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