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 "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_PARENT(stmt) \
 113         statement_t *const new_parent = (stmt); \
 114         statement_t *const old_parent = current_parent; \
 115         ((void)(current_parent = new_parent))
 116 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 117
 118 #define PUSH_SCOPE(scope) \
 119         size_t   const top       = environment_top(); \
 120         scope_t *const new_scope = (scope); \
 121         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 122 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 123 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 124
 125 #define PUSH_EXTENSION() \
 126         (void)0; \
 127         bool const old_gcc_extension = in_gcc_extension; \
 128         while (next_if(T___extension__)) { \
 129                 in_gcc_extension = true; \
 130         } \
 131         do {} while (0)
 132 #define POP_EXTENSION() \
 133         ((void)(in_gcc_extension = old_gcc_extension))
 134
 135 /** special symbol used for anonymous entities. */
 136 static symbol_t *sym_anonymous = NULL;
 137
 138 /** The token anchor set */
 139 static unsigned short token_anchor_set[T_LAST_TOKEN];
 140
 141 /** The current source position. */
 142 #define HERE (&token.base.source_position)
 143
 144 /** true if we are in GCC mode. */
 145 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 146
 147 static statement_t *parse_compound_statement(bool inside_expression_statement);
 148 static statement_t *parse_statement(void);
 149
 150 static expression_t *parse_subexpression(precedence_t);
 151 static expression_t *parse_expression(void);
 152 static type_t       *parse_typename(void);
 153 static void          parse_externals(void);
 154 static void          parse_external(void);
 155
 156 static void parse_compound_type_entries(compound_t *compound_declaration);
 157
 158 static void check_call_argument(type_t          *expected_type,
 159                                                                 call_argument_t *argument, unsigned pos);
 160
 161 typedef enum declarator_flags_t {
 162         DECL_FLAGS_NONE             = 0,
 163         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 164         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 165         DECL_IS_PARAMETER           = 1U << 2
 166 } declarator_flags_t;
 167
 168 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 169                                   declarator_flags_t flags);
 170
 171 static void semantic_comparison(binary_expression_t *expression);
 172
 173 #define STORAGE_CLASSES       \
 174         STORAGE_CLASSES_NO_EXTERN \
 175         case T_extern:
 176
 177 #define STORAGE_CLASSES_NO_EXTERN \
 178         case T_typedef:         \
 179         case T_static:          \
 180         case T_auto:            \
 181         case T_register:        \
 182         case T___thread:
 183
 184 #define TYPE_QUALIFIERS     \
 185         case T_const:           \
 186         case T_restrict:        \
 187         case T_volatile:        \
 188         case T_inline:          \
 189         case T__forceinline:    \
 190         case T___attribute__:
 191
 192 #define COMPLEX_SPECIFIERS  \
 193         case T__Complex:
 194 #define IMAGINARY_SPECIFIERS \
 195         case T__Imaginary:
 196
 197 #define TYPE_SPECIFIERS       \
 198         case T__Bool:             \
 199         case T___builtin_va_list: \
 200         case T___typeof__:        \
 201         case T__declspec:         \
 202         case T_bool:              \
 203         case T_char:              \
 204         case T_double:            \
 205         case T_enum:              \
 206         case T_float:             \
 207         case T_int:               \
 208         case T_long:              \
 209         case T_short:             \
 210         case T_signed:            \
 211         case T_struct:            \
 212         case T_union:             \
 213         case T_unsigned:          \
 214         case T_void:              \
 215         case T_wchar_t:           \
 216         case T__int8:             \
 217         case T__int16:            \
 218         case T__int32:            \
 219         case T__int64:            \
 220         case T__int128:           \
 221         COMPLEX_SPECIFIERS        \
 222         IMAGINARY_SPECIFIERS
 223
 224 #define DECLARATION_START   \
 225         STORAGE_CLASSES         \
 226         TYPE_QUALIFIERS         \
 227         TYPE_SPECIFIERS
 228
 229 #define DECLARATION_START_NO_EXTERN \
 230         STORAGE_CLASSES_NO_EXTERN       \
 231         TYPE_QUALIFIERS                 \
 232         TYPE_SPECIFIERS
 233
 234 #define EXPRESSION_START              \
 235         case '!':                         \
 236         case '&':                         \
 237         case '(':                         \
 238         case '*':                         \
 239         case '+':                         \
 240         case '-':                         \
 241         case '~':                         \
 242         case T_ANDAND:                    \
 243         case T_CHARACTER_CONSTANT:        \
 244         case T_FLOATINGPOINT:             \
 245         case T_FLOATINGPOINT_HEXADECIMAL: \
 246         case T_INTEGER:                   \
 247         case T_INTEGER_HEXADECIMAL:       \
 248         case T_INTEGER_OCTAL:             \
 249         case T_MINUSMINUS:                \
 250         case T_PLUSPLUS:                  \
 251         case T_STRING_LITERAL:            \
 252         case T_WIDE_CHARACTER_CONSTANT:   \
 253         case T_WIDE_STRING_LITERAL:       \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___FUNCTION__:              \
 257         case T___PRETTY_FUNCTION__:       \
 258         case T___alignof__:               \
 259         case T___builtin_classify_type:   \
 260         case T___builtin_constant_p:      \
 261         case T___builtin_isgreater:       \
 262         case T___builtin_isgreaterequal:  \
 263         case T___builtin_isless:          \
 264         case T___builtin_islessequal:     \
 265         case T___builtin_islessgreater:   \
 266         case T___builtin_isunordered:     \
 267         case T___builtin_offsetof:        \
 268         case T___builtin_va_arg:          \
 269         case T___builtin_va_copy:         \
 270         case T___builtin_va_start:        \
 271         case T___func__:                  \
 272         case T___noop:                    \
 273         case T__assume:                   \
 274         case T_delete:                    \
 275         case T_false:                     \
 276         case T_sizeof:                    \
 277         case T_throw:                     \
 278         case T_true:
 279
 280 /**
 281  * Returns the size of a statement node.
 282  *
 283  * @param kind  the statement kind
 284  */
 285 static size_t get_statement_struct_size(statement_kind_t kind)
 286 {
 287         static const size_t sizes[] = {
 288                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 289                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 290                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 291                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 292                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 293                 [STATEMENT_IF]            = sizeof(if_statement_t),
 294                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 295                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 296                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 297                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 298                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 299                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 300                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 301                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 302                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 303                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 304                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 305                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 306                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 307                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 308         };
 309         assert((size_t)kind < lengthof(sizes));
 310         assert(sizes[kind] != 0);
 311         return sizes[kind];
 312 }
 313
 314 /**
 315  * Returns the size of an expression node.
 316  *
 317  * @param kind  the expression kind
 318  */
 319 static size_t get_expression_struct_size(expression_kind_t kind)
 320 {
 321         static const size_t sizes[] = {
 322                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 323                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 324                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 325                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 331                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 332                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 333                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 334                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 335                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 336                 [EXPR_CALL]                       = sizeof(call_expression_t),
 337                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 338                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 339                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 340                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 341                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 342                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 343                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 344                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 345                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 346                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 347                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 348                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 349                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 350                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 351                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 352                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 353                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 354         };
 355         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 356                 return sizes[EXPR_UNARY_FIRST];
 357         }
 358         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 359                 return sizes[EXPR_BINARY_FIRST];
 360         }
 361         assert((size_t)kind < lengthof(sizes));
 362         assert(sizes[kind] != 0);
 363         return sizes[kind];
 364 }
 365
 366 /**
 367  * Allocate a statement node of given kind and initialize all
 368  * fields with zero. Sets its source position to the position
 369  * of the current token.
 370  */
 371 static statement_t *allocate_statement_zero(statement_kind_t kind)
 372 {
 373         size_t       size = get_statement_struct_size(kind);
 374         statement_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.parent          = current_parent;
 378         res->base.source_position = token.base.source_position;
 379         return res;
 380 }
 381
 382 /**
 383  * Allocate an expression node of given kind and initialize all
 384  * fields with zero.
 385  *
 386  * @param kind  the kind of the expression to allocate
 387  */
 388 static expression_t *allocate_expression_zero(expression_kind_t kind)
 389 {
 390         size_t        size = get_expression_struct_size(kind);
 391         expression_t *res  = allocate_ast_zero(size);
 392
 393         res->base.kind            = kind;
 394         res->base.type            = type_error_type;
 395         res->base.source_position = token.base.source_position;
 396         return res;
 397 }
 398
 399 /**
 400  * Creates a new invalid expression at the source position
 401  * of the current token.
 402  */
 403 static expression_t *create_error_expression(void)
 404 {
 405         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 406         expression->base.type = type_error_type;
 407         return expression;
 408 }
 409
 410 /**
 411  * Creates a new invalid statement.
 412  */
 413 static statement_t *create_error_statement(void)
 414 {
 415         return allocate_statement_zero(STATEMENT_ERROR);
 416 }
 417
 418 /**
 419  * Allocate a new empty statement.
 420  */
 421 static statement_t *create_empty_statement(void)
 422 {
 423         return allocate_statement_zero(STATEMENT_EMPTY);
 424 }
 425
 426 /**
 427  * Returns the size of an initializer node.
 428  *
 429  * @param kind  the initializer kind
 430  */
 431 static size_t get_initializer_size(initializer_kind_t kind)
 432 {
 433         static const size_t sizes[] = {
 434                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 435                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 436                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 437                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 438                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 439         };
 440         assert((size_t)kind < lengthof(sizes));
 441         assert(sizes[kind] != 0);
 442         return sizes[kind];
 443 }
 444
 445 /**
 446  * Allocate an initializer node of given kind and initialize all
 447  * fields with zero.
 448  */
 449 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 450 {
 451         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 452         result->kind          = kind;
 453
 454         return result;
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the environment stack.
 459  */
 460 static size_t environment_top(void)
 461 {
 462         return ARR_LEN(environment_stack);
 463 }
 464
 465 /**
 466  * Returns the index of the top element of the global label stack.
 467  */
 468 static size_t label_top(void)
 469 {
 470         return ARR_LEN(label_stack);
 471 }
 472
 473 /**
 474  * Return the next token.
 475  */
 476 static inline void next_token(void)
 477 {
 478         token                              = lookahead_buffer[lookahead_bufpos];
 479         lookahead_buffer[lookahead_bufpos] = lexer_token;
 480         lexer_next_token();
 481
 482         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 483
 484 #ifdef PRINT_TOKENS
 485         print_token(stderr, &token);
 486         fprintf(stderr, "\n");
 487 #endif
 488 }
 489
 490 static inline bool next_if(int const type)
 491 {
 492         if (token.kind == type) {
 493                 next_token();
 494                 return true;
 495         } else {
 496                 return false;
 497         }
 498 }
 499
 500 /**
 501  * Return the next token with a given lookahead.
 502  */
 503 static inline const token_t *look_ahead(size_t num)
 504 {
 505         assert(0 < num && num <= MAX_LOOKAHEAD);
 506         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 507         return &lookahead_buffer[pos];
 508 }
 509
 510 /**
 511  * Adds a token type to the token type anchor set (a multi-set).
 512  */
 513 static void add_anchor_token(int token_kind)
 514 {
 515         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 516         ++token_anchor_set[token_kind];
 517 }
 518
 519 /**
 520  * Remove a token type from the token type anchor set (a multi-set).
 521  */
 522 static void rem_anchor_token(int token_kind)
 523 {
 524         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 525         assert(token_anchor_set[token_kind] != 0);
 526         --token_anchor_set[token_kind];
 527 }
 528
 529 /**
 530  * Eat tokens until a matching token type is found.
 531  */
 532 static void eat_until_matching_token(int type)
 533 {
 534         int end_token;
 535         switch (type) {
 536                 case '(': end_token = ')';  break;
 537                 case '{': end_token = '}';  break;
 538                 case '[': end_token = ']';  break;
 539                 default:  end_token = type; break;
 540         }
 541
 542         unsigned parenthesis_count = 0;
 543         unsigned brace_count       = 0;
 544         unsigned bracket_count     = 0;
 545         while (token.kind        != end_token ||
 546                parenthesis_count != 0         ||
 547                brace_count       != 0         ||
 548                bracket_count     != 0) {
 549                 switch (token.kind) {
 550                 case T_EOF: return;
 551                 case '(': ++parenthesis_count; break;
 552                 case '{': ++brace_count;       break;
 553                 case '[': ++bracket_count;     break;
 554
 555                 case ')':
 556                         if (parenthesis_count > 0)
 557                                 --parenthesis_count;
 558                         goto check_stop;
 559
 560                 case '}':
 561                         if (brace_count > 0)
 562                                 --brace_count;
 563                         goto check_stop;
 564
 565                 case ']':
 566                         if (bracket_count > 0)
 567                                 --bracket_count;
 568 check_stop:
 569                         if (token.kind        == end_token &&
 570                             parenthesis_count == 0         &&
 571                             brace_count       == 0         &&
 572                             bracket_count     == 0)
 573                                 return;
 574                         break;
 575
 576                 default:
 577                         break;
 578                 }
 579                 next_token();
 580         }
 581 }
 582
 583 /**
 584  * Eat input tokens until an anchor is found.
 585  */
 586 static void eat_until_anchor(void)
 587 {
 588         while (token_anchor_set[token.kind] == 0) {
 589                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 590                         eat_until_matching_token(token.kind);
 591                 next_token();
 592         }
 593 }
 594
 595 /**
 596  * Eat a whole block from input tokens.
 597  */
 598 static void eat_block(void)
 599 {
 600         eat_until_matching_token('{');
 601         next_if('}');
 602 }
 603
 604 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 605
 606 /**
 607  * Report a parse error because an expected token was not found.
 608  */
 609 static
 610 #if defined __GNUC__ && __GNUC__ >= 4
 611 __attribute__((sentinel))
 612 #endif
 613 void parse_error_expected(const char *message, ...)
 614 {
 615         if (message != NULL) {
 616                 errorf(HERE, "%s", message);
 617         }
 618         va_list ap;
 619         va_start(ap, message);
 620         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 621         va_end(ap);
 622 }
 623
 624 /**
 625  * Report an incompatible type.
 626  */
 627 static void type_error_incompatible(const char *msg,
 628                 const source_position_t *source_position, type_t *type1, type_t *type2)
 629 {
 630         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 631                msg, type1, type2);
 632 }
 633
 634 /**
 635  * Expect the current token is the expected token.
 636  * If not, generate an error and skip until the next anchor.
 637  */
 638 static void expect(token_kind_t const expected)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(NULL, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return;
 647         }
 648         eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (token.kind != T_IDENTIFIER) {
 654                 parse_error_expected(context, T_IDENTIFIER, NULL);
 655                 add_anchor_token(T_IDENTIFIER);
 656                 eat_until_anchor();
 657                 rem_anchor_token(T_IDENTIFIER);
 658                 if (token.kind != T_IDENTIFIER)
 659                         return NULL;
 660         }
 661         symbol_t *const sym = token.identifier.symbol;
 662         if (pos)
 663                 *pos = *HERE;
 664         eat(T_IDENTIFIER);
 665         return sym;
 666 }
 667
 668 /**
 669  * Push a given scope on the scope stack and make it the
 670  * current scope
 671  */
 672 static scope_t *scope_push(scope_t *new_scope)
 673 {
 674         if (current_scope != NULL) {
 675                 new_scope->depth = current_scope->depth + 1;
 676         }
 677
 678         scope_t *old_scope = current_scope;
 679         current_scope      = new_scope;
 680         return old_scope;
 681 }
 682
 683 /**
 684  * Pop the current scope from the scope stack.
 685  */
 686 static void scope_pop(scope_t *old_scope)
 687 {
 688         current_scope = old_scope;
 689 }
 690
 691 /**
 692  * Search an entity by its symbol in a given namespace.
 693  */
 694 static entity_t *get_entity(const symbol_t *const symbol,
 695                             namespace_tag_t namespc)
 696 {
 697         entity_t *entity = symbol->entity;
 698         for (; entity != NULL; entity = entity->base.symbol_next) {
 699                 if ((namespace_tag_t)entity->base.namespc == namespc)
 700                         return entity;
 701         }
 702
 703         return NULL;
 704 }
 705
 706 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 707  * possible. */
 708 static entity_t *get_tag(symbol_t const *const symbol,
 709                          entity_kind_tag_t const kind)
 710 {
 711         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 712         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 713                 errorf(HERE,
 714                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 715                                 symbol, &entity->base.source_position);
 716                 entity = NULL;
 717         }
 718         return entity;
 719 }
 720
 721 /**
 722  * pushs an entity on the environment stack and links the corresponding symbol
 723  * it.
 724  */
 725 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 726 {
 727         symbol_t           *symbol  = entity->base.symbol;
 728         entity_namespace_t  namespc = entity->base.namespc;
 729         assert(namespc != 0);
 730
 731         /* replace/add entity into entity list of the symbol */
 732         entity_t **anchor;
 733         entity_t  *iter;
 734         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 735                 iter = *anchor;
 736                 if (iter == NULL)
 737                         break;
 738
 739                 /* replace an entry? */
 740                 if (iter->base.namespc == namespc) {
 741                         entity->base.symbol_next = iter->base.symbol_next;
 742                         break;
 743                 }
 744         }
 745         *anchor = entity;
 746
 747         /* remember old declaration */
 748         stack_entry_t entry;
 749         entry.symbol     = symbol;
 750         entry.old_entity = iter;
 751         entry.namespc    = namespc;
 752         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 753 }
 754
 755 /**
 756  * Push an entity on the environment stack.
 757  */
 758 static void environment_push(entity_t *entity)
 759 {
 760         assert(entity->base.source_position.input_name != NULL);
 761         assert(entity->base.parent_scope != NULL);
 762         stack_push(&environment_stack, entity);
 763 }
 764
 765 /**
 766  * Push a declaration on the global label stack.
 767  *
 768  * @param declaration  the declaration
 769  */
 770 static void label_push(entity_t *label)
 771 {
 772         /* we abuse the parameters scope as parent for the labels */
 773         label->base.parent_scope = &current_function->parameters;
 774         stack_push(&label_stack, label);
 775 }
 776
 777 /**
 778  * pops symbols from the environment stack until @p new_top is the top element
 779  */
 780 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 781 {
 782         stack_entry_t *stack = *stack_ptr;
 783         size_t         top   = ARR_LEN(stack);
 784         size_t         i;
 785
 786         assert(new_top <= top);
 787         if (new_top == top)
 788                 return;
 789
 790         for (i = top; i > new_top; --i) {
 791                 stack_entry_t *entry = &stack[i - 1];
 792
 793                 entity_t           *old_entity = entry->old_entity;
 794                 symbol_t           *symbol     = entry->symbol;
 795                 entity_namespace_t  namespc    = entry->namespc;
 796
 797                 /* replace with old_entity/remove */
 798                 entity_t **anchor;
 799                 entity_t  *iter;
 800                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 801                         iter = *anchor;
 802                         assert(iter != NULL);
 803                         /* replace an entry? */
 804                         if (iter->base.namespc == namespc)
 805                                 break;
 806                 }
 807
 808                 /* restore definition from outer scopes (if there was one) */
 809                 if (old_entity != NULL) {
 810                         old_entity->base.symbol_next = iter->base.symbol_next;
 811                         *anchor                      = old_entity;
 812                 } else {
 813                         /* remove entry from list */
 814                         *anchor = iter->base.symbol_next;
 815                 }
 816         }
 817
 818         ARR_SHRINKLEN(*stack_ptr, new_top);
 819 }
 820
 821 /**
 822  * Pop all entries from the environment stack until the new_top
 823  * is reached.
 824  *
 825  * @param new_top  the new stack top
 826  */
 827 static void environment_pop_to(size_t new_top)
 828 {
 829         stack_pop_to(&environment_stack, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the global label stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void label_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&label_stack, new_top);
 841 }
 842
 843 static atomic_type_kind_t get_akind(const type_t *type)
 844 {
 845         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 846                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 847         return type->atomic.akind;
 848 }
 849
 850 /**
 851  * §6.3.1.1:2  Do integer promotion for a given type.
 852  *
 853  * @param type  the type to promote
 854  * @return the promoted type
 855  */
 856 static type_t *promote_integer(type_t *type)
 857 {
 858         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 859                 type = type_int;
 860
 861         return type;
 862 }
 863
 864 /**
 865  * Check if a given expression represents a null pointer constant.
 866  *
 867  * @param expression  the expression to check
 868  */
 869 static bool is_null_pointer_constant(const expression_t *expression)
 870 {
 871         /* skip void* cast */
 872         if (expression->kind == EXPR_UNARY_CAST) {
 873                 type_t *const type = skip_typeref(expression->base.type);
 874                 if (types_compatible(type, type_void_ptr))
 875                         expression = expression->unary.value;
 876         }
 877
 878         type_t *const type = skip_typeref(expression->base.type);
 879         if (!is_type_integer(type))
 880                 return false;
 881         switch (is_constant_expression(expression)) {
 882                 case EXPR_CLASS_ERROR:    return true;
 883                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 884                 default:                  return false;
 885         }
 886 }
 887
 888 /**
 889  * Create an implicit cast expression.
 890  *
 891  * @param expression  the expression to cast
 892  * @param dest_type   the destination type
 893  */
 894 static expression_t *create_implicit_cast(expression_t *expression,
 895                                           type_t *dest_type)
 896 {
 897         type_t *const source_type = expression->base.type;
 898
 899         if (source_type == dest_type)
 900                 return expression;
 901
 902         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 903         cast->unary.value   = expression;
 904         cast->base.type     = dest_type;
 905         cast->base.implicit = true;
 906
 907         return cast;
 908 }
 909
 910 typedef enum assign_error_t {
 911         ASSIGN_SUCCESS,
 912         ASSIGN_ERROR_INCOMPATIBLE,
 913         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 914         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 915         ASSIGN_WARNING_POINTER_FROM_INT,
 916         ASSIGN_WARNING_INT_FROM_POINTER
 917 } assign_error_t;
 918
 919 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)
 920 {
 921         type_t *const orig_type_right = right->base.type;
 922         type_t *const type_left       = skip_typeref(orig_type_left);
 923         type_t *const type_right      = skip_typeref(orig_type_right);
 924
 925         switch (error) {
 926         case ASSIGN_SUCCESS:
 927                 return;
 928         case ASSIGN_ERROR_INCOMPATIBLE:
 929                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 930                 return;
 931
 932         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 933                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 934                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 935
 936                 /* the left type has all qualifiers from the right type */
 937                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 938                 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);
 939                 return;
 940         }
 941
 942         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 943                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_POINTER_FROM_INT:
 947                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         case ASSIGN_WARNING_INT_FROM_POINTER:
 951                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 952                 return;
 953
 954         default:
 955                 panic("invalid error value");
 956         }
 957 }
 958
 959 /** Implements the rules from §6.5.16.1 */
 960 static assign_error_t semantic_assign(type_t *orig_type_left,
 961                                       const expression_t *const right)
 962 {
 963         type_t *const orig_type_right = right->base.type;
 964         type_t *const type_left       = skip_typeref(orig_type_left);
 965         type_t *const type_right      = skip_typeref(orig_type_right);
 966
 967         if (is_type_pointer(type_left)) {
 968                 if (is_null_pointer_constant(right)) {
 969                         return ASSIGN_SUCCESS;
 970                 } else if (is_type_pointer(type_right)) {
 971                         type_t *points_to_left
 972                                 = skip_typeref(type_left->pointer.points_to);
 973                         type_t *points_to_right
 974                                 = skip_typeref(type_right->pointer.points_to);
 975                         assign_error_t res = ASSIGN_SUCCESS;
 976
 977                         /* the left type has all qualifiers from the right type */
 978                         unsigned missing_qualifiers
 979                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 980                         if (missing_qualifiers != 0) {
 981                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 982                         }
 983
 984                         points_to_left  = get_unqualified_type(points_to_left);
 985                         points_to_right = get_unqualified_type(points_to_right);
 986
 987                         if (is_type_void(points_to_left))
 988                                 return res;
 989
 990                         if (is_type_void(points_to_right)) {
 991                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 992                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 993                         }
 994
 995                         if (!types_compatible(points_to_left, points_to_right)) {
 996                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 997                         }
 998
 999                         return res;
1000                 } else if (is_type_integer(type_right)) {
1001                         return ASSIGN_WARNING_POINTER_FROM_INT;
1002                 }
1003         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1004                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1005                                 && is_type_pointer(type_right))) {
1006                 return ASSIGN_SUCCESS;
1007         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1008                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1009                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1010                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1011                         return ASSIGN_SUCCESS;
1012                 }
1013         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1014                 return ASSIGN_WARNING_INT_FROM_POINTER;
1015         }
1016
1017         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1018                 return ASSIGN_SUCCESS;
1019
1020         return ASSIGN_ERROR_INCOMPATIBLE;
1021 }
1022
1023 static expression_t *parse_constant_expression(void)
1024 {
1025         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1026
1027         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1028                 errorf(&result->base.source_position,
1029                        "expression '%E' is not constant", result);
1030         }
1031
1032         return result;
1033 }
1034
1035 static expression_t *parse_assignment_expression(void)
1036 {
1037         return parse_subexpression(PREC_ASSIGNMENT);
1038 }
1039
1040 static void warn_string_concat(const source_position_t *pos)
1041 {
1042         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1043 }
1044
1045 static string_t parse_string_literals(void)
1046 {
1047         assert(token.kind == T_STRING_LITERAL);
1048         string_t result = token.string.string;
1049
1050         next_token();
1051
1052         while (token.kind == T_STRING_LITERAL) {
1053                 warn_string_concat(&token.base.source_position);
1054                 result = concat_strings(&result, &token.string.string);
1055                 next_token();
1056         }
1057
1058         return result;
1059 }
1060
1061 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1062 {
1063         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1064         attribute->kind            = kind;
1065         attribute->source_position = *HERE;
1066         return attribute;
1067 }
1068
1069 /**
1070  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1071  *
1072  *  attribute:
1073  *    __attribute__ ( ( attribute-list ) )
1074  *
1075  *  attribute-list:
1076  *    attrib
1077  *    attribute_list , attrib
1078  *
1079  *  attrib:
1080  *    empty
1081  *    any-word
1082  *    any-word ( identifier )
1083  *    any-word ( identifier , nonempty-expr-list )
1084  *    any-word ( expr-list )
1085  *
1086  *  where the "identifier" must not be declared as a type, and
1087  *  "any-word" may be any identifier (including one declared as a
1088  *  type), a reserved word storage class specifier, type specifier or
1089  *  type qualifier.  ??? This still leaves out most reserved keywords
1090  *  (following the old parser), shouldn't we include them, and why not
1091  *  allow identifiers declared as types to start the arguments?
1092  *
1093  *  Matze: this all looks confusing and little systematic, so we're even less
1094  *  strict and parse any list of things which are identifiers or
1095  *  (assignment-)expressions.
1096  */
1097 static attribute_argument_t *parse_attribute_arguments(void)
1098 {
1099         attribute_argument_t  *first  = NULL;
1100         attribute_argument_t **anchor = &first;
1101         if (token.kind != ')') do {
1102                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1103
1104                 /* is it an identifier */
1105                 if (token.kind == T_IDENTIFIER
1106                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1107                         symbol_t *symbol   = token.identifier.symbol;
1108                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1109                         argument->v.symbol = symbol;
1110                         next_token();
1111                 } else {
1112                         /* must be an expression */
1113                         expression_t *expression = parse_assignment_expression();
1114
1115                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1116                         argument->v.expression = expression;
1117                 }
1118
1119                 /* append argument */
1120                 *anchor = argument;
1121                 anchor  = &argument->next;
1122         } while (next_if(','));
1123         expect(')');
1124         return first;
1125 }
1126
1127 static attribute_t *parse_attribute_asm(void)
1128 {
1129         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1130         eat(T_asm);
1131         expect('(');
1132         attribute->a.arguments = parse_attribute_arguments();
1133         return attribute;
1134 }
1135
1136 static symbol_t *get_symbol_from_token(void)
1137 {
1138         switch(token.kind) {
1139         case T_IDENTIFIER:
1140                 return token.identifier.symbol;
1141         case T_auto:
1142         case T_char:
1143         case T_double:
1144         case T_enum:
1145         case T_extern:
1146         case T_float:
1147         case T_int:
1148         case T_long:
1149         case T_register:
1150         case T_short:
1151         case T_static:
1152         case T_struct:
1153         case T_union:
1154         case T_unsigned:
1155         case T_void:
1156         case T_bool:
1157         case T__Bool:
1158         case T_class:
1159         case T_explicit:
1160         case T_export:
1161         case T_wchar_t:
1162         case T_const:
1163         case T_signed:
1164         case T___real__:
1165         case T___imag__:
1166         case T_restrict:
1167         case T_volatile:
1168         case T_inline:
1169                 /* maybe we need more tokens ... add them on demand */
1170                 return get_token_kind_symbol(token.kind);
1171         default:
1172                 return NULL;
1173         }
1174 }
1175
1176 static attribute_t *parse_attribute_gnu_single(void)
1177 {
1178         /* parse "any-word" */
1179         symbol_t *symbol = get_symbol_from_token();
1180         if (symbol == NULL) {
1181                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1182                 return NULL;
1183         }
1184
1185         attribute_kind_t  kind;
1186         char const *const name = symbol->string;
1187         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1188                 if (kind > ATTRIBUTE_GNU_LAST) {
1189                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1190                         /* TODO: we should still save the attribute in the list... */
1191                         kind = ATTRIBUTE_UNKNOWN;
1192                         break;
1193                 }
1194
1195                 const char *attribute_name = get_attribute_name(kind);
1196                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1197                         break;
1198         }
1199
1200         attribute_t *attribute = allocate_attribute_zero(kind);
1201         next_token();
1202
1203         /* parse arguments */
1204         if (next_if('('))
1205                 attribute->a.arguments = parse_attribute_arguments();
1206
1207         return attribute;
1208 }
1209
1210 static attribute_t *parse_attribute_gnu(void)
1211 {
1212         attribute_t  *first  = NULL;
1213         attribute_t **anchor = &first;
1214
1215         eat(T___attribute__);
1216         expect('(');
1217         expect('(');
1218
1219         add_anchor_token(')');
1220         add_anchor_token(',');
1221         if (token.kind != ')') do {
1222                 attribute_t *attribute = parse_attribute_gnu_single();
1223                 if (attribute) {
1224                         *anchor = attribute;
1225                         anchor  = &attribute->next;
1226                 }
1227         } while (next_if(','));
1228         rem_anchor_token(',');
1229         rem_anchor_token(')');
1230
1231         expect(')');
1232         expect(')');
1233         return first;
1234 }
1235
1236 /** Parse attributes. */
1237 static attribute_t *parse_attributes(attribute_t *first)
1238 {
1239         attribute_t **anchor = &first;
1240         for (;;) {
1241                 while (*anchor != NULL)
1242                         anchor = &(*anchor)->next;
1243
1244                 attribute_t *attribute;
1245                 switch (token.kind) {
1246                 case T___attribute__:
1247                         attribute = parse_attribute_gnu();
1248                         if (attribute == NULL)
1249                                 continue;
1250                         break;
1251
1252                 case T_asm:
1253                         attribute = parse_attribute_asm();
1254                         break;
1255
1256                 case T_cdecl:
1257                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1258                         eat(T_cdecl);
1259                         break;
1260
1261                 case T__fastcall:
1262                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1263                         eat(T__fastcall);
1264                         break;
1265
1266                 case T__forceinline:
1267                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1268                         eat(T__forceinline);
1269                         break;
1270
1271                 case T__stdcall:
1272                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1273                         eat(T__stdcall);
1274                         break;
1275
1276                 case T___thiscall:
1277                         /* TODO record modifier */
1278                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1279                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1280                         eat(T___thiscall);
1281                         break;
1282
1283                 default:
1284                         return first;
1285                 }
1286
1287                 *anchor = attribute;
1288                 anchor  = &attribute->next;
1289         }
1290 }
1291
1292 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1293
1294 static entity_t *determine_lhs_ent(expression_t *const expr,
1295                                    entity_t *lhs_ent)
1296 {
1297         switch (expr->kind) {
1298                 case EXPR_REFERENCE: {
1299                         entity_t *const entity = expr->reference.entity;
1300                         /* we should only find variables as lvalues... */
1301                         if (entity->base.kind != ENTITY_VARIABLE
1302                                         && entity->base.kind != ENTITY_PARAMETER)
1303                                 return NULL;
1304
1305                         return entity;
1306                 }
1307
1308                 case EXPR_ARRAY_ACCESS: {
1309                         expression_t *const ref = expr->array_access.array_ref;
1310                         entity_t     *      ent = NULL;
1311                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1312                                 ent     = determine_lhs_ent(ref, lhs_ent);
1313                                 lhs_ent = ent;
1314                         } else {
1315                                 mark_vars_read(ref, lhs_ent);
1316                         }
1317                         mark_vars_read(expr->array_access.index, lhs_ent);
1318                         return ent;
1319                 }
1320
1321                 case EXPR_SELECT: {
1322                         mark_vars_read(expr->select.compound, lhs_ent);
1323                         if (is_type_compound(skip_typeref(expr->base.type)))
1324                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1325                         return NULL;
1326                 }
1327
1328                 case EXPR_UNARY_DEREFERENCE: {
1329                         expression_t *const val = expr->unary.value;
1330                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1331                                 /* *&x is a NOP */
1332                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1333                         } else {
1334                                 mark_vars_read(val, NULL);
1335                                 return NULL;
1336                         }
1337                 }
1338
1339                 default:
1340                         mark_vars_read(expr, NULL);
1341                         return NULL;
1342         }
1343 }
1344
1345 #define ENT_ANY ((entity_t*)-1)
1346
1347 /**
1348  * Mark declarations, which are read.  This is used to detect variables, which
1349  * are never read.
1350  * Example:
1351  * x = x + 1;
1352  *   x is not marked as "read", because it is only read to calculate its own new
1353  *   value.
1354  *
1355  * x += y; y += x;
1356  *   x and y are not detected as "not read", because multiple variables are
1357  *   involved.
1358  */
1359 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1360 {
1361         switch (expr->kind) {
1362                 case EXPR_REFERENCE: {
1363                         entity_t *const entity = expr->reference.entity;
1364                         if (entity->kind != ENTITY_VARIABLE
1365                                         && entity->kind != ENTITY_PARAMETER)
1366                                 return;
1367
1368                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1369                                 if (entity->kind == ENTITY_VARIABLE) {
1370                                         entity->variable.read = true;
1371                                 } else {
1372                                         entity->parameter.read = true;
1373                                 }
1374                         }
1375                         return;
1376                 }
1377
1378                 case EXPR_CALL:
1379                         // TODO respect pure/const
1380                         mark_vars_read(expr->call.function, NULL);
1381                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1382                                 mark_vars_read(arg->expression, NULL);
1383                         }
1384                         return;
1385
1386                 case EXPR_CONDITIONAL:
1387                         // TODO lhs_decl should depend on whether true/false have an effect
1388                         mark_vars_read(expr->conditional.condition, NULL);
1389                         if (expr->conditional.true_expression != NULL)
1390                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1391                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1392                         return;
1393
1394                 case EXPR_SELECT:
1395                         if (lhs_ent == ENT_ANY
1396                                         && !is_type_compound(skip_typeref(expr->base.type)))
1397                                 lhs_ent = NULL;
1398                         mark_vars_read(expr->select.compound, lhs_ent);
1399                         return;
1400
1401                 case EXPR_ARRAY_ACCESS: {
1402                         mark_vars_read(expr->array_access.index, lhs_ent);
1403                         expression_t *const ref = expr->array_access.array_ref;
1404                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1405                                 if (lhs_ent == ENT_ANY)
1406                                         lhs_ent = NULL;
1407                         }
1408                         mark_vars_read(ref, lhs_ent);
1409                         return;
1410                 }
1411
1412                 case EXPR_VA_ARG:
1413                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1414                         return;
1415
1416                 case EXPR_VA_COPY:
1417                         mark_vars_read(expr->va_copye.src, lhs_ent);
1418                         return;
1419
1420                 case EXPR_UNARY_CAST:
1421                         /* Special case: Use void cast to mark a variable as "read" */
1422                         if (is_type_void(skip_typeref(expr->base.type)))
1423                                 lhs_ent = NULL;
1424                         goto unary;
1425
1426
1427                 case EXPR_UNARY_THROW:
1428                         if (expr->unary.value == NULL)
1429                                 return;
1430                         /* FALLTHROUGH */
1431                 case EXPR_UNARY_DEREFERENCE:
1432                 case EXPR_UNARY_DELETE:
1433                 case EXPR_UNARY_DELETE_ARRAY:
1434                         if (lhs_ent == ENT_ANY)
1435                                 lhs_ent = NULL;
1436                         goto unary;
1437
1438                 case EXPR_UNARY_NEGATE:
1439                 case EXPR_UNARY_PLUS:
1440                 case EXPR_UNARY_BITWISE_NEGATE:
1441                 case EXPR_UNARY_NOT:
1442                 case EXPR_UNARY_TAKE_ADDRESS:
1443                 case EXPR_UNARY_POSTFIX_INCREMENT:
1444                 case EXPR_UNARY_POSTFIX_DECREMENT:
1445                 case EXPR_UNARY_PREFIX_INCREMENT:
1446                 case EXPR_UNARY_PREFIX_DECREMENT:
1447                 case EXPR_UNARY_ASSUME:
1448 unary:
1449                         mark_vars_read(expr->unary.value, lhs_ent);
1450                         return;
1451
1452                 case EXPR_BINARY_ADD:
1453                 case EXPR_BINARY_SUB:
1454                 case EXPR_BINARY_MUL:
1455                 case EXPR_BINARY_DIV:
1456                 case EXPR_BINARY_MOD:
1457                 case EXPR_BINARY_EQUAL:
1458                 case EXPR_BINARY_NOTEQUAL:
1459                 case EXPR_BINARY_LESS:
1460                 case EXPR_BINARY_LESSEQUAL:
1461                 case EXPR_BINARY_GREATER:
1462                 case EXPR_BINARY_GREATEREQUAL:
1463                 case EXPR_BINARY_BITWISE_AND:
1464                 case EXPR_BINARY_BITWISE_OR:
1465                 case EXPR_BINARY_BITWISE_XOR:
1466                 case EXPR_BINARY_LOGICAL_AND:
1467                 case EXPR_BINARY_LOGICAL_OR:
1468                 case EXPR_BINARY_SHIFTLEFT:
1469                 case EXPR_BINARY_SHIFTRIGHT:
1470                 case EXPR_BINARY_COMMA:
1471                 case EXPR_BINARY_ISGREATER:
1472                 case EXPR_BINARY_ISGREATEREQUAL:
1473                 case EXPR_BINARY_ISLESS:
1474                 case EXPR_BINARY_ISLESSEQUAL:
1475                 case EXPR_BINARY_ISLESSGREATER:
1476                 case EXPR_BINARY_ISUNORDERED:
1477                         mark_vars_read(expr->binary.left,  lhs_ent);
1478                         mark_vars_read(expr->binary.right, lhs_ent);
1479                         return;
1480
1481                 case EXPR_BINARY_ASSIGN:
1482                 case EXPR_BINARY_MUL_ASSIGN:
1483                 case EXPR_BINARY_DIV_ASSIGN:
1484                 case EXPR_BINARY_MOD_ASSIGN:
1485                 case EXPR_BINARY_ADD_ASSIGN:
1486                 case EXPR_BINARY_SUB_ASSIGN:
1487                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1488                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1489                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1490                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1491                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1492                         if (lhs_ent == ENT_ANY)
1493                                 lhs_ent = NULL;
1494                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1495                         mark_vars_read(expr->binary.right, lhs_ent);
1496                         return;
1497                 }
1498
1499                 case EXPR_VA_START:
1500                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1501                         return;
1502
1503                 case EXPR_LITERAL_CASES:
1504                 case EXPR_ERROR:
1505                 case EXPR_STRING_LITERAL:
1506                 case EXPR_WIDE_STRING_LITERAL:
1507                 case EXPR_COMPOUND_LITERAL: // TODO init?
