warning.traditional && !type->function.unspecified_parameters) {
5696                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5697                         ndeclaration->base.symbol);
5698         }
5699         if (warning.old_style_definition && type->function.unspecified_parameters) {
5700                 warningf(HERE, "old-style function definition '%Y'",
5701                         ndeclaration->base.symbol);
5702         }
5703
5704         /* §6.7.5.3:14 a function definition with () means no
5705          * parameters (and not unspecified parameters) */
5706         if (type->function.unspecified_parameters &&
5707                         type->function.parameters == NULL) {
5708                 type_t *copy                          = duplicate_type(type);
5709                 copy->function.unspecified_parameters = false;
5710                 type                                  = identify_new_type(copy);
5711
5712                 ndeclaration->declaration.type = type;
5713         }
5714
5715         entity_t *const entity = record_entity(ndeclaration, true);
5716         assert(entity->kind == ENTITY_FUNCTION);
5717         assert(ndeclaration->kind == ENTITY_FUNCTION);
5718
5719         function_t *function = &entity->function;
5720         if (ndeclaration != entity) {
5721                 function->parameters = ndeclaration->function.parameters;
5722         }
5723         assert(is_declaration(entity));
5724         type = skip_typeref(entity->declaration.type);
5725
5726         /* push function parameters and switch scope */
5727         size_t const  top       = environment_top();
5728         scope_t      *old_scope = scope_push(&function->parameters);
5729
5730         entity_t *parameter = function->parameters.entities;
5731         for (; parameter != NULL; parameter = parameter->base.next) {
5732                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5733                         parameter->base.parent_scope = current_scope;
5734                 }
5735                 assert(parameter->base.parent_scope == NULL
5736                                 || parameter->base.parent_scope == current_scope);
5737                 parameter->base.parent_scope = current_scope;
5738                 if (parameter->base.symbol == NULL) {
5739                         errorf(&parameter->base.source_position, "parameter name omitted");
5740                         continue;
5741                 }
5742                 environment_push(parameter);
5743         }
5744
5745         if (function->statement != NULL) {
5746                 parser_error_multiple_definition(entity, HERE);
5747                 eat_block();
5748         } else {
5749                 /* parse function body */
5750                 int         label_stack_top      = label_top();
5751                 function_t *old_current_function = current_function;
5752                 current_function                 = function;
5753                 current_parent                   = NULL;
5754
5755                 goto_first   = NULL;
5756                 goto_anchor  = &goto_first;
5757                 label_first  = NULL;
5758                 label_anchor = &label_first;
5759
5760                 statement_t *const body = parse_compound_statement(false);
5761                 function->statement = body;
5762                 first_err = true;
5763                 check_labels();
5764                 check_declarations();
5765                 if (warning.return_type      ||
5766                     warning.unreachable_code ||
5767                     (warning.missing_noreturn
5768                      && !(function->base.modifiers & DM_NORETURN))) {
5769                         noreturn_candidate = true;
5770                         check_reachable(body);
5771                         if (warning.unreachable_code)
5772                                 walk_statements(body, check_unreachable, NULL);
5773                         if (warning.missing_noreturn &&
5774                             noreturn_candidate       &&
5775                             !(function->base.modifiers & DM_NORETURN)) {
5776                                 warningf(&body->base.source_position,
5777                                          "function '%#T' is candidate for attribute 'noreturn'",
5778                                          type, entity->base.symbol);
5779                         }
5780                 }
5781
5782                 assert(current_parent   == NULL);
5783                 assert(current_function == function);
5784                 current_function = old_current_function;
5785                 label_pop_to(label_stack_top);
5786         }
5787
5788         assert(current_scope == &function->parameters);
5789         scope_pop(old_scope);
5790         environment_pop_to(top);
5791 }
5792
5793 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5794                                   source_position_t *source_position,
5795                                   const symbol_t *symbol)
5796 {
5797         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5798
5799         type->bitfield.base_type       = base_type;
5800         type->bitfield.size_expression = size;
5801
5802         il_size_t bit_size;
5803         type_t *skipped_type = skip_typeref(base_type);
5804         if (!is_type_integer(skipped_type)) {
5805                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5806                         base_type);
5807                 bit_size = 0;
5808         } else {
5809                 bit_size = get_type_size(base_type) * 8;
5810         }
5811
5812         if (is_constant_expression(size)) {
5813                 long v = fold_constant_to_int(size);
5814                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5815
5816                 if (v < 0) {
5817                         errorf(source_position, "negative width in bit-field '%Y'",
5818                                user_symbol);
5819                 } else if (v == 0 && symbol != NULL) {
5820                         errorf(source_position, "zero width for bit-field '%Y'",
5821                                user_symbol);
5822                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5823                         errorf(source_position, "width of '%Y' exceeds its type",
5824                                user_symbol);
5825                 } else {
5826                         type->bitfield.bit_size = v;
5827                 }
5828         }
5829
5830         return type;
5831 }
5832
5833 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5834 {
5835         entity_t *iter = compound->members.entities;
5836         for (; iter != NULL; iter = iter->base.next) {
5837                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5838                         continue;
5839
5840                 if (iter->base.symbol == symbol) {
5841                         return iter;
5842                 } else if (iter->base.symbol == NULL) {
5843                         /* search in anonymous structs and unions */
5844                         type_t *type = skip_typeref(iter->declaration.type);
5845                         if (is_type_compound(type)) {
5846                                 if (find_compound_entry(type->compound.compound, symbol)
5847                                                 != NULL)
5848                                         return iter;
5849                         }
5850                         continue;
5851                 }
5852         }
5853
5854         return NULL;
5855 }
5856
5857 static void check_deprecated(const source_position_t *source_position,
5858                              const entity_t *entity)
5859 {
5860         if (!warning.deprecated_declarations)
5861                 return;
5862         if (!is_declaration(entity))
5863                 return;
5864         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5865                 return;
5866
5867         char const *const prefix = get_entity_kind_name(entity->kind);
5868         const char *deprecated_string
5869                         = get_deprecated_string(entity->declaration.attributes);
5870         if (deprecated_string != NULL) {
5871                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
5872                                  prefix, entity->base.symbol, &entity->base.source_position,
5873                                  deprecated_string);
5874         } else {
5875                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
5876                                  entity->base.symbol, &entity->base.source_position);
5877         }
5878 }
5879
5880
5881 static expression_t *create_select(const source_position_t *pos,
5882                                    expression_t *addr,
5883                                    type_qualifiers_t qualifiers,
5884                                                                    entity_t *entry)
5885 {
5886         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5887
5888         check_deprecated(pos, entry);
5889
5890         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5891         select->select.compound       = addr;
5892         select->select.compound_entry = entry;
5893
5894         type_t *entry_type = entry->declaration.type;
5895         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5896
5897         /* we always do the auto-type conversions; the & and sizeof parser contains
5898          * code to revert this! */
5899         select->base.type = automatic_type_conversion(res_type);
5900         if (res_type->kind == TYPE_BITFIELD) {
5901                 select->base.type = res_type->bitfield.base_type;
5902         }
5903
5904         return select;
5905 }
5906
5907 /**
5908  * Find entry with symbol in compound. Search anonymous structs and unions and
5909  * creates implicit select expressions for them.
5910  * Returns the adress for the innermost compound.
5911  */
5912 static expression_t *find_create_select(const source_position_t *pos,
5913                                         expression_t *addr,
5914                                         type_qualifiers_t qualifiers,
5915                                         compound_t *compound, symbol_t *symbol)
5916 {
5917         entity_t *iter = compound->members.entities;
5918         for (; iter != NULL; iter = iter->base.next) {
5919                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5920                         continue;
5921
5922                 symbol_t *iter_symbol = iter->base.symbol;
5923                 if (iter_symbol == NULL) {
5924                         type_t *type = iter->declaration.type;
5925                         if (type->kind != TYPE_COMPOUND_STRUCT
5926                                         && type->kind != TYPE_COMPOUND_UNION)
5927                                 continue;
5928
5929                         compound_t *sub_compound = type->compound.compound;
5930
5931                         if (find_compound_entry(sub_compound, symbol) == NULL)
5932                                 continue;
5933
5934                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5935                         sub_addr->base.source_position = *pos;
5936                         sub_addr->select.implicit      = true;
5937                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5938                                                   symbol);
5939                 }
5940
5941                 if (iter_symbol == symbol) {
5942                         return create_select(pos, addr, qualifiers, iter);
5943                 }
5944         }
5945
5946         return NULL;
5947 }
5948
5949 static void parse_compound_declarators(compound_t *compound,
5950                 const declaration_specifiers_t *specifiers)
5951 {
5952         while (true) {
5953                 entity_t *entity;
5954
5955                 if (token.type == ':') {
5956                         source_position_t source_position = *HERE;
5957                         next_token();
5958
5959                         type_t *base_type = specifiers->type;
5960                         expression_t *size = parse_constant_expression();
5961
5962                         type_t *type = make_bitfield_type(base_type, size,
5963                                         &source_position, NULL);
5964
5965                         attribute_t *attributes = parse_attributes(NULL);
5966                         if (attributes != NULL) {
5967                                 attribute_t *last = attributes;
5968                                 while (last->next != NULL)
5969                                         last = last->next;
5970                                 last->next = specifiers->attributes;
5971                         } else {
5972                                 attributes = specifiers->attributes;
5973                         }
5974
5975                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
5976                         entity->base.namespc                       = NAMESPACE_NORMAL;
5977                         entity->base.source_position               = source_position;
5978                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5979                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5980                         entity->declaration.type                   = type;
5981                         entity->declaration.attributes             = attributes;
5982
5983                         if (attributes != NULL) {
5984                                 handle_entity_attributes(attributes, entity);
5985                         }
5986                         append_entity(&compound->members, entity);
5987                 } else {
5988                         entity = parse_declarator(specifiers,
5989                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5990                         if (entity->kind == ENTITY_TYPEDEF) {
5991                                 errorf(&entity->base.source_position,
5992                                                 "typedef not allowed as compound member");
5993                         } else {
5994                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5995
5996                                 /* make sure we don't define a symbol multiple times */
5997                                 symbol_t *symbol = entity->base.symbol;
5998                                 if (symbol != NULL) {
5999                                         entity_t *prev = find_compound_entry(compound, symbol);
6000                                         if (prev != NULL) {
6001                                                 errorf(&entity->base.source_position,
6002                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6003                                                                 symbol, &prev->base.source_position);
6004                                         }
6005                                 }
6006
6007                                 if (token.type == ':') {
6008                                         source_position_t source_position = *HERE;
6009                                         next_token();
6010                                         expression_t *size = parse_constant_expression();
6011
6012                                         type_t *type          = entity->declaration.type;
6013                                         type_t *bitfield_type = make_bitfield_type(type, size,
6014                                                         &source_position, entity->base.symbol);
6015
6016                                         attribute_t *attributes = parse_attributes(NULL);
6017                                         entity->declaration.type = bitfield_type;
6018                                         handle_entity_attributes(attributes, entity);
6019                                 } else {
6020                                         type_t *orig_type = entity->declaration.type;
6021                                         type_t *type      = skip_typeref(orig_type);
6022                                         if (is_type_function(type)) {
6023                                                 errorf(&entity->base.source_position,
6024                                                                 "compound member '%Y' must not have function type '%T'",
6025                                                                 entity->base.symbol, orig_type);
6026                                         } else if (is_type_incomplete(type)) {
6027                                                 /* §6.7.2.1:16 flexible array member */
6028                                                 if (!is_type_array(type)       ||
6029                                                                 token.type          != ';' ||
6030                                                                 look_ahead(1)->type != '}') {
6031                                                         errorf(&entity->base.source_position,
6032                                                                         "compound member '%Y' has incomplete type '%T'",
6033                                                                         entity->base.symbol, orig_type);
6034                                                 }
6035                                         }
6036                                 }
6037
6038                                 append_entity(&compound->members, entity);
6039                         }
6040                 }
6041
6042                 if (token.type != ',')
6043                         break;
6044                 next_token();
6045         }
6046         expect(';', end_error);
6047
6048 end_error:
6049         anonymous_entity = NULL;
6050 }
6051
6052 static void parse_compound_type_entries(compound_t *compound)
6053 {
6054         eat('{');
6055         add_anchor_token('}');
6056
6057         while (token.type != '}') {
6058                 if (token.type == T_EOF) {
6059                         errorf(HERE, "EOF while parsing struct");
6060                         break;
6061                 }
6062                 declaration_specifiers_t specifiers;
6063                 memset(&specifiers, 0, sizeof(specifiers));
6064                 parse_declaration_specifiers(&specifiers);
6065
6066                 parse_compound_declarators(compound, &specifiers);
6067         }
6068         rem_anchor_token('}');
6069         next_token();
6070
6071         /* §6.7.2.1:7 */
6072         compound->complete = true;
6073 }
6074
6075 static type_t *parse_typename(void)
6076 {
6077         declaration_specifiers_t specifiers;
6078         memset(&specifiers, 0, sizeof(specifiers));
6079         parse_declaration_specifiers(&specifiers);
6080         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6081                         specifiers.thread_local) {
6082                 /* TODO: improve error message, user does probably not know what a
6083                  * storage class is...
6084                  */
6085                 errorf(HERE, "typename may not have a storage class");
6086         }
6087
6088         type_t *result = parse_abstract_declarator(specifiers.type);
6089
6090         return result;
6091 }
6092
6093
6094
6095
6096 typedef expression_t* (*parse_expression_function)(void);
6097 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6098
6099 typedef struct expression_parser_function_t expression_parser_function_t;
6100 struct expression_parser_function_t {
6101         parse_expression_function        parser;
6102         precedence_t                     infix_precedence;
6103         parse_expression_infix_function  infix_parser;
6104 };
6105
6106 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6107
6108 /**
6109  * Prints an error message if an expression was expected but not read
6110  */
6111 static expression_t *expected_expression_error(void)
6112 {
6113         /* skip the error message if the error token was read */
6114         if (token.type != T_ERROR) {
6115                 errorf(HERE, "expected expression, got token %K", &token);
6116         }
6117         next_token();
6118
6119         return create_invalid_expression();
6120 }
6121
6122 /**
6123  * Parse a string constant.
6124  */
6125 static expression_t *parse_string_const(void)
6126 {
6127         wide_string_t wres;
6128         if (token.type == T_STRING_LITERAL) {
6129                 string_t res = token.v.string;
6130                 next_token();
6131                 while (token.type == T_STRING_LITERAL) {
6132                         res = concat_strings(&res, &token.v.string);
6133                         next_token();
6134                 }
6135                 if (token.type != T_WIDE_STRING_LITERAL) {
6136                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6137                         /* note: that we use type_char_ptr here, which is already the
6138                          * automatic converted type. revert_automatic_type_conversion
6139                          * will construct the array type */
6140                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6141                         cnst->string.value = res;
6142                         return cnst;
6143                 }
6144
6145                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6146         } else {
6147                 wres = token.v.wide_string;
6148         }
6149         next_token();
6150
6151         for (;;) {
6152                 switch (token.type) {
6153                         case T_WIDE_STRING_LITERAL:
6154                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6155                                 break;
6156
6157                         case T_STRING_LITERAL:
6158                                 wres = concat_wide_string_string(&wres, &token.v.string);
6159                                 break;
6160
6161                         default: {
6162                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6163                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6164                                 cnst->wide_string.value = wres;
6165                                 return cnst;
6166                         }
6167                 }
6168                 next_token();
6169         }
6170 }
6171
6172 /**
6173  * Parse a boolean constant.
6174  */
6175 static expression_t *parse_bool_const(bool value)
6176 {
6177         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6178         cnst->base.type          = type_bool;
6179         cnst->conste.v.int_value = value;
6180
6181         next_token();
6182
6183         return cnst;
6184 }
6185
6186 /**
6187  * Parse an integer constant.
6188  */
6189 static expression_t *parse_int_const(void)
6190 {
6191         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6192         cnst->base.type          = token.datatype;
6193         cnst->conste.v.int_value = token.v.intvalue;
6194
6195         next_token();
6196
6197         return cnst;
6198 }
6199
6200 /**
6201  * Parse a character constant.
6202  */
6203 static expression_t *parse_character_constant(void)
6204 {
6205         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6206         cnst->base.type          = token.datatype;
6207         cnst->conste.v.character = token.v.string;
6208
6209         if (cnst->conste.v.character.size != 1) {
6210                 if (!GNU_MODE) {
6211                         errorf(HERE, "more than 1 character in character constant");
6212                 } else if (warning.multichar) {
6213                         warningf(HERE, "multi-character character constant");
6214                 }
6215         }
6216         next_token();
6217
6218         return cnst;
6219 }
6220
6221 /**
6222  * Parse a wide character constant.
6223  */
6224 static expression_t *parse_wide_character_constant(void)
6225 {
6226         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6227         cnst->base.type               = token.datatype;
6228         cnst->conste.v.wide_character = token.v.wide_string;
6229
6230         if (cnst->conste.v.wide_character.size != 1) {
6231                 if (!GNU_MODE) {
6232                         errorf(HERE, "more than 1 character in character constant");
6233                 } else if (warning.multichar) {
6234                         warningf(HERE, "multi-character character constant");
6235                 }
6236         }
6237         next_token();
6238
6239         return cnst;
6240 }
6241
6242 /**
6243  * Parse a float constant.
6244  */
6245 static expression_t *parse_float_const(void)
6246 {
6247         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6248         cnst->base.type            = token.datatype;
6249         cnst->conste.v.float_value = token.v.floatvalue;
6250
6251         next_token();
6252
6253         return cnst;
6254 }
6255
6256 static entity_t *create_implicit_function(symbol_t *symbol,
6257                 const source_position_t *source_position)
6258 {
6259         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6260         ntype->function.return_type            = type_int;
6261         ntype->function.unspecified_parameters = true;
6262         ntype->function.linkage                = LINKAGE_C;
6263         type_t *type                           = identify_new_type(ntype);
6264
6265         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6266         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6267         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6268         entity->declaration.type                   = type;
6269         entity->declaration.implicit               = true;
6270         entity->base.symbol                        = symbol;
6271         entity->base.source_position               = *source_position;
6272
6273         if (current_scope != NULL) {
6274                 bool strict_prototypes_old = warning.strict_prototypes;
6275                 warning.strict_prototypes  = false;
6276                 record_entity(entity, false);
6277                 warning.strict_prototypes = strict_prototypes_old;
6278         }
6279
6280         return entity;
6281 }
6282
6283 /**
6284  * Creates a return_type (func)(argument_type) function type if not
6285  * already exists.
6286  */
6287 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6288                                     type_t *argument_type2)
6289 {
6290         function_parameter_t *const parameter2 = allocate_parameter(argument_type2);
6291         function_parameter_t *const parameter1 = allocate_parameter(argument_type1);
6292         parameter1->next = parameter2;
6293
6294         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6295         type->function.return_type = return_type;
6296         type->function.parameters  = parameter1;
6297
6298         return identify_new_type(type);
6299 }
6300
6301 /**
6302  * Creates a return_type (func)(argument_type) function type if not
6303  * already exists.
6304  *
6305  * @param return_type    the return type
6306  * @param argument_type  the argument type
6307  */
6308 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6309 {
6310         function_parameter_t *const parameter = allocate_parameter(argument_type);
6311
6312         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6313         type->function.return_type = return_type;
6314         type->function.parameters  = parameter;
6315
6316         return identify_new_type(type);
6317 }
6318
6319 /**
6320  * Creates a return_type (func)(argument_type, ...) function type if not
6321  * already exists.
6322  *
6323  * @param return_type    the return type
6324  * @param argument_type  the argument type
6325  */
6326 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6327 {
6328         function_parameter_t *const parameter = allocate_parameter(argument_type);
6329
6330         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6331         type->function.return_type = return_type;
6332         type->function.parameters  = parameter;
6333         type->function.variadic    = true;
6334
6335         return identify_new_type(type);
6336 }
6337
6338 /**
6339  * Creates a return_type (func)(void) function type if not
6340  * already exists.
6341  *
6342  * @param return_type    the return type
6343  */
6344 static type_t *make_function_0_type(type_t *return_type)
6345 {
6346         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6347         type->function.return_type = return_type;
6348         type->function.parameters  = NULL;
6349
6350         return identify_new_type(type);
6351 }
6352
6353 /**
6354  * Creates a NO_RETURN return_type (func)(void) function type if not
6355  * already exists.
6356  *
6357  * @param return_type    the return type
6358  */
6359 static type_t *make_function_0_type_noreturn(type_t *return_type)
6360 {
6361         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6362         type->function.return_type = return_type;
6363         type->function.parameters  = NULL;
6364         type->function.modifiers  |= DM_NORETURN;
6365         return identify_new_type(type);
6366 }
6367
6368 /**
6369  * Performs automatic type cast as described in §6.3.2.1.
