nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "preprocessor.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "ast2firm.h"
  45 #include "adt/bitfiddle.h"
  46 #include "adt/error.h"
  47 #include "adt/array.h"
  48
  49 //#define PRINT_TOKENS
  50 #define MAX_LOOKAHEAD 1
  51
  52 typedef struct {
  53         entity_t           *old_entity;
  54         symbol_t           *symbol;
  55         entity_namespace_t  namespc;
  56 } stack_entry_t;
  57
  58 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  59 struct declaration_specifiers_t {
  60         position_t      pos;
  61         storage_class_t storage_class;
  62         unsigned char   alignment;         /**< Alignment, 0 if not set. */
  63         bool            is_inline    : 1;
  64         bool            thread_local : 1;
  65         attribute_t    *attributes;        /**< list of attributes */
  66         type_t         *type;
  67 };
  68
  69 /**
  70  * An environment for parsing initializers (and compound literals).
  71  */
  72 typedef struct parse_initializer_env_t {
  73         type_t     *type;   /**< the type of the initializer. In case of an
  74                                  array type with unspecified size this gets
  75                                  adjusted to the actual size. */
  76         entity_t   *entity; /**< the variable that is initialized if any */
  77         bool        must_be_constant;
  78 } parse_initializer_env_t;
  79
  80 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  81
  82 /** The current token. */
  83 static token_t              token;
  84 /** The lookahead ring-buffer. */
  85 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  86 /** Position of the next token in the lookahead buffer. */
  87 static size_t               lookahead_bufpos;
  88 static stack_entry_t       *environment_stack = NULL;
  89 static stack_entry_t       *label_stack       = NULL;
  90 static scope_t             *file_scope        = NULL;
  91 static scope_t             *current_scope     = NULL;
  92 /** Point to the current function declaration if inside a function. */
  93 static function_t          *current_function  = NULL;
  94 static entity_t            *current_entity    = NULL;
  95 static switch_statement_t  *current_switch    = NULL;
  96 static statement_t         *current_loop      = NULL;
  97 static statement_t         *current_parent    = NULL;
  98 static ms_try_statement_t  *current_try       = NULL;
  99 static linkage_kind_t       current_linkage;
 100 static goto_statement_t    *goto_first        = NULL;
 101 static goto_statement_t   **goto_anchor       = NULL;
 102 static label_statement_t   *label_first       = NULL;
 103 static label_statement_t  **label_anchor      = NULL;
 104 /** current translation unit. */
 105 static translation_unit_t  *unit              = NULL;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_CURRENT_ENTITY(entity) \
 115         entity_t *const new_current_entity = (entity); \
 116         entity_t *const old_current_entity = current_entity; \
 117         ((void)(current_entity = new_current_entity))
 118 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 119
 120 #define PUSH_PARENT(stmt) \
 121         statement_t *const new_parent = (stmt); \
 122         statement_t *const old_parent = current_parent; \
 123         ((void)(current_parent = new_parent))
 124 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 125
 126 #define PUSH_SCOPE(scope) \
 127         size_t   const top       = environment_top(); \
 128         scope_t *const new_scope = (scope); \
 129         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 130 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 131 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 132
 133 #define PUSH_EXTENSION() \
 134         (void)0; \
 135         bool const old_gcc_extension = in_gcc_extension; \
 136         while (accept(T___extension__)) { \
 137                 in_gcc_extension = true; \
 138         } \
 139         do {} while (0)
 140 #define POP_EXTENSION() \
 141         ((void)(in_gcc_extension = old_gcc_extension))
 142
 143 /** The token anchor set */
 144 static unsigned short token_anchor_set[T_LAST_TOKEN];
 145
 146 /** The current source position. */
 147 #define HERE (&token.base.pos)
 148
 149 /** true if we are in GCC mode. */
 150 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 151
 152 static statement_t *parse_compound_statement(bool inside_expression_statement);
 153 static statement_t *parse_statement(void);
 154
 155 static expression_t *parse_subexpression(precedence_t);
 156 static expression_t *parse_expression(void);
 157 static type_t       *parse_typename(void);
 158 static void          parse_externals(void);
 159 static void          parse_external(void);
 160
 161 static void parse_compound_type_entries(compound_t *compound_declaration);
 162
 163 static void check_call_argument(type_t          *expected_type,
 164                                                                 call_argument_t *argument, unsigned pos);
 165
 166 typedef enum declarator_flags_t {
 167         DECL_FLAGS_NONE             = 0,
 168         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 169         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 170         DECL_IS_PARAMETER           = 1U << 2
 171 } declarator_flags_t;
 172
 173 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 174                                   declarator_flags_t flags);
 175
 176 static void semantic_comparison(binary_expression_t *expression);
 177
 178 #define STORAGE_CLASSES       \
 179         STORAGE_CLASSES_NO_EXTERN \
 180         case T_extern:
 181
 182 #define STORAGE_CLASSES_NO_EXTERN \
 183         case T_typedef:         \
 184         case T_static:          \
 185         case T_auto:            \
 186         case T_register:        \
 187         case T__Thread_local:
 188
 189 #define TYPE_QUALIFIERS     \
 190         case T_const:           \
 191         case T_restrict:        \
 192         case T_volatile:        \
 193         case T_inline:          \
 194         case T__forceinline:    \
 195         case T___attribute__:
 196
 197 #define COMPLEX_SPECIFIERS  \
 198         case T__Complex:
 199 #define IMAGINARY_SPECIFIERS \
 200         case T__Imaginary:
 201
 202 #define TYPE_SPECIFIERS       \
 203         case T__Bool:             \
 204         case T___builtin_va_list: \
 205         case T___typeof__:        \
 206         case T__declspec:         \
 207         case T_bool:              \
 208         case T_char:              \
 209         case T_double:            \
 210         case T_enum:              \
 211         case T_float:             \
 212         case T_int:               \
 213         case T_long:              \
 214         case T_short:             \
 215         case T_signed:            \
 216         case T_struct:            \
 217         case T_union:             \
 218         case T_unsigned:          \
 219         case T_void:              \
 220         case T_wchar_t:           \
 221         case T__int8:             \
 222         case T__int16:            \
 223         case T__int32:            \
 224         case T__int64:            \
 225         case T__int128:           \
 226         COMPLEX_SPECIFIERS        \
 227         IMAGINARY_SPECIFIERS
 228
 229 #define DECLARATION_START   \
 230         STORAGE_CLASSES         \
 231         TYPE_QUALIFIERS         \
 232         TYPE_SPECIFIERS
 233
 234 #define DECLARATION_START_NO_EXTERN \
 235         STORAGE_CLASSES_NO_EXTERN       \
 236         TYPE_QUALIFIERS                 \
 237         TYPE_SPECIFIERS
 238
 239 #define EXPRESSION_START              \
 240         case '!':                         \
 241         case '&':                         \
 242         case '(':                         \
