nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T___FUNCDNAME__:             \
 256         case T___FUNCSIG__:               \
 257         case T___PRETTY_FUNCTION__:       \
 258         case T___alignof__:               \
 259         case T___builtin_classify_type:   \
 260         case T___builtin_constant_p:      \
 261         case T___builtin_isgreater:       \
 262         case T___builtin_isgreaterequal:  \
 263         case T___builtin_isless:          \
 264         case T___builtin_islessequal:     \
 265         case T___builtin_islessgreater:   \
 266         case T___builtin_isunordered:     \
 267         case T___builtin_offsetof:        \
 268         case T___builtin_va_arg:          \
 269         case T___builtin_va_copy:         \
 270         case T___builtin_va_start:        \
 271         case T___func__:                  \
 272         case T___noop:                    \
 273         case T__assume:                   \
 274         case T_delete:                    \
 275         case T_false:                     \
 276         case T_sizeof:                    \
 277         case T_throw:                     \
 278         case T_true:
 279
 280 /**
 281  * Returns the size of a statement node.
 282  *
 283  * @param kind  the statement kind
 284  */
 285 static size_t get_statement_struct_size(statement_kind_t kind)
 286 {
 287         static const size_t sizes[] = {
 288                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 289                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 290                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 291                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 292                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 293                 [STATEMENT_IF]            = sizeof(if_statement_t),
 294                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 295                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 296                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 297                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 298                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 299                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 300                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 301                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 302                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 303                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 304                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 305                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 306                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 307                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 308         };
 309         assert((size_t)kind < lengthof(sizes));
 310         assert(sizes[kind] != 0);
 311         return sizes[kind];
 312 }
 313
 314 /**
 315  * Returns the size of an expression node.
 316  *
 317  * @param kind  the expression kind
 318  */
 319 static size_t get_expression_struct_size(expression_kind_t kind)
 320 {
 321         static const size_t sizes[] = {
 322                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 323                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 324                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 325                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 329                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 330                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 331                 [EXPR_CALL]                       = sizeof(call_expression_t),
 332                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 333                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 334                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 335                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 336                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 337                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 338                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 339                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 340                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 341                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 342                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 343                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 344                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 345                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 346                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 347                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 348                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 349         };
 350         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 351                 return sizes[EXPR_UNARY_FIRST];
 352         }
 353         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 354                 return sizes[EXPR_BINARY_FIRST];
 355         }
 356         assert((size_t)kind < lengthof(sizes));
 357         assert(sizes[kind] != 0);
 358         return sizes[kind];
 359 }
 360
 361 /**
 362  * Allocate a statement node of given kind and initialize all
 363  * fields with zero. Sets its source position to the position
 364  * of the current token.
 365  */
 366 static statement_t *allocate_statement_zero(statement_kind_t kind)
 367 {
 368         size_t       size = get_statement_struct_size(kind);
 369         statement_t *res  = allocate_ast_zero(size);
 370
 371         res->base.kind            = kind;
 372         res->base.parent          = current_parent;
 373         res->base.source_position = *HERE;
 374         return res;
 375 }
 376
 377 /**
 378  * Allocate an expression node of given kind and initialize all
 379  * fields with zero.
 380  *
 381  * @param kind  the kind of the expression to allocate
 382  */
 383 static expression_t *allocate_expression_zero(expression_kind_t kind)
 384 {
 385         size_t        size = get_expression_struct_size(kind);
 386         expression_t *res  = allocate_ast_zero(size);
 387
 388         res->base.kind            = kind;
 389         res->base.type            = type_error_type;
 390         res->base.source_position = *HERE;
 391         return res;
 392 }
 393
 394 /**
 395  * Creates a new invalid expression at the source position
 396  * of the current token.
 397  */
 398 static expression_t *create_error_expression(void)
 399 {
 400         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 401         expression->base.type = type_error_type;
 402         return expression;
 403 }
 404
 405 /**
 406  * Creates a new invalid statement.
 407  */
 408 static statement_t *create_error_statement(void)
 409 {
 410         return allocate_statement_zero(STATEMENT_ERROR);
 411 }
 412
 413 /**
 414  * Allocate a new empty statement.
 415  */
 416 static statement_t *create_empty_statement(void)
 417 {
 418         return allocate_statement_zero(STATEMENT_EMPTY);
 419 }
 420
 421 /**
 422  * Returns the size of an initializer node.
 423  *
 424  * @param kind  the initializer kind
 425  */
 426 static size_t get_initializer_size(initializer_kind_t kind)
 427 {
 428         static const size_t sizes[] = {
 429                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 430                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert((size_t)kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = lexer_token;
 474         lexer_next_token();
 475
 476         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 477
 478 #ifdef PRINT_TOKENS
 479         print_token(stderr, &token);
 480         fprintf(stderr, "\n");
 481 #endif
 482 }
 483
 484 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 485
 486 static inline bool next_if(token_kind_t const type)
 487 {
 488         if (token.kind == type) {
 489                 eat(type);
 490                 return true;
 491         } else {
 492                 return false;
 493         }
 494 }
 495
 496 /**
 497  * Return the next token with a given lookahead.
 498  */
 499 static inline const token_t *look_ahead(size_t num)
 500 {
 501         assert(0 < num && num <= MAX_LOOKAHEAD);
 502         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 503         return &lookahead_buffer[pos];
 504 }
 505
 506 /**
 507  * Adds a token type to the token type anchor set (a multi-set).
 508  */
 509 static void add_anchor_token(token_kind_t const token_kind)
 510 {
 511         assert(token_kind < T_LAST_TOKEN);
 512         ++token_anchor_set[token_kind];
 513 }
 514
 515 /**
 516  * Remove a token type from the token type anchor set (a multi-set).
 517  */
 518 static void rem_anchor_token(token_kind_t const token_kind)
 519 {
 520         assert(token_kind < T_LAST_TOKEN);
 521         assert(token_anchor_set[token_kind] != 0);
 522         --token_anchor_set[token_kind];
 523 }
 524
 525 /**
 526  * Eat tokens until a matching token type is found.
 527  */
 528 static void eat_until_matching_token(token_kind_t const type)
 529 {
 530         token_kind_t end_token;
 531         switch (type) {
 532                 case '(': end_token = ')';  break;
 533                 case '{': end_token = '}';  break;
 534                 case '[': end_token = ']';  break;
 535                 default:  end_token = type; break;
 536         }
 537
 538         unsigned parenthesis_count = 0;
 539         unsigned brace_count       = 0;
 540         unsigned bracket_count     = 0;
 541         while (token.kind        != end_token ||
 542                parenthesis_count != 0         ||
 543                brace_count       != 0         ||
 544                bracket_count     != 0) {
 545                 switch (token.kind) {
 546                 case T_EOF: return;
 547                 case '(': ++parenthesis_count; break;
 548                 case '{': ++brace_count;       break;
 549                 case '[': ++bracket_count;     break;
 550
 551                 case ')':
 552                         if (parenthesis_count > 0)
 553                                 --parenthesis_count;
 554                         goto check_stop;
 555
 556                 case '}':
 557                         if (brace_count > 0)
 558                                 --brace_count;
 559                         goto check_stop;
 560
 561                 case ']':
 562                         if (bracket_count > 0)
 563                                 --bracket_count;
 564 check_stop:
 565                         if (token.kind        == end_token &&
 566                             parenthesis_count == 0         &&
 567                             brace_count       == 0         &&
 568                             bracket_count     == 0)
 569                                 return;
 570                         break;
 571
 572                 default:
 573                         break;
 574                 }
 575                 next_token();
 576         }
 577 }
 578
 579 /**
 580  * Eat input tokens until an anchor is found.
 581  */
 582 static void eat_until_anchor(void)
 583 {
 584         while (token_anchor_set[token.kind] == 0) {
 585                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 586                         eat_until_matching_token(token.kind);
 587                 next_token();
 588         }
 589 }
 590
 591 /**
 592  * Eat a whole block from input tokens.
 593  */
 594 static void eat_block(void)
 595 {
 596         eat_until_matching_token('{');
 597         next_if('}');
 598 }
 599
 600 /**
 601  * Report a parse error because an expected token was not found.
 602  */
 603 static
 604 #if defined __GNUC__ && __GNUC__ >= 4
 605 __attribute__((sentinel))
 606 #endif
 607 void parse_error_expected(const char *message, ...)
 608 {
 609         if (message != NULL) {
 610                 errorf(HERE, "%s", message);
 611         }
 612         va_list ap;
 613         va_start(ap, message);
 614         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 615         va_end(ap);
 616 }
 617
 618 /**
 619  * Report an incompatible type.
 620  */
 621 static void type_error_incompatible(const char *msg,
 622                 const source_position_t *source_position, type_t *type1, type_t *type2)
 623 {
 624         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 625                msg, type1, type2);
 626 }
 627
 628 static bool skip_till(token_kind_t const expected, char const *const context)
 629 {
 630         if (UNLIKELY(token.kind != expected)) {
 631                 parse_error_expected(context, expected, NULL);
 632                 add_anchor_token(expected);
 633                 eat_until_anchor();
 634                 rem_anchor_token(expected);
 635                 if (token.kind != expected)
 636                         return false;
 637         }
 638         return true;
 639 }
 640
 641 /**
 642  * Expect the current token is the expected token.
 643  * If not, generate an error and skip until the next anchor.
 644  */
 645 static void expect(token_kind_t const expected)
 646 {
 647         if (skip_till(expected, NULL))
 648                 eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (!skip_till(T_IDENTIFIER, context))
 654                 return NULL;
 655         symbol_t *const sym = token.base.symbol;
 656         if (pos)
 657                 *pos = *HERE;
 658         eat(T_IDENTIFIER);
 659         return sym;
 660 }
 661
 662 /**
 663  * Push a given scope on the scope stack and make it the
 664  * current scope
 665  */
 666 static scope_t *scope_push(scope_t *new_scope)
 667 {
 668         if (current_scope != NULL) {
 669                 new_scope->depth = current_scope->depth + 1;
 670         }
 671
 672         scope_t *old_scope = current_scope;
 673         current_scope      = new_scope;
 674         return old_scope;
 675 }
 676
 677 /**
 678  * Pop the current scope from the scope stack.
 679  */
 680 static void scope_pop(scope_t *old_scope)
 681 {
 682         current_scope = old_scope;
 683 }
 684
 685 /**
 686  * Search an entity by its symbol in a given namespace.
 687  */
 688 static entity_t *get_entity(const symbol_t *const symbol,
 689                             namespace_tag_t namespc)
 690 {
 691         entity_t *entity = symbol->entity;
 692         for (; entity != NULL; entity = entity->base.symbol_next) {
 693                 if ((namespace_tag_t)entity->base.namespc == namespc)
 694                         return entity;
 695         }
 696
 697         return NULL;
 698 }
 699
 700 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 701  * possible. */
 702 static entity_t *get_tag(symbol_t const *const symbol,
 703                          entity_kind_tag_t const kind)
 704 {
 705         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 706         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 707                 errorf(HERE,
 708                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 709                                 symbol, &entity->base.source_position);
 710                 entity = NULL;
 711         }
 712         return entity;
 713 }
 714
 715 /**
 716  * pushs an entity on the environment stack and links the corresponding symbol
 717  * it.
 718  */
 719 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 720 {
 721         symbol_t           *symbol  = entity->base.symbol;
 722         entity_namespace_t  namespc = entity->base.namespc;
 723         assert(namespc != 0);
 724
 725         /* replace/add entity into entity list of the symbol */
 726         entity_t **anchor;
 727         entity_t  *iter;
 728         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 729                 iter = *anchor;
 730                 if (iter == NULL)
 731                         break;
 732
 733                 /* replace an entry? */
 734                 if (iter->base.namespc == namespc) {
 735                         entity->base.symbol_next = iter->base.symbol_next;
 736                         break;
 737                 }
 738         }
 739         *anchor = entity;
 740
 741         /* remember old declaration */
 742         stack_entry_t entry;
 743         entry.symbol     = symbol;
 744         entry.old_entity = iter;
 745         entry.namespc    = namespc;
 746         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 747 }
 748
 749 /**
 750  * Push an entity on the environment stack.
 751  */
 752 static void environment_push(entity_t *entity)
 753 {
 754         assert(entity->base.source_position.input_name != NULL);
 755         assert(entity->base.parent_scope != NULL);
 756         stack_push(&environment_stack, entity);
 757 }
 758
 759 /**
 760  * Push a declaration on the global label stack.
 761  *
 762  * @param declaration  the declaration
 763  */
 764 static void label_push(entity_t *label)
 765 {
 766         /* we abuse the parameters scope as parent for the labels */
 767         label->base.parent_scope = &current_function->parameters;
 768         stack_push(&label_stack, label);
 769 }
 770
 771 /**
 772  * pops symbols from the environment stack until @p new_top is the top element
 773  */
 774 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 775 {
 776         stack_entry_t *stack = *stack_ptr;
 777         size_t         top   = ARR_LEN(stack);
 778         size_t         i;
 779
 780         assert(new_top <= top);
 781         if (new_top == top)
 782                 return;
 783
 784         for (i = top; i > new_top; --i) {
 785                 stack_entry_t *entry = &stack[i - 1];
 786
 787                 entity_t           *old_entity = entry->old_entity;
 788                 symbol_t           *symbol     = entry->symbol;
 789                 entity_namespace_t  namespc    = entry->namespc;
 790
 791                 /* replace with old_entity/remove */
 792                 entity_t **anchor;
 793                 entity_t  *iter;
 794                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 795                         iter = *anchor;
 796                         assert(iter != NULL);
 797                         /* replace an entry? */
 798                         if (iter->base.namespc == namespc)
 799                                 break;
 800                 }
 801
 802                 /* restore definition from outer scopes (if there was one) */
 803                 if (old_entity != NULL) {
 804                         old_entity->base.symbol_next = iter->base.symbol_next;
 805                         *anchor                      = old_entity;
 806                 } else {
 807                         /* remove entry from list */
 808                         *anchor = iter->base.symbol_next;
 809                 }
 810         }
 811
 812         ARR_SHRINKLEN(*stack_ptr, new_top);
 813 }
 814
 815 /**
 816  * Pop all entries from the environment stack until the new_top
 817  * is reached.
 818  *
 819  * @param new_top  the new stack top
 820  */
 821 static void environment_pop_to(size_t new_top)
 822 {
 823         stack_pop_to(&environment_stack, new_top);
 824 }
 825
 826 /**
 827  * Pop all entries from the global label stack until the new_top
 828  * is reached.
 829  *
 830  * @param new_top  the new stack top
 831  */
 832 static void label_pop_to(size_t new_top)
 833 {
 834         stack_pop_to(&label_stack, new_top);
 835 }
 836
 837 static atomic_type_kind_t get_akind(const type_t *type)
 838 {
 839         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 840                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 841         return type->atomic.akind;
 842 }
 843
 844 /**
 845  * §6.3.1.1:2  Do integer promotion for a given type.
 846  *
 847  * @param type  the type to promote
 848  * @return the promoted type
 849  */
 850 static type_t *promote_integer(type_t *type)
 851 {
 852         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 853                 type = type_int;
 854
 855         return type;
 856 }
 857
 858 /**
 859  * Check if a given expression represents a null pointer constant.
 860  *
 861  * @param expression  the expression to check
 862  */
 863 static bool is_null_pointer_constant(const expression_t *expression)
 864 {
 865         /* skip void* cast */
 866         if (expression->kind == EXPR_UNARY_CAST) {
 867                 type_t *const type = skip_typeref(expression->base.type);
 868                 if (types_compatible(type, type_void_ptr))
 869                         expression = expression->unary.value;
 870         }
 871
 872         type_t *const type = skip_typeref(expression->base.type);
 873         if (!is_type_integer(type))
 874                 return false;
 875         switch (is_constant_expression(expression)) {
 876                 case EXPR_CLASS_ERROR:    return true;
 877                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 878                 default:                  return false;
 879         }
 880 }
 881
 882 /**
 883  * Create an implicit cast expression.
 884  *
 885  * @param expression  the expression to cast
 886  * @param dest_type   the destination type
 887  */
 888 static expression_t *create_implicit_cast(expression_t *expression,
 889                                           type_t *dest_type)
 890 {
 891         type_t *const source_type = expression->base.type;
 892
 893         if (source_type == dest_type)
 894                 return expression;
 895
 896         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 897         cast->unary.value   = expression;
 898         cast->base.type     = dest_type;
 899         cast->base.implicit = true;
 900
 901         return cast;
 902 }
 903
 904 typedef enum assign_error_t {
 905         ASSIGN_SUCCESS,
 906         ASSIGN_ERROR_INCOMPATIBLE,
 907         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 908         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 909         ASSIGN_WARNING_POINTER_FROM_INT,
 910         ASSIGN_WARNING_INT_FROM_POINTER
 911 } assign_error_t;
 912
 913 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)
 914 {
 915         type_t *const orig_type_right = right->base.type;
 916         type_t *const type_left       = skip_typeref(orig_type_left);
 917         type_t *const type_right      = skip_typeref(orig_type_right);
 918
 919         switch (error) {
 920         case ASSIGN_SUCCESS:
 921                 return;
 922         case ASSIGN_ERROR_INCOMPATIBLE:
 923                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 924                 return;
 925
 926         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 927                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 928                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 929
 930                 /* the left type has all qualifiers from the right type */
 931                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 932                 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);
 933                 return;
 934         }
 935
 936         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 937                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 938                 return;
 939
 940         case ASSIGN_WARNING_POINTER_FROM_INT:
 941                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 942                 return;
 943
 944         case ASSIGN_WARNING_INT_FROM_POINTER:
 945                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 946                 return;
 947
 948         default:
 949                 panic("invalid error value");
 950         }
 951 }
 952
 953 /** Implements the rules from §6.5.16.1 */
 954 static assign_error_t semantic_assign(type_t *orig_type_left,
 955                                       const expression_t *const right)
 956 {
 957         type_t *const orig_type_right = right->base.type;
 958         type_t *const type_left       = skip_typeref(orig_type_left);
 959         type_t *const type_right      = skip_typeref(orig_type_right);
 960
 961         if (is_type_pointer(type_left)) {
 962                 if (is_null_pointer_constant(right)) {
 963                         return ASSIGN_SUCCESS;
 964                 } else if (is_type_pointer(type_right)) {
 965                         type_t *points_to_left
 966                                 = skip_typeref(type_left->pointer.points_to);
 967                         type_t *points_to_right
 968                                 = skip_typeref(type_right->pointer.points_to);
 969                         assign_error_t res = ASSIGN_SUCCESS;
 970
 971                         /* the left type has all qualifiers from the right type */
 972                         unsigned missing_qualifiers
 973                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 974                         if (missing_qualifiers != 0) {
 975                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 976                         }
 977
 978                         points_to_left  = get_unqualified_type(points_to_left);
 979                         points_to_right = get_unqualified_type(points_to_right);
 980
 981                         if (is_type_void(points_to_left))
 982                                 return res;
 983
 984                         if (is_type_void(points_to_right)) {
 985                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 986                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 987                         }
 988
 989                         if (!types_compatible(points_to_left, points_to_right)) {
 990                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 991                         }
 992
 993                         return res;
 994                 } else if (is_type_integer(type_right)) {
 995                         return ASSIGN_WARNING_POINTER_FROM_INT;
 996                 }
 997         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 998                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 999                                 && is_type_pointer(type_right))) {
1000                 return ASSIGN_SUCCESS;
1001         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1002                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1003                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1004                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1005                         return ASSIGN_SUCCESS;
1006                 }
1007         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1008                 return ASSIGN_WARNING_INT_FROM_POINTER;
1009         }
1010
1011         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1012                 return ASSIGN_SUCCESS;
1013
1014         return ASSIGN_ERROR_INCOMPATIBLE;
1015 }
1016
1017 static expression_t *parse_constant_expression(void)
1018 {
1019         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1020
1021         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1022                 errorf(&result->base.source_position,
1023                        "expression '%E' is not constant", result);
1024         }
1025
1026         return result;
1027 }
1028
1029 static expression_t *parse_assignment_expression(void)
1030 {
1031         return parse_subexpression(PREC_ASSIGNMENT);
1032 }
1033
1034 static void append_string(string_t const *const s)
1035 {
1036         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1037          * possible, because other tokens are grown there alongside. */
1038         obstack_grow(&ast_obstack, s->begin, s->size);
1039 }
1040
1041 static string_t finish_string(void)
1042 {
1043         obstack_1grow(&ast_obstack, '\0');
1044         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1045         char const *const string = obstack_finish(&ast_obstack);
1046         return (string_t){ string, size };
1047 }
1048
1049 static string_t concat_string_literals(string_encoding_t *const out_enc)
1050 {
1051         assert(token.kind == T_STRING_LITERAL);
1052
1053         string_t          result;
1054         string_encoding_t enc = token.string.encoding;
1055         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1056                 append_string(&token.string.string);
1057                 eat(T_STRING_LITERAL);
1058                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1059                 do {
1060                         if (token.string.encoding != STRING_ENCODING_CHAR) {
1061                                 enc = token.string.encoding;
1062                         }
1063                         append_string(&token.string.string);
1064                         eat(T_STRING_LITERAL);
1065                 } while (token.kind == T_STRING_LITERAL);
1066                 result = finish_string();
1067         } else {
1068                 result = token.string.string;
1069                 eat(T_STRING_LITERAL);
1070         }
1071
1072         *out_enc = enc;
1073         return result;
1074 }
1075
1076 static string_t parse_string_literals(char const *const context)
1077 {
1078         if (!skip_till(T_STRING_LITERAL, context))
1079                 return (string_t){ "", 0 };
1080
1081         string_encoding_t       enc;
1082         source_position_t const pos = *HERE;
1083         string_t          const res = concat_string_literals(&enc);
1084
1085         if (enc != STRING_ENCODING_CHAR) {
1086                 errorf(&pos, "expected plain string literal, got wide string literal");
1087         }
1088
1089         return res;
1090 }
1091
1092 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1093 {
1094         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1095         attribute->kind            = kind;
1096         attribute->source_position = *HERE;
1097         return attribute;
1098 }
1099
1100 /**
1101  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1102  *
1103  *  attribute:
1104  *    __attribute__ ( ( attribute-list ) )
1105  *
1106  *  attribute-list:
1107  *    attrib
1108  *    attribute_list , attrib
1109  *
1110  *  attrib:
1111  *    empty
1112  *    any-word
1113  *    any-word ( identifier )
1114  *    any-word ( identifier , nonempty-expr-list )
1115  *    any-word ( expr-list )
1116  *
1117  *  where the "identifier" must not be declared as a type, and
1118  *  "any-word" may be any identifier (including one declared as a
1119  *  type), a reserved word storage class specifier, type specifier or
1120  *  type qualifier.  ??? This still leaves out most reserved keywords
1121  *  (following the old parser), shouldn't we include them, and why not
1122  *  allow identifiers declared as types to start the arguments?
1123  *
1124  *  Matze: this all looks confusing and little systematic, so we're even less
1125  *  strict and parse any list of things which are identifiers or
1126  *  (assignment-)expressions.
1127  */
1128 static attribute_argument_t *parse_attribute_arguments(void)
1129 {
1130         attribute_argument_t  *first  = NULL;
1131         attribute_argument_t **anchor = &first;
1132         if (token.kind != ')') do {
1133                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1134
1135                 /* is it an identifier */
1136                 if (token.kind == T_IDENTIFIER
1137                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1138                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1139                         argument->v.symbol = token.base.symbol;
1140                         eat(T_IDENTIFIER);
1141                 } else {
1142                         /* must be an expression */
1143                         expression_t *expression = parse_assignment_expression();
1144
1145                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1146                         argument->v.expression = expression;
1147                 }
1148
1149                 /* append argument */
1150                 *anchor = argument;
1151                 anchor  = &argument->next;
1152         } while (next_if(','));
1153         expect(')');
1154         return first;
1155 }
1156
1157 static attribute_t *parse_attribute_asm(void)
1158 {
1159         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1160         eat(T_asm);
1161         expect('(');
1162         attribute->a.arguments = parse_attribute_arguments();
1163         return attribute;
1164 }
1165
1166 static attribute_t *parse_attribute_gnu_single(void)
1167 {
1168         /* parse "any-word" */
1169         symbol_t *const symbol = token.base.symbol;
1170         if (symbol == NULL) {
1171                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1172                 return NULL;
1173         }
1174
1175         attribute_kind_t  kind;
1176         char const *const name = symbol->string;
1177         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1178                 if (kind > ATTRIBUTE_GNU_LAST) {
1179                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1180                         /* TODO: we should still save the attribute in the list... */
1181                         kind = ATTRIBUTE_UNKNOWN;
1182                         break;
1183                 }
1184
1185                 const char *attribute_name = get_attribute_name(kind);
1186                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1187                         break;
1188         }
1189
1190         attribute_t *attribute = allocate_attribute_zero(kind);
1191         next_token();
1192
1193         /* parse arguments */
1194         if (next_if('('))
1195                 attribute->a.arguments = parse_attribute_arguments();
1196
1197         return attribute;
1198 }
1199
1200 static attribute_t *parse_attribute_gnu(void)
1201 {
1202         attribute_t  *first  = NULL;
1203         attribute_t **anchor = &first;
1204
1205         eat(T___attribute__);
1206         add_anchor_token(')');
1207         add_anchor_token(',');
1208         expect('(');
1209         expect('(');
1210
1211         if (token.kind != ')') do {
1212                 attribute_t *attribute = parse_attribute_gnu_single();
1213                 if (attribute) {
1214                         *anchor = attribute;
1215                         anchor  = &attribute->next;
1216                 }
1217         } while (next_if(','));
1218         rem_anchor_token(',');
1219         rem_anchor_token(')');
1220
1221         expect(')');
1222         expect(')');
1223         return first;
1224 }
1225
1226 /** Parse attributes. */
1227 static attribute_t *parse_attributes(attribute_t *first)
1228 {
1229         attribute_t **anchor = &first;
1230         for (;;) {
1231                 while (*anchor != NULL)
1232                         anchor = &(*anchor)->next;
1233
1234                 attribute_t *attribute;
1235                 switch (token.kind) {
1236                 case T___attribute__:
1237                         attribute = parse_attribute_gnu();
1238                         if (attribute == NULL)
1239                                 continue;
1240                         break;
1241
1242                 case T_asm:
1243                         attribute = parse_attribute_asm();
1244                         break;
1245
1246                 case T_cdecl:
1247                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1248                         eat(T_cdecl);
1249                         break;
1250
1251                 case T__fastcall:
1252                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1253                         eat(T__fastcall);
1254                         break;
1255
1256                 case T__forceinline:
1257                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1258                         eat(T__forceinline);
1259                         break;
1260
1261                 case T__stdcall:
1262                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1263                         eat(T__stdcall);
1264                         break;
1265
1266                 case T___thiscall:
1267                         /* TODO record modifier */
1268                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1270                         eat(T___thiscall);
1271                         break;
1272
1273                 default:
1274                         return first;
1275                 }
1276
1277                 *anchor = attribute;
1278                 anchor  = &attribute->next;
1279         }
1280 }
1281
1282 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1283
1284 static entity_t *determine_lhs_ent(expression_t *const expr,
1285                                    entity_t *lhs_ent)
1286 {
1287         switch (expr->kind) {
1288                 case EXPR_REFERENCE: {
1289                         entity_t *const entity = expr->reference.entity;
1290                         /* we should only find variables as lvalues... */
1291                         if (entity->base.kind != ENTITY_VARIABLE
1292                                         && entity->base.kind != ENTITY_PARAMETER)
1293                                 return NULL;
1294
1295                         return entity;
1296                 }
1297
1298                 case EXPR_ARRAY_ACCESS: {
1299                         expression_t *const ref = expr->array_access.array_ref;
1300                         entity_t     *      ent = NULL;
1301                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1302                                 ent     = determine_lhs_ent(ref, lhs_ent);
1303                                 lhs_ent = ent;
1304                         } else {
1305                                 mark_vars_read(ref, lhs_ent);
1306                         }
1307                         mark_vars_read(expr->array_access.index, lhs_ent);
1308                         return ent;
1309                 }
1310
1311                 case EXPR_SELECT: {
1312                         mark_vars_read(expr->select.compound, lhs_ent);
1313                         if (is_type_compound(skip_typeref(expr->base.type)))
1314                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1315                         return NULL;
1316                 }
1317
1318                 case EXPR_UNARY_DEREFERENCE: {
1319                         expression_t *const val = expr->unary.value;
1320                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1321                                 /* *&x is a NOP */
1322                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1323                         } else {
1324                                 mark_vars_read(val, NULL);
1325                                 return NULL;
1326                         }
1327                 }
1328
1329                 default:
1330                         mark_vars_read(expr, NULL);
1331                         return NULL;
1332         }
1333 }
1334
1335 #define ENT_ANY ((entity_t*)-1)
1336
1337 /**
1338  * Mark declarations, which are read.  This is used to detect variables, which
1339  * are never read.
1340  * Example:
1341  * x = x + 1;
1342  *   x is not marked as "read", because it is only read to calculate its own new
1343  *   value.
1344  *
1345  * x += y; y += x;
1346  *   x and y are not detected as "not read", because multiple variables are
1347  *   involved.
1348  */
1349 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1350 {
1351         switch (expr->kind) {
1352                 case EXPR_REFERENCE: {
1353                         entity_t *const entity = expr->reference.entity;
1354                         if (entity->kind != ENTITY_VARIABLE
1355                                         && entity->kind != ENTITY_PARAMETER)
1356                                 return;
1357
1358                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1359                                 entity->variable.read = true;
1360                         }
1361                         return;
1362                 }
1363
1364                 case EXPR_CALL:
1365                         // TODO respect pure/const
1366                         mark_vars_read(expr->call.function, NULL);
1367                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1368                                 mark_vars_read(arg->expression, NULL);
1369                         }
1370                         return;
1371
1372                 case EXPR_CONDITIONAL:
1373                         // TODO lhs_decl should depend on whether true/false have an effect
1374                         mark_vars_read(expr->conditional.condition, NULL);
1375                         if (expr->conditional.true_expression != NULL)
1376                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1377                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1378                         return;
1379
1380                 case EXPR_SELECT:
1381                         if (lhs_ent == ENT_ANY
1382                                         && !is_type_compound(skip_typeref(expr->base.type)))
1383                                 lhs_ent = NULL;
1384                         mark_vars_read(expr->select.compound, lhs_ent);
1385                         return;
1386
1387                 case EXPR_ARRAY_ACCESS: {
1388                         mark_vars_read(expr->array_access.index, lhs_ent);
1389                         expression_t *const ref = expr->array_access.array_ref;
1390                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1391                                 if (lhs_ent == ENT_ANY)
1392                                         lhs_ent = NULL;
1393                         }
1394                         mark_vars_read(ref, lhs_ent);
1395                         return;
1396                 }
1397
1398                 case EXPR_VA_ARG:
1399                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1400                         return;
1401
1402                 case EXPR_VA_COPY:
1403                         mark_vars_read(expr->va_copye.src, lhs_ent);
1404                         return;
1405
1406                 case EXPR_UNARY_CAST:
1407                         /* Special case: Use void cast to mark a variable as "read" */
1408                         if (is_type_void(skip_typeref(expr->base.type)))
1409                                 lhs_ent = NULL;
1410                         goto unary;
1411
1412
1413                 case EXPR_UNARY_THROW:
1414                         if (expr->unary.value == NULL)
1415                                 return;
1416                         /* FALLTHROUGH */
1417                 case EXPR_UNARY_DEREFERENCE:
1418                 case EXPR_UNARY_DELETE:
1419                 case EXPR_UNARY_DELETE_ARRAY:
1420                         if (lhs_ent == ENT_ANY)
1421                                 lhs_ent = NULL;
1422                         goto unary;
1423
1424                 case EXPR_UNARY_NEGATE:
1425                 case EXPR_UNARY_PLUS:
1426                 case EXPR_UNARY_BITWISE_NEGATE:
1427                 case EXPR_UNARY_NOT:
1428                 case EXPR_UNARY_TAKE_ADDRESS:
1429                 case EXPR_UNARY_POSTFIX_INCREMENT:
1430                 case EXPR_UNARY_POSTFIX_DECREMENT:
1431                 case EXPR_UNARY_PREFIX_INCREMENT:
1432                 case EXPR_UNARY_PREFIX_DECREMENT:
1433                 case EXPR_UNARY_ASSUME:
1434 unary:
1435                         mark_vars_read(expr->unary.value, lhs_ent);
1436                         return;
1437
1438                 case EXPR_BINARY_ADD:
1439                 case EXPR_BINARY_SUB:
1440                 case EXPR_BINARY_MUL:
1441                 case EXPR_BINARY_DIV:
1442                 case EXPR_BINARY_MOD:
1443                 case EXPR_BINARY_EQUAL:
1444                 case EXPR_BINARY_NOTEQUAL:
1445                 case EXPR_BINARY_LESS:
1446                 case EXPR_BINARY_LESSEQUAL:
1447                 case EXPR_BINARY_GREATER:
1448                 case EXPR_BINARY_GREATEREQUAL:
1449                 case EXPR_BINARY_BITWISE_AND:
1450                 case EXPR_BINARY_BITWISE_OR:
1451                 case EXPR_BINARY_BITWISE_XOR:
1452                 case EXPR_BINARY_LOGICAL_AND:
1453                 case EXPR_BINARY_LOGICAL_OR:
1454                 case EXPR_BINARY_SHIFTLEFT:
1455                 case EXPR_BINARY_SHIFTRIGHT:
1456                 case EXPR_BINARY_COMMA:
1457                 case EXPR_BINARY_ISGREATER:
1458                 case EXPR_BINARY_ISGREATEREQUAL:
1459                 case EXPR_BINARY_ISLESS:
1460                 case EXPR_BINARY_ISLESSEQUAL:
1461                 case EXPR_BINARY_ISLESSGREATER:
1462                 case EXPR_BINARY_ISUNORDERED:
1463                         mark_vars_read(expr->binary.left,  lhs_ent);
1464                         mark_vars_read(expr->binary.right, lhs_ent);
1465                         return;
1466
1467                 case EXPR_BINARY_ASSIGN:
1468                 case EXPR_BINARY_MUL_ASSIGN:
1469                 case EXPR_BINARY_DIV_ASSIGN:
1470                 case EXPR_BINARY_MOD_ASSIGN:
1471                 case EXPR_BINARY_ADD_ASSIGN:
1472                 case EXPR_BINARY_SUB_ASSIGN:
1473                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1474                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1475                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1476                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1478                         if (lhs_ent == ENT_ANY)
1479                                 lhs_ent = NULL;
1480                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1481                         mark_vars_read(expr->binary.right, lhs_ent);
1482                         return;
1483                 }
1484
1485                 case EXPR_VA_START:
1486                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1487                         return;
1488
1489                 case EXPR_LITERAL_CASES:
1490                 case EXPR_LITERAL_CHARACTER:
1491                 case EXPR_ERROR:
1492                 case EXPR_STRING_LITERAL:
1493                 case EXPR_COMPOUND_LITERAL: // TODO init?
1494                 case EXPR_SIZEOF:
1495                 case EXPR_CLASSIFY_TYPE:
1496                 case EXPR_ALIGNOF:
1497                 case EXPR_FUNCNAME:
1498                 case EXPR_BUILTIN_CONSTANT_P:
1499                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1500                 case EXPR_OFFSETOF:
1501                 case EXPR_STATEMENT: // TODO
1502                 case EXPR_LABEL_ADDRESS:
1503                 case EXPR_ENUM_CONSTANT:
1504                         return;
1505         }
1506
1507         panic("unhandled expression");
1508 }
1509
1510 static designator_t *parse_designation(void)
1511 {
1512         designator_t  *result = NULL;
1513         designator_t **anchor = &result;
1514
1515         for (;;) {
1516                 designator_t *designator;
1517                 switch (token.kind) {
1518                 case '[':
1519                         designator = allocate_ast_zero(sizeof(designator[0]));
1520                         designator->source_position = *HERE;
1521                         eat('[');
1522                         add_anchor_token(']');
1523                         designator->array_index = parse_constant_expression();
1524                         rem_anchor_token(']');
1525                         expect(']');
1526                         break;
1527                 case '.':
1528                         designator = allocate_ast_zero(sizeof(designator[0]));
1529                         designator->source_position = *HERE;
1530                         eat('.');
1531                         designator->symbol = expect_identifier("while parsing designator", NULL);
1532                         if (!designator->symbol)
1533                                 return NULL;
1534                         break;
1535                 default:
1536                         expect('=');
1537                         return result;
1538                 }
1539
1540                 assert(designator != NULL);
1541                 *anchor = designator;
1542                 anchor  = &designator->next;
1543         }
1544 }
1545
1546 /**
1547  * Build an initializer from a given expression.