6370  *
6371  * @param orig_type  the original type
6372  */
6373 static type_t *automatic_type_conversion(type_t *orig_type)
6374 {
6375         type_t *type = skip_typeref(orig_type);
6376         if (is_type_array(type)) {
6377                 array_type_t *array_type   = &type->array;
6378                 type_t       *element_type = array_type->element_type;
6379                 unsigned      qualifiers   = array_type->base.qualifiers;
6380
6381                 return make_pointer_type(element_type, qualifiers);
6382         }
6383
6384         if (is_type_function(type)) {
6385                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6386         }
6387
6388         return orig_type;
6389 }
6390
6391 /**
6392  * reverts the automatic casts of array to pointer types and function
6393  * to function-pointer types as defined §6.3.2.1
6394  */
6395 type_t *revert_automatic_type_conversion(const expression_t *expression)
6396 {
6397         switch (expression->kind) {
6398                 case EXPR_REFERENCE: {
6399                         entity_t *entity = expression->reference.entity;
6400                         if (is_declaration(entity)) {
6401                                 return entity->declaration.type;
6402                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6403                                 return entity->enum_value.enum_type;
6404                         } else {
6405                                 panic("no declaration or enum in reference");
6406                         }
6407                 }
6408
6409                 case EXPR_SELECT: {
6410                         entity_t *entity = expression->select.compound_entry;
6411                         assert(is_declaration(entity));
6412                         type_t   *type   = entity->declaration.type;
6413                         return get_qualified_type(type,
6414                                         expression->base.type->base.qualifiers);
6415                 }
6416
6417                 case EXPR_UNARY_DEREFERENCE: {
6418                         const expression_t *const value = expression->unary.value;
6419                         type_t             *const type  = skip_typeref(value->base.type);
6420                         if (!is_type_pointer(type))
6421                                 return type_error_type;
6422                         return type->pointer.points_to;
6423                 }
6424
6425                 case EXPR_ARRAY_ACCESS: {
6426                         const expression_t *array_ref = expression->array_access.array_ref;
6427                         type_t             *type_left = skip_typeref(array_ref->base.type);
6428                         if (!is_type_pointer(type_left))
6429                                 return type_error_type;
6430                         return type_left->pointer.points_to;
6431                 }
6432
6433                 case EXPR_STRING_LITERAL: {
6434                         size_t size = expression->string.value.size;
6435                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6436                 }
6437
6438                 case EXPR_WIDE_STRING_LITERAL: {
6439                         size_t size = expression->wide_string.value.size;
6440                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6441                 }
6442
6443                 case EXPR_COMPOUND_LITERAL:
6444                         return expression->compound_literal.type;
6445
6446                 default:
6447                         return expression->base.type;
6448         }
6449 }
6450
6451 /**
6452  * Find an entity matching a symbol in a scope.
6453  * Uses current scope if scope is NULL
6454  */
6455 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6456                                namespace_tag_t namespc)
6457 {
6458         if (scope == NULL) {
6459                 return get_entity(symbol, namespc);
6460         }
6461
6462         /* we should optimize here, if scope grows above a certain size we should
6463            construct a hashmap here... */
6464         entity_t *entity = scope->entities;
6465         for ( ; entity != NULL; entity = entity->base.next) {
6466                 if (entity->base.symbol == symbol && entity->base.namespc == namespc)
6467                         break;
6468         }
6469
6470         return entity;
6471 }
6472
6473 static entity_t *parse_qualified_identifier(void)
6474 {
6475         /* namespace containing the symbol */
6476         symbol_t      *symbol;
6477         const scope_t *lookup_scope = NULL;
6478
6479         if (token.type == T_COLONCOLON) {
6480                 next_token();
6481                 lookup_scope = &unit->scope;
6482         }
6483
6484         entity_t *entity;
6485         while (true) {
6486                 if (token.type != T_IDENTIFIER) {
6487                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6488                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6489                 }
6490                 symbol = token.v.symbol;
6491                 next_token();
6492
6493                 /* lookup entity */
6494                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6495
6496                 if (token.type != T_COLONCOLON)
6497                         break;
6498                 next_token();
6499
6500                 switch (entity->kind) {
6501                 case ENTITY_NAMESPACE:
6502                         lookup_scope = &entity->namespacee.members;
6503                         break;
6504                 case ENTITY_STRUCT:
6505                 case ENTITY_UNION:
6506                 case ENTITY_CLASS:
6507                         lookup_scope = &entity->compound.members;
6508                         break;
6509                 default:
6510                         errorf(HERE, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6511                                symbol, get_entity_kind_name(entity->kind));
6512                         goto end_error;
6513                 }
6514         }
6515
6516         if (entity == NULL) {
6517                 if (!strict_mode && token.type == '(') {
6518                         /* an implicitly declared function */
6519                         if (warning.error_implicit_function_declaration) {
6520                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
6521                         } else if (warning.implicit_function_declaration) {
6522                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
6523                         }
6524
6525                         entity = create_implicit_function(symbol, HERE);
6526                 } else {
6527                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
6528                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6529                 }
6530         }
6531
6532         return entity;
6533
6534 end_error:
6535         /* skip further qualifications */
6536         while (token.type == T_IDENTIFIER) {
6537                 next_token();
6538                 if (token.type != T_COLONCOLON)
6539                         break;
6540                 next_token();
6541         }
6542
6543         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6544 }
6545
6546 static expression_t *parse_reference(void)
6547 {
6548         entity_t *entity = parse_qualified_identifier();
6549
6550         type_t *orig_type;
6551         if (is_declaration(entity)) {
6552                 orig_type = entity->declaration.type;
6553         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6554                 orig_type = entity->enum_value.enum_type;
6555         } else {
6556                 panic("expected declaration or enum value in reference");
6557         }
6558
6559         /* we always do the auto-type conversions; the & and sizeof parser contains
6560          * code to revert this! */
6561         type_t *type = automatic_type_conversion(orig_type);
6562
6563         expression_kind_t kind = EXPR_REFERENCE;
6564         if (entity->kind == ENTITY_ENUM_VALUE)
6565                 kind = EXPR_REFERENCE_ENUM_VALUE;
6566
6567         expression_t *expression     = allocate_expression_zero(kind);
6568         expression->reference.entity = entity;
6569         expression->base.type        = type;
6570
6571         /* this declaration is used */
6572         if (is_declaration(entity)) {
6573                 entity->declaration.used = true;
6574         }
6575
6576         if (entity->base.parent_scope != file_scope
6577                 && (current_function != NULL && entity->base.parent_scope->depth < current_function->parameters.depth)
6578                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6579                 if (entity->kind == ENTITY_VARIABLE) {
6580                         /* access of a variable from an outer function */
6581                         entity->variable.address_taken = true;
6582                 } else if (entity->kind == ENTITY_PARAMETER) {
6583                         entity->parameter.address_taken = true;
6584                 }
6585                 current_function->need_closure = true;
6586         }
6587
6588         check_deprecated(HERE, entity);
6589
6590         if (warning.init_self && entity == current_init_decl && !in_type_prop
6591             && entity->kind == ENTITY_VARIABLE) {
6592                 current_init_decl = NULL;
6593                 warningf(HERE, "variable '%#T' is initialized by itself",
6594                          entity->declaration.type, entity->base.symbol);
6595         }
6596
6597         return expression;
6598 }
6599
6600 static bool semantic_cast(expression_t *cast)
6601 {
6602         expression_t            *expression      = cast->unary.value;
6603         type_t                  *orig_dest_type  = cast->base.type;
6604         type_t                  *orig_type_right = expression->base.type;
6605         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6606         type_t            const *src_type        = skip_typeref(orig_type_right);
6607         source_position_t const *pos             = &cast->base.source_position;
6608
6609         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6610         if (dst_type == type_void)
6611                 return true;
6612
6613         /* only integer and pointer can be casted to pointer */
6614         if (is_type_pointer(dst_type)  &&
6615             !is_type_pointer(src_type) &&
6616             !is_type_integer(src_type) &&
6617             is_type_valid(src_type)) {
6618                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6619                 return false;
6620         }
6621
6622         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6623                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6624                 return false;
6625         }
6626
6627         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6628                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6629                 return false;
6630         }
6631
6632         if (warning.cast_qual &&
6633             is_type_pointer(src_type) &&
6634             is_type_pointer(dst_type)) {
6635                 type_t *src = skip_typeref(src_type->pointer.points_to);
6636                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6637                 unsigned missing_qualifiers =
6638                         src->base.qualifiers & ~dst->base.qualifiers;
6639                 if (missing_qualifiers != 0) {
6640                         warningf(pos,
6641                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6642                                  missing_qualifiers, orig_type_right);
6643                 }
6644         }
6645         return true;
6646 }
6647
6648 static expression_t *parse_compound_literal(type_t *type)
6649 {
6650         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6651
6652         parse_initializer_env_t env;
6653         env.type             = type;
6654         env.entity           = NULL;
6655         env.must_be_constant = false;
6656         initializer_t *initializer = parse_initializer(&env);
6657         type = env.type;
6658
6659         expression->compound_literal.initializer = initializer;
6660         expression->compound_literal.type        = type;
6661         expression->base.type                    = automatic_type_conversion(type);
6662
6663         return expression;
6664 }
6665
6666 /**
6667  * Parse a cast expression.
6668  */
6669 static expression_t *parse_cast(void)
6670 {
6671         add_anchor_token(')');
6672
6673         source_position_t source_position = token.source_position;
6674
6675         type_t *type = parse_typename();
6676
6677         rem_anchor_token(')');
6678         expect(')', end_error);
6679
6680         if (token.type == '{') {
6681                 return parse_compound_literal(type);
6682         }
6683
6684         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6685         cast->base.source_position = source_position;
6686
6687         expression_t *value = parse_sub_expression(PREC_CAST);
6688         cast->base.type   = type;
6689         cast->unary.value = value;
6690
6691         if (! semantic_cast(cast)) {
6692                 /* TODO: record the error in the AST. else it is impossible to detect it */
6693         }
6694
6695         return cast;
6696 end_error:
6697         return create_invalid_expression();
6698 }
6699
6700 /**
6701  * Parse a statement expression.
6702  */
6703 static expression_t *parse_statement_expression(void)
6704 {
6705         add_anchor_token(')');
6706
6707         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6708
6709         statement_t *statement          = parse_compound_statement(true);
6710         statement->compound.stmt_expr   = true;
6711         expression->statement.statement = statement;
6712
6713         /* find last statement and use its type */
6714         type_t *type = type_void;
6715         const statement_t *stmt = statement->compound.statements;
6716         if (stmt != NULL) {
6717                 while (stmt->base.next != NULL)
6718                         stmt = stmt->base.next;
6719
6720                 if (stmt->kind == STATEMENT_EXPRESSION) {
6721                         type = stmt->expression.expression->base.type;
6722                 }
6723         } else if (warning.other) {
6724                 warningf(&expression->base.source_position, "empty statement expression ({})");
6725         }
6726         expression->base.type = type;
6727
6728         rem_anchor_token(')');
6729         expect(')', end_error);
6730
6731 end_error:
6732         return expression;
6733 }
6734
6735 /**
6736  * Parse a parenthesized expression.
6737  */
6738 static expression_t *parse_parenthesized_expression(void)
6739 {
6740         eat('(');
6741
6742         switch (token.type) {
6743         case '{':
6744                 /* gcc extension: a statement expression */
6745                 return parse_statement_expression();
6746
6747         TYPE_QUALIFIERS
6748         TYPE_SPECIFIERS
6749                 return parse_cast();
6750         case T_IDENTIFIER:
6751                 if (is_typedef_symbol(token.v.symbol)) {
6752                         return parse_cast();
6753                 }
6754         }
6755
6756         add_anchor_token(')');
6757         expression_t *result = parse_expression();
6758         result->base.parenthesized = true;
6759         rem_anchor_token(')');
6760         expect(')', end_error);
6761
6762 end_error:
6763         return result;
6764 }
6765
6766 static expression_t *parse_function_keyword(void)
6767 {
6768         /* TODO */
6769
6770         if (current_function == NULL) {
6771                 errorf(HERE, "'__func__' used outside of a function");
6772         }
6773
6774         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6775         expression->base.type     = type_char_ptr;
6776         expression->funcname.kind = FUNCNAME_FUNCTION;
6777
6778         next_token();
6779
6780         return expression;
6781 }
6782
6783 static expression_t *parse_pretty_function_keyword(void)
6784 {
6785         if (current_function == NULL) {
6786                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6787         }
6788
6789         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6790         expression->base.type     = type_char_ptr;
6791         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6792
6793         eat(T___PRETTY_FUNCTION__);
6794
6795         return expression;
6796 }
6797
6798 static expression_t *parse_funcsig_keyword(void)
6799 {
6800         if (current_function == NULL) {
6801                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6802         }
6803
6804         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6805         expression->base.type     = type_char_ptr;
6806         expression->funcname.kind = FUNCNAME_FUNCSIG;
6807
6808         eat(T___FUNCSIG__);
6809
6810         return expression;
6811 }
6812
6813 static expression_t *parse_funcdname_keyword(void)
6814 {
6815         if (current_function == NULL) {
6816                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6817         }
6818
6819         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6820         expression->base.type     = type_char_ptr;
6821         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6822
6823         eat(T___FUNCDNAME__);
6824
6825         return expression;
6826 }
6827
6828 static designator_t *parse_designator(void)
6829 {
6830         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6831         result->source_position = *HERE;
6832
6833         if (token.type != T_IDENTIFIER) {
6834                 parse_error_expected("while parsing member designator",
6835                                      T_IDENTIFIER, NULL);
6836                 return NULL;
6837         }
6838         result->symbol = token.v.symbol;
6839         next_token();
6840
6841         designator_t *last_designator = result;
6842         while (true) {
6843                 if (token.type == '.') {
6844                         next_token();
6845                         if (token.type != T_IDENTIFIER) {
6846                                 parse_error_expected("while parsing member designator",
6847                                                      T_IDENTIFIER, NULL);
6848                                 return NULL;
6849                         }
6850                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6851                         designator->source_position = *HERE;
6852                         designator->symbol          = token.v.symbol;
6853                         next_token();
6854
6855                         last_designator->next = designator;
6856                         last_designator       = designator;
6857                         continue;
6858                 }
6859                 if (token.type == '[') {
6860                         next_token();
6861                         add_anchor_token(']');
6862                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6863                         designator->source_position = *HERE;
6864                         designator->array_index     = parse_expression();
6865                         rem_anchor_token(']');
6866                         expect(']', end_error);
6867                         if (designator->array_index == NULL) {
6868                                 return NULL;
6869                         }
6870
6871                         last_designator->next = designator;
6872                         last_designator       = designator;
6873                         continue;
6874                 }
6875                 break;
6876         }
6877
6878         return result;
6879 end_error:
6880         return NULL;
6881 }
6882
6883 /**
6884  * Parse the __builtin_offsetof() expression.
6885  */
6886 static expression_t *parse_offsetof(void)
6887 {
6888         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6889         expression->base.type    = type_size_t;
6890
6891         eat(T___builtin_offsetof);
6892
6893         expect('(', end_error);
6894         add_anchor_token(',');
6895         type_t *type = parse_typename();
6896         rem_anchor_token(',');
6897         expect(',', end_error);
6898         add_anchor_token(')');
6899         designator_t *designator = parse_designator();
6900         rem_anchor_token(')');
6901         expect(')', end_error);
6902
6903         expression->offsetofe.type       = type;
6904         expression->offsetofe.designator = designator;
6905
6906         type_path_t path;
6907         memset(&path, 0, sizeof(path));
6908         path.top_type = type;
6909         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6910
6911         descend_into_subtype(&path);
6912
6913         if (!walk_designator(&path, designator, true)) {
6914                 return create_invalid_expression();
6915         }
6916
6917         DEL_ARR_F(path.path);
6918
6919         return expression;
6920 end_error:
6921         return create_invalid_expression();
6922 }
6923
6924 /**
6925  * Parses a _builtin_va_start() expression.
6926  */
6927 static expression_t *parse_va_start(void)
6928 {
6929         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6930
6931         eat(T___builtin_va_start);
6932
6933         expect('(', end_error);
6934         add_anchor_token(',');
6935         expression->va_starte.ap = parse_assignment_expression();
6936         rem_anchor_token(',');
6937         expect(',', end_error);
6938         expression_t *const expr = parse_assignment_expression();
6939         if (expr->kind == EXPR_REFERENCE) {
6940                 entity_t *const entity = expr->reference.entity;
6941                 if (!current_function->base.type->function.variadic) {
6942                         errorf(&expr->base.source_position,
6943                                         "'va_start' used in non-variadic function");
6944                 } else if (entity->base.parent_scope != &current_function->parameters ||
6945                                 entity->base.next != NULL ||
6946                                 entity->kind != ENTITY_PARAMETER) {
6947                         errorf(&expr->base.source_position,
6948                                "second argument of 'va_start' must be last parameter of the current function");
6949                 } else {
6950                         expression->va_starte.parameter = &entity->variable;
6951                 }
6952                 expect(')', end_error);
6953                 return expression;
6954         }
6955         expect(')', end_error);
6956 end_error:
6957         return create_invalid_expression();
6958 }
6959
6960 /**
6961  * Parses a __builtin_va_arg() expression.
6962  */
6963 static expression_t *parse_va_arg(void)
6964 {
6965         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6966
6967         eat(T___builtin_va_arg);
6968
6969         expect('(', end_error);
6970         call_argument_t ap;
6971         ap.expression = parse_assignment_expression();
6972         expression->va_arge.ap = ap.expression;
6973         check_call_argument(type_valist, &ap, 1);
6974
6975         expect(',', end_error);
6976         expression->base.type = parse_typename();
6977         expect(')', end_error);
6978
6979         return expression;
6980 end_error:
6981         return create_invalid_expression();
6982 }
6983
6984 /**
6985  * Parses a __builtin_va_copy() expression.
6986  */
6987 static expression_t *parse_va_copy(void)
6988 {
6989         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6990
6991         eat(T___builtin_va_copy);
6992
6993         expect('(', end_error);
6994         expression_t *dst = parse_assignment_expression();
6995         assign_error_t error = semantic_assign(type_valist, dst);
6996         report_assign_error(error, type_valist, dst, "call argument 1",
6997                             &dst->base.source_position);
6998         expression->va_copye.dst = dst;
6999
7000         expect(',', end_error);
7001
7002         call_argument_t src;
7003         src.expression = parse_assignment_expression();
7004         check_call_argument(type_valist, &src, 2);
7005         expression->va_copye.src = src.expression;
7006         expect(')', end_error);
7007
7008         return expression;
7009 end_error:
7010         return create_invalid_expression();
7011 }
7012
7013 /**
7014  * Parses a __builtin_constant_p() expression.
7015  */
7016 static expression_t *parse_builtin_constant(void)
7017 {
7018         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7019
7020         eat(T___builtin_constant_p);
7021
7022         expect('(', end_error);
7023         add_anchor_token(')');
7024         expression->builtin_constant.value = parse_assignment_expression();
7025         rem_anchor_token(')');
7026         expect(')', end_error);
7027         expression->base.type = type_int;
7028
7029         return expression;
7030 end_error:
7031         return create_invalid_expression();
7032 }
7033
7034 /**
7035  * Parses a __builtin_types_compatible_p() expression.
7036  */
7037 static expression_t *parse_builtin_types_compatible(void)
7038 {
7039         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7040
7041         eat(T___builtin_types_compatible_p);
7042
7043         expect('(', end_error);
7044         add_anchor_token(')');
7045         add_anchor_token(',');
7046         expression->builtin_types_compatible.left = parse_typename();
7047         rem_anchor_token(',');
7048         expect(',', end_error);
7049         expression->builtin_types_compatible.right = parse_typename();
7050         rem_anchor_token(')');
7051         expect(')', end_error);
7052         expression->base.type = type_int;
7053
7054         return expression;
7055 end_error:
7056         return create_invalid_expression();
7057 }
7058
7059 /**
7060  * Parses a __builtin_is_*() compare expression.
7061  */
7062 static expression_t *parse_compare_builtin(void)
7063 {
7064         expression_t *expression;
7065
7066         switch (token.type) {
7067         case T___builtin_isgreater:
7068                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7069                 break;
7070         case T___builtin_isgreaterequal:
7071                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7072                 break;
7073         case T___builtin_isless:
7074                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7075                 break;
7076         case T___builtin_islessequal:
7077                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7078                 break;
7079         case T___builtin_islessgreater:
7080                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7081                 break;
7082         case T___builtin_isunordered:
7083                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7084                 break;
7085         default:
7086                 internal_errorf(HERE, "invalid compare builtin found");
7087         }
7088         expression->base.source_position = *HERE;
7089         next_token();
7090
7091         expect('(', end_error);
7092         expression->binary.left = parse_assignment_expression();
7093         expect(',', end_error);
7094         expression->binary.right = parse_assignment_expression();
7095         expect(')', end_error);
7096
7097         type_t *const orig_type_left  = expression->binary.left->base.type;
7098         type_t *const orig_type_right = expression->binary.right->base.type;
7099
7100         type_t *const type_left  = skip_typeref(orig_type_left);
7101         type_t *const type_right = skip_typeref(orig_type_right);
7102         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7103                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7104                         type_error_incompatible("invalid operands in comparison",
7105                                 &expression->base.source_position, orig_type_left, orig_type_right);
7106                 }
7107         } else {
7108                 semantic_comparison(&expression->binary);
7109         }
7110
7111         return expression;
7112 end_error:
7113         return create_invalid_expression();
7114 }
7115
7116 /**
7117  * Parses a MS assume() expression.