 243         case '*':                         \
 244         case '+':                         \
 245         case '-':                         \
 246         case '~':                         \
 247         case T_ANDAND:                    \
 248         case T_CHARACTER_CONSTANT:        \
 249         case T_NUMBER:                    \
 250         case T_MINUSMINUS:                \
 251         case T_PLUSPLUS:                  \
 252         case T_STRING_LITERAL:            \
 253         case T__Alignof:                  \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___PRETTY_FUNCTION__:       \
 257         case T___builtin_classify_type:   \
 258         case T___builtin_constant_p:      \
 259         case T___builtin_isgreater:       \
 260         case T___builtin_isgreaterequal:  \
 261         case T___builtin_isless:          \
 262         case T___builtin_islessequal:     \
 263         case T___builtin_islessgreater:   \
 264         case T___builtin_isunordered:     \
 265         case T___builtin_offsetof:        \
 266         case T___builtin_va_arg:          \
 267         case T___builtin_va_copy:         \
 268         case T___builtin_va_start:        \
 269         case T___func__:                  \
 270         case T___noop:                    \
 271         case T__assume:                   \
 272         case T_delete:                    \
 273         case T_false:                     \
 274         case T_sizeof:                    \
 275         case T_throw:                     \
 276         case T_true:                      \
 277         case T___imag__:                  \
 278         case T___real__:
 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_DO_WHILE]      = sizeof(do_while_statement_t),
 303                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 304                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 305                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 306                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 307         };
 308         assert((size_t)kind < lengthof(sizes));
 309         assert(sizes[kind] != 0);
 310         return sizes[kind];
 311 }
 312
 313 /**
 314  * Returns the size of an expression node.
 315  *
 316  * @param kind  the expression kind
 317  */
 318 static size_t get_expression_struct_size(expression_kind_t kind)
 319 {
 320         static const size_t sizes[] = {
 321                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 322                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 323                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 324                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 328                 [EXPR_LITERAL_MS_NOOP]            = sizeof(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.pos    = *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.pos  = *HERE;
 391         return res;
 392 }
 393
 394 /**
 395  * Creates a new invalid expression at the source position
 396  * of the current token.
 397  */
 398 static expression_t *create_error_expression(void)
 399 {
 400         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 401         expression->base.type = type_error_type;
 402         return expression;
 403 }
 404
 405 /**
 406  * Creates a new invalid statement.
 407  */
 408 static statement_t *create_error_statement(void)
 409 {
 410         return allocate_statement_zero(STATEMENT_ERROR);
 411 }
 412
 413 /**
 414  * Allocate a new empty statement.
 415  */
 416 static statement_t *create_empty_statement(void)
 417 {
 418         return allocate_statement_zero(STATEMENT_EMPTY);
 419 }
 420
 421 /**
 422  * Returns the size of an initializer node.
 423  *
 424  * @param kind  the initializer kind
 425  */
 426 static size_t get_initializer_size(initializer_kind_t kind)
 427 {
 428         static const size_t sizes[] = {
 429                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 430                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert((size_t)kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = pp_token;
 474         next_preprocessing_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 static inline void eat(token_kind_t const kind)
 485 {
 486         assert(token.kind == kind);
 487         (void)kind;
 488         next_token();
 489 }
 490
 491 /**
 492  * Consume the current token, if it is of the expected kind.
 493  *
 494  * @param  kind  The kind of token to consume.
 495  * @return Whether the token was consumed.
 496  */
 497 static inline bool accept(token_kind_t const kind)
 498 {
 499         if (token.kind == kind) {
 500                 eat(kind);
 501                 return true;
 502         } else {
 503                 return false;
 504         }
 505 }
 506
 507 /**
 508  * Return the next token with a given lookahead.
 509  */
 510 static inline const token_t *look_ahead(size_t num)
 511 {
 512         assert(0 < num && num <= MAX_LOOKAHEAD);
 513         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 514         return &lookahead_buffer[pos];
 515 }
 516
 517 /**
 518  * Adds a token type to the token type anchor set (a multi-set).
 519  */
 520 static void add_anchor_token(token_kind_t const token_kind)
 521 {
 522         assert(token_kind < T_LAST_TOKEN);
 523         ++token_anchor_set[token_kind];
 524 }
 525
 526 /**
 527  * Remove a token type from the token type anchor set (a multi-set).
 528  */
 529 static void rem_anchor_token(token_kind_t const token_kind)
 530 {
 531         assert(token_kind < T_LAST_TOKEN);
 532         assert(token_anchor_set[token_kind] != 0);
 533         --token_anchor_set[token_kind];
 534 }
 535
 536 /**
 537  * Eat tokens until a matching token type is found.
 538  */
 539 static void eat_until_matching_token(token_kind_t const type)
 540 {
 541         token_kind_t end_token;
 542         switch (type) {
 543                 case '(': end_token = ')';  break;
 544                 case '{': end_token = '}';  break;
 545                 case '[': end_token = ']';  break;
 546                 default:  end_token = type; break;
 547         }
 548
 549         unsigned parenthesis_count = 0;
 550         unsigned brace_count       = 0;
 551         unsigned bracket_count     = 0;
 552         while (token.kind        != end_token ||
 553                parenthesis_count != 0         ||
 554                brace_count       != 0         ||
 555                bracket_count     != 0) {
 556                 switch (token.kind) {
 557                 case T_EOF: return;
 558                 case '(': ++parenthesis_count; break;
 559                 case '{': ++brace_count;       break;
 560                 case '[': ++bracket_count;     break;
 561
 562                 case ')':
 563                         if (parenthesis_count > 0)
 564                                 --parenthesis_count;
 565                         goto check_stop;
 566
 567                 case '}':
 568                         if (brace_count > 0)
 569                                 --brace_count;
 570                         goto check_stop;
 571
 572                 case ']':
 573                         if (bracket_count > 0)
 574                                 --bracket_count;
 575 check_stop:
 576                         if (token.kind        == end_token &&
 577                             parenthesis_count == 0         &&
 578                             brace_count       == 0         &&
 579                             bracket_count     == 0)
 580                                 return;
 581                         break;
 582
 583                 default:
 584                         break;
 585                 }
 586                 next_token();
 587         }
 588 }
 589
 590 /**
 591  * Eat input tokens until an anchor is found.