1508                 case EXPR_SIZEOF:
1509                 case EXPR_CLASSIFY_TYPE:
1510                 case EXPR_ALIGNOF:
1511                 case EXPR_FUNCNAME:
1512                 case EXPR_BUILTIN_CONSTANT_P:
1513                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1514                 case EXPR_OFFSETOF:
1515                 case EXPR_STATEMENT: // TODO
1516                 case EXPR_LABEL_ADDRESS:
1517                 case EXPR_ENUM_CONSTANT:
1518                         return;
1519         }
1520
1521         panic("unhandled expression");
1522 }
1523
1524 static designator_t *parse_designation(void)
1525 {
1526         designator_t  *result = NULL;
1527         designator_t **anchor = &result;
1528
1529         for (;;) {
1530                 designator_t *designator;
1531                 switch (token.kind) {
1532                 case '[':
1533                         designator = allocate_ast_zero(sizeof(designator[0]));
1534                         designator->source_position = token.base.source_position;
1535                         next_token();
1536                         add_anchor_token(']');
1537                         designator->array_index = parse_constant_expression();
1538                         rem_anchor_token(']');
1539                         expect(']');
1540                         break;
1541                 case '.':
1542                         designator = allocate_ast_zero(sizeof(designator[0]));
1543                         designator->source_position = token.base.source_position;
1544                         next_token();
1545                         designator->symbol = expect_identifier("while parsing designator", NULL);
1546                         if (!designator->symbol)
1547                                 return NULL;
1548                         break;
1549                 default:
1550                         expect('=');
1551                         return result;
1552                 }
1553
1554                 assert(designator != NULL);
1555                 *anchor = designator;
1556                 anchor  = &designator->next;
1557         }
1558 }
1559
1560 static initializer_t *initializer_from_string(array_type_t *const type,
1561                                               const string_t *const string)
1562 {
1563         /* TODO: check len vs. size of array type */
1564         (void) type;
1565
1566         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1567         initializer->string.string = *string;
1568
1569         return initializer;
1570 }
1571
1572 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1573                                                    const string_t *const string)
1574 {
1575         /* TODO: check len vs. size of array type */
1576         (void) type;
1577
1578         initializer_t *const initializer =
1579                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1580         initializer->wide_string.string = *string;
1581
1582         return initializer;
1583 }
1584
1585 /**
1586  * Build an initializer from a given expression.
1587  */
1588 static initializer_t *initializer_from_expression(type_t *orig_type,
1589                                                   expression_t *expression)
1590 {
1591         /* TODO check that expression is a constant expression */
1592
1593         /* §6.7.8.14/15 char array may be initialized by string literals */
1594         type_t *type           = skip_typeref(orig_type);
1595         type_t *expr_type_orig = expression->base.type;
1596         type_t *expr_type      = skip_typeref(expr_type_orig);
1597
1598         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1599                 array_type_t *const array_type   = &type->array;
1600                 type_t       *const element_type = skip_typeref(array_type->element_type);
1601
1602                 if (element_type->kind == TYPE_ATOMIC) {
1603                         atomic_type_kind_t akind = element_type->atomic.akind;
1604                         switch (expression->kind) {
1605                         case EXPR_STRING_LITERAL:
1606                                 if (akind == ATOMIC_TYPE_CHAR
1607                                                 || akind == ATOMIC_TYPE_SCHAR
1608                                                 || akind == ATOMIC_TYPE_UCHAR) {
1609                                         return initializer_from_string(array_type,
1610                                                         &expression->string_literal.value);
1611                                 }
1612                                 break;
1613
1614                         case EXPR_WIDE_STRING_LITERAL: {
1615                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1616                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1617                                         return initializer_from_wide_string(array_type,
1618                                                         &expression->string_literal.value);
1619                                 }
1620                                 break;
1621                         }
1622
1623                         default:
1624                                 break;
1625                         }
1626                 }
1627         }
1628
1629         assign_error_t error = semantic_assign(type, expression);
1630         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1631                 return NULL;
1632         report_assign_error(error, type, expression, "initializer",
1633                             &expression->base.source_position);
1634
1635         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1636         result->value.value = create_implicit_cast(expression, type);
1637
1638         return result;
1639 }
1640
1641 /**
1642  * Parses an scalar initializer.
1643  *
1644  * §6.7.8.11; eat {} without warning
1645  */
1646 static initializer_t *parse_scalar_initializer(type_t *type,
1647                                                bool must_be_constant)
1648 {
1649         /* there might be extra {} hierarchies */
1650         int braces = 0;
1651         if (token.kind == '{') {
1652                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1653                 do {
1654                         eat('{');
1655                         ++braces;
1656                 } while (token.kind == '{');
1657         }
1658
1659         expression_t *expression = parse_assignment_expression();
1660         mark_vars_read(expression, NULL);
1661         if (must_be_constant && !is_linker_constant(expression)) {
1662                 errorf(&expression->base.source_position,
1663                        "initialisation expression '%E' is not constant",
1664                        expression);
1665         }
1666
1667         initializer_t *initializer = initializer_from_expression(type, expression);
1668
1669         if (initializer == NULL) {
1670                 errorf(&expression->base.source_position,
1671                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1672                        expression, expression->base.type, type);
1673                 /* TODO */
1674                 return NULL;
1675         }
1676
1677         bool additional_warning_displayed = false;
1678         while (braces > 0) {
1679                 next_if(',');
1680                 if (token.kind != '}') {
1681                         if (!additional_warning_displayed) {
1682                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1683                                 additional_warning_displayed = true;
1684                         }
1685                 }
1686                 eat_block();
1687                 braces--;
1688         }
1689
1690         return initializer;
1691 }
1692
1693 /**
1694  * An entry in the type path.
1695  */
1696 typedef struct type_path_entry_t type_path_entry_t;
1697 struct type_path_entry_t {
1698         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1699         union {
1700                 size_t         index;          /**< For array types: the current index. */
1701                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1702         } v;
1703 };
1704
1705 /**
1706  * A type path expression a position inside compound or array types.
1707  */
1708 typedef struct type_path_t type_path_t;
1709 struct type_path_t {
1710         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1711         type_t            *top_type;     /**< type of the element the path points */
1712         size_t             max_index;    /**< largest index in outermost array */
1713 };
1714
1715 /**
1716  * Prints a type path for debugging.
1717  */
1718 static __attribute__((unused)) void debug_print_type_path(
1719                 const type_path_t *path)
1720 {
1721         size_t len = ARR_LEN(path->path);
1722
1723         for (size_t i = 0; i < len; ++i) {
1724                 const type_path_entry_t *entry = & path->path[i];
1725
1726                 type_t *type = skip_typeref(entry->type);
1727                 if (is_type_compound(type)) {
1728                         /* in gcc mode structs can have no members */
1729                         if (entry->v.compound_entry == NULL) {
1730                                 assert(i == len-1);
1731                                 continue;
1732                         }
1733                         fprintf(stderr, ".%s",
1734                                 entry->v.compound_entry->base.symbol->string);
1735                 } else if (is_type_array(type)) {
1736                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1737                 } else {
1738                         fprintf(stderr, "-INVALID-");
1739                 }
1740         }
1741         if (path->top_type != NULL) {
1742                 fprintf(stderr, "  (");
1743                 print_type(path->top_type);
1744                 fprintf(stderr, ")");
1745         }
1746 }
1747
1748 /**
1749  * Return the top type path entry, ie. in a path
1750  * (type).a.b returns the b.
1751  */
1752 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1753 {
1754         size_t len = ARR_LEN(path->path);
1755         assert(len > 0);
1756         return &path->path[len-1];
1757 }
1758
1759 /**
1760  * Enlarge the type path by an (empty) element.
1761  */
1762 static type_path_entry_t *append_to_type_path(type_path_t *path)
1763 {
1764         size_t len = ARR_LEN(path->path);
1765         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1766
1767         type_path_entry_t *result = & path->path[len];
1768         memset(result, 0, sizeof(result[0]));
1769         return result;
1770 }
1771
1772 /**
1773  * Descending into a sub-type. Enter the scope of the current top_type.
1774  */
1775 static void descend_into_subtype(type_path_t *path)
1776 {
1777         type_t *orig_top_type = path->top_type;
1778         type_t *top_type      = skip_typeref(orig_top_type);
1779
1780         type_path_entry_t *top = append_to_type_path(path);
1781         top->type              = top_type;
1782
1783         if (is_type_compound(top_type)) {
1784                 compound_t *const compound = top_type->compound.compound;
1785                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1786
1787                 if (entry != NULL) {
1788                         top->v.compound_entry = &entry->declaration;
1789                         path->top_type = entry->declaration.type;
1790                 } else {
1791                         path->top_type = NULL;
1792                 }
1793         } else if (is_type_array(top_type)) {
1794                 top->v.index   = 0;
1795                 path->top_type = top_type->array.element_type;
1796         } else {
1797                 assert(!is_type_valid(top_type));
1798         }
1799 }
1800
1801 /**
1802  * Pop an entry from the given type path, ie. returning from
1803  * (type).a.b to (type).a
1804  */
1805 static void ascend_from_subtype(type_path_t *path)
1806 {
1807         type_path_entry_t *top = get_type_path_top(path);
1808
1809         path->top_type = top->type;
1810
1811         size_t len = ARR_LEN(path->path);
1812         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1813 }
1814
1815 /**
1816  * Pop entries from the given type path until the given
1817  * path level is reached.
1818  */
1819 static void ascend_to(type_path_t *path, size_t top_path_level)
1820 {
1821         size_t len = ARR_LEN(path->path);
1822
1823         while (len > top_path_level) {
1824                 ascend_from_subtype(path);
1825                 len = ARR_LEN(path->path);
1826         }
1827 }
1828
1829 static bool walk_designator(type_path_t *path, const designator_t *designator,
1830                             bool used_in_offsetof)
1831 {
1832         for (; designator != NULL; designator = designator->next) {
1833                 type_path_entry_t *top       = get_type_path_top(path);
1834                 type_t            *orig_type = top->type;
1835
1836                 type_t *type = skip_typeref(orig_type);
1837
1838                 if (designator->symbol != NULL) {
1839                         symbol_t *symbol = designator->symbol;
1840                         if (!is_type_compound(type)) {
1841                                 if (is_type_valid(type)) {
1842                                         errorf(&designator->source_position,
1843                                                "'.%Y' designator used for non-compound type '%T'",
1844                                                symbol, orig_type);
1845                                 }
1846
1847                                 top->type             = type_error_type;
1848                                 top->v.compound_entry = NULL;
1849                                 orig_type             = type_error_type;
1850                         } else {
1851                                 compound_t *compound = type->compound.compound;
1852                                 entity_t   *iter     = compound->members.entities;
1853                                 for (; iter != NULL; iter = iter->base.next) {
1854                                         if (iter->base.symbol == symbol) {
1855                                                 break;
1856                                         }
1857                                 }
1858                                 if (iter == NULL) {
1859                                         errorf(&designator->source_position,
1860                                                "'%T' has no member named '%Y'", orig_type, symbol);
1861                                         return false;
1862                                 }
1863                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1864                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1865                                         errorf(&designator->source_position,
1866                                                    "offsetof designator '%Y' must not specify bitfield",
1867                                                    symbol);
1868                                         return false;
1869                                 }
1870
1871                                 top->type             = orig_type;
1872                                 top->v.compound_entry = &iter->declaration;
1873                                 orig_type             = iter->declaration.type;
1874                         }
1875                 } else {
1876                         expression_t *array_index = designator->array_index;
1877                         assert(designator->array_index != NULL);
1878
1879                         if (!is_type_array(type)) {
1880                                 if (is_type_valid(type)) {
1881                                         errorf(&designator->source_position,
1882                                                "[%E] designator used for non-array type '%T'",
1883                                                array_index, orig_type);
1884                                 }
1885                                 return false;
1886                         }
1887
1888                         long index = fold_constant_to_int(array_index);
1889                         if (!used_in_offsetof) {
1890                                 if (index < 0) {
1891                                         errorf(&designator->source_position,
1892                                                "array index [%E] must be positive", array_index);
1893                                 } else if (type->array.size_constant) {
1894                                         long array_size = type->array.size;
1895                                         if (index >= array_size) {
1896                                                 errorf(&designator->source_position,
1897                                                        "designator [%E] (%d) exceeds array size %d",
1898                                                        array_index, index, array_size);
1899                                         }
1900                                 }
1901                         }
1902
1903                         top->type    = orig_type;
1904                         top->v.index = (size_t) index;
1905                         orig_type    = type->array.element_type;
1906                 }
1907                 path->top_type = orig_type;
1908
1909                 if (designator->next != NULL) {
1910                         descend_into_subtype(path);
1911                 }
1912         }
1913         return true;
1914 }
1915
1916 static void advance_current_object(type_path_t *path, size_t top_path_level)
1917 {
1918         type_path_entry_t *top = get_type_path_top(path);
1919
1920         type_t *type = skip_typeref(top->type);
1921         if (is_type_union(type)) {
1922                 /* in unions only the first element is initialized */
1923                 top->v.compound_entry = NULL;
1924         } else if (is_type_struct(type)) {
1925                 declaration_t *entry = top->v.compound_entry;
1926
1927                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1928                 if (next_entity != NULL) {
1929                         assert(is_declaration(next_entity));
1930                         entry = &next_entity->declaration;
1931                 } else {
1932                         entry = NULL;
1933                 }
1934
1935                 top->v.compound_entry = entry;
1936                 if (entry != NULL) {
1937                         path->top_type = entry->type;
1938                         return;
1939                 }
1940         } else if (is_type_array(type)) {
1941                 assert(is_type_array(type));
1942
1943                 top->v.index++;
1944
1945                 if (!type->array.size_constant || top->v.index < type->array.size) {
1946                         return;
1947                 }
1948         } else {
1949                 assert(!is_type_valid(type));
1950                 return;
1951         }
1952
1953         /* we're past the last member of the current sub-aggregate, try if we
1954          * can ascend in the type hierarchy and continue with another subobject */
1955         size_t len = ARR_LEN(path->path);
1956
1957         if (len > top_path_level) {
1958                 ascend_from_subtype(path);
1959                 advance_current_object(path, top_path_level);
1960         } else {
1961                 path->top_type = NULL;
1962         }
1963 }
1964
1965 /**
1966  * skip any {...} blocks until a closing bracket is reached.
1967  */
1968 static void skip_initializers(void)
1969 {
1970         next_if('{');
1971
1972         while (token.kind != '}') {
1973                 if (token.kind == T_EOF)
1974                         return;
1975                 if (token.kind == '{') {
1976                         eat_block();
1977                         continue;
1978                 }
1979                 next_token();
1980         }
1981 }
1982
1983 static initializer_t *create_empty_initializer(void)
1984 {
1985         static initializer_t empty_initializer
1986                 = { .list = { { INITIALIZER_LIST }, 0 } };
1987         return &empty_initializer;
1988 }
1989
1990 /**
1991  * Parse a part of an initialiser for a struct or union,
1992  */
1993 static initializer_t *parse_sub_initializer(type_path_t *path,
1994                 type_t *outer_type, size_t top_path_level,
1995                 parse_initializer_env_t *env)
1996 {
1997         if (token.kind == '}') {
1998                 /* empty initializer */
1999                 return create_empty_initializer();
2000         }
2001
2002         type_t *orig_type = path->top_type;
2003         type_t *type      = NULL;
2004
2005         if (orig_type == NULL) {
2006                 /* We are initializing an empty compound. */
2007         } else {
2008                 type = skip_typeref(orig_type);
2009         }
2010
2011         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2012
2013         while (true) {
2014                 designator_t *designator = NULL;
2015                 if (token.kind == '.' || token.kind == '[') {
2016                         designator = parse_designation();
2017                         goto finish_designator;
2018                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2019                         /* GNU-style designator ("identifier: value") */
2020                         designator = allocate_ast_zero(sizeof(designator[0]));
2021                         designator->source_position = token.base.source_position;
2022                         designator->symbol          = token.identifier.symbol;
2023                         eat(T_IDENTIFIER);
2024                         eat(':');
2025
2026 finish_designator:
2027                         /* reset path to toplevel, evaluate designator from there */
2028                         ascend_to(path, top_path_level);
2029                         if (!walk_designator(path, designator, false)) {
2030                                 /* can't continue after designation error */
2031                                 goto end_error;
2032                         }
2033
2034                         initializer_t *designator_initializer
2035                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2036                         designator_initializer->designator.designator = designator;
2037                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2038
2039                         orig_type = path->top_type;
2040                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2041                 }
2042
2043                 initializer_t *sub;
2044
2045                 if (token.kind == '{') {
2046                         if (type != NULL && is_type_scalar(type)) {
2047                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2048                         } else {
2049                                 if (type == NULL) {
2050                                         if (env->entity != NULL) {
2051                                                 errorf(HERE,
2052                                                      "extra brace group at end of initializer for '%Y'",
2053                                                      env->entity->base.symbol);
2054                                         } else {
2055                                                 errorf(HERE, "extra brace group at end of initializer");
2056                                         }
2057                                         eat('{');
2058                                 } else {
2059                                         eat('{');
2060                                         descend_into_subtype(path);
2061                                 }
2062
2063                                 add_anchor_token('}');
2064                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2065                                                             env);
2066                                 rem_anchor_token('}');
2067
2068                                 expect('}');
2069
2070                                 if (!type)
2071                                         goto error_parse_next;
2072
2073                                 ascend_from_subtype(path);
2074                         }
2075                 } else {
2076                         /* must be an expression */
2077                         expression_t *expression = parse_assignment_expression();
2078                         mark_vars_read(expression, NULL);
2079
2080                         if (env->must_be_constant && !is_linker_constant(expression)) {
2081                                 errorf(&expression->base.source_position,
2082                                        "Initialisation expression '%E' is not constant",
2083                                        expression);
2084                         }
2085
2086                         if (type == NULL) {
2087                                 /* we are already outside, ... */
2088                                 if (outer_type == NULL)
2089                                         goto error_parse_next;
2090                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2091                                 if (is_type_compound(outer_type_skip) &&
2092                                                 !outer_type_skip->compound.compound->complete) {
2093                                         goto error_parse_next;
2094                                 }
2095
2096                                 source_position_t const* const pos = &expression->base.source_position;
2097                                 if (env->entity != NULL) {
2098                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2099                                 } else {
2100                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2101                                 }
2102                                 goto error_parse_next;
2103                         }
2104
2105                         /* handle { "string" } special case */
2106                         if ((expression->kind == EXPR_STRING_LITERAL
2107                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2108                                         && outer_type != NULL) {
2109                                 sub = initializer_from_expression(outer_type, expression);
2110                                 if (sub != NULL) {
2111                                         next_if(',');
2112                                         if (token.kind != '}') {
2113                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2114                                         }
2115                                         /* TODO: eat , ... */
2116                                         return sub;
2117                                 }
2118                         }
2119
2120                         /* descend into subtypes until expression matches type */
2121                         while (true) {
2122                                 orig_type = path->top_type;
2123                                 type      = skip_typeref(orig_type);
2124
2125                                 sub = initializer_from_expression(orig_type, expression);
2126                                 if (sub != NULL) {
2127                                         break;
2128                                 }
2129                                 if (!is_type_valid(type)) {
2130                                         goto end_error;
2131                                 }
2132                                 if (is_type_scalar(type)) {
2133                                         errorf(&expression->base.source_position,
2134                                                         "expression '%E' doesn't match expected type '%T'",
2135                                                         expression, orig_type);
2136                                         goto end_error;
2137                                 }
2138
2139                                 descend_into_subtype(path);
2140                         }
2141                 }
2142
2143                 /* update largest index of top array */
2144                 const type_path_entry_t *first      = &path->path[0];
2145                 type_t                  *first_type = first->type;
2146                 first_type                          = skip_typeref(first_type);
2147                 if (is_type_array(first_type)) {
2148                         size_t index = first->v.index;
2149                         if (index > path->max_index)
2150                                 path->max_index = index;
2151                 }
2152
2153                 /* append to initializers list */
2154                 ARR_APP1(initializer_t*, initializers, sub);
2155
2156 error_parse_next:
2157                 if (token.kind == '}') {
2158                         break;
2159                 }
2160                 add_anchor_token('}');
2161                 expect(',');
2162                 rem_anchor_token('}');
2163                 if (token.kind == '}') {
2164                         break;
2165                 }
2166
2167                 if (type != NULL) {
2168                         /* advance to the next declaration if we are not at the end */
2169                         advance_current_object(path, top_path_level);
2170                         orig_type = path->top_type;
2171                         if (orig_type != NULL)
2172                                 type = skip_typeref(orig_type);
2173                         else
2174                                 type = NULL;
2175                 }
2176         }
2177
2178         size_t len  = ARR_LEN(initializers);
2179         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2180         initializer_t *result = allocate_ast_zero(size);
2181         result->kind          = INITIALIZER_LIST;
2182         result->list.len      = len;
2183         memcpy(&result->list.initializers, initializers,
2184                len * sizeof(initializers[0]));
2185
2186         DEL_ARR_F(initializers);
2187         ascend_to(path, top_path_level+1);
2188
2189         return result;
2190
2191 end_error:
2192         skip_initializers();
2193         DEL_ARR_F(initializers);
2194         ascend_to(path, top_path_level+1);
2195         return NULL;
2196 }
2197
2198 static expression_t *make_size_literal(size_t value)
2199 {
2200         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2201         literal->base.type    = type_size_t;
2202
2203         char buf[128];
2204         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2205         literal->literal.value = make_string(buf);
2206
2207         return literal;
2208 }
2209
2210 /**
2211  * Parses an initializer. Parsers either a compound literal
2212  * (env->declaration == NULL) or an initializer of a declaration.
2213  */
2214 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2215 {
2216         type_t        *type      = skip_typeref(env->type);
2217         size_t         max_index = 0;
2218         initializer_t *result;
2219
2220         if (is_type_scalar(type)) {
2221                 result = parse_scalar_initializer(type, env->must_be_constant);
2222         } else if (token.kind == '{') {
2223                 eat('{');
2224
2225                 type_path_t path;
2226                 memset(&path, 0, sizeof(path));
2227                 path.top_type = env->type;
2228                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2229
2230                 descend_into_subtype(&path);
2231
2232                 add_anchor_token('}');
2233                 result = parse_sub_initializer(&path, env->type, 1, env);
2234                 rem_anchor_token('}');
2235
2236                 max_index = path.max_index;
2237                 DEL_ARR_F(path.path);
2238
2239                 expect('}');
2240         } else {
2241                 /* parse_scalar_initializer() also works in this case: we simply
2242                  * have an expression without {} around it */
2243                 result = parse_scalar_initializer(type, env->must_be_constant);
2244         }
2245
2246         /* §6.7.8:22 array initializers for arrays with unknown size determine
2247          * the array type size */
2248         if (is_type_array(type) && type->array.size_expression == NULL
2249                         && result != NULL) {
2250                 size_t size;
2251                 switch (result->kind) {
2252                 case INITIALIZER_LIST:
2253                         assert(max_index != 0xdeadbeaf);
2254                         size = max_index + 1;
2255                         break;
2256
2257                 case INITIALIZER_STRING:
2258                         size = result->string.string.size;
2259                         break;
2260
2261                 case INITIALIZER_WIDE_STRING:
2262                         size = result->wide_string.string.size;
2263                         break;
2264
2265                 case INITIALIZER_DESIGNATOR:
2266                 case INITIALIZER_VALUE:
2267                         /* can happen for parse errors */
2268                         size = 0;
2269                         break;
2270
2271                 default:
2272                         internal_errorf(HERE, "invalid initializer type");
2273                 }
2274
2275                 type_t *new_type = duplicate_type(type);
2276
2277                 new_type->array.size_expression   = make_size_literal(size);
2278                 new_type->array.size_constant     = true;
2279                 new_type->array.has_implicit_size = true;
2280                 new_type->array.size              = size;
2281                 env->type = new_type;
2282         }
2283
2284         return result;
2285 }
2286
2287 static void append_entity(scope_t *scope, entity_t *entity)
2288 {
2289         if (scope->last_entity != NULL) {
2290                 scope->last_entity->base.next = entity;
2291         } else {
2292                 scope->entities = entity;
2293         }
2294         entity->base.parent_entity = current_entity;
2295         scope->last_entity         = entity;
2296 }
2297
2298
2299 static compound_t *parse_compound_type_specifier(bool is_struct)
2300 {
2301         source_position_t const pos = *HERE;
2302         eat(is_struct ? T_struct : T_union);
2303
2304         symbol_t    *symbol     = NULL;
2305         entity_t    *entity     = NULL;
2306         attribute_t *attributes = NULL;
2307
2308         if (token.kind == T___attribute__) {
2309                 attributes = parse_attributes(NULL);
2310         }
2311
2312         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2313         if (token.kind == T_IDENTIFIER) {
2314                 /* the compound has a name, check if we have seen it already */
2315                 symbol = token.identifier.symbol;
2316                 entity = get_tag(symbol, kind);
2317                 next_token();
2318
2319                 if (entity != NULL) {
2320                         if (entity->base.parent_scope != current_scope &&
2321                             (token.kind == '{' || token.kind == ';')) {
2322                                 /* we're in an inner scope and have a definition. Shadow
2323                                  * existing definition in outer scope */
2324                                 entity = NULL;
2325                         } else if (entity->compound.complete && token.kind == '{') {
2326                                 source_position_t const *const ppos = &entity->base.source_position;
2327                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2328                                 /* clear members in the hope to avoid further errors */
2329                                 entity->compound.members.entities = NULL;
2330                         }
2331                 }
2332         } else if (token.kind != '{') {
2333                 char const *const msg =
2334                         is_struct ? "while parsing struct type specifier" :
2335                                     "while parsing union type specifier";
2336                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2337
2338                 return NULL;
2339         }
2340
2341         if (entity == NULL) {
2342                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2343                 entity->compound.alignment = 1;
2344                 entity->base.parent_scope  = current_scope;
2345                 if (symbol != NULL) {
2346                         environment_push(entity);
2347                 }
2348                 append_entity(current_scope, entity);
2349         }
2350
2351         if (token.kind == '{') {
2352                 parse_compound_type_entries(&entity->compound);
2353
2354                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2355                 if (symbol == NULL) {
2356                         assert(anonymous_entity == NULL);
2357                         anonymous_entity = entity;
2358                 }
2359         }
2360
2361         if (attributes != NULL) {
2362                 handle_entity_attributes(attributes, entity);
2363         }
2364
2365         return &entity->compound;
2366 }
2367
2368 static void parse_enum_entries(type_t *const enum_type)
2369 {
2370         eat('{');
2371
2372         if (token.kind == '}') {
2373                 errorf(HERE, "empty enum not allowed");
2374                 next_token();
2375                 return;
2376         }
2377
2378         add_anchor_token('}');
2379         add_anchor_token(',');
2380         do {
2381                 add_anchor_token('=');
2382                 source_position_t pos;
2383                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2384                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2385                 entity->enum_value.enum_type = enum_type;
2386                 rem_anchor_token('=');
2387
2388                 if (next_if('=')) {
2389                         expression_t *value = parse_constant_expression();
2390
2391                         value = create_implicit_cast(value, enum_type);
2392                         entity->enum_value.value = value;
2393
2394                         /* TODO semantic */
2395                 }
2396
2397                 record_entity(entity, false);
2398         } while (next_if(',') && token.kind != '}');
2399         rem_anchor_token(',');
2400         rem_anchor_token('}');
2401
2402         expect('}');
2403 }
2404
2405 static type_t *parse_enum_specifier(void)
2406 {
2407         source_position_t const pos = *HERE;
2408         entity_t               *entity;
2409         symbol_t               *symbol;
2410
2411         eat(T_enum);
2412         switch (token.kind) {
2413                 case T_IDENTIFIER:
2414                         symbol = token.identifier.symbol;
2415                         entity = get_tag(symbol, ENTITY_ENUM);
2416                         next_token();
2417
2418                         if (entity != NULL) {
2419                                 if (entity->base.parent_scope != current_scope &&
2420                                                 (token.kind == '{' || token.kind == ';')) {
2421                                         /* we're in an inner scope and have a definition. Shadow
2422                                          * existing definition in outer scope */
2423                                         entity = NULL;
2424                                 } else if (entity->enume.complete && token.kind == '{') {
2425                                         source_position_t const *const ppos = &entity->base.source_position;
2426                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2427                                 }
2428                         }
2429                         break;
2430
2431                 case '{':
2432                         entity = NULL;
2433                         symbol = NULL;
2434                         break;
2435
2436                 default:
2437                         parse_error_expected("while parsing enum type specifier",
2438                                         T_IDENTIFIER, '{', NULL);
2439                         return NULL;
2440         }
2441
2442         if (entity == NULL) {
2443                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2444                 entity->base.parent_scope = current_scope;
2445         }
2446
2447         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2448         type->enumt.enume      = &entity->enume;
2449         type->enumt.base.akind = ATOMIC_TYPE_INT;
2450
2451         if (token.kind == '{') {
2452                 if (symbol != NULL) {
2453                         environment_push(entity);
2454                 }
2455                 append_entity(current_scope, entity);
2456                 entity->enume.complete = true;
2457
2458                 parse_enum_entries(type);
2459                 parse_attributes(NULL);
2460
2461                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2462                 if (symbol == NULL) {
2463                         assert(anonymous_entity == NULL);
2464                         anonymous_entity = entity;
2465                 }
2466         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2467                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2468         }
2469
2470         return type;
2471 }
2472
2473 /**
2474  * if a symbol is a typedef to another type, return true
2475  */
2476 static bool is_typedef_symbol(symbol_t *symbol)
2477 {
2478         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2479         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2480 }
2481
2482 static type_t *parse_typeof(void)
2483 {
2484         eat(T___typeof__);
2485
2486         type_t *type;
2487
2488         expect('(');
2489         add_anchor_token(')');
2490
2491         expression_t *expression  = NULL;
2492
2493         switch (token.kind) {
2494         case T_IDENTIFIER:
2495                 if (is_typedef_symbol(token.identifier.symbol)) {
2496         DECLARATION_START
2497                         type = parse_typename();
2498                 } else {
2499         default:
2500                         expression = parse_expression();
2501                         type       = revert_automatic_type_conversion(expression);
2502                 }
2503                 break;
2504         }
2505
2506         rem_anchor_token(')');
2507         expect(')');
2508
2509         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2510         typeof_type->typeoft.expression  = expression;
2511         typeof_type->typeoft.typeof_type = type;
2512
2513         return typeof_type;
2514 }
2515
2516 typedef enum specifiers_t {
2517         SPECIFIER_SIGNED    = 1 << 0,
2518         SPECIFIER_UNSIGNED  = 1 << 1,
2519         SPECIFIER_LONG      = 1 << 2,
2520         SPECIFIER_INT       = 1 << 3,
2521         SPECIFIER_DOUBLE    = 1 << 4,
2522         SPECIFIER_CHAR      = 1 << 5,
2523         SPECIFIER_WCHAR_T   = 1 << 6,
2524         SPECIFIER_SHORT     = 1 << 7,
2525         SPECIFIER_LONG_LONG = 1 << 8,
2526         SPECIFIER_FLOAT     = 1 << 9,
2527         SPECIFIER_BOOL      = 1 << 10,
2528         SPECIFIER_VOID      = 1 << 11,
2529         SPECIFIER_INT8      = 1 << 12,
2530         SPECIFIER_INT16     = 1 << 13,
2531         SPECIFIER_INT32     = 1 << 14,
2532         SPECIFIER_INT64     = 1 << 15,
2533         SPECIFIER_INT128    = 1 << 16,
2534         SPECIFIER_COMPLEX   = 1 << 17,
2535         SPECIFIER_IMAGINARY = 1 << 18,
2536 } specifiers_t;
2537
2538 static type_t *get_typedef_type(symbol_t *symbol)
2539 {
2540         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2541         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2542                 return NULL;
2543
2544         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2545         type->typedeft.typedefe = &entity->typedefe;
2546
2547         return type;
2548 }
2549
2550 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2551 {
2552         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2553
2554         expect('(');
2555
2556         add_anchor_token(')');
2557         add_anchor_token(',');
2558         do {
2559                 add_anchor_token('=');
2560                 source_position_t pos;
2561                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2562                 rem_anchor_token('=');
2563
2564                 symbol_t **prop = NULL;
2565                 if (prop_sym) {
2566                         if (streq(prop_sym->string, "put")) {
2567                                 prop = &property->put_symbol;
2568                         } else if (streq(prop_sym->string, "get")) {
2569                                 prop = &property->get_symbol;
2570                         } else {
2571                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2572                         }
2573                 }
2574
2575                 add_anchor_token(T_IDENTIFIER);
2576                 expect('=');
2577                 rem_anchor_token(T_IDENTIFIER);
2578
2579                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2580                 if (prop != NULL)
2581                         *prop = sym ? sym : sym_anonymous;
2582         } while (next_if(','));
2583         rem_anchor_token(',');
2584         rem_anchor_token(')');
2585
2586         attribute->a.property = property;
2587
2588         expect(')');
2589         return attribute;
2590 }
2591
2592 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2593 {
2594         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2595         if (next_if(T_restrict)) {
2596                 kind = ATTRIBUTE_MS_RESTRICT;
2597         } else if (token.kind == T_IDENTIFIER) {
2598                 const char *name = token.identifier.symbol->string;
2599                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2600                      ++k) {
2601                         const char *attribute_name = get_attribute_name(k);
2602                         if (attribute_name != NULL && streq(attribute_name, name)) {
2603                                 kind = k;
2604                                 break;
2605                         }
2606                 }
2607
2608                 if (kind == ATTRIBUTE_UNKNOWN) {
2609                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2610                 }
2611         } else {
2612                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2613                 return NULL;
2614         }
2615
2616         attribute_t *attribute = allocate_attribute_zero(kind);
2617         eat(T_IDENTIFIER);
2618
2619         if (kind == ATTRIBUTE_MS_PROPERTY) {
2620                 return parse_attribute_ms_property(attribute);
2621         }
2622
2623         /* parse arguments */
2624         if (next_if('('))
2625                 attribute->a.arguments = parse_attribute_arguments();
2626
2627         return attribute;
2628 }
2629
2630 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2631 {
2632         eat(T__declspec);
2633
2634         expect('(');
2635         if (token.kind != ')') {
2636                 add_anchor_token(')');
2637
2638                 attribute_t **anchor = &first;
2639                 do {
2640                         while (*anchor != NULL)
2641                                 anchor = &(*anchor)->next;
2642
2643                         attribute_t *attribute
2644                                 = parse_microsoft_extended_decl_modifier_single();
2645                         if (attribute == NULL)
2646                                 break;
2647
2648                         *anchor = attribute;
2649                         anchor  = &attribute->next;
2650                 } while (next_if(','));
2651
2652                 rem_anchor_token(')');
2653         }
2654         expect(')');
2655         return first;
2656 }
2657
2658 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2659 {
2660         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2661         if (is_declaration(entity)) {
2662                 entity->declaration.type     = type_error_type;
2663                 entity->declaration.implicit = true;
2664         } else if (kind == ENTITY_TYPEDEF) {
2665                 entity->typedefe.type    = type_error_type;
2666                 entity->typedefe.builtin = true;
2667         }
2668         if (kind != ENTITY_COMPOUND_MEMBER)
2669                 record_entity(entity, false);
2670         return entity;
2671 }
2672
2673 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2674 {
2675         type_t            *type            = NULL;
2676         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2677         unsigned           type_specifiers = 0;
2678         bool               newtype         = false;
2679         bool               saw_error       = false;
2680
2681         memset(specifiers, 0, sizeof(*specifiers));
2682         specifiers->source_position = token.base.source_position;
2683
2684         while (true) {
2685                 specifiers->attributes = parse_attributes(specifiers->attributes);
2686
2687                 switch (token.kind) {
2688                 /* storage class */
2689 #define MATCH_STORAGE_CLASS(token, class)                                  \
2690                 case token:                                                        \
2691                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2692                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2693                         }                                                              \
2694                         specifiers->storage_class = class;                             \
2695                         if (specifiers->thread_local)                                  \
2696                                 goto check_thread_storage_class;                           \
2697                         next_token();                                                  \
2698                         break;
2699
2700                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2701                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2702                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2703                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2704                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2705
2706                 case T__declspec:
2707                         specifiers->attributes
2708                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2709                         break;
2710
2711                 case T___thread:
2712                         if (specifiers->thread_local) {
2713                                 errorf(HERE, "duplicate '__thread'");
2714                         } else {
2715                                 specifiers->thread_local = true;
2716 check_thread_storage_class:
2717                                 switch (specifiers->storage_class) {
2718                                         case STORAGE_CLASS_EXTERN:
2719                                         case STORAGE_CLASS_NONE:
2720                                         case STORAGE_CLASS_STATIC:
2721                                                 break;
2722
2723                                                 char const* wrong;
2724                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2725                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2726                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2727 wrong_thread_storage_class:
2728                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2729                                                 break;
2730                                 }
2731                         }
2732                         next_token();
2733                         break;
2734
2735                 /* type qualifiers */
2736 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2737                 case token:                                                     \
2738                         qualifiers |= qualifier;                                    \
2739                         next_token();                                               \
2740                         break
2741
2742                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2743                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2744                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2745                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2746                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2747                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2748                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2749                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2750
2751                 /* type specifiers */
2752 #define MATCH_SPECIFIER(token, specifier, name)                         \
2753                 case token:                                                     \
2754                         if (type_specifiers & specifier) {                           \
2755                                 errorf(HERE, "multiple " name " type specifiers given"); \
2756                         } else {                                                    \
2757                                 type_specifiers |= specifier;                           \
2758                         }                                                           \
2759                         next_token();                                               \
2760                         break
2761
2762                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2763                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2764                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2765                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2766                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2767                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2768                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2769                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2770                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2771                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2772                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2773                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2774                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2775                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2776                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2777                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2778                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2779                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2780