1548  */
1549 static initializer_t *initializer_from_expression(type_t *orig_type,
1550                                                   expression_t *expression)
1551 {
1552         /* TODO check that expression is a constant expression */
1553
1554         type_t *const type = skip_typeref(orig_type);
1555
1556         /* §6.7.8.14/15 char array may be initialized by string literals */
1557         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1558                 array_type_t *const array_type   = &type->array;
1559                 type_t       *const element_type = skip_typeref(array_type->element_type);
1560                 switch (expression->string_literal.encoding) {
1561                 case STRING_ENCODING_CHAR: {
1562                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1563                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1564                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1565                                 goto make_string_init;
1566                         }
1567                         break;
1568                 }
1569
1570                 case STRING_ENCODING_WIDE: {
1571                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1572                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1573 make_string_init:;
1574                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1575                                 init->value.value = expression;
1576                                 return init;
1577                         }
1578                         break;
1579                 }
1580                 }
1581         }
1582
1583         assign_error_t error = semantic_assign(type, expression);
1584         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1585                 return NULL;
1586         report_assign_error(error, type, expression, "initializer",
1587                             &expression->base.source_position);
1588
1589         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1590         result->value.value = create_implicit_cast(expression, type);
1591
1592         return result;
1593 }
1594
1595 /**
1596  * Parses an scalar initializer.
1597  *
1598  * §6.7.8.11; eat {} without warning
1599  */
1600 static initializer_t *parse_scalar_initializer(type_t *type,
1601                                                bool must_be_constant)
1602 {
1603         /* there might be extra {} hierarchies */
1604         int braces = 0;
1605         if (token.kind == '{') {
1606                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1607                 do {
1608                         eat('{');
1609                         ++braces;
1610                 } while (token.kind == '{');
1611         }
1612
1613         expression_t *expression = parse_assignment_expression();
1614         mark_vars_read(expression, NULL);
1615         if (must_be_constant && !is_linker_constant(expression)) {
1616                 errorf(&expression->base.source_position,
1617                        "initialisation expression '%E' is not constant",
1618                        expression);
1619         }
1620
1621         initializer_t *initializer = initializer_from_expression(type, expression);
1622
1623         if (initializer == NULL) {
1624                 errorf(&expression->base.source_position,
1625                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1626                        expression, expression->base.type, type);
1627                 /* TODO */
1628                 return NULL;
1629         }
1630
1631         bool additional_warning_displayed = false;
1632         while (braces > 0) {
1633                 next_if(',');
1634                 if (token.kind != '}') {
1635                         if (!additional_warning_displayed) {
1636                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1637                                 additional_warning_displayed = true;
1638                         }
1639                 }
1640                 eat_block();
1641                 braces--;
1642         }
1643
1644         return initializer;
1645 }
1646
1647 /**
1648  * An entry in the type path.
1649  */
1650 typedef struct type_path_entry_t type_path_entry_t;
1651 struct type_path_entry_t {
1652         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1653         union {
1654                 size_t         index;          /**< For array types: the current index. */
1655                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1656         } v;
1657 };
1658
1659 /**
1660  * A type path expression a position inside compound or array types.
1661  */
1662 typedef struct type_path_t type_path_t;
1663 struct type_path_t {
1664         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1665         type_t            *top_type;     /**< type of the element the path points */
1666         size_t             max_index;    /**< largest index in outermost array */
1667 };
1668
1669 /**
1670  * Prints a type path for debugging.
1671  */
1672 static __attribute__((unused)) void debug_print_type_path(
1673                 const type_path_t *path)
1674 {
1675         size_t len = ARR_LEN(path->path);
1676
1677         for (size_t i = 0; i < len; ++i) {
1678                 const type_path_entry_t *entry = & path->path[i];
1679
1680                 type_t *type = skip_typeref(entry->type);
1681                 if (is_type_compound(type)) {
1682                         /* in gcc mode structs can have no members */
1683                         if (entry->v.compound_entry == NULL) {
1684                                 assert(i == len-1);
1685                                 continue;
1686                         }
1687                         fprintf(stderr, ".%s",
1688                                 entry->v.compound_entry->base.symbol->string);
1689                 } else if (is_type_array(type)) {
1690                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1691                 } else {
1692                         fprintf(stderr, "-INVALID-");
1693                 }
1694         }
1695         if (path->top_type != NULL) {
1696                 fprintf(stderr, "  (");
1697                 print_type(path->top_type);
1698                 fprintf(stderr, ")");
1699         }
1700 }
1701
1702 /**
1703  * Return the top type path entry, ie. in a path
1704  * (type).a.b returns the b.
1705  */
1706 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1707 {
1708         size_t len = ARR_LEN(path->path);
1709         assert(len > 0);
1710         return &path->path[len-1];
1711 }
1712
1713 /**
1714  * Enlarge the type path by an (empty) element.
1715  */
1716 static type_path_entry_t *append_to_type_path(type_path_t *path)
1717 {
1718         size_t len = ARR_LEN(path->path);
1719         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1720
1721         type_path_entry_t *result = & path->path[len];
1722         memset(result, 0, sizeof(result[0]));
1723         return result;
1724 }
1725
1726 /**
1727  * Descending into a sub-type. Enter the scope of the current top_type.
1728  */
1729 static void descend_into_subtype(type_path_t *path)
1730 {
1731         type_t *orig_top_type = path->top_type;
1732         type_t *top_type      = skip_typeref(orig_top_type);
1733
1734         type_path_entry_t *top = append_to_type_path(path);
1735         top->type              = top_type;
1736
1737         if (is_type_compound(top_type)) {
1738                 compound_t *const compound = top_type->compound.compound;
1739                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1740
1741                 if (entry != NULL) {
1742                         top->v.compound_entry = &entry->declaration;
1743                         path->top_type = entry->declaration.type;
1744                 } else {
1745                         path->top_type = NULL;
1746                 }
1747         } else if (is_type_array(top_type)) {
1748                 top->v.index   = 0;
1749                 path->top_type = top_type->array.element_type;
1750         } else {
1751                 assert(!is_type_valid(top_type));
1752         }
1753 }
1754
1755 /**
1756  * Pop an entry from the given type path, ie. returning from
1757  * (type).a.b to (type).a
1758  */
1759 static void ascend_from_subtype(type_path_t *path)
1760 {
1761         type_path_entry_t *top = get_type_path_top(path);
1762
1763         path->top_type = top->type;
1764
1765         size_t len = ARR_LEN(path->path);
1766         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1767 }
1768
1769 /**
1770  * Pop entries from the given type path until the given
1771  * path level is reached.
1772  */
1773 static void ascend_to(type_path_t *path, size_t top_path_level)
1774 {
1775         size_t len = ARR_LEN(path->path);
1776
1777         while (len > top_path_level) {
1778                 ascend_from_subtype(path);
1779                 len = ARR_LEN(path->path);
1780         }
1781 }
1782
1783 static bool walk_designator(type_path_t *path, const designator_t *designator,
1784                             bool used_in_offsetof)
1785 {
1786         for (; designator != NULL; designator = designator->next) {
1787                 type_path_entry_t *top       = get_type_path_top(path);
1788                 type_t            *orig_type = top->type;
1789
1790                 type_t *type = skip_typeref(orig_type);
1791
1792                 if (designator->symbol != NULL) {
1793                         symbol_t *symbol = designator->symbol;
1794                         if (!is_type_compound(type)) {
1795                                 if (is_type_valid(type)) {
1796                                         errorf(&designator->source_position,
1797                                                "'.%Y' designator used for non-compound type '%T'",
1798                                                symbol, orig_type);
1799                                 }
1800
1801                                 top->type             = type_error_type;
1802                                 top->v.compound_entry = NULL;
1803                                 orig_type             = type_error_type;
1804                         } else {
1805                                 compound_t *compound = type->compound.compound;
1806                                 entity_t   *iter     = compound->members.entities;
1807                                 for (; iter != NULL; iter = iter->base.next) {
1808                                         if (iter->base.symbol == symbol) {
1809                                                 break;
1810                                         }
1811                                 }
1812                                 if (iter == NULL) {
1813                                         errorf(&designator->source_position,
1814                                                "'%T' has no member named '%Y'", orig_type, symbol);
1815                                         return false;
1816                                 }
1817                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1818                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1819                                         errorf(&designator->source_position,
1820                                                    "offsetof designator '%Y' must not specify bitfield",
1821                                                    symbol);
1822                                         return false;
1823                                 }
1824
1825                                 top->type             = orig_type;
1826                                 top->v.compound_entry = &iter->declaration;
1827                                 orig_type             = iter->declaration.type;
1828                         }
1829                 } else {
1830                         expression_t *array_index = designator->array_index;
1831                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1832                                 return true;
1833
1834                         if (!is_type_array(type)) {
1835                                 if (is_type_valid(type)) {
1836                                         errorf(&designator->source_position,
1837                                                "[%E] designator used for non-array type '%T'",
1838                                                array_index, orig_type);
1839                                 }
1840                                 return false;
1841                         }
1842
1843                         long index = fold_constant_to_int(array_index);
1844                         if (!used_in_offsetof) {
1845                                 if (index < 0) {
1846                                         errorf(&designator->source_position,
1847                                                "array index [%E] must be positive", array_index);
1848                                 } else if (type->array.size_constant) {
1849                                         long array_size = type->array.size;
1850                                         if (index >= array_size) {
1851                                                 errorf(&designator->source_position,
1852                                                        "designator [%E] (%d) exceeds array size %d",
1853                                                        array_index, index, array_size);
1854                                         }
1855                                 }
1856                         }
1857
1858                         top->type    = orig_type;
1859                         top->v.index = (size_t) index;
1860                         orig_type    = type->array.element_type;
1861                 }
1862                 path->top_type = orig_type;
1863
1864                 if (designator->next != NULL) {
1865                         descend_into_subtype(path);
1866                 }
1867         }
1868         return true;
1869 }
1870
1871 static void advance_current_object(type_path_t *path, size_t top_path_level)
1872 {
1873         type_path_entry_t *top = get_type_path_top(path);
1874
1875         type_t *type = skip_typeref(top->type);
1876         if (is_type_union(type)) {
1877                 /* in unions only the first element is initialized */
1878                 top->v.compound_entry = NULL;
1879         } else if (is_type_struct(type)) {
1880                 declaration_t *entry = top->v.compound_entry;
1881
1882                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1883                 if (next_entity != NULL) {
1884                         assert(is_declaration(next_entity));
1885                         entry = &next_entity->declaration;
1886                 } else {
1887                         entry = NULL;
1888                 }
1889
1890                 top->v.compound_entry = entry;
1891                 if (entry != NULL) {
1892                         path->top_type = entry->type;
1893                         return;
1894                 }
1895         } else if (is_type_array(type)) {
1896                 assert(is_type_array(type));
1897
1898                 top->v.index++;
1899
1900                 if (!type->array.size_constant || top->v.index < type->array.size) {
1901                         return;
1902                 }
1903         } else {
1904                 assert(!is_type_valid(type));
1905                 return;
1906         }
1907
1908         /* we're past the last member of the current sub-aggregate, try if we
1909          * can ascend in the type hierarchy and continue with another subobject */
1910         size_t len = ARR_LEN(path->path);
1911
1912         if (len > top_path_level) {
1913                 ascend_from_subtype(path);
1914                 advance_current_object(path, top_path_level);
1915         } else {
1916                 path->top_type = NULL;
1917         }
1918 }
1919
1920 /**
1921  * skip any {...} blocks until a closing bracket is reached.
1922  */
1923 static void skip_initializers(void)
1924 {
1925         next_if('{');
1926
1927         while (token.kind != '}') {
1928                 if (token.kind == T_EOF)
1929                         return;
1930                 if (token.kind == '{') {
1931                         eat_block();
1932                         continue;
1933                 }
1934                 next_token();
1935         }
1936 }
1937
1938 static initializer_t *create_empty_initializer(void)
1939 {
1940         static initializer_t empty_initializer
1941                 = { .list = { { INITIALIZER_LIST }, 0 } };
1942         return &empty_initializer;
1943 }
1944
1945 /**
1946  * Parse a part of an initialiser for a struct or union,
1947  */
1948 static initializer_t *parse_sub_initializer(type_path_t *path,
1949                 type_t *outer_type, size_t top_path_level,
1950                 parse_initializer_env_t *env)
1951 {
1952         if (token.kind == '}') {
1953                 /* empty initializer */
1954                 return create_empty_initializer();
1955         }
1956
1957         type_t *orig_type = path->top_type;
1958         type_t *type      = NULL;
1959
1960         if (orig_type == NULL) {
1961                 /* We are initializing an empty compound. */
1962         } else {
1963                 type = skip_typeref(orig_type);
1964         }
1965
1966         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1967
1968         while (true) {
1969                 designator_t *designator = NULL;
1970                 if (token.kind == '.' || token.kind == '[') {
1971                         designator = parse_designation();
1972                         goto finish_designator;
1973                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1974                         /* GNU-style designator ("identifier: value") */
1975                         designator = allocate_ast_zero(sizeof(designator[0]));
1976                         designator->source_position = *HERE;
1977                         designator->symbol          = token.base.symbol;
1978                         eat(T_IDENTIFIER);
1979                         eat(':');
1980
1981 finish_designator:
1982                         /* reset path to toplevel, evaluate designator from there */
1983                         ascend_to(path, top_path_level);
1984                         if (!walk_designator(path, designator, false)) {
1985                                 /* can't continue after designation error */
1986                                 goto end_error;
1987                         }
1988
1989                         initializer_t *designator_initializer
1990                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1991                         designator_initializer->designator.designator = designator;
1992                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1993
1994                         orig_type = path->top_type;
1995                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
1996                 }
1997
1998                 initializer_t *sub;
1999
2000                 if (token.kind == '{') {
2001                         if (type != NULL && is_type_scalar(type)) {
2002                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2003                         } else {
2004                                 if (type == NULL) {
2005                                         if (env->entity != NULL) {
2006                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2007                                         } else {
2008                                                 errorf(HERE, "extra brace group at end of initializer");
2009                                         }
2010                                         eat('{');
2011                                 } else {
2012                                         eat('{');
2013                                         descend_into_subtype(path);
2014                                 }
2015
2016                                 add_anchor_token('}');
2017                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2018                                                             env);
2019                                 rem_anchor_token('}');
2020
2021                                 expect('}');
2022
2023                                 if (!type)
2024                                         goto error_parse_next;
2025
2026                                 ascend_from_subtype(path);
2027                         }
2028                 } else {
2029                         /* must be an expression */
2030                         expression_t *expression = parse_assignment_expression();
2031                         mark_vars_read(expression, NULL);
2032
2033                         if (env->must_be_constant && !is_linker_constant(expression)) {
2034                                 errorf(&expression->base.source_position,
2035                                        "Initialisation expression '%E' is not constant",
2036                                        expression);
2037                         }
2038
2039                         if (type == NULL) {
2040                                 /* we are already outside, ... */
2041                                 if (outer_type == NULL)
2042                                         goto error_parse_next;
2043                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2044                                 if (is_type_compound(outer_type_skip) &&
2045                                                 !outer_type_skip->compound.compound->complete) {
2046                                         goto error_parse_next;
2047                                 }
2048
2049                                 source_position_t const* const pos = &expression->base.source_position;
2050                                 if (env->entity != NULL) {
2051                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2052                                 } else {
2053                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2054                                 }
2055                                 goto error_parse_next;
2056                         }
2057
2058                         /* handle { "string" } special case */
2059                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2060                                 sub = initializer_from_expression(outer_type, expression);
2061                                 if (sub != NULL) {
2062                                         next_if(',');
2063                                         if (token.kind != '}') {
2064                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2065                                         }
2066                                         /* TODO: eat , ... */
2067                                         return sub;
2068                                 }
2069                         }
2070
2071                         /* descend into subtypes until expression matches type */
2072                         while (true) {
2073                                 orig_type = path->top_type;
2074                                 type      = skip_typeref(orig_type);
2075
2076                                 sub = initializer_from_expression(orig_type, expression);
2077                                 if (sub != NULL) {
2078                                         break;
2079                                 }
2080                                 if (!is_type_valid(type)) {
2081                                         goto end_error;
2082                                 }
2083                                 if (is_type_scalar(type)) {
2084                                         errorf(&expression->base.source_position,
2085                                                         "expression '%E' doesn't match expected type '%T'",
2086                                                         expression, orig_type);
2087                                         goto end_error;
2088                                 }
2089
2090                                 descend_into_subtype(path);
2091                         }
2092                 }
2093
2094                 /* update largest index of top array */
2095                 const type_path_entry_t *first      = &path->path[0];
2096                 type_t                  *first_type = first->type;
2097                 first_type                          = skip_typeref(first_type);
2098                 if (is_type_array(first_type)) {
2099                         size_t index = first->v.index;
2100                         if (index > path->max_index)
2101                                 path->max_index = index;
2102                 }
2103
2104                 /* append to initializers list */
2105                 ARR_APP1(initializer_t*, initializers, sub);
2106
2107 error_parse_next:
2108                 if (token.kind == '}') {
2109                         break;
2110                 }
2111                 add_anchor_token('}');
2112                 expect(',');
2113                 rem_anchor_token('}');
2114                 if (token.kind == '}') {
2115                         break;
2116                 }
2117
2118                 if (type != NULL) {
2119                         /* advance to the next declaration if we are not at the end */
2120                         advance_current_object(path, top_path_level);
2121                         orig_type = path->top_type;
2122                         if (orig_type != NULL)
2123                                 type = skip_typeref(orig_type);
2124                         else
2125                                 type = NULL;
2126                 }
2127         }
2128
2129         size_t len  = ARR_LEN(initializers);
2130         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2131         initializer_t *result = allocate_ast_zero(size);
2132         result->kind          = INITIALIZER_LIST;
2133         result->list.len      = len;
2134         memcpy(&result->list.initializers, initializers,
2135                len * sizeof(initializers[0]));
2136
2137         DEL_ARR_F(initializers);
2138         ascend_to(path, top_path_level+1);
2139
2140         return result;
2141
2142 end_error:
2143         skip_initializers();
2144         DEL_ARR_F(initializers);
2145         ascend_to(path, top_path_level+1);
2146         return NULL;
2147 }
2148
2149 static expression_t *make_size_literal(size_t value)
2150 {
2151         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2152         literal->base.type    = type_size_t;
2153
2154         char buf[128];
2155         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2156         literal->literal.value = make_string(buf);
2157
2158         return literal;
2159 }
2160
2161 /**
2162  * Parses an initializer. Parsers either a compound literal
2163  * (env->declaration == NULL) or an initializer of a declaration.
2164  */
2165 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2166 {
2167         type_t        *type      = skip_typeref(env->type);
2168         size_t         max_index = 0;
2169         initializer_t *result;
2170
2171         if (is_type_scalar(type)) {
2172                 result = parse_scalar_initializer(type, env->must_be_constant);
2173         } else if (token.kind == '{') {
2174                 eat('{');
2175
2176                 type_path_t path;
2177                 memset(&path, 0, sizeof(path));
2178                 path.top_type = env->type;
2179                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2180
2181                 descend_into_subtype(&path);
2182
2183                 add_anchor_token('}');
2184                 result = parse_sub_initializer(&path, env->type, 1, env);
2185                 rem_anchor_token('}');
2186
2187                 max_index = path.max_index;
2188                 DEL_ARR_F(path.path);
2189
2190                 expect('}');
2191         } else {
2192                 /* parse_scalar_initializer() also works in this case: we simply
2193                  * have an expression without {} around it */
2194                 result = parse_scalar_initializer(type, env->must_be_constant);
2195         }
2196
2197         /* §6.7.8:22 array initializers for arrays with unknown size determine
2198          * the array type size */
2199         if (is_type_array(type) && type->array.size_expression == NULL
2200                         && result != NULL) {
2201                 size_t size;
2202                 switch (result->kind) {
2203                 case INITIALIZER_LIST:
2204                         assert(max_index != 0xdeadbeaf);
2205                         size = max_index + 1;
2206                         break;
2207
2208                 case INITIALIZER_STRING: {
2209                         string_literal_expression_t const *const str = get_init_string(result);
2210                         size = get_string_len(str->encoding, &str->value) + 1;
2211                         break;
2212                 }
2213
2214                 case INITIALIZER_DESIGNATOR:
2215                 case INITIALIZER_VALUE:
2216                         /* can happen for parse errors */
2217                         size = 0;
2218                         break;
2219
2220                 default:
2221                         internal_errorf(HERE, "invalid initializer type");
2222                 }
2223
2224                 type_t *new_type = duplicate_type(type);
2225
2226                 new_type->array.size_expression   = make_size_literal(size);
2227                 new_type->array.size_constant     = true;
2228                 new_type->array.has_implicit_size = true;
2229                 new_type->array.size              = size;
2230                 env->type = new_type;
2231         }
2232
2233         return result;
2234 }
2235
2236 static void append_entity(scope_t *scope, entity_t *entity)
2237 {
2238         if (scope->last_entity != NULL) {
2239                 scope->last_entity->base.next = entity;
2240         } else {
2241                 scope->entities = entity;
2242         }
2243         entity->base.parent_entity = current_entity;
2244         scope->last_entity         = entity;
2245 }
2246
2247
2248 static compound_t *parse_compound_type_specifier(bool is_struct)
2249 {
2250         source_position_t const pos = *HERE;
2251         eat(is_struct ? T_struct : T_union);
2252
2253         symbol_t    *symbol     = NULL;
2254         entity_t    *entity     = NULL;
2255         attribute_t *attributes = NULL;
2256
2257         if (token.kind == T___attribute__) {
2258                 attributes = parse_attributes(NULL);
2259         }
2260
2261         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2262         if (token.kind == T_IDENTIFIER) {
2263                 /* the compound has a name, check if we have seen it already */
2264                 symbol = token.base.symbol;
2265                 entity = get_tag(symbol, kind);
2266                 eat(T_IDENTIFIER);
2267
2268                 if (entity != NULL) {
2269                         if (entity->base.parent_scope != current_scope &&
2270                             (token.kind == '{' || token.kind == ';')) {
2271                                 /* we're in an inner scope and have a definition. Shadow
2272                                  * existing definition in outer scope */
2273                                 entity = NULL;
2274                         } else if (entity->compound.complete && token.kind == '{') {
2275                                 source_position_t const *const ppos = &entity->base.source_position;
2276                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2277                                 /* clear members in the hope to avoid further errors */
2278                                 entity->compound.members.entities = NULL;
2279                         }
2280                 }
2281         } else if (token.kind != '{') {
2282                 char const *const msg =
2283                         is_struct ? "while parsing struct type specifier" :
2284                                     "while parsing union type specifier";
2285                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2286
2287                 return NULL;
2288         }
2289
2290         if (entity == NULL) {
2291                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2292                 entity->compound.alignment = 1;
2293                 entity->base.parent_scope  = current_scope;
2294                 if (symbol != NULL) {
2295                         environment_push(entity);
2296                 }
2297                 append_entity(current_scope, entity);
2298         }
2299
2300         if (token.kind == '{') {
2301                 parse_compound_type_entries(&entity->compound);
2302
2303                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2304                 if (symbol == NULL) {
2305                         assert(anonymous_entity == NULL);
2306                         anonymous_entity = entity;
2307                 }
2308         }
2309
2310         if (attributes != NULL) {
2311                 handle_entity_attributes(attributes, entity);
2312         }
2313
2314         return &entity->compound;
2315 }
2316
2317 static void parse_enum_entries(type_t *const enum_type)
2318 {
2319         eat('{');
2320
2321         if (token.kind == '}') {
2322                 errorf(HERE, "empty enum not allowed");
2323                 eat('}');
2324                 return;
2325         }
2326
2327         add_anchor_token('}');
2328         add_anchor_token(',');
2329         do {
2330                 add_anchor_token('=');
2331                 source_position_t pos;
2332                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2333                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2334                 entity->enum_value.enum_type = enum_type;
2335                 rem_anchor_token('=');
2336
2337                 if (next_if('=')) {
2338                         expression_t *value = parse_constant_expression();
2339
2340                         value = create_implicit_cast(value, enum_type);
2341                         entity->enum_value.value = value;
2342
2343                         /* TODO semantic */
2344                 }
2345
2346                 record_entity(entity, false);
2347         } while (next_if(',') && token.kind != '}');
2348         rem_anchor_token(',');
2349         rem_anchor_token('}');
2350
2351         expect('}');
2352 }
2353
2354 static type_t *parse_enum_specifier(void)
2355 {
2356         source_position_t const pos = *HERE;
2357         entity_t               *entity;
2358         symbol_t               *symbol;
2359
2360         eat(T_enum);
2361         switch (token.kind) {
2362                 case T_IDENTIFIER:
2363                         symbol = token.base.symbol;
2364                         entity = get_tag(symbol, ENTITY_ENUM);
2365                         eat(T_IDENTIFIER);
2366
2367                         if (entity != NULL) {
2368                                 if (entity->base.parent_scope != current_scope &&
2369                                                 (token.kind == '{' || token.kind == ';')) {
2370                                         /* we're in an inner scope and have a definition. Shadow
2371                                          * existing definition in outer scope */
2372                                         entity = NULL;
2373                                 } else if (entity->enume.complete && token.kind == '{') {
2374                                         source_position_t const *const ppos = &entity->base.source_position;
2375                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2376                                 }
2377                         }
2378                         break;
2379
2380                 case '{':
2381                         entity = NULL;
2382                         symbol = NULL;
2383                         break;
2384
2385                 default:
2386                         parse_error_expected("while parsing enum type specifier",
2387                                         T_IDENTIFIER, '{', NULL);
2388                         return NULL;
2389         }
2390
2391         if (entity == NULL) {
2392                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2393                 entity->base.parent_scope = current_scope;
2394         }
2395
2396         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2397         type->enumt.enume      = &entity->enume;
2398         type->enumt.base.akind = ATOMIC_TYPE_INT;
2399
2400         if (token.kind == '{') {
2401                 if (symbol != NULL) {
2402                         environment_push(entity);
2403                 }
2404                 append_entity(current_scope, entity);
2405                 entity->enume.complete = true;
2406
2407                 parse_enum_entries(type);
2408                 parse_attributes(NULL);
2409
2410                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2411                 if (symbol == NULL) {
2412                         assert(anonymous_entity == NULL);
2413                         anonymous_entity = entity;
2414                 }
2415         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2416                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2417         }
2418
2419         return type;
2420 }
2421
2422 /**
2423  * if a symbol is a typedef to another type, return true
2424  */
2425 static bool is_typedef_symbol(symbol_t *symbol)
2426 {
2427         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2428         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2429 }
2430
2431 static type_t *parse_typeof(void)
2432 {
2433         eat(T___typeof__);
2434
2435         type_t *type;
2436
2437         add_anchor_token(')');
2438         expect('(');
2439
2440         expression_t *expression  = NULL;
2441
2442         switch (token.kind) {
2443         case T_IDENTIFIER:
2444                 if (is_typedef_symbol(token.base.symbol)) {
2445         DECLARATION_START
2446                         type = parse_typename();
2447                 } else {
2448         default:
2449                         expression = parse_expression();
2450                         type       = revert_automatic_type_conversion(expression);
2451                 }
2452                 break;
2453         }
2454
2455         rem_anchor_token(')');
2456         expect(')');
2457
2458         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2459         typeof_type->typeoft.expression  = expression;
2460         typeof_type->typeoft.typeof_type = type;
2461
2462         return typeof_type;
2463 }
2464
2465 typedef enum specifiers_t {
2466         SPECIFIER_SIGNED    = 1 << 0,
2467         SPECIFIER_UNSIGNED  = 1 << 1,
2468         SPECIFIER_LONG      = 1 << 2,
2469         SPECIFIER_INT       = 1 << 3,
2470         SPECIFIER_DOUBLE    = 1 << 4,
2471         SPECIFIER_CHAR      = 1 << 5,
2472         SPECIFIER_WCHAR_T   = 1 << 6,
2473         SPECIFIER_SHORT     = 1 << 7,
2474         SPECIFIER_LONG_LONG = 1 << 8,
2475         SPECIFIER_FLOAT     = 1 << 9,
2476         SPECIFIER_BOOL      = 1 << 10,
2477         SPECIFIER_VOID      = 1 << 11,
2478         SPECIFIER_INT8      = 1 << 12,
2479         SPECIFIER_INT16     = 1 << 13,
2480         SPECIFIER_INT32     = 1 << 14,
2481         SPECIFIER_INT64     = 1 << 15,
2482         SPECIFIER_INT128    = 1 << 16,
2483         SPECIFIER_COMPLEX   = 1 << 17,
2484         SPECIFIER_IMAGINARY = 1 << 18,
2485 } specifiers_t;
2486
2487 static type_t *get_typedef_type(symbol_t *symbol)
2488 {
2489         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2490         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2491                 return NULL;
2492
2493         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2494         type->typedeft.typedefe = &entity->typedefe;
2495
2496         return type;
2497 }
2498
2499 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2500 {
2501         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2502
2503         add_anchor_token(')');
2504         add_anchor_token(',');
2505         expect('(');
2506
2507         do {
2508                 add_anchor_token('=');
2509                 source_position_t pos;
2510                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2511                 rem_anchor_token('=');
2512
2513                 symbol_t **prop = NULL;
2514                 if (prop_sym) {
2515                         if (streq(prop_sym->string, "put")) {
2516                                 prop = &property->put_symbol;
2517                         } else if (streq(prop_sym->string, "get")) {
2518                                 prop = &property->get_symbol;
2519                         } else {
2520                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2521                         }
2522                 }
2523
2524                 add_anchor_token(T_IDENTIFIER);
2525                 expect('=');
2526                 rem_anchor_token(T_IDENTIFIER);
2527
2528                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2529                 if (prop != NULL)
2530                         *prop = sym ? sym : sym_anonymous;
2531         } while (next_if(','));
2532         rem_anchor_token(',');
2533         rem_anchor_token(')');
2534
2535         attribute->a.property = property;
2536
2537         expect(')');
2538         return attribute;
2539 }
2540
2541 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2542 {
2543         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2544         if (next_if(T_restrict)) {
2545                 kind = ATTRIBUTE_MS_RESTRICT;
2546         } else if (token.kind == T_IDENTIFIER) {
2547                 char const *const name = token.base.symbol->string;
2548                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2549                      ++k) {
2550                         const char *attribute_name = get_attribute_name(k);
2551                         if (attribute_name != NULL && streq(attribute_name, name)) {
2552                                 kind = k;
2553                                 break;
2554                         }
2555                 }
2556
2557                 if (kind == ATTRIBUTE_UNKNOWN) {
2558                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2559                 }
2560         } else {
2561                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2562                 return NULL;
2563         }
2564
2565         attribute_t *attribute = allocate_attribute_zero(kind);
2566         eat(T_IDENTIFIER);
2567
2568         if (kind == ATTRIBUTE_MS_PROPERTY) {
2569                 return parse_attribute_ms_property(attribute);
2570         }
2571
2572         /* parse arguments */
2573         if (next_if('('))
2574                 attribute->a.arguments = parse_attribute_arguments();
2575
2576         return attribute;
2577 }
2578
2579 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2580 {
2581         eat(T__declspec);
2582
2583         add_anchor_token(')');
2584         expect('(');
2585         if (token.kind != ')') {
2586                 attribute_t **anchor = &first;
2587                 do {
2588                         while (*anchor != NULL)
2589                                 anchor = &(*anchor)->next;
2590
2591                         attribute_t *attribute
2592                                 = parse_microsoft_extended_decl_modifier_single();
2593                         if (attribute == NULL)
2594                                 break;
2595
2596                         *anchor = attribute;
2597                         anchor  = &attribute->next;
2598                 } while (next_if(','));
2599         }
2600         rem_anchor_token(')');
2601         expect(')');
2602         return first;
2603 }
2604
2605 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2606 {
2607         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2608         if (is_declaration(entity)) {
2609                 entity->declaration.type     = type_error_type;
2610                 entity->declaration.implicit = true;
2611         } else if (kind == ENTITY_TYPEDEF) {
2612                 entity->typedefe.type    = type_error_type;
2613                 entity->typedefe.builtin = true;
2614         }
2615         if (kind != ENTITY_COMPOUND_MEMBER)
2616                 record_entity(entity, false);
2617         return entity;
2618 }
2619
2620 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2621 {
2622         type_t            *type            = NULL;
2623         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2624         unsigned           type_specifiers = 0;
2625         bool               newtype         = false;
2626         bool               saw_error       = false;
2627
2628         memset(specifiers, 0, sizeof(*specifiers));
2629         specifiers->source_position = *HERE;
2630
2631         while (true) {
2632                 specifiers->attributes = parse_attributes(specifiers->attributes);
2633
2634                 switch (token.kind) {
2635                 /* storage class */
2636 #define MATCH_STORAGE_CLASS(token, class)                                  \
2637                 case token:                                                        \
2638                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2639                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2640                         }                                                              \
2641                         specifiers->storage_class = class;                             \
2642                         if (specifiers->thread_local)                                  \
2643                                 goto check_thread_storage_class;                           \
2644                         eat(token); \
2645                         break;
2646
2647                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2648                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2649                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2650                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2651                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2652
2653                 case T__declspec:
2654                         specifiers->attributes
2655                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2656                         break;
2657
2658                 case T___thread:
2659                         if (specifiers->thread_local) {
2660                                 errorf(HERE, "duplicate '__thread'");
2661                         } else {
2662                                 specifiers->thread_local = true;
2663 check_thread_storage_class:
2664                                 switch (specifiers->storage_class) {
2665                                         case STORAGE_CLASS_EXTERN:
2666                                         case STORAGE_CLASS_NONE:
2667                                         case STORAGE_CLASS_STATIC:
2668                                                 break;
2669
2670                                                 char const* wrong;
2671                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2672                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2673                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2674 wrong_thread_storage_class:
2675                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2676                                                 break;
2677                                 }
2678                         }
2679                         next_token();
2680                         break;
2681
2682                 /* type qualifiers */
2683 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2684                 case token:                                                     \
2685                         qualifiers |= qualifier;                                    \
2686                         eat(token); \
2687                         break
2688
2689                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2690                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2691                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2692                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2693                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2694                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2695                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2696                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2697
2698                 /* type specifiers */
2699 #define MATCH_SPECIFIER(token, specifier, name)                         \
2700                 case token:                                                     \
2701                         if (type_specifiers & specifier) {                           \
2702                                 errorf(HERE, "multiple " name " type specifiers given"); \
2703                         } else {                                                    \
2704                                 type_specifiers |= specifier;                           \
2705                         }                                                           \
2706                         eat(token); \
2707                         break
2708
2709                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2710                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2711                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2712                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2713                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2714                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2715                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2716                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2717                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2718                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2719                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2720                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2721                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2722                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2723                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2724                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2725                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2726                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2727
2728                 case T_inline:
2729                         eat(T_inline);
2730                         specifiers->is_inline = true;
2731                         break;
2732
2733 #if 0
2734                 case T__forceinline:
2735                         eat(T__forceinline);
2736                         specifiers->modifiers |= DM_FORCEINLINE;
2737                         break;
2738 #endif
2739
2740                 case T_long:
2741                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2742                                 errorf(HERE, "too many long type specifiers given");
2743                         } else if (type_specifiers & SPECIFIER_LONG) {
2744                                 type_specifiers |= SPECIFIER_LONG_LONG;
2745                         } else {
2746                                 type_specifiers |= SPECIFIER_LONG;
2747                         }
2748                         eat(T_long);
2749                         break;
2750
2751 #define CHECK_DOUBLE_TYPE() \
2752         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2753
