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.h"
  40 #include "warning.h"
  41 #include "printer.h"
  42 #include "adt/bitfiddle.h"
  43 #include "adt/error.h"
  44 #include "adt/array.h"
  45
  46 //#define PRINT_TOKENS
  47 #define MAX_LOOKAHEAD 1
  48
  49 typedef struct {
  50         entity_t           *old_entity;
  51         symbol_t           *symbol;
  52         entity_namespace_t  namespc;
  53 } stack_entry_t;
  54
  55 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  56 struct declaration_specifiers_t {
  57         source_position_t  source_position;
  58         storage_class_t    storage_class;
  59         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  60         bool               is_inline    : 1;
  61         bool               thread_local : 1;  /**< GCC __thread */
  62         attribute_t       *attributes;        /**< list of attributes */
  63         type_t            *type;
  64 };
  65
  66 /**
  67  * An environment for parsing initializers (and compound literals).
  68  */
  69 typedef struct parse_initializer_env_t {
  70         type_t     *type;   /**< the type of the initializer. In case of an
  71                                  array type with unspecified size this gets
  72                                  adjusted to the actual size. */
  73         entity_t   *entity; /**< the variable that is initialized if any */
  74         bool        must_be_constant;
  75 } parse_initializer_env_t;
  76
  77 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  78
  79 /** The current token. */
  80 static token_t              token;
  81 /** The lookahead ring-buffer. */
  82 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  83 /** Position of the next token in the lookahead buffer. */
  84 static size_t               lookahead_bufpos;
  85 static stack_entry_t       *environment_stack = NULL;
  86 static stack_entry_t       *label_stack       = NULL;
  87 static scope_t             *file_scope        = NULL;
  88 static scope_t             *current_scope     = NULL;
  89 /** Point to the current function declaration if inside a function. */
  90 static function_t          *current_function  = NULL;
  91 static entity_t            *current_entity    = NULL;
  92 static switch_statement_t  *current_switch    = NULL;
  93 static statement_t         *current_loop      = NULL;
  94 static statement_t         *current_parent    = NULL;
  95 static ms_try_statement_t  *current_try       = NULL;
  96 static linkage_kind_t       current_linkage;
  97 static goto_statement_t    *goto_first        = NULL;
  98 static goto_statement_t   **goto_anchor       = NULL;
  99 static label_statement_t   *label_first       = NULL;
 100 static label_statement_t  **label_anchor      = NULL;
 101 /** current translation unit. */
 102 static translation_unit_t  *unit              = NULL;
 103 /** true if we are in an __extension__ context. */
 104 static bool                 in_gcc_extension  = false;
 105 static struct obstack       temp_obst;
 106 static entity_t            *anonymous_entity;
 107 static declaration_t      **incomplete_arrays;
 108 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 109
 110
 111 #define PUSH_PARENT(stmt) \
 112         statement_t *const new_parent = (stmt); \
 113         statement_t *const old_parent = current_parent; \
 114         ((void)(current_parent = new_parent))
 115 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 116
 117 #define PUSH_SCOPE(scope) \
 118         size_t   const top       = environment_top(); \
 119         scope_t *const new_scope = (scope); \
 120         scope_t *const old_scope = scope_push(new_scope)
 121 #define POP_SCOPE() (assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top))
 122
 123 #define PUSH_EXTENSION() \
 124         (void)0; \
 125         bool const old_gcc_extension = in_gcc_extension; \
 126         while (next_if(T___extension__)) { \
 127                 in_gcc_extension = true; \
 128         } \
 129         do {} while (0)
 130 #define POP_EXTENSION() \
 131         ((void)(in_gcc_extension = old_gcc_extension))
 132
 133 /** special symbol used for anonymous entities. */
 134 static symbol_t *sym_anonymous = NULL;
 135
 136 /** The token anchor set */
 137 static unsigned short token_anchor_set[T_LAST_TOKEN];
 138
 139 /** The current source position. */
 140 #define HERE (&token.base.source_position)
 141
 142 /** true if we are in GCC mode. */
 143 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 144
 145 static statement_t *parse_compound_statement(bool inside_expression_statement);
 146 static statement_t *parse_statement(void);
 147
 148 static expression_t *parse_subexpression(precedence_t);
 149 static expression_t *parse_expression(void);
 150 static type_t       *parse_typename(void);
 151 static void          parse_externals(void);
 152 static void          parse_external(void);
 153
 154 static void parse_compound_type_entries(compound_t *compound_declaration);
 155
 156 static void check_call_argument(type_t          *expected_type,
 157                                                                 call_argument_t *argument, unsigned pos);
 158
 159 typedef enum declarator_flags_t {
 160         DECL_FLAGS_NONE             = 0,
 161         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 162         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 163         DECL_IS_PARAMETER           = 1U << 2
 164 } declarator_flags_t;
 165
 166 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 167                                   declarator_flags_t flags);
 168
 169 static void semantic_comparison(binary_expression_t *expression);
 170
 171 #define STORAGE_CLASSES       \
 172         STORAGE_CLASSES_NO_EXTERN \
 173         case T_extern:
 174
 175 #define STORAGE_CLASSES_NO_EXTERN \
 176         case T_typedef:         \
 177         case T_static:          \
 178         case T_auto:            \
 179         case T_register:        \
 180         case T___thread:
 181
 182 #define TYPE_QUALIFIERS     \
 183         case T_const:           \
 184         case T_restrict:        \
 185         case T_volatile:        \
 186         case T_inline:          \
 187         case T__forceinline:    \
 188         case T___attribute__:
 189
 190 #define COMPLEX_SPECIFIERS  \
 191         case T__Complex:
 192 #define IMAGINARY_SPECIFIERS \
 193         case T__Imaginary:
 194
 195 #define TYPE_SPECIFIERS       \
 196         case T__Bool:             \
 197         case T___builtin_va_list: \
 198         case T___typeof__:        \
 199         case T__declspec:         \
 200         case T_bool:              \
 201         case T_char:              \
 202         case T_double:            \
 203         case T_enum:              \
 204         case T_float:             \
 205         case T_int:               \
 206         case T_long:              \
 207         case T_short:             \
 208         case T_signed:            \
 209         case T_struct:            \
 210         case T_union:             \
 211         case T_unsigned:          \
 212         case T_void:              \
 213         case T_wchar_t:           \
 214         case T__int8:             \
 215         case T__int16:            \
 216         case T__int32:            \
 217         case T__int64:            \
 218         case T__int128:           \
 219         COMPLEX_SPECIFIERS        \
 220         IMAGINARY_SPECIFIERS
 221
 222 #define DECLARATION_START   \
 223         STORAGE_CLASSES         \
 224         TYPE_QUALIFIERS         \
 225         TYPE_SPECIFIERS
 226
 227 #define DECLARATION_START_NO_EXTERN \
 228         STORAGE_CLASSES_NO_EXTERN       \
 229         TYPE_QUALIFIERS                 \
 230         TYPE_SPECIFIERS
 231
 232 #define EXPRESSION_START              \
 233         case '!':                         \
 234         case '&':                         \
 235         case '(':                         \
 236         case '*':                         \
 237         case '+':                         \
 238         case '-':                         \
 239         case '~':                         \
 240         case T_ANDAND:                    \
 241         case T_CHARACTER_CONSTANT:        \
 242         case T_FLOATINGPOINT:             \
 243         case T_FLOATINGPOINT_HEXADECIMAL: \
 244         case T_INTEGER:                   \
 245         case T_INTEGER_HEXADECIMAL:       \
 246         case T_INTEGER_OCTAL:             \
 247         case T_MINUSMINUS:                \
 248         case T_PLUSPLUS:                  \
 249         case T_STRING_LITERAL:            \
 250         case T_WIDE_CHARACTER_CONSTANT:   \
 251         case T_WIDE_STRING_LITERAL:       \
 252         case T___FUNCDNAME__:             \
 253         case T___FUNCSIG__:               \
 254         case T___FUNCTION__:              \
 255         case T___PRETTY_FUNCTION__:       \
 256         case T___alignof__:               \
 257         case T___builtin_classify_type:   \
 258         case T___builtin_constant_p:      \
 259         case T___builtin_isgreater:       \
 260         case T___builtin_isgreaterequal:  \
 261         case T___builtin_isless:          \
 262         case T___builtin_islessequal:     \
 263         case T___builtin_islessgreater:   \
 264         case T___builtin_isunordered:     \
 265         case T___builtin_offsetof:        \
 266         case T___builtin_va_arg:          \
 267         case T___builtin_va_copy:         \
 268         case T___builtin_va_start:        \
 269         case T___func__:                  \
 270         case T___noop:                    \
 271         case T__assume:                   \
 272         case T_delete:                    \
 273         case T_false:                     \
 274         case T_sizeof:                    \
 275         case T_throw:                     \
 276         case T_true:
 277
 278 /**
 279  * Returns the size of a statement node.
 280  *
 281  * @param kind  the statement kind
 282  */
 283 static size_t get_statement_struct_size(statement_kind_t kind)
 284 {
 285         static const size_t sizes[] = {
 286                 [STATEMENT_ERROR]       = sizeof(statement_base_t),
 287                 [STATEMENT_EMPTY]       = sizeof(statement_base_t),
 288                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 289                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 290                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 291                 [STATEMENT_IF]          = sizeof(if_statement_t),
 292                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 293                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 294                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 295                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 296                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 297                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 298                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 299                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 300                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 301                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 302                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 303                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 304                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 305         };
 306         assert((size_t)kind < lengthof(sizes));
 307         assert(sizes[kind] != 0);
 308         return sizes[kind];
 309 }
 310
 311 /**
 312  * Returns the size of an expression node.
 313  *
 314  * @param kind  the expression kind
 315  */
 316 static size_t get_expression_struct_size(expression_kind_t kind)
 317 {
 318         static const size_t sizes[] = {
 319                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 320                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 321                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 322                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 323                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 330                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 331                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 332                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 333                 [EXPR_CALL]                       = sizeof(call_expression_t),
 334                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 335                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 336                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 337                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 338                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 339                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 340                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 341                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 342                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 343                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 344                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 345                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 346                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 347                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 348                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 349                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 350                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 351         };
 352         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 353                 return sizes[EXPR_UNARY_FIRST];
 354         }
 355         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 356                 return sizes[EXPR_BINARY_FIRST];
 357         }
 358         assert((size_t)kind < lengthof(sizes));
 359         assert(sizes[kind] != 0);
 360         return sizes[kind];
 361 }
 362
 363 /**
 364  * Allocate a statement node of given kind and initialize all
 365  * fields with zero. Sets its source position to the position
 366  * of the current token.
 367  */
 368 static statement_t *allocate_statement_zero(statement_kind_t kind)
 369 {
 370         size_t       size = get_statement_struct_size(kind);
 371         statement_t *res  = allocate_ast_zero(size);
 372
 373         res->base.kind            = kind;
 374         res->base.parent          = current_parent;
 375         res->base.source_position = token.base.source_position;
 376         return res;
 377 }
 378
 379 /**
 380  * Allocate an expression node of given kind and initialize all
 381  * fields with zero.
 382  *
 383  * @param kind  the kind of the expression to allocate
 384  */
 385 static expression_t *allocate_expression_zero(expression_kind_t kind)
 386 {
 387         size_t        size = get_expression_struct_size(kind);
 388         expression_t *res  = allocate_ast_zero(size);
 389
 390         res->base.kind            = kind;
 391         res->base.type            = type_error_type;
 392         res->base.source_position = token.base.source_position;
 393         return res;
 394 }
 395
 396 /**
 397  * Creates a new invalid expression at the source position
 398  * of the current token.
 399  */
 400 static expression_t *create_error_expression(void)
 401 {
 402         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 403         expression->base.type = type_error_type;
 404         return expression;
 405 }
 406
 407 /**
 408  * Creates a new invalid statement.
 409  */
 410 static statement_t *create_error_statement(void)
 411 {
 412         return allocate_statement_zero(STATEMENT_ERROR);
 413 }
 414
 415 /**
 416  * Allocate a new empty statement.
 417  */
 418 static statement_t *create_empty_statement(void)
 419 {
 420         return allocate_statement_zero(STATEMENT_EMPTY);
 421 }
 422
 423 /**
 424  * Returns the size of an initializer node.
 425  *
 426  * @param kind  the initializer kind
 427  */
 428 static size_t get_initializer_size(initializer_kind_t kind)
 429 {
 430         static const size_t sizes[] = {
 431                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 432                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 433                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 434                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 435                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 436         };
 437         assert((size_t)kind < lengthof(sizes));
 438         assert(sizes[kind] != 0);
 439         return sizes[kind];
 440 }
 441
 442 /**
 443  * Allocate an initializer node of given kind and initialize all
 444  * fields with zero.
 445  */
 446 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 447 {
 448         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 449         result->kind          = kind;
 450
 451         return result;
 452 }
 453
 454 /**
 455  * Returns the index of the top element of the environment stack.
 456  */
 457 static size_t environment_top(void)
 458 {
 459         return ARR_LEN(environment_stack);
 460 }
 461
 462 /**
 463  * Returns the index of the top element of the global label stack.
 464  */
 465 static size_t label_top(void)
 466 {
 467         return ARR_LEN(label_stack);
 468 }
 469
 470 /**
 471  * Return the next token.
 472  */
 473 static inline void next_token(void)
 474 {
 475         token                              = lookahead_buffer[lookahead_bufpos];
 476         lookahead_buffer[lookahead_bufpos] = lexer_token;
 477         lexer_next_token();
 478
 479         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 480
 481 #ifdef PRINT_TOKENS
 482         print_token(stderr, &token);
 483         fprintf(stderr, "\n");
 484 #endif
 485 }
 486
 487 static inline bool next_if(int const type)
 488 {
 489         if (token.kind == type) {
 490                 next_token();
 491                 return true;
 492         } else {
 493                 return false;
 494         }
 495 }
 496
 497 /**
 498  * Return the next token with a given lookahead.
 499  */
 500 static inline const token_t *look_ahead(size_t num)
 501 {
 502         assert(0 < num && num <= MAX_LOOKAHEAD);
 503         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 504         return &lookahead_buffer[pos];
 505 }
 506
 507 /**
 508  * Adds a token type to the token type anchor set (a multi-set).
 509  */
 510 static void add_anchor_token(int token_kind)
 511 {
 512         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 513         ++token_anchor_set[token_kind];
 514 }
 515
 516 /**
 517  * Set the number of tokens types of the given type
 518  * to zero and return the old count.
 519  */
 520 static int save_and_reset_anchor_state(int token_kind)
 521 {
 522         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 523         int count = token_anchor_set[token_kind];
 524         token_anchor_set[token_kind] = 0;
 525         return count;
 526 }
 527
 528 /**
 529  * Restore the number of token types to the given count.
 530  */
 531 static void restore_anchor_state(int token_kind, int count)
 532 {
 533         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 534         token_anchor_set[token_kind] = count;
 535 }
 536
 537 /**
 538  * Remove a token type from the token type anchor set (a multi-set).
 539  */
 540 static void rem_anchor_token(int token_kind)
 541 {
 542         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 543         assert(token_anchor_set[token_kind] != 0);
 544         --token_anchor_set[token_kind];
 545 }
 546
 547 /**
 548  * Return true if the token type of the current token is
 549  * in the anchor set.
 550  */
 551 static bool at_anchor(void)
 552 {
 553         if (token.kind < 0)
 554                 return false;
 555         return token_anchor_set[token.kind];
 556 }
 557
 558 /**
 559  * Eat tokens until a matching token type is found.
 560  */
 561 static void eat_until_matching_token(int type)
 562 {
 563         int end_token;
 564         switch (type) {
 565                 case '(': end_token = ')';  break;
 566                 case '{': end_token = '}';  break;
 567                 case '[': end_token = ']';  break;
 568                 default:  end_token = type; break;
 569         }
 570
 571         unsigned parenthesis_count = 0;
 572         unsigned brace_count       = 0;
 573         unsigned bracket_count     = 0;
 574         while (token.kind        != end_token ||
 575                parenthesis_count != 0         ||
 576                brace_count       != 0         ||
 577                bracket_count     != 0) {
 578                 switch (token.kind) {
 579                 case T_EOF: return;
 580                 case '(': ++parenthesis_count; break;
 581                 case '{': ++brace_count;       break;
 582                 case '[': ++bracket_count;     break;
 583
 584                 case ')':
 585                         if (parenthesis_count > 0)
 586                                 --parenthesis_count;
 587                         goto check_stop;
 588
 589                 case '}':
 590                         if (brace_count > 0)
 591                                 --brace_count;
 592                         goto check_stop;
 593
 594                 case ']':
 595                         if (bracket_count > 0)
 596                                 --bracket_count;
 597 check_stop:
 598                         if (token.kind        == end_token &&
 599                             parenthesis_count == 0         &&
 600                             brace_count       == 0         &&
 601                             bracket_count     == 0)
 602                                 return;
 603                         break;
 604
 605                 default:
 606                         break;
 607                 }
 608                 next_token();
 609         }
 610 }
 611
 612 /**
 613  * Eat input tokens until an anchor is found.
 614  */
 615 static void eat_until_anchor(void)
 616 {
 617         while (token_anchor_set[token.kind] == 0) {
 618                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 619                         eat_until_matching_token(token.kind);
 620                 next_token();
 621         }
 622 }
 623
 624 /**
 625  * Eat a whole block from input tokens.
 626  */
 627 static void eat_block(void)
 628 {
 629         eat_until_matching_token('{');
 630         next_if('}');
 631 }
 632
 633 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 634
 635 /**
 636  * Report a parse error because an expected token was not found.
 637  */
 638 static
 639 #if defined __GNUC__ && __GNUC__ >= 4
 640 __attribute__((sentinel))
 641 #endif
 642 void parse_error_expected(const char *message, ...)
 643 {
 644         if (message != NULL) {
 645                 errorf(HERE, "%s", message);
 646         }
 647         va_list ap;
 648         va_start(ap, message);
 649         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 650         va_end(ap);
 651 }
 652
 653 /**
 654  * Report an incompatible type.
 655  */
 656 static void type_error_incompatible(const char *msg,
 657                 const source_position_t *source_position, type_t *type1, type_t *type2)
 658 {
 659         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 660                msg, type1, type2);
 661 }
 662
 663 /**
 664  * Expect the current token is the expected token.
 665  * If not, generate an error, eat the current statement,
 666  * and goto the error_label label.
 667  */
 668 #define expect(expected, error_label)                     \
 669         do {                                                  \
 670                 if (UNLIKELY(token.kind != (expected))) {         \
 671                         parse_error_expected(NULL, (expected), NULL); \
 672                         add_anchor_token(expected);                   \
 673                         eat_until_anchor();                           \
 674                         rem_anchor_token(expected);                   \
 675                         if (token.kind != (expected))                 \
 676                           goto error_label;                           \
 677                 }                                                 \
 678                 next_token();                                     \
 679         } while (0)
 680
 681 /**
 682  * Push a given scope on the scope stack and make it the
 683  * current scope
 684  */
 685 static scope_t *scope_push(scope_t *new_scope)
 686 {
 687         if (current_scope != NULL) {
 688                 new_scope->depth = current_scope->depth + 1;
 689         }
 690
 691         scope_t *old_scope = current_scope;
 692         current_scope      = new_scope;
 693         return old_scope;
 694 }
 695
 696 /**
 697  * Pop the current scope from the scope stack.
 698  */
 699 static void scope_pop(scope_t *old_scope)
 700 {
 701         current_scope = old_scope;
 702 }
 703
 704 /**
 705  * Search an entity by its symbol in a given namespace.
 706  */
 707 static entity_t *get_entity(const symbol_t *const symbol,
 708                             namespace_tag_t namespc)
 709 {
 710         entity_t *entity = symbol->entity;
 711         for (; entity != NULL; entity = entity->base.symbol_next) {
 712                 if ((namespace_tag_t)entity->base.namespc == namespc)
 713                         return entity;
 714         }
 715
 716         return NULL;
 717 }
 718
 719 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 720  * possible. */
 721 static entity_t *get_tag(symbol_t const *const symbol,
 722                          entity_kind_tag_t const kind)
 723 {
 724         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 725         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 726                 errorf(HERE,
 727                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 728                                 symbol, &entity->base.source_position);
 729                 entity = NULL;
 730         }
 731         return entity;
 732 }
 733
 734 /**
 735  * pushs an entity on the environment stack and links the corresponding symbol
 736  * it.
 737  */
 738 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 739 {
 740         symbol_t           *symbol  = entity->base.symbol;
 741         entity_namespace_t  namespc = entity->base.namespc;
 742         assert(namespc != 0);
 743
 744         /* replace/add entity into entity list of the symbol */
 745         entity_t **anchor;
 746         entity_t  *iter;
 747         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 748                 iter = *anchor;
 749                 if (iter == NULL)
 750                         break;
 751
 752                 /* replace an entry? */
 753                 if (iter->base.namespc == namespc) {
 754                         entity->base.symbol_next = iter->base.symbol_next;
 755                         break;
 756                 }
 757         }
 758         *anchor = entity;
 759
 760         /* remember old declaration */
 761         stack_entry_t entry;
 762         entry.symbol     = symbol;
 763         entry.old_entity = iter;
 764         entry.namespc    = namespc;
 765         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 766 }
 767
 768 /**
 769  * Push an entity on the environment stack.
 770  */
 771 static void environment_push(entity_t *entity)
 772 {
 773         assert(entity->base.source_position.input_name != NULL);
 774         assert(entity->base.parent_scope != NULL);
 775         stack_push(&environment_stack, entity);
 776 }
 777
 778 /**
 779  * Push a declaration on the global label stack.
 780  *
 781  * @param declaration  the declaration
 782  */
 783 static void label_push(entity_t *label)
 784 {
 785         /* we abuse the parameters scope as parent for the labels */
 786         label->base.parent_scope = &current_function->parameters;
 787         stack_push(&label_stack, label);
 788 }
 789
 790 /**
 791  * pops symbols from the environment stack until @p new_top is the top element
 792  */
 793 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 794 {
 795         stack_entry_t *stack = *stack_ptr;
 796         size_t         top   = ARR_LEN(stack);
 797         size_t         i;
 798
 799         assert(new_top <= top);
 800         if (new_top == top)
 801                 return;
 802
 803         for (i = top; i > new_top; --i) {
 804                 stack_entry_t *entry = &stack[i - 1];
 805
 806                 entity_t           *old_entity = entry->old_entity;
 807                 symbol_t           *symbol     = entry->symbol;
 808                 entity_namespace_t  namespc    = entry->namespc;
 809
 810                 /* replace with old_entity/remove */
 811                 entity_t **anchor;
 812                 entity_t  *iter;
 813                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 814                         iter = *anchor;
 815                         assert(iter != NULL);
 816                         /* replace an entry? */
 817                         if (iter->base.namespc == namespc)
 818                                 break;
 819                 }
 820
 821                 /* restore definition from outer scopes (if there was one) */
 822                 if (old_entity != NULL) {
 823                         old_entity->base.symbol_next = iter->base.symbol_next;
 824                         *anchor                      = old_entity;
 825                 } else {
 826                         /* remove entry from list */
 827                         *anchor = iter->base.symbol_next;
 828                 }
 829         }
 830
 831         ARR_SHRINKLEN(*stack_ptr, new_top);
 832 }
 833
 834 /**
 835  * Pop all entries from the environment stack until the new_top
 836  * is reached.
 837  *
 838  * @param new_top  the new stack top
 839  */
 840 static void environment_pop_to(size_t new_top)
 841 {
 842         stack_pop_to(&environment_stack, new_top);
 843 }
 844
 845 /**
 846  * Pop all entries from the global label stack until the new_top
 847  * is reached.
 848  *
 849  * @param new_top  the new stack top
 850  */
 851 static void label_pop_to(size_t new_top)
 852 {
 853         stack_pop_to(&label_stack, new_top);
 854 }
 855
 856 static int get_akind_rank(atomic_type_kind_t akind)
 857 {
 858         return (int) akind;
 859 }
 860
 861 /**
 862  * Return the type rank for an atomic type.
 863  */
 864 static int get_rank(const type_t *type)
 865 {
 866         assert(!is_typeref(type));
 867         if (type->kind == TYPE_ENUM)
 868                 return get_akind_rank(type->enumt.akind);
 869
 870         assert(type->kind == TYPE_ATOMIC);
 871         return get_akind_rank(type->atomic.akind);
 872 }
 873
 874 /**
 875  * §6.3.1.1:2  Do integer promotion for a given type.
 876  *
 877  * @param type  the type to promote
 878  * @return the promoted type
 879  */
 880 static type_t *promote_integer(type_t *type)
 881 {
 882         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 883                 type = type_int;
 884
 885         return type;
 886 }
 887
 888 /**
 889  * Check if a given expression represents a null pointer constant.
 890  *
 891  * @param expression  the expression to check
 892  */
 893 static bool is_null_pointer_constant(const expression_t *expression)
 894 {
 895         /* skip void* cast */
 896         if (expression->kind == EXPR_UNARY_CAST) {
 897                 type_t *const type = skip_typeref(expression->base.type);
 898                 if (types_compatible(type, type_void_ptr))
 899                         expression = expression->unary.value;
 900         }
 901
 902         type_t *const type = skip_typeref(expression->base.type);
 903         if (!is_type_integer(type))
 904                 return false;
 905         switch (is_constant_expression(expression)) {
 906                 case EXPR_CLASS_ERROR:    return true;
 907                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 908                 default:                  return false;
 909         }
 910 }
 911
 912 /**
 913  * Create an implicit cast expression.
 914  *
 915  * @param expression  the expression to cast
 916  * @param dest_type   the destination type
 917  */
 918 static expression_t *create_implicit_cast(expression_t *expression,
 919                                           type_t *dest_type)
 920 {
 921         type_t *const source_type = expression->base.type;
 922
 923         if (source_type == dest_type)
 924                 return expression;
 925
 926         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 927         cast->unary.value   = expression;
 928         cast->base.type     = dest_type;
 929         cast->base.implicit = true;
 930
 931         return cast;
 932 }
 933
 934 typedef enum assign_error_t {
 935         ASSIGN_SUCCESS,
 936         ASSIGN_ERROR_INCOMPATIBLE,
 937         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 938         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 939         ASSIGN_WARNING_POINTER_FROM_INT,
 940         ASSIGN_WARNING_INT_FROM_POINTER
 941 } assign_error_t;
 942
 943 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, source_position_t const *const pos)
 944 {
 945         type_t *const orig_type_right = right->base.type;
 946         type_t *const type_left       = skip_typeref(orig_type_left);
 947         type_t *const type_right      = skip_typeref(orig_type_right);
 948
 949         switch (error) {
 950         case ASSIGN_SUCCESS:
 951                 return;
 952         case ASSIGN_ERROR_INCOMPATIBLE:
 953                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 954                 return;
 955
 956         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 957                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 958                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 959
 960                 /* the left type has all qualifiers from the right type */
 961                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 962                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 963                 return;
 964         }
 965
 966         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 967                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 968                 return;
 969
 970         case ASSIGN_WARNING_POINTER_FROM_INT:
 971                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 972                 return;
 973
 974         case ASSIGN_WARNING_INT_FROM_POINTER:
 975                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 976                 return;
 977
 978         default:
 979                 panic("invalid error value");
 980         }
 981 }
 982
 983 /** Implements the rules from §6.5.16.1 */
 984 static assign_error_t semantic_assign(type_t *orig_type_left,
 985                                       const expression_t *const right)
 986 {
 987         type_t *const orig_type_right = right->base.type;
 988         type_t *const type_left       = skip_typeref(orig_type_left);
 989         type_t *const type_right      = skip_typeref(orig_type_right);
 990
 991         if (is_type_pointer(type_left)) {
 992                 if (is_null_pointer_constant(right)) {
 993                         return ASSIGN_SUCCESS;
 994                 } else if (is_type_pointer(type_right)) {
 995                         type_t *points_to_left
 996                                 = skip_typeref(type_left->pointer.points_to);
 997                         type_t *points_to_right
 998                                 = skip_typeref(type_right->pointer.points_to);
 999                         assign_error_t res = ASSIGN_SUCCESS;
1000
1001                         /* the left type has all qualifiers from the right type */
1002                         unsigned missing_qualifiers
1003                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1004                         if (missing_qualifiers != 0) {
1005                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1006                         }
1007
1008                         points_to_left  = get_unqualified_type(points_to_left);
1009                         points_to_right = get_unqualified_type(points_to_right);
1010
1011                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1012                                 return res;
1013
1014                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1015                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1016                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1017                         }
1018
1019                         if (!types_compatible(points_to_left, points_to_right)) {
1020                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1021                         }
1022
1023                         return res;
1024                 } else if (is_type_integer(type_right)) {
1025                         return ASSIGN_WARNING_POINTER_FROM_INT;
1026                 }
1027         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1028                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1029                                 && is_type_pointer(type_right))) {
1030                 return ASSIGN_SUCCESS;
1031         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1032                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1033                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1034                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1035                         return ASSIGN_SUCCESS;
1036                 }
1037         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1038                 return ASSIGN_WARNING_INT_FROM_POINTER;
1039         }
1040
1041         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1042                 return ASSIGN_SUCCESS;
1043
1044         return ASSIGN_ERROR_INCOMPATIBLE;
1045 }
1046
1047 static expression_t *parse_constant_expression(void)
1048 {
1049         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1050
1051         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1052                 errorf(&result->base.source_position,
1053                        "expression '%E' is not constant", result);
1054         }
1055
1056         return result;
1057 }
1058
1059 static expression_t *parse_assignment_expression(void)
1060 {
1061         return parse_subexpression(PREC_ASSIGNMENT);
1062 }
1063
1064 static void warn_string_concat(const source_position_t *pos)
1065 {
1066         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1067 }
1068
1069 static string_t parse_string_literals(void)
1070 {
1071         assert(token.kind == T_STRING_LITERAL);
1072         string_t result = token.string.string;
1073
1074         next_token();
1075
1076         while (token.kind == T_STRING_LITERAL) {
1077                 warn_string_concat(&token.base.source_position);
1078                 result = concat_strings(&result, &token.string.string);
1079                 next_token();
1080         }
1081
1082         return result;
1083 }
1084
1085 /**
1086  * compare two string, ignoring double underscores on the second.
1087  */
1088 static int strcmp_underscore(const char *s1, const char *s2)
1089 {
1090         if (s2[0] == '_' && s2[1] == '_') {
1091                 size_t len2 = strlen(s2);
1092                 size_t len1 = strlen(s1);
1093                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1094                         return strncmp(s1, s2+2, len2-4);
1095                 }
1096         }
1097
1098         return strcmp(s1, s2);
1099 }
1100
1101 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1102 {
1103         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1104         attribute->kind            = kind;
1105         attribute->source_position = *HERE;
1106         return attribute;
1107 }
1108
1109 /**
1110  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1111  *
1112  *  attribute:
1113  *    __attribute__ ( ( attribute-list ) )
1114  *
1115  *  attribute-list:
1116  *    attrib
1117  *    attribute_list , attrib
1118  *
1119  *  attrib:
1120  *    empty
1121  *    any-word
1122  *    any-word ( identifier )
1123  *    any-word ( identifier , nonempty-expr-list )
1124  *    any-word ( expr-list )
1125  *
1126  *  where the "identifier" must not be declared as a type, and
1127  *  "any-word" may be any identifier (including one declared as a
1128  *  type), a reserved word storage class specifier, type specifier or
1129  *  type qualifier.  ??? This still leaves out most reserved keywords
1130  *  (following the old parser), shouldn't we include them, and why not
1131  *  allow identifiers declared as types to start the arguments?
1132  *
1133  *  Matze: this all looks confusing and little systematic, so we're even less
1134  *  strict and parse any list of things which are identifiers or
1135  *  (assignment-)expressions.
1136  */
1137 static attribute_argument_t *parse_attribute_arguments(void)
1138 {
1139         attribute_argument_t  *first  = NULL;
1140         attribute_argument_t **anchor = &first;
1141         if (token.kind != ')') do {
1142                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1143
1144                 /* is it an identifier */
1145                 if (token.kind == T_IDENTIFIER
1146                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1147                         symbol_t *symbol   = token.identifier.symbol;
1148                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1149                         argument->v.symbol = symbol;
1150                         next_token();
1151                 } else {
1152                         /* must be an expression */
1153                         expression_t *expression = parse_assignment_expression();
1154
1155                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1156                         argument->v.expression = expression;
1157                 }
1158
1159                 /* append argument */
1160                 *anchor = argument;
1161                 anchor  = &argument->next;
1162         } while (next_if(','));
1163         expect(')', end_error);
1164
1165         return first;
1166
1167 end_error:
1168         /* TODO... */
1169         return first;
1170 }
1171
1172 static attribute_t *parse_attribute_asm(void)
1173 {
1174         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1175         eat(T_asm);
1176
1177         expect('(', end_error);
1178         attribute->a.arguments = parse_attribute_arguments();
1179         return attribute;
1180
1181 end_error:
1182         return NULL;
1183 }
1184
1185 static symbol_t *get_symbol_from_token(void)
1186 {
1187         switch(token.kind) {
1188         case T_IDENTIFIER:
1189                 return token.identifier.symbol;
1190         case T_auto:
1191         case T_char:
1192         case T_double:
1193         case T_enum:
1194         case T_extern:
1195         case T_float:
1196         case T_int:
1197         case T_long:
1198         case T_register:
1199         case T_short:
1200         case T_static:
1201         case T_struct:
1202         case T_union:
1203         case T_unsigned:
1204         case T_void:
1205         case T_bool:
1206         case T__Bool:
1207         case T_class:
1208         case T_explicit:
1209         case T_export:
1210         case T_wchar_t:
1211         case T_const:
1212         case T_signed:
1213         case T___real__:
1214         case T___imag__:
1215         case T_restrict:
1216         case T_volatile:
1217         case T_inline:
1218                 /* maybe we need more tokens ... add them on demand */
1219                 return get_token_kind_symbol(token.kind);
1220         default:
1221                 return NULL;
1222         }
1223 }
1224
1225 static attribute_t *parse_attribute_gnu_single(void)
1226 {
1227         /* parse "any-word" */
1228         symbol_t *symbol = get_symbol_from_token();
1229         if (symbol == NULL) {
1230                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1231                 return NULL;
1232         }
1233
1234         attribute_kind_t  kind;
1235         char const *const name = symbol->string;
1236         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1237                 if (kind > ATTRIBUTE_GNU_LAST) {
1238                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1239                         /* TODO: we should still save the attribute in the list... */
1240                         kind = ATTRIBUTE_UNKNOWN;
1241                         break;
1242                 }
1243
1244                 const char *attribute_name = get_attribute_name(kind);
1245                 if (attribute_name != NULL
1246                                 && strcmp_underscore(attribute_name, name) == 0)
1247                         break;
1248         }
1249
1250         attribute_t *attribute = allocate_attribute_zero(kind);
1251         next_token();
1252
1253         /* parse arguments */
1254         if (next_if('('))
1255                 attribute->a.arguments = parse_attribute_arguments();
1256
1257         return attribute;
1258 }
1259
1260 static attribute_t *parse_attribute_gnu(void)
1261 {
1262         attribute_t  *first  = NULL;
1263         attribute_t **anchor = &first;
1264
1265         eat(T___attribute__);
1266         expect('(', end_error);
1267         expect('(', end_error);
1268
1269         if (token.kind != ')') do {
1270                 attribute_t *attribute = parse_attribute_gnu_single();
1271                 if (attribute == NULL)
1272                         goto end_error;
1273
1274                 *anchor = attribute;
1275                 anchor  = &attribute->next;
1276         } while (next_if(','));
1277         expect(')', end_error);
1278         expect(')', end_error);
1279
1280 end_error:
1281         return first;
1282 }
1283
1284 /** Parse attributes. */
1285 static attribute_t *parse_attributes(attribute_t *first)
1286 {
1287         attribute_t **anchor = &first;
1288         for (;;) {
1289                 while (*anchor != NULL)
1290                         anchor = &(*anchor)->next;
1291
1292                 attribute_t *attribute;
1293                 switch (token.kind) {
1294                 case T___attribute__:
1295                         attribute = parse_attribute_gnu();
1296                         if (attribute == NULL)
1297                                 continue;
1298                         break;
1299
1300                 case T_asm:
1301                         attribute = parse_attribute_asm();
1302                         break;
1303
1304                 case T_cdecl:
1305                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1306                         eat(T_cdecl);
1307                         break;
1308
1309                 case T__fastcall:
1310                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1311                         eat(T__fastcall);
1312                         break;
1313
1314                 case T__forceinline:
1315                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1316                         eat(T__forceinline);
1317                         break;
1318
1319                 case T__stdcall:
1320                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1321                         eat(T__stdcall);
1322                         break;
1323
1324                 case T___thiscall:
1325                         /* TODO record modifier */
1326                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1327                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1328                         eat(T___thiscall);
1329                         break;
1330
1331                 default:
1332                         return first;
1333                 }
1334
1335                 *anchor = attribute;
1336                 anchor  = &attribute->next;
1337         }
1338 }
1339
1340 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1341
1342 static entity_t *determine_lhs_ent(expression_t *const expr,
1343                                    entity_t *lhs_ent)
1344 {
1345         switch (expr->kind) {
1346                 case EXPR_REFERENCE: {
1347                         entity_t *const entity = expr->reference.entity;
1348                         /* we should only find variables as lvalues... */
1349                         if (entity->base.kind != ENTITY_VARIABLE
1350                                         && entity->base.kind != ENTITY_PARAMETER)
1351                                 return NULL;
1352
1353                         return entity;
1354                 }
1355
1356                 case EXPR_ARRAY_ACCESS: {
1357                         expression_t *const ref = expr->array_access.array_ref;
1358                         entity_t     *      ent = NULL;
1359                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1360                                 ent     = determine_lhs_ent(ref, lhs_ent);
1361                                 lhs_ent = ent;
1362                         } else {
1363                                 mark_vars_read(ref, lhs_ent);
1364                         }
1365                         mark_vars_read(expr->array_access.index, lhs_ent);
1366                         return ent;
1367                 }
1368
1369                 case EXPR_SELECT: {
1370                         mark_vars_read(expr->select.compound, lhs_ent);
1371                         if (is_type_compound(skip_typeref(expr->base.type)))
1372                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1373                         return NULL;
1374                 }
1375
1376                 case EXPR_UNARY_DEREFERENCE: {
1377                         expression_t *const val = expr->unary.value;
1378                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1379                                 /* *&x is a NOP */
1380                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1381                         } else {
1382                                 mark_vars_read(val, NULL);
1383                                 return NULL;
1384                         }
1385                 }
1386
1387                 default:
1388                         mark_vars_read(expr, NULL);
1389                         return NULL;
1390         }
1391 }
1392
1393 #define ENT_ANY ((entity_t*)-1)
1394
1395 /**
1396  * Mark declarations, which are read.  This is used to detect variables, which
1397  * are never read.
1398  * Example:
1399  * x = x + 1;
1400  *   x is not marked as "read", because it is only read to calculate its own new
1401  *   value.
1402  *
1403  * x += y; y += x;
1404  *   x and y are not detected as "not read", because multiple variables are
1405  *   involved.