2781                 case T_inline:
2782                         next_token();
2783                         specifiers->is_inline = true;
2784                         break;
2785
2786 #if 0
2787                 case T__forceinline:
2788                         next_token();
2789                         specifiers->modifiers |= DM_FORCEINLINE;
2790                         break;
2791 #endif
2792
2793                 case T_long:
2794                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2795                                 errorf(HERE, "too many long type specifiers given");
2796                         } else if (type_specifiers & SPECIFIER_LONG) {
2797                                 type_specifiers |= SPECIFIER_LONG_LONG;
2798                         } else {
2799                                 type_specifiers |= SPECIFIER_LONG;
2800                         }
2801                         next_token();
2802                         break;
2803
2804 #define CHECK_DOUBLE_TYPE() \
2805         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2806
2807                 case T_struct:
2808                         CHECK_DOUBLE_TYPE();
2809                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2810
2811                         type->compound.compound = parse_compound_type_specifier(true);
2812                         break;
2813                 case T_union:
2814                         CHECK_DOUBLE_TYPE();
2815                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2816                         type->compound.compound = parse_compound_type_specifier(false);
2817                         break;
2818                 case T_enum:
2819                         CHECK_DOUBLE_TYPE();
2820                         type = parse_enum_specifier();
2821                         break;
2822                 case T___typeof__:
2823                         CHECK_DOUBLE_TYPE();
2824                         type = parse_typeof();
2825                         break;
2826                 case T___builtin_va_list:
2827                         CHECK_DOUBLE_TYPE();
2828                         type = duplicate_type(type_valist);
2829                         next_token();
2830                         break;
2831
2832                 case T_IDENTIFIER: {
2833                         /* only parse identifier if we haven't found a type yet */
2834                         if (type != NULL || type_specifiers != 0) {
2835                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2836                                  * declaration, so it doesn't generate errors about expecting '(' or
2837                                  * '{' later on. */
2838                                 switch (look_ahead(1)->kind) {
2839                                         STORAGE_CLASSES
2840                                         TYPE_SPECIFIERS
2841                                         case T_const:
2842                                         case T_restrict:
2843                                         case T_volatile:
2844                                         case T_inline:
2845                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2846                                         case T_IDENTIFIER:
2847                                         case '&':
2848                                         case '*':
2849                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2850                                                 next_token();
2851                                                 continue;
2852
2853                                         default:
2854                                                 goto finish_specifiers;
2855                                 }
2856                         }
2857
2858                         type_t *const typedef_type = get_typedef_type(token.identifier.symbol);
2859                         if (typedef_type == NULL) {
2860                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2861                                  * declaration, so it doesn't generate 'implicit int' followed by more
2862                                  * errors later on. */
2863                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2864                                 switch (la1_type) {
2865                                         DECLARATION_START
2866                                         case T_IDENTIFIER:
2867                                         case '&':
2868                                         case '*': {
2869                                                 errorf(HERE, "%K does not name a type", &token);
2870
2871                                                 symbol_t *symbol = token.identifier.symbol;
2872                                                 entity_t *entity
2873                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2874
2875                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2876                                                 type->typedeft.typedefe = &entity->typedefe;
2877
2878                                                 next_token();
2879                                                 saw_error = true;
2880                                                 continue;
2881                                         }
2882
2883                                         default:
2884                                                 goto finish_specifiers;
2885                                 }
2886                         }
2887
2888                         next_token();
2889                         type = typedef_type;
2890                         break;
2891                 }
2892
2893                 /* function specifier */
2894                 default:
2895                         goto finish_specifiers;
2896                 }
2897         }
2898
2899 finish_specifiers:
2900         specifiers->attributes = parse_attributes(specifiers->attributes);
2901
2902         if (type == NULL || (saw_error && type_specifiers != 0)) {
2903                 atomic_type_kind_t atomic_type;
2904
2905                 /* match valid basic types */
2906                 switch (type_specifiers) {
2907                 case SPECIFIER_VOID:
2908                         atomic_type = ATOMIC_TYPE_VOID;
2909                         break;
2910                 case SPECIFIER_WCHAR_T:
2911                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2912                         break;
2913                 case SPECIFIER_CHAR:
2914                         atomic_type = ATOMIC_TYPE_CHAR;
2915                         break;
2916                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2917                         atomic_type = ATOMIC_TYPE_SCHAR;
2918                         break;
2919                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2920                         atomic_type = ATOMIC_TYPE_UCHAR;
2921                         break;
2922                 case SPECIFIER_SHORT:
2923                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2924                 case SPECIFIER_SHORT | SPECIFIER_INT:
2925                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2926                         atomic_type = ATOMIC_TYPE_SHORT;
2927                         break;
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2929                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2930                         atomic_type = ATOMIC_TYPE_USHORT;
2931                         break;
2932                 case SPECIFIER_INT:
2933                 case SPECIFIER_SIGNED:
2934                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2935                         atomic_type = ATOMIC_TYPE_INT;
2936                         break;
2937                 case SPECIFIER_UNSIGNED:
2938                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2939                         atomic_type = ATOMIC_TYPE_UINT;
2940                         break;
2941                 case SPECIFIER_LONG:
2942                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2943                 case SPECIFIER_LONG | SPECIFIER_INT:
2944                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2945                         atomic_type = ATOMIC_TYPE_LONG;
2946                         break;
2947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2948                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2949                         atomic_type = ATOMIC_TYPE_ULONG;
2950                         break;
2951
2952                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2953                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2954                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2955                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2956                         | SPECIFIER_INT:
2957                         atomic_type = ATOMIC_TYPE_LONGLONG;
2958                         goto warn_about_long_long;
2959
2960                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2961                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2962                         | SPECIFIER_INT:
2963                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2964 warn_about_long_long:
2965                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2966                         break;
2967
2968                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2969                         atomic_type = unsigned_int8_type_kind;
2970                         break;
2971
2972                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2973                         atomic_type = unsigned_int16_type_kind;
2974                         break;
2975
2976                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2977                         atomic_type = unsigned_int32_type_kind;
2978                         break;
2979
2980                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2981                         atomic_type = unsigned_int64_type_kind;
2982                         break;
2983
2984                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2985                         atomic_type = unsigned_int128_type_kind;
2986                         break;
2987
2988                 case SPECIFIER_INT8:
2989                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2990                         atomic_type = int8_type_kind;
2991                         break;
2992
2993                 case SPECIFIER_INT16:
2994                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2995                         atomic_type = int16_type_kind;
2996                         break;
2997
2998                 case SPECIFIER_INT32:
2999                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3000                         atomic_type = int32_type_kind;
3001                         break;
3002
3003                 case SPECIFIER_INT64:
3004                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3005                         atomic_type = int64_type_kind;
3006                         break;
3007
3008                 case SPECIFIER_INT128:
3009                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3010                         atomic_type = int128_type_kind;
3011                         break;
3012
3013                 case SPECIFIER_FLOAT:
3014                         atomic_type = ATOMIC_TYPE_FLOAT;
3015                         break;
3016                 case SPECIFIER_DOUBLE:
3017                         atomic_type = ATOMIC_TYPE_DOUBLE;
3018                         break;
3019                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3020                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3021                         break;
3022                 case SPECIFIER_BOOL:
3023                         atomic_type = ATOMIC_TYPE_BOOL;
3024                         break;
3025                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3026                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3027                         atomic_type = ATOMIC_TYPE_FLOAT;
3028                         break;
3029                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3030                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3031                         atomic_type = ATOMIC_TYPE_DOUBLE;
3032                         break;
3033                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3034                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3035                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3036                         break;
3037                 default: {
3038                         /* invalid specifier combination, give an error message */
3039                         source_position_t const* const pos = &specifiers->source_position;
3040                         if (type_specifiers == 0) {
3041                                 if (!saw_error) {
3042                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3043                                         if (!(c_mode & _CXX) && !strict_mode) {
3044                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3045                                                 atomic_type = ATOMIC_TYPE_INT;
3046                                                 break;
3047                                         } else {
3048                                                 errorf(pos, "no type specifiers given in declaration");
3049                                         }
3050                                 }
3051                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3052                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3053                                 errorf(pos, "signed and unsigned specifiers given");
3054                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3055                                 errorf(pos, "only integer types can be signed or unsigned");
3056                         } else {
3057                                 errorf(pos, "multiple datatypes in declaration");
3058                         }
3059                         goto end_error;
3060                 }
3061                 }
3062
3063                 if (type_specifiers & SPECIFIER_COMPLEX) {
3064                         type = allocate_type_zero(TYPE_COMPLEX);
3065                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3066                         type = allocate_type_zero(TYPE_IMAGINARY);
3067                 } else {
3068                         type = allocate_type_zero(TYPE_ATOMIC);
3069                 }
3070                 type->atomic.akind = atomic_type;
3071                 newtype = true;
3072         } else if (type_specifiers != 0) {
3073                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3074         }
3075
3076         /* FIXME: check type qualifiers here */
3077         type->base.qualifiers = qualifiers;
3078
3079         if (newtype) {
3080                 type = identify_new_type(type);
3081         } else {
3082                 type = typehash_insert(type);
3083         }
3084
3085         if (specifiers->attributes != NULL)
3086                 type = handle_type_attributes(specifiers->attributes, type);
3087         specifiers->type = type;
3088         return;
3089
3090 end_error:
3091         specifiers->type = type_error_type;
3092 }
3093
3094 static type_qualifiers_t parse_type_qualifiers(void)
3095 {
3096         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3097
3098         while (true) {
3099                 switch (token.kind) {
3100                 /* type qualifiers */
3101                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3102                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3103                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3104                 /* microsoft extended type modifiers */
3105                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3106                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3107                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3108                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3109                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3110
3111                 default:
3112                         return qualifiers;
3113                 }
3114         }
3115 }
3116
3117 /**
3118  * Parses an K&R identifier list
3119  */
3120 static void parse_identifier_list(scope_t *scope)
3121 {
3122         assert(token.kind == T_IDENTIFIER);
3123         do {
3124                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol, HERE);
3125                 /* a K&R parameter has no type, yet */
3126                 next_token();
3127
3128                 if (scope != NULL)
3129                         append_entity(scope, entity);
3130         } while (next_if(',') && token.kind == T_IDENTIFIER);
3131 }
3132
3133 static entity_t *parse_parameter(void)
3134 {
3135         declaration_specifiers_t specifiers;
3136         parse_declaration_specifiers(&specifiers);
3137
3138         entity_t *entity = parse_declarator(&specifiers,
3139                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3140         anonymous_entity = NULL;
3141         return entity;
3142 }
3143
3144 static void semantic_parameter_incomplete(const entity_t *entity)
3145 {
3146         assert(entity->kind == ENTITY_PARAMETER);
3147
3148         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3149          *             list in a function declarator that is part of a
3150          *             definition of that function shall not have
3151          *             incomplete type. */
3152         type_t *type = skip_typeref(entity->declaration.type);
3153         if (is_type_incomplete(type)) {
3154                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3155         }
3156 }
3157
3158 static bool has_parameters(void)
3159 {
3160         /* func(void) is not a parameter */
3161         if (look_ahead(1)->kind != ')')
3162                 return true;
3163         if (token.kind == T_IDENTIFIER) {
3164                 entity_t const *const entity
3165                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3166                 if (entity == NULL)
3167                         return true;
3168                 if (entity->kind != ENTITY_TYPEDEF)
3169                         return true;
3170                 type_t const *const type = skip_typeref(entity->typedefe.type);
3171                 if (!is_type_void(type))
3172                         return true;
3173                 if (c_mode & _CXX) {
3174                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3175                          * is not allowed. */
3176                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3177                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3178                         /* §6.7.5.3:10  Qualification is not allowed here. */
3179                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3180                 }
3181         } else if (token.kind != T_void) {
3182                 return true;
3183         }
3184         next_token();
3185         return false;
3186 }
3187
3188 /**
3189  * Parses function type parameters (and optionally creates variable_t entities
3190  * for them in a scope)
3191  */
3192 static void parse_parameters(function_type_t *type, scope_t *scope)
3193 {
3194         eat('(');
3195         add_anchor_token(')');
3196
3197         if (token.kind == T_IDENTIFIER                  &&
3198             !is_typedef_symbol(token.identifier.symbol) &&
3199             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3200                 type->kr_style_parameters = true;
3201                 parse_identifier_list(scope);
3202         } else if (token.kind == ')') {
3203                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3204                 if (!(c_mode & _CXX))
3205                         type->unspecified_parameters = true;
3206         } else if (has_parameters()) {
3207                 function_parameter_t **anchor = &type->parameters;
3208                 add_anchor_token(',');
3209                 do {
3210                         switch (token.kind) {
3211                         case T_DOTDOTDOT:
3212                                 next_token();
3213                                 type->variadic = true;
3214                                 goto parameters_finished;
3215
3216                         case T_IDENTIFIER:
3217                         DECLARATION_START
3218                         {
3219                                 entity_t *entity = parse_parameter();
3220                                 if (entity->kind == ENTITY_TYPEDEF) {
3221                                         errorf(&entity->base.source_position,
3222                                                         "typedef not allowed as function parameter");
3223                                         break;
3224                                 }
3225                                 assert(is_declaration(entity));
3226
3227                                 semantic_parameter_incomplete(entity);
3228
3229                                 function_parameter_t *const parameter =
3230                                         allocate_parameter(entity->declaration.type);
3231
3232                                 if (scope != NULL) {
3233                                         append_entity(scope, entity);
3234                                 }
3235
3236                                 *anchor = parameter;
3237                                 anchor  = &parameter->next;
3238                                 break;
3239                         }
3240
3241                         default:
3242                                 goto parameters_finished;
3243                         }
3244                 } while (next_if(','));
3245 parameters_finished:
3246                 rem_anchor_token(',');
3247         }
3248
3249         rem_anchor_token(')');
3250         expect(')');
3251 }
3252
3253 typedef enum construct_type_kind_t {
3254         CONSTRUCT_POINTER = 1,
3255         CONSTRUCT_REFERENCE,
3256         CONSTRUCT_FUNCTION,
3257         CONSTRUCT_ARRAY
3258 } construct_type_kind_t;
3259
3260 typedef union construct_type_t construct_type_t;
3261
3262 typedef struct construct_type_base_t {
3263         construct_type_kind_t  kind;
3264         source_position_t      pos;
3265         construct_type_t      *next;
3266 } construct_type_base_t;
3267
3268 typedef struct parsed_pointer_t {
3269         construct_type_base_t  base;
3270         type_qualifiers_t      type_qualifiers;
3271         variable_t            *base_variable;  /**< MS __based extension. */
3272 } parsed_pointer_t;
3273
3274 typedef struct parsed_reference_t {
3275         construct_type_base_t base;
3276 } parsed_reference_t;
3277
3278 typedef struct construct_function_type_t {
3279         construct_type_base_t  base;
3280         type_t                *function_type;
3281 } construct_function_type_t;
3282
3283 typedef struct parsed_array_t {
3284         construct_type_base_t  base;
3285         type_qualifiers_t      type_qualifiers;
3286         bool                   is_static;
3287         bool                   is_variable;
3288         expression_t          *size;
3289 } parsed_array_t;
3290
3291 union construct_type_t {
3292         construct_type_kind_t     kind;
3293         construct_type_base_t     base;
3294         parsed_pointer_t          pointer;
3295         parsed_reference_t        reference;
3296         construct_function_type_t function;
3297         parsed_array_t            array;
3298 };
3299
3300 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3301 {
3302         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3303         memset(cons, 0, size);
3304         cons->kind     = kind;
3305         cons->base.pos = *HERE;
3306         return cons;
3307 }
3308
3309 /* §6.7.5.1 */
3310 static construct_type_t *parse_pointer_declarator(void)
3311 {
3312         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3313         eat('*');
3314         cons->pointer.type_qualifiers = parse_type_qualifiers();
3315         //cons->pointer.base_variable   = base_variable;
3316
3317         return cons;
3318 }
3319
3320 /* ISO/IEC 14882:1998(E) §8.3.2 */
3321 static construct_type_t *parse_reference_declarator(void)
3322 {
3323         if (!(c_mode & _CXX))
3324                 errorf(HERE, "references are only available for C++");
3325
3326         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3327         eat('&');
3328
3329         return cons;
3330 }
3331
3332 /* §6.7.5.2 */
3333 static construct_type_t *parse_array_declarator(void)
3334 {
3335         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3336         parsed_array_t   *const array = &cons->array;
3337
3338         eat('[');
3339         add_anchor_token(']');
3340
3341         bool is_static = next_if(T_static);
3342
3343         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3344
3345         if (!is_static)
3346                 is_static = next_if(T_static);
3347
3348         array->type_qualifiers = type_qualifiers;
3349         array->is_static       = is_static;
3350
3351         expression_t *size = NULL;
3352         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3353                 array->is_variable = true;
3354                 next_token();
3355         } else if (token.kind != ']') {
3356                 size = parse_assignment_expression();
3357
3358                 /* §6.7.5.2:1  Array size must have integer type */
3359                 type_t *const orig_type = size->base.type;
3360                 type_t *const type      = skip_typeref(orig_type);
3361                 if (!is_type_integer(type) && is_type_valid(type)) {
3362                         errorf(&size->base.source_position,
3363                                "array size '%E' must have integer type but has type '%T'",
3364                                size, orig_type);
3365                 }
3366
3367                 array->size = size;
3368                 mark_vars_read(size, NULL);
3369         }
3370
3371         if (is_static && size == NULL)
3372                 errorf(&array->base.pos, "static array parameters require a size");
3373
3374         rem_anchor_token(']');
3375         expect(']');
3376         return cons;
3377 }
3378
3379 /* §6.7.5.3 */
3380 static construct_type_t *parse_function_declarator(scope_t *scope)
3381 {
3382         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3383
3384         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3385         function_type_t *ftype = &type->function;
3386
3387         ftype->linkage            = current_linkage;
3388         ftype->calling_convention = CC_DEFAULT;
3389
3390         parse_parameters(ftype, scope);
3391
3392         cons->function.function_type = type;
3393
3394         return cons;
3395 }
3396
3397 typedef struct parse_declarator_env_t {
3398         bool               may_be_abstract : 1;
3399         bool               must_be_abstract : 1;
3400         decl_modifiers_t   modifiers;
3401         symbol_t          *symbol;
3402         source_position_t  source_position;
3403         scope_t            parameters;
3404         attribute_t       *attributes;
3405 } parse_declarator_env_t;
3406
3407 /* §6.7.5 */
3408 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3409 {
3410         /* construct a single linked list of construct_type_t's which describe
3411          * how to construct the final declarator type */
3412         construct_type_t  *first      = NULL;
3413         construct_type_t **anchor     = &first;
3414
3415         env->attributes = parse_attributes(env->attributes);
3416
3417         for (;;) {
3418                 construct_type_t *type;
3419                 //variable_t       *based = NULL; /* MS __based extension */
3420                 switch (token.kind) {
3421                         case '&':
3422                                 type = parse_reference_declarator();
3423                                 break;
3424
3425                         case T__based: {
3426                                 panic("based not supported anymore");
3427                                 /* FALLTHROUGH */
3428                         }
3429
3430                         case '*':
3431                                 type = parse_pointer_declarator();
3432                                 break;
3433
3434                         default:
3435                                 goto ptr_operator_end;
3436                 }
3437
3438                 *anchor = type;
3439                 anchor  = &type->base.next;
3440
3441                 /* TODO: find out if this is correct */
3442                 env->attributes = parse_attributes(env->attributes);
3443         }
3444
3445 ptr_operator_end: ;
3446         construct_type_t *inner_types = NULL;
3447
3448         switch (token.kind) {
3449         case T_IDENTIFIER:
3450                 if (env->must_be_abstract) {
3451                         errorf(HERE, "no identifier expected in typename");
3452                 } else {
3453                         env->symbol          = token.identifier.symbol;
3454                         env->source_position = token.base.source_position;
3455                 }
3456                 next_token();
3457                 break;
3458
3459         case '(': {
3460                 /* Parenthesized declarator or function declarator? */
3461                 token_t const *const la1 = look_ahead(1);
3462                 switch (la1->kind) {
3463                         case T_IDENTIFIER:
3464                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3465                         case ')':
3466                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3467                                          * interpreted as ``function with no parameter specification'', rather
3468                                          * than redundant parentheses around the omitted identifier. */
3469                         default:
3470                                         /* Function declarator. */
3471                                         if (!env->may_be_abstract) {
3472                                                 errorf(HERE, "function declarator must have a name");
3473                                         }
3474                                 } else {
3475                         case '&':
3476                         case '(':
3477                         case '*':
3478                         case '[':
3479                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3480                                         /* Paranthesized declarator. */
3481                                         next_token();
3482                                         add_anchor_token(')');
3483                                         inner_types = parse_inner_declarator(env);
3484                                         if (inner_types != NULL) {
3485                                                 /* All later declarators only modify the return type */
3486                                                 env->must_be_abstract = true;
3487                                         }
3488                                         rem_anchor_token(')');
3489                                         expect(')');
3490                                 }
3491                                 break;
3492                 }
3493                 break;
3494         }
3495
3496         default:
3497                 if (env->may_be_abstract)
3498                         break;
3499                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3500                 eat_until_anchor();
3501                 return NULL;
3502         }
3503
3504         construct_type_t **const p = anchor;
3505
3506         for (;;) {
3507                 construct_type_t *type;
3508                 switch (token.kind) {
3509                 case '(': {
3510                         scope_t *scope = NULL;
3511                         if (!env->must_be_abstract) {
3512                                 scope = &env->parameters;
3513                         }
3514
3515                         type = parse_function_declarator(scope);
3516                         break;
3517                 }
3518                 case '[':
3519                         type = parse_array_declarator();
3520                         break;
3521                 default:
3522                         goto declarator_finished;
3523                 }
3524
3525                 /* insert in the middle of the list (at p) */
3526                 type->base.next = *p;
3527                 *p              = type;
3528                 if (anchor == p)
3529                         anchor = &type->base.next;
3530         }
3531
3532 declarator_finished:
3533         /* append inner_types at the end of the list, we don't to set anchor anymore
3534          * as it's not needed anymore */
3535         *anchor = inner_types;
3536
3537         return first;
3538 }
3539
3540 static type_t *construct_declarator_type(construct_type_t *construct_list,
3541                                          type_t *type)
3542 {
3543         construct_type_t *iter = construct_list;
3544         for (; iter != NULL; iter = iter->base.next) {
3545                 source_position_t const* const pos = &iter->base.pos;
3546                 switch (iter->kind) {
3547                 case CONSTRUCT_FUNCTION: {
3548                         construct_function_type_t *function      = &iter->function;
3549                         type_t                    *function_type = function->function_type;
3550
3551                         function_type->function.return_type = type;
3552
3553                         type_t *skipped_return_type = skip_typeref(type);
3554                         /* §6.7.5.3:1 */
3555                         if (is_type_function(skipped_return_type)) {
3556                                 errorf(pos, "function returning function is not allowed");
3557                         } else if (is_type_array(skipped_return_type)) {
3558                                 errorf(pos, "function returning array is not allowed");
3559                         } else {
3560                                 if (skipped_return_type->base.qualifiers != 0) {
3561                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3562                                 }
3563                         }
3564
3565                         /* The function type was constructed earlier.  Freeing it here will
3566                          * destroy other types. */
3567                         type = typehash_insert(function_type);
3568                         continue;
3569                 }
3570
3571                 case CONSTRUCT_POINTER: {
3572                         if (is_type_reference(skip_typeref(type)))
3573                                 errorf(pos, "cannot declare a pointer to reference");
3574
3575                         parsed_pointer_t *pointer = &iter->pointer;
3576                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3577                         continue;
3578                 }
3579
3580                 case CONSTRUCT_REFERENCE:
3581                         if (is_type_reference(skip_typeref(type)))
3582                                 errorf(pos, "cannot declare a reference to reference");
3583
3584                         type = make_reference_type(type);
3585                         continue;
3586
3587                 case CONSTRUCT_ARRAY: {
3588                         if (is_type_reference(skip_typeref(type)))
3589                                 errorf(pos, "cannot declare an array of references");
3590
3591                         parsed_array_t *array      = &iter->array;
3592                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3593
3594                         expression_t *size_expression = array->size;
3595                         if (size_expression != NULL) {
3596                                 size_expression
3597                                         = create_implicit_cast(size_expression, type_size_t);
3598                         }
3599
3600                         array_type->base.qualifiers       = array->type_qualifiers;
3601                         array_type->array.element_type    = type;
3602                         array_type->array.is_static       = array->is_static;
3603                         array_type->array.is_variable     = array->is_variable;
3604                         array_type->array.size_expression = size_expression;
3605
3606                         if (size_expression != NULL) {
3607                                 switch (is_constant_expression(size_expression)) {
3608                                 case EXPR_CLASS_CONSTANT: {
3609                                         long const size = fold_constant_to_int(size_expression);
3610                                         array_type->array.size          = size;
3611                                         array_type->array.size_constant = true;
3612                                         /* §6.7.5.2:1  If the expression is a constant expression,
3613                                          * it shall have a value greater than zero. */
3614                                         if (size < 0) {
3615                                                 errorf(&size_expression->base.source_position,
3616                                                            "size of array must be greater than zero");
3617                                         } else if (size == 0 && !GNU_MODE) {
3618                                                 errorf(&size_expression->base.source_position,
3619                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3620                                         }
3621                                         break;
3622                                 }
3623
3624                                 case EXPR_CLASS_VARIABLE:
3625                                         array_type->array.is_vla = true;
3626                                         break;
3627
3628                                 case EXPR_CLASS_ERROR:
3629                                         break;
3630                                 }
3631                         }
3632
3633                         type_t *skipped_type = skip_typeref(type);
3634                         /* §6.7.5.2:1 */
3635                         if (is_type_incomplete(skipped_type)) {
3636                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3637                         } else if (is_type_function(skipped_type)) {
3638                                 errorf(pos, "array of functions is not allowed");
3639                         }
3640                         type = identify_new_type(array_type);
3641                         continue;
3642                 }
3643                 }
3644                 internal_errorf(pos, "invalid type construction found");
3645         }
3646
3647         return type;
3648 }
3649
3650 static type_t *automatic_type_conversion(type_t *orig_type);
3651
3652 static type_t *semantic_parameter(const source_position_t *pos,
3653                                   type_t *type,
3654                                   const declaration_specifiers_t *specifiers,
3655                                   entity_t const *const param)
3656 {
3657         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3658          *             shall be adjusted to ``qualified pointer to type'',
3659          *             [...]
3660          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3661          *             type'' shall be adjusted to ``pointer to function
3662          *             returning type'', as in 6.3.2.1. */
3663         type = automatic_type_conversion(type);
3664
3665         if (specifiers->is_inline && is_type_valid(type)) {
3666                 errorf(pos, "'%N' declared 'inline'", param);
3667         }
3668
3669         /* §6.9.1:6  The declarations in the declaration list shall contain
3670          *           no storage-class specifier other than register and no
3671          *           initializations. */
3672         if (specifiers->thread_local || (
3673                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3674                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3675            ) {
3676                 errorf(pos, "invalid storage class for '%N'", param);
3677         }
3678
3679         /* delay test for incomplete type, because we might have (void)
3680          * which is legal but incomplete... */
3681
3682         return type;
3683 }
3684
3685 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3686                                   declarator_flags_t flags)
3687 {
3688         parse_declarator_env_t env;
3689         memset(&env, 0, sizeof(env));
3690         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3691
3692         construct_type_t *construct_type = parse_inner_declarator(&env);
3693         type_t           *orig_type      =
3694                 construct_declarator_type(construct_type, specifiers->type);
3695         type_t           *type           = skip_typeref(orig_type);
3696
3697         if (construct_type != NULL) {
3698                 obstack_free(&temp_obst, construct_type);
3699         }
3700
3701         attribute_t *attributes = parse_attributes(env.attributes);
3702         /* append (shared) specifier attribute behind attributes of this
3703          * declarator */
3704         attribute_t **anchor = &attributes;
3705         while (*anchor != NULL)
3706                 anchor = &(*anchor)->next;
3707         *anchor = specifiers->attributes;
3708
3709         entity_t *entity;
3710         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3711                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3712                 entity->typedefe.type = orig_type;
3713
3714                 if (anonymous_entity != NULL) {
3715                         if (is_type_compound(type)) {
3716                                 assert(anonymous_entity->compound.alias == NULL);
3717                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3718                                        anonymous_entity->kind == ENTITY_UNION);
3719                                 anonymous_entity->compound.alias = entity;
3720                                 anonymous_entity = NULL;
3721                         } else if (is_type_enum(type)) {
3722                                 assert(anonymous_entity->enume.alias == NULL);
3723                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3724                                 anonymous_entity->enume.alias = entity;
3725                                 anonymous_entity = NULL;
3726                         }
3727                 }
3728         } else {
3729                 /* create a declaration type entity */
3730                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3731                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3732                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3733
3734                         if (env.symbol != NULL) {
3735                                 if (specifiers->is_inline && is_type_valid(type)) {
3736                                         errorf(&env.source_position,
3737                                                         "compound member '%Y' declared 'inline'", env.symbol);
3738                                 }
3739
3740                                 if (specifiers->thread_local ||
3741                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3742                                         errorf(&env.source_position,
3743                                                         "compound member '%Y' must have no storage class",
3744                                                         env.symbol);
3745                                 }
3746                         }
3747                 } else if (flags & DECL_IS_PARAMETER) {
3748                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3749                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3750                 } else if (is_type_function(type)) {
3751                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3752                         entity->function.is_inline      = specifiers->is_inline;
3753                         entity->function.elf_visibility = default_visibility;
3754                         entity->function.parameters     = env.parameters;
3755
3756                         if (env.symbol != NULL) {
3757                                 /* this needs fixes for C++ */
3758                                 bool in_function_scope = current_function != NULL;
3759
3760                                 if (specifiers->thread_local || (
3761                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3762                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3763                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3764                                                 )) {
3765                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3766                                 }
3767                         }
3768                 } else {
3769                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3770                         entity->variable.elf_visibility = default_visibility;
3771                         entity->variable.thread_local   = specifiers->thread_local;
3772
3773                         if (env.symbol != NULL) {
3774                                 if (specifiers->is_inline && is_type_valid(type)) {
3775                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3776                                 }
3777
3778                                 bool invalid_storage_class = false;
3779                                 if (current_scope == file_scope) {
3780                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3781                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3782                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3783                                                 invalid_storage_class = true;
3784                                         }
3785                                 } else {
3786                                         if (specifiers->thread_local &&
3787                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3788                                                 invalid_storage_class = true;
3789                                         }
3790                                 }
3791                                 if (invalid_storage_class) {
3792                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3793                                 }
3794                         }
3795                 }
3796
3797                 entity->declaration.type       = orig_type;
3798                 entity->declaration.alignment  = get_type_alignment(orig_type);
3799                 entity->declaration.modifiers  = env.modifiers;
3800                 entity->declaration.attributes = attributes;
3801
3802                 storage_class_t storage_class = specifiers->storage_class;
3803                 entity->declaration.declared_storage_class = storage_class;
3804
3805                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3806                         storage_class = STORAGE_CLASS_AUTO;
3807                 entity->declaration.storage_class = storage_class;
3808         }
3809
3810         if (attributes != NULL) {
3811                 handle_entity_attributes(attributes, entity);
3812         }
3813
3814         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3815                 adapt_special_functions(&entity->function);
3816         }
3817
3818         return entity;
3819 }
3820
3821 static type_t *parse_abstract_declarator(type_t *base_type)
3822 {
3823         parse_declarator_env_t env;
3824         memset(&env, 0, sizeof(env));
3825         env.may_be_abstract = true;
3826         env.must_be_abstract = true;
3827
3828         construct_type_t *construct_type = parse_inner_declarator(&env);
3829
3830         type_t *result = construct_declarator_type(construct_type, base_type);
3831         if (construct_type != NULL) {
3832                 obstack_free(&temp_obst, construct_type);
3833         }
3834         result = handle_type_attributes(env.attributes, result);
3835
3836         return result;
3837 }
3838
3839 /**
3840  * Check if the declaration of main is suspicious.  main should be a
3841  * function with external linkage, returning int, taking either zero
3842  * arguments, two, or three arguments of appropriate types, ie.
3843  *
3844  * int main([ int argc, char **argv [, char **env ] ]).
3845  *
3846  * @param decl    the declaration to check
3847  * @param type    the function type of the declaration
3848  */
3849 static void check_main(const entity_t *entity)
3850 {
3851         const source_position_t *pos = &entity->base.source_position;
3852         if (entity->kind != ENTITY_FUNCTION) {
3853                 warningf(WARN_MAIN, pos, "'main' is not a function");
3854                 return;
3855         }
3856
3857         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3858                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3859         }
3860
3861         type_t *type = skip_typeref(entity->declaration.type);
3862         assert(is_type_function(type));
3863
3864         function_type_t const *const func_type = &type->function;
3865         type_t                *const ret_type  = func_type->return_type;
3866         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3867                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3868         }
3869         const function_parameter_t *parm = func_type->parameters;
3870         if (parm != NULL) {
3871                 type_t *const first_type        = skip_typeref(parm->type);
3872                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3873                 if (!types_compatible(first_type_unqual, type_int)) {
3874                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3875                 }
3876                 parm = parm->next;
3877                 if (parm != NULL) {
3878                         type_t *const second_type = skip_typeref(parm->type);
3879                         type_t *const second_type_unqual
3880                                 = get_unqualified_type(second_type);
3881                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3882                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3883                         }
3884                         parm = parm->next;
3885                         if (parm != NULL) {
3886                                 type_t *const third_type = skip_typeref(parm->type);
3887                                 type_t *const third_type_unqual
3888                                         = get_unqualified_type(third_type);
3889                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3890                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3891                                 }
3892                                 parm = parm->next;
3893                                 if (parm != NULL)
3894                                         goto warn_arg_count;
3895                         }
3896                 } else {
3897 warn_arg_count:
3898                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3899                 }
3900         }
3901 }
3902
3903 /**
3904  * Check if a symbol is the equal to "main".
3905  */
3906 static bool is_sym_main(const symbol_t *const sym)
3907 {
3908         return streq(sym->string, "main");
3909 }
3910
3911 static void error_redefined_as_different_kind(const source_position_t *pos,
3912                 const entity_t *old, entity_kind_t new_kind)
3913 {
3914         char              const *const what = get_entity_kind_name(new_kind);
3915         source_position_t const *const ppos = &old->base.source_position;
3916         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3917 }
3918
3919 static bool is_entity_valid(entity_t *const ent)
3920 {
3921         if (is_declaration(ent)) {
3922                 return is_type_valid(skip_typeref(ent->declaration.type));
3923         } else if (ent->kind == ENTITY_TYPEDEF) {
3924                 return is_type_valid(skip_typeref(ent->typedefe.type));
3925         }
3926         return true;
3927 }
3928
3929 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3930 {
3931         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3932                 if (attributes_equal(tattr, attr))
3933                         return true;
3934         }
3935         return false;
3936 }
3937
3938 /**
3939  * test wether new_list contains any attributes not included in old_list
3940  */
3941 static bool has_new_attributes(const attribute_t *old_list,
3942                                const attribute_t *new_list)
3943 {
3944         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3945                 if (!contains_attribute(old_list, attr))
3946                         return true;
3947         }
3948         return false;
3949 }
3950
3951 /**
3952  * Merge in attributes from an attribute list (probably from a previous
3953  * declaration with the same name). Warning: destroys the old structure
3954  * of the attribute list - don't reuse attributes after this call.
