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 <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "preprocessor.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "ast2firm.h"
  45 #include "adt/bitfiddle.h"
  46 #include "adt/error.h"
  47 #include "adt/array.h"
  48
  49 //#define PRINT_TOKENS
  50 #define MAX_LOOKAHEAD 1
  51
  52 typedef struct {
  53         entity_t           *old_entity;
  54         symbol_t           *symbol;
  55         entity_namespace_t  namespc;
  56 } stack_entry_t;
  57
  58 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  59 struct declaration_specifiers_t {
  60         source_position_t  source_position;
  61         storage_class_t    storage_class;
  62         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  63         bool               is_inline    : 1;
  64         bool               thread_local : 1;
  65         attribute_t       *attributes;        /**< list of attributes */
  66         type_t            *type;
  67 };
  68
  69 /**
  70  * An environment for parsing initializers (and compound literals).
  71  */
  72 typedef struct parse_initializer_env_t {
  73         type_t     *type;   /**< the type of the initializer. In case of an
  74                                  array type with unspecified size this gets
  75                                  adjusted to the actual size. */
  76         entity_t   *entity; /**< the variable that is initialized if any */
  77         bool        must_be_constant;
  78 } parse_initializer_env_t;
  79
  80 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  81
  82 /** The current token. */
  83 static token_t              token;
  84 /** The lookahead ring-buffer. */
  85 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  86 /** Position of the next token in the lookahead buffer. */
  87 static size_t               lookahead_bufpos;
  88 static stack_entry_t       *environment_stack = NULL;
  89 static stack_entry_t       *label_stack       = NULL;
  90 static scope_t             *file_scope        = NULL;
  91 static scope_t             *current_scope     = NULL;
  92 /** Point to the current function declaration if inside a function. */
  93 static function_t          *current_function  = NULL;
  94 static entity_t            *current_entity    = NULL;
  95 static switch_statement_t  *current_switch    = NULL;
  96 static statement_t         *current_loop      = NULL;
  97 static statement_t         *current_parent    = NULL;
  98 static ms_try_statement_t  *current_try       = NULL;
  99 static linkage_kind_t       current_linkage;
 100 static goto_statement_t    *goto_first        = NULL;
 101 static goto_statement_t   **goto_anchor       = NULL;
 102 static label_statement_t   *label_first       = NULL;
 103 static label_statement_t  **label_anchor      = NULL;
 104 /** current translation unit. */
 105 static translation_unit_t  *unit              = NULL;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_CURRENT_ENTITY(entity) \
 115         entity_t *const new_current_entity = (entity); \
 116         entity_t *const old_current_entity = current_entity; \
 117         ((void)(current_entity = new_current_entity))
 118 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 119
 120 #define PUSH_PARENT(stmt) \
 121         statement_t *const new_parent = (stmt); \
 122         statement_t *const old_parent = current_parent; \
 123         ((void)(current_parent = new_parent))
 124 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 125
 126 #define PUSH_SCOPE(scope) \
 127         size_t   const top       = environment_top(); \
 128         scope_t *const new_scope = (scope); \
 129         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 130 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 131 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 132
 133 #define PUSH_EXTENSION() \
 134         (void)0; \
 135         bool const old_gcc_extension = in_gcc_extension; \
 136         while (next_if(T___extension__)) { \
 137                 in_gcc_extension = true; \
 138         } \
 139         do {} while (0)
 140 #define POP_EXTENSION() \
 141         ((void)(in_gcc_extension = old_gcc_extension))
 142
 143 /** The token anchor set */
 144 static unsigned short token_anchor_set[T_LAST_TOKEN];
 145
 146 /** The current source position. */
 147 #define HERE (&token.base.source_position)
 148
 149 /** true if we are in GCC mode. */
 150 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 151
 152 static statement_t *parse_compound_statement(bool inside_expression_statement);
 153 static statement_t *parse_statement(void);
 154
 155 static expression_t *parse_subexpression(precedence_t);
 156 static expression_t *parse_expression(void);
 157 static type_t       *parse_typename(void);
 158 static void          parse_externals(void);
 159 static void          parse_external(void);
 160
 161 static void parse_compound_type_entries(compound_t *compound_declaration);
 162
 163 static void check_call_argument(type_t          *expected_type,
 164                                                                 call_argument_t *argument, unsigned pos);
 165
 166 typedef enum declarator_flags_t {
 167         DECL_FLAGS_NONE             = 0,
 168         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 169         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 170         DECL_IS_PARAMETER           = 1U << 2
 171 } declarator_flags_t;
 172
 173 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 174                                   declarator_flags_t flags);
 175
 176 static void semantic_comparison(binary_expression_t *expression);
 177
 178 #define STORAGE_CLASSES       \
 179         STORAGE_CLASSES_NO_EXTERN \
 180         case T_extern:
 181
 182 #define STORAGE_CLASSES_NO_EXTERN \
 183         case T_typedef:         \
 184         case T_static:          \
 185         case T_auto:            \
 186         case T_register:        \
 187         case T__Thread_local:
 188
 189 #define TYPE_QUALIFIERS     \
 190         case T_const:           \
 191         case T_restrict:        \
 192         case T_volatile:        \
 193         case T_inline:          \
 194         case T__forceinline:    \
 195         case T___attribute__:
 196
 197 #define COMPLEX_SPECIFIERS  \
 198         case T__Complex:
 199 #define IMAGINARY_SPECIFIERS \
 200         case T__Imaginary:
 201
 202 #define TYPE_SPECIFIERS       \
 203         case T__Bool:             \
 204         case T___builtin_va_list: \
 205         case T___typeof__:        \
 206         case T__declspec:         \
 207         case T_bool:              \
 208         case T_char:              \
 209         case T_double:            \
 210         case T_enum:              \
 211         case T_float:             \
 212         case T_int:               \
 213         case T_long:              \
 214         case T_short:             \
 215         case T_signed:            \
 216         case T_struct:            \
 217         case T_union:             \
 218         case T_unsigned:          \
 219         case T_void:              \
 220         case T_wchar_t:           \
 221         case T__int8:             \
 222         case T__int16:            \
 223         case T__int32:            \
 224         case T__int64:            \
 225         case T__int128:           \
 226         COMPLEX_SPECIFIERS        \
 227         IMAGINARY_SPECIFIERS
 228
 229 #define DECLARATION_START   \
 230         STORAGE_CLASSES         \
 231         TYPE_QUALIFIERS         \
 232         TYPE_SPECIFIERS
 233
 234 #define DECLARATION_START_NO_EXTERN \
 235         STORAGE_CLASSES_NO_EXTERN       \
 236         TYPE_QUALIFIERS                 \
 237         TYPE_SPECIFIERS
 238
 239 #define EXPRESSION_START              \
 240         case '!':                         \
 241         case '&':                         \
 242         case '(':                         \
 243         case '*':                         \
 244         case '+':                         \
 245         case '-':                         \
 246         case '~':                         \
 247         case T_ANDAND:                    \
 248         case T_CHARACTER_CONSTANT:        \
 249         case T_NUMBER:                    \
 250         case T_MINUSMINUS:                \
 251         case T_PLUSPLUS:                  \
 252         case T_STRING_LITERAL:            \
 253         case T__Alignof:                  \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___PRETTY_FUNCTION__:       \
 257         case T___builtin_classify_type:   \
 258         case T___builtin_constant_p:      \
 259         case T___builtin_isgreater:       \
 260         case T___builtin_isgreaterequal:  \
 261         case T___builtin_isless:          \
 262         case T___builtin_islessequal:     \
 263         case T___builtin_islessgreater:   \
 264         case T___builtin_isunordered:     \
 265         case T___builtin_offsetof:        \
 266         case T___builtin_va_arg:          \
 267         case T___builtin_va_copy:         \
 268         case T___builtin_va_start:        \
 269         case T___func__:                  \
 270         case T___noop:                    \
 271         case T__assume:                   \
 272         case T_delete:                    \
 273         case T_false:                     \
 274         case T_sizeof:                    \
 275         case T_throw:                     \
 276         case T_true:
 277
 278 /**
 279  * Returns the size of a statement node.
 280  *
 281  * @param kind  the statement kind
 282  */
 283 static size_t get_statement_struct_size(statement_kind_t kind)
 284 {
 285         static const size_t sizes[] = {
 286                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 287                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 288                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 289                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 290                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 291                 [STATEMENT_IF]            = sizeof(if_statement_t),
 292                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 293                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 294                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 295                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 296                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 297                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 298                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 299                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 300                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 301                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 302                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 303                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 304                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 305         };
 306         assert((size_t)kind < lengthof(sizes));
 307         assert(sizes[kind] != 0);
 308         return sizes[kind];
 309 }
 310
 311 /**
 312  * Returns the size of an expression node.
 313  *
 314  * @param kind  the expression kind
 315  */
 316 static size_t get_expression_struct_size(expression_kind_t kind)
 317 {
 318         static const size_t sizes[] = {
 319                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 320                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 321                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 322                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 323                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 326                 [EXPR_LITERAL_MS_NOOP]            = sizeof(literal_expression_t),
 327                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 328                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 329                 [EXPR_CALL]                       = sizeof(call_expression_t),
 330                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 331                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 332                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 333                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 334                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 335                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 336                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 337                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 338                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 339                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 340                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 341                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 342                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 343                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 344                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 345                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 346                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 347         };
 348         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 349                 return sizes[EXPR_UNARY_FIRST];
 350         }
 351         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 352                 return sizes[EXPR_BINARY_FIRST];
 353         }
 354         assert((size_t)kind < lengthof(sizes));
 355         assert(sizes[kind] != 0);
 356         return sizes[kind];
 357 }
 358
 359 /**
 360  * Allocate a statement node of given kind and initialize all
 361  * fields with zero. Sets its source position to the position
 362  * of the current token.
 363  */
 364 static statement_t *allocate_statement_zero(statement_kind_t kind)
 365 {
 366         size_t       size = get_statement_struct_size(kind);
 367         statement_t *res  = allocate_ast_zero(size);
 368
 369         res->base.kind            = kind;
 370         res->base.parent          = current_parent;
 371         res->base.source_position = *HERE;
 372         return res;
 373 }
 374
 375 /**
 376  * Allocate an expression node of given kind and initialize all
 377  * fields with zero.
 378  *
 379  * @param kind  the kind of the expression to allocate
 380  */
 381 static expression_t *allocate_expression_zero(expression_kind_t kind)
 382 {
 383         size_t        size = get_expression_struct_size(kind);
 384         expression_t *res  = allocate_ast_zero(size);
 385
 386         res->base.kind            = kind;
 387         res->base.type            = type_error_type;
 388         res->base.source_position = *HERE;
 389         return res;
 390 }
 391
 392 /**
 393  * Creates a new invalid expression at the source position
 394  * of the current token.
 395  */
 396 static expression_t *create_error_expression(void)
 397 {
 398         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 399         expression->base.type = type_error_type;
 400         return expression;
 401 }
 402
 403 /**
 404  * Creates a new invalid statement.
 405  */
 406 static statement_t *create_error_statement(void)
 407 {
 408         return allocate_statement_zero(STATEMENT_ERROR);
 409 }
 410
 411 /**
 412  * Allocate a new empty statement.
 413  */
 414 static statement_t *create_empty_statement(void)
 415 {
 416         return allocate_statement_zero(STATEMENT_EMPTY);
 417 }
 418
 419 /**
 420  * Returns the size of an initializer node.
 421  *
 422  * @param kind  the initializer kind
 423  */
 424 static size_t get_initializer_size(initializer_kind_t kind)
 425 {
 426         static const size_t sizes[] = {
 427                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 428                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 429                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 430                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 431         };
 432         assert((size_t)kind < lengthof(sizes));
 433         assert(sizes[kind] != 0);
 434         return sizes[kind];
 435 }
 436
 437 /**
 438  * Allocate an initializer node of given kind and initialize all
 439  * fields with zero.
 440  */
 441 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 442 {
 443         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 444         result->kind          = kind;
 445
 446         return result;
 447 }
 448
 449 /**
 450  * Returns the index of the top element of the environment stack.
 451  */
 452 static size_t environment_top(void)
 453 {
 454         return ARR_LEN(environment_stack);
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the global label stack.
 459  */
 460 static size_t label_top(void)
 461 {
 462         return ARR_LEN(label_stack);
 463 }
 464
 465 /**
 466  * Return the next token.
 467  */
 468 static inline void next_token(void)
 469 {
 470         token                              = lookahead_buffer[lookahead_bufpos];
 471         lookahead_buffer[lookahead_bufpos] = pp_token;
 472         next_preprocessing_token();
 473
 474         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 475
 476 #ifdef PRINT_TOKENS
 477         print_token(stderr, &token);
 478         fprintf(stderr, "\n");
 479 #endif
 480 }
 481
 482 static inline void eat(token_kind_t const kind)
 483 {
 484         assert(token.kind == kind);
 485         (void)kind;
 486         next_token();
 487 }
 488
 489 static inline bool next_if(token_kind_t const kind)
 490 {
 491         if (token.kind == kind) {
 492                 eat(kind);
 493                 return true;
 494         } else {
 495                 return false;
 496         }
 497 }
 498
 499 /**
 500  * Return the next token with a given lookahead.
 501  */
 502 static inline const token_t *look_ahead(size_t num)
 503 {
 504         assert(0 < num && num <= MAX_LOOKAHEAD);
 505         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 506         return &lookahead_buffer[pos];
 507 }
 508
 509 /**
 510  * Adds a token type to the token type anchor set (a multi-set).
 511  */
 512 static void add_anchor_token(token_kind_t const token_kind)
 513 {
 514         assert(token_kind < T_LAST_TOKEN);
 515         ++token_anchor_set[token_kind];
 516 }
 517
 518 /**
 519  * Remove a token type from the token type anchor set (a multi-set).
 520  */
 521 static void rem_anchor_token(token_kind_t const token_kind)
 522 {
 523         assert(token_kind < T_LAST_TOKEN);
 524         assert(token_anchor_set[token_kind] != 0);
 525         --token_anchor_set[token_kind];
 526 }
 527
 528 /**
 529  * Eat tokens until a matching token type is found.
 530  */
 531 static void eat_until_matching_token(token_kind_t const type)
 532 {
 533         token_kind_t end_token;
 534         switch (type) {
 535                 case '(': end_token = ')';  break;
 536                 case '{': end_token = '}';  break;
 537                 case '[': end_token = ']';  break;
 538                 default:  end_token = type; break;
 539         }
 540
 541         unsigned parenthesis_count = 0;
 542         unsigned brace_count       = 0;
 543         unsigned bracket_count     = 0;
 544         while (token.kind        != end_token ||
 545                parenthesis_count != 0         ||
 546                brace_count       != 0         ||
 547                bracket_count     != 0) {
 548                 switch (token.kind) {
 549                 case T_EOF: return;
 550                 case '(': ++parenthesis_count; break;
 551                 case '{': ++brace_count;       break;
 552                 case '[': ++bracket_count;     break;
 553
 554                 case ')':
 555                         if (parenthesis_count > 0)
 556                                 --parenthesis_count;
 557                         goto check_stop;
 558
 559                 case '}':
 560                         if (brace_count > 0)
 561                                 --brace_count;
 562                         goto check_stop;
 563
 564                 case ']':
 565                         if (bracket_count > 0)
 566                                 --bracket_count;
 567 check_stop:
 568                         if (token.kind        == end_token &&
 569                             parenthesis_count == 0         &&
 570                             brace_count       == 0         &&
 571                             bracket_count     == 0)
 572                                 return;
 573                         break;
 574
 575                 default:
 576                         break;
 577                 }
 578                 next_token();
 579         }
 580 }
 581
 582 /**
 583  * Eat input tokens until an anchor is found.
 584  */
 585 static void eat_until_anchor(void)
 586 {
 587         while (token_anchor_set[token.kind] == 0) {
 588                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 589                         eat_until_matching_token(token.kind);
 590                 next_token();
 591         }
 592 }
 593
 594 /**
 595  * Eat a whole block from input tokens.
 596  */
 597 static void eat_block(void)
 598 {
 599         eat_until_matching_token('{');
 600         next_if('}');
 601 }
 602
 603 /**
 604  * Report a parse error because an expected token was not found.
 605  */
 606 static
 607 #if defined __GNUC__ && __GNUC__ >= 4
 608 __attribute__((sentinel))
 609 #endif
 610 void parse_error_expected(const char *message, ...)
 611 {
 612         if (message != NULL) {
 613                 errorf(HERE, "%s", message);
 614         }
 615         va_list ap;
 616         va_start(ap, message);
 617         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 618         va_end(ap);
 619 }
 620
 621 /**
 622  * Report an incompatible type.
 623  */
 624 static void type_error_incompatible(const char *msg,
 625                 const source_position_t *source_position, type_t *type1, type_t *type2)
 626 {
 627         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 628                msg, type1, type2);
 629 }
 630
 631 static bool skip_till(token_kind_t const expected, char const *const context)
 632 {
 633         if (UNLIKELY(token.kind != expected)) {
 634                 parse_error_expected(context, expected, NULL);
 635                 add_anchor_token(expected);
 636                 eat_until_anchor();
 637                 rem_anchor_token(expected);
 638                 if (token.kind != expected)
 639                         return false;
 640         }
 641         return true;
 642 }
 643
 644 /**
 645  * Expect the current token is the expected token.
 646  * If not, generate an error and skip until the next anchor.
 647  */
 648 static void expect(token_kind_t const expected)
 649 {
 650         if (skip_till(expected, NULL))
 651                 eat(expected);
 652 }
 653
 654 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 655 {
 656         if (!skip_till(T_IDENTIFIER, context))
 657                 return NULL;
 658         symbol_t *const sym = token.base.symbol;
 659         if (pos)
 660                 *pos = *HERE;
 661         eat(T_IDENTIFIER);
 662         return sym;
 663 }
 664
 665 /**
 666  * Push a given scope on the scope stack and make it the
 667  * current scope
 668  */
 669 static scope_t *scope_push(scope_t *new_scope)
 670 {
 671         if (current_scope != NULL) {
 672                 new_scope->depth = current_scope->depth + 1;
 673         }
 674
 675         scope_t *old_scope = current_scope;
 676         current_scope      = new_scope;
 677         return old_scope;
 678 }
 679
 680 /**
 681  * Pop the current scope from the scope stack.
 682  */
 683 static void scope_pop(scope_t *old_scope)
 684 {
 685         current_scope = old_scope;
 686 }
 687
 688 /**
 689  * Search an entity by its symbol in a given namespace.
 690  */
 691 static entity_t *get_entity(const symbol_t *const symbol,
 692                             namespace_tag_t namespc)
 693 {
 694         entity_t *entity = symbol->entity;
 695         for (; entity != NULL; entity = entity->base.symbol_next) {
 696                 if ((namespace_tag_t)entity->base.namespc == namespc)
 697                         return entity;
 698         }
 699
 700         return NULL;
 701 }
 702
 703 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 704  * possible. */
 705 static entity_t *get_tag(symbol_t const *const symbol,
 706                          entity_kind_tag_t const kind)
 707 {
 708         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 709         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 710                 errorf(HERE,
 711                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 712                                 symbol, &entity->base.source_position);
 713                 entity = NULL;
 714         }
 715         return entity;
 716 }
 717
 718 /**
 719  * pushs an entity on the environment stack and links the corresponding symbol
 720  * it.
 721  */
 722 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 723 {
 724         symbol_t           *symbol  = entity->base.symbol;
 725         entity_namespace_t  namespc = entity->base.namespc;
 726         assert(namespc != 0);
 727
 728         /* replace/add entity into entity list of the symbol */
 729         entity_t **anchor;
 730         entity_t  *iter;
 731         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 732                 iter = *anchor;
 733                 if (iter == NULL)
 734                         break;
 735
 736                 /* replace an entry? */
 737                 if (iter->base.namespc == namespc) {
 738                         entity->base.symbol_next = iter->base.symbol_next;
 739                         break;
 740                 }
 741         }
 742         *anchor = entity;
 743
 744         /* remember old declaration */
 745         stack_entry_t entry;
 746         entry.symbol     = symbol;
 747         entry.old_entity = iter;
 748         entry.namespc    = namespc;
 749         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 750 }
 751
 752 /**
 753  * Push an entity on the environment stack.
 754  */
 755 static void environment_push(entity_t *entity)
 756 {
 757         assert(entity->base.source_position.input_name != NULL);
 758         assert(entity->base.parent_scope != NULL);
 759         stack_push(&environment_stack, entity);
 760 }
 761
 762 /**
 763  * Push a declaration on the global label stack.
 764  *
 765  * @param declaration  the declaration
 766  */
 767 static void label_push(entity_t *label)
 768 {
 769         /* we abuse the parameters scope as parent for the labels */
 770         label->base.parent_scope = &current_function->parameters;
 771         stack_push(&label_stack, label);
 772 }
 773
 774 /**
 775  * pops symbols from the environment stack until @p new_top is the top element
 776  */
 777 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 778 {
 779         stack_entry_t *stack = *stack_ptr;
 780         size_t         top   = ARR_LEN(stack);
 781         size_t         i;
 782
 783         assert(new_top <= top);
 784         if (new_top == top)
 785                 return;
 786
 787         for (i = top; i > new_top; --i) {
 788                 stack_entry_t *entry = &stack[i - 1];
 789
 790                 entity_t           *old_entity = entry->old_entity;
 791                 symbol_t           *symbol     = entry->symbol;
 792                 entity_namespace_t  namespc    = entry->namespc;
 793
 794                 /* replace with old_entity/remove */
 795                 entity_t **anchor;
 796                 entity_t  *iter;
 797                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 798                         iter = *anchor;
 799                         assert(iter != NULL);
 800                         /* replace an entry? */
 801                         if (iter->base.namespc == namespc)
 802                                 break;
 803                 }
 804
 805                 /* restore definition from outer scopes (if there was one) */
 806                 if (old_entity != NULL) {
 807                         old_entity->base.symbol_next = iter->base.symbol_next;
 808                         *anchor                      = old_entity;
 809                 } else {
 810                         /* remove entry from list */
 811                         *anchor = iter->base.symbol_next;
 812                 }
 813         }
 814
 815         ARR_SHRINKLEN(*stack_ptr, new_top);
 816 }
 817
 818 /**
 819  * Pop all entries from the environment stack until the new_top
 820  * is reached.
 821  *
 822  * @param new_top  the new stack top
 823  */
 824 static void environment_pop_to(size_t new_top)
 825 {
 826         stack_pop_to(&environment_stack, new_top);
 827 }
 828
 829 /**
 830  * Pop all entries from the global label stack until the new_top
 831  * is reached.
 832  *
 833  * @param new_top  the new stack top
 834  */
 835 static void label_pop_to(size_t new_top)
 836 {
 837         stack_pop_to(&label_stack, new_top);
 838 }
 839
 840 static atomic_type_kind_t get_akind(const type_t *type)
 841 {
 842         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 843                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 844         return type->atomic.akind;
 845 }
 846
 847 /**
 848  * §6.3.1.1:2  Do integer promotion for a given type.
 849  *
 850  * @param type  the type to promote
 851  * @return the promoted type
 852  */
 853 static type_t *promote_integer(type_t *type)
 854 {
 855         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 856                 type = type_int;
 857
 858         return type;
 859 }
 860
 861 /**
 862  * Check if a given expression represents a null pointer constant.
 863  *
 864  * @param expression  the expression to check
 865  */
 866 static bool is_null_pointer_constant(const expression_t *expression)
 867 {
 868         /* skip void* cast */
 869         if (expression->kind == EXPR_UNARY_CAST) {
 870                 type_t *const type = skip_typeref(expression->base.type);
 871                 if (types_compatible(type, type_void_ptr))
 872                         expression = expression->unary.value;
 873         }
 874
 875         type_t *const type = skip_typeref(expression->base.type);
 876         if (!is_type_integer(type))
 877                 return false;
 878         switch (is_constant_expression(expression)) {
 879                 case EXPR_CLASS_ERROR:    return true;
 880                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 881                 default:                  return false;
 882         }
 883 }
 884
 885 /**
 886  * Create an implicit cast expression.
 887  *
 888  * @param expression  the expression to cast
 889  * @param dest_type   the destination type
 890  */
 891 static expression_t *create_implicit_cast(expression_t *expression,
 892                                           type_t *dest_type)
 893 {
 894         type_t *const source_type = expression->base.type;
 895
 896         if (source_type == dest_type)
 897                 return expression;
 898
 899         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 900         cast->unary.value   = expression;
 901         cast->base.type     = dest_type;
 902         cast->base.implicit = true;
 903
 904         return cast;
 905 }
 906
 907 typedef enum assign_error_t {
 908         ASSIGN_SUCCESS,
 909         ASSIGN_ERROR_INCOMPATIBLE,
 910         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 911         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 912         ASSIGN_WARNING_POINTER_FROM_INT,
 913         ASSIGN_WARNING_INT_FROM_POINTER
 914 } assign_error_t;
 915
 916 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)
 917 {
 918         type_t *const orig_type_right = right->base.type;
 919         type_t *const type_left       = skip_typeref(orig_type_left);
 920         type_t *const type_right      = skip_typeref(orig_type_right);
 921
 922         switch (error) {
 923         case ASSIGN_SUCCESS:
 924                 return;
 925         case ASSIGN_ERROR_INCOMPATIBLE:
 926                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 927                 return;
 928
 929         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 930                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 931                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 932
 933                 /* the left type has all qualifiers from the right type */
 934                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 935                 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);
 936                 return;
 937         }
 938
 939         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 940                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 941                 return;
 942
 943         case ASSIGN_WARNING_POINTER_FROM_INT:
 944                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 945                 return;
 946
 947         case ASSIGN_WARNING_INT_FROM_POINTER:
 948                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 949                 return;
 950
 951         default:
 952                 panic("invalid error value");
 953         }
 954 }
 955
 956 /** Implements the rules from §6.5.16.1 */
 957 static assign_error_t semantic_assign(type_t *orig_type_left,
 958                                       const expression_t *const right)
 959 {
 960         type_t *const orig_type_right = right->base.type;
 961         type_t *const type_left       = skip_typeref(orig_type_left);
 962         type_t *const type_right      = skip_typeref(orig_type_right);
 963
 964         if (is_type_pointer(type_left)) {
 965                 if (is_null_pointer_constant(right)) {
 966                         return ASSIGN_SUCCESS;
 967                 } else if (is_type_pointer(type_right)) {
 968                         type_t *points_to_left
 969                                 = skip_typeref(type_left->pointer.points_to);
 970                         type_t *points_to_right
 971                                 = skip_typeref(type_right->pointer.points_to);
 972                         assign_error_t res = ASSIGN_SUCCESS;
 973
 974                         /* the left type has all qualifiers from the right type */
 975                         unsigned missing_qualifiers
 976                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 977                         if (missing_qualifiers != 0) {
 978                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 979                         }
 980
 981                         points_to_left  = get_unqualified_type(points_to_left);
 982                         points_to_right = get_unqualified_type(points_to_right);
 983
 984                         if (is_type_void(points_to_left))
 985                                 return res;
 986
 987                         if (is_type_void(points_to_right)) {
 988                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 989                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 990                         }
 991
 992                         if (!types_compatible(points_to_left, points_to_right)) {
 993                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 994                         }
 995
 996                         return res;
 997                 } else if (is_type_integer(type_right)) {
 998                         return ASSIGN_WARNING_POINTER_FROM_INT;
 999                 }
1000         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1001                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1002                                 && is_type_pointer(type_right))) {
1003                 return ASSIGN_SUCCESS;
1004         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1005                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1006                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1007                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1008                         return ASSIGN_SUCCESS;
1009                 }
1010         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1011                 return ASSIGN_WARNING_INT_FROM_POINTER;
1012         }
1013
1014         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1015                 return ASSIGN_SUCCESS;
1016
1017         return ASSIGN_ERROR_INCOMPATIBLE;
1018 }
1019
1020 static expression_t *parse_constant_expression(void)
1021 {
1022         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1023
1024         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1025                 errorf(&result->base.source_position,
1026                        "expression '%E' is not constant", result);
1027         }
1028
1029         return result;
1030 }
1031
1032 static expression_t *parse_assignment_expression(void)
1033 {
1034         return parse_subexpression(PREC_ASSIGNMENT);
1035 }
1036
1037 static void append_string(string_t const *const s)
1038 {
1039         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1040          * possible, because other tokens are grown there alongside. */
1041         obstack_grow(&ast_obstack, s->begin, s->size);
1042 }
1043
1044 static string_t finish_string(string_encoding_t const enc)
1045 {
1046         obstack_1grow(&ast_obstack, '\0');
1047         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1048         char const *const string = obstack_finish(&ast_obstack);
1049         return (string_t){ string, size, enc };
1050 }
1051
1052 static string_t concat_string_literals(void)
1053 {
1054         assert(token.kind == T_STRING_LITERAL);
1055
1056         string_t result;
1057         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1058                 append_string(&token.literal.string);
1059                 eat(T_STRING_LITERAL);
1060                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1061                 string_encoding_t enc = token.literal.string.encoding;
1062                 do {
1063                         if (token.literal.string.encoding != STRING_ENCODING_CHAR) {
1064                                 enc = token.literal.string.encoding;
1065                         }
1066                         append_string(&token.literal.string);
1067                         eat(T_STRING_LITERAL);
1068                 } while (token.kind == T_STRING_LITERAL);
1069                 result = finish_string(enc);
1070         } else {
1071                 result = token.literal.string;
1072                 eat(T_STRING_LITERAL);
1073         }
1074
1075         return result;
1076 }
1077
1078 static string_t parse_string_literals(char const *const context)
1079 {
1080         if (!skip_till(T_STRING_LITERAL, context))
1081                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1082
1083         source_position_t const pos = *HERE;
1084         string_t          const res = concat_string_literals();
1085
1086         if (res.encoding != STRING_ENCODING_CHAR) {
1087                 errorf(&pos, "expected plain string literal, got wide string literal");
1088         }
1089
1090         return res;
1091 }
1092
1093 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1094 {
1095         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1096         attribute->kind            = kind;
1097         attribute->source_position = *HERE;
1098         return attribute;
1099 }
1100
1101 /**
1102  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1103  *
1104  *  attribute:
1105  *    __attribute__ ( ( attribute-list ) )
1106  *
1107  *  attribute-list:
1108  *    attrib
1109  *    attribute_list , attrib
1110  *
1111  *  attrib:
1112  *    empty
1113  *    any-word
1114  *    any-word ( identifier )
1115  *    any-word ( identifier , nonempty-expr-list )
1116  *    any-word ( expr-list )
1117  *
1118  *  where the "identifier" must not be declared as a type, and
1119  *  "any-word" may be any identifier (including one declared as a
1120  *  type), a reserved word storage class specifier, type specifier or
1121  *  type qualifier.  ??? This still leaves out most reserved keywords
1122  *  (following the old parser), shouldn't we include them, and why not
1123  *  allow identifiers declared as types to start the arguments?
1124  *
1125  *  Matze: this all looks confusing and little systematic, so we're even less
1126  *  strict and parse any list of things which are identifiers or
1127  *  (assignment-)expressions.
1128  */
1129 static attribute_argument_t *parse_attribute_arguments(void)
1130 {
1131         attribute_argument_t  *first  = NULL;
1132         attribute_argument_t **anchor = &first;
1133         if (token.kind != ')') do {
1134                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1135
1136                 /* is it an identifier */
1137                 if (token.kind == T_IDENTIFIER
1138                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1139                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1140                         argument->v.symbol = token.base.symbol;
1141                         eat(T_IDENTIFIER);
1142                 } else {
1143                         /* must be an expression */
1144                         expression_t *expression = parse_assignment_expression();
1145
1146                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1147                         argument->v.expression = expression;
1148                 }
1149
1150                 /* append argument */
1151                 *anchor = argument;
1152                 anchor  = &argument->next;
1153         } while (next_if(','));
1154         expect(')');
1155         return first;
1156 }
1157
1158 static attribute_t *parse_attribute_asm(void)
1159 {
1160         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1161         eat(T_asm);
1162         expect('(');
1163         attribute->a.arguments = parse_attribute_arguments();
1164         return attribute;
1165 }
1166
1167 static attribute_t *parse_attribute_gnu_single(void)
1168 {
1169         /* parse "any-word" */
1170         symbol_t *const symbol = token.base.symbol;
1171         if (symbol == NULL) {
1172                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1173                 return NULL;
1174         }
1175
1176         attribute_kind_t  kind;
1177         char const *const name = symbol->string;
1178         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1179                 if (kind > ATTRIBUTE_GNU_LAST) {
1180                         /* special case for "__const" */
1181                         if (token.kind == T_const) {
1182                                 kind = ATTRIBUTE_GNU_CONST;
1183                                 break;
1184                         }
1185
1186                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1187                         /* TODO: we should still save the attribute in the list... */
1188                         kind = ATTRIBUTE_UNKNOWN;
1189                         break;
1190                 }
1191
1192                 const char *attribute_name = get_attribute_name(kind);
1193                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1194                         break;
1195         }
1196
1197         attribute_t *attribute = allocate_attribute_zero(kind);
1198         next_token();
1199
1200         /* parse arguments */
1201         if (next_if('('))
1202                 attribute->a.arguments = parse_attribute_arguments();
1203
1204         return attribute;
1205 }
1206
1207 static attribute_t *parse_attribute_gnu(void)
1208 {
1209         attribute_t  *first  = NULL;
1210         attribute_t **anchor = &first;
1211
1212         eat(T___attribute__);
1213         add_anchor_token(')');
1214         add_anchor_token(',');
1215         expect('(');
1216         expect('(');
1217
1218         if (token.kind != ')') do {
1219                 attribute_t *attribute = parse_attribute_gnu_single();
1220                 if (attribute) {
1221                         *anchor = attribute;
1222                         anchor  = &attribute->next;
1223                 }
1224         } while (next_if(','));
1225         rem_anchor_token(',');
1226         rem_anchor_token(')');
1227
1228         expect(')');
1229         expect(')');
1230         return first;
1231 }
1232
1233 /** Parse attributes. */
1234 static attribute_t *parse_attributes(attribute_t *first)
1235 {
1236         attribute_t **anchor = &first;
1237         for (;;) {
1238                 while (*anchor != NULL)
1239                         anchor = &(*anchor)->next;
1240
1241                 attribute_t *attribute;
1242                 switch (token.kind) {
1243                 case T___attribute__:
1244                         attribute = parse_attribute_gnu();
1245                         if (attribute == NULL)
1246                                 continue;
1247                         break;
1248
1249                 case T_asm:
1250                         attribute = parse_attribute_asm();
1251                         break;
1252
1253                 case T_cdecl:
1254                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1255                         eat(T_cdecl);
1256                         break;
1257
1258                 case T__fastcall:
1259                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1260                         eat(T__fastcall);
1261                         break;
1262
1263                 case T__forceinline:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1265                         eat(T__forceinline);
1266                         break;
1267
1268                 case T__stdcall:
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1270                         eat(T__stdcall);
1271                         break;
1272
1273                 case T___thiscall:
1274                         /* TODO record modifier */
1275                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1276                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1277                         eat(T___thiscall);
1278                         break;
1279
1280                 default:
1281                         return first;
1282                 }
1283
1284                 *anchor = attribute;
1285                 anchor  = &attribute->next;
1286         }
1287 }
1288
1289 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1290
1291 static entity_t *determine_lhs_ent(expression_t *const expr,
1292                                    entity_t *lhs_ent)
1293 {
1294         switch (expr->kind) {
1295                 case EXPR_REFERENCE: {
1296                         entity_t *const entity = expr->reference.entity;
1297                         /* we should only find variables as lvalues... */
1298                         if (entity->base.kind != ENTITY_VARIABLE
1299                                         && entity->base.kind != ENTITY_PARAMETER)
1300                                 return NULL;
1301
1302                         return entity;
1303                 }
1304
1305                 case EXPR_ARRAY_ACCESS: {
1306                         expression_t *const ref = expr->array_access.array_ref;
1307                         entity_t     *      ent = NULL;
1308                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1309                                 ent     = determine_lhs_ent(ref, lhs_ent);
1310                                 lhs_ent = ent;
1311                         } else {
1312                                 mark_vars_read(ref, lhs_ent);
1313                         }
1314                         mark_vars_read(expr->array_access.index, lhs_ent);
1315                         return ent;
1316                 }
1317
1318                 case EXPR_SELECT: {
1319                         mark_vars_read(expr->select.compound, lhs_ent);
1320                         if (is_type_compound(skip_typeref(expr->base.type)))
1321                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1322                         return NULL;
1323                 }
1324
1325                 case EXPR_UNARY_DEREFERENCE: {
1326                         expression_t *const val = expr->unary.value;
1327                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1328                                 /* *&x is a NOP */
1329                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1330                         } else {
1331                                 mark_vars_read(val, NULL);
1332                                 return NULL;
1333                         }
1334                 }
1335
1336                 default:
1337                         mark_vars_read(expr, NULL);
1338                         return NULL;
1339         }
1340 }
1341
1342 #define ENT_ANY ((entity_t*)-1)
1343
1344 /**
1345  * Mark declarations, which are read.  This is used to detect variables, which
1346  * are never read.
1347  * Example:
1348  * x = x + 1;
1349  *   x is not marked as "read", because it is only read to calculate its own new
1350  *   value.
1351  *
1352  * x += y; y += x;
1353  *   x and y are not detected as "not read", because multiple variables are
1354  *   involved.