7118  */
7119 static expression_t *parse_assume(void)
7120 {
7121         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7122
7123         eat(T__assume);
7124
7125         expect('(', end_error);
7126         add_anchor_token(')');
7127         expression->unary.value = parse_assignment_expression();
7128         rem_anchor_token(')');
7129         expect(')', end_error);
7130
7131         expression->base.type = type_void;
7132         return expression;
7133 end_error:
7134         return create_invalid_expression();
7135 }
7136
7137 /**
7138  * Return the declaration for a given label symbol or create a new one.
7139  *
7140  * @param symbol  the symbol of the label
7141  */
7142 static label_t *get_label(symbol_t *symbol)
7143 {
7144         entity_t *label;
7145         assert(current_function != NULL);
7146
7147         label = get_entity(symbol, NAMESPACE_LABEL);
7148         /* if we found a local label, we already created the declaration */
7149         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7150                 if (label->base.parent_scope != current_scope) {
7151                         assert(label->base.parent_scope->depth < current_scope->depth);
7152                         current_function->goto_to_outer = true;
7153                 }
7154                 return &label->label;
7155         }
7156
7157         label = get_entity(symbol, NAMESPACE_LABEL);
7158         /* if we found a label in the same function, then we already created the
7159          * declaration */
7160         if (label != NULL
7161                         && label->base.parent_scope == &current_function->parameters) {
7162                 return &label->label;
7163         }
7164
7165         /* otherwise we need to create a new one */
7166         label               = allocate_entity_zero(ENTITY_LABEL);
7167         label->base.namespc = NAMESPACE_LABEL;
7168         label->base.symbol  = symbol;
7169
7170         label_push(label);
7171
7172         return &label->label;
7173 }
7174
7175 /**
7176  * Parses a GNU && label address expression.
7177  */
7178 static expression_t *parse_label_address(void)
7179 {
7180         source_position_t source_position = token.source_position;
7181         eat(T_ANDAND);
7182         if (token.type != T_IDENTIFIER) {
7183                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7184                 goto end_error;
7185         }
7186         symbol_t *symbol = token.v.symbol;
7187         next_token();
7188
7189         label_t *label       = get_label(symbol);
7190         label->used          = true;
7191         label->address_taken = true;
7192
7193         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7194         expression->base.source_position = source_position;
7195
7196         /* label address is threaten as a void pointer */
7197         expression->base.type           = type_void_ptr;
7198         expression->label_address.label = label;
7199         return expression;
7200 end_error:
7201         return create_invalid_expression();
7202 }
7203
7204 /**
7205  * Parse a microsoft __noop expression.
7206  */
7207 static expression_t *parse_noop_expression(void)
7208 {
7209         /* the result is a (int)0 */
7210         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7211         cnst->base.type            = type_int;
7212         cnst->conste.v.int_value   = 0;
7213         cnst->conste.is_ms_noop    = true;
7214
7215         eat(T___noop);
7216
7217         if (token.type == '(') {
7218                 /* parse arguments */
7219                 eat('(');
7220                 add_anchor_token(')');
7221                 add_anchor_token(',');
7222
7223                 if (token.type != ')') {
7224                         while (true) {
7225                                 (void)parse_assignment_expression();
7226                                 if (token.type != ',')
7227                                         break;
7228                                 next_token();
7229                         }
7230                 }
7231         }
7232         rem_anchor_token(',');
7233         rem_anchor_token(')');
7234         expect(')', end_error);
7235
7236 end_error:
7237         return cnst;
7238 }
7239
7240 /**
7241  * Parses a primary expression.
7242  */
7243 static expression_t *parse_primary_expression(void)
7244 {
7245         switch (token.type) {
7246                 case T_false:                        return parse_bool_const(false);
7247                 case T_true:                         return parse_bool_const(true);
7248                 case T_INTEGER:                      return parse_int_const();
7249                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7250                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7251                 case T_FLOATINGPOINT:                return parse_float_const();
7252                 case T_STRING_LITERAL:
7253                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7254                 case T___FUNCTION__:
7255                 case T___func__:                     return parse_function_keyword();
7256                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7257                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7258                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7259                 case T___builtin_offsetof:           return parse_offsetof();
7260                 case T___builtin_va_start:           return parse_va_start();
7261                 case T___builtin_va_arg:             return parse_va_arg();
7262                 case T___builtin_va_copy:            return parse_va_copy();
7263                 case T___builtin_isgreater:
7264                 case T___builtin_isgreaterequal:
7265                 case T___builtin_isless:
7266                 case T___builtin_islessequal:
7267                 case T___builtin_islessgreater:
7268                 case T___builtin_isunordered:        return parse_compare_builtin();
7269                 case T___builtin_constant_p:         return parse_builtin_constant();
7270                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7271                 case T__assume:                      return parse_assume();
7272                 case T_ANDAND:
7273                         if (GNU_MODE)
7274                                 return parse_label_address();
7275                         break;
7276
7277                 case '(':                            return parse_parenthesized_expression();
7278                 case T___noop:                       return parse_noop_expression();
7279
7280                 /* Gracefully handle type names while parsing expressions. */
7281                 case T_COLONCOLON:
7282                         return parse_reference();
7283                 case T_IDENTIFIER:
7284                         if (!is_typedef_symbol(token.v.symbol)) {
7285                                 return parse_reference();
7286                         }
7287                         /* FALLTHROUGH */
7288                 TYPENAME_START {
7289                         source_position_t  const pos  = *HERE;
7290                         type_t const      *const type = parse_typename();
7291                         errorf(&pos, "encountered type '%T' while parsing expression", type);
7292                         return create_invalid_expression();
7293                 }
7294         }
7295
7296         errorf(HERE, "unexpected token %K, expected an expression", &token);
7297         return create_invalid_expression();
7298 }
7299
7300 /**
7301  * Check if the expression has the character type and issue a warning then.
7302  */
7303 static void check_for_char_index_type(const expression_t *expression)
7304 {
7305         type_t       *const type      = expression->base.type;
7306         const type_t *const base_type = skip_typeref(type);
7307
7308         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7309                         warning.char_subscripts) {
7310                 warningf(&expression->base.source_position,
7311                          "array subscript has type '%T'", type);
7312         }
7313 }
7314
7315 static expression_t *parse_array_expression(expression_t *left)
7316 {
7317         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7318
7319         eat('[');
7320         add_anchor_token(']');
7321
7322         expression_t *inside = parse_expression();
7323
7324         type_t *const orig_type_left   = left->base.type;
7325         type_t *const orig_type_inside = inside->base.type;
7326
7327         type_t *const type_left   = skip_typeref(orig_type_left);
7328         type_t *const type_inside = skip_typeref(orig_type_inside);
7329
7330         type_t                    *return_type;
7331         array_access_expression_t *array_access = &expression->array_access;
7332         if (is_type_pointer(type_left)) {
7333                 return_type             = type_left->pointer.points_to;
7334                 array_access->array_ref = left;
7335                 array_access->index     = inside;
7336                 check_for_char_index_type(inside);
7337         } else if (is_type_pointer(type_inside)) {
7338                 return_type             = type_inside->pointer.points_to;
7339                 array_access->array_ref = inside;
7340                 array_access->index     = left;
7341                 array_access->flipped   = true;
7342                 check_for_char_index_type(left);
7343         } else {
7344                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7345                         errorf(HERE,
7346                                 "array access on object with non-pointer types '%T', '%T'",
7347                                 orig_type_left, orig_type_inside);
7348                 }
7349                 return_type             = type_error_type;
7350                 array_access->array_ref = left;
7351                 array_access->index     = inside;
7352         }
7353
7354         expression->base.type = automatic_type_conversion(return_type);
7355
7356         rem_anchor_token(']');
7357         expect(']', end_error);
7358 end_error:
7359         return expression;
7360 }
7361
7362 static expression_t *parse_typeprop(expression_kind_t const kind)
7363 {
7364         expression_t  *tp_expression = allocate_expression_zero(kind);
7365         tp_expression->base.type     = type_size_t;
7366
7367         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7368
7369         /* we only refer to a type property, mark this case */
7370         bool old     = in_type_prop;
7371         in_type_prop = true;
7372
7373         type_t       *orig_type;
7374         expression_t *expression;
7375         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7376                 next_token();
7377                 add_anchor_token(')');
7378                 orig_type = parse_typename();
7379                 rem_anchor_token(')');
7380                 expect(')', end_error);
7381
7382                 if (token.type == '{') {
7383                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7384                          * starting with a compound literal */
7385                         expression = parse_compound_literal(orig_type);
7386                         goto typeprop_expression;
7387                 }
7388         } else {
7389                 expression = parse_sub_expression(PREC_UNARY);
7390
7391 typeprop_expression:
7392                 tp_expression->typeprop.tp_expression = expression;
7393
7394                 orig_type = revert_automatic_type_conversion(expression);
7395                 expression->base.type = orig_type;
7396         }
7397
7398         tp_expression->typeprop.type   = orig_type;
7399         type_t const* const type       = skip_typeref(orig_type);
7400         char   const* const wrong_type =
7401                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7402                 is_type_incomplete(type)                           ? "incomplete"          :
7403                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7404                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7405                 NULL;
7406         if (wrong_type != NULL) {
7407                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7408                 errorf(&tp_expression->base.source_position,
7409                                 "operand of %s expression must not be of %s type '%T'",
7410                                 what, wrong_type, orig_type);
7411         }
7412
7413 end_error:
7414         in_type_prop = old;
7415         return tp_expression;
7416 }
7417
7418 static expression_t *parse_sizeof(void)
7419 {
7420         return parse_typeprop(EXPR_SIZEOF);
7421 }
7422
7423 static expression_t *parse_alignof(void)
7424 {
7425         return parse_typeprop(EXPR_ALIGNOF);
7426 }
7427
7428 static expression_t *parse_select_expression(expression_t *addr)
7429 {
7430         assert(token.type == '.' || token.type == T_MINUSGREATER);
7431         bool select_left_arrow = (token.type == T_MINUSGREATER);
7432         next_token();
7433
7434         if (token.type != T_IDENTIFIER) {
7435                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7436                 return create_invalid_expression();
7437         }
7438         symbol_t *symbol = token.v.symbol;
7439         next_token();
7440
7441         type_t *const orig_type = addr->base.type;
7442         type_t *const type      = skip_typeref(orig_type);
7443
7444         type_t *type_left;
7445         bool    saw_error = false;
7446         if (is_type_pointer(type)) {
7447                 if (!select_left_arrow) {
7448                         errorf(HERE,
7449                                "request for member '%Y' in something not a struct or union, but '%T'",
7450                                symbol, orig_type);
7451                         saw_error = true;
7452                 }
7453                 type_left = skip_typeref(type->pointer.points_to);
7454         } else {
7455                 if (select_left_arrow && is_type_valid(type)) {
7456                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7457                         saw_error = true;
7458                 }
7459                 type_left = type;
7460         }
7461
7462         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7463             type_left->kind != TYPE_COMPOUND_UNION) {
7464
7465                 if (is_type_valid(type_left) && !saw_error) {
7466                         errorf(HERE,
7467                                "request for member '%Y' in something not a struct or union, but '%T'",
7468                                symbol, type_left);
7469                 }
7470                 return create_invalid_expression();
7471         }
7472
7473         compound_t *compound = type_left->compound.compound;
7474         if (!compound->complete) {
7475                 errorf(HERE, "request for member '%Y' in incomplete type '%T'",
7476                        symbol, type_left);
7477                 return create_invalid_expression();
7478         }
7479
7480         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7481         expression_t      *result
7482                 = find_create_select(HERE, addr, qualifiers, compound, symbol);
7483
7484         if (result == NULL) {
7485                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7486                 return create_invalid_expression();
7487         }
7488
7489         return result;
7490 }
7491
7492 static void check_call_argument(type_t          *expected_type,
7493                                 call_argument_t *argument, unsigned pos)
7494 {
7495         type_t         *expected_type_skip = skip_typeref(expected_type);
7496         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7497         expression_t   *arg_expr           = argument->expression;
7498         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7499
7500         /* handle transparent union gnu extension */
7501         if (is_type_union(expected_type_skip)
7502                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7503                 compound_t *union_decl  = expected_type_skip->compound.compound;
7504                 type_t     *best_type   = NULL;
7505                 entity_t   *entry       = union_decl->members.entities;
7506                 for ( ; entry != NULL; entry = entry->base.next) {
7507                         assert(is_declaration(entry));
7508                         type_t *decl_type = entry->declaration.type;
7509                         error = semantic_assign(decl_type, arg_expr);
7510                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7511                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7512                                 continue;
7513
7514                         if (error == ASSIGN_SUCCESS) {
7515                                 best_type = decl_type;
7516                         } else if (best_type == NULL) {
7517                                 best_type = decl_type;
7518                         }
7519                 }
7520
7521                 if (best_type != NULL) {
7522                         expected_type = best_type;
7523                 }
7524         }
7525
7526         error                = semantic_assign(expected_type, arg_expr);
7527         argument->expression = create_implicit_cast(arg_expr, expected_type);
7528
7529         if (error != ASSIGN_SUCCESS) {
7530                 /* report exact scope in error messages (like "in argument 3") */
7531                 char buf[64];
7532                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7533                 report_assign_error(error, expected_type, arg_expr,     buf,
7534                                                         &arg_expr->base.source_position);
7535         } else if (warning.traditional || warning.conversion) {
7536                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7537                 if (!types_compatible(expected_type_skip, promoted_type) &&
7538                     !types_compatible(expected_type_skip, type_void_ptr) &&
7539                     !types_compatible(type_void_ptr,      promoted_type)) {
7540                         /* Deliberately show the skipped types in this warning */
7541                         warningf(&arg_expr->base.source_position,
7542                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7543                                 pos, expected_type_skip, promoted_type);
7544                 }
7545         }
7546 }
7547
7548 /**
7549  * Handle the semantic restrictions of builtin calls
7550  */
7551 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7552         switch (call->function->reference.entity->function.btk) {
7553                 case bk_gnu_builtin_return_address:
7554                 case bk_gnu_builtin_frame_address: {
7555                         /* argument must be constant */
7556                         call_argument_t *argument = call->arguments;
7557
7558                         if (! is_constant_expression(argument->expression)) {
7559                                 errorf(&call->base.source_position,
7560                                        "argument of '%Y' must be a constant expression",
7561                                        call->function->reference.entity->base.symbol);
7562                         }
7563                         break;
7564                 }
7565                 case bk_gnu_builtin_prefetch: {
7566                         /* second and third argument must be constant if existent */
7567                         call_argument_t *rw = call->arguments->next;
7568                         call_argument_t *locality = NULL;
7569
7570                         if (rw != NULL) {
7571                                 if (! is_constant_expression(rw->expression)) {
7572                                         errorf(&call->base.source_position,
7573                                                "second argument of '%Y' must be a constant expression",
7574                                                call->function->reference.entity->base.symbol);
7575                                 }
7576                                 locality = rw->next;
7577                         }
7578                         if (locality != NULL) {
7579                                 if (! is_constant_expression(locality->expression)) {
7580                                         errorf(&call->base.source_position,
7581                                                "third argument of '%Y' must be a constant expression",
7582                                                call->function->reference.entity->base.symbol);
7583                                 }
7584                                 locality = rw->next;
7585                         }
7586                         break;
7587                 }
7588                 default:
7589                         break;
7590         }
7591 }
7592
7593 /**
7594  * Parse a call expression, ie. expression '( ... )'.
7595  *
7596  * @param expression  the function address
7597  */
7598 static expression_t *parse_call_expression(expression_t *expression)
7599 {
7600         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7601         call_expression_t *call   = &result->call;
7602         call->function            = expression;
7603
7604         type_t *const orig_type = expression->base.type;
7605         type_t *const type      = skip_typeref(orig_type);
7606
7607         function_type_t *function_type = NULL;
7608         if (is_type_pointer(type)) {
7609                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7610
7611                 if (is_type_function(to_type)) {
7612                         function_type   = &to_type->function;
7613                         call->base.type = function_type->return_type;
7614                 }
7615         }
7616
7617         if (function_type == NULL && is_type_valid(type)) {
7618                 errorf(HERE,
7619                        "called object '%E' (type '%T') is not a pointer to a function",
7620                        expression, orig_type);
7621         }
7622
7623         /* parse arguments */
7624         eat('(');
7625         add_anchor_token(')');
7626         add_anchor_token(',');
7627
7628         if (token.type != ')') {
7629                 call_argument_t **anchor = &call->arguments;
7630                 for (;;) {
7631                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7632                         argument->expression = parse_assignment_expression();
7633
7634                         *anchor = argument;
7635                         anchor  = &argument->next;
7636
7637                         if (token.type != ',')
7638                                 break;
7639                         next_token();
7640                 }
7641         }
7642         rem_anchor_token(',');
7643         rem_anchor_token(')');
7644         expect(')', end_error);
7645
7646         if (function_type == NULL)
7647                 return result;
7648
7649         /* check type and count of call arguments */
7650         function_parameter_t *parameter = function_type->parameters;
7651         call_argument_t      *argument  = call->arguments;
7652         if (!function_type->unspecified_parameters) {
7653                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7654                                 parameter = parameter->next, argument = argument->next) {
7655                         check_call_argument(parameter->type, argument, ++pos);
7656                 }
7657
7658                 if (parameter != NULL) {
7659                         errorf(HERE, "too few arguments to function '%E'", expression);
7660                 } else if (argument != NULL && !function_type->variadic) {
7661                         errorf(HERE, "too many arguments to function '%E'", expression);
7662                 }
7663         }
7664
7665         /* do default promotion for other arguments */
7666         for (; argument != NULL; argument = argument->next) {
7667                 type_t *type = argument->expression->base.type;
7668
7669                 type = get_default_promoted_type(type);
7670
7671                 argument->expression
7672                         = create_implicit_cast(argument->expression, type);
7673         }
7674
7675         check_format(&result->call);
7676
7677         if (warning.aggregate_return &&
7678             is_type_compound(skip_typeref(function_type->return_type))) {
7679                 warningf(&result->base.source_position,
7680                          "function call has aggregate value");
7681         }
7682
7683         if (call->function->kind == EXPR_REFERENCE) {
7684                 reference_expression_t *reference = &call->function->reference;
7685                 if (reference->entity->kind == ENTITY_FUNCTION &&
7686                     reference->entity->function.btk != bk_none)
7687                         handle_builtin_argument_restrictions(call);
7688         }
7689
7690 end_error:
7691         return result;
7692 }
7693
7694 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7695
7696 static bool same_compound_type(const type_t *type1, const type_t *type2)
7697 {
7698         return
7699                 is_type_compound(type1) &&
7700                 type1->kind == type2->kind &&
7701                 type1->compound.compound == type2->compound.compound;
7702 }
7703
7704 static expression_t const *get_reference_address(expression_t const *expr)
7705 {
7706         bool regular_take_address = true;
7707         for (;;) {
7708                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7709                         expr = expr->unary.value;
7710                 } else {
7711                         regular_take_address = false;
7712                 }
7713
7714                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7715                         break;
7716
7717                 expr = expr->unary.value;
7718         }
7719
7720         if (expr->kind != EXPR_REFERENCE)
7721                 return NULL;
7722
7723         /* special case for functions which are automatically converted to a
7724          * pointer to function without an extra TAKE_ADDRESS operation */
7725         if (!regular_take_address &&
7726                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7727                 return NULL;
7728         }
7729
7730         return expr;
7731 }
7732
7733 static void warn_reference_address_as_bool(expression_t const* expr)
7734 {
7735         if (!warning.address)
7736                 return;
7737
7738         expr = get_reference_address(expr);
7739         if (expr != NULL) {
7740                 warningf(&expr->base.source_position,
7741                          "the address of '%Y' will always evaluate as 'true'",
7742                          expr->reference.entity->base.symbol);
7743         }
7744 }
7745
7746 static void warn_assignment_in_condition(const expression_t *const expr)
7747 {
7748         if (!warning.parentheses)
7749                 return;
7750         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7751                 return;
7752         if (expr->base.parenthesized)
7753                 return;
7754         warningf(&expr->base.source_position,
7755                         "suggest parentheses around assignment used as truth value");
7756 }
7757
7758 static void semantic_condition(expression_t const *const expr,
7759                                char const *const context)
7760 {
7761         type_t *const type = skip_typeref(expr->base.type);
7762         if (is_type_scalar(type)) {
7763                 warn_reference_address_as_bool(expr);
7764                 warn_assignment_in_condition(expr);
7765         } else if (is_type_valid(type)) {
7766                 errorf(&expr->base.source_position,
7767                                 "%s must have scalar type", context);
7768         }
7769 }
7770
7771 /**
7772  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7773  *
7774  * @param expression  the conditional expression
7775  */
7776 static expression_t *parse_conditional_expression(expression_t *expression)
7777 {
7778         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7779
7780         conditional_expression_t *conditional = &result->conditional;
7781         conditional->condition                = expression;
7782
7783         eat('?');
7784         add_anchor_token(':');
7785
7786         /* §6.5.15:2  The first operand shall have scalar type. */
7787         semantic_condition(expression, "condition of conditional operator");
7788
7789         expression_t *true_expression = expression;
7790         bool          gnu_cond = false;
7791         if (GNU_MODE && token.type == ':') {
7792                 gnu_cond = true;
7793         } else {
7794                 true_expression = parse_expression();
7795         }
7796         rem_anchor_token(':');
7797         expect(':', end_error);
7798 end_error:;
7799         expression_t *false_expression =
7800                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7801
7802         type_t *const orig_true_type  = true_expression->base.type;
7803         type_t *const orig_false_type = false_expression->base.type;
7804         type_t *const true_type       = skip_typeref(orig_true_type);
7805         type_t *const false_type      = skip_typeref(orig_false_type);
7806
7807         /* 6.5.15.3 */
7808         type_t *result_type;
7809         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7810                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7811                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7812                 if (true_expression->kind == EXPR_UNARY_THROW) {
7813                         result_type = false_type;
7814                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7815                         result_type = true_type;
7816                 } else {
7817                         if (warning.other && (
7818                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7819                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7820                                         )) {
7821                                 warningf(&conditional->base.source_position,
7822                                                 "ISO C forbids conditional expression with only one void side");
7823                         }
7824                         result_type = type_void;
7825                 }
7826         } else if (is_type_arithmetic(true_type)
7827                    && is_type_arithmetic(false_type)) {
7828                 result_type = semantic_arithmetic(true_type, false_type);
7829
7830                 true_expression  = create_implicit_cast(true_expression, result_type);
7831                 false_expression = create_implicit_cast(false_expression, result_type);
7832
7833                 conditional->true_expression  = true_expression;
7834                 conditional->false_expression = false_expression;
7835                 conditional->base.type        = result_type;
7836         } else if (same_compound_type(true_type, false_type)) {
7837                 /* just take 1 of the 2 types */
7838                 result_type = true_type;
7839         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7840                 type_t *pointer_type;
7841                 type_t *other_type;
7842                 expression_t *other_expression;
7843                 if (is_type_pointer(true_type) &&
7844                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7845                         pointer_type     = true_type;
7846                         other_type       = false_type;
7847                         other_expression = false_expression;
7848                 } else {
7849                         pointer_type     = false_type;
7850                         other_type       = true_type;
7851                         other_expression = true_expression;
7852                 }
7853
7854                 if (is_null_pointer_constant(other_expression)) {
7855                         result_type = pointer_type;
7856                 } else if (is_type_pointer(other_type)) {
7857                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7858                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7859
7860                         type_t *to;
7861                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7862                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7863                                 to = type_void;
7864                         } else if (types_compatible(get_unqualified_type(to1),
7865                                                     get_unqualified_type(to2))) {
7866                                 to = to1;
7867                         } else {
7868                                 if (warning.other) {
7869                                         warningf(&conditional->base.source_position,
7870                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7871                                                         true_type, false_type);
7872                                 }
7873                                 to = type_void;
7874                         }
7875
7876                         type_t *const type =
7877                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7878                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7879                 } else if (is_type_integer(other_type)) {
7880                         if (warning.other) {
7881                                 warningf(&conditional->base.source_position,
7882                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7883                         }
7884                         result_type = pointer_type;
7885                 } else {
7886                         if (is_type_valid(other_type)) {
7887                                 type_error_incompatible("while parsing conditional",
7888                                                 &expression->base.source_position, true_type, false_type);
7889                         }
7890                         result_type = type_error_type;
7891                 }
7892         } else {
7893                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7894                         type_error_incompatible("while parsing conditional",
7895                                                 &conditional->base.source_position, true_type,
7896                                                 false_type);
7897                 }
7898                 result_type = type_error_type;
7899         }
7900
7901         conditional->true_expression
7902                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7903         conditional->false_expression
7904                 = create_implicit_cast(false_expression, result_type);
7905         conditional->base.type = result_type;
7906         return result;
7907 }
7908
7909 /**
7910  * Parse an extension expression.