3955  */
3956 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3957 {
3958         attribute_t *next;
3959         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3960                 next = attr->next;
3961                 if (contains_attribute(decl->attributes, attr))
3962                         continue;
3963
3964                 /* move attribute to new declarations attributes list */
3965                 attr->next       = decl->attributes;
3966                 decl->attributes = attr;
3967         }
3968 }
3969
3970 /**
3971  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3972  * for various problems that occur for multiple definitions
3973  */
3974 entity_t *record_entity(entity_t *entity, const bool is_definition)
3975 {
3976         const symbol_t *const    symbol  = entity->base.symbol;
3977         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3978         const source_position_t *pos     = &entity->base.source_position;
3979
3980         /* can happen in error cases */
3981         if (symbol == NULL)
3982                 return entity;
3983
3984         entity_t *const previous_entity = get_entity(symbol, namespc);
3985         /* pushing the same entity twice will break the stack structure */
3986         assert(previous_entity != entity);
3987
3988         if (entity->kind == ENTITY_FUNCTION) {
3989                 type_t *const orig_type = entity->declaration.type;
3990                 type_t *const type      = skip_typeref(orig_type);
3991
3992                 assert(is_type_function(type));
3993                 if (type->function.unspecified_parameters &&
3994                     previous_entity == NULL               &&
3995                     !entity->declaration.implicit) {
3996                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3997                 }
3998
3999                 if (current_scope == file_scope && is_sym_main(symbol)) {
4000                         check_main(entity);
4001                 }
4002         }
4003
4004         if (is_declaration(entity)                                    &&
4005             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4006             current_scope != file_scope                               &&
4007             !entity->declaration.implicit) {
4008                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
4009         }
4010
4011         if (previous_entity != NULL) {
4012                 source_position_t const *const ppos = &previous_entity->base.source_position;
4013
4014                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4015                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4016                         assert(previous_entity->kind == ENTITY_PARAMETER);
4017                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4018                         goto finish;
4019                 }
4020
4021                 if (previous_entity->base.parent_scope == current_scope) {
4022                         if (previous_entity->kind != entity->kind) {
4023                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4024                                         error_redefined_as_different_kind(pos, previous_entity,
4025                                                         entity->kind);
4026                                 }
4027                                 goto finish;
4028                         }
4029                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4030                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4031                                 goto finish;
4032                         }
4033                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4034                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4035                                 type_t *const prev_type
4036                                         = skip_typeref(previous_entity->typedefe.type);
4037                                 if (c_mode & _CXX) {
4038                                         /* C++ allows double typedef if they are identical
4039                                          * (after skipping typedefs) */
4040                                         if (type == prev_type)
4041                                                 goto finish;
4042                                 } else {
4043                                         /* GCC extension: redef in system headers is allowed */
4044                                         if ((pos->is_system_header || ppos->is_system_header) &&
4045                                             types_compatible(type, prev_type))
4046                                                 goto finish;
4047                                 }
4048                                 errorf(pos, "redefinition of '%N' (declared %P)",
4049                                        entity, ppos);
4050                                 goto finish;
4051                         }
4052
4053                         /* at this point we should have only VARIABLES or FUNCTIONS */
4054                         assert(is_declaration(previous_entity) && is_declaration(entity));
4055
4056                         declaration_t *const prev_decl = &previous_entity->declaration;
4057                         declaration_t *const decl      = &entity->declaration;
4058
4059                         /* can happen for K&R style declarations */
4060                         if (prev_decl->type       == NULL             &&
4061                                         previous_entity->kind == ENTITY_PARAMETER &&
4062                                         entity->kind          == ENTITY_PARAMETER) {
4063                                 prev_decl->type                   = decl->type;
4064                                 prev_decl->storage_class          = decl->storage_class;
4065                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4066                                 prev_decl->modifiers              = decl->modifiers;
4067                                 return previous_entity;
4068                         }
4069
4070                         type_t *const type      = skip_typeref(decl->type);
4071                         type_t *const prev_type = skip_typeref(prev_decl->type);
4072
4073                         if (!types_compatible(type, prev_type)) {
4074                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4075                         } else {
4076                                 unsigned old_storage_class = prev_decl->storage_class;
4077
4078                                 if (is_definition                     &&
4079                                                 !prev_decl->used                  &&
4080                                                 !(prev_decl->modifiers & DM_USED) &&
4081                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4082                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4083                                 }
4084
4085                                 storage_class_t new_storage_class = decl->storage_class;
4086
4087                                 /* pretend no storage class means extern for function
4088                                  * declarations (except if the previous declaration is neither
4089                                  * none nor extern) */
4090                                 if (entity->kind == ENTITY_FUNCTION) {
4091                                         /* the previous declaration could have unspecified parameters or
4092                                          * be a typedef, so use the new type */
4093                                         if (prev_type->function.unspecified_parameters || is_definition)
4094                                                 prev_decl->type = type;
4095
4096                                         switch (old_storage_class) {
4097                                                 case STORAGE_CLASS_NONE:
4098                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4099                                                         /* FALLTHROUGH */
4100
4101                                                 case STORAGE_CLASS_EXTERN:
4102                                                         if (is_definition) {
4103                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4104                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4105                                                                 }
4106                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4107                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4108                                                         }
4109                                                         break;
4110
4111                                                 default:
4112                                                         break;
4113                                         }
4114                                 } else if (is_type_incomplete(prev_type)) {
4115                                         prev_decl->type = type;
4116                                 }
4117
4118                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4119                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4120
4121 warn_redundant_declaration: ;
4122                                         bool has_new_attrs
4123                                                 = has_new_attributes(prev_decl->attributes,
4124                                                                      decl->attributes);
4125                                         if (has_new_attrs) {
4126                                                 merge_in_attributes(decl, prev_decl->attributes);
4127                                         } else if (!is_definition        &&
4128                                                         is_type_valid(prev_type) &&
4129                                                         !pos->is_system_header) {
4130                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4131                                         }
4132                                 } else if (current_function == NULL) {
4133                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4134                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4135                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4136                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4137                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4138                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4139                                         } else {
4140                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4141                                                 if (c_mode & _CXX)
4142                                                         goto error_redeclaration;
4143                                                 goto warn_redundant_declaration;
4144                                         }
4145                                 } else if (is_type_valid(prev_type)) {
4146                                         if (old_storage_class == new_storage_class) {
4147 error_redeclaration:
4148                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4149                                         } else {
4150                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4151                                         }
4152                                 }
4153                         }
4154
4155                         prev_decl->modifiers |= decl->modifiers;
4156                         if (entity->kind == ENTITY_FUNCTION) {
4157                                 previous_entity->function.is_inline |= entity->function.is_inline;
4158                         }
4159                         return previous_entity;
4160                 }
4161
4162                 warning_t why;
4163                 if (is_warn_on(why = WARN_SHADOW) ||
4164                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4165                         char const *const what = get_entity_kind_name(previous_entity->kind);
4166                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4167                 }
4168         }
4169
4170         if (entity->kind == ENTITY_FUNCTION) {
4171                 if (is_definition &&
4172                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4173                                 !is_sym_main(symbol)) {
4174                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4175                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4176                         } else {
4177                                 goto warn_missing_declaration;
4178                         }
4179                 }
4180         } else if (entity->kind == ENTITY_VARIABLE) {
4181                 if (current_scope                     == file_scope &&
4182                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4183                                 !entity->declaration.implicit) {
4184 warn_missing_declaration:
4185                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4186                 }
4187         }
4188
4189 finish:
4190         assert(entity->base.parent_scope == NULL);
4191         assert(current_scope != NULL);
4192
4193         entity->base.parent_scope = current_scope;
4194         environment_push(entity);
4195         append_entity(current_scope, entity);
4196
4197         return entity;
4198 }
4199
4200 static void parser_error_multiple_definition(entity_t *entity,
4201                 const source_position_t *source_position)
4202 {
4203         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4204                entity->base.symbol, &entity->base.source_position);
4205 }
4206
4207 static bool is_declaration_specifier(const token_t *token)
4208 {
4209         switch (token->kind) {
4210                 DECLARATION_START
4211                         return true;
4212                 case T_IDENTIFIER:
4213                         return is_typedef_symbol(token->identifier.symbol);
4214
4215                 default:
4216                         return false;
4217         }
4218 }
4219
4220 static void parse_init_declarator_rest(entity_t *entity)
4221 {
4222         type_t *orig_type = type_error_type;
4223
4224         if (entity->base.kind == ENTITY_TYPEDEF) {
4225                 source_position_t const *const pos = &entity->base.source_position;
4226                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4227         } else {
4228                 assert(is_declaration(entity));
4229                 orig_type = entity->declaration.type;
4230         }
4231
4232         type_t *type = skip_typeref(orig_type);
4233
4234         if (entity->kind == ENTITY_VARIABLE
4235                         && entity->variable.initializer != NULL) {
4236                 parser_error_multiple_definition(entity, HERE);
4237         }
4238         eat('=');
4239
4240         declaration_t *const declaration = &entity->declaration;
4241         bool must_be_constant = false;
4242         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4243             entity->base.parent_scope  == file_scope) {
4244                 must_be_constant = true;
4245         }
4246
4247         if (is_type_function(type)) {
4248                 source_position_t const *const pos = &entity->base.source_position;
4249                 errorf(pos, "'%N' is initialized like a variable", entity);
4250                 orig_type = type_error_type;
4251         }
4252
4253         parse_initializer_env_t env;
4254         env.type             = orig_type;
4255         env.must_be_constant = must_be_constant;
4256         env.entity           = entity;
4257
4258         initializer_t *initializer = parse_initializer(&env);
4259
4260         if (entity->kind == ENTITY_VARIABLE) {
4261                 /* §6.7.5:22  array initializers for arrays with unknown size
4262                  * determine the array type size */
4263                 declaration->type            = env.type;
4264                 entity->variable.initializer = initializer;
4265         }
4266 }
4267
4268 /* parse rest of a declaration without any declarator */
4269 static void parse_anonymous_declaration_rest(
4270                 const declaration_specifiers_t *specifiers)
4271 {
4272         eat(';');
4273         anonymous_entity = NULL;
4274
4275         source_position_t const *const pos = &specifiers->source_position;
4276         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4277                         specifiers->thread_local) {
4278                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4279         }
4280
4281         type_t *type = specifiers->type;
4282         switch (type->kind) {
4283                 case TYPE_COMPOUND_STRUCT:
4284                 case TYPE_COMPOUND_UNION: {
4285                         if (type->compound.compound->base.symbol == NULL) {
4286                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4287                         }
4288                         break;
4289                 }
4290
4291                 case TYPE_ENUM:
4292                         break;
4293
4294                 default:
4295                         warningf(WARN_OTHER, pos, "empty declaration");
4296                         break;
4297         }
4298 }
4299
4300 static void check_variable_type_complete(entity_t *ent)
4301 {
4302         if (ent->kind != ENTITY_VARIABLE)
4303                 return;
4304
4305         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4306          *         type for the object shall be complete [...] */
4307         declaration_t *decl = &ent->declaration;
4308         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4309                         decl->storage_class == STORAGE_CLASS_STATIC)
4310                 return;
4311
4312         type_t *const type = skip_typeref(decl->type);
4313         if (!is_type_incomplete(type))
4314                 return;
4315
4316         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4317          * are given length one. */
4318         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4319                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4320                 return;
4321         }
4322
4323         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4324 }
4325
4326
4327 static void parse_declaration_rest(entity_t *ndeclaration,
4328                 const declaration_specifiers_t *specifiers,
4329                 parsed_declaration_func         finished_declaration,
4330                 declarator_flags_t              flags)
4331 {
4332         add_anchor_token(';');
4333         add_anchor_token(',');
4334         while (true) {
4335                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4336
4337                 if (token.kind == '=') {
4338                         parse_init_declarator_rest(entity);
4339                 } else if (entity->kind == ENTITY_VARIABLE) {
4340                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4341                          * [...] where the extern specifier is explicitly used. */
4342                         declaration_t *decl = &entity->declaration;
4343                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4344                             is_type_reference(skip_typeref(decl->type))) {
4345                                 source_position_t const *const pos = &entity->base.source_position;
4346                                 errorf(pos, "reference '%#N' must be initialized", entity);
4347                         }
4348                 }
4349
4350                 check_variable_type_complete(entity);
4351
4352                 if (!next_if(','))
4353                         break;
4354
4355                 add_anchor_token('=');
4356                 ndeclaration = parse_declarator(specifiers, flags);
4357                 rem_anchor_token('=');
4358         }
4359         rem_anchor_token(',');
4360         rem_anchor_token(';');
4361         expect(';');
4362
4363         anonymous_entity = NULL;
4364 }
4365
4366 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4367 {
4368         symbol_t *symbol = entity->base.symbol;
4369         if (symbol == NULL)
4370                 return entity;
4371
4372         assert(entity->base.namespc == NAMESPACE_NORMAL);
4373         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4374         if (previous_entity == NULL
4375                         || previous_entity->base.parent_scope != current_scope) {
4376                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4377                        symbol);
4378                 return entity;
4379         }
4380
4381         if (is_definition) {
4382                 errorf(HERE, "'%N' is initialised", entity);
4383         }
4384
4385         return record_entity(entity, false);
4386 }
4387
4388 static void parse_declaration(parsed_declaration_func finished_declaration,
4389                               declarator_flags_t      flags)
4390 {
4391         add_anchor_token(';');
4392         declaration_specifiers_t specifiers;
4393         parse_declaration_specifiers(&specifiers);
4394         rem_anchor_token(';');
4395
4396         if (token.kind == ';') {
4397                 parse_anonymous_declaration_rest(&specifiers);
4398         } else {
4399                 entity_t *entity = parse_declarator(&specifiers, flags);
4400                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4401         }
4402 }
4403
4404 /* §6.5.2.2:6 */
4405 static type_t *get_default_promoted_type(type_t *orig_type)
4406 {
4407         type_t *result = orig_type;
4408
4409         type_t *type = skip_typeref(orig_type);
4410         if (is_type_integer(type)) {
4411                 result = promote_integer(type);
4412         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4413                 result = type_double;
4414         }
4415
4416         return result;
4417 }
4418
4419 static void parse_kr_declaration_list(entity_t *entity)
4420 {
4421         if (entity->kind != ENTITY_FUNCTION)
4422                 return;
4423
4424         type_t *type = skip_typeref(entity->declaration.type);
4425         assert(is_type_function(type));
4426         if (!type->function.kr_style_parameters)
4427                 return;
4428
4429         add_anchor_token('{');
4430
4431         PUSH_SCOPE(&entity->function.parameters);
4432
4433         entity_t *parameter = entity->function.parameters.entities;
4434         for ( ; parameter != NULL; parameter = parameter->base.next) {
4435                 assert(parameter->base.parent_scope == NULL);
4436                 parameter->base.parent_scope = current_scope;
4437                 environment_push(parameter);
4438         }
4439
4440         /* parse declaration list */
4441         for (;;) {
4442                 switch (token.kind) {
4443                         DECLARATION_START
4444                         /* This covers symbols, which are no type, too, and results in
4445                          * better error messages.  The typical cases are misspelled type
4446                          * names and missing includes. */
4447                         case T_IDENTIFIER:
4448                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4449                                 break;
4450                         default:
4451                                 goto decl_list_end;
4452                 }
4453         }
4454 decl_list_end:
4455
4456         POP_SCOPE();
4457
4458         /* update function type */
4459         type_t *new_type = duplicate_type(type);
4460
4461         function_parameter_t  *parameters = NULL;
4462         function_parameter_t **anchor     = &parameters;
4463
4464         /* did we have an earlier prototype? */
4465         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4466         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4467                 proto_type = NULL;
4468
4469         function_parameter_t *proto_parameter = NULL;
4470         if (proto_type != NULL) {
4471                 type_t *proto_type_type = proto_type->declaration.type;
4472                 proto_parameter         = proto_type_type->function.parameters;
4473                 /* If a K&R function definition has a variadic prototype earlier, then
4474                  * make the function definition variadic, too. This should conform to
4475                  * §6.7.5.3:15 and §6.9.1:8. */
4476                 new_type->function.variadic = proto_type_type->function.variadic;
4477         } else {
4478                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4479                  * prototype */
4480                 new_type->function.unspecified_parameters = true;
4481         }
4482
4483         bool need_incompatible_warning = false;
4484         parameter = entity->function.parameters.entities;
4485         for (; parameter != NULL; parameter = parameter->base.next,
4486                         proto_parameter =
4487                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4488                 if (parameter->kind != ENTITY_PARAMETER)
4489                         continue;
4490
4491                 type_t *parameter_type = parameter->declaration.type;
4492                 if (parameter_type == NULL) {
4493                         source_position_t const* const pos = &parameter->base.source_position;
4494                         if (strict_mode) {
4495                                 errorf(pos, "no type specified for function '%N'", parameter);
4496                                 parameter_type = type_error_type;
4497                         } else {
4498                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4499                                 parameter_type = type_int;
4500                         }
4501                         parameter->declaration.type = parameter_type;
4502                 }
4503
4504                 semantic_parameter_incomplete(parameter);
4505
4506                 /* we need the default promoted types for the function type */
4507                 type_t *not_promoted = parameter_type;
4508                 parameter_type       = get_default_promoted_type(parameter_type);
4509
4510                 /* gcc special: if the type of the prototype matches the unpromoted
4511                  * type don't promote */
4512                 if (!strict_mode && proto_parameter != NULL) {
4513                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4514                         type_t *promo_skip   = skip_typeref(parameter_type);
4515                         type_t *param_skip   = skip_typeref(not_promoted);
4516                         if (!types_compatible(proto_p_type, promo_skip)
4517                                 && types_compatible(proto_p_type, param_skip)) {
4518                                 /* don't promote */
4519                                 need_incompatible_warning = true;
4520                                 parameter_type = not_promoted;
4521                         }
4522                 }
4523                 function_parameter_t *const function_parameter
4524                         = allocate_parameter(parameter_type);
4525
4526                 *anchor = function_parameter;
4527                 anchor  = &function_parameter->next;
4528         }
4529
4530         new_type->function.parameters = parameters;
4531         new_type = identify_new_type(new_type);
4532
4533         if (need_incompatible_warning) {
4534                 symbol_t          const *const sym  = entity->base.symbol;
4535                 source_position_t const *const pos  = &entity->base.source_position;
4536                 source_position_t const *const ppos = &proto_type->base.source_position;
4537                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4538         }
4539         entity->declaration.type = new_type;
4540
4541         rem_anchor_token('{');
4542 }
4543
4544 static bool first_err = true;
4545
4546 /**
4547  * When called with first_err set, prints the name of the current function,
4548  * else does noting.
4549  */
4550 static void print_in_function(void)
4551 {
4552         if (first_err) {
4553                 first_err = false;
4554                 char const *const file = current_function->base.base.source_position.input_name;
4555                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4556         }
4557 }
4558
4559 /**
4560  * Check if all labels are defined in the current function.
4561  * Check if all labels are used in the current function.
4562  */
4563 static void check_labels(void)
4564 {
4565         for (const goto_statement_t *goto_statement = goto_first;
4566             goto_statement != NULL;
4567             goto_statement = goto_statement->next) {
4568                 label_t *label = goto_statement->label;
4569                 if (label->base.source_position.input_name == NULL) {
4570                         print_in_function();
4571                         source_position_t const *const pos = &goto_statement->base.source_position;
4572                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4573                  }
4574         }
4575
4576         if (is_warn_on(WARN_UNUSED_LABEL)) {
4577                 for (const label_statement_t *label_statement = label_first;
4578                          label_statement != NULL;
4579                          label_statement = label_statement->next) {
4580                         label_t *label = label_statement->label;
4581
4582                         if (! label->used) {
4583                                 print_in_function();
4584                                 source_position_t const *const pos = &label_statement->base.source_position;
4585                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4586                         }
4587                 }
4588         }
4589 }
4590
4591 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4592 {
4593         entity_t const *const end = last != NULL ? last->base.next : NULL;
4594         for (; entity != end; entity = entity->base.next) {
4595                 if (!is_declaration(entity))
4596                         continue;
4597
4598                 declaration_t *declaration = &entity->declaration;
4599                 if (declaration->implicit)
4600                         continue;
4601
4602                 if (!declaration->used) {
4603                         print_in_function();
4604                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4605                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4606                         print_in_function();
4607                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4608                 }
4609         }
4610 }
4611
4612 static void check_unused_variables(statement_t *const stmt, void *const env)
4613 {
4614         (void)env;
4615
4616         switch (stmt->kind) {
4617                 case STATEMENT_DECLARATION: {
4618                         declaration_statement_t const *const decls = &stmt->declaration;
4619                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4620                         return;
4621                 }
4622
4623                 case STATEMENT_FOR:
4624                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4625                         return;
4626
4627                 default:
4628                         return;
4629         }
4630 }
4631
4632 /**
4633  * Check declarations of current_function for unused entities.
4634  */
4635 static void check_declarations(void)
4636 {
4637         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4638                 const scope_t *scope = &current_function->parameters;
4639
4640                 /* do not issue unused warnings for main */
4641                 if (!is_sym_main(current_function->base.base.symbol)) {
4642                         warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4643                 }
4644         }
4645         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4646                 walk_statements(current_function->statement, check_unused_variables,
4647                                 NULL);
4648         }
4649 }
4650
4651 static int determine_truth(expression_t const* const cond)
4652 {
4653         return
4654                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4655                 fold_constant_to_bool(cond)                         ? 1 :
4656                 -1;
4657 }
4658
4659 static void check_reachable(statement_t *);
4660 static bool reaches_end;
4661
4662 static bool expression_returns(expression_t const *const expr)
4663 {
4664         switch (expr->kind) {
4665                 case EXPR_CALL: {
4666                         expression_t const *const func = expr->call.function;
4667                         type_t       const *const type = skip_typeref(func->base.type);
4668                         if (type->kind == TYPE_POINTER) {
4669                                 type_t const *const points_to
4670                                         = skip_typeref(type->pointer.points_to);
4671                                 if (points_to->kind == TYPE_FUNCTION
4672                                     && points_to->function.modifiers & DM_NORETURN)
4673                                         return false;
4674                         }
4675
4676                         if (!expression_returns(func))
4677                                 return false;
4678
4679                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4680                                 if (!expression_returns(arg->expression))
4681                                         return false;
4682                         }
4683
4684                         return true;
4685                 }
4686
4687                 case EXPR_REFERENCE:
4688                 case EXPR_ENUM_CONSTANT:
4689                 case EXPR_LITERAL_CASES:
4690                 case EXPR_STRING_LITERAL:
4691                 case EXPR_WIDE_STRING_LITERAL:
4692                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4693                 case EXPR_LABEL_ADDRESS:
4694                 case EXPR_CLASSIFY_TYPE:
4695                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4696                 case EXPR_ALIGNOF:
4697                 case EXPR_FUNCNAME:
4698                 case EXPR_BUILTIN_CONSTANT_P:
4699                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4700                 case EXPR_OFFSETOF:
4701                 case EXPR_ERROR:
4702                         return true;
4703
4704                 case EXPR_STATEMENT: {
4705                         bool old_reaches_end = reaches_end;
4706                         reaches_end = false;
4707                         check_reachable(expr->statement.statement);
4708                         bool returns = reaches_end;
4709                         reaches_end = old_reaches_end;
4710                         return returns;
4711                 }
4712
4713                 case EXPR_CONDITIONAL:
4714                         // TODO handle constant expression
4715
4716                         if (!expression_returns(expr->conditional.condition))
4717                                 return false;
4718
4719                         if (expr->conditional.true_expression != NULL
4720                                         && expression_returns(expr->conditional.true_expression))
4721                                 return true;
4722
4723                         return expression_returns(expr->conditional.false_expression);
4724
4725                 case EXPR_SELECT:
4726                         return expression_returns(expr->select.compound);
4727
4728                 case EXPR_ARRAY_ACCESS:
4729                         return
4730                                 expression_returns(expr->array_access.array_ref) &&
4731                                 expression_returns(expr->array_access.index);
4732
4733                 case EXPR_VA_START:
4734                         return expression_returns(expr->va_starte.ap);
4735
4736                 case EXPR_VA_ARG:
4737                         return expression_returns(expr->va_arge.ap);
4738
4739                 case EXPR_VA_COPY:
4740                         return expression_returns(expr->va_copye.src);
4741
4742                 case EXPR_UNARY_CASES_MANDATORY:
4743                         return expression_returns(expr->unary.value);
4744
4745                 case EXPR_UNARY_THROW:
4746                         return false;
4747
4748                 case EXPR_BINARY_CASES:
4749                         // TODO handle constant lhs of && and ||
4750                         return
4751                                 expression_returns(expr->binary.left) &&
4752                                 expression_returns(expr->binary.right);
4753         }
4754
4755         panic("unhandled expression");
4756 }
4757
4758 static bool initializer_returns(initializer_t const *const init)
4759 {
4760         switch (init->kind) {
4761                 case INITIALIZER_VALUE:
4762                         return expression_returns(init->value.value);
4763
4764                 case INITIALIZER_LIST: {
4765                         initializer_t * const*       i       = init->list.initializers;
4766                         initializer_t * const* const end     = i + init->list.len;
4767                         bool                         returns = true;
4768                         for (; i != end; ++i) {
4769                                 if (!initializer_returns(*i))
4770                                         returns = false;
4771                         }
4772                         return returns;
4773                 }
4774
4775                 case INITIALIZER_STRING:
4776                 case INITIALIZER_WIDE_STRING:
4777                 case INITIALIZER_DESIGNATOR: // designators have no payload
4778                         return true;
4779         }
4780         panic("unhandled initializer");
4781 }
4782
4783 static bool noreturn_candidate;
4784
4785 static void check_reachable(statement_t *const stmt)
4786 {
4787         if (stmt->base.reachable)
4788                 return;
4789         if (stmt->kind != STATEMENT_DO_WHILE)
4790                 stmt->base.reachable = true;
4791
4792         statement_t *last = stmt;
4793         statement_t *next;
4794         switch (stmt->kind) {
4795                 case STATEMENT_ERROR:
4796                 case STATEMENT_EMPTY:
4797                 case STATEMENT_ASM:
4798                         next = stmt->base.next;
4799                         break;
4800
4801                 case STATEMENT_DECLARATION: {
4802                         declaration_statement_t const *const decl = &stmt->declaration;
4803                         entity_t                const *      ent  = decl->declarations_begin;
4804                         entity_t                const *const last_decl = decl->declarations_end;
4805                         if (ent != NULL) {
4806                                 for (;; ent = ent->base.next) {
4807                                         if (ent->kind                 == ENTITY_VARIABLE &&
4808                                             ent->variable.initializer != NULL            &&
4809                                             !initializer_returns(ent->variable.initializer)) {
4810                                                 return;
4811                                         }
4812                                         if (ent == last_decl)
4813                                                 break;
4814                                 }
4815                         }
4816                         next = stmt->base.next;
4817                         break;
4818                 }
4819
4820                 case STATEMENT_COMPOUND:
4821                         next = stmt->compound.statements;
4822                         if (next == NULL)
4823                                 next = stmt->base.next;
4824                         break;
4825
4826                 case STATEMENT_RETURN: {
4827                         expression_t const *const val = stmt->returns.value;
4828                         if (val == NULL || expression_returns(val))
4829                                 noreturn_candidate = false;
4830                         return;
4831                 }
4832
4833                 case STATEMENT_IF: {
4834                         if_statement_t const *const ifs  = &stmt->ifs;
4835                         expression_t   const *const cond = ifs->condition;
4836
4837                         if (!expression_returns(cond))
4838                                 return;
4839
4840                         int const val = determine_truth(cond);
4841
4842                         if (val >= 0)
4843                                 check_reachable(ifs->true_statement);
4844
4845                         if (val > 0)
4846                                 return;
4847
4848                         if (ifs->false_statement != NULL) {
4849                                 check_reachable(ifs->false_statement);
4850                                 return;
4851                         }
4852
4853                         next = stmt->base.next;
4854                         break;
4855                 }
4856
4857                 case STATEMENT_SWITCH: {
4858                         switch_statement_t const *const switchs = &stmt->switchs;
4859                         expression_t       const *const expr    = switchs->expression;
4860
4861                         if (!expression_returns(expr))
4862                                 return;
4863
4864                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4865                                 long                    const val      = fold_constant_to_int(expr);
4866                                 case_label_statement_t *      defaults = NULL;
4867                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4868                                         if (i->expression == NULL) {
4869                                                 defaults = i;
4870                                                 continue;
4871                                         }
4872
4873                                         if (i->first_case <= val && val <= i->last_case) {
4874                                                 check_reachable((statement_t*)i);
4875                                                 return;
4876                                         }
4877                                 }
4878
4879                                 if (defaults != NULL) {
4880                                         check_reachable((statement_t*)defaults);
4881                                         return;
4882                                 }
4883                         } else {
4884                                 bool has_default = false;
4885                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4886                                         if (i->expression == NULL)
4887                                                 has_default = true;
4888
4889                                         check_reachable((statement_t*)i);
4890                                 }
4891
4892                                 if (has_default)
4893                                         return;
4894                         }
4895
4896                         next = stmt->base.next;
4897                         break;
4898                 }
4899
4900                 case STATEMENT_EXPRESSION: {
4901                         /* Check for noreturn function call */
4902                         expression_t const *const expr = stmt->expression.expression;
4903                         if (!expression_returns(expr))
4904                                 return;
4905
4906                         next = stmt->base.next;
4907                         break;
4908                 }
4909
4910                 case STATEMENT_CONTINUE:
4911                         for (statement_t *parent = stmt;;) {
4912                                 parent = parent->base.parent;
4913                                 if (parent == NULL) /* continue not within loop */
4914                                         return;
4915
4916                                 next = parent;
4917                                 switch (parent->kind) {
4918                                         case STATEMENT_WHILE:    goto continue_while;
4919                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4920                                         case STATEMENT_FOR:      goto continue_for;
4921
4922                                         default: break;
4923                                 }
4924                         }
4925
4926                 case STATEMENT_BREAK:
4927                         for (statement_t *parent = stmt;;) {
4928                                 parent = parent->base.parent;
4929                                 if (parent == NULL) /* break not within loop/switch */
4930                                         return;
4931
4932                                 switch (parent->kind) {
4933                                         case STATEMENT_SWITCH:
4934                                         case STATEMENT_WHILE:
4935                                         case STATEMENT_DO_WHILE:
4936                                         case STATEMENT_FOR:
4937                                                 last = parent;
4938                                                 next = parent->base.next;
4939                                                 goto found_break_parent;
4940
4941                                         default: break;
4942                                 }
4943                         }
4944 found_break_parent:
4945                         break;
4946
4947                 case STATEMENT_COMPUTED_GOTO: {
4948                         if (!expression_returns(stmt->computed_goto.expression))
4949                                 return;
4950
4951                         statement_t *parent = stmt->base.parent;
4952                         if (parent == NULL) /* top level goto */
4953                                 return;
4954                         next = parent;
4955                         break;
4956                 }
4957
4958                 case STATEMENT_GOTO:
4959                         next = stmt->gotos.label->statement;
4960                         if (next == NULL) /* missing label */
4961                                 return;
4962                         break;
4963
4964                 case STATEMENT_LABEL:
4965                         next = stmt->label.statement;
4966                         break;
4967
4968                 case STATEMENT_CASE_LABEL:
4969                         next = stmt->case_label.statement;
4970                         break;
4971
4972                 case STATEMENT_WHILE: {
4973                         while_statement_t const *const whiles = &stmt->whiles;
4974                         expression_t      const *const cond   = whiles->condition;
4975
4976                         if (!expression_returns(cond))
4977                                 return;
4978
4979                         int const val = determine_truth(cond);
4980
4981                         if (val >= 0)
4982                                 check_reachable(whiles->body);
4983
4984                         if (val > 0)
4985                                 return;
4986
4987                         next = stmt->base.next;
4988                         break;
4989                 }
4990
4991                 case STATEMENT_DO_WHILE:
4992                         next = stmt->do_while.body;
4993                         break;
4994
4995                 case STATEMENT_FOR: {
4996                         for_statement_t *const fors = &stmt->fors;
4997
4998                         if (fors->condition_reachable)
4999                                 return;
5000                         fors->condition_reachable = true;
5001
5002                         expression_t const *const cond = fors->condition;
5003
5004                         int val;
5005                         if (cond == NULL) {
5006                                 val = 1;
5007                         } else if (expression_returns(cond)) {
5008                                 val = determine_truth(cond);
5009                         } else {
5010                                 return;
5011                         }
5012
5013                         if (val >= 0)
5014                                 check_reachable(fors->body);
5015
5016                         if (val > 0)
5017                                 return;
5018
5019                         next = stmt->base.next;
5020                         break;
5021                 }
5022
5023                 case STATEMENT_MS_TRY: {
5024                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5025                         check_reachable(ms_try->try_statement);
5026                         next = ms_try->final_statement;
5027                         break;
5028                 }
5029
5030                 case STATEMENT_LEAVE: {
5031                         statement_t *parent = stmt;
5032                         for (;;) {
5033                                 parent = parent->base.parent;
5034                                 if (parent == NULL) /* __leave not within __try */
5035                                         return;
5036
5037                                 if (parent->kind == STATEMENT_MS_TRY) {
5038                                         last = parent;
5039                                         next = parent->ms_try.final_statement;
5040                                         break;
5041                                 }
5042                         }
5043                         break;
5044                 }
5045
5046                 default:
5047                         panic("invalid statement kind");
5048         }
5049
5050         while (next == NULL) {
5051                 next = last->base.parent;
5052                 if (next == NULL) {
5053                         noreturn_candidate = false;
5054
5055                         type_t *const type = skip_typeref(current_function->base.type);
5056                         assert(is_type_function(type));
5057                         type_t *const ret  = skip_typeref(type->function.return_type);
5058                         if (!is_type_void(ret) &&
5059                             is_type_valid(ret) &&
5060                             !is_sym_main(current_function->base.base.symbol)) {
5061                                 source_position_t const *const pos = &stmt->base.source_position;
5062                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5063                         }
5064                         return;
5065                 }
5066
5067                 switch (next->kind) {
5068                         case STATEMENT_ERROR:
5069                         case STATEMENT_EMPTY:
5070                         case STATEMENT_DECLARATION:
5071                         case STATEMENT_EXPRESSION:
5072                         case STATEMENT_ASM:
5073                         case STATEMENT_RETURN:
5074                         case STATEMENT_CONTINUE:
5075                         case STATEMENT_BREAK:
5076                         case STATEMENT_COMPUTED_GOTO:
5077                         case STATEMENT_GOTO:
5078                         case STATEMENT_LEAVE:
5079                                 panic("invalid control flow in function");
5080
5081                         case STATEMENT_COMPOUND:
5082                                 if (next->compound.stmt_expr) {
5083                                         reaches_end = true;
5084                                         return;
5085                                 }
5086                                 /* FALLTHROUGH */
5087                         case STATEMENT_IF:
5088                         case STATEMENT_SWITCH:
5089                         case STATEMENT_LABEL:
5090                         case STATEMENT_CASE_LABEL:
5091                                 last = next;
5092                                 next = next->base.next;
5093                                 break;
5094
5095                         case STATEMENT_WHILE: {
5096 continue_while:
5097                                 if (next->base.reachable)
5098                                         return;
5099                                 next->base.reachable = true;
5100
5101                                 while_statement_t const *const whiles = &next->whiles;
5102                                 expression_t      const *const cond   = whiles->condition;
5103
5104                                 if (!expression_returns(cond))
5105                                         return;
5106
5107                                 int const val = determine_truth(cond);
5108
5109                                 if (val >= 0)
5110                                         check_reachable(whiles->body);
5111
5112                                 if (val > 0)
5113                                         return;
5114
5115                                 last = next;
5116                                 next = next->base.next;
5117                                 break;
5118                         }
5119
5120                         case STATEMENT_DO_WHILE: {
5121 continue_do_while:
5122                                 if (next->base.reachable)
5123                                         return;
5124                                 next->base.reachable = true;
5125
5126                                 do_while_statement_t const *const dw   = &next->do_while;
5127                                 expression_t         const *const cond = dw->condition;
5128
5129                                 if (!expression_returns(cond))
5130                                         return;
5131
5132                                 int const val = determine_truth(cond);
5133
5134                                 if (val >= 0)
5135                                         check_reachable(dw->body);
5136
5137                                 if (val > 0)
5138                                         return;
5139
5140                                 last = next;
5141                                 next = next->base.next;
5142                                 break;
5143                         }
5144
5145                         case STATEMENT_FOR: {
5146 continue_for:;
5147                                 for_statement_t *const fors = &next->fors;
5148
5149                                 fors->step_reachable = true;
5150
5151                                 if (fors->condition_reachable)
5152                                         return;
5153                                 fors->condition_reachable = true;
5154
5155                                 expression_t const *const cond = fors->condition;
5156
5157                                 int val;
5158                                 if (cond == NULL) {
5159                                         val = 1;
5160                                 } else if (expression_returns(cond)) {
5161                                         val = determine_truth(cond);
5162                                 } else {
5163                                         return;
5164                                 }
5165
5166                                 if (val >= 0)
5167                                         check_reachable(fors->body);
5168
5169                                 if (val > 0)
5170                                         return;
5171
5172                                 last = next;
5173                                 next = next->base.next;
5174                                 break;
5175                         }
5176
5177                         case STATEMENT_MS_TRY:
5178                                 last = next;
5179                                 next = next->ms_try.final_statement;
5180                                 break;
5181                 }
5182         }
5183
5184         check_reachable(next);
5185 }
5186
5187 static void check_unreachable(statement_t* const stmt, void *const env)
5188 {
5189         (void)env;
5190
5191         switch (stmt->kind) {
5192                 case STATEMENT_DO_WHILE:
5193                         if (!stmt->base.reachable) {
5194                                 expression_t const *const cond = stmt->do_while.condition;
5195                                 if (determine_truth(cond) >= 0) {
5196                                         source_position_t const *const pos = &cond->base.source_position;
5197                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5198                                 }
5199                         }
5200                         return;
5201
5202                 case STATEMENT_FOR: {
5203                         for_statement_t const* const fors = &stmt->fors;
5204
5205                         // if init and step are unreachable, cond is unreachable, too
5206                         if (!stmt->base.reachable && !fors->step_reachable) {
5207                                 goto warn_unreachable;
5208                         } else {
5209                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5210                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5211                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5212                                 }
5213
5214                                 if (!fors->condition_reachable && fors->condition != NULL) {
5215                                         source_position_t const *const pos = &fors->condition->base.source_position;
5216                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5217                                 }
5218
5219                                 if (!fors->step_reachable && fors->step != NULL) {
5220                                         source_position_t const *const pos = &fors->step->base.source_position;
5221                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5222                                 }
5223                         }
5224                         return;
5225                 }
5226
5227                 case STATEMENT_COMPOUND:
5228                         if (stmt->compound.statements != NULL)
5229                                 return;
5230                         goto warn_unreachable;
5231
5232                 case STATEMENT_DECLARATION: {
5233                         /* Only warn if there is at least one declarator with an initializer.