1355  */
1356 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1357 {
1358         switch (expr->kind) {
1359                 case EXPR_REFERENCE: {
1360                         entity_t *const entity = expr->reference.entity;
1361                         if (entity->kind != ENTITY_VARIABLE
1362                                         && entity->kind != ENTITY_PARAMETER)
1363                                 return;
1364
1365                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1366                                 entity->variable.read = true;
1367                         }
1368                         return;
1369                 }
1370
1371                 case EXPR_CALL:
1372                         // TODO respect pure/const
1373                         mark_vars_read(expr->call.function, NULL);
1374                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1375                                 mark_vars_read(arg->expression, NULL);
1376                         }
1377                         return;
1378
1379                 case EXPR_CONDITIONAL:
1380                         // TODO lhs_decl should depend on whether true/false have an effect
1381                         mark_vars_read(expr->conditional.condition, NULL);
1382                         if (expr->conditional.true_expression != NULL)
1383                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1384                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1385                         return;
1386
1387                 case EXPR_SELECT:
1388                         if (lhs_ent == ENT_ANY
1389                                         && !is_type_compound(skip_typeref(expr->base.type)))
1390                                 lhs_ent = NULL;
1391                         mark_vars_read(expr->select.compound, lhs_ent);
1392                         return;
1393
1394                 case EXPR_ARRAY_ACCESS: {
1395                         mark_vars_read(expr->array_access.index, lhs_ent);
1396                         expression_t *const ref = expr->array_access.array_ref;
1397                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1398                                 if (lhs_ent == ENT_ANY)
1399                                         lhs_ent = NULL;
1400                         }
1401                         mark_vars_read(ref, lhs_ent);
1402                         return;
1403                 }
1404
1405                 case EXPR_VA_ARG:
1406                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1407                         return;
1408
1409                 case EXPR_VA_COPY:
1410                         mark_vars_read(expr->va_copye.src, lhs_ent);
1411                         return;
1412
1413                 case EXPR_UNARY_CAST:
1414                         /* Special case: Use void cast to mark a variable as "read" */
1415                         if (is_type_void(skip_typeref(expr->base.type)))
1416                                 lhs_ent = NULL;
1417                         goto unary;
1418
1419
1420                 case EXPR_UNARY_THROW:
1421                         if (expr->unary.value == NULL)
1422                                 return;
1423                         /* FALLTHROUGH */
1424                 case EXPR_UNARY_DEREFERENCE:
1425                 case EXPR_UNARY_DELETE:
1426                 case EXPR_UNARY_DELETE_ARRAY:
1427                         if (lhs_ent == ENT_ANY)
1428                                 lhs_ent = NULL;
1429                         goto unary;
1430
1431                 case EXPR_UNARY_NEGATE:
1432                 case EXPR_UNARY_PLUS:
1433                 case EXPR_UNARY_BITWISE_NEGATE:
1434                 case EXPR_UNARY_NOT:
1435                 case EXPR_UNARY_TAKE_ADDRESS:
1436                 case EXPR_UNARY_POSTFIX_INCREMENT:
1437                 case EXPR_UNARY_POSTFIX_DECREMENT:
1438                 case EXPR_UNARY_PREFIX_INCREMENT:
1439                 case EXPR_UNARY_PREFIX_DECREMENT:
1440                 case EXPR_UNARY_ASSUME:
1441 unary:
1442                         mark_vars_read(expr->unary.value, lhs_ent);
1443                         return;
1444
1445                 case EXPR_BINARY_ADD:
1446                 case EXPR_BINARY_SUB:
1447                 case EXPR_BINARY_MUL:
1448                 case EXPR_BINARY_DIV:
1449                 case EXPR_BINARY_MOD:
1450                 case EXPR_BINARY_EQUAL:
1451                 case EXPR_BINARY_NOTEQUAL:
1452                 case EXPR_BINARY_LESS:
1453                 case EXPR_BINARY_LESSEQUAL:
1454                 case EXPR_BINARY_GREATER:
1455                 case EXPR_BINARY_GREATEREQUAL:
1456                 case EXPR_BINARY_BITWISE_AND:
1457                 case EXPR_BINARY_BITWISE_OR:
1458                 case EXPR_BINARY_BITWISE_XOR:
1459                 case EXPR_BINARY_LOGICAL_AND:
1460                 case EXPR_BINARY_LOGICAL_OR:
1461                 case EXPR_BINARY_SHIFTLEFT:
1462                 case EXPR_BINARY_SHIFTRIGHT:
1463                 case EXPR_BINARY_COMMA:
1464                 case EXPR_BINARY_ISGREATER:
1465                 case EXPR_BINARY_ISGREATEREQUAL:
1466                 case EXPR_BINARY_ISLESS:
1467                 case EXPR_BINARY_ISLESSEQUAL:
1468                 case EXPR_BINARY_ISLESSGREATER:
1469                 case EXPR_BINARY_ISUNORDERED:
1470                         mark_vars_read(expr->binary.left,  lhs_ent);
1471                         mark_vars_read(expr->binary.right, lhs_ent);
1472                         return;
1473
1474                 case EXPR_BINARY_ASSIGN:
1475                 case EXPR_BINARY_MUL_ASSIGN:
1476                 case EXPR_BINARY_DIV_ASSIGN:
1477                 case EXPR_BINARY_MOD_ASSIGN:
1478                 case EXPR_BINARY_ADD_ASSIGN:
1479                 case EXPR_BINARY_SUB_ASSIGN:
1480                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1481                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1482                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1483                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1484                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1485                         if (lhs_ent == ENT_ANY)
1486                                 lhs_ent = NULL;
1487                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1488                         mark_vars_read(expr->binary.right, lhs_ent);
1489                         return;
1490                 }
1491
1492                 case EXPR_VA_START:
1493                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1494                         return;
1495
1496                 case EXPR_LITERAL_CASES:
1497                 case EXPR_LITERAL_CHARACTER:
1498                 case EXPR_ERROR:
1499                 case EXPR_STRING_LITERAL:
1500                 case EXPR_COMPOUND_LITERAL: // TODO init?
1501                 case EXPR_SIZEOF:
1502                 case EXPR_CLASSIFY_TYPE:
1503                 case EXPR_ALIGNOF:
1504                 case EXPR_FUNCNAME:
1505                 case EXPR_BUILTIN_CONSTANT_P:
1506                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1507                 case EXPR_OFFSETOF:
1508                 case EXPR_STATEMENT: // TODO
1509                 case EXPR_LABEL_ADDRESS:
1510                 case EXPR_ENUM_CONSTANT:
1511                         return;
1512         }
1513
1514         panic("unhandled expression");
1515 }
1516
1517 static designator_t *parse_designation(void)
1518 {
1519         designator_t  *result = NULL;
1520         designator_t **anchor = &result;
1521
1522         for (;;) {
1523                 designator_t *designator;
1524                 switch (token.kind) {
1525                 case '[':
1526                         designator = allocate_ast_zero(sizeof(designator[0]));
1527                         designator->source_position = *HERE;
1528                         eat('[');
1529                         add_anchor_token(']');
1530                         designator->array_index = parse_constant_expression();
1531                         rem_anchor_token(']');
1532                         expect(']');
1533                         break;
1534                 case '.':
1535                         designator = allocate_ast_zero(sizeof(designator[0]));
1536                         designator->source_position = *HERE;
1537                         eat('.');
1538                         designator->symbol = expect_identifier("while parsing designator", NULL);
1539                         if (!designator->symbol)
1540                                 return NULL;
1541                         break;
1542                 default:
1543                         expect('=');
1544                         return result;
1545                 }
1546
1547                 assert(designator != NULL);
1548                 *anchor = designator;
1549                 anchor  = &designator->next;
1550         }
1551 }
1552
1553 /**
1554  * Build an initializer from a given expression.
1555  */
1556 static initializer_t *initializer_from_expression(type_t *orig_type,
1557                                                   expression_t *expression)
1558 {
1559         /* TODO check that expression is a constant expression */
1560
1561         type_t *const type = skip_typeref(orig_type);
1562
1563         /* §6.7.8.14/15 char array may be initialized by string literals */
1564         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1565                 array_type_t *const array_type   = &type->array;
1566                 type_t       *const element_type = skip_typeref(array_type->element_type);
1567                 switch (expression->string_literal.value.encoding) {
1568                 case STRING_ENCODING_CHAR: {
1569                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1570                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1571                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1572                                 goto make_string_init;
1573                         }
1574                         break;
1575                 }
1576
1577                 case STRING_ENCODING_WIDE: {
1578                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1579                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1580 make_string_init:;
1581                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1582                                 init->value.value = expression;
1583                                 return init;
1584                         }
1585                         break;
1586                 }
1587                 }
1588         }
1589
1590         assign_error_t error = semantic_assign(type, expression);
1591         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1592                 return NULL;
1593         report_assign_error(error, type, expression, "initializer",
1594                             &expression->base.source_position);
1595
1596         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1597         result->value.value = create_implicit_cast(expression, type);
1598
1599         return result;
1600 }
1601
1602 /**
1603  * Parses an scalar initializer.
1604  *
1605  * §6.7.8.11; eat {} without warning
1606  */
1607 static initializer_t *parse_scalar_initializer(type_t *type,
1608                                                bool must_be_constant)
1609 {
1610         /* there might be extra {} hierarchies */
1611         int braces = 0;
1612         if (token.kind == '{') {
1613                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1614                 do {
1615                         eat('{');
1616                         ++braces;
1617                 } while (token.kind == '{');
1618         }
1619
1620         expression_t *expression = parse_assignment_expression();
1621         mark_vars_read(expression, NULL);
1622         if (must_be_constant && !is_linker_constant(expression)) {
1623                 errorf(&expression->base.source_position,
1624                        "initialisation expression '%E' is not constant",
1625                        expression);
1626         }
1627
1628         initializer_t *initializer = initializer_from_expression(type, expression);
1629
1630         if (initializer == NULL) {
1631                 errorf(&expression->base.source_position,
1632                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1633                        expression, expression->base.type, type);
1634                 /* TODO */
1635                 return NULL;
1636         }
1637
1638         bool additional_warning_displayed = false;
1639         while (braces > 0) {
1640                 next_if(',');
1641                 if (token.kind != '}') {
1642                         if (!additional_warning_displayed) {
1643                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1644                                 additional_warning_displayed = true;
1645                         }
1646                 }
1647                 eat_block();
1648                 braces--;
1649         }
1650
1651         return initializer;
1652 }
1653
1654 /**
1655  * An entry in the type path.
1656  */
1657 typedef struct type_path_entry_t type_path_entry_t;
1658 struct type_path_entry_t {
1659         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1660         union {
1661                 size_t         index;          /**< For array types: the current index. */
1662                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1663         } v;
1664 };
1665
1666 /**
1667  * A type path expression a position inside compound or array types.
1668  */
1669 typedef struct type_path_t type_path_t;
1670 struct type_path_t {
1671         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1672         type_t            *top_type;     /**< type of the element the path points */
1673         size_t             max_index;    /**< largest index in outermost array */
1674 };
1675
1676 /**
1677  * Prints a type path for debugging.
1678  */
1679 static __attribute__((unused)) void debug_print_type_path(
1680                 const type_path_t *path)
1681 {
1682         size_t len = ARR_LEN(path->path);
1683
1684         for (size_t i = 0; i < len; ++i) {
1685                 const type_path_entry_t *entry = & path->path[i];
1686
1687                 type_t *type = skip_typeref(entry->type);
1688                 if (is_type_compound(type)) {
1689                         /* in gcc mode structs can have no members */
1690                         if (entry->v.compound_entry == NULL) {
1691                                 assert(i == len-1);
1692                                 continue;
1693                         }
1694                         fprintf(stderr, ".%s",
1695                                 entry->v.compound_entry->base.symbol->string);
1696                 } else if (is_type_array(type)) {
1697                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1698                 } else {
1699                         fprintf(stderr, "-INVALID-");
1700                 }
1701         }
1702         if (path->top_type != NULL) {
1703                 fprintf(stderr, "  (");
1704                 print_type(path->top_type);
1705                 fprintf(stderr, ")");
1706         }
1707 }
1708
1709 /**
1710  * Return the top type path entry, ie. in a path
1711  * (type).a.b returns the b.
1712  */
1713 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1714 {
1715         size_t len = ARR_LEN(path->path);
1716         assert(len > 0);
1717         return &path->path[len-1];
1718 }
1719
1720 /**
1721  * Enlarge the type path by an (empty) element.
1722  */
1723 static type_path_entry_t *append_to_type_path(type_path_t *path)
1724 {
1725         size_t len = ARR_LEN(path->path);
1726         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1727
1728         type_path_entry_t *result = & path->path[len];
1729         memset(result, 0, sizeof(result[0]));
1730         return result;
1731 }
1732
1733 /**
1734  * Descending into a sub-type. Enter the scope of the current top_type.
1735  */
1736 static void descend_into_subtype(type_path_t *path)
1737 {
1738         type_t *orig_top_type = path->top_type;
1739         type_t *top_type      = skip_typeref(orig_top_type);
1740
1741         type_path_entry_t *top = append_to_type_path(path);
1742         top->type              = top_type;
1743
1744         if (is_type_compound(top_type)) {
1745                 compound_t *const compound = top_type->compound.compound;
1746                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1747
1748                 if (entry != NULL) {
1749                         top->v.compound_entry = &entry->declaration;
1750                         path->top_type = entry->declaration.type;
1751                 } else {
1752                         path->top_type = NULL;
1753                 }
1754         } else if (is_type_array(top_type)) {
1755                 top->v.index   = 0;
1756                 path->top_type = top_type->array.element_type;
1757         } else {
1758                 assert(!is_type_valid(top_type));
1759         }
1760 }
1761
1762 /**
1763  * Pop an entry from the given type path, ie. returning from
1764  * (type).a.b to (type).a
1765  */
1766 static void ascend_from_subtype(type_path_t *path)
1767 {
1768         type_path_entry_t *top = get_type_path_top(path);
1769
1770         path->top_type = top->type;
1771
1772         size_t len = ARR_LEN(path->path);
1773         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1774 }
1775
1776 /**
1777  * Pop entries from the given type path until the given
1778  * path level is reached.
1779  */
1780 static void ascend_to(type_path_t *path, size_t top_path_level)
1781 {
1782         size_t len = ARR_LEN(path->path);
1783
1784         while (len > top_path_level) {
1785                 ascend_from_subtype(path);
1786                 len = ARR_LEN(path->path);
1787         }
1788 }
1789
1790 static bool walk_designator(type_path_t *path, const designator_t *designator,
1791                             bool used_in_offsetof)
1792 {
1793         for (; designator != NULL; designator = designator->next) {
1794                 type_path_entry_t *top       = get_type_path_top(path);
1795                 type_t            *orig_type = top->type;
1796
1797                 type_t *type = skip_typeref(orig_type);
1798
1799                 if (designator->symbol != NULL) {
1800                         symbol_t *symbol = designator->symbol;
1801                         if (!is_type_compound(type)) {
1802                                 if (is_type_valid(type)) {
1803                                         errorf(&designator->source_position,
1804                                                "'.%Y' designator used for non-compound type '%T'",
1805                                                symbol, orig_type);
1806                                 }
1807
1808                                 top->type             = type_error_type;
1809                                 top->v.compound_entry = NULL;
1810                                 orig_type             = type_error_type;
1811                         } else {
1812                                 compound_t *compound = type->compound.compound;
1813                                 entity_t   *iter     = compound->members.entities;
1814                                 for (; iter != NULL; iter = iter->base.next) {
1815                                         if (iter->base.symbol == symbol) {
1816                                                 break;
1817                                         }
1818                                 }
1819                                 if (iter == NULL) {
1820                                         errorf(&designator->source_position,
1821                                                "'%T' has no member named '%Y'", orig_type, symbol);
1822                                         return false;
1823                                 }
1824                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1825                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1826                                         errorf(&designator->source_position,
1827                                                    "offsetof designator '%Y' must not specify bitfield",
1828                                                    symbol);
1829                                         return false;
1830                                 }
1831
1832                                 top->type             = orig_type;
1833                                 top->v.compound_entry = &iter->declaration;
1834                                 orig_type             = iter->declaration.type;
1835                         }
1836                 } else {
1837                         expression_t *array_index = designator->array_index;
1838                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1839                                 return true;
1840
1841                         if (!is_type_array(type)) {
1842                                 if (is_type_valid(type)) {
1843                                         errorf(&designator->source_position,
1844                                                "[%E] designator used for non-array type '%T'",
1845                                                array_index, orig_type);
1846                                 }
1847                                 return false;
1848                         }
1849
1850                         long index = fold_constant_to_int(array_index);
1851                         if (!used_in_offsetof) {
1852                                 if (index < 0) {
1853                                         errorf(&designator->source_position,
1854                                                "array index [%E] must be positive", array_index);
1855                                 } else if (type->array.size_constant) {
1856                                         long array_size = type->array.size;
1857                                         if (index >= array_size) {
1858                                                 errorf(&designator->source_position,
1859                                                        "designator [%E] (%d) exceeds array size %d",
1860                                                        array_index, index, array_size);
1861                                         }
1862                                 }
1863                         }
1864
1865                         top->type    = orig_type;
1866                         top->v.index = (size_t) index;
1867                         orig_type    = type->array.element_type;
1868                 }
1869                 path->top_type = orig_type;
1870
1871                 if (designator->next != NULL) {
1872                         descend_into_subtype(path);
1873                 }
1874         }
1875         return true;
1876 }
1877
1878 static void advance_current_object(type_path_t *path, size_t top_path_level)
1879 {
1880         type_path_entry_t *top = get_type_path_top(path);
1881
1882         type_t *type = skip_typeref(top->type);
1883         if (is_type_union(type)) {
1884                 /* in unions only the first element is initialized */
1885                 top->v.compound_entry = NULL;
1886         } else if (is_type_struct(type)) {
1887                 declaration_t *entry = top->v.compound_entry;
1888
1889                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1890                 if (next_entity != NULL) {
1891                         assert(is_declaration(next_entity));
1892                         entry = &next_entity->declaration;
1893                 } else {
1894                         entry = NULL;
1895                 }
1896
1897                 top->v.compound_entry = entry;
1898                 if (entry != NULL) {
1899                         path->top_type = entry->type;
1900                         return;
1901                 }
1902         } else if (is_type_array(type)) {
1903                 assert(is_type_array(type));
1904
1905                 top->v.index++;
1906
1907                 if (!type->array.size_constant || top->v.index < type->array.size) {
1908                         return;
1909                 }
1910         } else {
1911                 assert(!is_type_valid(type));
1912                 return;
1913         }
1914
1915         /* we're past the last member of the current sub-aggregate, try if we
1916          * can ascend in the type hierarchy and continue with another subobject */
1917         size_t len = ARR_LEN(path->path);
1918
1919         if (len > top_path_level) {
1920                 ascend_from_subtype(path);
1921                 advance_current_object(path, top_path_level);
1922         } else {
1923                 path->top_type = NULL;
1924         }
1925 }
1926
1927 /**
1928  * skip any {...} blocks until a closing bracket is reached.
1929  */
1930 static void skip_initializers(void)
1931 {
1932         next_if('{');
1933
1934         while (token.kind != '}') {
1935                 if (token.kind == T_EOF)
1936                         return;
1937                 if (token.kind == '{') {
1938                         eat_block();
1939                         continue;
1940                 }
1941                 next_token();
1942         }
1943 }
1944
1945 static initializer_t *create_empty_initializer(void)
1946 {
1947         static initializer_t empty_initializer
1948                 = { .list = { { INITIALIZER_LIST }, 0 } };
1949         return &empty_initializer;
1950 }
1951
1952 /**
1953  * Parse a part of an initialiser for a struct or union,
1954  */
1955 static initializer_t *parse_sub_initializer(type_path_t *path,
1956                 type_t *outer_type, size_t top_path_level,
1957                 parse_initializer_env_t *env)
1958 {
1959         if (token.kind == '}') {
1960                 /* empty initializer */
1961                 return create_empty_initializer();
1962         }
1963
1964         initializer_t *result = NULL;
1965
1966         type_t *orig_type = path->top_type;
1967         type_t *type      = NULL;
1968
1969         if (orig_type == NULL) {
1970                 /* We are initializing an empty compound. */
1971         } else {
1972                 type = skip_typeref(orig_type);
1973         }
1974
1975         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1976
1977         while (true) {
1978                 designator_t *designator = NULL;
1979                 if (token.kind == '.' || token.kind == '[') {
1980                         designator = parse_designation();
1981                         goto finish_designator;
1982                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1983                         /* GNU-style designator ("identifier: value") */
1984                         designator = allocate_ast_zero(sizeof(designator[0]));
1985                         designator->source_position = *HERE;
1986                         designator->symbol          = token.base.symbol;
1987                         eat(T_IDENTIFIER);
1988                         eat(':');
1989
1990 finish_designator:
1991                         /* reset path to toplevel, evaluate designator from there */
1992                         ascend_to(path, top_path_level);
1993                         if (!walk_designator(path, designator, false)) {
1994                                 /* can't continue after designation error */
1995                                 goto end_error;
1996                         }
1997
1998                         initializer_t *designator_initializer
1999                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2000                         designator_initializer->designator.designator = designator;
2001                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2002
2003                         orig_type = path->top_type;
2004                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2005                 }
2006
2007                 initializer_t *sub;
2008
2009                 if (token.kind == '{') {
2010                         if (type != NULL && is_type_scalar(type)) {
2011                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2012                         } else {
2013                                 if (type == NULL) {
2014                                         if (env->entity != NULL) {
2015                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2016                                         } else {
2017                                                 errorf(HERE, "extra brace group at end of initializer");
2018                                         }
2019                                         eat('{');
2020                                 } else {
2021                                         eat('{');
2022                                         descend_into_subtype(path);
2023                                 }
2024
2025                                 add_anchor_token('}');
2026                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2027                                                             env);
2028                                 rem_anchor_token('}');
2029
2030                                 expect('}');
2031
2032                                 if (!type)
2033                                         goto error_parse_next;
2034
2035                                 ascend_from_subtype(path);
2036                         }
2037                 } else {
2038                         /* must be an expression */
2039                         expression_t *expression = parse_assignment_expression();
2040                         mark_vars_read(expression, NULL);
2041
2042                         if (env->must_be_constant && !is_linker_constant(expression)) {
2043                                 errorf(&expression->base.source_position,
2044                                        "Initialisation expression '%E' is not constant",
2045                                        expression);
2046                         }
2047
2048                         if (type == NULL) {
2049                                 /* we are already outside, ... */
2050                                 if (outer_type == NULL)
2051                                         goto error_parse_next;
2052                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2053                                 if (is_type_compound(outer_type_skip) &&
2054                                                 !outer_type_skip->compound.compound->complete) {
2055                                         goto error_parse_next;
2056                                 }
2057
2058                                 source_position_t const* const pos = &expression->base.source_position;
2059                                 if (env->entity != NULL) {
2060                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2061                                 } else {
2062                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2063                                 }
2064                                 goto error_parse_next;
2065                         }
2066
2067                         /* handle { "string" } special case */
2068                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2069                                 result = initializer_from_expression(outer_type, expression);
2070                                 if (result != NULL) {
2071                                         next_if(',');
2072                                         if (token.kind != '}') {
2073                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2074                                         }
2075                                         /* TODO: eat , ... */
2076                                         goto out;
2077                                 }
2078                         }
2079
2080                         /* descend into subtypes until expression matches type */
2081                         while (true) {
2082                                 orig_type = path->top_type;
2083                                 type      = skip_typeref(orig_type);
2084
2085                                 sub = initializer_from_expression(orig_type, expression);
2086                                 if (sub != NULL) {
2087                                         break;
2088                                 }
2089                                 if (!is_type_valid(type)) {
2090                                         goto end_error;
2091                                 }
2092                                 if (is_type_scalar(type)) {
2093                                         errorf(&expression->base.source_position,
2094                                                         "expression '%E' doesn't match expected type '%T'",
2095                                                         expression, orig_type);
2096                                         goto end_error;
2097                                 }
2098
2099                                 descend_into_subtype(path);
2100                         }
2101                 }
2102
2103                 /* update largest index of top array */
2104                 const type_path_entry_t *first      = &path->path[0];
2105                 type_t                  *first_type = first->type;
2106                 first_type                          = skip_typeref(first_type);
2107                 if (is_type_array(first_type)) {
2108                         size_t index = first->v.index;
2109                         if (index > path->max_index)
2110                                 path->max_index = index;
2111                 }
2112
2113                 /* append to initializers list */
2114                 ARR_APP1(initializer_t*, initializers, sub);
2115
2116 error_parse_next:
2117                 if (!next_if(','))
2118                         break;
2119                 if (token.kind == '}') {
2120                         break;
2121                 }
2122
2123                 if (type != NULL) {
2124                         /* advance to the next declaration if we are not at the end */
2125                         advance_current_object(path, top_path_level);
2126                         orig_type = path->top_type;
2127                         if (orig_type != NULL)
2128                                 type = skip_typeref(orig_type);
2129                         else
2130                                 type = NULL;
2131                 }
2132         }
2133
2134         size_t len  = ARR_LEN(initializers);
2135         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2136         result = allocate_ast_zero(size);
2137         result->kind     = INITIALIZER_LIST;
2138         result->list.len = len;
2139         memcpy(&result->list.initializers, initializers,
2140                len * sizeof(initializers[0]));
2141         goto out;
2142
2143 end_error:
2144         skip_initializers();
2145 out:
2146         DEL_ARR_F(initializers);
2147         ascend_to(path, top_path_level+1);
2148         return result;
2149 }
2150
2151 static expression_t *make_size_literal(size_t value)
2152 {
2153         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2154         literal->base.type    = type_size_t;
2155
2156         char buf[128];
2157         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2158         literal->literal.value = make_string(buf);
2159
2160         return literal;
2161 }
2162
2163 /**
2164  * Parses an initializer. Parsers either a compound literal
2165  * (env->declaration == NULL) or an initializer of a declaration.
2166  */
2167 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2168 {
2169         type_t        *type      = skip_typeref(env->type);
2170         size_t         max_index = 0;
2171         initializer_t *result;
2172
2173         if (is_type_scalar(type)) {
2174                 result = parse_scalar_initializer(type, env->must_be_constant);
2175         } else if (token.kind == '{') {
2176                 eat('{');
2177
2178                 type_path_t path;
2179                 memset(&path, 0, sizeof(path));
2180                 path.top_type = env->type;
2181                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2182
2183                 descend_into_subtype(&path);
2184
2185                 add_anchor_token('}');
2186                 result = parse_sub_initializer(&path, env->type, 1, env);
2187                 rem_anchor_token('}');
2188
2189                 max_index = path.max_index;
2190                 DEL_ARR_F(path.path);
2191
2192                 expect('}');
2193         } else {
2194                 /* parse_scalar_initializer() also works in this case: we simply
2195                  * have an expression without {} around it */
2196                 result = parse_scalar_initializer(type, env->must_be_constant);
2197         }
2198
2199         /* §6.7.8:22 array initializers for arrays with unknown size determine
2200          * the array type size */
2201         if (is_type_array(type) && type->array.size_expression == NULL
2202                         && result != NULL) {
2203                 size_t size;
2204                 switch (result->kind) {
2205                 case INITIALIZER_LIST:
2206                         assert(max_index != 0xdeadbeaf);
2207                         size = max_index + 1;
2208                         break;
2209
2210                 case INITIALIZER_STRING: {
2211                         size = get_string_len(&get_init_string(result)->value) + 1;
2212                         break;
2213                 }
2214
2215                 case INITIALIZER_DESIGNATOR:
2216                 case INITIALIZER_VALUE:
2217                         /* can happen for parse errors */
2218                         size = 0;
2219                         break;
2220
2221                 default:
2222                         internal_errorf(HERE, "invalid initializer type");
2223                 }
2224
2225                 type_t *new_type = duplicate_type(type);
2226
2227                 new_type->array.size_expression   = make_size_literal(size);
2228                 new_type->array.size_constant     = true;
2229                 new_type->array.has_implicit_size = true;
2230                 new_type->array.size              = size;
2231                 env->type = new_type;
2232         }
2233
2234         return result;
2235 }
2236
2237 static void append_entity(scope_t *scope, entity_t *entity)
2238 {
2239         if (scope->last_entity != NULL) {
2240                 scope->last_entity->base.next = entity;
2241         } else {
2242                 scope->entities = entity;
2243         }
2244         entity->base.parent_entity = current_entity;
2245         scope->last_entity         = entity;
2246 }
2247
2248
2249 static compound_t *parse_compound_type_specifier(bool is_struct)
2250 {
2251         source_position_t const pos = *HERE;
2252         eat(is_struct ? T_struct : T_union);
2253
2254         symbol_t    *symbol     = NULL;
2255         entity_t    *entity     = NULL;
2256         attribute_t *attributes = NULL;
2257
2258         if (token.kind == T___attribute__) {
2259                 attributes = parse_attributes(NULL);
2260         }
2261
2262         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2263         if (token.kind == T_IDENTIFIER) {
2264                 /* the compound has a name, check if we have seen it already */
2265                 symbol = token.base.symbol;
2266                 entity = get_tag(symbol, kind);
2267                 eat(T_IDENTIFIER);
2268
2269                 if (entity != NULL) {
2270                         if (entity->base.parent_scope != current_scope &&
2271                             (token.kind == '{' || token.kind == ';')) {
2272                                 /* we're in an inner scope and have a definition. Shadow
2273                                  * existing definition in outer scope */
2274                                 entity = NULL;
2275                         } else if (entity->compound.complete && token.kind == '{') {
2276                                 source_position_t const *const ppos = &entity->base.source_position;
2277                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2278                                 /* clear members in the hope to avoid further errors */
2279                                 entity->compound.members.entities = NULL;
2280                         }
2281                 }
2282         } else if (token.kind != '{') {
2283                 char const *const msg =
2284                         is_struct ? "while parsing struct type specifier" :
2285                                     "while parsing union type specifier";
2286                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2287
2288                 return NULL;
2289         }
2290
2291         if (entity == NULL) {
2292                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2293                 entity->compound.alignment = 1;
2294                 entity->base.parent_scope  = current_scope;
2295                 if (symbol != NULL) {
2296                         environment_push(entity);
2297                 }
2298                 append_entity(current_scope, entity);
2299         }
2300
2301         if (token.kind == '{') {
2302                 parse_compound_type_entries(&entity->compound);
2303
2304                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2305                 if (symbol == NULL) {
2306                         assert(anonymous_entity == NULL);
2307                         anonymous_entity = entity;
2308                 }
2309         }
2310
2311         if (attributes != NULL) {
2312                 entity->compound.attributes = attributes;
2313                 handle_entity_attributes(attributes, entity);
2314         }
2315
2316         return &entity->compound;
2317 }
2318
2319 static void parse_enum_entries(type_t *const enum_type)
2320 {
2321         eat('{');
2322
2323         if (token.kind == '}') {
2324                 errorf(HERE, "empty enum not allowed");
2325                 eat('}');
2326                 return;
2327         }
2328
2329         add_anchor_token('}');
2330         add_anchor_token(',');
2331         do {
2332                 add_anchor_token('=');
2333                 source_position_t pos;
2334                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2335                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2336                 entity->enum_value.enum_type = enum_type;
2337                 rem_anchor_token('=');
2338
2339                 if (next_if('=')) {
2340                         expression_t *value = parse_constant_expression();
2341
2342                         value = create_implicit_cast(value, enum_type);
2343                         entity->enum_value.value = value;
2344
2345                         /* TODO semantic */
2346                 }
2347
2348                 record_entity(entity, false);
2349         } while (next_if(',') && token.kind != '}');
2350         rem_anchor_token(',');
2351         rem_anchor_token('}');
2352
2353         expect('}');
2354 }
2355
2356 static type_t *parse_enum_specifier(void)
2357 {
2358         source_position_t const pos = *HERE;
2359         entity_t               *entity;
2360         symbol_t               *symbol;
2361
2362         eat(T_enum);
2363         switch (token.kind) {
2364                 case T_IDENTIFIER:
2365                         symbol = token.base.symbol;
2366                         entity = get_tag(symbol, ENTITY_ENUM);
2367                         eat(T_IDENTIFIER);
2368
2369                         if (entity != NULL) {
2370                                 if (entity->base.parent_scope != current_scope &&
2371                                                 (token.kind == '{' || token.kind == ';')) {
2372                                         /* we're in an inner scope and have a definition. Shadow
2373                                          * existing definition in outer scope */
2374                                         entity = NULL;
2375                                 } else if (entity->enume.complete && token.kind == '{') {
2376                                         source_position_t const *const ppos = &entity->base.source_position;
2377                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2378                                 }
2379                         }
2380                         break;
2381
2382                 case '{':
2383                         entity = NULL;
2384                         symbol = NULL;
2385                         break;
2386
2387                 default:
2388                         parse_error_expected("while parsing enum type specifier",
2389                                         T_IDENTIFIER, '{', NULL);
2390                         return NULL;
2391         }
2392
2393         if (entity == NULL) {
2394                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2395                 entity->base.parent_scope = current_scope;
2396         }
2397
2398         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2399         type->enumt.enume      = &entity->enume;
2400         type->enumt.base.akind = ATOMIC_TYPE_INT;
2401
2402         if (token.kind == '{') {
2403                 if (symbol != NULL) {
2404                         environment_push(entity);
2405                 }
2406                 append_entity(current_scope, entity);
2407                 entity->enume.complete = true;
2408
2409                 parse_enum_entries(type);
2410                 parse_attributes(NULL);
2411
2412                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2413                 if (symbol == NULL) {
2414                         assert(anonymous_entity == NULL);
2415                         anonymous_entity = entity;
2416                 }
2417         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2418                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2419         }
2420
2421         return type;
2422 }
2423
2424 /**
2425  * if a symbol is a typedef to another type, return true
2426  */
2427 static bool is_typedef_symbol(symbol_t *symbol)
2428 {
2429         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2430         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2431 }
2432
2433 static type_t *parse_typeof(void)
2434 {
2435         eat(T___typeof__);
2436
2437         type_t *type;
2438
2439         add_anchor_token(')');
2440         expect('(');
2441
2442         expression_t *expression  = NULL;
2443
2444         switch (token.kind) {
2445         case T_IDENTIFIER:
2446                 if (is_typedef_symbol(token.base.symbol)) {
2447         DECLARATION_START
2448                         type = parse_typename();
2449                 } else {
2450         default:
2451                         expression = parse_expression();
2452                         type       = revert_automatic_type_conversion(expression);
2453                 }
2454                 break;
2455         }
2456
2457         rem_anchor_token(')');
2458         expect(')');
2459
2460         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2461         typeof_type->typeoft.expression  = expression;
2462         typeof_type->typeoft.typeof_type = type;
2463
2464         return typeof_type;
2465 }
2466
2467 typedef enum specifiers_t {
2468         SPECIFIER_NONE      = 0,
2469         SPECIFIER_SIGNED    = 1 << 0,
2470         SPECIFIER_UNSIGNED  = 1 << 1,
2471         SPECIFIER_LONG      = 1 << 2,
2472         SPECIFIER_INT       = 1 << 3,
2473         SPECIFIER_DOUBLE    = 1 << 4,
2474         SPECIFIER_CHAR      = 1 << 5,
2475         SPECIFIER_WCHAR_T   = 1 << 6,
2476         SPECIFIER_SHORT     = 1 << 7,
2477         SPECIFIER_LONG_LONG = 1 << 8,
2478         SPECIFIER_FLOAT     = 1 << 9,
2479         SPECIFIER_BOOL      = 1 << 10,
2480         SPECIFIER_VOID      = 1 << 11,
2481         SPECIFIER_INT8      = 1 << 12,
2482         SPECIFIER_INT16     = 1 << 13,
2483         SPECIFIER_INT32     = 1 << 14,
2484         SPECIFIER_INT64     = 1 << 15,
2485         SPECIFIER_INT128    = 1 << 16,
2486         SPECIFIER_COMPLEX   = 1 << 17,
2487         SPECIFIER_IMAGINARY = 1 << 18,
2488 } specifiers_t;
2489
2490 static type_t *get_typedef_type(symbol_t *symbol)
2491 {
2492         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2493         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2494                 return NULL;
2495
2496         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2497         type->typedeft.typedefe = &entity->typedefe;
2498
2499         return type;
2500 }
2501
2502 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2503 {
2504         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2505
2506         add_anchor_token(')');
2507         add_anchor_token(',');
2508         expect('(');
2509
2510         do {
2511                 add_anchor_token('=');
2512                 source_position_t pos;
2513                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2514                 rem_anchor_token('=');
2515
2516                 symbol_t **prop = NULL;
2517                 if (prop_sym) {
2518                         if (streq(prop_sym->string, "put")) {
2519                                 prop = &property->put_symbol;
2520                         } else if (streq(prop_sym->string, "get")) {
2521                                 prop = &property->get_symbol;
2522                         } else {
2523                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2524                         }
2525                 }
2526
2527                 add_anchor_token(T_IDENTIFIER);
2528                 expect('=');
2529                 rem_anchor_token(T_IDENTIFIER);
2530
2531                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2532                 if (prop != NULL)
2533                         *prop = sym ? sym : sym_anonymous;
2534         } while (next_if(','));
2535         rem_anchor_token(',');
2536         rem_anchor_token(')');
2537
2538         attribute->a.property = property;
2539
2540         expect(')');
2541         return attribute;
2542 }
2543
2544 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2545 {
2546         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2547         if (next_if(T_restrict)) {
2548                 kind = ATTRIBUTE_MS_RESTRICT;
2549         } else if (token.kind == T_IDENTIFIER) {
2550                 char const *const name = token.base.symbol->string;
2551                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2552                      ++k) {
2553                         const char *attribute_name = get_attribute_name(k);
2554                         if (attribute_name != NULL && streq(attribute_name, name)) {
2555                                 kind = k;
2556                                 break;
2557                         }
2558                 }
2559
2560                 if (kind == ATTRIBUTE_UNKNOWN) {
2561                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2562                 }
2563         } else {
2564                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2565                 return NULL;
2566         }
2567
2568         attribute_t *attribute = allocate_attribute_zero(kind);
2569         eat(T_IDENTIFIER);
2570
2571         if (kind == ATTRIBUTE_MS_PROPERTY) {
2572                 return parse_attribute_ms_property(attribute);
2573         }
2574
2575         /* parse arguments */
2576         if (next_if('('))
2577                 attribute->a.arguments = parse_attribute_arguments();
2578
2579         return attribute;
2580 }
2581
2582 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2583 {
2584         eat(T__declspec);
2585
2586         add_anchor_token(')');
2587         expect('(');
2588         if (token.kind != ')') {
2589                 attribute_t **anchor = &first;
2590                 do {
2591                         while (*anchor != NULL)
2592                                 anchor = &(*anchor)->next;
2593
2594                         attribute_t *attribute
2595                                 = parse_microsoft_extended_decl_modifier_single();
2596                         if (attribute == NULL)
2597                                 break;
2598
2599                         *anchor = attribute;
2600                         anchor  = &attribute->next;
2601                 } while (next_if(','));
2602         }
2603         rem_anchor_token(')');
2604         expect(')');
2605         return first;
2606 }
2607
2608 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2609 {
2610         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2611         if (is_declaration(entity)) {
2612                 entity->declaration.type     = type_error_type;
2613                 entity->declaration.implicit = true;
2614         } else if (kind == ENTITY_TYPEDEF) {
2615                 entity->typedefe.type    = type_error_type;
2616                 entity->typedefe.builtin = true;
2617         }
2618         if (kind != ENTITY_COMPOUND_MEMBER)
2619                 record_entity(entity, false);
2620         return entity;
2621 }
2622
2623 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2624 {
2625         type_t            *type            = NULL;
2626         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2627         unsigned           type_specifiers = 0;
2628         bool               newtype         = false;
2629         bool               saw_error       = false;
2630
2631         memset(specifiers, 0, sizeof(*specifiers));
2632         specifiers->source_position = *HERE;
2633
2634         while (true) {
2635                 specifiers->attributes = parse_attributes(specifiers->attributes);
2636
2637                 switch (token.kind) {
2638                 /* storage class */
2639 #define MATCH_STORAGE_CLASS(token, class)                                  \
2640                 case token:                                                        \
2641                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2642                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2643                         }                                                              \
2644                         specifiers->storage_class = class;                             \
2645                         if (specifiers->thread_local)                                  \
2646                                 goto check_thread_storage_class;                           \
2647                         eat(token); \
2648                         break;
2649
2650                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2651                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2652                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2653                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2654                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2655
2656                 case T__declspec:
2657                         specifiers->attributes
2658                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2659                         break;
2660
2661                 case T__Thread_local:
2662                         if (specifiers->thread_local) {
2663                                 errorf(HERE, "duplicate %K", &token);
2664                         } else {
2665                                 specifiers->thread_local = true;
2666 check_thread_storage_class:
2667                                 switch (specifiers->storage_class) {
2668                                         case STORAGE_CLASS_EXTERN:
2669                                         case STORAGE_CLASS_NONE:
2670                                         case STORAGE_CLASS_STATIC:
2671                                                 break;
2672
2673                                                 char const* wrong;