1406  */
1407 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1408 {
1409         switch (expr->kind) {
1410                 case EXPR_REFERENCE: {
1411                         entity_t *const entity = expr->reference.entity;
1412                         if (entity->kind != ENTITY_VARIABLE
1413                                         && entity->kind != ENTITY_PARAMETER)
1414                                 return;
1415
1416                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1417                                 if (entity->kind == ENTITY_VARIABLE) {
1418                                         entity->variable.read = true;
1419                                 } else {
1420                                         entity->parameter.read = true;
1421                                 }
1422                         }
1423                         return;
1424                 }
1425
1426                 case EXPR_CALL:
1427                         // TODO respect pure/const
1428                         mark_vars_read(expr->call.function, NULL);
1429                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1430                                 mark_vars_read(arg->expression, NULL);
1431                         }
1432                         return;
1433
1434                 case EXPR_CONDITIONAL:
1435                         // TODO lhs_decl should depend on whether true/false have an effect
1436                         mark_vars_read(expr->conditional.condition, NULL);
1437                         if (expr->conditional.true_expression != NULL)
1438                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1439                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1440                         return;
1441
1442                 case EXPR_SELECT:
1443                         if (lhs_ent == ENT_ANY
1444                                         && !is_type_compound(skip_typeref(expr->base.type)))
1445                                 lhs_ent = NULL;
1446                         mark_vars_read(expr->select.compound, lhs_ent);
1447                         return;
1448
1449                 case EXPR_ARRAY_ACCESS: {
1450                         mark_vars_read(expr->array_access.index, lhs_ent);
1451                         expression_t *const ref = expr->array_access.array_ref;
1452                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1453                                 if (lhs_ent == ENT_ANY)
1454                                         lhs_ent = NULL;
1455                         }
1456                         mark_vars_read(ref, lhs_ent);
1457                         return;
1458                 }
1459
1460                 case EXPR_VA_ARG:
1461                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1462                         return;
1463
1464                 case EXPR_VA_COPY:
1465                         mark_vars_read(expr->va_copye.src, lhs_ent);
1466                         return;
1467
1468                 case EXPR_UNARY_CAST:
1469                         /* Special case: Use void cast to mark a variable as "read" */
1470                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1471                                 lhs_ent = NULL;
1472                         goto unary;
1473
1474
1475                 case EXPR_UNARY_THROW:
1476                         if (expr->unary.value == NULL)
1477                                 return;
1478                         /* FALLTHROUGH */
1479                 case EXPR_UNARY_DEREFERENCE:
1480                 case EXPR_UNARY_DELETE:
1481                 case EXPR_UNARY_DELETE_ARRAY:
1482                         if (lhs_ent == ENT_ANY)
1483                                 lhs_ent = NULL;
1484                         goto unary;
1485
1486                 case EXPR_UNARY_NEGATE:
1487                 case EXPR_UNARY_PLUS:
1488                 case EXPR_UNARY_BITWISE_NEGATE:
1489                 case EXPR_UNARY_NOT:
1490                 case EXPR_UNARY_TAKE_ADDRESS:
1491                 case EXPR_UNARY_POSTFIX_INCREMENT:
1492                 case EXPR_UNARY_POSTFIX_DECREMENT:
1493                 case EXPR_UNARY_PREFIX_INCREMENT:
1494                 case EXPR_UNARY_PREFIX_DECREMENT:
1495                 case EXPR_UNARY_ASSUME:
1496 unary:
1497                         mark_vars_read(expr->unary.value, lhs_ent);
1498                         return;
1499
1500                 case EXPR_BINARY_ADD:
1501                 case EXPR_BINARY_SUB:
1502                 case EXPR_BINARY_MUL:
1503                 case EXPR_BINARY_DIV:
1504                 case EXPR_BINARY_MOD:
1505                 case EXPR_BINARY_EQUAL:
1506                 case EXPR_BINARY_NOTEQUAL:
1507                 case EXPR_BINARY_LESS:
1508                 case EXPR_BINARY_LESSEQUAL:
1509                 case EXPR_BINARY_GREATER:
1510                 case EXPR_BINARY_GREATEREQUAL:
1511                 case EXPR_BINARY_BITWISE_AND:
1512                 case EXPR_BINARY_BITWISE_OR:
1513                 case EXPR_BINARY_BITWISE_XOR:
1514                 case EXPR_BINARY_LOGICAL_AND:
1515                 case EXPR_BINARY_LOGICAL_OR:
1516                 case EXPR_BINARY_SHIFTLEFT:
1517                 case EXPR_BINARY_SHIFTRIGHT:
1518                 case EXPR_BINARY_COMMA:
1519                 case EXPR_BINARY_ISGREATER:
1520                 case EXPR_BINARY_ISGREATEREQUAL:
1521                 case EXPR_BINARY_ISLESS:
1522                 case EXPR_BINARY_ISLESSEQUAL:
1523                 case EXPR_BINARY_ISLESSGREATER:
1524                 case EXPR_BINARY_ISUNORDERED:
1525                         mark_vars_read(expr->binary.left,  lhs_ent);
1526                         mark_vars_read(expr->binary.right, lhs_ent);
1527                         return;
1528
1529                 case EXPR_BINARY_ASSIGN:
1530                 case EXPR_BINARY_MUL_ASSIGN:
1531                 case EXPR_BINARY_DIV_ASSIGN:
1532                 case EXPR_BINARY_MOD_ASSIGN:
1533                 case EXPR_BINARY_ADD_ASSIGN:
1534                 case EXPR_BINARY_SUB_ASSIGN:
1535                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1536                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1537                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1538                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1539                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1540                         if (lhs_ent == ENT_ANY)
1541                                 lhs_ent = NULL;
1542                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1543                         mark_vars_read(expr->binary.right, lhs_ent);
1544                         return;
1545                 }
1546
1547                 case EXPR_VA_START:
1548                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1549                         return;
1550
1551                 EXPR_LITERAL_CASES
1552                 case EXPR_ERROR:
1553                 case EXPR_STRING_LITERAL:
1554                 case EXPR_WIDE_STRING_LITERAL:
1555                 case EXPR_COMPOUND_LITERAL: // TODO init?
1556                 case EXPR_SIZEOF:
1557                 case EXPR_CLASSIFY_TYPE:
1558                 case EXPR_ALIGNOF:
1559                 case EXPR_FUNCNAME:
1560                 case EXPR_BUILTIN_CONSTANT_P:
1561                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1562                 case EXPR_OFFSETOF:
1563                 case EXPR_STATEMENT: // TODO
1564                 case EXPR_LABEL_ADDRESS:
1565                 case EXPR_REFERENCE_ENUM_VALUE:
1566                         return;
1567         }
1568
1569         panic("unhandled expression");
1570 }
1571
1572 static designator_t *parse_designation(void)
1573 {
1574         designator_t  *result = NULL;
1575         designator_t **anchor = &result;
1576
1577         for (;;) {
1578                 designator_t *designator;
1579                 switch (token.kind) {
1580                 case '[':
1581                         designator = allocate_ast_zero(sizeof(designator[0]));
1582                         designator->source_position = token.base.source_position;
1583                         next_token();
1584                         add_anchor_token(']');
1585                         designator->array_index = parse_constant_expression();
1586                         rem_anchor_token(']');
1587                         expect(']', end_error);
1588                         break;
1589                 case '.':
1590                         designator = allocate_ast_zero(sizeof(designator[0]));
1591                         designator->source_position = token.base.source_position;
1592                         next_token();
1593                         if (token.kind != T_IDENTIFIER) {
1594                                 parse_error_expected("while parsing designator",
1595                                                      T_IDENTIFIER, NULL);
1596                                 return NULL;
1597                         }
1598                         designator->symbol = token.identifier.symbol;
1599                         next_token();
1600                         break;
1601                 default:
1602                         expect('=', end_error);
1603                         return result;
1604                 }
1605
1606                 assert(designator != NULL);
1607                 *anchor = designator;
1608                 anchor  = &designator->next;
1609         }
1610 end_error:
1611         return NULL;
1612 }
1613
1614 static initializer_t *initializer_from_string(array_type_t *const type,
1615                                               const string_t *const string)
1616 {
1617         /* TODO: check len vs. size of array type */
1618         (void) type;
1619
1620         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1621         initializer->string.string = *string;
1622
1623         return initializer;
1624 }
1625
1626 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1627                                                    const string_t *const string)
1628 {
1629         /* TODO: check len vs. size of array type */
1630         (void) type;
1631
1632         initializer_t *const initializer =
1633                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1634         initializer->wide_string.string = *string;
1635
1636         return initializer;
1637 }
1638
1639 /**
1640  * Build an initializer from a given expression.
1641  */
1642 static initializer_t *initializer_from_expression(type_t *orig_type,
1643                                                   expression_t *expression)
1644 {
1645         /* TODO check that expression is a constant expression */
1646
1647         /* §6.7.8.14/15 char array may be initialized by string literals */
1648         type_t *type           = skip_typeref(orig_type);
1649         type_t *expr_type_orig = expression->base.type;
1650         type_t *expr_type      = skip_typeref(expr_type_orig);
1651
1652         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1653                 array_type_t *const array_type   = &type->array;
1654                 type_t       *const element_type = skip_typeref(array_type->element_type);
1655
1656                 if (element_type->kind == TYPE_ATOMIC) {
1657                         atomic_type_kind_t akind = element_type->atomic.akind;
1658                         switch (expression->kind) {
1659                         case EXPR_STRING_LITERAL:
1660                                 if (akind == ATOMIC_TYPE_CHAR
1661                                                 || akind == ATOMIC_TYPE_SCHAR
1662                                                 || akind == ATOMIC_TYPE_UCHAR) {
1663                                         return initializer_from_string(array_type,
1664                                                         &expression->string_literal.value);
1665                                 }
1666                                 break;
1667
1668                         case EXPR_WIDE_STRING_LITERAL: {
1669                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1670                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1671                                         return initializer_from_wide_string(array_type,
1672                                                         &expression->string_literal.value);
1673                                 }
1674                                 break;
1675                         }
1676
1677                         default:
1678                                 break;
1679                         }
1680                 }
1681         }
1682
1683         assign_error_t error = semantic_assign(type, expression);
1684         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1685                 return NULL;
1686         report_assign_error(error, type, expression, "initializer",
1687                             &expression->base.source_position);
1688
1689         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1690         result->value.value = create_implicit_cast(expression, type);
1691
1692         return result;
1693 }
1694
1695 /**
1696  * Checks if a given expression can be used as a constant initializer.
1697  */
1698 static bool is_initializer_constant(const expression_t *expression)
1699 {
1700         return is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1701                is_linker_constant(expression)     != EXPR_CLASS_VARIABLE;
1702 }
1703
1704 /**
1705  * Parses an scalar initializer.
1706  *
1707  * §6.7.8.11; eat {} without warning
1708  */
1709 static initializer_t *parse_scalar_initializer(type_t *type,
1710                                                bool must_be_constant)
1711 {
1712         /* there might be extra {} hierarchies */
1713         int braces = 0;
1714         if (token.kind == '{') {
1715                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1716                 do {
1717                         eat('{');
1718                         ++braces;
1719                 } while (token.kind == '{');
1720         }
1721
1722         expression_t *expression = parse_assignment_expression();
1723         mark_vars_read(expression, NULL);
1724         if (must_be_constant && !is_initializer_constant(expression)) {
1725                 errorf(&expression->base.source_position,
1726                        "initialisation expression '%E' is not constant",
1727                        expression);
1728         }
1729
1730         initializer_t *initializer = initializer_from_expression(type, expression);
1731
1732         if (initializer == NULL) {
1733                 errorf(&expression->base.source_position,
1734                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1735                        expression, expression->base.type, type);
1736                 /* TODO */
1737                 return NULL;
1738         }
1739
1740         bool additional_warning_displayed = false;
1741         while (braces > 0) {
1742                 next_if(',');
1743                 if (token.kind != '}') {
1744                         if (!additional_warning_displayed) {
1745                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1746                                 additional_warning_displayed = true;
1747                         }
1748                 }
1749                 eat_block();
1750                 braces--;
1751         }
1752
1753         return initializer;
1754 }
1755
1756 /**
1757  * An entry in the type path.
1758  */
1759 typedef struct type_path_entry_t type_path_entry_t;
1760 struct type_path_entry_t {
1761         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1762         union {
1763                 size_t         index;          /**< For array types: the current index. */
1764                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1765         } v;
1766 };
1767
1768 /**
1769  * A type path expression a position inside compound or array types.
1770  */
1771 typedef struct type_path_t type_path_t;
1772 struct type_path_t {
1773         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1774         type_t            *top_type;     /**< type of the element the path points */
1775         size_t             max_index;    /**< largest index in outermost array */
1776 };
1777
1778 /**
1779  * Prints a type path for debugging.
1780  */
1781 static __attribute__((unused)) void debug_print_type_path(
1782                 const type_path_t *path)
1783 {
1784         size_t len = ARR_LEN(path->path);
1785
1786         for (size_t i = 0; i < len; ++i) {
1787                 const type_path_entry_t *entry = & path->path[i];
1788
1789                 type_t *type = skip_typeref(entry->type);
1790                 if (is_type_compound(type)) {
1791                         /* in gcc mode structs can have no members */
1792                         if (entry->v.compound_entry == NULL) {
1793                                 assert(i == len-1);
1794                                 continue;
1795                         }
1796                         fprintf(stderr, ".%s",
1797                                 entry->v.compound_entry->base.symbol->string);
1798                 } else if (is_type_array(type)) {
1799                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1800                 } else {
1801                         fprintf(stderr, "-INVALID-");
1802                 }
1803         }
1804         if (path->top_type != NULL) {
1805                 fprintf(stderr, "  (");
1806                 print_type(path->top_type);
1807                 fprintf(stderr, ")");
1808         }
1809 }
1810
1811 /**
1812  * Return the top type path entry, ie. in a path
1813  * (type).a.b returns the b.
1814  */
1815 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1816 {
1817         size_t len = ARR_LEN(path->path);
1818         assert(len > 0);
1819         return &path->path[len-1];
1820 }
1821
1822 /**
1823  * Enlarge the type path by an (empty) element.
1824  */
1825 static type_path_entry_t *append_to_type_path(type_path_t *path)
1826 {
1827         size_t len = ARR_LEN(path->path);
1828         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1829
1830         type_path_entry_t *result = & path->path[len];
1831         memset(result, 0, sizeof(result[0]));
1832         return result;
1833 }
1834
1835 /**
1836  * Descending into a sub-type. Enter the scope of the current top_type.
1837  */
1838 static void descend_into_subtype(type_path_t *path)
1839 {
1840         type_t *orig_top_type = path->top_type;
1841         type_t *top_type      = skip_typeref(orig_top_type);
1842
1843         type_path_entry_t *top = append_to_type_path(path);
1844         top->type              = top_type;
1845
1846         if (is_type_compound(top_type)) {
1847                 compound_t *compound  = top_type->compound.compound;
1848                 entity_t   *entry     = compound->members.entities;
1849
1850                 if (entry != NULL) {
1851                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1852                         top->v.compound_entry = &entry->declaration;
1853                         path->top_type = entry->declaration.type;
1854                 } else {
1855                         path->top_type = NULL;
1856                 }
1857         } else if (is_type_array(top_type)) {
1858                 top->v.index   = 0;
1859                 path->top_type = top_type->array.element_type;
1860         } else {
1861                 assert(!is_type_valid(top_type));
1862         }
1863 }
1864
1865 /**
1866  * Pop an entry from the given type path, ie. returning from
1867  * (type).a.b to (type).a
1868  */
1869 static void ascend_from_subtype(type_path_t *path)
1870 {
1871         type_path_entry_t *top = get_type_path_top(path);
1872
1873         path->top_type = top->type;
1874
1875         size_t len = ARR_LEN(path->path);
1876         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1877 }
1878
1879 /**
1880  * Pop entries from the given type path until the given
1881  * path level is reached.
1882  */
1883 static void ascend_to(type_path_t *path, size_t top_path_level)
1884 {
1885         size_t len = ARR_LEN(path->path);
1886
1887         while (len > top_path_level) {
1888                 ascend_from_subtype(path);
1889                 len = ARR_LEN(path->path);
1890         }
1891 }
1892
1893 static bool walk_designator(type_path_t *path, const designator_t *designator,
1894                             bool used_in_offsetof)
1895 {
1896         for (; designator != NULL; designator = designator->next) {
1897                 type_path_entry_t *top       = get_type_path_top(path);
1898                 type_t            *orig_type = top->type;
1899
1900                 type_t *type = skip_typeref(orig_type);
1901
1902                 if (designator->symbol != NULL) {
1903                         symbol_t *symbol = designator->symbol;
1904                         if (!is_type_compound(type)) {
1905                                 if (is_type_valid(type)) {
1906                                         errorf(&designator->source_position,
1907                                                "'.%Y' designator used for non-compound type '%T'",
1908                                                symbol, orig_type);
1909                                 }
1910
1911                                 top->type             = type_error_type;
1912                                 top->v.compound_entry = NULL;
1913                                 orig_type             = type_error_type;
1914                         } else {
1915                                 compound_t *compound = type->compound.compound;
1916                                 entity_t   *iter     = compound->members.entities;
1917                                 for (; iter != NULL; iter = iter->base.next) {
1918                                         if (iter->base.symbol == symbol) {
1919                                                 break;
1920                                         }
1921                                 }
1922                                 if (iter == NULL) {
1923                                         errorf(&designator->source_position,
1924                                                "'%T' has no member named '%Y'", orig_type, symbol);
1925                                         return false;
1926                                 }
1927                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1928                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1929                                         errorf(&designator->source_position,
1930                                                    "offsetof designator '%Y' must not specify bitfield",
1931                                                    symbol);
1932                                         return false;
1933                                 }
1934
1935                                 top->type             = orig_type;
1936                                 top->v.compound_entry = &iter->declaration;
1937                                 orig_type             = iter->declaration.type;
1938                         }
1939                 } else {
1940                         expression_t *array_index = designator->array_index;
1941                         assert(designator->array_index != NULL);
1942
1943                         if (!is_type_array(type)) {
1944                                 if (is_type_valid(type)) {
1945                                         errorf(&designator->source_position,
1946                                                "[%E] designator used for non-array type '%T'",
1947                                                array_index, orig_type);
1948                                 }
1949                                 return false;
1950                         }
1951
1952                         long index = fold_constant_to_int(array_index);
1953                         if (!used_in_offsetof) {
1954                                 if (index < 0) {
1955                                         errorf(&designator->source_position,
1956                                                "array index [%E] must be positive", array_index);
1957                                 } else if (type->array.size_constant) {
1958                                         long array_size = type->array.size;
1959                                         if (index >= array_size) {
1960                                                 errorf(&designator->source_position,
1961                                                        "designator [%E] (%d) exceeds array size %d",
1962                                                        array_index, index, array_size);
1963                                         }
1964                                 }
1965                         }
1966
1967                         top->type    = orig_type;
1968                         top->v.index = (size_t) index;
1969                         orig_type    = type->array.element_type;
1970                 }
1971                 path->top_type = orig_type;
1972
1973                 if (designator->next != NULL) {
1974                         descend_into_subtype(path);
1975                 }
1976         }
1977         return true;
1978 }
1979
1980 static void advance_current_object(type_path_t *path, size_t top_path_level)
1981 {
1982         type_path_entry_t *top = get_type_path_top(path);
1983
1984         type_t *type = skip_typeref(top->type);
1985         if (is_type_union(type)) {
1986                 /* in unions only the first element is initialized */
1987                 top->v.compound_entry = NULL;
1988         } else if (is_type_struct(type)) {
1989                 declaration_t *entry = top->v.compound_entry;
1990
1991                 entity_t *next_entity = entry->base.next;
1992                 if (next_entity != NULL) {
1993                         assert(is_declaration(next_entity));
1994                         entry = &next_entity->declaration;
1995                 } else {
1996                         entry = NULL;
1997                 }
1998
1999                 top->v.compound_entry = entry;
2000                 if (entry != NULL) {
2001                         path->top_type = entry->type;
2002                         return;
2003                 }
2004         } else if (is_type_array(type)) {
2005                 assert(is_type_array(type));
2006
2007                 top->v.index++;
2008
2009                 if (!type->array.size_constant || top->v.index < type->array.size) {
2010                         return;
2011                 }
2012         } else {
2013                 assert(!is_type_valid(type));
2014                 return;
2015         }
2016
2017         /* we're past the last member of the current sub-aggregate, try if we
2018          * can ascend in the type hierarchy and continue with another subobject */
2019         size_t len = ARR_LEN(path->path);
2020
2021         if (len > top_path_level) {
2022                 ascend_from_subtype(path);
2023                 advance_current_object(path, top_path_level);
2024         } else {
2025                 path->top_type = NULL;
2026         }
2027 }
2028
2029 /**
2030  * skip any {...} blocks until a closing bracket is reached.
2031  */
2032 static void skip_initializers(void)
2033 {
2034         next_if('{');
2035
2036         while (token.kind != '}') {
2037                 if (token.kind == T_EOF)
2038                         return;
2039                 if (token.kind == '{') {
2040                         eat_block();
2041                         continue;
2042                 }
2043                 next_token();
2044         }
2045 }
2046
2047 static initializer_t *create_empty_initializer(void)
2048 {
2049         static initializer_t empty_initializer
2050                 = { .list = { { INITIALIZER_LIST }, 0 } };
2051         return &empty_initializer;
2052 }
2053
2054 /**
2055  * Parse a part of an initialiser for a struct or union,
2056  */
2057 static initializer_t *parse_sub_initializer(type_path_t *path,
2058                 type_t *outer_type, size_t top_path_level,
2059                 parse_initializer_env_t *env)
2060 {
2061         if (token.kind == '}') {
2062                 /* empty initializer */
2063                 return create_empty_initializer();
2064         }
2065
2066         type_t *orig_type = path->top_type;
2067         type_t *type      = NULL;
2068
2069         if (orig_type == NULL) {
2070                 /* We are initializing an empty compound. */
2071         } else {
2072                 type = skip_typeref(orig_type);
2073         }
2074
2075         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2076
2077         while (true) {
2078                 designator_t *designator = NULL;
2079                 if (token.kind == '.' || token.kind == '[') {
2080                         designator = parse_designation();
2081                         goto finish_designator;
2082                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2083                         /* GNU-style designator ("identifier: value") */
2084                         designator = allocate_ast_zero(sizeof(designator[0]));
2085                         designator->source_position = token.base.source_position;
2086                         designator->symbol          = token.identifier.symbol;
2087                         eat(T_IDENTIFIER);
2088                         eat(':');
2089
2090 finish_designator:
2091                         /* reset path to toplevel, evaluate designator from there */
2092                         ascend_to(path, top_path_level);
2093                         if (!walk_designator(path, designator, false)) {
2094                                 /* can't continue after designation error */
2095                                 goto end_error;
2096                         }
2097
2098                         initializer_t *designator_initializer
2099                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2100                         designator_initializer->designator.designator = designator;
2101                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2102
2103                         orig_type = path->top_type;
2104                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2105                 }
2106
2107                 initializer_t *sub;
2108
2109                 if (token.kind == '{') {
2110                         if (type != NULL && is_type_scalar(type)) {
2111                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2112                         } else {
2113                                 if (type == NULL) {
2114                                         if (env->entity != NULL) {
2115                                                 errorf(HERE,
2116                                                      "extra brace group at end of initializer for '%Y'",
2117                                                      env->entity->base.symbol);
2118                                         } else {
2119                                                 errorf(HERE, "extra brace group at end of initializer");
2120                                         }
2121                                         eat('{');
2122                                 } else {
2123                                         eat('{');
2124                                         descend_into_subtype(path);
2125                                 }
2126
2127                                 add_anchor_token('}');
2128                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2129                                                             env);
2130                                 rem_anchor_token('}');
2131
2132                                 if (type != NULL) {
2133                                         ascend_from_subtype(path);
2134                                         expect('}', end_error);
2135                                 } else {
2136                                         expect('}', end_error);
2137                                         goto error_parse_next;
2138                                 }
2139                         }
2140                 } else {
2141                         /* must be an expression */
2142                         expression_t *expression = parse_assignment_expression();
2143                         mark_vars_read(expression, NULL);
2144
2145                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2146                                 errorf(&expression->base.source_position,
2147                                        "Initialisation expression '%E' is not constant",
2148                                        expression);
2149                         }
2150
2151                         if (type == NULL) {
2152                                 /* we are already outside, ... */
2153                                 if (outer_type == NULL)
2154                                         goto error_parse_next;
2155                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2156                                 if (is_type_compound(outer_type_skip) &&
2157                                                 !outer_type_skip->compound.compound->complete) {
2158                                         goto error_parse_next;
2159                                 }
2160
2161                                 source_position_t const* const pos = &expression->base.source_position;
2162                                 if (env->entity != NULL) {
2163                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2164                                 } else {
2165                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2166                                 }
2167                                 goto error_parse_next;
2168                         }
2169
2170                         /* handle { "string" } special case */
2171                         if ((expression->kind == EXPR_STRING_LITERAL
2172                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2173                                         && outer_type != NULL) {
2174                                 sub = initializer_from_expression(outer_type, expression);
2175                                 if (sub != NULL) {
2176                                         next_if(',');
2177                                         if (token.kind != '}') {
2178                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2179                                         }
2180                                         /* TODO: eat , ... */
2181                                         return sub;
2182                                 }
2183                         }
2184
2185                         /* descend into subtypes until expression matches type */
2186                         while (true) {
2187                                 orig_type = path->top_type;
2188                                 type      = skip_typeref(orig_type);
2189
2190                                 sub = initializer_from_expression(orig_type, expression);
2191                                 if (sub != NULL) {
2192                                         break;
2193                                 }
2194                                 if (!is_type_valid(type)) {
2195                                         goto end_error;
2196                                 }
2197                                 if (is_type_scalar(type)) {
2198                                         errorf(&expression->base.source_position,
2199                                                         "expression '%E' doesn't match expected type '%T'",
2200                                                         expression, orig_type);
2201                                         goto end_error;
2202                                 }
2203
2204                                 descend_into_subtype(path);
2205                         }
2206                 }
2207
2208                 /* update largest index of top array */
2209                 const type_path_entry_t *first      = &path->path[0];
2210                 type_t                  *first_type = first->type;
2211                 first_type                          = skip_typeref(first_type);
2212                 if (is_type_array(first_type)) {
2213                         size_t index = first->v.index;
2214                         if (index > path->max_index)
2215                                 path->max_index = index;
2216                 }
2217
2218                 /* append to initializers list */
2219                 ARR_APP1(initializer_t*, initializers, sub);
2220
2221 error_parse_next:
2222                 if (token.kind == '}') {
2223                         break;
2224                 }
2225                 expect(',', end_error);
2226                 if (token.kind == '}') {
2227                         break;
2228                 }
2229
2230                 if (type != NULL) {
2231                         /* advance to the next declaration if we are not at the end */
2232                         advance_current_object(path, top_path_level);
2233                         orig_type = path->top_type;
2234                         if (orig_type != NULL)
2235                                 type = skip_typeref(orig_type);
2236                         else
2237                                 type = NULL;
2238                 }
2239         }
2240
2241         size_t len  = ARR_LEN(initializers);
2242         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2243         initializer_t *result = allocate_ast_zero(size);
2244         result->kind          = INITIALIZER_LIST;
2245         result->list.len      = len;
2246         memcpy(&result->list.initializers, initializers,
2247                len * sizeof(initializers[0]));
2248
2249         DEL_ARR_F(initializers);
2250         ascend_to(path, top_path_level+1);
2251
2252         return result;
2253
2254 end_error:
2255         skip_initializers();
2256         DEL_ARR_F(initializers);
2257         ascend_to(path, top_path_level+1);
2258         return NULL;
2259 }
2260
2261 static expression_t *make_size_literal(size_t value)
2262 {
2263         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2264         literal->base.type    = type_size_t;
2265
2266         char buf[128];
2267         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2268         literal->literal.value = make_string(buf);
2269
2270         return literal;
2271 }
2272
2273 /**
2274  * Parses an initializer. Parsers either a compound literal
2275  * (env->declaration == NULL) or an initializer of a declaration.
2276  */
2277 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2278 {
2279         type_t        *type      = skip_typeref(env->type);
2280         size_t         max_index = 0;
2281         initializer_t *result;
2282
2283         if (is_type_scalar(type)) {
2284                 result = parse_scalar_initializer(type, env->must_be_constant);
2285         } else if (token.kind == '{') {
2286                 eat('{');
2287
2288                 type_path_t path;
2289                 memset(&path, 0, sizeof(path));
2290                 path.top_type = env->type;
2291                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2292
2293                 descend_into_subtype(&path);
2294
2295                 add_anchor_token('}');
2296                 result = parse_sub_initializer(&path, env->type, 1, env);
2297                 rem_anchor_token('}');
2298
2299                 max_index = path.max_index;
2300                 DEL_ARR_F(path.path);
2301
2302                 expect('}', end_error);
2303 end_error:;
2304         } else {
2305                 /* parse_scalar_initializer() also works in this case: we simply
2306                  * have an expression without {} around it */
2307                 result = parse_scalar_initializer(type, env->must_be_constant);
2308         }
2309
2310         /* §6.7.8:22 array initializers for arrays with unknown size determine
2311          * the array type size */
2312         if (is_type_array(type) && type->array.size_expression == NULL
2313                         && result != NULL) {
2314                 size_t size;
2315                 switch (result->kind) {
2316                 case INITIALIZER_LIST:
2317                         assert(max_index != 0xdeadbeaf);
2318                         size = max_index + 1;
2319                         break;
2320
2321                 case INITIALIZER_STRING:
2322                         size = result->string.string.size;
2323                         break;
2324
2325                 case INITIALIZER_WIDE_STRING:
2326                         size = result->wide_string.string.size;
2327                         break;
2328
2329                 case INITIALIZER_DESIGNATOR:
2330                 case INITIALIZER_VALUE:
2331                         /* can happen for parse errors */
2332                         size = 0;
2333                         break;
2334
2335                 default:
2336                         internal_errorf(HERE, "invalid initializer type");
2337                 }
2338
2339                 type_t *new_type = duplicate_type(type);
2340
2341                 new_type->array.size_expression   = make_size_literal(size);
2342                 new_type->array.size_constant     = true;
2343                 new_type->array.has_implicit_size = true;
2344                 new_type->array.size              = size;
2345                 env->type = new_type;
2346         }
2347
2348         return result;
2349 }
2350
2351 static void append_entity(scope_t *scope, entity_t *entity)
2352 {
2353         if (scope->last_entity != NULL) {
2354                 scope->last_entity->base.next = entity;
2355         } else {
2356                 scope->entities = entity;
2357         }
2358         entity->base.parent_entity = current_entity;
2359         scope->last_entity         = entity;
2360 }
2361
2362
2363 static compound_t *parse_compound_type_specifier(bool is_struct)
2364 {
2365         source_position_t const pos = *HERE;
2366         eat(is_struct ? T_struct : T_union);
2367
2368         symbol_t    *symbol     = NULL;
2369         entity_t    *entity     = NULL;
2370         attribute_t *attributes = NULL;
2371
2372         if (token.kind == T___attribute__) {
2373                 attributes = parse_attributes(NULL);
2374         }
2375
2376         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2377         if (token.kind == T_IDENTIFIER) {
2378                 /* the compound has a name, check if we have seen it already */
2379                 symbol = token.identifier.symbol;
2380                 entity = get_tag(symbol, kind);
2381                 next_token();
2382
2383                 if (entity != NULL) {
2384                         if (entity->base.parent_scope != current_scope &&
2385                             (token.kind == '{' || token.kind == ';')) {
2386                                 /* we're in an inner scope and have a definition. Shadow
2387                                  * existing definition in outer scope */
2388                                 entity = NULL;
2389                         } else if (entity->compound.complete && token.kind == '{') {
2390                                 source_position_t const *const ppos = &entity->base.source_position;
2391                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2392                                 /* clear members in the hope to avoid further errors */
2393                                 entity->compound.members.entities = NULL;
2394                         }
2395                 }
2396         } else if (token.kind != '{') {
2397                 char const *const msg =
2398                         is_struct ? "while parsing struct type specifier" :
2399                                     "while parsing union type specifier";
2400                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2401
2402                 return NULL;
2403         }
2404
2405         if (entity == NULL) {
2406                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2407                 entity->compound.alignment   = 1;
2408                 entity->base.source_position = pos;
2409                 entity->base.parent_scope    = current_scope;
2410                 if (symbol != NULL) {
2411                         environment_push(entity);
2412                 }
2413                 append_entity(current_scope, entity);
2414         }
2415
2416         if (token.kind == '{') {
2417                 parse_compound_type_entries(&entity->compound);
2418
2419                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2420                 if (symbol == NULL) {
2421                         assert(anonymous_entity == NULL);
2422                         anonymous_entity = entity;
2423                 }
2424         }
2425
2426         if (attributes != NULL) {
2427                 handle_entity_attributes(attributes, entity);
2428         }
2429
2430         return &entity->compound;
2431 }
2432
2433 static void parse_enum_entries(type_t *const enum_type)
2434 {
2435         eat('{');
2436
2437         if (token.kind == '}') {
2438                 errorf(HERE, "empty enum not allowed");
2439                 next_token();
2440                 return;
2441         }
2442
2443         add_anchor_token('}');
2444         do {
2445                 if (token.kind != T_IDENTIFIER) {
2446                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2447                         eat_block();
2448                         rem_anchor_token('}');
2449                         return;
2450                 }
2451
2452                 symbol_t *symbol       = token.identifier.symbol;
2453                 entity_t *const entity
2454                         = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol);
2455                 entity->enum_value.enum_type = enum_type;
2456                 entity->base.source_position = token.base.source_position;
2457                 next_token();
2458
2459                 if (next_if('=')) {
2460                         expression_t *value = parse_constant_expression();
2461
2462                         value = create_implicit_cast(value, enum_type);
2463                         entity->enum_value.value = value;
2464
2465                         /* TODO semantic */
2466                 }
2467
2468                 record_entity(entity, false);
2469         } while (next_if(',') && token.kind != '}');
2470         rem_anchor_token('}');
2471
2472         expect('}', end_error);
2473
2474 end_error:
2475         ;
2476 }
2477
2478 static type_t *parse_enum_specifier(void)
2479 {
2480         source_position_t const pos = *HERE;
2481         entity_t               *entity;
2482         symbol_t               *symbol;
2483
2484         eat(T_enum);
2485         switch (token.kind) {
2486                 case T_IDENTIFIER:
2487                         symbol = token.identifier.symbol;
2488                         entity = get_tag(symbol, ENTITY_ENUM);
2489                         next_token();
2490
2491                         if (entity != NULL) {
2492                                 if (entity->base.parent_scope != current_scope &&
2493                                                 (token.kind == '{' || token.kind == ';')) {
2494                                         /* we're in an inner scope and have a definition. Shadow
2495                                          * existing definition in outer scope */
2496                                         entity = NULL;
2497                                 } else if (entity->enume.complete && token.kind == '{') {
2498                                         source_position_t const *const ppos = &entity->base.source_position;
2499                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2500                                 }
2501                         }
2502                         break;
2503
2504                 case '{':
2505                         entity = NULL;
2506                         symbol = NULL;
2507                         break;
2508
2509                 default:
2510                         parse_error_expected("while parsing enum type specifier",
2511                                         T_IDENTIFIER, '{', NULL);
2512                         return NULL;
2513         }
2514
2515         if (entity == NULL) {
2516                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2517                 entity->base.source_position = pos;
2518                 entity->base.parent_scope    = current_scope;
2519         }
2520
2521         type_t *const type = allocate_type_zero(TYPE_ENUM);
2522         type->enumt.enume  = &entity->enume;
2523         type->enumt.akind  = ATOMIC_TYPE_INT;
2524
2525         if (token.kind == '{') {
2526                 if (symbol != NULL) {
2527                         environment_push(entity);
2528                 }
2529                 append_entity(current_scope, entity);
2530                 entity->enume.complete = true;
2531
2532                 parse_enum_entries(type);
2533                 parse_attributes(NULL);
2534
2535                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2536                 if (symbol == NULL) {
2537                         assert(anonymous_entity == NULL);
2538                         anonymous_entity = entity;
2539                 }
2540         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2541                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2542         }
2543
2544         return type;
2545 }
2546
2547 /**
2548  * if a symbol is a typedef to another type, return true
2549  */
2550 static bool is_typedef_symbol(symbol_t *symbol)
2551 {
2552         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2553         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2554 }
2555
2556 static type_t *parse_typeof(void)
2557 {
2558         eat(T___typeof__);
2559
2560         type_t *type;
2561
2562         expect('(', end_error);
2563         add_anchor_token(')');
2564
2565         expression_t *expression  = NULL;
2566
2567         switch (token.kind) {
2568         case T_IDENTIFIER:
2569                 if (is_typedef_symbol(token.identifier.symbol)) {
2570         DECLARATION_START
2571                         type = parse_typename();
2572                 } else {
2573         default:
2574                         expression = parse_expression();
2575                         type       = revert_automatic_type_conversion(expression);
2576                 }
2577                 break;
2578         }
2579
2580         rem_anchor_token(')');
2581         expect(')', end_error);
2582
2583         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2584         typeof_type->typeoft.expression  = expression;
2585         typeof_type->typeoft.typeof_type = type;
2586
2587         return typeof_type;
2588 end_error:
2589         return NULL;
2590 }
2591
2592 typedef enum specifiers_t {
2593         SPECIFIER_SIGNED    = 1 << 0,
2594         SPECIFIER_UNSIGNED  = 1 << 1,
2595         SPECIFIER_LONG      = 1 << 2,
2596         SPECIFIER_INT       = 1 << 3,
2597         SPECIFIER_DOUBLE    = 1 << 4,
2598         SPECIFIER_CHAR      = 1 << 5,
2599         SPECIFIER_WCHAR_T   = 1 << 6,
2600         SPECIFIER_SHORT     = 1 << 7,
2601         SPECIFIER_LONG_LONG = 1 << 8,
2602         SPECIFIER_FLOAT     = 1 << 9,
2603         SPECIFIER_BOOL      = 1 << 10,
2604         SPECIFIER_VOID      = 1 << 11,
2605         SPECIFIER_INT8      = 1 << 12,
2606         SPECIFIER_INT16     = 1 << 13,
2607         SPECIFIER_INT32     = 1 << 14,
2608         SPECIFIER_INT64     = 1 << 15,
2609         SPECIFIER_INT128    = 1 << 16,
2610         SPECIFIER_COMPLEX   = 1 << 17,
2611         SPECIFIER_IMAGINARY = 1 << 18,
2612 } specifiers_t;
2613
2614 static type_t *get_typedef_type(symbol_t *symbol)
2615 {
2616         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2617         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2618                 return NULL;
2619
2620         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2621         type->typedeft.typedefe = &entity->typedefe;
2622
2623         return type;
2624 }
2625
2626 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2627 {
2628         expect('(', end_error);
2629
2630         attribute_property_argument_t *property
2631                 = allocate_ast_zero(sizeof(*property));
2632
2633         do {
2634                 if (token.kind != T_IDENTIFIER) {
2635                         parse_error_expected("while parsing property declspec",
2636                                              T_IDENTIFIER, NULL);
2637                         goto end_error;
2638                 }
2639
2640                 symbol_t **prop;
2641                 symbol_t  *symbol = token.identifier.symbol;
2642                 if (strcmp(symbol->string, "put") == 0) {
2643                         prop = &property->put_symbol;
2644                 } else if (strcmp(symbol->string, "get") == 0) {
2645                         prop = &property->get_symbol;
2646                 } else {
2647                         errorf(HERE, "expected put or get in property declspec");
2648                         prop = NULL;
2649                 }
2650                 eat(T_IDENTIFIER);
2651                 expect('=', end_error);
2652                 if (token.kind != T_IDENTIFIER) {
2653                         parse_error_expected("while parsing property declspec",
2654                                              T_IDENTIFIER, NULL);
2655                         goto end_error;
2656                 }
2657                 if (prop != NULL)
2658                         *prop = token.identifier.symbol;
2659                 next_token();
2660         } while (next_if(','));
2661
2662         attribute->a.property = property;
2663
2664         expect(')', end_error);
2665
2666 end_error:
2667         return attribute;
2668 }
2669
2670 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2671 {
2672         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2673         if (next_if(T_restrict)) {
2674                 kind = ATTRIBUTE_MS_RESTRICT;
2675         } else if (token.kind == T_IDENTIFIER) {
2676                 const char *name = token.identifier.symbol->string;
2677                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2678                      ++k) {
2679                         const char *attribute_name = get_attribute_name(k);
2680                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2681                                 kind = k;
2682                                 break;
2683                         }
2684                 }
2685
2686                 if (kind == ATTRIBUTE_UNKNOWN) {
2687                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2688                 }
2689         } else {
2690                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2691                 return NULL;
2692         }
2693
2694         attribute_t *attribute = allocate_attribute_zero(kind);
2695         eat(T_IDENTIFIER);
2696
2697         if (kind == ATTRIBUTE_MS_PROPERTY) {
2698                 return parse_attribute_ms_property(attribute);
2699         }
2700
2701         /* parse arguments */
2702         if (next_if('('))
2703                 attribute->a.arguments = parse_attribute_arguments();
2704
2705         return attribute;
2706 }
2707
2708 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2709 {
2710         eat(T__declspec);
2711
2712         expect('(', end_error);
2713
2714         if (next_if(')'))
2715                 return NULL;
2716
2717         add_anchor_token(')');
2718
2719         attribute_t **anchor = &first;
2720         do {
2721                 while (*anchor != NULL)
2722                         anchor = &(*anchor)->next;
2723
2724                 attribute_t *attribute
2725                         = parse_microsoft_extended_decl_modifier_single();
2726                 if (attribute == NULL)
2727                         goto end_error;
2728
2729                 *anchor = attribute;
2730                 anchor  = &attribute->next;
2731         } while (next_if(','));
2732
2733         rem_anchor_token(')');
2734         expect(')', end_error);
2735         return first;
2736
2737 end_error:
2738         rem_anchor_token(')');
2739         return first;
2740 }
2741
2742 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2743 {
2744         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2745         entity->base.source_position = *HERE;
2746         if (is_declaration(entity)) {
2747                 entity->declaration.type     = type_error_type;
2748                 entity->declaration.implicit = true;
2749         } else if (kind == ENTITY_TYPEDEF) {
2750                 entity->typedefe.type    = type_error_type;
2751                 entity->typedefe.builtin = true;
2752         }
2753         if (kind != ENTITY_COMPOUND_MEMBER)
2754                 record_entity(entity, false);
2755         return entity;
2756 }
2757
2758 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2759 {
2760         type_t            *type            = NULL;
2761         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2762         unsigned           type_specifiers = 0;
2763         bool               newtype         = false;
2764         bool               saw_error       = false;
2765
2766         memset(specifiers, 0, sizeof(*specifiers));
2767         specifiers->source_position = token.base.source_position;
2768
2769         while (true) {
2770                 specifiers->attributes = parse_attributes(specifiers->attributes);
2771
2772                 switch (token.kind) {
2773                 /* storage class */
2774 #define MATCH_STORAGE_CLASS(token, class)                                  \
2775                 case token:                                                        \
2776                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2777                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2778                         }                                                              \
2779                         specifiers->storage_class = class;                             \
2780                         if (specifiers->thread_local)                                  \
2781                                 goto check_thread_storage_class;                           \
2782                         next_token();                                                  \