5234                          * This typically occurs in switch statements. */
5235                         declaration_statement_t const *const decl = &stmt->declaration;
5236                         entity_t                const *      ent  = decl->declarations_begin;
5237                         entity_t                const *const last = decl->declarations_end;
5238                         if (ent != NULL) {
5239                                 for (;; ent = ent->base.next) {
5240                                         if (ent->kind                 == ENTITY_VARIABLE &&
5241                                                         ent->variable.initializer != NULL) {
5242                                                 goto warn_unreachable;
5243                                         }
5244                                         if (ent == last)
5245                                                 return;
5246                                 }
5247                         }
5248                 }
5249
5250                 default:
5251 warn_unreachable:
5252                         if (!stmt->base.reachable) {
5253                                 source_position_t const *const pos = &stmt->base.source_position;
5254                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5255                         }
5256                         return;
5257         }
5258 }
5259
5260 static bool is_main(entity_t *entity)
5261 {
5262         static symbol_t *sym_main = NULL;
5263         if (sym_main == NULL) {
5264                 sym_main = symbol_table_insert("main");
5265         }
5266
5267         if (entity->base.symbol != sym_main)
5268                 return false;
5269         /* must be in outermost scope */
5270         if (entity->base.parent_scope != file_scope)
5271                 return false;
5272
5273         return true;
5274 }
5275
5276 static void parse_external_declaration(void)
5277 {
5278         /* function-definitions and declarations both start with declaration
5279          * specifiers */
5280         add_anchor_token(';');
5281         declaration_specifiers_t specifiers;
5282         parse_declaration_specifiers(&specifiers);
5283         rem_anchor_token(';');
5284
5285         /* must be a declaration */
5286         if (token.kind == ';') {
5287                 parse_anonymous_declaration_rest(&specifiers);
5288                 return;
5289         }
5290
5291         add_anchor_token(',');
5292         add_anchor_token('=');
5293         add_anchor_token(';');
5294         add_anchor_token('{');
5295
5296         /* declarator is common to both function-definitions and declarations */
5297         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5298
5299         rem_anchor_token('{');
5300         rem_anchor_token(';');
5301         rem_anchor_token('=');
5302         rem_anchor_token(',');
5303
5304         /* must be a declaration */
5305         switch (token.kind) {
5306                 case ',':
5307                 case ';':
5308                 case '=':
5309                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5310                                         DECL_FLAGS_NONE);
5311                         return;
5312         }
5313
5314         /* must be a function definition */
5315         parse_kr_declaration_list(ndeclaration);
5316
5317         if (token.kind != '{') {
5318                 parse_error_expected("while parsing function definition", '{', NULL);
5319                 eat_until_matching_token(';');
5320                 return;
5321         }
5322
5323         assert(is_declaration(ndeclaration));
5324         type_t *const orig_type = ndeclaration->declaration.type;
5325         type_t *      type      = skip_typeref(orig_type);
5326
5327         if (!is_type_function(type)) {
5328                 if (is_type_valid(type)) {
5329                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5330                 }
5331                 eat_block();
5332                 return;
5333         }
5334
5335         source_position_t const *const pos = &ndeclaration->base.source_position;
5336         if (is_typeref(orig_type)) {
5337                 /* §6.9.1:2 */
5338                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5339         }
5340
5341         if (is_type_compound(skip_typeref(type->function.return_type))) {
5342                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5343         }
5344         if (type->function.unspecified_parameters) {
5345                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5346         } else {
5347                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5348         }
5349
5350         /* §6.7.5.3:14 a function definition with () means no
5351          * parameters (and not unspecified parameters) */
5352         if (type->function.unspecified_parameters &&
5353                         type->function.parameters == NULL) {
5354                 type_t *copy                          = duplicate_type(type);
5355                 copy->function.unspecified_parameters = false;
5356                 type                                  = identify_new_type(copy);
5357
5358                 ndeclaration->declaration.type = type;
5359         }
5360
5361         entity_t *const entity = record_entity(ndeclaration, true);
5362         assert(entity->kind == ENTITY_FUNCTION);
5363         assert(ndeclaration->kind == ENTITY_FUNCTION);
5364
5365         function_t *const function = &entity->function;
5366         if (ndeclaration != entity) {
5367                 function->parameters = ndeclaration->function.parameters;
5368         }
5369         assert(is_declaration(entity));
5370         type = skip_typeref(entity->declaration.type);
5371
5372         PUSH_SCOPE(&function->parameters);
5373
5374         entity_t *parameter = function->parameters.entities;
5375         for (; parameter != NULL; parameter = parameter->base.next) {
5376                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5377                         parameter->base.parent_scope = current_scope;
5378                 }
5379                 assert(parameter->base.parent_scope == NULL
5380                                 || parameter->base.parent_scope == current_scope);
5381                 parameter->base.parent_scope = current_scope;
5382                 if (parameter->base.symbol == NULL) {
5383                         errorf(&parameter->base.source_position, "parameter name omitted");
5384                         continue;
5385                 }
5386                 environment_push(parameter);
5387         }
5388
5389         if (function->statement != NULL) {
5390                 parser_error_multiple_definition(entity, HERE);
5391                 eat_block();
5392         } else {
5393                 /* parse function body */
5394                 int         label_stack_top      = label_top();
5395                 function_t *old_current_function = current_function;
5396                 entity_t   *old_current_entity   = current_entity;
5397                 current_function                 = function;
5398                 current_entity                   = entity;
5399                 PUSH_PARENT(NULL);
5400
5401                 goto_first   = NULL;
5402                 goto_anchor  = &goto_first;
5403                 label_first  = NULL;
5404                 label_anchor = &label_first;
5405
5406                 statement_t *const body = parse_compound_statement(false);
5407                 function->statement = body;
5408                 first_err = true;
5409                 check_labels();
5410                 check_declarations();
5411                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5412                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5413                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5414                         noreturn_candidate = true;
5415                         check_reachable(body);
5416                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5417                                 walk_statements(body, check_unreachable, NULL);
5418                         if (noreturn_candidate &&
5419                             !(function->base.modifiers & DM_NORETURN)) {
5420                                 source_position_t const *const pos = &body->base.source_position;
5421                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5422                         }
5423                 }
5424
5425                 if (is_main(entity) && enable_main_collect2_hack)
5426                         prepare_main_collect2(entity);
5427
5428                 POP_PARENT();
5429                 assert(current_function == function);
5430                 assert(current_entity   == entity);
5431                 current_entity   = old_current_entity;
5432                 current_function = old_current_function;
5433                 label_pop_to(label_stack_top);
5434         }
5435
5436         POP_SCOPE();
5437 }
5438
5439 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5440 {
5441         entity_t *iter = compound->members.entities;
5442         for (; iter != NULL; iter = iter->base.next) {
5443                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5444                         continue;
5445
5446                 if (iter->base.symbol == symbol) {
5447                         return iter;
5448                 } else if (iter->base.symbol == NULL) {
5449                         /* search in anonymous structs and unions */
5450                         type_t *type = skip_typeref(iter->declaration.type);
5451                         if (is_type_compound(type)) {
5452                                 if (find_compound_entry(type->compound.compound, symbol)
5453                                                 != NULL)
5454                                         return iter;
5455                         }
5456                         continue;
5457                 }
5458         }
5459
5460         return NULL;
5461 }
5462
5463 static void check_deprecated(const source_position_t *source_position,
5464                              const entity_t *entity)
5465 {
5466         if (!is_declaration(entity))
5467                 return;
5468         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5469                 return;
5470
5471         source_position_t const *const epos = &entity->base.source_position;
5472         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5473         if (msg != NULL) {
5474                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5475         } else {
5476                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5477         }
5478 }
5479
5480
5481 static expression_t *create_select(const source_position_t *pos,
5482                                    expression_t *addr,
5483                                    type_qualifiers_t qualifiers,
5484                                                                    entity_t *entry)
5485 {
5486         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5487
5488         check_deprecated(pos, entry);
5489
5490         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5491         select->select.compound       = addr;
5492         select->select.compound_entry = entry;
5493
5494         type_t *entry_type = entry->declaration.type;
5495         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5496
5497         /* bitfields need special treatment */
5498         if (entry->compound_member.bitfield) {
5499                 unsigned bit_size = entry->compound_member.bit_size;
5500                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5501                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5502                         res_type = type_int;
5503                 }
5504         }
5505
5506         /* we always do the auto-type conversions; the & and sizeof parser contains
5507          * code to revert this! */
5508         select->base.type = automatic_type_conversion(res_type);
5509
5510
5511         return select;
5512 }
5513
5514 /**
5515  * Find entry with symbol in compound. Search anonymous structs and unions and
5516  * creates implicit select expressions for them.
5517  * Returns the adress for the innermost compound.
5518  */
5519 static expression_t *find_create_select(const source_position_t *pos,
5520                                         expression_t *addr,
5521                                         type_qualifiers_t qualifiers,
5522                                         compound_t *compound, symbol_t *symbol)
5523 {
5524         entity_t *iter = compound->members.entities;
5525         for (; iter != NULL; iter = iter->base.next) {
5526                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5527                         continue;
5528
5529                 symbol_t *iter_symbol = iter->base.symbol;
5530                 if (iter_symbol == NULL) {
5531                         type_t *type = iter->declaration.type;
5532                         if (type->kind != TYPE_COMPOUND_STRUCT
5533                                         && type->kind != TYPE_COMPOUND_UNION)
5534                                 continue;
5535
5536                         compound_t *sub_compound = type->compound.compound;
5537
5538                         if (find_compound_entry(sub_compound, symbol) == NULL)
5539                                 continue;
5540
5541                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5542                         sub_addr->base.source_position = *pos;
5543                         sub_addr->base.implicit        = true;
5544                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5545                                                   symbol);
5546                 }
5547
5548                 if (iter_symbol == symbol) {
5549                         return create_select(pos, addr, qualifiers, iter);
5550                 }
5551         }
5552
5553         return NULL;
5554 }
5555
5556 static void parse_bitfield_member(entity_t *entity)
5557 {
5558         eat(':');
5559
5560         expression_t *size = parse_constant_expression();
5561         long          size_long;
5562
5563         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5564         type_t *type = entity->declaration.type;
5565         if (!is_type_integer(skip_typeref(type))) {
5566                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5567                            type);
5568         }
5569
5570         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5571                 /* error already reported by parse_constant_expression */
5572                 size_long = get_type_size(type) * 8;
5573         } else {
5574                 size_long = fold_constant_to_int(size);
5575
5576                 const symbol_t *symbol = entity->base.symbol;
5577                 const symbol_t *user_symbol
5578                         = symbol == NULL ? sym_anonymous : symbol;
5579                 unsigned bit_size = get_type_size(type) * 8;
5580                 if (size_long < 0) {
5581                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5582                 } else if (size_long == 0 && symbol != NULL) {
5583                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5584                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5585                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5586                                    user_symbol);
5587                 } else {
5588                         /* hope that people don't invent crazy types with more bits
5589                          * than our struct can hold */
5590                         assert(size_long <
5591                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5592                 }
5593         }
5594
5595         entity->compound_member.bitfield = true;
5596         entity->compound_member.bit_size = (unsigned char)size_long;
5597 }
5598
5599 static void parse_compound_declarators(compound_t *compound,
5600                 const declaration_specifiers_t *specifiers)
5601 {
5602         add_anchor_token(';');
5603         add_anchor_token(',');
5604         do {
5605                 entity_t *entity;
5606
5607                 if (token.kind == ':') {
5608                         /* anonymous bitfield */
5609                         type_t *type = specifiers->type;
5610                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5611                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5612                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5613                         entity->declaration.type                   = type;
5614
5615                         parse_bitfield_member(entity);
5616
5617                         attribute_t  *attributes = parse_attributes(NULL);
5618                         attribute_t **anchor     = &attributes;
5619                         while (*anchor != NULL)
5620                                 anchor = &(*anchor)->next;
5621                         *anchor = specifiers->attributes;
5622                         if (attributes != NULL) {
5623                                 handle_entity_attributes(attributes, entity);
5624                         }
5625                         entity->declaration.attributes = attributes;
5626
5627                         append_entity(&compound->members, entity);
5628                 } else {
5629                         entity = parse_declarator(specifiers,
5630                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5631                         source_position_t const *const pos = &entity->base.source_position;
5632                         if (entity->kind == ENTITY_TYPEDEF) {
5633                                 errorf(pos, "typedef not allowed as compound member");
5634                         } else {
5635                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5636
5637                                 /* make sure we don't define a symbol multiple times */
5638                                 symbol_t *symbol = entity->base.symbol;
5639                                 if (symbol != NULL) {
5640                                         entity_t *prev = find_compound_entry(compound, symbol);
5641                                         if (prev != NULL) {
5642                                                 source_position_t const *const ppos = &prev->base.source_position;
5643                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5644                                         }
5645                                 }
5646
5647                                 if (token.kind == ':') {
5648                                         parse_bitfield_member(entity);
5649
5650                                         attribute_t *attributes = parse_attributes(NULL);
5651                                         handle_entity_attributes(attributes, entity);
5652                                 } else {
5653                                         type_t *orig_type = entity->declaration.type;
5654                                         type_t *type      = skip_typeref(orig_type);
5655                                         if (is_type_function(type)) {
5656                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5657                                         } else if (is_type_incomplete(type)) {
5658                                                 /* §6.7.2.1:16 flexible array member */
5659                                                 if (!is_type_array(type)       ||
5660                                                                 token.kind          != ';' ||
5661                                                                 look_ahead(1)->kind != '}') {
5662                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5663                                                 } else if (compound->members.entities == NULL) {
5664                                                         errorf(pos, "flexible array member in otherwise empty struct");
5665                                                 }
5666                                         }
5667                                 }
5668
5669                                 append_entity(&compound->members, entity);
5670                         }
5671                 }
5672         } while (next_if(','));
5673         rem_anchor_token(',');
5674         rem_anchor_token(';');
5675         expect(';');
5676
5677         anonymous_entity = NULL;
5678 }
5679
5680 static void parse_compound_type_entries(compound_t *compound)
5681 {
5682         eat('{');
5683         add_anchor_token('}');
5684
5685         for (;;) {
5686                 switch (token.kind) {
5687                         DECLARATION_START
5688                         case T___extension__:
5689                         case T_IDENTIFIER: {
5690                                 PUSH_EXTENSION();
5691                                 declaration_specifiers_t specifiers;
5692                                 parse_declaration_specifiers(&specifiers);
5693                                 parse_compound_declarators(compound, &specifiers);
5694                                 POP_EXTENSION();
5695                                 break;
5696                         }
5697
5698                         default:
5699                                 rem_anchor_token('}');
5700                                 expect('}');
5701                                 /* §6.7.2.1:7 */
5702                                 compound->complete = true;
5703                                 return;
5704                 }
5705         }
5706 }
5707
5708 static type_t *parse_typename(void)
5709 {
5710         declaration_specifiers_t specifiers;
5711         parse_declaration_specifiers(&specifiers);
5712         if (specifiers.storage_class != STORAGE_CLASS_NONE
5713                         || specifiers.thread_local) {
5714                 /* TODO: improve error message, user does probably not know what a
5715                  * storage class is...
5716                  */
5717                 errorf(&specifiers.source_position, "typename must not have a storage class");
5718         }
5719
5720         type_t *result = parse_abstract_declarator(specifiers.type);
5721
5722         return result;
5723 }
5724
5725
5726
5727
5728 typedef expression_t* (*parse_expression_function)(void);
5729 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5730
5731 typedef struct expression_parser_function_t expression_parser_function_t;
5732 struct expression_parser_function_t {
5733         parse_expression_function        parser;
5734         precedence_t                     infix_precedence;
5735         parse_expression_infix_function  infix_parser;
5736 };
5737
5738 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5739
5740 /**
5741  * Prints an error message if an expression was expected but not read
5742  */
5743 static expression_t *expected_expression_error(void)
5744 {
5745         /* skip the error message if the error token was read */
5746         if (token.kind != T_ERROR) {
5747                 errorf(HERE, "expected expression, got token %K", &token);
5748         }
5749         next_token();
5750
5751         return create_error_expression();
5752 }
5753
5754 static type_t *get_string_type(void)
5755 {
5756         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5757 }
5758
5759 static type_t *get_wide_string_type(void)
5760 {
5761         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5762 }
5763
5764 /**
5765  * Parse a string constant.
5766  */
5767 static expression_t *parse_string_literal(void)
5768 {
5769         source_position_t begin   = token.base.source_position;
5770         string_t          res     = token.string.string;
5771         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5772
5773         next_token();
5774         while (token.kind == T_STRING_LITERAL
5775                         || token.kind == T_WIDE_STRING_LITERAL) {
5776                 warn_string_concat(&token.base.source_position);
5777                 res = concat_strings(&res, &token.string.string);
5778                 next_token();
5779                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5780         }
5781
5782         expression_t *literal;
5783         if (is_wide) {
5784                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5785                 literal->base.type = get_wide_string_type();
5786         } else {
5787                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5788                 literal->base.type = get_string_type();
5789         }
5790         literal->base.source_position = begin;
5791         literal->literal.value        = res;
5792
5793         return literal;
5794 }
5795
5796 /**
5797  * Parse a boolean constant.
5798  */
5799 static expression_t *parse_boolean_literal(bool value)
5800 {
5801         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5802         literal->base.type           = type_bool;
5803         literal->literal.value.begin = value ? "true" : "false";
5804         literal->literal.value.size  = value ? 4 : 5;
5805
5806         next_token();
5807         return literal;
5808 }
5809
5810 static void warn_traditional_suffix(void)
5811 {
5812         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5813                  &token.number.suffix);
5814 }
5815
5816 static void check_integer_suffix(void)
5817 {
5818         const string_t *suffix = &token.number.suffix;
5819         if (suffix->size == 0)
5820                 return;
5821
5822         bool not_traditional = false;
5823         const char *c = suffix->begin;
5824         if (*c == 'l' || *c == 'L') {
5825                 ++c;
5826                 if (*c == *(c-1)) {
5827                         not_traditional = true;
5828                         ++c;
5829                         if (*c == 'u' || *c == 'U') {
5830                                 ++c;
5831                         }
5832                 } else if (*c == 'u' || *c == 'U') {
5833                         not_traditional = true;
5834                         ++c;
5835                 }
5836         } else if (*c == 'u' || *c == 'U') {
5837                 not_traditional = true;
5838                 ++c;
5839                 if (*c == 'l' || *c == 'L') {
5840                         ++c;
5841                         if (*c == *(c-1)) {
5842                                 ++c;
5843                         }
5844                 }
5845         }
5846         if (*c != '\0') {
5847                 errorf(&token.base.source_position,
5848                        "invalid suffix '%S' on integer constant", suffix);
5849         } else if (not_traditional) {
5850                 warn_traditional_suffix();
5851         }
5852 }
5853
5854 static type_t *check_floatingpoint_suffix(void)
5855 {
5856         const string_t *suffix = &token.number.suffix;
5857         type_t         *type   = type_double;
5858         if (suffix->size == 0)
5859                 return type;
5860
5861         bool not_traditional = false;
5862         const char *c = suffix->begin;
5863         if (*c == 'f' || *c == 'F') {
5864                 ++c;
5865                 type = type_float;
5866         } else if (*c == 'l' || *c == 'L') {
5867                 ++c;
5868                 type = type_long_double;
5869         }
5870         if (*c != '\0') {
5871                 errorf(&token.base.source_position,
5872                        "invalid suffix '%S' on floatingpoint constant", suffix);
5873         } else if (not_traditional) {
5874                 warn_traditional_suffix();
5875         }
5876
5877         return type;
5878 }
5879
5880 /**
5881  * Parse an integer constant.
5882  */
5883 static expression_t *parse_number_literal(void)
5884 {
5885         expression_kind_t  kind;
5886         type_t            *type;
5887
5888         switch (token.kind) {
5889         case T_INTEGER:
5890                 kind = EXPR_LITERAL_INTEGER;
5891                 check_integer_suffix();
5892                 type = type_int;
5893                 break;
5894         case T_INTEGER_OCTAL:
5895                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5896                 check_integer_suffix();
5897                 type = type_int;
5898                 break;
5899         case T_INTEGER_HEXADECIMAL:
5900                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5901                 check_integer_suffix();
5902                 type = type_int;
5903                 break;
5904         case T_FLOATINGPOINT:
5905                 kind = EXPR_LITERAL_FLOATINGPOINT;
5906                 type = check_floatingpoint_suffix();
5907                 break;
5908         case T_FLOATINGPOINT_HEXADECIMAL:
5909                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5910                 type = check_floatingpoint_suffix();
5911                 break;
5912         default:
5913                 panic("unexpected token type in parse_number_literal");
5914         }
5915
5916         expression_t *literal = allocate_expression_zero(kind);
5917         literal->base.type      = type;
5918         literal->literal.value  = token.number.number;
5919         literal->literal.suffix = token.number.suffix;
5920         next_token();
5921
5922         /* integer type depends on the size of the number and the size
5923          * representable by the types. The backend/codegeneration has to determine
5924          * that
5925          */
5926         determine_literal_type(&literal->literal);
5927         return literal;
5928 }
5929
5930 /**
5931  * Parse a character constant.
5932  */
5933 static expression_t *parse_character_constant(void)
5934 {
5935         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5936         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5937         literal->literal.value = token.string.string;
5938
5939         size_t len = literal->literal.value.size;
5940         if (len > 1) {
5941                 if (!GNU_MODE && !(c_mode & _C99)) {
5942                         errorf(HERE, "more than 1 character in character constant");
5943                 } else {
5944                         literal->base.type = type_int;
5945                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5946                 }
5947         }
5948
5949         next_token();
5950         return literal;
5951 }
5952
5953 /**
5954  * Parse a wide character constant.
5955  */
5956 static expression_t *parse_wide_character_constant(void)
5957 {
5958         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5959         literal->base.type     = type_int;
5960         literal->literal.value = token.string.string;
5961
5962         size_t len = wstrlen(&literal->literal.value);
5963         if (len > 1) {
5964                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5965         }
5966
5967         next_token();
5968         return literal;
5969 }
5970
5971 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5972 {
5973         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5974         ntype->function.return_type            = type_int;
5975         ntype->function.unspecified_parameters = true;
5976         ntype->function.linkage                = LINKAGE_C;
5977         type_t *type                           = identify_new_type(ntype);
5978
5979         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5980         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5981         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5982         entity->declaration.type                   = type;
5983         entity->declaration.implicit               = true;
5984
5985         if (current_scope != NULL)
5986                 record_entity(entity, false);
5987
5988         return entity;
5989 }
5990
5991 /**
5992  * Performs automatic type cast as described in §6.3.2.1.
5993  *
5994  * @param orig_type  the original type
5995  */
5996 static type_t *automatic_type_conversion(type_t *orig_type)
5997 {
5998         type_t *type = skip_typeref(orig_type);
5999         if (is_type_array(type)) {
6000                 array_type_t *array_type   = &type->array;
6001                 type_t       *element_type = array_type->element_type;
6002                 unsigned      qualifiers   = array_type->base.qualifiers;
6003
6004                 return make_pointer_type(element_type, qualifiers);
6005         }
6006
6007         if (is_type_function(type)) {
6008                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6009         }
6010
6011         return orig_type;
6012 }
6013
6014 /**
6015  * reverts the automatic casts of array to pointer types and function
6016  * to function-pointer types as defined §6.3.2.1
6017  */
6018 type_t *revert_automatic_type_conversion(const expression_t *expression)
6019 {
6020         switch (expression->kind) {
6021         case EXPR_REFERENCE: {
6022                 entity_t *entity = expression->reference.entity;
6023                 if (is_declaration(entity)) {
6024                         return entity->declaration.type;
6025                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6026                         return entity->enum_value.enum_type;
6027                 } else {
6028                         panic("no declaration or enum in reference");
6029                 }
6030         }
6031
6032         case EXPR_SELECT: {
6033                 entity_t *entity = expression->select.compound_entry;
6034                 assert(is_declaration(entity));
6035                 type_t   *type   = entity->declaration.type;
6036                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6037         }
6038
6039         case EXPR_UNARY_DEREFERENCE: {
6040                 const expression_t *const value = expression->unary.value;
6041                 type_t             *const type  = skip_typeref(value->base.type);
6042                 if (!is_type_pointer(type))
6043                         return type_error_type;
6044                 return type->pointer.points_to;
6045         }
6046
6047         case EXPR_ARRAY_ACCESS: {
6048                 const expression_t *array_ref = expression->array_access.array_ref;
6049                 type_t             *type_left = skip_typeref(array_ref->base.type);
6050                 if (!is_type_pointer(type_left))
6051                         return type_error_type;
6052                 return type_left->pointer.points_to;
6053         }
6054
6055         case EXPR_STRING_LITERAL: {
6056                 size_t size = expression->string_literal.value.size;
6057                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6058         }
6059
6060         case EXPR_WIDE_STRING_LITERAL: {
6061                 size_t size = wstrlen(&expression->string_literal.value);
6062                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6063         }
6064
6065         case EXPR_COMPOUND_LITERAL:
6066                 return expression->compound_literal.type;
6067
6068         default:
6069                 break;
6070         }
6071         return expression->base.type;
6072 }
6073
6074 /**
6075  * Find an entity matching a symbol in a scope.
6076  * Uses current scope if scope is NULL
6077  */
6078 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6079                                namespace_tag_t namespc)
6080 {
6081         if (scope == NULL) {
6082                 return get_entity(symbol, namespc);
6083         }
6084
6085         /* we should optimize here, if scope grows above a certain size we should
6086            construct a hashmap here... */
6087         entity_t *entity = scope->entities;
6088         for ( ; entity != NULL; entity = entity->base.next) {
6089                 if (entity->base.symbol == symbol
6090                     && (namespace_tag_t)entity->base.namespc == namespc)
6091                         break;
6092         }
6093
6094         return entity;
6095 }
6096
6097 static entity_t *parse_qualified_identifier(void)
6098 {
6099         /* namespace containing the symbol */
6100         symbol_t          *symbol;
6101         source_position_t  pos;
6102         const scope_t     *lookup_scope = NULL;
6103
6104         if (next_if(T_COLONCOLON))
6105                 lookup_scope = &unit->scope;
6106
6107         entity_t *entity;
6108         while (true) {
6109                 symbol = expect_identifier("while parsing identifier", &pos);
6110                 if (!symbol)
6111                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6112
6113                 /* lookup entity */
6114                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6115
6116                 if (!next_if(T_COLONCOLON))
6117                         break;
6118
6119                 switch (entity->kind) {
6120                 case ENTITY_NAMESPACE:
6121                         lookup_scope = &entity->namespacee.members;
6122                         break;
6123                 case ENTITY_STRUCT:
6124                 case ENTITY_UNION:
6125                 case ENTITY_CLASS:
6126                         lookup_scope = &entity->compound.members;
6127                         break;
6128                 default:
6129                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6130                                symbol, get_entity_kind_name(entity->kind));
6131
6132                         /* skip further qualifications */
6133                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6134
6135                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6136                 }
6137         }
6138
6139         if (entity == NULL) {
6140                 if (!strict_mode && token.kind == '(') {
6141                         /* an implicitly declared function */
6142                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6143                                  "implicit declaration of function '%Y'", symbol);
6144                         entity = create_implicit_function(symbol, &pos);
6145                 } else {
6146                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6147                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6148                 }
6149         }
6150
6151         return entity;
6152 }
6153
6154 static expression_t *parse_reference(void)
6155 {
6156         source_position_t const pos    = token.base.source_position;
6157         entity_t         *const entity = parse_qualified_identifier();
6158
6159         type_t *orig_type;
6160         if (is_declaration(entity)) {
6161                 orig_type = entity->declaration.type;
6162         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6163                 orig_type = entity->enum_value.enum_type;
6164         } else {
6165                 panic("expected declaration or enum value in reference");
6166         }
6167
6168         /* we always do the auto-type conversions; the & and sizeof parser contains
6169          * code to revert this! */
6170         type_t *type = automatic_type_conversion(orig_type);
6171
6172         expression_kind_t kind = EXPR_REFERENCE;
6173         if (entity->kind == ENTITY_ENUM_VALUE)
6174                 kind = EXPR_ENUM_CONSTANT;
6175
6176         expression_t *expression         = allocate_expression_zero(kind);
6177         expression->base.source_position = pos;
6178         expression->base.type            = type;
6179         expression->reference.entity     = entity;
6180
6181         /* this declaration is used */
6182         if (is_declaration(entity)) {
6183                 entity->declaration.used = true;
6184         }
6185
6186         if (entity->base.parent_scope != file_scope
6187                 && (current_function != NULL
6188                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6189                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6190                 if (entity->kind == ENTITY_VARIABLE) {
6191                         /* access of a variable from an outer function */
6192                         entity->variable.address_taken = true;
6193                 } else if (entity->kind == ENTITY_PARAMETER) {
6194                         entity->parameter.address_taken = true;
6195                 }
6196                 current_function->need_closure = true;
6197         }
6198
6199         check_deprecated(&pos, entity);
6200
6201         return expression;
6202 }
6203
6204 static bool semantic_cast(expression_t *cast)
6205 {
6206         expression_t            *expression      = cast->unary.value;
6207         type_t                  *orig_dest_type  = cast->base.type;
6208         type_t                  *orig_type_right = expression->base.type;
6209         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6210         type_t            const *src_type        = skip_typeref(orig_type_right);
6211         source_position_t const *pos             = &cast->base.source_position;
6212
6213         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6214         if (is_type_void(dst_type))
6215                 return true;
6216
6217         /* only integer and pointer can be casted to pointer */
6218         if (is_type_pointer(dst_type)  &&
6219             !is_type_pointer(src_type) &&
6220             !is_type_integer(src_type) &&
6221             is_type_valid(src_type)) {
6222                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6223                 return false;
6224         }
6225
6226         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6227                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6228                 return false;
6229         }
6230
6231         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6232                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6233                 return false;
6234         }
6235
6236         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6237                 type_t *src = skip_typeref(src_type->pointer.points_to);
6238                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6239                 unsigned missing_qualifiers =
6240                         src->base.qualifiers & ~dst->base.qualifiers;
6241                 if (missing_qualifiers != 0) {
6242                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6243                 }
6244         }
6245         return true;
6246 }
6247
6248 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6249 {
6250         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6251         expression->base.source_position = *pos;
6252
6253         parse_initializer_env_t env;
6254         env.type             = type;
6255         env.entity           = NULL;
6256         env.must_be_constant = false;
6257         initializer_t *initializer = parse_initializer(&env);
6258         type = env.type;
6259
6260         expression->compound_literal.initializer = initializer;
6261         expression->compound_literal.type        = type;
6262         expression->base.type                    = automatic_type_conversion(type);
6263
6264         return expression;
6265 }
6266
6267 /**
6268  * Parse a cast expression.
6269  */
6270 static expression_t *parse_cast(void)
6271 {
6272         source_position_t const pos = *HERE;
6273
6274         eat('(');
6275         add_anchor_token(')');
6276
6277         type_t *type = parse_typename();
6278
6279         rem_anchor_token(')');
6280         expect(')');
6281
6282         if (token.kind == '{') {
6283                 return parse_compound_literal(&pos, type);
6284         }
6285
6286         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6287         cast->base.source_position = pos;
6288
6289         expression_t *value = parse_subexpression(PREC_CAST);
6290         cast->base.type   = type;
6291         cast->unary.value = value;
6292
6293         if (! semantic_cast(cast)) {
6294                 /* TODO: record the error in the AST. else it is impossible to detect it */
6295         }
6296
6297         return cast;
6298 }
6299
6300 /**
6301  * Parse a statement expression.
6302  */
6303 static expression_t *parse_statement_expression(void)
6304 {
6305         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6306
6307         eat('(');
6308         add_anchor_token(')');
6309
6310         statement_t *statement          = parse_compound_statement(true);
6311         statement->compound.stmt_expr   = true;
6312         expression->statement.statement = statement;
6313
6314         /* find last statement and use its type */
6315         type_t *type = type_void;
6316         const statement_t *stmt = statement->compound.statements;
6317         if (stmt != NULL) {
6318                 while (stmt->base.next != NULL)
6319                         stmt = stmt->base.next;
6320
6321                 if (stmt->kind == STATEMENT_EXPRESSION) {
6322                         type = stmt->expression.expression->base.type;
6323                 }
6324         } else {
6325                 source_position_t const *const pos = &expression->base.source_position;
6326                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6327         }
6328         expression->base.type = type;
6329
6330         rem_anchor_token(')');
6331         expect(')');
6332         return expression;
6333 }
6334
6335 /**
6336  * Parse a parenthesized expression.
6337  */
6338 static expression_t *parse_parenthesized_expression(void)
6339 {
6340         token_t const* const la1 = look_ahead(1);
6341         switch (la1->kind) {
6342         case '{':
6343                 /* gcc extension: a statement expression */
6344                 return parse_statement_expression();
6345
6346         case T_IDENTIFIER:
6347                 if (is_typedef_symbol(la1->identifier.symbol)) {
6348         DECLARATION_START
6349                         return parse_cast();
6350                 }
6351         }
6352
6353         eat('(');
6354         add_anchor_token(')');
6355         expression_t *result = parse_expression();
6356         result->base.parenthesized = true;
6357         rem_anchor_token(')');
6358         expect(')');
6359
6360         return result;
6361 }
6362
6363 static expression_t *parse_function_keyword(void)
6364 {
6365         /* TODO */
6366
6367         if (current_function == NULL) {
6368                 errorf(HERE, "'__func__' used outside of a function");
6369         }
6370
6371         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6372         expression->base.type     = type_char_ptr;
6373         expression->funcname.kind = FUNCNAME_FUNCTION;
6374
6375         next_token();
6376
6377         return expression;
6378 }
6379
6380 static expression_t *parse_pretty_function_keyword(void)
6381 {
6382         if (current_function == NULL) {
6383                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6384         }
6385
6386         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6387         expression->base.type     = type_char_ptr;
6388         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6389
6390         eat(T___PRETTY_FUNCTION__);
6391
6392         return expression;
6393 }
6394
6395 static expression_t *parse_funcsig_keyword(void)
6396 {
6397         if (current_function == NULL) {
6398                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6399         }
6400
6401         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6402         expression->base.type     = type_char_ptr;
6403         expression->funcname.kind = FUNCNAME_FUNCSIG;
6404
6405         eat(T___FUNCSIG__);
6406
6407         return expression;
6408 }
6409
6410 static expression_t *parse_funcdname_keyword(void)
6411 {
6412         if (current_function == NULL) {
6413                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6414         }
6415
6416         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6417         expression->base.type     = type_char_ptr;
6418         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6419
6420         eat(T___FUNCDNAME__);
6421
6422         return expression;
6423 }
6424
6425 static designator_t *parse_designator(void)
6426 {
6427         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6428         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6429         if (!result->symbol)
6430                 return NULL;
6431
6432         designator_t *last_designator = result;
6433         while (true) {
6434                 if (next_if('.')) {
6435                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6436                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6437                         if (!designator->symbol)
6438                                 return NULL;
6439
6440                         last_designator->next = designator;
6441                         last_designator       = designator;
6442                         continue;
6443                 }
6444                 if (next_if('[')) {
6445                         add_anchor_token(']');
6446                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6447                         designator->source_position = *HERE;
6448                         designator->array_index     = parse_expression();
6449                         rem_anchor_token(']');
6450                         expect(']');
6451                         if (designator->array_index == NULL) {
6452                                 return NULL;
6453                         }
6454
6455                         last_designator->next = designator;
6456                         last_designator       = designator;
6457                         continue;
6458                 }
6459                 break;
6460         }
6461
6462         return result;
6463 }
6464
6465 /**
6466  * Parse the __builtin_offsetof() expression.
6467  */
6468 static expression_t *parse_offsetof(void)
6469 {
6470         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6471         expression->base.type    = type_size_t;
6472
6473         eat(T___builtin_offsetof);
6474
6475         expect('(');
6476         add_anchor_token(')');
6477         add_anchor_token(',');
6478         type_t *type = parse_typename();
6479         rem_anchor_token(',');
6480         expect(',');
6481         designator_t *designator = parse_designator();
6482         rem_anchor_token(')');
6483         expect(')');
6484
6485         expression->offsetofe.type       = type;
6486         expression->offsetofe.designator = designator;
6487
6488         type_path_t path;
6489         memset(&path, 0, sizeof(path));
6490         path.top_type = type;
6491         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6492
6493         descend_into_subtype(&path);
6494
6495         if (!walk_designator(&path, designator, true)) {
6496                 return create_error_expression();
6497         }
6498
6499         DEL_ARR_F(path.path);
6500
6501         return expression;
6502 }
6503
6504 /**
6505  * Parses a _builtin_va_start() expression.
6506  */
6507 static expression_t *parse_va_start(void)
6508 {
6509         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6510
6511         eat(T___builtin_va_start);
6512
6513         expect('(');
6514         add_anchor_token(')');
6515         add_anchor_token(',');
6516         expression->va_starte.ap = parse_assignment_expression();
6517         rem_anchor_token(',');
6518         expect(',');
6519         expression_t *const expr = parse_assignment_expression();
6520         if (expr->kind == EXPR_REFERENCE) {
6521                 entity_t *const entity = expr->reference.entity;
6522                 if (!current_function->base.type->function.variadic) {
6523                         errorf(&expr->base.source_position,
6524                                         "'va_start' used in non-variadic function");
6525                 } else if (entity->base.parent_scope != &current_function->parameters ||
6526                                 entity->base.next != NULL ||
6527                                 entity->kind != ENTITY_PARAMETER) {
6528                         errorf(&expr->base.source_position,
6529                                "second argument of 'va_start' must be last parameter of the current function");
6530                 } else {
6531                         expression->va_starte.parameter = &entity->variable;
6532                 }
6533         } else {
6534                 expression = create_error_expression();
6535         }
6536         rem_anchor_token(')');
6537         expect(')');
6538         return expression;
6539 }
6540
6541 /**
6542  * Parses a __builtin_va_arg() expression.
6543  */
6544 static expression_t *parse_va_arg(void)
6545 {
6546         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6547
6548         eat(T___builtin_va_arg);
6549
6550         expect('(');
6551         add_anchor_token(')');
6552         add_anchor_token(',');
6553         call_argument_t ap;
6554         ap.expression = parse_assignment_expression();
6555         expression->va_arge.ap = ap.expression;
6556         check_call_argument(type_valist, &ap, 1);
6557
6558         rem_anchor_token(',');
6559         expect(',');
6560         expression->base.type = parse_typename();
6561         rem_anchor_token(')');
6562         expect(')');
6563
6564         return expression;
6565 }
6566
6567 /**
6568  * Parses a __builtin_va_copy() expression.
6569  */
6570 static expression_t *parse_va_copy(void)
6571 {
6572         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6573
6574         eat(T___builtin_va_copy);
6575
6576         expect('(');
6577         add_anchor_token(')');
6578         add_anchor_token(',');
6579         expression_t *dst = parse_assignment_expression();
6580         assign_error_t error = semantic_assign(type_valist, dst);
6581         report_assign_error(error, type_valist, dst, "call argument 1",
6582                             &dst->base.source_position);
6583         expression->va_copye.dst = dst;
6584
6585         rem_anchor_token(',');
6586         expect(',');
6587
6588         call_argument_t src;
6589         src.expression = parse_assignment_expression();
6590         check_call_argument(type_valist, &src, 2);
6591         expression->va_copye.src = src.expression;
6592         rem_anchor_token(')');
6593         expect(')');
6594
6595         return expression;
6596 }
6597
6598 /**
6599  * Parses a __builtin_constant_p() expression.
6600  */
6601 static expression_t *parse_builtin_constant(void)
6602 {
6603         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6604
6605         eat(T___builtin_constant_p);
6606
6607         expect('(');
6608         add_anchor_token(')');
6609         expression->builtin_constant.value = parse_assignment_expression();
6610         rem_anchor_token(')');
6611         expect(')');
6612         expression->base.type = type_int;
6613
6614         return expression;
6615 }
6616
6617 /**
6618  * Parses a __builtin_types_compatible_p() expression.
6619  */
6620 static expression_t *parse_builtin_types_compatible(void)
6621 {
6622         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6623
6624         eat(T___builtin_types_compatible_p);
6625
6626         expect('(');
6627         add_anchor_token(')');
6628         add_anchor_token(',');
6629         expression->builtin_types_compatible.left = parse_typename();
6630         rem_anchor_token(',');
6631         expect(',');
6632         expression->builtin_types_compatible.right = parse_typename();
6633         rem_anchor_token(')');
6634         expect(')');
6635         expression->base.type = type_int;
6636
6637         return expression;
6638 }
6639
6640 /**
6641  * Parses a __builtin_is_*() compare expression.
6642  */
6643 static expression_t *parse_compare_builtin(void)
6644 {
6645         expression_t *expression;
6646
6647         switch (token.kind) {
6648         case T___builtin_isgreater:
6649                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6650                 break;
6651         case T___builtin_isgreaterequal:
6652                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6653                 break;
6654         case T___builtin_isless:
6655                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6656                 break;
6657         case T___builtin_islessequal:
6658                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6659                 break;
6660         case T___builtin_islessgreater:
6661                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6662                 break;
6663         case T___builtin_isunordered:
6664                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6665                 break;
6666         default:
6667                 internal_errorf(HERE, "invalid compare builtin found");
6668         }
6669         expression->base.source_position = *HERE;
6670         next_token();
6671
6672         expect('(');
6673         add_anchor_token(')');
6674         add_anchor_token(',');
6675         expression->binary.left = parse_assignment_expression();
6676         rem_anchor_token(',');
6677         expect(',');
6678         expression->binary.right = parse_assignment_expression();
6679         rem_anchor_token(')');
6680         expect(')');
6681
6682         type_t *const orig_type_left  = expression->binary.left->base.type;
6683         type_t *const orig_type_right = expression->binary.right->base.type;
6684
6685         type_t *const type_left  = skip_typeref(orig_type_left);
6686         type_t *const type_right = skip_typeref(orig_type_right);
6687         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6688                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6689                         type_error_incompatible("invalid operands in comparison",
6690                                 &expression->base.source_position, orig_type_left, orig_type_right);
6691                 }
6692         } else {
6693                 semantic_comparison(&expression->binary);
6694         }
6695
6696         return expression;
6697 }
6698
6699 /**
6700  * Parses a MS assume() expression.