2674                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2675                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2676                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2677 wrong_thread_storage_class:
2678                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2679                                                 break;
2680                                 }
2681                         }
2682                         next_token();
2683                         break;
2684
2685                 /* type qualifiers */
2686 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2687                 case token:                                                     \
2688                         qualifiers |= qualifier;                                    \
2689                         eat(token); \
2690                         break
2691
2692                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2693                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2694                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2695                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2696                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2697                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2698                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2699                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2700
2701                 /* type specifiers */
2702 #define MATCH_SPECIFIER(token, specifier, name)                         \
2703                 case token:                                                     \
2704                         if (type_specifiers & specifier) {                           \
2705                                 errorf(HERE, "multiple " name " type specifiers given"); \
2706                         } else {                                                    \
2707                                 type_specifiers |= specifier;                           \
2708                         }                                                           \
2709                         eat(token); \
2710                         break
2711
2712                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2713                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2714                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2715                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2716                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2717                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2718                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2719                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2720                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2721                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2722                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2723                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2724                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2725                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2726                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2727                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2728                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2729                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2730
2731                 case T_inline:
2732                         eat(T_inline);
2733                         specifiers->is_inline = true;
2734                         break;
2735
2736 #if 0
2737                 case T__forceinline:
2738                         eat(T__forceinline);
2739                         specifiers->modifiers |= DM_FORCEINLINE;
2740                         break;
2741 #endif
2742
2743                 case T_long:
2744                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2745                                 errorf(HERE, "too many long type specifiers given");
2746                         } else if (type_specifiers & SPECIFIER_LONG) {
2747                                 type_specifiers |= SPECIFIER_LONG_LONG;
2748                         } else {
2749                                 type_specifiers |= SPECIFIER_LONG;
2750                         }
2751                         eat(T_long);
2752                         break;
2753
2754 #define CHECK_DOUBLE_TYPE() \
2755         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2756
2757                 case T_struct:
2758                         CHECK_DOUBLE_TYPE();
2759                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2760
2761                         type->compound.compound = parse_compound_type_specifier(true);
2762                         break;
2763                 case T_union:
2764                         CHECK_DOUBLE_TYPE();
2765                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2766                         type->compound.compound = parse_compound_type_specifier(false);
2767                         break;
2768                 case T_enum:
2769                         CHECK_DOUBLE_TYPE();
2770                         type = parse_enum_specifier();
2771                         break;
2772                 case T___typeof__:
2773                         CHECK_DOUBLE_TYPE();
2774                         type = parse_typeof();
2775                         break;
2776                 case T___builtin_va_list:
2777                         CHECK_DOUBLE_TYPE();
2778                         type = duplicate_type(type_valist);
2779                         eat(T___builtin_va_list);
2780                         break;
2781
2782                 case T_IDENTIFIER: {
2783                         /* only parse identifier if we haven't found a type yet */
2784                         if (type != NULL || type_specifiers != 0) {
2785                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2786                                  * declaration, so it doesn't generate errors about expecting '(' or
2787                                  * '{' later on. */
2788                                 switch (look_ahead(1)->kind) {
2789                                         STORAGE_CLASSES
2790                                         TYPE_SPECIFIERS
2791                                         case T_const:
2792                                         case T_restrict:
2793                                         case T_volatile:
2794                                         case T_inline:
2795                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2796                                         case T_IDENTIFIER:
2797                                         case '&':
2798                                         case '*':
2799                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2800                                                 eat(T_IDENTIFIER);
2801                                                 continue;
2802
2803                                         default:
2804                                                 goto finish_specifiers;
2805                                 }
2806                         }
2807
2808                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2809                         if (typedef_type == NULL) {
2810                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2811                                  * declaration, so it doesn't generate 'implicit int' followed by more
2812                                  * errors later on. */
2813                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2814                                 switch (la1_type) {
2815                                         DECLARATION_START
2816                                         case T_IDENTIFIER:
2817                                         case '&':
2818                                         case '*': {
2819                                                 errorf(HERE, "%K does not name a type", &token);
2820
2821                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2822
2823                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2824                                                 type->typedeft.typedefe = &entity->typedefe;
2825
2826                                                 eat(T_IDENTIFIER);
2827                                                 saw_error = true;
2828                                                 continue;
2829                                         }
2830
2831                                         default:
2832                                                 goto finish_specifiers;
2833                                 }
2834                         }
2835
2836                         eat(T_IDENTIFIER);
2837                         type = typedef_type;
2838                         break;
2839                 }
2840
2841                 /* function specifier */
2842                 default:
2843                         goto finish_specifiers;
2844                 }
2845         }
2846
2847 finish_specifiers:
2848         specifiers->attributes = parse_attributes(specifiers->attributes);
2849
2850         if (type == NULL || (saw_error && type_specifiers != 0)) {
2851                 atomic_type_kind_t atomic_type;
2852
2853                 /* match valid basic types */
2854                 switch (type_specifiers) {
2855                 case SPECIFIER_VOID:
2856                         atomic_type = ATOMIC_TYPE_VOID;
2857                         break;
2858                 case SPECIFIER_WCHAR_T:
2859                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2860                         break;
2861                 case SPECIFIER_CHAR:
2862                         atomic_type = ATOMIC_TYPE_CHAR;
2863                         break;
2864                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2865                         atomic_type = ATOMIC_TYPE_SCHAR;
2866                         break;
2867                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2868                         atomic_type = ATOMIC_TYPE_UCHAR;
2869                         break;
2870                 case SPECIFIER_SHORT:
2871                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2872                 case SPECIFIER_SHORT | SPECIFIER_INT:
2873                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2874                         atomic_type = ATOMIC_TYPE_SHORT;
2875                         break;
2876                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2877                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2878                         atomic_type = ATOMIC_TYPE_USHORT;
2879                         break;
2880                 case SPECIFIER_INT:
2881                 case SPECIFIER_SIGNED:
2882                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2883                         atomic_type = ATOMIC_TYPE_INT;
2884                         break;
2885                 case SPECIFIER_UNSIGNED:
2886                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2887                         atomic_type = ATOMIC_TYPE_UINT;
2888                         break;
2889                 case SPECIFIER_LONG:
2890                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2891                 case SPECIFIER_LONG | SPECIFIER_INT:
2892                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2893                         atomic_type = ATOMIC_TYPE_LONG;
2894                         break;
2895                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2896                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2897                         atomic_type = ATOMIC_TYPE_ULONG;
2898                         break;
2899
2900                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2901                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2902                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2904                         | SPECIFIER_INT:
2905                         atomic_type = ATOMIC_TYPE_LONGLONG;
2906                         goto warn_about_long_long;
2907
2908                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2909                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2910                         | SPECIFIER_INT:
2911                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2912 warn_about_long_long:
2913                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2914                         break;
2915
2916                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2917                         atomic_type = unsigned_int8_type_kind;
2918                         break;
2919
2920                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2921                         atomic_type = unsigned_int16_type_kind;
2922                         break;
2923
2924                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2925                         atomic_type = unsigned_int32_type_kind;
2926                         break;
2927
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2929                         atomic_type = unsigned_int64_type_kind;
2930                         break;
2931
2932                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2933                         atomic_type = unsigned_int128_type_kind;
2934                         break;
2935
2936                 case SPECIFIER_INT8:
2937                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2938                         atomic_type = int8_type_kind;
2939                         break;
2940
2941                 case SPECIFIER_INT16:
2942                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2943                         atomic_type = int16_type_kind;
2944                         break;
2945
2946                 case SPECIFIER_INT32:
2947                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2948                         atomic_type = int32_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_INT64:
2952                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2953                         atomic_type = int64_type_kind;
2954                         break;
2955
2956                 case SPECIFIER_INT128:
2957                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2958                         atomic_type = int128_type_kind;
2959                         break;
2960
2961                 case SPECIFIER_FLOAT:
2962                         atomic_type = ATOMIC_TYPE_FLOAT;
2963                         break;
2964                 case SPECIFIER_DOUBLE:
2965                         atomic_type = ATOMIC_TYPE_DOUBLE;
2966                         break;
2967                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2968                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2969                         break;
2970                 case SPECIFIER_BOOL:
2971                         atomic_type = ATOMIC_TYPE_BOOL;
2972                         break;
2973                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2974                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2975                         atomic_type = ATOMIC_TYPE_FLOAT;
2976                         break;
2977                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2978                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2979                         atomic_type = ATOMIC_TYPE_DOUBLE;
2980                         break;
2981                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2982                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2983                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2984                         break;
2985                 default: {
2986                         /* invalid specifier combination, give an error message */
2987                         source_position_t const* const pos = &specifiers->source_position;
2988                         if (type_specifiers == 0) {
2989                                 if (!saw_error) {
2990                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2991                                         if (!(c_mode & _CXX) && !strict_mode) {
2992                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2993                                                 atomic_type = ATOMIC_TYPE_INT;
2994                                                 break;
2995                                         } else {
2996                                                 errorf(pos, "no type specifiers given in declaration");
2997                                         }
2998                                 }
2999                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3000                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3001                                 errorf(pos, "signed and unsigned specifiers given");
3002                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3003                                 errorf(pos, "only integer types can be signed or unsigned");
3004                         } else {
3005                                 errorf(pos, "multiple datatypes in declaration");
3006                         }
3007                         specifiers->type = type_error_type;
3008                         return;
3009                 }
3010                 }
3011
3012                 if (type_specifiers & SPECIFIER_COMPLEX) {
3013                         type = allocate_type_zero(TYPE_COMPLEX);
3014                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3015                         type = allocate_type_zero(TYPE_IMAGINARY);
3016                 } else {
3017                         type = allocate_type_zero(TYPE_ATOMIC);
3018                 }
3019                 type->atomic.akind = atomic_type;
3020                 newtype = true;
3021         } else if (type_specifiers != 0) {
3022                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3023         }
3024
3025         /* FIXME: check type qualifiers here */
3026         type->base.qualifiers = qualifiers;
3027
3028         if (newtype) {
3029                 type = identify_new_type(type);
3030         } else {
3031                 type = typehash_insert(type);
3032         }
3033
3034         if (specifiers->attributes != NULL)
3035                 type = handle_type_attributes(specifiers->attributes, type);
3036         specifiers->type = type;
3037 }
3038
3039 static type_qualifiers_t parse_type_qualifiers(void)
3040 {
3041         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3042
3043         while (true) {
3044                 switch (token.kind) {
3045                 /* type qualifiers */
3046                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3047                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3048                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3049                 /* microsoft extended type modifiers */
3050                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3051                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3052                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3053                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3054                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3055
3056                 default:
3057                         return qualifiers;
3058                 }
3059         }
3060 }
3061
3062 /**
3063  * Parses an K&R identifier list
3064  */
3065 static void parse_identifier_list(scope_t *scope)
3066 {
3067         assert(token.kind == T_IDENTIFIER);
3068         do {
3069                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3070                 /* a K&R parameter has no type, yet */
3071                 eat(T_IDENTIFIER);
3072
3073                 if (scope != NULL)
3074                         append_entity(scope, entity);
3075         } while (next_if(',') && token.kind == T_IDENTIFIER);
3076 }
3077
3078 static entity_t *parse_parameter(void)
3079 {
3080         declaration_specifiers_t specifiers;
3081         parse_declaration_specifiers(&specifiers);
3082
3083         entity_t *entity = parse_declarator(&specifiers,
3084                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3085         anonymous_entity = NULL;
3086         return entity;
3087 }
3088
3089 static void semantic_parameter_incomplete(const entity_t *entity)
3090 {
3091         assert(entity->kind == ENTITY_PARAMETER);
3092
3093         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3094          *             list in a function declarator that is part of a
3095          *             definition of that function shall not have
3096          *             incomplete type. */
3097         type_t *type = skip_typeref(entity->declaration.type);
3098         if (is_type_incomplete(type)) {
3099                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3100         }
3101 }
3102
3103 static bool has_parameters(void)
3104 {
3105         /* func(void) is not a parameter */
3106         if (look_ahead(1)->kind != ')')
3107                 return true;
3108         if (token.kind == T_IDENTIFIER) {
3109                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3110                 if (entity == NULL)
3111                         return true;
3112                 if (entity->kind != ENTITY_TYPEDEF)
3113                         return true;
3114                 type_t const *const type = skip_typeref(entity->typedefe.type);
3115                 if (!is_type_void(type))
3116                         return true;
3117                 if (c_mode & _CXX) {
3118                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3119                          * is not allowed. */
3120                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3121                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3122                         /* §6.7.5.3:10  Qualification is not allowed here. */
3123                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3124                 }
3125         } else if (token.kind != T_void) {
3126                 return true;
3127         }
3128         next_token();
3129         return false;
3130 }
3131
3132 /**
3133  * Parses function type parameters (and optionally creates variable_t entities
3134  * for them in a scope)
3135  */
3136 static void parse_parameters(function_type_t *type, scope_t *scope)
3137 {
3138         add_anchor_token(')');
3139         eat('(');
3140
3141         if (token.kind == T_IDENTIFIER            &&
3142             !is_typedef_symbol(token.base.symbol) &&
3143             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3144                 type->kr_style_parameters = true;
3145                 parse_identifier_list(scope);
3146         } else if (token.kind == ')') {
3147                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3148                 if (!(c_mode & _CXX))
3149                         type->unspecified_parameters = true;
3150         } else if (has_parameters()) {
3151                 function_parameter_t **anchor = &type->parameters;
3152                 add_anchor_token(',');
3153                 do {
3154                         switch (token.kind) {
3155                         case T_DOTDOTDOT:
3156                                 eat(T_DOTDOTDOT);
3157                                 type->variadic = true;
3158                                 goto parameters_finished;
3159
3160                         case T_IDENTIFIER:
3161                         DECLARATION_START
3162                         {
3163                                 entity_t *entity = parse_parameter();
3164                                 if (entity->kind == ENTITY_TYPEDEF) {
3165                                         errorf(&entity->base.source_position,
3166                                                         "typedef not allowed as function parameter");
3167                                         break;
3168                                 }
3169                                 assert(is_declaration(entity));
3170
3171                                 semantic_parameter_incomplete(entity);
3172
3173                                 function_parameter_t *const parameter =
3174                                         allocate_parameter(entity->declaration.type);
3175
3176                                 if (scope != NULL) {
3177                                         append_entity(scope, entity);
3178                                 }
3179
3180                                 *anchor = parameter;
3181                                 anchor  = &parameter->next;
3182                                 break;
3183                         }
3184
3185                         default:
3186                                 goto parameters_finished;
3187                         }
3188                 } while (next_if(','));
3189 parameters_finished:
3190                 rem_anchor_token(',');
3191         }
3192
3193         rem_anchor_token(')');
3194         expect(')');
3195 }
3196
3197 typedef enum construct_type_kind_t {
3198         CONSTRUCT_POINTER = 1,
3199         CONSTRUCT_REFERENCE,
3200         CONSTRUCT_FUNCTION,
3201         CONSTRUCT_ARRAY
3202 } construct_type_kind_t;
3203
3204 typedef union construct_type_t construct_type_t;
3205
3206 typedef struct construct_type_base_t {
3207         construct_type_kind_t  kind;
3208         source_position_t      pos;
3209         construct_type_t      *next;
3210 } construct_type_base_t;
3211
3212 typedef struct parsed_pointer_t {
3213         construct_type_base_t  base;
3214         type_qualifiers_t      type_qualifiers;
3215         variable_t            *base_variable;  /**< MS __based extension. */
3216 } parsed_pointer_t;
3217
3218 typedef struct parsed_reference_t {
3219         construct_type_base_t base;
3220 } parsed_reference_t;
3221
3222 typedef struct construct_function_type_t {
3223         construct_type_base_t  base;
3224         type_t                *function_type;
3225 } construct_function_type_t;
3226
3227 typedef struct parsed_array_t {
3228         construct_type_base_t  base;
3229         type_qualifiers_t      type_qualifiers;
3230         bool                   is_static;
3231         bool                   is_variable;
3232         expression_t          *size;
3233 } parsed_array_t;
3234
3235 union construct_type_t {
3236         construct_type_kind_t     kind;
3237         construct_type_base_t     base;
3238         parsed_pointer_t          pointer;
3239         parsed_reference_t        reference;
3240         construct_function_type_t function;
3241         parsed_array_t            array;
3242 };
3243
3244 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3245 {
3246         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3247         memset(cons, 0, size);
3248         cons->kind     = kind;
3249         cons->base.pos = *HERE;
3250         return cons;
3251 }
3252
3253 /* §6.7.5.1 */
3254 static construct_type_t *parse_pointer_declarator(void)
3255 {
3256         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3257         eat('*');
3258         cons->pointer.type_qualifiers = parse_type_qualifiers();
3259         //cons->pointer.base_variable   = base_variable;
3260
3261         return cons;
3262 }
3263
3264 /* ISO/IEC 14882:1998(E) §8.3.2 */
3265 static construct_type_t *parse_reference_declarator(void)
3266 {
3267         if (!(c_mode & _CXX))
3268                 errorf(HERE, "references are only available for C++");
3269
3270         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3271         eat('&');
3272
3273         return cons;
3274 }
3275
3276 /* §6.7.5.2 */
3277 static construct_type_t *parse_array_declarator(void)
3278 {
3279         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3280         parsed_array_t   *const array = &cons->array;
3281
3282         eat('[');
3283         add_anchor_token(']');
3284
3285         bool is_static = next_if(T_static);
3286
3287         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3288
3289         if (!is_static)
3290                 is_static = next_if(T_static);
3291
3292         array->type_qualifiers = type_qualifiers;
3293         array->is_static       = is_static;
3294
3295         expression_t *size = NULL;
3296         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3297                 array->is_variable = true;
3298                 eat('*');
3299         } else if (token.kind != ']') {
3300                 size = parse_assignment_expression();
3301
3302                 /* §6.7.5.2:1  Array size must have integer type */
3303                 type_t *const orig_type = size->base.type;
3304                 type_t *const type      = skip_typeref(orig_type);
3305                 if (!is_type_integer(type) && is_type_valid(type)) {
3306                         errorf(&size->base.source_position,
3307                                "array size '%E' must have integer type but has type '%T'",
3308                                size, orig_type);
3309                 }
3310
3311                 array->size = size;
3312                 mark_vars_read(size, NULL);
3313         }
3314
3315         if (is_static && size == NULL)
3316                 errorf(&array->base.pos, "static array parameters require a size");
3317
3318         rem_anchor_token(']');
3319         expect(']');
3320         return cons;
3321 }
3322
3323 /* §6.7.5.3 */
3324 static construct_type_t *parse_function_declarator(scope_t *scope)
3325 {
3326         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3327
3328         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3329         function_type_t *ftype = &type->function;
3330
3331         ftype->linkage            = current_linkage;
3332         ftype->calling_convention = CC_DEFAULT;
3333
3334         parse_parameters(ftype, scope);
3335
3336         cons->function.function_type = type;
3337
3338         return cons;
3339 }
3340
3341 typedef struct parse_declarator_env_t {
3342         bool               may_be_abstract : 1;
3343         bool               must_be_abstract : 1;
3344         decl_modifiers_t   modifiers;
3345         symbol_t          *symbol;
3346         source_position_t  source_position;
3347         scope_t            parameters;
3348         attribute_t       *attributes;
3349 } parse_declarator_env_t;
3350
3351 /* §6.7.5 */
3352 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3353 {
3354         /* construct a single linked list of construct_type_t's which describe
3355          * how to construct the final declarator type */
3356         construct_type_t  *first      = NULL;
3357         construct_type_t **anchor     = &first;
3358
3359         env->attributes = parse_attributes(env->attributes);
3360
3361         for (;;) {
3362                 construct_type_t *type;
3363                 //variable_t       *based = NULL; /* MS __based extension */
3364                 switch (token.kind) {
3365                         case '&':
3366                                 type = parse_reference_declarator();
3367                                 break;
3368
3369                         case T__based: {
3370                                 panic("based not supported anymore");
3371                                 /* FALLTHROUGH */
3372                         }
3373
3374                         case '*':
3375                                 type = parse_pointer_declarator();
3376                                 break;
3377
3378                         default:
3379                                 goto ptr_operator_end;
3380                 }
3381
3382                 *anchor = type;
3383                 anchor  = &type->base.next;
3384
3385                 /* TODO: find out if this is correct */
3386                 env->attributes = parse_attributes(env->attributes);
3387         }
3388
3389 ptr_operator_end: ;
3390         construct_type_t *inner_types = NULL;
3391
3392         switch (token.kind) {
3393         case T_IDENTIFIER:
3394                 if (env->must_be_abstract) {
3395                         errorf(HERE, "no identifier expected in typename");
3396                 } else {
3397                         env->symbol          = token.base.symbol;
3398                         env->source_position = *HERE;
3399                 }
3400                 eat(T_IDENTIFIER);
3401                 break;
3402
3403         case '(': {
3404                 /* Parenthesized declarator or function declarator? */
3405                 token_t const *const la1 = look_ahead(1);
3406                 switch (la1->kind) {
3407                         case T_IDENTIFIER:
3408                                 if (is_typedef_symbol(la1->base.symbol)) {
3409                         case ')':
3410                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3411                                          * interpreted as ``function with no parameter specification'', rather
3412                                          * than redundant parentheses around the omitted identifier. */
3413                         default:
3414                                         /* Function declarator. */
3415                                         if (!env->may_be_abstract) {
3416                                                 errorf(HERE, "function declarator must have a name");
3417                                         }
3418                                 } else {
3419                         case '&':
3420                         case '(':
3421                         case '*':
3422                         case '[':
3423                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3424                                         /* Paranthesized declarator. */
3425                                         eat('(');
3426                                         add_anchor_token(')');
3427                                         inner_types = parse_inner_declarator(env);
3428                                         if (inner_types != NULL) {
3429                                                 /* All later declarators only modify the return type */
3430                                                 env->must_be_abstract = true;
3431                                         }
3432                                         rem_anchor_token(')');
3433                                         expect(')');
3434                                 }
3435                                 break;
3436                 }
3437                 break;
3438         }
3439
3440         default:
3441                 if (env->may_be_abstract)
3442                         break;
3443                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3444                 eat_until_anchor();
3445                 return NULL;
3446         }
3447
3448         construct_type_t **const p = anchor;
3449
3450         for (;;) {
3451                 construct_type_t *type;
3452                 switch (token.kind) {
3453                 case '(': {
3454                         scope_t *scope = NULL;
3455                         if (!env->must_be_abstract) {
3456                                 scope = &env->parameters;
3457                         }
3458
3459                         type = parse_function_declarator(scope);
3460                         break;
3461                 }
3462                 case '[':
3463                         type = parse_array_declarator();
3464                         break;
3465                 default:
3466                         goto declarator_finished;
3467                 }
3468
3469                 /* insert in the middle of the list (at p) */
3470                 type->base.next = *p;
3471                 *p              = type;
3472                 if (anchor == p)
3473                         anchor = &type->base.next;
3474         }
3475
3476 declarator_finished:
3477         /* append inner_types at the end of the list, we don't to set anchor anymore
3478          * as it's not needed anymore */
3479         *anchor = inner_types;
3480
3481         return first;
3482 }
3483
3484 static type_t *construct_declarator_type(construct_type_t *construct_list,
3485                                          type_t *type)
3486 {
3487         construct_type_t *iter = construct_list;
3488         for (; iter != NULL; iter = iter->base.next) {
3489                 source_position_t const* const pos = &iter->base.pos;
3490                 switch (iter->kind) {
3491                 case CONSTRUCT_FUNCTION: {
3492                         construct_function_type_t *function      = &iter->function;
3493                         type_t                    *function_type = function->function_type;
3494
3495                         function_type->function.return_type = type;
3496
3497                         type_t *skipped_return_type = skip_typeref(type);
3498                         /* §6.7.5.3:1 */
3499                         if (is_type_function(skipped_return_type)) {
3500                                 errorf(pos, "function returning function is not allowed");
3501                         } else if (is_type_array(skipped_return_type)) {
3502                                 errorf(pos, "function returning array is not allowed");
3503                         } else {
3504                                 if (skipped_return_type->base.qualifiers != 0) {
3505                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3506                                 }
3507                         }
3508
3509                         /* The function type was constructed earlier.  Freeing it here will
3510                          * destroy other types. */
3511                         type = typehash_insert(function_type);
3512                         continue;
3513                 }
3514
3515                 case CONSTRUCT_POINTER: {
3516                         if (is_type_reference(skip_typeref(type)))
3517                                 errorf(pos, "cannot declare a pointer to reference");
3518
3519                         parsed_pointer_t *pointer = &iter->pointer;
3520                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3521                         continue;
3522                 }
3523
3524                 case CONSTRUCT_REFERENCE:
3525                         if (is_type_reference(skip_typeref(type)))
3526                                 errorf(pos, "cannot declare a reference to reference");
3527
3528                         type = make_reference_type(type);
3529                         continue;
3530
3531                 case CONSTRUCT_ARRAY: {
3532                         if (is_type_reference(skip_typeref(type)))
3533                                 errorf(pos, "cannot declare an array of references");
3534
3535                         parsed_array_t *array      = &iter->array;
3536                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3537
3538                         expression_t *size_expression = array->size;
3539                         if (size_expression != NULL) {
3540                                 size_expression
3541                                         = create_implicit_cast(size_expression, type_size_t);
3542                         }
3543
3544                         array_type->base.qualifiers       = array->type_qualifiers;
3545                         array_type->array.element_type    = type;
3546                         array_type->array.is_static       = array->is_static;
3547                         array_type->array.is_variable     = array->is_variable;
3548                         array_type->array.size_expression = size_expression;
3549
3550                         if (size_expression != NULL) {
3551                                 switch (is_constant_expression(size_expression)) {
3552                                 case EXPR_CLASS_CONSTANT: {
3553                                         long const size = fold_constant_to_int(size_expression);
3554                                         array_type->array.size          = size;
3555                                         array_type->array.size_constant = true;
3556                                         /* §6.7.5.2:1  If the expression is a constant expression,
3557                                          * it shall have a value greater than zero. */
3558                                         if (size < 0) {
3559                                                 errorf(&size_expression->base.source_position,
3560                                                            "size of array must be greater than zero");
3561                                         } else if (size == 0 && !GNU_MODE) {
3562                                                 errorf(&size_expression->base.source_position,
3563                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3564                                         }
3565                                         break;
3566                                 }
3567
3568                                 case EXPR_CLASS_VARIABLE:
3569                                         array_type->array.is_vla = true;
3570                                         break;
3571
3572                                 case EXPR_CLASS_ERROR:
3573                                         break;
3574                                 }
3575                         }
3576
3577                         type_t *skipped_type = skip_typeref(type);
3578                         /* §6.7.5.2:1 */
3579                         if (is_type_incomplete(skipped_type)) {
3580                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3581                         } else if (is_type_function(skipped_type)) {
3582                                 errorf(pos, "array of functions is not allowed");
3583                         }
3584                         type = identify_new_type(array_type);
3585                         continue;
3586                 }
3587                 }
3588                 internal_errorf(pos, "invalid type construction found");
3589         }
3590
3591         return type;
3592 }
3593
3594 static type_t *automatic_type_conversion(type_t *orig_type);
3595
3596 static type_t *semantic_parameter(const source_position_t *pos,
3597                                   type_t *type,
3598                                   const declaration_specifiers_t *specifiers,
3599                                   entity_t const *const param)
3600 {
3601         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3602          *             shall be adjusted to ``qualified pointer to type'',
3603          *             [...]
3604          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3605          *             type'' shall be adjusted to ``pointer to function
3606          *             returning type'', as in 6.3.2.1. */
3607         type = automatic_type_conversion(type);
3608
3609         if (specifiers->is_inline && is_type_valid(type)) {
3610                 errorf(pos, "'%N' declared 'inline'", param);
3611         }
3612
3613         /* §6.9.1:6  The declarations in the declaration list shall contain
3614          *           no storage-class specifier other than register and no
3615          *           initializations. */
3616         if (specifiers->thread_local || (
3617                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3618                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3619            ) {
3620                 errorf(pos, "invalid storage class for '%N'", param);
3621         }
3622
3623         /* delay test for incomplete type, because we might have (void)
3624          * which is legal but incomplete... */
3625
3626         return type;
3627 }
3628
3629 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3630                                   declarator_flags_t flags)
3631 {
3632         parse_declarator_env_t env;
3633         memset(&env, 0, sizeof(env));
3634         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3635
3636         construct_type_t *construct_type = parse_inner_declarator(&env);
3637         type_t           *orig_type      =
3638                 construct_declarator_type(construct_type, specifiers->type);
3639         type_t           *type           = skip_typeref(orig_type);
3640
3641         if (construct_type != NULL) {
3642                 obstack_free(&temp_obst, construct_type);
3643         }
3644
3645         attribute_t *attributes = parse_attributes(env.attributes);
3646         /* append (shared) specifier attribute behind attributes of this
3647          * declarator */
3648         attribute_t **anchor = &attributes;
3649         while (*anchor != NULL)
3650                 anchor = &(*anchor)->next;
3651         *anchor = specifiers->attributes;
3652
3653         entity_t *entity;
3654         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3655                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3656                 entity->typedefe.type = orig_type;
3657
3658                 if (anonymous_entity != NULL) {
3659                         if (is_type_compound(type)) {
3660                                 assert(anonymous_entity->compound.alias == NULL);
3661                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3662                                        anonymous_entity->kind == ENTITY_UNION);
3663                                 anonymous_entity->compound.alias = entity;
3664                                 anonymous_entity = NULL;
3665                         } else if (is_type_enum(type)) {
3666                                 assert(anonymous_entity->enume.alias == NULL);
3667                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3668                                 anonymous_entity->enume.alias = entity;
3669                                 anonymous_entity = NULL;
3670                         }
3671                 }
3672         } else {
3673                 /* create a declaration type entity */
3674                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3675                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3676                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3677
3678                         if (env.symbol != NULL) {
3679                                 if (specifiers->is_inline && is_type_valid(type)) {
3680                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3681                                 }
3682
3683                                 if (specifiers->thread_local ||
3684                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3685                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3686                                 }
3687                         }
3688                 } else if (flags & DECL_IS_PARAMETER) {
3689                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3690                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3691                 } else if (is_type_function(type)) {
3692                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3693                         entity->function.is_inline      = specifiers->is_inline;
3694                         entity->function.elf_visibility = default_visibility;
3695                         entity->function.parameters     = env.parameters;
3696
3697                         if (env.symbol != NULL) {
3698                                 /* this needs fixes for C++ */
3699                                 bool in_function_scope = current_function != NULL;
3700
3701                                 if (specifiers->thread_local || (
3702                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3703                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3704                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3705                                                 )) {
3706                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3707                                 }
3708                         }
3709                 } else {
3710                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3711                         entity->variable.elf_visibility = default_visibility;
3712                         entity->variable.thread_local   = specifiers->thread_local;
3713
3714                         if (env.symbol != NULL) {
3715                                 if (specifiers->is_inline && is_type_valid(type)) {
3716                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3717                                 }
3718
3719                                 bool invalid_storage_class = false;
3720                                 if (current_scope == file_scope) {
3721                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3722                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3723                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3724                                                 invalid_storage_class = true;
3725                                         }
3726                                 } else {
3727                                         if (specifiers->thread_local &&
3728                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3729                                                 invalid_storage_class = true;
3730                                         }
3731                                 }
3732                                 if (invalid_storage_class) {
3733                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3734                                 }
3735                         }
3736                 }
3737
3738                 entity->declaration.type       = orig_type;
3739                 entity->declaration.alignment  = get_type_alignment(orig_type);
3740                 entity->declaration.modifiers  = env.modifiers;
3741                 entity->declaration.attributes = attributes;
3742
3743                 storage_class_t storage_class = specifiers->storage_class;
3744                 entity->declaration.declared_storage_class = storage_class;
3745
3746                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3747                         storage_class = STORAGE_CLASS_AUTO;
3748                 entity->declaration.storage_class = storage_class;
3749         }
3750
3751         if (attributes != NULL) {
3752                 handle_entity_attributes(attributes, entity);
3753         }
3754
3755         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3756                 adapt_special_functions(&entity->function);
3757         }
3758
3759         return entity;
3760 }
3761
3762 static type_t *parse_abstract_declarator(type_t *base_type)
3763 {
3764         parse_declarator_env_t env;
3765         memset(&env, 0, sizeof(env));
3766         env.may_be_abstract = true;
3767         env.must_be_abstract = true;
3768
3769         construct_type_t *construct_type = parse_inner_declarator(&env);
3770
3771         type_t *result = construct_declarator_type(construct_type, base_type);
3772         if (construct_type != NULL) {
3773                 obstack_free(&temp_obst, construct_type);
3774         }
3775         result = handle_type_attributes(env.attributes, result);
3776
3777         return result;
3778 }
3779
3780 /**
3781  * Check if the declaration of main is suspicious.  main should be a
3782  * function with external linkage, returning int, taking either zero
3783  * arguments, two, or three arguments of appropriate types, ie.
3784  *
3785  * int main([ int argc, char **argv [, char **env ] ]).
3786  *
3787  * @param decl    the declaration to check
3788  * @param type    the function type of the declaration
3789  */
3790 static void check_main(const entity_t *entity)
3791 {
3792         const source_position_t *pos = &entity->base.source_position;
3793         if (entity->kind != ENTITY_FUNCTION) {
3794                 warningf(WARN_MAIN, pos, "'main' is not a function");
3795                 return;
3796         }
3797
3798         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3799                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3800         }
3801
3802         type_t *type = skip_typeref(entity->declaration.type);
3803         assert(is_type_function(type));
3804
3805         function_type_t const *const func_type = &type->function;
3806         type_t                *const ret_type  = func_type->return_type;
3807         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3808                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3809         }
3810         const function_parameter_t *parm = func_type->parameters;
3811         if (parm != NULL) {
3812                 type_t *const first_type        = skip_typeref(parm->type);
3813                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3814                 if (!types_compatible(first_type_unqual, type_int)) {
3815                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3816                 }
3817                 parm = parm->next;
3818                 if (parm != NULL) {
3819                         type_t *const second_type = skip_typeref(parm->type);
3820                         type_t *const second_type_unqual
3821                                 = get_unqualified_type(second_type);
3822                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3823                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3824                         }
3825                         parm = parm->next;
3826                         if (parm != NULL) {
3827                                 type_t *const third_type = skip_typeref(parm->type);
3828                                 type_t *const third_type_unqual
3829                                         = get_unqualified_type(third_type);
3830                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3831                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3832                                 }
3833                                 parm = parm->next;
3834                                 if (parm != NULL)
3835                                         goto warn_arg_count;
3836                         }
3837                 } else {
3838 warn_arg_count:
3839                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3840                 }
3841         }
3842 }
3843
3844 static void error_redefined_as_different_kind(const source_position_t *pos,
3845                 const entity_t *old, entity_kind_t new_kind)
3846 {
3847         char              const *const what = get_entity_kind_name(new_kind);
3848         source_position_t const *const ppos = &old->base.source_position;
3849         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3850 }
3851
3852 static bool is_entity_valid(entity_t *const ent)
3853 {
3854         if (is_declaration(ent)) {
3855                 return is_type_valid(skip_typeref(ent->declaration.type));
3856         } else if (ent->kind == ENTITY_TYPEDEF) {
3857                 return is_type_valid(skip_typeref(ent->typedefe.type));
3858         }
3859         return true;
3860 }
3861
3862 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3863 {
3864         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3865                 if (attributes_equal(tattr, attr))
3866                         return true;
3867         }
3868         return false;
3869 }
3870
3871 /**
3872  * test wether new_list contains any attributes not included in old_list
3873  */
3874 static bool has_new_attributes(const attribute_t *old_list,
3875                                const attribute_t *new_list)
3876 {
3877         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3878                 if (!contains_attribute(old_list, attr))
3879                         return true;
3880         }
3881         return false;
3882 }
3883
3884 /**
3885  * Merge in attributes from an attribute list (probably from a previous
3886  * declaration with the same name). Warning: destroys the old structure
3887  * of the attribute list - don't reuse attributes after this call.