2783                         break;
2784
2785                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2786                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2787                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2788                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2789                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2790
2791                 case T__declspec:
2792                         specifiers->attributes
2793                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2794                         break;
2795
2796                 case T___thread:
2797                         if (specifiers->thread_local) {
2798                                 errorf(HERE, "duplicate '__thread'");
2799                         } else {
2800                                 specifiers->thread_local = true;
2801 check_thread_storage_class:
2802                                 switch (specifiers->storage_class) {
2803                                         case STORAGE_CLASS_EXTERN:
2804                                         case STORAGE_CLASS_NONE:
2805                                         case STORAGE_CLASS_STATIC:
2806                                                 break;
2807
2808                                                 char const* wrong;
2809                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2810                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2811                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2812 wrong_thread_storage_class:
2813                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2814                                                 break;
2815                                 }
2816                         }
2817                         next_token();
2818                         break;
2819
2820                 /* type qualifiers */
2821 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2822                 case token:                                                     \
2823                         qualifiers |= qualifier;                                    \
2824                         next_token();                                               \
2825                         break
2826
2827                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2828                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2829                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2830                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2831                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2832                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2833                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2834                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2835
2836                 /* type specifiers */
2837 #define MATCH_SPECIFIER(token, specifier, name)                         \
2838                 case token:                                                     \
2839                         if (type_specifiers & specifier) {                           \
2840                                 errorf(HERE, "multiple " name " type specifiers given"); \
2841                         } else {                                                    \
2842                                 type_specifiers |= specifier;                           \
2843                         }                                                           \
2844                         next_token();                                               \
2845                         break
2846
2847                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2848                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2849                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2850                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2851                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2852                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2853                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2854                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2855                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2856                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2857                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2858                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2859                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2860                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2861                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2862                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2863                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2864                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2865
2866                 case T_inline:
2867                         next_token();
2868                         specifiers->is_inline = true;
2869                         break;
2870
2871 #if 0
2872                 case T__forceinline:
2873                         next_token();
2874                         specifiers->modifiers |= DM_FORCEINLINE;
2875                         break;
2876 #endif
2877
2878                 case T_long:
2879                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2880                                 errorf(HERE, "too many long type specifiers given");
2881                         } else if (type_specifiers & SPECIFIER_LONG) {
2882                                 type_specifiers |= SPECIFIER_LONG_LONG;
2883                         } else {
2884                                 type_specifiers |= SPECIFIER_LONG;
2885                         }
2886                         next_token();
2887                         break;
2888
2889 #define CHECK_DOUBLE_TYPE() \
2890         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2891
2892                 case T_struct:
2893                         CHECK_DOUBLE_TYPE();
2894                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2895
2896                         type->compound.compound = parse_compound_type_specifier(true);
2897                         break;
2898                 case T_union:
2899                         CHECK_DOUBLE_TYPE();
2900                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2901                         type->compound.compound = parse_compound_type_specifier(false);
2902                         break;
2903                 case T_enum:
2904                         CHECK_DOUBLE_TYPE();
2905                         type = parse_enum_specifier();
2906                         break;
2907                 case T___typeof__:
2908                         CHECK_DOUBLE_TYPE();
2909                         type = parse_typeof();
2910                         break;
2911                 case T___builtin_va_list:
2912                         CHECK_DOUBLE_TYPE();
2913                         type = duplicate_type(type_valist);
2914                         next_token();
2915                         break;
2916
2917                 case T_IDENTIFIER: {
2918                         /* only parse identifier if we haven't found a type yet */
2919                         if (type != NULL || type_specifiers != 0) {
2920                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2921                                  * declaration, so it doesn't generate errors about expecting '(' or
2922                                  * '{' later on. */
2923                                 switch (look_ahead(1)->kind) {
2924                                         STORAGE_CLASSES
2925                                         TYPE_SPECIFIERS
2926                                         case T_const:
2927                                         case T_restrict:
2928                                         case T_volatile:
2929                                         case T_inline:
2930                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2931                                         case T_IDENTIFIER:
2932                                         case '&':
2933                                         case '*':
2934                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2935                                                 next_token();
2936                                                 continue;
2937
2938                                         default:
2939                                                 goto finish_specifiers;
2940                                 }
2941                         }
2942
2943                         type_t *const typedef_type = get_typedef_type(token.identifier.symbol);
2944                         if (typedef_type == NULL) {
2945                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2946                                  * declaration, so it doesn't generate 'implicit int' followed by more
2947                                  * errors later on. */
2948                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2949                                 switch (la1_type) {
2950                                         DECLARATION_START
2951                                         case T_IDENTIFIER:
2952                                         case '&':
2953                                         case '*': {
2954                                                 errorf(HERE, "%K does not name a type", &token);
2955
2956                                                 symbol_t *symbol = token.identifier.symbol;
2957                                                 entity_t *entity
2958                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2959
2960                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2961                                                 type->typedeft.typedefe = &entity->typedefe;
2962
2963                                                 next_token();
2964                                                 saw_error = true;
2965                                                 continue;
2966                                         }
2967
2968                                         default:
2969                                                 goto finish_specifiers;
2970                                 }
2971                         }
2972
2973                         next_token();
2974                         type = typedef_type;
2975                         break;
2976                 }
2977
2978                 /* function specifier */
2979                 default:
2980                         goto finish_specifiers;
2981                 }
2982         }
2983
2984 finish_specifiers:
2985         specifiers->attributes = parse_attributes(specifiers->attributes);
2986
2987         if (type == NULL || (saw_error && type_specifiers != 0)) {
2988                 atomic_type_kind_t atomic_type;
2989
2990                 /* match valid basic types */
2991                 switch (type_specifiers) {
2992                 case SPECIFIER_VOID:
2993                         atomic_type = ATOMIC_TYPE_VOID;
2994                         break;
2995                 case SPECIFIER_WCHAR_T:
2996                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2997                         break;
2998                 case SPECIFIER_CHAR:
2999                         atomic_type = ATOMIC_TYPE_CHAR;
3000                         break;
3001                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3002                         atomic_type = ATOMIC_TYPE_SCHAR;
3003                         break;
3004                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3005                         atomic_type = ATOMIC_TYPE_UCHAR;
3006                         break;
3007                 case SPECIFIER_SHORT:
3008                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3009                 case SPECIFIER_SHORT | SPECIFIER_INT:
3010                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3011                         atomic_type = ATOMIC_TYPE_SHORT;
3012                         break;
3013                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3014                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3015                         atomic_type = ATOMIC_TYPE_USHORT;
3016                         break;
3017                 case SPECIFIER_INT:
3018                 case SPECIFIER_SIGNED:
3019                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3020                         atomic_type = ATOMIC_TYPE_INT;
3021                         break;
3022                 case SPECIFIER_UNSIGNED:
3023                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3024                         atomic_type = ATOMIC_TYPE_UINT;
3025                         break;
3026                 case SPECIFIER_LONG:
3027                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3028                 case SPECIFIER_LONG | SPECIFIER_INT:
3029                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3030                         atomic_type = ATOMIC_TYPE_LONG;
3031                         break;
3032                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3033                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3034                         atomic_type = ATOMIC_TYPE_ULONG;
3035                         break;
3036
3037                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3038                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3039                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3040                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3041                         | SPECIFIER_INT:
3042                         atomic_type = ATOMIC_TYPE_LONGLONG;
3043                         goto warn_about_long_long;
3044
3045                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3046                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3047                         | SPECIFIER_INT:
3048                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3049 warn_about_long_long:
3050                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
3051                         break;
3052
3053                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3054                         atomic_type = unsigned_int8_type_kind;
3055                         break;
3056
3057                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3058                         atomic_type = unsigned_int16_type_kind;
3059                         break;
3060
3061                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3062                         atomic_type = unsigned_int32_type_kind;
3063                         break;
3064
3065                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3066                         atomic_type = unsigned_int64_type_kind;
3067                         break;
3068
3069                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3070                         atomic_type = unsigned_int128_type_kind;
3071                         break;
3072
3073                 case SPECIFIER_INT8:
3074                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3075                         atomic_type = int8_type_kind;
3076                         break;
3077
3078                 case SPECIFIER_INT16:
3079                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3080                         atomic_type = int16_type_kind;
3081                         break;
3082
3083                 case SPECIFIER_INT32:
3084                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3085                         atomic_type = int32_type_kind;
3086                         break;
3087
3088                 case SPECIFIER_INT64:
3089                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3090                         atomic_type = int64_type_kind;
3091                         break;
3092
3093                 case SPECIFIER_INT128:
3094                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3095                         atomic_type = int128_type_kind;
3096                         break;
3097
3098                 case SPECIFIER_FLOAT:
3099                         atomic_type = ATOMIC_TYPE_FLOAT;
3100                         break;
3101                 case SPECIFIER_DOUBLE:
3102                         atomic_type = ATOMIC_TYPE_DOUBLE;
3103                         break;
3104                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3105                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3106                         break;
3107                 case SPECIFIER_BOOL:
3108                         atomic_type = ATOMIC_TYPE_BOOL;
3109                         break;
3110                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3111                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3112                         atomic_type = ATOMIC_TYPE_FLOAT;
3113                         break;
3114                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3115                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3116                         atomic_type = ATOMIC_TYPE_DOUBLE;
3117                         break;
3118                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3119                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3120                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3121                         break;
3122                 default: {
3123                         /* invalid specifier combination, give an error message */
3124                         source_position_t const* const pos = &specifiers->source_position;
3125                         if (type_specifiers == 0) {
3126                                 if (!saw_error) {
3127                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3128                                         if (!(c_mode & _CXX) && !strict_mode) {
3129                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3130                                                 atomic_type = ATOMIC_TYPE_INT;
3131                                                 break;
3132                                         } else {
3133                                                 errorf(pos, "no type specifiers given in declaration");
3134                                         }
3135                                 }
3136                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3137                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3138                                 errorf(pos, "signed and unsigned specifiers given");
3139                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3140                                 errorf(pos, "only integer types can be signed or unsigned");
3141                         } else {
3142                                 errorf(pos, "multiple datatypes in declaration");
3143                         }
3144                         goto end_error;
3145                 }
3146                 }
3147
3148                 if (type_specifiers & SPECIFIER_COMPLEX) {
3149                         type                = allocate_type_zero(TYPE_COMPLEX);
3150                         type->complex.akind = atomic_type;
3151                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3152                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3153                         type->imaginary.akind = atomic_type;
3154                 } else {
3155                         type                 = allocate_type_zero(TYPE_ATOMIC);
3156                         type->atomic.akind   = atomic_type;
3157                 }
3158                 newtype = true;
3159         } else if (type_specifiers != 0) {
3160                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3161         }
3162
3163         /* FIXME: check type qualifiers here */
3164         type->base.qualifiers = qualifiers;
3165
3166         if (newtype) {
3167                 type = identify_new_type(type);
3168         } else {
3169                 type = typehash_insert(type);
3170         }
3171
3172         if (specifiers->attributes != NULL)
3173                 type = handle_type_attributes(specifiers->attributes, type);
3174         specifiers->type = type;
3175         return;
3176
3177 end_error:
3178         specifiers->type = type_error_type;
3179 }
3180
3181 static type_qualifiers_t parse_type_qualifiers(void)
3182 {
3183         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3184
3185         while (true) {
3186                 switch (token.kind) {
3187                 /* type qualifiers */
3188                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3189                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3190                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3191                 /* microsoft extended type modifiers */
3192                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3193                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3194                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3195                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3196                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3197
3198                 default:
3199                         return qualifiers;
3200                 }
3201         }
3202 }
3203
3204 /**
3205  * Parses an K&R identifier list
3206  */
3207 static void parse_identifier_list(scope_t *scope)
3208 {
3209         assert(token.kind == T_IDENTIFIER);
3210         do {
3211                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol);
3212                 entity->base.source_position = token.base.source_position;
3213                 /* a K&R parameter has no type, yet */
3214                 next_token();
3215
3216                 if (scope != NULL)
3217                         append_entity(scope, entity);
3218         } while (next_if(',') && token.kind == T_IDENTIFIER);
3219 }
3220
3221 static entity_t *parse_parameter(void)
3222 {
3223         declaration_specifiers_t specifiers;
3224         parse_declaration_specifiers(&specifiers);
3225
3226         entity_t *entity = parse_declarator(&specifiers,
3227                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3228         anonymous_entity = NULL;
3229         return entity;
3230 }
3231
3232 static void semantic_parameter_incomplete(const entity_t *entity)
3233 {
3234         assert(entity->kind == ENTITY_PARAMETER);
3235
3236         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3237          *             list in a function declarator that is part of a
3238          *             definition of that function shall not have
3239          *             incomplete type. */
3240         type_t *type = skip_typeref(entity->declaration.type);
3241         if (is_type_incomplete(type)) {
3242                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3243         }
3244 }
3245
3246 static bool has_parameters(void)
3247 {
3248         /* func(void) is not a parameter */
3249         if (token.kind == T_IDENTIFIER) {
3250                 entity_t const *const entity
3251                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3252                 if (entity == NULL)
3253                         return true;
3254                 if (entity->kind != ENTITY_TYPEDEF)
3255                         return true;
3256                 if (skip_typeref(entity->typedefe.type) != type_void)
3257                         return true;
3258         } else if (token.kind != T_void) {
3259                 return true;
3260         }
3261         if (look_ahead(1)->kind != ')')
3262                 return true;
3263         next_token();
3264         return false;
3265 }
3266
3267 /**
3268  * Parses function type parameters (and optionally creates variable_t entities
3269  * for them in a scope)
3270  */
3271 static void parse_parameters(function_type_t *type, scope_t *scope)
3272 {
3273         eat('(');
3274         add_anchor_token(')');
3275         int saved_comma_state = save_and_reset_anchor_state(',');
3276
3277         if (token.kind == T_IDENTIFIER
3278             && !is_typedef_symbol(token.identifier.symbol)) {
3279                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
3280                 if (la1_type == ',' || la1_type == ')') {
3281                         type->kr_style_parameters = true;
3282                         parse_identifier_list(scope);
3283                         goto parameters_finished;
3284                 }
3285         }
3286
3287         if (token.kind == ')') {
3288                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3289                 if (!(c_mode & _CXX))
3290                         type->unspecified_parameters = true;
3291         } else if (has_parameters()) {
3292                 function_parameter_t **anchor = &type->parameters;
3293                 do {
3294                         switch (token.kind) {
3295                         case T_DOTDOTDOT:
3296                                 next_token();
3297                                 type->variadic = true;
3298                                 goto parameters_finished;
3299
3300                         case T_IDENTIFIER:
3301                         DECLARATION_START
3302                         {
3303                                 entity_t *entity = parse_parameter();
3304                                 if (entity->kind == ENTITY_TYPEDEF) {
3305                                         errorf(&entity->base.source_position,
3306                                                         "typedef not allowed as function parameter");
3307                                         break;
3308                                 }
3309                                 assert(is_declaration(entity));
3310
3311                                 semantic_parameter_incomplete(entity);
3312
3313                                 function_parameter_t *const parameter =
3314                                         allocate_parameter(entity->declaration.type);
3315
3316                                 if (scope != NULL) {
3317                                         append_entity(scope, entity);
3318                                 }
3319
3320                                 *anchor = parameter;
3321                                 anchor  = &parameter->next;
3322                                 break;
3323                         }
3324
3325                         default:
3326                                 goto parameters_finished;
3327                         }
3328                 } while (next_if(','));
3329         }
3330
3331 parameters_finished:
3332         rem_anchor_token(')');
3333         expect(')', end_error);
3334
3335 end_error:
3336         restore_anchor_state(',', saved_comma_state);
3337 }
3338
3339 typedef enum construct_type_kind_t {
3340         CONSTRUCT_POINTER = 1,
3341         CONSTRUCT_REFERENCE,
3342         CONSTRUCT_FUNCTION,
3343         CONSTRUCT_ARRAY
3344 } construct_type_kind_t;
3345
3346 typedef union construct_type_t construct_type_t;
3347
3348 typedef struct construct_type_base_t {
3349         construct_type_kind_t  kind;
3350         source_position_t      pos;
3351         construct_type_t      *next;
3352 } construct_type_base_t;
3353
3354 typedef struct parsed_pointer_t {
3355         construct_type_base_t  base;
3356         type_qualifiers_t      type_qualifiers;
3357         variable_t            *base_variable;  /**< MS __based extension. */
3358 } parsed_pointer_t;
3359
3360 typedef struct parsed_reference_t {
3361         construct_type_base_t base;
3362 } parsed_reference_t;
3363
3364 typedef struct construct_function_type_t {
3365         construct_type_base_t  base;
3366         type_t                *function_type;
3367 } construct_function_type_t;
3368
3369 typedef struct parsed_array_t {
3370         construct_type_base_t  base;
3371         type_qualifiers_t      type_qualifiers;
3372         bool                   is_static;
3373         bool                   is_variable;
3374         expression_t          *size;
3375 } parsed_array_t;
3376
3377 union construct_type_t {
3378         construct_type_kind_t     kind;
3379         construct_type_base_t     base;
3380         parsed_pointer_t          pointer;
3381         parsed_reference_t        reference;
3382         construct_function_type_t function;
3383         parsed_array_t            array;
3384 };
3385
3386 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3387 {
3388         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3389         memset(cons, 0, size);
3390         cons->kind     = kind;
3391         cons->base.pos = *HERE;
3392         return cons;
3393 }
3394
3395 /* §6.7.5.1 */
3396 static construct_type_t *parse_pointer_declarator(void)
3397 {
3398         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3399         eat('*');
3400         cons->pointer.type_qualifiers = parse_type_qualifiers();
3401         //cons->pointer.base_variable   = base_variable;
3402
3403         return cons;
3404 }
3405
3406 /* ISO/IEC 14882:1998(E) §8.3.2 */
3407 static construct_type_t *parse_reference_declarator(void)
3408 {
3409         if (!(c_mode & _CXX))
3410                 errorf(HERE, "references are only available for C++");
3411
3412         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3413         eat('&');
3414
3415         return cons;
3416 }
3417
3418 /* §6.7.5.2 */
3419 static construct_type_t *parse_array_declarator(void)
3420 {
3421         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3422         parsed_array_t   *const array = &cons->array;
3423
3424         eat('[');
3425         add_anchor_token(']');
3426
3427         bool is_static = next_if(T_static);
3428
3429         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3430
3431         if (!is_static)
3432                 is_static = next_if(T_static);
3433
3434         array->type_qualifiers = type_qualifiers;
3435         array->is_static       = is_static;
3436
3437         expression_t *size = NULL;
3438         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3439                 array->is_variable = true;
3440                 next_token();
3441         } else if (token.kind != ']') {
3442                 size = parse_assignment_expression();
3443
3444                 /* §6.7.5.2:1  Array size must have integer type */
3445                 type_t *const orig_type = size->base.type;
3446                 type_t *const type      = skip_typeref(orig_type);
3447                 if (!is_type_integer(type) && is_type_valid(type)) {
3448                         errorf(&size->base.source_position,
3449                                "array size '%E' must have integer type but has type '%T'",
3450                                size, orig_type);
3451                 }
3452
3453                 array->size = size;
3454                 mark_vars_read(size, NULL);
3455         }
3456
3457         if (is_static && size == NULL)
3458                 errorf(&array->base.pos, "static array parameters require a size");
3459
3460         rem_anchor_token(']');
3461         expect(']', end_error);
3462
3463 end_error:
3464         return cons;
3465 }
3466
3467 /* §6.7.5.3 */
3468 static construct_type_t *parse_function_declarator(scope_t *scope)
3469 {
3470         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3471
3472         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3473         function_type_t *ftype = &type->function;
3474
3475         ftype->linkage            = current_linkage;
3476         ftype->calling_convention = CC_DEFAULT;
3477
3478         parse_parameters(ftype, scope);
3479
3480         cons->function.function_type = type;
3481
3482         return cons;
3483 }
3484
3485 typedef struct parse_declarator_env_t {
3486         bool               may_be_abstract : 1;
3487         bool               must_be_abstract : 1;
3488         decl_modifiers_t   modifiers;
3489         symbol_t          *symbol;
3490         source_position_t  source_position;
3491         scope_t            parameters;
3492         attribute_t       *attributes;
3493 } parse_declarator_env_t;
3494
3495 /* §6.7.5 */
3496 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3497 {
3498         /* construct a single linked list of construct_type_t's which describe
3499          * how to construct the final declarator type */
3500         construct_type_t  *first      = NULL;
3501         construct_type_t **anchor     = &first;
3502
3503         env->attributes = parse_attributes(env->attributes);
3504
3505         for (;;) {
3506                 construct_type_t *type;
3507                 //variable_t       *based = NULL; /* MS __based extension */
3508                 switch (token.kind) {
3509                         case '&':
3510                                 type = parse_reference_declarator();
3511                                 break;
3512
3513                         case T__based: {
3514                                 panic("based not supported anymore");
3515                                 /* FALLTHROUGH */
3516                         }
3517
3518                         case '*':
3519                                 type = parse_pointer_declarator();
3520                                 break;
3521
3522                         default:
3523                                 goto ptr_operator_end;
3524                 }
3525
3526                 *anchor = type;
3527                 anchor  = &type->base.next;
3528
3529                 /* TODO: find out if this is correct */
3530                 env->attributes = parse_attributes(env->attributes);
3531         }
3532
3533 ptr_operator_end: ;
3534         construct_type_t *inner_types = NULL;
3535
3536         switch (token.kind) {
3537         case T_IDENTIFIER:
3538                 if (env->must_be_abstract) {
3539                         errorf(HERE, "no identifier expected in typename");
3540                 } else {
3541                         env->symbol          = token.identifier.symbol;
3542                         env->source_position = token.base.source_position;
3543                 }
3544                 next_token();
3545                 break;
3546
3547         case '(': {
3548                 /* Parenthesized declarator or function declarator? */
3549                 token_t const *const la1 = look_ahead(1);
3550                 switch (la1->kind) {
3551                         case T_IDENTIFIER:
3552                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3553                         case ')':
3554                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3555                                          * interpreted as ``function with no parameter specification'', rather
3556                                          * than redundant parentheses around the omitted identifier. */
3557                         default:
3558                                         /* Function declarator. */
3559                                         if (!env->may_be_abstract) {
3560                                                 errorf(HERE, "function declarator must have a name");
3561                                         }
3562                                 } else {
3563                         case '&':
3564                         case '(':
3565                         case '*':
3566                         case '[':
3567                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3568                                         /* Paranthesized declarator. */
3569                                         next_token();
3570                                         add_anchor_token(')');
3571                                         inner_types = parse_inner_declarator(env);
3572                                         if (inner_types != NULL) {
3573                                                 /* All later declarators only modify the return type */
3574                                                 env->must_be_abstract = true;
3575                                         }
3576                                         rem_anchor_token(')');
3577                                         expect(')', end_error);
3578                                 }
3579                                 break;
3580                 }
3581                 break;
3582         }
3583
3584         default:
3585                 if (env->may_be_abstract)
3586                         break;
3587                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3588                 eat_until_anchor();
3589                 return NULL;
3590         }
3591
3592         construct_type_t **const p = anchor;
3593
3594         for (;;) {
3595                 construct_type_t *type;
3596                 switch (token.kind) {
3597                 case '(': {
3598                         scope_t *scope = NULL;
3599                         if (!env->must_be_abstract) {
3600                                 scope = &env->parameters;
3601                         }
3602
3603                         type = parse_function_declarator(scope);
3604                         break;
3605                 }
3606                 case '[':
3607                         type = parse_array_declarator();
3608                         break;
3609                 default:
3610                         goto declarator_finished;
3611                 }
3612
3613                 /* insert in the middle of the list (at p) */
3614                 type->base.next = *p;
3615                 *p              = type;
3616                 if (anchor == p)
3617                         anchor = &type->base.next;
3618         }
3619
3620 declarator_finished:
3621         /* append inner_types at the end of the list, we don't to set anchor anymore
3622          * as it's not needed anymore */
3623         *anchor = inner_types;
3624
3625         return first;
3626 end_error:
3627         return NULL;
3628 }
3629
3630 static type_t *construct_declarator_type(construct_type_t *construct_list,
3631                                          type_t *type)
3632 {
3633         construct_type_t *iter = construct_list;
3634         for (; iter != NULL; iter = iter->base.next) {
3635                 source_position_t const* const pos = &iter->base.pos;
3636                 switch (iter->kind) {
3637                 case CONSTRUCT_FUNCTION: {
3638                         construct_function_type_t *function      = &iter->function;
3639                         type_t                    *function_type = function->function_type;
3640
3641                         function_type->function.return_type = type;
3642
3643                         type_t *skipped_return_type = skip_typeref(type);
3644                         /* §6.7.5.3:1 */
3645                         if (is_type_function(skipped_return_type)) {
3646                                 errorf(pos, "function returning function is not allowed");
3647                         } else if (is_type_array(skipped_return_type)) {
3648                                 errorf(pos, "function returning array is not allowed");
3649                         } else {
3650                                 if (skipped_return_type->base.qualifiers != 0) {
3651                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3652                                 }
3653                         }
3654
3655                         /* The function type was constructed earlier.  Freeing it here will
3656                          * destroy other types. */
3657                         type = typehash_insert(function_type);
3658                         continue;
3659                 }
3660
3661                 case CONSTRUCT_POINTER: {
3662                         if (is_type_reference(skip_typeref(type)))
3663                                 errorf(pos, "cannot declare a pointer to reference");
3664
3665                         parsed_pointer_t *pointer = &iter->pointer;
3666                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3667                         continue;
3668                 }
3669
3670                 case CONSTRUCT_REFERENCE:
3671                         if (is_type_reference(skip_typeref(type)))
3672                                 errorf(pos, "cannot declare a reference to reference");
3673
3674                         type = make_reference_type(type);
3675                         continue;
3676
3677                 case CONSTRUCT_ARRAY: {
3678                         if (is_type_reference(skip_typeref(type)))
3679                                 errorf(pos, "cannot declare an array of references");
3680
3681                         parsed_array_t *array      = &iter->array;
3682                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3683
3684                         expression_t *size_expression = array->size;
3685                         if (size_expression != NULL) {
3686                                 size_expression
3687                                         = create_implicit_cast(size_expression, type_size_t);
3688                         }
3689
3690                         array_type->base.qualifiers       = array->type_qualifiers;
3691                         array_type->array.element_type    = type;
3692                         array_type->array.is_static       = array->is_static;
3693                         array_type->array.is_variable     = array->is_variable;
3694                         array_type->array.size_expression = size_expression;
3695
3696                         if (size_expression != NULL) {
3697                                 switch (is_constant_expression(size_expression)) {
3698                                 case EXPR_CLASS_CONSTANT: {
3699                                         long const size = fold_constant_to_int(size_expression);
3700                                         array_type->array.size          = size;
3701                                         array_type->array.size_constant = true;
3702                                         /* §6.7.5.2:1  If the expression is a constant expression,
3703                                          * it shall have a value greater than zero. */
3704                                         if (size < 0) {
3705                                                 errorf(&size_expression->base.source_position,
3706                                                            "size of array must be greater than zero");
3707                                         } else if (size == 0 && !GNU_MODE) {
3708                                                 errorf(&size_expression->base.source_position,
3709                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3710                                         }
3711                                         break;
3712                                 }
3713
3714                                 case EXPR_CLASS_VARIABLE:
3715                                         array_type->array.is_vla = true;
3716                                         break;
3717
3718                                 case EXPR_CLASS_ERROR:
3719                                         break;
3720                                 }
3721                         }
3722
3723                         type_t *skipped_type = skip_typeref(type);
3724                         /* §6.7.5.2:1 */
3725                         if (is_type_incomplete(skipped_type)) {
3726                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3727                         } else if (is_type_function(skipped_type)) {
3728                                 errorf(pos, "array of functions is not allowed");
3729                         }
3730                         type = identify_new_type(array_type);
3731                         continue;
3732                 }
3733                 }
3734                 internal_errorf(pos, "invalid type construction found");
3735         }
3736
3737         return type;
3738 }
3739
3740 static type_t *automatic_type_conversion(type_t *orig_type);
3741
3742 static type_t *semantic_parameter(const source_position_t *pos,
3743                                   type_t *type,
3744                                   const declaration_specifiers_t *specifiers,
3745                                   entity_t const *const param)
3746 {
3747         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3748          *             shall be adjusted to ``qualified pointer to type'',
3749          *             [...]
3750          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3751          *             type'' shall be adjusted to ``pointer to function
3752          *             returning type'', as in 6.3.2.1. */
3753         type = automatic_type_conversion(type);
3754
3755         if (specifiers->is_inline && is_type_valid(type)) {
3756                 errorf(pos, "'%N' declared 'inline'", param);
3757         }
3758
3759         /* §6.9.1:6  The declarations in the declaration list shall contain
3760          *           no storage-class specifier other than register and no
3761          *           initializations. */
3762         if (specifiers->thread_local || (
3763                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3764                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3765            ) {
3766                 errorf(pos, "invalid storage class for '%N'", param);
3767         }
3768
3769         /* delay test for incomplete type, because we might have (void)
3770          * which is legal but incomplete... */
3771
3772         return type;
3773 }
3774
3775 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3776                                   declarator_flags_t flags)
3777 {
3778         parse_declarator_env_t env;
3779         memset(&env, 0, sizeof(env));
3780         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3781
3782         construct_type_t *construct_type = parse_inner_declarator(&env);
3783         type_t           *orig_type      =
3784                 construct_declarator_type(construct_type, specifiers->type);
3785         type_t           *type           = skip_typeref(orig_type);
3786
3787         if (construct_type != NULL) {
3788                 obstack_free(&temp_obst, construct_type);
3789         }
3790
3791         attribute_t *attributes = parse_attributes(env.attributes);
3792         /* append (shared) specifier attribute behind attributes of this
3793          * declarator */
3794         attribute_t **anchor = &attributes;
3795         while (*anchor != NULL)
3796                 anchor = &(*anchor)->next;
3797         *anchor = specifiers->attributes;
3798
3799         entity_t *entity;
3800         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3801                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3802                 entity->base.source_position = env.source_position;
3803                 entity->typedefe.type        = orig_type;
3804
3805                 if (anonymous_entity != NULL) {
3806                         if (is_type_compound(type)) {
3807                                 assert(anonymous_entity->compound.alias == NULL);
3808                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3809                                        anonymous_entity->kind == ENTITY_UNION);
3810                                 anonymous_entity->compound.alias = entity;
3811                                 anonymous_entity = NULL;
3812                         } else if (is_type_enum(type)) {
3813                                 assert(anonymous_entity->enume.alias == NULL);
3814                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3815                                 anonymous_entity->enume.alias = entity;
3816                                 anonymous_entity = NULL;
3817                         }
3818                 }
3819         } else {
3820                 /* create a declaration type entity */
3821                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3822                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3823
3824                         if (env.symbol != NULL) {
3825                                 if (specifiers->is_inline && is_type_valid(type)) {
3826                                         errorf(&env.source_position,
3827                                                         "compound member '%Y' declared 'inline'", env.symbol);
3828                                 }
3829
3830                                 if (specifiers->thread_local ||
3831                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3832                                         errorf(&env.source_position,
3833                                                         "compound member '%Y' must have no storage class",
3834                                                         env.symbol);
3835                                 }
3836                         }
3837                 } else if (flags & DECL_IS_PARAMETER) {
3838                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3839                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3840                 } else if (is_type_function(type)) {
3841                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3842                         entity->function.is_inline      = specifiers->is_inline;
3843                         entity->function.elf_visibility = default_visibility;
3844                         entity->function.parameters     = env.parameters;
3845
3846                         if (env.symbol != NULL) {
3847                                 /* this needs fixes for C++ */
3848                                 bool in_function_scope = current_function != NULL;
3849
3850                                 if (specifiers->thread_local || (
3851                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3852                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3853                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3854                                                 )) {
3855                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3856                                 }
3857                         }
3858                 } else {
3859                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3860                         entity->variable.elf_visibility = default_visibility;
3861                         entity->variable.thread_local   = specifiers->thread_local;
3862
3863                         if (env.symbol != NULL) {
3864                                 if (specifiers->is_inline && is_type_valid(type)) {
3865                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3866                                 }
3867
3868                                 bool invalid_storage_class = false;
3869                                 if (current_scope == file_scope) {
3870                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3871                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3872                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3873                                                 invalid_storage_class = true;
3874                                         }
3875                                 } else {
3876                                         if (specifiers->thread_local &&
3877                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3878                                                 invalid_storage_class = true;
3879                                         }
3880                                 }
3881                                 if (invalid_storage_class) {
3882                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3883                                 }
3884                         }
3885                 }
3886
3887                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3888                 entity->declaration.type       = orig_type;
3889                 entity->declaration.alignment  = get_type_alignment(orig_type);
3890                 entity->declaration.modifiers  = env.modifiers;
3891                 entity->declaration.attributes = attributes;
3892
3893                 storage_class_t storage_class = specifiers->storage_class;
3894                 entity->declaration.declared_storage_class = storage_class;
3895
3896                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3897                         storage_class = STORAGE_CLASS_AUTO;
3898                 entity->declaration.storage_class = storage_class;
3899         }
3900
3901         if (attributes != NULL) {
3902                 handle_entity_attributes(attributes, entity);
3903         }
3904
3905         return entity;
3906 }
3907
3908 static type_t *parse_abstract_declarator(type_t *base_type)
3909 {
3910         parse_declarator_env_t env;
3911         memset(&env, 0, sizeof(env));
3912         env.may_be_abstract = true;
3913         env.must_be_abstract = true;
3914
3915         construct_type_t *construct_type = parse_inner_declarator(&env);
3916
3917         type_t *result = construct_declarator_type(construct_type, base_type);
3918         if (construct_type != NULL) {
3919                 obstack_free(&temp_obst, construct_type);
3920         }
3921         result = handle_type_attributes(env.attributes, result);
3922
3923         return result;
3924 }
3925
3926 /**
3927  * Check if the declaration of main is suspicious.  main should be a
3928  * function with external linkage, returning int, taking either zero
3929  * arguments, two, or three arguments of appropriate types, ie.
3930  *
3931  * int main([ int argc, char **argv [, char **env ] ]).
3932  *
3933  * @param decl    the declaration to check
3934  * @param type    the function type of the declaration
3935  */
3936 static void check_main(const entity_t *entity)
3937 {
3938         const source_position_t *pos = &entity->base.source_position;
3939         if (entity->kind != ENTITY_FUNCTION) {
3940                 warningf(WARN_MAIN, pos, "'main' is not a function");
3941                 return;
3942         }
3943
3944         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3945                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3946         }
3947
3948         type_t *type = skip_typeref(entity->declaration.type);
3949         assert(is_type_function(type));
3950
3951         function_type_t const *const func_type = &type->function;
3952         type_t                *const ret_type  = func_type->return_type;
3953         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3954                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3955         }
3956         const function_parameter_t *parm = func_type->parameters;
3957         if (parm != NULL) {
3958                 type_t *const first_type        = skip_typeref(parm->type);
3959                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3960                 if (!types_compatible(first_type_unqual, type_int)) {
3961                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3962                 }
3963                 parm = parm->next;
3964                 if (parm != NULL) {
3965                         type_t *const second_type = skip_typeref(parm->type);
3966                         type_t *const second_type_unqual
3967                                 = get_unqualified_type(second_type);
3968                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3969                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3970                         }
3971                         parm = parm->next;
3972                         if (parm != NULL) {
3973                                 type_t *const third_type = skip_typeref(parm->type);
3974                                 type_t *const third_type_unqual
3975                                         = get_unqualified_type(third_type);
3976                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3977                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3978                                 }
3979                                 parm = parm->next;
3980                                 if (parm != NULL)
3981                                         goto warn_arg_count;
3982                         }
3983                 } else {
3984 warn_arg_count:
3985                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3986                 }
3987         }
3988 }
3989
3990 /**
3991  * Check if a symbol is the equal to "main".
3992  */
3993 static bool is_sym_main(const symbol_t *const sym)
3994 {
3995         return strcmp(sym->string, "main") == 0;
3996 }
3997
3998 static void error_redefined_as_different_kind(const source_position_t *pos,
3999                 const entity_t *old, entity_kind_t new_kind)
4000 {
4001         char              const *const what = get_entity_kind_name(new_kind);
4002         source_position_t const *const ppos = &old->base.source_position;
4003         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
4004 }
4005
4006 static bool is_entity_valid(entity_t *const ent)
4007 {
4008         if (is_declaration(ent)) {
4009                 return is_type_valid(skip_typeref(ent->declaration.type));
4010         } else if (ent->kind == ENTITY_TYPEDEF) {
4011                 return is_type_valid(skip_typeref(ent->typedefe.type));
4012         }
4013         return true;
4014 }
4015
4016 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4017 {
4018         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4019                 if (attributes_equal(tattr, attr))
4020                         return true;
4021         }
4022         return false;
4023 }
4024
4025 /**
4026  * test wether new_list contains any attributes not included in old_list
4027  */
4028 static bool has_new_attributes(const attribute_t *old_list,
4029                                const attribute_t *new_list)
4030 {
4031         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4032                 if (!contains_attribute(old_list, attr))
4033                         return true;
4034         }
4035         return false;
4036 }
4037
4038 /**
4039  * Merge in attributes from an attribute list (probably from a previous
4040  * declaration with the same name). Warning: destroys the old structure
4041  * of the attribute list - don't reuse attributes after this call.