6701  */
6702 static expression_t *parse_assume(void)
6703 {
6704         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6705
6706         eat(T__assume);
6707
6708         expect('(');
6709         add_anchor_token(')');
6710         expression->unary.value = parse_assignment_expression();
6711         rem_anchor_token(')');
6712         expect(')');
6713
6714         expression->base.type = type_void;
6715         return expression;
6716 }
6717
6718 /**
6719  * Return the label for the current symbol or create a new one.
6720  */
6721 static label_t *get_label(void)
6722 {
6723         assert(token.kind == T_IDENTIFIER);
6724         assert(current_function != NULL);
6725
6726         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6727         /* If we find a local label, we already created the declaration. */
6728         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6729                 if (label->base.parent_scope != current_scope) {
6730                         assert(label->base.parent_scope->depth < current_scope->depth);
6731                         current_function->goto_to_outer = true;
6732                 }
6733         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6734                 /* There is no matching label in the same function, so create a new one. */
6735                 source_position_t const nowhere = { NULL, 0, 0, false };
6736                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol, &nowhere);
6737                 label_push(label);
6738         }
6739
6740         eat(T_IDENTIFIER);
6741         return &label->label;
6742 }
6743
6744 /**
6745  * Parses a GNU && label address expression.
6746  */
6747 static expression_t *parse_label_address(void)
6748 {
6749         source_position_t source_position = token.base.source_position;
6750         eat(T_ANDAND);
6751         if (token.kind != T_IDENTIFIER) {
6752                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6753                 return create_error_expression();
6754         }
6755
6756         label_t *const label = get_label();
6757         label->used          = true;
6758         label->address_taken = true;
6759
6760         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6761         expression->base.source_position = source_position;
6762
6763         /* label address is treated as a void pointer */
6764         expression->base.type           = type_void_ptr;
6765         expression->label_address.label = label;
6766         return expression;
6767 }
6768
6769 /**
6770  * Parse a microsoft __noop expression.
6771  */
6772 static expression_t *parse_noop_expression(void)
6773 {
6774         /* the result is a (int)0 */
6775         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6776         literal->base.type           = type_int;
6777         literal->literal.value.begin = "__noop";
6778         literal->literal.value.size  = 6;
6779
6780         eat(T___noop);
6781
6782         if (token.kind == '(') {
6783                 /* parse arguments */
6784                 eat('(');
6785                 add_anchor_token(')');
6786                 add_anchor_token(',');
6787
6788                 if (token.kind != ')') do {
6789                         (void)parse_assignment_expression();
6790                 } while (next_if(','));
6791
6792                 rem_anchor_token(',');
6793                 rem_anchor_token(')');
6794         }
6795         expect(')');
6796
6797         return literal;
6798 }
6799
6800 /**
6801  * Parses a primary expression.
6802  */
6803 static expression_t *parse_primary_expression(void)
6804 {
6805         switch (token.kind) {
6806         case T_false:                        return parse_boolean_literal(false);
6807         case T_true:                         return parse_boolean_literal(true);
6808         case T_INTEGER:
6809         case T_INTEGER_OCTAL:
6810         case T_INTEGER_HEXADECIMAL:
6811         case T_FLOATINGPOINT:
6812         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6813         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6814         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6815         case T_STRING_LITERAL:
6816         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6817         case T___FUNCTION__:
6818         case T___func__:                     return parse_function_keyword();
6819         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6820         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6821         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6822         case T___builtin_offsetof:           return parse_offsetof();
6823         case T___builtin_va_start:           return parse_va_start();
6824         case T___builtin_va_arg:             return parse_va_arg();
6825         case T___builtin_va_copy:            return parse_va_copy();
6826         case T___builtin_isgreater:
6827         case T___builtin_isgreaterequal:
6828         case T___builtin_isless:
6829         case T___builtin_islessequal:
6830         case T___builtin_islessgreater:
6831         case T___builtin_isunordered:        return parse_compare_builtin();
6832         case T___builtin_constant_p:         return parse_builtin_constant();
6833         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6834         case T__assume:                      return parse_assume();
6835         case T_ANDAND:
6836                 if (GNU_MODE)
6837                         return parse_label_address();
6838                 break;
6839
6840         case '(':                            return parse_parenthesized_expression();
6841         case T___noop:                       return parse_noop_expression();
6842
6843         /* Gracefully handle type names while parsing expressions. */
6844         case T_COLONCOLON:
6845                 return parse_reference();
6846         case T_IDENTIFIER:
6847                 if (!is_typedef_symbol(token.identifier.symbol)) {
6848                         return parse_reference();
6849                 }
6850                 /* FALLTHROUGH */
6851         DECLARATION_START {
6852                 source_position_t const  pos = *HERE;
6853                 declaration_specifiers_t specifiers;
6854                 parse_declaration_specifiers(&specifiers);
6855                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6856                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6857                 return create_error_expression();
6858         }
6859         }
6860
6861         errorf(HERE, "unexpected token %K, expected an expression", &token);
6862         eat_until_anchor();
6863         return create_error_expression();
6864 }
6865
6866 static expression_t *parse_array_expression(expression_t *left)
6867 {
6868         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6869         array_access_expression_t *const arr  = &expr->array_access;
6870
6871         eat('[');
6872         add_anchor_token(']');
6873
6874         expression_t *const inside = parse_expression();
6875
6876         type_t *const orig_type_left   = left->base.type;
6877         type_t *const orig_type_inside = inside->base.type;
6878
6879         type_t *const type_left   = skip_typeref(orig_type_left);
6880         type_t *const type_inside = skip_typeref(orig_type_inside);
6881
6882         expression_t *ref;
6883         expression_t *idx;
6884         type_t       *idx_type;
6885         type_t       *res_type;
6886         if (is_type_pointer(type_left)) {
6887                 ref      = left;
6888                 idx      = inside;
6889                 idx_type = type_inside;
6890                 res_type = type_left->pointer.points_to;
6891                 goto check_idx;
6892         } else if (is_type_pointer(type_inside)) {
6893                 arr->flipped = true;
6894                 ref      = inside;
6895                 idx      = left;
6896                 idx_type = type_left;
6897                 res_type = type_inside->pointer.points_to;
6898 check_idx:
6899                 res_type = automatic_type_conversion(res_type);
6900                 if (!is_type_integer(idx_type)) {
6901                         errorf(&idx->base.source_position, "array subscript must have integer type");
6902                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6903                         source_position_t const *const pos = &idx->base.source_position;
6904                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6905                 }
6906         } else {
6907                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6908                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6909                 }
6910                 res_type = type_error_type;
6911                 ref      = left;
6912                 idx      = inside;
6913         }
6914
6915         arr->array_ref = ref;
6916         arr->index     = idx;
6917         arr->base.type = res_type;
6918
6919         rem_anchor_token(']');
6920         expect(']');
6921         return expr;
6922 }
6923
6924 static bool is_bitfield(const expression_t *expression)
6925 {
6926         return expression->kind == EXPR_SELECT
6927                 && expression->select.compound_entry->compound_member.bitfield;
6928 }
6929
6930 static expression_t *parse_typeprop(expression_kind_t const kind)
6931 {
6932         expression_t  *tp_expression = allocate_expression_zero(kind);
6933         tp_expression->base.type     = type_size_t;
6934
6935         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6936
6937         type_t       *orig_type;
6938         expression_t *expression;
6939         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6940                 source_position_t const pos = *HERE;
6941                 next_token();
6942                 add_anchor_token(')');
6943                 orig_type = parse_typename();
6944                 rem_anchor_token(')');
6945                 expect(')');
6946
6947                 if (token.kind == '{') {
6948                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6949                          * starting with a compound literal */
6950                         expression = parse_compound_literal(&pos, orig_type);
6951                         goto typeprop_expression;
6952                 }
6953         } else {
6954                 expression = parse_subexpression(PREC_UNARY);
6955
6956 typeprop_expression:
6957                 if (is_bitfield(expression)) {
6958                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6959                         errorf(&tp_expression->base.source_position,
6960                                    "operand of %s expression must not be a bitfield", what);
6961                 }
6962
6963                 tp_expression->typeprop.tp_expression = expression;
6964
6965                 orig_type = revert_automatic_type_conversion(expression);
6966                 expression->base.type = orig_type;
6967         }
6968
6969         tp_expression->typeprop.type   = orig_type;
6970         type_t const* const type       = skip_typeref(orig_type);
6971         char   const*       wrong_type = NULL;
6972         if (is_type_incomplete(type)) {
6973                 if (!is_type_void(type) || !GNU_MODE)
6974                         wrong_type = "incomplete";
6975         } else if (type->kind == TYPE_FUNCTION) {
6976                 if (GNU_MODE) {
6977                         /* function types are allowed (and return 1) */
6978                         source_position_t const *const pos  = &tp_expression->base.source_position;
6979                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6980                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6981                 } else {
6982                         wrong_type = "function";
6983                 }
6984         }
6985
6986         if (wrong_type != NULL) {
6987                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6988                 errorf(&tp_expression->base.source_position,
6989                                 "operand of %s expression must not be of %s type '%T'",
6990                                 what, wrong_type, orig_type);
6991         }
6992
6993         return tp_expression;
6994 }
6995
6996 static expression_t *parse_sizeof(void)
6997 {
6998         return parse_typeprop(EXPR_SIZEOF);
6999 }
7000
7001 static expression_t *parse_alignof(void)
7002 {
7003         return parse_typeprop(EXPR_ALIGNOF);
7004 }
7005
7006 static expression_t *parse_select_expression(expression_t *addr)
7007 {
7008         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
7009         bool select_left_arrow = (token.kind == T_MINUSGREATER);
7010         source_position_t const pos = *HERE;
7011         next_token();
7012
7013         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
7014         if (!symbol)
7015                 return create_error_expression();
7016
7017         type_t *const orig_type = addr->base.type;
7018         type_t *const type      = skip_typeref(orig_type);
7019
7020         type_t *type_left;
7021         bool    saw_error = false;
7022         if (is_type_pointer(type)) {
7023                 if (!select_left_arrow) {
7024                         errorf(&pos,
7025                                "request for member '%Y' in something not a struct or union, but '%T'",
7026                                symbol, orig_type);
7027                         saw_error = true;
7028                 }
7029                 type_left = skip_typeref(type->pointer.points_to);
7030         } else {
7031                 if (select_left_arrow && is_type_valid(type)) {
7032                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7033                         saw_error = true;
7034                 }
7035                 type_left = type;
7036         }
7037
7038         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7039             type_left->kind != TYPE_COMPOUND_UNION) {
7040
7041                 if (is_type_valid(type_left) && !saw_error) {
7042                         errorf(&pos,
7043                                "request for member '%Y' in something not a struct or union, but '%T'",
7044                                symbol, type_left);
7045                 }
7046                 return create_error_expression();
7047         }
7048
7049         compound_t *compound = type_left->compound.compound;
7050         if (!compound->complete) {
7051                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7052                        symbol, type_left);
7053                 return create_error_expression();
7054         }
7055
7056         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7057         expression_t      *result     =
7058                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7059
7060         if (result == NULL) {
7061                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7062                 return create_error_expression();
7063         }
7064
7065         return result;
7066 }
7067
7068 static void check_call_argument(type_t          *expected_type,
7069                                 call_argument_t *argument, unsigned pos)
7070 {
7071         type_t         *expected_type_skip = skip_typeref(expected_type);
7072         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7073         expression_t   *arg_expr           = argument->expression;
7074         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7075
7076         /* handle transparent union gnu extension */
7077         if (is_type_union(expected_type_skip)
7078                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7079                 compound_t *union_decl  = expected_type_skip->compound.compound;
7080                 type_t     *best_type   = NULL;
7081                 entity_t   *entry       = union_decl->members.entities;
7082                 for ( ; entry != NULL; entry = entry->base.next) {
7083                         assert(is_declaration(entry));
7084                         type_t *decl_type = entry->declaration.type;
7085                         error = semantic_assign(decl_type, arg_expr);
7086                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7087                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7088                                 continue;
7089
7090                         if (error == ASSIGN_SUCCESS) {
7091                                 best_type = decl_type;
7092                         } else if (best_type == NULL) {
7093                                 best_type = decl_type;
7094                         }
7095                 }
7096
7097                 if (best_type != NULL) {
7098                         expected_type = best_type;
7099                 }
7100         }
7101
7102         error                = semantic_assign(expected_type, arg_expr);
7103         argument->expression = create_implicit_cast(arg_expr, expected_type);
7104
7105         if (error != ASSIGN_SUCCESS) {
7106                 /* report exact scope in error messages (like "in argument 3") */
7107                 char buf[64];
7108                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7109                 report_assign_error(error, expected_type, arg_expr, buf,
7110                                     &arg_expr->base.source_position);
7111         } else {
7112                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7113                 if (!types_compatible(expected_type_skip, promoted_type) &&
7114                     !types_compatible(expected_type_skip, type_void_ptr) &&
7115                     !types_compatible(type_void_ptr,      promoted_type)) {
7116                         /* Deliberately show the skipped types in this warning */
7117                         source_position_t const *const apos = &arg_expr->base.source_position;
7118                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7119                 }
7120         }
7121 }
7122
7123 /**
7124  * Handle the semantic restrictions of builtin calls
7125  */
7126 static void handle_builtin_argument_restrictions(call_expression_t *call)
7127 {
7128         entity_t *entity = call->function->reference.entity;
7129         switch (entity->function.btk) {
7130         case BUILTIN_FIRM:
7131                 switch (entity->function.b.firm_builtin_kind) {
7132                 case ir_bk_return_address:
7133                 case ir_bk_frame_address: {
7134                         /* argument must be constant */
7135                         call_argument_t *argument = call->arguments;
7136
7137                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7138                                 errorf(&call->base.source_position,
7139                                            "argument of '%Y' must be a constant expression",
7140                                            call->function->reference.entity->base.symbol);
7141                         }
7142                         break;
7143                 }
7144                 case ir_bk_prefetch:
7145                         /* second and third argument must be constant if existent */
7146                         if (call->arguments == NULL)
7147                                 break;
7148                         call_argument_t *rw = call->arguments->next;
7149                         call_argument_t *locality = NULL;
7150
7151                         if (rw != NULL) {
7152                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7153                                         errorf(&call->base.source_position,
7154                                                    "second argument of '%Y' must be a constant expression",
7155                                                    call->function->reference.entity->base.symbol);
7156                                 }
7157                                 locality = rw->next;
7158                         }
7159                         if (locality != NULL) {
7160                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7161                                         errorf(&call->base.source_position,
7162                                                    "third argument of '%Y' must be a constant expression",
7163                                                    call->function->reference.entity->base.symbol);
7164                                 }
7165                                 locality = rw->next;
7166                         }
7167                         break;
7168                 default:
7169                         break;
7170                 }
7171
7172         case BUILTIN_OBJECT_SIZE:
7173                 if (call->arguments == NULL)
7174                         break;
7175
7176                 call_argument_t *arg = call->arguments->next;
7177                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7178                         errorf(&call->base.source_position,
7179                                    "second argument of '%Y' must be a constant expression",
7180                                    call->function->reference.entity->base.symbol);
7181                 }
7182                 break;
7183         default:
7184                 break;
7185         }
7186 }
7187
7188 /**
7189  * Parse a call expression, ie. expression '( ... )'.
7190  *
7191  * @param expression  the function address
7192  */
7193 static expression_t *parse_call_expression(expression_t *expression)
7194 {
7195         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7196         call_expression_t *call   = &result->call;
7197         call->function            = expression;
7198
7199         type_t *const orig_type = expression->base.type;
7200         type_t *const type      = skip_typeref(orig_type);
7201
7202         function_type_t *function_type = NULL;
7203         if (is_type_pointer(type)) {
7204                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7205
7206                 if (is_type_function(to_type)) {
7207                         function_type   = &to_type->function;
7208                         call->base.type = function_type->return_type;
7209                 }
7210         }
7211
7212         if (function_type == NULL && is_type_valid(type)) {
7213                 errorf(HERE,
7214                        "called object '%E' (type '%T') is not a pointer to a function",
7215                        expression, orig_type);
7216         }
7217
7218         /* parse arguments */
7219         eat('(');
7220         add_anchor_token(')');
7221         add_anchor_token(',');
7222
7223         if (token.kind != ')') {
7224                 call_argument_t **anchor = &call->arguments;
7225                 do {
7226                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7227                         argument->expression = parse_assignment_expression();
7228
7229                         *anchor = argument;
7230                         anchor  = &argument->next;
7231                 } while (next_if(','));
7232         }
7233         rem_anchor_token(',');
7234         rem_anchor_token(')');
7235         expect(')');
7236
7237         if (function_type == NULL)
7238                 return result;
7239
7240         /* check type and count of call arguments */
7241         function_parameter_t *parameter = function_type->parameters;
7242         call_argument_t      *argument  = call->arguments;
7243         if (!function_type->unspecified_parameters) {
7244                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7245                                 parameter = parameter->next, argument = argument->next) {
7246                         check_call_argument(parameter->type, argument, ++pos);
7247                 }
7248
7249                 if (parameter != NULL) {
7250                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7251                 } else if (argument != NULL && !function_type->variadic) {
7252                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7253                 }
7254         }
7255
7256         /* do default promotion for other arguments */
7257         for (; argument != NULL; argument = argument->next) {
7258                 type_t *argument_type = argument->expression->base.type;
7259                 if (!is_type_object(skip_typeref(argument_type))) {
7260                         errorf(&argument->expression->base.source_position,
7261                                "call argument '%E' must not be void", argument->expression);
7262                 }
7263
7264                 argument_type = get_default_promoted_type(argument_type);
7265
7266                 argument->expression
7267                         = create_implicit_cast(argument->expression, argument_type);
7268         }
7269
7270         check_format(call);
7271
7272         if (is_type_compound(skip_typeref(function_type->return_type))) {
7273                 source_position_t const *const pos = &expression->base.source_position;
7274                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7275         }
7276
7277         if (expression->kind == EXPR_REFERENCE) {
7278                 reference_expression_t *reference = &expression->reference;
7279                 if (reference->entity->kind == ENTITY_FUNCTION &&
7280                     reference->entity->function.btk != BUILTIN_NONE)
7281                         handle_builtin_argument_restrictions(call);
7282         }
7283
7284         return result;
7285 }
7286
7287 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7288
7289 static bool same_compound_type(const type_t *type1, const type_t *type2)
7290 {
7291         return
7292                 is_type_compound(type1) &&
7293                 type1->kind == type2->kind &&
7294                 type1->compound.compound == type2->compound.compound;
7295 }
7296
7297 static expression_t const *get_reference_address(expression_t const *expr)
7298 {
7299         bool regular_take_address = true;
7300         for (;;) {
7301                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7302                         expr = expr->unary.value;
7303                 } else {
7304                         regular_take_address = false;
7305                 }
7306
7307                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7308                         break;
7309
7310                 expr = expr->unary.value;
7311         }
7312
7313         if (expr->kind != EXPR_REFERENCE)
7314                 return NULL;
7315
7316         /* special case for functions which are automatically converted to a
7317          * pointer to function without an extra TAKE_ADDRESS operation */
7318         if (!regular_take_address &&
7319                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7320                 return NULL;
7321         }
7322
7323         return expr;
7324 }
7325
7326 static void warn_reference_address_as_bool(expression_t const* expr)
7327 {
7328         expr = get_reference_address(expr);
7329         if (expr != NULL) {
7330                 source_position_t const *const pos = &expr->base.source_position;
7331                 entity_t          const *const ent = expr->reference.entity;
7332                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7333         }
7334 }
7335
7336 static void warn_assignment_in_condition(const expression_t *const expr)
7337 {
7338         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7339                 return;
7340         if (expr->base.parenthesized)
7341                 return;
7342         source_position_t const *const pos = &expr->base.source_position;
7343         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7344 }
7345
7346 static void semantic_condition(expression_t const *const expr,
7347                                char const *const context)
7348 {
7349         type_t *const type = skip_typeref(expr->base.type);
7350         if (is_type_scalar(type)) {
7351                 warn_reference_address_as_bool(expr);
7352                 warn_assignment_in_condition(expr);
7353         } else if (is_type_valid(type)) {
7354                 errorf(&expr->base.source_position,
7355                                 "%s must have scalar type", context);
7356         }
7357 }
7358
7359 /**
7360  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7361  *
7362  * @param expression  the conditional expression
7363  */
7364 static expression_t *parse_conditional_expression(expression_t *expression)
7365 {
7366         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7367
7368         conditional_expression_t *conditional = &result->conditional;
7369         conditional->condition                = expression;
7370
7371         eat('?');
7372         add_anchor_token(':');
7373
7374         /* §6.5.15:2  The first operand shall have scalar type. */
7375         semantic_condition(expression, "condition of conditional operator");
7376
7377         expression_t *true_expression = expression;
7378         bool          gnu_cond = false;
7379         if (GNU_MODE && token.kind == ':') {
7380                 gnu_cond = true;
7381         } else {
7382                 true_expression = parse_expression();
7383         }
7384         rem_anchor_token(':');
7385         expect(':');
7386         expression_t *false_expression =
7387                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7388
7389         type_t *const orig_true_type  = true_expression->base.type;
7390         type_t *const orig_false_type = false_expression->base.type;
7391         type_t *const true_type       = skip_typeref(orig_true_type);
7392         type_t *const false_type      = skip_typeref(orig_false_type);
7393
7394         /* 6.5.15.3 */
7395         source_position_t const *const pos = &conditional->base.source_position;
7396         type_t                        *result_type;
7397         if (is_type_void(true_type) || is_type_void(false_type)) {
7398                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7399                 if (true_expression->kind == EXPR_UNARY_THROW) {
7400                         result_type = false_type;
7401                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7402                         result_type = true_type;
7403                 } else {
7404                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7405                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7406                         }
7407                         result_type = type_void;
7408                 }
7409         } else if (is_type_arithmetic(true_type)
7410                    && is_type_arithmetic(false_type)) {
7411                 result_type = semantic_arithmetic(true_type, false_type);
7412         } else if (same_compound_type(true_type, false_type)) {
7413                 /* just take 1 of the 2 types */
7414                 result_type = true_type;
7415         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7416                 type_t *pointer_type;
7417                 type_t *other_type;
7418                 expression_t *other_expression;
7419                 if (is_type_pointer(true_type) &&
7420                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7421                         pointer_type     = true_type;
7422                         other_type       = false_type;
7423                         other_expression = false_expression;
7424                 } else {
7425                         pointer_type     = false_type;
7426                         other_type       = true_type;
7427                         other_expression = true_expression;
7428                 }
7429
7430                 if (is_null_pointer_constant(other_expression)) {
7431                         result_type = pointer_type;
7432                 } else if (is_type_pointer(other_type)) {
7433                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7434                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7435
7436                         type_t *to;
7437                         if (is_type_void(to1) || is_type_void(to2)) {
7438                                 to = type_void;
7439                         } else if (types_compatible(get_unqualified_type(to1),
7440                                                     get_unqualified_type(to2))) {
7441                                 to = to1;
7442                         } else {
7443                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7444                                 to = type_void;
7445                         }
7446
7447                         type_t *const type =
7448                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7449                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7450                 } else if (is_type_integer(other_type)) {
7451                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7452                         result_type = pointer_type;
7453                 } else {
7454                         goto types_incompatible;
7455                 }
7456         } else {
7457 types_incompatible:
7458                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7459                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7460                 }
7461                 result_type = type_error_type;
7462         }
7463
7464         conditional->true_expression
7465                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7466         conditional->false_expression
7467                 = create_implicit_cast(false_expression, result_type);
7468         conditional->base.type = result_type;
7469         return result;
7470 }
7471
7472 /**
7473  * Parse an extension expression.
7474  */
7475 static expression_t *parse_extension(void)
7476 {
7477         PUSH_EXTENSION();
7478         expression_t *expression = parse_subexpression(PREC_UNARY);
7479         POP_EXTENSION();
7480         return expression;
7481 }
7482
7483 /**
7484  * Parse a __builtin_classify_type() expression.
7485  */
7486 static expression_t *parse_builtin_classify_type(void)
7487 {
7488         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7489         result->base.type    = type_int;
7490
7491         eat(T___builtin_classify_type);
7492
7493         expect('(');
7494         add_anchor_token(')');
7495         expression_t *expression = parse_expression();
7496         rem_anchor_token(')');
7497         expect(')');
7498         result->classify_type.type_expression = expression;
7499
7500         return result;
7501 }
7502
7503 /**
7504  * Parse a delete expression
7505  * ISO/IEC 14882:1998(E) §5.3.5
7506  */
7507 static expression_t *parse_delete(void)
7508 {
7509         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7510         result->base.type          = type_void;
7511
7512         eat(T_delete);
7513
7514         if (next_if('[')) {
7515                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7516                 expect(']');
7517         }
7518
7519         expression_t *const value = parse_subexpression(PREC_CAST);
7520         result->unary.value = value;
7521
7522         type_t *const type = skip_typeref(value->base.type);
7523         if (!is_type_pointer(type)) {
7524                 if (is_type_valid(type)) {
7525                         errorf(&value->base.source_position,
7526                                         "operand of delete must have pointer type");
7527                 }
7528         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7529                 source_position_t const *const pos = &value->base.source_position;
7530                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7531         }
7532
7533         return result;
7534 }
7535
7536 /**
7537  * Parse a throw expression
7538  * ISO/IEC 14882:1998(E) §15:1
7539  */
7540 static expression_t *parse_throw(void)
7541 {
7542         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7543         result->base.type          = type_void;
7544
7545         eat(T_throw);
7546
7547         expression_t *value = NULL;
7548         switch (token.kind) {
7549                 EXPRESSION_START {
7550                         value = parse_assignment_expression();
7551                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7552                         type_t *const orig_type = value->base.type;
7553                         type_t *const type      = skip_typeref(orig_type);
7554                         if (is_type_incomplete(type)) {
7555                                 errorf(&value->base.source_position,
7556                                                 "cannot throw object of incomplete type '%T'", orig_type);
7557                         } else if (is_type_pointer(type)) {
7558                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7559                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7560                                         errorf(&value->base.source_position,
7561                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7562                                 }
7563                         }
7564                 }
7565
7566                 default:
7567                         break;
7568         }
7569         result->unary.value = value;
7570
7571         return result;
7572 }
7573
7574 static bool check_pointer_arithmetic(const source_position_t *source_position,
7575                                      type_t *pointer_type,
7576                                      type_t *orig_pointer_type)
7577 {
7578         type_t *points_to = pointer_type->pointer.points_to;
7579         points_to = skip_typeref(points_to);
7580
7581         if (is_type_incomplete(points_to)) {
7582                 if (!GNU_MODE || !is_type_void(points_to)) {
7583                         errorf(source_position,
7584                                "arithmetic with pointer to incomplete type '%T' not allowed",
7585                                orig_pointer_type);
7586                         return false;
7587                 } else {
7588                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7589                 }
7590         } else if (is_type_function(points_to)) {
7591                 if (!GNU_MODE) {
7592                         errorf(source_position,
7593                                "arithmetic with pointer to function type '%T' not allowed",
7594                                orig_pointer_type);
7595                         return false;
7596                 } else {
7597                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7598                 }
7599         }
7600         return true;
7601 }
7602
7603 static bool is_lvalue(const expression_t *expression)
7604 {
7605         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7606         switch (expression->kind) {
7607         case EXPR_ARRAY_ACCESS:
7608         case EXPR_COMPOUND_LITERAL:
7609         case EXPR_REFERENCE:
7610         case EXPR_SELECT:
7611         case EXPR_UNARY_DEREFERENCE:
7612                 return true;
7613
7614         default: {
7615                 type_t *type = skip_typeref(expression->base.type);
7616                 return
7617                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7618                         is_type_reference(type) ||
7619                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7620                          * error before, which maybe prevented properly recognizing it as
7621                          * lvalue. */
7622                         !is_type_valid(type);
7623         }
7624         }
7625 }
7626
7627 static void semantic_incdec(unary_expression_t *expression)
7628 {
7629         type_t *const orig_type = expression->value->base.type;
7630         type_t *const type      = skip_typeref(orig_type);
7631         if (is_type_pointer(type)) {
7632                 if (!check_pointer_arithmetic(&expression->base.source_position,
7633                                               type, orig_type)) {
7634                         return;
7635                 }
7636         } else if (!is_type_real(type) && is_type_valid(type)) {
7637                 /* TODO: improve error message */
7638                 errorf(&expression->base.source_position,
7639                        "operation needs an arithmetic or pointer type");
7640                 return;
7641         }
7642         if (!is_lvalue(expression->value)) {
7643                 /* TODO: improve error message */
7644                 errorf(&expression->base.source_position, "lvalue required as operand");
7645         }
7646         expression->base.type = orig_type;
7647 }
7648
7649 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7650 {
7651         type_t *const res_type = promote_integer(type);
7652         expr->base.type = res_type;
7653         expr->value     = create_implicit_cast(expr->value, res_type);
7654 }
7655
7656 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7657 {
7658         type_t *const orig_type = expression->value->base.type;
7659         type_t *const type      = skip_typeref(orig_type);
7660         if (!is_type_arithmetic(type)) {
7661                 if (is_type_valid(type)) {
7662                         /* TODO: improve error message */
7663                         errorf(&expression->base.source_position,
7664                                 "operation needs an arithmetic type");
7665                 }
7666                 return;
7667         } else if (is_type_integer(type)) {
7668                 promote_unary_int_expr(expression, type);
7669         } else {
7670                 expression->base.type = orig_type;
7671         }
7672 }
7673
7674 static void semantic_unexpr_plus(unary_expression_t *expression)
7675 {
7676         semantic_unexpr_arithmetic(expression);
7677         source_position_t const *const pos = &expression->base.source_position;
7678         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7679 }
7680
7681 static void semantic_not(unary_expression_t *expression)
7682 {
7683         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7684         semantic_condition(expression->value, "operand of !");
7685         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7686 }
7687
7688 static void semantic_unexpr_integer(unary_expression_t *expression)
7689 {
7690         type_t *const orig_type = expression->value->base.type;
7691         type_t *const type      = skip_typeref(orig_type);
7692         if (!is_type_integer(type)) {
7693                 if (is_type_valid(type)) {
7694                         errorf(&expression->base.source_position,
7695                                "operand of ~ must be of integer type");
7696                 }
7697                 return;
7698         }
7699
7700         promote_unary_int_expr(expression, type);
7701 }
7702
7703 static void semantic_dereference(unary_expression_t *expression)
7704 {
7705         type_t *const orig_type = expression->value->base.type;
7706         type_t *const type      = skip_typeref(orig_type);
7707         if (!is_type_pointer(type)) {
7708                 if (is_type_valid(type)) {
7709                         errorf(&expression->base.source_position,
7710                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7711                 }
7712                 return;
7713         }
7714
7715         type_t *result_type   = type->pointer.points_to;
7716         result_type           = automatic_type_conversion(result_type);
7717         expression->base.type = result_type;
7718 }
7719
7720 /**
7721  * Record that an address is taken (expression represents an lvalue).
7722  *
7723  * @param expression       the expression
7724  * @param may_be_register  if true, the expression might be an register
7725  */
7726 static void set_address_taken(expression_t *expression, bool may_be_register)
7727 {
7728         if (expression->kind != EXPR_REFERENCE)
7729                 return;
7730
7731         entity_t *const entity = expression->reference.entity;
7732
7733         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7734                 return;
7735
7736         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7737                         && !may_be_register) {
7738                 source_position_t const *const pos = &expression->base.source_position;
7739                 errorf(pos, "address of register '%N' requested", entity);
7740         }
7741
7742         if (entity->kind == ENTITY_VARIABLE) {
7743                 entity->variable.address_taken = true;
7744         } else {
7745                 assert(entity->kind == ENTITY_PARAMETER);
7746                 entity->parameter.address_taken = true;
7747         }
7748 }
7749
7750 /**
7751  * Check the semantic of the address taken expression.
7752  */
7753 static void semantic_take_addr(unary_expression_t *expression)
7754 {
7755         expression_t *value = expression->value;
7756         value->base.type    = revert_automatic_type_conversion(value);
7757
7758         type_t *orig_type = value->base.type;
7759         type_t *type      = skip_typeref(orig_type);
7760         if (!is_type_valid(type))
7761                 return;
7762
7763         /* §6.5.3.2 */
7764         if (!is_lvalue(value)) {
7765                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7766         }
7767         if (is_bitfield(value)) {
7768                 errorf(&expression->base.source_position,
7769                        "'&' not allowed on bitfield");
7770         }
7771
7772         set_address_taken(value, false);
7773
7774         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7775 }
7776
7777 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7778 static expression_t *parse_##unexpression_type(void)                         \
7779 {                                                                            \
7780         expression_t *unary_expression                                           \
7781                 = allocate_expression_zero(unexpression_type);                       \
7782         eat(token_kind);                                                         \
7783         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7784                                                                                  \
7785         sfunc(&unary_expression->unary);                                         \
7786                                                                                  \
7787         return unary_expression;                                                 \
7788 }
7789
7790 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7791                                semantic_unexpr_arithmetic)
7792 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7793                                semantic_unexpr_plus)
7794 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7795                                semantic_not)
7796 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7797                                semantic_dereference)
7798 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7799                                semantic_take_addr)
7800 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7801                                semantic_unexpr_integer)
7802 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7803                                semantic_incdec)
7804 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7805                                semantic_incdec)
7806
7807 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7808                                                sfunc)                         \
7809 static expression_t *parse_##unexpression_type(expression_t *left)            \
7810 {                                                                             \
7811         expression_t *unary_expression                                            \
7812                 = allocate_expression_zero(unexpression_type);                        \
7813         eat(token_kind);                                                          \
7814         unary_expression->unary.value = left;                                     \
7815                                                                                   \
7816         sfunc(&unary_expression->unary);                                          \
7817                                                                               \
7818         return unary_expression;                                                  \
7819 }
7820
7821 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7822                                        EXPR_UNARY_POSTFIX_INCREMENT,
7823                                        semantic_incdec)
7824 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7825                                        EXPR_UNARY_POSTFIX_DECREMENT,
7826                                        semantic_incdec)
7827
7828 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7829 {
7830         /* TODO: handle complex + imaginary types */
7831
7832         type_left  = get_unqualified_type(type_left);
7833         type_right = get_unqualified_type(type_right);
7834
7835         /* §6.3.1.8 Usual arithmetic conversions */
7836         if (type_left == type_long_double || type_right == type_long_double) {
7837                 return type_long_double;
7838         } else if (type_left == type_double || type_right == type_double) {
7839                 return type_double;
7840         } else if (type_left == type_float || type_right == type_float) {
7841                 return type_float;
7842         }
7843
7844         type_left  = promote_integer(type_left);
7845         type_right = promote_integer(type_right);
7846
7847         if (type_left == type_right)
7848                 return type_left;
7849
7850         bool     const signed_left  = is_type_signed(type_left);
7851         bool     const signed_right = is_type_signed(type_right);
7852         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7853         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7854
7855         if (signed_left == signed_right)
7856                 return rank_left >= rank_right ? type_left : type_right;
7857
7858         unsigned           s_rank;
7859         unsigned           u_rank;
7860         atomic_type_kind_t s_akind;
7861         atomic_type_kind_t u_akind;
7862         type_t *s_type;
7863         type_t *u_type;
7864         if (signed_left) {
7865                 s_type = type_left;
7866                 u_type = type_right;
7867         } else {
7868                 s_type = type_right;
7869                 u_type = type_left;
7870         }
7871         s_akind = get_akind(s_type);
7872         u_akind = get_akind(u_type);
7873         s_rank  = get_akind_rank(s_akind);
7874         u_rank  = get_akind_rank(u_akind);
7875
7876         if (u_rank >= s_rank)
7877                 return u_type;
7878
7879         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7880                 return s_type;
7881
7882         switch (s_akind) {
7883         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7884         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7885         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7886
7887         default: panic("invalid atomic type");
7888         }
7889 }
7890
7891 /**
7892  * Check the semantic restrictions for a binary expression.
7893  */
7894 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7895 {
7896         expression_t *const left            = expression->left;
7897         expression_t *const right           = expression->right;
7898         type_t       *const orig_type_left  = left->base.type;
7899         type_t       *const orig_type_right = right->base.type;
7900         type_t       *const type_left       = skip_typeref(orig_type_left);
7901         type_t       *const type_right      = skip_typeref(orig_type_right);
7902
7903         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7904                 /* TODO: improve error message */
7905                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7906                         errorf(&expression->base.source_position,
7907                                "operation needs arithmetic types");
7908                 }
7909                 return;
7910         }
7911
7912         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7913         expression->left      = create_implicit_cast(left, arithmetic_type);
7914         expression->right     = create_implicit_cast(right, arithmetic_type);
7915         expression->base.type = arithmetic_type;
7916 }
7917
7918 static void semantic_binexpr_integer(binary_expression_t *const expression)
7919 {
7920         expression_t *const left            = expression->left;
7921         expression_t *const right           = expression->right;
7922         type_t       *const orig_type_left  = left->base.type;
7923         type_t       *const orig_type_right = right->base.type;
7924         type_t       *const type_left       = skip_typeref(orig_type_left);
7925         type_t       *const type_right      = skip_typeref(orig_type_right);
7926
7927         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7928                 /* TODO: improve error message */
7929                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7930                         errorf(&expression->base.source_position,
7931                                "operation needs integer types");
7932                 }
7933                 return;
7934         }
7935
7936         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7937         expression->left      = create_implicit_cast(left, result_type);
7938         expression->right     = create_implicit_cast(right, result_type);
7939         expression->base.type = result_type;
7940 }
7941
7942 static void warn_div_by_zero(binary_expression_t const *const expression)
7943 {
7944         if (!is_type_integer(expression->base.type))
7945                 return;
7946
7947         expression_t const *const right = expression->right;
7948         /* The type of the right operand can be different for /= */
7949         if (is_type_integer(right->base.type)                    &&
7950             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7951             !fold_constant_to_bool(right)) {
7952                 source_position_t const *const pos = &expression->base.source_position;
7953                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7954         }
7955 }
7956
7957 /**
7958  * Check the semantic restrictions for a div/mod expression.