 592  */
 593 static void eat_until_anchor(void)
 594 {
 595         while (token_anchor_set[token.kind] == 0) {
 596                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 597                         eat_until_matching_token(token.kind);
 598                 next_token();
 599         }
 600 }
 601
 602 /**
 603  * Eat a whole block from input tokens.
 604  */
 605 static void eat_block(void)
 606 {
 607         eat_until_matching_token('{');
 608         accept('}');
 609 }
 610
 611 /**
 612  * Report a parse error because an expected token was not found.
 613  */
 614 static
 615 #if defined __GNUC__ && __GNUC__ >= 4
 616 __attribute__((sentinel))
 617 #endif
 618 void parse_error_expected(const char *message, ...)
 619 {
 620         if (message != NULL) {
 621                 errorf(HERE, "%s", message);
 622         }
 623         va_list ap;
 624         va_start(ap, message);
 625         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 626         va_end(ap);
 627 }
 628
 629 /**
 630  * Report an incompatible type.
 631  */
 632 static void type_error_incompatible(const char *msg,
 633                 const position_t *pos, type_t *type1, type_t *type2)
 634 {
 635         errorf(pos, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 636 }
 637
 638 static bool skip_till(token_kind_t const expected, char const *const context)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(context, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return false;
 647         }
 648         return true;
 649 }
 650
 651 /**
 652  * Expect the current token is the expected token.
 653  * If not, generate an error and skip until the next anchor.
 654  */
 655 static void expect(token_kind_t const expected)
 656 {
 657         if (skip_till(expected, NULL))
 658                 eat(expected);
 659 }
 660
 661 static symbol_t *expect_identifier(char const *const context,
 662                                    position_t *const pos)
 663 {
 664         if (!skip_till(T_IDENTIFIER, context))
 665                 return NULL;
 666         symbol_t *const sym = token.base.symbol;
 667         if (pos)
 668                 *pos = *HERE;
 669         eat(T_IDENTIFIER);
 670         return sym;
 671 }
 672
 673 /**
 674  * Push a given scope on the scope stack and make it the
 675  * current scope
 676  */
 677 static scope_t *scope_push(scope_t *new_scope)
 678 {
 679         if (current_scope != NULL) {
 680                 new_scope->depth = current_scope->depth + 1;
 681         }
 682
 683         scope_t *old_scope = current_scope;
 684         current_scope      = new_scope;
 685         return old_scope;
 686 }
 687
 688 /**
 689  * Pop the current scope from the scope stack.
 690  */
 691 static void scope_pop(scope_t *old_scope)
 692 {
 693         current_scope = old_scope;
 694 }
 695
 696 /**
 697  * Search an entity by its symbol in a given namespace.
 698  */
 699 static entity_t *get_entity(const symbol_t *const symbol,
 700                             namespace_tag_t namespc)
 701 {
 702         entity_t *entity = symbol->entity;
 703         for (; entity != NULL; entity = entity->base.symbol_next) {
 704                 if ((namespace_tag_t)entity->base.namespc == namespc)
 705                         return entity;
 706         }
 707
 708         return NULL;
 709 }
 710
 711 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 712  * possible. */
 713 static entity_t *get_tag(symbol_t const *const symbol,
 714                          entity_kind_tag_t const kind)
 715 {
 716         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 717         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 718                 errorf(HERE,
 719                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 720                                 symbol, &entity->base.pos);
 721                 entity = NULL;
 722         }
 723         return entity;
 724 }
 725
 726 /**
 727  * pushs an entity on the environment stack and links the corresponding symbol
 728  * it.
 729  */
 730 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 731 {
 732         symbol_t           *symbol  = entity->base.symbol;
 733         entity_namespace_t  namespc = entity->base.namespc;
 734         assert(namespc != 0);
 735
 736         /* replace/add entity into entity list of the symbol */
 737         entity_t **anchor;
 738         entity_t  *iter;
 739         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 740                 iter = *anchor;
 741                 if (iter == NULL)
 742                         break;
 743
 744                 /* replace an entry? */
 745                 if (iter->base.namespc == namespc) {
 746                         entity->base.symbol_next = iter->base.symbol_next;
 747                         break;
 748                 }
 749         }
 750         *anchor = entity;
 751
 752         /* remember old declaration */
 753         stack_entry_t entry;
 754         entry.symbol     = symbol;
 755         entry.old_entity = iter;
 756         entry.namespc    = namespc;
 757         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 758 }
 759
 760 /**
 761  * Push an entity on the environment stack.
 762  */
 763 static void environment_push(entity_t *entity)
 764 {
 765         assert(entity->base.pos.input_name != NULL);
 766         assert(entity->base.parent_scope != NULL);
 767         stack_push(&environment_stack, entity);
 768 }
 769
 770 /**
 771  * Push a declaration on the global label stack.