3888  */
3889 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3890 {
3891         attribute_t *next;
3892         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3893                 next = attr->next;
3894                 if (contains_attribute(decl->attributes, attr))
3895                         continue;
3896
3897                 /* move attribute to new declarations attributes list */
3898                 attr->next       = decl->attributes;
3899                 decl->attributes = attr;
3900         }
3901 }
3902
3903 static bool is_main(entity_t*);
3904
3905 /**
3906  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3907  * for various problems that occur for multiple definitions
3908  */
3909 entity_t *record_entity(entity_t *entity, const bool is_definition)
3910 {
3911         const symbol_t *const    symbol  = entity->base.symbol;
3912         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3913         const source_position_t *pos     = &entity->base.source_position;
3914
3915         /* can happen in error cases */
3916         if (symbol == NULL)
3917                 return entity;
3918
3919         assert(!entity->base.parent_scope);
3920         assert(current_scope);
3921         entity->base.parent_scope = current_scope;
3922
3923         entity_t *const previous_entity = get_entity(symbol, namespc);
3924         /* pushing the same entity twice will break the stack structure */
3925         assert(previous_entity != entity);
3926
3927         if (entity->kind == ENTITY_FUNCTION) {
3928                 type_t *const orig_type = entity->declaration.type;
3929                 type_t *const type      = skip_typeref(orig_type);
3930
3931                 assert(is_type_function(type));
3932                 if (type->function.unspecified_parameters &&
3933                     previous_entity == NULL               &&
3934                     !entity->declaration.implicit) {
3935                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3936                 }
3937
3938                 if (is_main(entity)) {
3939                         check_main(entity);
3940                 }
3941         }
3942
3943         if (is_declaration(entity)                                    &&
3944             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3945             current_scope != file_scope                               &&
3946             !entity->declaration.implicit) {
3947                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3948         }
3949
3950         if (previous_entity != NULL) {
3951                 source_position_t const *const ppos = &previous_entity->base.source_position;
3952
3953                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3954                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3955                         assert(previous_entity->kind == ENTITY_PARAMETER);
3956                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3957                         goto finish;
3958                 }
3959
3960                 if (previous_entity->base.parent_scope == current_scope) {
3961                         if (previous_entity->kind != entity->kind) {
3962                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3963                                         error_redefined_as_different_kind(pos, previous_entity,
3964                                                         entity->kind);
3965                                 }
3966                                 goto finish;
3967                         }
3968                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3969                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3970                                 goto finish;
3971                         }
3972                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3973                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3974                                 type_t *const prev_type
3975                                         = skip_typeref(previous_entity->typedefe.type);
3976                                 if (c_mode & _CXX) {
3977                                         /* C++ allows double typedef if they are identical
3978                                          * (after skipping typedefs) */
3979                                         if (type == prev_type)
3980                                                 goto finish;
3981                                 } else {
3982                                         /* GCC extension: redef in system headers is allowed */
3983                                         if ((pos->is_system_header || ppos->is_system_header) &&
3984                                             types_compatible(type, prev_type))
3985                                                 goto finish;
3986                                 }
3987                                 errorf(pos, "redefinition of '%N' (declared %P)",
3988                                        entity, ppos);
3989                                 goto finish;
3990                         }
3991
3992                         /* at this point we should have only VARIABLES or FUNCTIONS */
3993                         assert(is_declaration(previous_entity) && is_declaration(entity));
3994
3995                         declaration_t *const prev_decl = &previous_entity->declaration;
3996                         declaration_t *const decl      = &entity->declaration;
3997
3998                         /* can happen for K&R style declarations */
3999                         if (prev_decl->type       == NULL             &&
4000                                         previous_entity->kind == ENTITY_PARAMETER &&
4001                                         entity->kind          == ENTITY_PARAMETER) {
4002                                 prev_decl->type                   = decl->type;
4003                                 prev_decl->storage_class          = decl->storage_class;
4004                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4005                                 prev_decl->modifiers              = decl->modifiers;
4006                                 return previous_entity;
4007                         }
4008
4009                         type_t *const type      = skip_typeref(decl->type);
4010                         type_t *const prev_type = skip_typeref(prev_decl->type);
4011
4012                         if (!types_compatible(type, prev_type)) {
4013                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4014                         } else {
4015                                 unsigned old_storage_class = prev_decl->storage_class;
4016
4017                                 if (is_definition                     &&
4018                                                 !prev_decl->used                  &&
4019                                                 !(prev_decl->modifiers & DM_USED) &&
4020                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4021                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4022                                 }
4023
4024                                 storage_class_t new_storage_class = decl->storage_class;
4025
4026                                 /* pretend no storage class means extern for function
4027                                  * declarations (except if the previous declaration is neither
4028                                  * none nor extern) */
4029                                 if (entity->kind == ENTITY_FUNCTION) {
4030                                         /* the previous declaration could have unspecified parameters or
4031                                          * be a typedef, so use the new type */
4032                                         if (prev_type->function.unspecified_parameters || is_definition)
4033                                                 prev_decl->type = type;
4034
4035                                         switch (old_storage_class) {
4036                                                 case STORAGE_CLASS_NONE:
4037                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4038                                                         /* FALLTHROUGH */
4039
4040                                                 case STORAGE_CLASS_EXTERN:
4041                                                         if (is_definition) {
4042                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4043                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4044                                                                 }
4045                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4046                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4047                                                         }
4048                                                         break;
4049
4050                                                 default:
4051                                                         break;
4052                                         }
4053                                 } else if (is_type_incomplete(prev_type)) {
4054                                         prev_decl->type = type;
4055                                 }
4056
4057                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4058                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4059
4060 warn_redundant_declaration: ;
4061                                         bool has_new_attrs
4062                                                 = has_new_attributes(prev_decl->attributes,
4063                                                                      decl->attributes);
4064                                         if (has_new_attrs) {
4065                                                 merge_in_attributes(decl, prev_decl->attributes);
4066                                         } else if (!is_definition        &&
4067                                                         is_type_valid(prev_type) &&
4068                                                         !pos->is_system_header) {
4069                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4070                                         }
4071                                 } else if (current_function == NULL) {
4072                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4073                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4074                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4075                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4076                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4077                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4078                                         } else {
4079                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4080                                                 if (c_mode & _CXX)
4081                                                         goto error_redeclaration;
4082                                                 goto warn_redundant_declaration;
4083                                         }
4084                                 } else if (is_type_valid(prev_type)) {
4085                                         if (old_storage_class == new_storage_class) {
4086 error_redeclaration:
4087                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4088                                         } else {
4089                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4090                                         }
4091                                 }
4092                         }
4093
4094                         prev_decl->modifiers |= decl->modifiers;
4095                         if (entity->kind == ENTITY_FUNCTION) {
4096                                 previous_entity->function.is_inline |= entity->function.is_inline;
4097                         }
4098                         return previous_entity;
4099                 }
4100
4101                 warning_t why;
4102                 if (is_warn_on(why = WARN_SHADOW) ||
4103                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4104                         char const *const what = get_entity_kind_name(previous_entity->kind);
4105                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4106                 }
4107         }
4108
4109         if (entity->kind == ENTITY_FUNCTION) {
4110                 if (is_definition &&
4111                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4112                                 !is_main(entity)) {
4113                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4114                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4115                         } else {
4116                                 goto warn_missing_declaration;
4117                         }
4118                 }
4119         } else if (entity->kind == ENTITY_VARIABLE) {
4120                 if (current_scope                     == file_scope &&
4121                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4122                                 !entity->declaration.implicit) {
4123 warn_missing_declaration:
4124                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4125                 }
4126         }
4127
4128 finish:
4129         environment_push(entity);
4130         append_entity(current_scope, entity);
4131
4132         return entity;
4133 }
4134
4135 static void parser_error_multiple_definition(entity_t *entity,
4136                 const source_position_t *source_position)
4137 {
4138         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4139 }
4140
4141 static bool is_declaration_specifier(const token_t *token)
4142 {
4143         switch (token->kind) {
4144                 DECLARATION_START
4145                         return true;
4146                 case T_IDENTIFIER:
4147                         return is_typedef_symbol(token->base.symbol);
4148
4149                 default:
4150                         return false;
4151         }
4152 }
4153
4154 static void parse_init_declarator_rest(entity_t *entity)
4155 {
4156         type_t *orig_type = type_error_type;
4157
4158         if (entity->base.kind == ENTITY_TYPEDEF) {
4159                 source_position_t const *const pos = &entity->base.source_position;
4160                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4161         } else {
4162                 assert(is_declaration(entity));
4163                 orig_type = entity->declaration.type;
4164         }
4165
4166         type_t *type = skip_typeref(orig_type);
4167
4168         if (entity->kind == ENTITY_VARIABLE
4169                         && entity->variable.initializer != NULL) {
4170                 parser_error_multiple_definition(entity, HERE);
4171         }
4172         eat('=');
4173
4174         declaration_t *const declaration = &entity->declaration;
4175         bool must_be_constant = false;
4176         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4177             entity->base.parent_scope  == file_scope) {
4178                 must_be_constant = true;
4179         }
4180
4181         if (is_type_function(type)) {
4182                 source_position_t const *const pos = &entity->base.source_position;
4183                 errorf(pos, "'%N' is initialized like a variable", entity);
4184                 orig_type = type_error_type;
4185         }
4186
4187         parse_initializer_env_t env;
4188         env.type             = orig_type;
4189         env.must_be_constant = must_be_constant;
4190         env.entity           = entity;
4191
4192         initializer_t *initializer = parse_initializer(&env);
4193
4194         if (entity->kind == ENTITY_VARIABLE) {
4195                 /* §6.7.5:22  array initializers for arrays with unknown size
4196                  * determine the array type size */
4197                 declaration->type            = env.type;
4198                 entity->variable.initializer = initializer;
4199         }
4200 }
4201
4202 /* parse rest of a declaration without any declarator */
4203 static void parse_anonymous_declaration_rest(
4204                 const declaration_specifiers_t *specifiers)
4205 {
4206         eat(';');
4207         anonymous_entity = NULL;
4208
4209         source_position_t const *const pos = &specifiers->source_position;
4210         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4211                         specifiers->thread_local) {
4212                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4213         }
4214
4215         type_t *type = specifiers->type;
4216         switch (type->kind) {
4217                 case TYPE_COMPOUND_STRUCT:
4218                 case TYPE_COMPOUND_UNION: {
4219                         if (type->compound.compound->base.symbol == NULL) {
4220                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4221                         }
4222                         break;
4223                 }
4224
4225                 case TYPE_ENUM:
4226                         break;
4227
4228                 default:
4229                         warningf(WARN_OTHER, pos, "empty declaration");
4230                         break;
4231         }
4232 }
4233
4234 static void check_variable_type_complete(entity_t *ent)
4235 {
4236         if (ent->kind != ENTITY_VARIABLE)
4237                 return;
4238
4239         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4240          *         type for the object shall be complete [...] */
4241         declaration_t *decl = &ent->declaration;
4242         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4243                         decl->storage_class == STORAGE_CLASS_STATIC)
4244                 return;
4245
4246         type_t *const type = skip_typeref(decl->type);
4247         if (!is_type_incomplete(type))
4248                 return;
4249
4250         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4251          * are given length one. */
4252         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4253                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4254                 return;
4255         }
4256
4257         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4258 }
4259
4260
4261 static void parse_declaration_rest(entity_t *ndeclaration,
4262                 const declaration_specifiers_t *specifiers,
4263                 parsed_declaration_func         finished_declaration,
4264                 declarator_flags_t              flags)
4265 {
4266         add_anchor_token(';');
4267         add_anchor_token(',');
4268         while (true) {
4269                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4270
4271                 if (token.kind == '=') {
4272                         parse_init_declarator_rest(entity);
4273                 } else if (entity->kind == ENTITY_VARIABLE) {
4274                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4275                          * [...] where the extern specifier is explicitly used. */
4276                         declaration_t *decl = &entity->declaration;
4277                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4278                             is_type_reference(skip_typeref(decl->type))) {
4279                                 source_position_t const *const pos = &entity->base.source_position;
4280                                 errorf(pos, "reference '%#N' must be initialized", entity);
4281                         }
4282                 }
4283
4284                 check_variable_type_complete(entity);
4285
4286                 if (!next_if(','))
4287                         break;
4288
4289                 add_anchor_token('=');
4290                 ndeclaration = parse_declarator(specifiers, flags);
4291                 rem_anchor_token('=');
4292         }
4293         rem_anchor_token(',');
4294         rem_anchor_token(';');
4295         expect(';');
4296
4297         anonymous_entity = NULL;
4298 }
4299
4300 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4301 {
4302         symbol_t *symbol = entity->base.symbol;
4303         if (symbol == NULL)
4304                 return entity;
4305
4306         assert(entity->base.namespc == NAMESPACE_NORMAL);
4307         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4308         if (previous_entity == NULL
4309                         || previous_entity->base.parent_scope != current_scope) {
4310                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4311                        symbol);
4312                 return entity;
4313         }
4314
4315         if (is_definition) {
4316                 errorf(HERE, "'%N' is initialised", entity);
4317         }
4318
4319         return record_entity(entity, false);
4320 }
4321
4322 static void parse_declaration(parsed_declaration_func finished_declaration,
4323                               declarator_flags_t      flags)
4324 {
4325         add_anchor_token(';');
4326         declaration_specifiers_t specifiers;
4327         parse_declaration_specifiers(&specifiers);
4328         rem_anchor_token(';');
4329
4330         if (token.kind == ';') {
4331                 parse_anonymous_declaration_rest(&specifiers);
4332         } else {
4333                 entity_t *entity = parse_declarator(&specifiers, flags);
4334                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4335         }
4336 }
4337
4338 /* §6.5.2.2:6 */
4339 static type_t *get_default_promoted_type(type_t *orig_type)
4340 {
4341         type_t *result = orig_type;
4342
4343         type_t *type = skip_typeref(orig_type);
4344         if (is_type_integer(type)) {
4345                 result = promote_integer(type);
4346         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4347                 result = type_double;
4348         }
4349
4350         return result;
4351 }
4352
4353 static void parse_kr_declaration_list(entity_t *entity)
4354 {
4355         if (entity->kind != ENTITY_FUNCTION)
4356                 return;
4357
4358         type_t *type = skip_typeref(entity->declaration.type);
4359         assert(is_type_function(type));
4360         if (!type->function.kr_style_parameters)
4361                 return;
4362
4363         add_anchor_token('{');
4364
4365         PUSH_SCOPE(&entity->function.parameters);
4366
4367         entity_t *parameter = entity->function.parameters.entities;
4368         for ( ; parameter != NULL; parameter = parameter->base.next) {
4369                 assert(parameter->base.parent_scope == NULL);
4370                 parameter->base.parent_scope = current_scope;
4371                 environment_push(parameter);
4372         }
4373
4374         /* parse declaration list */
4375         for (;;) {
4376                 switch (token.kind) {
4377                         DECLARATION_START
4378                         /* This covers symbols, which are no type, too, and results in
4379                          * better error messages.  The typical cases are misspelled type
4380                          * names and missing includes. */
4381                         case T_IDENTIFIER:
4382                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4383                                 break;
4384                         default:
4385                                 goto decl_list_end;
4386                 }
4387         }
4388 decl_list_end:
4389
4390         POP_SCOPE();
4391
4392         /* update function type */
4393         type_t *new_type = duplicate_type(type);
4394
4395         function_parameter_t  *parameters = NULL;
4396         function_parameter_t **anchor     = &parameters;
4397
4398         /* did we have an earlier prototype? */
4399         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4400         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4401                 proto_type = NULL;
4402
4403         function_parameter_t *proto_parameter = NULL;
4404         if (proto_type != NULL) {
4405                 type_t *proto_type_type = proto_type->declaration.type;
4406                 proto_parameter         = proto_type_type->function.parameters;
4407                 /* If a K&R function definition has a variadic prototype earlier, then
4408                  * make the function definition variadic, too. This should conform to
4409                  * §6.7.5.3:15 and §6.9.1:8. */
4410                 new_type->function.variadic = proto_type_type->function.variadic;
4411         } else {
4412                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4413                  * prototype */
4414                 new_type->function.unspecified_parameters = true;
4415         }
4416
4417         bool need_incompatible_warning = false;
4418         parameter = entity->function.parameters.entities;
4419         for (; parameter != NULL; parameter = parameter->base.next,
4420                         proto_parameter =
4421                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4422                 if (parameter->kind != ENTITY_PARAMETER)
4423                         continue;
4424
4425                 type_t *parameter_type = parameter->declaration.type;
4426                 if (parameter_type == NULL) {
4427                         source_position_t const* const pos = &parameter->base.source_position;
4428                         if (strict_mode) {
4429                                 errorf(pos, "no type specified for function '%N'", parameter);
4430                                 parameter_type = type_error_type;
4431                         } else {
4432                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4433                                 parameter_type = type_int;
4434                         }
4435                         parameter->declaration.type = parameter_type;
4436                 }
4437
4438                 semantic_parameter_incomplete(parameter);
4439
4440                 /* we need the default promoted types for the function type */
4441                 type_t *not_promoted = parameter_type;
4442                 parameter_type       = get_default_promoted_type(parameter_type);
4443
4444                 /* gcc special: if the type of the prototype matches the unpromoted
4445                  * type don't promote */
4446                 if (!strict_mode && proto_parameter != NULL) {
4447                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4448                         type_t *promo_skip   = skip_typeref(parameter_type);
4449                         type_t *param_skip   = skip_typeref(not_promoted);
4450                         if (!types_compatible(proto_p_type, promo_skip)
4451                                 && types_compatible(proto_p_type, param_skip)) {
4452                                 /* don't promote */
4453                                 need_incompatible_warning = true;
4454                                 parameter_type = not_promoted;
4455                         }
4456                 }
4457                 function_parameter_t *const function_parameter
4458                         = allocate_parameter(parameter_type);
4459
4460                 *anchor = function_parameter;
4461                 anchor  = &function_parameter->next;
4462         }
4463
4464         new_type->function.parameters = parameters;
4465         new_type = identify_new_type(new_type);
4466
4467         if (need_incompatible_warning) {
4468                 symbol_t          const *const sym  = entity->base.symbol;
4469                 source_position_t const *const pos  = &entity->base.source_position;
4470                 source_position_t const *const ppos = &proto_type->base.source_position;
4471                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4472         }
4473         entity->declaration.type = new_type;
4474
4475         rem_anchor_token('{');
4476 }
4477
4478 static bool first_err = true;
4479
4480 /**
4481  * When called with first_err set, prints the name of the current function,
4482  * else does noting.
4483  */
4484 static void print_in_function(void)
4485 {
4486         if (first_err) {
4487                 first_err = false;
4488                 char const *const file = current_function->base.base.source_position.input_name;
4489                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4490         }
4491 }
4492
4493 /**
4494  * Check if all labels are defined in the current function.
4495  * Check if all labels are used in the current function.
4496  */
4497 static void check_labels(void)
4498 {
4499         for (const goto_statement_t *goto_statement = goto_first;
4500             goto_statement != NULL;
4501             goto_statement = goto_statement->next) {
4502                 label_t *label = goto_statement->label;
4503                 if (label->base.source_position.input_name == NULL) {
4504                         print_in_function();
4505                         source_position_t const *const pos = &goto_statement->base.source_position;
4506                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4507                  }
4508         }
4509
4510         if (is_warn_on(WARN_UNUSED_LABEL)) {
4511                 for (const label_statement_t *label_statement = label_first;
4512                          label_statement != NULL;
4513                          label_statement = label_statement->next) {
4514                         label_t *label = label_statement->label;
4515
4516                         if (! label->used) {
4517                                 print_in_function();
4518                                 source_position_t const *const pos = &label_statement->base.source_position;
4519                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4520                         }
4521                 }
4522         }
4523 }
4524
4525 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4526 {
4527         entity_t const *const end = last != NULL ? last->base.next : NULL;
4528         for (; entity != end; entity = entity->base.next) {
4529                 if (!is_declaration(entity))
4530                         continue;
4531
4532                 declaration_t *declaration = &entity->declaration;
4533                 if (declaration->implicit)
4534                         continue;
4535
4536                 if (!declaration->used) {
4537                         print_in_function();
4538                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4539                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4540                         print_in_function();
4541                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4542                 }
4543         }
4544 }
4545
4546 static void check_unused_variables(statement_t *const stmt, void *const env)
4547 {
4548         (void)env;
4549
4550         switch (stmt->kind) {
4551                 case STATEMENT_DECLARATION: {
4552                         declaration_statement_t const *const decls = &stmt->declaration;
4553                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4554                         return;
4555                 }
4556
4557                 case STATEMENT_FOR:
4558                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4559                         return;
4560
4561                 default:
4562                         return;
4563         }
4564 }
4565
4566 /**
4567  * Check declarations of current_function for unused entities.
4568  */
4569 static void check_declarations(void)
4570 {
4571         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4572                 const scope_t *scope = &current_function->parameters;
4573                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4574         }
4575         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4576                 walk_statements(current_function->body, check_unused_variables, NULL);
4577         }
4578 }
4579
4580 static int determine_truth(expression_t const* const cond)
4581 {
4582         return
4583                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4584                 fold_constant_to_bool(cond)                         ? 1 :
4585                 -1;
4586 }
4587
4588 static void check_reachable(statement_t *);
4589 static bool reaches_end;
4590
4591 static bool expression_returns(expression_t const *const expr)
4592 {
4593         switch (expr->kind) {
4594                 case EXPR_CALL: {
4595                         expression_t const *const func = expr->call.function;
4596                         type_t       const *const type = skip_typeref(func->base.type);
4597                         if (type->kind == TYPE_POINTER) {
4598                                 type_t const *const points_to
4599                                         = skip_typeref(type->pointer.points_to);
4600                                 if (points_to->kind == TYPE_FUNCTION
4601                                     && points_to->function.modifiers & DM_NORETURN)
4602                                         return false;
4603                         }
4604
4605                         if (!expression_returns(func))
4606                                 return false;
4607
4608                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4609                                 if (!expression_returns(arg->expression))
4610                                         return false;
4611                         }
4612
4613                         return true;
4614                 }
4615
4616                 case EXPR_REFERENCE:
4617                 case EXPR_ENUM_CONSTANT:
4618                 case EXPR_LITERAL_CASES:
4619                 case EXPR_LITERAL_CHARACTER:
4620                 case EXPR_STRING_LITERAL:
4621                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4622                 case EXPR_LABEL_ADDRESS:
4623                 case EXPR_CLASSIFY_TYPE:
4624                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4625                 case EXPR_ALIGNOF:
4626                 case EXPR_FUNCNAME:
4627                 case EXPR_BUILTIN_CONSTANT_P:
4628                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4629                 case EXPR_OFFSETOF:
4630                 case EXPR_ERROR:
4631                         return true;
4632
4633                 case EXPR_STATEMENT: {
4634                         bool old_reaches_end = reaches_end;
4635                         reaches_end = false;
4636                         check_reachable(expr->statement.statement);
4637                         bool returns = reaches_end;
4638                         reaches_end = old_reaches_end;
4639                         return returns;
4640                 }
4641
4642                 case EXPR_CONDITIONAL:
4643                         // TODO handle constant expression
4644
4645                         if (!expression_returns(expr->conditional.condition))
4646                                 return false;
4647
4648                         if (expr->conditional.true_expression != NULL
4649                                         && expression_returns(expr->conditional.true_expression))
4650                                 return true;
4651
4652                         return expression_returns(expr->conditional.false_expression);
4653
4654                 case EXPR_SELECT:
4655                         return expression_returns(expr->select.compound);
4656
4657                 case EXPR_ARRAY_ACCESS:
4658                         return
4659                                 expression_returns(expr->array_access.array_ref) &&
4660                                 expression_returns(expr->array_access.index);
4661
4662                 case EXPR_VA_START:
4663                         return expression_returns(expr->va_starte.ap);
4664
4665                 case EXPR_VA_ARG:
4666                         return expression_returns(expr->va_arge.ap);
4667
4668                 case EXPR_VA_COPY:
4669                         return expression_returns(expr->va_copye.src);
4670
4671                 case EXPR_UNARY_CASES_MANDATORY:
4672                         return expression_returns(expr->unary.value);
4673
4674                 case EXPR_UNARY_THROW:
4675                         return false;
4676
4677                 case EXPR_BINARY_CASES:
4678                         // TODO handle constant lhs of && and ||
4679                         return
4680                                 expression_returns(expr->binary.left) &&
4681                                 expression_returns(expr->binary.right);
4682         }
4683
4684         panic("unhandled expression");
4685 }
4686
4687 static bool initializer_returns(initializer_t const *const init)
4688 {
4689         switch (init->kind) {
4690                 case INITIALIZER_VALUE:
4691                         return expression_returns(init->value.value);
4692
4693                 case INITIALIZER_LIST: {
4694                         initializer_t * const*       i       = init->list.initializers;
4695                         initializer_t * const* const end     = i + init->list.len;
4696                         bool                         returns = true;
4697                         for (; i != end; ++i) {
4698                                 if (!initializer_returns(*i))
4699                                         returns = false;
4700                         }
4701                         return returns;
4702                 }
4703
4704                 case INITIALIZER_STRING:
4705                 case INITIALIZER_DESIGNATOR: // designators have no payload
4706                         return true;
4707         }
4708         panic("unhandled initializer");
4709 }
4710
4711 static bool noreturn_candidate;
4712
4713 static void check_reachable(statement_t *const stmt)
4714 {
4715         if (stmt->base.reachable)
4716                 return;
4717         if (stmt->kind != STATEMENT_DO_WHILE)
4718                 stmt->base.reachable = true;
4719
4720         statement_t *last = stmt;
4721         statement_t *next;
4722         switch (stmt->kind) {
4723                 case STATEMENT_ERROR:
4724                 case STATEMENT_EMPTY:
4725                 case STATEMENT_ASM:
4726                         next = stmt->base.next;
4727                         break;
4728
4729                 case STATEMENT_DECLARATION: {
4730                         declaration_statement_t const *const decl = &stmt->declaration;
4731                         entity_t                const *      ent  = decl->declarations_begin;
4732                         entity_t                const *const last_decl = decl->declarations_end;
4733                         if (ent != NULL) {
4734                                 for (;; ent = ent->base.next) {
4735                                         if (ent->kind                 == ENTITY_VARIABLE &&
4736                                             ent->variable.initializer != NULL            &&
4737                                             !initializer_returns(ent->variable.initializer)) {
4738                                                 return;
4739                                         }
4740                                         if (ent == last_decl)
4741                                                 break;
4742                                 }
4743                         }
4744                         next = stmt->base.next;
4745                         break;
4746                 }
4747
4748                 case STATEMENT_COMPOUND:
4749                         next = stmt->compound.statements;
4750                         if (next == NULL)
4751                                 next = stmt->base.next;
4752                         break;
4753
4754                 case STATEMENT_RETURN: {
4755                         expression_t const *const val = stmt->returns.value;
4756                         if (val == NULL || expression_returns(val))
4757                                 noreturn_candidate = false;
4758                         return;
4759                 }
4760
4761                 case STATEMENT_IF: {
4762                         if_statement_t const *const ifs  = &stmt->ifs;
4763                         expression_t   const *const cond = ifs->condition;
4764
4765                         if (!expression_returns(cond))
4766                                 return;
4767
4768                         int const val = determine_truth(cond);
4769
4770                         if (val >= 0)
4771                                 check_reachable(ifs->true_statement);
4772
4773                         if (val > 0)
4774                                 return;
4775
4776                         if (ifs->false_statement != NULL) {
4777                                 check_reachable(ifs->false_statement);
4778                                 return;
4779                         }
4780
4781                         next = stmt->base.next;
4782                         break;
4783                 }
4784
4785                 case STATEMENT_SWITCH: {
4786                         switch_statement_t const *const switchs = &stmt->switchs;
4787                         expression_t       const *const expr    = switchs->expression;
4788
4789                         if (!expression_returns(expr))
4790                                 return;
4791
4792                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4793                                 ir_tarval              *const val      = fold_constant_to_tarval(expr);
4794                                 case_label_statement_t *      defaults = NULL;
4795                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4796                                         if (i->expression == NULL) {
4797                                                 defaults = i;
4798                                                 continue;
4799                                         }
4800
4801                                         if (i->first_case == val || i->last_case == val ||
4802                                                 ((tarval_cmp(i->first_case, val) & ir_relation_less_equal)
4803                                             && (tarval_cmp(val, i->last_case) & ir_relation_less_equal))) {
4804                                                 check_reachable((statement_t*)i);
4805                                                 return;
4806                                         }
4807                                 }
4808
4809                                 if (defaults != NULL) {
4810                                         check_reachable((statement_t*)defaults);
4811                                         return;
4812                                 }
4813                         } else {
4814                                 bool has_default = false;
4815                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4816                                         if (i->expression == NULL)
4817                                                 has_default = true;
4818
4819                                         check_reachable((statement_t*)i);
4820                                 }
4821
4822                                 if (has_default)
4823                                         return;
4824                         }
4825
4826                         next = stmt->base.next;
4827                         break;
4828                 }
4829
4830                 case STATEMENT_EXPRESSION: {
4831                         /* Check for noreturn function call */
4832                         expression_t const *const expr = stmt->expression.expression;
4833                         if (!expression_returns(expr))
4834                                 return;
4835
4836                         next = stmt->base.next;
4837                         break;
4838                 }
4839
4840                 case STATEMENT_CONTINUE:
4841                         for (statement_t *parent = stmt;;) {
4842                                 parent = parent->base.parent;
4843                                 if (parent == NULL) /* continue not within loop */
4844                                         return;
4845
4846                                 next = parent;
4847                                 switch (parent->kind) {
4848                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4849                                         case STATEMENT_FOR:      goto continue_for;
4850
4851                                         default: break;
4852                                 }
4853                         }
4854
4855                 case STATEMENT_BREAK:
4856                         for (statement_t *parent = stmt;;) {
4857                                 parent = parent->base.parent;
4858                                 if (parent == NULL) /* break not within loop/switch */
4859                                         return;
4860
4861                                 switch (parent->kind) {
4862                                         case STATEMENT_SWITCH:
4863                                         case STATEMENT_DO_WHILE:
4864                                         case STATEMENT_FOR:
4865                                                 last = parent;
4866                                                 next = parent->base.next;
4867                                                 goto found_break_parent;
4868
4869                                         default: break;
4870                                 }
4871                         }
4872 found_break_parent:
4873                         break;
4874
4875                 case STATEMENT_COMPUTED_GOTO: {
4876                         if (!expression_returns(stmt->computed_goto.expression))
4877                                 return;
4878
4879                         statement_t *parent = stmt->base.parent;
4880                         if (parent == NULL) /* top level goto */
4881                                 return;
4882                         next = parent;
4883                         break;
4884                 }
4885
4886                 case STATEMENT_GOTO:
4887                         next = stmt->gotos.label->statement;
4888                         if (next == NULL) /* missing label */
4889                                 return;
4890                         break;
4891
4892                 case STATEMENT_LABEL:
4893                         next = stmt->label.statement;
4894                         break;
4895
4896                 case STATEMENT_CASE_LABEL:
4897                         next = stmt->case_label.statement;
4898                         break;
4899
4900                 case STATEMENT_DO_WHILE:
4901                         next = stmt->do_while.body;
4902                         break;
4903
4904                 case STATEMENT_FOR: {
4905                         for_statement_t *const fors = &stmt->fors;
4906
4907                         if (fors->condition_reachable)
4908                                 return;
4909                         fors->condition_reachable = true;
4910
4911                         expression_t const *const cond = fors->condition;
4912
4913                         int val;
4914                         if (cond == NULL) {
4915                                 val = 1;
4916                         } else if (expression_returns(cond)) {
4917                                 val = determine_truth(cond);
4918                         } else {
4919                                 return;
4920                         }
4921
4922                         if (val >= 0)
4923                                 check_reachable(fors->body);
4924
4925                         if (val > 0)
4926                                 return;
4927
4928                         next = stmt->base.next;
4929                         break;
4930                 }
4931
4932                 case STATEMENT_MS_TRY: {
4933                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4934                         check_reachable(ms_try->try_statement);
4935                         next = ms_try->final_statement;
4936                         break;
4937                 }
4938
4939                 case STATEMENT_LEAVE: {
4940                         statement_t *parent = stmt;
4941                         for (;;) {
4942                                 parent = parent->base.parent;
4943                                 if (parent == NULL) /* __leave not within __try */
4944                                         return;
4945
4946                                 if (parent->kind == STATEMENT_MS_TRY) {
4947                                         last = parent;
4948                                         next = parent->ms_try.final_statement;
4949                                         break;
4950                                 }
4951                         }
4952                         break;
4953                 }
4954
4955                 default:
4956                         panic("invalid statement kind");
4957         }
4958
4959         while (next == NULL) {
4960                 next = last->base.parent;
4961                 if (next == NULL) {
4962                         noreturn_candidate = false;
4963
4964                         type_t *const type = skip_typeref(current_function->base.type);
4965                         assert(is_type_function(type));
4966                         type_t *const ret  = skip_typeref(type->function.return_type);
4967                         if (!is_type_void(ret) &&
4968                             is_type_valid(ret) &&
4969                             !is_main(current_entity)) {
4970                                 source_position_t const *const pos = &stmt->base.source_position;
4971                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4972                         }
4973                         return;
4974                 }
4975
4976                 switch (next->kind) {
4977                         case STATEMENT_ERROR:
4978                         case STATEMENT_EMPTY:
4979                         case STATEMENT_DECLARATION:
4980                         case STATEMENT_EXPRESSION:
4981                         case STATEMENT_ASM:
4982                         case STATEMENT_RETURN:
4983                         case STATEMENT_CONTINUE:
4984                         case STATEMENT_BREAK:
4985                         case STATEMENT_COMPUTED_GOTO:
4986                         case STATEMENT_GOTO:
4987                         case STATEMENT_LEAVE:
4988                                 panic("invalid control flow in function");
4989
4990                         case STATEMENT_COMPOUND:
4991                                 if (next->compound.stmt_expr) {
4992                                         reaches_end = true;
4993                                         return;
4994                                 }
4995                                 /* FALLTHROUGH */
4996                         case STATEMENT_IF:
4997                         case STATEMENT_SWITCH:
4998                         case STATEMENT_LABEL:
4999                         case STATEMENT_CASE_LABEL:
5000                                 last = next;
5001                                 next = next->base.next;
5002                                 break;
5003
5004                         case STATEMENT_DO_WHILE: {
5005 continue_do_while:
5006                                 if (next->base.reachable)
5007                                         return;
5008                                 next->base.reachable = true;
5009
5010                                 do_while_statement_t const *const dw   = &next->do_while;
5011                                 expression_t         const *const cond = dw->condition;
5012
5013                                 if (!expression_returns(cond))
5014                                         return;
5015
5016                                 int const val = determine_truth(cond);
5017
5018                                 if (val >= 0)
5019                                         check_reachable(dw->body);
5020
5021                                 if (val > 0)
5022                                         return;
5023
5024                                 last = next;
5025                                 next = next->base.next;
5026                                 break;
5027                         }
5028
5029                         case STATEMENT_FOR: {
5030 continue_for:;
5031                                 for_statement_t *const fors = &next->fors;
5032
5033                                 fors->step_reachable = true;
5034
5035                                 if (fors->condition_reachable)
5036                                         return;
5037                                 fors->condition_reachable = true;
5038
5039                                 expression_t const *const cond = fors->condition;
5040
5041                                 int val;
5042                                 if (cond == NULL) {
5043                                         val = 1;
5044                                 } else if (expression_returns(cond)) {
5045                                         val = determine_truth(cond);
5046                                 } else {
5047                                         return;
5048                                 }
5049
5050                                 if (val >= 0)
5051                                         check_reachable(fors->body);
5052
5053                                 if (val > 0)
5054                                         return;
5055
5056                                 last = next;
5057                                 next = next->base.next;
5058                                 break;
5059                         }
5060
5061                         case STATEMENT_MS_TRY:
5062                                 last = next;
5063                                 next = next->ms_try.final_statement;
5064                                 break;
5065                 }
5066         }
5067
5068         check_reachable(next);
5069 }
5070
5071 static void check_unreachable(statement_t* const stmt, void *const env)
5072 {
5073         (void)env;
5074
5075         switch (stmt->kind) {
5076                 case STATEMENT_DO_WHILE:
5077                         if (!stmt->base.reachable) {
5078                                 expression_t const *const cond = stmt->do_while.condition;
5079                                 if (determine_truth(cond) >= 0) {
5080                                         source_position_t const *const pos = &cond->base.source_position;
5081                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5082                                 }
5083                         }
5084                         return;
5085
5086                 case STATEMENT_FOR: {
5087                         for_statement_t const* const fors = &stmt->fors;
5088
5089                         // if init and step are unreachable, cond is unreachable, too
5090                         if (!stmt->base.reachable && !fors->step_reachable) {
5091                                 goto warn_unreachable;
5092                         } else {
5093                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5094                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5095                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5096                                 }
5097
5098                                 if (!fors->condition_reachable && fors->condition != NULL) {
5099                                         source_position_t const *const pos = &fors->condition->base.source_position;
5100                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5101                                 }
5102
5103                                 if (!fors->step_reachable && fors->step != NULL) {
5104                                         source_position_t const *const pos = &fors->step->base.source_position;
5105                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5106                                 }
5107                         }
5108                         return;
5109                 }
5110
5111                 case STATEMENT_COMPOUND:
5112                         if (stmt->compound.statements != NULL)
5113                                 return;
5114                         goto warn_unreachable;
5115
5116                 case STATEMENT_DECLARATION: {
5117                         /* Only warn if there is at least one declarator with an initializer.