2754                 case T_struct:
2755                         CHECK_DOUBLE_TYPE();
2756                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2757
2758                         type->compound.compound = parse_compound_type_specifier(true);
2759                         break;
2760                 case T_union:
2761                         CHECK_DOUBLE_TYPE();
2762                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2763                         type->compound.compound = parse_compound_type_specifier(false);
2764                         break;
2765                 case T_enum:
2766                         CHECK_DOUBLE_TYPE();
2767                         type = parse_enum_specifier();
2768                         break;
2769                 case T___typeof__:
2770                         CHECK_DOUBLE_TYPE();
2771                         type = parse_typeof();
2772                         break;
2773                 case T___builtin_va_list:
2774                         CHECK_DOUBLE_TYPE();
2775                         type = duplicate_type(type_valist);
2776                         eat(T___builtin_va_list);
2777                         break;
2778
2779                 case T_IDENTIFIER: {
2780                         /* only parse identifier if we haven't found a type yet */
2781                         if (type != NULL || type_specifiers != 0) {
2782                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2783                                  * declaration, so it doesn't generate errors about expecting '(' or
2784                                  * '{' later on. */
2785                                 switch (look_ahead(1)->kind) {
2786                                         STORAGE_CLASSES
2787                                         TYPE_SPECIFIERS
2788                                         case T_const:
2789                                         case T_restrict:
2790                                         case T_volatile:
2791                                         case T_inline:
2792                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2793                                         case T_IDENTIFIER:
2794                                         case '&':
2795                                         case '*':
2796                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2797                                                 eat(T_IDENTIFIER);
2798                                                 continue;
2799
2800                                         default:
2801                                                 goto finish_specifiers;
2802                                 }
2803                         }
2804
2805                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2806                         if (typedef_type == NULL) {
2807                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2808                                  * declaration, so it doesn't generate 'implicit int' followed by more
2809                                  * errors later on. */
2810                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2811                                 switch (la1_type) {
2812                                         DECLARATION_START
2813                                         case T_IDENTIFIER:
2814                                         case '&':
2815                                         case '*': {
2816                                                 errorf(HERE, "%K does not name a type", &token);
2817
2818                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2819
2820                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2821                                                 type->typedeft.typedefe = &entity->typedefe;
2822
2823                                                 eat(T_IDENTIFIER);
2824                                                 saw_error = true;
2825                                                 continue;
2826                                         }
2827
2828                                         default:
2829                                                 goto finish_specifiers;
2830                                 }
2831                         }
2832
2833                         eat(T_IDENTIFIER);
2834                         type = typedef_type;
2835                         break;
2836                 }
2837
2838                 /* function specifier */
2839                 default:
2840                         goto finish_specifiers;
2841                 }
2842         }
2843
2844 finish_specifiers:
2845         specifiers->attributes = parse_attributes(specifiers->attributes);
2846
2847         if (type == NULL || (saw_error && type_specifiers != 0)) {
2848                 atomic_type_kind_t atomic_type;
2849
2850                 /* match valid basic types */
2851                 switch (type_specifiers) {
2852                 case SPECIFIER_VOID:
2853                         atomic_type = ATOMIC_TYPE_VOID;
2854                         break;
2855                 case SPECIFIER_WCHAR_T:
2856                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2857                         break;
2858                 case SPECIFIER_CHAR:
2859                         atomic_type = ATOMIC_TYPE_CHAR;
2860                         break;
2861                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2862                         atomic_type = ATOMIC_TYPE_SCHAR;
2863                         break;
2864                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2865                         atomic_type = ATOMIC_TYPE_UCHAR;
2866                         break;
2867                 case SPECIFIER_SHORT:
2868                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2869                 case SPECIFIER_SHORT | SPECIFIER_INT:
2870                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2871                         atomic_type = ATOMIC_TYPE_SHORT;
2872                         break;
2873                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2874                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2875                         atomic_type = ATOMIC_TYPE_USHORT;
2876                         break;
2877                 case SPECIFIER_INT:
2878                 case SPECIFIER_SIGNED:
2879                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2880                         atomic_type = ATOMIC_TYPE_INT;
2881                         break;
2882                 case SPECIFIER_UNSIGNED:
2883                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2884                         atomic_type = ATOMIC_TYPE_UINT;
2885                         break;
2886                 case SPECIFIER_LONG:
2887                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2888                 case SPECIFIER_LONG | SPECIFIER_INT:
2889                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2890                         atomic_type = ATOMIC_TYPE_LONG;
2891                         break;
2892                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2893                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2894                         atomic_type = ATOMIC_TYPE_ULONG;
2895                         break;
2896
2897                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2898                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2899                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2900                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2901                         | SPECIFIER_INT:
2902                         atomic_type = ATOMIC_TYPE_LONGLONG;
2903                         goto warn_about_long_long;
2904
2905                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2906                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2907                         | SPECIFIER_INT:
2908                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2909 warn_about_long_long:
2910                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2911                         break;
2912
2913                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2914                         atomic_type = unsigned_int8_type_kind;
2915                         break;
2916
2917                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2918                         atomic_type = unsigned_int16_type_kind;
2919                         break;
2920
2921                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2922                         atomic_type = unsigned_int32_type_kind;
2923                         break;
2924
2925                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2926                         atomic_type = unsigned_int64_type_kind;
2927                         break;
2928
2929                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2930                         atomic_type = unsigned_int128_type_kind;
2931                         break;
2932
2933                 case SPECIFIER_INT8:
2934                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2935                         atomic_type = int8_type_kind;
2936                         break;
2937
2938                 case SPECIFIER_INT16:
2939                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2940                         atomic_type = int16_type_kind;
2941                         break;
2942
2943                 case SPECIFIER_INT32:
2944                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2945                         atomic_type = int32_type_kind;
2946                         break;
2947
2948                 case SPECIFIER_INT64:
2949                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2950                         atomic_type = int64_type_kind;
2951                         break;
2952
2953                 case SPECIFIER_INT128:
2954                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2955                         atomic_type = int128_type_kind;
2956                         break;
2957
2958                 case SPECIFIER_FLOAT:
2959                         atomic_type = ATOMIC_TYPE_FLOAT;
2960                         break;
2961                 case SPECIFIER_DOUBLE:
2962                         atomic_type = ATOMIC_TYPE_DOUBLE;
2963                         break;
2964                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2965                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2966                         break;
2967                 case SPECIFIER_BOOL:
2968                         atomic_type = ATOMIC_TYPE_BOOL;
2969                         break;
2970                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2971                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2972                         atomic_type = ATOMIC_TYPE_FLOAT;
2973                         break;
2974                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2975                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2976                         atomic_type = ATOMIC_TYPE_DOUBLE;
2977                         break;
2978                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2979                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2980                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2981                         break;
2982                 default: {
2983                         /* invalid specifier combination, give an error message */
2984                         source_position_t const* const pos = &specifiers->source_position;
2985                         if (type_specifiers == 0) {
2986                                 if (!saw_error) {
2987                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2988                                         if (!(c_mode & _CXX) && !strict_mode) {
2989                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2990                                                 atomic_type = ATOMIC_TYPE_INT;
2991                                                 break;
2992                                         } else {
2993                                                 errorf(pos, "no type specifiers given in declaration");
2994                                         }
2995                                 }
2996                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
2997                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
2998                                 errorf(pos, "signed and unsigned specifiers given");
2999                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3000                                 errorf(pos, "only integer types can be signed or unsigned");
3001                         } else {
3002                                 errorf(pos, "multiple datatypes in declaration");
3003                         }
3004                         specifiers->type = type_error_type;
3005                         return;
3006                 }
3007                 }
3008
3009                 if (type_specifiers & SPECIFIER_COMPLEX) {
3010                         type = allocate_type_zero(TYPE_COMPLEX);
3011                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3012                         type = allocate_type_zero(TYPE_IMAGINARY);
3013                 } else {
3014                         type = allocate_type_zero(TYPE_ATOMIC);
3015                 }
3016                 type->atomic.akind = atomic_type;
3017                 newtype = true;
3018         } else if (type_specifiers != 0) {
3019                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3020         }
3021
3022         /* FIXME: check type qualifiers here */
3023         type->base.qualifiers = qualifiers;
3024
3025         if (newtype) {
3026                 type = identify_new_type(type);
3027         } else {
3028                 type = typehash_insert(type);
3029         }
3030
3031         if (specifiers->attributes != NULL)
3032                 type = handle_type_attributes(specifiers->attributes, type);
3033         specifiers->type = type;
3034 }
3035
3036 static type_qualifiers_t parse_type_qualifiers(void)
3037 {
3038         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3039
3040         while (true) {
3041                 switch (token.kind) {
3042                 /* type qualifiers */
3043                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3044                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3045                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3046                 /* microsoft extended type modifiers */
3047                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3048                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3049                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3050                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3051                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3052
3053                 default:
3054                         return qualifiers;
3055                 }
3056         }
3057 }
3058
3059 /**
3060  * Parses an K&R identifier list
3061  */
3062 static void parse_identifier_list(scope_t *scope)
3063 {
3064         assert(token.kind == T_IDENTIFIER);
3065         do {
3066                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3067                 /* a K&R parameter has no type, yet */
3068                 eat(T_IDENTIFIER);
3069
3070                 if (scope != NULL)
3071                         append_entity(scope, entity);
3072         } while (next_if(',') && token.kind == T_IDENTIFIER);
3073 }
3074
3075 static entity_t *parse_parameter(void)
3076 {
3077         declaration_specifiers_t specifiers;
3078         parse_declaration_specifiers(&specifiers);
3079
3080         entity_t *entity = parse_declarator(&specifiers,
3081                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3082         anonymous_entity = NULL;
3083         return entity;
3084 }
3085
3086 static void semantic_parameter_incomplete(const entity_t *entity)
3087 {
3088         assert(entity->kind == ENTITY_PARAMETER);
3089
3090         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3091          *             list in a function declarator that is part of a
3092          *             definition of that function shall not have
3093          *             incomplete type. */
3094         type_t *type = skip_typeref(entity->declaration.type);
3095         if (is_type_incomplete(type)) {
3096                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3097         }
3098 }
3099
3100 static bool has_parameters(void)
3101 {
3102         /* func(void) is not a parameter */
3103         if (look_ahead(1)->kind != ')')
3104                 return true;
3105         if (token.kind == T_IDENTIFIER) {
3106                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3107                 if (entity == NULL)
3108                         return true;
3109                 if (entity->kind != ENTITY_TYPEDEF)
3110                         return true;
3111                 type_t const *const type = skip_typeref(entity->typedefe.type);
3112                 if (!is_type_void(type))
3113                         return true;
3114                 if (c_mode & _CXX) {
3115                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3116                          * is not allowed. */
3117                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3118                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3119                         /* §6.7.5.3:10  Qualification is not allowed here. */
3120                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3121                 }
3122         } else if (token.kind != T_void) {
3123                 return true;
3124         }
3125         next_token();
3126         return false;
3127 }
3128
3129 /**
3130  * Parses function type parameters (and optionally creates variable_t entities
3131  * for them in a scope)
3132  */
3133 static void parse_parameters(function_type_t *type, scope_t *scope)
3134 {
3135         add_anchor_token(')');
3136         eat('(');
3137
3138         if (token.kind == T_IDENTIFIER            &&
3139             !is_typedef_symbol(token.base.symbol) &&
3140             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3141                 type->kr_style_parameters = true;
3142                 parse_identifier_list(scope);
3143         } else if (token.kind == ')') {
3144                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3145                 if (!(c_mode & _CXX))
3146                         type->unspecified_parameters = true;
3147         } else if (has_parameters()) {
3148                 function_parameter_t **anchor = &type->parameters;
3149                 add_anchor_token(',');
3150                 do {
3151                         switch (token.kind) {
3152                         case T_DOTDOTDOT:
3153                                 eat(T_DOTDOTDOT);
3154                                 type->variadic = true;
3155                                 goto parameters_finished;
3156
3157                         case T_IDENTIFIER:
3158                         DECLARATION_START
3159                         {
3160                                 entity_t *entity = parse_parameter();
3161                                 if (entity->kind == ENTITY_TYPEDEF) {
3162                                         errorf(&entity->base.source_position,
3163                                                         "typedef not allowed as function parameter");
3164                                         break;
3165                                 }
3166                                 assert(is_declaration(entity));
3167
3168                                 semantic_parameter_incomplete(entity);
3169
3170                                 function_parameter_t *const parameter =
3171                                         allocate_parameter(entity->declaration.type);
3172
3173                                 if (scope != NULL) {
3174                                         append_entity(scope, entity);
3175                                 }
3176
3177                                 *anchor = parameter;
3178                                 anchor  = &parameter->next;
3179                                 break;
3180                         }
3181
3182                         default:
3183                                 goto parameters_finished;
3184                         }
3185                 } while (next_if(','));
3186 parameters_finished:
3187                 rem_anchor_token(',');
3188         }
3189
3190         rem_anchor_token(')');
3191         expect(')');
3192 }
3193
3194 typedef enum construct_type_kind_t {
3195         CONSTRUCT_POINTER = 1,
3196         CONSTRUCT_REFERENCE,
3197         CONSTRUCT_FUNCTION,
3198         CONSTRUCT_ARRAY
3199 } construct_type_kind_t;
3200
3201 typedef union construct_type_t construct_type_t;
3202
3203 typedef struct construct_type_base_t {
3204         construct_type_kind_t  kind;
3205         source_position_t      pos;
3206         construct_type_t      *next;
3207 } construct_type_base_t;
3208
3209 typedef struct parsed_pointer_t {
3210         construct_type_base_t  base;
3211         type_qualifiers_t      type_qualifiers;
3212         variable_t            *base_variable;  /**< MS __based extension. */
3213 } parsed_pointer_t;
3214
3215 typedef struct parsed_reference_t {
3216         construct_type_base_t base;
3217 } parsed_reference_t;
3218
3219 typedef struct construct_function_type_t {
3220         construct_type_base_t  base;
3221         type_t                *function_type;
3222 } construct_function_type_t;
3223
3224 typedef struct parsed_array_t {
3225         construct_type_base_t  base;
3226         type_qualifiers_t      type_qualifiers;
3227         bool                   is_static;
3228         bool                   is_variable;
3229         expression_t          *size;
3230 } parsed_array_t;
3231
3232 union construct_type_t {
3233         construct_type_kind_t     kind;
3234         construct_type_base_t     base;
3235         parsed_pointer_t          pointer;
3236         parsed_reference_t        reference;
3237         construct_function_type_t function;
3238         parsed_array_t            array;
3239 };
3240
3241 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3242 {
3243         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3244         memset(cons, 0, size);
3245         cons->kind     = kind;
3246         cons->base.pos = *HERE;
3247         return cons;
3248 }
3249
3250 /* §6.7.5.1 */
3251 static construct_type_t *parse_pointer_declarator(void)
3252 {
3253         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3254         eat('*');
3255         cons->pointer.type_qualifiers = parse_type_qualifiers();
3256         //cons->pointer.base_variable   = base_variable;
3257
3258         return cons;
3259 }
3260
3261 /* ISO/IEC 14882:1998(E) §8.3.2 */
3262 static construct_type_t *parse_reference_declarator(void)
3263 {
3264         if (!(c_mode & _CXX))
3265                 errorf(HERE, "references are only available for C++");
3266
3267         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3268         eat('&');
3269
3270         return cons;
3271 }
3272
3273 /* §6.7.5.2 */
3274 static construct_type_t *parse_array_declarator(void)
3275 {
3276         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3277         parsed_array_t   *const array = &cons->array;
3278
3279         eat('[');
3280         add_anchor_token(']');
3281
3282         bool is_static = next_if(T_static);
3283
3284         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3285
3286         if (!is_static)
3287                 is_static = next_if(T_static);
3288
3289         array->type_qualifiers = type_qualifiers;
3290         array->is_static       = is_static;
3291
3292         expression_t *size = NULL;
3293         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3294                 array->is_variable = true;
3295                 eat('*');
3296         } else if (token.kind != ']') {
3297                 size = parse_assignment_expression();
3298
3299                 /* §6.7.5.2:1  Array size must have integer type */
3300                 type_t *const orig_type = size->base.type;
3301                 type_t *const type      = skip_typeref(orig_type);
3302                 if (!is_type_integer(type) && is_type_valid(type)) {
3303                         errorf(&size->base.source_position,
3304                                "array size '%E' must have integer type but has type '%T'",
3305                                size, orig_type);
3306                 }
3307
3308                 array->size = size;
3309                 mark_vars_read(size, NULL);
3310         }
3311
3312         if (is_static && size == NULL)
3313                 errorf(&array->base.pos, "static array parameters require a size");
3314
3315         rem_anchor_token(']');
3316         expect(']');
3317         return cons;
3318 }
3319
3320 /* §6.7.5.3 */
3321 static construct_type_t *parse_function_declarator(scope_t *scope)
3322 {
3323         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3324
3325         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3326         function_type_t *ftype = &type->function;
3327
3328         ftype->linkage            = current_linkage;
3329         ftype->calling_convention = CC_DEFAULT;
3330
3331         parse_parameters(ftype, scope);
3332
3333         cons->function.function_type = type;
3334
3335         return cons;
3336 }
3337
3338 typedef struct parse_declarator_env_t {
3339         bool               may_be_abstract : 1;
3340         bool               must_be_abstract : 1;
3341         decl_modifiers_t   modifiers;
3342         symbol_t          *symbol;
3343         source_position_t  source_position;
3344         scope_t            parameters;
3345         attribute_t       *attributes;
3346 } parse_declarator_env_t;
3347
3348 /* §6.7.5 */
3349 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3350 {
3351         /* construct a single linked list of construct_type_t's which describe
3352          * how to construct the final declarator type */
3353         construct_type_t  *first      = NULL;
3354         construct_type_t **anchor     = &first;
3355
3356         env->attributes = parse_attributes(env->attributes);
3357
3358         for (;;) {
3359                 construct_type_t *type;
3360                 //variable_t       *based = NULL; /* MS __based extension */
3361                 switch (token.kind) {
3362                         case '&':
3363                                 type = parse_reference_declarator();
3364                                 break;
3365
3366                         case T__based: {
3367                                 panic("based not supported anymore");
3368                                 /* FALLTHROUGH */
3369                         }
3370
3371                         case '*':
3372                                 type = parse_pointer_declarator();
3373                                 break;
3374
3375                         default:
3376                                 goto ptr_operator_end;
3377                 }
3378
3379                 *anchor = type;
3380                 anchor  = &type->base.next;
3381
3382                 /* TODO: find out if this is correct */
3383                 env->attributes = parse_attributes(env->attributes);
3384         }
3385
3386 ptr_operator_end: ;
3387         construct_type_t *inner_types = NULL;
3388
3389         switch (token.kind) {
3390         case T_IDENTIFIER:
3391                 if (env->must_be_abstract) {
3392                         errorf(HERE, "no identifier expected in typename");
3393                 } else {
3394                         env->symbol          = token.base.symbol;
3395                         env->source_position = *HERE;
3396                 }
3397                 eat(T_IDENTIFIER);
3398                 break;
3399
3400         case '(': {
3401                 /* Parenthesized declarator or function declarator? */
3402                 token_t const *const la1 = look_ahead(1);
3403                 switch (la1->kind) {
3404                         case T_IDENTIFIER:
3405                                 if (is_typedef_symbol(la1->base.symbol)) {
3406                         case ')':
3407                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3408                                          * interpreted as ``function with no parameter specification'', rather
3409                                          * than redundant parentheses around the omitted identifier. */
3410                         default:
3411                                         /* Function declarator. */
3412                                         if (!env->may_be_abstract) {
3413                                                 errorf(HERE, "function declarator must have a name");
3414                                         }
3415                                 } else {
3416                         case '&':
3417                         case '(':
3418                         case '*':
3419                         case '[':
3420                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3421                                         /* Paranthesized declarator. */
3422                                         eat('(');
3423                                         add_anchor_token(')');
3424                                         inner_types = parse_inner_declarator(env);
3425                                         if (inner_types != NULL) {
3426                                                 /* All later declarators only modify the return type */
3427                                                 env->must_be_abstract = true;
3428                                         }
3429                                         rem_anchor_token(')');
3430                                         expect(')');
3431                                 }
3432                                 break;
3433                 }
3434                 break;
3435         }
3436
3437         default:
3438                 if (env->may_be_abstract)
3439                         break;
3440                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3441                 eat_until_anchor();
3442                 return NULL;
3443         }
3444
3445         construct_type_t **const p = anchor;
3446
3447         for (;;) {
3448                 construct_type_t *type;
3449                 switch (token.kind) {
3450                 case '(': {
3451                         scope_t *scope = NULL;
3452                         if (!env->must_be_abstract) {
3453                                 scope = &env->parameters;
3454                         }
3455
3456                         type = parse_function_declarator(scope);
3457                         break;
3458                 }
3459                 case '[':
3460                         type = parse_array_declarator();
3461                         break;
3462                 default:
3463                         goto declarator_finished;
3464                 }
3465
3466                 /* insert in the middle of the list (at p) */
3467                 type->base.next = *p;
3468                 *p              = type;
3469                 if (anchor == p)
3470                         anchor = &type->base.next;
3471         }
3472
3473 declarator_finished:
3474         /* append inner_types at the end of the list, we don't to set anchor anymore
3475          * as it's not needed anymore */
3476         *anchor = inner_types;
3477
3478         return first;
3479 }
3480
3481 static type_t *construct_declarator_type(construct_type_t *construct_list,
3482                                          type_t *type)
3483 {
3484         construct_type_t *iter = construct_list;
3485         for (; iter != NULL; iter = iter->base.next) {
3486                 source_position_t const* const pos = &iter->base.pos;
3487                 switch (iter->kind) {
3488                 case CONSTRUCT_FUNCTION: {
3489                         construct_function_type_t *function      = &iter->function;
3490                         type_t                    *function_type = function->function_type;
3491
3492                         function_type->function.return_type = type;
3493
3494                         type_t *skipped_return_type = skip_typeref(type);
3495                         /* §6.7.5.3:1 */
3496                         if (is_type_function(skipped_return_type)) {
3497                                 errorf(pos, "function returning function is not allowed");
3498                         } else if (is_type_array(skipped_return_type)) {
3499                                 errorf(pos, "function returning array is not allowed");
3500                         } else {
3501                                 if (skipped_return_type->base.qualifiers != 0) {
3502                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3503                                 }
3504                         }
3505
3506                         /* The function type was constructed earlier.  Freeing it here will
3507                          * destroy other types. */
3508                         type = typehash_insert(function_type);
3509                         continue;
3510                 }
3511
3512                 case CONSTRUCT_POINTER: {
3513                         if (is_type_reference(skip_typeref(type)))
3514                                 errorf(pos, "cannot declare a pointer to reference");
3515
3516                         parsed_pointer_t *pointer = &iter->pointer;
3517                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3518                         continue;
3519                 }
3520
3521                 case CONSTRUCT_REFERENCE:
3522                         if (is_type_reference(skip_typeref(type)))
3523                                 errorf(pos, "cannot declare a reference to reference");
3524
3525                         type = make_reference_type(type);
3526                         continue;
3527
3528                 case CONSTRUCT_ARRAY: {
3529                         if (is_type_reference(skip_typeref(type)))
3530                                 errorf(pos, "cannot declare an array of references");
3531
3532                         parsed_array_t *array      = &iter->array;
3533                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3534
3535                         expression_t *size_expression = array->size;
3536                         if (size_expression != NULL) {
3537                                 size_expression
3538                                         = create_implicit_cast(size_expression, type_size_t);
3539                         }
3540
3541                         array_type->base.qualifiers       = array->type_qualifiers;
3542                         array_type->array.element_type    = type;
3543                         array_type->array.is_static       = array->is_static;
3544                         array_type->array.is_variable     = array->is_variable;
3545                         array_type->array.size_expression = size_expression;
3546
3547                         if (size_expression != NULL) {
3548                                 switch (is_constant_expression(size_expression)) {
3549                                 case EXPR_CLASS_CONSTANT: {
3550                                         long const size = fold_constant_to_int(size_expression);
3551                                         array_type->array.size          = size;
3552                                         array_type->array.size_constant = true;
3553                                         /* §6.7.5.2:1  If the expression is a constant expression,
3554                                          * it shall have a value greater than zero. */
3555                                         if (size < 0) {
3556                                                 errorf(&size_expression->base.source_position,
3557                                                            "size of array must be greater than zero");
3558                                         } else if (size == 0 && !GNU_MODE) {
3559                                                 errorf(&size_expression->base.source_position,
3560                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3561                                         }
3562                                         break;
3563                                 }
3564
3565                                 case EXPR_CLASS_VARIABLE:
3566                                         array_type->array.is_vla = true;
3567                                         break;
3568
3569                                 case EXPR_CLASS_ERROR:
3570                                         break;
3571                                 }
3572                         }
3573
3574                         type_t *skipped_type = skip_typeref(type);
3575                         /* §6.7.5.2:1 */
3576                         if (is_type_incomplete(skipped_type)) {
3577                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3578                         } else if (is_type_function(skipped_type)) {
3579                                 errorf(pos, "array of functions is not allowed");
3580                         }
3581                         type = identify_new_type(array_type);
3582                         continue;
3583                 }
3584                 }
3585                 internal_errorf(pos, "invalid type construction found");
3586         }
3587
3588         return type;
3589 }
3590
3591 static type_t *automatic_type_conversion(type_t *orig_type);
3592
3593 static type_t *semantic_parameter(const source_position_t *pos,
3594                                   type_t *type,
3595                                   const declaration_specifiers_t *specifiers,
3596                                   entity_t const *const param)
3597 {
3598         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3599          *             shall be adjusted to ``qualified pointer to type'',
3600          *             [...]
3601          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3602          *             type'' shall be adjusted to ``pointer to function
3603          *             returning type'', as in 6.3.2.1. */
3604         type = automatic_type_conversion(type);
3605
3606         if (specifiers->is_inline && is_type_valid(type)) {
3607                 errorf(pos, "'%N' declared 'inline'", param);
3608         }
3609
3610         /* §6.9.1:6  The declarations in the declaration list shall contain
3611          *           no storage-class specifier other than register and no
3612          *           initializations. */
3613         if (specifiers->thread_local || (
3614                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3615                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3616            ) {
3617                 errorf(pos, "invalid storage class for '%N'", param);
3618         }
3619
3620         /* delay test for incomplete type, because we might have (void)
3621          * which is legal but incomplete... */
3622
3623         return type;
3624 }
3625
3626 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3627                                   declarator_flags_t flags)
3628 {
3629         parse_declarator_env_t env;
3630         memset(&env, 0, sizeof(env));
3631         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3632
3633         construct_type_t *construct_type = parse_inner_declarator(&env);
3634         type_t           *orig_type      =
3635                 construct_declarator_type(construct_type, specifiers->type);
3636         type_t           *type           = skip_typeref(orig_type);
3637
3638         if (construct_type != NULL) {
3639                 obstack_free(&temp_obst, construct_type);
3640         }
3641
3642         attribute_t *attributes = parse_attributes(env.attributes);
3643         /* append (shared) specifier attribute behind attributes of this
3644          * declarator */
3645         attribute_t **anchor = &attributes;
3646         while (*anchor != NULL)
3647                 anchor = &(*anchor)->next;
3648         *anchor = specifiers->attributes;
3649
3650         entity_t *entity;
3651         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3652                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3653                 entity->typedefe.type = orig_type;
3654
3655                 if (anonymous_entity != NULL) {
3656                         if (is_type_compound(type)) {
3657                                 assert(anonymous_entity->compound.alias == NULL);
3658                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3659                                        anonymous_entity->kind == ENTITY_UNION);
3660                                 anonymous_entity->compound.alias = entity;
3661                                 anonymous_entity = NULL;
3662                         } else if (is_type_enum(type)) {
3663                                 assert(anonymous_entity->enume.alias == NULL);
3664                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3665                                 anonymous_entity->enume.alias = entity;
3666                                 anonymous_entity = NULL;
3667                         }
3668                 }
3669         } else {
3670                 /* create a declaration type entity */
3671                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3672                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3673                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3674
3675                         if (env.symbol != NULL) {
3676                                 if (specifiers->is_inline && is_type_valid(type)) {
3677                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3678                                 }
3679
3680                                 if (specifiers->thread_local ||
3681                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3682                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3683                                 }
3684                         }
3685                 } else if (flags & DECL_IS_PARAMETER) {
3686                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3687                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3688                 } else if (is_type_function(type)) {
3689                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3690                         entity->function.is_inline      = specifiers->is_inline;
3691                         entity->function.elf_visibility = default_visibility;
3692                         entity->function.parameters     = env.parameters;
3693
3694                         if (env.symbol != NULL) {
3695                                 /* this needs fixes for C++ */
3696                                 bool in_function_scope = current_function != NULL;
3697
3698                                 if (specifiers->thread_local || (
3699                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3700                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3701                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3702                                                 )) {
3703                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3704                                 }
3705                         }
3706                 } else {
3707                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3708                         entity->variable.elf_visibility = default_visibility;
3709                         entity->variable.thread_local   = specifiers->thread_local;
3710
3711                         if (env.symbol != NULL) {
3712                                 if (specifiers->is_inline && is_type_valid(type)) {
3713                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3714                                 }
3715
3716                                 bool invalid_storage_class = false;
3717                                 if (current_scope == file_scope) {
3718                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3719                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3720                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3721                                                 invalid_storage_class = true;
3722                                         }
3723                                 } else {
3724                                         if (specifiers->thread_local &&
3725                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3726                                                 invalid_storage_class = true;
3727                                         }
3728                                 }
3729                                 if (invalid_storage_class) {
3730                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3731                                 }
3732                         }
3733                 }
3734
3735                 entity->declaration.type       = orig_type;
3736                 entity->declaration.alignment  = get_type_alignment(orig_type);
3737                 entity->declaration.modifiers  = env.modifiers;
3738                 entity->declaration.attributes = attributes;
3739
3740                 storage_class_t storage_class = specifiers->storage_class;
3741                 entity->declaration.declared_storage_class = storage_class;
3742
3743                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3744                         storage_class = STORAGE_CLASS_AUTO;
3745                 entity->declaration.storage_class = storage_class;
3746         }
3747
3748         if (attributes != NULL) {
3749                 handle_entity_attributes(attributes, entity);
3750         }
3751
3752         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3753                 adapt_special_functions(&entity->function);
3754         }
3755
3756         return entity;
3757 }
3758
3759 static type_t *parse_abstract_declarator(type_t *base_type)
3760 {
3761         parse_declarator_env_t env;
3762         memset(&env, 0, sizeof(env));
3763         env.may_be_abstract = true;
3764         env.must_be_abstract = true;
3765
3766         construct_type_t *construct_type = parse_inner_declarator(&env);
3767
3768         type_t *result = construct_declarator_type(construct_type, base_type);
3769         if (construct_type != NULL) {
3770                 obstack_free(&temp_obst, construct_type);
3771         }
3772         result = handle_type_attributes(env.attributes, result);
3773
3774         return result;
3775 }
3776
3777 /**
3778  * Check if the declaration of main is suspicious.  main should be a
3779  * function with external linkage, returning int, taking either zero
3780  * arguments, two, or three arguments of appropriate types, ie.
3781  *
3782  * int main([ int argc, char **argv [, char **env ] ]).
3783  *
3784  * @param decl    the declaration to check
3785  * @param type    the function type of the declaration
3786  */
3787 static void check_main(const entity_t *entity)
3788 {
3789         const source_position_t *pos = &entity->base.source_position;
3790         if (entity->kind != ENTITY_FUNCTION) {
3791                 warningf(WARN_MAIN, pos, "'main' is not a function");
3792                 return;
3793         }
3794
3795         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3796                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3797         }
3798
3799         type_t *type = skip_typeref(entity->declaration.type);
3800         assert(is_type_function(type));
3801
3802         function_type_t const *const func_type = &type->function;
3803         type_t                *const ret_type  = func_type->return_type;
3804         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3805                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3806         }
3807         const function_parameter_t *parm = func_type->parameters;
3808         if (parm != NULL) {
3809                 type_t *const first_type        = skip_typeref(parm->type);
3810                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3811                 if (!types_compatible(first_type_unqual, type_int)) {
3812                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3813                 }
3814                 parm = parm->next;
3815                 if (parm != NULL) {
3816                         type_t *const second_type = skip_typeref(parm->type);
3817                         type_t *const second_type_unqual
3818                                 = get_unqualified_type(second_type);
3819                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3820                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3821                         }
3822                         parm = parm->next;
3823                         if (parm != NULL) {
3824                                 type_t *const third_type = skip_typeref(parm->type);
3825                                 type_t *const third_type_unqual
3826                                         = get_unqualified_type(third_type);
3827                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3828                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3829                                 }
3830                                 parm = parm->next;
3831                                 if (parm != NULL)
3832                                         goto warn_arg_count;
3833                         }
3834                 } else {
3835 warn_arg_count:
3836                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3837                 }
3838         }
3839 }
3840
3841 static void error_redefined_as_different_kind(const source_position_t *pos,
3842                 const entity_t *old, entity_kind_t new_kind)
3843 {
3844         char              const *const what = get_entity_kind_name(new_kind);
3845         source_position_t const *const ppos = &old->base.source_position;
3846         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3847 }
3848
3849 static bool is_entity_valid(entity_t *const ent)
3850 {
3851         if (is_declaration(ent)) {
3852                 return is_type_valid(skip_typeref(ent->declaration.type));
3853         } else if (ent->kind == ENTITY_TYPEDEF) {
3854                 return is_type_valid(skip_typeref(ent->typedefe.type));
3855         }
3856         return true;
3857 }
3858
3859 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3860 {
3861         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3862                 if (attributes_equal(tattr, attr))
3863                         return true;
3864         }
3865         return false;
3866 }
3867
3868 /**
3869  * test wether new_list contains any attributes not included in old_list
3870  */
3871 static bool has_new_attributes(const attribute_t *old_list,
3872                                const attribute_t *new_list)
3873 {
3874         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3875                 if (!contains_attribute(old_list, attr))
3876                         return true;
3877         }
3878         return false;
3879 }
3880
3881 /**
3882  * Merge in attributes from an attribute list (probably from a previous
3883  * declaration with the same name). Warning: destroys the old structure
3884  * of the attribute list - don't reuse attributes after this call.