 772  *
 773  * @param declaration  the declaration
 774  */
 775 static void label_push(entity_t *label)
 776 {
 777         /* we abuse the parameters scope as parent for the labels */
 778         label->base.parent_scope = &current_function->parameters;
 779         stack_push(&label_stack, label);
 780 }
 781
 782 /**
 783  * pops symbols from the environment stack until @p new_top is the top element
 784  */
 785 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 786 {
 787         stack_entry_t *stack = *stack_ptr;
 788         size_t         top   = ARR_LEN(stack);
 789         size_t         i;
 790
 791         assert(new_top <= top);
 792         if (new_top == top)
 793                 return;
 794
 795         for (i = top; i > new_top; --i) {
 796                 stack_entry_t *entry = &stack[i - 1];
 797
 798                 entity_t           *old_entity = entry->old_entity;
 799                 symbol_t           *symbol     = entry->symbol;
 800                 entity_namespace_t  namespc    = entry->namespc;
 801
 802                 /* replace with old_entity/remove */
 803                 entity_t **anchor;
 804                 entity_t  *iter;
 805                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 806                         iter = *anchor;
 807                         assert(iter != NULL);
 808                         /* replace an entry? */
 809                         if (iter->base.namespc == namespc)
 810                                 break;
 811                 }
 812
 813                 /* restore definition from outer scopes (if there was one) */
 814                 if (old_entity != NULL) {
 815                         old_entity->base.symbol_next = iter->base.symbol_next;
 816                         *anchor                      = old_entity;
 817                 } else {
 818                         /* remove entry from list */
 819                         *anchor = iter->base.symbol_next;
 820                 }
 821         }
 822
 823         ARR_SHRINKLEN(*stack_ptr, new_top);
 824 }
 825
 826 /**
 827  * Pop all entries from the environment stack until the new_top
 828  * is reached.
 829  *
 830  * @param new_top  the new stack top
 831  */
 832 static void environment_pop_to(size_t new_top)
 833 {
 834         stack_pop_to(&environment_stack, new_top);
 835 }
 836
 837 /**
 838  * Pop all entries from the global label stack until the new_top
 839  * is reached.
 840  *
 841  * @param new_top  the new stack top
 842  */
 843 static void label_pop_to(size_t new_top)
 844 {
 845         stack_pop_to(&label_stack, new_top);
 846 }
 847
 848 /**
 849  * §6.3.1.1:2  Do integer promotion for a given type.
 850  *
 851  * @param type  the type to promote
 852  * @return the promoted type
 853  */
 854 static type_t *promote_integer(type_t *type)
 855 {
 856         atomic_type_kind_t akind = get_arithmetic_akind(type);
 857         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT))
 858                 type = type_int;
 859
 860         return type;
 861 }
 862
 863 /**
 864  * Check if a given expression represents a null pointer constant.
 865  *
 866  * @param expression  the expression to check
 867  */
 868 static bool is_null_pointer_constant(const expression_t *expression)
 869 {
 870         /* skip void* cast */
 871         if (expression->kind == EXPR_UNARY_CAST) {
 872                 type_t *const type = skip_typeref(expression->base.type);
 873                 if (types_compatible(type, type_void_ptr))
 874                         expression = expression->unary.value;
 875         }
 876
 877         type_t *const type = skip_typeref(expression->base.type);
 878         if (!is_type_integer(type))
 879                 return false;
 880         switch (is_constant_expression(expression)) {
 881                 case EXPR_CLASS_ERROR:    return true;
 882                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 883                 default:                  return false;
 884         }
 885 }
 886
 887 /**
 888  * Create an implicit cast expression.
 889  *
 890  * @param expression  the expression to cast
 891  * @param dest_type   the destination type
 892  */
 893 static expression_t *create_implicit_cast(expression_t *expression,
 894                                           type_t *dest_type)
 895 {
 896         type_t *const source_type = skip_typeref(expression->base.type);
 897         if (source_type == skip_typeref(dest_type))
 898                 return expression;
 899
 900         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 901         cast->unary.value   = expression;
 902         cast->base.type     = dest_type;
 903         cast->base.implicit = true;
 904
 905         return cast;
 906 }
 907
 908 typedef enum assign_error_t {
 909         ASSIGN_SUCCESS,
 910         ASSIGN_ERROR_INCOMPATIBLE,
 911         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 912         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 913         ASSIGN_WARNING_POINTER_FROM_INT,
 914         ASSIGN_WARNING_INT_FROM_POINTER
 915 } assign_error_t;
 916
 917 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, position_t const *const pos)
 918 {
 919         type_t *const orig_type_right = right->base.type;
 920         type_t *const type_left       = skip_typeref(orig_type_left);
 921         type_t *const type_right      = skip_typeref(orig_type_right);
 922
 923         switch (error) {
 924         case ASSIGN_SUCCESS:
 925                 return;
 926         case ASSIGN_ERROR_INCOMPATIBLE:
 927                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 928                 return;
 929
 930         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 931                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 932                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 933
 934                 /* the left type has all qualifiers from the right type */
 935                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 936                 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);
 937                 return;
 938         }
 939
 940         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 941                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 942                 return;
 943
 944         case ASSIGN_WARNING_POINTER_FROM_INT:
 945                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 946                 return;
 947
 948         case ASSIGN_WARNING_INT_FROM_POINTER:
 949                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 950                 return;
 951
 952         default:
 953                 panic("invalid error value");
 954         }
 955 }
 956
 957 /** Implements the rules from §6.5.16.1 */
 958 static assign_error_t semantic_assign(type_t *orig_type_left,
 959                                       const expression_t *const right)
 960 {
 961         type_t *const orig_type_right = right->base.type;
 962         type_t *const type_left       = skip_typeref(orig_type_left);
 963         type_t *const type_right      = skip_typeref(orig_type_right);
 964
 965         if (is_type_pointer(type_left)) {