7911  */
7912 static expression_t *parse_extension(void)
7913 {
7914         eat(T___extension__);
7915
7916         bool old_gcc_extension   = in_gcc_extension;
7917         in_gcc_extension         = true;
7918         expression_t *expression = parse_sub_expression(PREC_UNARY);
7919         in_gcc_extension         = old_gcc_extension;
7920         return expression;
7921 }
7922
7923 /**
7924  * Parse a __builtin_classify_type() expression.
7925  */
7926 static expression_t *parse_builtin_classify_type(void)
7927 {
7928         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7929         result->base.type    = type_int;
7930
7931         eat(T___builtin_classify_type);
7932
7933         expect('(', end_error);
7934         add_anchor_token(')');
7935         expression_t *expression = parse_expression();
7936         rem_anchor_token(')');
7937         expect(')', end_error);
7938         result->classify_type.type_expression = expression;
7939
7940         return result;
7941 end_error:
7942         return create_invalid_expression();
7943 }
7944
7945 /**
7946  * Parse a delete expression
7947  * ISO/IEC 14882:1998(E) §5.3.5
7948  */
7949 static expression_t *parse_delete(void)
7950 {
7951         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7952         result->base.type          = type_void;
7953
7954         eat(T_delete);
7955
7956         if (token.type == '[') {
7957                 next_token();
7958                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7959                 expect(']', end_error);
7960 end_error:;
7961         }
7962
7963         expression_t *const value = parse_sub_expression(PREC_CAST);
7964         result->unary.value = value;
7965
7966         type_t *const type = skip_typeref(value->base.type);
7967         if (!is_type_pointer(type)) {
7968                 if (is_type_valid(type)) {
7969                         errorf(&value->base.source_position,
7970                                         "operand of delete must have pointer type");
7971                 }
7972         } else if (warning.other &&
7973                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7974                 warningf(&value->base.source_position,
7975                                 "deleting 'void*' is undefined");
7976         }
7977
7978         return result;
7979 }
7980
7981 /**
7982  * Parse a throw expression
7983  * ISO/IEC 14882:1998(E) §15:1
7984  */
7985 static expression_t *parse_throw(void)
7986 {
7987         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7988         result->base.type          = type_void;
7989
7990         eat(T_throw);
7991
7992         expression_t *value = NULL;
7993         switch (token.type) {
7994                 EXPRESSION_START {
7995                         value = parse_assignment_expression();
7996                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7997                         type_t *const orig_type = value->base.type;
7998                         type_t *const type      = skip_typeref(orig_type);
7999                         if (is_type_incomplete(type)) {
8000                                 errorf(&value->base.source_position,
8001                                                 "cannot throw object of incomplete type '%T'", orig_type);
8002                         } else if (is_type_pointer(type)) {
8003                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8004                                 if (is_type_incomplete(points_to) &&
8005                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8006                                         errorf(&value->base.source_position,
8007                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8008                                 }
8009                         }
8010                 }
8011
8012                 default:
8013                         break;
8014         }
8015         result->unary.value = value;
8016
8017         return result;
8018 }
8019
8020 static bool check_pointer_arithmetic(const source_position_t *source_position,
8021                                      type_t *pointer_type,
8022                                      type_t *orig_pointer_type)
8023 {
8024         type_t *points_to = pointer_type->pointer.points_to;
8025         points_to = skip_typeref(points_to);
8026
8027         if (is_type_incomplete(points_to)) {
8028                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8029                         errorf(source_position,
8030                                "arithmetic with pointer to incomplete type '%T' not allowed",
8031                                orig_pointer_type);
8032                         return false;
8033                 } else if (warning.pointer_arith) {
8034                         warningf(source_position,
8035                                  "pointer of type '%T' used in arithmetic",
8036                                  orig_pointer_type);
8037                 }
8038         } else if (is_type_function(points_to)) {
8039                 if (!GNU_MODE) {
8040                         errorf(source_position,
8041                                "arithmetic with pointer to function type '%T' not allowed",
8042                                orig_pointer_type);
8043                         return false;
8044                 } else if (warning.pointer_arith) {
8045                         warningf(source_position,
8046                                  "pointer to a function '%T' used in arithmetic",
8047                                  orig_pointer_type);
8048                 }
8049         }
8050         return true;
8051 }
8052
8053 static bool is_lvalue(const expression_t *expression)
8054 {
8055         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8056         switch (expression->kind) {
8057         case EXPR_ARRAY_ACCESS:
8058         case EXPR_COMPOUND_LITERAL:
8059         case EXPR_REFERENCE:
8060         case EXPR_SELECT:
8061         case EXPR_UNARY_DEREFERENCE:
8062                 return true;
8063
8064         default: {
8065           type_t *type = skip_typeref(expression->base.type);
8066           return
8067                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8068                 is_type_reference(type) ||
8069                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8070                  * error before, which maybe prevented properly recognizing it as
8071                  * lvalue. */
8072                 !is_type_valid(type);
8073         }
8074         }
8075 }
8076
8077 static void semantic_incdec(unary_expression_t *expression)
8078 {
8079         type_t *const orig_type = expression->value->base.type;
8080         type_t *const type      = skip_typeref(orig_type);
8081         if (is_type_pointer(type)) {
8082                 if (!check_pointer_arithmetic(&expression->base.source_position,
8083                                               type, orig_type)) {
8084                         return;
8085                 }
8086         } else if (!is_type_real(type) && is_type_valid(type)) {
8087                 /* TODO: improve error message */
8088                 errorf(&expression->base.source_position,
8089                        "operation needs an arithmetic or pointer type");
8090                 return;
8091         }
8092         if (!is_lvalue(expression->value)) {
8093                 /* TODO: improve error message */
8094                 errorf(&expression->base.source_position, "lvalue required as operand");
8095         }
8096         expression->base.type = orig_type;
8097 }
8098
8099 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8100 {
8101         type_t *const orig_type = expression->value->base.type;
8102         type_t *const type      = skip_typeref(orig_type);
8103         if (!is_type_arithmetic(type)) {
8104                 if (is_type_valid(type)) {
8105                         /* TODO: improve error message */
8106                         errorf(&expression->base.source_position,
8107                                 "operation needs an arithmetic type");
8108                 }
8109                 return;
8110         }
8111
8112         expression->base.type = orig_type;
8113 }
8114
8115 static void semantic_unexpr_plus(unary_expression_t *expression)
8116 {
8117         semantic_unexpr_arithmetic(expression);
8118         if (warning.traditional)
8119                 warningf(&expression->base.source_position,
8120                         "traditional C rejects the unary plus operator");
8121 }
8122
8123 static void semantic_not(unary_expression_t *expression)
8124 {
8125         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8126         semantic_condition(expression->value, "operand of !");
8127         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8128 }
8129
8130 static void semantic_unexpr_integer(unary_expression_t *expression)
8131 {
8132         type_t *const orig_type = expression->value->base.type;
8133         type_t *const type      = skip_typeref(orig_type);
8134         if (!is_type_integer(type)) {
8135                 if (is_type_valid(type)) {
8136                         errorf(&expression->base.source_position,
8137                                "operand of ~ must be of integer type");
8138                 }
8139                 return;
8140         }
8141
8142         expression->base.type = orig_type;
8143 }
8144
8145 static void semantic_dereference(unary_expression_t *expression)
8146 {
8147         type_t *const orig_type = expression->value->base.type;
8148         type_t *const type      = skip_typeref(orig_type);
8149         if (!is_type_pointer(type)) {
8150                 if (is_type_valid(type)) {
8151                         errorf(&expression->base.source_position,
8152                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8153                 }
8154                 return;
8155         }
8156
8157         type_t *result_type   = type->pointer.points_to;
8158         result_type           = automatic_type_conversion(result_type);
8159         expression->base.type = result_type;
8160 }
8161
8162 /**
8163  * Record that an address is taken (expression represents an lvalue).
8164  *
8165  * @param expression       the expression
8166  * @param may_be_register  if true, the expression might be an register
8167  */
8168 static void set_address_taken(expression_t *expression, bool may_be_register)
8169 {
8170         if (expression->kind != EXPR_REFERENCE)
8171                 return;
8172
8173         entity_t *const entity = expression->reference.entity;
8174
8175         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8176                 return;
8177
8178         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8179                         && !may_be_register) {
8180                 errorf(&expression->base.source_position,
8181                                 "address of register %s '%Y' requested",
8182                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8183         }
8184
8185         if (entity->kind == ENTITY_VARIABLE) {
8186                 entity->variable.address_taken = true;
8187         } else {
8188                 assert(entity->kind == ENTITY_PARAMETER);
8189                 entity->parameter.address_taken = true;
8190         }
8191 }
8192
8193 /**
8194  * Check the semantic of the address taken expression.
8195  */
8196 static void semantic_take_addr(unary_expression_t *expression)
8197 {
8198         expression_t *value = expression->value;
8199         value->base.type    = revert_automatic_type_conversion(value);
8200
8201         type_t *orig_type = value->base.type;
8202         type_t *type      = skip_typeref(orig_type);
8203         if (!is_type_valid(type))
8204                 return;
8205
8206         /* §6.5.3.2 */
8207         if (!is_lvalue(value)) {
8208                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8209         }
8210         if (type->kind == TYPE_BITFIELD) {
8211                 errorf(&expression->base.source_position,
8212                        "'&' not allowed on object with bitfield type '%T'",
8213                        type);
8214         }
8215
8216         set_address_taken(value, false);
8217
8218         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8219 }
8220
8221 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8222 static expression_t *parse_##unexpression_type(void)                         \
8223 {                                                                            \
8224         expression_t *unary_expression                                           \
8225                 = allocate_expression_zero(unexpression_type);                       \
8226         eat(token_type);                                                         \
8227         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8228                                                                                  \
8229         sfunc(&unary_expression->unary);                                         \
8230                                                                                  \
8231         return unary_expression;                                                 \
8232 }
8233
8234 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8235                                semantic_unexpr_arithmetic)
8236 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8237                                semantic_unexpr_plus)
8238 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8239                                semantic_not)
8240 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8241                                semantic_dereference)
8242 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8243                                semantic_take_addr)
8244 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8245                                semantic_unexpr_integer)
8246 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8247                                semantic_incdec)
8248 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8249                                semantic_incdec)
8250
8251 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8252                                                sfunc)                         \
8253 static expression_t *parse_##unexpression_type(expression_t *left)            \
8254 {                                                                             \
8255         expression_t *unary_expression                                            \
8256                 = allocate_expression_zero(unexpression_type);                        \
8257         eat(token_type);                                                          \
8258         unary_expression->unary.value = left;                                     \
8259                                                                                   \
8260         sfunc(&unary_expression->unary);                                          \
8261                                                                               \
8262         return unary_expression;                                                  \
8263 }
8264
8265 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8266                                        EXPR_UNARY_POSTFIX_INCREMENT,
8267                                        semantic_incdec)
8268 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8269                                        EXPR_UNARY_POSTFIX_DECREMENT,
8270                                        semantic_incdec)
8271
8272 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8273 {
8274         /* TODO: handle complex + imaginary types */
8275
8276         type_left  = get_unqualified_type(type_left);
8277         type_right = get_unqualified_type(type_right);
8278
8279         /* §6.3.1.8 Usual arithmetic conversions */
8280         if (type_left == type_long_double || type_right == type_long_double) {
8281                 return type_long_double;
8282         } else if (type_left == type_double || type_right == type_double) {
8283                 return type_double;
8284         } else if (type_left == type_float || type_right == type_float) {
8285                 return type_float;
8286         }
8287
8288         type_left  = promote_integer(type_left);
8289         type_right = promote_integer(type_right);
8290
8291         if (type_left == type_right)
8292                 return type_left;
8293
8294         bool const signed_left  = is_type_signed(type_left);
8295         bool const signed_right = is_type_signed(type_right);
8296         int const  rank_left    = get_rank(type_left);
8297         int const  rank_right   = get_rank(type_right);
8298
8299         if (signed_left == signed_right)
8300                 return rank_left >= rank_right ? type_left : type_right;
8301
8302         int     s_rank;
8303         int     u_rank;
8304         type_t *s_type;
8305         type_t *u_type;
8306         if (signed_left) {
8307                 s_rank = rank_left;
8308                 s_type = type_left;
8309                 u_rank = rank_right;
8310                 u_type = type_right;
8311         } else {
8312                 s_rank = rank_right;
8313                 s_type = type_right;
8314                 u_rank = rank_left;
8315                 u_type = type_left;
8316         }
8317
8318         if (u_rank >= s_rank)
8319                 return u_type;
8320
8321         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8322          * easier here... */
8323         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8324                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8325                 return s_type;
8326
8327         switch (s_rank) {
8328                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8329                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8330                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8331
8332                 default: panic("invalid atomic type");
8333         }
8334 }
8335
8336 /**
8337  * Check the semantic restrictions for a binary expression.
8338  */
8339 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8340 {
8341         expression_t *const left            = expression->left;
8342         expression_t *const right           = expression->right;
8343         type_t       *const orig_type_left  = left->base.type;
8344         type_t       *const orig_type_right = right->base.type;
8345         type_t       *const type_left       = skip_typeref(orig_type_left);
8346         type_t       *const type_right      = skip_typeref(orig_type_right);
8347
8348         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8349                 /* TODO: improve error message */
8350                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8351                         errorf(&expression->base.source_position,
8352                                "operation needs arithmetic types");
8353                 }
8354                 return;
8355         }
8356
8357         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8358         expression->left      = create_implicit_cast(left, arithmetic_type);
8359         expression->right     = create_implicit_cast(right, arithmetic_type);
8360         expression->base.type = arithmetic_type;
8361 }
8362
8363 static void warn_div_by_zero(binary_expression_t const *const expression)
8364 {
8365         if (!warning.div_by_zero ||
8366             !is_type_integer(expression->base.type))
8367                 return;
8368
8369         expression_t const *const right = expression->right;
8370         /* The type of the right operand can be different for /= */
8371         if (is_type_integer(right->base.type) &&
8372             is_constant_expression(right)     &&
8373             !fold_constant_to_bool(right)) {
8374                 warningf(&expression->base.source_position, "division by zero");
8375         }
8376 }
8377
8378 /**
8379  * Check the semantic restrictions for a div/mod expression.