3885  */
3886 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3887 {
3888         attribute_t *next;
3889         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3890                 next = attr->next;
3891                 if (contains_attribute(decl->attributes, attr))
3892                         continue;
3893
3894                 /* move attribute to new declarations attributes list */
3895                 attr->next       = decl->attributes;
3896                 decl->attributes = attr;
3897         }
3898 }
3899
3900 static bool is_main(entity_t*);
3901
3902 /**
3903  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3904  * for various problems that occur for multiple definitions
3905  */
3906 entity_t *record_entity(entity_t *entity, const bool is_definition)
3907 {
3908         const symbol_t *const    symbol  = entity->base.symbol;
3909         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3910         const source_position_t *pos     = &entity->base.source_position;
3911
3912         /* can happen in error cases */
3913         if (symbol == NULL)
3914                 return entity;
3915
3916         assert(!entity->base.parent_scope);
3917         assert(current_scope);
3918         entity->base.parent_scope = current_scope;
3919
3920         entity_t *const previous_entity = get_entity(symbol, namespc);
3921         /* pushing the same entity twice will break the stack structure */
3922         assert(previous_entity != entity);
3923
3924         if (entity->kind == ENTITY_FUNCTION) {
3925                 type_t *const orig_type = entity->declaration.type;
3926                 type_t *const type      = skip_typeref(orig_type);
3927
3928                 assert(is_type_function(type));
3929                 if (type->function.unspecified_parameters &&
3930                     previous_entity == NULL               &&
3931                     !entity->declaration.implicit) {
3932                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3933                 }
3934
3935                 if (is_main(entity)) {
3936                         check_main(entity);
3937                 }
3938         }
3939
3940         if (is_declaration(entity)                                    &&
3941             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3942             current_scope != file_scope                               &&
3943             !entity->declaration.implicit) {
3944                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3945         }
3946
3947         if (previous_entity != NULL) {
3948                 source_position_t const *const ppos = &previous_entity->base.source_position;
3949
3950                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3951                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3952                         assert(previous_entity->kind == ENTITY_PARAMETER);
3953                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3954                         goto finish;
3955                 }
3956
3957                 if (previous_entity->base.parent_scope == current_scope) {
3958                         if (previous_entity->kind != entity->kind) {
3959                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3960                                         error_redefined_as_different_kind(pos, previous_entity,
3961                                                         entity->kind);
3962                                 }
3963                                 goto finish;
3964                         }
3965                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3966                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3967                                 goto finish;
3968                         }
3969                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3970                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3971                                 type_t *const prev_type
3972                                         = skip_typeref(previous_entity->typedefe.type);
3973                                 if (c_mode & _CXX) {
3974                                         /* C++ allows double typedef if they are identical
3975                                          * (after skipping typedefs) */
3976                                         if (type == prev_type)
3977                                                 goto finish;
3978                                 } else {
3979                                         /* GCC extension: redef in system headers is allowed */
3980                                         if ((pos->is_system_header || ppos->is_system_header) &&
3981                                             types_compatible(type, prev_type))
3982                                                 goto finish;
3983                                 }
3984                                 errorf(pos, "redefinition of '%N' (declared %P)",
3985                                        entity, ppos);
3986                                 goto finish;
3987                         }
3988
3989                         /* at this point we should have only VARIABLES or FUNCTIONS */
3990                         assert(is_declaration(previous_entity) && is_declaration(entity));
3991
3992                         declaration_t *const prev_decl = &previous_entity->declaration;
3993                         declaration_t *const decl      = &entity->declaration;
3994
3995                         /* can happen for K&R style declarations */
3996                         if (prev_decl->type       == NULL             &&
3997                                         previous_entity->kind == ENTITY_PARAMETER &&
3998                                         entity->kind          == ENTITY_PARAMETER) {
3999                                 prev_decl->type                   = decl->type;
4000                                 prev_decl->storage_class          = decl->storage_class;
4001                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4002                                 prev_decl->modifiers              = decl->modifiers;
4003                                 return previous_entity;
4004                         }
4005
4006                         type_t *const type      = skip_typeref(decl->type);
4007                         type_t *const prev_type = skip_typeref(prev_decl->type);
4008
4009                         if (!types_compatible(type, prev_type)) {
4010                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4011                         } else {
4012                                 unsigned old_storage_class = prev_decl->storage_class;
4013
4014                                 if (is_definition                     &&
4015                                                 !prev_decl->used                  &&
4016                                                 !(prev_decl->modifiers & DM_USED) &&
4017                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4018                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4019                                 }
4020
4021                                 storage_class_t new_storage_class = decl->storage_class;
4022
4023                                 /* pretend no storage class means extern for function
4024                                  * declarations (except if the previous declaration is neither
4025                                  * none nor extern) */
4026                                 if (entity->kind == ENTITY_FUNCTION) {
4027                                         /* the previous declaration could have unspecified parameters or
4028                                          * be a typedef, so use the new type */
4029                                         if (prev_type->function.unspecified_parameters || is_definition)
4030                                                 prev_decl->type = type;
4031
4032                                         switch (old_storage_class) {
4033                                                 case STORAGE_CLASS_NONE:
4034                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4035                                                         /* FALLTHROUGH */
4036
4037                                                 case STORAGE_CLASS_EXTERN:
4038                                                         if (is_definition) {
4039                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4040                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4041                                                                 }
4042                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4043                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4044                                                         }
4045                                                         break;
4046
4047                                                 default:
4048                                                         break;
4049                                         }
4050                                 } else if (is_type_incomplete(prev_type)) {
4051                                         prev_decl->type = type;
4052                                 }
4053
4054                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4055                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4056
4057 warn_redundant_declaration: ;
4058                                         bool has_new_attrs
4059                                                 = has_new_attributes(prev_decl->attributes,
4060                                                                      decl->attributes);
4061                                         if (has_new_attrs) {
4062                                                 merge_in_attributes(decl, prev_decl->attributes);
4063                                         } else if (!is_definition        &&
4064                                                         is_type_valid(prev_type) &&
4065                                                         !pos->is_system_header) {
4066                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4067                                         }
4068                                 } else if (current_function == NULL) {
4069                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4070                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4071                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4072                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4073                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4074                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4075                                         } else {
4076                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4077                                                 if (c_mode & _CXX)
4078                                                         goto error_redeclaration;
4079                                                 goto warn_redundant_declaration;
4080                                         }
4081                                 } else if (is_type_valid(prev_type)) {
4082                                         if (old_storage_class == new_storage_class) {
4083 error_redeclaration:
4084                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4085                                         } else {
4086                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4087                                         }
4088                                 }
4089                         }
4090
4091                         prev_decl->modifiers |= decl->modifiers;
4092                         if (entity->kind == ENTITY_FUNCTION) {
4093                                 previous_entity->function.is_inline |= entity->function.is_inline;
4094                         }
4095                         return previous_entity;
4096                 }
4097
4098                 warning_t why;
4099                 if (is_warn_on(why = WARN_SHADOW) ||
4100                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4101                         char const *const what = get_entity_kind_name(previous_entity->kind);
4102                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4103                 }
4104         }
4105
4106         if (entity->kind == ENTITY_FUNCTION) {
4107                 if (is_definition &&
4108                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4109                                 !is_main(entity)) {
4110                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4111                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4112                         } else {
4113                                 goto warn_missing_declaration;
4114                         }
4115                 }
4116         } else if (entity->kind == ENTITY_VARIABLE) {
4117                 if (current_scope                     == file_scope &&
4118                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4119                                 !entity->declaration.implicit) {
4120 warn_missing_declaration:
4121                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4122                 }
4123         }
4124
4125 finish:
4126         environment_push(entity);
4127         append_entity(current_scope, entity);
4128
4129         return entity;
4130 }
4131
4132 static void parser_error_multiple_definition(entity_t *entity,
4133                 const source_position_t *source_position)
4134 {
4135         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4136 }
4137
4138 static bool is_declaration_specifier(const token_t *token)
4139 {
4140         switch (token->kind) {
4141                 DECLARATION_START
4142                         return true;
4143                 case T_IDENTIFIER:
4144                         return is_typedef_symbol(token->base.symbol);
4145
4146                 default:
4147                         return false;
4148         }
4149 }
4150
4151 static void parse_init_declarator_rest(entity_t *entity)
4152 {
4153         type_t *orig_type = type_error_type;
4154
4155         if (entity->base.kind == ENTITY_TYPEDEF) {
4156                 source_position_t const *const pos = &entity->base.source_position;
4157                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4158         } else {
4159                 assert(is_declaration(entity));
4160                 orig_type = entity->declaration.type;
4161         }
4162
4163         type_t *type = skip_typeref(orig_type);
4164
4165         if (entity->kind == ENTITY_VARIABLE
4166                         && entity->variable.initializer != NULL) {
4167                 parser_error_multiple_definition(entity, HERE);
4168         }
4169         eat('=');
4170
4171         declaration_t *const declaration = &entity->declaration;
4172         bool must_be_constant = false;
4173         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4174             entity->base.parent_scope  == file_scope) {
4175                 must_be_constant = true;
4176         }
4177
4178         if (is_type_function(type)) {
4179                 source_position_t const *const pos = &entity->base.source_position;
4180                 errorf(pos, "'%N' is initialized like a variable", entity);
4181                 orig_type = type_error_type;
4182         }
4183
4184         parse_initializer_env_t env;
4185         env.type             = orig_type;
4186         env.must_be_constant = must_be_constant;
4187         env.entity           = entity;
4188
4189         initializer_t *initializer = parse_initializer(&env);
4190
4191         if (entity->kind == ENTITY_VARIABLE) {
4192                 /* §6.7.5:22  array initializers for arrays with unknown size
4193                  * determine the array type size */
4194                 declaration->type            = env.type;
4195                 entity->variable.initializer = initializer;
4196         }
4197 }
4198
4199 /* parse rest of a declaration without any declarator */
4200 static void parse_anonymous_declaration_rest(
4201                 const declaration_specifiers_t *specifiers)
4202 {
4203         eat(';');
4204         anonymous_entity = NULL;
4205
4206         source_position_t const *const pos = &specifiers->source_position;
4207         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4208                         specifiers->thread_local) {
4209                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4210         }
4211
4212         type_t *type = specifiers->type;
4213         switch (type->kind) {
4214                 case TYPE_COMPOUND_STRUCT:
4215                 case TYPE_COMPOUND_UNION: {
4216                         if (type->compound.compound->base.symbol == NULL) {
4217                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4218                         }
4219                         break;
4220                 }
4221
4222                 case TYPE_ENUM:
4223                         break;
4224
4225                 default:
4226                         warningf(WARN_OTHER, pos, "empty declaration");
4227                         break;
4228         }
4229 }
4230
4231 static void check_variable_type_complete(entity_t *ent)
4232 {
4233         if (ent->kind != ENTITY_VARIABLE)
4234                 return;
4235
4236         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4237          *         type for the object shall be complete [...] */
4238         declaration_t *decl = &ent->declaration;
4239         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4240                         decl->storage_class == STORAGE_CLASS_STATIC)
4241                 return;
4242
4243         type_t *const type = skip_typeref(decl->type);
4244         if (!is_type_incomplete(type))
4245                 return;
4246
4247         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4248          * are given length one. */
4249         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4250                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4251                 return;
4252         }
4253
4254         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4255 }
4256
4257
4258 static void parse_declaration_rest(entity_t *ndeclaration,
4259                 const declaration_specifiers_t *specifiers,
4260                 parsed_declaration_func         finished_declaration,
4261                 declarator_flags_t              flags)
4262 {
4263         add_anchor_token(';');
4264         add_anchor_token(',');
4265         while (true) {
4266                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4267
4268                 if (token.kind == '=') {
4269                         parse_init_declarator_rest(entity);
4270                 } else if (entity->kind == ENTITY_VARIABLE) {
4271                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4272                          * [...] where the extern specifier is explicitly used. */
4273                         declaration_t *decl = &entity->declaration;
4274                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4275                             is_type_reference(skip_typeref(decl->type))) {
4276                                 source_position_t const *const pos = &entity->base.source_position;
4277                                 errorf(pos, "reference '%#N' must be initialized", entity);
4278                         }
4279                 }
4280
4281                 check_variable_type_complete(entity);
4282
4283                 if (!next_if(','))
4284                         break;
4285
4286                 add_anchor_token('=');
4287                 ndeclaration = parse_declarator(specifiers, flags);
4288                 rem_anchor_token('=');
4289         }
4290         rem_anchor_token(',');
4291         rem_anchor_token(';');
4292         expect(';');
4293
4294         anonymous_entity = NULL;
4295 }
4296
4297 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4298 {
4299         symbol_t *symbol = entity->base.symbol;
4300         if (symbol == NULL)
4301                 return entity;
4302
4303         assert(entity->base.namespc == NAMESPACE_NORMAL);
4304         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4305         if (previous_entity == NULL
4306                         || previous_entity->base.parent_scope != current_scope) {
4307                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4308                        symbol);
4309                 return entity;
4310         }
4311
4312         if (is_definition) {
4313                 errorf(HERE, "'%N' is initialised", entity);
4314         }
4315
4316         return record_entity(entity, false);
4317 }
4318
4319 static void parse_declaration(parsed_declaration_func finished_declaration,
4320                               declarator_flags_t      flags)
4321 {
4322         add_anchor_token(';');
4323         declaration_specifiers_t specifiers;
4324         parse_declaration_specifiers(&specifiers);
4325         rem_anchor_token(';');
4326
4327         if (token.kind == ';') {
4328                 parse_anonymous_declaration_rest(&specifiers);
4329         } else {
4330                 entity_t *entity = parse_declarator(&specifiers, flags);
4331                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4332         }
4333 }
4334
4335 /* §6.5.2.2:6 */
4336 static type_t *get_default_promoted_type(type_t *orig_type)
4337 {
4338         type_t *result = orig_type;
4339
4340         type_t *type = skip_typeref(orig_type);
4341         if (is_type_integer(type)) {
4342                 result = promote_integer(type);
4343         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4344                 result = type_double;
4345         }
4346
4347         return result;
4348 }
4349
4350 static void parse_kr_declaration_list(entity_t *entity)
4351 {
4352         if (entity->kind != ENTITY_FUNCTION)
4353                 return;
4354
4355         type_t *type = skip_typeref(entity->declaration.type);
4356         assert(is_type_function(type));
4357         if (!type->function.kr_style_parameters)
4358                 return;
4359
4360         add_anchor_token('{');
4361
4362         PUSH_SCOPE(&entity->function.parameters);
4363
4364         entity_t *parameter = entity->function.parameters.entities;
4365         for ( ; parameter != NULL; parameter = parameter->base.next) {
4366                 assert(parameter->base.parent_scope == NULL);
4367                 parameter->base.parent_scope = current_scope;
4368                 environment_push(parameter);
4369         }
4370
4371         /* parse declaration list */
4372         for (;;) {
4373                 switch (token.kind) {
4374                         DECLARATION_START
4375                         /* This covers symbols, which are no type, too, and results in
4376                          * better error messages.  The typical cases are misspelled type
4377                          * names and missing includes. */
4378                         case T_IDENTIFIER:
4379                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4380                                 break;
4381                         default:
4382                                 goto decl_list_end;
4383                 }
4384         }
4385 decl_list_end:
4386
4387         POP_SCOPE();
4388
4389         /* update function type */
4390         type_t *new_type = duplicate_type(type);
4391
4392         function_parameter_t  *parameters = NULL;
4393         function_parameter_t **anchor     = &parameters;
4394
4395         /* did we have an earlier prototype? */
4396         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4397         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4398                 proto_type = NULL;
4399
4400         function_parameter_t *proto_parameter = NULL;
4401         if (proto_type != NULL) {
4402                 type_t *proto_type_type = proto_type->declaration.type;
4403                 proto_parameter         = proto_type_type->function.parameters;
4404                 /* If a K&R function definition has a variadic prototype earlier, then
4405                  * make the function definition variadic, too. This should conform to
4406                  * §6.7.5.3:15 and §6.9.1:8. */
4407                 new_type->function.variadic = proto_type_type->function.variadic;
4408         } else {
4409                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4410                  * prototype */
4411                 new_type->function.unspecified_parameters = true;
4412         }
4413
4414         bool need_incompatible_warning = false;
4415         parameter = entity->function.parameters.entities;
4416         for (; parameter != NULL; parameter = parameter->base.next,
4417                         proto_parameter =
4418                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4419                 if (parameter->kind != ENTITY_PARAMETER)
4420                         continue;
4421
4422                 type_t *parameter_type = parameter->declaration.type;
4423                 if (parameter_type == NULL) {
4424                         source_position_t const* const pos = &parameter->base.source_position;
4425                         if (strict_mode) {
4426                                 errorf(pos, "no type specified for function '%N'", parameter);
4427                                 parameter_type = type_error_type;
4428                         } else {
4429                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4430                                 parameter_type = type_int;
4431                         }
4432                         parameter->declaration.type = parameter_type;
4433                 }
4434
4435                 semantic_parameter_incomplete(parameter);
4436
4437                 /* we need the default promoted types for the function type */
4438                 type_t *not_promoted = parameter_type;
4439                 parameter_type       = get_default_promoted_type(parameter_type);
4440
4441                 /* gcc special: if the type of the prototype matches the unpromoted
4442                  * type don't promote */
4443                 if (!strict_mode && proto_parameter != NULL) {
4444                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4445                         type_t *promo_skip   = skip_typeref(parameter_type);
4446                         type_t *param_skip   = skip_typeref(not_promoted);
4447                         if (!types_compatible(proto_p_type, promo_skip)
4448                                 && types_compatible(proto_p_type, param_skip)) {
4449                                 /* don't promote */
4450                                 need_incompatible_warning = true;
4451                                 parameter_type = not_promoted;
4452                         }
4453                 }
4454                 function_parameter_t *const function_parameter
4455                         = allocate_parameter(parameter_type);
4456
4457                 *anchor = function_parameter;
4458                 anchor  = &function_parameter->next;
4459         }
4460
4461         new_type->function.parameters = parameters;
4462         new_type = identify_new_type(new_type);
4463
4464         if (need_incompatible_warning) {
4465                 symbol_t          const *const sym  = entity->base.symbol;
4466                 source_position_t const *const pos  = &entity->base.source_position;
4467                 source_position_t const *const ppos = &proto_type->base.source_position;
4468                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4469         }
4470         entity->declaration.type = new_type;
4471
4472         rem_anchor_token('{');
4473 }
4474
4475 static bool first_err = true;
4476
4477 /**
4478  * When called with first_err set, prints the name of the current function,
4479  * else does noting.
4480  */
4481 static void print_in_function(void)
4482 {
4483         if (first_err) {
4484                 first_err = false;
4485                 char const *const file = current_function->base.base.source_position.input_name;
4486                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4487         }
4488 }
4489
4490 /**
4491  * Check if all labels are defined in the current function.
4492  * Check if all labels are used in the current function.
4493  */
4494 static void check_labels(void)
4495 {
4496         for (const goto_statement_t *goto_statement = goto_first;
4497             goto_statement != NULL;
4498             goto_statement = goto_statement->next) {
4499                 label_t *label = goto_statement->label;
4500                 if (label->base.source_position.input_name == NULL) {
4501                         print_in_function();
4502                         source_position_t const *const pos = &goto_statement->base.source_position;
4503                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4504                  }
4505         }
4506
4507         if (is_warn_on(WARN_UNUSED_LABEL)) {
4508                 for (const label_statement_t *label_statement = label_first;
4509                          label_statement != NULL;
4510                          label_statement = label_statement->next) {
4511                         label_t *label = label_statement->label;
4512
4513                         if (! label->used) {
4514                                 print_in_function();
4515                                 source_position_t const *const pos = &label_statement->base.source_position;
4516                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4517                         }
4518                 }
4519         }
4520 }
4521
4522 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4523 {
4524         entity_t const *const end = last != NULL ? last->base.next : NULL;
4525         for (; entity != end; entity = entity->base.next) {
4526                 if (!is_declaration(entity))
4527                         continue;
4528
4529                 declaration_t *declaration = &entity->declaration;
4530                 if (declaration->implicit)
4531                         continue;
4532
4533                 if (!declaration->used) {
4534                         print_in_function();
4535                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4536                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4537                         print_in_function();
4538                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4539                 }
4540         }
4541 }
4542
4543 static void check_unused_variables(statement_t *const stmt, void *const env)
4544 {
4545         (void)env;
4546
4547         switch (stmt->kind) {
4548                 case STATEMENT_DECLARATION: {
4549                         declaration_statement_t const *const decls = &stmt->declaration;
4550                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4551                         return;
4552                 }
4553
4554                 case STATEMENT_FOR:
4555                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4556                         return;
4557
4558                 default:
4559                         return;
4560         }
4561 }
4562
4563 /**
4564  * Check declarations of current_function for unused entities.
4565  */
4566 static void check_declarations(void)
4567 {
4568         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4569                 const scope_t *scope = &current_function->parameters;
4570                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4571         }
4572         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4573                 walk_statements(current_function->statement, check_unused_variables,
4574                                 NULL);
4575         }
4576 }
4577
4578 static int determine_truth(expression_t const* const cond)
4579 {
4580         return
4581                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4582                 fold_constant_to_bool(cond)                         ? 1 :
4583                 -1;
4584 }
4585
4586 static void check_reachable(statement_t *);
4587 static bool reaches_end;
4588
4589 static bool expression_returns(expression_t const *const expr)
4590 {
4591         switch (expr->kind) {
4592                 case EXPR_CALL: {
4593                         expression_t const *const func = expr->call.function;
4594                         type_t       const *const type = skip_typeref(func->base.type);
4595                         if (type->kind == TYPE_POINTER) {
4596                                 type_t const *const points_to
4597                                         = skip_typeref(type->pointer.points_to);
4598                                 if (points_to->kind == TYPE_FUNCTION
4599                                     && points_to->function.modifiers & DM_NORETURN)
4600                                         return false;
4601                         }
4602
4603                         if (!expression_returns(func))
4604                                 return false;
4605
4606                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4607                                 if (!expression_returns(arg->expression))
4608                                         return false;
4609                         }
4610
4611                         return true;
4612                 }
4613
4614                 case EXPR_REFERENCE:
4615                 case EXPR_ENUM_CONSTANT:
4616                 case EXPR_LITERAL_CASES:
4617                 case EXPR_LITERAL_CHARACTER:
4618                 case EXPR_STRING_LITERAL:
4619                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4620                 case EXPR_LABEL_ADDRESS:
4621                 case EXPR_CLASSIFY_TYPE:
4622                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4623                 case EXPR_ALIGNOF:
4624                 case EXPR_FUNCNAME:
4625                 case EXPR_BUILTIN_CONSTANT_P:
4626                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4627                 case EXPR_OFFSETOF:
4628                 case EXPR_ERROR:
4629                         return true;
4630
4631                 case EXPR_STATEMENT: {
4632                         bool old_reaches_end = reaches_end;
4633                         reaches_end = false;
4634                         check_reachable(expr->statement.statement);
4635                         bool returns = reaches_end;
4636                         reaches_end = old_reaches_end;
4637                         return returns;
4638                 }
4639
4640                 case EXPR_CONDITIONAL:
4641                         // TODO handle constant expression
4642
4643                         if (!expression_returns(expr->conditional.condition))
4644                                 return false;
4645
4646                         if (expr->conditional.true_expression != NULL
4647                                         && expression_returns(expr->conditional.true_expression))
4648                                 return true;
4649
4650                         return expression_returns(expr->conditional.false_expression);
4651
4652                 case EXPR_SELECT:
4653                         return expression_returns(expr->select.compound);
4654
4655                 case EXPR_ARRAY_ACCESS:
4656                         return
4657                                 expression_returns(expr->array_access.array_ref) &&
4658                                 expression_returns(expr->array_access.index);
4659
4660                 case EXPR_VA_START:
4661                         return expression_returns(expr->va_starte.ap);
4662
4663                 case EXPR_VA_ARG:
4664                         return expression_returns(expr->va_arge.ap);
4665
4666                 case EXPR_VA_COPY:
4667                         return expression_returns(expr->va_copye.src);
4668
4669                 case EXPR_UNARY_CASES_MANDATORY:
4670                         return expression_returns(expr->unary.value);
4671
4672                 case EXPR_UNARY_THROW:
4673                         return false;
4674
4675                 case EXPR_BINARY_CASES:
4676                         // TODO handle constant lhs of && and ||
4677                         return
4678                                 expression_returns(expr->binary.left) &&
4679                                 expression_returns(expr->binary.right);
4680         }
4681
4682         panic("unhandled expression");
4683 }
4684
4685 static bool initializer_returns(initializer_t const *const init)
4686 {
4687         switch (init->kind) {
4688                 case INITIALIZER_VALUE:
4689                         return expression_returns(init->value.value);
4690
4691                 case INITIALIZER_LIST: {
4692                         initializer_t * const*       i       = init->list.initializers;
4693                         initializer_t * const* const end     = i + init->list.len;
4694                         bool                         returns = true;
4695                         for (; i != end; ++i) {
4696                                 if (!initializer_returns(*i))
4697                                         returns = false;
4698                         }
4699                         return returns;
4700                 }
4701
4702                 case INITIALIZER_STRING:
4703                 case INITIALIZER_DESIGNATOR: // designators have no payload
4704                         return true;
4705         }
4706         panic("unhandled initializer");
4707 }
4708
4709 static bool noreturn_candidate;
4710
4711 static void check_reachable(statement_t *const stmt)
4712 {
4713         if (stmt->base.reachable)
4714                 return;
4715         if (stmt->kind != STATEMENT_DO_WHILE)
4716                 stmt->base.reachable = true;
4717
4718         statement_t *last = stmt;
4719         statement_t *next;
4720         switch (stmt->kind) {
4721                 case STATEMENT_ERROR:
4722                 case STATEMENT_EMPTY:
4723                 case STATEMENT_ASM:
4724                         next = stmt->base.next;
4725                         break;
4726
4727                 case STATEMENT_DECLARATION: {
4728                         declaration_statement_t const *const decl = &stmt->declaration;
4729                         entity_t                const *      ent  = decl->declarations_begin;
4730                         entity_t                const *const last_decl = decl->declarations_end;
4731                         if (ent != NULL) {
4732                                 for (;; ent = ent->base.next) {
4733                                         if (ent->kind                 == ENTITY_VARIABLE &&
4734                                             ent->variable.initializer != NULL            &&
4735                                             !initializer_returns(ent->variable.initializer)) {
4736                                                 return;
4737                                         }
4738                                         if (ent == last_decl)
4739                                                 break;
4740                                 }
4741                         }
4742                         next = stmt->base.next;
4743                         break;
4744                 }
4745
4746                 case STATEMENT_COMPOUND:
4747                         next = stmt->compound.statements;
4748                         if (next == NULL)
4749                                 next = stmt->base.next;
4750                         break;
4751
4752                 case STATEMENT_RETURN: {
4753                         expression_t const *const val = stmt->returns.value;
4754                         if (val == NULL || expression_returns(val))
4755                                 noreturn_candidate = false;
4756                         return;
4757                 }
4758
4759                 case STATEMENT_IF: {
4760                         if_statement_t const *const ifs  = &stmt->ifs;
4761                         expression_t   const *const cond = ifs->condition;
4762
4763                         if (!expression_returns(cond))
4764                                 return;
4765
4766                         int const val = determine_truth(cond);
4767
4768                         if (val >= 0)
4769                                 check_reachable(ifs->true_statement);
4770
4771                         if (val > 0)
4772                                 return;
4773
4774                         if (ifs->false_statement != NULL) {
4775                                 check_reachable(ifs->false_statement);
4776                                 return;
4777                         }
4778
4779                         next = stmt->base.next;
4780                         break;
4781                 }
4782
4783                 case STATEMENT_SWITCH: {
4784                         switch_statement_t const *const switchs = &stmt->switchs;
4785                         expression_t       const *const expr    = switchs->expression;
4786
4787                         if (!expression_returns(expr))
4788                                 return;
4789
4790                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4791                                 long                    const val      = fold_constant_to_int(expr);
4792                                 case_label_statement_t *      defaults = NULL;
4793                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4794                                         if (i->expression == NULL) {
4795                                                 defaults = i;
4796                                                 continue;
4797                                         }
4798
4799                                         if (i->first_case <= val && val <= i->last_case) {
4800                                                 check_reachable((statement_t*)i);
4801                                                 return;
4802                                         }
4803                                 }
4804
4805                                 if (defaults != NULL) {
4806                                         check_reachable((statement_t*)defaults);
4807                                         return;
4808                                 }
4809                         } else {
4810                                 bool has_default = false;
4811                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4812                                         if (i->expression == NULL)
4813                                                 has_default = true;
4814
4815                                         check_reachable((statement_t*)i);
4816                                 }
4817
4818                                 if (has_default)
4819                                         return;
4820                         }
4821
4822                         next = stmt->base.next;
4823                         break;
4824                 }
4825
4826                 case STATEMENT_EXPRESSION: {
4827                         /* Check for noreturn function call */
4828                         expression_t const *const expr = stmt->expression.expression;
4829                         if (!expression_returns(expr))
4830                                 return;
4831
4832                         next = stmt->base.next;
4833                         break;
4834                 }
4835
4836                 case STATEMENT_CONTINUE:
4837                         for (statement_t *parent = stmt;;) {
4838                                 parent = parent->base.parent;
4839                                 if (parent == NULL) /* continue not within loop */
4840                                         return;
4841
4842                                 next = parent;
4843                                 switch (parent->kind) {
4844                                         case STATEMENT_WHILE:    goto continue_while;
4845                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4846                                         case STATEMENT_FOR:      goto continue_for;
4847
4848                                         default: break;
4849                                 }
4850                         }
4851
4852                 case STATEMENT_BREAK:
4853                         for (statement_t *parent = stmt;;) {
4854                                 parent = parent->base.parent;
4855                                 if (parent == NULL) /* break not within loop/switch */
4856                                         return;
4857
4858                                 switch (parent->kind) {
4859                                         case STATEMENT_SWITCH:
4860                                         case STATEMENT_WHILE:
4861                                         case STATEMENT_DO_WHILE:
4862                                         case STATEMENT_FOR:
4863                                                 last = parent;
4864                                                 next = parent->base.next;
4865                                                 goto found_break_parent;
4866
4867                                         default: break;
4868                                 }
4869                         }
4870 found_break_parent:
4871                         break;
4872
4873                 case STATEMENT_COMPUTED_GOTO: {
4874                         if (!expression_returns(stmt->computed_goto.expression))
4875                                 return;
4876
4877                         statement_t *parent = stmt->base.parent;
4878                         if (parent == NULL) /* top level goto */
4879                                 return;
4880                         next = parent;
4881                         break;
4882                 }
4883
4884                 case STATEMENT_GOTO:
4885                         next = stmt->gotos.label->statement;
4886                         if (next == NULL) /* missing label */
4887                                 return;
4888                         break;
4889
4890                 case STATEMENT_LABEL:
4891                         next = stmt->label.statement;
4892                         break;
4893
4894                 case STATEMENT_CASE_LABEL:
4895                         next = stmt->case_label.statement;
4896                         break;
4897
4898                 case STATEMENT_WHILE: {
4899                         while_statement_t const *const whiles = &stmt->whiles;
4900                         expression_t      const *const cond   = whiles->condition;
4901
4902                         if (!expression_returns(cond))
4903                                 return;
4904
4905                         int const val = determine_truth(cond);
4906
4907                         if (val >= 0)
4908                                 check_reachable(whiles->body);
4909
4910                         if (val > 0)
4911                                 return;
4912
4913                         next = stmt->base.next;
4914                         break;
4915                 }
4916
4917                 case STATEMENT_DO_WHILE:
4918                         next = stmt->do_while.body;
4919                         break;
4920
4921                 case STATEMENT_FOR: {
4922                         for_statement_t *const fors = &stmt->fors;
4923
4924                         if (fors->condition_reachable)
4925                                 return;
4926                         fors->condition_reachable = true;
4927
4928                         expression_t const *const cond = fors->condition;
4929
4930                         int val;
4931                         if (cond == NULL) {
4932                                 val = 1;
4933                         } else if (expression_returns(cond)) {
4934                                 val = determine_truth(cond);
4935                         } else {
4936                                 return;
4937                         }
4938
4939                         if (val >= 0)
4940                                 check_reachable(fors->body);
4941
4942                         if (val > 0)
4943                                 return;
4944
4945                         next = stmt->base.next;
4946                         break;
4947                 }
4948
4949                 case STATEMENT_MS_TRY: {
4950                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4951                         check_reachable(ms_try->try_statement);
4952                         next = ms_try->final_statement;
4953                         break;
4954                 }
4955
4956                 case STATEMENT_LEAVE: {
4957                         statement_t *parent = stmt;
4958                         for (;;) {
4959                                 parent = parent->base.parent;
4960                                 if (parent == NULL) /* __leave not within __try */
4961                                         return;
4962
4963                                 if (parent->kind == STATEMENT_MS_TRY) {
4964                                         last = parent;
4965                                         next = parent->ms_try.final_statement;
4966                                         break;
4967                                 }
4968                         }
4969                         break;
4970                 }
4971
4972                 default:
4973                         panic("invalid statement kind");
4974         }
4975
4976         while (next == NULL) {
4977                 next = last->base.parent;
4978                 if (next == NULL) {
4979                         noreturn_candidate = false;
4980
4981                         type_t *const type = skip_typeref(current_function->base.type);
4982                         assert(is_type_function(type));
4983                         type_t *const ret  = skip_typeref(type->function.return_type);
4984                         if (!is_type_void(ret) &&
4985                             is_type_valid(ret) &&
4986                             !is_main(current_entity)) {
4987                                 source_position_t const *const pos = &stmt->base.source_position;
4988                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4989                         }
4990                         return;
4991                 }
4992
4993                 switch (next->kind) {
4994                         case STATEMENT_ERROR:
4995                         case STATEMENT_EMPTY:
4996                         case STATEMENT_DECLARATION:
4997                         case STATEMENT_EXPRESSION:
4998                         case STATEMENT_ASM:
4999                         case STATEMENT_RETURN:
5000                         case STATEMENT_CONTINUE:
5001                         case STATEMENT_BREAK:
5002                         case STATEMENT_COMPUTED_GOTO:
5003                         case STATEMENT_GOTO:
5004                         case STATEMENT_LEAVE:
5005                                 panic("invalid control flow in function");
5006
5007                         case STATEMENT_COMPOUND:
5008                                 if (next->compound.stmt_expr) {
5009                                         reaches_end = true;
5010                                         return;
5011                                 }
5012                                 /* FALLTHROUGH */
5013                         case STATEMENT_IF:
5014                         case STATEMENT_SWITCH:
5015                         case STATEMENT_LABEL:
5016                         case STATEMENT_CASE_LABEL:
5017                                 last = next;
5018                                 next = next->base.next;
5019                                 break;
5020
5021                         case STATEMENT_WHILE: {
5022 continue_while:
5023                                 if (next->base.reachable)
5024                                         return;
5025                                 next->base.reachable = true;
5026
5027                                 while_statement_t const *const whiles = &next->whiles;
5028                                 expression_t      const *const cond   = whiles->condition;
5029
5030                                 if (!expression_returns(cond))
5031                                         return;
5032
5033                                 int const val = determine_truth(cond);
5034
5035                                 if (val >= 0)
5036                                         check_reachable(whiles->body);
5037
5038                                 if (val > 0)
5039                                         return;
5040
5041                                 last = next;
5042                                 next = next->base.next;
5043                                 break;
5044                         }
5045
5046                         case STATEMENT_DO_WHILE: {
5047 continue_do_while:
5048                                 if (next->base.reachable)
5049                                         return;
5050                                 next->base.reachable = true;
5051
5052                                 do_while_statement_t const *const dw   = &next->do_while;
5053                                 expression_t         const *const cond = dw->condition;
5054
5055                                 if (!expression_returns(cond))
5056                                         return;
5057
5058                                 int const val = determine_truth(cond);
5059
5060                                 if (val >= 0)
5061                                         check_reachable(dw->body);
5062
5063                                 if (val > 0)
5064                                         return;
5065
5066                                 last = next;
5067                                 next = next->base.next;
5068                                 break;
5069                         }
5070
5071                         case STATEMENT_FOR: {
5072 continue_for:;
5073                                 for_statement_t *const fors = &next->fors;
5074
5075                                 fors->step_reachable = true;
5076
5077                                 if (fors->condition_reachable)
5078                                         return;
5079                                 fors->condition_reachable = true;
5080
5081                                 expression_t const *const cond = fors->condition;
5082
5083                                 int val;
5084                                 if (cond == NULL) {
5085                                         val = 1;
5086                                 } else if (expression_returns(cond)) {
5087                                         val = determine_truth(cond);
5088                                 } else {
5089                                         return;
5090                                 }
5091
5092                                 if (val >= 0)
5093                                         check_reachable(fors->body);
5094
5095                                 if (val > 0)
5096                                         return;
5097
5098                                 last = next;
5099                                 next = next->base.next;
5100                                 break;
5101                         }
5102
5103                         case STATEMENT_MS_TRY:
5104                                 last = next;
5105                                 next = next->ms_try.final_statement;
5106                                 break;
5107                 }
5108         }
5109
5110         check_reachable(next);
5111 }
5112
5113 static void check_unreachable(statement_t* const stmt, void *const env)
5114 {
5115         (void)env;
5116
5117         switch (stmt->kind) {
5118                 case STATEMENT_DO_WHILE:
5119                         if (!stmt->base.reachable) {
5120                                 expression_t const *const cond = stmt->do_while.condition;
5121                                 if (determine_truth(cond) >= 0) {
5122                                         source_position_t const *const pos = &cond->base.source_position;
5123                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5124                                 }
5125                         }
5126                         return;
5127
5128                 case STATEMENT_FOR: {
5129                         for_statement_t const* const fors = &stmt->fors;
5130
5131                         // if init and step are unreachable, cond is unreachable, too
5132                         if (!stmt->base.reachable && !fors->step_reachable) {
5133                                 goto warn_unreachable;
5134                         } else {
5135                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5136                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5137                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5138                                 }
5139
5140                                 if (!fors->condition_reachable && fors->condition != NULL) {
5141                                         source_position_t const *const pos = &fors->condition->base.source_position;
5142                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5143                                 }
5144
5145                                 if (!fors->step_reachable && fors->step != NULL) {
5146                                         source_position_t const *const pos = &fors->step->base.source_position;
5147                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5148                                 }
5149                         }
5150                         return;
5151                 }
5152
5153                 case STATEMENT_COMPOUND:
5154                         if (stmt->compound.statements != NULL)
5155                                 return;
5156                         goto warn_unreachable;
5157
5158                 case STATEMENT_DECLARATION: {
5159                         /* Only warn if there is at least one declarator with an initializer.