 966                 if (is_null_pointer_constant(right)) {
 967                         return ASSIGN_SUCCESS;
 968                 } else if (is_type_pointer(type_right)) {
 969                         type_t *points_to_left
 970                                 = skip_typeref(type_left->pointer.points_to);
 971                         type_t *points_to_right
 972                                 = skip_typeref(type_right->pointer.points_to);
 973                         assign_error_t res = ASSIGN_SUCCESS;
 974
 975                         /* the left type has all qualifiers from the right type */
 976                         unsigned missing_qualifiers
 977                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 978                         if (missing_qualifiers != 0) {
 979                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 980                         }
 981
 982                         points_to_left  = get_unqualified_type(points_to_left);
 983                         points_to_right = get_unqualified_type(points_to_right);
 984
 985                         if (is_type_void(points_to_left))
 986                                 return res;
 987
 988                         if (is_type_void(points_to_right)) {
 989                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 990                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 991                         }
 992
 993                         if (!types_compatible(points_to_left, points_to_right)) {
 994                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 995                         }
 996
 997                         return res;
 998                 } else if (is_type_integer(type_right)) {
 999                         return ASSIGN_WARNING_POINTER_FROM_INT;
1000                 }
1001         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1002                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1003                                 && is_type_pointer(type_right))) {
1004                 return ASSIGN_SUCCESS;
1005         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1006                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1007                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1008                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1009                         return ASSIGN_SUCCESS;
1010                 }
1011         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1012                 return ASSIGN_WARNING_INT_FROM_POINTER;
1013         }
1014
1015         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1016                 return ASSIGN_SUCCESS;
1017
1018         return ASSIGN_ERROR_INCOMPATIBLE;
1019 }
1020
1021 static expression_t *parse_constant_expression(void)
1022 {
1023         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1024
1025         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1026                 errorf(&result->base.pos, "expression '%E' is not constant", result);
1027         }
1028
1029         return result;
1030 }
1031
1032 static expression_t *parse_assignment_expression(void)
1033 {
1034         return parse_subexpression(PREC_ASSIGNMENT);
1035 }
1036
1037 static void append_string(string_t const *const s)
1038 {
1039         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1040          * possible, because other tokens are grown there alongside. */
1041         obstack_grow(&ast_obstack, s->begin, s->size);
1042 }
1043
1044 static string_t finish_string(string_encoding_t const enc)
1045 {
1046         obstack_1grow(&ast_obstack, '\0');
1047         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1048         char const *const string = obstack_finish(&ast_obstack);
1049         return (string_t){ string, size, enc };
1050 }
1051
1052 static string_t concat_string_literals(void)
1053 {
1054         assert(token.kind == T_STRING_LITERAL);
1055
1056         string_t result;
1057         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1058                 append_string(&token.literal.string);
1059                 eat(T_STRING_LITERAL);
1060                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1061                 string_encoding_t enc = token.literal.string.encoding;
1062                 do {
1063                         string_encoding_t const new_enc = token.literal.string.encoding;
1064                         if (new_enc != enc && new_enc != STRING_ENCODING_CHAR) {
1065                                 if (enc == STRING_ENCODING_CHAR) {
1066                                         enc = new_enc;
1067                                 } else {
1068                                         errorf(HERE, "concatenating string literals with encodings %s and %s", get_string_encoding_prefix(enc), get_string_encoding_prefix(new_enc));
1069                                 }
1070                         }
1071                         append_string(&token.literal.string);
1072                         eat(T_STRING_LITERAL);
1073                 } while (token.kind == T_STRING_LITERAL);
1074                 result = finish_string(enc);
1075         } else {
1076                 result = token.literal.string;
1077                 eat(T_STRING_LITERAL);
1078         }
1079
1080         return result;
1081 }
1082
1083 static string_t parse_string_literals(char const *const context)
1084 {
1085         if (!skip_till(T_STRING_LITERAL, context))
1086                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1087
1088         position_t const pos = *HERE;
1089         string_t   const res = concat_string_literals();
1090
1091         if (res.encoding != STRING_ENCODING_CHAR) {
1092                 errorf(&pos, "expected plain string literal, got %s string literal", get_string_encoding_prefix(res.encoding));
1093         }
1094
1095         return res;
1096 }
1097
1098 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1099 {
1100         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1101         attribute->kind = kind;
1102         attribute->pos  = *HERE;
1103         return attribute;
1104 }
1105
1106 /**
1107  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1108  *
1109  *  attribute:
1110  *    __attribute__ ( ( attribute-list ) )
1111  *
1112  *  attribute-list:
1113  *    attrib
1114  *    attribute_list , attrib
1115  *
1116  *  attrib:
1117  *    empty
1118  *    any-word
1119  *    any-word ( identifier )
1120  *    any-word ( identifier , nonempty-expr-list )
1121  *    any-word ( expr-list )
1122  *
1123  *  where the "identifier" must not be declared as a type, and
1124  *  "any-word" may be any identifier (including one declared as a
1125  *  type), a reserved word storage class specifier, type specifier or
1126  *  type qualifier.  ??? This still leaves out most reserved keywords
1127  *  (following the old parser), shouldn't we include them, and why not
1128  *  allow identifiers declared as types to start the arguments?
1129  *
1130  *  Matze: this all looks confusing and little systematic, so we're even less
1131  *  strict and parse any list of things which are identifiers or
1132  *  (assignment-)expressions.