7959  */
7960 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7961 {
7962         semantic_binexpr_arithmetic(expression);
7963         warn_div_by_zero(expression);
7964 }
7965
7966 static void warn_addsub_in_shift(const expression_t *const expr)
7967 {
7968         if (expr->base.parenthesized)
7969                 return;
7970
7971         char op;
7972         switch (expr->kind) {
7973                 case EXPR_BINARY_ADD: op = '+'; break;
7974                 case EXPR_BINARY_SUB: op = '-'; break;
7975                 default:              return;
7976         }
7977
7978         source_position_t const *const pos = &expr->base.source_position;
7979         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7980 }
7981
7982 static bool semantic_shift(binary_expression_t *expression)
7983 {
7984         expression_t *const left            = expression->left;
7985         expression_t *const right           = expression->right;
7986         type_t       *const orig_type_left  = left->base.type;
7987         type_t       *const orig_type_right = right->base.type;
7988         type_t       *      type_left       = skip_typeref(orig_type_left);
7989         type_t       *      type_right      = skip_typeref(orig_type_right);
7990
7991         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7992                 /* TODO: improve error message */
7993                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7994                         errorf(&expression->base.source_position,
7995                                "operands of shift operation must have integer types");
7996                 }
7997                 return false;
7998         }
7999
8000         type_left = promote_integer(type_left);
8001
8002         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8003                 source_position_t const *const pos   = &right->base.source_position;
8004                 long                     const count = fold_constant_to_int(right);
8005                 if (count < 0) {
8006                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
8007                 } else if ((unsigned long)count >=
8008                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8009                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8010                 }
8011         }
8012
8013         type_right        = promote_integer(type_right);
8014         expression->right = create_implicit_cast(right, type_right);
8015
8016         return true;
8017 }
8018
8019 static void semantic_shift_op(binary_expression_t *expression)
8020 {
8021         expression_t *const left  = expression->left;
8022         expression_t *const right = expression->right;
8023
8024         if (!semantic_shift(expression))
8025                 return;
8026
8027         warn_addsub_in_shift(left);
8028         warn_addsub_in_shift(right);
8029
8030         type_t *const orig_type_left = left->base.type;
8031         type_t *      type_left      = skip_typeref(orig_type_left);
8032
8033         type_left             = promote_integer(type_left);
8034         expression->left      = create_implicit_cast(left, type_left);
8035         expression->base.type = type_left;
8036 }
8037
8038 static void semantic_add(binary_expression_t *expression)
8039 {
8040         expression_t *const left            = expression->left;
8041         expression_t *const right           = expression->right;
8042         type_t       *const orig_type_left  = left->base.type;
8043         type_t       *const orig_type_right = right->base.type;
8044         type_t       *const type_left       = skip_typeref(orig_type_left);
8045         type_t       *const type_right      = skip_typeref(orig_type_right);
8046
8047         /* §6.5.6 */
8048         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8049                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8050                 expression->left  = create_implicit_cast(left, arithmetic_type);
8051                 expression->right = create_implicit_cast(right, arithmetic_type);
8052                 expression->base.type = arithmetic_type;
8053         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8054                 check_pointer_arithmetic(&expression->base.source_position,
8055                                          type_left, orig_type_left);
8056                 expression->base.type = type_left;
8057         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8058                 check_pointer_arithmetic(&expression->base.source_position,
8059                                          type_right, orig_type_right);
8060                 expression->base.type = type_right;
8061         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8062                 errorf(&expression->base.source_position,
8063                        "invalid operands to binary + ('%T', '%T')",
8064                        orig_type_left, orig_type_right);
8065         }
8066 }
8067
8068 static void semantic_sub(binary_expression_t *expression)
8069 {
8070         expression_t            *const left            = expression->left;
8071         expression_t            *const right           = expression->right;
8072         type_t                  *const orig_type_left  = left->base.type;
8073         type_t                  *const orig_type_right = right->base.type;
8074         type_t                  *const type_left       = skip_typeref(orig_type_left);
8075         type_t                  *const type_right      = skip_typeref(orig_type_right);
8076         source_position_t const *const pos             = &expression->base.source_position;
8077
8078         /* §5.6.5 */
8079         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8080                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8081                 expression->left        = create_implicit_cast(left, arithmetic_type);
8082                 expression->right       = create_implicit_cast(right, arithmetic_type);
8083                 expression->base.type =  arithmetic_type;
8084         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8085                 check_pointer_arithmetic(&expression->base.source_position,
8086                                          type_left, orig_type_left);
8087                 expression->base.type = type_left;
8088         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8089                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8090                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8091                 if (!types_compatible(unqual_left, unqual_right)) {
8092                         errorf(pos,
8093                                "subtracting pointers to incompatible types '%T' and '%T'",
8094                                orig_type_left, orig_type_right);
8095                 } else if (!is_type_object(unqual_left)) {
8096                         if (!is_type_void(unqual_left)) {
8097                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8098                                        orig_type_left);
8099                         } else {
8100                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8101                         }
8102                 }
8103                 expression->base.type = type_ptrdiff_t;
8104         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8105                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8106                        orig_type_left, orig_type_right);
8107         }
8108 }
8109
8110 static void warn_string_literal_address(expression_t const* expr)
8111 {
8112         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8113                 expr = expr->unary.value;
8114                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8115                         return;
8116                 expr = expr->unary.value;
8117         }
8118
8119         if (expr->kind == EXPR_STRING_LITERAL
8120                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8121                 source_position_t const *const pos = &expr->base.source_position;
8122                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8123         }
8124 }
8125
8126 static bool maybe_negative(expression_t const *const expr)
8127 {
8128         switch (is_constant_expression(expr)) {
8129                 case EXPR_CLASS_ERROR:    return false;
8130                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8131                 default:                  return true;
8132         }
8133 }
8134
8135 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8136 {
8137         warn_string_literal_address(expr);
8138
8139         expression_t const* const ref = get_reference_address(expr);
8140         if (ref != NULL && is_null_pointer_constant(other)) {
8141                 entity_t const *const ent = ref->reference.entity;
8142                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8143         }
8144
8145         if (!expr->base.parenthesized) {
8146                 switch (expr->base.kind) {
8147                         case EXPR_BINARY_LESS:
8148                         case EXPR_BINARY_GREATER:
8149                         case EXPR_BINARY_LESSEQUAL:
8150                         case EXPR_BINARY_GREATEREQUAL:
8151                         case EXPR_BINARY_NOTEQUAL:
8152                         case EXPR_BINARY_EQUAL:
8153                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8154                                 break;
8155                         default:
8156                                 break;
8157                 }
8158         }
8159 }
8160
8161 /**
8162  * Check the semantics of comparison expressions.
8163  *
8164  * @param expression   The expression to check.
8165  */
8166 static void semantic_comparison(binary_expression_t *expression)
8167 {
8168         source_position_t const *const pos   = &expression->base.source_position;
8169         expression_t            *const left  = expression->left;
8170         expression_t            *const right = expression->right;
8171
8172         warn_comparison(pos, left, right);
8173         warn_comparison(pos, right, left);
8174
8175         type_t *orig_type_left  = left->base.type;
8176         type_t *orig_type_right = right->base.type;
8177         type_t *type_left       = skip_typeref(orig_type_left);
8178         type_t *type_right      = skip_typeref(orig_type_right);
8179
8180         /* TODO non-arithmetic types */
8181         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8182                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8183
8184                 /* test for signed vs unsigned compares */
8185                 if (is_type_integer(arithmetic_type)) {
8186                         bool const signed_left  = is_type_signed(type_left);
8187                         bool const signed_right = is_type_signed(type_right);
8188                         if (signed_left != signed_right) {
8189                                 /* FIXME long long needs better const folding magic */
8190                                 /* TODO check whether constant value can be represented by other type */
8191                                 if ((signed_left  && maybe_negative(left)) ||
8192                                                 (signed_right && maybe_negative(right))) {
8193                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8194                                 }
8195                         }
8196                 }
8197
8198                 expression->left        = create_implicit_cast(left, arithmetic_type);
8199                 expression->right       = create_implicit_cast(right, arithmetic_type);
8200                 expression->base.type   = arithmetic_type;
8201                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8202                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8203                     is_type_float(arithmetic_type)) {
8204                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8205                 }
8206         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8207                 /* TODO check compatibility */
8208         } else if (is_type_pointer(type_left)) {
8209                 expression->right = create_implicit_cast(right, type_left);
8210         } else if (is_type_pointer(type_right)) {
8211                 expression->left = create_implicit_cast(left, type_right);
8212         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8213                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8214         }
8215         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8216 }
8217
8218 /**
8219  * Checks if a compound type has constant fields.
8220  */
8221 static bool has_const_fields(const compound_type_t *type)
8222 {
8223         compound_t *compound = type->compound;
8224         entity_t   *entry    = compound->members.entities;
8225
8226         for (; entry != NULL; entry = entry->base.next) {
8227                 if (!is_declaration(entry))
8228                         continue;
8229
8230                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8231                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8232                         return true;
8233         }
8234
8235         return false;
8236 }
8237
8238 static bool is_valid_assignment_lhs(expression_t const* const left)
8239 {
8240         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8241         type_t *const type_left      = skip_typeref(orig_type_left);
8242
8243         if (!is_lvalue(left)) {
8244                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8245                        left);
8246                 return false;
8247         }
8248
8249         if (left->kind == EXPR_REFERENCE
8250                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8251                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8252                 return false;
8253         }
8254
8255         if (is_type_array(type_left)) {
8256                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8257                 return false;
8258         }
8259         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8260                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8261                        orig_type_left);
8262                 return false;
8263         }
8264         if (is_type_incomplete(type_left)) {
8265                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8266                        left, orig_type_left);
8267                 return false;
8268         }
8269         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8270                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8271                        left, orig_type_left);
8272                 return false;
8273         }
8274
8275         return true;
8276 }
8277
8278 static void semantic_arithmetic_assign(binary_expression_t *expression)
8279 {
8280         expression_t *left            = expression->left;
8281         expression_t *right           = expression->right;
8282         type_t       *orig_type_left  = left->base.type;
8283         type_t       *orig_type_right = right->base.type;
8284
8285         if (!is_valid_assignment_lhs(left))
8286                 return;
8287
8288         type_t *type_left  = skip_typeref(orig_type_left);
8289         type_t *type_right = skip_typeref(orig_type_right);
8290
8291         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8292                 /* TODO: improve error message */
8293                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8294                         errorf(&expression->base.source_position,
8295                                "operation needs arithmetic types");
8296                 }
8297                 return;
8298         }
8299
8300         /* combined instructions are tricky. We can't create an implicit cast on
8301          * the left side, because we need the uncasted form for the store.
8302          * The ast2firm pass has to know that left_type must be right_type
8303          * for the arithmetic operation and create a cast by itself */
8304         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8305         expression->right       = create_implicit_cast(right, arithmetic_type);
8306         expression->base.type   = type_left;
8307 }
8308
8309 static void semantic_divmod_assign(binary_expression_t *expression)
8310 {
8311         semantic_arithmetic_assign(expression);
8312         warn_div_by_zero(expression);
8313 }
8314
8315 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8316 {
8317         expression_t *const left            = expression->left;
8318         expression_t *const right           = expression->right;
8319         type_t       *const orig_type_left  = left->base.type;
8320         type_t       *const orig_type_right = right->base.type;
8321         type_t       *const type_left       = skip_typeref(orig_type_left);
8322         type_t       *const type_right      = skip_typeref(orig_type_right);
8323
8324         if (!is_valid_assignment_lhs(left))
8325                 return;
8326
8327         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8328                 /* combined instructions are tricky. We can't create an implicit cast on
8329                  * the left side, because we need the uncasted form for the store.
8330                  * The ast2firm pass has to know that left_type must be right_type
8331                  * for the arithmetic operation and create a cast by itself */
8332                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8333                 expression->right     = create_implicit_cast(right, arithmetic_type);
8334                 expression->base.type = type_left;
8335         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8336                 check_pointer_arithmetic(&expression->base.source_position,
8337                                          type_left, orig_type_left);
8338                 expression->base.type = type_left;
8339         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8340                 errorf(&expression->base.source_position,
8341                        "incompatible types '%T' and '%T' in assignment",
8342                        orig_type_left, orig_type_right);
8343         }
8344 }
8345
8346 static void semantic_integer_assign(binary_expression_t *expression)
8347 {
8348         expression_t *left            = expression->left;
8349         expression_t *right           = expression->right;
8350         type_t       *orig_type_left  = left->base.type;
8351         type_t       *orig_type_right = right->base.type;
8352
8353         if (!is_valid_assignment_lhs(left))
8354                 return;
8355
8356         type_t *type_left  = skip_typeref(orig_type_left);
8357         type_t *type_right = skip_typeref(orig_type_right);
8358
8359         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8360                 /* TODO: improve error message */
8361                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8362                         errorf(&expression->base.source_position,
8363                                "operation needs integer types");
8364                 }
8365                 return;
8366         }
8367
8368         /* combined instructions are tricky. We can't create an implicit cast on
8369          * the left side, because we need the uncasted form for the store.
8370          * The ast2firm pass has to know that left_type must be right_type
8371          * for the arithmetic operation and create a cast by itself */
8372         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8373         expression->right       = create_implicit_cast(right, arithmetic_type);
8374         expression->base.type   = type_left;
8375 }
8376
8377 static void semantic_shift_assign(binary_expression_t *expression)
8378 {
8379         expression_t *left           = expression->left;
8380
8381         if (!is_valid_assignment_lhs(left))
8382                 return;
8383
8384         if (!semantic_shift(expression))
8385                 return;
8386
8387         expression->base.type = skip_typeref(left->base.type);
8388 }
8389
8390 static void warn_logical_and_within_or(const expression_t *const expr)
8391 {
8392         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8393                 return;
8394         if (expr->base.parenthesized)
8395                 return;
8396         source_position_t const *const pos = &expr->base.source_position;
8397         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8398 }
8399
8400 /**
8401  * Check the semantic restrictions of a logical expression.
8402  */
8403 static void semantic_logical_op(binary_expression_t *expression)
8404 {
8405         /* §6.5.13:2  Each of the operands shall have scalar type.
8406          * §6.5.14:2  Each of the operands shall have scalar type. */
8407         semantic_condition(expression->left,   "left operand of logical operator");
8408         semantic_condition(expression->right, "right operand of logical operator");
8409         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8410                 warn_logical_and_within_or(expression->left);
8411                 warn_logical_and_within_or(expression->right);
8412         }
8413         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8414 }
8415
8416 /**
8417  * Check the semantic restrictions of a binary assign expression.
8418  */
8419 static void semantic_binexpr_assign(binary_expression_t *expression)
8420 {
8421         expression_t *left           = expression->left;
8422         type_t       *orig_type_left = left->base.type;
8423
8424         if (!is_valid_assignment_lhs(left))
8425                 return;
8426
8427         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8428         report_assign_error(error, orig_type_left, expression->right,
8429                         "assignment", &left->base.source_position);
8430         expression->right = create_implicit_cast(expression->right, orig_type_left);
8431         expression->base.type = orig_type_left;
8432 }
8433
8434 /**
8435  * Determine if the outermost operation (or parts thereof) of the given
8436  * expression has no effect in order to generate a warning about this fact.
8437  * Therefore in some cases this only examines some of the operands of the
8438  * expression (see comments in the function and examples below).
8439  * Examples:
8440  *   f() + 23;    // warning, because + has no effect
8441  *   x || f();    // no warning, because x controls execution of f()
8442  *   x ? y : f(); // warning, because y has no effect
8443  *   (void)x;     // no warning to be able to suppress the warning
8444  * This function can NOT be used for an "expression has definitely no effect"-
8445  * analysis. */
8446 static bool expression_has_effect(const expression_t *const expr)
8447 {
8448         switch (expr->kind) {
8449                 case EXPR_ERROR:                      return true; /* do NOT warn */
8450                 case EXPR_REFERENCE:                  return false;
8451                 case EXPR_ENUM_CONSTANT:              return false;
8452                 case EXPR_LABEL_ADDRESS:              return false;
8453
8454                 /* suppress the warning for microsoft __noop operations */
8455                 case EXPR_LITERAL_MS_NOOP:            return true;
8456                 case EXPR_LITERAL_BOOLEAN:
8457                 case EXPR_LITERAL_CHARACTER:
8458                 case EXPR_LITERAL_WIDE_CHARACTER:
8459                 case EXPR_LITERAL_INTEGER:
8460                 case EXPR_LITERAL_INTEGER_OCTAL:
8461                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8462                 case EXPR_LITERAL_FLOATINGPOINT:
8463                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8464                 case EXPR_STRING_LITERAL:             return false;
8465                 case EXPR_WIDE_STRING_LITERAL:        return false;
8466
8467                 case EXPR_CALL: {
8468                         const call_expression_t *const call = &expr->call;
8469                         if (call->function->kind != EXPR_REFERENCE)
8470                                 return true;
8471
8472                         switch (call->function->reference.entity->function.btk) {
8473                                 /* FIXME: which builtins have no effect? */
8474                                 default:                      return true;
8475                         }
8476                 }
8477
8478                 /* Generate the warning if either the left or right hand side of a
8479                  * conditional expression has no effect */
8480                 case EXPR_CONDITIONAL: {
8481                         conditional_expression_t const *const cond = &expr->conditional;
8482                         expression_t             const *const t    = cond->true_expression;
8483                         return
8484                                 (t == NULL || expression_has_effect(t)) &&
8485                                 expression_has_effect(cond->false_expression);
8486                 }
8487
8488                 case EXPR_SELECT:                     return false;
8489                 case EXPR_ARRAY_ACCESS:               return false;
8490                 case EXPR_SIZEOF:                     return false;
8491                 case EXPR_CLASSIFY_TYPE:              return false;
8492                 case EXPR_ALIGNOF:                    return false;
8493
8494                 case EXPR_FUNCNAME:                   return false;
8495                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8496                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8497                 case EXPR_OFFSETOF:                   return false;
8498                 case EXPR_VA_START:                   return true;
8499                 case EXPR_VA_ARG:                     return true;
8500                 case EXPR_VA_COPY:                    return true;
8501                 case EXPR_STATEMENT:                  return true; // TODO
8502                 case EXPR_COMPOUND_LITERAL:           return false;
8503
8504                 case EXPR_UNARY_NEGATE:               return false;
8505                 case EXPR_UNARY_PLUS:                 return false;
8506                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8507                 case EXPR_UNARY_NOT:                  return false;
8508                 case EXPR_UNARY_DEREFERENCE:          return false;
8509                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8510                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8511                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8512                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8513                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8514
8515                 /* Treat void casts as if they have an effect in order to being able to
8516                  * suppress the warning */
8517                 case EXPR_UNARY_CAST: {
8518                         type_t *const type = skip_typeref(expr->base.type);
8519                         return is_type_void(type);
8520                 }
8521
8522                 case EXPR_UNARY_ASSUME:               return true;
8523                 case EXPR_UNARY_DELETE:               return true;
8524                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8525                 case EXPR_UNARY_THROW:                return true;
8526
8527                 case EXPR_BINARY_ADD:                 return false;
8528                 case EXPR_BINARY_SUB:                 return false;
8529                 case EXPR_BINARY_MUL:                 return false;
8530                 case EXPR_BINARY_DIV:                 return false;
8531                 case EXPR_BINARY_MOD:                 return false;
8532                 case EXPR_BINARY_EQUAL:               return false;
8533                 case EXPR_BINARY_NOTEQUAL:            return false;
8534                 case EXPR_BINARY_LESS:                return false;
8535                 case EXPR_BINARY_LESSEQUAL:           return false;
8536                 case EXPR_BINARY_GREATER:             return false;
8537                 case EXPR_BINARY_GREATEREQUAL:        return false;
8538                 case EXPR_BINARY_BITWISE_AND:         return false;
8539                 case EXPR_BINARY_BITWISE_OR:          return false;
8540                 case EXPR_BINARY_BITWISE_XOR:         return false;
8541                 case EXPR_BINARY_SHIFTLEFT:           return false;
8542                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8543                 case EXPR_BINARY_ASSIGN:              return true;
8544                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8545                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8546                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8547                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8548                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8549                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8550                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8551                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8552                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8553                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8554
8555                 /* Only examine the right hand side of && and ||, because the left hand
8556                  * side already has the effect of controlling the execution of the right
8557                  * hand side */
8558                 case EXPR_BINARY_LOGICAL_AND:
8559                 case EXPR_BINARY_LOGICAL_OR:
8560                 /* Only examine the right hand side of a comma expression, because the left
8561                  * hand side has a separate warning */
8562                 case EXPR_BINARY_COMMA:
8563                         return expression_has_effect(expr->binary.right);
8564
8565                 case EXPR_BINARY_ISGREATER:           return false;
8566                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8567                 case EXPR_BINARY_ISLESS:              return false;
8568                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8569                 case EXPR_BINARY_ISLESSGREATER:       return false;
8570                 case EXPR_BINARY_ISUNORDERED:         return false;
8571         }
8572
8573         internal_errorf(HERE, "unexpected expression");
8574 }
8575
8576 static void semantic_comma(binary_expression_t *expression)
8577 {
8578         const expression_t *const left = expression->left;
8579         if (!expression_has_effect(left)) {
8580                 source_position_t const *const pos = &left->base.source_position;
8581                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8582         }
8583         expression->base.type = expression->right->base.type;
8584 }
8585
8586 /**
8587  * @param prec_r precedence of the right operand
8588  */
8589 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8590 static expression_t *parse_##binexpression_type(expression_t *left)          \
8591 {                                                                            \
8592         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8593         binexpr->binary.left  = left;                                            \
8594         eat(token_kind);                                                         \
8595                                                                              \
8596         expression_t *right = parse_subexpression(prec_r);                       \
8597                                                                              \
8598         binexpr->binary.right = right;                                           \
8599         sfunc(&binexpr->binary);                                                 \
8600                                                                              \
8601         return binexpr;                                                          \
8602 }
8603
8604 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8605 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8606 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8607 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8608 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8609 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8610 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8611 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8612 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8613 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8614 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8615 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8616 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8617 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8618 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8619 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8620 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8621 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8622 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8623 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8624 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8625 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8626 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8627 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8628 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8629 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8630 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8631 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8632 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8633 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8634
8635
8636 static expression_t *parse_subexpression(precedence_t precedence)
8637 {
8638         if (token.kind < 0) {
8639                 return expected_expression_error();
8640         }
8641
8642         expression_parser_function_t *parser
8643                 = &expression_parsers[token.kind];
8644         expression_t                 *left;
8645
8646         if (parser->parser != NULL) {
8647                 left = parser->parser();
8648         } else {
8649                 left = parse_primary_expression();
8650         }
8651         assert(left != NULL);
8652
8653         while (true) {
8654                 if (token.kind < 0) {
8655                         return expected_expression_error();
8656                 }
8657
8658                 parser = &expression_parsers[token.kind];
8659                 if (parser->infix_parser == NULL)
8660                         break;
8661                 if (parser->infix_precedence < precedence)
8662                         break;
8663
8664                 left = parser->infix_parser(left);
8665
8666                 assert(left != NULL);
8667         }
8668
8669         return left;
8670 }
8671
8672 /**
8673  * Parse an expression.
8674  */
8675 static expression_t *parse_expression(void)
8676 {
8677         return parse_subexpression(PREC_EXPRESSION);
8678 }
8679
8680 /**
8681  * Register a parser for a prefix-like operator.
8682  *
8683  * @param parser      the parser function
8684  * @param token_kind  the token type of the prefix token
8685  */
8686 static void register_expression_parser(parse_expression_function parser,
8687                                        int token_kind)
8688 {
8689         expression_parser_function_t *entry = &expression_parsers[token_kind];
8690
8691         if (entry->parser != NULL) {
8692                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8693                 panic("trying to register multiple expression parsers for a token");
8694         }
8695         entry->parser = parser;
8696 }
8697
8698 /**
8699  * Register a parser for an infix operator with given precedence.
8700  *
8701  * @param parser      the parser function
8702  * @param token_kind  the token type of the infix operator
8703  * @param precedence  the precedence of the operator
8704  */
8705 static void register_infix_parser(parse_expression_infix_function parser,
8706                                   int token_kind, precedence_t precedence)
8707 {
8708         expression_parser_function_t *entry = &expression_parsers[token_kind];
8709
8710         if (entry->infix_parser != NULL) {
8711                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8712                 panic("trying to register multiple infix expression parsers for a "
8713                       "token");
8714         }
8715         entry->infix_parser     = parser;
8716         entry->infix_precedence = precedence;
8717 }
8718
8719 /**
8720  * Initialize the expression parsers.
8721  */
8722 static void init_expression_parsers(void)
8723 {
8724         memset(&expression_parsers, 0, sizeof(expression_parsers));
8725
8726         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8727         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8728         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8729         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8730         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8731         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8732         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8733         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8734         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8735         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8736         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8737         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8738         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8739         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8740         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8741         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8742         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8743         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8744         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8745         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8746         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8747         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8748         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8749         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8750         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8751         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8752         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8753         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8754         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8755         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8756         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8757         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8758         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8759         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8760         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8761         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8762         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8763
8764         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8765         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8766         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8767         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8768         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8769         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8770         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8771         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8772         register_expression_parser(parse_sizeof,                      T_sizeof);
8773         register_expression_parser(parse_alignof,                     T___alignof__);
8774         register_expression_parser(parse_extension,                   T___extension__);
8775         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8776         register_expression_parser(parse_delete,                      T_delete);
8777         register_expression_parser(parse_throw,                       T_throw);
8778 }
8779
8780 /**
8781  * Parse a asm statement arguments specification.
8782  */
8783 static asm_argument_t *parse_asm_arguments(bool is_out)
8784 {
8785         asm_argument_t  *result = NULL;
8786         asm_argument_t **anchor = &result;
8787
8788         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8789                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8790
8791                 if (next_if('[')) {
8792                         add_anchor_token(']');
8793                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8794                         rem_anchor_token(']');
8795                         expect(']');
8796                         if (!argument->symbol)
8797                                 return NULL;
8798                 }
8799
8800                 argument->constraints = parse_string_literals();
8801                 expect('(');
8802                 add_anchor_token(')');
8803                 expression_t *expression = parse_expression();
8804                 rem_anchor_token(')');
8805                 if (is_out) {
8806                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8807                          * change size or type representation (e.g. int -> long is ok, but
8808                          * int -> float is not) */
8809                         if (expression->kind == EXPR_UNARY_CAST) {
8810                                 type_t      *const type = expression->base.type;
8811                                 type_kind_t  const kind = type->kind;
8812                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8813                                         unsigned flags;
8814                                         unsigned size;
8815                                         if (kind == TYPE_ATOMIC) {
8816                                                 atomic_type_kind_t const akind = type->atomic.akind;
8817                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8818                                                 size  = get_atomic_type_size(akind);
8819                                         } else {
8820                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8821                                                 size  = get_type_size(type_void_ptr);
8822                                         }
8823
8824                                         do {
8825                                                 expression_t *const value      = expression->unary.value;
8826                                                 type_t       *const value_type = value->base.type;
8827                                                 type_kind_t   const value_kind = value_type->kind;
8828
8829                                                 unsigned value_flags;
8830                                                 unsigned value_size;
8831                                                 if (value_kind == TYPE_ATOMIC) {
8832                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8833                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8834                                                         value_size  = get_atomic_type_size(value_akind);
8835                                                 } else if (value_kind == TYPE_POINTER) {
8836                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8837                                                         value_size  = get_type_size(type_void_ptr);
8838                                                 } else {
8839                                                         break;
8840                                                 }
8841
8842                                                 if (value_flags != flags || value_size != size)
8843                                                         break;
8844
8845                                                 expression = value;
8846                                         } while (expression->kind == EXPR_UNARY_CAST);
8847                                 }
8848                         }
8849
8850                         if (!is_lvalue(expression)) {
8851                                 errorf(&expression->base.source_position,
8852                                        "asm output argument is not an lvalue");
8853                         }
8854
8855                         if (argument->constraints.begin[0] == '=')
8856                                 determine_lhs_ent(expression, NULL);
8857                         else
8858                                 mark_vars_read(expression, NULL);
8859                 } else {
8860                         mark_vars_read(expression, NULL);
8861                 }
8862                 argument->expression = expression;
8863                 expect(')');
8864
8865                 set_address_taken(expression, true);
8866
8867                 *anchor = argument;
8868                 anchor  = &argument->next;
8869
8870                 if (!next_if(','))
8871                         break;
8872         }
8873
8874         return result;
8875 }
8876
8877 /**
8878  * Parse a asm statement clobber specification.
8879  */
8880 static asm_clobber_t *parse_asm_clobbers(void)
8881 {
8882         asm_clobber_t *result  = NULL;
8883         asm_clobber_t **anchor = &result;
8884
8885         while (token.kind == T_STRING_LITERAL) {
8886                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8887                 clobber->clobber       = parse_string_literals();
8888
8889                 *anchor = clobber;
8890                 anchor  = &clobber->next;
8891
8892                 if (!next_if(','))
8893                         break;
8894         }
8895
8896         return result;
8897 }
8898
8899 /**
8900  * Parse an asm statement.
8901  */
8902 static statement_t *parse_asm_statement(void)
8903 {
8904         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8905         asm_statement_t *asm_statement = &statement->asms;
8906
8907         eat(T_asm);
8908
8909         if (next_if(T_volatile))
8910                 asm_statement->is_volatile = true;
8911
8912         expect('(');
8913         add_anchor_token(')');
8914         if (token.kind != T_STRING_LITERAL) {
8915                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8916                 goto end_of_asm;
8917         }
8918         asm_statement->asm_text = parse_string_literals();
8919
8920         add_anchor_token(':');
8921         if (!next_if(':')) {
8922                 rem_anchor_token(':');
8923                 goto end_of_asm;
8924         }
8925
8926         asm_statement->outputs = parse_asm_arguments(true);
8927         if (!next_if(':')) {
8928                 rem_anchor_token(':');
8929                 goto end_of_asm;
8930         }
8931
8932         asm_statement->inputs = parse_asm_arguments(false);
8933         if (!next_if(':')) {
8934                 rem_anchor_token(':');
8935                 goto end_of_asm;
8936         }
8937         rem_anchor_token(':');
8938
8939         asm_statement->clobbers = parse_asm_clobbers();
8940
8941 end_of_asm:
8942         rem_anchor_token(')');
8943         expect(')');
8944         expect(';');
8945
8946         if (asm_statement->outputs == NULL) {
8947                 /* GCC: An 'asm' instruction without any output operands will be treated
8948                  * identically to a volatile 'asm' instruction. */
8949                 asm_statement->is_volatile = true;
8950         }
8951
8952         return statement;
8953 }
8954
8955 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8956 {
8957         statement_t *inner_stmt;
8958         switch (token.kind) {
8959                 case '}':
8960                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8961                         inner_stmt = create_error_statement();
8962                         break;
8963
8964                 case ';':
8965                         if (label->kind == STATEMENT_LABEL) {
8966                                 /* Eat an empty statement here, to avoid the warning about an empty
8967                                  * statement after a label.  label:; is commonly used to have a label
8968                                  * before a closing brace. */
8969                                 inner_stmt = create_empty_statement();
8970                                 next_token();
8971                                 break;
8972                         }
8973                         /* FALLTHROUGH */
8974
8975                 default:
8976                         inner_stmt = parse_statement();
8977                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8978                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8979                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8980                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8981                         }
8982                         break;
8983         }
8984         return inner_stmt;
8985 }
8986
8987 /**
8988  * Parse a case statement.
8989  */
8990 static statement_t *parse_case_statement(void)
8991 {
8992         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8993         source_position_t *const pos       = &statement->base.source_position;
8994
8995         eat(T_case);
8996         add_anchor_token(':');
8997
8998         expression_t *expression = parse_expression();
8999         type_t *expression_type = expression->base.type;
9000         type_t *skipped         = skip_typeref(expression_type);
9001         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9002                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9003                        expression, expression_type);
9004         }
9005
9006         type_t *type = expression_type;
9007         if (current_switch != NULL) {
9008                 type_t *switch_type = current_switch->expression->base.type;
9009                 if (is_type_valid(switch_type)) {
9010                         expression = create_implicit_cast(expression, switch_type);
9011                 }
9012         }
9013
9014         statement->case_label.expression = expression;
9015         expression_classification_t const expr_class = is_constant_expression(expression);
9016         if (expr_class != EXPR_CLASS_CONSTANT) {
9017                 if (expr_class != EXPR_CLASS_ERROR) {
9018                         errorf(pos, "case label does not reduce to an integer constant");
9019                 }
9020                 statement->case_label.is_bad = true;
9021         } else {
9022                 long const val = fold_constant_to_int(expression);
9023                 statement->case_label.first_case = val;
9024                 statement->case_label.last_case  = val;
9025         }
9026
9027         if (GNU_MODE) {
9028                 if (next_if(T_DOTDOTDOT)) {
9029                         expression_t *end_range = parse_expression();
9030                         expression_type = expression->base.type;
9031                         skipped         = skip_typeref(expression_type);
9032                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9033                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9034                                            expression, expression_type);
9035                         }
9036
9037                         end_range = create_implicit_cast(end_range, type);
9038                         statement->case_label.end_range = end_range;
9039                         expression_classification_t const end_class = is_constant_expression(end_range);
9040                         if (end_class != EXPR_CLASS_CONSTANT) {
9041                                 if (end_class != EXPR_CLASS_ERROR) {
9042                                         errorf(pos, "case range does not reduce to an integer constant");
9043                                 }
9044                                 statement->case_label.is_bad = true;
9045                         } else {
9046                                 long const val = fold_constant_to_int(end_range);
9047                                 statement->case_label.last_case = val;
9048
9049                                 if (val < statement->case_label.first_case) {
9050                                         statement->case_label.is_empty_range = true;
9051                                         warningf(WARN_OTHER, pos, "empty range specified");
9052                                 }
9053                         }
9054                 }
9055         }
9056
9057         PUSH_PARENT(statement);
9058
9059         rem_anchor_token(':');
9060         expect(':');
9061
9062         if (current_switch != NULL) {
9063                 if (! statement->case_label.is_bad) {
9064                         /* Check for duplicate case values */
9065                         case_label_statement_t *c = &statement->case_label;
9066                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9067                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9068                                         continue;
9069
9070                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9071                                         continue;
9072
9073                                 errorf(pos, "duplicate case value (previously used %P)",
9074                                        &l->base.source_position);
9075                                 break;
9076                         }
9077                 }
9078                 /* link all cases into the switch statement */
9079                 if (current_switch->last_case == NULL) {
9080                         current_switch->first_case      = &statement->case_label;
9081                 } else {
9082                         current_switch->last_case->next = &statement->case_label;
9083                 }
9084                 current_switch->last_case = &statement->case_label;
9085         } else {
9086                 errorf(pos, "case label not within a switch statement");
9087         }
9088
9089         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9090
9091         POP_PARENT();
9092         return statement;
9093 }
9094
9095 /**
9096  * Parse a default statement.
9097  */
9098 static statement_t *parse_default_statement(void)
9099 {
9100         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9101
9102         eat(T_default);
9103
9104         PUSH_PARENT(statement);
9105
9106         expect(':');
9107
9108         if (current_switch != NULL) {
9109                 const case_label_statement_t *def_label = current_switch->default_label;
9110                 if (def_label != NULL) {
9111                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9112                 } else {
9113                         current_switch->default_label = &statement->case_label;
9114
9115                         /* link all cases into the switch statement */
9116                         if (current_switch->last_case == NULL) {
9117                                 current_switch->first_case      = &statement->case_label;
9118                         } else {
9119                                 current_switch->last_case->next = &statement->case_label;
9120                         }
9121                         current_switch->last_case = &statement->case_label;
9122                 }
9123         } else {
9124                 errorf(&statement->base.source_position,
9125                         "'default' label not within a switch statement");
9126         }
9127
9128         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9129
9130         POP_PARENT();
9131         return statement;
9132 }
9133
9134 /**
9135  * Parse a label statement.
9136  */
9137 static statement_t *parse_label_statement(void)
9138 {
9139         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9140         label_t     *const label     = get_label();
9141         statement->label.label = label;
9142
9143         PUSH_PARENT(statement);
9144
9145         /* if statement is already set then the label is defined twice,
9146          * otherwise it was just mentioned in a goto/local label declaration so far
9147          */
9148         source_position_t const* const pos = &statement->base.source_position;
9149         if (label->statement != NULL) {
9150                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9151         } else {
9152                 label->base.source_position = *pos;
9153                 label->statement            = statement;
9154         }
9155
9156         eat(':');
9157
9158         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9159                 parse_attributes(NULL); // TODO process attributes
9160         }
9161
9162         statement->label.statement = parse_label_inner_statement(statement, "label");
9163
9164         /* remember the labels in a list for later checking */
9165         *label_anchor = &statement->label;
9166         label_anchor  = &statement->label.next;
9167
9168         POP_PARENT();
9169         return statement;
9170 }
9171
9172 static statement_t *parse_inner_statement(void)
9173 {
9174         statement_t *const stmt = parse_statement();
9175         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9176         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9177         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9178                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9179         }
9180         return stmt;
9181 }
9182
9183 /**
9184  * Parse an expression in parentheses and mark its variables as read.
9185  */
9186 static expression_t *parse_condition(void)
9187 {
9188         expect('(');
9189         add_anchor_token(')');
9190         expression_t *const expr = parse_expression();
9191         mark_vars_read(expr, NULL);
9192         rem_anchor_token(')');
9193         expect(')');
9194         return expr;
9195 }
9196
9197 /**
9198  * Parse an if statement.
9199  */
9200 static statement_t *parse_if(void)
9201 {
9202         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9203
9204         eat(T_if);
9205
9206         PUSH_PARENT(statement);
9207         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9208
9209         add_anchor_token(T_else);
9210
9211         expression_t *const expr = parse_condition();
9212         statement->ifs.condition = expr;
9213         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9214          *             scalar type. */
9215         semantic_condition(expr, "condition of 'if'-statment");
9216
9217         statement_t *const true_stmt = parse_inner_statement();
9218         statement->ifs.true_statement = true_stmt;
9219         rem_anchor_token(T_else);
9220
9221         if (true_stmt->kind == STATEMENT_EMPTY) {
9222                 warningf(WARN_EMPTY_BODY, HERE,
9223                         "suggest braces around empty body in an ‘if’ statement");
9224         }
9225
9226         if (next_if(T_else)) {
9227                 statement->ifs.false_statement = parse_inner_statement();
9228
9229                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9230                         warningf(WARN_EMPTY_BODY, HERE,
9231                                         "suggest braces around empty body in an ‘if’ statement");
9232                 }
9233         } else if (true_stmt->kind == STATEMENT_IF &&
9234                         true_stmt->ifs.false_statement != NULL) {
9235                 source_position_t const *const pos = &true_stmt->base.source_position;
9236                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9237         }
9238
9239         POP_SCOPE();
9240         POP_PARENT();
9241         return statement;
9242 }
9243
9244 /**
9245  * Check that all enums are handled in a switch.