8380  */
8381 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8382 {
8383         semantic_binexpr_arithmetic(expression);
8384         warn_div_by_zero(expression);
8385 }
8386
8387 static void warn_addsub_in_shift(const expression_t *const expr)
8388 {
8389         if (expr->base.parenthesized)
8390                 return;
8391
8392         char op;
8393         switch (expr->kind) {
8394                 case EXPR_BINARY_ADD: op = '+'; break;
8395                 case EXPR_BINARY_SUB: op = '-'; break;
8396                 default:              return;
8397         }
8398
8399         warningf(&expr->base.source_position,
8400                         "suggest parentheses around '%c' inside shift", op);
8401 }
8402
8403 static bool semantic_shift(binary_expression_t *expression)
8404 {
8405         expression_t *const left            = expression->left;
8406         expression_t *const right           = expression->right;
8407         type_t       *const orig_type_left  = left->base.type;
8408         type_t       *const orig_type_right = right->base.type;
8409         type_t       *      type_left       = skip_typeref(orig_type_left);
8410         type_t       *      type_right      = skip_typeref(orig_type_right);
8411
8412         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8413                 /* TODO: improve error message */
8414                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8415                         errorf(&expression->base.source_position,
8416                                "operands of shift operation must have integer types");
8417                 }
8418                 return false;
8419         }
8420
8421         type_left = promote_integer(type_left);
8422
8423         if (is_constant_expression(right)) {
8424                 long count = fold_constant_to_int(right);
8425                 if (count < 0) {
8426                         warningf(&right->base.source_position,
8427                                         "shift count must be non-negative");
8428                 } else if ((unsigned long)count >=
8429                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8430                         warningf(&right->base.source_position,
8431                                         "shift count must be less than type width");
8432                 }
8433         }
8434
8435         type_right        = promote_integer(type_right);
8436         expression->right = create_implicit_cast(right, type_right);
8437
8438         return true;
8439 }
8440
8441 static void semantic_shift_op(binary_expression_t *expression)
8442 {
8443         expression_t *const left  = expression->left;
8444         expression_t *const right = expression->right;
8445
8446         if (!semantic_shift(expression))
8447                 return;
8448
8449         if (warning.parentheses) {
8450                 warn_addsub_in_shift(left);
8451                 warn_addsub_in_shift(right);
8452         }
8453
8454         type_t *const orig_type_left = left->base.type;
8455         type_t *      type_left      = skip_typeref(orig_type_left);
8456
8457         type_left             = promote_integer(type_left);
8458         expression->left      = create_implicit_cast(left, type_left);
8459         expression->base.type = type_left;
8460 }
8461
8462 static void semantic_add(binary_expression_t *expression)
8463 {
8464         expression_t *const left            = expression->left;
8465         expression_t *const right           = expression->right;
8466         type_t       *const orig_type_left  = left->base.type;
8467         type_t       *const orig_type_right = right->base.type;
8468         type_t       *const type_left       = skip_typeref(orig_type_left);
8469         type_t       *const type_right      = skip_typeref(orig_type_right);
8470
8471         /* §6.5.6 */
8472         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8473                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8474                 expression->left  = create_implicit_cast(left, arithmetic_type);
8475                 expression->right = create_implicit_cast(right, arithmetic_type);
8476                 expression->base.type = arithmetic_type;
8477         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8478                 check_pointer_arithmetic(&expression->base.source_position,
8479                                          type_left, orig_type_left);
8480                 expression->base.type = type_left;
8481         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8482                 check_pointer_arithmetic(&expression->base.source_position,
8483                                          type_right, orig_type_right);
8484                 expression->base.type = type_right;
8485         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8486                 errorf(&expression->base.source_position,
8487                        "invalid operands to binary + ('%T', '%T')",
8488                        orig_type_left, orig_type_right);
8489         }
8490 }
8491
8492 static void semantic_sub(binary_expression_t *expression)
8493 {
8494         expression_t            *const left            = expression->left;
8495         expression_t            *const right           = expression->right;
8496         type_t                  *const orig_type_left  = left->base.type;
8497         type_t                  *const orig_type_right = right->base.type;
8498         type_t                  *const type_left       = skip_typeref(orig_type_left);
8499         type_t                  *const type_right      = skip_typeref(orig_type_right);
8500         source_position_t const *const pos             = &expression->base.source_position;
8501
8502         /* §5.6.5 */
8503         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8504                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8505                 expression->left        = create_implicit_cast(left, arithmetic_type);
8506                 expression->right       = create_implicit_cast(right, arithmetic_type);
8507                 expression->base.type =  arithmetic_type;
8508         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8509                 check_pointer_arithmetic(&expression->base.source_position,
8510                                          type_left, orig_type_left);
8511                 expression->base.type = type_left;
8512         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8513                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8514                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8515                 if (!types_compatible(unqual_left, unqual_right)) {
8516                         errorf(pos,
8517                                "subtracting pointers to incompatible types '%T' and '%T'",
8518                                orig_type_left, orig_type_right);
8519                 } else if (!is_type_object(unqual_left)) {
8520                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8521                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8522                                        orig_type_left);
8523                         } else if (warning.other) {
8524                                 warningf(pos, "subtracting pointers to void");
8525                         }
8526                 }
8527                 expression->base.type = type_ptrdiff_t;
8528         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8529                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8530                        orig_type_left, orig_type_right);
8531         }
8532 }
8533
8534 static void warn_string_literal_address(expression_t const* expr)
8535 {
8536         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8537                 expr = expr->unary.value;
8538                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8539                         return;
8540                 expr = expr->unary.value;
8541         }
8542
8543         if (expr->kind == EXPR_STRING_LITERAL ||
8544             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8545                 warningf(&expr->base.source_position,
8546                         "comparison with string literal results in unspecified behaviour");
8547         }
8548 }
8549
8550 static void warn_comparison_in_comparison(const expression_t *const expr)
8551 {
8552         if (expr->base.parenthesized)
8553                 return;
8554         switch (expr->base.kind) {
8555                 case EXPR_BINARY_LESS:
8556                 case EXPR_BINARY_GREATER:
8557                 case EXPR_BINARY_LESSEQUAL:
8558                 case EXPR_BINARY_GREATEREQUAL:
8559                 case EXPR_BINARY_NOTEQUAL:
8560                 case EXPR_BINARY_EQUAL:
8561                         warningf(&expr->base.source_position,
8562                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8563                         break;
8564                 default:
8565                         break;
8566         }
8567 }
8568
8569 static bool maybe_negative(expression_t const *const expr)
8570 {
8571         return
8572                 !is_constant_expression(expr) ||
8573                 fold_constant_to_int(expr) < 0;
8574 }
8575
8576 /**
8577  * Check the semantics of comparison expressions.
8578  *
8579  * @param expression   The expression to check.
8580  */
8581 static void semantic_comparison(binary_expression_t *expression)
8582 {
8583         expression_t *left  = expression->left;
8584         expression_t *right = expression->right;
8585
8586         if (warning.address) {
8587                 warn_string_literal_address(left);
8588                 warn_string_literal_address(right);
8589
8590                 expression_t const* const func_left = get_reference_address(left);
8591                 if (func_left != NULL && is_null_pointer_constant(right)) {
8592                         warningf(&expression->base.source_position,
8593                                  "the address of '%Y' will never be NULL",
8594                                  func_left->reference.entity->base.symbol);
8595                 }
8596
8597                 expression_t const* const func_right = get_reference_address(right);
8598                 if (func_right != NULL && is_null_pointer_constant(right)) {
8599                         warningf(&expression->base.source_position,
8600                                  "the address of '%Y' will never be NULL",
8601                                  func_right->reference.entity->base.symbol);
8602                 }
8603         }
8604
8605         if (warning.parentheses) {
8606                 warn_comparison_in_comparison(left);
8607                 warn_comparison_in_comparison(right);
8608         }
8609
8610         type_t *orig_type_left  = left->base.type;
8611         type_t *orig_type_right = right->base.type;
8612         type_t *type_left       = skip_typeref(orig_type_left);
8613         type_t *type_right      = skip_typeref(orig_type_right);
8614
8615         /* TODO non-arithmetic types */
8616         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8617                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8618
8619                 /* test for signed vs unsigned compares */
8620                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8621                         bool const signed_left  = is_type_signed(type_left);
8622                         bool const signed_right = is_type_signed(type_right);
8623                         if (signed_left != signed_right) {
8624                                 /* FIXME long long needs better const folding magic */
8625                                 /* TODO check whether constant value can be represented by other type */
8626                                 if ((signed_left  && maybe_negative(left)) ||
8627                                                 (signed_right && maybe_negative(right))) {
8628                                         warningf(&expression->base.source_position,
8629                                                         "comparison between signed and unsigned");
8630                                 }
8631                         }
8632                 }
8633
8634                 expression->left        = create_implicit_cast(left, arithmetic_type);
8635                 expression->right       = create_implicit_cast(right, arithmetic_type);
8636                 expression->base.type   = arithmetic_type;
8637                 if (warning.float_equal &&
8638                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8639                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8640                     is_type_float(arithmetic_type)) {
8641                         warningf(&expression->base.source_position,
8642                                  "comparing floating point with == or != is unsafe");
8643                 }
8644         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8645                 /* TODO check compatibility */
8646         } else if (is_type_pointer(type_left)) {
8647                 expression->right = create_implicit_cast(right, type_left);
8648         } else if (is_type_pointer(type_right)) {
8649                 expression->left = create_implicit_cast(left, type_right);
8650         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8651                 type_error_incompatible("invalid operands in comparison",
8652                                         &expression->base.source_position,
8653                                         type_left, type_right);
8654         }
8655         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8656 }
8657
8658 /**
8659  * Checks if a compound type has constant fields.
8660  */
8661 static bool has_const_fields(const compound_type_t *type)
8662 {
8663         compound_t *compound = type->compound;
8664         entity_t   *entry    = compound->members.entities;
8665
8666         for (; entry != NULL; entry = entry->base.next) {
8667                 if (!is_declaration(entry))
8668                         continue;
8669
8670                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8671                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8672                         return true;
8673         }
8674
8675         return false;
8676 }
8677
8678 static bool is_valid_assignment_lhs(expression_t const* const left)
8679 {
8680         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8681         type_t *const type_left      = skip_typeref(orig_type_left);
8682
8683         if (!is_lvalue(left)) {
8684                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8685                        left);
8686                 return false;
8687         }
8688
8689         if (left->kind == EXPR_REFERENCE
8690                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8691                 errorf(HERE, "cannot assign to function '%E'", left);
8692                 return false;
8693         }
8694
8695         if (is_type_array(type_left)) {
8696                 errorf(HERE, "cannot assign to array '%E'", left);
8697                 return false;
8698         }
8699         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8700                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8701                        orig_type_left);
8702                 return false;
8703         }
8704         if (is_type_incomplete(type_left)) {
8705                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8706                        left, orig_type_left);
8707                 return false;
8708         }
8709         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8710                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8711                        left, orig_type_left);
8712                 return false;
8713         }
8714
8715         return true;
8716 }
8717
8718 static void semantic_arithmetic_assign(binary_expression_t *expression)
8719 {
8720         expression_t *left            = expression->left;
8721         expression_t *right           = expression->right;
8722         type_t       *orig_type_left  = left->base.type;
8723         type_t       *orig_type_right = right->base.type;
8724
8725         if (!is_valid_assignment_lhs(left))
8726                 return;
8727
8728         type_t *type_left  = skip_typeref(orig_type_left);
8729         type_t *type_right = skip_typeref(orig_type_right);
8730
8731         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8732                 /* TODO: improve error message */
8733                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8734                         errorf(&expression->base.source_position,
8735                                "operation needs arithmetic types");
8736                 }
8737                 return;
8738         }
8739
8740         /* combined instructions are tricky. We can't create an implicit cast on
8741          * the left side, because we need the uncasted form for the store.
8742          * The ast2firm pass has to know that left_type must be right_type
8743          * for the arithmetic operation and create a cast by itself */
8744         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8745         expression->right       = create_implicit_cast(right, arithmetic_type);
8746         expression->base.type   = type_left;
8747 }
8748
8749 static void semantic_divmod_assign(binary_expression_t *expression)
8750 {
8751         semantic_arithmetic_assign(expression);
8752         warn_div_by_zero(expression);
8753 }
8754
8755 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8756 {
8757         expression_t *const left            = expression->left;
8758         expression_t *const right           = expression->right;
8759         type_t       *const orig_type_left  = left->base.type;
8760         type_t       *const orig_type_right = right->base.type;
8761         type_t       *const type_left       = skip_typeref(orig_type_left);
8762         type_t       *const type_right      = skip_typeref(orig_type_right);
8763
8764         if (!is_valid_assignment_lhs(left))
8765                 return;
8766
8767         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8768                 /* combined instructions are tricky. We can't create an implicit cast on
8769                  * the left side, because we need the uncasted form for the store.
8770                  * The ast2firm pass has to know that left_type must be right_type
8771                  * for the arithmetic operation and create a cast by itself */
8772                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8773                 expression->right     = create_implicit_cast(right, arithmetic_type);
8774                 expression->base.type = type_left;
8775         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8776                 check_pointer_arithmetic(&expression->base.source_position,
8777                                          type_left, orig_type_left);
8778                 expression->base.type = type_left;
8779         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8780                 errorf(&expression->base.source_position,
8781                        "incompatible types '%T' and '%T' in assignment",
8782                        orig_type_left, orig_type_right);
8783         }
8784 }
8785
8786 static void semantic_integer_assign(binary_expression_t *expression)
8787 {
8788         expression_t *left            = expression->left;
8789         expression_t *right           = expression->right;
8790         type_t       *orig_type_left  = left->base.type;
8791         type_t       *orig_type_right = right->base.type;
8792
8793         if (!is_valid_assignment_lhs(left))
8794                 return;
8795
8796         type_t *type_left  = skip_typeref(orig_type_left);
8797         type_t *type_right = skip_typeref(orig_type_right);
8798
8799         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8800                 /* TODO: improve error message */
8801                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8802                         errorf(&expression->base.source_position,
8803                                "operation needs integer types");
8804                 }
8805                 return;
8806         }
8807
8808         /* combined instructions are tricky. We can't create an implicit cast on
8809          * the left side, because we need the uncasted form for the store.
8810          * The ast2firm pass has to know that left_type must be right_type
8811          * for the arithmetic operation and create a cast by itself */
8812         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8813         expression->right       = create_implicit_cast(right, arithmetic_type);
8814         expression->base.type   = type_left;
8815 }
8816
8817 static void semantic_shift_assign(binary_expression_t *expression)
8818 {
8819         expression_t *left           = expression->left;
8820
8821         if (!is_valid_assignment_lhs(left))
8822                 return;
8823
8824         if (!semantic_shift(expression))
8825                 return;
8826
8827         expression->base.type = skip_typeref(left->base.type);
8828 }
8829
8830 static void warn_logical_and_within_or(const expression_t *const expr)
8831 {
8832         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8833                 return;
8834         if (expr->base.parenthesized)
8835                 return;
8836         warningf(&expr->base.source_position,
8837                         "suggest parentheses around && within ||");
8838 }
8839
8840 /**
8841  * Check the semantic restrictions of a logical expression.
8842  */
8843 static void semantic_logical_op(binary_expression_t *expression)
8844 {
8845         /* §6.5.13:2  Each of the operands shall have scalar type.
8846          * §6.5.14:2  Each of the operands shall have scalar type. */
8847         semantic_condition(expression->left,   "left operand of logical operator");
8848         semantic_condition(expression->right, "right operand of logical operator");
8849         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8850                         warning.parentheses) {
8851                 warn_logical_and_within_or(expression->left);
8852                 warn_logical_and_within_or(expression->right);
8853         }
8854         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8855 }
8856
8857 /**
8858  * Check the semantic restrictions of a binary assign expression.
8859  */
8860 static void semantic_binexpr_assign(binary_expression_t *expression)
8861 {
8862         expression_t *left           = expression->left;
8863         type_t       *orig_type_left = left->base.type;
8864
8865         if (!is_valid_assignment_lhs(left))
8866                 return;
8867
8868         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8869         report_assign_error(error, orig_type_left, expression->right,
8870                         "assignment", &left->base.source_position);
8871         expression->right = create_implicit_cast(expression->right, orig_type_left);
8872         expression->base.type = orig_type_left;
8873 }
8874
8875 /**
8876  * Determine if the outermost operation (or parts thereof) of the given
8877  * expression has no effect in order to generate a warning about this fact.
8878  * Therefore in some cases this only examines some of the operands of the
8879  * expression (see comments in the function and examples below).
8880  * Examples:
8881  *   f() + 23;    // warning, because + has no effect
8882  *   x || f();    // no warning, because x controls execution of f()
8883  *   x ? y : f(); // warning, because y has no effect
8884  *   (void)x;     // no warning to be able to suppress the warning
8885  * This function can NOT be used for an "expression has definitely no effect"-
8886  * analysis. */
8887 static bool expression_has_effect(const expression_t *const expr)
8888 {
8889         switch (expr->kind) {
8890                 case EXPR_UNKNOWN:                    break;
8891                 case EXPR_INVALID:                    return true; /* do NOT warn */
8892                 case EXPR_REFERENCE:                  return false;
8893                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8894                 /* suppress the warning for microsoft __noop operations */
8895                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
8896                 case EXPR_CHARACTER_CONSTANT:         return false;
8897                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
8898                 case EXPR_STRING_LITERAL:             return false;
8899                 case EXPR_WIDE_STRING_LITERAL:        return false;
8900                 case EXPR_LABEL_ADDRESS:              return false;
8901
8902                 case EXPR_CALL: {
8903                         const call_expression_t *const call = &expr->call;
8904                         if (call->function->kind != EXPR_REFERENCE)
8905                                 return true;
8906
8907                         switch (call->function->reference.entity->function.btk) {
8908                                 /* FIXME: which builtins have no effect? */
8909                                 default:                      return true;
8910                         }
8911                 }
8912
8913                 /* Generate the warning if either the left or right hand side of a
8914                  * conditional expression has no effect */
8915                 case EXPR_CONDITIONAL: {
8916                         conditional_expression_t const *const cond = &expr->conditional;
8917                         expression_t             const *const t    = cond->true_expression;
8918                         return
8919                                 (t == NULL || expression_has_effect(t)) &&
8920                                 expression_has_effect(cond->false_expression);
8921                 }
8922
8923                 case EXPR_SELECT:                     return false;
8924                 case EXPR_ARRAY_ACCESS:               return false;
8925                 case EXPR_SIZEOF:                     return false;
8926                 case EXPR_CLASSIFY_TYPE:              return false;
8927                 case EXPR_ALIGNOF:                    return false;
8928
8929                 case EXPR_FUNCNAME:                   return false;
8930                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8931                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8932                 case EXPR_OFFSETOF:                   return false;
8933                 case EXPR_VA_START:                   return true;
8934                 case EXPR_VA_ARG:                     return true;
8935                 case EXPR_VA_COPY:                    return true;
8936                 case EXPR_STATEMENT:                  return true; // TODO
8937                 case EXPR_COMPOUND_LITERAL:           return false;
8938
8939                 case EXPR_UNARY_NEGATE:               return false;
8940                 case EXPR_UNARY_PLUS:                 return false;
8941                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8942                 case EXPR_UNARY_NOT:                  return false;
8943                 case EXPR_UNARY_DEREFERENCE:          return false;
8944                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8945                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8946                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8947                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8948                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8949
8950                 /* Treat void casts as if they have an effect in order to being able to
8951                  * suppress the warning */
8952                 case EXPR_UNARY_CAST: {
8953                         type_t *const type = skip_typeref(expr->base.type);
8954                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8955                 }
8956
8957                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8958                 case EXPR_UNARY_ASSUME:               return true;
8959                 case EXPR_UNARY_DELETE:               return true;
8960                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8961                 case EXPR_UNARY_THROW:                return true;
8962
8963                 case EXPR_BINARY_ADD:                 return false;
8964                 case EXPR_BINARY_SUB:                 return false;
8965                 case EXPR_BINARY_MUL:                 return false;
8966                 case EXPR_BINARY_DIV:                 return false;
8967                 case EXPR_BINARY_MOD:                 return false;
8968                 case EXPR_BINARY_EQUAL:               return false;
8969                 case EXPR_BINARY_NOTEQUAL:            return false;
8970                 case EXPR_BINARY_LESS:                return false;
8971                 case EXPR_BINARY_LESSEQUAL:           return false;
8972                 case EXPR_BINARY_GREATER:             return false;
8973                 case EXPR_BINARY_GREATEREQUAL:        return false;
8974                 case EXPR_BINARY_BITWISE_AND:         return false;
8975                 case EXPR_BINARY_BITWISE_OR:          return false;
8976                 case EXPR_BINARY_BITWISE_XOR:         return false;
8977                 case EXPR_BINARY_SHIFTLEFT:           return false;
8978                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8979                 case EXPR_BINARY_ASSIGN:              return true;
8980                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8981                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8982                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8983                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8984                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8985                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8986                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8987                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8988                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8989                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8990
8991                 /* Only examine the right hand side of && and ||, because the left hand
8992                  * side already has the effect of controlling the execution of the right
8993                  * hand side */
8994                 case EXPR_BINARY_LOGICAL_AND:
8995                 case EXPR_BINARY_LOGICAL_OR:
8996                 /* Only examine the right hand side of a comma expression, because the left
8997                  * hand side has a separate warning */
8998                 case EXPR_BINARY_COMMA:
8999                         return expression_has_effect(expr->binary.right);
9000
9001                 case EXPR_BINARY_ISGREATER:           return false;
9002                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9003                 case EXPR_BINARY_ISLESS:              return false;
9004                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9005                 case EXPR_BINARY_ISLESSGREATER:       return false;
9006                 case EXPR_BINARY_ISUNORDERED:         return false;
9007         }
9008
9009         internal_errorf(HERE, "unexpected expression");
9010 }
9011
9012 static void semantic_comma(binary_expression_t *expression)
9013 {
9014         if (warning.unused_value) {
9015                 const expression_t *const left = expression->left;
9016                 if (!expression_has_effect(left)) {
9017                         warningf(&left->base.source_position,
9018                                  "left-hand operand of comma expression has no effect");
9019                 }
9020         }
9021         expression->base.type = expression->right->base.type;
9022 }
9023
9024 /**
9025  * @param prec_r precedence of the right operand
9026  */
9027 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9028 static expression_t *parse_##binexpression_type(expression_t *left)          \
9029 {                                                                            \
9030         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9031         binexpr->binary.left  = left;                                            \
9032         eat(token_type);                                                         \
9033                                                                              \
9034         expression_t *right = parse_sub_expression(prec_r);                      \
9035                                                                              \
9036         binexpr->binary.right = right;                                           \
9037         sfunc(&binexpr->binary);                                                 \
9038                                                                              \
9039         return binexpr;                                                          \
9040 }
9041
9042 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9043 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9044 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9045 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9046 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9047 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9048 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9049 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9050 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9051 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9052 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9053 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9054 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9055 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9056 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9057 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9058 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9059 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9060 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9061 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9062 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9063 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9064 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9065 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9066 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
9067 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
9068 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9069 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
9070 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9071 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9072
9073
9074 static expression_t *parse_sub_expression(precedence_t precedence)
9075 {
9076         if (token.type < 0) {
9077                 return expected_expression_error();
9078         }
9079
9080         expression_parser_function_t *parser
9081                 = &expression_parsers[token.type];
9082         source_position_t             source_position = token.source_position;
9083         expression_t                 *left;
9084
9085         if (parser->parser != NULL) {
9086                 left = parser->parser();
9087         } else {
9088                 left = parse_primary_expression();
9089         }
9090         assert(left != NULL);
9091         left->base.source_position = source_position;
9092
9093         while (true) {
9094                 if (token.type < 0) {
9095                         return expected_expression_error();
9096                 }
9097
9098                 parser = &expression_parsers[token.type];
9099                 if (parser->infix_parser == NULL)
9100                         break;
9101                 if (parser->infix_precedence < precedence)
9102                         break;
9103
9104                 left = parser->infix_parser(left);
9105
9106                 assert(left != NULL);
9107                 assert(left->kind != EXPR_UNKNOWN);
9108                 left->base.source_position = source_position;
9109         }
9110
9111         return left;
9112 }
9113
9114 /**
9115  * Parse an expression.