5160                          * This typically occurs in switch statements. */
5161                         declaration_statement_t const *const decl = &stmt->declaration;
5162                         entity_t                const *      ent  = decl->declarations_begin;
5163                         entity_t                const *const last = decl->declarations_end;
5164                         if (ent != NULL) {
5165                                 for (;; ent = ent->base.next) {
5166                                         if (ent->kind                 == ENTITY_VARIABLE &&
5167                                                         ent->variable.initializer != NULL) {
5168                                                 goto warn_unreachable;
5169                                         }
5170                                         if (ent == last)
5171                                                 return;
5172                                 }
5173                         }
5174                 }
5175
5176                 default:
5177 warn_unreachable:
5178                         if (!stmt->base.reachable) {
5179                                 source_position_t const *const pos = &stmt->base.source_position;
5180                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5181                         }
5182                         return;
5183         }
5184 }
5185
5186 static bool is_main(entity_t *entity)
5187 {
5188         static symbol_t *sym_main = NULL;
5189         if (sym_main == NULL) {
5190                 sym_main = symbol_table_insert("main");
5191         }
5192
5193         if (entity->base.symbol != sym_main)
5194                 return false;
5195         /* must be in outermost scope */
5196         if (entity->base.parent_scope != file_scope)
5197                 return false;
5198
5199         return true;
5200 }
5201
5202 static void prepare_main_collect2(entity_t*);
5203
5204 static void parse_external_declaration(void)
5205 {
5206         /* function-definitions and declarations both start with declaration
5207          * specifiers */
5208         add_anchor_token(';');
5209         declaration_specifiers_t specifiers;
5210         parse_declaration_specifiers(&specifiers);
5211         rem_anchor_token(';');
5212
5213         /* must be a declaration */
5214         if (token.kind == ';') {
5215                 parse_anonymous_declaration_rest(&specifiers);
5216                 return;
5217         }
5218
5219         add_anchor_token(',');
5220         add_anchor_token('=');
5221         add_anchor_token(';');
5222         add_anchor_token('{');
5223
5224         /* declarator is common to both function-definitions and declarations */
5225         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5226
5227         rem_anchor_token('{');
5228         rem_anchor_token(';');
5229         rem_anchor_token('=');
5230         rem_anchor_token(',');
5231
5232         /* must be a declaration */
5233         switch (token.kind) {
5234                 case ',':
5235                 case ';':
5236                 case '=':
5237                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5238                                         DECL_FLAGS_NONE);
5239                         return;
5240         }
5241
5242         /* must be a function definition */
5243         parse_kr_declaration_list(ndeclaration);
5244
5245         if (token.kind != '{') {
5246                 parse_error_expected("while parsing function definition", '{', NULL);
5247                 eat_until_matching_token(';');
5248                 return;
5249         }
5250
5251         assert(is_declaration(ndeclaration));
5252         type_t *const orig_type = ndeclaration->declaration.type;
5253         type_t *      type      = skip_typeref(orig_type);
5254
5255         if (!is_type_function(type)) {
5256                 if (is_type_valid(type)) {
5257                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5258                 }
5259                 eat_block();
5260                 return;
5261         }
5262
5263         source_position_t const *const pos = &ndeclaration->base.source_position;
5264         if (is_typeref(orig_type)) {
5265                 /* §6.9.1:2 */
5266                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5267         }
5268
5269         if (is_type_compound(skip_typeref(type->function.return_type))) {
5270                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5271         }
5272         if (type->function.unspecified_parameters) {
5273                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5274         } else {
5275                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5276         }
5277
5278         /* §6.7.5.3:14 a function definition with () means no
5279          * parameters (and not unspecified parameters) */
5280         if (type->function.unspecified_parameters &&
5281                         type->function.parameters == NULL) {
5282                 type_t *copy                          = duplicate_type(type);
5283                 copy->function.unspecified_parameters = false;
5284                 type                                  = identify_new_type(copy);
5285
5286                 ndeclaration->declaration.type = type;
5287         }
5288
5289         entity_t *const entity = record_entity(ndeclaration, true);
5290         assert(entity->kind == ENTITY_FUNCTION);
5291         assert(ndeclaration->kind == ENTITY_FUNCTION);
5292
5293         function_t *const function = &entity->function;
5294         if (ndeclaration != entity) {
5295                 function->parameters = ndeclaration->function.parameters;
5296         }
5297
5298         PUSH_SCOPE(&function->parameters);
5299
5300         entity_t *parameter = function->parameters.entities;
5301         for (; parameter != NULL; parameter = parameter->base.next) {
5302                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5303                         parameter->base.parent_scope = current_scope;
5304                 }
5305                 assert(parameter->base.parent_scope == NULL
5306                                 || parameter->base.parent_scope == current_scope);
5307                 parameter->base.parent_scope = current_scope;
5308                 if (parameter->base.symbol == NULL) {
5309                         errorf(&parameter->base.source_position, "parameter name omitted");
5310                         continue;
5311                 }
5312                 environment_push(parameter);
5313         }
5314
5315         if (function->statement != NULL) {
5316                 parser_error_multiple_definition(entity, HERE);
5317                 eat_block();
5318         } else {
5319                 /* parse function body */
5320                 int         label_stack_top      = label_top();
5321                 function_t *old_current_function = current_function;
5322                 current_function                 = function;
5323                 PUSH_CURRENT_ENTITY(entity);
5324                 PUSH_PARENT(NULL);
5325
5326                 goto_first   = NULL;
5327                 goto_anchor  = &goto_first;
5328                 label_first  = NULL;
5329                 label_anchor = &label_first;
5330
5331                 statement_t *const body = parse_compound_statement(false);
5332                 function->statement = body;
5333                 first_err = true;
5334                 check_labels();
5335                 check_declarations();
5336                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5337                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5338                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5339                         noreturn_candidate = true;
5340                         check_reachable(body);
5341                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5342                                 walk_statements(body, check_unreachable, NULL);
5343                         if (noreturn_candidate &&
5344                             !(function->base.modifiers & DM_NORETURN)) {
5345                                 source_position_t const *const pos = &body->base.source_position;
5346                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5347                         }
5348                 }
5349
5350                 if (is_main(entity)) {
5351                         /* Force main to C linkage. */
5352                         type_t *const type = entity->declaration.type;
5353                         assert(is_type_function(type));
5354                         if (type->function.linkage != LINKAGE_C) {
5355                                 type_t *new_type           = duplicate_type(type);
5356                                 new_type->function.linkage = LINKAGE_C;
5357                                 entity->declaration.type   = identify_new_type(new_type);
5358                         }
5359
5360                         if (enable_main_collect2_hack)
5361                                 prepare_main_collect2(entity);
5362                 }
5363
5364                 POP_CURRENT_ENTITY();
5365                 POP_PARENT();
5366                 assert(current_function == function);
5367                 current_function = old_current_function;
5368                 label_pop_to(label_stack_top);
5369         }
5370
5371         POP_SCOPE();
5372 }
5373
5374 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5375 {
5376         entity_t *iter = compound->members.entities;
5377         for (; iter != NULL; iter = iter->base.next) {
5378                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5379                         continue;
5380
5381                 if (iter->base.symbol == symbol) {
5382                         return iter;
5383                 } else if (iter->base.symbol == NULL) {
5384                         /* search in anonymous structs and unions */
5385                         type_t *type = skip_typeref(iter->declaration.type);
5386                         if (is_type_compound(type)) {
5387                                 if (find_compound_entry(type->compound.compound, symbol)
5388                                                 != NULL)
5389                                         return iter;
5390                         }
5391                         continue;
5392                 }
5393         }
5394
5395         return NULL;
5396 }
5397
5398 static void check_deprecated(const source_position_t *source_position,
5399                              const entity_t *entity)
5400 {
5401         if (!is_declaration(entity))
5402                 return;
5403         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5404                 return;
5405
5406         source_position_t const *const epos = &entity->base.source_position;
5407         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5408         if (msg != NULL) {
5409                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5410         } else {
5411                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5412         }
5413 }
5414
5415
5416 static expression_t *create_select(const source_position_t *pos,
5417                                    expression_t *addr,
5418                                    type_qualifiers_t qualifiers,
5419                                                                    entity_t *entry)
5420 {
5421         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5422
5423         check_deprecated(pos, entry);
5424
5425         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5426         select->select.compound       = addr;
5427         select->select.compound_entry = entry;
5428
5429         type_t *entry_type = entry->declaration.type;
5430         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5431
5432         /* bitfields need special treatment */
5433         if (entry->compound_member.bitfield) {
5434                 unsigned bit_size = entry->compound_member.bit_size;
5435                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5436                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5437                         res_type = type_int;
5438                 }
5439         }
5440
5441         /* we always do the auto-type conversions; the & and sizeof parser contains
5442          * code to revert this! */
5443         select->base.type = automatic_type_conversion(res_type);
5444
5445
5446         return select;
5447 }
5448
5449 /**
5450  * Find entry with symbol in compound. Search anonymous structs and unions and
5451  * creates implicit select expressions for them.
5452  * Returns the adress for the innermost compound.
5453  */
5454 static expression_t *find_create_select(const source_position_t *pos,
5455                                         expression_t *addr,
5456                                         type_qualifiers_t qualifiers,
5457                                         compound_t *compound, symbol_t *symbol)
5458 {
5459         entity_t *iter = compound->members.entities;
5460         for (; iter != NULL; iter = iter->base.next) {
5461                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5462                         continue;
5463
5464                 symbol_t *iter_symbol = iter->base.symbol;
5465                 if (iter_symbol == NULL) {
5466                         type_t *type = iter->declaration.type;
5467                         if (!is_type_compound(type))
5468                                 continue;
5469
5470                         compound_t *sub_compound = type->compound.compound;
5471
5472                         if (find_compound_entry(sub_compound, symbol) == NULL)
5473                                 continue;
5474
5475                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5476                         sub_addr->base.source_position = *pos;
5477                         sub_addr->base.implicit        = true;
5478                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5479                                                   symbol);
5480                 }
5481
5482                 if (iter_symbol == symbol) {
5483                         return create_select(pos, addr, qualifiers, iter);
5484                 }
5485         }
5486
5487         return NULL;
5488 }
5489
5490 static void parse_bitfield_member(entity_t *entity)
5491 {
5492         eat(':');
5493
5494         expression_t *size = parse_constant_expression();
5495         long          size_long;
5496
5497         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5498         type_t *type = entity->declaration.type;
5499         if (!is_type_integer(skip_typeref(type))) {
5500                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5501                            type);
5502         }
5503
5504         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5505                 /* error already reported by parse_constant_expression */
5506                 size_long = get_type_size(type) * 8;
5507         } else {
5508                 size_long = fold_constant_to_int(size);
5509
5510                 const symbol_t *symbol = entity->base.symbol;
5511                 const symbol_t *user_symbol
5512                         = symbol == NULL ? sym_anonymous : symbol;
5513                 unsigned bit_size = get_type_size(type) * 8;
5514                 if (size_long < 0) {
5515                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5516                 } else if (size_long == 0 && symbol != NULL) {
5517                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5518                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5519                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5520                                    user_symbol);
5521                 } else {
5522                         /* hope that people don't invent crazy types with more bits
5523                          * than our struct can hold */
5524                         assert(size_long <
5525                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5526                 }
5527         }
5528
5529         entity->compound_member.bitfield = true;
5530         entity->compound_member.bit_size = (unsigned char)size_long;
5531 }
5532
5533 static void parse_compound_declarators(compound_t *compound,
5534                 const declaration_specifiers_t *specifiers)
5535 {
5536         add_anchor_token(';');
5537         add_anchor_token(',');
5538         do {
5539                 entity_t *entity;
5540
5541                 if (token.kind == ':') {
5542                         /* anonymous bitfield */
5543                         type_t *type = specifiers->type;
5544                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5545                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5546                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5547                         entity->declaration.type                   = type;
5548
5549                         parse_bitfield_member(entity);
5550
5551                         attribute_t  *attributes = parse_attributes(NULL);
5552                         attribute_t **anchor     = &attributes;
5553                         while (*anchor != NULL)
5554                                 anchor = &(*anchor)->next;
5555                         *anchor = specifiers->attributes;
5556                         if (attributes != NULL) {
5557                                 handle_entity_attributes(attributes, entity);
5558                         }
5559                         entity->declaration.attributes = attributes;
5560
5561                         append_entity(&compound->members, entity);
5562                 } else {
5563                         entity = parse_declarator(specifiers,
5564                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5565                         source_position_t const *const pos = &entity->base.source_position;
5566                         if (entity->kind == ENTITY_TYPEDEF) {
5567                                 errorf(pos, "typedef not allowed as compound member");
5568                         } else {
5569                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5570
5571                                 /* make sure we don't define a symbol multiple times */
5572                                 symbol_t *symbol = entity->base.symbol;
5573                                 if (symbol != NULL) {
5574                                         entity_t *prev = find_compound_entry(compound, symbol);
5575                                         if (prev != NULL) {
5576                                                 source_position_t const *const ppos = &prev->base.source_position;
5577                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5578                                         }
5579                                 }
5580
5581                                 if (token.kind == ':') {
5582                                         parse_bitfield_member(entity);
5583
5584                                         attribute_t *attributes = parse_attributes(NULL);
5585                                         handle_entity_attributes(attributes, entity);
5586                                 } else {
5587                                         type_t *orig_type = entity->declaration.type;
5588                                         type_t *type      = skip_typeref(orig_type);
5589                                         if (is_type_function(type)) {
5590                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5591                                         } else if (is_type_incomplete(type)) {
5592                                                 /* §6.7.2.1:16 flexible array member */
5593                                                 if (!is_type_array(type)       ||
5594                                                                 token.kind          != ';' ||
5595                                                                 look_ahead(1)->kind != '}') {
5596                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5597                                                 } else if (compound->members.entities == NULL) {
5598                                                         errorf(pos, "flexible array member in otherwise empty struct");
5599                                                 }
5600                                         }
5601                                 }
5602
5603                                 append_entity(&compound->members, entity);
5604                         }
5605                 }
5606         } while (next_if(','));
5607         rem_anchor_token(',');
5608         rem_anchor_token(';');
5609         expect(';');
5610
5611         anonymous_entity = NULL;
5612 }
5613
5614 static void parse_compound_type_entries(compound_t *compound)
5615 {
5616         eat('{');
5617         add_anchor_token('}');
5618
5619         for (;;) {
5620                 switch (token.kind) {
5621                         DECLARATION_START
5622                         case T___extension__:
5623                         case T_IDENTIFIER: {
5624                                 PUSH_EXTENSION();
5625                                 declaration_specifiers_t specifiers;
5626                                 parse_declaration_specifiers(&specifiers);
5627                                 parse_compound_declarators(compound, &specifiers);
5628                                 POP_EXTENSION();
5629                                 break;
5630                         }
5631
5632                         default:
5633                                 rem_anchor_token('}');
5634                                 expect('}');
5635                                 /* §6.7.2.1:7 */
5636                                 compound->complete = true;
5637                                 return;
5638                 }
5639         }
5640 }
5641
5642 static type_t *parse_typename(void)
5643 {
5644         declaration_specifiers_t specifiers;
5645         parse_declaration_specifiers(&specifiers);
5646         if (specifiers.storage_class != STORAGE_CLASS_NONE
5647                         || specifiers.thread_local) {
5648                 /* TODO: improve error message, user does probably not know what a
5649                  * storage class is...
5650                  */
5651                 errorf(&specifiers.source_position, "typename must not have a storage class");
5652         }
5653
5654         type_t *result = parse_abstract_declarator(specifiers.type);
5655
5656         return result;
5657 }
5658
5659
5660
5661
5662 typedef expression_t* (*parse_expression_function)(void);
5663 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5664
5665 typedef struct expression_parser_function_t expression_parser_function_t;
5666 struct expression_parser_function_t {
5667         parse_expression_function        parser;
5668         precedence_t                     infix_precedence;
5669         parse_expression_infix_function  infix_parser;
5670 };
5671
5672 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5673
5674 static type_t *get_string_type(string_encoding_t const enc)
5675 {
5676         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5677         switch (enc) {
5678         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5679         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5680         }
5681         panic("invalid string encoding");
5682 }
5683
5684 /**
5685  * Parse a string constant.
5686  */
5687 static expression_t *parse_string_literal(void)
5688 {
5689         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5690         expr->string_literal.value = concat_string_literals(&expr->string_literal.encoding);
5691         expr->base.type            = get_string_type(expr->string_literal.encoding);
5692         return expr;
5693 }
5694
5695 /**
5696  * Parse a boolean constant.
5697  */
5698 static expression_t *parse_boolean_literal(bool value)
5699 {
5700         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5701         literal->base.type           = type_bool;
5702         literal->literal.value.begin = value ? "true" : "false";
5703         literal->literal.value.size  = value ? 4 : 5;
5704
5705         eat(value ? T_true : T_false);
5706         return literal;
5707 }
5708
5709 static void warn_traditional_suffix(void)
5710 {
5711         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5712                  &token.number.suffix);
5713 }
5714
5715 static void check_integer_suffix(void)
5716 {
5717         const string_t *suffix = &token.number.suffix;
5718         if (suffix->size == 0)
5719                 return;
5720
5721         bool not_traditional = false;
5722         const char *c = suffix->begin;
5723         if (*c == 'l' || *c == 'L') {
5724                 ++c;
5725                 if (*c == *(c-1)) {
5726                         not_traditional = true;
5727                         ++c;
5728                         if (*c == 'u' || *c == 'U') {
5729                                 ++c;
5730                         }
5731                 } else if (*c == 'u' || *c == 'U') {
5732                         not_traditional = true;
5733                         ++c;
5734                 }
5735         } else if (*c == 'u' || *c == 'U') {
5736                 not_traditional = true;
5737                 ++c;
5738                 if (*c == 'l' || *c == 'L') {
5739                         ++c;
5740                         if (*c == *(c-1)) {
5741                                 ++c;
5742                         }
5743                 }
5744         }
5745         if (*c != '\0') {
5746                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5747         } else if (not_traditional) {
5748                 warn_traditional_suffix();
5749         }
5750 }
5751
5752 static type_t *check_floatingpoint_suffix(void)
5753 {
5754         const string_t *suffix = &token.number.suffix;
5755         type_t         *type   = type_double;
5756         if (suffix->size == 0)
5757                 return type;
5758
5759         bool not_traditional = false;
5760         const char *c = suffix->begin;
5761         if (*c == 'f' || *c == 'F') {
5762                 ++c;
5763                 type = type_float;
5764         } else if (*c == 'l' || *c == 'L') {
5765                 ++c;
5766                 type = type_long_double;
5767         }
5768         if (*c != '\0') {
5769                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5770         } else if (not_traditional) {
5771                 warn_traditional_suffix();
5772         }
5773
5774         return type;
5775 }
5776
5777 /**
5778  * Parse an integer constant.
5779  */
5780 static expression_t *parse_number_literal(void)
5781 {
5782         expression_kind_t  kind;
5783         type_t            *type;
5784
5785         switch (token.kind) {
5786         case T_INTEGER:
5787                 kind = EXPR_LITERAL_INTEGER;
5788                 check_integer_suffix();
5789                 type = type_int;
5790                 break;
5791
5792         case T_FLOATINGPOINT:
5793                 kind = EXPR_LITERAL_FLOATINGPOINT;
5794                 type = check_floatingpoint_suffix();
5795                 break;
5796
5797         default:
5798                 panic("unexpected token type in parse_number_literal");
5799         }
5800
5801         expression_t *literal = allocate_expression_zero(kind);
5802         literal->base.type      = type;
5803         literal->literal.value  = token.number.number;
5804         literal->literal.suffix = token.number.suffix;
5805         next_token();
5806
5807         /* integer type depends on the size of the number and the size
5808          * representable by the types. The backend/codegeneration has to determine
5809          * that
5810          */
5811         determine_literal_type(&literal->literal);
5812         return literal;
5813 }
5814
5815 /**
5816  * Parse a character constant.
5817  */
5818 static expression_t *parse_character_constant(void)
5819 {
5820         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5821         literal->string_literal.encoding = token.string.encoding;
5822         literal->string_literal.value    = token.string.string;
5823
5824         size_t const size = get_string_len(token.string.encoding, &token.string.string);
5825         switch (token.string.encoding) {
5826         case STRING_ENCODING_CHAR:
5827                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5828                 if (size > 1) {
5829                         if (!GNU_MODE && !(c_mode & _C99)) {
5830                                 errorf(HERE, "more than 1 character in character constant");
5831                         } else {
5832                                 literal->base.type = type_int;
5833                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5834                         }
5835                 }
5836                 break;
5837
5838         case STRING_ENCODING_WIDE:
5839                 literal->base.type = type_int;
5840                 if (size > 1) {
5841                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5842                 }
5843                 break;
5844         }
5845
5846         eat(T_CHARACTER_CONSTANT);
5847         return literal;
5848 }
5849
5850 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5851 {
5852         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5853         ntype->function.return_type            = type_int;
5854         ntype->function.unspecified_parameters = true;
5855         ntype->function.linkage                = LINKAGE_C;
5856         type_t *type                           = identify_new_type(ntype);
5857
5858         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5859         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5860         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5861         entity->declaration.type                   = type;
5862         entity->declaration.implicit               = true;
5863
5864         if (current_scope != NULL)
5865                 record_entity(entity, false);
5866
5867         return entity;
5868 }
5869
5870 /**
5871  * Performs automatic type cast as described in §6.3.2.1.
5872  *
5873  * @param orig_type  the original type
5874  */
5875 static type_t *automatic_type_conversion(type_t *orig_type)
5876 {
5877         type_t *type = skip_typeref(orig_type);
5878         if (is_type_array(type)) {
5879                 array_type_t *array_type   = &type->array;
5880                 type_t       *element_type = array_type->element_type;
5881                 unsigned      qualifiers   = array_type->base.qualifiers;
5882
5883                 return make_pointer_type(element_type, qualifiers);
5884         }
5885
5886         if (is_type_function(type)) {
5887                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5888         }
5889
5890         return orig_type;
5891 }
5892
5893 /**
5894  * reverts the automatic casts of array to pointer types and function
5895  * to function-pointer types as defined §6.3.2.1
5896  */
5897 type_t *revert_automatic_type_conversion(const expression_t *expression)
5898 {
5899         switch (expression->kind) {
5900         case EXPR_REFERENCE: {
5901                 entity_t *entity = expression->reference.entity;
5902                 if (is_declaration(entity)) {
5903                         return entity->declaration.type;
5904                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5905                         return entity->enum_value.enum_type;
5906                 } else {
5907                         panic("no declaration or enum in reference");
5908                 }
5909         }
5910
5911         case EXPR_SELECT: {
5912                 entity_t *entity = expression->select.compound_entry;
5913                 assert(is_declaration(entity));
5914                 type_t   *type   = entity->declaration.type;
5915                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5916         }
5917
5918         case EXPR_UNARY_DEREFERENCE: {
5919                 const expression_t *const value = expression->unary.value;
5920                 type_t             *const type  = skip_typeref(value->base.type);
5921                 if (!is_type_pointer(type))
5922                         return type_error_type;
5923                 return type->pointer.points_to;
5924         }
5925
5926         case EXPR_ARRAY_ACCESS: {
5927                 const expression_t *array_ref = expression->array_access.array_ref;
5928                 type_t             *type_left = skip_typeref(array_ref->base.type);
5929                 if (!is_type_pointer(type_left))
5930                         return type_error_type;
5931                 return type_left->pointer.points_to;
5932         }
5933
5934         case EXPR_STRING_LITERAL: {
5935                 size_t  const size = get_string_len(expression->string_literal.encoding, &expression->string_literal.value) + 1;
5936                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5937                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5938         }
5939
5940         case EXPR_COMPOUND_LITERAL:
5941                 return expression->compound_literal.type;
5942
5943         default:
5944                 break;
5945         }
5946         return expression->base.type;
5947 }
5948
5949 /**
5950  * Find an entity matching a symbol in a scope.
5951  * Uses current scope if scope is NULL
5952  */
5953 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5954                                namespace_tag_t namespc)
5955 {
5956         if (scope == NULL) {
5957                 return get_entity(symbol, namespc);
5958         }
5959
5960         /* we should optimize here, if scope grows above a certain size we should
5961            construct a hashmap here... */
5962         entity_t *entity = scope->entities;
5963         for ( ; entity != NULL; entity = entity->base.next) {
5964                 if (entity->base.symbol == symbol
5965                     && (namespace_tag_t)entity->base.namespc == namespc)
5966                         break;
5967         }
5968
5969         return entity;
5970 }
5971
5972 static entity_t *parse_qualified_identifier(void)
5973 {
5974         /* namespace containing the symbol */
5975         symbol_t          *symbol;
5976         source_position_t  pos;
5977         const scope_t     *lookup_scope = NULL;
5978
5979         if (next_if(T_COLONCOLON))
5980                 lookup_scope = &unit->scope;
5981
5982         entity_t *entity;
5983         while (true) {
5984                 symbol = expect_identifier("while parsing identifier", &pos);
5985                 if (!symbol)
5986                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
5987
5988                 /* lookup entity */
5989                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
5990
5991                 if (!next_if(T_COLONCOLON))
5992                         break;
5993
5994                 switch (entity->kind) {
5995                 case ENTITY_NAMESPACE:
5996                         lookup_scope = &entity->namespacee.members;
5997                         break;
5998                 case ENTITY_STRUCT:
5999                 case ENTITY_UNION:
6000                 case ENTITY_CLASS:
6001                         lookup_scope = &entity->compound.members;
6002                         break;
6003                 default:
6004                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6005                                symbol, get_entity_kind_name(entity->kind));
6006
6007                         /* skip further qualifications */
6008                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6009
6010                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6011                 }
6012         }
6013
6014         if (entity == NULL) {
6015                 if (!strict_mode && token.kind == '(') {
6016                         /* an implicitly declared function */
6017                         entity = create_implicit_function(symbol, &pos);
6018                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6019                 } else {
6020                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6021                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6022                 }
6023         }
6024
6025         return entity;
6026 }
6027
6028 static expression_t *parse_reference(void)
6029 {
6030         source_position_t const pos    = *HERE;
6031         entity_t         *const entity = parse_qualified_identifier();
6032
6033         type_t *orig_type;
6034         if (is_declaration(entity)) {
6035                 orig_type = entity->declaration.type;
6036         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6037                 orig_type = entity->enum_value.enum_type;
6038         } else {
6039                 panic("expected declaration or enum value in reference");
6040         }
6041
6042         /* we always do the auto-type conversions; the & and sizeof parser contains
6043          * code to revert this! */
6044         type_t *type = automatic_type_conversion(orig_type);
6045
6046         expression_kind_t kind = EXPR_REFERENCE;
6047         if (entity->kind == ENTITY_ENUM_VALUE)
6048                 kind = EXPR_ENUM_CONSTANT;
6049
6050         expression_t *expression         = allocate_expression_zero(kind);
6051         expression->base.source_position = pos;
6052         expression->base.type            = type;
6053         expression->reference.entity     = entity;
6054
6055         /* this declaration is used */
6056         if (is_declaration(entity)) {
6057                 entity->declaration.used = true;
6058         }
6059
6060         if (entity->base.parent_scope != file_scope
6061                 && (current_function != NULL
6062                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6063                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6064                 /* access of a variable from an outer function */
6065                 entity->variable.address_taken = true;
6066                 current_function->need_closure = true;
6067         }
6068
6069         check_deprecated(&pos, entity);
6070
6071         return expression;
6072 }
6073
6074 static bool semantic_cast(expression_t *cast)
6075 {
6076         expression_t            *expression      = cast->unary.value;
6077         type_t                  *orig_dest_type  = cast->base.type;
6078         type_t                  *orig_type_right = expression->base.type;
6079         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6080         type_t            const *src_type        = skip_typeref(orig_type_right);
6081         source_position_t const *pos             = &cast->base.source_position;
6082
6083         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6084         if (is_type_void(dst_type))
6085                 return true;
6086
6087         /* only integer and pointer can be casted to pointer */
6088         if (is_type_pointer(dst_type)  &&
6089             !is_type_pointer(src_type) &&
6090             !is_type_integer(src_type) &&
6091             is_type_valid(src_type)) {
6092                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6093                 return false;
6094         }
6095
6096         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6097                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6098                 return false;
6099         }
6100
6101         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6102                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6103                 return false;
6104         }
6105
6106         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6107                 type_t *src = skip_typeref(src_type->pointer.points_to);
6108                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6109                 unsigned missing_qualifiers =
6110                         src->base.qualifiers & ~dst->base.qualifiers;
6111                 if (missing_qualifiers != 0) {
6112                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6113                 }
6114         }
6115         return true;
6116 }
6117
6118 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6119 {
6120         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6121         expression->base.source_position = *pos;
6122
6123         parse_initializer_env_t env;
6124         env.type             = type;
6125         env.entity           = NULL;
6126         env.must_be_constant = false;
6127         initializer_t *initializer = parse_initializer(&env);
6128         type = env.type;
6129
6130         expression->compound_literal.initializer = initializer;
6131         expression->compound_literal.type        = type;
6132         expression->base.type                    = automatic_type_conversion(type);
6133
6134         return expression;
6135 }
6136
6137 /**
6138  * Parse a cast expression.
6139  */
6140 static expression_t *parse_cast(void)
6141 {
6142         source_position_t const pos = *HERE;
6143
6144         eat('(');
6145         add_anchor_token(')');
6146
6147         type_t *type = parse_typename();
6148
6149         rem_anchor_token(')');
6150         expect(')');
6151
6152         if (token.kind == '{') {
6153                 return parse_compound_literal(&pos, type);
6154         }
6155
6156         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6157         cast->base.source_position = pos;
6158
6159         expression_t *value = parse_subexpression(PREC_CAST);
6160         cast->base.type   = type;
6161         cast->unary.value = value;
6162
6163         if (! semantic_cast(cast)) {
6164                 /* TODO: record the error in the AST. else it is impossible to detect it */
6165         }
6166
6167         return cast;
6168 }
6169
6170 /**
6171  * Parse a statement expression.
6172  */
6173 static expression_t *parse_statement_expression(void)
6174 {
6175         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6176
6177         eat('(');
6178         add_anchor_token(')');
6179
6180         statement_t *statement          = parse_compound_statement(true);
6181         statement->compound.stmt_expr   = true;
6182         expression->statement.statement = statement;
6183
6184         /* find last statement and use its type */
6185         type_t *type = type_void;
6186         const statement_t *stmt = statement->compound.statements;
6187         if (stmt != NULL) {
6188                 while (stmt->base.next != NULL)
6189                         stmt = stmt->base.next;
6190
6191                 if (stmt->kind == STATEMENT_EXPRESSION) {
6192                         type = stmt->expression.expression->base.type;
6193                 }
6194         } else {
6195                 source_position_t const *const pos = &expression->base.source_position;
6196                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6197         }
6198         expression->base.type = type;
6199
6200         rem_anchor_token(')');
6201         expect(')');
6202         return expression;
6203 }
6204
6205 /**
6206  * Parse a parenthesized expression.
6207  */
6208 static expression_t *parse_parenthesized_expression(void)
6209 {
6210         token_t const* const la1 = look_ahead(1);
6211         switch (la1->kind) {
6212         case '{':
6213                 /* gcc extension: a statement expression */
6214                 return parse_statement_expression();
6215
6216         case T_IDENTIFIER:
6217                 if (is_typedef_symbol(la1->base.symbol)) {
6218         DECLARATION_START
6219                         return parse_cast();
6220                 }
6221         }
6222
6223         eat('(');
6224         add_anchor_token(')');
6225         expression_t *result = parse_expression();
6226         result->base.parenthesized = true;
6227         rem_anchor_token(')');
6228         expect(')');
6229
6230         return result;
6231 }
6232
6233 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6234 {
6235         if (current_function == NULL) {
6236                 errorf(HERE, "'%K' used outside of a function", &token);
6237         }
6238
6239         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6240         expression->base.type     = type_char_ptr;
6241         expression->funcname.kind = kind;
6242
6243         next_token();
6244
6245         return expression;
6246 }
6247
6248 static designator_t *parse_designator(void)
6249 {
6250         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6251         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6252         if (!result->symbol)
6253                 return NULL;
6254
6255         designator_t *last_designator = result;
6256         while (true) {
6257                 if (next_if('.')) {
6258                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6259                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6260                         if (!designator->symbol)
6261                                 return NULL;
6262
6263                         last_designator->next = designator;
6264                         last_designator       = designator;
6265                         continue;
6266                 }
6267                 if (next_if('[')) {
6268                         add_anchor_token(']');
6269                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6270                         designator->source_position = *HERE;
6271                         designator->array_index     = parse_expression();
6272                         rem_anchor_token(']');
6273                         expect(']');
6274                         if (designator->array_index == NULL) {
6275                                 return NULL;
6276                         }
6277
6278                         last_designator->next = designator;
6279                         last_designator       = designator;
6280                         continue;
6281                 }
6282                 break;
6283         }
6284
6285         return result;
6286 }
6287
6288 /**
6289  * Parse the __builtin_offsetof() expression.
6290  */
6291 static expression_t *parse_offsetof(void)
6292 {
6293         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6294         expression->base.type    = type_size_t;
6295
6296         eat(T___builtin_offsetof);
6297
6298         add_anchor_token(')');
6299         add_anchor_token(',');
6300         expect('(');
6301         type_t *type = parse_typename();
6302         rem_anchor_token(',');
6303         expect(',');
6304         designator_t *designator = parse_designator();
6305         rem_anchor_token(')');
6306         expect(')');
6307
6308         expression->offsetofe.type       = type;
6309         expression->offsetofe.designator = designator;
6310
6311         type_path_t path;
6312         memset(&path, 0, sizeof(path));
6313         path.top_type = type;
6314         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6315
6316         descend_into_subtype(&path);
6317
6318         if (!walk_designator(&path, designator, true)) {
6319                 return create_error_expression();
6320         }
6321
6322         DEL_ARR_F(path.path);
6323
6324         return expression;
6325 }
6326
6327 static bool is_last_parameter(expression_t *const param)
6328 {
6329         if (param->kind == EXPR_REFERENCE) {
6330                 entity_t *const entity = param->reference.entity;
6331                 if (entity->kind == ENTITY_PARAMETER &&
6332                     !entity->base.next               &&
6333                     entity->base.parent_scope == &current_function->parameters) {
6334                         return true;
6335                 }
6336         }
6337
6338         if (!is_type_valid(skip_typeref(param->base.type)))
6339                 return true;
6340
6341         return false;
6342 }
6343
6344 /**
6345  * Parses a __builtin_va_start() expression.
6346  */
6347 static expression_t *parse_va_start(void)
6348 {
6349         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6350
6351         eat(T___builtin_va_start);
6352
6353         add_anchor_token(')');
6354         add_anchor_token(',');
6355         expect('(');
6356         expression->va_starte.ap = parse_assignment_expression();
6357         rem_anchor_token(',');
6358         expect(',');
6359         expression_t *const param = parse_assignment_expression();
6360         expression->va_starte.parameter = param;
6361         rem_anchor_token(')');
6362         expect(')');
6363
6364         if (!current_function) {
6365                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6366         } else if (!current_function->base.type->function.variadic) {
6367                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6368         } else if (!is_last_parameter(param)) {
6369                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6370         }
6371
6372         return expression;
6373 }
6374
6375 /**
6376  * Parses a __builtin_va_arg() expression.
6377  */
6378 static expression_t *parse_va_arg(void)
6379 {
6380         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6381
6382         eat(T___builtin_va_arg);
6383
6384         add_anchor_token(')');
6385         add_anchor_token(',');
6386         expect('(');
6387         call_argument_t ap;
6388         ap.expression = parse_assignment_expression();
6389         expression->va_arge.ap = ap.expression;
6390         check_call_argument(type_valist, &ap, 1);
6391
6392         rem_anchor_token(',');
6393         expect(',');
6394         expression->base.type = parse_typename();
6395         rem_anchor_token(')');
6396         expect(')');
6397
6398         return expression;
6399 }
6400
6401 /**
6402  * Parses a __builtin_va_copy() expression.
6403  */
6404 static expression_t *parse_va_copy(void)
6405 {
6406         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6407
6408         eat(T___builtin_va_copy);
6409
6410         add_anchor_token(')');
6411         add_anchor_token(',');
6412         expect('(');
6413         expression_t *dst = parse_assignment_expression();
6414         assign_error_t error = semantic_assign(type_valist, dst);
6415         report_assign_error(error, type_valist, dst, "call argument 1",
6416                             &dst->base.source_position);
6417         expression->va_copye.dst = dst;
6418
6419         rem_anchor_token(',');
6420         expect(',');
6421
6422         call_argument_t src;
6423         src.expression = parse_assignment_expression();
6424         check_call_argument(type_valist, &src, 2);
6425         expression->va_copye.src = src.expression;
6426         rem_anchor_token(')');
6427         expect(')');
6428
6429         return expression;
6430 }
6431
6432 /**
6433  * Parses a __builtin_constant_p() expression.
6434  */
6435 static expression_t *parse_builtin_constant(void)
6436 {
6437         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6438
6439         eat(T___builtin_constant_p);
6440
6441         add_anchor_token(')');
6442         expect('(');
6443         expression->builtin_constant.value = parse_assignment_expression();
6444         rem_anchor_token(')');
6445         expect(')');
6446         expression->base.type = type_int;
6447
6448         return expression;
6449 }
6450
6451 /**
6452  * Parses a __builtin_types_compatible_p() expression.
6453  */
6454 static expression_t *parse_builtin_types_compatible(void)
6455 {
6456         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6457
6458         eat(T___builtin_types_compatible_p);
6459
6460         add_anchor_token(')');
6461         add_anchor_token(',');
6462         expect('(');
6463         expression->builtin_types_compatible.left = parse_typename();
6464         rem_anchor_token(',');
6465         expect(',');
6466         expression->builtin_types_compatible.right = parse_typename();
6467         rem_anchor_token(')');
6468         expect(')');
6469         expression->base.type = type_int;
6470
6471         return expression;
6472 }
6473
6474 /**
6475  * Parses a __builtin_is_*() compare expression.
6476  */
6477 static expression_t *parse_compare_builtin(void)
6478 {
6479         expression_kind_t kind;
6480         switch (token.kind) {
6481         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6482         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6483         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6484         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6485         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6486         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6487         default: internal_errorf(HERE, "invalid compare builtin found");
6488         }
6489         expression_t *const expression = allocate_expression_zero(kind);
6490         next_token();
6491
6492         add_anchor_token(')');
6493         add_anchor_token(',');
6494         expect('(');
6495         expression->binary.left = parse_assignment_expression();
6496         rem_anchor_token(',');
6497         expect(',');
6498         expression->binary.right = parse_assignment_expression();
6499         rem_anchor_token(')');
6500         expect(')');
6501
6502         type_t *const orig_type_left  = expression->binary.left->base.type;
6503         type_t *const orig_type_right = expression->binary.right->base.type;
6504
6505         type_t *const type_left  = skip_typeref(orig_type_left);
6506         type_t *const type_right = skip_typeref(orig_type_right);
6507         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6508                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6509                         type_error_incompatible("invalid operands in comparison",
6510                                 &expression->base.source_position, orig_type_left, orig_type_right);
6511                 }
6512         } else {
6513                 semantic_comparison(&expression->binary);
6514         }
6515
6516         return expression;
6517 }
6518
6519 /**
6520  * Parses a MS assume() expression.
6521  */
6522 static expression_t *parse_assume(void)
6523 {
6524         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6525
6526         eat(T__assume);
6527
6528         add_anchor_token(')');
6529         expect('(');
6530         expression->unary.value = parse_assignment_expression();
6531         rem_anchor_token(')');
6532         expect(')');
6533
6534         expression->base.type = type_void;
6535         return expression;
6536 }
6537
6538 /**
6539  * Return the label for the current symbol or create a new one.
6540  */
6541 static label_t *get_label(char const *const context)
6542 {
6543         assert(current_function != NULL);
6544
6545         symbol_t *const sym = expect_identifier(context, NULL);
6546         if (!sym)
6547                 return NULL;
6548
6549         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6550         /* If we find a local label, we already created the declaration. */
6551         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6552                 if (label->base.parent_scope != current_scope) {
6553                         assert(label->base.parent_scope->depth < current_scope->depth);
6554                         current_function->goto_to_outer = true;
6555                 }
6556         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6557                 /* There is no matching label in the same function, so create a new one. */
6558                 source_position_t const nowhere = { NULL, 0, 0, false };
6559                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6560                 label_push(label);
6561         }
6562
6563         return &label->label;
6564 }
6565
6566 /**
6567  * Parses a GNU && label address expression.
6568  */
6569 static expression_t *parse_label_address(void)
6570 {
6571         source_position_t const source_position = *HERE;
6572         eat(T_ANDAND);
6573
6574         label_t *const label = get_label("while parsing label address");
6575         if (!label)
6576                 return create_error_expression();
6577
6578         label->used          = true;
6579         label->address_taken = true;
6580
6581         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6582         expression->base.source_position = source_position;
6583
6584         /* label address is treated as a void pointer */
6585         expression->base.type           = type_void_ptr;
6586         expression->label_address.label = label;
6587         return expression;
6588 }
6589
6590 /**
6591  * Parse a microsoft __noop expression.