9246  *
9247  * @param statement  the switch statement to check
9248  */
9249 static void check_enum_cases(const switch_statement_t *statement)
9250 {
9251         if (!is_warn_on(WARN_SWITCH_ENUM))
9252                 return;
9253         const type_t *type = skip_typeref(statement->expression->base.type);
9254         if (! is_type_enum(type))
9255                 return;
9256         const enum_type_t *enumt = &type->enumt;
9257
9258         /* if we have a default, no warnings */
9259         if (statement->default_label != NULL)
9260                 return;
9261
9262         /* FIXME: calculation of value should be done while parsing */
9263         /* TODO: quadratic algorithm here. Change to an n log n one */
9264         long            last_value = -1;
9265         const entity_t *entry      = enumt->enume->base.next;
9266         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9267              entry = entry->base.next) {
9268                 const expression_t *expression = entry->enum_value.value;
9269                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9270                 bool                found      = false;
9271                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9272                         if (l->expression == NULL)
9273                                 continue;
9274                         if (l->first_case <= value && value <= l->last_case) {
9275                                 found = true;
9276                                 break;
9277                         }
9278                 }
9279                 if (!found) {
9280                         source_position_t const *const pos = &statement->base.source_position;
9281                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9282                 }
9283                 last_value = value;
9284         }
9285 }
9286
9287 /**
9288  * Parse a switch statement.
9289  */
9290 static statement_t *parse_switch(void)
9291 {
9292         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9293
9294         eat(T_switch);
9295
9296         PUSH_PARENT(statement);
9297         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9298
9299         expression_t *const expr = parse_condition();
9300         type_t       *      type = skip_typeref(expr->base.type);
9301         if (is_type_integer(type)) {
9302                 type = promote_integer(type);
9303                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9304                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9305                 }
9306         } else if (is_type_valid(type)) {
9307                 errorf(&expr->base.source_position,
9308                        "switch quantity is not an integer, but '%T'", type);
9309                 type = type_error_type;
9310         }
9311         statement->switchs.expression = create_implicit_cast(expr, type);
9312
9313         switch_statement_t *rem = current_switch;
9314         current_switch          = &statement->switchs;
9315         statement->switchs.body = parse_inner_statement();
9316         current_switch          = rem;
9317
9318         if (statement->switchs.default_label == NULL) {
9319                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9320         }
9321         check_enum_cases(&statement->switchs);
9322
9323         POP_SCOPE();
9324         POP_PARENT();
9325         return statement;
9326 }
9327
9328 static statement_t *parse_loop_body(statement_t *const loop)
9329 {
9330         statement_t *const rem = current_loop;
9331         current_loop = loop;
9332
9333         statement_t *const body = parse_inner_statement();
9334
9335         current_loop = rem;
9336         return body;
9337 }
9338
9339 /**
9340  * Parse a while statement.
9341  */
9342 static statement_t *parse_while(void)
9343 {
9344         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9345
9346         eat(T_while);
9347
9348         PUSH_PARENT(statement);
9349         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9350
9351         expression_t *const cond = parse_condition();
9352         statement->whiles.condition = cond;
9353         /* §6.8.5:2    The controlling expression of an iteration statement shall
9354          *             have scalar type. */
9355         semantic_condition(cond, "condition of 'while'-statement");
9356
9357         statement->whiles.body = parse_loop_body(statement);
9358
9359         POP_SCOPE();
9360         POP_PARENT();
9361         return statement;
9362 }
9363
9364 /**
9365  * Parse a do statement.
9366  */
9367 static statement_t *parse_do(void)
9368 {
9369         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9370
9371         eat(T_do);
9372
9373         PUSH_PARENT(statement);
9374         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9375
9376         add_anchor_token(T_while);
9377         statement->do_while.body = parse_loop_body(statement);
9378         rem_anchor_token(T_while);
9379
9380         expect(T_while);
9381         expression_t *const cond = parse_condition();
9382         statement->do_while.condition = cond;
9383         /* §6.8.5:2    The controlling expression of an iteration statement shall
9384          *             have scalar type. */
9385         semantic_condition(cond, "condition of 'do-while'-statement");
9386         expect(';');
9387
9388         POP_SCOPE();
9389         POP_PARENT();
9390         return statement;
9391 }
9392
9393 /**
9394  * Parse a for statement.
9395  */
9396 static statement_t *parse_for(void)
9397 {
9398         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9399
9400         eat(T_for);
9401
9402         PUSH_PARENT(statement);
9403         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9404
9405         expect('(');
9406         add_anchor_token(')');
9407
9408         PUSH_EXTENSION();
9409
9410         if (next_if(';')) {
9411         } else if (is_declaration_specifier(&token)) {
9412                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9413         } else {
9414                 add_anchor_token(';');
9415                 expression_t *const init = parse_expression();
9416                 statement->fors.initialisation = init;
9417                 mark_vars_read(init, ENT_ANY);
9418                 if (!expression_has_effect(init)) {
9419                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9420                 }
9421                 rem_anchor_token(';');
9422                 expect(';');
9423         }
9424
9425         POP_EXTENSION();
9426
9427         if (token.kind != ';') {
9428                 add_anchor_token(';');
9429                 expression_t *const cond = parse_expression();
9430                 statement->fors.condition = cond;
9431                 /* §6.8.5:2    The controlling expression of an iteration statement
9432                  *             shall have scalar type. */
9433                 semantic_condition(cond, "condition of 'for'-statement");
9434                 mark_vars_read(cond, NULL);
9435                 rem_anchor_token(';');
9436         }
9437         expect(';');
9438         if (token.kind != ')') {
9439                 expression_t *const step = parse_expression();
9440                 statement->fors.step = step;
9441                 mark_vars_read(step, ENT_ANY);
9442                 if (!expression_has_effect(step)) {
9443                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9444                 }
9445         }
9446         rem_anchor_token(')');
9447         expect(')');
9448         statement->fors.body = parse_loop_body(statement);
9449
9450         POP_SCOPE();
9451         POP_PARENT();
9452         return statement;
9453 }
9454
9455 /**
9456  * Parse a goto statement.
9457  */
9458 static statement_t *parse_goto(void)
9459 {
9460         statement_t *statement;
9461         if (GNU_MODE && look_ahead(1)->kind == '*') {
9462                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9463                 eat(T_goto);
9464                 eat('*');
9465
9466                 expression_t *expression = parse_expression();
9467                 mark_vars_read(expression, NULL);
9468
9469                 /* Argh: although documentation says the expression must be of type void*,
9470                  * gcc accepts anything that can be casted into void* without error */
9471                 type_t *type = expression->base.type;
9472
9473                 if (type != type_error_type) {
9474                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9475                                 errorf(&expression->base.source_position,
9476                                         "cannot convert to a pointer type");
9477                         } else if (type != type_void_ptr) {
9478                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9479                         }
9480                         expression = create_implicit_cast(expression, type_void_ptr);
9481                 }
9482
9483                 statement->computed_goto.expression = expression;
9484         } else {
9485                 statement = allocate_statement_zero(STATEMENT_GOTO);
9486                 eat(T_goto);
9487                 if (token.kind == T_IDENTIFIER) {
9488                         label_t *const label = get_label();
9489                         label->used            = true;
9490                         statement->gotos.label = label;
9491
9492                         /* remember the goto's in a list for later checking */
9493                         *goto_anchor = &statement->gotos;
9494                         goto_anchor  = &statement->gotos.next;
9495                 } else {
9496                         if (GNU_MODE)
9497                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9498                         else
9499                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9500                         eat_until_anchor();
9501                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9502                 }
9503         }
9504
9505         expect(';');
9506         return statement;
9507 }
9508
9509 /**
9510  * Parse a continue statement.
9511  */
9512 static statement_t *parse_continue(void)
9513 {
9514         if (current_loop == NULL) {
9515                 errorf(HERE, "continue statement not within loop");
9516         }
9517
9518         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9519
9520         eat(T_continue);
9521         expect(';');
9522         return statement;
9523 }
9524
9525 /**
9526  * Parse a break statement.
9527  */
9528 static statement_t *parse_break(void)
9529 {
9530         if (current_switch == NULL && current_loop == NULL) {
9531                 errorf(HERE, "break statement not within loop or switch");
9532         }
9533
9534         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9535
9536         eat(T_break);
9537         expect(';');
9538         return statement;
9539 }
9540
9541 /**
9542  * Parse a __leave statement.
9543  */
9544 static statement_t *parse_leave_statement(void)
9545 {
9546         if (current_try == NULL) {
9547                 errorf(HERE, "__leave statement not within __try");
9548         }
9549
9550         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9551
9552         eat(T___leave);
9553         expect(';');
9554         return statement;
9555 }
9556
9557 /**
9558  * Check if a given entity represents a local variable.
9559  */
9560 static bool is_local_variable(const entity_t *entity)
9561 {
9562         if (entity->kind != ENTITY_VARIABLE)
9563                 return false;
9564
9565         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9566         case STORAGE_CLASS_AUTO:
9567         case STORAGE_CLASS_REGISTER: {
9568                 const type_t *type = skip_typeref(entity->declaration.type);
9569                 if (is_type_function(type)) {
9570                         return false;
9571                 } else {
9572                         return true;
9573                 }
9574         }
9575         default:
9576                 return false;
9577         }
9578 }
9579
9580 /**
9581  * Check if a given expression represents a local variable.
9582  */
9583 static bool expression_is_local_variable(const expression_t *expression)
9584 {
9585         if (expression->base.kind != EXPR_REFERENCE) {
9586                 return false;
9587         }
9588         const entity_t *entity = expression->reference.entity;
9589         return is_local_variable(entity);
9590 }
9591
9592 /**
9593  * Check if a given expression represents a local variable and
9594  * return its declaration then, else return NULL.
9595  */
9596 entity_t *expression_is_variable(const expression_t *expression)
9597 {
9598         if (expression->base.kind != EXPR_REFERENCE) {
9599                 return NULL;
9600         }
9601         entity_t *entity = expression->reference.entity;
9602         if (entity->kind != ENTITY_VARIABLE)
9603                 return NULL;
9604
9605         return entity;
9606 }
9607
9608 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9609 {
9610         if (c_mode & _CXX || strict_mode) {
9611                 errorf(pos, msg);
9612         } else {
9613                 warningf(WARN_OTHER, pos, msg);
9614         }
9615 }
9616
9617 /**
9618  * Parse a return statement.
9619  */
9620 static statement_t *parse_return(void)
9621 {
9622         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9623         eat(T_return);
9624
9625         expression_t *return_value = NULL;
9626         if (token.kind != ';') {
9627                 return_value = parse_expression();
9628                 mark_vars_read(return_value, NULL);
9629         }
9630
9631         const type_t *const func_type = skip_typeref(current_function->base.type);
9632         assert(is_type_function(func_type));
9633         type_t *const return_type = skip_typeref(func_type->function.return_type);
9634
9635         source_position_t const *const pos = &statement->base.source_position;
9636         if (return_value != NULL) {
9637                 type_t *return_value_type = skip_typeref(return_value->base.type);
9638
9639                 if (is_type_void(return_type)) {
9640                         if (!is_type_void(return_value_type)) {
9641                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9642                                 /* Only warn in C mode, because GCC does the same */
9643                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9644                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9645                                 /* Only warn in C mode, because GCC does the same */
9646                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9647                         }
9648                 } else {
9649                         assign_error_t error = semantic_assign(return_type, return_value);
9650                         report_assign_error(error, return_type, return_value, "'return'",
9651                                             pos);
9652                 }
9653                 return_value = create_implicit_cast(return_value, return_type);
9654                 /* check for returning address of a local var */
9655                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9656                         const expression_t *expression = return_value->unary.value;
9657                         if (expression_is_local_variable(expression)) {
9658                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9659                         }
9660                 }
9661         } else if (!is_type_void(return_type)) {
9662                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9663                 err_or_warn(pos, "'return' without value, in function returning non-void");
9664         }
9665         statement->returns.value = return_value;
9666
9667         expect(';');
9668         return statement;
9669 }
9670
9671 /**
9672  * Parse a declaration statement.
9673  */
9674 static statement_t *parse_declaration_statement(void)
9675 {
9676         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9677
9678         entity_t *before = current_scope->last_entity;
9679         if (GNU_MODE) {
9680                 parse_external_declaration();
9681         } else {
9682                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9683         }
9684
9685         declaration_statement_t *const decl  = &statement->declaration;
9686         entity_t                *const begin =
9687                 before != NULL ? before->base.next : current_scope->entities;
9688         decl->declarations_begin = begin;
9689         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9690
9691         return statement;
9692 }
9693
9694 /**
9695  * Parse an expression statement, ie. expr ';'.
9696  */
9697 static statement_t *parse_expression_statement(void)
9698 {
9699         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9700
9701         expression_t *const expr         = parse_expression();
9702         statement->expression.expression = expr;
9703         mark_vars_read(expr, ENT_ANY);
9704
9705         expect(';');
9706         return statement;
9707 }
9708
9709 /**
9710  * Parse a microsoft __try { } __finally { } or
9711  * __try{ } __except() { }
9712  */
9713 static statement_t *parse_ms_try_statment(void)
9714 {
9715         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9716         eat(T___try);
9717
9718         PUSH_PARENT(statement);
9719
9720         ms_try_statement_t *rem = current_try;
9721         current_try = &statement->ms_try;
9722         statement->ms_try.try_statement = parse_compound_statement(false);
9723         current_try = rem;
9724
9725         POP_PARENT();
9726
9727         if (next_if(T___except)) {
9728                 expression_t *const expr = parse_condition();
9729                 type_t       *      type = skip_typeref(expr->base.type);
9730                 if (is_type_integer(type)) {
9731                         type = promote_integer(type);
9732                 } else if (is_type_valid(type)) {
9733                         errorf(&expr->base.source_position,
9734                                "__expect expression is not an integer, but '%T'", type);
9735                         type = type_error_type;
9736                 }
9737                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9738         } else if (!next_if(T__finally)) {
9739                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9740         }
9741         statement->ms_try.final_statement = parse_compound_statement(false);
9742         return statement;
9743 }
9744
9745 static statement_t *parse_empty_statement(void)
9746 {
9747         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9748         statement_t *const statement = create_empty_statement();
9749         eat(';');
9750         return statement;
9751 }
9752
9753 static statement_t *parse_local_label_declaration(void)
9754 {
9755         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9756
9757         eat(T___label__);
9758
9759         entity_t *begin   = NULL;
9760         entity_t *end     = NULL;
9761         entity_t **anchor = &begin;
9762         do {
9763                 source_position_t pos;
9764                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9765                 if (!symbol)
9766                         goto end_error;
9767
9768                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9769                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9770                         source_position_t const *const ppos = &entity->base.source_position;
9771                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9772                 } else {
9773                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9774                         entity->base.parent_scope = current_scope;
9775
9776                         *anchor = entity;
9777                         anchor  = &entity->base.next;
9778                         end     = entity;
9779
9780                         environment_push(entity);
9781                 }
9782         } while (next_if(','));
9783         expect(';');
9784 end_error:
9785         statement->declaration.declarations_begin = begin;
9786         statement->declaration.declarations_end   = end;
9787         return statement;
9788 }
9789
9790 static void parse_namespace_definition(void)
9791 {
9792         eat(T_namespace);
9793
9794         entity_t *entity = NULL;
9795         symbol_t *symbol = NULL;
9796
9797         if (token.kind == T_IDENTIFIER) {
9798                 symbol = token.identifier.symbol;
9799                 next_token();
9800
9801                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9802                 if (entity != NULL
9803                                 && entity->kind != ENTITY_NAMESPACE
9804                                 && entity->base.parent_scope == current_scope) {
9805                         if (is_entity_valid(entity)) {
9806                                 error_redefined_as_different_kind(&token.base.source_position,
9807                                                 entity, ENTITY_NAMESPACE);
9808                         }
9809                         entity = NULL;
9810                 }
9811         }
9812
9813         if (entity == NULL) {
9814                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9815                 entity->base.parent_scope = current_scope;
9816         }
9817
9818         if (token.kind == '=') {
9819                 /* TODO: parse namespace alias */
9820                 panic("namespace alias definition not supported yet");
9821         }
9822
9823         environment_push(entity);
9824         append_entity(current_scope, entity);
9825
9826         PUSH_SCOPE(&entity->namespacee.members);
9827
9828         entity_t     *old_current_entity = current_entity;
9829         current_entity = entity;
9830
9831         add_anchor_token('}');
9832         expect('{');
9833         parse_externals();
9834         rem_anchor_token('}');
9835         expect('}');
9836
9837         assert(current_entity == entity);
9838         current_entity = old_current_entity;
9839         POP_SCOPE();
9840 }
9841
9842 /**
9843  * Parse a statement.
9844  * There's also parse_statement() which additionally checks for
9845  * "statement has no effect" warnings
9846  */
9847 static statement_t *intern_parse_statement(void)
9848 {
9849         /* declaration or statement */
9850         statement_t *statement;
9851         switch (token.kind) {
9852         case T_IDENTIFIER: {
9853                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9854                 if (la1_type == ':') {
9855                         statement = parse_label_statement();
9856                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9857                         statement = parse_declaration_statement();
9858                 } else {
9859                         /* it's an identifier, the grammar says this must be an
9860                          * expression statement. However it is common that users mistype
9861                          * declaration types, so we guess a bit here to improve robustness
9862                          * for incorrect programs */
9863                         switch (la1_type) {
9864                         case '&':
9865                         case '*':
9866                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9867                         default:
9868                                         statement = parse_expression_statement();
9869                                 } else {
9870                         DECLARATION_START
9871                         case T_IDENTIFIER:
9872                                         statement = parse_declaration_statement();
9873                                 }
9874                                 break;
9875                         }
9876                 }
9877                 break;
9878         }
9879
9880         case T___extension__: {
9881                 /* This can be a prefix to a declaration or an expression statement.
9882                  * We simply eat it now and parse the rest with tail recursion. */
9883                 PUSH_EXTENSION();
9884                 statement = intern_parse_statement();
9885                 POP_EXTENSION();
9886                 break;
9887         }
9888
9889         DECLARATION_START
9890                 statement = parse_declaration_statement();
9891                 break;
9892
9893         case T___label__:
9894                 statement = parse_local_label_declaration();
9895                 break;
9896
9897         case ';':         statement = parse_empty_statement();         break;
9898         case '{':         statement = parse_compound_statement(false); break;
9899         case T___leave:   statement = parse_leave_statement();         break;
9900         case T___try:     statement = parse_ms_try_statment();         break;
9901         case T_asm:       statement = parse_asm_statement();           break;
9902         case T_break:     statement = parse_break();                   break;
9903         case T_case:      statement = parse_case_statement();          break;
9904         case T_continue:  statement = parse_continue();                break;
9905         case T_default:   statement = parse_default_statement();       break;
9906         case T_do:        statement = parse_do();                      break;
9907         case T_for:       statement = parse_for();                     break;
9908         case T_goto:      statement = parse_goto();                    break;
9909         case T_if:        statement = parse_if();                      break;
9910         case T_return:    statement = parse_return();                  break;
9911         case T_switch:    statement = parse_switch();                  break;
9912         case T_while:     statement = parse_while();                   break;
9913
9914         EXPRESSION_START
9915                 statement = parse_expression_statement();
9916                 break;
9917
9918         default:
9919                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9920                 statement = create_error_statement();
9921                 eat_until_anchor();
9922                 break;
9923         }
9924
9925         return statement;
9926 }
9927
9928 /**
9929  * parse a statement and emits "statement has no effect" warning if needed
9930  * (This is really a wrapper around intern_parse_statement with check for 1
9931  *  single warning. It is needed, because for statement expressions we have
9932  *  to avoid the warning on the last statement)
9933  */
9934 static statement_t *parse_statement(void)
9935 {
9936         statement_t *statement = intern_parse_statement();
9937
9938         if (statement->kind == STATEMENT_EXPRESSION) {
9939                 expression_t *expression = statement->expression.expression;
9940                 if (!expression_has_effect(expression)) {
9941                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9942                 }
9943         }
9944
9945         return statement;
9946 }
9947
9948 /**
9949  * Parse a compound statement.
9950  */
9951 static statement_t *parse_compound_statement(bool inside_expression_statement)
9952 {
9953         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9954
9955         PUSH_PARENT(statement);
9956         PUSH_SCOPE(&statement->compound.scope);
9957
9958         eat('{');
9959         add_anchor_token('}');
9960         /* tokens, which can start a statement */
9961         /* TODO MS, __builtin_FOO */
9962         add_anchor_token('!');
9963         add_anchor_token('&');
9964         add_anchor_token('(');
9965         add_anchor_token('*');
9966         add_anchor_token('+');
9967         add_anchor_token('-');
9968         add_anchor_token(';');
9969         add_anchor_token('{');
9970         add_anchor_token('~');
9971         add_anchor_token(T_CHARACTER_CONSTANT);
9972         add_anchor_token(T_COLONCOLON);
9973         add_anchor_token(T_FLOATINGPOINT);
9974         add_anchor_token(T_IDENTIFIER);
9975         add_anchor_token(T_INTEGER);
9976         add_anchor_token(T_MINUSMINUS);
9977         add_anchor_token(T_PLUSPLUS);
9978         add_anchor_token(T_STRING_LITERAL);
9979         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9980         add_anchor_token(T_WIDE_STRING_LITERAL);
9981         add_anchor_token(T__Bool);
9982         add_anchor_token(T__Complex);
9983         add_anchor_token(T__Imaginary);
9984         add_anchor_token(T___FUNCTION__);
9985         add_anchor_token(T___PRETTY_FUNCTION__);
9986         add_anchor_token(T___alignof__);
9987         add_anchor_token(T___attribute__);
9988         add_anchor_token(T___builtin_va_start);
9989         add_anchor_token(T___extension__);
9990         add_anchor_token(T___func__);
9991         add_anchor_token(T___imag__);
9992         add_anchor_token(T___label__);
9993         add_anchor_token(T___real__);
9994         add_anchor_token(T___thread);
9995         add_anchor_token(T_asm);
9996         add_anchor_token(T_auto);
9997         add_anchor_token(T_bool);
9998         add_anchor_token(T_break);
9999         add_anchor_token(T_case);
10000         add_anchor_token(T_char);
10001         add_anchor_token(T_class);
10002         add_anchor_token(T_const);
10003         add_anchor_token(T_const_cast);
10004         add_anchor_token(T_continue);
10005         add_anchor_token(T_default);
10006         add_anchor_token(T_delete);
10007         add_anchor_token(T_double);
10008         add_anchor_token(T_do);
10009         add_anchor_token(T_dynamic_cast);
10010         add_anchor_token(T_enum);
10011         add_anchor_token(T_extern);
10012         add_anchor_token(T_false);
10013         add_anchor_token(T_float);
10014         add_anchor_token(T_for);
10015         add_anchor_token(T_goto);
10016         add_anchor_token(T_if);
10017         add_anchor_token(T_inline);
10018         add_anchor_token(T_int);
10019         add_anchor_token(T_long);
10020         add_anchor_token(T_new);
10021         add_anchor_token(T_operator);
10022         add_anchor_token(T_register);
10023         add_anchor_token(T_reinterpret_cast);
10024         add_anchor_token(T_restrict);
10025         add_anchor_token(T_return);
10026         add_anchor_token(T_short);
10027         add_anchor_token(T_signed);
10028         add_anchor_token(T_sizeof);
10029         add_anchor_token(T_static);
10030         add_anchor_token(T_static_cast);
10031         add_anchor_token(T_struct);
10032         add_anchor_token(T_switch);
10033         add_anchor_token(T_template);
10034         add_anchor_token(T_this);
10035         add_anchor_token(T_throw);
10036         add_anchor_token(T_true);
10037         add_anchor_token(T_try);
10038         add_anchor_token(T_typedef);
10039         add_anchor_token(T_typeid);
10040         add_anchor_token(T_typename);
10041         add_anchor_token(T_typeof);
10042         add_anchor_token(T_union);
10043         add_anchor_token(T_unsigned);
10044         add_anchor_token(T_using);
10045         add_anchor_token(T_void);
10046         add_anchor_token(T_volatile);
10047         add_anchor_token(T_wchar_t);
10048         add_anchor_token(T_while);
10049
10050         statement_t **anchor            = &statement->compound.statements;
10051         bool          only_decls_so_far = true;
10052         while (token.kind != '}' && token.kind != T_EOF) {
10053                 statement_t *sub_statement = intern_parse_statement();
10054                 if (sub_statement->kind == STATEMENT_ERROR) {
10055                         break;
10056                 }
10057
10058                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10059                         only_decls_so_far = false;
10060                 } else if (!only_decls_so_far) {
10061                         source_position_t const *const pos = &sub_statement->base.source_position;
10062                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10063                 }
10064
10065                 *anchor = sub_statement;
10066                 anchor  = &sub_statement->base.next;
10067         }
10068         expect('}');
10069
10070         /* look over all statements again to produce no effect warnings */
10071         if (is_warn_on(WARN_UNUSED_VALUE)) {
10072                 statement_t *sub_statement = statement->compound.statements;
10073                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10074                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10075                                 continue;
10076                         /* don't emit a warning for the last expression in an expression
10077                          * statement as it has always an effect */
10078                         if (inside_expression_statement && sub_statement->base.next == NULL)
10079                                 continue;
10080
10081                         expression_t *expression = sub_statement->expression.expression;
10082                         if (!expression_has_effect(expression)) {
10083                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10084                         }
10085                 }
10086         }
10087
10088         rem_anchor_token(T_while);
10089         rem_anchor_token(T_wchar_t);
10090         rem_anchor_token(T_volatile);
10091         rem_anchor_token(T_void);
10092         rem_anchor_token(T_using);
10093         rem_anchor_token(T_unsigned);
10094         rem_anchor_token(T_union);
10095         rem_anchor_token(T_typeof);
10096         rem_anchor_token(T_typename);
10097         rem_anchor_token(T_typeid);
10098         rem_anchor_token(T_typedef);
10099         rem_anchor_token(T_try);
10100         rem_anchor_token(T_true);
10101         rem_anchor_token(T_throw);
10102         rem_anchor_token(T_this);
10103         rem_anchor_token(T_template);
10104         rem_anchor_token(T_switch);
10105         rem_anchor_token(T_struct);
10106         rem_anchor_token(T_static_cast);
10107         rem_anchor_token(T_static);
10108         rem_anchor_token(T_sizeof);
10109         rem_anchor_token(T_signed);
10110         rem_anchor_token(T_short);
10111         rem_anchor_token(T_return);
10112         rem_anchor_token(T_restrict);
10113         rem_anchor_token(T_reinterpret_cast);
10114         rem_anchor_token(T_register);
10115         rem_anchor_token(T_operator);
10116         rem_anchor_token(T_new);
10117         rem_anchor_token(T_long);
10118         rem_anchor_token(T_int);
10119         rem_anchor_token(T_inline);
10120         rem_anchor_token(T_if);
10121         rem_anchor_token(T_goto);
10122         rem_anchor_token(T_for);
10123         rem_anchor_token(T_float);
10124         rem_anchor_token(T_false);
10125         rem_anchor_token(T_extern);
10126         rem_anchor_token(T_enum);
10127         rem_anchor_token(T_dynamic_cast);
10128         rem_anchor_token(T_do);
10129         rem_anchor_token(T_double);
10130         rem_anchor_token(T_delete);
10131         rem_anchor_token(T_default);
10132         rem_anchor_token(T_continue);
10133         rem_anchor_token(T_const_cast);
10134         rem_anchor_token(T_const);
10135         rem_anchor_token(T_class);
10136         rem_anchor_token(T_char);
10137         rem_anchor_token(T_case);
10138         rem_anchor_token(T_break);
10139         rem_anchor_token(T_bool);
10140         rem_anchor_token(T_auto);
10141         rem_anchor_token(T_asm);
10142         rem_anchor_token(T___thread);
10143         rem_anchor_token(T___real__);
10144         rem_anchor_token(T___label__);
10145         rem_anchor_token(T___imag__);
10146         rem_anchor_token(T___func__);
10147         rem_anchor_token(T___extension__);
10148         rem_anchor_token(T___builtin_va_start);
10149         rem_anchor_token(T___attribute__);
10150         rem_anchor_token(T___alignof__);
10151         rem_anchor_token(T___PRETTY_FUNCTION__);
10152         rem_anchor_token(T___FUNCTION__);
10153         rem_anchor_token(T__Imaginary);
10154         rem_anchor_token(T__Complex);
10155         rem_anchor_token(T__Bool);
10156         rem_anchor_token(T_WIDE_STRING_LITERAL);
10157         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10158         rem_anchor_token(T_STRING_LITERAL);
10159         rem_anchor_token(T_PLUSPLUS);
10160         rem_anchor_token(T_MINUSMINUS);
10161         rem_anchor_token(T_INTEGER);
10162         rem_anchor_token(T_IDENTIFIER);
10163         rem_anchor_token(T_FLOATINGPOINT);
10164         rem_anchor_token(T_COLONCOLON);
10165         rem_anchor_token(T_CHARACTER_CONSTANT);
10166         rem_anchor_token('~');
10167         rem_anchor_token('{');
10168         rem_anchor_token(';');
10169         rem_anchor_token('-');
10170         rem_anchor_token('+');
10171         rem_anchor_token('*');
10172         rem_anchor_token('(');
10173         rem_anchor_token('&');
10174         rem_anchor_token('!');
10175         rem_anchor_token('}');
10176
10177         POP_SCOPE();
10178         POP_PARENT();
10179         return statement;
10180 }
10181
10182 /**
10183  * Check for unused global static functions and variables
10184  */
10185 static void check_unused_globals(void)
10186 {
10187         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10188                 return;
10189
10190         for (const entity_t *entity = file_scope->entities; entity != NULL;
10191              entity = entity->base.next) {
10192                 if (!is_declaration(entity))
10193                         continue;
10194
10195                 const declaration_t *declaration = &entity->declaration;
10196                 if (declaration->used                  ||
10197                     declaration->modifiers & DM_UNUSED ||
10198                     declaration->modifiers & DM_USED   ||
10199                     declaration->storage_class != STORAGE_CLASS_STATIC)
10200                         continue;
10201
10202                 warning_t   why;
10203                 char const *s;
10204                 if (entity->kind == ENTITY_FUNCTION) {
10205                         /* inhibit warning for static inline functions */
10206                         if (entity->function.is_inline)
10207                                 continue;
10208
10209                         why = WARN_UNUSED_FUNCTION;
10210                         s   = entity->function.statement != NULL ? "defined" : "declared";
10211                 } else {
10212                         why = WARN_UNUSED_VARIABLE;
10213                         s   = "defined";
10214                 }
10215
10216                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10217         }
10218 }
10219
10220 static void parse_global_asm(void)
10221 {
10222         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10223
10224         eat(T_asm);
10225         add_anchor_token(';');
10226         add_anchor_token(')');
10227         add_anchor_token(T_STRING_LITERAL);
10228         expect('(');
10229
10230         rem_anchor_token(T_STRING_LITERAL);
10231         statement->asms.asm_text = parse_string_literals();
10232         statement->base.next     = unit->global_asm;
10233         unit->global_asm         = statement;
10234
10235         rem_anchor_token(')');
10236         expect(')');
10237         rem_anchor_token(';');
10238         expect(';');
10239 }
10240
10241 static void parse_linkage_specification(void)
10242 {
10243         eat(T_extern);
10244
10245         source_position_t const pos     = *HERE;
10246         char const       *const linkage = parse_string_literals().begin;
10247
10248         linkage_kind_t old_linkage = current_linkage;
10249         linkage_kind_t new_linkage;
10250         if (streq(linkage, "C")) {
10251                 new_linkage = LINKAGE_C;
10252         } else if (streq(linkage, "C++")) {
10253                 new_linkage = LINKAGE_CXX;
10254         } else {
10255                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10256                 new_linkage = LINKAGE_C;
10257         }
10258         current_linkage = new_linkage;
10259
10260         if (next_if('{')) {
10261                 parse_externals();
10262                 expect('}');
10263         } else {
10264                 parse_external();
10265         }
10266
10267         assert(current_linkage == new_linkage);
10268         current_linkage = old_linkage;
10269 }
10270
10271 static void parse_external(void)
10272 {
10273         switch (token.kind) {
10274                 case T_extern:
10275                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10276                                 parse_linkage_specification();
10277                         } else {
10278                 DECLARATION_START_NO_EXTERN
10279                 case T_IDENTIFIER:
10280                 case T___extension__:
10281                 /* tokens below are for implicit int */
10282                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10283                               implicit int) */
10284                 case '*':  /* * x; -> int* x; */
10285                 case '(':  /* (x); -> int (x); */
10286                                 PUSH_EXTENSION();
10287                                 parse_external_declaration();
10288                                 POP_EXTENSION();
10289                         }
10290                         return;
10291
10292                 case T_asm:
10293                         parse_global_asm();
10294                         return;
10295
10296                 case T_namespace:
10297                         parse_namespace_definition();
10298                         return;
10299
10300                 case ';':
10301                         if (!strict_mode) {
10302                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10303                                 next_token();
10304                                 return;
10305                         }
10306                         /* FALLTHROUGH */
10307
10308                 default:
10309                         errorf(HERE, "stray %K outside of function", &token);
10310                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10311                                 eat_until_matching_token(token.kind);
10312                         next_token();
10313                         return;
10314         }
10315 }
10316
10317 static void parse_externals(void)
10318 {
10319         add_anchor_token('}');
10320         add_anchor_token(T_EOF);
10321
10322 #ifndef NDEBUG
10323         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10324         unsigned short token_anchor_copy[T_LAST_TOKEN];
10325         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10326 #endif
10327
10328         while (token.kind != T_EOF && token.kind != '}') {
10329 #ifndef NDEBUG
10330                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10331                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10332                         if (count != 0) {
10333                                 /* the anchor set and its copy differs */
10334                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10335                         }
10336                 }
10337                 if (in_gcc_extension) {
10338                         /* an gcc extension scope was not closed */
10339                         internal_errorf(HERE, "Leaked __extension__");
10340                 }
10341 #endif
10342
10343                 parse_external();
10344         }
10345
10346         rem_anchor_token(T_EOF);
10347         rem_anchor_token('}');
10348 }
10349
10350 /**
10351  * Parse a translation unit.
10352  */
10353 static void parse_translation_unit(void)
10354 {
10355         add_anchor_token(T_EOF);
10356
10357         while (true) {
10358                 parse_externals();
10359
10360                 if (token.kind == T_EOF)
10361                         break;
10362
10363                 errorf(HERE, "stray %K outside of function", &token);
10364                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10365                         eat_until_matching_token(token.kind);
10366                 next_token();
10367         }
10368 }
10369
10370 void set_default_visibility(elf_visibility_tag_t visibility)
10371 {
10372         default_visibility = visibility;
10373 }
10374
10375 /**
10376  * Parse the input.
10377  *
10378  * @return  the translation unit or NULL if errors occurred.
10379  */
10380 void start_parsing(void)
10381 {
10382         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10383         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10384         diagnostic_count  = 0;
10385         error_count       = 0;
10386         warning_count     = 0;
10387
10388         print_to_file(stderr);
10389
10390         assert(unit == NULL);
10391         unit = allocate_ast_zero(sizeof(unit[0]));
10392
10393         assert(file_scope == NULL);
10394         file_scope = &unit->scope;
10395
10396         assert(current_scope == NULL);
10397         scope_push(&unit->scope);
10398
10399         create_gnu_builtins();
10400         if (c_mode & _MS)
10401                 create_microsoft_intrinsics();
10402 }
10403
10404 translation_unit_t *finish_parsing(void)
10405 {
10406         assert(current_scope == &unit->scope);
10407         scope_pop(NULL);
10408
10409         assert(file_scope == &unit->scope);
10410         check_unused_globals();
10411         file_scope = NULL;
10412
10413         DEL_ARR_F(environment_stack);
10414         DEL_ARR_F(label_stack);
10415
10416         translation_unit_t *result = unit;
10417         unit = NULL;
10418         return result;
10419 }
10420
10421 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10422  * are given length one. */
10423 static void complete_incomplete_arrays(void)
10424 {
10425         size_t n = ARR_LEN(incomplete_arrays);
10426         for (size_t i = 0; i != n; ++i) {
10427                 declaration_t *const decl = incomplete_arrays[i];
10428                 type_t        *const type = skip_typeref(decl->type);
10429
10430                 if (!is_type_incomplete(type))
10431                         continue;
10432
10433                 source_position_t const *const pos = &decl->base.source_position;
10434                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10435
10436                 type_t *const new_type = duplicate_type(type);
10437                 new_type->array.size_constant     = true;
10438                 new_type->array.has_implicit_size = true;
10439                 new_type->array.size              = 1;
10440
10441                 type_t *const result = identify_new_type(new_type);
10442
10443                 decl->type = result;
10444         }
10445 }
10446
10447 void prepare_main_collect2(entity_t *entity)
10448 {
10449         PUSH_SCOPE(&entity->function.statement->compound.scope);
10450
10451         // create call to __main
10452         symbol_t *symbol         = symbol_table_insert("__main");
10453         entity_t *subsubmain_ent
10454                 = create_implicit_function(symbol, &builtin_source_position);
10455
10456         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10457         type_t       *ftype       = subsubmain_ent->declaration.type;
10458         ref->base.source_position = builtin_source_position;
10459         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10460         ref->reference.entity     = subsubmain_ent;
10461
10462         expression_t *call = allocate_expression_zero(EXPR_CALL);
10463         call->base.source_position = builtin_source_position;
10464         call->base.type            = type_void;
10465         call->call.function        = ref;
10466
10467         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10468         expr_statement->base.source_position  = builtin_source_position;
10469         expr_statement->expression.expression = call;
10470
10471         statement_t *statement = entity->function.statement;
10472         assert(statement->kind == STATEMENT_COMPOUND);
10473         compound_statement_t *compounds = &statement->compound;
10474
10475         expr_statement->base.next = compounds->statements;
10476         compounds->statements     = expr_statement;
10477
10478         POP_SCOPE();
10479 }
10480
10481 void parse(void)
10482 {
10483         lookahead_bufpos = 0;
10484         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10485                 next_token();
10486         }
10487         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10488         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10489         parse_translation_unit();
10490         complete_incomplete_arrays();
10491         DEL_ARR_F(incomplete_arrays);
10492         incomplete_arrays = NULL;
10493 }
10494
10495 /**
10496  * Initialize the parser.
10497  */
10498 void init_parser(void)
10499 {
10500         sym_anonymous = symbol_table_insert("<anonymous>");
10501
10502         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10503
10504         init_expression_parsers();
10505         obstack_init(&temp_obst);
10506 }
10507
10508 /**
10509  * Terminate the parser.
10510  */
10511 void exit_parser(void)
10512 {
10513         obstack_free(&temp_obst, NULL);
10514 }