1133  */
1134 static attribute_argument_t *parse_attribute_arguments(void)
1135 {
1136         attribute_argument_t  *first  = NULL;
1137         attribute_argument_t **anchor = &first;
1138         if (token.kind != ')') do {
1139                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1140
1141                 /* is it an identifier */
1142                 if (token.kind == T_IDENTIFIER
1143                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1144                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1145                         argument->v.symbol = token.base.symbol;
1146                         eat(T_IDENTIFIER);
1147                 } else {
1148                         /* must be an expression */
1149                         expression_t *expression = parse_assignment_expression();
1150
1151                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1152                         argument->v.expression = expression;
1153                 }
1154
1155                 /* append argument */
1156                 *anchor = argument;
1157                 anchor  = &argument->next;
1158         } while (accept(','));
1159         expect(')');
1160         return first;
1161 }
1162
1163 static attribute_t *parse_attribute_asm(void)
1164 {
1165         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1166         eat(T_asm);
1167         expect('(');
1168         attribute->a.arguments = parse_attribute_arguments();
1169         return attribute;
1170 }
1171
1172 static attribute_t *parse_attribute_gnu_single(void)
1173 {
1174         /* parse "any-word" */
1175         symbol_t *const symbol = token.base.symbol;
1176         if (symbol == NULL) {
1177                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1178                 return NULL;
1179         }
1180
1181         attribute_kind_t  kind;
1182         char const *const name = symbol->string;
1183         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1184                 if (kind > ATTRIBUTE_GNU_LAST) {
1185                         /* special case for "__const" */
1186                         if (token.kind == T_const) {
1187                                 kind = ATTRIBUTE_GNU_CONST;
1188                                 break;
1189                         }
1190
1191                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1192                         /* TODO: we should still save the attribute in the list... */
1193                         kind = ATTRIBUTE_UNKNOWN;
1194                         break;
1195                 }
1196
1197                 const char *attribute_name = get_attribute_name(kind);
1198                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1199                         break;
1200         }
1201
1202         attribute_t *attribute = allocate_attribute_zero(kind);
1203         next_token();
1204
1205         /* parse arguments */
1206         if (accept('('))
1207                 attribute->a.arguments = parse_attribute_arguments();
1208
1209         return attribute;
1210 }
1211
1212 static attribute_t *parse_attribute_gnu(void)
1213 {
1214         attribute_t  *first  = NULL;
1215         attribute_t **anchor = &first;
1216
1217         eat(T___attribute__);
1218         add_anchor_token(')');
1219         add_anchor_token(',');
1220         expect('(');
1221         expect('(');
1222
1223         if (token.kind != ')') do {
1224                 attribute_t *attribute = parse_attribute_gnu_single();
1225                 if (attribute) {
1226                         *anchor = attribute;
1227                         anchor  = &attribute->next;
1228                 }
1229         } while (accept(','));
1230         rem_anchor_token(',');
1231         rem_anchor_token(')');
1232
1233         expect(')');
1234         expect(')');
1235         return first;
1236 }
1237
1238 /** Parse attributes. */
1239 static attribute_t *parse_attributes(attribute_t *first)
1240 {
1241         attribute_t **anchor = &first;
1242         for (;;) {
1243                 while (*anchor != NULL)
1244                         anchor = &(*anchor)->next;
1245
1246                 attribute_t *attribute;
1247                 switch (token.kind) {
1248                 case T___attribute__:
1249                         attribute = parse_attribute_gnu();
1250                         if (attribute == NULL)
1251                                 continue;
1252                         break;
1253
1254                 case T_asm:
1255                         attribute = parse_attribute_asm();
1256                         break;
1257
1258                 case T_cdecl:
1259                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1260                         eat(T_cdecl);
1261                         break;
1262
1263                 case T__fastcall:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1265                         eat(T__fastcall);
1266                         break;
1267
1268                 case T__forceinline:
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1270                         eat(T__forceinline);
1271                         break;
1272
1273                 case T__stdcall:
1274                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1275                         eat(T__stdcall);
1276                         break;
1277
1278                 case T___thiscall:
1279                         /* TODO record modifier */
1280                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1281                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1282                         eat(T___thiscall);
1283                         break;
1284
1285                 default:
1286                         return first;
1287                 }
1288
1289                 *anchor = attribute;
1290                 anchor  = &attribute->next;
1291         }
1292 }
1293
1294 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1295
1296 static entity_t *determine_lhs_ent(expression_t *const expr,
1297                                    entity_t *lhs_ent)
1298 {
1299         switch (expr->kind) {
1300                 case EXPR_REFERENCE: {
1301                         entity_t *const entity = expr->reference.entity;
1302                         /* we should only find variables as lvalues... */
1303                         if (entity->base.kind != ENTITY_VARIABLE
1304                                         && entity->base.kind != ENTITY_PARAMETER)
1305                                 return NULL;
1306
1307                         return entity;
1308                 }
1309
1310                 case EXPR_ARRAY_ACCESS: {
1311                         expression_t *const ref = expr->array_access.array_ref;
1312                         entity_t     *      ent = NULL;
1313                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1314                                 ent     = determine_lhs_ent(ref, lhs_ent);
1315                                 lhs_ent = ent;
1316                         } else {
1317                                 mark_vars_read(ref, lhs_ent);
1318                         }
1319                         mark_vars_read(expr->array_access.index, lhs_ent);
1320                         return ent;
1321                 }
1322
1323                 case EXPR_SELECT: {
1324                         mark_vars_read(expr->select.compound, lhs_ent);
1325                         if (is_type_compound(skip_typeref(expr->base.type)))
1326                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1327                         return NULL;
1328                 }
1329
1330                 case EXPR_UNARY_DEREFERENCE: {
1331                         expression_t *const val = expr->unary.value;
1332                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1333                                 /* *&x is a NOP */
1334                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1335                         } else {
1336                                 mark_vars_read(val, NULL);
1337                                 return NULL;
1338                         }
1339                 }
1340
1341                 default:
1342                         mark_vars_read(expr, NULL);
1343                         return NULL;
1344         }
1345 }
1346
1347 #define ENT_ANY ((entity_t*)-1)
1348
1349 /**
1350  * Mark declarations, which are read.  This is used to detect variables, which
1351  * are never read.
1352  * Example:
1353  * x = x + 1;
1354  *   x is not marked as "read", because it is only read to calculate its own new
1355  *   value.
1356  *
1357  * x += y; y += x;
1358  *   x and y are not detected as "not read", because multiple variables are
1359  *   involved.