6592  */
6593 static expression_t *parse_noop_expression(void)
6594 {
6595         /* the result is a (int)0 */
6596         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6597         literal->base.type           = type_int;
6598         literal->literal.value.begin = "__noop";
6599         literal->literal.value.size  = 6;
6600
6601         eat(T___noop);
6602
6603         if (token.kind == '(') {
6604                 /* parse arguments */
6605                 eat('(');
6606                 add_anchor_token(')');
6607                 add_anchor_token(',');
6608
6609                 if (token.kind != ')') do {
6610                         (void)parse_assignment_expression();
6611                 } while (next_if(','));
6612
6613                 rem_anchor_token(',');
6614                 rem_anchor_token(')');
6615         }
6616         expect(')');
6617
6618         return literal;
6619 }
6620
6621 /**
6622  * Parses a primary expression.
6623  */
6624 static expression_t *parse_primary_expression(void)
6625 {
6626         switch (token.kind) {
6627         case T_false:                        return parse_boolean_literal(false);
6628         case T_true:                         return parse_boolean_literal(true);
6629         case T_INTEGER:
6630         case T_FLOATINGPOINT:                return parse_number_literal();
6631         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6632         case T_STRING_LITERAL:               return parse_string_literal();
6633         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6634         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6635         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6636         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6637         case T___builtin_offsetof:           return parse_offsetof();
6638         case T___builtin_va_start:           return parse_va_start();
6639         case T___builtin_va_arg:             return parse_va_arg();
6640         case T___builtin_va_copy:            return parse_va_copy();
6641         case T___builtin_isgreater:
6642         case T___builtin_isgreaterequal:
6643         case T___builtin_isless:
6644         case T___builtin_islessequal:
6645         case T___builtin_islessgreater:
6646         case T___builtin_isunordered:        return parse_compare_builtin();
6647         case T___builtin_constant_p:         return parse_builtin_constant();
6648         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6649         case T__assume:                      return parse_assume();
6650         case T_ANDAND:
6651                 if (GNU_MODE)
6652                         return parse_label_address();
6653                 break;
6654
6655         case '(':                            return parse_parenthesized_expression();
6656         case T___noop:                       return parse_noop_expression();
6657
6658         /* Gracefully handle type names while parsing expressions. */
6659         case T_COLONCOLON:
6660                 return parse_reference();
6661         case T_IDENTIFIER:
6662                 if (!is_typedef_symbol(token.base.symbol)) {
6663                         return parse_reference();
6664                 }
6665                 /* FALLTHROUGH */
6666         DECLARATION_START {
6667                 source_position_t const  pos = *HERE;
6668                 declaration_specifiers_t specifiers;
6669                 parse_declaration_specifiers(&specifiers);
6670                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6671                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6672                 return create_error_expression();
6673         }
6674         }
6675
6676         errorf(HERE, "unexpected token %K, expected an expression", &token);
6677         eat_until_anchor();
6678         return create_error_expression();
6679 }
6680
6681 static expression_t *parse_array_expression(expression_t *left)
6682 {
6683         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6684         array_access_expression_t *const arr  = &expr->array_access;
6685
6686         eat('[');
6687         add_anchor_token(']');
6688
6689         expression_t *const inside = parse_expression();
6690
6691         type_t *const orig_type_left   = left->base.type;
6692         type_t *const orig_type_inside = inside->base.type;
6693
6694         type_t *const type_left   = skip_typeref(orig_type_left);
6695         type_t *const type_inside = skip_typeref(orig_type_inside);
6696
6697         expression_t *ref;
6698         expression_t *idx;
6699         type_t       *idx_type;
6700         type_t       *res_type;
6701         if (is_type_pointer(type_left)) {
6702                 ref      = left;
6703                 idx      = inside;
6704                 idx_type = type_inside;
6705                 res_type = type_left->pointer.points_to;
6706                 goto check_idx;
6707         } else if (is_type_pointer(type_inside)) {
6708                 arr->flipped = true;
6709                 ref      = inside;
6710                 idx      = left;
6711                 idx_type = type_left;
6712                 res_type = type_inside->pointer.points_to;
6713 check_idx:
6714                 res_type = automatic_type_conversion(res_type);
6715                 if (!is_type_integer(idx_type)) {
6716                         errorf(&idx->base.source_position, "array subscript must have integer type");
6717                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6718                         source_position_t const *const pos = &idx->base.source_position;
6719                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6720                 }
6721         } else {
6722                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6723                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6724                 }
6725                 res_type = type_error_type;
6726                 ref      = left;
6727                 idx      = inside;
6728         }
6729
6730         arr->array_ref = ref;
6731         arr->index     = idx;
6732         arr->base.type = res_type;
6733
6734         rem_anchor_token(']');
6735         expect(']');
6736         return expr;
6737 }
6738
6739 static bool is_bitfield(const expression_t *expression)
6740 {
6741         return expression->kind == EXPR_SELECT
6742                 && expression->select.compound_entry->compound_member.bitfield;
6743 }
6744
6745 static expression_t *parse_typeprop(expression_kind_t const kind)
6746 {
6747         expression_t  *tp_expression = allocate_expression_zero(kind);
6748         tp_expression->base.type     = type_size_t;
6749
6750         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6751
6752         type_t       *orig_type;
6753         expression_t *expression;
6754         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6755                 source_position_t const pos = *HERE;
6756                 eat('(');
6757                 add_anchor_token(')');
6758                 orig_type = parse_typename();
6759                 rem_anchor_token(')');
6760                 expect(')');
6761
6762                 if (token.kind == '{') {
6763                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6764                          * starting with a compound literal */
6765                         expression = parse_compound_literal(&pos, orig_type);
6766                         goto typeprop_expression;
6767                 }
6768         } else {
6769                 expression = parse_subexpression(PREC_UNARY);
6770
6771 typeprop_expression:
6772                 if (is_bitfield(expression)) {
6773                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6774                         errorf(&tp_expression->base.source_position,
6775                                    "operand of %s expression must not be a bitfield", what);
6776                 }
6777
6778                 tp_expression->typeprop.tp_expression = expression;
6779
6780                 orig_type = revert_automatic_type_conversion(expression);
6781                 expression->base.type = orig_type;
6782         }
6783
6784         tp_expression->typeprop.type   = orig_type;
6785         type_t const* const type       = skip_typeref(orig_type);
6786         char   const*       wrong_type = NULL;
6787         if (is_type_incomplete(type)) {
6788                 if (!is_type_void(type) || !GNU_MODE)
6789                         wrong_type = "incomplete";
6790         } else if (type->kind == TYPE_FUNCTION) {
6791                 if (GNU_MODE) {
6792                         /* function types are allowed (and return 1) */
6793                         source_position_t const *const pos  = &tp_expression->base.source_position;
6794                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6795                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6796                 } else {
6797                         wrong_type = "function";
6798                 }
6799         }
6800
6801         if (wrong_type != NULL) {
6802                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6803                 errorf(&tp_expression->base.source_position,
6804                                 "operand of %s expression must not be of %s type '%T'",
6805                                 what, wrong_type, orig_type);
6806         }
6807
6808         return tp_expression;
6809 }
6810
6811 static expression_t *parse_sizeof(void)
6812 {
6813         return parse_typeprop(EXPR_SIZEOF);
6814 }
6815
6816 static expression_t *parse_alignof(void)
6817 {
6818         return parse_typeprop(EXPR_ALIGNOF);
6819 }
6820
6821 static expression_t *parse_select_expression(expression_t *addr)
6822 {
6823         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6824         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6825         source_position_t const pos = *HERE;
6826         next_token();
6827
6828         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6829         if (!symbol)
6830                 return create_error_expression();
6831
6832         type_t *const orig_type = addr->base.type;
6833         type_t *const type      = skip_typeref(orig_type);
6834
6835         type_t *type_left;
6836         bool    saw_error = false;
6837         if (is_type_pointer(type)) {
6838                 if (!select_left_arrow) {
6839                         errorf(&pos,
6840                                "request for member '%Y' in something not a struct or union, but '%T'",
6841                                symbol, orig_type);
6842                         saw_error = true;
6843                 }
6844                 type_left = skip_typeref(type->pointer.points_to);
6845         } else {
6846                 if (select_left_arrow && is_type_valid(type)) {
6847                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6848                         saw_error = true;
6849                 }
6850                 type_left = type;
6851         }
6852
6853         if (!is_type_compound(type_left)) {
6854                 if (is_type_valid(type_left) && !saw_error) {
6855                         errorf(&pos,
6856                                "request for member '%Y' in something not a struct or union, but '%T'",
6857                                symbol, type_left);
6858                 }
6859                 return create_error_expression();
6860         }
6861
6862         compound_t *compound = type_left->compound.compound;
6863         if (!compound->complete) {
6864                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6865                        symbol, type_left);
6866                 return create_error_expression();
6867         }
6868
6869         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6870         expression_t      *result     =
6871                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6872
6873         if (result == NULL) {
6874                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6875                 return create_error_expression();
6876         }
6877
6878         return result;
6879 }
6880
6881 static void check_call_argument(type_t          *expected_type,
6882                                 call_argument_t *argument, unsigned pos)
6883 {
6884         type_t         *expected_type_skip = skip_typeref(expected_type);
6885         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6886         expression_t   *arg_expr           = argument->expression;
6887         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6888
6889         /* handle transparent union gnu extension */
6890         if (is_type_union(expected_type_skip)
6891                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6892                 compound_t *union_decl  = expected_type_skip->compound.compound;
6893                 type_t     *best_type   = NULL;
6894                 entity_t   *entry       = union_decl->members.entities;
6895                 for ( ; entry != NULL; entry = entry->base.next) {
6896                         assert(is_declaration(entry));
6897                         type_t *decl_type = entry->declaration.type;
6898                         error = semantic_assign(decl_type, arg_expr);
6899                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6900                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6901                                 continue;
6902
6903                         if (error == ASSIGN_SUCCESS) {
6904                                 best_type = decl_type;
6905                         } else if (best_type == NULL) {
6906                                 best_type = decl_type;
6907                         }
6908                 }
6909
6910                 if (best_type != NULL) {
6911                         expected_type = best_type;
6912                 }
6913         }
6914
6915         error                = semantic_assign(expected_type, arg_expr);
6916         argument->expression = create_implicit_cast(arg_expr, expected_type);
6917
6918         if (error != ASSIGN_SUCCESS) {
6919                 /* report exact scope in error messages (like "in argument 3") */
6920                 char buf[64];
6921                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6922                 report_assign_error(error, expected_type, arg_expr, buf,
6923                                     &arg_expr->base.source_position);
6924         } else {
6925                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6926                 if (!types_compatible(expected_type_skip, promoted_type) &&
6927                     !types_compatible(expected_type_skip, type_void_ptr) &&
6928                     !types_compatible(type_void_ptr,      promoted_type)) {
6929                         /* Deliberately show the skipped types in this warning */
6930                         source_position_t const *const apos = &arg_expr->base.source_position;
6931                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6932                 }
6933         }
6934 }
6935
6936 /**
6937  * Handle the semantic restrictions of builtin calls
6938  */
6939 static void handle_builtin_argument_restrictions(call_expression_t *call)
6940 {
6941         entity_t *entity = call->function->reference.entity;
6942         switch (entity->function.btk) {
6943         case BUILTIN_FIRM:
6944                 switch (entity->function.b.firm_builtin_kind) {
6945                 case ir_bk_return_address:
6946                 case ir_bk_frame_address: {
6947                         /* argument must be constant */
6948                         call_argument_t *argument = call->arguments;
6949
6950                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6951                                 errorf(&call->base.source_position,
6952                                            "argument of '%Y' must be a constant expression",
6953                                            call->function->reference.entity->base.symbol);
6954                         }
6955                         break;
6956                 }
6957                 case ir_bk_prefetch:
6958                         /* second and third argument must be constant if existent */
6959                         if (call->arguments == NULL)
6960                                 break;
6961                         call_argument_t *rw = call->arguments->next;
6962                         call_argument_t *locality = NULL;
6963
6964                         if (rw != NULL) {
6965                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
6966                                         errorf(&call->base.source_position,
6967                                                    "second argument of '%Y' must be a constant expression",
6968                                                    call->function->reference.entity->base.symbol);
6969                                 }
6970                                 locality = rw->next;
6971                         }
6972                         if (locality != NULL) {
6973                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
6974                                         errorf(&call->base.source_position,
6975                                                    "third argument of '%Y' must be a constant expression",
6976                                                    call->function->reference.entity->base.symbol);
6977                                 }
6978                                 locality = rw->next;
6979                         }
6980                         break;
6981                 default:
6982                         break;
6983                 }
6984
6985         case BUILTIN_OBJECT_SIZE:
6986                 if (call->arguments == NULL)
6987                         break;
6988
6989                 call_argument_t *arg = call->arguments->next;
6990                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
6991                         errorf(&call->base.source_position,
6992                                    "second argument of '%Y' must be a constant expression",
6993                                    call->function->reference.entity->base.symbol);
6994                 }
6995                 break;
6996         default:
6997                 break;
6998         }
6999 }
7000
7001 /**
7002  * Parse a call expression, ie. expression '( ... )'.
7003  *
7004  * @param expression  the function address
7005  */
7006 static expression_t *parse_call_expression(expression_t *expression)
7007 {
7008         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7009         call_expression_t *call   = &result->call;
7010         call->function            = expression;
7011
7012         type_t *const orig_type = expression->base.type;
7013         type_t *const type      = skip_typeref(orig_type);
7014
7015         function_type_t *function_type = NULL;
7016         if (is_type_pointer(type)) {
7017                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7018
7019                 if (is_type_function(to_type)) {
7020                         function_type   = &to_type->function;
7021                         call->base.type = function_type->return_type;
7022                 }
7023         }
7024
7025         if (function_type == NULL && is_type_valid(type)) {
7026                 errorf(HERE,
7027                        "called object '%E' (type '%T') is not a pointer to a function",
7028                        expression, orig_type);
7029         }
7030
7031         /* parse arguments */
7032         eat('(');
7033         add_anchor_token(')');
7034         add_anchor_token(',');
7035
7036         if (token.kind != ')') {
7037                 call_argument_t **anchor = &call->arguments;
7038                 do {
7039                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7040                         argument->expression = parse_assignment_expression();
7041
7042                         *anchor = argument;
7043                         anchor  = &argument->next;
7044                 } while (next_if(','));
7045         }
7046         rem_anchor_token(',');
7047         rem_anchor_token(')');
7048         expect(')');
7049
7050         if (function_type == NULL)
7051                 return result;
7052
7053         /* check type and count of call arguments */
7054         function_parameter_t *parameter = function_type->parameters;
7055         call_argument_t      *argument  = call->arguments;
7056         if (!function_type->unspecified_parameters) {
7057                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7058                                 parameter = parameter->next, argument = argument->next) {
7059                         check_call_argument(parameter->type, argument, ++pos);
7060                 }
7061
7062                 if (parameter != NULL) {
7063                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7064                 } else if (argument != NULL && !function_type->variadic) {
7065                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7066                 }
7067         }
7068
7069         /* do default promotion for other arguments */
7070         for (; argument != NULL; argument = argument->next) {
7071                 type_t *argument_type = argument->expression->base.type;
7072                 if (!is_type_object(skip_typeref(argument_type))) {
7073                         errorf(&argument->expression->base.source_position,
7074                                "call argument '%E' must not be void", argument->expression);
7075                 }
7076
7077                 argument_type = get_default_promoted_type(argument_type);
7078
7079                 argument->expression
7080                         = create_implicit_cast(argument->expression, argument_type);
7081         }
7082
7083         check_format(call);
7084
7085         if (is_type_compound(skip_typeref(function_type->return_type))) {
7086                 source_position_t const *const pos = &expression->base.source_position;
7087                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7088         }
7089
7090         if (expression->kind == EXPR_REFERENCE) {
7091                 reference_expression_t *reference = &expression->reference;
7092                 if (reference->entity->kind == ENTITY_FUNCTION &&
7093                     reference->entity->function.btk != BUILTIN_NONE)
7094                         handle_builtin_argument_restrictions(call);
7095         }
7096
7097         return result;
7098 }
7099
7100 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7101
7102 static bool same_compound_type(const type_t *type1, const type_t *type2)
7103 {
7104         return
7105                 is_type_compound(type1) &&
7106                 type1->kind == type2->kind &&
7107                 type1->compound.compound == type2->compound.compound;
7108 }
7109
7110 static expression_t const *get_reference_address(expression_t const *expr)
7111 {
7112         bool regular_take_address = true;
7113         for (;;) {
7114                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7115                         expr = expr->unary.value;
7116                 } else {
7117                         regular_take_address = false;
7118                 }
7119
7120                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7121                         break;
7122
7123                 expr = expr->unary.value;
7124         }
7125
7126         if (expr->kind != EXPR_REFERENCE)
7127                 return NULL;
7128
7129         /* special case for functions which are automatically converted to a
7130          * pointer to function without an extra TAKE_ADDRESS operation */
7131         if (!regular_take_address &&
7132                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7133                 return NULL;
7134         }
7135
7136         return expr;
7137 }
7138
7139 static void warn_reference_address_as_bool(expression_t const* expr)
7140 {
7141         expr = get_reference_address(expr);
7142         if (expr != NULL) {
7143                 source_position_t const *const pos = &expr->base.source_position;
7144                 entity_t          const *const ent = expr->reference.entity;
7145                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7146         }
7147 }
7148
7149 static void warn_assignment_in_condition(const expression_t *const expr)
7150 {
7151         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7152                 return;
7153         if (expr->base.parenthesized)
7154                 return;
7155         source_position_t const *const pos = &expr->base.source_position;
7156         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7157 }
7158
7159 static void semantic_condition(expression_t const *const expr,
7160                                char const *const context)
7161 {
7162         type_t *const type = skip_typeref(expr->base.type);
7163         if (is_type_scalar(type)) {
7164                 warn_reference_address_as_bool(expr);
7165                 warn_assignment_in_condition(expr);
7166         } else if (is_type_valid(type)) {
7167                 errorf(&expr->base.source_position,
7168                                 "%s must have scalar type", context);
7169         }
7170 }
7171
7172 /**
7173  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7174  *
7175  * @param expression  the conditional expression
7176  */
7177 static expression_t *parse_conditional_expression(expression_t *expression)
7178 {
7179         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7180
7181         conditional_expression_t *conditional = &result->conditional;
7182         conditional->condition                = expression;
7183
7184         eat('?');
7185         add_anchor_token(':');
7186
7187         /* §6.5.15:2  The first operand shall have scalar type. */
7188         semantic_condition(expression, "condition of conditional operator");
7189
7190         expression_t *true_expression = expression;
7191         bool          gnu_cond = false;
7192         if (GNU_MODE && token.kind == ':') {
7193                 gnu_cond = true;
7194         } else {
7195                 true_expression = parse_expression();
7196         }
7197         rem_anchor_token(':');
7198         expect(':');
7199         expression_t *false_expression =
7200                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7201
7202         type_t *const orig_true_type  = true_expression->base.type;
7203         type_t *const orig_false_type = false_expression->base.type;
7204         type_t *const true_type       = skip_typeref(orig_true_type);
7205         type_t *const false_type      = skip_typeref(orig_false_type);
7206
7207         /* 6.5.15.3 */
7208         source_position_t const *const pos = &conditional->base.source_position;
7209         type_t                        *result_type;
7210         if (is_type_void(true_type) || is_type_void(false_type)) {
7211                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7212                 if (true_expression->kind == EXPR_UNARY_THROW) {
7213                         result_type = false_type;
7214                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7215                         result_type = true_type;
7216                 } else {
7217                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7218                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7219                         }
7220                         result_type = type_void;
7221                 }
7222         } else if (is_type_arithmetic(true_type)
7223                    && is_type_arithmetic(false_type)) {
7224                 result_type = semantic_arithmetic(true_type, false_type);
7225         } else if (same_compound_type(true_type, false_type)) {
7226                 /* just take 1 of the 2 types */
7227                 result_type = true_type;
7228         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7229                 type_t *pointer_type;
7230                 type_t *other_type;
7231                 expression_t *other_expression;
7232                 if (is_type_pointer(true_type) &&
7233                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7234                         pointer_type     = true_type;
7235                         other_type       = false_type;
7236                         other_expression = false_expression;
7237                 } else {
7238                         pointer_type     = false_type;
7239                         other_type       = true_type;
7240                         other_expression = true_expression;
7241                 }
7242
7243                 if (is_null_pointer_constant(other_expression)) {
7244                         result_type = pointer_type;
7245                 } else if (is_type_pointer(other_type)) {
7246                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7247                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7248
7249                         type_t *to;
7250                         if (is_type_void(to1) || is_type_void(to2)) {
7251                                 to = type_void;
7252                         } else if (types_compatible(get_unqualified_type(to1),
7253                                                     get_unqualified_type(to2))) {
7254                                 to = to1;
7255                         } else {
7256                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7257                                 to = type_void;
7258                         }
7259
7260                         type_t *const type =
7261                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7262                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7263                 } else if (is_type_integer(other_type)) {
7264                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7265                         result_type = pointer_type;
7266                 } else {
7267                         goto types_incompatible;
7268                 }
7269         } else {
7270 types_incompatible:
7271                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7272                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7273                 }
7274                 result_type = type_error_type;
7275         }
7276
7277         conditional->true_expression
7278                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7279         conditional->false_expression
7280                 = create_implicit_cast(false_expression, result_type);
7281         conditional->base.type = result_type;
7282         return result;
7283 }
7284
7285 /**
7286  * Parse an extension expression.
7287  */
7288 static expression_t *parse_extension(void)
7289 {
7290         PUSH_EXTENSION();
7291         expression_t *expression = parse_subexpression(PREC_UNARY);
7292         POP_EXTENSION();
7293         return expression;
7294 }
7295
7296 /**
7297  * Parse a __builtin_classify_type() expression.
7298  */
7299 static expression_t *parse_builtin_classify_type(void)
7300 {
7301         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7302         result->base.type    = type_int;
7303
7304         eat(T___builtin_classify_type);
7305
7306         add_anchor_token(')');
7307         expect('(');
7308         expression_t *expression = parse_expression();
7309         rem_anchor_token(')');
7310         expect(')');
7311         result->classify_type.type_expression = expression;
7312
7313         return result;
7314 }
7315
7316 /**
7317  * Parse a delete expression
7318  * ISO/IEC 14882:1998(E) §5.3.5
7319  */
7320 static expression_t *parse_delete(void)
7321 {
7322         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7323         result->base.type          = type_void;
7324
7325         eat(T_delete);
7326
7327         if (next_if('[')) {
7328                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7329                 expect(']');
7330         }
7331
7332         expression_t *const value = parse_subexpression(PREC_CAST);
7333         result->unary.value = value;
7334
7335         type_t *const type = skip_typeref(value->base.type);
7336         if (!is_type_pointer(type)) {
7337                 if (is_type_valid(type)) {
7338                         errorf(&value->base.source_position,
7339                                         "operand of delete must have pointer type");
7340                 }
7341         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7342                 source_position_t const *const pos = &value->base.source_position;
7343                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7344         }
7345
7346         return result;
7347 }
7348
7349 /**
7350  * Parse a throw expression
7351  * ISO/IEC 14882:1998(E) §15:1
7352  */
7353 static expression_t *parse_throw(void)
7354 {
7355         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7356         result->base.type          = type_void;
7357
7358         eat(T_throw);
7359
7360         expression_t *value = NULL;
7361         switch (token.kind) {
7362                 EXPRESSION_START {
7363                         value = parse_assignment_expression();
7364                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7365                         type_t *const orig_type = value->base.type;
7366                         type_t *const type      = skip_typeref(orig_type);
7367                         if (is_type_incomplete(type)) {
7368                                 errorf(&value->base.source_position,
7369                                                 "cannot throw object of incomplete type '%T'", orig_type);
7370                         } else if (is_type_pointer(type)) {
7371                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7372                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7373                                         errorf(&value->base.source_position,
7374                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7375                                 }
7376                         }
7377                 }
7378
7379                 default:
7380                         break;
7381         }
7382         result->unary.value = value;
7383
7384         return result;
7385 }
7386
7387 static bool check_pointer_arithmetic(const source_position_t *source_position,
7388                                      type_t *pointer_type,
7389                                      type_t *orig_pointer_type)
7390 {
7391         type_t *points_to = pointer_type->pointer.points_to;
7392         points_to = skip_typeref(points_to);
7393
7394         if (is_type_incomplete(points_to)) {
7395                 if (!GNU_MODE || !is_type_void(points_to)) {
7396                         errorf(source_position,
7397                                "arithmetic with pointer to incomplete type '%T' not allowed",
7398                                orig_pointer_type);
7399                         return false;
7400                 } else {
7401                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7402                 }
7403         } else if (is_type_function(points_to)) {
7404                 if (!GNU_MODE) {
7405                         errorf(source_position,
7406                                "arithmetic with pointer to function type '%T' not allowed",
7407                                orig_pointer_type);
7408                         return false;
7409                 } else {
7410                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7411                 }
7412         }
7413         return true;
7414 }
7415
7416 static bool is_lvalue(const expression_t *expression)
7417 {
7418         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7419         switch (expression->kind) {
7420         case EXPR_ARRAY_ACCESS:
7421         case EXPR_COMPOUND_LITERAL:
7422         case EXPR_REFERENCE:
7423         case EXPR_SELECT:
7424         case EXPR_UNARY_DEREFERENCE:
7425                 return true;
7426
7427         default: {
7428                 type_t *type = skip_typeref(expression->base.type);
7429                 return
7430                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7431                         is_type_reference(type) ||
7432                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7433                          * error before, which maybe prevented properly recognizing it as
7434                          * lvalue. */
7435                         !is_type_valid(type);
7436         }
7437         }
7438 }
7439
7440 static void semantic_incdec(unary_expression_t *expression)
7441 {
7442         type_t *const orig_type = expression->value->base.type;
7443         type_t *const type      = skip_typeref(orig_type);
7444         if (is_type_pointer(type)) {
7445                 if (!check_pointer_arithmetic(&expression->base.source_position,
7446                                               type, orig_type)) {
7447                         return;
7448                 }
7449         } else if (!is_type_real(type) && is_type_valid(type)) {
7450                 /* TODO: improve error message */
7451                 errorf(&expression->base.source_position,
7452                        "operation needs an arithmetic or pointer type");
7453                 return;
7454         }
7455         if (!is_lvalue(expression->value)) {
7456                 /* TODO: improve error message */
7457                 errorf(&expression->base.source_position, "lvalue required as operand");
7458         }
7459         expression->base.type = orig_type;
7460 }
7461
7462 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7463 {
7464         type_t *const res_type = promote_integer(type);
7465         expr->base.type = res_type;
7466         expr->value     = create_implicit_cast(expr->value, res_type);
7467 }
7468
7469 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7470 {
7471         type_t *const orig_type = expression->value->base.type;
7472         type_t *const type      = skip_typeref(orig_type);
7473         if (!is_type_arithmetic(type)) {
7474                 if (is_type_valid(type)) {
7475                         /* TODO: improve error message */
7476                         errorf(&expression->base.source_position,
7477                                 "operation needs an arithmetic type");
7478                 }
7479                 return;
7480         } else if (is_type_integer(type)) {
7481                 promote_unary_int_expr(expression, type);
7482         } else {
7483                 expression->base.type = orig_type;
7484         }
7485 }
7486
7487 static void semantic_unexpr_plus(unary_expression_t *expression)
7488 {
7489         semantic_unexpr_arithmetic(expression);
7490         source_position_t const *const pos = &expression->base.source_position;
7491         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7492 }
7493
7494 static void semantic_not(unary_expression_t *expression)
7495 {
7496         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7497         semantic_condition(expression->value, "operand of !");
7498         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7499 }
7500
7501 static void semantic_unexpr_integer(unary_expression_t *expression)
7502 {
7503         type_t *const orig_type = expression->value->base.type;
7504         type_t *const type      = skip_typeref(orig_type);
7505         if (!is_type_integer(type)) {
7506                 if (is_type_valid(type)) {
7507                         errorf(&expression->base.source_position,
7508                                "operand of ~ must be of integer type");
7509                 }
7510                 return;
7511         }
7512
7513         promote_unary_int_expr(expression, type);
7514 }
7515
7516 static void semantic_dereference(unary_expression_t *expression)
7517 {
7518         type_t *const orig_type = expression->value->base.type;
7519         type_t *const type      = skip_typeref(orig_type);
7520         if (!is_type_pointer(type)) {
7521                 if (is_type_valid(type)) {
7522                         errorf(&expression->base.source_position,
7523                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7524                 }
7525                 return;
7526         }
7527
7528         type_t *result_type   = type->pointer.points_to;
7529         result_type           = automatic_type_conversion(result_type);
7530         expression->base.type = result_type;
7531 }
7532
7533 /**
7534  * Record that an address is taken (expression represents an lvalue).
7535  *
7536  * @param expression       the expression
7537  * @param may_be_register  if true, the expression might be an register
7538  */
7539 static void set_address_taken(expression_t *expression, bool may_be_register)
7540 {
7541         if (expression->kind != EXPR_REFERENCE)
7542                 return;
7543
7544         entity_t *const entity = expression->reference.entity;
7545
7546         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7547                 return;
7548
7549         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7550                         && !may_be_register) {
7551                 source_position_t const *const pos = &expression->base.source_position;
7552                 errorf(pos, "address of register '%N' requested", entity);
7553         }
7554
7555         entity->variable.address_taken = true;
7556 }
7557
7558 /**
7559  * Check the semantic of the address taken expression.
7560  */
7561 static void semantic_take_addr(unary_expression_t *expression)
7562 {
7563         expression_t *value = expression->value;
7564         value->base.type    = revert_automatic_type_conversion(value);
7565
7566         type_t *orig_type = value->base.type;
7567         type_t *type      = skip_typeref(orig_type);
7568         if (!is_type_valid(type))
7569                 return;
7570
7571         /* §6.5.3.2 */
7572         if (!is_lvalue(value)) {
7573                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7574         }
7575         if (is_bitfield(value)) {
7576                 errorf(&expression->base.source_position,
7577                        "'&' not allowed on bitfield");
7578         }
7579
7580         set_address_taken(value, false);
7581
7582         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7583 }
7584
7585 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7586 static expression_t *parse_##unexpression_type(void)                         \
7587 {                                                                            \
7588         expression_t *unary_expression                                           \
7589                 = allocate_expression_zero(unexpression_type);                       \
7590         eat(token_kind);                                                         \
7591         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7592                                                                                  \
7593         sfunc(&unary_expression->unary);                                         \
7594                                                                                  \
7595         return unary_expression;                                                 \
7596 }
7597
7598 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7599                                semantic_unexpr_arithmetic)
7600 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7601                                semantic_unexpr_plus)
7602 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7603                                semantic_not)
7604 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7605                                semantic_dereference)
7606 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7607                                semantic_take_addr)
7608 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7609                                semantic_unexpr_integer)
7610 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7611                                semantic_incdec)
7612 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7613                                semantic_incdec)
7614
7615 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7616                                                sfunc)                         \
7617 static expression_t *parse_##unexpression_type(expression_t *left)            \
7618 {                                                                             \
7619         expression_t *unary_expression                                            \
7620                 = allocate_expression_zero(unexpression_type);                        \
7621         eat(token_kind);                                                          \
7622         unary_expression->unary.value = left;                                     \
7623                                                                                   \
7624         sfunc(&unary_expression->unary);                                          \
7625                                                                               \
7626         return unary_expression;                                                  \
7627 }
7628
7629 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7630                                        EXPR_UNARY_POSTFIX_INCREMENT,
7631                                        semantic_incdec)
7632 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7633                                        EXPR_UNARY_POSTFIX_DECREMENT,
7634                                        semantic_incdec)
7635
7636 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7637 {
7638         /* TODO: handle complex + imaginary types */
7639
7640         type_left  = get_unqualified_type(type_left);
7641         type_right = get_unqualified_type(type_right);
7642
7643         /* §6.3.1.8 Usual arithmetic conversions */
7644         if (type_left == type_long_double || type_right == type_long_double) {
7645                 return type_long_double;
7646         } else if (type_left == type_double || type_right == type_double) {
7647                 return type_double;
7648         } else if (type_left == type_float || type_right == type_float) {
7649                 return type_float;
7650         }
7651
7652         type_left  = promote_integer(type_left);
7653         type_right = promote_integer(type_right);
7654
7655         if (type_left == type_right)
7656                 return type_left;
7657
7658         bool     const signed_left  = is_type_signed(type_left);
7659         bool     const signed_right = is_type_signed(type_right);
7660         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7661         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7662
7663         if (signed_left == signed_right)
7664                 return rank_left >= rank_right ? type_left : type_right;
7665
7666         unsigned           s_rank;
7667         unsigned           u_rank;
7668         atomic_type_kind_t s_akind;
7669         atomic_type_kind_t u_akind;
7670         type_t *s_type;
7671         type_t *u_type;
7672         if (signed_left) {
7673                 s_type = type_left;
7674                 u_type = type_right;
7675         } else {
7676                 s_type = type_right;
7677                 u_type = type_left;
7678         }
7679         s_akind = get_akind(s_type);
7680         u_akind = get_akind(u_type);
7681         s_rank  = get_akind_rank(s_akind);
7682         u_rank  = get_akind_rank(u_akind);
7683
7684         if (u_rank >= s_rank)
7685                 return u_type;
7686
7687         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7688                 return s_type;
7689
7690         switch (s_akind) {
7691         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7692         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7693         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7694
7695         default: panic("invalid atomic type");
7696         }
7697 }
7698
7699 /**
7700  * Check the semantic restrictions for a binary expression.
7701  */
7702 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7703 {
7704         expression_t *const left            = expression->left;
7705         expression_t *const right           = expression->right;
7706         type_t       *const orig_type_left  = left->base.type;
7707         type_t       *const orig_type_right = right->base.type;
7708         type_t       *const type_left       = skip_typeref(orig_type_left);
7709         type_t       *const type_right      = skip_typeref(orig_type_right);
7710
7711         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7712                 /* TODO: improve error message */
7713                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7714                         errorf(&expression->base.source_position,
7715                                "operation needs arithmetic types");
7716                 }
7717                 return;
7718         }
7719
7720         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7721         expression->left      = create_implicit_cast(left, arithmetic_type);
7722         expression->right     = create_implicit_cast(right, arithmetic_type);
7723         expression->base.type = arithmetic_type;
7724 }
7725
7726 static void semantic_binexpr_integer(binary_expression_t *const expression)
7727 {
7728         expression_t *const left            = expression->left;
7729         expression_t *const right           = expression->right;
7730         type_t       *const orig_type_left  = left->base.type;
7731         type_t       *const orig_type_right = right->base.type;
7732         type_t       *const type_left       = skip_typeref(orig_type_left);
7733         type_t       *const type_right      = skip_typeref(orig_type_right);
7734
7735         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7736                 /* TODO: improve error message */
7737                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7738                         errorf(&expression->base.source_position,
7739                                "operation needs integer types");
7740                 }
7741                 return;
7742         }
7743
7744         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7745         expression->left      = create_implicit_cast(left, result_type);
7746         expression->right     = create_implicit_cast(right, result_type);
7747         expression->base.type = result_type;
7748 }
7749
7750 static void warn_div_by_zero(binary_expression_t const *const expression)
7751 {
7752         if (!is_type_integer(expression->base.type))
7753                 return;
7754
7755         expression_t const *const right = expression->right;
7756         /* The type of the right operand can be different for /= */
7757         if (is_type_integer(right->base.type)                    &&
7758             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7759             !fold_constant_to_bool(right)) {
7760                 source_position_t const *const pos = &expression->base.source_position;
7761                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7762         }
7763 }
7764
7765 /**
7766  * Check the semantic restrictions for a div/mod expression.