4042  */
4043 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4044 {
4045         attribute_t *next;
4046         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4047                 next = attr->next;
4048                 if (contains_attribute(decl->attributes, attr))
4049                         continue;
4050
4051                 /* move attribute to new declarations attributes list */
4052                 attr->next       = decl->attributes;
4053                 decl->attributes = attr;
4054         }
4055 }
4056
4057 /**
4058  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4059  * for various problems that occur for multiple definitions
4060  */
4061 entity_t *record_entity(entity_t *entity, const bool is_definition)
4062 {
4063         const symbol_t *const    symbol  = entity->base.symbol;
4064         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4065         const source_position_t *pos     = &entity->base.source_position;
4066
4067         /* can happen in error cases */
4068         if (symbol == NULL)
4069                 return entity;
4070
4071         entity_t *const previous_entity = get_entity(symbol, namespc);
4072         /* pushing the same entity twice will break the stack structure */
4073         assert(previous_entity != entity);
4074
4075         if (entity->kind == ENTITY_FUNCTION) {
4076                 type_t *const orig_type = entity->declaration.type;
4077                 type_t *const type      = skip_typeref(orig_type);
4078
4079                 assert(is_type_function(type));
4080                 if (type->function.unspecified_parameters &&
4081                     previous_entity == NULL               &&
4082                     !entity->declaration.implicit) {
4083                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
4084                 }
4085
4086                 if (current_scope == file_scope && is_sym_main(symbol)) {
4087                         check_main(entity);
4088                 }
4089         }
4090
4091         if (is_declaration(entity)                                    &&
4092             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4093             current_scope != file_scope                               &&
4094             !entity->declaration.implicit) {
4095                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
4096         }
4097
4098         if (previous_entity != NULL) {
4099                 source_position_t const *const ppos = &previous_entity->base.source_position;
4100
4101                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4102                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4103                         assert(previous_entity->kind == ENTITY_PARAMETER);
4104                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4105                         goto finish;
4106                 }
4107
4108                 if (previous_entity->base.parent_scope == current_scope) {
4109                         if (previous_entity->kind != entity->kind) {
4110                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4111                                         error_redefined_as_different_kind(pos, previous_entity,
4112                                                         entity->kind);
4113                                 }
4114                                 goto finish;
4115                         }
4116                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4117                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4118                                 goto finish;
4119                         }
4120                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4121                                 /* TODO: C++ allows this for exactly the same type */
4122                                 errorf(pos, "redefinition of '%N' (declared %P)", entity, ppos);
4123                                 goto finish;
4124                         }
4125
4126                         /* at this point we should have only VARIABLES or FUNCTIONS */
4127                         assert(is_declaration(previous_entity) && is_declaration(entity));
4128
4129                         declaration_t *const prev_decl = &previous_entity->declaration;
4130                         declaration_t *const decl      = &entity->declaration;
4131
4132                         /* can happen for K&R style declarations */
4133                         if (prev_decl->type       == NULL             &&
4134                                         previous_entity->kind == ENTITY_PARAMETER &&
4135                                         entity->kind          == ENTITY_PARAMETER) {
4136                                 prev_decl->type                   = decl->type;
4137                                 prev_decl->storage_class          = decl->storage_class;
4138                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4139                                 prev_decl->modifiers              = decl->modifiers;
4140                                 return previous_entity;
4141                         }
4142
4143                         type_t *const type      = skip_typeref(decl->type);
4144                         type_t *const prev_type = skip_typeref(prev_decl->type);
4145
4146                         if (!types_compatible(type, prev_type)) {
4147                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4148                         } else {
4149                                 unsigned old_storage_class = prev_decl->storage_class;
4150
4151                                 if (is_definition                     &&
4152                                                 !prev_decl->used                  &&
4153                                                 !(prev_decl->modifiers & DM_USED) &&
4154                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4155                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4156                                 }
4157
4158                                 storage_class_t new_storage_class = decl->storage_class;
4159
4160                                 /* pretend no storage class means extern for function
4161                                  * declarations (except if the previous declaration is neither
4162                                  * none nor extern) */
4163                                 if (entity->kind == ENTITY_FUNCTION) {
4164                                         /* the previous declaration could have unspecified parameters or
4165                                          * be a typedef, so use the new type */
4166                                         if (prev_type->function.unspecified_parameters || is_definition)
4167                                                 prev_decl->type = type;
4168
4169                                         switch (old_storage_class) {
4170                                                 case STORAGE_CLASS_NONE:
4171                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4172                                                         /* FALLTHROUGH */
4173
4174                                                 case STORAGE_CLASS_EXTERN:
4175                                                         if (is_definition) {
4176                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4177                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4178                                                                 }
4179                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4180                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4181                                                         }
4182                                                         break;
4183
4184                                                 default:
4185                                                         break;
4186                                         }
4187                                 } else if (is_type_incomplete(prev_type)) {
4188                                         prev_decl->type = type;
4189                                 }
4190
4191                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4192                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4193
4194 warn_redundant_declaration: ;
4195                                         bool has_new_attrs
4196                                                 = has_new_attributes(prev_decl->attributes,
4197                                                                      decl->attributes);
4198                                         if (has_new_attrs) {
4199                                                 merge_in_attributes(decl, prev_decl->attributes);
4200                                         } else if (!is_definition        &&
4201                                                         is_type_valid(prev_type) &&
4202                                                         strcmp(ppos->input_name, "<builtin>") != 0) {
4203                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4204                                         }
4205                                 } else if (current_function == NULL) {
4206                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4207                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4208                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4209                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4210                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4211                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4212                                         } else {
4213                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4214                                                 if (c_mode & _CXX)
4215                                                         goto error_redeclaration;
4216                                                 goto warn_redundant_declaration;
4217                                         }
4218                                 } else if (is_type_valid(prev_type)) {
4219                                         if (old_storage_class == new_storage_class) {
4220 error_redeclaration:
4221                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4222                                         } else {
4223                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4224                                         }
4225                                 }
4226                         }
4227
4228                         prev_decl->modifiers |= decl->modifiers;
4229                         if (entity->kind == ENTITY_FUNCTION) {
4230                                 previous_entity->function.is_inline |= entity->function.is_inline;
4231                         }
4232                         return previous_entity;
4233                 }
4234
4235                 warning_t why;
4236                 if (is_warn_on(why = WARN_SHADOW) ||
4237                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4238                         char const *const what = get_entity_kind_name(previous_entity->kind);
4239                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4240                 }
4241         }
4242
4243         if (entity->kind == ENTITY_FUNCTION) {
4244                 if (is_definition &&
4245                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4246                                 !is_sym_main(symbol)) {
4247                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4248                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4249                         } else {
4250                                 goto warn_missing_declaration;
4251                         }
4252                 }
4253         } else if (entity->kind == ENTITY_VARIABLE) {
4254                 if (current_scope                     == file_scope &&
4255                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4256                                 !entity->declaration.implicit) {
4257 warn_missing_declaration:
4258                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4259                 }
4260         }
4261
4262 finish:
4263         assert(entity->base.parent_scope == NULL);
4264         assert(current_scope != NULL);
4265
4266         entity->base.parent_scope = current_scope;
4267         environment_push(entity);
4268         append_entity(current_scope, entity);
4269
4270         return entity;
4271 }
4272
4273 static void parser_error_multiple_definition(entity_t *entity,
4274                 const source_position_t *source_position)
4275 {
4276         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4277                entity->base.symbol, &entity->base.source_position);
4278 }
4279
4280 static bool is_declaration_specifier(const token_t *token)
4281 {
4282         switch (token->kind) {
4283                 DECLARATION_START
4284                         return true;
4285                 case T_IDENTIFIER:
4286                         return is_typedef_symbol(token->identifier.symbol);
4287
4288                 default:
4289                         return false;
4290         }
4291 }
4292
4293 static void parse_init_declarator_rest(entity_t *entity)
4294 {
4295         type_t *orig_type = type_error_type;
4296
4297         if (entity->base.kind == ENTITY_TYPEDEF) {
4298                 source_position_t const *const pos = &entity->base.source_position;
4299                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4300         } else {
4301                 assert(is_declaration(entity));
4302                 orig_type = entity->declaration.type;
4303         }
4304
4305         type_t *type = skip_typeref(orig_type);
4306
4307         if (entity->kind == ENTITY_VARIABLE
4308                         && entity->variable.initializer != NULL) {
4309                 parser_error_multiple_definition(entity, HERE);
4310         }
4311         eat('=');
4312
4313         declaration_t *const declaration = &entity->declaration;
4314         bool must_be_constant = false;
4315         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4316             entity->base.parent_scope  == file_scope) {
4317                 must_be_constant = true;
4318         }
4319
4320         if (is_type_function(type)) {
4321                 source_position_t const *const pos = &entity->base.source_position;
4322                 errorf(pos, "'%N' is initialized like a variable", entity);
4323                 orig_type = type_error_type;
4324         }
4325
4326         parse_initializer_env_t env;
4327         env.type             = orig_type;
4328         env.must_be_constant = must_be_constant;
4329         env.entity           = entity;
4330
4331         initializer_t *initializer = parse_initializer(&env);
4332
4333         if (entity->kind == ENTITY_VARIABLE) {
4334                 /* §6.7.5:22  array initializers for arrays with unknown size
4335                  * determine the array type size */
4336                 declaration->type            = env.type;
4337                 entity->variable.initializer = initializer;
4338         }
4339 }
4340
4341 /* parse rest of a declaration without any declarator */
4342 static void parse_anonymous_declaration_rest(
4343                 const declaration_specifiers_t *specifiers)
4344 {
4345         eat(';');
4346         anonymous_entity = NULL;
4347
4348         source_position_t const *const pos = &specifiers->source_position;
4349         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4350                         specifiers->thread_local) {
4351                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4352         }
4353
4354         type_t *type = specifiers->type;
4355         switch (type->kind) {
4356                 case TYPE_COMPOUND_STRUCT:
4357                 case TYPE_COMPOUND_UNION: {
4358                         if (type->compound.compound->base.symbol == NULL) {
4359                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4360                         }
4361                         break;
4362                 }
4363
4364                 case TYPE_ENUM:
4365                         break;
4366
4367                 default:
4368                         warningf(WARN_OTHER, pos, "empty declaration");
4369                         break;
4370         }
4371 }
4372
4373 static void check_variable_type_complete(entity_t *ent)
4374 {
4375         if (ent->kind != ENTITY_VARIABLE)
4376                 return;
4377
4378         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4379          *         type for the object shall be complete [...] */
4380         declaration_t *decl = &ent->declaration;
4381         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4382                         decl->storage_class == STORAGE_CLASS_STATIC)
4383                 return;
4384
4385         type_t *const type = skip_typeref(decl->type);
4386         if (!is_type_incomplete(type))
4387                 return;
4388
4389         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4390          * are given length one. */
4391         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4392                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4393                 return;
4394         }
4395
4396         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4397 }
4398
4399
4400 static void parse_declaration_rest(entity_t *ndeclaration,
4401                 const declaration_specifiers_t *specifiers,
4402                 parsed_declaration_func         finished_declaration,
4403                 declarator_flags_t              flags)
4404 {
4405         add_anchor_token(';');
4406         add_anchor_token(',');
4407         while (true) {
4408                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4409
4410                 if (token.kind == '=') {
4411                         parse_init_declarator_rest(entity);
4412                 } else if (entity->kind == ENTITY_VARIABLE) {
4413                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4414                          * [...] where the extern specifier is explicitly used. */
4415                         declaration_t *decl = &entity->declaration;
4416                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4417                                 type_t *type = decl->type;
4418                                 if (is_type_reference(skip_typeref(type))) {
4419                                         source_position_t const *const pos = &entity->base.source_position;
4420                                         errorf(pos, "reference '%#N' must be initialized", entity);
4421                                 }
4422                         }
4423                 }
4424
4425                 check_variable_type_complete(entity);
4426
4427                 if (!next_if(','))
4428                         break;
4429
4430                 add_anchor_token('=');
4431                 ndeclaration = parse_declarator(specifiers, flags);
4432                 rem_anchor_token('=');
4433         }
4434         expect(';', end_error);
4435
4436 end_error:
4437         anonymous_entity = NULL;
4438         rem_anchor_token(';');
4439         rem_anchor_token(',');
4440 }
4441
4442 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4443 {
4444         symbol_t *symbol = entity->base.symbol;
4445         if (symbol == NULL)
4446                 return entity;
4447
4448         assert(entity->base.namespc == NAMESPACE_NORMAL);
4449         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4450         if (previous_entity == NULL
4451                         || previous_entity->base.parent_scope != current_scope) {
4452                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4453                        symbol);
4454                 return entity;
4455         }
4456
4457         if (is_definition) {
4458                 errorf(HERE, "'%N' is initialised", entity);
4459         }
4460
4461         return record_entity(entity, false);
4462 }
4463
4464 static void parse_declaration(parsed_declaration_func finished_declaration,
4465                               declarator_flags_t      flags)
4466 {
4467         add_anchor_token(';');
4468         declaration_specifiers_t specifiers;
4469         parse_declaration_specifiers(&specifiers);
4470         rem_anchor_token(';');
4471
4472         if (token.kind == ';') {
4473                 parse_anonymous_declaration_rest(&specifiers);
4474         } else {
4475                 entity_t *entity = parse_declarator(&specifiers, flags);
4476                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4477         }
4478 }
4479
4480 /* §6.5.2.2:6 */
4481 static type_t *get_default_promoted_type(type_t *orig_type)
4482 {
4483         type_t *result = orig_type;
4484
4485         type_t *type = skip_typeref(orig_type);
4486         if (is_type_integer(type)) {
4487                 result = promote_integer(type);
4488         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4489                 result = type_double;
4490         }
4491
4492         return result;
4493 }
4494
4495 static void parse_kr_declaration_list(entity_t *entity)
4496 {
4497         if (entity->kind != ENTITY_FUNCTION)
4498                 return;
4499
4500         type_t *type = skip_typeref(entity->declaration.type);
4501         assert(is_type_function(type));
4502         if (!type->function.kr_style_parameters)
4503                 return;
4504
4505         add_anchor_token('{');
4506
4507         PUSH_SCOPE(&entity->function.parameters);
4508
4509         entity_t *parameter = entity->function.parameters.entities;
4510         for ( ; parameter != NULL; parameter = parameter->base.next) {
4511                 assert(parameter->base.parent_scope == NULL);
4512                 parameter->base.parent_scope = current_scope;
4513                 environment_push(parameter);
4514         }
4515
4516         /* parse declaration list */
4517         for (;;) {
4518                 switch (token.kind) {
4519                         DECLARATION_START
4520                         /* This covers symbols, which are no type, too, and results in
4521                          * better error messages.  The typical cases are misspelled type
4522                          * names and missing includes. */
4523                         case T_IDENTIFIER:
4524                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4525                                 break;
4526                         default:
4527                                 goto decl_list_end;
4528                 }
4529         }
4530 decl_list_end:
4531
4532         POP_SCOPE();
4533
4534         /* update function type */
4535         type_t *new_type = duplicate_type(type);
4536
4537         function_parameter_t  *parameters = NULL;
4538         function_parameter_t **anchor     = &parameters;
4539
4540         /* did we have an earlier prototype? */
4541         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4542         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4543                 proto_type = NULL;
4544
4545         function_parameter_t *proto_parameter = NULL;
4546         if (proto_type != NULL) {
4547                 type_t *proto_type_type = proto_type->declaration.type;
4548                 proto_parameter         = proto_type_type->function.parameters;
4549                 /* If a K&R function definition has a variadic prototype earlier, then
4550                  * make the function definition variadic, too. This should conform to
4551                  * §6.7.5.3:15 and §6.9.1:8. */
4552                 new_type->function.variadic = proto_type_type->function.variadic;
4553         } else {
4554                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4555                  * prototype */
4556                 new_type->function.unspecified_parameters = true;
4557         }
4558
4559         bool need_incompatible_warning = false;
4560         parameter = entity->function.parameters.entities;
4561         for (; parameter != NULL; parameter = parameter->base.next,
4562                         proto_parameter =
4563                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4564                 if (parameter->kind != ENTITY_PARAMETER)
4565                         continue;
4566
4567                 type_t *parameter_type = parameter->declaration.type;
4568                 if (parameter_type == NULL) {
4569                         source_position_t const* const pos = &parameter->base.source_position;
4570                         if (strict_mode) {
4571                                 errorf(pos, "no type specified for function '%N'", parameter);
4572                                 parameter_type = type_error_type;
4573                         } else {
4574                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4575                                 parameter_type = type_int;
4576                         }
4577                         parameter->declaration.type = parameter_type;
4578                 }
4579
4580                 semantic_parameter_incomplete(parameter);
4581
4582                 /* we need the default promoted types for the function type */
4583                 type_t *not_promoted = parameter_type;
4584                 parameter_type       = get_default_promoted_type(parameter_type);
4585
4586                 /* gcc special: if the type of the prototype matches the unpromoted
4587                  * type don't promote */
4588                 if (!strict_mode && proto_parameter != NULL) {
4589                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4590                         type_t *promo_skip   = skip_typeref(parameter_type);
4591                         type_t *param_skip   = skip_typeref(not_promoted);
4592                         if (!types_compatible(proto_p_type, promo_skip)
4593                                 && types_compatible(proto_p_type, param_skip)) {
4594                                 /* don't promote */
4595                                 need_incompatible_warning = true;
4596                                 parameter_type = not_promoted;
4597                         }
4598                 }
4599                 function_parameter_t *const function_parameter
4600                         = allocate_parameter(parameter_type);
4601
4602                 *anchor = function_parameter;
4603                 anchor  = &function_parameter->next;
4604         }
4605
4606         new_type->function.parameters = parameters;
4607         new_type = identify_new_type(new_type);
4608
4609         if (need_incompatible_warning) {
4610                 symbol_t          const *const sym  = entity->base.symbol;
4611                 source_position_t const *const pos  = &entity->base.source_position;
4612                 source_position_t const *const ppos = &proto_type->base.source_position;
4613                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4614         }
4615         entity->declaration.type = new_type;
4616
4617         rem_anchor_token('{');
4618 }
4619
4620 static bool first_err = true;
4621
4622 /**
4623  * When called with first_err set, prints the name of the current function,
4624  * else does noting.
4625  */
4626 static void print_in_function(void)
4627 {
4628         if (first_err) {
4629                 first_err = false;
4630                 char const *const file = current_function->base.base.source_position.input_name;
4631                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4632         }
4633 }
4634
4635 /**
4636  * Check if all labels are defined in the current function.
4637  * Check if all labels are used in the current function.
4638  */
4639 static void check_labels(void)
4640 {
4641         for (const goto_statement_t *goto_statement = goto_first;
4642             goto_statement != NULL;
4643             goto_statement = goto_statement->next) {
4644                 /* skip computed gotos */
4645                 if (goto_statement->expression != NULL)
4646                         continue;
4647
4648                 label_t *label = goto_statement->label;
4649                 if (label->base.source_position.input_name == NULL) {
4650                         print_in_function();
4651                         source_position_t const *const pos = &goto_statement->base.source_position;
4652                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4653                  }
4654         }
4655
4656         if (is_warn_on(WARN_UNUSED_LABEL)) {
4657                 for (const label_statement_t *label_statement = label_first;
4658                          label_statement != NULL;
4659                          label_statement = label_statement->next) {
4660                         label_t *label = label_statement->label;
4661
4662                         if (! label->used) {
4663                                 print_in_function();
4664                                 source_position_t const *const pos = &label_statement->base.source_position;
4665                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4666                         }
4667                 }
4668         }
4669 }
4670
4671 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4672 {
4673         entity_t const *const end = last != NULL ? last->base.next : NULL;
4674         for (; entity != end; entity = entity->base.next) {
4675                 if (!is_declaration(entity))
4676                         continue;
4677
4678                 declaration_t *declaration = &entity->declaration;
4679                 if (declaration->implicit)
4680                         continue;
4681
4682                 if (!declaration->used) {
4683                         print_in_function();
4684                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4685                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4686                         print_in_function();
4687                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4688                 }
4689         }
4690 }
4691
4692 static void check_unused_variables(statement_t *const stmt, void *const env)
4693 {
4694         (void)env;
4695
4696         switch (stmt->kind) {
4697                 case STATEMENT_DECLARATION: {
4698                         declaration_statement_t const *const decls = &stmt->declaration;
4699                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4700                         return;
4701                 }
4702
4703                 case STATEMENT_FOR:
4704                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4705                         return;
4706
4707                 default:
4708                         return;
4709         }
4710 }
4711
4712 /**
4713  * Check declarations of current_function for unused entities.
4714  */
4715 static void check_declarations(void)
4716 {
4717         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4718                 const scope_t *scope = &current_function->parameters;
4719
4720                 /* do not issue unused warnings for main */
4721                 if (!is_sym_main(current_function->base.base.symbol)) {
4722                         warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4723                 }
4724         }
4725         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4726                 walk_statements(current_function->statement, check_unused_variables,
4727                                 NULL);
4728         }
4729 }
4730
4731 static int determine_truth(expression_t const* const cond)
4732 {
4733         return
4734                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4735                 fold_constant_to_bool(cond)                         ? 1 :
4736                 -1;
4737 }
4738
4739 static void check_reachable(statement_t *);
4740 static bool reaches_end;
4741
4742 static bool expression_returns(expression_t const *const expr)
4743 {
4744         switch (expr->kind) {
4745                 case EXPR_CALL: {
4746                         expression_t const *const func = expr->call.function;
4747                         if (func->kind == EXPR_REFERENCE) {
4748                                 entity_t *entity = func->reference.entity;
4749                                 if (entity->kind == ENTITY_FUNCTION
4750                                                 && entity->declaration.modifiers & DM_NORETURN)
4751                                         return false;
4752                         }
4753
4754                         if (!expression_returns(func))
4755                                 return false;
4756
4757                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4758                                 if (!expression_returns(arg->expression))
4759                                         return false;
4760                         }
4761
4762                         return true;
4763                 }
4764
4765                 case EXPR_REFERENCE:
4766                 case EXPR_REFERENCE_ENUM_VALUE:
4767                 EXPR_LITERAL_CASES
4768                 case EXPR_STRING_LITERAL:
4769                 case EXPR_WIDE_STRING_LITERAL:
4770                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4771                 case EXPR_LABEL_ADDRESS:
4772                 case EXPR_CLASSIFY_TYPE:
4773                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4774                 case EXPR_ALIGNOF:
4775                 case EXPR_FUNCNAME:
4776                 case EXPR_BUILTIN_CONSTANT_P:
4777                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4778                 case EXPR_OFFSETOF:
4779                 case EXPR_ERROR:
4780                         return true;
4781
4782                 case EXPR_STATEMENT: {
4783                         bool old_reaches_end = reaches_end;
4784                         reaches_end = false;
4785                         check_reachable(expr->statement.statement);
4786                         bool returns = reaches_end;
4787                         reaches_end = old_reaches_end;
4788                         return returns;
4789                 }
4790
4791                 case EXPR_CONDITIONAL:
4792                         // TODO handle constant expression
4793
4794                         if (!expression_returns(expr->conditional.condition))
4795                                 return false;
4796
4797                         if (expr->conditional.true_expression != NULL
4798                                         && expression_returns(expr->conditional.true_expression))
4799                                 return true;
4800
4801                         return expression_returns(expr->conditional.false_expression);
4802
4803                 case EXPR_SELECT:
4804                         return expression_returns(expr->select.compound);
4805
4806                 case EXPR_ARRAY_ACCESS:
4807                         return
4808                                 expression_returns(expr->array_access.array_ref) &&
4809                                 expression_returns(expr->array_access.index);
4810
4811                 case EXPR_VA_START:
4812                         return expression_returns(expr->va_starte.ap);
4813
4814                 case EXPR_VA_ARG:
4815                         return expression_returns(expr->va_arge.ap);
4816
4817                 case EXPR_VA_COPY:
4818                         return expression_returns(expr->va_copye.src);
4819
4820                 EXPR_UNARY_CASES_MANDATORY
4821                         return expression_returns(expr->unary.value);
4822
4823                 case EXPR_UNARY_THROW:
4824                         return false;
4825
4826                 EXPR_BINARY_CASES
4827                         // TODO handle constant lhs of && and ||
4828                         return
4829                                 expression_returns(expr->binary.left) &&
4830                                 expression_returns(expr->binary.right);
4831         }
4832
4833         panic("unhandled expression");
4834 }
4835
4836 static bool initializer_returns(initializer_t const *const init)
4837 {
4838         switch (init->kind) {
4839                 case INITIALIZER_VALUE:
4840                         return expression_returns(init->value.value);
4841
4842                 case INITIALIZER_LIST: {
4843                         initializer_t * const*       i       = init->list.initializers;
4844                         initializer_t * const* const end     = i + init->list.len;
4845                         bool                         returns = true;
4846                         for (; i != end; ++i) {
4847                                 if (!initializer_returns(*i))
4848                                         returns = false;
4849                         }
4850                         return returns;
4851                 }
4852
4853                 case INITIALIZER_STRING:
4854                 case INITIALIZER_WIDE_STRING:
4855                 case INITIALIZER_DESIGNATOR: // designators have no payload
4856                         return true;
4857         }
4858         panic("unhandled initializer");
4859 }
4860
4861 static bool noreturn_candidate;
4862
4863 static void check_reachable(statement_t *const stmt)
4864 {
4865         if (stmt->base.reachable)
4866                 return;
4867         if (stmt->kind != STATEMENT_DO_WHILE)
4868                 stmt->base.reachable = true;
4869
4870         statement_t *last = stmt;
4871         statement_t *next;
4872         switch (stmt->kind) {
4873                 case STATEMENT_ERROR:
4874                 case STATEMENT_EMPTY:
4875                 case STATEMENT_ASM:
4876                         next = stmt->base.next;
4877                         break;
4878
4879                 case STATEMENT_DECLARATION: {
4880                         declaration_statement_t const *const decl = &stmt->declaration;
4881                         entity_t                const *      ent  = decl->declarations_begin;
4882                         entity_t                const *const last_decl = decl->declarations_end;
4883                         if (ent != NULL) {
4884                                 for (;; ent = ent->base.next) {
4885                                         if (ent->kind                 == ENTITY_VARIABLE &&
4886                                             ent->variable.initializer != NULL            &&
4887                                             !initializer_returns(ent->variable.initializer)) {
4888                                                 return;
4889                                         }
4890                                         if (ent == last_decl)
4891                                                 break;
4892                                 }
4893                         }
4894                         next = stmt->base.next;
4895                         break;
4896                 }
4897
4898                 case STATEMENT_COMPOUND:
4899                         next = stmt->compound.statements;
4900                         if (next == NULL)
4901                                 next = stmt->base.next;
4902                         break;
4903
4904                 case STATEMENT_RETURN: {
4905                         expression_t const *const val = stmt->returns.value;
4906                         if (val == NULL || expression_returns(val))
4907                                 noreturn_candidate = false;
4908                         return;
4909                 }
4910
4911                 case STATEMENT_IF: {
4912                         if_statement_t const *const ifs  = &stmt->ifs;
4913                         expression_t   const *const cond = ifs->condition;
4914
4915                         if (!expression_returns(cond))
4916                                 return;
4917
4918                         int const val = determine_truth(cond);
4919
4920                         if (val >= 0)
4921                                 check_reachable(ifs->true_statement);
4922
4923                         if (val > 0)
4924                                 return;
4925
4926                         if (ifs->false_statement != NULL) {
4927                                 check_reachable(ifs->false_statement);
4928                                 return;
4929                         }
4930
4931                         next = stmt->base.next;
4932                         break;
4933                 }
4934
4935                 case STATEMENT_SWITCH: {
4936                         switch_statement_t const *const switchs = &stmt->switchs;
4937                         expression_t       const *const expr    = switchs->expression;
4938
4939                         if (!expression_returns(expr))
4940                                 return;
4941
4942                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4943                                 long                    const val      = fold_constant_to_int(expr);
4944                                 case_label_statement_t *      defaults = NULL;
4945                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4946                                         if (i->expression == NULL) {
4947                                                 defaults = i;
4948                                                 continue;
4949                                         }
4950
4951                                         if (i->first_case <= val && val <= i->last_case) {
4952                                                 check_reachable((statement_t*)i);
4953                                                 return;
4954                                         }
4955                                 }
4956
4957                                 if (defaults != NULL) {
4958                                         check_reachable((statement_t*)defaults);
4959                                         return;
4960                                 }
4961                         } else {
4962                                 bool has_default = false;
4963                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4964                                         if (i->expression == NULL)
4965                                                 has_default = true;
4966
4967                                         check_reachable((statement_t*)i);
4968                                 }
4969
4970                                 if (has_default)
4971                                         return;
4972                         }
4973
4974                         next = stmt->base.next;
4975                         break;
4976                 }
4977
4978                 case STATEMENT_EXPRESSION: {
4979                         /* Check for noreturn function call */
4980                         expression_t const *const expr = stmt->expression.expression;
4981                         if (!expression_returns(expr))
4982                                 return;
4983
4984                         next = stmt->base.next;
4985                         break;
4986                 }
4987
4988                 case STATEMENT_CONTINUE:
4989                         for (statement_t *parent = stmt;;) {
4990                                 parent = parent->base.parent;
4991                                 if (parent == NULL) /* continue not within loop */
4992                                         return;
4993
4994                                 next = parent;
4995                                 switch (parent->kind) {
4996                                         case STATEMENT_WHILE:    goto continue_while;
4997                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4998                                         case STATEMENT_FOR:      goto continue_for;
4999
5000                                         default: break;
5001                                 }
5002                         }
5003
5004                 case STATEMENT_BREAK:
5005                         for (statement_t *parent = stmt;;) {
5006                                 parent = parent->base.parent;
5007                                 if (parent == NULL) /* break not within loop/switch */
5008                                         return;
5009
5010                                 switch (parent->kind) {
5011                                         case STATEMENT_SWITCH:
5012                                         case STATEMENT_WHILE:
5013                                         case STATEMENT_DO_WHILE:
5014                                         case STATEMENT_FOR:
5015                                                 last = parent;
5016                                                 next = parent->base.next;
5017                                                 goto found_break_parent;
5018
5019                                         default: break;
5020                                 }
5021                         }
5022 found_break_parent:
5023                         break;
5024
5025                 case STATEMENT_GOTO:
5026                         if (stmt->gotos.expression) {
5027                                 if (!expression_returns(stmt->gotos.expression))
5028                                         return;
5029
5030                                 statement_t *parent = stmt->base.parent;
5031                                 if (parent == NULL) /* top level goto */
5032                                         return;
5033                                 next = parent;
5034                         } else {
5035                                 next = stmt->gotos.label->statement;
5036                                 if (next == NULL) /* missing label */
5037                                         return;
5038                         }
5039                         break;
5040
5041                 case STATEMENT_LABEL:
5042                         next = stmt->label.statement;
5043                         break;
5044
5045                 case STATEMENT_CASE_LABEL:
5046                         next = stmt->case_label.statement;
5047                         break;
5048
5049                 case STATEMENT_WHILE: {
5050                         while_statement_t const *const whiles = &stmt->whiles;
5051                         expression_t      const *const cond   = whiles->condition;
5052
5053                         if (!expression_returns(cond))
5054                                 return;
5055
5056                         int const val = determine_truth(cond);
5057
5058                         if (val >= 0)
5059                                 check_reachable(whiles->body);
5060
5061                         if (val > 0)
5062                                 return;
5063
5064                         next = stmt->base.next;
5065                         break;
5066                 }
5067
5068                 case STATEMENT_DO_WHILE:
5069                         next = stmt->do_while.body;
5070                         break;
5071
5072                 case STATEMENT_FOR: {
5073                         for_statement_t *const fors = &stmt->fors;
5074
5075                         if (fors->condition_reachable)
5076                                 return;
5077                         fors->condition_reachable = true;
5078
5079                         expression_t const *const cond = fors->condition;
5080
5081                         int val;
5082                         if (cond == NULL) {
5083                                 val = 1;
5084                         } else if (expression_returns(cond)) {
5085                                 val = determine_truth(cond);
5086                         } else {
5087                                 return;
5088                         }
5089
5090                         if (val >= 0)
5091                                 check_reachable(fors->body);
5092
5093                         if (val > 0)
5094                                 return;
5095
5096                         next = stmt->base.next;
5097                         break;
5098                 }
5099
5100                 case STATEMENT_MS_TRY: {
5101                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5102                         check_reachable(ms_try->try_statement);
5103                         next = ms_try->final_statement;
5104                         break;
5105                 }
5106
5107                 case STATEMENT_LEAVE: {
5108                         statement_t *parent = stmt;
5109                         for (;;) {
5110                                 parent = parent->base.parent;
5111                                 if (parent == NULL) /* __leave not within __try */
5112                                         return;
5113
5114                                 if (parent->kind == STATEMENT_MS_TRY) {
5115                                         last = parent;
5116                                         next = parent->ms_try.final_statement;
5117                                         break;
5118                                 }
5119                         }
5120                         break;
5121                 }
5122
5123                 default:
5124                         panic("invalid statement kind");
5125         }
5126
5127         while (next == NULL) {
5128                 next = last->base.parent;
5129                 if (next == NULL) {
5130                         noreturn_candidate = false;
5131
5132                         type_t *const type = skip_typeref(current_function->base.type);
5133                         assert(is_type_function(type));
5134                         type_t *const ret  = skip_typeref(type->function.return_type);
5135                         if (!is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5136                             is_type_valid(ret)                     &&
5137                             !is_sym_main(current_function->base.base.symbol)) {
5138                                 source_position_t const *const pos = &stmt->base.source_position;
5139                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5140                         }
5141                         return;
5142                 }
5143
5144                 switch (next->kind) {
5145                         case STATEMENT_ERROR:
5146                         case STATEMENT_EMPTY:
5147                         case STATEMENT_DECLARATION:
5148                         case STATEMENT_EXPRESSION:
5149                         case STATEMENT_ASM:
5150                         case STATEMENT_RETURN:
5151                         case STATEMENT_CONTINUE:
5152                         case STATEMENT_BREAK:
5153                         case STATEMENT_GOTO:
5154                         case STATEMENT_LEAVE:
5155                                 panic("invalid control flow in function");
5156
5157                         case STATEMENT_COMPOUND:
5158                                 if (next->compound.stmt_expr) {
5159                                         reaches_end = true;
5160                                         return;
5161                                 }
5162                                 /* FALLTHROUGH */
5163                         case STATEMENT_IF:
5164                         case STATEMENT_SWITCH:
5165                         case STATEMENT_LABEL:
5166                         case STATEMENT_CASE_LABEL:
5167                                 last = next;
5168                                 next = next->base.next;
5169                                 break;
5170
5171                         case STATEMENT_WHILE: {
5172 continue_while:
5173                                 if (next->base.reachable)
5174                                         return;
5175                                 next->base.reachable = true;
5176
5177                                 while_statement_t const *const whiles = &next->whiles;
5178                                 expression_t      const *const cond   = whiles->condition;
5179
5180                                 if (!expression_returns(cond))
5181                                         return;
5182
5183                                 int const val = determine_truth(cond);
5184
5185                                 if (val >= 0)
5186                                         check_reachable(whiles->body);
5187
5188                                 if (val > 0)
5189                                         return;
5190
5191                                 last = next;
5192                                 next = next->base.next;
5193                                 break;
5194                         }
5195
5196                         case STATEMENT_DO_WHILE: {
5197 continue_do_while:
5198                                 if (next->base.reachable)
5199                                         return;
5200                                 next->base.reachable = true;
5201
5202                                 do_while_statement_t const *const dw   = &next->do_while;
5203                                 expression_t         const *const cond = dw->condition;
5204
5205                                 if (!expression_returns(cond))
5206                                         return;
5207
5208                                 int const val = determine_truth(cond);
5209
5210                                 if (val >= 0)
5211                                         check_reachable(dw->body);
5212
5213                                 if (val > 0)
5214                                         return;
5215
5216                                 last = next;
5217                                 next = next->base.next;
5218                                 break;
5219                         }
5220
5221                         case STATEMENT_FOR: {
5222 continue_for:;
5223                                 for_statement_t *const fors = &next->fors;
5224
5225                                 fors->step_reachable = true;
5226
5227                                 if (fors->condition_reachable)
5228                                         return;
5229                                 fors->condition_reachable = true;
5230
5231                                 expression_t const *const cond = fors->condition;
5232
5233                                 int val;
5234                                 if (cond == NULL) {
5235                                         val = 1;
5236                                 } else if (expression_returns(cond)) {
5237                                         val = determine_truth(cond);
5238                                 } else {
5239                                         return;
5240                                 }
5241
5242                                 if (val >= 0)
5243                                         check_reachable(fors->body);
5244
5245                                 if (val > 0)
5246                                         return;
5247
5248                                 last = next;
5249                                 next = next->base.next;
5250                                 break;
5251                         }
5252
5253                         case STATEMENT_MS_TRY:
5254                                 last = next;
5255                                 next = next->ms_try.final_statement;
5256                                 break;
5257                 }
5258         }
5259
5260         check_reachable(next);
5261 }
5262
5263 static void check_unreachable(statement_t* const stmt, void *const env)
5264 {
5265         (void)env;
5266
5267         switch (stmt->kind) {
5268                 case STATEMENT_DO_WHILE:
5269                         if (!stmt->base.reachable) {
5270                                 expression_t const *const cond = stmt->do_while.condition;
5271                                 if (determine_truth(cond) >= 0) {
5272                                         source_position_t const *const pos = &cond->base.source_position;
5273                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5274                                 }
5275                         }
5276                         return;
5277
5278                 case STATEMENT_FOR: {
5279                         for_statement_t const* const fors = &stmt->fors;
5280
5281                         // if init and step are unreachable, cond is unreachable, too
5282                         if (!stmt->base.reachable && !fors->step_reachable) {
5283                                 goto warn_unreachable;
5284                         } else {
5285                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5286                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5287                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5288                                 }
5289
5290                                 if (!fors->condition_reachable && fors->condition != NULL) {
5291                                         source_position_t const *const pos = &fors->condition->base.source_position;
5292                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5293                                 }
5294
5295                                 if (!fors->step_reachable && fors->step != NULL) {
5296                                         source_position_t const *const pos = &fors->step->base.source_position;
5297                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5298                                 }
5299                         }
5300                         return;
5301                 }
5302
5303                 case STATEMENT_COMPOUND:
5304                         if (stmt->compound.statements != NULL)
5305                                 return;
5306                         goto warn_unreachable;
5307
5308                 case STATEMENT_DECLARATION: {
5309                         /* Only warn if there is at least one declarator with an initializer.