5118                          * This typically occurs in switch statements. */
5119                         declaration_statement_t const *const decl = &stmt->declaration;
5120                         entity_t                const *      ent  = decl->declarations_begin;
5121                         entity_t                const *const last = decl->declarations_end;
5122                         if (ent != NULL) {
5123                                 for (;; ent = ent->base.next) {
5124                                         if (ent->kind                 == ENTITY_VARIABLE &&
5125                                                         ent->variable.initializer != NULL) {
5126                                                 goto warn_unreachable;
5127                                         }
5128                                         if (ent == last)
5129                                                 return;
5130                                 }
5131                         }
5132                 }
5133
5134                 default:
5135 warn_unreachable:
5136                         if (!stmt->base.reachable) {
5137                                 source_position_t const *const pos = &stmt->base.source_position;
5138                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5139                         }
5140                         return;
5141         }
5142 }
5143
5144 static bool is_main(entity_t *entity)
5145 {
5146         static symbol_t *sym_main = NULL;
5147         if (sym_main == NULL) {
5148                 sym_main = symbol_table_insert("main");
5149         }
5150
5151         if (entity->base.symbol != sym_main)
5152                 return false;
5153         /* must be in outermost scope */
5154         if (entity->base.parent_scope != file_scope)
5155                 return false;
5156
5157         return true;
5158 }
5159
5160 static void prepare_main_collect2(entity_t*);
5161
5162 static void parse_external_declaration(void)
5163 {
5164         /* function-definitions and declarations both start with declaration
5165          * specifiers */
5166         add_anchor_token(';');
5167         declaration_specifiers_t specifiers;
5168         parse_declaration_specifiers(&specifiers);
5169         rem_anchor_token(';');
5170
5171         /* must be a declaration */
5172         if (token.kind == ';') {
5173                 parse_anonymous_declaration_rest(&specifiers);
5174                 return;
5175         }
5176
5177         add_anchor_token(',');
5178         add_anchor_token('=');
5179         add_anchor_token(';');
5180         add_anchor_token('{');
5181
5182         /* declarator is common to both function-definitions and declarations */
5183         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5184
5185         rem_anchor_token('{');
5186         rem_anchor_token(';');
5187         rem_anchor_token('=');
5188         rem_anchor_token(',');
5189
5190         /* must be a declaration */
5191         switch (token.kind) {
5192                 case ',':
5193                 case ';':
5194                 case '=':
5195                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5196                                         DECL_FLAGS_NONE);
5197                         return;
5198         }
5199
5200         /* must be a function definition */
5201         parse_kr_declaration_list(ndeclaration);
5202
5203         if (token.kind != '{') {
5204                 parse_error_expected("while parsing function definition", '{', NULL);
5205                 eat_until_matching_token(';');
5206                 return;
5207         }
5208
5209         assert(is_declaration(ndeclaration));
5210         type_t *const orig_type = ndeclaration->declaration.type;
5211         type_t *      type      = skip_typeref(orig_type);
5212
5213         if (!is_type_function(type)) {
5214                 if (is_type_valid(type)) {
5215                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5216                 }
5217                 eat_block();
5218                 return;
5219         }
5220
5221         source_position_t const *const pos = &ndeclaration->base.source_position;
5222         if (is_typeref(orig_type)) {
5223                 /* §6.9.1:2 */
5224                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5225         }
5226
5227         if (is_type_compound(skip_typeref(type->function.return_type))) {
5228                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5229         }
5230         if (type->function.unspecified_parameters) {
5231                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5232         } else {
5233                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5234         }
5235
5236         /* §6.7.5.3:14 a function definition with () means no
5237          * parameters (and not unspecified parameters) */
5238         if (type->function.unspecified_parameters &&
5239                         type->function.parameters == NULL) {
5240                 type_t *copy                          = duplicate_type(type);
5241                 copy->function.unspecified_parameters = false;
5242                 type                                  = identify_new_type(copy);
5243
5244                 ndeclaration->declaration.type = type;
5245         }
5246
5247         entity_t *const entity = record_entity(ndeclaration, true);
5248         assert(entity->kind == ENTITY_FUNCTION);
5249         assert(ndeclaration->kind == ENTITY_FUNCTION);
5250
5251         function_t *const function = &entity->function;
5252         if (ndeclaration != entity) {
5253                 function->parameters = ndeclaration->function.parameters;
5254         }
5255
5256         PUSH_SCOPE(&function->parameters);
5257
5258         entity_t *parameter = function->parameters.entities;
5259         for (; parameter != NULL; parameter = parameter->base.next) {
5260                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5261                         parameter->base.parent_scope = current_scope;
5262                 }
5263                 assert(parameter->base.parent_scope == NULL
5264                                 || parameter->base.parent_scope == current_scope);
5265                 parameter->base.parent_scope = current_scope;
5266                 if (parameter->base.symbol == NULL) {
5267                         errorf(&parameter->base.source_position, "parameter name omitted");
5268                         continue;
5269                 }
5270                 environment_push(parameter);
5271         }
5272
5273         if (function->body != NULL) {
5274                 parser_error_multiple_definition(entity, HERE);
5275                 eat_block();
5276         } else {
5277                 /* parse function body */
5278                 int         label_stack_top      = label_top();
5279                 function_t *old_current_function = current_function;
5280                 current_function                 = function;
5281                 PUSH_CURRENT_ENTITY(entity);
5282                 PUSH_PARENT(NULL);
5283
5284                 goto_first   = NULL;
5285                 goto_anchor  = &goto_first;
5286                 label_first  = NULL;
5287                 label_anchor = &label_first;
5288
5289                 statement_t *const body = parse_compound_statement(false);
5290                 function->body = body;
5291                 first_err = true;
5292                 check_labels();
5293                 check_declarations();
5294                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5295                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5296                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5297                         noreturn_candidate = true;
5298                         check_reachable(body);
5299                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5300                                 walk_statements(body, check_unreachable, NULL);
5301                         if (noreturn_candidate &&
5302                             !(function->base.modifiers & DM_NORETURN)) {
5303                                 source_position_t const *const pos = &body->base.source_position;
5304                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5305                         }
5306                 }
5307
5308                 if (is_main(entity)) {
5309                         /* Force main to C linkage. */
5310                         type_t *const type = entity->declaration.type;
5311                         assert(is_type_function(type));
5312                         if (type->function.linkage != LINKAGE_C) {
5313                                 type_t *new_type           = duplicate_type(type);
5314                                 new_type->function.linkage = LINKAGE_C;
5315                                 entity->declaration.type   = identify_new_type(new_type);
5316                         }
5317
5318                         if (enable_main_collect2_hack)
5319                                 prepare_main_collect2(entity);
5320                 }
5321
5322                 POP_CURRENT_ENTITY();
5323                 POP_PARENT();
5324                 assert(current_function == function);
5325                 current_function = old_current_function;
5326                 label_pop_to(label_stack_top);
5327         }
5328
5329         POP_SCOPE();
5330 }
5331
5332 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5333 {
5334         entity_t *iter = compound->members.entities;
5335         for (; iter != NULL; iter = iter->base.next) {
5336                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5337                         continue;
5338
5339                 if (iter->base.symbol == symbol) {
5340                         return iter;
5341                 } else if (iter->base.symbol == NULL) {
5342                         /* search in anonymous structs and unions */
5343                         type_t *type = skip_typeref(iter->declaration.type);
5344                         if (is_type_compound(type)) {
5345                                 if (find_compound_entry(type->compound.compound, symbol)
5346                                                 != NULL)
5347                                         return iter;
5348                         }
5349                         continue;
5350                 }
5351         }
5352
5353         return NULL;
5354 }
5355
5356 static void check_deprecated(const source_position_t *source_position,
5357                              const entity_t *entity)
5358 {
5359         if (!is_declaration(entity))
5360                 return;
5361         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5362                 return;
5363
5364         source_position_t const *const epos = &entity->base.source_position;
5365         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5366         if (msg != NULL) {
5367                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5368         } else {
5369                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5370         }
5371 }
5372
5373
5374 static expression_t *create_select(const source_position_t *pos,
5375                                    expression_t *addr,
5376                                    type_qualifiers_t qualifiers,
5377                                                                    entity_t *entry)
5378 {
5379         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5380
5381         check_deprecated(pos, entry);
5382
5383         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5384         select->select.compound       = addr;
5385         select->select.compound_entry = entry;
5386
5387         type_t *entry_type = entry->declaration.type;
5388         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5389
5390         /* bitfields need special treatment */
5391         if (entry->compound_member.bitfield) {
5392                 unsigned bit_size = entry->compound_member.bit_size;
5393                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5394                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5395                         res_type = type_int;
5396                 }
5397         }
5398
5399         /* we always do the auto-type conversions; the & and sizeof parser contains
5400          * code to revert this! */
5401         select->base.type = automatic_type_conversion(res_type);
5402
5403
5404         return select;
5405 }
5406
5407 /**
5408  * Find entry with symbol in compound. Search anonymous structs and unions and
5409  * creates implicit select expressions for them.
5410  * Returns the adress for the innermost compound.
5411  */
5412 static expression_t *find_create_select(const source_position_t *pos,
5413                                         expression_t *addr,
5414                                         type_qualifiers_t qualifiers,
5415                                         compound_t *compound, symbol_t *symbol)
5416 {
5417         entity_t *iter = compound->members.entities;
5418         for (; iter != NULL; iter = iter->base.next) {
5419                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5420                         continue;
5421
5422                 symbol_t *iter_symbol = iter->base.symbol;
5423                 if (iter_symbol == NULL) {
5424                         type_t *type = iter->declaration.type;
5425                         if (!is_type_compound(type))
5426                                 continue;
5427
5428                         compound_t *sub_compound = type->compound.compound;
5429
5430                         if (find_compound_entry(sub_compound, symbol) == NULL)
5431                                 continue;
5432
5433                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5434                         sub_addr->base.source_position = *pos;
5435                         sub_addr->base.implicit        = true;
5436                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5437                                                   symbol);
5438                 }
5439
5440                 if (iter_symbol == symbol) {
5441                         return create_select(pos, addr, qualifiers, iter);
5442                 }
5443         }
5444
5445         return NULL;
5446 }
5447
5448 static void parse_bitfield_member(entity_t *entity)
5449 {
5450         eat(':');
5451
5452         expression_t *size = parse_constant_expression();
5453         long          size_long;
5454
5455         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5456         type_t *type = entity->declaration.type;
5457         if (!is_type_integer(skip_typeref(type))) {
5458                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5459                            type);
5460         }
5461
5462         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5463                 /* error already reported by parse_constant_expression */
5464                 size_long = get_type_size(type) * 8;
5465         } else {
5466                 size_long = fold_constant_to_int(size);
5467
5468                 const symbol_t *symbol = entity->base.symbol;
5469                 const symbol_t *user_symbol
5470                         = symbol == NULL ? sym_anonymous : symbol;
5471                 unsigned bit_size = get_type_size(type) * 8;
5472                 if (size_long < 0) {
5473                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5474                 } else if (size_long == 0 && symbol != NULL) {
5475                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5476                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5477                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5478                                    user_symbol);
5479                 } else {
5480                         /* hope that people don't invent crazy types with more bits
5481                          * than our struct can hold */
5482                         assert(size_long <
5483                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5484                 }
5485         }
5486
5487         entity->compound_member.bitfield = true;
5488         entity->compound_member.bit_size = (unsigned char)size_long;
5489 }
5490
5491 static void parse_compound_declarators(compound_t *compound,
5492                 const declaration_specifiers_t *specifiers)
5493 {
5494         add_anchor_token(';');
5495         add_anchor_token(',');
5496         do {
5497                 entity_t *entity;
5498
5499                 if (token.kind == ':') {
5500                         /* anonymous bitfield */
5501                         type_t *type = specifiers->type;
5502                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5503                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5504                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5505                         entity->declaration.type                   = type;
5506
5507                         parse_bitfield_member(entity);
5508
5509                         attribute_t  *attributes = parse_attributes(NULL);
5510                         attribute_t **anchor     = &attributes;
5511                         while (*anchor != NULL)
5512                                 anchor = &(*anchor)->next;
5513                         *anchor = specifiers->attributes;
5514                         if (attributes != NULL) {
5515                                 handle_entity_attributes(attributes, entity);
5516                         }
5517                         entity->declaration.attributes = attributes;
5518
5519                         append_entity(&compound->members, entity);
5520                 } else {
5521                         entity = parse_declarator(specifiers,
5522                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5523                         source_position_t const *const pos = &entity->base.source_position;
5524                         if (entity->kind == ENTITY_TYPEDEF) {
5525                                 errorf(pos, "typedef not allowed as compound member");
5526                         } else {
5527                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5528
5529                                 /* make sure we don't define a symbol multiple times */
5530                                 symbol_t *symbol = entity->base.symbol;
5531                                 if (symbol != NULL) {
5532                                         entity_t *prev = find_compound_entry(compound, symbol);
5533                                         if (prev != NULL) {
5534                                                 source_position_t const *const ppos = &prev->base.source_position;
5535                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5536                                         }
5537                                 }
5538
5539                                 if (token.kind == ':') {
5540                                         parse_bitfield_member(entity);
5541
5542                                         attribute_t *attributes = parse_attributes(NULL);
5543                                         handle_entity_attributes(attributes, entity);
5544                                 } else {
5545                                         type_t *orig_type = entity->declaration.type;
5546                                         type_t *type      = skip_typeref(orig_type);
5547                                         if (is_type_function(type)) {
5548                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5549                                         } else if (is_type_incomplete(type)) {
5550                                                 /* §6.7.2.1:16 flexible array member */
5551                                                 if (!is_type_array(type)       ||
5552                                                                 token.kind          != ';' ||
5553                                                                 look_ahead(1)->kind != '}') {
5554                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5555                                                 } else if (compound->members.entities == NULL) {
5556                                                         errorf(pos, "flexible array member in otherwise empty struct");
5557                                                 }
5558                                         }
5559                                 }
5560
5561                                 append_entity(&compound->members, entity);
5562                         }
5563                 }
5564         } while (next_if(','));
5565         rem_anchor_token(',');
5566         rem_anchor_token(';');
5567         expect(';');
5568
5569         anonymous_entity = NULL;
5570 }
5571
5572 static void parse_compound_type_entries(compound_t *compound)
5573 {
5574         eat('{');
5575         add_anchor_token('}');
5576
5577         for (;;) {
5578                 switch (token.kind) {
5579                         DECLARATION_START
5580                         case T___extension__:
5581                         case T_IDENTIFIER: {
5582                                 PUSH_EXTENSION();
5583                                 declaration_specifiers_t specifiers;
5584                                 parse_declaration_specifiers(&specifiers);
5585                                 parse_compound_declarators(compound, &specifiers);
5586                                 POP_EXTENSION();
5587                                 break;
5588                         }
5589
5590                         default:
5591                                 rem_anchor_token('}');
5592                                 expect('}');
5593                                 /* §6.7.2.1:7 */
5594                                 compound->complete = true;
5595                                 return;
5596                 }
5597         }
5598 }
5599
5600 static type_t *parse_typename(void)
5601 {
5602         declaration_specifiers_t specifiers;
5603         parse_declaration_specifiers(&specifiers);
5604         if (specifiers.storage_class != STORAGE_CLASS_NONE
5605                         || specifiers.thread_local) {
5606                 /* TODO: improve error message, user does probably not know what a
5607                  * storage class is...
5608                  */
5609                 errorf(&specifiers.source_position, "typename must not have a storage class");
5610         }
5611
5612         type_t *result = parse_abstract_declarator(specifiers.type);
5613
5614         return result;
5615 }
5616
5617
5618
5619
5620 typedef expression_t* (*parse_expression_function)(void);
5621 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5622
5623 typedef struct expression_parser_function_t expression_parser_function_t;
5624 struct expression_parser_function_t {
5625         parse_expression_function        parser;
5626         precedence_t                     infix_precedence;
5627         parse_expression_infix_function  infix_parser;
5628 };
5629
5630 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5631
5632 static type_t *get_string_type(string_encoding_t const enc)
5633 {
5634         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5635         switch (enc) {
5636         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5637         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5638         }
5639         panic("invalid string encoding");
5640 }
5641
5642 /**
5643  * Parse a string constant.
5644  */
5645 static expression_t *parse_string_literal(void)
5646 {
5647         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5648         expr->string_literal.value = concat_string_literals();
5649         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5650         return expr;
5651 }
5652
5653 /**
5654  * Parse a boolean constant.
5655  */
5656 static expression_t *parse_boolean_literal(bool value)
5657 {
5658         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5659         literal->base.type           = type_bool;
5660         literal->literal.value.begin = value ? "true" : "false";
5661         literal->literal.value.size  = value ? 4 : 5;
5662
5663         eat(value ? T_true : T_false);
5664         return literal;
5665 }
5666
5667 static void warn_traditional_suffix(char const *const suffix)
5668 {
5669         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5670 }
5671
5672 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5673 {
5674         unsigned     spec = SPECIFIER_NONE;
5675         char const  *c    = suffix;
5676         for (;;) {
5677                 specifiers_t add;
5678                 if (*c == 'L' || *c == 'l') {
5679                         add = SPECIFIER_LONG;
5680                         if (*c == c[1]) {
5681                                 add |= SPECIFIER_LONG_LONG;
5682                                 ++c;
5683                         }
5684                 } else if (*c == 'U' || *c == 'u') {
5685                         add = SPECIFIER_UNSIGNED;
5686                 } else {
5687                         break;
5688                 }
5689                 ++c;
5690                 if (spec & add)
5691                         goto error;
5692                 spec |= add;
5693         }
5694
5695         if (*c == '\0') {
5696                 type_t *type;
5697                 switch (spec) {
5698                 case SPECIFIER_NONE:                                            type = type_int;                break;
5699                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5700                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5701                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5702                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5703                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5704                 default: panic("inconsistent suffix");
5705                 }
5706                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5707                         warn_traditional_suffix(suffix);
5708                 }
5709                 expr->base.type = type;
5710                 /* Integer type depends on the size of the number and the size
5711                  * representable by the types. The backend/codegeneration has to
5712                  * determine that. */
5713                 determine_literal_type(&expr->literal);
5714         } else {
5715 error:
5716                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5717         }
5718 }
5719
5720 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5721 {
5722         type_t     *type;
5723         char const *c    = suffix;
5724         switch (*c) {
5725         case 'F':
5726         case 'f': type = type_float;       ++c; break;
5727         case 'L':
5728         case 'l': type = type_long_double; ++c; break;
5729         default:  type = type_double;           break;
5730         }
5731
5732         if (*c == '\0') {
5733                 expr->base.type = type;
5734                 if (suffix[0] != '\0') {
5735                         warn_traditional_suffix(suffix);
5736                 }
5737         } else {
5738                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5739         }
5740 }
5741
5742 static expression_t *parse_number_literal(void)
5743 {
5744         string_t const *const str      = &token.literal.string;
5745         char     const *      i        = str->begin;
5746         unsigned              digits   = 0;
5747         bool                  is_float = false;
5748
5749         /* Parse base prefix. */
5750         unsigned base;
5751         if (*i == '0') {
5752                 switch (*++i) {
5753                 case 'B': case 'b': base =  2; ++i;               break;
5754                 case 'X': case 'x': base = 16; ++i;               break;
5755                 default:            base =  8; digits |= 1U << 0; break;
5756                 }
5757         } else {
5758                 base = 10;
5759         }
5760
5761         /* Parse mantissa. */
5762         for (;; ++i) {
5763                 unsigned digit;
5764                 switch (*i) {
5765                 case '.':
5766                         if (is_float) {
5767                                 errorf(HERE, "multiple decimal points in %K", &token);
5768                                 i = 0;
5769                                 goto done;
5770                         }
5771                         is_float = true;
5772                         if (base == 8)
5773                                 base = 10;
5774                         continue;
5775
5776                 case '0':           digit =  0; break;
5777                 case '1':           digit =  1; break;
5778                 case '2':           digit =  2; break;
5779                 case '3':           digit =  3; break;
5780                 case '4':           digit =  4; break;
5781                 case '5':           digit =  5; break;
5782                 case '6':           digit =  6; break;
5783                 case '7':           digit =  7; break;
5784                 case '8':           digit =  8; break;
5785                 case '9':           digit =  9; break;
5786                 case 'A': case 'a': digit = 10; break;
5787                 case 'B': case 'b': digit = 11; break;
5788                 case 'C': case 'c': digit = 12; break;
5789                 case 'D': case 'd': digit = 13; break;
5790                 case 'E': case 'e': digit = 14; break;
5791                 case 'F': case 'f': digit = 15; break;
5792
5793                 default: goto done_mantissa;
5794                 }
5795
5796                 if (digit >= 10 && base != 16)
5797                         goto done_mantissa;
5798
5799                 digits |= 1U << digit;
5800         }
5801 done_mantissa:
5802
5803         /* Parse exponent. */
5804         switch (base) {
5805         case 2:
5806                 if (is_float)
5807                         errorf(HERE, "binary floating %K not allowed", &token);
5808                 break;
5809
5810         case  8:
5811         case 10:
5812                 if (*i == 'E' || *i == 'e') {
5813                         base = 10;
5814                         goto parse_exponent;
5815                 }
5816                 break;
5817
5818         case 16:
5819                 if (*i == 'P' || *i == 'p') {
5820 parse_exponent:
5821                         ++i;
5822                         is_float = true;
5823
5824                         if (*i == '-' || *i == '+')
5825                                 ++i;
5826
5827                         if (isdigit(*i)) {
5828                                 do {
5829                                         ++i;
5830                                 } while (isdigit(*i));
5831                         } else {
5832                                 errorf(HERE, "exponent of %K has no digits", &token);
5833                         }
5834                 } else if (is_float) {
5835                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5836                         i = 0;
5837                 }
5838                 break;
5839
5840         default:
5841                 panic("invalid base");
5842         }
5843
5844 done:;
5845         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5846         expr->literal.value = *str;
5847
5848         if (i) {
5849                 if (digits == 0) {
5850                         errorf(HERE, "%K has no digits", &token);
5851                 } else if (digits & ~((1U << base) - 1)) {
5852                         errorf(HERE, "invalid digit in %K", &token);
5853                 } else {
5854                         expr->literal.suffix = i;
5855                         if (is_float) {
5856                                 check_floatingpoint_suffix(expr, i);
5857                         } else {
5858                                 check_integer_suffix(expr, i);
5859                         }
5860                 }
5861         }
5862
5863         eat(T_NUMBER);
5864         return expr;
5865 }
5866
5867 /**
5868  * Parse a character constant.
5869  */
5870 static expression_t *parse_character_constant(void)
5871 {
5872         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5873         literal->string_literal.value = token.literal.string;
5874
5875         size_t const size = get_string_len(&token.literal.string);
5876         switch (token.literal.string.encoding) {
5877         case STRING_ENCODING_CHAR:
5878                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5879                 if (size > 1) {
5880                         if (!GNU_MODE && !(c_mode & _C99)) {
5881                                 errorf(HERE, "more than 1 character in character constant");
5882                         } else {
5883                                 literal->base.type = type_int;
5884                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5885                         }
5886                 }
5887                 break;
5888
5889         case STRING_ENCODING_WIDE:
5890                 literal->base.type = type_int;
5891                 if (size > 1) {
5892                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5893                 }
5894                 break;
5895         }
5896
5897         eat(T_CHARACTER_CONSTANT);
5898         return literal;
5899 }
5900
5901 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5902 {
5903         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5904         ntype->function.return_type            = type_int;
5905         ntype->function.unspecified_parameters = true;
5906         ntype->function.linkage                = LINKAGE_C;
5907         type_t *type                           = identify_new_type(ntype);
5908
5909         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5910         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5911         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5912         entity->declaration.type                   = type;
5913         entity->declaration.implicit               = true;
5914
5915         if (current_scope != NULL)
5916                 record_entity(entity, false);
5917
5918         return entity;
5919 }
5920
5921 /**
5922  * Performs automatic type cast as described in §6.3.2.1.
5923  *
5924  * @param orig_type  the original type
5925  */
5926 static type_t *automatic_type_conversion(type_t *orig_type)
5927 {
5928         type_t *type = skip_typeref(orig_type);
5929         if (is_type_array(type)) {
5930                 array_type_t *array_type   = &type->array;
5931                 type_t       *element_type = array_type->element_type;
5932                 unsigned      qualifiers   = array_type->base.qualifiers;
5933
5934                 return make_pointer_type(element_type, qualifiers);
5935         }
5936
5937         if (is_type_function(type)) {
5938                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5939         }
5940
5941         return orig_type;
5942 }
5943
5944 /**
5945  * reverts the automatic casts of array to pointer types and function
5946  * to function-pointer types as defined §6.3.2.1
5947  */
5948 type_t *revert_automatic_type_conversion(const expression_t *expression)
5949 {
5950         switch (expression->kind) {
5951         case EXPR_REFERENCE: {
5952                 entity_t *entity = expression->reference.entity;
5953                 if (is_declaration(entity)) {
5954                         return entity->declaration.type;
5955                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5956                         return entity->enum_value.enum_type;
5957                 } else {
5958                         panic("no declaration or enum in reference");
5959                 }
5960         }
5961
5962         case EXPR_SELECT: {
5963                 entity_t *entity = expression->select.compound_entry;
5964                 assert(is_declaration(entity));
5965                 type_t   *type   = entity->declaration.type;
5966                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5967         }
5968
5969         case EXPR_UNARY_DEREFERENCE: {
5970                 const expression_t *const value = expression->unary.value;
5971                 type_t             *const type  = skip_typeref(value->base.type);
5972                 if (!is_type_pointer(type))
5973                         return type_error_type;
5974                 return type->pointer.points_to;
5975         }
5976
5977         case EXPR_ARRAY_ACCESS: {
5978                 const expression_t *array_ref = expression->array_access.array_ref;
5979                 type_t             *type_left = skip_typeref(array_ref->base.type);
5980                 if (!is_type_pointer(type_left))
5981                         return type_error_type;
5982                 return type_left->pointer.points_to;
5983         }
5984
5985         case EXPR_STRING_LITERAL: {
5986                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
5987                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5988                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5989         }
5990
5991         case EXPR_COMPOUND_LITERAL:
5992                 return expression->compound_literal.type;
5993
5994         default:
5995                 break;
5996         }
5997         return expression->base.type;
5998 }
5999
6000 /**
6001  * Find an entity matching a symbol in a scope.
6002  * Uses current scope if scope is NULL
6003  */
6004 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6005                                namespace_tag_t namespc)
6006 {
6007         if (scope == NULL) {
6008                 return get_entity(symbol, namespc);
6009         }
6010
6011         /* we should optimize here, if scope grows above a certain size we should
6012            construct a hashmap here... */
6013         entity_t *entity = scope->entities;
6014         for ( ; entity != NULL; entity = entity->base.next) {
6015                 if (entity->base.symbol == symbol
6016                     && (namespace_tag_t)entity->base.namespc == namespc)
6017                         break;
6018         }
6019
6020         return entity;
6021 }
6022
6023 static entity_t *parse_qualified_identifier(void)
6024 {
6025         /* namespace containing the symbol */
6026         symbol_t          *symbol;
6027         source_position_t  pos;
6028         const scope_t     *lookup_scope = NULL;
6029
6030         if (next_if(T_COLONCOLON))
6031                 lookup_scope = &unit->scope;
6032
6033         entity_t *entity;
6034         while (true) {
6035                 symbol = expect_identifier("while parsing identifier", &pos);
6036                 if (!symbol)
6037                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6038
6039                 /* lookup entity */
6040                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6041
6042                 if (!next_if(T_COLONCOLON))
6043                         break;
6044
6045                 switch (entity->kind) {
6046                 case ENTITY_NAMESPACE:
6047                         lookup_scope = &entity->namespacee.members;
6048                         break;
6049                 case ENTITY_STRUCT:
6050                 case ENTITY_UNION:
6051                 case ENTITY_CLASS:
6052                         lookup_scope = &entity->compound.members;
6053                         break;
6054                 default:
6055                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6056                                symbol, get_entity_kind_name(entity->kind));
6057
6058                         /* skip further qualifications */
6059                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6060
6061                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6062                 }
6063         }
6064
6065         if (entity == NULL) {
6066                 if (!strict_mode && token.kind == '(') {
6067                         /* an implicitly declared function */
6068                         entity = create_implicit_function(symbol, &pos);
6069                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6070                 } else {
6071                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6072                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6073                 }
6074         }
6075
6076         return entity;
6077 }
6078
6079 static expression_t *parse_reference(void)
6080 {
6081         source_position_t const pos    = *HERE;
6082         entity_t         *const entity = parse_qualified_identifier();
6083
6084         type_t *orig_type;
6085         if (is_declaration(entity)) {
6086                 orig_type = entity->declaration.type;
6087         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6088                 orig_type = entity->enum_value.enum_type;
6089         } else {
6090                 panic("expected declaration or enum value in reference");
6091         }
6092
6093         /* we always do the auto-type conversions; the & and sizeof parser contains
6094          * code to revert this! */
6095         type_t *type = automatic_type_conversion(orig_type);
6096
6097         expression_kind_t kind = EXPR_REFERENCE;
6098         if (entity->kind == ENTITY_ENUM_VALUE)
6099                 kind = EXPR_ENUM_CONSTANT;
6100
6101         expression_t *expression         = allocate_expression_zero(kind);
6102         expression->base.source_position = pos;
6103         expression->base.type            = type;
6104         expression->reference.entity     = entity;
6105
6106         /* this declaration is used */
6107         if (is_declaration(entity)) {
6108                 entity->declaration.used = true;
6109         }
6110
6111         if (entity->base.parent_scope != file_scope
6112                 && (current_function != NULL
6113                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6114                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6115                 /* access of a variable from an outer function */
6116                 entity->variable.address_taken = true;
6117                 current_function->need_closure = true;
6118         }
6119
6120         check_deprecated(&pos, entity);
6121
6122         return expression;
6123 }
6124
6125 static bool semantic_cast(expression_t *cast)
6126 {
6127         expression_t            *expression      = cast->unary.value;
6128         type_t                  *orig_dest_type  = cast->base.type;
6129         type_t                  *orig_type_right = expression->base.type;
6130         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6131         type_t            const *src_type        = skip_typeref(orig_type_right);
6132         source_position_t const *pos             = &cast->base.source_position;
6133
6134         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6135         if (is_type_void(dst_type))
6136                 return true;
6137
6138         /* only integer and pointer can be casted to pointer */
6139         if (is_type_pointer(dst_type)  &&
6140             !is_type_pointer(src_type) &&
6141             !is_type_integer(src_type) &&
6142             is_type_valid(src_type)) {
6143                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6144                 return false;
6145         }
6146
6147         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6148                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6149                 return false;
6150         }
6151
6152         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6153                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6154                 return false;
6155         }
6156
6157         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6158                 type_t *src = skip_typeref(src_type->pointer.points_to);
6159                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6160                 unsigned missing_qualifiers =
6161                         src->base.qualifiers & ~dst->base.qualifiers;
6162                 if (missing_qualifiers != 0) {
6163                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6164                 }
6165         }
6166         return true;
6167 }
6168
6169 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6170 {
6171         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6172         expression->base.source_position = *pos;
6173
6174         parse_initializer_env_t env;
6175         env.type             = type;
6176         env.entity           = NULL;
6177         env.must_be_constant = false;
6178         initializer_t *initializer = parse_initializer(&env);
6179         type = env.type;
6180
6181         expression->compound_literal.initializer = initializer;
6182         expression->compound_literal.type        = type;
6183         expression->base.type                    = automatic_type_conversion(type);
6184
6185         return expression;
6186 }
6187
6188 /**
6189  * Parse a cast expression.
6190  */
6191 static expression_t *parse_cast(void)
6192 {
6193         source_position_t const pos = *HERE;
6194
6195         eat('(');
6196         add_anchor_token(')');
6197
6198         type_t *type = parse_typename();
6199
6200         rem_anchor_token(')');
6201         expect(')');
6202
6203         if (token.kind == '{') {
6204                 return parse_compound_literal(&pos, type);
6205         }
6206
6207         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6208         cast->base.source_position = pos;
6209
6210         expression_t *value = parse_subexpression(PREC_CAST);
6211         cast->base.type   = type;
6212         cast->unary.value = value;
6213
6214         if (! semantic_cast(cast)) {
6215                 /* TODO: record the error in the AST. else it is impossible to detect it */
6216         }
6217
6218         return cast;
6219 }
6220
6221 /**
6222  * Parse a statement expression.
6223  */
6224 static expression_t *parse_statement_expression(void)
6225 {
6226         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6227
6228         eat('(');
6229         add_anchor_token(')');
6230
6231         statement_t *statement          = parse_compound_statement(true);
6232         statement->compound.stmt_expr   = true;
6233         expression->statement.statement = statement;
6234
6235         /* find last statement and use its type */
6236         type_t *type = type_void;
6237         const statement_t *stmt = statement->compound.statements;
6238         if (stmt != NULL) {
6239                 while (stmt->base.next != NULL)
6240                         stmt = stmt->base.next;
6241
6242                 if (stmt->kind == STATEMENT_EXPRESSION) {
6243                         type = stmt->expression.expression->base.type;
6244                 }
6245         } else {
6246                 source_position_t const *const pos = &expression->base.source_position;
6247                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6248         }
6249         expression->base.type = type;
6250
6251         rem_anchor_token(')');
6252         expect(')');
6253         return expression;
6254 }
6255
6256 /**
6257  * Parse a parenthesized expression.
6258  */
6259 static expression_t *parse_parenthesized_expression(void)
6260 {
6261         token_t const* const la1 = look_ahead(1);
6262         switch (la1->kind) {
6263         case '{':
6264                 /* gcc extension: a statement expression */
6265                 return parse_statement_expression();
6266
6267         case T_IDENTIFIER:
6268                 if (is_typedef_symbol(la1->base.symbol)) {
6269         DECLARATION_START
6270                         return parse_cast();
6271                 }
6272         }
6273
6274         eat('(');
6275         add_anchor_token(')');
6276         expression_t *result = parse_expression();
6277         result->base.parenthesized = true;
6278         rem_anchor_token(')');
6279         expect(')');
6280
6281         return result;
6282 }
6283
6284 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6285 {
6286         if (current_function == NULL) {
6287                 errorf(HERE, "'%K' used outside of a function", &token);
6288         }
6289
6290         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6291         expression->base.type     = type_char_ptr;
6292         expression->funcname.kind = kind;
6293
6294         next_token();
6295
6296         return expression;
6297 }
6298
6299 static designator_t *parse_designator(void)
6300 {
6301         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6302         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6303         if (!result->symbol)
6304                 return NULL;
6305
6306         designator_t *last_designator = result;
6307         while (true) {
6308                 if (next_if('.')) {
6309                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6310                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6311                         if (!designator->symbol)
6312                                 return NULL;
6313
6314                         last_designator->next = designator;
6315                         last_designator       = designator;
6316                         continue;
6317                 }
6318                 if (next_if('[')) {
6319                         add_anchor_token(']');
6320                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6321                         designator->source_position = *HERE;
6322                         designator->array_index     = parse_expression();
6323                         rem_anchor_token(']');
6324                         expect(']');
6325                         if (designator->array_index == NULL) {
6326                                 return NULL;
6327                         }
6328
6329                         last_designator->next = designator;
6330                         last_designator       = designator;
6331                         continue;
6332                 }
6333                 break;
6334         }
6335
6336         return result;
6337 }
6338
6339 /**
6340  * Parse the __builtin_offsetof() expression.
6341  */
6342 static expression_t *parse_offsetof(void)
6343 {
6344         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6345         expression->base.type    = type_size_t;
6346
6347         eat(T___builtin_offsetof);
6348
6349         add_anchor_token(')');
6350         add_anchor_token(',');
6351         expect('(');
6352         type_t *type = parse_typename();
6353         rem_anchor_token(',');
6354         expect(',');
6355         designator_t *designator = parse_designator();
6356         rem_anchor_token(')');
6357         expect(')');
6358
6359         expression->offsetofe.type       = type;
6360         expression->offsetofe.designator = designator;
6361
6362         type_path_t path;
6363         memset(&path, 0, sizeof(path));
6364         path.top_type = type;
6365         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6366
6367         descend_into_subtype(&path);
6368
6369         if (!walk_designator(&path, designator, true)) {
6370                 return create_error_expression();
6371         }
6372
6373         DEL_ARR_F(path.path);
6374
6375         return expression;
6376 }
6377
6378 static bool is_last_parameter(expression_t *const param)
6379 {
6380         if (param->kind == EXPR_REFERENCE) {
6381                 entity_t *const entity = param->reference.entity;
6382                 if (entity->kind == ENTITY_PARAMETER &&
6383                     !entity->base.next               &&
6384                     entity->base.parent_scope == &current_function->parameters) {
6385                         return true;
6386                 }
6387         }
6388
6389         if (!is_type_valid(skip_typeref(param->base.type)))
6390                 return true;
6391
6392         return false;
6393 }
6394
6395 /**
6396  * Parses a __builtin_va_start() expression.
6397  */
6398 static expression_t *parse_va_start(void)
6399 {
6400         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6401
6402         eat(T___builtin_va_start);
6403
6404         add_anchor_token(')');
6405         add_anchor_token(',');
6406         expect('(');
6407         expression->va_starte.ap = parse_assignment_expression();
6408         rem_anchor_token(',');
6409         expect(',');
6410         expression_t *const param = parse_assignment_expression();
6411         expression->va_starte.parameter = param;
6412         rem_anchor_token(')');
6413         expect(')');
6414
6415         if (!current_function) {
6416                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6417         } else if (!current_function->base.type->function.variadic) {
6418                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6419         } else if (!is_last_parameter(param)) {
6420                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6421         }
6422
6423         return expression;
6424 }
6425
6426 /**
6427  * Parses a __builtin_va_arg() expression.
6428  */
6429 static expression_t *parse_va_arg(void)
6430 {
6431         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6432
6433         eat(T___builtin_va_arg);
6434
6435         add_anchor_token(')');
6436         add_anchor_token(',');
6437         expect('(');
6438         call_argument_t ap;
6439         ap.expression = parse_assignment_expression();
6440         expression->va_arge.ap = ap.expression;
6441         check_call_argument(type_valist, &ap, 1);
6442
6443         rem_anchor_token(',');
6444         expect(',');
6445         expression->base.type = parse_typename();
6446         rem_anchor_token(')');
6447         expect(')');
6448
6449         return expression;
6450 }
6451
6452 /**
6453  * Parses a __builtin_va_copy() expression.
6454  */
6455 static expression_t *parse_va_copy(void)
6456 {
6457         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6458
6459         eat(T___builtin_va_copy);
6460
6461         add_anchor_token(')');
6462         add_anchor_token(',');
6463         expect('(');
6464         expression_t *dst = parse_assignment_expression();
6465         assign_error_t error = semantic_assign(type_valist, dst);
6466         report_assign_error(error, type_valist, dst, "call argument 1",
6467                             &dst->base.source_position);
6468         expression->va_copye.dst = dst;
6469
6470         rem_anchor_token(',');
6471         expect(',');
6472
6473         call_argument_t src;
6474         src.expression = parse_assignment_expression();
6475         check_call_argument(type_valist, &src, 2);
6476         expression->va_copye.src = src.expression;
6477         rem_anchor_token(')');
6478         expect(')');
6479
6480         return expression;
6481 }
6482
6483 /**
6484  * Parses a __builtin_constant_p() expression.
6485  */
6486 static expression_t *parse_builtin_constant(void)
6487 {
6488         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6489
6490         eat(T___builtin_constant_p);
6491
6492         add_anchor_token(')');
6493         expect('(');
6494         expression->builtin_constant.value = parse_assignment_expression();
6495         rem_anchor_token(')');
6496         expect(')');
6497         expression->base.type = type_int;
6498
6499         return expression;
6500 }
6501
6502 /**
6503  * Parses a __builtin_types_compatible_p() expression.