7767  */
7768 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7769 {
7770         semantic_binexpr_arithmetic(expression);
7771         warn_div_by_zero(expression);
7772 }
7773
7774 static void warn_addsub_in_shift(const expression_t *const expr)
7775 {
7776         if (expr->base.parenthesized)
7777                 return;
7778
7779         char op;
7780         switch (expr->kind) {
7781                 case EXPR_BINARY_ADD: op = '+'; break;
7782                 case EXPR_BINARY_SUB: op = '-'; break;
7783                 default:              return;
7784         }
7785
7786         source_position_t const *const pos = &expr->base.source_position;
7787         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7788 }
7789
7790 static bool semantic_shift(binary_expression_t *expression)
7791 {
7792         expression_t *const left            = expression->left;
7793         expression_t *const right           = expression->right;
7794         type_t       *const orig_type_left  = left->base.type;
7795         type_t       *const orig_type_right = right->base.type;
7796         type_t       *      type_left       = skip_typeref(orig_type_left);
7797         type_t       *      type_right      = skip_typeref(orig_type_right);
7798
7799         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7800                 /* TODO: improve error message */
7801                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7802                         errorf(&expression->base.source_position,
7803                                "operands of shift operation must have integer types");
7804                 }
7805                 return false;
7806         }
7807
7808         type_left = promote_integer(type_left);
7809
7810         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7811                 source_position_t const *const pos   = &right->base.source_position;
7812                 long                     const count = fold_constant_to_int(right);
7813                 if (count < 0) {
7814                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7815                 } else if ((unsigned long)count >=
7816                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7817                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7818                 }
7819         }
7820
7821         type_right        = promote_integer(type_right);
7822         expression->right = create_implicit_cast(right, type_right);
7823
7824         return true;
7825 }
7826
7827 static void semantic_shift_op(binary_expression_t *expression)
7828 {
7829         expression_t *const left  = expression->left;
7830         expression_t *const right = expression->right;
7831
7832         if (!semantic_shift(expression))
7833                 return;
7834
7835         warn_addsub_in_shift(left);
7836         warn_addsub_in_shift(right);
7837
7838         type_t *const orig_type_left = left->base.type;
7839         type_t *      type_left      = skip_typeref(orig_type_left);
7840
7841         type_left             = promote_integer(type_left);
7842         expression->left      = create_implicit_cast(left, type_left);
7843         expression->base.type = type_left;
7844 }
7845
7846 static void semantic_add(binary_expression_t *expression)
7847 {
7848         expression_t *const left            = expression->left;
7849         expression_t *const right           = expression->right;
7850         type_t       *const orig_type_left  = left->base.type;
7851         type_t       *const orig_type_right = right->base.type;
7852         type_t       *const type_left       = skip_typeref(orig_type_left);
7853         type_t       *const type_right      = skip_typeref(orig_type_right);
7854
7855         /* §6.5.6 */
7856         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7857                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7858                 expression->left  = create_implicit_cast(left, arithmetic_type);
7859                 expression->right = create_implicit_cast(right, arithmetic_type);
7860                 expression->base.type = arithmetic_type;
7861         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7862                 check_pointer_arithmetic(&expression->base.source_position,
7863                                          type_left, orig_type_left);
7864                 expression->base.type = type_left;
7865         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7866                 check_pointer_arithmetic(&expression->base.source_position,
7867                                          type_right, orig_type_right);
7868                 expression->base.type = type_right;
7869         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7870                 errorf(&expression->base.source_position,
7871                        "invalid operands to binary + ('%T', '%T')",
7872                        orig_type_left, orig_type_right);
7873         }
7874 }
7875
7876 static void semantic_sub(binary_expression_t *expression)
7877 {
7878         expression_t            *const left            = expression->left;
7879         expression_t            *const right           = expression->right;
7880         type_t                  *const orig_type_left  = left->base.type;
7881         type_t                  *const orig_type_right = right->base.type;
7882         type_t                  *const type_left       = skip_typeref(orig_type_left);
7883         type_t                  *const type_right      = skip_typeref(orig_type_right);
7884         source_position_t const *const pos             = &expression->base.source_position;
7885
7886         /* §5.6.5 */
7887         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7888                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7889                 expression->left        = create_implicit_cast(left, arithmetic_type);
7890                 expression->right       = create_implicit_cast(right, arithmetic_type);
7891                 expression->base.type =  arithmetic_type;
7892         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7893                 check_pointer_arithmetic(&expression->base.source_position,
7894                                          type_left, orig_type_left);
7895                 expression->base.type = type_left;
7896         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7897                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7898                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7899                 if (!types_compatible(unqual_left, unqual_right)) {
7900                         errorf(pos,
7901                                "subtracting pointers to incompatible types '%T' and '%T'",
7902                                orig_type_left, orig_type_right);
7903                 } else if (!is_type_object(unqual_left)) {
7904                         if (!is_type_void(unqual_left)) {
7905                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7906                                        orig_type_left);
7907                         } else {
7908                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7909                         }
7910                 }
7911                 expression->base.type = type_ptrdiff_t;
7912         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7913                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7914                        orig_type_left, orig_type_right);
7915         }
7916 }
7917
7918 static void warn_string_literal_address(expression_t const* expr)
7919 {
7920         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7921                 expr = expr->unary.value;
7922                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7923                         return;
7924                 expr = expr->unary.value;
7925         }
7926
7927         if (expr->kind == EXPR_STRING_LITERAL) {
7928                 source_position_t const *const pos = &expr->base.source_position;
7929                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7930         }
7931 }
7932
7933 static bool maybe_negative(expression_t const *const expr)
7934 {
7935         switch (is_constant_expression(expr)) {
7936                 case EXPR_CLASS_ERROR:    return false;
7937                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7938                 default:                  return true;
7939         }
7940 }
7941
7942 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7943 {
7944         warn_string_literal_address(expr);
7945
7946         expression_t const* const ref = get_reference_address(expr);
7947         if (ref != NULL && is_null_pointer_constant(other)) {
7948                 entity_t const *const ent = ref->reference.entity;
7949                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7950         }
7951
7952         if (!expr->base.parenthesized) {
7953                 switch (expr->base.kind) {
7954                         case EXPR_BINARY_LESS:
7955                         case EXPR_BINARY_GREATER:
7956                         case EXPR_BINARY_LESSEQUAL:
7957                         case EXPR_BINARY_GREATEREQUAL:
7958                         case EXPR_BINARY_NOTEQUAL:
7959                         case EXPR_BINARY_EQUAL:
7960                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
7961                                 break;
7962                         default:
7963                                 break;
7964                 }
7965         }
7966 }
7967
7968 /**
7969  * Check the semantics of comparison expressions.
7970  *
7971  * @param expression   The expression to check.
7972  */
7973 static void semantic_comparison(binary_expression_t *expression)
7974 {
7975         source_position_t const *const pos   = &expression->base.source_position;
7976         expression_t            *const left  = expression->left;
7977         expression_t            *const right = expression->right;
7978
7979         warn_comparison(pos, left, right);
7980         warn_comparison(pos, right, left);
7981
7982         type_t *orig_type_left  = left->base.type;
7983         type_t *orig_type_right = right->base.type;
7984         type_t *type_left       = skip_typeref(orig_type_left);
7985         type_t *type_right      = skip_typeref(orig_type_right);
7986
7987         /* TODO non-arithmetic types */
7988         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7989                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7990
7991                 /* test for signed vs unsigned compares */
7992                 if (is_type_integer(arithmetic_type)) {
7993                         bool const signed_left  = is_type_signed(type_left);
7994                         bool const signed_right = is_type_signed(type_right);
7995                         if (signed_left != signed_right) {
7996                                 /* FIXME long long needs better const folding magic */
7997                                 /* TODO check whether constant value can be represented by other type */
7998                                 if ((signed_left  && maybe_negative(left)) ||
7999                                                 (signed_right && maybe_negative(right))) {
8000                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8001                                 }
8002                         }
8003                 }
8004
8005                 expression->left        = create_implicit_cast(left, arithmetic_type);
8006                 expression->right       = create_implicit_cast(right, arithmetic_type);
8007                 expression->base.type   = arithmetic_type;
8008                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8009                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8010                     is_type_float(arithmetic_type)) {
8011                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8012                 }
8013         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8014                 /* TODO check compatibility */
8015         } else if (is_type_pointer(type_left)) {
8016                 expression->right = create_implicit_cast(right, type_left);
8017         } else if (is_type_pointer(type_right)) {
8018                 expression->left = create_implicit_cast(left, type_right);
8019         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8020                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8021         }
8022         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8023 }
8024
8025 /**
8026  * Checks if a compound type has constant fields.
8027  */
8028 static bool has_const_fields(const compound_type_t *type)
8029 {
8030         compound_t *compound = type->compound;
8031         entity_t   *entry    = compound->members.entities;
8032
8033         for (; entry != NULL; entry = entry->base.next) {
8034                 if (!is_declaration(entry))
8035                         continue;
8036
8037                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8038                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8039                         return true;
8040         }
8041
8042         return false;
8043 }
8044
8045 static bool is_valid_assignment_lhs(expression_t const* const left)
8046 {
8047         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8048         type_t *const type_left      = skip_typeref(orig_type_left);
8049
8050         if (!is_lvalue(left)) {
8051                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8052                        left);
8053                 return false;
8054         }
8055
8056         if (left->kind == EXPR_REFERENCE
8057                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8058                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8059                 return false;
8060         }
8061
8062         if (is_type_array(type_left)) {
8063                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8064                 return false;
8065         }
8066         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8067                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8068                        orig_type_left);
8069                 return false;
8070         }
8071         if (is_type_incomplete(type_left)) {
8072                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8073                        left, orig_type_left);
8074                 return false;
8075         }
8076         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8077                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8078                        left, orig_type_left);
8079                 return false;
8080         }
8081
8082         return true;
8083 }
8084
8085 static void semantic_arithmetic_assign(binary_expression_t *expression)
8086 {
8087         expression_t *left            = expression->left;
8088         expression_t *right           = expression->right;
8089         type_t       *orig_type_left  = left->base.type;
8090         type_t       *orig_type_right = right->base.type;
8091
8092         if (!is_valid_assignment_lhs(left))
8093                 return;
8094
8095         type_t *type_left  = skip_typeref(orig_type_left);
8096         type_t *type_right = skip_typeref(orig_type_right);
8097
8098         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8099                 /* TODO: improve error message */
8100                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8101                         errorf(&expression->base.source_position,
8102                                "operation needs arithmetic types");
8103                 }
8104                 return;
8105         }
8106
8107         /* combined instructions are tricky. We can't create an implicit cast on
8108          * the left side, because we need the uncasted form for the store.
8109          * The ast2firm pass has to know that left_type must be right_type
8110          * for the arithmetic operation and create a cast by itself */
8111         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8112         expression->right       = create_implicit_cast(right, arithmetic_type);
8113         expression->base.type   = type_left;
8114 }
8115
8116 static void semantic_divmod_assign(binary_expression_t *expression)
8117 {
8118         semantic_arithmetic_assign(expression);
8119         warn_div_by_zero(expression);
8120 }
8121
8122 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8123 {
8124         expression_t *const left            = expression->left;
8125         expression_t *const right           = expression->right;
8126         type_t       *const orig_type_left  = left->base.type;
8127         type_t       *const orig_type_right = right->base.type;
8128         type_t       *const type_left       = skip_typeref(orig_type_left);
8129         type_t       *const type_right      = skip_typeref(orig_type_right);
8130
8131         if (!is_valid_assignment_lhs(left))
8132                 return;
8133
8134         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8135                 /* combined instructions are tricky. We can't create an implicit cast on
8136                  * the left side, because we need the uncasted form for the store.
8137                  * The ast2firm pass has to know that left_type must be right_type
8138                  * for the arithmetic operation and create a cast by itself */
8139                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8140                 expression->right     = create_implicit_cast(right, arithmetic_type);
8141                 expression->base.type = type_left;
8142         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8143                 check_pointer_arithmetic(&expression->base.source_position,
8144                                          type_left, orig_type_left);
8145                 expression->base.type = type_left;
8146         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8147                 errorf(&expression->base.source_position,
8148                        "incompatible types '%T' and '%T' in assignment",
8149                        orig_type_left, orig_type_right);
8150         }
8151 }
8152
8153 static void semantic_integer_assign(binary_expression_t *expression)
8154 {
8155         expression_t *left            = expression->left;
8156         expression_t *right           = expression->right;
8157         type_t       *orig_type_left  = left->base.type;
8158         type_t       *orig_type_right = right->base.type;
8159
8160         if (!is_valid_assignment_lhs(left))
8161                 return;
8162
8163         type_t *type_left  = skip_typeref(orig_type_left);
8164         type_t *type_right = skip_typeref(orig_type_right);
8165
8166         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8167                 /* TODO: improve error message */
8168                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8169                         errorf(&expression->base.source_position,
8170                                "operation needs integer types");
8171                 }
8172                 return;
8173         }
8174
8175         /* combined instructions are tricky. We can't create an implicit cast on
8176          * the left side, because we need the uncasted form for the store.
8177          * The ast2firm pass has to know that left_type must be right_type
8178          * for the arithmetic operation and create a cast by itself */
8179         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8180         expression->right       = create_implicit_cast(right, arithmetic_type);
8181         expression->base.type   = type_left;
8182 }
8183
8184 static void semantic_shift_assign(binary_expression_t *expression)
8185 {
8186         expression_t *left           = expression->left;
8187
8188         if (!is_valid_assignment_lhs(left))
8189                 return;
8190
8191         if (!semantic_shift(expression))
8192                 return;
8193
8194         expression->base.type = skip_typeref(left->base.type);
8195 }
8196
8197 static void warn_logical_and_within_or(const expression_t *const expr)
8198 {
8199         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8200                 return;
8201         if (expr->base.parenthesized)
8202                 return;
8203         source_position_t const *const pos = &expr->base.source_position;
8204         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8205 }
8206
8207 /**
8208  * Check the semantic restrictions of a logical expression.
8209  */
8210 static void semantic_logical_op(binary_expression_t *expression)
8211 {
8212         /* §6.5.13:2  Each of the operands shall have scalar type.
8213          * §6.5.14:2  Each of the operands shall have scalar type. */
8214         semantic_condition(expression->left,   "left operand of logical operator");
8215         semantic_condition(expression->right, "right operand of logical operator");
8216         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8217                 warn_logical_and_within_or(expression->left);
8218                 warn_logical_and_within_or(expression->right);
8219         }
8220         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8221 }
8222
8223 /**
8224  * Check the semantic restrictions of a binary assign expression.
8225  */
8226 static void semantic_binexpr_assign(binary_expression_t *expression)
8227 {
8228         expression_t *left           = expression->left;
8229         type_t       *orig_type_left = left->base.type;
8230
8231         if (!is_valid_assignment_lhs(left))
8232                 return;
8233
8234         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8235         report_assign_error(error, orig_type_left, expression->right,
8236                         "assignment", &left->base.source_position);
8237         expression->right = create_implicit_cast(expression->right, orig_type_left);
8238         expression->base.type = orig_type_left;
8239 }
8240
8241 /**
8242  * Determine if the outermost operation (or parts thereof) of the given
8243  * expression has no effect in order to generate a warning about this fact.
8244  * Therefore in some cases this only examines some of the operands of the
8245  * expression (see comments in the function and examples below).
8246  * Examples:
8247  *   f() + 23;    // warning, because + has no effect
8248  *   x || f();    // no warning, because x controls execution of f()
8249  *   x ? y : f(); // warning, because y has no effect
8250  *   (void)x;     // no warning to be able to suppress the warning
8251  * This function can NOT be used for an "expression has definitely no effect"-
8252  * analysis. */
8253 static bool expression_has_effect(const expression_t *const expr)
8254 {
8255         switch (expr->kind) {
8256                 case EXPR_ERROR:                      return true; /* do NOT warn */
8257                 case EXPR_REFERENCE:                  return false;
8258                 case EXPR_ENUM_CONSTANT:              return false;
8259                 case EXPR_LABEL_ADDRESS:              return false;
8260
8261                 /* suppress the warning for microsoft __noop operations */
8262                 case EXPR_LITERAL_MS_NOOP:            return true;
8263                 case EXPR_LITERAL_BOOLEAN:
8264                 case EXPR_LITERAL_CHARACTER:
8265                 case EXPR_LITERAL_INTEGER:
8266                 case EXPR_LITERAL_FLOATINGPOINT:
8267                 case EXPR_STRING_LITERAL:             return false;
8268
8269                 case EXPR_CALL: {
8270                         const call_expression_t *const call = &expr->call;
8271                         if (call->function->kind != EXPR_REFERENCE)
8272                                 return true;
8273
8274                         switch (call->function->reference.entity->function.btk) {
8275                                 /* FIXME: which builtins have no effect? */
8276                                 default:                      return true;
8277                         }
8278                 }
8279
8280                 /* Generate the warning if either the left or right hand side of a
8281                  * conditional expression has no effect */
8282                 case EXPR_CONDITIONAL: {
8283                         conditional_expression_t const *const cond = &expr->conditional;
8284                         expression_t             const *const t    = cond->true_expression;
8285                         return
8286                                 (t == NULL || expression_has_effect(t)) &&
8287                                 expression_has_effect(cond->false_expression);
8288                 }
8289
8290                 case EXPR_SELECT:                     return false;
8291                 case EXPR_ARRAY_ACCESS:               return false;
8292                 case EXPR_SIZEOF:                     return false;
8293                 case EXPR_CLASSIFY_TYPE:              return false;
8294                 case EXPR_ALIGNOF:                    return false;
8295
8296                 case EXPR_FUNCNAME:                   return false;
8297                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8298                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8299                 case EXPR_OFFSETOF:                   return false;
8300                 case EXPR_VA_START:                   return true;
8301                 case EXPR_VA_ARG:                     return true;
8302                 case EXPR_VA_COPY:                    return true;
8303                 case EXPR_STATEMENT:                  return true; // TODO
8304                 case EXPR_COMPOUND_LITERAL:           return false;
8305
8306                 case EXPR_UNARY_NEGATE:               return false;
8307                 case EXPR_UNARY_PLUS:                 return false;
8308                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8309                 case EXPR_UNARY_NOT:                  return false;
8310                 case EXPR_UNARY_DEREFERENCE:          return false;
8311                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8312                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8313                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8314                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8315                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8316
8317                 /* Treat void casts as if they have an effect in order to being able to
8318                  * suppress the warning */
8319                 case EXPR_UNARY_CAST: {
8320                         type_t *const type = skip_typeref(expr->base.type);
8321                         return is_type_void(type);
8322                 }
8323
8324                 case EXPR_UNARY_ASSUME:               return true;
8325                 case EXPR_UNARY_DELETE:               return true;
8326                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8327                 case EXPR_UNARY_THROW:                return true;
8328
8329                 case EXPR_BINARY_ADD:                 return false;
8330                 case EXPR_BINARY_SUB:                 return false;
8331                 case EXPR_BINARY_MUL:                 return false;
8332                 case EXPR_BINARY_DIV:                 return false;
8333                 case EXPR_BINARY_MOD:                 return false;
8334                 case EXPR_BINARY_EQUAL:               return false;
8335                 case EXPR_BINARY_NOTEQUAL:            return false;
8336                 case EXPR_BINARY_LESS:                return false;
8337                 case EXPR_BINARY_LESSEQUAL:           return false;
8338                 case EXPR_BINARY_GREATER:             return false;
8339                 case EXPR_BINARY_GREATEREQUAL:        return false;
8340                 case EXPR_BINARY_BITWISE_AND:         return false;
8341                 case EXPR_BINARY_BITWISE_OR:          return false;
8342                 case EXPR_BINARY_BITWISE_XOR:         return false;
8343                 case EXPR_BINARY_SHIFTLEFT:           return false;
8344                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8345                 case EXPR_BINARY_ASSIGN:              return true;
8346                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8347                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8348                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8349                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8350                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8351                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8352                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8353                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8354                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8355                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8356
8357                 /* Only examine the right hand side of && and ||, because the left hand
8358                  * side already has the effect of controlling the execution of the right
8359                  * hand side */
8360                 case EXPR_BINARY_LOGICAL_AND:
8361                 case EXPR_BINARY_LOGICAL_OR:
8362                 /* Only examine the right hand side of a comma expression, because the left
8363                  * hand side has a separate warning */
8364                 case EXPR_BINARY_COMMA:
8365                         return expression_has_effect(expr->binary.right);
8366
8367                 case EXPR_BINARY_ISGREATER:           return false;
8368                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8369                 case EXPR_BINARY_ISLESS:              return false;
8370                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8371                 case EXPR_BINARY_ISLESSGREATER:       return false;
8372                 case EXPR_BINARY_ISUNORDERED:         return false;
8373         }
8374
8375         internal_errorf(HERE, "unexpected expression");
8376 }
8377
8378 static void semantic_comma(binary_expression_t *expression)
8379 {
8380         const expression_t *const left = expression->left;
8381         if (!expression_has_effect(left)) {
8382                 source_position_t const *const pos = &left->base.source_position;
8383                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8384         }
8385         expression->base.type = expression->right->base.type;
8386 }
8387
8388 /**
8389  * @param prec_r precedence of the right operand
8390  */
8391 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8392 static expression_t *parse_##binexpression_type(expression_t *left)          \
8393 {                                                                            \
8394         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8395         binexpr->binary.left  = left;                                            \
8396         eat(token_kind);                                                         \
8397                                                                              \
8398         expression_t *right = parse_subexpression(prec_r);                       \
8399                                                                              \
8400         binexpr->binary.right = right;                                           \
8401         sfunc(&binexpr->binary);                                                 \
8402                                                                              \
8403         return binexpr;                                                          \
8404 }
8405
8406 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8407 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8408 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8409 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8410 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8411 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8412 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8413 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8414 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8415 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8416 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8417 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8418 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8419 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8420 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8421 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8422 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8423 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8424 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8425 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8426 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8427 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8428 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8429 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8430 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8431 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8432 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8433 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8434 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8435 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8436
8437
8438 static expression_t *parse_subexpression(precedence_t precedence)
8439 {
8440         expression_parser_function_t *parser
8441                 = &expression_parsers[token.kind];
8442         expression_t                 *left;
8443
8444         if (parser->parser != NULL) {
8445                 left = parser->parser();
8446         } else {
8447                 left = parse_primary_expression();
8448         }
8449         assert(left != NULL);
8450
8451         while (true) {
8452                 parser = &expression_parsers[token.kind];
8453                 if (parser->infix_parser == NULL)
8454                         break;
8455                 if (parser->infix_precedence < precedence)
8456                         break;
8457
8458                 left = parser->infix_parser(left);
8459
8460                 assert(left != NULL);
8461         }
8462
8463         return left;
8464 }
8465
8466 /**
8467  * Parse an expression.
8468  */
8469 static expression_t *parse_expression(void)
8470 {
8471         return parse_subexpression(PREC_EXPRESSION);
8472 }
8473
8474 /**
8475  * Register a parser for a prefix-like operator.
8476  *
8477  * @param parser      the parser function
8478  * @param token_kind  the token type of the prefix token
8479  */
8480 static void register_expression_parser(parse_expression_function parser,
8481                                        int token_kind)
8482 {
8483         expression_parser_function_t *entry = &expression_parsers[token_kind];
8484
8485         assert(!entry->parser);
8486         entry->parser = parser;
8487 }
8488
8489 /**
8490  * Register a parser for an infix operator with given precedence.
8491  *
8492  * @param parser      the parser function
8493  * @param token_kind  the token type of the infix operator
8494  * @param precedence  the precedence of the operator
8495  */
8496 static void register_infix_parser(parse_expression_infix_function parser,
8497                                   int token_kind, precedence_t precedence)
8498 {
8499         expression_parser_function_t *entry = &expression_parsers[token_kind];
8500
8501         assert(!entry->infix_parser);
8502         entry->infix_parser     = parser;
8503         entry->infix_precedence = precedence;
8504 }
8505
8506 /**
8507  * Initialize the expression parsers.
8508  */
8509 static void init_expression_parsers(void)
8510 {
8511         memset(&expression_parsers, 0, sizeof(expression_parsers));
8512
8513         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8514         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8515         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8516         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8517         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8518         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8519         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8520         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8521         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8522         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8523         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8524         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8525         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8526         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8527         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8528         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8529         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8530         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8531         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8532         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8533         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8534         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8535         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8536         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8537         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8538         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8539         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8540         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8541         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8542         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8543         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8544         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8545         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8546         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8547         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8548         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8549         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8550
8551         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8552         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8553         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8554         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8555         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8556         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8557         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8558         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8559         register_expression_parser(parse_sizeof,                      T_sizeof);
8560         register_expression_parser(parse_alignof,                     T___alignof__);
8561         register_expression_parser(parse_extension,                   T___extension__);
8562         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8563         register_expression_parser(parse_delete,                      T_delete);
8564         register_expression_parser(parse_throw,                       T_throw);
8565 }
8566
8567 /**
8568  * Parse a asm statement arguments specification.
8569  */
8570 static asm_argument_t *parse_asm_arguments(bool is_out)
8571 {
8572         asm_argument_t  *result = NULL;
8573         asm_argument_t **anchor = &result;
8574
8575         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8576                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8577
8578                 if (next_if('[')) {
8579                         add_anchor_token(']');
8580                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8581                         rem_anchor_token(']');
8582                         expect(']');
8583                         if (!argument->symbol)
8584                                 return NULL;
8585                 }
8586
8587                 argument->constraints = parse_string_literals("asm argument");
8588                 add_anchor_token(')');
8589                 expect('(');
8590                 expression_t *expression = parse_expression();
8591                 rem_anchor_token(')');
8592                 if (is_out) {
8593                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8594                          * change size or type representation (e.g. int -> long is ok, but
8595                          * int -> float is not) */
8596                         if (expression->kind == EXPR_UNARY_CAST) {
8597                                 type_t      *const type = expression->base.type;
8598                                 type_kind_t  const kind = type->kind;
8599                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8600                                         unsigned flags;
8601                                         unsigned size;
8602                                         if (kind == TYPE_ATOMIC) {
8603                                                 atomic_type_kind_t const akind = type->atomic.akind;
8604                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8605                                                 size  = get_atomic_type_size(akind);
8606                                         } else {
8607                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8608                                                 size  = get_type_size(type_void_ptr);
8609                                         }
8610
8611                                         do {
8612                                                 expression_t *const value      = expression->unary.value;
8613                                                 type_t       *const value_type = value->base.type;
8614                                                 type_kind_t   const value_kind = value_type->kind;
8615
8616                                                 unsigned value_flags;
8617                                                 unsigned value_size;
8618                                                 if (value_kind == TYPE_ATOMIC) {
8619                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8620                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8621                                                         value_size  = get_atomic_type_size(value_akind);
8622                                                 } else if (value_kind == TYPE_POINTER) {
8623                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8624                                                         value_size  = get_type_size(type_void_ptr);
8625                                                 } else {
8626                                                         break;
8627                                                 }
8628
8629                                                 if (value_flags != flags || value_size != size)
8630                                                         break;
8631
8632                                                 expression = value;
8633                                         } while (expression->kind == EXPR_UNARY_CAST);
8634                                 }
8635                         }
8636
8637                         if (!is_lvalue(expression)) {
8638                                 errorf(&expression->base.source_position,
8639                                        "asm output argument is not an lvalue");
8640                         }
8641
8642                         if (argument->constraints.begin[0] == '=')
8643                                 determine_lhs_ent(expression, NULL);
8644                         else
8645                                 mark_vars_read(expression, NULL);
8646                 } else {
8647                         mark_vars_read(expression, NULL);
8648                 }
8649                 argument->expression = expression;
8650                 expect(')');
8651
8652                 set_address_taken(expression, true);
8653
8654                 *anchor = argument;
8655                 anchor  = &argument->next;
8656
8657                 if (!next_if(','))
8658                         break;
8659         }
8660
8661         return result;
8662 }
8663
8664 /**
8665  * Parse a asm statement clobber specification.
8666  */
8667 static asm_clobber_t *parse_asm_clobbers(void)
8668 {
8669         asm_clobber_t *result  = NULL;
8670         asm_clobber_t **anchor = &result;
8671
8672         while (token.kind == T_STRING_LITERAL) {
8673                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8674                 clobber->clobber       = parse_string_literals(NULL);
8675
8676                 *anchor = clobber;
8677                 anchor  = &clobber->next;
8678
8679                 if (!next_if(','))
8680                         break;
8681         }
8682
8683         return result;
8684 }
8685
8686 /**
8687  * Parse an asm statement.
8688  */
8689 static statement_t *parse_asm_statement(void)
8690 {
8691         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8692         asm_statement_t *asm_statement = &statement->asms;
8693
8694         eat(T_asm);
8695         add_anchor_token(')');
8696         add_anchor_token(':');
8697         add_anchor_token(T_STRING_LITERAL);
8698
8699         if (next_if(T_volatile))
8700                 asm_statement->is_volatile = true;
8701
8702         expect('(');
8703         rem_anchor_token(T_STRING_LITERAL);
8704         asm_statement->asm_text = parse_string_literals("asm statement");
8705
8706         if (next_if(':'))
8707                 asm_statement->outputs = parse_asm_arguments(true);
8708
8709         if (next_if(':'))
8710                 asm_statement->inputs = parse_asm_arguments(false);
8711
8712         rem_anchor_token(':');
8713         if (next_if(':'))
8714                 asm_statement->clobbers = parse_asm_clobbers();
8715
8716         rem_anchor_token(')');
8717         expect(')');
8718         expect(';');
8719
8720         if (asm_statement->outputs == NULL) {
8721                 /* GCC: An 'asm' instruction without any output operands will be treated
8722                  * identically to a volatile 'asm' instruction. */
8723                 asm_statement->is_volatile = true;
8724         }
8725
8726         return statement;
8727 }
8728
8729 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8730 {
8731         statement_t *inner_stmt;
8732         switch (token.kind) {
8733                 case '}':
8734                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8735                         inner_stmt = create_error_statement();
8736                         break;
8737
8738                 case ';':
8739                         if (label->kind == STATEMENT_LABEL) {
8740                                 /* Eat an empty statement here, to avoid the warning about an empty
8741                                  * statement after a label.  label:; is commonly used to have a label
8742                                  * before a closing brace. */
8743                                 inner_stmt = create_empty_statement();
8744                                 eat(';');
8745                                 break;
8746                         }
8747                         /* FALLTHROUGH */
8748
8749                 default:
8750                         inner_stmt = parse_statement();
8751                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8752                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8753                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8754                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8755                         }
8756                         break;
8757         }
8758         return inner_stmt;
8759 }
8760
8761 /**
8762  * Parse a case statement.
8763  */
8764 static statement_t *parse_case_statement(void)
8765 {
8766         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8767         source_position_t *const pos       = &statement->base.source_position;
8768
8769         eat(T_case);
8770         add_anchor_token(':');
8771
8772         expression_t *expression = parse_expression();
8773         type_t *expression_type = expression->base.type;
8774         type_t *skipped         = skip_typeref(expression_type);
8775         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8776                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8777                        expression, expression_type);
8778         }
8779
8780         type_t *type = expression_type;
8781         if (current_switch != NULL) {
8782                 type_t *switch_type = current_switch->expression->base.type;
8783                 if (is_type_valid(switch_type)) {
8784                         expression = create_implicit_cast(expression, switch_type);
8785                 }
8786         }
8787
8788         statement->case_label.expression = expression;
8789         expression_classification_t const expr_class = is_constant_expression(expression);
8790         if (expr_class != EXPR_CLASS_CONSTANT) {
8791                 if (expr_class != EXPR_CLASS_ERROR) {
8792                         errorf(pos, "case label does not reduce to an integer constant");
8793                 }
8794                 statement->case_label.is_bad = true;
8795         } else {
8796                 long const val = fold_constant_to_int(expression);
8797                 statement->case_label.first_case = val;
8798                 statement->case_label.last_case  = val;
8799         }
8800
8801         if (GNU_MODE) {
8802                 if (next_if(T_DOTDOTDOT)) {
8803                         expression_t *end_range = parse_expression();
8804                         expression_type = expression->base.type;
8805                         skipped         = skip_typeref(expression_type);
8806                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8807                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8808                                            expression, expression_type);
8809                         }
8810
8811                         end_range = create_implicit_cast(end_range, type);
8812                         statement->case_label.end_range = end_range;
8813                         expression_classification_t const end_class = is_constant_expression(end_range);
8814                         if (end_class != EXPR_CLASS_CONSTANT) {
8815                                 if (end_class != EXPR_CLASS_ERROR) {
8816                                         errorf(pos, "case range does not reduce to an integer constant");
8817                                 }
8818                                 statement->case_label.is_bad = true;
8819                         } else {
8820                                 long const val = fold_constant_to_int(end_range);
8821                                 statement->case_label.last_case = val;
8822
8823                                 if (val < statement->case_label.first_case) {
8824                                         statement->case_label.is_empty_range = true;
8825                                         warningf(WARN_OTHER, pos, "empty range specified");
8826                                 }
8827                         }
8828                 }
8829         }
8830
8831         PUSH_PARENT(statement);
8832
8833         rem_anchor_token(':');
8834         expect(':');
8835
8836         if (current_switch != NULL) {
8837                 if (! statement->case_label.is_bad) {
8838                         /* Check for duplicate case values */
8839                         case_label_statement_t *c = &statement->case_label;
8840                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8841                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8842                                         continue;
8843
8844                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8845                                         continue;
8846
8847                                 errorf(pos, "duplicate case value (previously used %P)",
8848                                        &l->base.source_position);
8849                                 break;
8850                         }
8851                 }
8852                 /* link all cases into the switch statement */
8853                 if (current_switch->last_case == NULL) {
8854                         current_switch->first_case      = &statement->case_label;
8855                 } else {
8856                         current_switch->last_case->next = &statement->case_label;
8857                 }
8858                 current_switch->last_case = &statement->case_label;
8859         } else {
8860                 errorf(pos, "case label not within a switch statement");
8861         }
8862
8863         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8864
8865         POP_PARENT();
8866         return statement;
8867 }
8868
8869 /**
8870  * Parse a default statement.
8871  */
8872 static statement_t *parse_default_statement(void)
8873 {
8874         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8875
8876         eat(T_default);
8877
8878         PUSH_PARENT(statement);
8879
8880         expect(':');
8881
8882         if (current_switch != NULL) {
8883                 const case_label_statement_t *def_label = current_switch->default_label;
8884                 if (def_label != NULL) {
8885                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8886                 } else {
8887                         current_switch->default_label = &statement->case_label;
8888
8889                         /* link all cases into the switch statement */
8890                         if (current_switch->last_case == NULL) {
8891                                 current_switch->first_case      = &statement->case_label;
8892                         } else {
8893                                 current_switch->last_case->next = &statement->case_label;
8894                         }
8895                         current_switch->last_case = &statement->case_label;
8896                 }
8897         } else {
8898                 errorf(&statement->base.source_position,
8899                         "'default' label not within a switch statement");
8900         }
8901
8902         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8903
8904         POP_PARENT();
8905         return statement;
8906 }
8907
8908 /**
8909  * Parse a label statement.
8910  */
8911 static statement_t *parse_label_statement(void)
8912 {
8913         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8914         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8915         statement->label.label = label;
8916
8917         PUSH_PARENT(statement);
8918
8919         /* if statement is already set then the label is defined twice,
8920          * otherwise it was just mentioned in a goto/local label declaration so far
8921          */
8922         source_position_t const* const pos = &statement->base.source_position;
8923         if (label->statement != NULL) {
8924                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8925         } else {
8926                 label->base.source_position = *pos;
8927                 label->statement            = statement;
8928         }
8929
8930         eat(':');
8931
8932         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8933                 parse_attributes(NULL); // TODO process attributes
8934         }
8935
8936         statement->label.statement = parse_label_inner_statement(statement, "label");
8937
8938         /* remember the labels in a list for later checking */
8939         *label_anchor = &statement->label;
8940         label_anchor  = &statement->label.next;
8941
8942         POP_PARENT();
8943         return statement;
8944 }
8945
8946 static statement_t *parse_inner_statement(void)
8947 {
8948         statement_t *const stmt = parse_statement();
8949         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8950         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8951         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8952                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
8953         }
8954         return stmt;
8955 }
8956
8957 /**
8958  * Parse an expression in parentheses and mark its variables as read.
8959  */
8960 static expression_t *parse_condition(void)
8961 {
8962         add_anchor_token(')');
8963         expect('(');
8964         expression_t *const expr = parse_expression();
8965         mark_vars_read(expr, NULL);
8966         rem_anchor_token(')');
8967         expect(')');
8968         return expr;
8969 }
8970
8971 /**
8972  * Parse an if statement.
8973  */
8974 static statement_t *parse_if(void)
8975 {
8976         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
8977
8978         eat(T_if);
8979
8980         PUSH_PARENT(statement);
8981         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
8982
8983         add_anchor_token(T_else);
8984
8985         expression_t *const expr = parse_condition();
8986         statement->ifs.condition = expr;
8987         /* §6.8.4.1:1  The controlling expression of an if statement shall have
8988          *             scalar type. */
8989         semantic_condition(expr, "condition of 'if'-statment");
8990
8991         statement_t *const true_stmt = parse_inner_statement();
8992         statement->ifs.true_statement = true_stmt;
8993         rem_anchor_token(T_else);
8994
8995         if (true_stmt->kind == STATEMENT_EMPTY) {
8996                 warningf(WARN_EMPTY_BODY, HERE,
8997                         "suggest braces around empty body in an ‘if’ statement");
8998         }
8999
9000         if (next_if(T_else)) {
9001                 statement->ifs.false_statement = parse_inner_statement();
9002
9003                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9004                         warningf(WARN_EMPTY_BODY, HERE,
9005                                         "suggest braces around empty body in an ‘if’ statement");
9006                 }
9007         } else if (true_stmt->kind == STATEMENT_IF &&
9008                         true_stmt->ifs.false_statement != NULL) {
9009                 source_position_t const *const pos = &true_stmt->base.source_position;
9010                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9011         }
9012
9013         POP_SCOPE();
9014         POP_PARENT();
9015         return statement;
9016 }
9017
9018 /**
9019  * Check that all enums are handled in a switch.