5310                          * This typically occurs in switch statements. */
5311                         declaration_statement_t const *const decl = &stmt->declaration;
5312                         entity_t                const *      ent  = decl->declarations_begin;
5313                         entity_t                const *const last = decl->declarations_end;
5314                         if (ent != NULL) {
5315                                 for (;; ent = ent->base.next) {
5316                                         if (ent->kind                 == ENTITY_VARIABLE &&
5317                                                         ent->variable.initializer != NULL) {
5318                                                 goto warn_unreachable;
5319                                         }
5320                                         if (ent == last)
5321                                                 return;
5322                                 }
5323                         }
5324                 }
5325
5326                 default:
5327 warn_unreachable:
5328                         if (!stmt->base.reachable) {
5329                                 source_position_t const *const pos = &stmt->base.source_position;
5330                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5331                         }
5332                         return;
5333         }
5334 }
5335
5336 static void parse_external_declaration(void)
5337 {
5338         /* function-definitions and declarations both start with declaration
5339          * specifiers */
5340         add_anchor_token(';');
5341         declaration_specifiers_t specifiers;
5342         parse_declaration_specifiers(&specifiers);
5343         rem_anchor_token(';');
5344
5345         /* must be a declaration */
5346         if (token.kind == ';') {
5347                 parse_anonymous_declaration_rest(&specifiers);
5348                 return;
5349         }
5350
5351         add_anchor_token(',');
5352         add_anchor_token('=');
5353         add_anchor_token(';');
5354         add_anchor_token('{');
5355
5356         /* declarator is common to both function-definitions and declarations */
5357         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5358
5359         rem_anchor_token('{');
5360         rem_anchor_token(';');
5361         rem_anchor_token('=');
5362         rem_anchor_token(',');
5363
5364         /* must be a declaration */
5365         switch (token.kind) {
5366                 case ',':
5367                 case ';':
5368                 case '=':
5369                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5370                                         DECL_FLAGS_NONE);
5371                         return;
5372         }
5373
5374         /* must be a function definition */
5375         parse_kr_declaration_list(ndeclaration);
5376
5377         if (token.kind != '{') {
5378                 parse_error_expected("while parsing function definition", '{', NULL);
5379                 eat_until_matching_token(';');
5380                 return;
5381         }
5382
5383         assert(is_declaration(ndeclaration));
5384         type_t *const orig_type = ndeclaration->declaration.type;
5385         type_t *      type      = skip_typeref(orig_type);
5386
5387         if (!is_type_function(type)) {
5388                 if (is_type_valid(type)) {
5389                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5390                 }
5391                 eat_block();
5392                 return;
5393         }
5394
5395         source_position_t const *const pos = &ndeclaration->base.source_position;
5396         if (is_typeref(orig_type)) {
5397                 /* §6.9.1:2 */
5398                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5399         }
5400
5401         if (is_type_compound(skip_typeref(type->function.return_type))) {
5402                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5403         }
5404         if (type->function.unspecified_parameters) {
5405                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5406         } else {
5407                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5408         }
5409
5410         /* §6.7.5.3:14 a function definition with () means no
5411          * parameters (and not unspecified parameters) */
5412         if (type->function.unspecified_parameters &&
5413                         type->function.parameters == NULL) {
5414                 type_t *copy                          = duplicate_type(type);
5415                 copy->function.unspecified_parameters = false;
5416                 type                                  = identify_new_type(copy);
5417
5418                 ndeclaration->declaration.type = type;
5419         }
5420
5421         entity_t *const entity = record_entity(ndeclaration, true);
5422         assert(entity->kind == ENTITY_FUNCTION);
5423         assert(ndeclaration->kind == ENTITY_FUNCTION);
5424
5425         function_t *const function = &entity->function;
5426         if (ndeclaration != entity) {
5427                 function->parameters = ndeclaration->function.parameters;
5428         }
5429         assert(is_declaration(entity));
5430         type = skip_typeref(entity->declaration.type);
5431
5432         PUSH_SCOPE(&function->parameters);
5433
5434         entity_t *parameter = function->parameters.entities;
5435         for (; parameter != NULL; parameter = parameter->base.next) {
5436                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5437                         parameter->base.parent_scope = current_scope;
5438                 }
5439                 assert(parameter->base.parent_scope == NULL
5440                                 || parameter->base.parent_scope == current_scope);
5441                 parameter->base.parent_scope = current_scope;
5442                 if (parameter->base.symbol == NULL) {
5443                         errorf(&parameter->base.source_position, "parameter name omitted");
5444                         continue;
5445                 }
5446                 environment_push(parameter);
5447         }
5448
5449         if (function->statement != NULL) {
5450                 parser_error_multiple_definition(entity, HERE);
5451                 eat_block();
5452         } else {
5453                 /* parse function body */
5454                 int         label_stack_top      = label_top();
5455                 function_t *old_current_function = current_function;
5456                 entity_t   *old_current_entity   = current_entity;
5457                 current_function                 = function;
5458                 current_entity                   = entity;
5459                 PUSH_PARENT(NULL);
5460
5461                 goto_first   = NULL;
5462                 goto_anchor  = &goto_first;
5463                 label_first  = NULL;
5464                 label_anchor = &label_first;
5465
5466                 statement_t *const body = parse_compound_statement(false);
5467                 function->statement = body;
5468                 first_err = true;
5469                 check_labels();
5470                 check_declarations();
5471                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5472                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5473                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5474                         noreturn_candidate = true;
5475                         check_reachable(body);
5476                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5477                                 walk_statements(body, check_unreachable, NULL);
5478                         if (noreturn_candidate &&
5479                             !(function->base.modifiers & DM_NORETURN)) {
5480                                 source_position_t const *const pos = &body->base.source_position;
5481                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5482                         }
5483                 }
5484
5485                 POP_PARENT();
5486                 assert(current_function == function);
5487                 assert(current_entity   == entity);
5488                 current_entity   = old_current_entity;
5489                 current_function = old_current_function;
5490                 label_pop_to(label_stack_top);
5491         }
5492
5493         POP_SCOPE();
5494 }
5495
5496 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5497 {
5498         entity_t *iter = compound->members.entities;
5499         for (; iter != NULL; iter = iter->base.next) {
5500                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5501                         continue;
5502
5503                 if (iter->base.symbol == symbol) {
5504                         return iter;
5505                 } else if (iter->base.symbol == NULL) {
5506                         /* search in anonymous structs and unions */
5507                         type_t *type = skip_typeref(iter->declaration.type);
5508                         if (is_type_compound(type)) {
5509                                 if (find_compound_entry(type->compound.compound, symbol)
5510                                                 != NULL)
5511                                         return iter;
5512                         }
5513                         continue;
5514                 }
5515         }
5516
5517         return NULL;
5518 }
5519
5520 static void check_deprecated(const source_position_t *source_position,
5521                              const entity_t *entity)
5522 {
5523         if (!is_declaration(entity))
5524                 return;
5525         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5526                 return;
5527
5528         source_position_t const *const epos = &entity->base.source_position;
5529         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5530         if (msg != NULL) {
5531                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5532         } else {
5533                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5534         }
5535 }
5536
5537
5538 static expression_t *create_select(const source_position_t *pos,
5539                                    expression_t *addr,
5540                                    type_qualifiers_t qualifiers,
5541                                                                    entity_t *entry)
5542 {
5543         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5544
5545         check_deprecated(pos, entry);
5546
5547         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5548         select->select.compound       = addr;
5549         select->select.compound_entry = entry;
5550
5551         type_t *entry_type = entry->declaration.type;
5552         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5553
5554         /* bitfields need special treatment */
5555         if (entry->compound_member.bitfield) {
5556                 unsigned bit_size = entry->compound_member.bit_size;
5557                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5558                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5559                         res_type = type_int;
5560                 }
5561         }
5562
5563         /* we always do the auto-type conversions; the & and sizeof parser contains
5564          * code to revert this! */
5565         select->base.type = automatic_type_conversion(res_type);
5566
5567
5568         return select;
5569 }
5570
5571 /**
5572  * Find entry with symbol in compound. Search anonymous structs and unions and
5573  * creates implicit select expressions for them.
5574  * Returns the adress for the innermost compound.
5575  */
5576 static expression_t *find_create_select(const source_position_t *pos,
5577                                         expression_t *addr,
5578                                         type_qualifiers_t qualifiers,
5579                                         compound_t *compound, symbol_t *symbol)
5580 {
5581         entity_t *iter = compound->members.entities;
5582         for (; iter != NULL; iter = iter->base.next) {
5583                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5584                         continue;
5585
5586                 symbol_t *iter_symbol = iter->base.symbol;
5587                 if (iter_symbol == NULL) {
5588                         type_t *type = iter->declaration.type;
5589                         if (type->kind != TYPE_COMPOUND_STRUCT
5590                                         && type->kind != TYPE_COMPOUND_UNION)
5591                                 continue;
5592
5593                         compound_t *sub_compound = type->compound.compound;
5594
5595                         if (find_compound_entry(sub_compound, symbol) == NULL)
5596                                 continue;
5597
5598                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5599                         sub_addr->base.source_position = *pos;
5600                         sub_addr->base.implicit        = true;
5601                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5602                                                   symbol);
5603                 }
5604
5605                 if (iter_symbol == symbol) {
5606                         return create_select(pos, addr, qualifiers, iter);
5607                 }
5608         }
5609
5610         return NULL;
5611 }
5612
5613 static void parse_bitfield_member(entity_t *entity)
5614 {
5615         eat(':');
5616
5617         expression_t *size = parse_constant_expression();
5618         long          size_long;
5619
5620         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5621         type_t *type = entity->declaration.type;
5622         if (!is_type_integer(skip_typeref(type))) {
5623                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5624                            type);
5625         }
5626
5627         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5628                 /* error already reported by parse_constant_expression */
5629                 size_long = get_type_size(type) * 8;
5630         } else {
5631                 size_long = fold_constant_to_int(size);
5632
5633                 const symbol_t *symbol = entity->base.symbol;
5634                 const symbol_t *user_symbol
5635                         = symbol == NULL ? sym_anonymous : symbol;
5636                 unsigned bit_size = get_type_size(type) * 8;
5637                 if (size_long < 0) {
5638                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5639                 } else if (size_long == 0 && symbol != NULL) {
5640                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5641                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5642                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5643                                    user_symbol);
5644                 } else {
5645                         /* hope that people don't invent crazy types with more bits
5646                          * than our struct can hold */
5647                         assert(size_long <
5648                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5649                 }
5650         }
5651
5652         entity->compound_member.bitfield = true;
5653         entity->compound_member.bit_size = (unsigned char)size_long;
5654 }
5655
5656 static void parse_compound_declarators(compound_t *compound,
5657                 const declaration_specifiers_t *specifiers)
5658 {
5659         do {
5660                 entity_t *entity;
5661
5662                 if (token.kind == ':') {
5663                         /* anonymous bitfield */
5664                         type_t *type = specifiers->type;
5665                         entity_t *entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER,
5666                                                                 NAMESPACE_NORMAL, NULL);
5667                         entity->base.source_position               = *HERE;
5668                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5669                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5670                         entity->declaration.type                   = type;
5671
5672                         parse_bitfield_member(entity);
5673
5674                         attribute_t  *attributes = parse_attributes(NULL);
5675                         attribute_t **anchor     = &attributes;
5676                         while (*anchor != NULL)
5677                                 anchor = &(*anchor)->next;
5678                         *anchor = specifiers->attributes;
5679                         if (attributes != NULL) {
5680                                 handle_entity_attributes(attributes, entity);
5681                         }
5682                         entity->declaration.attributes = attributes;
5683
5684                         append_entity(&compound->members, entity);
5685                 } else {
5686                         entity = parse_declarator(specifiers,
5687                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5688                         source_position_t const *const pos = &entity->base.source_position;
5689                         if (entity->kind == ENTITY_TYPEDEF) {
5690                                 errorf(pos, "typedef not allowed as compound member");
5691                         } else {
5692                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5693
5694                                 /* make sure we don't define a symbol multiple times */
5695                                 symbol_t *symbol = entity->base.symbol;
5696                                 if (symbol != NULL) {
5697                                         entity_t *prev = find_compound_entry(compound, symbol);
5698                                         if (prev != NULL) {
5699                                                 source_position_t const *const ppos = &prev->base.source_position;
5700                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5701                                         }
5702                                 }
5703
5704                                 if (token.kind == ':') {
5705                                         parse_bitfield_member(entity);
5706
5707                                         attribute_t *attributes = parse_attributes(NULL);
5708                                         handle_entity_attributes(attributes, entity);
5709                                 } else {
5710                                         type_t *orig_type = entity->declaration.type;
5711                                         type_t *type      = skip_typeref(orig_type);
5712                                         if (is_type_function(type)) {
5713                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5714                                         } else if (is_type_incomplete(type)) {
5715                                                 /* §6.7.2.1:16 flexible array member */
5716                                                 if (!is_type_array(type)       ||
5717                                                                 token.kind          != ';' ||
5718                                                                 look_ahead(1)->kind != '}') {
5719                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5720                                                 }
5721                                         }
5722                                 }
5723
5724                                 append_entity(&compound->members, entity);
5725                         }
5726                 }
5727         } while (next_if(','));
5728         expect(';', end_error);
5729
5730 end_error:
5731         anonymous_entity = NULL;
5732 }
5733
5734 static void parse_compound_type_entries(compound_t *compound)
5735 {
5736         eat('{');
5737         add_anchor_token('}');
5738
5739         for (;;) {
5740                 switch (token.kind) {
5741                         DECLARATION_START
5742                         case T___extension__:
5743                         case T_IDENTIFIER: {
5744                                 PUSH_EXTENSION();
5745                                 declaration_specifiers_t specifiers;
5746                                 parse_declaration_specifiers(&specifiers);
5747                                 parse_compound_declarators(compound, &specifiers);
5748                                 POP_EXTENSION();
5749                                 break;
5750                         }
5751
5752                         default:
5753                                 rem_anchor_token('}');
5754                                 expect('}', end_error);
5755 end_error:
5756                                 /* §6.7.2.1:7 */
5757                                 compound->complete = true;
5758                                 return;
5759                 }
5760         }
5761 }
5762
5763 static type_t *parse_typename(void)
5764 {
5765         declaration_specifiers_t specifiers;
5766         parse_declaration_specifiers(&specifiers);
5767         if (specifiers.storage_class != STORAGE_CLASS_NONE
5768                         || specifiers.thread_local) {
5769                 /* TODO: improve error message, user does probably not know what a
5770                  * storage class is...
5771                  */
5772                 errorf(&specifiers.source_position, "typename must not have a storage class");
5773         }
5774
5775         type_t *result = parse_abstract_declarator(specifiers.type);
5776
5777         return result;
5778 }
5779
5780
5781
5782
5783 typedef expression_t* (*parse_expression_function)(void);
5784 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5785
5786 typedef struct expression_parser_function_t expression_parser_function_t;
5787 struct expression_parser_function_t {
5788         parse_expression_function        parser;
5789         precedence_t                     infix_precedence;
5790         parse_expression_infix_function  infix_parser;
5791 };
5792
5793 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5794
5795 /**
5796  * Prints an error message if an expression was expected but not read
5797  */
5798 static expression_t *expected_expression_error(void)
5799 {
5800         /* skip the error message if the error token was read */
5801         if (token.kind != T_ERROR) {
5802                 errorf(HERE, "expected expression, got token %K", &token);
5803         }
5804         next_token();
5805
5806         return create_error_expression();
5807 }
5808
5809 static type_t *get_string_type(void)
5810 {
5811         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5812 }
5813
5814 static type_t *get_wide_string_type(void)
5815 {
5816         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5817 }
5818
5819 /**
5820  * Parse a string constant.
5821  */
5822 static expression_t *parse_string_literal(void)
5823 {
5824         source_position_t begin   = token.base.source_position;
5825         string_t          res     = token.string.string;
5826         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5827
5828         next_token();
5829         while (token.kind == T_STRING_LITERAL
5830                         || token.kind == T_WIDE_STRING_LITERAL) {
5831                 warn_string_concat(&token.base.source_position);
5832                 res = concat_strings(&res, &token.string.string);
5833                 next_token();
5834                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5835         }
5836
5837         expression_t *literal;
5838         if (is_wide) {
5839                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5840                 literal->base.type = get_wide_string_type();
5841         } else {
5842                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5843                 literal->base.type = get_string_type();
5844         }
5845         literal->base.source_position = begin;
5846         literal->literal.value        = res;
5847
5848         return literal;
5849 }
5850
5851 /**
5852  * Parse a boolean constant.
5853  */
5854 static expression_t *parse_boolean_literal(bool value)
5855 {
5856         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5857         literal->base.type           = type_bool;
5858         literal->literal.value.begin = value ? "true" : "false";
5859         literal->literal.value.size  = value ? 4 : 5;
5860
5861         next_token();
5862         return literal;
5863 }
5864
5865 static void warn_traditional_suffix(void)
5866 {
5867         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5868                  &token.number.suffix);
5869 }
5870
5871 static void check_integer_suffix(void)
5872 {
5873         const string_t *suffix = &token.number.suffix;
5874         if (suffix->size == 0)
5875                 return;
5876
5877         bool not_traditional = false;
5878         const char *c = suffix->begin;
5879         if (*c == 'l' || *c == 'L') {
5880                 ++c;
5881                 if (*c == *(c-1)) {
5882                         not_traditional = true;
5883                         ++c;
5884                         if (*c == 'u' || *c == 'U') {
5885                                 ++c;
5886                         }
5887                 } else if (*c == 'u' || *c == 'U') {
5888                         not_traditional = true;
5889                         ++c;
5890                 }
5891         } else if (*c == 'u' || *c == 'U') {
5892                 not_traditional = true;
5893                 ++c;
5894                 if (*c == 'l' || *c == 'L') {
5895                         ++c;
5896                         if (*c == *(c-1)) {
5897                                 ++c;
5898                         }
5899                 }
5900         }
5901         if (*c != '\0') {
5902                 errorf(&token.base.source_position,
5903                        "invalid suffix '%S' on integer constant", suffix);
5904         } else if (not_traditional) {
5905                 warn_traditional_suffix();
5906         }
5907 }
5908
5909 static type_t *check_floatingpoint_suffix(void)
5910 {
5911         const string_t *suffix = &token.number.suffix;
5912         type_t         *type   = type_double;
5913         if (suffix->size == 0)
5914                 return type;
5915
5916         bool not_traditional = false;
5917         const char *c = suffix->begin;
5918         if (*c == 'f' || *c == 'F') {
5919                 ++c;
5920                 type = type_float;
5921         } else if (*c == 'l' || *c == 'L') {
5922                 ++c;
5923                 type = type_long_double;
5924         }
5925         if (*c != '\0') {
5926                 errorf(&token.base.source_position,
5927                        "invalid suffix '%S' on floatingpoint constant", suffix);
5928         } else if (not_traditional) {
5929                 warn_traditional_suffix();
5930         }
5931
5932         return type;
5933 }
5934
5935 /**
5936  * Parse an integer constant.
5937  */
5938 static expression_t *parse_number_literal(void)
5939 {
5940         expression_kind_t  kind;
5941         type_t            *type;
5942
5943         switch (token.kind) {
5944         case T_INTEGER:
5945                 kind = EXPR_LITERAL_INTEGER;
5946                 check_integer_suffix();
5947                 type = type_int;
5948                 break;
5949         case T_INTEGER_OCTAL:
5950                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5951                 check_integer_suffix();
5952                 type = type_int;
5953                 break;
5954         case T_INTEGER_HEXADECIMAL:
5955                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5956                 check_integer_suffix();
5957                 type = type_int;
5958                 break;
5959         case T_FLOATINGPOINT:
5960                 kind = EXPR_LITERAL_FLOATINGPOINT;
5961                 type = check_floatingpoint_suffix();
5962                 break;
5963         case T_FLOATINGPOINT_HEXADECIMAL:
5964                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5965                 type = check_floatingpoint_suffix();
5966                 break;
5967         default:
5968                 panic("unexpected token type in parse_number_literal");
5969         }
5970
5971         expression_t *literal = allocate_expression_zero(kind);
5972         literal->base.type      = type;
5973         literal->literal.value  = token.number.number;
5974         literal->literal.suffix = token.number.suffix;
5975         next_token();
5976
5977         /* integer type depends on the size of the number and the size
5978          * representable by the types. The backend/codegeneration has to determine
5979          * that
5980          */
5981         determine_literal_type(&literal->literal);
5982         return literal;
5983 }
5984
5985 /**
5986  * Parse a character constant.
5987  */
5988 static expression_t *parse_character_constant(void)
5989 {
5990         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5991         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5992         literal->literal.value = token.string.string;
5993
5994         size_t len = literal->literal.value.size;
5995         if (len > 1) {
5996                 if (!GNU_MODE && !(c_mode & _C99)) {
5997                         errorf(HERE, "more than 1 character in character constant");
5998                 } else {
5999                         literal->base.type = type_int;
6000                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
6001                 }
6002         }
6003
6004         next_token();
6005         return literal;
6006 }
6007
6008 /**
6009  * Parse a wide character constant.
6010  */
6011 static expression_t *parse_wide_character_constant(void)
6012 {
6013         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6014         literal->base.type     = type_int;
6015         literal->literal.value = token.string.string;
6016
6017         size_t len = wstrlen(&literal->literal.value);
6018         if (len > 1) {
6019                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
6020         }
6021
6022         next_token();
6023         return literal;
6024 }
6025
6026 static entity_t *create_implicit_function(symbol_t *symbol,
6027                 const source_position_t *source_position)
6028 {
6029         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6030         ntype->function.return_type            = type_int;
6031         ntype->function.unspecified_parameters = true;
6032         ntype->function.linkage                = LINKAGE_C;
6033         type_t *type                           = identify_new_type(ntype);
6034
6035         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6036         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6037         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6038         entity->declaration.type                   = type;
6039         entity->declaration.implicit               = true;
6040         entity->base.source_position               = *source_position;
6041
6042         if (current_scope != NULL)
6043                 record_entity(entity, false);
6044
6045         return entity;
6046 }
6047
6048 /**
6049  * Performs automatic type cast as described in §6.3.2.1.
6050  *
6051  * @param orig_type  the original type
6052  */
6053 static type_t *automatic_type_conversion(type_t *orig_type)
6054 {
6055         type_t *type = skip_typeref(orig_type);
6056         if (is_type_array(type)) {
6057                 array_type_t *array_type   = &type->array;
6058                 type_t       *element_type = array_type->element_type;
6059                 unsigned      qualifiers   = array_type->base.qualifiers;
6060
6061                 return make_pointer_type(element_type, qualifiers);
6062         }
6063
6064         if (is_type_function(type)) {
6065                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6066         }
6067
6068         return orig_type;
6069 }
6070
6071 /**
6072  * reverts the automatic casts of array to pointer types and function
6073  * to function-pointer types as defined §6.3.2.1
6074  */
6075 type_t *revert_automatic_type_conversion(const expression_t *expression)
6076 {
6077         switch (expression->kind) {
6078         case EXPR_REFERENCE: {
6079                 entity_t *entity = expression->reference.entity;
6080                 if (is_declaration(entity)) {
6081                         return entity->declaration.type;
6082                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6083                         return entity->enum_value.enum_type;
6084                 } else {
6085                         panic("no declaration or enum in reference");
6086                 }
6087         }
6088
6089         case EXPR_SELECT: {
6090                 entity_t *entity = expression->select.compound_entry;
6091                 assert(is_declaration(entity));
6092                 type_t   *type   = entity->declaration.type;
6093                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6094         }
6095
6096         case EXPR_UNARY_DEREFERENCE: {
6097                 const expression_t *const value = expression->unary.value;
6098                 type_t             *const type  = skip_typeref(value->base.type);
6099                 if (!is_type_pointer(type))
6100                         return type_error_type;
6101                 return type->pointer.points_to;
6102         }
6103
6104         case EXPR_ARRAY_ACCESS: {
6105                 const expression_t *array_ref = expression->array_access.array_ref;
6106                 type_t             *type_left = skip_typeref(array_ref->base.type);
6107                 if (!is_type_pointer(type_left))
6108                         return type_error_type;
6109                 return type_left->pointer.points_to;
6110         }
6111
6112         case EXPR_STRING_LITERAL: {
6113                 size_t size = expression->string_literal.value.size;
6114                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6115         }
6116
6117         case EXPR_WIDE_STRING_LITERAL: {
6118                 size_t size = wstrlen(&expression->string_literal.value);
6119                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6120         }
6121
6122         case EXPR_COMPOUND_LITERAL:
6123                 return expression->compound_literal.type;
6124
6125         default:
6126                 break;
6127         }
6128         return expression->base.type;
6129 }
6130
6131 /**
6132  * Find an entity matching a symbol in a scope.
6133  * Uses current scope if scope is NULL
6134  */
6135 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6136                                namespace_tag_t namespc)
6137 {
6138         if (scope == NULL) {
6139                 return get_entity(symbol, namespc);
6140         }
6141
6142         /* we should optimize here, if scope grows above a certain size we should
6143            construct a hashmap here... */
6144         entity_t *entity = scope->entities;
6145         for ( ; entity != NULL; entity = entity->base.next) {
6146                 if (entity->base.symbol == symbol
6147                     && (namespace_tag_t)entity->base.namespc == namespc)
6148                         break;
6149         }
6150
6151         return entity;
6152 }
6153
6154 static entity_t *parse_qualified_identifier(void)
6155 {
6156         /* namespace containing the symbol */
6157         symbol_t          *symbol;
6158         source_position_t  pos;
6159         const scope_t     *lookup_scope = NULL;
6160
6161         if (next_if(T_COLONCOLON))
6162                 lookup_scope = &unit->scope;
6163
6164         entity_t *entity;
6165         while (true) {
6166                 if (token.kind != T_IDENTIFIER) {
6167                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6168                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6169                 }
6170                 symbol = token.identifier.symbol;
6171                 pos    = *HERE;
6172                 next_token();
6173
6174                 /* lookup entity */
6175                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6176
6177                 if (!next_if(T_COLONCOLON))
6178                         break;
6179
6180                 switch (entity->kind) {
6181                 case ENTITY_NAMESPACE:
6182                         lookup_scope = &entity->namespacee.members;
6183                         break;
6184                 case ENTITY_STRUCT:
6185                 case ENTITY_UNION:
6186                 case ENTITY_CLASS:
6187                         lookup_scope = &entity->compound.members;
6188                         break;
6189                 default:
6190                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6191                                symbol, get_entity_kind_name(entity->kind));
6192
6193                         /* skip further qualifications */
6194                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6195
6196                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6197                 }
6198         }
6199
6200         if (entity == NULL) {
6201                 if (!strict_mode && token.kind == '(') {
6202                         /* an implicitly declared function */
6203                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of function '%Y'", symbol);
6204                         entity = create_implicit_function(symbol, &pos);
6205                 } else {
6206                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6207                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6208                 }
6209         }
6210
6211         return entity;
6212 }
6213
6214 static expression_t *parse_reference(void)
6215 {
6216         source_position_t const pos    = token.base.source_position;
6217         entity_t         *const entity = parse_qualified_identifier();
6218
6219         type_t *orig_type;
6220         if (is_declaration(entity)) {
6221                 orig_type = entity->declaration.type;
6222         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6223                 orig_type = entity->enum_value.enum_type;
6224         } else {
6225                 panic("expected declaration or enum value in reference");
6226         }
6227
6228         /* we always do the auto-type conversions; the & and sizeof parser contains
6229          * code to revert this! */
6230         type_t *type = automatic_type_conversion(orig_type);
6231
6232         expression_kind_t kind = EXPR_REFERENCE;
6233         if (entity->kind == ENTITY_ENUM_VALUE)
6234                 kind = EXPR_REFERENCE_ENUM_VALUE;
6235
6236         expression_t *expression         = allocate_expression_zero(kind);
6237         expression->base.source_position = pos;
6238         expression->base.type            = type;
6239         expression->reference.entity     = entity;
6240
6241         /* this declaration is used */
6242         if (is_declaration(entity)) {
6243                 entity->declaration.used = true;
6244         }
6245
6246         if (entity->base.parent_scope != file_scope
6247                 && (current_function != NULL
6248                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6249                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6250                 if (entity->kind == ENTITY_VARIABLE) {
6251                         /* access of a variable from an outer function */
6252                         entity->variable.address_taken = true;
6253                 } else if (entity->kind == ENTITY_PARAMETER) {
6254                         entity->parameter.address_taken = true;
6255                 }
6256                 current_function->need_closure = true;
6257         }
6258
6259         check_deprecated(&pos, entity);
6260
6261         return expression;
6262 }
6263
6264 static bool semantic_cast(expression_t *cast)
6265 {
6266         expression_t            *expression      = cast->unary.value;
6267         type_t                  *orig_dest_type  = cast->base.type;
6268         type_t                  *orig_type_right = expression->base.type;
6269         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6270         type_t            const *src_type        = skip_typeref(orig_type_right);
6271         source_position_t const *pos             = &cast->base.source_position;
6272
6273         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6274         if (dst_type == type_void)
6275                 return true;
6276
6277         /* only integer and pointer can be casted to pointer */
6278         if (is_type_pointer(dst_type)  &&
6279             !is_type_pointer(src_type) &&
6280             !is_type_integer(src_type) &&
6281             is_type_valid(src_type)) {
6282                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6283                 return false;
6284         }
6285
6286         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6287                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6288                 return false;
6289         }
6290
6291         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6292                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6293                 return false;
6294         }
6295
6296         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6297                 type_t *src = skip_typeref(src_type->pointer.points_to);
6298                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6299                 unsigned missing_qualifiers =
6300                         src->base.qualifiers & ~dst->base.qualifiers;
6301                 if (missing_qualifiers != 0) {
6302                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6303                 }
6304         }
6305         return true;
6306 }
6307
6308 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6309 {
6310         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6311         expression->base.source_position = *pos;
6312
6313         parse_initializer_env_t env;
6314         env.type             = type;
6315         env.entity           = NULL;
6316         env.must_be_constant = false;
6317         initializer_t *initializer = parse_initializer(&env);
6318         type = env.type;
6319
6320         expression->compound_literal.initializer = initializer;
6321         expression->compound_literal.type        = type;
6322         expression->base.type                    = automatic_type_conversion(type);
6323
6324         return expression;
6325 }
6326
6327 /**
6328  * Parse a cast expression.
6329  */
6330 static expression_t *parse_cast(void)
6331 {
6332         source_position_t const pos = *HERE;
6333
6334         eat('(');
6335         add_anchor_token(')');
6336
6337         type_t *type = parse_typename();
6338
6339         rem_anchor_token(')');
6340         expect(')', end_error);
6341
6342         if (token.kind == '{') {
6343                 return parse_compound_literal(&pos, type);
6344         }
6345
6346         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6347         cast->base.source_position = pos;
6348
6349         expression_t *value = parse_subexpression(PREC_CAST);
6350         cast->base.type   = type;
6351         cast->unary.value = value;
6352
6353         if (! semantic_cast(cast)) {
6354                 /* TODO: record the error in the AST. else it is impossible to detect it */
6355         }
6356
6357         return cast;
6358 end_error:
6359         return create_error_expression();
6360 }
6361
6362 /**
6363  * Parse a statement expression.
6364  */
6365 static expression_t *parse_statement_expression(void)
6366 {
6367         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6368
6369         eat('(');
6370         add_anchor_token(')');
6371
6372         statement_t *statement          = parse_compound_statement(true);
6373         statement->compound.stmt_expr   = true;
6374         expression->statement.statement = statement;
6375
6376         /* find last statement and use its type */
6377         type_t *type = type_void;
6378         const statement_t *stmt = statement->compound.statements;
6379         if (stmt != NULL) {
6380                 while (stmt->base.next != NULL)
6381                         stmt = stmt->base.next;
6382
6383                 if (stmt->kind == STATEMENT_EXPRESSION) {
6384                         type = stmt->expression.expression->base.type;
6385                 }
6386         } else {
6387                 source_position_t const *const pos = &expression->base.source_position;
6388                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6389         }
6390         expression->base.type = type;
6391
6392         rem_anchor_token(')');
6393         expect(')', end_error);
6394
6395 end_error:
6396         return expression;
6397 }
6398
6399 /**
6400  * Parse a parenthesized expression.
6401  */
6402 static expression_t *parse_parenthesized_expression(void)
6403 {
6404         token_t const* const la1 = look_ahead(1);
6405         switch (la1->kind) {
6406         case '{':
6407                 /* gcc extension: a statement expression */
6408                 return parse_statement_expression();
6409
6410         case T_IDENTIFIER:
6411                 if (is_typedef_symbol(la1->identifier.symbol)) {
6412         DECLARATION_START
6413                         return parse_cast();
6414                 }
6415         }
6416
6417         eat('(');
6418         add_anchor_token(')');
6419         expression_t *result = parse_expression();
6420         result->base.parenthesized = true;
6421         rem_anchor_token(')');
6422         expect(')', end_error);
6423
6424 end_error:
6425         return result;
6426 }
6427
6428 static expression_t *parse_function_keyword(void)
6429 {
6430         /* TODO */
6431
6432         if (current_function == NULL) {
6433                 errorf(HERE, "'__func__' used outside of a function");
6434         }
6435
6436         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6437         expression->base.type     = type_char_ptr;
6438         expression->funcname.kind = FUNCNAME_FUNCTION;
6439
6440         next_token();
6441
6442         return expression;
6443 }
6444
6445 static expression_t *parse_pretty_function_keyword(void)
6446 {
6447         if (current_function == NULL) {
6448                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6449         }
6450
6451         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6452         expression->base.type     = type_char_ptr;
6453         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6454
6455         eat(T___PRETTY_FUNCTION__);
6456
6457         return expression;
6458 }
6459
6460 static expression_t *parse_funcsig_keyword(void)
6461 {
6462         if (current_function == NULL) {
6463                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6464         }
6465
6466         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6467         expression->base.type     = type_char_ptr;
6468         expression->funcname.kind = FUNCNAME_FUNCSIG;
6469
6470         eat(T___FUNCSIG__);
6471
6472         return expression;
6473 }
6474
6475 static expression_t *parse_funcdname_keyword(void)
6476 {
6477         if (current_function == NULL) {
6478                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6479         }
6480
6481         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6482         expression->base.type     = type_char_ptr;
6483         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6484
6485         eat(T___FUNCDNAME__);
6486
6487         return expression;
6488 }
6489
6490 static designator_t *parse_designator(void)
6491 {
6492         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6493         result->source_position = *HERE;
6494
6495         if (token.kind != T_IDENTIFIER) {
6496                 parse_error_expected("while parsing member designator",
6497                                      T_IDENTIFIER, NULL);
6498                 return NULL;
6499         }
6500         result->symbol = token.identifier.symbol;
6501         next_token();
6502
6503         designator_t *last_designator = result;
6504         while (true) {
6505                 if (next_if('.')) {
6506                         if (token.kind != T_IDENTIFIER) {
6507                                 parse_error_expected("while parsing member designator",
6508                                                      T_IDENTIFIER, NULL);
6509                                 return NULL;
6510                         }
6511                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6512                         designator->source_position = *HERE;
6513                         designator->symbol          = token.identifier.symbol;
6514                         next_token();
6515
6516                         last_designator->next = designator;
6517                         last_designator       = designator;
6518                         continue;
6519                 }
6520                 if (next_if('[')) {
6521                         add_anchor_token(']');
6522                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6523                         designator->source_position = *HERE;
6524                         designator->array_index     = parse_expression();
6525                         rem_anchor_token(']');
6526                         expect(']', end_error);
6527                         if (designator->array_index == NULL) {
6528                                 return NULL;
6529                         }
6530
6531                         last_designator->next = designator;
6532                         last_designator       = designator;
6533                         continue;
6534                 }
6535                 break;
6536         }
6537
6538         return result;
6539 end_error:
6540         return NULL;
6541 }
6542
6543 /**
6544  * Parse the __builtin_offsetof() expression.
6545  */
6546 static expression_t *parse_offsetof(void)
6547 {
6548         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6549         expression->base.type    = type_size_t;
6550
6551         eat(T___builtin_offsetof);
6552
6553         expect('(', end_error);
6554         add_anchor_token(',');
6555         type_t *type = parse_typename();
6556         rem_anchor_token(',');
6557         expect(',', end_error);
6558         add_anchor_token(')');
6559         designator_t *designator = parse_designator();
6560         rem_anchor_token(')');
6561         expect(')', end_error);
6562
6563         expression->offsetofe.type       = type;
6564         expression->offsetofe.designator = designator;
6565
6566         type_path_t path;
6567         memset(&path, 0, sizeof(path));
6568         path.top_type = type;
6569         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6570
6571         descend_into_subtype(&path);
6572
6573         if (!walk_designator(&path, designator, true)) {
6574                 return create_error_expression();
6575         }
6576
6577         DEL_ARR_F(path.path);
6578
6579         return expression;
6580 end_error:
6581         return create_error_expression();
6582 }
6583
6584 /**
6585  * Parses a _builtin_va_start() expression.
6586  */
6587 static expression_t *parse_va_start(void)
6588 {
6589         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6590
6591         eat(T___builtin_va_start);
6592
6593         expect('(', end_error);
6594         add_anchor_token(',');
6595         expression->va_starte.ap = parse_assignment_expression();
6596         rem_anchor_token(',');
6597         expect(',', end_error);
6598         expression_t *const expr = parse_assignment_expression();
6599         if (expr->kind == EXPR_REFERENCE) {
6600                 entity_t *const entity = expr->reference.entity;
6601                 if (!current_function->base.type->function.variadic) {
6602                         errorf(&expr->base.source_position,
6603                                         "'va_start' used in non-variadic function");
6604                 } else if (entity->base.parent_scope != &current_function->parameters ||
6605                                 entity->base.next != NULL ||
6606                                 entity->kind != ENTITY_PARAMETER) {
6607                         errorf(&expr->base.source_position,
6608                                "second argument of 'va_start' must be last parameter of the current function");
6609                 } else {
6610                         expression->va_starte.parameter = &entity->variable;
6611                 }
6612                 expect(')', end_error);
6613                 return expression;
6614         }
6615         expect(')', end_error);
6616 end_error:
6617         return create_error_expression();
6618 }
6619
6620 /**
6621  * Parses a __builtin_va_arg() expression.
6622  */
6623 static expression_t *parse_va_arg(void)
6624 {
6625         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6626
6627         eat(T___builtin_va_arg);
6628
6629         expect('(', end_error);
6630         call_argument_t ap;
6631         ap.expression = parse_assignment_expression();
6632         expression->va_arge.ap = ap.expression;
6633         check_call_argument(type_valist, &ap, 1);
6634
6635         expect(',', end_error);
6636         expression->base.type = parse_typename();
6637         expect(')', end_error);
6638
6639         return expression;
6640 end_error:
6641         return create_error_expression();
6642 }
6643
6644 /**
6645  * Parses a __builtin_va_copy() expression.
6646  */
6647 static expression_t *parse_va_copy(void)
6648 {
6649         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6650
6651         eat(T___builtin_va_copy);
6652
6653         expect('(', end_error);
6654         expression_t *dst = parse_assignment_expression();
6655         assign_error_t error = semantic_assign(type_valist, dst);
6656         report_assign_error(error, type_valist, dst, "call argument 1",
6657                             &dst->base.source_position);
6658         expression->va_copye.dst = dst;
6659
6660         expect(',', end_error);
6661
6662         call_argument_t src;
6663         src.expression = parse_assignment_expression();
6664         check_call_argument(type_valist, &src, 2);
6665         expression->va_copye.src = src.expression;
6666         expect(')', end_error);
6667
6668         return expression;
6669 end_error:
6670         return create_error_expression();
6671 }
6672
6673 /**
6674  * Parses a __builtin_constant_p() expression.
6675  */
6676 static expression_t *parse_builtin_constant(void)
6677 {
6678         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6679
6680         eat(T___builtin_constant_p);
6681
6682         expect('(', end_error);
6683         add_anchor_token(')');
6684         expression->builtin_constant.value = parse_assignment_expression();
6685         rem_anchor_token(')');
6686         expect(')', end_error);
6687         expression->base.type = type_int;
6688
6689         return expression;
6690 end_error:
6691         return create_error_expression();
6692 }
6693
6694 /**
6695  * Parses a __builtin_types_compatible_p() expression.