1360  */
1361 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1362 {
1363         switch (expr->kind) {
1364                 case EXPR_REFERENCE: {
1365                         entity_t *const entity = expr->reference.entity;
1366                         if (entity->kind != ENTITY_VARIABLE
1367                                         && entity->kind != ENTITY_PARAMETER)
1368                                 return;
1369
1370                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1371                                 entity->variable.read = true;
1372                         }
1373                         return;
1374                 }
1375
1376                 case EXPR_CALL:
1377                         // TODO respect pure/const
1378                         mark_vars_read(expr->call.function, NULL);
1379                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1380                                 mark_vars_read(arg->expression, NULL);
1381                         }
1382                         return;
1383
1384                 case EXPR_CONDITIONAL:
1385                         // TODO lhs_decl should depend on whether true/false have an effect
1386                         mark_vars_read(expr->conditional.condition, NULL);
1387                         if (expr->conditional.true_expression != NULL)
1388                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1389                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1390                         return;
1391
1392                 case EXPR_SELECT:
1393                         if (lhs_ent == ENT_ANY
1394                                         && !is_type_compound(skip_typeref(expr->base.type)))
1395                                 lhs_ent = NULL;
1396                         mark_vars_read(expr->select.compound, lhs_ent);
1397                         return;
1398
1399                 case EXPR_ARRAY_ACCESS: {
1400                         mark_vars_read(expr->array_access.index, lhs_ent);
1401                         expression_t *const ref = expr->array_access.array_ref;
1402                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1403                                 if (lhs_ent == ENT_ANY)
1404                                         lhs_ent = NULL;
1405                         }
1406                         mark_vars_read(ref, lhs_ent);
1407                         return;
1408                 }
1409
1410                 case EXPR_VA_ARG:
1411                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1412                         return;
1413
1414                 case EXPR_VA_COPY:
1415                         mark_vars_read(expr->va_copye.src, lhs_ent);
1416                         return;
1417
1418                 case EXPR_UNARY_CAST:
1419                         /* Special case: Use void cast to mark a variable as "read" */
1420                         if (is_type_void(skip_typeref(expr->base.type)))
1421                                 lhs_ent = NULL;
1422                         goto unary;
1423
1424
1425                 case EXPR_UNARY_THROW:
1426                         if (expr->unary.value == NULL)
1427                                 return;
1428                         /* FALLTHROUGH */
1429                 case EXPR_UNARY_DEREFERENCE:
1430                 case EXPR_UNARY_DELETE:
1431                 case EXPR_UNARY_DELETE_ARRAY:
1432                         if (lhs_ent == ENT_ANY)
1433                                 lhs_ent = NULL;
1434                         goto unary;
1435
1436                 case EXPR_UNARY_NEGATE:
1437                 case EXPR_UNARY_PLUS:
1438                 case EXPR_UNARY_COMPLEMENT:
1439                 case EXPR_UNARY_NOT:
1440                 case EXPR_UNARY_TAKE_ADDRESS:
1441                 case EXPR_UNARY_POSTFIX_INCREMENT:
1442                 case EXPR_UNARY_POSTFIX_DECREMENT:
1443                 case EXPR_UNARY_PREFIX_INCREMENT:
1444                 case EXPR_UNARY_PREFIX_DECREMENT:
1445                 case EXPR_UNARY_ASSUME:
1446                 case EXPR_UNARY_IMAG:
1447                 case EXPR_UNARY_REAL:
1448 unary:
1449                         mark_vars_read(expr->unary.value, lhs_ent);
1450                         return;
1451
1452                 case EXPR_BINARY_ADD:
1453                 case EXPR_BINARY_SUB:
1454                 case EXPR_BINARY_MUL:
1455                 case EXPR_BINARY_DIV:
1456                 case EXPR_BINARY_MOD:
1457                 case EXPR_BINARY_EQUAL:
1458                 case EXPR_BINARY_NOTEQUAL:
1459                 case EXPR_BINARY_LESS:
1460                 case EXPR_BINARY_LESSEQUAL:
1461                 case EXPR_BINARY_GREATER:
1462                 case EXPR_BINARY_GREATEREQUAL:
1463                 case EXPR_BINARY_BITWISE_AND:
1464                 case EXPR_BINARY_BITWISE_OR:
1465                 case EXPR_BINARY_BITWISE_XOR:
1466                 case EXPR_BINARY_LOGICAL_AND:
1467                 case EXPR_BINARY_LOGICAL_OR:
1468                 case EXPR_BINARY_SHIFTLEFT:
1469                 case EXPR_BINARY_SHIFTRIGHT:
1470                 case EXPR_BINARY_COMMA:
1471                 case EXPR_BINARY_ISGREATER:
1472                 case EXPR_BINARY_ISGREATEREQUAL:
1473                 case EXPR_BINARY_ISLESS:
1474                 case EXPR_BINARY_ISLESSEQUAL:
1475                 case EXPR_BINARY_ISLESSGREATER:
1476                 case EXPR_BINARY_ISUNORDERED:
1477                         mark_vars_read(expr->binary.left,  lhs_ent);
1478                         mark_vars_read(expr->binary.right, lhs_ent);
1479                         return;
1480
1481                 case EXPR_BINARY_ASSIGN:
1482                 case EXPR_BINARY_MUL_ASSIGN:
1483                 case EXPR_BINARY_DIV_ASSIGN:
1484                 case EXPR_BINARY_MOD_ASSIGN:
1485                 case EXPR_BINARY_ADD_ASSIGN:
1486                 case EXPR_BINARY_SUB_ASSIGN:
1487                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1488                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1489                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1490                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1491                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1492                         if (lhs_ent == ENT_ANY)
1493                                 lhs_ent = NULL;
1494                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1495                         mark_vars_read(expr->binary.right, lhs_ent);
1496                         return;
1497                 }
1498
1499                 case EXPR_VA_START:
1500                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1501                         return;
1502
1503                 case EXPR_LITERAL_CASES:
1504                 case EXPR_LITERAL_CHARACTER:
1505                 case EXPR_ERROR:
1506                 case EXPR_STRING_LITERAL:
1507                 case EXPR_COMPOUND_LITERAL: // TODO init?
1508                 case EXPR_SIZEOF:
1509                 case EXPR_CLASSIFY_TYPE:
1510                 case EXPR_ALIGNOF:
1511                 case EXPR_FUNCNAME:
1512                 case EXPR_BUILTIN_CONSTANT_P:
1513                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1514                 case EXPR_OFFSETOF:
1515                 case EXPR_STATEMENT: // TODO
1516                 case EXPR_LABEL_ADDRESS:
1517                 case EXPR_ENUM_CONSTANT:
1518                         return;
1519         }
1520
1521         panic("unhandled expression");
1522 }
1523
1524 static designator_t *parse_designation(void)
1525 {
1526         designator_t  *result = NULL;
1527         designator_t **anchor = &result;
1528
1529         for (;;) {
1530                 designator_t *designator;
1531                 switch (token.kind) {
1532                 case '[':
1533                         designator      = allocate_ast_zero(sizeof(designator[0]));
1534                         designator->pos = *HERE;
1535                         eat('[');
1536                         add_anchor_token(']');
1537                         designator->array_index = parse_constant_expression();
1538                         rem_anchor_token(']');
1539                         expect(']');
1540                         break;
1541                 case '.':
1542                         designator      = allocate_ast_zero(sizeof(designator[0]));
1543                         designator->pos = *HERE;
1544                         eat('.');
1545                         designator->symbol = expect_identifier("while parsing designator", NULL);
1546                         if (!designator->symbol)
1547                                 return NULL;
1548                         break;
1549                 default:
1550                         expect('=');
1551                         return result;
1552                 }
1553
1554                 assert(designator != NULL);
1555                 *anchor = designator;
1556                 anchor  = &designator->next;
1557         }
1558 }
1559
1560 /**
1561  * Build an initializer from a given expression.