9020  *
9021  * @param statement  the switch statement to check
9022  */
9023 static void check_enum_cases(const switch_statement_t *statement)
9024 {
9025         if (!is_warn_on(WARN_SWITCH_ENUM))
9026                 return;
9027         const type_t *type = skip_typeref(statement->expression->base.type);
9028         if (! is_type_enum(type))
9029                 return;
9030         const enum_type_t *enumt = &type->enumt;
9031
9032         /* if we have a default, no warnings */
9033         if (statement->default_label != NULL)
9034                 return;
9035
9036         /* FIXME: calculation of value should be done while parsing */
9037         /* TODO: quadratic algorithm here. Change to an n log n one */
9038         long            last_value = -1;
9039         const entity_t *entry      = enumt->enume->base.next;
9040         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9041              entry = entry->base.next) {
9042                 const expression_t *expression = entry->enum_value.value;
9043                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9044                 bool                found      = false;
9045                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9046                         if (l->expression == NULL)
9047                                 continue;
9048                         if (l->first_case <= value && value <= l->last_case) {
9049                                 found = true;
9050                                 break;
9051                         }
9052                 }
9053                 if (!found) {
9054                         source_position_t const *const pos = &statement->base.source_position;
9055                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9056                 }
9057                 last_value = value;
9058         }
9059 }
9060
9061 /**
9062  * Parse a switch statement.
9063  */
9064 static statement_t *parse_switch(void)
9065 {
9066         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9067
9068         eat(T_switch);
9069
9070         PUSH_PARENT(statement);
9071         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9072
9073         expression_t *const expr = parse_condition();
9074         type_t       *      type = skip_typeref(expr->base.type);
9075         if (is_type_integer(type)) {
9076                 type = promote_integer(type);
9077                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9078                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9079                 }
9080         } else if (is_type_valid(type)) {
9081                 errorf(&expr->base.source_position,
9082                        "switch quantity is not an integer, but '%T'", type);
9083                 type = type_error_type;
9084         }
9085         statement->switchs.expression = create_implicit_cast(expr, type);
9086
9087         switch_statement_t *rem = current_switch;
9088         current_switch          = &statement->switchs;
9089         statement->switchs.body = parse_inner_statement();
9090         current_switch          = rem;
9091
9092         if (statement->switchs.default_label == NULL) {
9093                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9094         }
9095         check_enum_cases(&statement->switchs);
9096
9097         POP_SCOPE();
9098         POP_PARENT();
9099         return statement;
9100 }
9101
9102 static statement_t *parse_loop_body(statement_t *const loop)
9103 {
9104         statement_t *const rem = current_loop;
9105         current_loop = loop;
9106
9107         statement_t *const body = parse_inner_statement();
9108
9109         current_loop = rem;
9110         return body;
9111 }
9112
9113 /**
9114  * Parse a while statement.
9115  */
9116 static statement_t *parse_while(void)
9117 {
9118         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9119
9120         eat(T_while);
9121
9122         PUSH_PARENT(statement);
9123         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9124
9125         expression_t *const cond = parse_condition();
9126         statement->whiles.condition = cond;
9127         /* §6.8.5:2    The controlling expression of an iteration statement shall
9128          *             have scalar type. */
9129         semantic_condition(cond, "condition of 'while'-statement");
9130
9131         statement->whiles.body = parse_loop_body(statement);
9132
9133         POP_SCOPE();
9134         POP_PARENT();
9135         return statement;
9136 }
9137
9138 /**
9139  * Parse a do statement.
9140  */
9141 static statement_t *parse_do(void)
9142 {
9143         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9144
9145         eat(T_do);
9146
9147         PUSH_PARENT(statement);
9148         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9149
9150         add_anchor_token(T_while);
9151         statement->do_while.body = parse_loop_body(statement);
9152         rem_anchor_token(T_while);
9153
9154         expect(T_while);
9155         expression_t *const cond = parse_condition();
9156         statement->do_while.condition = cond;
9157         /* §6.8.5:2    The controlling expression of an iteration statement shall
9158          *             have scalar type. */
9159         semantic_condition(cond, "condition of 'do-while'-statement");
9160         expect(';');
9161
9162         POP_SCOPE();
9163         POP_PARENT();
9164         return statement;
9165 }
9166
9167 /**
9168  * Parse a for statement.
9169  */
9170 static statement_t *parse_for(void)
9171 {
9172         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9173
9174         eat(T_for);
9175
9176         PUSH_PARENT(statement);
9177         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9178
9179         add_anchor_token(')');
9180         expect('(');
9181
9182         PUSH_EXTENSION();
9183
9184         if (next_if(';')) {
9185         } else if (is_declaration_specifier(&token)) {
9186                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9187         } else {
9188                 add_anchor_token(';');
9189                 expression_t *const init = parse_expression();
9190                 statement->fors.initialisation = init;
9191                 mark_vars_read(init, ENT_ANY);
9192                 if (!expression_has_effect(init)) {
9193                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9194                 }
9195                 rem_anchor_token(';');
9196                 expect(';');
9197         }
9198
9199         POP_EXTENSION();
9200
9201         if (token.kind != ';') {
9202                 add_anchor_token(';');
9203                 expression_t *const cond = parse_expression();
9204                 statement->fors.condition = cond;
9205                 /* §6.8.5:2    The controlling expression of an iteration statement
9206                  *             shall have scalar type. */
9207                 semantic_condition(cond, "condition of 'for'-statement");
9208                 mark_vars_read(cond, NULL);
9209                 rem_anchor_token(';');
9210         }
9211         expect(';');
9212         if (token.kind != ')') {
9213                 expression_t *const step = parse_expression();
9214                 statement->fors.step = step;
9215                 mark_vars_read(step, ENT_ANY);
9216                 if (!expression_has_effect(step)) {
9217                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9218                 }
9219         }
9220         rem_anchor_token(')');
9221         expect(')');
9222         statement->fors.body = parse_loop_body(statement);
9223
9224         POP_SCOPE();
9225         POP_PARENT();
9226         return statement;
9227 }
9228
9229 /**
9230  * Parse a goto statement.
9231  */
9232 static statement_t *parse_goto(void)
9233 {
9234         statement_t *statement;
9235         if (GNU_MODE && look_ahead(1)->kind == '*') {
9236                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9237                 eat(T_goto);
9238                 eat('*');
9239
9240                 expression_t *expression = parse_expression();
9241                 mark_vars_read(expression, NULL);
9242
9243                 /* Argh: although documentation says the expression must be of type void*,
9244                  * gcc accepts anything that can be casted into void* without error */
9245                 type_t *type = expression->base.type;
9246
9247                 if (type != type_error_type) {
9248                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9249                                 errorf(&expression->base.source_position,
9250                                         "cannot convert to a pointer type");
9251                         } else if (type != type_void_ptr) {
9252                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9253                         }
9254                         expression = create_implicit_cast(expression, type_void_ptr);
9255                 }
9256
9257                 statement->computed_goto.expression = expression;
9258         } else {
9259                 statement = allocate_statement_zero(STATEMENT_GOTO);
9260                 eat(T_goto);
9261
9262                 label_t *const label = get_label("while parsing goto");
9263                 if (label) {
9264                         label->used            = true;
9265                         statement->gotos.label = label;
9266
9267                         /* remember the goto's in a list for later checking */
9268                         *goto_anchor = &statement->gotos;
9269                         goto_anchor  = &statement->gotos.next;
9270                 } else {
9271                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9272                 }
9273         }
9274
9275         expect(';');
9276         return statement;
9277 }
9278
9279 /**
9280  * Parse a continue statement.
9281  */
9282 static statement_t *parse_continue(void)
9283 {
9284         if (current_loop == NULL) {
9285                 errorf(HERE, "continue statement not within loop");
9286         }
9287
9288         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9289
9290         eat(T_continue);
9291         expect(';');
9292         return statement;
9293 }
9294
9295 /**
9296  * Parse a break statement.
9297  */
9298 static statement_t *parse_break(void)
9299 {
9300         if (current_switch == NULL && current_loop == NULL) {
9301                 errorf(HERE, "break statement not within loop or switch");
9302         }
9303
9304         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9305
9306         eat(T_break);
9307         expect(';');
9308         return statement;
9309 }
9310
9311 /**
9312  * Parse a __leave statement.
9313  */
9314 static statement_t *parse_leave_statement(void)
9315 {
9316         if (current_try == NULL) {
9317                 errorf(HERE, "__leave statement not within __try");
9318         }
9319
9320         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9321
9322         eat(T___leave);
9323         expect(';');
9324         return statement;
9325 }
9326
9327 /**
9328  * Check if a given entity represents a local variable.
9329  */
9330 static bool is_local_variable(const entity_t *entity)
9331 {
9332         if (entity->kind != ENTITY_VARIABLE)
9333                 return false;
9334
9335         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9336         case STORAGE_CLASS_AUTO:
9337         case STORAGE_CLASS_REGISTER: {
9338                 const type_t *type = skip_typeref(entity->declaration.type);
9339                 if (is_type_function(type)) {
9340                         return false;
9341                 } else {
9342                         return true;
9343                 }
9344         }
9345         default:
9346                 return false;
9347         }
9348 }
9349
9350 /**
9351  * Check if a given expression represents a local variable.
9352  */
9353 static bool expression_is_local_variable(const expression_t *expression)
9354 {
9355         if (expression->base.kind != EXPR_REFERENCE) {
9356                 return false;
9357         }
9358         const entity_t *entity = expression->reference.entity;
9359         return is_local_variable(entity);
9360 }
9361
9362 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9363 {
9364         if (c_mode & _CXX || strict_mode) {
9365                 errorf(pos, msg);
9366         } else {
9367                 warningf(WARN_OTHER, pos, msg);
9368         }
9369 }
9370
9371 /**
9372  * Parse a return statement.
9373  */
9374 static statement_t *parse_return(void)
9375 {
9376         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9377         eat(T_return);
9378
9379         expression_t *return_value = NULL;
9380         if (token.kind != ';') {
9381                 return_value = parse_expression();
9382                 mark_vars_read(return_value, NULL);
9383         }
9384
9385         const type_t *const func_type = skip_typeref(current_function->base.type);
9386         assert(is_type_function(func_type));
9387         type_t *const return_type = skip_typeref(func_type->function.return_type);
9388
9389         source_position_t const *const pos = &statement->base.source_position;
9390         if (return_value != NULL) {
9391                 type_t *return_value_type = skip_typeref(return_value->base.type);
9392
9393                 if (is_type_void(return_type)) {
9394                         if (!is_type_void(return_value_type)) {
9395                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9396                                 /* Only warn in C mode, because GCC does the same */
9397                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9398                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9399                                 /* Only warn in C mode, because GCC does the same */
9400                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9401                         }
9402                 } else {
9403                         assign_error_t error = semantic_assign(return_type, return_value);
9404                         report_assign_error(error, return_type, return_value, "'return'",
9405                                             pos);
9406                 }
9407                 return_value = create_implicit_cast(return_value, return_type);
9408                 /* check for returning address of a local var */
9409                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9410                         const expression_t *expression = return_value->unary.value;
9411                         if (expression_is_local_variable(expression)) {
9412                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9413                         }
9414                 }
9415         } else if (!is_type_void(return_type)) {
9416                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9417                 err_or_warn(pos, "'return' without value, in function returning non-void");
9418         }
9419         statement->returns.value = return_value;
9420
9421         expect(';');
9422         return statement;
9423 }
9424
9425 /**
9426  * Parse a declaration statement.
9427  */
9428 static statement_t *parse_declaration_statement(void)
9429 {
9430         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9431
9432         entity_t *before = current_scope->last_entity;
9433         if (GNU_MODE) {
9434                 parse_external_declaration();
9435         } else {
9436                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9437         }
9438
9439         declaration_statement_t *const decl  = &statement->declaration;
9440         entity_t                *const begin =
9441                 before != NULL ? before->base.next : current_scope->entities;
9442         decl->declarations_begin = begin;
9443         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9444
9445         return statement;
9446 }
9447
9448 /**
9449  * Parse an expression statement, ie. expr ';'.
9450  */
9451 static statement_t *parse_expression_statement(void)
9452 {
9453         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9454
9455         expression_t *const expr         = parse_expression();
9456         statement->expression.expression = expr;
9457         mark_vars_read(expr, ENT_ANY);
9458
9459         expect(';');
9460         return statement;
9461 }
9462
9463 /**
9464  * Parse a microsoft __try { } __finally { } or
9465  * __try{ } __except() { }
9466  */
9467 static statement_t *parse_ms_try_statment(void)
9468 {
9469         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9470         eat(T___try);
9471
9472         PUSH_PARENT(statement);
9473
9474         ms_try_statement_t *rem = current_try;
9475         current_try = &statement->ms_try;
9476         statement->ms_try.try_statement = parse_compound_statement(false);
9477         current_try = rem;
9478
9479         POP_PARENT();
9480
9481         if (next_if(T___except)) {
9482                 expression_t *const expr = parse_condition();
9483                 type_t       *      type = skip_typeref(expr->base.type);
9484                 if (is_type_integer(type)) {
9485                         type = promote_integer(type);
9486                 } else if (is_type_valid(type)) {
9487                         errorf(&expr->base.source_position,
9488                                "__expect expression is not an integer, but '%T'", type);
9489                         type = type_error_type;
9490                 }
9491                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9492         } else if (!next_if(T__finally)) {
9493                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9494         }
9495         statement->ms_try.final_statement = parse_compound_statement(false);
9496         return statement;
9497 }
9498
9499 static statement_t *parse_empty_statement(void)
9500 {
9501         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9502         statement_t *const statement = create_empty_statement();
9503         eat(';');
9504         return statement;
9505 }
9506
9507 static statement_t *parse_local_label_declaration(void)
9508 {
9509         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9510
9511         eat(T___label__);
9512
9513         entity_t *begin   = NULL;
9514         entity_t *end     = NULL;
9515         entity_t **anchor = &begin;
9516         add_anchor_token(';');
9517         add_anchor_token(',');
9518         do {
9519                 source_position_t pos;
9520                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9521                 if (symbol) {
9522                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9523                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9524                                 source_position_t const *const ppos = &entity->base.source_position;
9525                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9526                         } else {
9527                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9528                                 entity->base.parent_scope = current_scope;
9529
9530                                 *anchor = entity;
9531                                 anchor  = &entity->base.next;
9532                                 end     = entity;
9533
9534                                 environment_push(entity);
9535                         }
9536                 }
9537         } while (next_if(','));
9538         rem_anchor_token(',');
9539         rem_anchor_token(';');
9540         expect(';');
9541         statement->declaration.declarations_begin = begin;
9542         statement->declaration.declarations_end   = end;
9543         return statement;
9544 }
9545
9546 static void parse_namespace_definition(void)
9547 {
9548         eat(T_namespace);
9549
9550         entity_t *entity = NULL;
9551         symbol_t *symbol = NULL;
9552
9553         if (token.kind == T_IDENTIFIER) {
9554                 symbol = token.base.symbol;
9555                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9556                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9557                         entity = NULL;
9558                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9559                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9560                         }
9561                 }
9562                 eat(T_IDENTIFIER);
9563         }
9564
9565         if (entity == NULL) {
9566                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9567                 entity->base.parent_scope = current_scope;
9568         }
9569
9570         if (token.kind == '=') {
9571                 /* TODO: parse namespace alias */
9572                 panic("namespace alias definition not supported yet");
9573         }
9574
9575         environment_push(entity);
9576         append_entity(current_scope, entity);
9577
9578         PUSH_SCOPE(&entity->namespacee.members);
9579         PUSH_CURRENT_ENTITY(entity);
9580
9581         add_anchor_token('}');
9582         expect('{');
9583         parse_externals();
9584         rem_anchor_token('}');
9585         expect('}');
9586
9587         POP_CURRENT_ENTITY();
9588         POP_SCOPE();
9589 }
9590
9591 /**
9592  * Parse a statement.
9593  * There's also parse_statement() which additionally checks for
9594  * "statement has no effect" warnings
9595  */
9596 static statement_t *intern_parse_statement(void)
9597 {
9598         /* declaration or statement */
9599         statement_t *statement;
9600         switch (token.kind) {
9601         case T_IDENTIFIER: {
9602                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9603                 if (la1_type == ':') {
9604                         statement = parse_label_statement();
9605                 } else if (is_typedef_symbol(token.base.symbol)) {
9606                         statement = parse_declaration_statement();
9607                 } else {
9608                         /* it's an identifier, the grammar says this must be an
9609                          * expression statement. However it is common that users mistype
9610                          * declaration types, so we guess a bit here to improve robustness
9611                          * for incorrect programs */
9612                         switch (la1_type) {
9613                         case '&':
9614                         case '*':
9615                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9616                         default:
9617                                         statement = parse_expression_statement();
9618                                 } else {
9619                         DECLARATION_START
9620                         case T_IDENTIFIER:
9621                                         statement = parse_declaration_statement();
9622                                 }
9623                                 break;
9624                         }
9625                 }
9626                 break;
9627         }
9628
9629         case T___extension__: {
9630                 /* This can be a prefix to a declaration or an expression statement.
9631                  * We simply eat it now and parse the rest with tail recursion. */
9632                 PUSH_EXTENSION();
9633                 statement = intern_parse_statement();
9634                 POP_EXTENSION();
9635                 break;
9636         }
9637
9638         DECLARATION_START
9639                 statement = parse_declaration_statement();
9640                 break;
9641
9642         case T___label__:
9643                 statement = parse_local_label_declaration();
9644                 break;
9645
9646         case ';':         statement = parse_empty_statement();         break;
9647         case '{':         statement = parse_compound_statement(false); break;
9648         case T___leave:   statement = parse_leave_statement();         break;
9649         case T___try:     statement = parse_ms_try_statment();         break;
9650         case T_asm:       statement = parse_asm_statement();           break;
9651         case T_break:     statement = parse_break();                   break;
9652         case T_case:      statement = parse_case_statement();          break;
9653         case T_continue:  statement = parse_continue();                break;
9654         case T_default:   statement = parse_default_statement();       break;
9655         case T_do:        statement = parse_do();                      break;
9656         case T_for:       statement = parse_for();                     break;
9657         case T_goto:      statement = parse_goto();                    break;
9658         case T_if:        statement = parse_if();                      break;
9659         case T_return:    statement = parse_return();                  break;
9660         case T_switch:    statement = parse_switch();                  break;
9661         case T_while:     statement = parse_while();                   break;
9662
9663         EXPRESSION_START
9664                 statement = parse_expression_statement();
9665                 break;
9666
9667         default:
9668                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9669                 statement = create_error_statement();
9670                 eat_until_anchor();
9671                 break;
9672         }
9673
9674         return statement;
9675 }
9676
9677 /**
9678  * parse a statement and emits "statement has no effect" warning if needed
9679  * (This is really a wrapper around intern_parse_statement with check for 1
9680  *  single warning. It is needed, because for statement expressions we have
9681  *  to avoid the warning on the last statement)
9682  */
9683 static statement_t *parse_statement(void)
9684 {
9685         statement_t *statement = intern_parse_statement();
9686
9687         if (statement->kind == STATEMENT_EXPRESSION) {
9688                 expression_t *expression = statement->expression.expression;
9689                 if (!expression_has_effect(expression)) {
9690                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9691                 }
9692         }
9693
9694         return statement;
9695 }
9696
9697 /**
9698  * Parse a compound statement.
9699  */
9700 static statement_t *parse_compound_statement(bool inside_expression_statement)
9701 {
9702         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9703
9704         PUSH_PARENT(statement);
9705         PUSH_SCOPE(&statement->compound.scope);
9706
9707         eat('{');
9708         add_anchor_token('}');
9709         /* tokens, which can start a statement */
9710         /* TODO MS, __builtin_FOO */
9711         add_anchor_token('!');
9712         add_anchor_token('&');
9713         add_anchor_token('(');
9714         add_anchor_token('*');
9715         add_anchor_token('+');
9716         add_anchor_token('-');
9717         add_anchor_token(';');
9718         add_anchor_token('{');
9719         add_anchor_token('~');
9720         add_anchor_token(T_CHARACTER_CONSTANT);
9721         add_anchor_token(T_COLONCOLON);
9722         add_anchor_token(T_FLOATINGPOINT);
9723         add_anchor_token(T_IDENTIFIER);
9724         add_anchor_token(T_INTEGER);
9725         add_anchor_token(T_MINUSMINUS);
9726         add_anchor_token(T_PLUSPLUS);
9727         add_anchor_token(T_STRING_LITERAL);
9728         add_anchor_token(T__Bool);
9729         add_anchor_token(T__Complex);
9730         add_anchor_token(T__Imaginary);
9731         add_anchor_token(T___PRETTY_FUNCTION__);
9732         add_anchor_token(T___alignof__);
9733         add_anchor_token(T___attribute__);
9734         add_anchor_token(T___builtin_va_start);
9735         add_anchor_token(T___extension__);
9736         add_anchor_token(T___func__);
9737         add_anchor_token(T___imag__);
9738         add_anchor_token(T___label__);
9739         add_anchor_token(T___real__);
9740         add_anchor_token(T___thread);
9741         add_anchor_token(T_asm);
9742         add_anchor_token(T_auto);
9743         add_anchor_token(T_bool);
9744         add_anchor_token(T_break);
9745         add_anchor_token(T_case);
9746         add_anchor_token(T_char);
9747         add_anchor_token(T_class);
9748         add_anchor_token(T_const);
9749         add_anchor_token(T_const_cast);
9750         add_anchor_token(T_continue);
9751         add_anchor_token(T_default);
9752         add_anchor_token(T_delete);
9753         add_anchor_token(T_double);
9754         add_anchor_token(T_do);
9755         add_anchor_token(T_dynamic_cast);
9756         add_anchor_token(T_enum);
9757         add_anchor_token(T_extern);
9758         add_anchor_token(T_false);
9759         add_anchor_token(T_float);
9760         add_anchor_token(T_for);
9761         add_anchor_token(T_goto);
9762         add_anchor_token(T_if);
9763         add_anchor_token(T_inline);
9764         add_anchor_token(T_int);
9765         add_anchor_token(T_long);
9766         add_anchor_token(T_new);
9767         add_anchor_token(T_operator);
9768         add_anchor_token(T_register);
9769         add_anchor_token(T_reinterpret_cast);
9770         add_anchor_token(T_restrict);
9771         add_anchor_token(T_return);
9772         add_anchor_token(T_short);
9773         add_anchor_token(T_signed);
9774         add_anchor_token(T_sizeof);
9775         add_anchor_token(T_static);
9776         add_anchor_token(T_static_cast);
9777         add_anchor_token(T_struct);
9778         add_anchor_token(T_switch);
9779         add_anchor_token(T_template);
9780         add_anchor_token(T_this);
9781         add_anchor_token(T_throw);
9782         add_anchor_token(T_true);
9783         add_anchor_token(T_try);
9784         add_anchor_token(T_typedef);
9785         add_anchor_token(T_typeid);
9786         add_anchor_token(T_typename);
9787         add_anchor_token(T_typeof);
9788         add_anchor_token(T_union);
9789         add_anchor_token(T_unsigned);
9790         add_anchor_token(T_using);
9791         add_anchor_token(T_void);
9792         add_anchor_token(T_volatile);
9793         add_anchor_token(T_wchar_t);
9794         add_anchor_token(T_while);
9795
9796         statement_t **anchor            = &statement->compound.statements;
9797         bool          only_decls_so_far = true;
9798         while (token.kind != '}' && token.kind != T_EOF) {
9799                 statement_t *sub_statement = intern_parse_statement();
9800                 if (sub_statement->kind == STATEMENT_ERROR) {
9801                         break;
9802                 }
9803
9804                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9805                         only_decls_so_far = false;
9806                 } else if (!only_decls_so_far) {
9807                         source_position_t const *const pos = &sub_statement->base.source_position;
9808                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9809                 }
9810
9811                 *anchor = sub_statement;
9812                 anchor  = &sub_statement->base.next;
9813         }
9814         expect('}');
9815
9816         /* look over all statements again to produce no effect warnings */
9817         if (is_warn_on(WARN_UNUSED_VALUE)) {
9818                 statement_t *sub_statement = statement->compound.statements;
9819                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9820                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9821                                 continue;
9822                         /* don't emit a warning for the last expression in an expression
9823                          * statement as it has always an effect */
9824                         if (inside_expression_statement && sub_statement->base.next == NULL)
9825                                 continue;
9826
9827                         expression_t *expression = sub_statement->expression.expression;
9828                         if (!expression_has_effect(expression)) {
9829                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9830                         }
9831                 }
9832         }
9833
9834         rem_anchor_token(T_while);
9835         rem_anchor_token(T_wchar_t);
9836         rem_anchor_token(T_volatile);
9837         rem_anchor_token(T_void);
9838         rem_anchor_token(T_using);
9839         rem_anchor_token(T_unsigned);
9840         rem_anchor_token(T_union);
9841         rem_anchor_token(T_typeof);
9842         rem_anchor_token(T_typename);
9843         rem_anchor_token(T_typeid);
9844         rem_anchor_token(T_typedef);
9845         rem_anchor_token(T_try);
9846         rem_anchor_token(T_true);
9847         rem_anchor_token(T_throw);
9848         rem_anchor_token(T_this);
9849         rem_anchor_token(T_template);
9850         rem_anchor_token(T_switch);
9851         rem_anchor_token(T_struct);
9852         rem_anchor_token(T_static_cast);
9853         rem_anchor_token(T_static);
9854         rem_anchor_token(T_sizeof);
9855         rem_anchor_token(T_signed);
9856         rem_anchor_token(T_short);
9857         rem_anchor_token(T_return);
9858         rem_anchor_token(T_restrict);
9859         rem_anchor_token(T_reinterpret_cast);
9860         rem_anchor_token(T_register);
9861         rem_anchor_token(T_operator);
9862         rem_anchor_token(T_new);
9863         rem_anchor_token(T_long);
9864         rem_anchor_token(T_int);
9865         rem_anchor_token(T_inline);
9866         rem_anchor_token(T_if);
9867         rem_anchor_token(T_goto);
9868         rem_anchor_token(T_for);
9869         rem_anchor_token(T_float);
9870         rem_anchor_token(T_false);
9871         rem_anchor_token(T_extern);
9872         rem_anchor_token(T_enum);
9873         rem_anchor_token(T_dynamic_cast);
9874         rem_anchor_token(T_do);
9875         rem_anchor_token(T_double);
9876         rem_anchor_token(T_delete);
9877         rem_anchor_token(T_default);
9878         rem_anchor_token(T_continue);
9879         rem_anchor_token(T_const_cast);
9880         rem_anchor_token(T_const);
9881         rem_anchor_token(T_class);
9882         rem_anchor_token(T_char);
9883         rem_anchor_token(T_case);
9884         rem_anchor_token(T_break);
9885         rem_anchor_token(T_bool);
9886         rem_anchor_token(T_auto);
9887         rem_anchor_token(T_asm);
9888         rem_anchor_token(T___thread);
9889         rem_anchor_token(T___real__);
9890         rem_anchor_token(T___label__);
9891         rem_anchor_token(T___imag__);
9892         rem_anchor_token(T___func__);
9893         rem_anchor_token(T___extension__);
9894         rem_anchor_token(T___builtin_va_start);
9895         rem_anchor_token(T___attribute__);
9896         rem_anchor_token(T___alignof__);
9897         rem_anchor_token(T___PRETTY_FUNCTION__);
9898         rem_anchor_token(T__Imaginary);
9899         rem_anchor_token(T__Complex);
9900         rem_anchor_token(T__Bool);
9901         rem_anchor_token(T_STRING_LITERAL);
9902         rem_anchor_token(T_PLUSPLUS);
9903         rem_anchor_token(T_MINUSMINUS);
9904         rem_anchor_token(T_INTEGER);
9905         rem_anchor_token(T_IDENTIFIER);
9906         rem_anchor_token(T_FLOATINGPOINT);
9907         rem_anchor_token(T_COLONCOLON);
9908         rem_anchor_token(T_CHARACTER_CONSTANT);
9909         rem_anchor_token('~');
9910         rem_anchor_token('{');
9911         rem_anchor_token(';');
9912         rem_anchor_token('-');
9913         rem_anchor_token('+');
9914         rem_anchor_token('*');
9915         rem_anchor_token('(');
9916         rem_anchor_token('&');
9917         rem_anchor_token('!');
9918         rem_anchor_token('}');
9919
9920         POP_SCOPE();
9921         POP_PARENT();
9922         return statement;
9923 }
9924
9925 /**
9926  * Check for unused global static functions and variables
9927  */
9928 static void check_unused_globals(void)
9929 {
9930         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9931                 return;
9932
9933         for (const entity_t *entity = file_scope->entities; entity != NULL;
9934              entity = entity->base.next) {
9935                 if (!is_declaration(entity))
9936                         continue;
9937
9938                 const declaration_t *declaration = &entity->declaration;
9939                 if (declaration->used                  ||
9940                     declaration->modifiers & DM_UNUSED ||
9941                     declaration->modifiers & DM_USED   ||
9942                     declaration->storage_class != STORAGE_CLASS_STATIC)
9943                         continue;
9944
9945                 warning_t   why;
9946                 char const *s;
9947                 if (entity->kind == ENTITY_FUNCTION) {
9948                         /* inhibit warning for static inline functions */
9949                         if (entity->function.is_inline)
9950                                 continue;
9951
9952                         why = WARN_UNUSED_FUNCTION;
9953                         s   = entity->function.statement != NULL ? "defined" : "declared";
9954                 } else {
9955                         why = WARN_UNUSED_VARIABLE;
9956                         s   = "defined";
9957                 }
9958
9959                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
9960         }
9961 }
9962
9963 static void parse_global_asm(void)
9964 {
9965         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
9966
9967         eat(T_asm);
9968         add_anchor_token(';');
9969         add_anchor_token(')');
9970         add_anchor_token(T_STRING_LITERAL);
9971         expect('(');
9972
9973         rem_anchor_token(T_STRING_LITERAL);
9974         statement->asms.asm_text = parse_string_literals("global asm");
9975         statement->base.next     = unit->global_asm;
9976         unit->global_asm         = statement;
9977
9978         rem_anchor_token(')');
9979         expect(')');
9980         rem_anchor_token(';');
9981         expect(';');
9982 }
9983
9984 static void parse_linkage_specification(void)
9985 {
9986         eat(T_extern);
9987
9988         source_position_t const pos     = *HERE;
9989         char const       *const linkage = parse_string_literals(NULL).begin;
9990
9991         linkage_kind_t old_linkage = current_linkage;
9992         linkage_kind_t new_linkage;
9993         if (streq(linkage, "C")) {
9994                 new_linkage = LINKAGE_C;
9995         } else if (streq(linkage, "C++")) {
9996                 new_linkage = LINKAGE_CXX;
9997         } else {
9998                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
9999                 new_linkage = LINKAGE_C;
10000         }
10001         current_linkage = new_linkage;
10002
10003         if (next_if('{')) {
10004                 parse_externals();
10005                 expect('}');
10006         } else {
10007                 parse_external();
10008         }
10009
10010         assert(current_linkage == new_linkage);
10011         current_linkage = old_linkage;
10012 }
10013
10014 static void parse_external(void)
10015 {
10016         switch (token.kind) {
10017                 case T_extern:
10018                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10019                                 parse_linkage_specification();
10020                         } else {
10021                 DECLARATION_START_NO_EXTERN
10022                 case T_IDENTIFIER:
10023                 case T___extension__:
10024                 /* tokens below are for implicit int */
10025                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10026                               implicit int) */
10027                 case '*':  /* * x; -> int* x; */
10028                 case '(':  /* (x); -> int (x); */
10029                                 PUSH_EXTENSION();
10030                                 parse_external_declaration();
10031                                 POP_EXTENSION();
10032                         }
10033                         return;
10034
10035                 case T_asm:
10036                         parse_global_asm();
10037                         return;
10038
10039                 case T_namespace:
10040                         parse_namespace_definition();
10041                         return;
10042
10043                 case ';':
10044                         if (!strict_mode) {
10045                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10046                                 eat(';');
10047                                 return;
10048                         }
10049                         /* FALLTHROUGH */
10050
10051                 default:
10052                         errorf(HERE, "stray %K outside of function", &token);
10053                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10054                                 eat_until_matching_token(token.kind);
10055                         next_token();
10056                         return;
10057         }
10058 }
10059
10060 static void parse_externals(void)
10061 {
10062         add_anchor_token('}');
10063         add_anchor_token(T_EOF);
10064
10065 #ifndef NDEBUG
10066         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10067         unsigned short token_anchor_copy[T_LAST_TOKEN];
10068         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10069 #endif
10070
10071         while (token.kind != T_EOF && token.kind != '}') {
10072 #ifndef NDEBUG
10073                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10074                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10075                         if (count != 0) {
10076                                 /* the anchor set and its copy differs */
10077                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10078                         }
10079                 }
10080                 if (in_gcc_extension) {
10081                         /* an gcc extension scope was not closed */
10082                         internal_errorf(HERE, "Leaked __extension__");
10083                 }
10084 #endif
10085
10086                 parse_external();
10087         }
10088
10089         rem_anchor_token(T_EOF);
10090         rem_anchor_token('}');
10091 }
10092
10093 /**
10094  * Parse a translation unit.
10095  */
10096 static void parse_translation_unit(void)
10097 {
10098         add_anchor_token(T_EOF);
10099
10100         while (true) {
10101                 parse_externals();
10102
10103                 if (token.kind == T_EOF)
10104                         break;
10105
10106                 errorf(HERE, "stray %K outside of function", &token);
10107                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10108                         eat_until_matching_token(token.kind);
10109                 next_token();
10110         }
10111 }
10112
10113 void set_default_visibility(elf_visibility_tag_t visibility)
10114 {
10115         default_visibility = visibility;
10116 }
10117
10118 /**
10119  * Parse the input.
10120  *
10121  * @return  the translation unit or NULL if errors occurred.
10122  */
10123 void start_parsing(void)
10124 {
10125         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10126         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10127         error_count       = 0;
10128         warning_count     = 0;
10129
10130         print_to_file(stderr);
10131
10132         assert(unit == NULL);
10133         unit = allocate_ast_zero(sizeof(unit[0]));
10134
10135         assert(file_scope == NULL);
10136         file_scope = &unit->scope;
10137
10138         assert(current_scope == NULL);
10139         scope_push(&unit->scope);
10140
10141         create_gnu_builtins();
10142         if (c_mode & _MS)
10143                 create_microsoft_intrinsics();
10144 }
10145
10146 translation_unit_t *finish_parsing(void)
10147 {
10148         assert(current_scope == &unit->scope);
10149         scope_pop(NULL);
10150
10151         assert(file_scope == &unit->scope);
10152         check_unused_globals();
10153         file_scope = NULL;
10154
10155         DEL_ARR_F(environment_stack);
10156         DEL_ARR_F(label_stack);
10157
10158         translation_unit_t *result = unit;
10159         unit = NULL;
10160         return result;
10161 }
10162
10163 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10164  * are given length one. */
10165 static void complete_incomplete_arrays(void)
10166 {
10167         size_t n = ARR_LEN(incomplete_arrays);
10168         for (size_t i = 0; i != n; ++i) {
10169                 declaration_t *const decl = incomplete_arrays[i];
10170                 type_t        *const type = skip_typeref(decl->type);
10171
10172                 if (!is_type_incomplete(type))
10173                         continue;
10174
10175                 source_position_t const *const pos = &decl->base.source_position;
10176                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10177
10178                 type_t *const new_type = duplicate_type(type);
10179                 new_type->array.size_constant     = true;
10180                 new_type->array.has_implicit_size = true;
10181                 new_type->array.size              = 1;
10182
10183                 type_t *const result = identify_new_type(new_type);
10184
10185                 decl->type = result;
10186         }
10187 }
10188
10189 static void prepare_main_collect2(entity_t *const entity)
10190 {
10191         PUSH_SCOPE(&entity->function.statement->compound.scope);
10192
10193         // create call to __main
10194         symbol_t *symbol         = symbol_table_insert("__main");
10195         entity_t *subsubmain_ent
10196                 = create_implicit_function(symbol, &builtin_source_position);
10197
10198         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10199         type_t       *ftype       = subsubmain_ent->declaration.type;
10200         ref->base.source_position = builtin_source_position;
10201         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10202         ref->reference.entity     = subsubmain_ent;
10203
10204         expression_t *call = allocate_expression_zero(EXPR_CALL);
10205         call->base.source_position = builtin_source_position;
10206         call->base.type            = type_void;
10207         call->call.function        = ref;
10208
10209         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10210         expr_statement->base.source_position  = builtin_source_position;
10211         expr_statement->expression.expression = call;
10212
10213         statement_t *statement = entity->function.statement;
10214         assert(statement->kind == STATEMENT_COMPOUND);
10215         compound_statement_t *compounds = &statement->compound;
10216
10217         expr_statement->base.next = compounds->statements;
10218         compounds->statements     = expr_statement;
10219
10220         POP_SCOPE();
10221 }
10222
10223 void parse(void)
10224 {
10225         lookahead_bufpos = 0;
10226         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10227                 next_token();
10228         }
10229         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10230         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10231         parse_translation_unit();
10232         complete_incomplete_arrays();
10233         DEL_ARR_F(incomplete_arrays);
10234         incomplete_arrays = NULL;
10235 }
10236
10237 /**
10238  * Initialize the parser.
10239  */
10240 void init_parser(void)
10241 {
10242         sym_anonymous = symbol_table_insert("<anonymous>");
10243
10244         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10245
10246         init_expression_parsers();
10247         obstack_init(&temp_obst);
10248 }
10249
10250 /**
10251  * Terminate the parser.
10252  */
10253 void exit_parser(void)
10254 {
10255         obstack_free(&temp_obst, NULL);
10256 }