6504  */
6505 static expression_t *parse_builtin_types_compatible(void)
6506 {
6507         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6508
6509         eat(T___builtin_types_compatible_p);
6510
6511         add_anchor_token(')');
6512         add_anchor_token(',');
6513         expect('(');
6514         expression->builtin_types_compatible.left = parse_typename();
6515         rem_anchor_token(',');
6516         expect(',');
6517         expression->builtin_types_compatible.right = parse_typename();
6518         rem_anchor_token(')');
6519         expect(')');
6520         expression->base.type = type_int;
6521
6522         return expression;
6523 }
6524
6525 /**
6526  * Parses a __builtin_is_*() compare expression.
6527  */
6528 static expression_t *parse_compare_builtin(void)
6529 {
6530         expression_kind_t kind;
6531         switch (token.kind) {
6532         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6533         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6534         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6535         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6536         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6537         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6538         default: internal_errorf(HERE, "invalid compare builtin found");
6539         }
6540         expression_t *const expression = allocate_expression_zero(kind);
6541         next_token();
6542
6543         add_anchor_token(')');
6544         add_anchor_token(',');
6545         expect('(');
6546         expression->binary.left = parse_assignment_expression();
6547         rem_anchor_token(',');
6548         expect(',');
6549         expression->binary.right = parse_assignment_expression();
6550         rem_anchor_token(')');
6551         expect(')');
6552
6553         type_t *const orig_type_left  = expression->binary.left->base.type;
6554         type_t *const orig_type_right = expression->binary.right->base.type;
6555
6556         type_t *const type_left  = skip_typeref(orig_type_left);
6557         type_t *const type_right = skip_typeref(orig_type_right);
6558         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6559                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6560                         type_error_incompatible("invalid operands in comparison",
6561                                 &expression->base.source_position, orig_type_left, orig_type_right);
6562                 }
6563         } else {
6564                 semantic_comparison(&expression->binary);
6565         }
6566
6567         return expression;
6568 }
6569
6570 /**
6571  * Parses a MS assume() expression.
6572  */
6573 static expression_t *parse_assume(void)
6574 {
6575         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6576
6577         eat(T__assume);
6578
6579         add_anchor_token(')');
6580         expect('(');
6581         expression->unary.value = parse_assignment_expression();
6582         rem_anchor_token(')');
6583         expect(')');
6584
6585         expression->base.type = type_void;
6586         return expression;
6587 }
6588
6589 /**
6590  * Return the label for the current symbol or create a new one.
6591  */
6592 static label_t *get_label(char const *const context)
6593 {
6594         assert(current_function != NULL);
6595
6596         symbol_t *const sym = expect_identifier(context, NULL);
6597         if (!sym)
6598                 return NULL;
6599
6600         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6601         /* If we find a local label, we already created the declaration. */
6602         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6603                 if (label->base.parent_scope != current_scope) {
6604                         assert(label->base.parent_scope->depth < current_scope->depth);
6605                         current_function->goto_to_outer = true;
6606                 }
6607         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6608                 /* There is no matching label in the same function, so create a new one. */
6609                 source_position_t const nowhere = { NULL, 0, 0, false };
6610                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6611                 label_push(label);
6612         }
6613
6614         return &label->label;
6615 }
6616
6617 /**
6618  * Parses a GNU && label address expression.
6619  */
6620 static expression_t *parse_label_address(void)
6621 {
6622         source_position_t const source_position = *HERE;
6623         eat(T_ANDAND);
6624
6625         label_t *const label = get_label("while parsing label address");
6626         if (!label)
6627                 return create_error_expression();
6628
6629         label->used          = true;
6630         label->address_taken = true;
6631
6632         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6633         expression->base.source_position = source_position;
6634
6635         /* label address is treated as a void pointer */
6636         expression->base.type           = type_void_ptr;
6637         expression->label_address.label = label;
6638         return expression;
6639 }
6640
6641 /**
6642  * Parse a microsoft __noop expression.
6643  */
6644 static expression_t *parse_noop_expression(void)
6645 {
6646         /* the result is a (int)0 */
6647         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6648         literal->base.type           = type_int;
6649         literal->literal.value.begin = "__noop";
6650         literal->literal.value.size  = 6;
6651
6652         eat(T___noop);
6653
6654         if (token.kind == '(') {
6655                 /* parse arguments */
6656                 eat('(');
6657                 add_anchor_token(')');
6658                 add_anchor_token(',');
6659
6660                 if (token.kind != ')') do {
6661                         (void)parse_assignment_expression();
6662                 } while (next_if(','));
6663
6664                 rem_anchor_token(',');
6665                 rem_anchor_token(')');
6666         }
6667         expect(')');
6668
6669         return literal;
6670 }
6671
6672 /**
6673  * Parses a primary expression.
6674  */
6675 static expression_t *parse_primary_expression(void)
6676 {
6677         switch (token.kind) {
6678         case T_false:                        return parse_boolean_literal(false);
6679         case T_true:                         return parse_boolean_literal(true);
6680         case T_NUMBER:                       return parse_number_literal();
6681         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6682         case T_STRING_LITERAL:               return parse_string_literal();
6683         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6684         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6685         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6686         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6687         case T___builtin_offsetof:           return parse_offsetof();
6688         case T___builtin_va_start:           return parse_va_start();
6689         case T___builtin_va_arg:             return parse_va_arg();
6690         case T___builtin_va_copy:            return parse_va_copy();
6691         case T___builtin_isgreater:
6692         case T___builtin_isgreaterequal:
6693         case T___builtin_isless:
6694         case T___builtin_islessequal:
6695         case T___builtin_islessgreater:
6696         case T___builtin_isunordered:        return parse_compare_builtin();
6697         case T___builtin_constant_p:         return parse_builtin_constant();
6698         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6699         case T__assume:                      return parse_assume();
6700         case T_ANDAND:
6701                 if (GNU_MODE)
6702                         return parse_label_address();
6703                 break;
6704
6705         case '(':                            return parse_parenthesized_expression();
6706         case T___noop:                       return parse_noop_expression();
6707
6708         /* Gracefully handle type names while parsing expressions. */
6709         case T_COLONCOLON:
6710                 return parse_reference();
6711         case T_IDENTIFIER:
6712                 if (!is_typedef_symbol(token.base.symbol)) {
6713                         return parse_reference();
6714                 }
6715                 /* FALLTHROUGH */
6716         DECLARATION_START {
6717                 source_position_t const  pos = *HERE;
6718                 declaration_specifiers_t specifiers;
6719                 parse_declaration_specifiers(&specifiers);
6720                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6721                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6722                 return create_error_expression();
6723         }
6724         }
6725
6726         errorf(HERE, "unexpected token %K, expected an expression", &token);
6727         eat_until_anchor();
6728         return create_error_expression();
6729 }
6730
6731 static expression_t *parse_array_expression(expression_t *left)
6732 {
6733         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6734         array_access_expression_t *const arr  = &expr->array_access;
6735
6736         eat('[');
6737         add_anchor_token(']');
6738
6739         expression_t *const inside = parse_expression();
6740
6741         type_t *const orig_type_left   = left->base.type;
6742         type_t *const orig_type_inside = inside->base.type;
6743
6744         type_t *const type_left   = skip_typeref(orig_type_left);
6745         type_t *const type_inside = skip_typeref(orig_type_inside);
6746
6747         expression_t *ref;
6748         expression_t *idx;
6749         type_t       *idx_type;
6750         type_t       *res_type;
6751         if (is_type_pointer(type_left)) {
6752                 ref      = left;
6753                 idx      = inside;
6754                 idx_type = type_inside;
6755                 res_type = type_left->pointer.points_to;
6756                 goto check_idx;
6757         } else if (is_type_pointer(type_inside)) {
6758                 arr->flipped = true;
6759                 ref      = inside;
6760                 idx      = left;
6761                 idx_type = type_left;
6762                 res_type = type_inside->pointer.points_to;
6763 check_idx:
6764                 res_type = automatic_type_conversion(res_type);
6765                 if (!is_type_integer(idx_type)) {
6766                         errorf(&idx->base.source_position, "array subscript must have integer type");
6767                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6768                         source_position_t const *const pos = &idx->base.source_position;
6769                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6770                 }
6771         } else {
6772                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6773                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6774                 }
6775                 res_type = type_error_type;
6776                 ref      = left;
6777                 idx      = inside;
6778         }
6779
6780         arr->array_ref = ref;
6781         arr->index     = idx;
6782         arr->base.type = res_type;
6783
6784         rem_anchor_token(']');
6785         expect(']');
6786         return expr;
6787 }
6788
6789 static bool is_bitfield(const expression_t *expression)
6790 {
6791         return expression->kind == EXPR_SELECT
6792                 && expression->select.compound_entry->compound_member.bitfield;
6793 }
6794
6795 static expression_t *parse_typeprop(expression_kind_t const kind)
6796 {
6797         expression_t  *tp_expression = allocate_expression_zero(kind);
6798         tp_expression->base.type     = type_size_t;
6799
6800         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6801
6802         type_t       *orig_type;
6803         expression_t *expression;
6804         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6805                 source_position_t const pos = *HERE;
6806                 eat('(');
6807                 add_anchor_token(')');
6808                 orig_type = parse_typename();
6809                 rem_anchor_token(')');
6810                 expect(')');
6811
6812                 if (token.kind == '{') {
6813                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6814                          * starting with a compound literal */
6815                         expression = parse_compound_literal(&pos, orig_type);
6816                         goto typeprop_expression;
6817                 }
6818         } else {
6819                 expression = parse_subexpression(PREC_UNARY);
6820
6821 typeprop_expression:
6822                 if (is_bitfield(expression)) {
6823                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6824                         errorf(&tp_expression->base.source_position,
6825                                    "operand of %s expression must not be a bitfield", what);
6826                 }
6827
6828                 tp_expression->typeprop.tp_expression = expression;
6829
6830                 orig_type = revert_automatic_type_conversion(expression);
6831                 expression->base.type = orig_type;
6832         }
6833
6834         tp_expression->typeprop.type   = orig_type;
6835         type_t const* const type       = skip_typeref(orig_type);
6836         char   const*       wrong_type = NULL;
6837         if (is_type_incomplete(type)) {
6838                 if (!is_type_void(type) || !GNU_MODE)
6839                         wrong_type = "incomplete";
6840         } else if (type->kind == TYPE_FUNCTION) {
6841                 if (GNU_MODE) {
6842                         /* function types are allowed (and return 1) */
6843                         source_position_t const *const pos  = &tp_expression->base.source_position;
6844                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6845                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6846                 } else {
6847                         wrong_type = "function";
6848                 }
6849         }
6850
6851         if (wrong_type != NULL) {
6852                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6853                 errorf(&tp_expression->base.source_position,
6854                                 "operand of %s expression must not be of %s type '%T'",
6855                                 what, wrong_type, orig_type);
6856         }
6857
6858         return tp_expression;
6859 }
6860
6861 static expression_t *parse_sizeof(void)
6862 {
6863         return parse_typeprop(EXPR_SIZEOF);
6864 }
6865
6866 static expression_t *parse_alignof(void)
6867 {
6868         return parse_typeprop(EXPR_ALIGNOF);
6869 }
6870
6871 static expression_t *parse_select_expression(expression_t *addr)
6872 {
6873         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6874         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6875         source_position_t const pos = *HERE;
6876         next_token();
6877
6878         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6879         if (!symbol)
6880                 return create_error_expression();
6881
6882         type_t *const orig_type = addr->base.type;
6883         type_t *const type      = skip_typeref(orig_type);
6884
6885         type_t *type_left;
6886         bool    saw_error = false;
6887         if (is_type_pointer(type)) {
6888                 if (!select_left_arrow) {
6889                         errorf(&pos,
6890                                "request for member '%Y' in something not a struct or union, but '%T'",
6891                                symbol, orig_type);
6892                         saw_error = true;
6893                 }
6894                 type_left = skip_typeref(type->pointer.points_to);
6895         } else {
6896                 if (select_left_arrow && is_type_valid(type)) {
6897                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6898                         saw_error = true;
6899                 }
6900                 type_left = type;
6901         }
6902
6903         if (!is_type_compound(type_left)) {
6904                 if (is_type_valid(type_left) && !saw_error) {
6905                         errorf(&pos,
6906                                "request for member '%Y' in something not a struct or union, but '%T'",
6907                                symbol, type_left);
6908                 }
6909                 return create_error_expression();
6910         }
6911
6912         compound_t *compound = type_left->compound.compound;
6913         if (!compound->complete) {
6914                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6915                        symbol, type_left);
6916                 return create_error_expression();
6917         }
6918
6919         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6920         expression_t      *result     =
6921                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6922
6923         if (result == NULL) {
6924                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6925                 return create_error_expression();
6926         }
6927
6928         return result;
6929 }
6930
6931 static void check_call_argument(type_t          *expected_type,
6932                                 call_argument_t *argument, unsigned pos)
6933 {
6934         type_t         *expected_type_skip = skip_typeref(expected_type);
6935         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6936         expression_t   *arg_expr           = argument->expression;
6937         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6938
6939         /* handle transparent union gnu extension */
6940         if (is_type_union(expected_type_skip)
6941                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6942                 compound_t *union_decl  = expected_type_skip->compound.compound;
6943                 type_t     *best_type   = NULL;
6944                 entity_t   *entry       = union_decl->members.entities;
6945                 for ( ; entry != NULL; entry = entry->base.next) {
6946                         assert(is_declaration(entry));
6947                         type_t *decl_type = entry->declaration.type;
6948                         error = semantic_assign(decl_type, arg_expr);
6949                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6950                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6951                                 continue;
6952
6953                         if (error == ASSIGN_SUCCESS) {
6954                                 best_type = decl_type;
6955                         } else if (best_type == NULL) {
6956                                 best_type = decl_type;
6957                         }
6958                 }
6959
6960                 if (best_type != NULL) {
6961                         expected_type = best_type;
6962                 }
6963         }
6964
6965         error                = semantic_assign(expected_type, arg_expr);
6966         argument->expression = create_implicit_cast(arg_expr, expected_type);
6967
6968         if (error != ASSIGN_SUCCESS) {
6969                 /* report exact scope in error messages (like "in argument 3") */
6970                 char buf[64];
6971                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6972                 report_assign_error(error, expected_type, arg_expr, buf,
6973                                     &arg_expr->base.source_position);
6974         } else {
6975                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6976                 if (!types_compatible(expected_type_skip, promoted_type) &&
6977                     !types_compatible(expected_type_skip, type_void_ptr) &&
6978                     !types_compatible(type_void_ptr,      promoted_type)) {
6979                         /* Deliberately show the skipped types in this warning */
6980                         source_position_t const *const apos = &arg_expr->base.source_position;
6981                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6982                 }
6983         }
6984 }
6985
6986 /**
6987  * Handle the semantic restrictions of builtin calls
6988  */
6989 static void handle_builtin_argument_restrictions(call_expression_t *call)
6990 {
6991         entity_t *entity = call->function->reference.entity;
6992         switch (entity->function.btk) {
6993         case BUILTIN_FIRM:
6994                 switch (entity->function.b.firm_builtin_kind) {
6995                 case ir_bk_return_address:
6996                 case ir_bk_frame_address: {
6997                         /* argument must be constant */
6998                         call_argument_t *argument = call->arguments;
6999
7000                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7001                                 errorf(&call->base.source_position,
7002                                            "argument of '%Y' must be a constant expression",
7003                                            call->function->reference.entity->base.symbol);
7004                         }
7005                         break;
7006                 }
7007                 case ir_bk_prefetch:
7008                         /* second and third argument must be constant if existent */
7009                         if (call->arguments == NULL)
7010                                 break;
7011                         call_argument_t *rw = call->arguments->next;
7012                         call_argument_t *locality = NULL;
7013
7014                         if (rw != NULL) {
7015                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7016                                         errorf(&call->base.source_position,
7017                                                    "second argument of '%Y' must be a constant expression",
7018                                                    call->function->reference.entity->base.symbol);
7019                                 }
7020                                 locality = rw->next;
7021                         }
7022                         if (locality != NULL) {
7023                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7024                                         errorf(&call->base.source_position,
7025                                                    "third argument of '%Y' must be a constant expression",
7026                                                    call->function->reference.entity->base.symbol);
7027                                 }
7028                         }
7029                         break;
7030                 default:
7031                         break;
7032                 }
7033
7034         case BUILTIN_OBJECT_SIZE:
7035                 if (call->arguments == NULL)
7036                         break;
7037
7038                 call_argument_t *arg = call->arguments->next;
7039                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7040                         errorf(&call->base.source_position,
7041                                    "second argument of '%Y' must be a constant expression",
7042                                    call->function->reference.entity->base.symbol);
7043                 }
7044                 break;
7045         default:
7046                 break;
7047         }
7048 }
7049
7050 /**
7051  * Parse a call expression, ie. expression '( ... )'.
7052  *
7053  * @param expression  the function address
7054  */
7055 static expression_t *parse_call_expression(expression_t *expression)
7056 {
7057         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7058         call_expression_t *call   = &result->call;
7059         call->function            = expression;
7060
7061         type_t *const orig_type = expression->base.type;
7062         type_t *const type      = skip_typeref(orig_type);
7063
7064         function_type_t *function_type = NULL;
7065         if (is_type_pointer(type)) {
7066                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7067
7068                 if (is_type_function(to_type)) {
7069                         function_type   = &to_type->function;
7070                         call->base.type = function_type->return_type;
7071                 }
7072         }
7073
7074         if (function_type == NULL && is_type_valid(type)) {
7075                 errorf(HERE,
7076                        "called object '%E' (type '%T') is not a pointer to a function",
7077                        expression, orig_type);
7078         }
7079
7080         /* parse arguments */
7081         eat('(');
7082         add_anchor_token(')');
7083         add_anchor_token(',');
7084
7085         if (token.kind != ')') {
7086                 call_argument_t **anchor = &call->arguments;
7087                 do {
7088                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7089                         argument->expression = parse_assignment_expression();
7090
7091                         *anchor = argument;
7092                         anchor  = &argument->next;
7093                 } while (next_if(','));
7094         }
7095         rem_anchor_token(',');
7096         rem_anchor_token(')');
7097         expect(')');
7098
7099         if (function_type == NULL)
7100                 return result;
7101
7102         /* check type and count of call arguments */
7103         function_parameter_t *parameter = function_type->parameters;
7104         call_argument_t      *argument  = call->arguments;
7105         if (!function_type->unspecified_parameters) {
7106                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7107                                 parameter = parameter->next, argument = argument->next) {
7108                         check_call_argument(parameter->type, argument, ++pos);
7109                 }
7110
7111                 if (parameter != NULL) {
7112                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7113                 } else if (argument != NULL && !function_type->variadic) {
7114                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7115                 }
7116         }
7117
7118         /* do default promotion for other arguments */
7119         for (; argument != NULL; argument = argument->next) {
7120                 type_t *argument_type = argument->expression->base.type;
7121                 if (!is_type_object(skip_typeref(argument_type))) {
7122                         errorf(&argument->expression->base.source_position,
7123                                "call argument '%E' must not be void", argument->expression);
7124                 }
7125
7126                 argument_type = get_default_promoted_type(argument_type);
7127
7128                 argument->expression
7129                         = create_implicit_cast(argument->expression, argument_type);
7130         }
7131
7132         check_format(call);
7133
7134         if (is_type_compound(skip_typeref(function_type->return_type))) {
7135                 source_position_t const *const pos = &expression->base.source_position;
7136                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7137         }
7138
7139         if (expression->kind == EXPR_REFERENCE) {
7140                 reference_expression_t *reference = &expression->reference;
7141                 if (reference->entity->kind == ENTITY_FUNCTION &&
7142                     reference->entity->function.btk != BUILTIN_NONE)
7143                         handle_builtin_argument_restrictions(call);
7144         }
7145
7146         return result;
7147 }
7148
7149 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7150
7151 static bool same_compound_type(const type_t *type1, const type_t *type2)
7152 {
7153         return
7154                 is_type_compound(type1) &&
7155                 type1->kind == type2->kind &&
7156                 type1->compound.compound == type2->compound.compound;
7157 }
7158
7159 static expression_t const *get_reference_address(expression_t const *expr)
7160 {
7161         bool regular_take_address = true;
7162         for (;;) {
7163                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7164                         expr = expr->unary.value;
7165                 } else {
7166                         regular_take_address = false;
7167                 }
7168
7169                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7170                         break;
7171
7172                 expr = expr->unary.value;
7173         }
7174
7175         if (expr->kind != EXPR_REFERENCE)
7176                 return NULL;
7177
7178         /* special case for functions which are automatically converted to a
7179          * pointer to function without an extra TAKE_ADDRESS operation */
7180         if (!regular_take_address &&
7181                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7182                 return NULL;
7183         }
7184
7185         return expr;
7186 }
7187
7188 static void warn_reference_address_as_bool(expression_t const* expr)
7189 {
7190         expr = get_reference_address(expr);
7191         if (expr != NULL) {
7192                 source_position_t const *const pos = &expr->base.source_position;
7193                 entity_t          const *const ent = expr->reference.entity;
7194                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7195         }
7196 }
7197
7198 static void warn_assignment_in_condition(const expression_t *const expr)
7199 {
7200         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7201                 return;
7202         if (expr->base.parenthesized)
7203                 return;
7204         source_position_t const *const pos = &expr->base.source_position;
7205         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7206 }
7207
7208 static void semantic_condition(expression_t const *const expr,
7209                                char const *const context)
7210 {
7211         type_t *const type = skip_typeref(expr->base.type);
7212         if (is_type_scalar(type)) {
7213                 warn_reference_address_as_bool(expr);
7214                 warn_assignment_in_condition(expr);
7215         } else if (is_type_valid(type)) {
7216                 errorf(&expr->base.source_position,
7217                                 "%s must have scalar type", context);
7218         }
7219 }
7220
7221 /**
7222  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7223  *
7224  * @param expression  the conditional expression
7225  */
7226 static expression_t *parse_conditional_expression(expression_t *expression)
7227 {
7228         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7229
7230         conditional_expression_t *conditional = &result->conditional;
7231         conditional->condition                = expression;
7232
7233         eat('?');
7234         add_anchor_token(':');
7235
7236         /* §6.5.15:2  The first operand shall have scalar type. */
7237         semantic_condition(expression, "condition of conditional operator");
7238
7239         expression_t *true_expression = expression;
7240         bool          gnu_cond = false;
7241         if (GNU_MODE && token.kind == ':') {
7242                 gnu_cond = true;
7243         } else {
7244                 true_expression = parse_expression();
7245         }
7246         rem_anchor_token(':');
7247         expect(':');
7248         expression_t *false_expression =
7249                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7250
7251         type_t *const orig_true_type  = true_expression->base.type;
7252         type_t *const orig_false_type = false_expression->base.type;
7253         type_t *const true_type       = skip_typeref(orig_true_type);
7254         type_t *const false_type      = skip_typeref(orig_false_type);
7255
7256         /* 6.5.15.3 */
7257         source_position_t const *const pos = &conditional->base.source_position;
7258         type_t                        *result_type;
7259         if (is_type_void(true_type) || is_type_void(false_type)) {
7260                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7261                 if (true_expression->kind == EXPR_UNARY_THROW) {
7262                         result_type = false_type;
7263                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7264                         result_type = true_type;
7265                 } else {
7266                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7267                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7268                         }
7269                         result_type = type_void;
7270                 }
7271         } else if (is_type_arithmetic(true_type)
7272                    && is_type_arithmetic(false_type)) {
7273                 result_type = semantic_arithmetic(true_type, false_type);
7274         } else if (same_compound_type(true_type, false_type)) {
7275                 /* just take 1 of the 2 types */
7276                 result_type = true_type;
7277         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7278                 type_t *pointer_type;
7279                 type_t *other_type;
7280                 expression_t *other_expression;
7281                 if (is_type_pointer(true_type) &&
7282                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7283                         pointer_type     = true_type;
7284                         other_type       = false_type;
7285                         other_expression = false_expression;
7286                 } else {
7287                         pointer_type     = false_type;
7288                         other_type       = true_type;
7289                         other_expression = true_expression;
7290                 }
7291
7292                 if (is_null_pointer_constant(other_expression)) {
7293                         result_type = pointer_type;
7294                 } else if (is_type_pointer(other_type)) {
7295                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7296                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7297
7298                         type_t *to;
7299                         if (is_type_void(to1) || is_type_void(to2)) {
7300                                 to = type_void;
7301                         } else if (types_compatible(get_unqualified_type(to1),
7302                                                     get_unqualified_type(to2))) {
7303                                 to = to1;
7304                         } else {
7305                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7306                                 to = type_void;
7307                         }
7308
7309                         type_t *const type =
7310                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7311                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7312                 } else if (is_type_integer(other_type)) {
7313                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7314                         result_type = pointer_type;
7315                 } else {
7316                         goto types_incompatible;
7317                 }
7318         } else {
7319 types_incompatible:
7320                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7321                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7322                 }
7323                 result_type = type_error_type;
7324         }
7325
7326         conditional->true_expression
7327                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7328         conditional->false_expression
7329                 = create_implicit_cast(false_expression, result_type);
7330         conditional->base.type = result_type;
7331         return result;
7332 }
7333
7334 /**
7335  * Parse an extension expression.
7336  */
7337 static expression_t *parse_extension(void)
7338 {
7339         PUSH_EXTENSION();
7340         expression_t *expression = parse_subexpression(PREC_UNARY);
7341         POP_EXTENSION();
7342         return expression;
7343 }
7344
7345 /**
7346  * Parse a __builtin_classify_type() expression.
7347  */
7348 static expression_t *parse_builtin_classify_type(void)
7349 {
7350         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7351         result->base.type    = type_int;
7352
7353         eat(T___builtin_classify_type);
7354
7355         add_anchor_token(')');
7356         expect('(');
7357         expression_t *expression = parse_expression();
7358         rem_anchor_token(')');
7359         expect(')');
7360         result->classify_type.type_expression = expression;
7361
7362         return result;
7363 }
7364
7365 /**
7366  * Parse a delete expression
7367  * ISO/IEC 14882:1998(E) §5.3.5
7368  */
7369 static expression_t *parse_delete(void)
7370 {
7371         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7372         result->base.type          = type_void;
7373
7374         eat(T_delete);
7375
7376         if (next_if('[')) {
7377                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7378                 expect(']');
7379         }
7380
7381         expression_t *const value = parse_subexpression(PREC_CAST);
7382         result->unary.value = value;
7383
7384         type_t *const type = skip_typeref(value->base.type);
7385         if (!is_type_pointer(type)) {
7386                 if (is_type_valid(type)) {
7387                         errorf(&value->base.source_position,
7388                                         "operand of delete must have pointer type");
7389                 }
7390         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7391                 source_position_t const *const pos = &value->base.source_position;
7392                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7393         }
7394
7395         return result;
7396 }
7397
7398 /**
7399  * Parse a throw expression
7400  * ISO/IEC 14882:1998(E) §15:1
7401  */
7402 static expression_t *parse_throw(void)
7403 {
7404         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7405         result->base.type          = type_void;
7406
7407         eat(T_throw);
7408
7409         expression_t *value = NULL;
7410         switch (token.kind) {
7411                 EXPRESSION_START {
7412                         value = parse_assignment_expression();
7413                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7414                         type_t *const orig_type = value->base.type;
7415                         type_t *const type      = skip_typeref(orig_type);
7416                         if (is_type_incomplete(type)) {
7417                                 errorf(&value->base.source_position,
7418                                                 "cannot throw object of incomplete type '%T'", orig_type);
7419                         } else if (is_type_pointer(type)) {
7420                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7421                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7422                                         errorf(&value->base.source_position,
7423                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7424                                 }
7425                         }
7426                 }
7427
7428                 default:
7429                         break;
7430         }
7431         result->unary.value = value;
7432
7433         return result;
7434 }
7435
7436 static bool check_pointer_arithmetic(const source_position_t *source_position,
7437                                      type_t *pointer_type,
7438                                      type_t *orig_pointer_type)
7439 {
7440         type_t *points_to = pointer_type->pointer.points_to;
7441         points_to = skip_typeref(points_to);
7442
7443         if (is_type_incomplete(points_to)) {
7444                 if (!GNU_MODE || !is_type_void(points_to)) {
7445                         errorf(source_position,
7446                                "arithmetic with pointer to incomplete type '%T' not allowed",
7447                                orig_pointer_type);
7448                         return false;
7449                 } else {
7450                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7451                 }
7452         } else if (is_type_function(points_to)) {
7453                 if (!GNU_MODE) {
7454                         errorf(source_position,
7455                                "arithmetic with pointer to function type '%T' not allowed",
7456                                orig_pointer_type);
7457                         return false;
7458                 } else {
7459                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7460                 }
7461         }
7462         return true;
7463 }
7464
7465 static bool is_lvalue(const expression_t *expression)
7466 {
7467         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7468         switch (expression->kind) {
7469         case EXPR_ARRAY_ACCESS:
7470         case EXPR_COMPOUND_LITERAL:
7471         case EXPR_REFERENCE:
7472         case EXPR_SELECT:
7473         case EXPR_UNARY_DEREFERENCE:
7474                 return true;
7475
7476         default: {
7477                 type_t *type = skip_typeref(expression->base.type);
7478                 return
7479                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7480                         is_type_reference(type) ||
7481                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7482                          * error before, which maybe prevented properly recognizing it as
7483                          * lvalue. */
7484                         !is_type_valid(type);
7485         }
7486         }
7487 }
7488
7489 static void semantic_incdec(unary_expression_t *expression)
7490 {
7491         type_t *const orig_type = expression->value->base.type;
7492         type_t *const type      = skip_typeref(orig_type);
7493         if (is_type_pointer(type)) {
7494                 if (!check_pointer_arithmetic(&expression->base.source_position,
7495                                               type, orig_type)) {
7496                         return;
7497                 }
7498         } else if (!is_type_real(type) && is_type_valid(type)) {
7499                 /* TODO: improve error message */
7500                 errorf(&expression->base.source_position,
7501                        "operation needs an arithmetic or pointer type");
7502                 return;
7503         }
7504         if (!is_lvalue(expression->value)) {
7505                 /* TODO: improve error message */
7506                 errorf(&expression->base.source_position, "lvalue required as operand");
7507         }
7508         expression->base.type = orig_type;
7509 }
7510
7511 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7512 {
7513         type_t *const res_type = promote_integer(type);
7514         expr->base.type = res_type;
7515         expr->value     = create_implicit_cast(expr->value, res_type);
7516 }
7517
7518 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7519 {
7520         type_t *const orig_type = expression->value->base.type;
7521         type_t *const type      = skip_typeref(orig_type);
7522         if (!is_type_arithmetic(type)) {
7523                 if (is_type_valid(type)) {
7524                         /* TODO: improve error message */
7525                         errorf(&expression->base.source_position,
7526                                 "operation needs an arithmetic type");
7527                 }
7528                 return;
7529         } else if (is_type_integer(type)) {
7530                 promote_unary_int_expr(expression, type);
7531         } else {
7532                 expression->base.type = orig_type;
7533         }
7534 }
7535
7536 static void semantic_unexpr_plus(unary_expression_t *expression)
7537 {
7538         semantic_unexpr_arithmetic(expression);
7539         source_position_t const *const pos = &expression->base.source_position;
7540         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7541 }
7542
7543 static void semantic_not(unary_expression_t *expression)
7544 {
7545         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7546         semantic_condition(expression->value, "operand of !");
7547         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7548 }
7549
7550 static void semantic_unexpr_integer(unary_expression_t *expression)
7551 {
7552         type_t *const orig_type = expression->value->base.type;
7553         type_t *const type      = skip_typeref(orig_type);
7554         if (!is_type_integer(type)) {
7555                 if (is_type_valid(type)) {
7556                         errorf(&expression->base.source_position,
7557                                "operand of ~ must be of integer type");
7558                 }
7559                 return;
7560         }
7561
7562         promote_unary_int_expr(expression, type);
7563 }
7564
7565 static void semantic_dereference(unary_expression_t *expression)
7566 {
7567         type_t *const orig_type = expression->value->base.type;
7568         type_t *const type      = skip_typeref(orig_type);
7569         if (!is_type_pointer(type)) {
7570                 if (is_type_valid(type)) {
7571                         errorf(&expression->base.source_position,
7572                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7573                 }
7574                 return;
7575         }
7576
7577         type_t *result_type   = type->pointer.points_to;
7578         result_type           = automatic_type_conversion(result_type);
7579         expression->base.type = result_type;
7580 }
7581
7582 /**
7583  * Record that an address is taken (expression represents an lvalue).
7584  *
7585  * @param expression       the expression
7586  * @param may_be_register  if true, the expression might be an register
7587  */
7588 static void set_address_taken(expression_t *expression, bool may_be_register)
7589 {
7590         if (expression->kind != EXPR_REFERENCE)
7591                 return;
7592
7593         entity_t *const entity = expression->reference.entity;
7594
7595         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7596                 return;
7597
7598         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7599                         && !may_be_register) {
7600                 source_position_t const *const pos = &expression->base.source_position;
7601                 errorf(pos, "address of register '%N' requested", entity);
7602         }
7603
7604         entity->variable.address_taken = true;
7605 }
7606
7607 /**
7608  * Check the semantic of the address taken expression.
7609  */
7610 static void semantic_take_addr(unary_expression_t *expression)
7611 {
7612         expression_t *value = expression->value;
7613         value->base.type    = revert_automatic_type_conversion(value);
7614
7615         type_t *orig_type = value->base.type;
7616         type_t *type      = skip_typeref(orig_type);
7617         if (!is_type_valid(type))
7618                 return;
7619
7620         /* §6.5.3.2 */
7621         if (!is_lvalue(value)) {
7622                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7623         }
7624         if (is_bitfield(value)) {
7625                 errorf(&expression->base.source_position,
7626                        "'&' not allowed on bitfield");
7627         }
7628
7629         set_address_taken(value, false);
7630
7631         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7632 }
7633
7634 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7635 static expression_t *parse_##unexpression_type(void)                         \
7636 {                                                                            \
7637         expression_t *unary_expression                                           \
7638                 = allocate_expression_zero(unexpression_type);                       \
7639         eat(token_kind);                                                         \
7640         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7641                                                                                  \
7642         sfunc(&unary_expression->unary);                                         \
7643                                                                                  \
7644         return unary_expression;                                                 \
7645 }
7646
7647 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7648                                semantic_unexpr_arithmetic)
7649 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7650                                semantic_unexpr_plus)
7651 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7652                                semantic_not)
7653 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7654                                semantic_dereference)
7655 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7656                                semantic_take_addr)
7657 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7658                                semantic_unexpr_integer)
7659 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7660                                semantic_incdec)
7661 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7662                                semantic_incdec)
7663
7664 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7665                                                sfunc)                         \
7666 static expression_t *parse_##unexpression_type(expression_t *left)            \
7667 {                                                                             \
7668         expression_t *unary_expression                                            \
7669                 = allocate_expression_zero(unexpression_type);                        \
7670         eat(token_kind);                                                          \
7671         unary_expression->unary.value = left;                                     \
7672                                                                                   \
7673         sfunc(&unary_expression->unary);                                          \
7674                                                                               \
7675         return unary_expression;                                                  \
7676 }
7677
7678 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7679                                        EXPR_UNARY_POSTFIX_INCREMENT,
7680                                        semantic_incdec)
7681 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7682                                        EXPR_UNARY_POSTFIX_DECREMENT,
7683                                        semantic_incdec)
7684
7685 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7686 {
7687         /* TODO: handle complex + imaginary types */
7688
7689         type_left  = get_unqualified_type(type_left);
7690         type_right = get_unqualified_type(type_right);
7691
7692         /* §6.3.1.8 Usual arithmetic conversions */
7693         if (type_left == type_long_double || type_right == type_long_double) {
7694                 return type_long_double;
7695         } else if (type_left == type_double || type_right == type_double) {
7696                 return type_double;
7697         } else if (type_left == type_float || type_right == type_float) {
7698                 return type_float;
7699         }
7700
7701         type_left  = promote_integer(type_left);
7702         type_right = promote_integer(type_right);
7703
7704         if (type_left == type_right)
7705                 return type_left;
7706
7707         bool     const signed_left  = is_type_signed(type_left);
7708         bool     const signed_right = is_type_signed(type_right);
7709         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7710         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7711
7712         if (signed_left == signed_right)
7713                 return rank_left >= rank_right ? type_left : type_right;
7714
7715         unsigned           s_rank;
7716         unsigned           u_rank;
7717         atomic_type_kind_t s_akind;
7718         atomic_type_kind_t u_akind;
7719         type_t *s_type;
7720         type_t *u_type;
7721         if (signed_left) {
7722                 s_type = type_left;
7723                 u_type = type_right;
7724         } else {
7725                 s_type = type_right;
7726                 u_type = type_left;
7727         }
7728         s_akind = get_akind(s_type);
7729         u_akind = get_akind(u_type);
7730         s_rank  = get_akind_rank(s_akind);
7731         u_rank  = get_akind_rank(u_akind);
7732
7733         if (u_rank >= s_rank)
7734                 return u_type;
7735
7736         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7737                 return s_type;
7738
7739         switch (s_akind) {
7740         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7741         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7742         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7743
7744         default: panic("invalid atomic type");
7745         }
7746 }
7747
7748 /**
7749  * Check the semantic restrictions for a binary expression.
7750  */
7751 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7752 {
7753         expression_t *const left            = expression->left;
7754         expression_t *const right           = expression->right;
7755         type_t       *const orig_type_left  = left->base.type;
7756         type_t       *const orig_type_right = right->base.type;
7757         type_t       *const type_left       = skip_typeref(orig_type_left);
7758         type_t       *const type_right      = skip_typeref(orig_type_right);
7759
7760         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7761                 /* TODO: improve error message */
7762                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7763                         errorf(&expression->base.source_position,
7764                                "operation needs arithmetic types");
7765                 }
7766                 return;
7767         }
7768
7769         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7770         expression->left      = create_implicit_cast(left, arithmetic_type);
7771         expression->right     = create_implicit_cast(right, arithmetic_type);
7772         expression->base.type = arithmetic_type;
7773 }
7774
7775 static void semantic_binexpr_integer(binary_expression_t *const expression)
7776 {
7777         expression_t *const left            = expression->left;
7778         expression_t *const right           = expression->right;
7779         type_t       *const orig_type_left  = left->base.type;
7780         type_t       *const orig_type_right = right->base.type;
7781         type_t       *const type_left       = skip_typeref(orig_type_left);
7782         type_t       *const type_right      = skip_typeref(orig_type_right);
7783
7784         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7785                 /* TODO: improve error message */
7786                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7787                         errorf(&expression->base.source_position,
7788                                "operation needs integer types");
7789                 }
7790                 return;
7791         }
7792
7793         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7794         expression->left      = create_implicit_cast(left, result_type);
7795         expression->right     = create_implicit_cast(right, result_type);
7796         expression->base.type = result_type;
7797 }
7798
7799 static void warn_div_by_zero(binary_expression_t const *const expression)
7800 {
7801         if (!is_type_integer(expression->base.type))
7802                 return;
7803
7804         expression_t const *const right = expression->right;
7805         /* The type of the right operand can be different for /= */
7806         if (is_type_integer(right->base.type)                    &&
7807             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7808             !fold_constant_to_bool(right)) {
7809                 source_position_t const *const pos = &expression->base.source_position;
7810                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7811         }
7812 }
7813
7814 /**
7815  * Check the semantic restrictions for a div/mod expression.