9116  */
9117 static expression_t *parse_expression(void)
9118 {
9119         return parse_sub_expression(PREC_EXPRESSION);
9120 }
9121
9122 /**
9123  * Register a parser for a prefix-like operator.
9124  *
9125  * @param parser      the parser function
9126  * @param token_type  the token type of the prefix token
9127  */
9128 static void register_expression_parser(parse_expression_function parser,
9129                                        int token_type)
9130 {
9131         expression_parser_function_t *entry = &expression_parsers[token_type];
9132
9133         if (entry->parser != NULL) {
9134                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9135                 panic("trying to register multiple expression parsers for a token");
9136         }
9137         entry->parser = parser;
9138 }
9139
9140 /**
9141  * Register a parser for an infix operator with given precedence.
9142  *
9143  * @param parser      the parser function
9144  * @param token_type  the token type of the infix operator
9145  * @param precedence  the precedence of the operator
9146  */
9147 static void register_infix_parser(parse_expression_infix_function parser,
9148                 int token_type, precedence_t precedence)
9149 {
9150         expression_parser_function_t *entry = &expression_parsers[token_type];
9151
9152         if (entry->infix_parser != NULL) {
9153                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9154                 panic("trying to register multiple infix expression parsers for a "
9155                       "token");
9156         }
9157         entry->infix_parser     = parser;
9158         entry->infix_precedence = precedence;
9159 }
9160
9161 /**
9162  * Initialize the expression parsers.
9163  */
9164 static void init_expression_parsers(void)
9165 {
9166         memset(&expression_parsers, 0, sizeof(expression_parsers));
9167
9168         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9169         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9170         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9171         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9172         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9173         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9174         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9175         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9176         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9177         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9178         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9179         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9180         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9181         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9182         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9183         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9184         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9185         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9186         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9187         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9188         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9189         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9190         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9191         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9192         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9193         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9194         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9195         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9196         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9197         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9198         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9199         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9200         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9201         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9202         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9203         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9204         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9205
9206         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9207         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9208         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9209         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9210         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9211         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9212         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9213         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9214         register_expression_parser(parse_sizeof,                      T_sizeof);
9215         register_expression_parser(parse_alignof,                     T___alignof__);
9216         register_expression_parser(parse_extension,                   T___extension__);
9217         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9218         register_expression_parser(parse_delete,                      T_delete);
9219         register_expression_parser(parse_throw,                       T_throw);
9220 }
9221
9222 /**
9223  * Parse a asm statement arguments specification.
9224  */
9225 static asm_argument_t *parse_asm_arguments(bool is_out)
9226 {
9227         asm_argument_t  *result = NULL;
9228         asm_argument_t **anchor = &result;
9229
9230         while (token.type == T_STRING_LITERAL || token.type == '[') {
9231                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9232                 memset(argument, 0, sizeof(argument[0]));
9233
9234                 if (token.type == '[') {
9235                         eat('[');
9236                         if (token.type != T_IDENTIFIER) {
9237                                 parse_error_expected("while parsing asm argument",
9238                                                      T_IDENTIFIER, NULL);
9239                                 return NULL;
9240                         }
9241                         argument->symbol = token.v.symbol;
9242
9243                         expect(']', end_error);
9244                 }
9245
9246                 argument->constraints = parse_string_literals();
9247                 expect('(', end_error);
9248                 add_anchor_token(')');
9249                 expression_t *expression = parse_expression();
9250                 rem_anchor_token(')');
9251                 if (is_out) {
9252                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9253                          * change size or type representation (e.g. int -> long is ok, but
9254                          * int -> float is not) */
9255                         if (expression->kind == EXPR_UNARY_CAST) {
9256                                 type_t      *const type = expression->base.type;
9257                                 type_kind_t  const kind = type->kind;
9258                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9259                                         unsigned flags;
9260                                         unsigned size;
9261                                         if (kind == TYPE_ATOMIC) {
9262                                                 atomic_type_kind_t const akind = type->atomic.akind;
9263                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9264                                                 size  = get_atomic_type_size(akind);
9265                                         } else {
9266                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9267                                                 size  = get_atomic_type_size(get_intptr_kind());
9268                                         }
9269
9270                                         do {
9271                                                 expression_t *const value      = expression->unary.value;
9272                                                 type_t       *const value_type = value->base.type;
9273                                                 type_kind_t   const value_kind = value_type->kind;
9274
9275                                                 unsigned value_flags;
9276                                                 unsigned value_size;
9277                                                 if (value_kind == TYPE_ATOMIC) {
9278                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9279                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9280                                                         value_size  = get_atomic_type_size(value_akind);
9281                                                 } else if (value_kind == TYPE_POINTER) {
9282                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9283                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9284                                                 } else {
9285                                                         break;
9286                                                 }
9287
9288                                                 if (value_flags != flags || value_size != size)
9289                                                         break;
9290
9291                                                 expression = value;
9292                                         } while (expression->kind == EXPR_UNARY_CAST);
9293                                 }
9294                         }
9295
9296                         if (!is_lvalue(expression)) {
9297                                 errorf(&expression->base.source_position,
9298                                        "asm output argument is not an lvalue");
9299                         }
9300
9301                         if (argument->constraints.begin[0] == '+')
9302                                 mark_vars_read(expression, NULL);
9303                 } else {
9304                         mark_vars_read(expression, NULL);
9305                 }
9306                 argument->expression = expression;
9307                 expect(')', end_error);
9308
9309                 set_address_taken(expression, true);
9310
9311                 *anchor = argument;
9312                 anchor  = &argument->next;
9313
9314                 if (token.type != ',')
9315                         break;
9316                 eat(',');
9317         }
9318
9319         return result;
9320 end_error:
9321         return NULL;
9322 }
9323
9324 /**
9325  * Parse a asm statement clobber specification.
9326  */
9327 static asm_clobber_t *parse_asm_clobbers(void)
9328 {
9329         asm_clobber_t *result = NULL;
9330         asm_clobber_t *last   = NULL;
9331
9332         while (token.type == T_STRING_LITERAL) {
9333                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9334                 clobber->clobber       = parse_string_literals();
9335
9336                 if (last != NULL) {
9337                         last->next = clobber;
9338                 } else {
9339                         result = clobber;
9340                 }
9341                 last = clobber;
9342
9343                 if (token.type != ',')
9344                         break;
9345                 eat(',');
9346         }
9347
9348         return result;
9349 }
9350
9351 /**
9352  * Parse an asm statement.
9353  */
9354 static statement_t *parse_asm_statement(void)
9355 {
9356         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9357         asm_statement_t *asm_statement = &statement->asms;
9358
9359         eat(T_asm);
9360
9361         if (token.type == T_volatile) {
9362                 next_token();
9363                 asm_statement->is_volatile = true;
9364         }
9365
9366         expect('(', end_error);
9367         add_anchor_token(')');
9368         add_anchor_token(':');
9369         asm_statement->asm_text = parse_string_literals();
9370
9371         if (token.type != ':') {
9372                 rem_anchor_token(':');
9373                 goto end_of_asm;
9374         }
9375         eat(':');
9376
9377         asm_statement->outputs = parse_asm_arguments(true);
9378         if (token.type != ':') {
9379                 rem_anchor_token(':');
9380                 goto end_of_asm;
9381         }
9382         eat(':');
9383
9384         asm_statement->inputs = parse_asm_arguments(false);
9385         if (token.type != ':') {
9386                 rem_anchor_token(':');
9387                 goto end_of_asm;
9388         }
9389         rem_anchor_token(':');
9390         eat(':');
9391
9392         asm_statement->clobbers = parse_asm_clobbers();
9393
9394 end_of_asm:
9395         rem_anchor_token(')');
9396         expect(')', end_error);
9397         expect(';', end_error);
9398
9399         if (asm_statement->outputs == NULL) {
9400                 /* GCC: An 'asm' instruction without any output operands will be treated
9401                  * identically to a volatile 'asm' instruction. */
9402                 asm_statement->is_volatile = true;
9403         }
9404
9405         return statement;
9406 end_error:
9407         return create_invalid_statement();
9408 }
9409
9410 /**
9411  * Parse a case statement.
9412  */
9413 static statement_t *parse_case_statement(void)
9414 {
9415         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9416         source_position_t *const pos       = &statement->base.source_position;
9417
9418         eat(T_case);
9419
9420         expression_t *const expression   = parse_expression();
9421         statement->case_label.expression = expression;
9422         if (!is_constant_expression(expression)) {
9423                 /* This check does not prevent the error message in all cases of an
9424                  * prior error while parsing the expression.  At least it catches the
9425                  * common case of a mistyped enum entry. */
9426                 if (is_type_valid(skip_typeref(expression->base.type))) {
9427                         errorf(pos, "case label does not reduce to an integer constant");
9428                 }
9429                 statement->case_label.is_bad = true;
9430         } else {
9431                 long const val = fold_constant_to_int(expression);
9432                 statement->case_label.first_case = val;
9433                 statement->case_label.last_case  = val;
9434         }
9435
9436         if (GNU_MODE) {
9437                 if (token.type == T_DOTDOTDOT) {
9438                         next_token();
9439                         expression_t *const end_range   = parse_expression();
9440                         statement->case_label.end_range = end_range;
9441                         if (!is_constant_expression(end_range)) {
9442                                 /* This check does not prevent the error message in all cases of an
9443                                  * prior error while parsing the expression.  At least it catches the
9444                                  * common case of a mistyped enum entry. */
9445                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9446                                         errorf(pos, "case range does not reduce to an integer constant");
9447                                 }
9448                                 statement->case_label.is_bad = true;
9449                         } else {
9450                                 long const val = fold_constant_to_int(end_range);
9451                                 statement->case_label.last_case = val;
9452
9453                                 if (warning.other && val < statement->case_label.first_case) {
9454                                         statement->case_label.is_empty_range = true;
9455                                         warningf(pos, "empty range specified");
9456                                 }
9457                         }
9458                 }
9459         }
9460
9461         PUSH_PARENT(statement);
9462
9463         expect(':', end_error);
9464 end_error:
9465
9466         if (current_switch != NULL) {
9467                 if (! statement->case_label.is_bad) {
9468                         /* Check for duplicate case values */
9469                         case_label_statement_t *c = &statement->case_label;
9470                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9471                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9472                                         continue;
9473
9474                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9475                                         continue;
9476
9477                                 errorf(pos, "duplicate case value (previously used %P)",
9478                                        &l->base.source_position);
9479                                 break;
9480                         }
9481                 }
9482                 /* link all cases into the switch statement */
9483                 if (current_switch->last_case == NULL) {
9484                         current_switch->first_case      = &statement->case_label;
9485                 } else {
9486                         current_switch->last_case->next = &statement->case_label;
9487                 }
9488                 current_switch->last_case = &statement->case_label;
9489         } else {
9490                 errorf(pos, "case label not within a switch statement");
9491         }
9492
9493         statement_t *const inner_stmt = parse_statement();
9494         statement->case_label.statement = inner_stmt;
9495         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9496                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9497         }
9498
9499         POP_PARENT;
9500         return statement;
9501 }
9502
9503 /**
9504  * Parse a default statement.
9505  */
9506 static statement_t *parse_default_statement(void)
9507 {
9508         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9509
9510         eat(T_default);
9511
9512         PUSH_PARENT(statement);
9513
9514         expect(':', end_error);
9515         if (current_switch != NULL) {
9516                 const case_label_statement_t *def_label = current_switch->default_label;
9517                 if (def_label != NULL) {
9518                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9519                                &def_label->base.source_position);
9520                 } else {
9521                         current_switch->default_label = &statement->case_label;
9522
9523                         /* link all cases into the switch statement */
9524                         if (current_switch->last_case == NULL) {
9525                                 current_switch->first_case      = &statement->case_label;
9526                         } else {
9527                                 current_switch->last_case->next = &statement->case_label;
9528                         }
9529                         current_switch->last_case = &statement->case_label;
9530                 }
9531         } else {
9532                 errorf(&statement->base.source_position,
9533                         "'default' label not within a switch statement");
9534         }
9535
9536         statement_t *const inner_stmt = parse_statement();
9537         statement->case_label.statement = inner_stmt;
9538         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9539                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9540         }
9541
9542         POP_PARENT;
9543         return statement;
9544 end_error:
9545         POP_PARENT;
9546         return create_invalid_statement();
9547 }
9548
9549 /**
9550  * Parse a label statement.
9551  */
9552 static statement_t *parse_label_statement(void)
9553 {
9554         assert(token.type == T_IDENTIFIER);
9555         symbol_t *symbol = token.v.symbol;
9556         label_t  *label  = get_label(symbol);
9557
9558         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9559         statement->label.label       = label;
9560
9561         next_token();
9562
9563         PUSH_PARENT(statement);
9564
9565         /* if statement is already set then the label is defined twice,
9566          * otherwise it was just mentioned in a goto/local label declaration so far
9567          */
9568         if (label->statement != NULL) {
9569                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9570                        symbol, &label->base.source_position);
9571         } else {
9572                 label->base.source_position = token.source_position;
9573                 label->statement            = statement;
9574         }
9575
9576         eat(':');
9577
9578         if (token.type == '}') {
9579                 /* TODO only warn? */
9580                 if (warning.other && false) {
9581                         warningf(HERE, "label at end of compound statement");
9582                         statement->label.statement = create_empty_statement();
9583                 } else {
9584                         errorf(HERE, "label at end of compound statement");
9585                         statement->label.statement = create_invalid_statement();
9586                 }
9587         } else if (token.type == ';') {
9588                 /* Eat an empty statement here, to avoid the warning about an empty
9589                  * statement after a label.  label:; is commonly used to have a label
9590                  * before a closing brace. */
9591                 statement->label.statement = create_empty_statement();
9592                 next_token();
9593         } else {
9594                 statement_t *const inner_stmt = parse_statement();
9595                 statement->label.statement = inner_stmt;
9596                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9597                         errorf(&inner_stmt->base.source_position, "declaration after label");
9598                 }
9599         }
9600
9601         /* remember the labels in a list for later checking */
9602         *label_anchor = &statement->label;
9603         label_anchor  = &statement->label.next;
9604
9605         POP_PARENT;
9606         return statement;
9607 }
9608
9609 /**
9610  * Parse an if statement.
9611  */
9612 static statement_t *parse_if(void)
9613 {
9614         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9615
9616         eat(T_if);
9617
9618         PUSH_PARENT(statement);
9619
9620         add_anchor_token('{');
9621
9622         expect('(', end_error);
9623         add_anchor_token(')');
9624         expression_t *const expr = parse_expression();
9625         statement->ifs.condition = expr;
9626         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9627          *             scalar type. */
9628         semantic_condition(expr, "condition of 'if'-statment");
9629         mark_vars_read(expr, NULL);
9630         rem_anchor_token(')');
9631         expect(')', end_error);
9632
9633 end_error:
9634         rem_anchor_token('{');
9635
9636         add_anchor_token(T_else);
9637         statement_t *const true_stmt = parse_statement();
9638         statement->ifs.true_statement = true_stmt;
9639         rem_anchor_token(T_else);
9640
9641         if (token.type == T_else) {
9642                 next_token();
9643                 statement->ifs.false_statement = parse_statement();
9644         } else if (warning.parentheses &&
9645                         true_stmt->kind == STATEMENT_IF &&
9646                         true_stmt->ifs.false_statement != NULL) {
9647                 warningf(&true_stmt->base.source_position,
9648                                 "suggest explicit braces to avoid ambiguous 'else'");
9649         }
9650
9651         POP_PARENT;
9652         return statement;
9653 }
9654
9655 /**
9656  * Check that all enums are handled in a switch.
9657  *
9658  * @param statement  the switch statement to check
9659  */
9660 static void check_enum_cases(const switch_statement_t *statement)
9661 {
9662         const type_t *type = skip_typeref(statement->expression->base.type);
9663         if (! is_type_enum(type))
9664                 return;
9665         const enum_type_t *enumt = &type->enumt;
9666
9667         /* if we have a default, no warnings */
9668         if (statement->default_label != NULL)
9669                 return;
9670
9671         /* FIXME: calculation of value should be done while parsing */
9672         /* TODO: quadratic algorithm here. Change to an n log n one */
9673         long            last_value = -1;
9674         const entity_t *entry      = enumt->enume->base.next;
9675         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9676              entry = entry->base.next) {
9677                 const expression_t *expression = entry->enum_value.value;
9678                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9679                 bool                found      = false;
9680                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9681                         if (l->expression == NULL)
9682                                 continue;
9683                         if (l->first_case <= value && value <= l->last_case) {
9684                                 found = true;
9685                                 break;
9686                         }
9687                 }
9688                 if (! found) {
9689                         warningf(&statement->base.source_position,
9690                                  "enumeration value '%Y' not handled in switch",
9691                                  entry->base.symbol);
9692                 }
9693                 last_value = value;
9694         }
9695 }
9696
9697 /**
9698  * Parse a switch statement.
9699  */
9700 static statement_t *parse_switch(void)
9701 {
9702         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9703
9704         eat(T_switch);
9705
9706         PUSH_PARENT(statement);
9707
9708         expect('(', end_error);
9709         add_anchor_token(')');
9710         expression_t *const expr = parse_expression();
9711         mark_vars_read(expr, NULL);
9712         type_t       *      type = skip_typeref(expr->base.type);
9713         if (is_type_integer(type)) {
9714                 type = promote_integer(type);
9715                 if (warning.traditional) {
9716                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9717                                 warningf(&expr->base.source_position,
9718                                         "'%T' switch expression not converted to '%T' in ISO C",
9719                                         type, type_int);
9720                         }
9721                 }
9722         } else if (is_type_valid(type)) {
9723                 errorf(&expr->base.source_position,
9724                        "switch quantity is not an integer, but '%T'", type);
9725                 type = type_error_type;
9726         }
9727         statement->switchs.expression = create_implicit_cast(expr, type);
9728         expect(')', end_error);
9729         rem_anchor_token(')');
9730
9731         switch_statement_t *rem = current_switch;
9732         current_switch          = &statement->switchs;
9733         statement->switchs.body = parse_statement();
9734         current_switch          = rem;
9735
9736         if (warning.switch_default &&
9737             statement->switchs.default_label == NULL) {
9738                 warningf(&statement->base.source_position, "switch has no default case");
9739         }
9740         if (warning.switch_enum)
9741                 check_enum_cases(&statement->switchs);
9742
9743         POP_PARENT;
9744         return statement;
9745 end_error:
9746         POP_PARENT;
9747         return create_invalid_statement();
9748 }
9749
9750 static statement_t *parse_loop_body(statement_t *const loop)
9751 {
9752         statement_t *const rem = current_loop;
9753         current_loop = loop;
9754
9755         statement_t *const body = parse_statement();
9756
9757         current_loop = rem;
9758         return body;
9759 }
9760
9761 /**
9762  * Parse a while statement.
9763  */
9764 static statement_t *parse_while(void)
9765 {
9766         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9767
9768         eat(T_while);
9769
9770         PUSH_PARENT(statement);
9771
9772         expect('(', end_error);
9773         add_anchor_token(')');
9774         expression_t *const cond = parse_expression();
9775         statement->whiles.condition = cond;
9776         /* §6.8.5:2    The controlling expression of an iteration statement shall
9777          *             have scalar type. */
9778         semantic_condition(cond, "condition of 'while'-statement");
9779         mark_vars_read(cond, NULL);
9780         rem_anchor_token(')');
9781         expect(')', end_error);
9782
9783         statement->whiles.body = parse_loop_body(statement);
9784
9785         POP_PARENT;
9786         return statement;
9787 end_error:
9788         POP_PARENT;
9789         return create_invalid_statement();
9790 }
9791
9792 /**
9793  * Parse a do statement.