6696  */
6697 static expression_t *parse_builtin_types_compatible(void)
6698 {
6699         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6700
6701         eat(T___builtin_types_compatible_p);
6702
6703         expect('(', end_error);
6704         add_anchor_token(')');
6705         add_anchor_token(',');
6706         expression->builtin_types_compatible.left = parse_typename();
6707         rem_anchor_token(',');
6708         expect(',', end_error);
6709         expression->builtin_types_compatible.right = parse_typename();
6710         rem_anchor_token(')');
6711         expect(')', end_error);
6712         expression->base.type = type_int;
6713
6714         return expression;
6715 end_error:
6716         return create_error_expression();
6717 }
6718
6719 /**
6720  * Parses a __builtin_is_*() compare expression.
6721  */
6722 static expression_t *parse_compare_builtin(void)
6723 {
6724         expression_t *expression;
6725
6726         switch (token.kind) {
6727         case T___builtin_isgreater:
6728                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6729                 break;
6730         case T___builtin_isgreaterequal:
6731                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6732                 break;
6733         case T___builtin_isless:
6734                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6735                 break;
6736         case T___builtin_islessequal:
6737                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6738                 break;
6739         case T___builtin_islessgreater:
6740                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6741                 break;
6742         case T___builtin_isunordered:
6743                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6744                 break;
6745         default:
6746                 internal_errorf(HERE, "invalid compare builtin found");
6747         }
6748         expression->base.source_position = *HERE;
6749         next_token();
6750
6751         expect('(', end_error);
6752         expression->binary.left = parse_assignment_expression();
6753         expect(',', end_error);
6754         expression->binary.right = parse_assignment_expression();
6755         expect(')', end_error);
6756
6757         type_t *const orig_type_left  = expression->binary.left->base.type;
6758         type_t *const orig_type_right = expression->binary.right->base.type;
6759
6760         type_t *const type_left  = skip_typeref(orig_type_left);
6761         type_t *const type_right = skip_typeref(orig_type_right);
6762         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6763                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6764                         type_error_incompatible("invalid operands in comparison",
6765                                 &expression->base.source_position, orig_type_left, orig_type_right);
6766                 }
6767         } else {
6768                 semantic_comparison(&expression->binary);
6769         }
6770
6771         return expression;
6772 end_error:
6773         return create_error_expression();
6774 }
6775
6776 /**
6777  * Parses a MS assume() expression.
6778  */
6779 static expression_t *parse_assume(void)
6780 {
6781         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6782
6783         eat(T__assume);
6784
6785         expect('(', end_error);
6786         add_anchor_token(')');
6787         expression->unary.value = parse_assignment_expression();
6788         rem_anchor_token(')');
6789         expect(')', end_error);
6790
6791         expression->base.type = type_void;
6792         return expression;
6793 end_error:
6794         return create_error_expression();
6795 }
6796
6797 /**
6798  * Return the label for the current symbol or create a new one.
6799  */
6800 static label_t *get_label(void)
6801 {
6802         assert(token.kind == T_IDENTIFIER);
6803         assert(current_function != NULL);
6804
6805         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6806         /* If we find a local label, we already created the declaration. */
6807         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6808                 if (label->base.parent_scope != current_scope) {
6809                         assert(label->base.parent_scope->depth < current_scope->depth);
6810                         current_function->goto_to_outer = true;
6811                 }
6812         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6813                 /* There is no matching label in the same function, so create a new one. */
6814                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol);
6815                 label_push(label);
6816         }
6817
6818         eat(T_IDENTIFIER);
6819         return &label->label;
6820 }
6821
6822 /**
6823  * Parses a GNU && label address expression.
6824  */
6825 static expression_t *parse_label_address(void)
6826 {
6827         source_position_t source_position = token.base.source_position;
6828         eat(T_ANDAND);
6829         if (token.kind != T_IDENTIFIER) {
6830                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6831                 return create_error_expression();
6832         }
6833
6834         label_t *const label = get_label();
6835         label->used          = true;
6836         label->address_taken = true;
6837
6838         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6839         expression->base.source_position = source_position;
6840
6841         /* label address is treated as a void pointer */
6842         expression->base.type           = type_void_ptr;
6843         expression->label_address.label = label;
6844         return expression;
6845 }
6846
6847 /**
6848  * Parse a microsoft __noop expression.
6849  */
6850 static expression_t *parse_noop_expression(void)
6851 {
6852         /* the result is a (int)0 */
6853         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6854         literal->base.type           = type_int;
6855         literal->literal.value.begin = "__noop";
6856         literal->literal.value.size  = 6;
6857
6858         eat(T___noop);
6859
6860         if (token.kind == '(') {
6861                 /* parse arguments */
6862                 eat('(');
6863                 add_anchor_token(')');
6864                 add_anchor_token(',');
6865
6866                 if (token.kind != ')') do {
6867                         (void)parse_assignment_expression();
6868                 } while (next_if(','));
6869         }
6870         rem_anchor_token(',');
6871         rem_anchor_token(')');
6872         expect(')', end_error);
6873
6874 end_error:
6875         return literal;
6876 }
6877
6878 /**
6879  * Parses a primary expression.
6880  */
6881 static expression_t *parse_primary_expression(void)
6882 {
6883         switch (token.kind) {
6884         case T_false:                        return parse_boolean_literal(false);
6885         case T_true:                         return parse_boolean_literal(true);
6886         case T_INTEGER:
6887         case T_INTEGER_OCTAL:
6888         case T_INTEGER_HEXADECIMAL:
6889         case T_FLOATINGPOINT:
6890         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6891         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6892         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6893         case T_STRING_LITERAL:
6894         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6895         case T___FUNCTION__:
6896         case T___func__:                     return parse_function_keyword();
6897         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6898         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6899         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6900         case T___builtin_offsetof:           return parse_offsetof();
6901         case T___builtin_va_start:           return parse_va_start();
6902         case T___builtin_va_arg:             return parse_va_arg();
6903         case T___builtin_va_copy:            return parse_va_copy();
6904         case T___builtin_isgreater:
6905         case T___builtin_isgreaterequal:
6906         case T___builtin_isless:
6907         case T___builtin_islessequal:
6908         case T___builtin_islessgreater:
6909         case T___builtin_isunordered:        return parse_compare_builtin();
6910         case T___builtin_constant_p:         return parse_builtin_constant();
6911         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6912         case T__assume:                      return parse_assume();
6913         case T_ANDAND:
6914                 if (GNU_MODE)
6915                         return parse_label_address();
6916                 break;
6917
6918         case '(':                            return parse_parenthesized_expression();
6919         case T___noop:                       return parse_noop_expression();
6920
6921         /* Gracefully handle type names while parsing expressions. */
6922         case T_COLONCOLON:
6923                 return parse_reference();
6924         case T_IDENTIFIER:
6925                 if (!is_typedef_symbol(token.identifier.symbol)) {
6926                         return parse_reference();
6927                 }
6928                 /* FALLTHROUGH */
6929         DECLARATION_START {
6930                 source_position_t const  pos = *HERE;
6931                 declaration_specifiers_t specifiers;
6932                 parse_declaration_specifiers(&specifiers);
6933                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6934                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6935                 return create_error_expression();
6936         }
6937         }
6938
6939         errorf(HERE, "unexpected token %K, expected an expression", &token);
6940         eat_until_anchor();
6941         return create_error_expression();
6942 }
6943
6944 static expression_t *parse_array_expression(expression_t *left)
6945 {
6946         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6947         array_access_expression_t *const arr  = &expr->array_access;
6948
6949         eat('[');
6950         add_anchor_token(']');
6951
6952         expression_t *const inside = parse_expression();
6953
6954         type_t *const orig_type_left   = left->base.type;
6955         type_t *const orig_type_inside = inside->base.type;
6956
6957         type_t *const type_left   = skip_typeref(orig_type_left);
6958         type_t *const type_inside = skip_typeref(orig_type_inside);
6959
6960         expression_t *ref;
6961         expression_t *idx;
6962         type_t       *idx_type;
6963         type_t       *res_type;
6964         if (is_type_pointer(type_left)) {
6965                 ref      = left;
6966                 idx      = inside;
6967                 idx_type = type_inside;
6968                 res_type = type_left->pointer.points_to;
6969                 goto check_idx;
6970         } else if (is_type_pointer(type_inside)) {
6971                 arr->flipped = true;
6972                 ref      = inside;
6973                 idx      = left;
6974                 idx_type = type_left;
6975                 res_type = type_inside->pointer.points_to;
6976 check_idx:
6977                 res_type = automatic_type_conversion(res_type);
6978                 if (!is_type_integer(idx_type)) {
6979                         errorf(&idx->base.source_position, "array subscript must have integer type");
6980                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6981                         source_position_t const *const pos = &idx->base.source_position;
6982                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6983                 }
6984         } else {
6985                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6986                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6987                 }
6988                 res_type = type_error_type;
6989                 ref      = left;
6990                 idx      = inside;
6991         }
6992
6993         arr->array_ref = ref;
6994         arr->index     = idx;
6995         arr->base.type = res_type;
6996
6997         rem_anchor_token(']');
6998         expect(']', end_error);
6999 end_error:
7000         return expr;
7001 }
7002
7003 static bool is_bitfield(const expression_t *expression)
7004 {
7005         return expression->kind == EXPR_SELECT
7006                 && expression->select.compound_entry->compound_member.bitfield;
7007 }
7008
7009 static expression_t *parse_typeprop(expression_kind_t const kind)
7010 {
7011         expression_t  *tp_expression = allocate_expression_zero(kind);
7012         tp_expression->base.type     = type_size_t;
7013
7014         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7015
7016         type_t       *orig_type;
7017         expression_t *expression;
7018         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
7019                 source_position_t const pos = *HERE;
7020                 next_token();
7021                 add_anchor_token(')');
7022                 orig_type = parse_typename();
7023                 rem_anchor_token(')');
7024                 expect(')', end_error);
7025
7026                 if (token.kind == '{') {
7027                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7028                          * starting with a compound literal */
7029                         expression = parse_compound_literal(&pos, orig_type);
7030                         goto typeprop_expression;
7031                 }
7032         } else {
7033                 expression = parse_subexpression(PREC_UNARY);
7034
7035 typeprop_expression:
7036                 if (is_bitfield(expression)) {
7037                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7038                         errorf(&tp_expression->base.source_position,
7039                                    "operand of %s expression must not be a bitfield", what);
7040                 }
7041
7042                 tp_expression->typeprop.tp_expression = expression;
7043
7044                 orig_type = revert_automatic_type_conversion(expression);
7045                 expression->base.type = orig_type;
7046         }
7047
7048         tp_expression->typeprop.type   = orig_type;
7049         type_t const* const type       = skip_typeref(orig_type);
7050         char   const*       wrong_type = NULL;
7051         if (is_type_incomplete(type)) {
7052                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7053                         wrong_type = "incomplete";
7054         } else if (type->kind == TYPE_FUNCTION) {
7055                 if (GNU_MODE) {
7056                         /* function types are allowed (and return 1) */
7057                         source_position_t const *const pos  = &tp_expression->base.source_position;
7058                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7059                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
7060                 } else {
7061                         wrong_type = "function";
7062                 }
7063         }
7064
7065         if (wrong_type != NULL) {
7066                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7067                 errorf(&tp_expression->base.source_position,
7068                                 "operand of %s expression must not be of %s type '%T'",
7069                                 what, wrong_type, orig_type);
7070         }
7071
7072 end_error:
7073         return tp_expression;
7074 }
7075
7076 static expression_t *parse_sizeof(void)
7077 {
7078         return parse_typeprop(EXPR_SIZEOF);
7079 }
7080
7081 static expression_t *parse_alignof(void)
7082 {
7083         return parse_typeprop(EXPR_ALIGNOF);
7084 }
7085
7086 static expression_t *parse_select_expression(expression_t *addr)
7087 {
7088         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
7089         bool select_left_arrow = (token.kind == T_MINUSGREATER);
7090         source_position_t const pos = *HERE;
7091         next_token();
7092
7093         if (token.kind != T_IDENTIFIER) {
7094                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7095                 return create_error_expression();
7096         }
7097         symbol_t *symbol = token.identifier.symbol;
7098         next_token();
7099
7100         type_t *const orig_type = addr->base.type;
7101         type_t *const type      = skip_typeref(orig_type);
7102
7103         type_t *type_left;
7104         bool    saw_error = false;
7105         if (is_type_pointer(type)) {
7106                 if (!select_left_arrow) {
7107                         errorf(&pos,
7108                                "request for member '%Y' in something not a struct or union, but '%T'",
7109                                symbol, orig_type);
7110                         saw_error = true;
7111                 }
7112                 type_left = skip_typeref(type->pointer.points_to);
7113         } else {
7114                 if (select_left_arrow && is_type_valid(type)) {
7115                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7116                         saw_error = true;
7117                 }
7118                 type_left = type;
7119         }
7120
7121         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7122             type_left->kind != TYPE_COMPOUND_UNION) {
7123
7124                 if (is_type_valid(type_left) && !saw_error) {
7125                         errorf(&pos,
7126                                "request for member '%Y' in something not a struct or union, but '%T'",
7127                                symbol, type_left);
7128                 }
7129                 return create_error_expression();
7130         }
7131
7132         compound_t *compound = type_left->compound.compound;
7133         if (!compound->complete) {
7134                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7135                        symbol, type_left);
7136                 return create_error_expression();
7137         }
7138
7139         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7140         expression_t      *result     =
7141                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7142
7143         if (result == NULL) {
7144                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7145                 return create_error_expression();
7146         }
7147
7148         return result;
7149 }
7150
7151 static void check_call_argument(type_t          *expected_type,
7152                                 call_argument_t *argument, unsigned pos)
7153 {
7154         type_t         *expected_type_skip = skip_typeref(expected_type);
7155         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7156         expression_t   *arg_expr           = argument->expression;
7157         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7158
7159         /* handle transparent union gnu extension */
7160         if (is_type_union(expected_type_skip)
7161                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7162                 compound_t *union_decl  = expected_type_skip->compound.compound;
7163                 type_t     *best_type   = NULL;
7164                 entity_t   *entry       = union_decl->members.entities;
7165                 for ( ; entry != NULL; entry = entry->base.next) {
7166                         assert(is_declaration(entry));
7167                         type_t *decl_type = entry->declaration.type;
7168                         error = semantic_assign(decl_type, arg_expr);
7169                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7170                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7171                                 continue;
7172
7173                         if (error == ASSIGN_SUCCESS) {
7174                                 best_type = decl_type;
7175                         } else if (best_type == NULL) {
7176                                 best_type = decl_type;
7177                         }
7178                 }
7179
7180                 if (best_type != NULL) {
7181                         expected_type = best_type;
7182                 }
7183         }
7184
7185         error                = semantic_assign(expected_type, arg_expr);
7186         argument->expression = create_implicit_cast(arg_expr, expected_type);
7187
7188         if (error != ASSIGN_SUCCESS) {
7189                 /* report exact scope in error messages (like "in argument 3") */
7190                 char buf[64];
7191                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7192                 report_assign_error(error, expected_type, arg_expr, buf,
7193                                     &arg_expr->base.source_position);
7194         } else {
7195                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7196                 if (!types_compatible(expected_type_skip, promoted_type) &&
7197                     !types_compatible(expected_type_skip, type_void_ptr) &&
7198                     !types_compatible(type_void_ptr,      promoted_type)) {
7199                         /* Deliberately show the skipped types in this warning */
7200                         source_position_t const *const apos = &arg_expr->base.source_position;
7201                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7202                 }
7203         }
7204 }
7205
7206 /**
7207  * Handle the semantic restrictions of builtin calls
7208  */
7209 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7210         switch (call->function->reference.entity->function.btk) {
7211                 case bk_gnu_builtin_return_address:
7212                 case bk_gnu_builtin_frame_address: {
7213                         /* argument must be constant */
7214                         call_argument_t *argument = call->arguments;
7215
7216                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7217                                 errorf(&call->base.source_position,
7218                                        "argument of '%Y' must be a constant expression",
7219                                        call->function->reference.entity->base.symbol);
7220                         }
7221                         break;
7222                 }
7223                 case bk_gnu_builtin_object_size:
7224                         if (call->arguments == NULL)
7225                                 break;
7226
7227                         call_argument_t *arg = call->arguments->next;
7228                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7229                                 errorf(&call->base.source_position,
7230                                            "second argument of '%Y' must be a constant expression",
7231                                            call->function->reference.entity->base.symbol);
7232                         }
7233                         break;
7234                 case bk_gnu_builtin_prefetch:
7235                         /* second and third argument must be constant if existent */
7236                         if (call->arguments == NULL)
7237                                 break;
7238                         call_argument_t *rw = call->arguments->next;
7239                         call_argument_t *locality = NULL;
7240
7241                         if (rw != NULL) {
7242                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7243                                         errorf(&call->base.source_position,
7244                                                "second argument of '%Y' must be a constant expression",
7245                                                call->function->reference.entity->base.symbol);
7246                                 }
7247                                 locality = rw->next;
7248                         }
7249                         if (locality != NULL) {
7250                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7251                                         errorf(&call->base.source_position,
7252                                                "third argument of '%Y' must be a constant expression",
7253                                                call->function->reference.entity->base.symbol);
7254                                 }
7255                                 locality = rw->next;
7256                         }
7257                         break;
7258                 default:
7259                         break;
7260         }
7261 }
7262
7263 /**
7264  * Parse a call expression, ie. expression '( ... )'.
7265  *
7266  * @param expression  the function address
7267  */
7268 static expression_t *parse_call_expression(expression_t *expression)
7269 {
7270         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7271         call_expression_t *call   = &result->call;
7272         call->function            = expression;
7273
7274         type_t *const orig_type = expression->base.type;
7275         type_t *const type      = skip_typeref(orig_type);
7276
7277         function_type_t *function_type = NULL;
7278         if (is_type_pointer(type)) {
7279                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7280
7281                 if (is_type_function(to_type)) {
7282                         function_type   = &to_type->function;
7283                         call->base.type = function_type->return_type;
7284                 }
7285         }
7286
7287         if (function_type == NULL && is_type_valid(type)) {
7288                 errorf(HERE,
7289                        "called object '%E' (type '%T') is not a pointer to a function",
7290                        expression, orig_type);
7291         }
7292
7293         /* parse arguments */
7294         eat('(');
7295         add_anchor_token(')');
7296         add_anchor_token(',');
7297
7298         if (token.kind != ')') {
7299                 call_argument_t **anchor = &call->arguments;
7300                 do {
7301                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7302                         argument->expression = parse_assignment_expression();
7303
7304                         *anchor = argument;
7305                         anchor  = &argument->next;
7306                 } while (next_if(','));
7307         }
7308         rem_anchor_token(',');
7309         rem_anchor_token(')');
7310         expect(')', end_error);
7311
7312         if (function_type == NULL)
7313                 return result;
7314
7315         /* check type and count of call arguments */
7316         function_parameter_t *parameter = function_type->parameters;
7317         call_argument_t      *argument  = call->arguments;
7318         if (!function_type->unspecified_parameters) {
7319                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7320                                 parameter = parameter->next, argument = argument->next) {
7321                         check_call_argument(parameter->type, argument, ++pos);
7322                 }
7323
7324                 if (parameter != NULL) {
7325                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7326                 } else if (argument != NULL && !function_type->variadic) {
7327                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7328                 }
7329         }
7330
7331         /* do default promotion for other arguments */
7332         for (; argument != NULL; argument = argument->next) {
7333                 type_t *argument_type = argument->expression->base.type;
7334                 if (!is_type_object(skip_typeref(argument_type))) {
7335                         errorf(&argument->expression->base.source_position,
7336                                "call argument '%E' must not be void", argument->expression);
7337                 }
7338
7339                 argument_type = get_default_promoted_type(argument_type);
7340
7341                 argument->expression
7342                         = create_implicit_cast(argument->expression, argument_type);
7343         }
7344
7345         check_format(call);
7346
7347         if (is_type_compound(skip_typeref(function_type->return_type))) {
7348                 source_position_t const *const pos = &expression->base.source_position;
7349                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7350         }
7351
7352         if (expression->kind == EXPR_REFERENCE) {
7353                 reference_expression_t *reference = &expression->reference;
7354                 if (reference->entity->kind == ENTITY_FUNCTION &&
7355                     reference->entity->function.btk != bk_none)
7356                         handle_builtin_argument_restrictions(call);
7357         }
7358
7359 end_error:
7360         return result;
7361 }
7362
7363 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7364
7365 static bool same_compound_type(const type_t *type1, const type_t *type2)
7366 {
7367         return
7368                 is_type_compound(type1) &&
7369                 type1->kind == type2->kind &&
7370                 type1->compound.compound == type2->compound.compound;
7371 }
7372
7373 static expression_t const *get_reference_address(expression_t const *expr)
7374 {
7375         bool regular_take_address = true;
7376         for (;;) {
7377                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7378                         expr = expr->unary.value;
7379                 } else {
7380                         regular_take_address = false;
7381                 }
7382
7383                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7384                         break;
7385
7386                 expr = expr->unary.value;
7387         }
7388
7389         if (expr->kind != EXPR_REFERENCE)
7390                 return NULL;
7391
7392         /* special case for functions which are automatically converted to a
7393          * pointer to function without an extra TAKE_ADDRESS operation */
7394         if (!regular_take_address &&
7395                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7396                 return NULL;
7397         }
7398
7399         return expr;
7400 }
7401
7402 static void warn_reference_address_as_bool(expression_t const* expr)
7403 {
7404         expr = get_reference_address(expr);
7405         if (expr != NULL) {
7406                 source_position_t const *const pos = &expr->base.source_position;
7407                 entity_t          const *const ent = expr->reference.entity;
7408                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7409         }
7410 }
7411
7412 static void warn_assignment_in_condition(const expression_t *const expr)
7413 {
7414         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7415                 return;
7416         if (expr->base.parenthesized)
7417                 return;
7418         source_position_t const *const pos = &expr->base.source_position;
7419         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7420 }
7421
7422 static void semantic_condition(expression_t const *const expr,
7423                                char const *const context)
7424 {
7425         type_t *const type = skip_typeref(expr->base.type);
7426         if (is_type_scalar(type)) {
7427                 warn_reference_address_as_bool(expr);
7428                 warn_assignment_in_condition(expr);
7429         } else if (is_type_valid(type)) {
7430                 errorf(&expr->base.source_position,
7431                                 "%s must have scalar type", context);
7432         }
7433 }
7434
7435 /**
7436  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7437  *
7438  * @param expression  the conditional expression
7439  */
7440 static expression_t *parse_conditional_expression(expression_t *expression)
7441 {
7442         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7443
7444         conditional_expression_t *conditional = &result->conditional;
7445         conditional->condition                = expression;
7446
7447         eat('?');
7448         add_anchor_token(':');
7449
7450         /* §6.5.15:2  The first operand shall have scalar type. */
7451         semantic_condition(expression, "condition of conditional operator");
7452
7453         expression_t *true_expression = expression;
7454         bool          gnu_cond = false;
7455         if (GNU_MODE && token.kind == ':') {
7456                 gnu_cond = true;
7457         } else {
7458                 true_expression = parse_expression();
7459         }
7460         rem_anchor_token(':');
7461         expect(':', end_error);
7462 end_error:;
7463         expression_t *false_expression =
7464                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7465
7466         type_t *const orig_true_type  = true_expression->base.type;
7467         type_t *const orig_false_type = false_expression->base.type;
7468         type_t *const true_type       = skip_typeref(orig_true_type);
7469         type_t *const false_type      = skip_typeref(orig_false_type);
7470
7471         /* 6.5.15.3 */
7472         source_position_t const *const pos = &conditional->base.source_position;
7473         type_t                        *result_type;
7474         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7475                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7476                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7477                 if (true_expression->kind == EXPR_UNARY_THROW) {
7478                         result_type = false_type;
7479                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7480                         result_type = true_type;
7481                 } else {
7482                         if (!is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7483                             !is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7484                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7485                         }
7486                         result_type = type_void;
7487                 }
7488         } else if (is_type_arithmetic(true_type)
7489                    && is_type_arithmetic(false_type)) {
7490                 result_type = semantic_arithmetic(true_type, false_type);
7491         } else if (same_compound_type(true_type, false_type)) {
7492                 /* just take 1 of the 2 types */
7493                 result_type = true_type;
7494         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7495                 type_t *pointer_type;
7496                 type_t *other_type;
7497                 expression_t *other_expression;
7498                 if (is_type_pointer(true_type) &&
7499                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7500                         pointer_type     = true_type;
7501                         other_type       = false_type;
7502                         other_expression = false_expression;
7503                 } else {
7504                         pointer_type     = false_type;
7505                         other_type       = true_type;
7506                         other_expression = true_expression;
7507                 }
7508
7509                 if (is_null_pointer_constant(other_expression)) {
7510                         result_type = pointer_type;
7511                 } else if (is_type_pointer(other_type)) {
7512                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7513                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7514
7515                         type_t *to;
7516                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7517                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7518                                 to = type_void;
7519                         } else if (types_compatible(get_unqualified_type(to1),
7520                                                     get_unqualified_type(to2))) {
7521                                 to = to1;
7522                         } else {
7523                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7524                                 to = type_void;
7525                         }
7526
7527                         type_t *const type =
7528                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7529                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7530                 } else if (is_type_integer(other_type)) {
7531                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7532                         result_type = pointer_type;
7533                 } else {
7534                         goto types_incompatible;
7535                 }
7536         } else {
7537 types_incompatible:
7538                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7539                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7540                 }
7541                 result_type = type_error_type;
7542         }
7543
7544         conditional->true_expression
7545                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7546         conditional->false_expression
7547                 = create_implicit_cast(false_expression, result_type);
7548         conditional->base.type = result_type;
7549         return result;
7550 }
7551
7552 /**
7553  * Parse an extension expression.
7554  */
7555 static expression_t *parse_extension(void)
7556 {
7557         PUSH_EXTENSION();
7558         expression_t *expression = parse_subexpression(PREC_UNARY);
7559         POP_EXTENSION();
7560         return expression;
7561 }
7562
7563 /**
7564  * Parse a __builtin_classify_type() expression.
7565  */
7566 static expression_t *parse_builtin_classify_type(void)
7567 {
7568         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7569         result->base.type    = type_int;
7570
7571         eat(T___builtin_classify_type);
7572
7573         expect('(', end_error);
7574         add_anchor_token(')');
7575         expression_t *expression = parse_expression();
7576         rem_anchor_token(')');
7577         expect(')', end_error);
7578         result->classify_type.type_expression = expression;
7579
7580         return result;
7581 end_error:
7582         return create_error_expression();
7583 }
7584
7585 /**
7586  * Parse a delete expression
7587  * ISO/IEC 14882:1998(E) §5.3.5
7588  */
7589 static expression_t *parse_delete(void)
7590 {
7591         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7592         result->base.type          = type_void;
7593
7594         eat(T_delete);
7595
7596         if (next_if('[')) {
7597                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7598                 expect(']', end_error);
7599 end_error:;
7600         }
7601
7602         expression_t *const value = parse_subexpression(PREC_CAST);
7603         result->unary.value = value;
7604
7605         type_t *const type = skip_typeref(value->base.type);
7606         if (!is_type_pointer(type)) {
7607                 if (is_type_valid(type)) {
7608                         errorf(&value->base.source_position,
7609                                         "operand of delete must have pointer type");
7610                 }
7611         } else if (is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7612                 source_position_t const *const pos = &value->base.source_position;
7613                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7614         }
7615
7616         return result;
7617 }
7618
7619 /**
7620  * Parse a throw expression
7621  * ISO/IEC 14882:1998(E) §15:1
7622  */
7623 static expression_t *parse_throw(void)
7624 {
7625         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7626         result->base.type          = type_void;
7627
7628         eat(T_throw);
7629
7630         expression_t *value = NULL;
7631         switch (token.kind) {
7632                 EXPRESSION_START {
7633                         value = parse_assignment_expression();
7634                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7635                         type_t *const orig_type = value->base.type;
7636                         type_t *const type      = skip_typeref(orig_type);
7637                         if (is_type_incomplete(type)) {
7638                                 errorf(&value->base.source_position,
7639                                                 "cannot throw object of incomplete type '%T'", orig_type);
7640                         } else if (is_type_pointer(type)) {
7641                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7642                                 if (is_type_incomplete(points_to) &&
7643                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7644                                         errorf(&value->base.source_position,
7645                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7646                                 }
7647                         }
7648                 }
7649
7650                 default:
7651                         break;
7652         }
7653         result->unary.value = value;
7654
7655         return result;
7656 }
7657
7658 static bool check_pointer_arithmetic(const source_position_t *source_position,
7659                                      type_t *pointer_type,
7660                                      type_t *orig_pointer_type)
7661 {
7662         type_t *points_to = pointer_type->pointer.points_to;
7663         points_to = skip_typeref(points_to);
7664
7665         if (is_type_incomplete(points_to)) {
7666                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7667                         errorf(source_position,
7668                                "arithmetic with pointer to incomplete type '%T' not allowed",
7669                                orig_pointer_type);
7670                         return false;
7671                 } else {
7672                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7673                 }
7674         } else if (is_type_function(points_to)) {
7675                 if (!GNU_MODE) {
7676                         errorf(source_position,
7677                                "arithmetic with pointer to function type '%T' not allowed",
7678                                orig_pointer_type);
7679                         return false;
7680                 } else {
7681                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7682                 }
7683         }
7684         return true;
7685 }
7686
7687 static bool is_lvalue(const expression_t *expression)
7688 {
7689         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7690         switch (expression->kind) {
7691         case EXPR_ARRAY_ACCESS:
7692         case EXPR_COMPOUND_LITERAL:
7693         case EXPR_REFERENCE:
7694         case EXPR_SELECT:
7695         case EXPR_UNARY_DEREFERENCE:
7696                 return true;
7697
7698         default: {
7699                 type_t *type = skip_typeref(expression->base.type);
7700                 return
7701                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7702                         is_type_reference(type) ||
7703                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7704                          * error before, which maybe prevented properly recognizing it as
7705                          * lvalue. */
7706                         !is_type_valid(type);
7707         }
7708         }
7709 }
7710
7711 static void semantic_incdec(unary_expression_t *expression)
7712 {
7713         type_t *const orig_type = expression->value->base.type;
7714         type_t *const type      = skip_typeref(orig_type);
7715         if (is_type_pointer(type)) {
7716                 if (!check_pointer_arithmetic(&expression->base.source_position,
7717                                               type, orig_type)) {
7718                         return;
7719                 }
7720         } else if (!is_type_real(type) && is_type_valid(type)) {
7721                 /* TODO: improve error message */
7722                 errorf(&expression->base.source_position,
7723                        "operation needs an arithmetic or pointer type");
7724                 return;
7725         }
7726         if (!is_lvalue(expression->value)) {
7727                 /* TODO: improve error message */
7728                 errorf(&expression->base.source_position, "lvalue required as operand");
7729         }
7730         expression->base.type = orig_type;
7731 }
7732
7733 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7734 {
7735         type_t *const orig_type = expression->value->base.type;
7736         type_t *const type      = skip_typeref(orig_type);
7737         if (!is_type_arithmetic(type)) {
7738                 if (is_type_valid(type)) {
7739                         /* TODO: improve error message */
7740                         errorf(&expression->base.source_position,
7741                                 "operation needs an arithmetic type");
7742                 }
7743                 return;
7744         }
7745
7746         expression->base.type = orig_type;
7747 }
7748
7749 static void semantic_unexpr_plus(unary_expression_t *expression)
7750 {
7751         semantic_unexpr_arithmetic(expression);
7752         source_position_t const *const pos = &expression->base.source_position;
7753         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7754 }
7755
7756 static void semantic_not(unary_expression_t *expression)
7757 {
7758         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7759         semantic_condition(expression->value, "operand of !");
7760         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7761 }
7762
7763 static void semantic_unexpr_integer(unary_expression_t *expression)
7764 {
7765         type_t *const orig_type = expression->value->base.type;
7766         type_t *const type      = skip_typeref(orig_type);
7767         if (!is_type_integer(type)) {
7768                 if (is_type_valid(type)) {
7769                         errorf(&expression->base.source_position,
7770                                "operand of ~ must be of integer type");
7771                 }
7772                 return;
7773         }
7774
7775         expression->base.type = orig_type;
7776 }
7777
7778 static void semantic_dereference(unary_expression_t *expression)
7779 {
7780         type_t *const orig_type = expression->value->base.type;
7781         type_t *const type      = skip_typeref(orig_type);
7782         if (!is_type_pointer(type)) {
7783                 if (is_type_valid(type)) {
7784                         errorf(&expression->base.source_position,
7785                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7786                 }
7787                 return;
7788         }
7789
7790         type_t *result_type   = type->pointer.points_to;
7791         result_type           = automatic_type_conversion(result_type);
7792         expression->base.type = result_type;
7793 }
7794
7795 /**
7796  * Record that an address is taken (expression represents an lvalue).
7797  *
7798  * @param expression       the expression
7799  * @param may_be_register  if true, the expression might be an register
7800  */
7801 static void set_address_taken(expression_t *expression, bool may_be_register)
7802 {
7803         if (expression->kind != EXPR_REFERENCE)
7804                 return;
7805
7806         entity_t *const entity = expression->reference.entity;
7807
7808         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7809                 return;
7810
7811         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7812                         && !may_be_register) {
7813                 source_position_t const *const pos = &expression->base.source_position;
7814                 errorf(pos, "address of register '%N' requested", entity);
7815         }
7816
7817         if (entity->kind == ENTITY_VARIABLE) {
7818                 entity->variable.address_taken = true;
7819         } else {
7820                 assert(entity->kind == ENTITY_PARAMETER);
7821                 entity->parameter.address_taken = true;
7822         }
7823 }
7824
7825 /**
7826  * Check the semantic of the address taken expression.
7827  */
7828 static void semantic_take_addr(unary_expression_t *expression)
7829 {
7830         expression_t *value = expression->value;
7831         value->base.type    = revert_automatic_type_conversion(value);
7832
7833         type_t *orig_type = value->base.type;
7834         type_t *type      = skip_typeref(orig_type);
7835         if (!is_type_valid(type))
7836                 return;
7837
7838         /* §6.5.3.2 */
7839         if (!is_lvalue(value)) {
7840                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7841         }
7842         if (is_bitfield(value)) {
7843                 errorf(&expression->base.source_position,
7844                        "'&' not allowed on bitfield");
7845         }
7846
7847         set_address_taken(value, false);
7848
7849         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7850 }
7851
7852 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7853 static expression_t *parse_##unexpression_type(void)                         \
7854 {                                                                            \
7855         expression_t *unary_expression                                           \
7856                 = allocate_expression_zero(unexpression_type);                       \
7857         eat(token_kind);                                                         \
7858         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7859                                                                                  \
7860         sfunc(&unary_expression->unary);                                         \
7861                                                                                  \
7862         return unary_expression;                                                 \
7863 }
7864
7865 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7866                                semantic_unexpr_arithmetic)
7867 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7868                                semantic_unexpr_plus)
7869 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7870                                semantic_not)
7871 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7872                                semantic_dereference)
7873 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7874                                semantic_take_addr)
7875 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7876                                semantic_unexpr_integer)
7877 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7878                                semantic_incdec)
7879 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7880                                semantic_incdec)
7881
7882 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7883                                                sfunc)                         \
7884 static expression_t *parse_##unexpression_type(expression_t *left)            \
7885 {                                                                             \
7886         expression_t *unary_expression                                            \
7887                 = allocate_expression_zero(unexpression_type);                        \
7888         eat(token_kind);                                                          \
7889         unary_expression->unary.value = left;                                     \
7890                                                                                   \
7891         sfunc(&unary_expression->unary);                                          \
7892                                                                               \
7893         return unary_expression;                                                  \
7894 }
7895
7896 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7897                                        EXPR_UNARY_POSTFIX_INCREMENT,
7898                                        semantic_incdec)
7899 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7900                                        EXPR_UNARY_POSTFIX_DECREMENT,
7901                                        semantic_incdec)
7902
7903 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7904 {
7905         /* TODO: handle complex + imaginary types */
7906
7907         type_left  = get_unqualified_type(type_left);
7908         type_right = get_unqualified_type(type_right);
7909
7910         /* §6.3.1.8 Usual arithmetic conversions */
7911         if (type_left == type_long_double || type_right == type_long_double) {
7912                 return type_long_double;
7913         } else if (type_left == type_double || type_right == type_double) {
7914                 return type_double;
7915         } else if (type_left == type_float || type_right == type_float) {
7916                 return type_float;
7917         }
7918
7919         type_left  = promote_integer(type_left);
7920         type_right = promote_integer(type_right);
7921
7922         if (type_left == type_right)
7923                 return type_left;
7924
7925         bool const signed_left  = is_type_signed(type_left);
7926         bool const signed_right = is_type_signed(type_right);
7927         int const  rank_left    = get_rank(type_left);
7928         int const  rank_right   = get_rank(type_right);
7929
7930         if (signed_left == signed_right)
7931                 return rank_left >= rank_right ? type_left : type_right;
7932
7933         int     s_rank;
7934         int     u_rank;
7935         type_t *s_type;
7936         type_t *u_type;
7937         if (signed_left) {
7938                 s_rank = rank_left;
7939                 s_type = type_left;
7940                 u_rank = rank_right;
7941                 u_type = type_right;
7942         } else {
7943                 s_rank = rank_right;
7944                 s_type = type_right;
7945                 u_rank = rank_left;
7946                 u_type = type_left;
7947         }
7948
7949         if (u_rank >= s_rank)
7950                 return u_type;
7951
7952         /* casting rank to atomic_type_kind is a bit hacky, but makes things
7953          * easier here... */
7954         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
7955                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
7956                 return s_type;
7957
7958         switch (s_rank) {
7959                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
7960                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7961                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7962
7963                 default: panic("invalid atomic type");
7964         }
7965 }
7966
7967 /**
7968  * Check the semantic restrictions for a binary expression.
7969  */
7970 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7971 {
7972         expression_t *const left            = expression->left;
7973         expression_t *const right           = expression->right;
7974         type_t       *const orig_type_left  = left->base.type;
7975         type_t       *const orig_type_right = right->base.type;
7976         type_t       *const type_left       = skip_typeref(orig_type_left);
7977         type_t       *const type_right      = skip_typeref(orig_type_right);
7978
7979         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7980                 /* TODO: improve error message */
7981                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7982                         errorf(&expression->base.source_position,
7983                                "operation needs arithmetic types");
7984                 }
7985                 return;
7986         }
7987
7988         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7989         expression->left      = create_implicit_cast(left, arithmetic_type);
7990         expression->right     = create_implicit_cast(right, arithmetic_type);
7991         expression->base.type = arithmetic_type;
7992 }
7993
7994 static void semantic_binexpr_integer(binary_expression_t *const expression)
7995 {
7996         expression_t *const left            = expression->left;
7997         expression_t *const right           = expression->right;
7998         type_t       *const orig_type_left  = left->base.type;
7999         type_t       *const orig_type_right = right->base.type;
8000         type_t       *const type_left       = skip_typeref(orig_type_left);
8001         type_t       *const type_right      = skip_typeref(orig_type_right);
8002
8003         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8004                 /* TODO: improve error message */
8005                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8006                         errorf(&expression->base.source_position,
8007                                "operation needs integer types");
8008                 }
8009                 return;
8010         }
8011
8012         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8013         expression->left      = create_implicit_cast(left, result_type);
8014         expression->right     = create_implicit_cast(right, result_type);
8015         expression->base.type = result_type;
8016 }
8017
8018 static void warn_div_by_zero(binary_expression_t const *const expression)
8019 {
8020         if (!is_type_integer(expression->base.type))
8021                 return;
8022
8023         expression_t const *const right = expression->right;
8024         /* The type of the right operand can be different for /= */
8025         if (is_type_integer(right->base.type)                    &&
8026             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8027             !fold_constant_to_bool(right)) {
8028                 source_position_t const *const pos = &expression->base.source_position;
8029                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
8030         }
8031 }
8032
8033 /**
8034  * Check the semantic restrictions for a div/mod expression.