7816  */
7817 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7818 {
7819         semantic_binexpr_arithmetic(expression);
7820         warn_div_by_zero(expression);
7821 }
7822
7823 static void warn_addsub_in_shift(const expression_t *const expr)
7824 {
7825         if (expr->base.parenthesized)
7826                 return;
7827
7828         char op;
7829         switch (expr->kind) {
7830                 case EXPR_BINARY_ADD: op = '+'; break;
7831                 case EXPR_BINARY_SUB: op = '-'; break;
7832                 default:              return;
7833         }
7834
7835         source_position_t const *const pos = &expr->base.source_position;
7836         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7837 }
7838
7839 static bool semantic_shift(binary_expression_t *expression)
7840 {
7841         expression_t *const left            = expression->left;
7842         expression_t *const right           = expression->right;
7843         type_t       *const orig_type_left  = left->base.type;
7844         type_t       *const orig_type_right = right->base.type;
7845         type_t       *      type_left       = skip_typeref(orig_type_left);
7846         type_t       *      type_right      = skip_typeref(orig_type_right);
7847
7848         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7849                 /* TODO: improve error message */
7850                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7851                         errorf(&expression->base.source_position,
7852                                "operands of shift operation must have integer types");
7853                 }
7854                 return false;
7855         }
7856
7857         type_left = promote_integer(type_left);
7858
7859         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7860                 source_position_t const *const pos   = &right->base.source_position;
7861                 long                     const count = fold_constant_to_int(right);
7862                 if (count < 0) {
7863                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7864                 } else if ((unsigned long)count >=
7865                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7866                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7867                 }
7868         }
7869
7870         type_right        = promote_integer(type_right);
7871         expression->right = create_implicit_cast(right, type_right);
7872
7873         return true;
7874 }
7875
7876 static void semantic_shift_op(binary_expression_t *expression)
7877 {
7878         expression_t *const left  = expression->left;
7879         expression_t *const right = expression->right;
7880
7881         if (!semantic_shift(expression))
7882                 return;
7883
7884         warn_addsub_in_shift(left);
7885         warn_addsub_in_shift(right);
7886
7887         type_t *const orig_type_left = left->base.type;
7888         type_t *      type_left      = skip_typeref(orig_type_left);
7889
7890         type_left             = promote_integer(type_left);
7891         expression->left      = create_implicit_cast(left, type_left);
7892         expression->base.type = type_left;
7893 }
7894
7895 static void semantic_add(binary_expression_t *expression)
7896 {
7897         expression_t *const left            = expression->left;
7898         expression_t *const right           = expression->right;
7899         type_t       *const orig_type_left  = left->base.type;
7900         type_t       *const orig_type_right = right->base.type;
7901         type_t       *const type_left       = skip_typeref(orig_type_left);
7902         type_t       *const type_right      = skip_typeref(orig_type_right);
7903
7904         /* §6.5.6 */
7905         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7906                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7907                 expression->left  = create_implicit_cast(left, arithmetic_type);
7908                 expression->right = create_implicit_cast(right, arithmetic_type);
7909                 expression->base.type = arithmetic_type;
7910         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7911                 check_pointer_arithmetic(&expression->base.source_position,
7912                                          type_left, orig_type_left);
7913                 expression->base.type = type_left;
7914         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7915                 check_pointer_arithmetic(&expression->base.source_position,
7916                                          type_right, orig_type_right);
7917                 expression->base.type = type_right;
7918         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7919                 errorf(&expression->base.source_position,
7920                        "invalid operands to binary + ('%T', '%T')",
7921                        orig_type_left, orig_type_right);
7922         }
7923 }
7924
7925 static void semantic_sub(binary_expression_t *expression)
7926 {
7927         expression_t            *const left            = expression->left;
7928         expression_t            *const right           = expression->right;
7929         type_t                  *const orig_type_left  = left->base.type;
7930         type_t                  *const orig_type_right = right->base.type;
7931         type_t                  *const type_left       = skip_typeref(orig_type_left);
7932         type_t                  *const type_right      = skip_typeref(orig_type_right);
7933         source_position_t const *const pos             = &expression->base.source_position;
7934
7935         /* §5.6.5 */
7936         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7937                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7938                 expression->left        = create_implicit_cast(left, arithmetic_type);
7939                 expression->right       = create_implicit_cast(right, arithmetic_type);
7940                 expression->base.type =  arithmetic_type;
7941         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7942                 check_pointer_arithmetic(&expression->base.source_position,
7943                                          type_left, orig_type_left);
7944                 expression->base.type = type_left;
7945         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7946                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7947                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7948                 if (!types_compatible(unqual_left, unqual_right)) {
7949                         errorf(pos,
7950                                "subtracting pointers to incompatible types '%T' and '%T'",
7951                                orig_type_left, orig_type_right);
7952                 } else if (!is_type_object(unqual_left)) {
7953                         if (!is_type_void(unqual_left)) {
7954                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7955                                        orig_type_left);
7956                         } else {
7957                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7958                         }
7959                 }
7960                 expression->base.type = type_ptrdiff_t;
7961         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7962                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7963                        orig_type_left, orig_type_right);
7964         }
7965 }
7966
7967 static void warn_string_literal_address(expression_t const* expr)
7968 {
7969         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7970                 expr = expr->unary.value;
7971                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7972                         return;
7973                 expr = expr->unary.value;
7974         }
7975
7976         if (expr->kind == EXPR_STRING_LITERAL) {
7977                 source_position_t const *const pos = &expr->base.source_position;
7978                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7979         }
7980 }
7981
7982 static bool maybe_negative(expression_t const *const expr)
7983 {
7984         switch (is_constant_expression(expr)) {
7985                 case EXPR_CLASS_ERROR:    return false;
7986                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7987                 default:                  return true;
7988         }
7989 }
7990
7991 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7992 {
7993         warn_string_literal_address(expr);
7994
7995         expression_t const* const ref = get_reference_address(expr);
7996         if (ref != NULL && is_null_pointer_constant(other)) {
7997                 entity_t const *const ent = ref->reference.entity;
7998                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7999         }
8000
8001         if (!expr->base.parenthesized) {
8002                 switch (expr->base.kind) {
8003                         case EXPR_BINARY_LESS:
8004                         case EXPR_BINARY_GREATER:
8005                         case EXPR_BINARY_LESSEQUAL:
8006                         case EXPR_BINARY_GREATEREQUAL:
8007                         case EXPR_BINARY_NOTEQUAL:
8008                         case EXPR_BINARY_EQUAL:
8009                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8010                                 break;
8011                         default:
8012                                 break;
8013                 }
8014         }
8015 }
8016
8017 /**
8018  * Check the semantics of comparison expressions.
8019  *
8020  * @param expression   The expression to check.
8021  */
8022 static void semantic_comparison(binary_expression_t *expression)
8023 {
8024         source_position_t const *const pos   = &expression->base.source_position;
8025         expression_t            *const left  = expression->left;
8026         expression_t            *const right = expression->right;
8027
8028         warn_comparison(pos, left, right);
8029         warn_comparison(pos, right, left);
8030
8031         type_t *orig_type_left  = left->base.type;
8032         type_t *orig_type_right = right->base.type;
8033         type_t *type_left       = skip_typeref(orig_type_left);
8034         type_t *type_right      = skip_typeref(orig_type_right);
8035
8036         /* TODO non-arithmetic types */
8037         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8038                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8039
8040                 /* test for signed vs unsigned compares */
8041                 if (is_type_integer(arithmetic_type)) {
8042                         bool const signed_left  = is_type_signed(type_left);
8043                         bool const signed_right = is_type_signed(type_right);
8044                         if (signed_left != signed_right) {
8045                                 /* FIXME long long needs better const folding magic */
8046                                 /* TODO check whether constant value can be represented by other type */
8047                                 if ((signed_left  && maybe_negative(left)) ||
8048                                                 (signed_right && maybe_negative(right))) {
8049                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8050                                 }
8051                         }
8052                 }
8053
8054                 expression->left        = create_implicit_cast(left, arithmetic_type);
8055                 expression->right       = create_implicit_cast(right, arithmetic_type);
8056                 expression->base.type   = arithmetic_type;
8057                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8058                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8059                     is_type_float(arithmetic_type)) {
8060                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8061                 }
8062         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8063                 /* TODO check compatibility */
8064         } else if (is_type_pointer(type_left)) {
8065                 expression->right = create_implicit_cast(right, type_left);
8066         } else if (is_type_pointer(type_right)) {
8067                 expression->left = create_implicit_cast(left, type_right);
8068         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8069                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8070         }
8071         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8072 }
8073
8074 /**
8075  * Checks if a compound type has constant fields.
8076  */
8077 static bool has_const_fields(const compound_type_t *type)
8078 {
8079         compound_t *compound = type->compound;
8080         entity_t   *entry    = compound->members.entities;
8081
8082         for (; entry != NULL; entry = entry->base.next) {
8083                 if (!is_declaration(entry))
8084                         continue;
8085
8086                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8087                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8088                         return true;
8089         }
8090
8091         return false;
8092 }
8093
8094 static bool is_valid_assignment_lhs(expression_t const* const left)
8095 {
8096         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8097         type_t *const type_left      = skip_typeref(orig_type_left);
8098
8099         if (!is_lvalue(left)) {
8100                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8101                        left);
8102                 return false;
8103         }
8104
8105         if (left->kind == EXPR_REFERENCE
8106                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8107                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8108                 return false;
8109         }
8110
8111         if (is_type_array(type_left)) {
8112                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8113                 return false;
8114         }
8115         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8116                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8117                        orig_type_left);
8118                 return false;
8119         }
8120         if (is_type_incomplete(type_left)) {
8121                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8122                        left, orig_type_left);
8123                 return false;
8124         }
8125         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8126                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8127                        left, orig_type_left);
8128                 return false;
8129         }
8130
8131         return true;
8132 }
8133
8134 static void semantic_arithmetic_assign(binary_expression_t *expression)
8135 {
8136         expression_t *left            = expression->left;
8137         expression_t *right           = expression->right;
8138         type_t       *orig_type_left  = left->base.type;
8139         type_t       *orig_type_right = right->base.type;
8140
8141         if (!is_valid_assignment_lhs(left))
8142                 return;
8143
8144         type_t *type_left  = skip_typeref(orig_type_left);
8145         type_t *type_right = skip_typeref(orig_type_right);
8146
8147         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8148                 /* TODO: improve error message */
8149                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8150                         errorf(&expression->base.source_position,
8151                                "operation needs arithmetic types");
8152                 }
8153                 return;
8154         }
8155
8156         /* combined instructions are tricky. We can't create an implicit cast on
8157          * the left side, because we need the uncasted form for the store.
8158          * The ast2firm pass has to know that left_type must be right_type
8159          * for the arithmetic operation and create a cast by itself */
8160         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8161         expression->right       = create_implicit_cast(right, arithmetic_type);
8162         expression->base.type   = type_left;
8163 }
8164
8165 static void semantic_divmod_assign(binary_expression_t *expression)
8166 {
8167         semantic_arithmetic_assign(expression);
8168         warn_div_by_zero(expression);
8169 }
8170
8171 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8172 {
8173         expression_t *const left            = expression->left;
8174         expression_t *const right           = expression->right;
8175         type_t       *const orig_type_left  = left->base.type;
8176         type_t       *const orig_type_right = right->base.type;
8177         type_t       *const type_left       = skip_typeref(orig_type_left);
8178         type_t       *const type_right      = skip_typeref(orig_type_right);
8179
8180         if (!is_valid_assignment_lhs(left))
8181                 return;
8182
8183         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8184                 /* combined instructions are tricky. We can't create an implicit cast on
8185                  * the left side, because we need the uncasted form for the store.
8186                  * The ast2firm pass has to know that left_type must be right_type
8187                  * for the arithmetic operation and create a cast by itself */
8188                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8189                 expression->right     = create_implicit_cast(right, arithmetic_type);
8190                 expression->base.type = type_left;
8191         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8192                 check_pointer_arithmetic(&expression->base.source_position,
8193                                          type_left, orig_type_left);
8194                 expression->base.type = type_left;
8195         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8196                 errorf(&expression->base.source_position,
8197                        "incompatible types '%T' and '%T' in assignment",
8198                        orig_type_left, orig_type_right);
8199         }
8200 }
8201
8202 static void semantic_integer_assign(binary_expression_t *expression)
8203 {
8204         expression_t *left            = expression->left;
8205         expression_t *right           = expression->right;
8206         type_t       *orig_type_left  = left->base.type;
8207         type_t       *orig_type_right = right->base.type;
8208
8209         if (!is_valid_assignment_lhs(left))
8210                 return;
8211
8212         type_t *type_left  = skip_typeref(orig_type_left);
8213         type_t *type_right = skip_typeref(orig_type_right);
8214
8215         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8216                 /* TODO: improve error message */
8217                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8218                         errorf(&expression->base.source_position,
8219                                "operation needs integer types");
8220                 }
8221                 return;
8222         }
8223
8224         /* combined instructions are tricky. We can't create an implicit cast on
8225          * the left side, because we need the uncasted form for the store.
8226          * The ast2firm pass has to know that left_type must be right_type
8227          * for the arithmetic operation and create a cast by itself */
8228         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8229         expression->right       = create_implicit_cast(right, arithmetic_type);
8230         expression->base.type   = type_left;
8231 }
8232
8233 static void semantic_shift_assign(binary_expression_t *expression)
8234 {
8235         expression_t *left           = expression->left;
8236
8237         if (!is_valid_assignment_lhs(left))
8238                 return;
8239
8240         if (!semantic_shift(expression))
8241                 return;
8242
8243         expression->base.type = skip_typeref(left->base.type);
8244 }
8245
8246 static void warn_logical_and_within_or(const expression_t *const expr)
8247 {
8248         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8249                 return;
8250         if (expr->base.parenthesized)
8251                 return;
8252         source_position_t const *const pos = &expr->base.source_position;
8253         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8254 }
8255
8256 /**
8257  * Check the semantic restrictions of a logical expression.
8258  */
8259 static void semantic_logical_op(binary_expression_t *expression)
8260 {
8261         /* §6.5.13:2  Each of the operands shall have scalar type.
8262          * §6.5.14:2  Each of the operands shall have scalar type. */
8263         semantic_condition(expression->left,   "left operand of logical operator");
8264         semantic_condition(expression->right, "right operand of logical operator");
8265         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8266                 warn_logical_and_within_or(expression->left);
8267                 warn_logical_and_within_or(expression->right);
8268         }
8269         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8270 }
8271
8272 /**
8273  * Check the semantic restrictions of a binary assign expression.
8274  */
8275 static void semantic_binexpr_assign(binary_expression_t *expression)
8276 {
8277         expression_t *left           = expression->left;
8278         type_t       *orig_type_left = left->base.type;
8279
8280         if (!is_valid_assignment_lhs(left))
8281                 return;
8282
8283         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8284         report_assign_error(error, orig_type_left, expression->right,
8285                         "assignment", &left->base.source_position);
8286         expression->right = create_implicit_cast(expression->right, orig_type_left);
8287         expression->base.type = orig_type_left;
8288 }
8289
8290 /**
8291  * Determine if the outermost operation (or parts thereof) of the given
8292  * expression has no effect in order to generate a warning about this fact.
8293  * Therefore in some cases this only examines some of the operands of the
8294  * expression (see comments in the function and examples below).
8295  * Examples:
8296  *   f() + 23;    // warning, because + has no effect
8297  *   x || f();    // no warning, because x controls execution of f()
8298  *   x ? y : f(); // warning, because y has no effect
8299  *   (void)x;     // no warning to be able to suppress the warning
8300  * This function can NOT be used for an "expression has definitely no effect"-
8301  * analysis. */
8302 static bool expression_has_effect(const expression_t *const expr)
8303 {
8304         switch (expr->kind) {
8305                 case EXPR_ERROR:                      return true; /* do NOT warn */
8306                 case EXPR_REFERENCE:                  return false;
8307                 case EXPR_ENUM_CONSTANT:              return false;
8308                 case EXPR_LABEL_ADDRESS:              return false;
8309
8310                 /* suppress the warning for microsoft __noop operations */
8311                 case EXPR_LITERAL_MS_NOOP:            return true;
8312                 case EXPR_LITERAL_BOOLEAN:
8313                 case EXPR_LITERAL_CHARACTER:
8314                 case EXPR_LITERAL_INTEGER:
8315                 case EXPR_LITERAL_FLOATINGPOINT:
8316                 case EXPR_STRING_LITERAL:             return false;
8317
8318                 case EXPR_CALL: {
8319                         const call_expression_t *const call = &expr->call;
8320                         if (call->function->kind != EXPR_REFERENCE)
8321                                 return true;
8322
8323                         switch (call->function->reference.entity->function.btk) {
8324                                 /* FIXME: which builtins have no effect? */
8325                                 default:                      return true;
8326                         }
8327                 }
8328
8329                 /* Generate the warning if either the left or right hand side of a
8330                  * conditional expression has no effect */
8331                 case EXPR_CONDITIONAL: {
8332                         conditional_expression_t const *const cond = &expr->conditional;
8333                         expression_t             const *const t    = cond->true_expression;
8334                         return
8335                                 (t == NULL || expression_has_effect(t)) &&
8336                                 expression_has_effect(cond->false_expression);
8337                 }
8338
8339                 case EXPR_SELECT:                     return false;
8340                 case EXPR_ARRAY_ACCESS:               return false;
8341                 case EXPR_SIZEOF:                     return false;
8342                 case EXPR_CLASSIFY_TYPE:              return false;
8343                 case EXPR_ALIGNOF:                    return false;
8344
8345                 case EXPR_FUNCNAME:                   return false;
8346                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8347                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8348                 case EXPR_OFFSETOF:                   return false;
8349                 case EXPR_VA_START:                   return true;
8350                 case EXPR_VA_ARG:                     return true;
8351                 case EXPR_VA_COPY:                    return true;
8352                 case EXPR_STATEMENT:                  return true; // TODO
8353                 case EXPR_COMPOUND_LITERAL:           return false;
8354
8355                 case EXPR_UNARY_NEGATE:               return false;
8356                 case EXPR_UNARY_PLUS:                 return false;
8357                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8358                 case EXPR_UNARY_NOT:                  return false;
8359                 case EXPR_UNARY_DEREFERENCE:          return false;
8360                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8361                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8362                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8363                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8364                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8365
8366                 /* Treat void casts as if they have an effect in order to being able to
8367                  * suppress the warning */
8368                 case EXPR_UNARY_CAST: {
8369                         type_t *const type = skip_typeref(expr->base.type);
8370                         return is_type_void(type);
8371                 }
8372
8373                 case EXPR_UNARY_ASSUME:               return true;
8374                 case EXPR_UNARY_DELETE:               return true;
8375                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8376                 case EXPR_UNARY_THROW:                return true;
8377
8378                 case EXPR_BINARY_ADD:                 return false;
8379                 case EXPR_BINARY_SUB:                 return false;
8380                 case EXPR_BINARY_MUL:                 return false;
8381                 case EXPR_BINARY_DIV:                 return false;
8382                 case EXPR_BINARY_MOD:                 return false;
8383                 case EXPR_BINARY_EQUAL:               return false;
8384                 case EXPR_BINARY_NOTEQUAL:            return false;
8385                 case EXPR_BINARY_LESS:                return false;
8386                 case EXPR_BINARY_LESSEQUAL:           return false;
8387                 case EXPR_BINARY_GREATER:             return false;
8388                 case EXPR_BINARY_GREATEREQUAL:        return false;
8389                 case EXPR_BINARY_BITWISE_AND:         return false;
8390                 case EXPR_BINARY_BITWISE_OR:          return false;
8391                 case EXPR_BINARY_BITWISE_XOR:         return false;
8392                 case EXPR_BINARY_SHIFTLEFT:           return false;
8393                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8394                 case EXPR_BINARY_ASSIGN:              return true;
8395                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8396                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8397                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8398                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8399                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8400                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8401                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8402                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8403                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8404                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8405
8406                 /* Only examine the right hand side of && and ||, because the left hand
8407                  * side already has the effect of controlling the execution of the right
8408                  * hand side */
8409                 case EXPR_BINARY_LOGICAL_AND:
8410                 case EXPR_BINARY_LOGICAL_OR:
8411                 /* Only examine the right hand side of a comma expression, because the left
8412                  * hand side has a separate warning */
8413                 case EXPR_BINARY_COMMA:
8414                         return expression_has_effect(expr->binary.right);
8415
8416                 case EXPR_BINARY_ISGREATER:           return false;
8417                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8418                 case EXPR_BINARY_ISLESS:              return false;
8419                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8420                 case EXPR_BINARY_ISLESSGREATER:       return false;
8421                 case EXPR_BINARY_ISUNORDERED:         return false;
8422         }
8423
8424         internal_errorf(HERE, "unexpected expression");
8425 }
8426
8427 static void semantic_comma(binary_expression_t *expression)
8428 {
8429         const expression_t *const left = expression->left;
8430         if (!expression_has_effect(left)) {
8431                 source_position_t const *const pos = &left->base.source_position;
8432                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8433         }
8434         expression->base.type = expression->right->base.type;
8435 }
8436
8437 /**
8438  * @param prec_r precedence of the right operand
8439  */
8440 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8441 static expression_t *parse_##binexpression_type(expression_t *left)          \
8442 {                                                                            \
8443         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8444         binexpr->binary.left  = left;                                            \
8445         eat(token_kind);                                                         \
8446                                                                              \
8447         expression_t *right = parse_subexpression(prec_r);                       \
8448                                                                              \
8449         binexpr->binary.right = right;                                           \
8450         sfunc(&binexpr->binary);                                                 \
8451                                                                              \
8452         return binexpr;                                                          \
8453 }
8454
8455 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8456 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8457 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8458 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8459 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8460 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8461 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8462 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8463 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8464 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8465 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8466 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8467 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8468 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8469 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8470 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8471 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8472 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8473 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8474 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8475 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8476 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8477 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8478 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8479 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8480 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8481 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8482 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8483 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8484 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8485
8486
8487 static expression_t *parse_subexpression(precedence_t precedence)
8488 {
8489         expression_parser_function_t *parser
8490                 = &expression_parsers[token.kind];
8491         expression_t                 *left;
8492
8493         if (parser->parser != NULL) {
8494                 left = parser->parser();
8495         } else {
8496                 left = parse_primary_expression();
8497         }
8498         assert(left != NULL);
8499
8500         while (true) {
8501                 parser = &expression_parsers[token.kind];
8502                 if (parser->infix_parser == NULL)
8503                         break;
8504                 if (parser->infix_precedence < precedence)
8505                         break;
8506
8507                 left = parser->infix_parser(left);
8508
8509                 assert(left != NULL);
8510         }
8511
8512         return left;
8513 }
8514
8515 /**
8516  * Parse an expression.
8517  */
8518 static expression_t *parse_expression(void)
8519 {
8520         return parse_subexpression(PREC_EXPRESSION);
8521 }
8522
8523 /**
8524  * Register a parser for a prefix-like operator.
8525  *
8526  * @param parser      the parser function
8527  * @param token_kind  the token type of the prefix token
8528  */
8529 static void register_expression_parser(parse_expression_function parser,
8530                                        int token_kind)
8531 {
8532         expression_parser_function_t *entry = &expression_parsers[token_kind];
8533
8534         assert(!entry->parser);
8535         entry->parser = parser;
8536 }
8537
8538 /**
8539  * Register a parser for an infix operator with given precedence.
8540  *
8541  * @param parser      the parser function
8542  * @param token_kind  the token type of the infix operator
8543  * @param precedence  the precedence of the operator
8544  */
8545 static void register_infix_parser(parse_expression_infix_function parser,
8546                                   int token_kind, precedence_t precedence)
8547 {
8548         expression_parser_function_t *entry = &expression_parsers[token_kind];
8549
8550         assert(!entry->infix_parser);
8551         entry->infix_parser     = parser;
8552         entry->infix_precedence = precedence;
8553 }
8554
8555 /**
8556  * Initialize the expression parsers.
8557  */
8558 static void init_expression_parsers(void)
8559 {
8560         memset(&expression_parsers, 0, sizeof(expression_parsers));
8561
8562         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8563         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8564         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8565         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8566         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8567         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8568         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8569         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8570         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8571         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8572         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8573         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8574         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8575         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8576         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8577         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8578         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8579         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8580         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8581         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8582         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8583         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8584         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8585         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8586         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8587         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8588         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8589         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8590         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8591         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8592         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8593         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8594         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8595         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8596         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8597         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8598         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8599
8600         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8601         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8602         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8603         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8604         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8605         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8606         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8607         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8608         register_expression_parser(parse_sizeof,                      T_sizeof);
8609         register_expression_parser(parse_alignof,                     T__Alignof);
8610         register_expression_parser(parse_extension,                   T___extension__);
8611         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8612         register_expression_parser(parse_delete,                      T_delete);
8613         register_expression_parser(parse_throw,                       T_throw);
8614 }
8615
8616 /**
8617  * Parse a asm statement arguments specification.
8618  */
8619 static asm_argument_t *parse_asm_arguments(bool is_out)
8620 {
8621         asm_argument_t  *result = NULL;
8622         asm_argument_t **anchor = &result;
8623
8624         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8625                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8626
8627                 if (next_if('[')) {
8628                         add_anchor_token(']');
8629                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8630                         rem_anchor_token(']');
8631                         expect(']');
8632                         if (!argument->symbol)
8633                                 return NULL;
8634                 }
8635
8636                 argument->constraints = parse_string_literals("asm argument");
8637                 add_anchor_token(')');
8638                 expect('(');
8639                 expression_t *expression = parse_expression();
8640                 rem_anchor_token(')');
8641                 if (is_out) {
8642                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8643                          * change size or type representation (e.g. int -> long is ok, but
8644                          * int -> float is not) */
8645                         if (expression->kind == EXPR_UNARY_CAST) {
8646                                 type_t      *const type = expression->base.type;
8647                                 type_kind_t  const kind = type->kind;
8648                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8649                                         unsigned flags;
8650                                         unsigned size;
8651                                         if (kind == TYPE_ATOMIC) {
8652                                                 atomic_type_kind_t const akind = type->atomic.akind;
8653                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8654                                                 size  = get_atomic_type_size(akind);
8655                                         } else {
8656                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8657                                                 size  = get_type_size(type_void_ptr);
8658                                         }
8659
8660                                         do {
8661                                                 expression_t *const value      = expression->unary.value;
8662                                                 type_t       *const value_type = value->base.type;
8663                                                 type_kind_t   const value_kind = value_type->kind;
8664
8665                                                 unsigned value_flags;
8666                                                 unsigned value_size;
8667                                                 if (value_kind == TYPE_ATOMIC) {
8668                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8669                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8670                                                         value_size  = get_atomic_type_size(value_akind);
8671                                                 } else if (value_kind == TYPE_POINTER) {
8672                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8673                                                         value_size  = get_type_size(type_void_ptr);
8674                                                 } else {
8675                                                         break;
8676                                                 }
8677
8678                                                 if (value_flags != flags || value_size != size)
8679                                                         break;
8680
8681                                                 expression = value;
8682                                         } while (expression->kind == EXPR_UNARY_CAST);
8683                                 }
8684                         }
8685
8686                         if (!is_lvalue(expression)) {
8687                                 errorf(&expression->base.source_position,
8688                                        "asm output argument is not an lvalue");
8689                         }
8690
8691                         if (argument->constraints.begin[0] == '=')
8692                                 determine_lhs_ent(expression, NULL);
8693                         else
8694                                 mark_vars_read(expression, NULL);
8695                 } else {
8696                         mark_vars_read(expression, NULL);
8697                 }
8698                 argument->expression = expression;
8699                 expect(')');
8700
8701                 set_address_taken(expression, true);
8702
8703                 *anchor = argument;
8704                 anchor  = &argument->next;
8705
8706                 if (!next_if(','))
8707                         break;
8708         }
8709
8710         return result;
8711 }
8712
8713 /**
8714  * Parse a asm statement clobber specification.
8715  */
8716 static asm_clobber_t *parse_asm_clobbers(void)
8717 {
8718         asm_clobber_t *result  = NULL;
8719         asm_clobber_t **anchor = &result;
8720
8721         while (token.kind == T_STRING_LITERAL) {
8722                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8723                 clobber->clobber       = parse_string_literals(NULL);
8724
8725                 *anchor = clobber;
8726                 anchor  = &clobber->next;
8727
8728                 if (!next_if(','))
8729                         break;
8730         }
8731
8732         return result;
8733 }
8734
8735 /**
8736  * Parse an asm statement.
8737  */
8738 static statement_t *parse_asm_statement(void)
8739 {
8740         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8741         asm_statement_t *asm_statement = &statement->asms;
8742
8743         eat(T_asm);
8744         add_anchor_token(')');
8745         add_anchor_token(':');
8746         add_anchor_token(T_STRING_LITERAL);
8747
8748         if (next_if(T_volatile))
8749                 asm_statement->is_volatile = true;
8750
8751         expect('(');
8752         rem_anchor_token(T_STRING_LITERAL);
8753         asm_statement->asm_text = parse_string_literals("asm statement");
8754
8755         if (next_if(':'))
8756                 asm_statement->outputs = parse_asm_arguments(true);
8757
8758         if (next_if(':'))
8759                 asm_statement->inputs = parse_asm_arguments(false);
8760
8761         rem_anchor_token(':');
8762         if (next_if(':'))
8763                 asm_statement->clobbers = parse_asm_clobbers();
8764
8765         rem_anchor_token(')');
8766         expect(')');
8767         expect(';');
8768
8769         if (asm_statement->outputs == NULL) {
8770                 /* GCC: An 'asm' instruction without any output operands will be treated
8771                  * identically to a volatile 'asm' instruction. */
8772                 asm_statement->is_volatile = true;
8773         }
8774
8775         return statement;
8776 }
8777
8778 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8779 {
8780         statement_t *inner_stmt;
8781         switch (token.kind) {
8782                 case '}':
8783                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8784                         inner_stmt = create_error_statement();
8785                         break;
8786
8787                 case ';':
8788                         if (label->kind == STATEMENT_LABEL) {
8789                                 /* Eat an empty statement here, to avoid the warning about an empty
8790                                  * statement after a label.  label:; is commonly used to have a label
8791                                  * before a closing brace. */
8792                                 inner_stmt = create_empty_statement();
8793                                 eat(';');
8794                                 break;
8795                         }
8796                         /* FALLTHROUGH */
8797
8798                 default:
8799                         inner_stmt = parse_statement();
8800                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8801                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8802                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8803                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8804                         }
8805                         break;
8806         }
8807         return inner_stmt;
8808 }
8809
8810 /**
8811  * Parse a case statement.
8812  */
8813 static statement_t *parse_case_statement(void)
8814 {
8815         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8816         source_position_t *const pos       = &statement->base.source_position;
8817
8818         eat(T_case);
8819         add_anchor_token(':');
8820
8821         expression_t *expression = parse_expression();
8822         type_t *expression_type = expression->base.type;
8823         type_t *skipped         = skip_typeref(expression_type);
8824         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8825                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8826                        expression, expression_type);
8827         }
8828
8829         type_t *type = expression_type;
8830         if (current_switch != NULL) {
8831                 type_t *switch_type = current_switch->expression->base.type;
8832                 if (is_type_valid(switch_type)) {
8833                         expression = create_implicit_cast(expression, switch_type);
8834                 }
8835         }
8836
8837         statement->case_label.expression = expression;
8838         expression_classification_t const expr_class = is_constant_expression(expression);
8839         if (expr_class != EXPR_CLASS_CONSTANT) {
8840                 if (expr_class != EXPR_CLASS_ERROR) {
8841                         errorf(pos, "case label does not reduce to an integer constant");
8842                 }
8843                 statement->case_label.is_bad = true;
8844         } else {
8845                 ir_tarval *val = fold_constant_to_tarval(expression);
8846                 statement->case_label.first_case = val;
8847                 statement->case_label.last_case  = val;
8848         }
8849
8850         if (GNU_MODE) {
8851                 if (next_if(T_DOTDOTDOT)) {
8852                         expression_t *end_range = parse_expression();
8853                         expression_type = expression->base.type;
8854                         skipped         = skip_typeref(expression_type);
8855                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8856                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8857                                            expression, expression_type);
8858                         }
8859
8860                         end_range = create_implicit_cast(end_range, type);
8861                         statement->case_label.end_range = end_range;
8862                         expression_classification_t const end_class = is_constant_expression(end_range);
8863                         if (end_class != EXPR_CLASS_CONSTANT) {
8864                                 if (end_class != EXPR_CLASS_ERROR) {
8865                                         errorf(pos, "case range does not reduce to an integer constant");
8866                                 }
8867                                 statement->case_label.is_bad = true;
8868                         } else {
8869                                 ir_tarval *val = fold_constant_to_tarval(end_range);
8870                                 statement->case_label.last_case = val;
8871
8872                                 if (tarval_cmp(val, statement->case_label.first_case)
8873                                     == ir_relation_less) {
8874                                         statement->case_label.is_empty_range = true;
8875                                         warningf(WARN_OTHER, pos, "empty range specified");
8876                                 }
8877                         }
8878                 }
8879         }
8880
8881         PUSH_PARENT(statement);
8882
8883         rem_anchor_token(':');
8884         expect(':');
8885
8886         if (current_switch != NULL) {
8887                 if (! statement->case_label.is_bad) {
8888                         /* Check for duplicate case values */
8889                         case_label_statement_t *c = &statement->case_label;
8890                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8891                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8892                                         continue;
8893
8894                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8895                                         continue;
8896
8897                                 errorf(pos, "duplicate case value (previously used %P)",
8898                                        &l->base.source_position);
8899                                 break;
8900                         }
8901                 }
8902                 /* link all cases into the switch statement */
8903                 if (current_switch->last_case == NULL) {
8904                         current_switch->first_case      = &statement->case_label;
8905                 } else {
8906                         current_switch->last_case->next = &statement->case_label;
8907                 }
8908                 current_switch->last_case = &statement->case_label;
8909         } else {
8910                 errorf(pos, "case label not within a switch statement");
8911         }
8912
8913         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8914
8915         POP_PARENT();
8916         return statement;
8917 }
8918
8919 /**
8920  * Parse a default statement.
8921  */
8922 static statement_t *parse_default_statement(void)
8923 {
8924         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8925
8926         eat(T_default);
8927
8928         PUSH_PARENT(statement);
8929
8930         expect(':');
8931
8932         if (current_switch != NULL) {
8933                 const case_label_statement_t *def_label = current_switch->default_label;
8934                 if (def_label != NULL) {
8935                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8936                 } else {
8937                         current_switch->default_label = &statement->case_label;
8938
8939                         /* link all cases into the switch statement */
8940                         if (current_switch->last_case == NULL) {
8941                                 current_switch->first_case      = &statement->case_label;
8942                         } else {
8943                                 current_switch->last_case->next = &statement->case_label;
8944                         }
8945                         current_switch->last_case = &statement->case_label;
8946                 }
8947         } else {
8948                 errorf(&statement->base.source_position,
8949                         "'default' label not within a switch statement");
8950         }
8951
8952         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8953
8954         POP_PARENT();
8955         return statement;
8956 }
8957
8958 /**
8959  * Parse a label statement.
8960  */
8961 static statement_t *parse_label_statement(void)
8962 {
8963         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8964         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8965         statement->label.label = label;
8966
8967         PUSH_PARENT(statement);
8968
8969         /* if statement is already set then the label is defined twice,
8970          * otherwise it was just mentioned in a goto/local label declaration so far
8971          */
8972         source_position_t const* const pos = &statement->base.source_position;
8973         if (label->statement != NULL) {
8974                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8975         } else {
8976                 label->base.source_position = *pos;
8977                 label->statement            = statement;
8978                 label->n_users             += 1;
8979         }
8980
8981         eat(':');
8982
8983         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8984                 parse_attributes(NULL); // TODO process attributes
8985         }
8986
8987         statement->label.statement = parse_label_inner_statement(statement, "label");
8988
8989         /* remember the labels in a list for later checking */
8990         *label_anchor = &statement->label;
8991         label_anchor  = &statement->label.next;
8992
8993         POP_PARENT();
8994         return statement;
8995 }
8996
8997 static statement_t *parse_inner_statement(void)
8998 {
8999         statement_t *const stmt = parse_statement();
9000         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9001         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9002         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9003                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9004         }
9005         return stmt;
9006 }
9007
9008 /**
9009  * Parse an expression in parentheses and mark its variables as read.
9010  */
9011 static expression_t *parse_condition(void)
9012 {
9013         add_anchor_token(')');
9014         expect('(');
9015         expression_t *const expr = parse_expression();
9016         mark_vars_read(expr, NULL);
9017         rem_anchor_token(')');
9018         expect(')');
9019         return expr;
9020 }
9021
9022 /**
9023  * Parse an if statement.
9024  */
9025 static statement_t *parse_if(void)
9026 {
9027         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9028
9029         eat(T_if);
9030
9031         PUSH_PARENT(statement);
9032         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9033
9034         add_anchor_token(T_else);
9035
9036         expression_t *const expr = parse_condition();
9037         statement->ifs.condition = expr;
9038         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9039          *             scalar type. */
9040         semantic_condition(expr, "condition of 'if'-statment");
9041
9042         statement_t *const true_stmt = parse_inner_statement();
9043         statement->ifs.true_statement = true_stmt;
9044         rem_anchor_token(T_else);
9045
9046         if (true_stmt->kind == STATEMENT_EMPTY) {
9047                 warningf(WARN_EMPTY_BODY, HERE,
9048                         "suggest braces around empty body in an ‘if’ statement");
9049         }
9050
9051         if (next_if(T_else)) {
9052                 statement->ifs.false_statement = parse_inner_statement();
9053
9054                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9055                         warningf(WARN_EMPTY_BODY, HERE,
9056                                         "suggest braces around empty body in an ‘if’ statement");
9057                 }
9058         } else if (true_stmt->kind == STATEMENT_IF &&
9059                         true_stmt->ifs.false_statement != NULL) {
9060                 source_position_t const *const pos = &true_stmt->base.source_position;
9061                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9062         }
9063
9064         POP_SCOPE();
9065         POP_PARENT();
9066         return statement;
9067 }
9068
9069 /**
9070  * Check that all enums are handled in a switch.