9794  */
9795 static statement_t *parse_do(void)
9796 {
9797         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9798
9799         eat(T_do);
9800
9801         PUSH_PARENT(statement);
9802
9803         add_anchor_token(T_while);
9804         statement->do_while.body = parse_loop_body(statement);
9805         rem_anchor_token(T_while);
9806
9807         expect(T_while, end_error);
9808         expect('(', end_error);
9809         add_anchor_token(')');
9810         expression_t *const cond = parse_expression();
9811         statement->do_while.condition = cond;
9812         /* §6.8.5:2    The controlling expression of an iteration statement shall
9813          *             have scalar type. */
9814         semantic_condition(cond, "condition of 'do-while'-statement");
9815         mark_vars_read(cond, NULL);
9816         rem_anchor_token(')');
9817         expect(')', end_error);
9818         expect(';', end_error);
9819
9820         POP_PARENT;
9821         return statement;
9822 end_error:
9823         POP_PARENT;
9824         return create_invalid_statement();
9825 }
9826
9827 /**
9828  * Parse a for statement.
9829  */
9830 static statement_t *parse_for(void)
9831 {
9832         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9833
9834         eat(T_for);
9835
9836         expect('(', end_error1);
9837         add_anchor_token(')');
9838
9839         PUSH_PARENT(statement);
9840
9841         size_t const  top       = environment_top();
9842         scope_t      *old_scope = scope_push(&statement->fors.scope);
9843
9844         bool old_gcc_extension = in_gcc_extension;
9845         while (token.type == T___extension__) {
9846                 next_token();
9847                 in_gcc_extension = true;
9848         }
9849
9850         if (token.type == ';') {
9851                 next_token();
9852         } else if (is_declaration_specifier(&token, false)) {
9853                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9854         } else {
9855                 add_anchor_token(';');
9856                 expression_t *const init = parse_expression();
9857                 statement->fors.initialisation = init;
9858                 mark_vars_read(init, ENT_ANY);
9859                 if (warning.unused_value && !expression_has_effect(init)) {
9860                         warningf(&init->base.source_position,
9861                                         "initialisation of 'for'-statement has no effect");
9862                 }
9863                 rem_anchor_token(';');
9864                 expect(';', end_error2);
9865         }
9866         in_gcc_extension = old_gcc_extension;
9867
9868         if (token.type != ';') {
9869                 add_anchor_token(';');
9870                 expression_t *const cond = parse_expression();
9871                 statement->fors.condition = cond;
9872                 /* §6.8.5:2    The controlling expression of an iteration statement
9873                  *             shall have scalar type. */
9874                 semantic_condition(cond, "condition of 'for'-statement");
9875                 mark_vars_read(cond, NULL);
9876                 rem_anchor_token(';');
9877         }
9878         expect(';', end_error2);
9879         if (token.type != ')') {
9880                 expression_t *const step = parse_expression();
9881                 statement->fors.step = step;
9882                 mark_vars_read(step, ENT_ANY);
9883                 if (warning.unused_value && !expression_has_effect(step)) {
9884                         warningf(&step->base.source_position,
9885                                  "step of 'for'-statement has no effect");
9886                 }
9887         }
9888         expect(')', end_error2);
9889         rem_anchor_token(')');
9890         statement->fors.body = parse_loop_body(statement);
9891
9892         assert(current_scope == &statement->fors.scope);
9893         scope_pop(old_scope);
9894         environment_pop_to(top);
9895
9896         POP_PARENT;
9897         return statement;
9898
9899 end_error2:
9900         POP_PARENT;
9901         rem_anchor_token(')');
9902         assert(current_scope == &statement->fors.scope);
9903         scope_pop(old_scope);
9904         environment_pop_to(top);
9905         /* fallthrough */
9906
9907 end_error1:
9908         return create_invalid_statement();
9909 }
9910
9911 /**
9912  * Parse a goto statement.
9913  */
9914 static statement_t *parse_goto(void)
9915 {
9916         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9917         eat(T_goto);
9918
9919         if (GNU_MODE && token.type == '*') {
9920                 next_token();
9921                 expression_t *expression = parse_expression();
9922                 mark_vars_read(expression, NULL);
9923
9924                 /* Argh: although documentation says the expression must be of type void*,
9925                  * gcc accepts anything that can be casted into void* without error */
9926                 type_t *type = expression->base.type;
9927
9928                 if (type != type_error_type) {
9929                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9930                                 errorf(&expression->base.source_position,
9931                                         "cannot convert to a pointer type");
9932                         } else if (warning.other && type != type_void_ptr) {
9933                                 warningf(&expression->base.source_position,
9934                                         "type of computed goto expression should be 'void*' not '%T'", type);
9935                         }
9936                         expression = create_implicit_cast(expression, type_void_ptr);
9937                 }
9938
9939                 statement->gotos.expression = expression;
9940         } else if (token.type == T_IDENTIFIER) {
9941                 symbol_t *symbol = token.v.symbol;
9942                 next_token();
9943                 statement->gotos.label = get_label(symbol);
9944         } else {
9945                 if (GNU_MODE)
9946                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9947                 else
9948                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9949                 eat_until_anchor();
9950                 goto end_error;
9951         }
9952
9953         /* remember the goto's in a list for later checking */
9954         *goto_anchor = &statement->gotos;
9955         goto_anchor  = &statement->gotos.next;
9956
9957         expect(';', end_error);
9958
9959         return statement;
9960 end_error:
9961         return create_invalid_statement();
9962 }
9963
9964 /**
9965  * Parse a continue statement.
9966  */
9967 static statement_t *parse_continue(void)
9968 {
9969         if (current_loop == NULL) {
9970                 errorf(HERE, "continue statement not within loop");
9971         }
9972
9973         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9974
9975         eat(T_continue);
9976         expect(';', end_error);
9977
9978 end_error:
9979         return statement;
9980 }
9981
9982 /**
9983  * Parse a break statement.
9984  */
9985 static statement_t *parse_break(void)
9986 {
9987         if (current_switch == NULL && current_loop == NULL) {
9988                 errorf(HERE, "break statement not within loop or switch");
9989         }
9990
9991         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9992
9993         eat(T_break);
9994         expect(';', end_error);
9995
9996 end_error:
9997         return statement;
9998 }
9999
10000 /**
10001  * Parse a __leave statement.
10002  */
10003 static statement_t *parse_leave_statement(void)
10004 {
10005         if (current_try == NULL) {
10006                 errorf(HERE, "__leave statement not within __try");
10007         }
10008
10009         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10010
10011         eat(T___leave);
10012         expect(';', end_error);
10013
10014 end_error:
10015         return statement;
10016 }
10017
10018 /**
10019  * Check if a given entity represents a local variable.
10020  */
10021 static bool is_local_variable(const entity_t *entity)
10022 {
10023         if (entity->kind != ENTITY_VARIABLE)
10024                 return false;
10025
10026         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10027         case STORAGE_CLASS_AUTO:
10028         case STORAGE_CLASS_REGISTER: {
10029                 const type_t *type = skip_typeref(entity->declaration.type);
10030                 if (is_type_function(type)) {
10031                         return false;
10032                 } else {
10033                         return true;
10034                 }
10035         }
10036         default:
10037                 return false;
10038         }
10039 }
10040
10041 /**
10042  * Check if a given expression represents a local variable.
10043  */
10044 static bool expression_is_local_variable(const expression_t *expression)
10045 {
10046         if (expression->base.kind != EXPR_REFERENCE) {
10047                 return false;
10048         }
10049         const entity_t *entity = expression->reference.entity;
10050         return is_local_variable(entity);
10051 }
10052
10053 /**
10054  * Check if a given expression represents a local variable and
10055  * return its declaration then, else return NULL.
10056  */
10057 entity_t *expression_is_variable(const expression_t *expression)
10058 {
10059         if (expression->base.kind != EXPR_REFERENCE) {
10060                 return NULL;
10061         }
10062         entity_t *entity = expression->reference.entity;
10063         if (entity->kind != ENTITY_VARIABLE)
10064                 return NULL;
10065
10066         return entity;
10067 }
10068
10069 /**
10070  * Parse a return statement.
10071  */
10072 static statement_t *parse_return(void)
10073 {
10074         eat(T_return);
10075
10076         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10077
10078         expression_t *return_value = NULL;
10079         if (token.type != ';') {
10080                 return_value = parse_expression();
10081                 mark_vars_read(return_value, NULL);
10082         }
10083
10084         const type_t *const func_type = skip_typeref(current_function->base.type);
10085         assert(is_type_function(func_type));
10086         type_t *const return_type = skip_typeref(func_type->function.return_type);
10087
10088         source_position_t const *const pos = &statement->base.source_position;
10089         if (return_value != NULL) {
10090                 type_t *return_value_type = skip_typeref(return_value->base.type);
10091
10092                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10093                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10094                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10095                                 /* Only warn in C mode, because GCC does the same */
10096                                 if (c_mode & _CXX || strict_mode) {
10097                                         errorf(pos,
10098                                                         "'return' with a value, in function returning 'void'");
10099                                 } else if (warning.other) {
10100                                         warningf(pos,
10101                                                         "'return' with a value, in function returning 'void'");
10102                                 }
10103                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10104                                 /* Only warn in C mode, because GCC does the same */
10105                                 if (strict_mode) {
10106                                         errorf(pos,
10107                                                         "'return' with expression in function returning 'void'");
10108                                 } else if (warning.other) {
10109                                         warningf(pos,
10110                                                         "'return' with expression in function returning 'void'");
10111                                 }
10112                         }
10113                 } else {
10114                         assign_error_t error = semantic_assign(return_type, return_value);
10115                         report_assign_error(error, return_type, return_value, "'return'",
10116                                         pos);
10117                 }
10118                 return_value = create_implicit_cast(return_value, return_type);
10119                 /* check for returning address of a local var */
10120                 if (warning.other && return_value != NULL
10121                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10122                         const expression_t *expression = return_value->unary.value;
10123                         if (expression_is_local_variable(expression)) {
10124                                 warningf(pos, "function returns address of local variable");
10125                         }
10126                 }
10127         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10128                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10129                 if (c_mode & _CXX || strict_mode) {
10130                         errorf(pos,
10131                                         "'return' without value, in function returning non-void");
10132                 } else {
10133                         warningf(pos,
10134                                         "'return' without value, in function returning non-void");
10135                 }
10136         }
10137         statement->returns.value = return_value;
10138
10139         expect(';', end_error);
10140
10141 end_error:
10142         return statement;
10143 }
10144
10145 /**
10146  * Parse a declaration statement.
10147  */
10148 static statement_t *parse_declaration_statement(void)
10149 {
10150         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10151
10152         entity_t *before = current_scope->last_entity;
10153         if (GNU_MODE) {
10154                 parse_external_declaration();
10155         } else {
10156                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10157         }
10158
10159         declaration_statement_t *const decl  = &statement->declaration;
10160         entity_t                *const begin =
10161                 before != NULL ? before->base.next : current_scope->entities;
10162         decl->declarations_begin = begin;
10163         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10164
10165         return statement;
10166 }
10167
10168 /**
10169  * Parse an expression statement, ie. expr ';'.
10170  */
10171 static statement_t *parse_expression_statement(void)
10172 {
10173         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10174
10175         expression_t *const expr         = parse_expression();
10176         statement->expression.expression = expr;
10177         mark_vars_read(expr, ENT_ANY);
10178
10179         expect(';', end_error);
10180
10181 end_error:
10182         return statement;
10183 }
10184
10185 /**
10186  * Parse a microsoft __try { } __finally { } or
10187  * __try{ } __except() { }
10188  */
10189 static statement_t *parse_ms_try_statment(void)
10190 {
10191         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10192         eat(T___try);
10193
10194         PUSH_PARENT(statement);
10195
10196         ms_try_statement_t *rem = current_try;
10197         current_try = &statement->ms_try;
10198         statement->ms_try.try_statement = parse_compound_statement(false);
10199         current_try = rem;
10200
10201         POP_PARENT;
10202
10203         if (token.type == T___except) {
10204                 eat(T___except);
10205                 expect('(', end_error);
10206                 add_anchor_token(')');
10207                 expression_t *const expr = parse_expression();
10208                 mark_vars_read(expr, NULL);
10209                 type_t       *      type = skip_typeref(expr->base.type);
10210                 if (is_type_integer(type)) {
10211                         type = promote_integer(type);
10212                 } else if (is_type_valid(type)) {
10213                         errorf(&expr->base.source_position,
10214                                "__expect expression is not an integer, but '%T'", type);
10215                         type = type_error_type;
10216                 }
10217                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10218                 rem_anchor_token(')');
10219                 expect(')', end_error);
10220                 statement->ms_try.final_statement = parse_compound_statement(false);
10221         } else if (token.type == T__finally) {
10222                 eat(T___finally);
10223                 statement->ms_try.final_statement = parse_compound_statement(false);
10224         } else {
10225                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10226                 return create_invalid_statement();
10227         }
10228         return statement;
10229 end_error:
10230         return create_invalid_statement();
10231 }
10232
10233 static statement_t *parse_empty_statement(void)
10234 {
10235         if (warning.empty_statement) {
10236                 warningf(HERE, "statement is empty");
10237         }
10238         statement_t *const statement = create_empty_statement();
10239         eat(';');
10240         return statement;
10241 }
10242
10243 static statement_t *parse_local_label_declaration(void)
10244 {
10245         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10246
10247         eat(T___label__);
10248
10249         entity_t *begin = NULL, *end = NULL;
10250
10251         while (true) {
10252                 if (token.type != T_IDENTIFIER) {
10253                         parse_error_expected("while parsing local label declaration",
10254                                 T_IDENTIFIER, NULL);
10255                         goto end_error;
10256                 }
10257                 symbol_t *symbol = token.v.symbol;
10258                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10259                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10260                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10261                                symbol, &entity->base.source_position);
10262                 } else {
10263                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10264
10265                         entity->base.parent_scope    = current_scope;
10266                         entity->base.namespc         = NAMESPACE_LABEL;
10267                         entity->base.source_position = token.source_position;
10268                         entity->base.symbol          = symbol;
10269
10270                         if (end != NULL)
10271                                 end->base.next = entity;
10272                         end = entity;
10273                         if (begin == NULL)
10274                                 begin = entity;
10275
10276                         environment_push(entity);
10277                 }
10278                 next_token();
10279
10280                 if (token.type != ',')
10281                         break;
10282                 next_token();
10283         }
10284         eat(';');
10285 end_error:
10286         statement->declaration.declarations_begin = begin;
10287         statement->declaration.declarations_end   = end;
10288         return statement;
10289 }
10290
10291 static void parse_namespace_definition(void)
10292 {
10293         eat(T_namespace);
10294
10295         entity_t *entity = NULL;
10296         symbol_t *symbol = NULL;
10297
10298         if (token.type == T_IDENTIFIER) {
10299                 symbol = token.v.symbol;
10300                 next_token();
10301
10302                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10303                 if (entity       != NULL             &&
10304                                 entity->kind != ENTITY_NAMESPACE &&
10305                                 entity->base.parent_scope == current_scope) {
10306                         if (!is_error_entity(entity)) {
10307                                 error_redefined_as_different_kind(&token.source_position,
10308                                                 entity, ENTITY_NAMESPACE);
10309                         }
10310                         entity = NULL;
10311                 }
10312         }
10313
10314         if (entity == NULL) {
10315                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10316                 entity->base.symbol          = symbol;
10317                 entity->base.source_position = token.source_position;
10318                 entity->base.namespc         = NAMESPACE_NORMAL;
10319                 entity->base.parent_scope    = current_scope;
10320         }
10321
10322         if (token.type == '=') {
10323                 /* TODO: parse namespace alias */
10324                 panic("namespace alias definition not supported yet");
10325         }
10326
10327         environment_push(entity);
10328         append_entity(current_scope, entity);
10329
10330         size_t const  top       = environment_top();
10331         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10332
10333         expect('{', end_error);
10334         parse_externals();
10335         expect('}', end_error);
10336
10337 end_error:
10338         assert(current_scope == &entity->namespacee.members);
10339         scope_pop(old_scope);
10340         environment_pop_to(top);
10341 }
10342
10343 /**
10344  * Parse a statement.
10345  * There's also parse_statement() which additionally checks for
10346  * "statement has no effect" warnings
10347  */
10348 static statement_t *intern_parse_statement(void)
10349 {
10350         statement_t *statement = NULL;
10351
10352         /* declaration or statement */
10353         add_anchor_token(';');
10354         switch (token.type) {
10355         case T_IDENTIFIER: {
10356                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10357                 if (la1_type == ':') {
10358                         statement = parse_label_statement();
10359                 } else if (is_typedef_symbol(token.v.symbol)) {
10360                         statement = parse_declaration_statement();
10361                 } else {
10362                         /* it's an identifier, the grammar says this must be an
10363                          * expression statement. However it is common that users mistype
10364                          * declaration types, so we guess a bit here to improve robustness
10365                          * for incorrect programs */
10366                         switch (la1_type) {
10367                         case '&':
10368                         case '*':
10369                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10370                                         goto expression_statment;
10371                                 /* FALLTHROUGH */
10372
10373                         DECLARATION_START
10374                         case T_IDENTIFIER:
10375                                 statement = parse_declaration_statement();
10376                                 break;
10377
10378                         default:
10379 expression_statment:
10380                                 statement = parse_expression_statement();
10381                                 break;
10382                         }
10383                 }
10384                 break;
10385         }
10386
10387         case T___extension__:
10388                 /* This can be a prefix to a declaration or an expression statement.
10389                  * We simply eat it now and parse the rest with tail recursion. */
10390                 do {
10391                         next_token();
10392                 } while (token.type == T___extension__);
10393                 bool old_gcc_extension = in_gcc_extension;
10394                 in_gcc_extension       = true;
10395                 statement = intern_parse_statement();
10396                 in_gcc_extension = old_gcc_extension;
10397                 break;
10398
10399         DECLARATION_START
10400                 statement = parse_declaration_statement();
10401                 break;
10402
10403         case T___label__:
10404                 statement = parse_local_label_declaration();
10405                 break;
10406
10407         case ';':         statement = parse_empty_statement();         break;
10408         case '{':         statement = parse_compound_statement(false); break;
10409         case T___leave:   statement = parse_leave_statement();         break;
10410         case T___try:     statement = parse_ms_try_statment();         break;
10411         case T_asm:       statement = parse_asm_statement();           break;
10412         case T_break:     statement = parse_break();                   break;
10413         case T_case:      statement = parse_case_statement();          break;
10414         case T_continue:  statement = parse_continue();                break;
10415         case T_default:   statement = parse_default_statement();       break;
10416         case T_do:        statement = parse_do();                      break;
10417         case T_for:       statement = parse_for();                     break;
10418         case T_goto:      statement = parse_goto();                    break;
10419         case T_if:        statement = parse_if();                      break;
10420         case T_return:    statement = parse_return();                  break;
10421         case T_switch:    statement = parse_switch();                  break;
10422         case T_while:     statement = parse_while();                   break;
10423
10424         EXPRESSION_START
10425                 statement = parse_expression_statement();
10426                 break;
10427
10428         default:
10429                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10430                 statement = create_invalid_statement();
10431                 if (!at_anchor())
10432                         next_token();
10433                 break;
10434         }
10435         rem_anchor_token(';');
10436
10437         assert(statement != NULL
10438                         && statement->base.source_position.input_name != NULL);
10439
10440         return statement;
10441 }
10442
10443 /**
10444  * parse a statement and emits "statement has no effect" warning if needed
10445  * (This is really a wrapper around intern_parse_statement with check for 1
10446  *  single warning. It is needed, because for statement expressions we have
10447  *  to avoid the warning on the last statement)
10448  */
10449 static statement_t *parse_statement(void)
10450 {
10451         statement_t *statement = intern_parse_statement();
10452
10453         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10454                 expression_t *expression = statement->expression.expression;
10455                 if (!expression_has_effect(expression)) {
10456                         warningf(&expression->base.source_position,
10457                                         "statement has no effect");
10458                 }
10459         }
10460
10461         return statement;
10462 }
10463
10464 /**
10465  * Parse a compound statement.