8035  */
8036 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8037 {
8038         semantic_binexpr_arithmetic(expression);
8039         warn_div_by_zero(expression);
8040 }
8041
8042 static void warn_addsub_in_shift(const expression_t *const expr)
8043 {
8044         if (expr->base.parenthesized)
8045                 return;
8046
8047         char op;
8048         switch (expr->kind) {
8049                 case EXPR_BINARY_ADD: op = '+'; break;
8050                 case EXPR_BINARY_SUB: op = '-'; break;
8051                 default:              return;
8052         }
8053
8054         source_position_t const *const pos = &expr->base.source_position;
8055         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
8056 }
8057
8058 static bool semantic_shift(binary_expression_t *expression)
8059 {
8060         expression_t *const left            = expression->left;
8061         expression_t *const right           = expression->right;
8062         type_t       *const orig_type_left  = left->base.type;
8063         type_t       *const orig_type_right = right->base.type;
8064         type_t       *      type_left       = skip_typeref(orig_type_left);
8065         type_t       *      type_right      = skip_typeref(orig_type_right);
8066
8067         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8068                 /* TODO: improve error message */
8069                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8070                         errorf(&expression->base.source_position,
8071                                "operands of shift operation must have integer types");
8072                 }
8073                 return false;
8074         }
8075
8076         type_left = promote_integer(type_left);
8077
8078         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8079                 source_position_t const *const pos   = &right->base.source_position;
8080                 long                     const count = fold_constant_to_int(right);
8081                 if (count < 0) {
8082                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
8083                 } else if ((unsigned long)count >=
8084                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8085                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8086                 }
8087         }
8088
8089         type_right        = promote_integer(type_right);
8090         expression->right = create_implicit_cast(right, type_right);
8091
8092         return true;
8093 }
8094
8095 static void semantic_shift_op(binary_expression_t *expression)
8096 {
8097         expression_t *const left  = expression->left;
8098         expression_t *const right = expression->right;
8099
8100         if (!semantic_shift(expression))
8101                 return;
8102
8103         warn_addsub_in_shift(left);
8104         warn_addsub_in_shift(right);
8105
8106         type_t *const orig_type_left = left->base.type;
8107         type_t *      type_left      = skip_typeref(orig_type_left);
8108
8109         type_left             = promote_integer(type_left);
8110         expression->left      = create_implicit_cast(left, type_left);
8111         expression->base.type = type_left;
8112 }
8113
8114 static void semantic_add(binary_expression_t *expression)
8115 {
8116         expression_t *const left            = expression->left;
8117         expression_t *const right           = expression->right;
8118         type_t       *const orig_type_left  = left->base.type;
8119         type_t       *const orig_type_right = right->base.type;
8120         type_t       *const type_left       = skip_typeref(orig_type_left);
8121         type_t       *const type_right      = skip_typeref(orig_type_right);
8122
8123         /* §6.5.6 */
8124         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8125                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8126                 expression->left  = create_implicit_cast(left, arithmetic_type);
8127                 expression->right = create_implicit_cast(right, arithmetic_type);
8128                 expression->base.type = arithmetic_type;
8129         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8130                 check_pointer_arithmetic(&expression->base.source_position,
8131                                          type_left, orig_type_left);
8132                 expression->base.type = type_left;
8133         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8134                 check_pointer_arithmetic(&expression->base.source_position,
8135                                          type_right, orig_type_right);
8136                 expression->base.type = type_right;
8137         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8138                 errorf(&expression->base.source_position,
8139                        "invalid operands to binary + ('%T', '%T')",
8140                        orig_type_left, orig_type_right);
8141         }
8142 }
8143
8144 static void semantic_sub(binary_expression_t *expression)
8145 {
8146         expression_t            *const left            = expression->left;
8147         expression_t            *const right           = expression->right;
8148         type_t                  *const orig_type_left  = left->base.type;
8149         type_t                  *const orig_type_right = right->base.type;
8150         type_t                  *const type_left       = skip_typeref(orig_type_left);
8151         type_t                  *const type_right      = skip_typeref(orig_type_right);
8152         source_position_t const *const pos             = &expression->base.source_position;
8153
8154         /* §5.6.5 */
8155         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8156                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8157                 expression->left        = create_implicit_cast(left, arithmetic_type);
8158                 expression->right       = create_implicit_cast(right, arithmetic_type);
8159                 expression->base.type =  arithmetic_type;
8160         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8161                 check_pointer_arithmetic(&expression->base.source_position,
8162                                          type_left, orig_type_left);
8163                 expression->base.type = type_left;
8164         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8165                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8166                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8167                 if (!types_compatible(unqual_left, unqual_right)) {
8168                         errorf(pos,
8169                                "subtracting pointers to incompatible types '%T' and '%T'",
8170                                orig_type_left, orig_type_right);
8171                 } else if (!is_type_object(unqual_left)) {
8172                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8173                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8174                                        orig_type_left);
8175                         } else {
8176                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8177                         }
8178                 }
8179                 expression->base.type = type_ptrdiff_t;
8180         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8181                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8182                        orig_type_left, orig_type_right);
8183         }
8184 }
8185
8186 static void warn_string_literal_address(expression_t const* expr)
8187 {
8188         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8189                 expr = expr->unary.value;
8190                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8191                         return;
8192                 expr = expr->unary.value;
8193         }
8194
8195         if (expr->kind == EXPR_STRING_LITERAL
8196                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8197                 source_position_t const *const pos = &expr->base.source_position;
8198                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8199         }
8200 }
8201
8202 static bool maybe_negative(expression_t const *const expr)
8203 {
8204         switch (is_constant_expression(expr)) {
8205                 case EXPR_CLASS_ERROR:    return false;
8206                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8207                 default:                  return true;
8208         }
8209 }
8210
8211 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8212 {
8213         warn_string_literal_address(expr);
8214
8215         expression_t const* const ref = get_reference_address(expr);
8216         if (ref != NULL && is_null_pointer_constant(other)) {
8217                 entity_t const *const ent = ref->reference.entity;
8218                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8219         }
8220
8221         if (!expr->base.parenthesized) {
8222                 switch (expr->base.kind) {
8223                         case EXPR_BINARY_LESS:
8224                         case EXPR_BINARY_GREATER:
8225                         case EXPR_BINARY_LESSEQUAL:
8226                         case EXPR_BINARY_GREATEREQUAL:
8227                         case EXPR_BINARY_NOTEQUAL:
8228                         case EXPR_BINARY_EQUAL:
8229                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8230                                 break;
8231                         default:
8232                                 break;
8233                 }
8234         }
8235 }
8236
8237 /**
8238  * Check the semantics of comparison expressions.
8239  *
8240  * @param expression   The expression to check.
8241  */
8242 static void semantic_comparison(binary_expression_t *expression)
8243 {
8244         source_position_t const *const pos   = &expression->base.source_position;
8245         expression_t            *const left  = expression->left;
8246         expression_t            *const right = expression->right;
8247
8248         warn_comparison(pos, left, right);
8249         warn_comparison(pos, right, left);
8250
8251         type_t *orig_type_left  = left->base.type;
8252         type_t *orig_type_right = right->base.type;
8253         type_t *type_left       = skip_typeref(orig_type_left);
8254         type_t *type_right      = skip_typeref(orig_type_right);
8255
8256         /* TODO non-arithmetic types */
8257         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8258                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8259
8260                 /* test for signed vs unsigned compares */
8261                 if (is_type_integer(arithmetic_type)) {
8262                         bool const signed_left  = is_type_signed(type_left);
8263                         bool const signed_right = is_type_signed(type_right);
8264                         if (signed_left != signed_right) {
8265                                 /* FIXME long long needs better const folding magic */
8266                                 /* TODO check whether constant value can be represented by other type */
8267                                 if ((signed_left  && maybe_negative(left)) ||
8268                                                 (signed_right && maybe_negative(right))) {
8269                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8270                                 }
8271                         }
8272                 }
8273
8274                 expression->left        = create_implicit_cast(left, arithmetic_type);
8275                 expression->right       = create_implicit_cast(right, arithmetic_type);
8276                 expression->base.type   = arithmetic_type;
8277                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8278                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8279                     is_type_float(arithmetic_type)) {
8280                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8281                 }
8282         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8283                 /* TODO check compatibility */
8284         } else if (is_type_pointer(type_left)) {
8285                 expression->right = create_implicit_cast(right, type_left);
8286         } else if (is_type_pointer(type_right)) {
8287                 expression->left = create_implicit_cast(left, type_right);
8288         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8289                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8290         }
8291         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8292 }
8293
8294 /**
8295  * Checks if a compound type has constant fields.
8296  */
8297 static bool has_const_fields(const compound_type_t *type)
8298 {
8299         compound_t *compound = type->compound;
8300         entity_t   *entry    = compound->members.entities;
8301
8302         for (; entry != NULL; entry = entry->base.next) {
8303                 if (!is_declaration(entry))
8304                         continue;
8305
8306                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8307                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8308                         return true;
8309         }
8310
8311         return false;
8312 }
8313
8314 static bool is_valid_assignment_lhs(expression_t const* const left)
8315 {
8316         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8317         type_t *const type_left      = skip_typeref(orig_type_left);
8318
8319         if (!is_lvalue(left)) {
8320                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8321                        left);
8322                 return false;
8323         }
8324
8325         if (left->kind == EXPR_REFERENCE
8326                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8327                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8328                 return false;
8329         }
8330
8331         if (is_type_array(type_left)) {
8332                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8333                 return false;
8334         }
8335         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8336                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8337                        orig_type_left);
8338                 return false;
8339         }
8340         if (is_type_incomplete(type_left)) {
8341                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8342                        left, orig_type_left);
8343                 return false;
8344         }
8345         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8346                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8347                        left, orig_type_left);
8348                 return false;
8349         }
8350
8351         return true;
8352 }
8353
8354 static void semantic_arithmetic_assign(binary_expression_t *expression)
8355 {
8356         expression_t *left            = expression->left;
8357         expression_t *right           = expression->right;
8358         type_t       *orig_type_left  = left->base.type;
8359         type_t       *orig_type_right = right->base.type;
8360
8361         if (!is_valid_assignment_lhs(left))
8362                 return;
8363
8364         type_t *type_left  = skip_typeref(orig_type_left);
8365         type_t *type_right = skip_typeref(orig_type_right);
8366
8367         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8368                 /* TODO: improve error message */
8369                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8370                         errorf(&expression->base.source_position,
8371                                "operation needs arithmetic types");
8372                 }
8373                 return;
8374         }
8375
8376         /* combined instructions are tricky. We can't create an implicit cast on
8377          * the left side, because we need the uncasted form for the store.
8378          * The ast2firm pass has to know that left_type must be right_type
8379          * for the arithmetic operation and create a cast by itself */
8380         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8381         expression->right       = create_implicit_cast(right, arithmetic_type);
8382         expression->base.type   = type_left;
8383 }
8384
8385 static void semantic_divmod_assign(binary_expression_t *expression)
8386 {
8387         semantic_arithmetic_assign(expression);
8388         warn_div_by_zero(expression);
8389 }
8390
8391 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8392 {
8393         expression_t *const left            = expression->left;
8394         expression_t *const right           = expression->right;
8395         type_t       *const orig_type_left  = left->base.type;
8396         type_t       *const orig_type_right = right->base.type;
8397         type_t       *const type_left       = skip_typeref(orig_type_left);
8398         type_t       *const type_right      = skip_typeref(orig_type_right);
8399
8400         if (!is_valid_assignment_lhs(left))
8401                 return;
8402
8403         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8404                 /* combined instructions are tricky. We can't create an implicit cast on
8405                  * the left side, because we need the uncasted form for the store.
8406                  * The ast2firm pass has to know that left_type must be right_type
8407                  * for the arithmetic operation and create a cast by itself */
8408                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8409                 expression->right     = create_implicit_cast(right, arithmetic_type);
8410                 expression->base.type = type_left;
8411         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8412                 check_pointer_arithmetic(&expression->base.source_position,
8413                                          type_left, orig_type_left);
8414                 expression->base.type = type_left;
8415         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8416                 errorf(&expression->base.source_position,
8417                        "incompatible types '%T' and '%T' in assignment",
8418                        orig_type_left, orig_type_right);
8419         }
8420 }
8421
8422 static void semantic_integer_assign(binary_expression_t *expression)
8423 {
8424         expression_t *left            = expression->left;
8425         expression_t *right           = expression->right;
8426         type_t       *orig_type_left  = left->base.type;
8427         type_t       *orig_type_right = right->base.type;
8428
8429         if (!is_valid_assignment_lhs(left))
8430                 return;
8431
8432         type_t *type_left  = skip_typeref(orig_type_left);
8433         type_t *type_right = skip_typeref(orig_type_right);
8434
8435         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8436                 /* TODO: improve error message */
8437                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8438                         errorf(&expression->base.source_position,
8439                                "operation needs integer types");
8440                 }
8441                 return;
8442         }
8443
8444         /* combined instructions are tricky. We can't create an implicit cast on
8445          * the left side, because we need the uncasted form for the store.
8446          * The ast2firm pass has to know that left_type must be right_type
8447          * for the arithmetic operation and create a cast by itself */
8448         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8449         expression->right       = create_implicit_cast(right, arithmetic_type);
8450         expression->base.type   = type_left;
8451 }
8452
8453 static void semantic_shift_assign(binary_expression_t *expression)
8454 {
8455         expression_t *left           = expression->left;
8456
8457         if (!is_valid_assignment_lhs(left))
8458                 return;
8459
8460         if (!semantic_shift(expression))
8461                 return;
8462
8463         expression->base.type = skip_typeref(left->base.type);
8464 }
8465
8466 static void warn_logical_and_within_or(const expression_t *const expr)
8467 {
8468         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8469                 return;
8470         if (expr->base.parenthesized)
8471                 return;
8472         source_position_t const *const pos = &expr->base.source_position;
8473         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8474 }
8475
8476 /**
8477  * Check the semantic restrictions of a logical expression.
8478  */
8479 static void semantic_logical_op(binary_expression_t *expression)
8480 {
8481         /* §6.5.13:2  Each of the operands shall have scalar type.
8482          * §6.5.14:2  Each of the operands shall have scalar type. */
8483         semantic_condition(expression->left,   "left operand of logical operator");
8484         semantic_condition(expression->right, "right operand of logical operator");
8485         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8486                 warn_logical_and_within_or(expression->left);
8487                 warn_logical_and_within_or(expression->right);
8488         }
8489         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8490 }
8491
8492 /**
8493  * Check the semantic restrictions of a binary assign expression.
8494  */
8495 static void semantic_binexpr_assign(binary_expression_t *expression)
8496 {
8497         expression_t *left           = expression->left;
8498         type_t       *orig_type_left = left->base.type;
8499
8500         if (!is_valid_assignment_lhs(left))
8501                 return;
8502
8503         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8504         report_assign_error(error, orig_type_left, expression->right,
8505                         "assignment", &left->base.source_position);
8506         expression->right = create_implicit_cast(expression->right, orig_type_left);
8507         expression->base.type = orig_type_left;
8508 }
8509
8510 /**
8511  * Determine if the outermost operation (or parts thereof) of the given
8512  * expression has no effect in order to generate a warning about this fact.
8513  * Therefore in some cases this only examines some of the operands of the
8514  * expression (see comments in the function and examples below).
8515  * Examples:
8516  *   f() + 23;    // warning, because + has no effect
8517  *   x || f();    // no warning, because x controls execution of f()
8518  *   x ? y : f(); // warning, because y has no effect
8519  *   (void)x;     // no warning to be able to suppress the warning
8520  * This function can NOT be used for an "expression has definitely no effect"-
8521  * analysis. */
8522 static bool expression_has_effect(const expression_t *const expr)
8523 {
8524         switch (expr->kind) {
8525                 case EXPR_ERROR:                      return true; /* do NOT warn */
8526                 case EXPR_REFERENCE:                  return false;
8527                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8528                 case EXPR_LABEL_ADDRESS:              return false;
8529
8530                 /* suppress the warning for microsoft __noop operations */
8531                 case EXPR_LITERAL_MS_NOOP:            return true;
8532                 case EXPR_LITERAL_BOOLEAN:
8533                 case EXPR_LITERAL_CHARACTER:
8534                 case EXPR_LITERAL_WIDE_CHARACTER:
8535                 case EXPR_LITERAL_INTEGER:
8536                 case EXPR_LITERAL_INTEGER_OCTAL:
8537                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8538                 case EXPR_LITERAL_FLOATINGPOINT:
8539                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8540                 case EXPR_STRING_LITERAL:             return false;
8541                 case EXPR_WIDE_STRING_LITERAL:        return false;
8542
8543                 case EXPR_CALL: {
8544                         const call_expression_t *const call = &expr->call;
8545                         if (call->function->kind != EXPR_REFERENCE)
8546                                 return true;
8547
8548                         switch (call->function->reference.entity->function.btk) {
8549                                 /* FIXME: which builtins have no effect? */
8550                                 default:                      return true;
8551                         }
8552                 }
8553
8554                 /* Generate the warning if either the left or right hand side of a
8555                  * conditional expression has no effect */
8556                 case EXPR_CONDITIONAL: {
8557                         conditional_expression_t const *const cond = &expr->conditional;
8558                         expression_t             const *const t    = cond->true_expression;
8559                         return
8560                                 (t == NULL || expression_has_effect(t)) &&
8561                                 expression_has_effect(cond->false_expression);
8562                 }
8563
8564                 case EXPR_SELECT:                     return false;
8565                 case EXPR_ARRAY_ACCESS:               return false;
8566                 case EXPR_SIZEOF:                     return false;
8567                 case EXPR_CLASSIFY_TYPE:              return false;
8568                 case EXPR_ALIGNOF:                    return false;
8569
8570                 case EXPR_FUNCNAME:                   return false;
8571                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8572                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8573                 case EXPR_OFFSETOF:                   return false;
8574                 case EXPR_VA_START:                   return true;
8575                 case EXPR_VA_ARG:                     return true;
8576                 case EXPR_VA_COPY:                    return true;
8577                 case EXPR_STATEMENT:                  return true; // TODO
8578                 case EXPR_COMPOUND_LITERAL:           return false;
8579
8580                 case EXPR_UNARY_NEGATE:               return false;
8581                 case EXPR_UNARY_PLUS:                 return false;
8582                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8583                 case EXPR_UNARY_NOT:                  return false;
8584                 case EXPR_UNARY_DEREFERENCE:          return false;
8585                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8586                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8587                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8588                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8589                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8590
8591                 /* Treat void casts as if they have an effect in order to being able to
8592                  * suppress the warning */
8593                 case EXPR_UNARY_CAST: {
8594                         type_t *const type = skip_typeref(expr->base.type);
8595                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8596                 }
8597
8598                 case EXPR_UNARY_ASSUME:               return true;
8599                 case EXPR_UNARY_DELETE:               return true;
8600                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8601                 case EXPR_UNARY_THROW:                return true;
8602
8603                 case EXPR_BINARY_ADD:                 return false;
8604                 case EXPR_BINARY_SUB:                 return false;
8605                 case EXPR_BINARY_MUL:                 return false;
8606                 case EXPR_BINARY_DIV:                 return false;
8607                 case EXPR_BINARY_MOD:                 return false;
8608                 case EXPR_BINARY_EQUAL:               return false;
8609                 case EXPR_BINARY_NOTEQUAL:            return false;
8610                 case EXPR_BINARY_LESS:                return false;
8611                 case EXPR_BINARY_LESSEQUAL:           return false;
8612                 case EXPR_BINARY_GREATER:             return false;
8613                 case EXPR_BINARY_GREATEREQUAL:        return false;
8614                 case EXPR_BINARY_BITWISE_AND:         return false;
8615                 case EXPR_BINARY_BITWISE_OR:          return false;
8616                 case EXPR_BINARY_BITWISE_XOR:         return false;
8617                 case EXPR_BINARY_SHIFTLEFT:           return false;
8618                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8619                 case EXPR_BINARY_ASSIGN:              return true;
8620                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8621                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8622                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8623                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8624                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8625                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8626                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8627                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8628                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8629                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8630
8631                 /* Only examine the right hand side of && and ||, because the left hand
8632                  * side already has the effect of controlling the execution of the right
8633                  * hand side */
8634                 case EXPR_BINARY_LOGICAL_AND:
8635                 case EXPR_BINARY_LOGICAL_OR:
8636                 /* Only examine the right hand side of a comma expression, because the left
8637                  * hand side has a separate warning */
8638                 case EXPR_BINARY_COMMA:
8639                         return expression_has_effect(expr->binary.right);
8640
8641                 case EXPR_BINARY_ISGREATER:           return false;
8642                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8643                 case EXPR_BINARY_ISLESS:              return false;
8644                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8645                 case EXPR_BINARY_ISLESSGREATER:       return false;
8646                 case EXPR_BINARY_ISUNORDERED:         return false;
8647         }
8648
8649         internal_errorf(HERE, "unexpected expression");
8650 }
8651
8652 static void semantic_comma(binary_expression_t *expression)
8653 {
8654         const expression_t *const left = expression->left;
8655         if (!expression_has_effect(left)) {
8656                 source_position_t const *const pos = &left->base.source_position;
8657                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8658         }
8659         expression->base.type = expression->right->base.type;
8660 }
8661
8662 /**
8663  * @param prec_r precedence of the right operand
8664  */
8665 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8666 static expression_t *parse_##binexpression_type(expression_t *left)          \
8667 {                                                                            \
8668         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8669         binexpr->binary.left  = left;                                            \
8670         eat(token_kind);                                                         \
8671                                                                              \
8672         expression_t *right = parse_subexpression(prec_r);                       \
8673                                                                              \
8674         binexpr->binary.right = right;                                           \
8675         sfunc(&binexpr->binary);                                                 \
8676                                                                              \
8677         return binexpr;                                                          \
8678 }
8679
8680 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8681 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8682 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8683 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8684 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8685 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8686 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8687 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8688 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8689 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8690 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8691 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8692 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8693 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8694 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8695 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8696 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8697 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8698 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8699 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8700 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8701 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8702 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8703 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8704 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8705 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8706 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8707 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8708 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8709 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8710
8711
8712 static expression_t *parse_subexpression(precedence_t precedence)
8713 {
8714         if (token.kind < 0) {
8715                 return expected_expression_error();
8716         }
8717
8718         expression_parser_function_t *parser
8719                 = &expression_parsers[token.kind];
8720         expression_t                 *left;
8721
8722         if (parser->parser != NULL) {
8723                 left = parser->parser();
8724         } else {
8725                 left = parse_primary_expression();
8726         }
8727         assert(left != NULL);
8728
8729         while (true) {
8730                 if (token.kind < 0) {
8731                         return expected_expression_error();
8732                 }
8733
8734                 parser = &expression_parsers[token.kind];
8735                 if (parser->infix_parser == NULL)
8736                         break;
8737                 if (parser->infix_precedence < precedence)
8738                         break;
8739
8740                 left = parser->infix_parser(left);
8741
8742                 assert(left != NULL);
8743         }
8744
8745         return left;
8746 }
8747
8748 /**
8749  * Parse an expression.
8750  */
8751 static expression_t *parse_expression(void)
8752 {
8753         return parse_subexpression(PREC_EXPRESSION);
8754 }
8755
8756 /**
8757  * Register a parser for a prefix-like operator.
8758  *
8759  * @param parser      the parser function
8760  * @param token_kind  the token type of the prefix token
8761  */
8762 static void register_expression_parser(parse_expression_function parser,
8763                                        int token_kind)
8764 {
8765         expression_parser_function_t *entry = &expression_parsers[token_kind];
8766
8767         if (entry->parser != NULL) {
8768                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8769                 panic("trying to register multiple expression parsers for a token");
8770         }
8771         entry->parser = parser;
8772 }
8773
8774 /**
8775  * Register a parser for an infix operator with given precedence.
8776  *
8777  * @param parser      the parser function
8778  * @param token_kind  the token type of the infix operator
8779  * @param precedence  the precedence of the operator
8780  */
8781 static void register_infix_parser(parse_expression_infix_function parser,
8782                                   int token_kind, precedence_t precedence)
8783 {
8784         expression_parser_function_t *entry = &expression_parsers[token_kind];
8785
8786         if (entry->infix_parser != NULL) {
8787                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8788                 panic("trying to register multiple infix expression parsers for a "
8789                       "token");
8790         }
8791         entry->infix_parser     = parser;
8792         entry->infix_precedence = precedence;
8793 }
8794
8795 /**
8796  * Initialize the expression parsers.
8797  */
8798 static void init_expression_parsers(void)
8799 {
8800         memset(&expression_parsers, 0, sizeof(expression_parsers));
8801
8802         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8803         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8804         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8805         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8806         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8807         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8808         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8809         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8810         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8811         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8812         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8813         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8814         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8815         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8816         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8817         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8818         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8819         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8820         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8821         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8822         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8823         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8824         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8825         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8826         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8827         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8828         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8829         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8830         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8831         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8832         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8833         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8834         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8835         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8836         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8837         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8838         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8839
8840         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8841         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8842         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8843         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8844         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8845         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8846         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8847         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8848         register_expression_parser(parse_sizeof,                      T_sizeof);
8849         register_expression_parser(parse_alignof,                     T___alignof__);
8850         register_expression_parser(parse_extension,                   T___extension__);
8851         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8852         register_expression_parser(parse_delete,                      T_delete);
8853         register_expression_parser(parse_throw,                       T_throw);
8854 }
8855
8856 /**
8857  * Parse a asm statement arguments specification.
8858  */
8859 static asm_argument_t *parse_asm_arguments(bool is_out)
8860 {
8861         asm_argument_t  *result = NULL;
8862         asm_argument_t **anchor = &result;
8863
8864         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8865                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8866                 memset(argument, 0, sizeof(argument[0]));
8867
8868                 if (next_if('[')) {
8869                         if (token.kind != T_IDENTIFIER) {
8870                                 parse_error_expected("while parsing asm argument",
8871                                                      T_IDENTIFIER, NULL);
8872                                 return NULL;
8873                         }
8874                         argument->symbol = token.identifier.symbol;
8875
8876                         expect(']', end_error);
8877                 }
8878
8879                 argument->constraints = parse_string_literals();
8880                 expect('(', end_error);
8881                 add_anchor_token(')');
8882                 expression_t *expression = parse_expression();
8883                 rem_anchor_token(')');
8884                 if (is_out) {
8885                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8886                          * change size or type representation (e.g. int -> long is ok, but
8887                          * int -> float is not) */
8888                         if (expression->kind == EXPR_UNARY_CAST) {
8889                                 type_t      *const type = expression->base.type;
8890                                 type_kind_t  const kind = type->kind;
8891                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8892                                         unsigned flags;
8893                                         unsigned size;
8894                                         if (kind == TYPE_ATOMIC) {
8895                                                 atomic_type_kind_t const akind = type->atomic.akind;
8896                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8897                                                 size  = get_atomic_type_size(akind);
8898                                         } else {
8899                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8900                                                 size  = get_type_size(type_void_ptr);
8901                                         }
8902
8903                                         do {
8904                                                 expression_t *const value      = expression->unary.value;
8905                                                 type_t       *const value_type = value->base.type;
8906                                                 type_kind_t   const value_kind = value_type->kind;
8907
8908                                                 unsigned value_flags;
8909                                                 unsigned value_size;
8910                                                 if (value_kind == TYPE_ATOMIC) {
8911                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8912                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8913                                                         value_size  = get_atomic_type_size(value_akind);
8914                                                 } else if (value_kind == TYPE_POINTER) {
8915                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8916                                                         value_size  = get_type_size(type_void_ptr);
8917                                                 } else {
8918                                                         break;
8919                                                 }
8920
8921                                                 if (value_flags != flags || value_size != size)
8922                                                         break;
8923
8924                                                 expression = value;
8925                                         } while (expression->kind == EXPR_UNARY_CAST);
8926                                 }
8927                         }
8928
8929                         if (!is_lvalue(expression)) {
8930                                 errorf(&expression->base.source_position,
8931                                        "asm output argument is not an lvalue");
8932                         }
8933
8934                         if (argument->constraints.begin[0] == '=')
8935                                 determine_lhs_ent(expression, NULL);
8936                         else
8937                                 mark_vars_read(expression, NULL);
8938                 } else {
8939                         mark_vars_read(expression, NULL);
8940                 }
8941                 argument->expression = expression;
8942                 expect(')', end_error);
8943
8944                 set_address_taken(expression, true);
8945
8946                 *anchor = argument;
8947                 anchor  = &argument->next;
8948
8949                 if (!next_if(','))
8950                         break;
8951         }
8952
8953         return result;
8954 end_error:
8955         return NULL;
8956 }
8957
8958 /**
8959  * Parse a asm statement clobber specification.
8960  */
8961 static asm_clobber_t *parse_asm_clobbers(void)
8962 {
8963         asm_clobber_t *result  = NULL;
8964         asm_clobber_t **anchor = &result;
8965
8966         while (token.kind == T_STRING_LITERAL) {
8967                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8968                 clobber->clobber       = parse_string_literals();
8969
8970                 *anchor = clobber;
8971                 anchor  = &clobber->next;
8972
8973                 if (!next_if(','))
8974                         break;
8975         }
8976
8977         return result;
8978 }
8979
8980 /**
8981  * Parse an asm statement.
8982  */
8983 static statement_t *parse_asm_statement(void)
8984 {
8985         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8986         asm_statement_t *asm_statement = &statement->asms;
8987
8988         eat(T_asm);
8989
8990         if (next_if(T_volatile))
8991                 asm_statement->is_volatile = true;
8992
8993         expect('(', end_error);
8994         add_anchor_token(')');
8995         if (token.kind != T_STRING_LITERAL) {
8996                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8997                 goto end_of_asm;
8998         }
8999         asm_statement->asm_text = parse_string_literals();
9000
9001         add_anchor_token(':');
9002         if (!next_if(':')) {
9003                 rem_anchor_token(':');
9004                 goto end_of_asm;
9005         }
9006
9007         asm_statement->outputs = parse_asm_arguments(true);
9008         if (!next_if(':')) {
9009                 rem_anchor_token(':');
9010                 goto end_of_asm;
9011         }
9012
9013         asm_statement->inputs = parse_asm_arguments(false);
9014         if (!next_if(':')) {
9015                 rem_anchor_token(':');
9016                 goto end_of_asm;
9017         }
9018         rem_anchor_token(':');
9019
9020         asm_statement->clobbers = parse_asm_clobbers();
9021
9022 end_of_asm:
9023         rem_anchor_token(')');
9024         expect(')', end_error);
9025         expect(';', end_error);
9026
9027         if (asm_statement->outputs == NULL) {
9028                 /* GCC: An 'asm' instruction without any output operands will be treated
9029                  * identically to a volatile 'asm' instruction. */
9030                 asm_statement->is_volatile = true;
9031         }
9032
9033         return statement;
9034 end_error:
9035         return create_error_statement();
9036 }
9037
9038 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9039 {
9040         statement_t *inner_stmt;
9041         switch (token.kind) {
9042                 case '}':
9043                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9044                         inner_stmt = create_error_statement();
9045                         break;
9046
9047                 case ';':
9048                         if (label->kind == STATEMENT_LABEL) {
9049                                 /* Eat an empty statement here, to avoid the warning about an empty
9050                                  * statement after a label.  label:; is commonly used to have a label
9051                                  * before a closing brace. */
9052                                 inner_stmt = create_empty_statement();
9053                                 next_token();
9054                                 break;
9055                         }
9056                         /* FALLTHROUGH */
9057
9058                 default:
9059                         inner_stmt = parse_statement();
9060                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9061                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9062                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9063                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9064                         }
9065                         break;
9066         }
9067         return inner_stmt;
9068 }
9069
9070 /**
9071  * Parse a case statement.
9072  */
9073 static statement_t *parse_case_statement(void)
9074 {
9075         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9076         source_position_t *const pos       = &statement->base.source_position;
9077
9078         eat(T_case);
9079
9080         expression_t *const expression   = parse_expression();
9081         statement->case_label.expression = expression;
9082         expression_classification_t const expr_class = is_constant_expression(expression);
9083         if (expr_class != EXPR_CLASS_CONSTANT) {
9084                 if (expr_class != EXPR_CLASS_ERROR) {
9085                         errorf(pos, "case label does not reduce to an integer constant");
9086                 }
9087                 statement->case_label.is_bad = true;
9088         } else {
9089                 long const val = fold_constant_to_int(expression);
9090                 statement->case_label.first_case = val;
9091                 statement->case_label.last_case  = val;
9092         }
9093
9094         if (GNU_MODE) {
9095                 if (next_if(T_DOTDOTDOT)) {
9096                         expression_t *const end_range   = parse_expression();
9097                         statement->case_label.end_range = end_range;
9098                         expression_classification_t const end_class = is_constant_expression(end_range);
9099                         if (end_class != EXPR_CLASS_CONSTANT) {
9100                                 if (end_class != EXPR_CLASS_ERROR) {
9101                                         errorf(pos, "case range does not reduce to an integer constant");
9102                                 }
9103                                 statement->case_label.is_bad = true;
9104                         } else {
9105                                 long const val = fold_constant_to_int(end_range);
9106                                 statement->case_label.last_case = val;
9107
9108                                 if (val < statement->case_label.first_case) {
9109                                         statement->case_label.is_empty_range = true;
9110                                         warningf(WARN_OTHER, pos, "empty range specified");
9111                                 }
9112                         }
9113                 }
9114         }
9115
9116         PUSH_PARENT(statement);
9117
9118         expect(':', end_error);
9119 end_error:
9120
9121         if (current_switch != NULL) {
9122                 if (! statement->case_label.is_bad) {
9123                         /* Check for duplicate case values */
9124                         case_label_statement_t *c = &statement->case_label;
9125                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9126                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9127                                         continue;
9128
9129                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9130                                         continue;
9131
9132                                 errorf(pos, "duplicate case value (previously used %P)",
9133                                        &l->base.source_position);
9134                                 break;
9135                         }
9136                 }
9137                 /* link all cases into the switch statement */
9138                 if (current_switch->last_case == NULL) {
9139                         current_switch->first_case      = &statement->case_label;
9140                 } else {
9141                         current_switch->last_case->next = &statement->case_label;
9142                 }
9143                 current_switch->last_case = &statement->case_label;
9144         } else {
9145                 errorf(pos, "case label not within a switch statement");
9146         }
9147
9148         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9149
9150         POP_PARENT();
9151         return statement;
9152 }
9153
9154 /**
9155  * Parse a default statement.
9156  */
9157 static statement_t *parse_default_statement(void)
9158 {
9159         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9160
9161         eat(T_default);
9162
9163         PUSH_PARENT(statement);
9164
9165         expect(':', end_error);
9166 end_error:
9167
9168         if (current_switch != NULL) {
9169                 const case_label_statement_t *def_label = current_switch->default_label;
9170                 if (def_label != NULL) {
9171                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9172                 } else {
9173                         current_switch->default_label = &statement->case_label;
9174
9175                         /* link all cases into the switch statement */
9176                         if (current_switch->last_case == NULL) {
9177                                 current_switch->first_case      = &statement->case_label;
9178                         } else {
9179                                 current_switch->last_case->next = &statement->case_label;
9180                         }
9181                         current_switch->last_case = &statement->case_label;
9182                 }
9183         } else {
9184                 errorf(&statement->base.source_position,
9185                         "'default' label not within a switch statement");
9186         }
9187
9188         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9189
9190         POP_PARENT();
9191         return statement;
9192 }
9193
9194 /**
9195  * Parse a label statement.
9196  */
9197 static statement_t *parse_label_statement(void)
9198 {
9199         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9200         label_t     *const label     = get_label();
9201         statement->label.label = label;
9202
9203         PUSH_PARENT(statement);
9204
9205         /* if statement is already set then the label is defined twice,
9206          * otherwise it was just mentioned in a goto/local label declaration so far
9207          */
9208         source_position_t const* const pos = &statement->base.source_position;
9209         if (label->statement != NULL) {
9210                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9211         } else {
9212                 label->base.source_position = *pos;
9213                 label->statement            = statement;
9214         }
9215
9216         eat(':');
9217
9218         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9219                 parse_attributes(NULL); // TODO process attributes
9220         }
9221
9222         statement->label.statement = parse_label_inner_statement(statement, "label");
9223
9224         /* remember the labels in a list for later checking */
9225         *label_anchor = &statement->label;
9226         label_anchor  = &statement->label.next;
9227
9228         POP_PARENT();
9229         return statement;
9230 }
9231
9232 static statement_t *parse_inner_statement(void)
9233 {
9234         statement_t *const stmt = parse_statement();
9235         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9236         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9237         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9238                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9239         }
9240         return stmt;
9241 }
9242
9243 /**
9244  * Parse an if statement.
9245  */
9246 static statement_t *parse_if(void)
9247 {
9248         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9249
9250         eat(T_if);
9251
9252         PUSH_PARENT(statement);
9253
9254         add_anchor_token('{');
9255
9256         expect('(', end_error);
9257         add_anchor_token(')');
9258         expression_t *const expr = parse_expression();
9259         statement->ifs.condition = expr;
9260         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9261          *             scalar type. */
9262         semantic_condition(expr, "condition of 'if'-statment");
9263         mark_vars_read(expr, NULL);
9264         rem_anchor_token(')');
9265         expect(')', end_error);
9266
9267 end_error:
9268         rem_anchor_token('{');
9269
9270         add_anchor_token(T_else);
9271         statement_t *const true_stmt = parse_inner_statement();
9272         statement->ifs.true_statement = true_stmt;
9273         rem_anchor_token(T_else);
9274
9275         if (true_stmt->kind == STATEMENT_EMPTY) {
9276                 warningf(WARN_EMPTY_BODY, HERE,
9277                         "suggest braces around empty body in an ‘if’ statement");
9278         }
9279
9280         if (next_if(T_else)) {
9281                 statement->ifs.false_statement = parse_inner_statement();
9282
9283                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9284                         warningf(WARN_EMPTY_BODY, HERE,
9285                                         "suggest braces around empty body in an ‘if’ statement");
9286                 }
9287         } else if (true_stmt->kind == STATEMENT_IF &&
9288                         true_stmt->ifs.false_statement != NULL) {
9289                 source_position_t const *const pos = &true_stmt->base.source_position;
9290                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9291         }
9292
9293         POP_PARENT();
9294         return statement;
9295 }
9296
9297 /**
9298  * Check that all enums are handled in a switch.
9299  *
9300  * @param statement  the switch statement to check
9301  */
9302 static void check_enum_cases(const switch_statement_t *statement)
9303 {
9304         if (!is_warn_on(WARN_SWITCH_ENUM))
9305                 return;
9306         const type_t *type = skip_typeref(statement->expression->base.type);
9307         if (! is_type_enum(type))
9308                 return;
9309         const enum_type_t *enumt = &type->enumt;
9310
9311         /* if we have a default, no warnings */
9312         if (statement->default_label != NULL)
9313                 return;
9314
9315         /* FIXME: calculation of value should be done while parsing */
9316         /* TODO: quadratic algorithm here. Change to an n log n one */
9317         long            last_value = -1;
9318         const entity_t *entry      = enumt->enume->base.next;
9319         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9320              entry = entry->base.next) {
9321                 const expression_t *expression = entry->enum_value.value;
9322                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9323                 bool                found      = false;
9324                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9325                         if (l->expression == NULL)
9326                                 continue;
9327                         if (l->first_case <= value && value <= l->last_case) {
9328                                 found = true;
9329                                 break;
9330                         }
9331                 }
9332                 if (!found) {
9333                         source_position_t const *const pos = &statement->base.source_position;
9334                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9335                 }
9336                 last_value = value;
9337         }
9338 }
9339
9340 /**
9341  * Parse a switch statement.