9071  *
9072  * @param statement  the switch statement to check
9073  */
9074 static void check_enum_cases(const switch_statement_t *statement)
9075 {
9076         if (!is_warn_on(WARN_SWITCH_ENUM))
9077                 return;
9078         type_t *type = skip_typeref(statement->expression->base.type);
9079         if (! is_type_enum(type))
9080                 return;
9081         enum_type_t *enumt = &type->enumt;
9082
9083         /* if we have a default, no warnings */
9084         if (statement->default_label != NULL)
9085                 return;
9086
9087         determine_enum_values(enumt);
9088
9089         /* FIXME: calculation of value should be done while parsing */
9090         /* TODO: quadratic algorithm here. Change to an n log n one */
9091         const entity_t *entry = enumt->enume->base.next;
9092         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9093              entry = entry->base.next) {
9094                 ir_tarval *value = entry->enum_value.tv;
9095                 bool       found = false;
9096                 for (const case_label_statement_t *l = statement->first_case; l != NULL;
9097                      l = l->next) {
9098                         if (l->expression == NULL)
9099                                 continue;
9100                         if (l->first_case == l->last_case && l->first_case != value)
9101                                 continue;
9102                         if ((tarval_cmp(l->first_case, value) & ir_relation_less_equal)
9103                          && (tarval_cmp(value, l->last_case) & ir_relation_less_equal)) {
9104                                 found = true;
9105                                 break;
9106                         }
9107                 }
9108                 if (!found) {
9109                         source_position_t const *const pos = &statement->base.source_position;
9110                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9111                 }
9112         }
9113 }
9114
9115 /**
9116  * Parse a switch statement.
9117  */
9118 static statement_t *parse_switch(void)
9119 {
9120         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9121
9122         eat(T_switch);
9123
9124         PUSH_PARENT(statement);
9125         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9126
9127         expression_t *const expr = parse_condition();
9128         type_t       *      type = skip_typeref(expr->base.type);
9129         if (is_type_integer(type)) {
9130                 type = promote_integer(type);
9131                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9132                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9133                 }
9134         } else if (is_type_valid(type)) {
9135                 errorf(&expr->base.source_position,
9136                        "switch quantity is not an integer, but '%T'", type);
9137                 type = type_error_type;
9138         }
9139         statement->switchs.expression = create_implicit_cast(expr, type);
9140
9141         switch_statement_t *rem = current_switch;
9142         current_switch          = &statement->switchs;
9143         statement->switchs.body = parse_inner_statement();
9144         current_switch          = rem;
9145
9146         if (statement->switchs.default_label == NULL) {
9147                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9148         }
9149         check_enum_cases(&statement->switchs);
9150
9151         POP_SCOPE();
9152         POP_PARENT();
9153         return statement;
9154 }
9155
9156 static statement_t *parse_loop_body(statement_t *const loop)
9157 {
9158         statement_t *const rem = current_loop;
9159         current_loop = loop;
9160
9161         statement_t *const body = parse_inner_statement();
9162
9163         current_loop = rem;
9164         return body;
9165 }
9166
9167 /**
9168  * Parse a while statement.
9169  */
9170 static statement_t *parse_while(void)
9171 {
9172         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9173
9174         eat(T_while);
9175
9176         PUSH_PARENT(statement);
9177         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9178
9179         expression_t *const cond = parse_condition();
9180         statement->fors.condition = cond;
9181         /* §6.8.5:2    The controlling expression of an iteration statement shall
9182          *             have scalar type. */
9183         semantic_condition(cond, "condition of 'while'-statement");
9184
9185         statement->fors.body = parse_loop_body(statement);
9186
9187         POP_SCOPE();
9188         POP_PARENT();
9189         return statement;
9190 }
9191
9192 /**
9193  * Parse a do statement.
9194  */
9195 static statement_t *parse_do(void)
9196 {
9197         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9198
9199         eat(T_do);
9200
9201         PUSH_PARENT(statement);
9202         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9203
9204         add_anchor_token(T_while);
9205         statement->do_while.body = parse_loop_body(statement);
9206         rem_anchor_token(T_while);
9207
9208         expect(T_while);
9209         expression_t *const cond = parse_condition();
9210         statement->do_while.condition = cond;
9211         /* §6.8.5:2    The controlling expression of an iteration statement shall
9212          *             have scalar type. */
9213         semantic_condition(cond, "condition of 'do-while'-statement");
9214         expect(';');
9215
9216         POP_SCOPE();
9217         POP_PARENT();
9218         return statement;
9219 }
9220
9221 /**
9222  * Parse a for statement.
9223  */
9224 static statement_t *parse_for(void)
9225 {
9226         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9227
9228         eat(T_for);
9229
9230         PUSH_PARENT(statement);
9231         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9232
9233         add_anchor_token(')');
9234         expect('(');
9235
9236         PUSH_EXTENSION();
9237
9238         if (next_if(';')) {
9239         } else if (is_declaration_specifier(&token)) {
9240                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9241         } else {
9242                 add_anchor_token(';');
9243                 expression_t *const init = parse_expression();
9244                 statement->fors.initialisation = init;
9245                 mark_vars_read(init, ENT_ANY);
9246                 if (!expression_has_effect(init)) {
9247                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9248                 }
9249                 rem_anchor_token(';');
9250                 expect(';');
9251         }
9252
9253         POP_EXTENSION();
9254
9255         if (token.kind != ';') {
9256                 add_anchor_token(';');
9257                 expression_t *const cond = parse_expression();
9258                 statement->fors.condition = cond;
9259                 /* §6.8.5:2    The controlling expression of an iteration statement
9260                  *             shall have scalar type. */
9261                 semantic_condition(cond, "condition of 'for'-statement");
9262                 mark_vars_read(cond, NULL);
9263                 rem_anchor_token(';');
9264         }
9265         expect(';');
9266         if (token.kind != ')') {
9267                 expression_t *const step = parse_expression();
9268                 statement->fors.step = step;
9269                 mark_vars_read(step, ENT_ANY);
9270                 if (!expression_has_effect(step)) {
9271                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9272                 }
9273         }
9274         rem_anchor_token(')');
9275         expect(')');
9276         statement->fors.body = parse_loop_body(statement);
9277
9278         POP_SCOPE();
9279         POP_PARENT();
9280         return statement;
9281 }
9282
9283 /**
9284  * Parse a goto statement.
9285  */
9286 static statement_t *parse_goto(void)
9287 {
9288         statement_t *statement;
9289         if (GNU_MODE && look_ahead(1)->kind == '*') {
9290                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9291                 eat(T_goto);
9292                 eat('*');
9293
9294                 expression_t *expression = parse_expression();
9295                 mark_vars_read(expression, NULL);
9296
9297                 /* Argh: although documentation says the expression must be of type void*,
9298                  * gcc accepts anything that can be casted into void* without error */
9299                 type_t *type = expression->base.type;
9300
9301                 if (type != type_error_type) {
9302                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9303                                 errorf(&expression->base.source_position,
9304                                         "cannot convert to a pointer type");
9305                         } else if (type != type_void_ptr) {
9306                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9307                         }
9308                         expression = create_implicit_cast(expression, type_void_ptr);
9309                 }
9310
9311                 statement->computed_goto.expression = expression;
9312         } else {
9313                 statement = allocate_statement_zero(STATEMENT_GOTO);
9314                 eat(T_goto);
9315
9316                 label_t *const label = get_label("while parsing goto");
9317                 if (label) {
9318                         label->n_users        += 1;
9319                         label->used            = true;
9320                         statement->gotos.label = label;
9321
9322                         /* remember the goto's in a list for later checking */
9323                         *goto_anchor = &statement->gotos;
9324                         goto_anchor  = &statement->gotos.next;
9325                 } else {
9326                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9327                 }
9328         }
9329
9330         expect(';');
9331         return statement;
9332 }
9333
9334 /**
9335  * Parse a continue statement.
9336  */
9337 static statement_t *parse_continue(void)
9338 {
9339         if (current_loop == NULL) {
9340                 errorf(HERE, "continue statement not within loop");
9341         }
9342
9343         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9344
9345         eat(T_continue);
9346         expect(';');
9347         return statement;
9348 }
9349
9350 /**
9351  * Parse a break statement.
9352  */
9353 static statement_t *parse_break(void)
9354 {
9355         if (current_switch == NULL && current_loop == NULL) {
9356                 errorf(HERE, "break statement not within loop or switch");
9357         }
9358
9359         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9360
9361         eat(T_break);
9362         expect(';');
9363         return statement;
9364 }
9365
9366 /**
9367  * Parse a __leave statement.
9368  */
9369 static statement_t *parse_leave_statement(void)
9370 {
9371         if (current_try == NULL) {
9372                 errorf(HERE, "__leave statement not within __try");
9373         }
9374
9375         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9376
9377         eat(T___leave);
9378         expect(';');
9379         return statement;
9380 }
9381
9382 /**
9383  * Check if a given entity represents a local variable.
9384  */
9385 static bool is_local_variable(const entity_t *entity)
9386 {
9387         if (entity->kind != ENTITY_VARIABLE)
9388                 return false;
9389
9390         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9391         case STORAGE_CLASS_AUTO:
9392         case STORAGE_CLASS_REGISTER: {
9393                 const type_t *type = skip_typeref(entity->declaration.type);
9394                 if (is_type_function(type)) {
9395                         return false;
9396                 } else {
9397                         return true;
9398                 }
9399         }
9400         default:
9401                 return false;
9402         }
9403 }
9404
9405 /**
9406  * Check if a given expression represents a local variable.
9407  */
9408 static bool expression_is_local_variable(const expression_t *expression)
9409 {
9410         if (expression->base.kind != EXPR_REFERENCE) {
9411                 return false;
9412         }
9413         const entity_t *entity = expression->reference.entity;
9414         return is_local_variable(entity);
9415 }
9416
9417 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9418 {
9419         if (c_mode & _CXX || strict_mode) {
9420                 errorf(pos, msg);
9421         } else {
9422                 warningf(WARN_OTHER, pos, msg);
9423         }
9424 }
9425
9426 /**
9427  * Parse a return statement.
9428  */
9429 static statement_t *parse_return(void)
9430 {
9431         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9432         eat(T_return);
9433
9434         expression_t *return_value = NULL;
9435         if (token.kind != ';') {
9436                 return_value = parse_expression();
9437                 mark_vars_read(return_value, NULL);
9438         }
9439
9440         const type_t *const func_type = skip_typeref(current_function->base.type);
9441         assert(is_type_function(func_type));
9442         type_t *const return_type = skip_typeref(func_type->function.return_type);
9443
9444         source_position_t const *const pos = &statement->base.source_position;
9445         if (return_value != NULL) {
9446                 type_t *return_value_type = skip_typeref(return_value->base.type);
9447
9448                 if (is_type_void(return_type)) {
9449                         if (!is_type_void(return_value_type)) {
9450                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9451                                 /* Only warn in C mode, because GCC does the same */
9452                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9453                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9454                                 /* Only warn in C mode, because GCC does the same */
9455                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9456                         }
9457                 } else {
9458                         assign_error_t error = semantic_assign(return_type, return_value);
9459                         report_assign_error(error, return_type, return_value, "'return'",
9460                                             pos);
9461                 }
9462                 return_value = create_implicit_cast(return_value, return_type);
9463                 /* check for returning address of a local var */
9464                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9465                         const expression_t *expression = return_value->unary.value;
9466                         if (expression_is_local_variable(expression)) {
9467                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9468                         }
9469                 }
9470         } else if (!is_type_void(return_type)) {
9471                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9472                 err_or_warn(pos, "'return' without value, in function returning non-void");
9473         }
9474         statement->returns.value = return_value;
9475
9476         expect(';');
9477         return statement;
9478 }
9479
9480 /**
9481  * Parse a declaration statement.
9482  */
9483 static statement_t *parse_declaration_statement(void)
9484 {
9485         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9486
9487         entity_t *before = current_scope->last_entity;
9488         if (GNU_MODE) {
9489                 parse_external_declaration();
9490         } else {
9491                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9492         }
9493
9494         declaration_statement_t *const decl  = &statement->declaration;
9495         entity_t                *const begin =
9496                 before != NULL ? before->base.next : current_scope->entities;
9497         decl->declarations_begin = begin;
9498         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9499
9500         return statement;
9501 }
9502
9503 /**
9504  * Parse an expression statement, ie. expr ';'.
9505  */
9506 static statement_t *parse_expression_statement(void)
9507 {
9508         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9509
9510         expression_t *const expr         = parse_expression();
9511         statement->expression.expression = expr;
9512         mark_vars_read(expr, ENT_ANY);
9513
9514         expect(';');
9515         return statement;
9516 }
9517
9518 /**
9519  * Parse a microsoft __try { } __finally { } or
9520  * __try{ } __except() { }
9521  */
9522 static statement_t *parse_ms_try_statment(void)
9523 {
9524         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9525         eat(T___try);
9526
9527         PUSH_PARENT(statement);
9528
9529         ms_try_statement_t *rem = current_try;
9530         current_try = &statement->ms_try;
9531         statement->ms_try.try_statement = parse_compound_statement(false);
9532         current_try = rem;
9533
9534         POP_PARENT();
9535
9536         if (next_if(T___except)) {
9537                 expression_t *const expr = parse_condition();
9538                 type_t       *      type = skip_typeref(expr->base.type);
9539                 if (is_type_integer(type)) {
9540                         type = promote_integer(type);
9541                 } else if (is_type_valid(type)) {
9542                         errorf(&expr->base.source_position,
9543                                "__expect expression is not an integer, but '%T'", type);
9544                         type = type_error_type;
9545                 }
9546                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9547         } else if (!next_if(T__finally)) {
9548                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9549         }
9550         statement->ms_try.final_statement = parse_compound_statement(false);
9551         return statement;
9552 }
9553
9554 static statement_t *parse_empty_statement(void)
9555 {
9556         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9557         statement_t *const statement = create_empty_statement();
9558         eat(';');
9559         return statement;
9560 }
9561
9562 static statement_t *parse_local_label_declaration(void)
9563 {
9564         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9565
9566         eat(T___label__);
9567
9568         entity_t *begin   = NULL;
9569         entity_t *end     = NULL;
9570         entity_t **anchor = &begin;
9571         add_anchor_token(';');
9572         add_anchor_token(',');
9573         do {
9574                 source_position_t pos;
9575                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9576                 if (symbol) {
9577                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9578                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9579                                 source_position_t const *const ppos = &entity->base.source_position;
9580                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9581                         } else {
9582                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9583                                 entity->base.parent_scope = current_scope;
9584
9585                                 *anchor = entity;
9586                                 anchor  = &entity->base.next;
9587                                 end     = entity;
9588
9589                                 environment_push(entity);
9590                         }
9591                 }
9592         } while (next_if(','));
9593         rem_anchor_token(',');
9594         rem_anchor_token(';');
9595         expect(';');
9596         statement->declaration.declarations_begin = begin;
9597         statement->declaration.declarations_end   = end;
9598         return statement;
9599 }
9600
9601 static void parse_namespace_definition(void)
9602 {
9603         eat(T_namespace);
9604
9605         entity_t *entity = NULL;
9606         symbol_t *symbol = NULL;
9607
9608         if (token.kind == T_IDENTIFIER) {
9609                 symbol = token.base.symbol;
9610                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9611                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9612                         entity = NULL;
9613                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9614                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9615                         }
9616                 }
9617                 eat(T_IDENTIFIER);
9618         }
9619
9620         if (entity == NULL) {
9621                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9622                 entity->base.parent_scope = current_scope;
9623         }
9624
9625         if (token.kind == '=') {
9626                 /* TODO: parse namespace alias */
9627                 panic("namespace alias definition not supported yet");
9628         }
9629
9630         environment_push(entity);
9631         append_entity(current_scope, entity);
9632
9633         PUSH_SCOPE(&entity->namespacee.members);
9634         PUSH_CURRENT_ENTITY(entity);
9635
9636         add_anchor_token('}');
9637         expect('{');
9638         parse_externals();
9639         rem_anchor_token('}');
9640         expect('}');
9641
9642         POP_CURRENT_ENTITY();
9643         POP_SCOPE();
9644 }
9645
9646 /**
9647  * Parse a statement.
9648  * There's also parse_statement() which additionally checks for
9649  * "statement has no effect" warnings
9650  */
9651 static statement_t *intern_parse_statement(void)
9652 {
9653         /* declaration or statement */
9654         statement_t *statement;
9655         switch (token.kind) {
9656         case T_IDENTIFIER: {
9657                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9658                 if (la1_type == ':') {
9659                         statement = parse_label_statement();
9660                 } else if (is_typedef_symbol(token.base.symbol)) {
9661                         statement = parse_declaration_statement();
9662                 } else {
9663                         /* it's an identifier, the grammar says this must be an
9664                          * expression statement. However it is common that users mistype
9665                          * declaration types, so we guess a bit here to improve robustness
9666                          * for incorrect programs */
9667                         switch (la1_type) {
9668                         case '&':
9669                         case '*':
9670                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9671                         default:
9672                                         statement = parse_expression_statement();
9673                                 } else {
9674                         DECLARATION_START
9675                         case T_IDENTIFIER:
9676                                         statement = parse_declaration_statement();
9677                                 }
9678                                 break;
9679                         }
9680                 }
9681                 break;
9682         }
9683
9684         case T___extension__: {
9685                 /* This can be a prefix to a declaration or an expression statement.
9686                  * We simply eat it now and parse the rest with tail recursion. */
9687                 PUSH_EXTENSION();
9688                 statement = intern_parse_statement();
9689                 POP_EXTENSION();
9690                 break;
9691         }
9692
9693         DECLARATION_START
9694                 statement = parse_declaration_statement();
9695                 break;
9696
9697         case T___label__:
9698                 statement = parse_local_label_declaration();
9699                 break;
9700
9701         case ';':         statement = parse_empty_statement();         break;
9702         case '{':         statement = parse_compound_statement(false); break;
9703         case T___leave:   statement = parse_leave_statement();         break;
9704         case T___try:     statement = parse_ms_try_statment();         break;
9705         case T_asm:       statement = parse_asm_statement();           break;
9706         case T_break:     statement = parse_break();                   break;
9707         case T_case:      statement = parse_case_statement();          break;
9708         case T_continue:  statement = parse_continue();                break;
9709         case T_default:   statement = parse_default_statement();       break;
9710         case T_do:        statement = parse_do();                      break;
9711         case T_for:       statement = parse_for();                     break;
9712         case T_goto:      statement = parse_goto();                    break;
9713         case T_if:        statement = parse_if();                      break;
9714         case T_return:    statement = parse_return();                  break;
9715         case T_switch:    statement = parse_switch();                  break;
9716         case T_while:     statement = parse_while();                   break;
9717
9718         EXPRESSION_START
9719                 statement = parse_expression_statement();
9720                 break;
9721
9722         default:
9723                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9724                 statement = create_error_statement();
9725                 eat_until_anchor();
9726                 break;
9727         }
9728
9729         return statement;
9730 }
9731
9732 /**
9733  * parse a statement and emits "statement has no effect" warning if needed
9734  * (This is really a wrapper around intern_parse_statement with check for 1
9735  *  single warning. It is needed, because for statement expressions we have
9736  *  to avoid the warning on the last statement)
9737  */
9738 static statement_t *parse_statement(void)
9739 {
9740         statement_t *statement = intern_parse_statement();
9741
9742         if (statement->kind == STATEMENT_EXPRESSION) {
9743                 expression_t *expression = statement->expression.expression;
9744                 if (!expression_has_effect(expression)) {
9745                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9746                 }
9747         }
9748
9749         return statement;
9750 }
9751
9752 /**
9753  * Parse a compound statement.
9754  */
9755 static statement_t *parse_compound_statement(bool inside_expression_statement)
9756 {
9757         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9758
9759         PUSH_PARENT(statement);
9760         PUSH_SCOPE(&statement->compound.scope);
9761
9762         eat('{');
9763         add_anchor_token('}');
9764         /* tokens, which can start a statement */
9765         /* TODO MS, __builtin_FOO */
9766         add_anchor_token('!');
9767         add_anchor_token('&');
9768         add_anchor_token('(');
9769         add_anchor_token('*');
9770         add_anchor_token('+');
9771         add_anchor_token('-');
9772         add_anchor_token(';');
9773         add_anchor_token('{');
9774         add_anchor_token('~');
9775         add_anchor_token(T_CHARACTER_CONSTANT);
9776         add_anchor_token(T_COLONCOLON);
9777         add_anchor_token(T_IDENTIFIER);
9778         add_anchor_token(T_MINUSMINUS);
9779         add_anchor_token(T_NUMBER);
9780         add_anchor_token(T_PLUSPLUS);
9781         add_anchor_token(T_STRING_LITERAL);
9782         add_anchor_token(T__Alignof);
9783         add_anchor_token(T__Bool);
9784         add_anchor_token(T__Complex);
9785         add_anchor_token(T__Imaginary);
9786         add_anchor_token(T__Thread_local);
9787         add_anchor_token(T___PRETTY_FUNCTION__);
9788         add_anchor_token(T___attribute__);
9789         add_anchor_token(T___builtin_va_start);
9790         add_anchor_token(T___extension__);
9791         add_anchor_token(T___func__);
9792         add_anchor_token(T___imag__);
9793         add_anchor_token(T___label__);
9794         add_anchor_token(T___real__);
9795         add_anchor_token(T_asm);
9796         add_anchor_token(T_auto);
9797         add_anchor_token(T_bool);
9798         add_anchor_token(T_break);
9799         add_anchor_token(T_case);
9800         add_anchor_token(T_char);
9801         add_anchor_token(T_class);
9802         add_anchor_token(T_const);
9803         add_anchor_token(T_const_cast);
9804         add_anchor_token(T_continue);
9805         add_anchor_token(T_default);
9806         add_anchor_token(T_delete);
9807         add_anchor_token(T_double);
9808         add_anchor_token(T_do);
9809         add_anchor_token(T_dynamic_cast);
9810         add_anchor_token(T_enum);
9811         add_anchor_token(T_extern);
9812         add_anchor_token(T_false);
9813         add_anchor_token(T_float);
9814         add_anchor_token(T_for);
9815         add_anchor_token(T_goto);
9816         add_anchor_token(T_if);
9817         add_anchor_token(T_inline);
9818         add_anchor_token(T_int);
9819         add_anchor_token(T_long);
9820         add_anchor_token(T_new);
9821         add_anchor_token(T_operator);
9822         add_anchor_token(T_register);
9823         add_anchor_token(T_reinterpret_cast);
9824         add_anchor_token(T_restrict);
9825         add_anchor_token(T_return);
9826         add_anchor_token(T_short);
9827         add_anchor_token(T_signed);
9828         add_anchor_token(T_sizeof);
9829         add_anchor_token(T_static);
9830         add_anchor_token(T_static_cast);
9831         add_anchor_token(T_struct);
9832         add_anchor_token(T_switch);
9833         add_anchor_token(T_template);
9834         add_anchor_token(T_this);
9835         add_anchor_token(T_throw);
9836         add_anchor_token(T_true);
9837         add_anchor_token(T_try);
9838         add_anchor_token(T_typedef);
9839         add_anchor_token(T_typeid);
9840         add_anchor_token(T_typename);
9841         add_anchor_token(T_typeof);
9842         add_anchor_token(T_union);
9843         add_anchor_token(T_unsigned);
9844         add_anchor_token(T_using);
9845         add_anchor_token(T_void);
9846         add_anchor_token(T_volatile);
9847         add_anchor_token(T_wchar_t);
9848         add_anchor_token(T_while);
9849
9850         statement_t **anchor            = &statement->compound.statements;
9851         bool          only_decls_so_far = true;
9852         while (token.kind != '}' && token.kind != T_EOF) {
9853                 statement_t *sub_statement = intern_parse_statement();
9854                 if (sub_statement->kind == STATEMENT_ERROR) {
9855                         break;
9856                 }
9857
9858                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9859                         only_decls_so_far = false;
9860                 } else if (!only_decls_so_far) {
9861                         source_position_t const *const pos = &sub_statement->base.source_position;
9862                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9863                 }
9864
9865                 *anchor = sub_statement;
9866                 anchor  = &sub_statement->base.next;
9867         }
9868         expect('}');
9869
9870         /* look over all statements again to produce no effect warnings */
9871         if (is_warn_on(WARN_UNUSED_VALUE)) {
9872                 statement_t *sub_statement = statement->compound.statements;
9873                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9874                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9875                                 continue;
9876                         /* don't emit a warning for the last expression in an expression
9877                          * statement as it has always an effect */
9878                         if (inside_expression_statement && sub_statement->base.next == NULL)
9879                                 continue;
9880
9881                         expression_t *expression = sub_statement->expression.expression;
9882                         if (!expression_has_effect(expression)) {
9883                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9884                         }
9885                 }
9886         }
9887
9888         rem_anchor_token(T_while);
9889         rem_anchor_token(T_wchar_t);
9890         rem_anchor_token(T_volatile);
9891         rem_anchor_token(T_void);
9892         rem_anchor_token(T_using);
9893         rem_anchor_token(T_unsigned);
9894         rem_anchor_token(T_union);
9895         rem_anchor_token(T_typeof);
9896         rem_anchor_token(T_typename);
9897         rem_anchor_token(T_typeid);
9898         rem_anchor_token(T_typedef);
9899         rem_anchor_token(T_try);
9900         rem_anchor_token(T_true);
9901         rem_anchor_token(T_throw);
9902         rem_anchor_token(T_this);
9903         rem_anchor_token(T_template);
9904         rem_anchor_token(T_switch);
9905         rem_anchor_token(T_struct);
9906         rem_anchor_token(T_static_cast);
9907         rem_anchor_token(T_static);
9908         rem_anchor_token(T_sizeof);
9909         rem_anchor_token(T_signed);
9910         rem_anchor_token(T_short);
9911         rem_anchor_token(T_return);
9912         rem_anchor_token(T_restrict);
9913         rem_anchor_token(T_reinterpret_cast);
9914         rem_anchor_token(T_register);
9915         rem_anchor_token(T_operator);
9916         rem_anchor_token(T_new);
9917         rem_anchor_token(T_long);
9918         rem_anchor_token(T_int);
9919         rem_anchor_token(T_inline);
9920         rem_anchor_token(T_if);
9921         rem_anchor_token(T_goto);
9922         rem_anchor_token(T_for);
9923         rem_anchor_token(T_float);
9924         rem_anchor_token(T_false);
9925         rem_anchor_token(T_extern);
9926         rem_anchor_token(T_enum);
9927         rem_anchor_token(T_dynamic_cast);
9928         rem_anchor_token(T_do);
9929         rem_anchor_token(T_double);
9930         rem_anchor_token(T_delete);
9931         rem_anchor_token(T_default);
9932         rem_anchor_token(T_continue);
9933         rem_anchor_token(T_const_cast);
9934         rem_anchor_token(T_const);
9935         rem_anchor_token(T_class);
9936         rem_anchor_token(T_char);
9937         rem_anchor_token(T_case);
9938         rem_anchor_token(T_break);
9939         rem_anchor_token(T_bool);
9940         rem_anchor_token(T_auto);
9941         rem_anchor_token(T_asm);
9942         rem_anchor_token(T___real__);
9943         rem_anchor_token(T___label__);
9944         rem_anchor_token(T___imag__);
9945         rem_anchor_token(T___func__);
9946         rem_anchor_token(T___extension__);
9947         rem_anchor_token(T___builtin_va_start);
9948         rem_anchor_token(T___attribute__);
9949         rem_anchor_token(T___PRETTY_FUNCTION__);
9950         rem_anchor_token(T__Thread_local);
9951         rem_anchor_token(T__Imaginary);
9952         rem_anchor_token(T__Complex);
9953         rem_anchor_token(T__Bool);
9954         rem_anchor_token(T__Alignof);
9955         rem_anchor_token(T_STRING_LITERAL);
9956         rem_anchor_token(T_PLUSPLUS);
9957         rem_anchor_token(T_NUMBER);
9958         rem_anchor_token(T_MINUSMINUS);
9959         rem_anchor_token(T_IDENTIFIER);
9960         rem_anchor_token(T_COLONCOLON);
9961         rem_anchor_token(T_CHARACTER_CONSTANT);
9962         rem_anchor_token('~');
9963         rem_anchor_token('{');
9964         rem_anchor_token(';');
9965         rem_anchor_token('-');
9966         rem_anchor_token('+');
9967         rem_anchor_token('*');
9968         rem_anchor_token('(');
9969         rem_anchor_token('&');
9970         rem_anchor_token('!');
9971         rem_anchor_token('}');
9972
9973         POP_SCOPE();
9974         POP_PARENT();
9975         return statement;
9976 }
9977
9978 /**
9979  * Check for unused global static functions and variables
9980  */
9981 static void check_unused_globals(void)
9982 {
9983         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9984                 return;
9985
9986         for (const entity_t *entity = file_scope->entities; entity != NULL;
9987              entity = entity->base.next) {
9988                 if (!is_declaration(entity))
9989                         continue;
9990
9991                 const declaration_t *declaration = &entity->declaration;
9992                 if (declaration->used                  ||
9993                     declaration->modifiers & DM_UNUSED ||
9994                     declaration->modifiers & DM_USED   ||
9995                     declaration->storage_class != STORAGE_CLASS_STATIC)
9996                         continue;
9997
9998                 warning_t   why;
9999                 char const *s;
10000                 if (entity->kind == ENTITY_FUNCTION) {
10001                         /* inhibit warning for static inline functions */
10002                         if (entity->function.is_inline)
10003                                 continue;
10004
10005                         why = WARN_UNUSED_FUNCTION;
10006                         s   = entity->function.body != NULL ? "defined" : "declared";
10007                 } else {
10008                         why = WARN_UNUSED_VARIABLE;
10009                         s   = "defined";
10010                 }
10011
10012                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10013         }
10014 }
10015
10016 static void parse_global_asm(void)
10017 {
10018         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10019
10020         eat(T_asm);
10021         add_anchor_token(';');
10022         add_anchor_token(')');
10023         add_anchor_token(T_STRING_LITERAL);
10024         expect('(');
10025
10026         rem_anchor_token(T_STRING_LITERAL);
10027         statement->asms.asm_text = parse_string_literals("global asm");
10028         statement->base.next     = unit->global_asm;
10029         unit->global_asm         = statement;
10030
10031         rem_anchor_token(')');
10032         expect(')');
10033         rem_anchor_token(';');
10034         expect(';');
10035 }
10036
10037 static void parse_linkage_specification(void)
10038 {
10039         eat(T_extern);
10040
10041         source_position_t const pos     = *HERE;
10042         char const       *const linkage = parse_string_literals(NULL).begin;
10043
10044         linkage_kind_t old_linkage = current_linkage;
10045         linkage_kind_t new_linkage;
10046         if (streq(linkage, "C")) {
10047                 new_linkage = LINKAGE_C;
10048         } else if (streq(linkage, "C++")) {
10049                 new_linkage = LINKAGE_CXX;
10050         } else {
10051                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10052                 new_linkage = LINKAGE_C;
10053         }
10054         current_linkage = new_linkage;
10055
10056         if (next_if('{')) {
10057                 parse_externals();
10058                 expect('}');
10059         } else {
10060                 parse_external();
10061         }
10062
10063         assert(current_linkage == new_linkage);
10064         current_linkage = old_linkage;
10065 }
10066
10067 static void parse_external(void)
10068 {
10069         switch (token.kind) {
10070                 case T_extern:
10071                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10072                                 parse_linkage_specification();
10073                         } else {
10074                 DECLARATION_START_NO_EXTERN
10075                 case T_IDENTIFIER:
10076                 case T___extension__:
10077                 /* tokens below are for implicit int */
10078                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10079                               implicit int) */
10080                 case '*':  /* * x; -> int* x; */
10081                 case '(':  /* (x); -> int (x); */
10082                                 PUSH_EXTENSION();
10083                                 parse_external_declaration();
10084                                 POP_EXTENSION();
10085                         }
10086                         return;
10087
10088                 case T_asm:
10089                         parse_global_asm();
10090                         return;
10091
10092                 case T_namespace:
10093                         parse_namespace_definition();
10094                         return;
10095
10096                 case ';':
10097                         if (!strict_mode) {
10098                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10099                                 eat(';');
10100                                 return;
10101                         }
10102                         /* FALLTHROUGH */
10103
10104                 default:
10105                         errorf(HERE, "stray %K outside of function", &token);
10106                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10107                                 eat_until_matching_token(token.kind);
10108                         next_token();
10109                         return;
10110         }
10111 }
10112
10113 static void parse_externals(void)
10114 {
10115         add_anchor_token('}');
10116         add_anchor_token(T_EOF);
10117
10118 #ifndef NDEBUG
10119         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10120         unsigned short token_anchor_copy[T_LAST_TOKEN];
10121         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10122 #endif
10123
10124         while (token.kind != T_EOF && token.kind != '}') {
10125 #ifndef NDEBUG
10126                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10127                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10128                         if (count != 0) {
10129                                 /* the anchor set and its copy differs */
10130                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10131                         }
10132                 }
10133                 if (in_gcc_extension) {
10134                         /* an gcc extension scope was not closed */
10135                         internal_errorf(HERE, "Leaked __extension__");
10136                 }
10137 #endif
10138
10139                 parse_external();
10140         }
10141
10142         rem_anchor_token(T_EOF);
10143         rem_anchor_token('}');
10144 }
10145
10146 /**
10147  * Parse a translation unit.
10148  */
10149 static void parse_translation_unit(void)
10150 {
10151         add_anchor_token(T_EOF);
10152
10153         while (true) {
10154                 parse_externals();
10155
10156                 if (token.kind == T_EOF)
10157                         break;
10158
10159                 errorf(HERE, "stray %K outside of function", &token);
10160                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10161                         eat_until_matching_token(token.kind);
10162                 next_token();
10163         }
10164 }
10165
10166 void set_default_visibility(elf_visibility_tag_t visibility)
10167 {
10168         default_visibility = visibility;
10169 }
10170
10171 /**
10172  * Parse the input.
10173  *
10174  * @return  the translation unit or NULL if errors occurred.
10175  */
10176 void start_parsing(void)
10177 {
10178         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10179         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10180
10181         print_to_file(stderr);
10182
10183         assert(unit == NULL);
10184         unit = allocate_ast_zero(sizeof(unit[0]));
10185
10186         assert(file_scope == NULL);
10187         file_scope = &unit->scope;
10188
10189         assert(current_scope == NULL);
10190         scope_push(&unit->scope);
10191
10192         create_gnu_builtins();
10193         if (c_mode & _MS)
10194                 create_microsoft_intrinsics();
10195 }
10196
10197 translation_unit_t *finish_parsing(void)
10198 {
10199         assert(current_scope == &unit->scope);
10200         scope_pop(NULL);
10201
10202         assert(file_scope == &unit->scope);
10203         check_unused_globals();
10204         file_scope = NULL;
10205
10206         DEL_ARR_F(environment_stack);
10207         DEL_ARR_F(label_stack);
10208
10209         translation_unit_t *result = unit;
10210         unit = NULL;
10211         return result;
10212 }
10213
10214 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10215  * are given length one. */
10216 static void complete_incomplete_arrays(void)
10217 {
10218         size_t n = ARR_LEN(incomplete_arrays);
10219         for (size_t i = 0; i != n; ++i) {
10220                 declaration_t *const decl = incomplete_arrays[i];
10221                 type_t        *const type = skip_typeref(decl->type);
10222
10223                 if (!is_type_incomplete(type))
10224                         continue;
10225
10226                 source_position_t const *const pos = &decl->base.source_position;
10227                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10228
10229                 type_t *const new_type = duplicate_type(type);
10230                 new_type->array.size_constant     = true;
10231                 new_type->array.has_implicit_size = true;
10232                 new_type->array.size              = 1;
10233
10234                 type_t *const result = identify_new_type(new_type);
10235
10236                 decl->type = result;
10237         }
10238 }
10239
10240 static void prepare_main_collect2(entity_t *const entity)
10241 {
10242         PUSH_SCOPE(&entity->function.body->compound.scope);
10243
10244         // create call to __main
10245         symbol_t *symbol         = symbol_table_insert("__main");
10246         entity_t *subsubmain_ent
10247                 = create_implicit_function(symbol, &builtin_source_position);
10248
10249         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10250         type_t       *ftype       = subsubmain_ent->declaration.type;
10251         ref->base.source_position = builtin_source_position;
10252         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10253         ref->reference.entity     = subsubmain_ent;
10254
10255         expression_t *call = allocate_expression_zero(EXPR_CALL);
10256         call->base.source_position = builtin_source_position;
10257         call->base.type            = type_void;
10258         call->call.function        = ref;
10259
10260         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10261         expr_statement->base.source_position  = builtin_source_position;
10262         expr_statement->expression.expression = call;
10263
10264         statement_t *const body = entity->function.body;
10265         assert(body->kind == STATEMENT_COMPOUND);
10266         compound_statement_t *compounds = &body->compound;
10267
10268         expr_statement->base.next = compounds->statements;
10269         compounds->statements     = expr_statement;
10270
10271         POP_SCOPE();
10272 }
10273
10274 void parse(void)
10275 {
10276         lookahead_bufpos = 0;
10277         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10278                 next_token();
10279         }
10280         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10281         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10282         parse_translation_unit();
10283         complete_incomplete_arrays();
10284         DEL_ARR_F(incomplete_arrays);
10285         incomplete_arrays = NULL;
10286 }
10287
10288 /**
10289  * Initialize the parser.
10290  */
10291 void init_parser(void)
10292 {
10293         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10294
10295         init_expression_parsers();
10296         obstack_init(&temp_obst);
10297 }
10298
10299 /**
10300  * Terminate the parser.
10301  */
10302 void exit_parser(void)
10303 {
10304         obstack_free(&temp_obst, NULL);
10305 }