10466  */
10467 static statement_t *parse_compound_statement(bool inside_expression_statement)
10468 {
10469         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10470
10471         PUSH_PARENT(statement);
10472
10473         eat('{');
10474         add_anchor_token('}');
10475         /* tokens, which can start a statement */
10476         /* TODO MS, __builtin_FOO */
10477         add_anchor_token('!');
10478         add_anchor_token('&');
10479         add_anchor_token('(');
10480         add_anchor_token('*');
10481         add_anchor_token('+');
10482         add_anchor_token('-');
10483         add_anchor_token('{');
10484         add_anchor_token('~');
10485         add_anchor_token(T_CHARACTER_CONSTANT);
10486         add_anchor_token(T_COLONCOLON);
10487         add_anchor_token(T_FLOATINGPOINT);
10488         add_anchor_token(T_IDENTIFIER);
10489         add_anchor_token(T_INTEGER);
10490         add_anchor_token(T_MINUSMINUS);
10491         add_anchor_token(T_PLUSPLUS);
10492         add_anchor_token(T_STRING_LITERAL);
10493         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10494         add_anchor_token(T_WIDE_STRING_LITERAL);
10495         add_anchor_token(T__Bool);
10496         add_anchor_token(T__Complex);
10497         add_anchor_token(T__Imaginary);
10498         add_anchor_token(T___FUNCTION__);
10499         add_anchor_token(T___PRETTY_FUNCTION__);
10500         add_anchor_token(T___alignof__);
10501         add_anchor_token(T___attribute__);
10502         add_anchor_token(T___builtin_va_start);
10503         add_anchor_token(T___extension__);
10504         add_anchor_token(T___func__);
10505         add_anchor_token(T___imag__);
10506         add_anchor_token(T___label__);
10507         add_anchor_token(T___real__);
10508         add_anchor_token(T___thread);
10509         add_anchor_token(T_asm);
10510         add_anchor_token(T_auto);
10511         add_anchor_token(T_bool);
10512         add_anchor_token(T_break);
10513         add_anchor_token(T_case);
10514         add_anchor_token(T_char);
10515         add_anchor_token(T_class);
10516         add_anchor_token(T_const);
10517         add_anchor_token(T_const_cast);
10518         add_anchor_token(T_continue);
10519         add_anchor_token(T_default);
10520         add_anchor_token(T_delete);
10521         add_anchor_token(T_double);
10522         add_anchor_token(T_do);
10523         add_anchor_token(T_dynamic_cast);
10524         add_anchor_token(T_enum);
10525         add_anchor_token(T_extern);
10526         add_anchor_token(T_false);
10527         add_anchor_token(T_float);
10528         add_anchor_token(T_for);
10529         add_anchor_token(T_goto);
10530         add_anchor_token(T_if);
10531         add_anchor_token(T_inline);
10532         add_anchor_token(T_int);
10533         add_anchor_token(T_long);
10534         add_anchor_token(T_new);
10535         add_anchor_token(T_operator);
10536         add_anchor_token(T_register);
10537         add_anchor_token(T_reinterpret_cast);
10538         add_anchor_token(T_restrict);
10539         add_anchor_token(T_return);
10540         add_anchor_token(T_short);
10541         add_anchor_token(T_signed);
10542         add_anchor_token(T_sizeof);
10543         add_anchor_token(T_static);
10544         add_anchor_token(T_static_cast);
10545         add_anchor_token(T_struct);
10546         add_anchor_token(T_switch);
10547         add_anchor_token(T_template);
10548         add_anchor_token(T_this);
10549         add_anchor_token(T_throw);
10550         add_anchor_token(T_true);
10551         add_anchor_token(T_try);
10552         add_anchor_token(T_typedef);
10553         add_anchor_token(T_typeid);
10554         add_anchor_token(T_typename);
10555         add_anchor_token(T_typeof);
10556         add_anchor_token(T_union);
10557         add_anchor_token(T_unsigned);
10558         add_anchor_token(T_using);
10559         add_anchor_token(T_void);
10560         add_anchor_token(T_volatile);
10561         add_anchor_token(T_wchar_t);
10562         add_anchor_token(T_while);
10563
10564         size_t const  top       = environment_top();
10565         scope_t      *old_scope = scope_push(&statement->compound.scope);
10566
10567         statement_t **anchor            = &statement->compound.statements;
10568         bool          only_decls_so_far = true;
10569         while (token.type != '}') {
10570                 if (token.type == T_EOF) {
10571                         errorf(&statement->base.source_position,
10572                                "EOF while parsing compound statement");
10573                         break;
10574                 }
10575                 statement_t *sub_statement = intern_parse_statement();
10576                 if (is_invalid_statement(sub_statement)) {
10577                         /* an error occurred. if we are at an anchor, return */
10578                         if (at_anchor())
10579                                 goto end_error;
10580                         continue;
10581                 }
10582
10583                 if (warning.declaration_after_statement) {
10584                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10585                                 only_decls_so_far = false;
10586                         } else if (!only_decls_so_far) {
10587                                 warningf(&sub_statement->base.source_position,
10588                                          "ISO C90 forbids mixed declarations and code");
10589                         }
10590                 }
10591
10592                 *anchor = sub_statement;
10593
10594                 while (sub_statement->base.next != NULL)
10595                         sub_statement = sub_statement->base.next;
10596
10597                 anchor = &sub_statement->base.next;
10598         }
10599         next_token();
10600
10601         /* look over all statements again to produce no effect warnings */
10602         if (warning.unused_value) {
10603                 statement_t *sub_statement = statement->compound.statements;
10604                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10605                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10606                                 continue;
10607                         /* don't emit a warning for the last expression in an expression
10608                          * statement as it has always an effect */
10609                         if (inside_expression_statement && sub_statement->base.next == NULL)
10610                                 continue;
10611
10612                         expression_t *expression = sub_statement->expression.expression;
10613                         if (!expression_has_effect(expression)) {
10614                                 warningf(&expression->base.source_position,
10615                                          "statement has no effect");
10616                         }
10617                 }
10618         }
10619
10620 end_error:
10621         rem_anchor_token(T_while);
10622         rem_anchor_token(T_wchar_t);
10623         rem_anchor_token(T_volatile);
10624         rem_anchor_token(T_void);
10625         rem_anchor_token(T_using);
10626         rem_anchor_token(T_unsigned);
10627         rem_anchor_token(T_union);
10628         rem_anchor_token(T_typeof);
10629         rem_anchor_token(T_typename);
10630         rem_anchor_token(T_typeid);
10631         rem_anchor_token(T_typedef);
10632         rem_anchor_token(T_try);
10633         rem_anchor_token(T_true);
10634         rem_anchor_token(T_throw);
10635         rem_anchor_token(T_this);
10636         rem_anchor_token(T_template);
10637         rem_anchor_token(T_switch);
10638         rem_anchor_token(T_struct);
10639         rem_anchor_token(T_static_cast);
10640         rem_anchor_token(T_static);
10641         rem_anchor_token(T_sizeof);
10642         rem_anchor_token(T_signed);
10643         rem_anchor_token(T_short);
10644         rem_anchor_token(T_return);
10645         rem_anchor_token(T_restrict);
10646         rem_anchor_token(T_reinterpret_cast);
10647         rem_anchor_token(T_register);
10648         rem_anchor_token(T_operator);
10649         rem_anchor_token(T_new);
10650         rem_anchor_token(T_long);
10651         rem_anchor_token(T_int);
10652         rem_anchor_token(T_inline);
10653         rem_anchor_token(T_if);
10654         rem_anchor_token(T_goto);
10655         rem_anchor_token(T_for);
10656         rem_anchor_token(T_float);
10657         rem_anchor_token(T_false);
10658         rem_anchor_token(T_extern);
10659         rem_anchor_token(T_enum);
10660         rem_anchor_token(T_dynamic_cast);
10661         rem_anchor_token(T_do);
10662         rem_anchor_token(T_double);
10663         rem_anchor_token(T_delete);
10664         rem_anchor_token(T_default);
10665         rem_anchor_token(T_continue);
10666         rem_anchor_token(T_const_cast);
10667         rem_anchor_token(T_const);
10668         rem_anchor_token(T_class);
10669         rem_anchor_token(T_char);
10670         rem_anchor_token(T_case);
10671         rem_anchor_token(T_break);
10672         rem_anchor_token(T_bool);
10673         rem_anchor_token(T_auto);
10674         rem_anchor_token(T_asm);
10675         rem_anchor_token(T___thread);
10676         rem_anchor_token(T___real__);
10677         rem_anchor_token(T___label__);
10678         rem_anchor_token(T___imag__);
10679         rem_anchor_token(T___func__);
10680         rem_anchor_token(T___extension__);
10681         rem_anchor_token(T___builtin_va_start);
10682         rem_anchor_token(T___attribute__);
10683         rem_anchor_token(T___alignof__);
10684         rem_anchor_token(T___PRETTY_FUNCTION__);
10685         rem_anchor_token(T___FUNCTION__);
10686         rem_anchor_token(T__Imaginary);
10687         rem_anchor_token(T__Complex);
10688         rem_anchor_token(T__Bool);
10689         rem_anchor_token(T_WIDE_STRING_LITERAL);
10690         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10691         rem_anchor_token(T_STRING_LITERAL);
10692         rem_anchor_token(T_PLUSPLUS);
10693         rem_anchor_token(T_MINUSMINUS);
10694         rem_anchor_token(T_INTEGER);
10695         rem_anchor_token(T_IDENTIFIER);
10696         rem_anchor_token(T_FLOATINGPOINT);
10697         rem_anchor_token(T_COLONCOLON);
10698         rem_anchor_token(T_CHARACTER_CONSTANT);
10699         rem_anchor_token('~');
10700         rem_anchor_token('{');
10701         rem_anchor_token('-');
10702         rem_anchor_token('+');
10703         rem_anchor_token('*');
10704         rem_anchor_token('(');
10705         rem_anchor_token('&');
10706         rem_anchor_token('!');
10707         rem_anchor_token('}');
10708         assert(current_scope == &statement->compound.scope);
10709         scope_pop(old_scope);
10710         environment_pop_to(top);
10711
10712         POP_PARENT;
10713         return statement;
10714 }
10715
10716 /**
10717  * Check for unused global static functions and variables
10718  */
10719 static void check_unused_globals(void)
10720 {
10721         if (!warning.unused_function && !warning.unused_variable)
10722                 return;
10723
10724         for (const entity_t *entity = file_scope->entities; entity != NULL;
10725              entity = entity->base.next) {
10726                 if (!is_declaration(entity))
10727                         continue;
10728
10729                 const declaration_t *declaration = &entity->declaration;
10730                 if (declaration->used                  ||
10731                     declaration->modifiers & DM_UNUSED ||
10732                     declaration->modifiers & DM_USED   ||
10733                     declaration->storage_class != STORAGE_CLASS_STATIC)
10734                         continue;
10735
10736                 type_t *const type = declaration->type;
10737                 const char *s;
10738                 if (entity->kind == ENTITY_FUNCTION) {
10739                         /* inhibit warning for static inline functions */
10740                         if (entity->function.is_inline)
10741                                 continue;
10742
10743                         s = entity->function.statement != NULL ? "defined" : "declared";
10744                 } else {
10745                         s = "defined";
10746                 }
10747
10748                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10749                         type, declaration->base.symbol, s);
10750         }
10751 }
10752
10753 static void parse_global_asm(void)
10754 {
10755         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10756
10757         eat(T_asm);
10758         expect('(', end_error);
10759
10760         statement->asms.asm_text = parse_string_literals();
10761         statement->base.next     = unit->global_asm;
10762         unit->global_asm         = statement;
10763
10764         expect(')', end_error);
10765         expect(';', end_error);
10766
10767 end_error:;
10768 }
10769
10770 static void parse_linkage_specification(void)
10771 {
10772         eat(T_extern);
10773         assert(token.type == T_STRING_LITERAL);
10774
10775         const char *linkage = parse_string_literals().begin;
10776
10777         linkage_kind_t old_linkage = current_linkage;
10778         linkage_kind_t new_linkage;
10779         if (strcmp(linkage, "C") == 0) {
10780                 new_linkage = LINKAGE_C;
10781         } else if (strcmp(linkage, "C++") == 0) {
10782                 new_linkage = LINKAGE_CXX;
10783         } else {
10784                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10785                 new_linkage = LINKAGE_INVALID;
10786         }
10787         current_linkage = new_linkage;
10788
10789         if (token.type == '{') {
10790                 next_token();
10791                 parse_externals();
10792                 expect('}', end_error);
10793         } else {
10794                 parse_external();
10795         }
10796
10797 end_error:
10798         assert(current_linkage == new_linkage);
10799         current_linkage = old_linkage;
10800 }
10801
10802 static void parse_external(void)
10803 {
10804         switch (token.type) {
10805                 DECLARATION_START_NO_EXTERN
10806                 case T_IDENTIFIER:
10807                 case T___extension__:
10808                 /* tokens below are for implicit int */
10809                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10810                              implicit int) */
10811                 case '*': /* * x; -> int* x; */
10812                 case '(': /* (x); -> int (x); */
10813                         parse_external_declaration();
10814                         return;
10815
10816                 case T_extern:
10817                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10818                                 parse_linkage_specification();
10819                         } else {
10820                                 parse_external_declaration();
10821                         }
10822                         return;
10823
10824                 case T_asm:
10825                         parse_global_asm();
10826                         return;
10827
10828                 case T_namespace:
10829                         parse_namespace_definition();
10830                         return;
10831
10832                 case ';':
10833                         if (!strict_mode) {
10834                                 if (warning.other)
10835                                         warningf(HERE, "stray ';' outside of function");
10836                                 next_token();
10837                                 return;
10838                         }
10839                         /* FALLTHROUGH */
10840
10841                 default:
10842                         errorf(HERE, "stray %K outside of function", &token);
10843                         if (token.type == '(' || token.type == '{' || token.type == '[')
10844                                 eat_until_matching_token(token.type);
10845                         next_token();
10846                         return;
10847         }
10848 }
10849
10850 static void parse_externals(void)
10851 {
10852         add_anchor_token('}');
10853         add_anchor_token(T_EOF);
10854
10855 #ifndef NDEBUG
10856         unsigned char token_anchor_copy[T_LAST_TOKEN];
10857         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10858 #endif
10859
10860         while (token.type != T_EOF && token.type != '}') {
10861 #ifndef NDEBUG
10862                 bool anchor_leak = false;
10863                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10864                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10865                         if (count != 0) {
10866                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10867                                 anchor_leak = true;
10868                         }
10869                 }
10870                 if (in_gcc_extension) {
10871                         errorf(HERE, "Leaked __extension__");
10872                         anchor_leak = true;
10873                 }
10874
10875                 if (anchor_leak)
10876                         abort();
10877 #endif
10878
10879                 parse_external();
10880         }
10881
10882         rem_anchor_token(T_EOF);
10883         rem_anchor_token('}');
10884 }
10885
10886 /**
10887  * Parse a translation unit.
10888  */
10889 static void parse_translation_unit(void)
10890 {
10891         add_anchor_token(T_EOF);
10892
10893         while (true) {
10894                 parse_externals();
10895
10896                 if (token.type == T_EOF)
10897                         break;
10898
10899                 errorf(HERE, "stray %K outside of function", &token);
10900                 if (token.type == '(' || token.type == '{' || token.type == '[')
10901                         eat_until_matching_token(token.type);
10902                 next_token();
10903         }
10904 }
10905
10906 /**
10907  * Parse the input.
10908  *
10909  * @return  the translation unit or NULL if errors occurred.
10910  */
10911 void start_parsing(void)
10912 {
10913         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10914         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10915         diagnostic_count  = 0;
10916         error_count       = 0;
10917         warning_count     = 0;
10918
10919         type_set_output(stderr);
10920         ast_set_output(stderr);
10921
10922         assert(unit == NULL);
10923         unit = allocate_ast_zero(sizeof(unit[0]));
10924
10925         assert(file_scope == NULL);
10926         file_scope = &unit->scope;
10927
10928         assert(current_scope == NULL);
10929         scope_push(&unit->scope);
10930
10931         create_gnu_builtins();
10932         if (c_mode & _MS)
10933                 create_microsoft_intrinsics();
10934 }
10935
10936 translation_unit_t *finish_parsing(void)
10937 {
10938         assert(current_scope == &unit->scope);
10939         scope_pop(NULL);
10940
10941         assert(file_scope == &unit->scope);
10942         check_unused_globals();
10943         file_scope = NULL;
10944
10945         DEL_ARR_F(environment_stack);
10946         DEL_ARR_F(label_stack);
10947
10948         translation_unit_t *result = unit;
10949         unit = NULL;
10950         return result;
10951 }
10952
10953 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10954  * are given length one. */
10955 static void complete_incomplete_arrays(void)
10956 {
10957         size_t n = ARR_LEN(incomplete_arrays);
10958         for (size_t i = 0; i != n; ++i) {
10959                 declaration_t *const decl      = incomplete_arrays[i];
10960                 type_t        *const orig_type = decl->type;
10961                 type_t        *const type      = skip_typeref(orig_type);
10962
10963                 if (!is_type_incomplete(type))
10964                         continue;
10965
10966                 if (warning.other) {
10967                         warningf(&decl->base.source_position,
10968                                         "array '%#T' assumed to have one element",
10969                                         orig_type, decl->base.symbol);
10970                 }
10971
10972                 type_t *const new_type = duplicate_type(type);
10973                 new_type->array.size_constant     = true;
10974                 new_type->array.has_implicit_size = true;
10975                 new_type->array.size              = 1;
10976
10977                 type_t *const result = identify_new_type(new_type);
10978
10979                 decl->type = result;
10980         }
10981 }
10982
10983 void prepare_main_collect2(entity_t *entity)
10984 {
10985         // create call to __main
10986         symbol_t *symbol         = symbol_table_insert("__main");
10987         entity_t *subsubmain_ent
10988                 = create_implicit_function(symbol, &builtin_source_position);
10989
10990         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10991         type_t       *ftype       = subsubmain_ent->declaration.type;
10992         ref->base.source_position = builtin_source_position;
10993         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10994         ref->reference.entity     = subsubmain_ent;
10995
10996         expression_t *call = allocate_expression_zero(EXPR_CALL);
10997         call->base.source_position = builtin_source_position;
10998         call->base.type            = type_void;
10999         call->call.function        = ref;
11000
11001         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
11002         expr_statement->base.source_position  = builtin_source_position;
11003         expr_statement->expression.expression = call;
11004
11005         statement_t *statement = entity->function.statement;
11006         assert(statement->kind == STATEMENT_COMPOUND);
11007         compound_statement_t *compounds = &statement->compound;
11008
11009         expr_statement->base.next = compounds->statements;
11010         compounds->statements     = expr_statement;
11011 }
11012
11013 void parse(void)
11014 {
11015         lookahead_bufpos = 0;
11016         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11017                 next_token();
11018         }
11019         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11020         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11021         parse_translation_unit();
11022         complete_incomplete_arrays();
11023         DEL_ARR_F(incomplete_arrays);
11024         incomplete_arrays = NULL;
11025 }
11026
11027 /**
11028  * create a builtin function.
11029  */
11030 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
11031 {
11032         symbol_t *symbol = symbol_table_insert(name);
11033         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
11034         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
11035         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
11036         entity->declaration.type                   = function_type;
11037         entity->declaration.implicit               = true;
11038         entity->base.symbol                        = symbol;
11039         entity->base.source_position               = builtin_source_position;
11040
11041         entity->function.btk                       = kind;
11042
11043         record_entity(entity, /*is_definition=*/false);
11044         return entity;
11045 }
11046
11047
11048 /**
11049  * Create predefined gnu builtins.
11050  */
11051 static void create_gnu_builtins(void)
11052 {
11053 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
11054
11055         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
11056         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
11057         GNU_BUILTIN(inf,            make_function_0_type(type_double));
11058         GNU_BUILTIN(inff,           make_function_0_type(type_float));
11059         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
11060         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
11061         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
11062         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
11063         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
11064         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
11065         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
11066         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
11067         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
11068         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
11069         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
11070         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
11071         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
11072         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
11073         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
11074
11075 #undef GNU_BUILTIN
11076 }
11077
11078 /**
11079  * Create predefined MS intrinsics.
11080  */
11081 static void create_microsoft_intrinsics(void)
11082 {
11083 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11084
11085         /* intrinsics for all architectures */
11086         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11087         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11088         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11089         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11090         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11091         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11092         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11093
11094         MS_BUILTIN(__debugbreak,            make_function_0_type(type_void));
11095         MS_BUILTIN(_ReturnAddress,          make_function_0_type(type_void_ptr));
11096         MS_BUILTIN(_AddressOfReturnAddress, make_function_0_type(type_void_ptr));
11097         MS_BUILTIN(__popcount,              make_function_1_type(type_unsigned_int, type_unsigned_int));
11098
11099         /* x86/x64 only */
11100         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11101         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11102         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11103         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11104         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11105         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11106         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11107         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11108         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11109         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11110         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11111         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11112         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11113
11114         if (machine_size <= 32) {
11115                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11116                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11117         } else {
11118                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11119                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11120         }
11121
11122 #undef MS_BUILTIN
11123 }
11124
11125 /**
11126  * Initialize the parser.
11127  */
11128 void init_parser(void)
11129 {
11130         sym_anonymous = symbol_table_insert("<anonymous>");
11131
11132         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11133
11134         init_expression_parsers();
11135         obstack_init(&temp_obst);
11136
11137         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11138         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11139 }
11140
11141 /**
11142  * Terminate the parser.
11143  */
11144 void exit_parser(void)
11145 {
11146         obstack_free(&temp_obst, NULL);
11147 }