9342  */
9343 static statement_t *parse_switch(void)
9344 {
9345         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9346
9347         eat(T_switch);
9348
9349         PUSH_PARENT(statement);
9350
9351         expect('(', end_error);
9352         add_anchor_token(')');
9353         expression_t *const expr = parse_expression();
9354         mark_vars_read(expr, NULL);
9355         type_t       *      type = skip_typeref(expr->base.type);
9356         if (is_type_integer(type)) {
9357                 type = promote_integer(type);
9358                 if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9359                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9360                 }
9361         } else if (is_type_valid(type)) {
9362                 errorf(&expr->base.source_position,
9363                        "switch quantity is not an integer, but '%T'", type);
9364                 type = type_error_type;
9365         }
9366         statement->switchs.expression = create_implicit_cast(expr, type);
9367         expect(')', end_error);
9368         rem_anchor_token(')');
9369
9370         switch_statement_t *rem = current_switch;
9371         current_switch          = &statement->switchs;
9372         statement->switchs.body = parse_inner_statement();
9373         current_switch          = rem;
9374
9375         if (statement->switchs.default_label == NULL) {
9376                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9377         }
9378         check_enum_cases(&statement->switchs);
9379
9380         POP_PARENT();
9381         return statement;
9382 end_error:
9383         POP_PARENT();
9384         return create_error_statement();
9385 }
9386
9387 static statement_t *parse_loop_body(statement_t *const loop)
9388 {
9389         statement_t *const rem = current_loop;
9390         current_loop = loop;
9391
9392         statement_t *const body = parse_inner_statement();
9393
9394         current_loop = rem;
9395         return body;
9396 }
9397
9398 /**
9399  * Parse a while statement.
9400  */
9401 static statement_t *parse_while(void)
9402 {
9403         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9404
9405         eat(T_while);
9406
9407         PUSH_PARENT(statement);
9408
9409         expect('(', end_error);
9410         add_anchor_token(')');
9411         expression_t *const cond = parse_expression();
9412         statement->whiles.condition = cond;
9413         /* §6.8.5:2    The controlling expression of an iteration statement shall
9414          *             have scalar type. */
9415         semantic_condition(cond, "condition of 'while'-statement");
9416         mark_vars_read(cond, NULL);
9417         rem_anchor_token(')');
9418         expect(')', end_error);
9419
9420         statement->whiles.body = parse_loop_body(statement);
9421
9422         POP_PARENT();
9423         return statement;
9424 end_error:
9425         POP_PARENT();
9426         return create_error_statement();
9427 }
9428
9429 /**
9430  * Parse a do statement.
9431  */
9432 static statement_t *parse_do(void)
9433 {
9434         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9435
9436         eat(T_do);
9437
9438         PUSH_PARENT(statement);
9439
9440         add_anchor_token(T_while);
9441         statement->do_while.body = parse_loop_body(statement);
9442         rem_anchor_token(T_while);
9443
9444         expect(T_while, end_error);
9445         expect('(', end_error);
9446         add_anchor_token(')');
9447         expression_t *const cond = parse_expression();
9448         statement->do_while.condition = cond;
9449         /* §6.8.5:2    The controlling expression of an iteration statement shall
9450          *             have scalar type. */
9451         semantic_condition(cond, "condition of 'do-while'-statement");
9452         mark_vars_read(cond, NULL);
9453         rem_anchor_token(')');
9454         expect(')', end_error);
9455         expect(';', end_error);
9456
9457         POP_PARENT();
9458         return statement;
9459 end_error:
9460         POP_PARENT();
9461         return create_error_statement();
9462 }
9463
9464 /**
9465  * Parse a for statement.
9466  */
9467 static statement_t *parse_for(void)
9468 {
9469         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9470
9471         eat(T_for);
9472
9473         expect('(', end_error1);
9474         add_anchor_token(')');
9475
9476         PUSH_PARENT(statement);
9477         PUSH_SCOPE(&statement->fors.scope);
9478
9479         PUSH_EXTENSION();
9480
9481         if (next_if(';')) {
9482         } else if (is_declaration_specifier(&token)) {
9483                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9484         } else {
9485                 add_anchor_token(';');
9486                 expression_t *const init = parse_expression();
9487                 statement->fors.initialisation = init;
9488                 mark_vars_read(init, ENT_ANY);
9489                 if (!expression_has_effect(init)) {
9490                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9491                 }
9492                 rem_anchor_token(';');
9493                 expect(';', end_error2);
9494         }
9495
9496         POP_EXTENSION();
9497
9498         if (token.kind != ';') {
9499                 add_anchor_token(';');
9500                 expression_t *const cond = parse_expression();
9501                 statement->fors.condition = cond;
9502                 /* §6.8.5:2    The controlling expression of an iteration statement
9503                  *             shall have scalar type. */
9504                 semantic_condition(cond, "condition of 'for'-statement");
9505                 mark_vars_read(cond, NULL);
9506                 rem_anchor_token(';');
9507         }
9508         expect(';', end_error2);
9509         if (token.kind != ')') {
9510                 expression_t *const step = parse_expression();
9511                 statement->fors.step = step;
9512                 mark_vars_read(step, ENT_ANY);
9513                 if (!expression_has_effect(step)) {
9514                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9515                 }
9516         }
9517         expect(')', end_error2);
9518         rem_anchor_token(')');
9519         statement->fors.body = parse_loop_body(statement);
9520
9521         POP_SCOPE();
9522         POP_PARENT();
9523         return statement;
9524
9525 end_error2:
9526         POP_PARENT();
9527         rem_anchor_token(')');
9528         POP_SCOPE();
9529         /* fallthrough */
9530
9531 end_error1:
9532         return create_error_statement();
9533 }
9534
9535 /**
9536  * Parse a goto statement.
9537  */
9538 static statement_t *parse_goto(void)
9539 {
9540         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9541         eat(T_goto);
9542
9543         if (GNU_MODE && next_if('*')) {
9544                 expression_t *expression = parse_expression();
9545                 mark_vars_read(expression, NULL);
9546
9547                 /* Argh: although documentation says the expression must be of type void*,
9548                  * gcc accepts anything that can be casted into void* without error */
9549                 type_t *type = expression->base.type;
9550
9551                 if (type != type_error_type) {
9552                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9553                                 errorf(&expression->base.source_position,
9554                                         "cannot convert to a pointer type");
9555                         } else if (type != type_void_ptr) {
9556                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9557                         }
9558                         expression = create_implicit_cast(expression, type_void_ptr);
9559                 }
9560
9561                 statement->gotos.expression = expression;
9562         } else if (token.kind == T_IDENTIFIER) {
9563                 label_t *const label = get_label();
9564                 label->used            = true;
9565                 statement->gotos.label = label;
9566         } else {
9567                 if (GNU_MODE)
9568                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9569                 else
9570                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9571                 eat_until_anchor();
9572                 return create_error_statement();
9573         }
9574
9575         /* remember the goto's in a list for later checking */
9576         *goto_anchor = &statement->gotos;
9577         goto_anchor  = &statement->gotos.next;
9578
9579         expect(';', end_error);
9580
9581 end_error:
9582         return statement;
9583 }
9584
9585 /**
9586  * Parse a continue statement.
9587  */
9588 static statement_t *parse_continue(void)
9589 {
9590         if (current_loop == NULL) {
9591                 errorf(HERE, "continue statement not within loop");
9592         }
9593
9594         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9595
9596         eat(T_continue);
9597         expect(';', end_error);
9598
9599 end_error:
9600         return statement;
9601 }
9602
9603 /**
9604  * Parse a break statement.
9605  */
9606 static statement_t *parse_break(void)
9607 {
9608         if (current_switch == NULL && current_loop == NULL) {
9609                 errorf(HERE, "break statement not within loop or switch");
9610         }
9611
9612         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9613
9614         eat(T_break);
9615         expect(';', end_error);
9616
9617 end_error:
9618         return statement;
9619 }
9620
9621 /**
9622  * Parse a __leave statement.
9623  */
9624 static statement_t *parse_leave_statement(void)
9625 {
9626         if (current_try == NULL) {
9627                 errorf(HERE, "__leave statement not within __try");
9628         }
9629
9630         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9631
9632         eat(T___leave);
9633         expect(';', end_error);
9634
9635 end_error:
9636         return statement;
9637 }
9638
9639 /**
9640  * Check if a given entity represents a local variable.
9641  */
9642 static bool is_local_variable(const entity_t *entity)
9643 {
9644         if (entity->kind != ENTITY_VARIABLE)
9645                 return false;
9646
9647         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9648         case STORAGE_CLASS_AUTO:
9649         case STORAGE_CLASS_REGISTER: {
9650                 const type_t *type = skip_typeref(entity->declaration.type);
9651                 if (is_type_function(type)) {
9652                         return false;
9653                 } else {
9654                         return true;
9655                 }
9656         }
9657         default:
9658                 return false;
9659         }
9660 }
9661
9662 /**
9663  * Check if a given expression represents a local variable.
9664  */
9665 static bool expression_is_local_variable(const expression_t *expression)
9666 {
9667         if (expression->base.kind != EXPR_REFERENCE) {
9668                 return false;
9669         }
9670         const entity_t *entity = expression->reference.entity;
9671         return is_local_variable(entity);
9672 }
9673
9674 /**
9675  * Check if a given expression represents a local variable and
9676  * return its declaration then, else return NULL.
9677  */
9678 entity_t *expression_is_variable(const expression_t *expression)
9679 {
9680         if (expression->base.kind != EXPR_REFERENCE) {
9681                 return NULL;
9682         }
9683         entity_t *entity = expression->reference.entity;
9684         if (entity->kind != ENTITY_VARIABLE)
9685                 return NULL;
9686
9687         return entity;
9688 }
9689
9690 /**
9691  * Parse a return statement.
9692  */
9693 static statement_t *parse_return(void)
9694 {
9695         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9696         eat(T_return);
9697
9698         expression_t *return_value = NULL;
9699         if (token.kind != ';') {
9700                 return_value = parse_expression();
9701                 mark_vars_read(return_value, NULL);
9702         }
9703
9704         const type_t *const func_type = skip_typeref(current_function->base.type);
9705         assert(is_type_function(func_type));
9706         type_t *const return_type = skip_typeref(func_type->function.return_type);
9707
9708         source_position_t const *const pos = &statement->base.source_position;
9709         if (return_value != NULL) {
9710                 type_t *return_value_type = skip_typeref(return_value->base.type);
9711
9712                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9713                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9714                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9715                                 /* Only warn in C mode, because GCC does the same */
9716                                 if (c_mode & _CXX || strict_mode) {
9717                                         errorf(pos,
9718                                                         "'return' with a value, in function returning 'void'");
9719                                 } else {
9720                                         warningf(WARN_OTHER, pos, "'return' with a value, in function returning 'void'");
9721                                 }
9722                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9723                                 /* Only warn in C mode, because GCC does the same */
9724                                 if (strict_mode) {
9725                                         errorf(pos,
9726                                                         "'return' with expression in function returning 'void'");
9727                                 } else {
9728                                         warningf(WARN_OTHER, pos, "'return' with expression in function returning 'void'");
9729                                 }
9730                         }
9731                 } else {
9732                         assign_error_t error = semantic_assign(return_type, return_value);
9733                         report_assign_error(error, return_type, return_value, "'return'",
9734                                             pos);
9735                 }
9736                 return_value = create_implicit_cast(return_value, return_type);
9737                 /* check for returning address of a local var */
9738                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9739                         const expression_t *expression = return_value->unary.value;
9740                         if (expression_is_local_variable(expression)) {
9741                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9742                         }
9743                 }
9744         } else if (!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9745                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9746                 if (c_mode & _CXX || strict_mode) {
9747                         errorf(pos,
9748                                "'return' without value, in function returning non-void");
9749                 } else {
9750                         warningf(WARN_OTHER, pos, "'return' without value, in function returning non-void");
9751                 }
9752         }
9753         statement->returns.value = return_value;
9754
9755         expect(';', end_error);
9756
9757 end_error:
9758         return statement;
9759 }
9760
9761 /**
9762  * Parse a declaration statement.
9763  */
9764 static statement_t *parse_declaration_statement(void)
9765 {
9766         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9767
9768         entity_t *before = current_scope->last_entity;
9769         if (GNU_MODE) {
9770                 parse_external_declaration();
9771         } else {
9772                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9773         }
9774
9775         declaration_statement_t *const decl  = &statement->declaration;
9776         entity_t                *const begin =
9777                 before != NULL ? before->base.next : current_scope->entities;
9778         decl->declarations_begin = begin;
9779         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9780
9781         return statement;
9782 }
9783
9784 /**
9785  * Parse an expression statement, ie. expr ';'.
9786  */
9787 static statement_t *parse_expression_statement(void)
9788 {
9789         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9790
9791         expression_t *const expr         = parse_expression();
9792         statement->expression.expression = expr;
9793         mark_vars_read(expr, ENT_ANY);
9794
9795         expect(';', end_error);
9796
9797 end_error:
9798         return statement;
9799 }
9800
9801 /**
9802  * Parse a microsoft __try { } __finally { } or
9803  * __try{ } __except() { }
9804  */
9805 static statement_t *parse_ms_try_statment(void)
9806 {
9807         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9808         eat(T___try);
9809
9810         PUSH_PARENT(statement);
9811
9812         ms_try_statement_t *rem = current_try;
9813         current_try = &statement->ms_try;
9814         statement->ms_try.try_statement = parse_compound_statement(false);
9815         current_try = rem;
9816
9817         POP_PARENT();
9818
9819         if (next_if(T___except)) {
9820                 expect('(', end_error);
9821                 add_anchor_token(')');
9822                 expression_t *const expr = parse_expression();
9823                 mark_vars_read(expr, NULL);
9824                 type_t       *      type = skip_typeref(expr->base.type);
9825                 if (is_type_integer(type)) {
9826                         type = promote_integer(type);
9827                 } else if (is_type_valid(type)) {
9828                         errorf(&expr->base.source_position,
9829                                "__expect expression is not an integer, but '%T'", type);
9830                         type = type_error_type;
9831                 }
9832                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9833                 rem_anchor_token(')');
9834                 expect(')', end_error);
9835                 statement->ms_try.final_statement = parse_compound_statement(false);
9836         } else if (next_if(T__finally)) {
9837                 statement->ms_try.final_statement = parse_compound_statement(false);
9838         } else {
9839                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9840                 return create_error_statement();
9841         }
9842         return statement;
9843 end_error:
9844         return create_error_statement();
9845 }
9846
9847 static statement_t *parse_empty_statement(void)
9848 {
9849         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9850         statement_t *const statement = create_empty_statement();
9851         eat(';');
9852         return statement;
9853 }
9854
9855 static statement_t *parse_local_label_declaration(void)
9856 {
9857         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9858
9859         eat(T___label__);
9860
9861         entity_t *begin   = NULL;
9862         entity_t *end     = NULL;
9863         entity_t **anchor = &begin;
9864         do {
9865                 if (token.kind != T_IDENTIFIER) {
9866                         parse_error_expected("while parsing local label declaration",
9867                                 T_IDENTIFIER, NULL);
9868                         goto end_error;
9869                 }
9870                 symbol_t *symbol = token.identifier.symbol;
9871                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9872                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9873                         source_position_t const *const ppos = &entity->base.source_position;
9874                         errorf(HERE, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9875                 } else {
9876                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
9877                         entity->base.parent_scope    = current_scope;
9878                         entity->base.source_position = token.base.source_position;
9879
9880                         *anchor = entity;
9881                         anchor  = &entity->base.next;
9882                         end     = entity;
9883
9884                         environment_push(entity);
9885                 }
9886                 next_token();
9887         } while (next_if(','));
9888         expect(';', end_error);
9889 end_error:
9890         statement->declaration.declarations_begin = begin;
9891         statement->declaration.declarations_end   = end;
9892         return statement;
9893 }
9894
9895 static void parse_namespace_definition(void)
9896 {
9897         eat(T_namespace);
9898
9899         entity_t *entity = NULL;
9900         symbol_t *symbol = NULL;
9901
9902         if (token.kind == T_IDENTIFIER) {
9903                 symbol = token.identifier.symbol;
9904                 next_token();
9905
9906                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9907                 if (entity != NULL
9908                                 && entity->kind != ENTITY_NAMESPACE
9909                                 && entity->base.parent_scope == current_scope) {
9910                         if (is_entity_valid(entity)) {
9911                                 error_redefined_as_different_kind(&token.base.source_position,
9912                                                 entity, ENTITY_NAMESPACE);
9913                         }
9914                         entity = NULL;
9915                 }
9916         }
9917
9918         if (entity == NULL) {
9919                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
9920                 entity->base.source_position = token.base.source_position;
9921                 entity->base.parent_scope    = current_scope;
9922         }
9923
9924         if (token.kind == '=') {
9925                 /* TODO: parse namespace alias */
9926                 panic("namespace alias definition not supported yet");
9927         }
9928
9929         environment_push(entity);
9930         append_entity(current_scope, entity);
9931
9932         PUSH_SCOPE(&entity->namespacee.members);
9933
9934         entity_t     *old_current_entity = current_entity;
9935         current_entity = entity;
9936
9937         expect('{', end_error);
9938         parse_externals();
9939         expect('}', end_error);
9940
9941 end_error:
9942         assert(current_entity == entity);
9943         current_entity = old_current_entity;
9944         POP_SCOPE();
9945 }
9946
9947 /**
9948  * Parse a statement.
9949  * There's also parse_statement() which additionally checks for
9950  * "statement has no effect" warnings
9951  */
9952 static statement_t *intern_parse_statement(void)
9953 {
9954         statement_t *statement = NULL;
9955
9956         /* declaration or statement */
9957         add_anchor_token(';');
9958         switch (token.kind) {
9959         case T_IDENTIFIER: {
9960                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9961                 if (la1_type == ':') {
9962                         statement = parse_label_statement();
9963                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9964                         statement = parse_declaration_statement();
9965                 } else {
9966                         /* it's an identifier, the grammar says this must be an
9967                          * expression statement. However it is common that users mistype
9968                          * declaration types, so we guess a bit here to improve robustness
9969                          * for incorrect programs */
9970                         switch (la1_type) {
9971                         case '&':
9972                         case '*':
9973                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9974                         default:
9975                                         statement = parse_expression_statement();
9976                                 } else {
9977                         DECLARATION_START
9978                         case T_IDENTIFIER:
9979                                         statement = parse_declaration_statement();
9980                                 }
9981                                 break;
9982                         }
9983                 }
9984                 break;
9985         }
9986
9987         case T___extension__: {
9988                 /* This can be a prefix to a declaration or an expression statement.
9989                  * We simply eat it now and parse the rest with tail recursion. */
9990                 PUSH_EXTENSION();
9991                 statement = intern_parse_statement();
9992                 POP_EXTENSION();
9993                 break;
9994         }
9995
9996         DECLARATION_START
9997                 statement = parse_declaration_statement();
9998                 break;
9999
10000         case T___label__:
10001                 statement = parse_local_label_declaration();
10002                 break;
10003
10004         case ';':         statement = parse_empty_statement();         break;
10005         case '{':         statement = parse_compound_statement(false); break;
10006         case T___leave:   statement = parse_leave_statement();         break;
10007         case T___try:     statement = parse_ms_try_statment();         break;
10008         case T_asm:       statement = parse_asm_statement();           break;
10009         case T_break:     statement = parse_break();                   break;
10010         case T_case:      statement = parse_case_statement();          break;
10011         case T_continue:  statement = parse_continue();                break;
10012         case T_default:   statement = parse_default_statement();       break;
10013         case T_do:        statement = parse_do();                      break;
10014         case T_for:       statement = parse_for();                     break;
10015         case T_goto:      statement = parse_goto();                    break;
10016         case T_if:        statement = parse_if();                      break;
10017         case T_return:    statement = parse_return();                  break;
10018         case T_switch:    statement = parse_switch();                  break;
10019         case T_while:     statement = parse_while();                   break;
10020
10021         EXPRESSION_START
10022                 statement = parse_expression_statement();
10023                 break;
10024
10025         default:
10026                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10027                 statement = create_error_statement();
10028                 if (!at_anchor())
10029                         next_token();
10030                 break;
10031         }
10032         rem_anchor_token(';');
10033
10034         assert(statement != NULL
10035                         && statement->base.source_position.input_name != NULL);
10036
10037         return statement;
10038 }
10039
10040 /**
10041  * parse a statement and emits "statement has no effect" warning if needed
10042  * (This is really a wrapper around intern_parse_statement with check for 1
10043  *  single warning. It is needed, because for statement expressions we have
10044  *  to avoid the warning on the last statement)
10045  */
10046 static statement_t *parse_statement(void)
10047 {
10048         statement_t *statement = intern_parse_statement();
10049
10050         if (statement->kind == STATEMENT_EXPRESSION) {
10051                 expression_t *expression = statement->expression.expression;
10052                 if (!expression_has_effect(expression)) {
10053                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10054                 }
10055         }
10056
10057         return statement;
10058 }
10059
10060 /**
10061  * Parse a compound statement.
10062  */
10063 static statement_t *parse_compound_statement(bool inside_expression_statement)
10064 {
10065         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10066
10067         PUSH_PARENT(statement);
10068         PUSH_SCOPE(&statement->compound.scope);
10069
10070         eat('{');
10071         add_anchor_token('}');
10072         /* tokens, which can start a statement */
10073         /* TODO MS, __builtin_FOO */
10074         add_anchor_token('!');
10075         add_anchor_token('&');
10076         add_anchor_token('(');
10077         add_anchor_token('*');
10078         add_anchor_token('+');
10079         add_anchor_token('-');
10080         add_anchor_token('{');
10081         add_anchor_token('~');
10082         add_anchor_token(T_CHARACTER_CONSTANT);
10083         add_anchor_token(T_COLONCOLON);
10084         add_anchor_token(T_FLOATINGPOINT);
10085         add_anchor_token(T_IDENTIFIER);
10086         add_anchor_token(T_INTEGER);
10087         add_anchor_token(T_MINUSMINUS);
10088         add_anchor_token(T_PLUSPLUS);
10089         add_anchor_token(T_STRING_LITERAL);
10090         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10091         add_anchor_token(T_WIDE_STRING_LITERAL);
10092         add_anchor_token(T__Bool);
10093         add_anchor_token(T__Complex);
10094         add_anchor_token(T__Imaginary);
10095         add_anchor_token(T___FUNCTION__);
10096         add_anchor_token(T___PRETTY_FUNCTION__);
10097         add_anchor_token(T___alignof__);
10098         add_anchor_token(T___attribute__);
10099         add_anchor_token(T___builtin_va_start);
10100         add_anchor_token(T___extension__);
10101         add_anchor_token(T___func__);
10102         add_anchor_token(T___imag__);
10103         add_anchor_token(T___label__);
10104         add_anchor_token(T___real__);
10105         add_anchor_token(T___thread);
10106         add_anchor_token(T_asm);
10107         add_anchor_token(T_auto);
10108         add_anchor_token(T_bool);
10109         add_anchor_token(T_break);
10110         add_anchor_token(T_case);
10111         add_anchor_token(T_char);
10112         add_anchor_token(T_class);
10113         add_anchor_token(T_const);
10114         add_anchor_token(T_const_cast);
10115         add_anchor_token(T_continue);
10116         add_anchor_token(T_default);
10117         add_anchor_token(T_delete);
10118         add_anchor_token(T_double);
10119         add_anchor_token(T_do);
10120         add_anchor_token(T_dynamic_cast);
10121         add_anchor_token(T_enum);
10122         add_anchor_token(T_extern);
10123         add_anchor_token(T_false);
10124         add_anchor_token(T_float);
10125         add_anchor_token(T_for);
10126         add_anchor_token(T_goto);
10127         add_anchor_token(T_if);
10128         add_anchor_token(T_inline);
10129         add_anchor_token(T_int);
10130         add_anchor_token(T_long);
10131         add_anchor_token(T_new);
10132         add_anchor_token(T_operator);
10133         add_anchor_token(T_register);
10134         add_anchor_token(T_reinterpret_cast);
10135         add_anchor_token(T_restrict);
10136         add_anchor_token(T_return);
10137         add_anchor_token(T_short);
10138         add_anchor_token(T_signed);
10139         add_anchor_token(T_sizeof);
10140         add_anchor_token(T_static);
10141         add_anchor_token(T_static_cast);
10142         add_anchor_token(T_struct);
10143         add_anchor_token(T_switch);
10144         add_anchor_token(T_template);
10145         add_anchor_token(T_this);
10146         add_anchor_token(T_throw);
10147         add_anchor_token(T_true);
10148         add_anchor_token(T_try);
10149         add_anchor_token(T_typedef);
10150         add_anchor_token(T_typeid);
10151         add_anchor_token(T_typename);
10152         add_anchor_token(T_typeof);
10153         add_anchor_token(T_union);
10154         add_anchor_token(T_unsigned);
10155         add_anchor_token(T_using);
10156         add_anchor_token(T_void);
10157         add_anchor_token(T_volatile);
10158         add_anchor_token(T_wchar_t);
10159         add_anchor_token(T_while);
10160
10161         statement_t **anchor            = &statement->compound.statements;
10162         bool          only_decls_so_far = true;
10163         while (token.kind != '}') {
10164                 if (token.kind == T_EOF) {
10165                         errorf(&statement->base.source_position,
10166                                "EOF while parsing compound statement");
10167                         break;
10168                 }
10169                 statement_t *sub_statement = intern_parse_statement();
10170                 if (sub_statement->kind == STATEMENT_ERROR) {
10171                         /* an error occurred. if we are at an anchor, return */
10172                         if (at_anchor())
10173                                 goto end_error;
10174                         continue;
10175                 }
10176
10177                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10178                         only_decls_so_far = false;
10179                 } else if (!only_decls_so_far) {
10180                         source_position_t const *const pos = &sub_statement->base.source_position;
10181                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10182                 }
10183
10184                 *anchor = sub_statement;
10185
10186                 while (sub_statement->base.next != NULL)
10187                         sub_statement = sub_statement->base.next;
10188
10189                 anchor = &sub_statement->base.next;
10190         }
10191         next_token();
10192
10193         /* look over all statements again to produce no effect warnings */
10194         if (is_warn_on(WARN_UNUSED_VALUE)) {
10195                 statement_t *sub_statement = statement->compound.statements;
10196                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10197                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10198                                 continue;
10199                         /* don't emit a warning for the last expression in an expression
10200                          * statement as it has always an effect */
10201                         if (inside_expression_statement && sub_statement->base.next == NULL)
10202                                 continue;
10203
10204                         expression_t *expression = sub_statement->expression.expression;
10205                         if (!expression_has_effect(expression)) {
10206                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10207                         }
10208                 }
10209         }
10210
10211 end_error:
10212         rem_anchor_token(T_while);
10213         rem_anchor_token(T_wchar_t);
10214         rem_anchor_token(T_volatile);
10215         rem_anchor_token(T_void);
10216         rem_anchor_token(T_using);
10217         rem_anchor_token(T_unsigned);
10218         rem_anchor_token(T_union);
10219         rem_anchor_token(T_typeof);
10220         rem_anchor_token(T_typename);
10221         rem_anchor_token(T_typeid);
10222         rem_anchor_token(T_typedef);
10223         rem_anchor_token(T_try);
10224         rem_anchor_token(T_true);
10225         rem_anchor_token(T_throw);
10226         rem_anchor_token(T_this);
10227         rem_anchor_token(T_template);
10228         rem_anchor_token(T_switch);
10229         rem_anchor_token(T_struct);
10230         rem_anchor_token(T_static_cast);
10231         rem_anchor_token(T_static);
10232         rem_anchor_token(T_sizeof);
10233         rem_anchor_token(T_signed);
10234         rem_anchor_token(T_short);
10235         rem_anchor_token(T_return);
10236         rem_anchor_token(T_restrict);
10237         rem_anchor_token(T_reinterpret_cast);
10238         rem_anchor_token(T_register);
10239         rem_anchor_token(T_operator);
10240         rem_anchor_token(T_new);
10241         rem_anchor_token(T_long);
10242         rem_anchor_token(T_int);
10243         rem_anchor_token(T_inline);
10244         rem_anchor_token(T_if);
10245         rem_anchor_token(T_goto);
10246         rem_anchor_token(T_for);
10247         rem_anchor_token(T_float);
10248         rem_anchor_token(T_false);
10249         rem_anchor_token(T_extern);
10250         rem_anchor_token(T_enum);
10251         rem_anchor_token(T_dynamic_cast);
10252         rem_anchor_token(T_do);
10253         rem_anchor_token(T_double);
10254         rem_anchor_token(T_delete);
10255         rem_anchor_token(T_default);
10256         rem_anchor_token(T_continue);
10257         rem_anchor_token(T_const_cast);
10258         rem_anchor_token(T_const);
10259         rem_anchor_token(T_class);
10260         rem_anchor_token(T_char);
10261         rem_anchor_token(T_case);
10262         rem_anchor_token(T_break);
10263         rem_anchor_token(T_bool);
10264         rem_anchor_token(T_auto);
10265         rem_anchor_token(T_asm);
10266         rem_anchor_token(T___thread);
10267         rem_anchor_token(T___real__);
10268         rem_anchor_token(T___label__);
10269         rem_anchor_token(T___imag__);
10270         rem_anchor_token(T___func__);
10271         rem_anchor_token(T___extension__);
10272         rem_anchor_token(T___builtin_va_start);
10273         rem_anchor_token(T___attribute__);
10274         rem_anchor_token(T___alignof__);
10275         rem_anchor_token(T___PRETTY_FUNCTION__);
10276         rem_anchor_token(T___FUNCTION__);
10277         rem_anchor_token(T__Imaginary);
10278         rem_anchor_token(T__Complex);
10279         rem_anchor_token(T__Bool);
10280         rem_anchor_token(T_WIDE_STRING_LITERAL);
10281         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10282         rem_anchor_token(T_STRING_LITERAL);
10283         rem_anchor_token(T_PLUSPLUS);
10284         rem_anchor_token(T_MINUSMINUS);
10285         rem_anchor_token(T_INTEGER);
10286         rem_anchor_token(T_IDENTIFIER);
10287         rem_anchor_token(T_FLOATINGPOINT);
10288         rem_anchor_token(T_COLONCOLON);
10289         rem_anchor_token(T_CHARACTER_CONSTANT);
10290         rem_anchor_token('~');
10291         rem_anchor_token('{');
10292         rem_anchor_token('-');
10293         rem_anchor_token('+');
10294         rem_anchor_token('*');
10295         rem_anchor_token('(');
10296         rem_anchor_token('&');
10297         rem_anchor_token('!');
10298         rem_anchor_token('}');
10299
10300         POP_SCOPE();
10301         POP_PARENT();
10302         return statement;
10303 }
10304
10305 /**
10306  * Check for unused global static functions and variables
10307  */
10308 static void check_unused_globals(void)
10309 {
10310         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10311                 return;
10312
10313         for (const entity_t *entity = file_scope->entities; entity != NULL;
10314              entity = entity->base.next) {
10315                 if (!is_declaration(entity))
10316                         continue;
10317
10318                 const declaration_t *declaration = &entity->declaration;
10319                 if (declaration->used                  ||
10320                     declaration->modifiers & DM_UNUSED ||
10321                     declaration->modifiers & DM_USED   ||
10322                     declaration->storage_class != STORAGE_CLASS_STATIC)
10323                         continue;
10324
10325                 warning_t   why;
10326                 char const *s;
10327                 if (entity->kind == ENTITY_FUNCTION) {
10328                         /* inhibit warning for static inline functions */
10329                         if (entity->function.is_inline)
10330                                 continue;
10331
10332                         why = WARN_UNUSED_FUNCTION;
10333                         s   = entity->function.statement != NULL ? "defined" : "declared";
10334                 } else {
10335                         why = WARN_UNUSED_VARIABLE;
10336                         s   = "defined";
10337                 }
10338
10339                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10340         }
10341 }
10342
10343 static void parse_global_asm(void)
10344 {
10345         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10346
10347         eat(T_asm);
10348         expect('(', end_error);
10349
10350         statement->asms.asm_text = parse_string_literals();
10351         statement->base.next     = unit->global_asm;
10352         unit->global_asm         = statement;
10353
10354         expect(')', end_error);
10355         expect(';', end_error);
10356
10357 end_error:;
10358 }
10359
10360 static void parse_linkage_specification(void)
10361 {
10362         eat(T_extern);
10363
10364         source_position_t const pos     = *HERE;
10365         char const       *const linkage = parse_string_literals().begin;
10366
10367         linkage_kind_t old_linkage = current_linkage;
10368         linkage_kind_t new_linkage;
10369         if (strcmp(linkage, "C") == 0) {
10370                 new_linkage = LINKAGE_C;
10371         } else if (strcmp(linkage, "C++") == 0) {
10372                 new_linkage = LINKAGE_CXX;
10373         } else {
10374                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10375                 new_linkage = LINKAGE_C;
10376         }
10377         current_linkage = new_linkage;
10378
10379         if (next_if('{')) {
10380                 parse_externals();
10381                 expect('}', end_error);
10382         } else {
10383                 parse_external();
10384         }
10385
10386 end_error:
10387         assert(current_linkage == new_linkage);
10388         current_linkage = old_linkage;
10389 }
10390
10391 static void parse_external(void)
10392 {
10393         switch (token.kind) {
10394                 case T_extern:
10395                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10396                                 parse_linkage_specification();
10397                         } else {
10398                 DECLARATION_START_NO_EXTERN
10399                 case T_IDENTIFIER:
10400                 case T___extension__:
10401                 /* tokens below are for implicit int */
10402                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10403                               implicit int) */
10404                 case '*':  /* * x; -> int* x; */
10405                 case '(':  /* (x); -> int (x); */
10406                                 PUSH_EXTENSION();
10407                                 parse_external_declaration();
10408                                 POP_EXTENSION();
10409                         }
10410                         return;
10411
10412                 case T_asm:
10413                         parse_global_asm();
10414                         return;
10415
10416                 case T_namespace:
10417                         parse_namespace_definition();
10418                         return;
10419
10420                 case ';':
10421                         if (!strict_mode) {
10422                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10423                                 next_token();
10424                                 return;
10425                         }
10426                         /* FALLTHROUGH */
10427
10428                 default:
10429                         errorf(HERE, "stray %K outside of function", &token);
10430                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10431                                 eat_until_matching_token(token.kind);
10432                         next_token();
10433                         return;
10434         }
10435 }
10436
10437 static void parse_externals(void)
10438 {
10439         add_anchor_token('}');
10440         add_anchor_token(T_EOF);
10441
10442 #ifndef NDEBUG
10443         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10444         unsigned short token_anchor_copy[T_LAST_TOKEN];
10445         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10446 #endif
10447
10448         while (token.kind != T_EOF && token.kind != '}') {
10449 #ifndef NDEBUG
10450                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10451                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10452                         if (count != 0) {
10453                                 /* the anchor set and its copy differs */
10454                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10455                         }
10456                 }
10457                 if (in_gcc_extension) {
10458                         /* an gcc extension scope was not closed */
10459                         internal_errorf(HERE, "Leaked __extension__");
10460                 }
10461 #endif
10462
10463                 parse_external();
10464         }
10465
10466         rem_anchor_token(T_EOF);
10467         rem_anchor_token('}');
10468 }
10469
10470 /**
10471  * Parse a translation unit.
10472  */
10473 static void parse_translation_unit(void)
10474 {
10475         add_anchor_token(T_EOF);
10476
10477         while (true) {
10478                 parse_externals();
10479
10480                 if (token.kind == T_EOF)
10481                         break;
10482
10483                 errorf(HERE, "stray %K outside of function", &token);
10484                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10485                         eat_until_matching_token(token.kind);
10486                 next_token();
10487         }
10488 }
10489
10490 void set_default_visibility(elf_visibility_tag_t visibility)
10491 {
10492         default_visibility = visibility;
10493 }
10494
10495 /**
10496  * Parse the input.
10497  *
10498  * @return  the translation unit or NULL if errors occurred.
10499  */
10500 void start_parsing(void)
10501 {
10502         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10503         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10504         diagnostic_count  = 0;
10505         error_count       = 0;
10506         warning_count     = 0;
10507
10508         print_to_file(stderr);
10509
10510         assert(unit == NULL);
10511         unit = allocate_ast_zero(sizeof(unit[0]));
10512
10513         assert(file_scope == NULL);
10514         file_scope = &unit->scope;
10515
10516         assert(current_scope == NULL);
10517         scope_push(&unit->scope);
10518
10519         create_gnu_builtins();
10520         if (c_mode & _MS)
10521                 create_microsoft_intrinsics();
10522 }
10523
10524 translation_unit_t *finish_parsing(void)
10525 {
10526         assert(current_scope == &unit->scope);
10527         scope_pop(NULL);
10528
10529         assert(file_scope == &unit->scope);
10530         check_unused_globals();
10531         file_scope = NULL;
10532
10533         DEL_ARR_F(environment_stack);
10534         DEL_ARR_F(label_stack);
10535
10536         translation_unit_t *result = unit;
10537         unit = NULL;
10538         return result;
10539 }
10540
10541 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10542  * are given length one. */
10543 static void complete_incomplete_arrays(void)
10544 {
10545         size_t n = ARR_LEN(incomplete_arrays);
10546         for (size_t i = 0; i != n; ++i) {
10547                 declaration_t *const decl = incomplete_arrays[i];
10548                 type_t        *const type = skip_typeref(decl->type);
10549
10550                 if (!is_type_incomplete(type))
10551                         continue;
10552
10553                 source_position_t const *const pos = &decl->base.source_position;
10554                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10555
10556                 type_t *const new_type = duplicate_type(type);
10557                 new_type->array.size_constant     = true;
10558                 new_type->array.has_implicit_size = true;
10559                 new_type->array.size              = 1;
10560
10561                 type_t *const result = identify_new_type(new_type);
10562
10563                 decl->type = result;
10564         }
10565 }
10566
10567 void prepare_main_collect2(entity_t *entity)
10568 {
10569         // create call to __main
10570         symbol_t *symbol         = symbol_table_insert("__main");
10571         entity_t *subsubmain_ent
10572                 = create_implicit_function(symbol, &builtin_source_position);
10573
10574         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10575         type_t       *ftype       = subsubmain_ent->declaration.type;
10576         ref->base.source_position = builtin_source_position;
10577         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10578         ref->reference.entity     = subsubmain_ent;
10579
10580         expression_t *call = allocate_expression_zero(EXPR_CALL);
10581         call->base.source_position = builtin_source_position;
10582         call->base.type            = type_void;
10583         call->call.function        = ref;
10584
10585         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10586         expr_statement->base.source_position  = builtin_source_position;
10587         expr_statement->expression.expression = call;
10588
10589         statement_t *statement = entity->function.statement;
10590         assert(statement->kind == STATEMENT_COMPOUND);
10591         compound_statement_t *compounds = &statement->compound;
10592
10593         expr_statement->base.next = compounds->statements;
10594         compounds->statements     = expr_statement;
10595 }
10596
10597 void parse(void)
10598 {
10599         lookahead_bufpos = 0;
10600         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10601                 next_token();
10602         }
10603         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10604         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10605         parse_translation_unit();
10606         complete_incomplete_arrays();
10607         DEL_ARR_F(incomplete_arrays);
10608         incomplete_arrays = NULL;
10609 }
10610
10611 /**
10612  * Initialize the parser.
10613  */
10614 void init_parser(void)
10615 {
10616         sym_anonymous = symbol_table_insert("<anonymous>");
10617
10618         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10619
10620         init_expression_parsers();
10621         obstack_init(&temp_obst);
10622 }
10623
10624 /**
10625  * Terminate the parser.
10626  */
10627 void exit_parser(void)
10628 {
10629         obstack_free(&temp_obst, NULL);
10630 }