1562  */
1563 static initializer_t *initializer_from_expression(type_t *orig_type,
1564                                                   expression_t *expression)
1565 {
1566         /* TODO check that expression is a constant expression */
1567
1568         type_t *const type = skip_typeref(orig_type);
1569
1570         /* §6.7.8.14/15 char array may be initialized by string literals */
1571         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1572                 array_type_t *const array_type   = &type->array;
1573                 type_t       *const element_type = skip_typeref(array_type->element_type);
1574                 switch (expression->string_literal.value.encoding) {
1575                 case STRING_ENCODING_CHAR:
1576                 case STRING_ENCODING_UTF8: {
1577                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1578                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1579                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1580                                 goto make_string_init;
1581                         }
1582                         break;
1583                 }
1584
1585                 case STRING_ENCODING_CHAR16:
1586                 case STRING_ENCODING_CHAR32:
1587                 case STRING_ENCODING_WIDE: {
1588                         assert(is_type_pointer(expression->base.type));
1589                         type_t *const init_type = get_unqualified_type(expression->base.type->pointer.points_to);
1590                         if (types_compatible(get_unqualified_type(element_type), init_type)) {
1591 make_string_init:;
1592                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1593                                 init->value.value = expression;
1594                                 return init;
1595                         }
1596                         break;
1597                 }
1598                 }
1599         }
1600
1601         assign_error_t error = semantic_assign(type, expression);
1602         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1603                 return NULL;
1604         report_assign_error(error, type, expression, "initializer",
1605                             &expression->base.pos);
1606
1607         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1608         result->value.value = create_implicit_cast(expression, type);
1609
1610         return result;
1611 }
1612
1613 /**
1614  * Parses an scalar initializer.
1615  *
1616  * §6.7.8.11; eat {} without warning
1617  */
1618 static initializer_t *parse_scalar_initializer(type_t *type,
1619                                                bool must_be_constant)
1620 {
1621         /* there might be extra {} hierarchies */
1622         int braces = 0;
1623         if (token.kind == '{') {
1624                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1625                 do {
1626                         eat('{');
1627                         ++braces;
1628                 } while (token.kind == '{');
1629         }
1630
1631         expression_t *expression = parse_assignment_expression();
1632         mark_vars_read(expression, NULL);
1633         if (must_be_constant && !is_linker_constant(expression)) {
1634                 errorf(&expression->base.pos,
1635                        "initialisation expression '%E' is not constant",
1636                        expression);
1637         }
1638
1639         initializer_t *initializer = initializer_from_expression(type, expression);
1640
1641         if (initializer == NULL) {
1642                 errorf(&expression->base.pos,
1643                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1644                        expression, expression->base.type, type);
1645                 /* TODO */
1646                 return NULL;
1647         }
1648
1649         bool additional_warning_displayed = false;
1650         while (braces > 0) {
1651                 accept(',');
1652                 if (token.kind != '}') {
1653                         if (!additional_warning_displayed) {
1654                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1655                                 additional_warning_displayed = true;
1656                         }
1657                 }
1658                 eat_block();
1659                 braces--;
1660         }
1661
1662         return initializer;
1663 }
1664
1665 /**
1666  * An entry in the type path.
1667  */
1668 typedef struct type_path_entry_t type_path_entry_t;
1669 struct type_path_entry_t {
1670         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1671         union {
1672                 size_t         index;          /**< For array types: the current index. */
1673                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1674         } v;
1675 };
1676
1677 /**
1678  * A type path expression a position inside compound or array types.
1679  */
1680 typedef struct type_path_t type_path_t;
1681 struct type_path_t {
1682         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1683         type_t            *top_type;     /**< type of the element the path points */
1684         size_t             max_index;    /**< largest index in outermost array */
1685 };
1686
1687 /**
1688  * Prints a type path for debugging.
1689  */
1690 static __attribute__((unused)) void debug_print_type_path(
1691                 const type_path_t *path)
1692 {
1693         size_t len = ARR_LEN(path->path);
1694
1695         for (size_t i = 0; i < len; ++i) {
1696                 const type_path_entry_t *entry = & path->path[i];
1697
1698                 type_t *type = skip_typeref(entry->type);
1699                 if (is_type_compound(type)) {
1700                         /* in gcc mode structs can have no members */
1701                         if (entry->v.compound_entry == NULL) {
1702                                 assert(i == len-1);
1703                                 continue;
1704                         }
1705                         fprintf(stderr, ".%s",
1706                                 entry->v.compound_entry->base.symbol->string);
1707                 } else if (is_type_array(type)) {
1708                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1709                 } else {
1710                         fprintf(stderr, "-INVALID-");
1711                 }
1712         }
1713         if (path->top_type != NULL) {
1714                 fprintf(stderr, "  (");
1715                 print_type(path->top_type);
1716                 fprintf(stderr, ")");
1717         }
1718 }
1719
1720 /**
1721  * Return the top type path entry, i.e. in a path
1722  * (type).a.b returns the b.
1723  */
1724 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1725 {
1726         size_t len = ARR_LEN(path->path);
1727         assert(len > 0);
1728         return &path->path[len-1];
1729 }
1730
1731 /**
1732  * Enlarge the type path by an (empty) element.
1733  */
1734 static type_path_entry_t *append_to_type_path(type_path_t *path)
1735 {
1736         size_t len = ARR_LEN(path->path);
1737         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1738
1739         type_path_entry_t *result = & path->path[len];
1740         memset(result, 0, sizeof(result[0]));
1741         return result;
1742 }
1743
1744 /**
1745  * Descending into a sub-type. Enter the scope of the current top_type.
1746  */
1747 static void descend_into_subtype(type_path_t *path)
1748 {
1749         type_t *orig_top_type = path->top_type;
1750         type_t *top_type      = skip_typeref(orig_top_type);
1751
1752         type_path_entry_t *top = append_to_type_path(path);
1753         top->type              = top_type;
1754
1755         if (is_type_compound(top_type)) {
1756                 compound_t *const compound = top_type->compound.compound;
1757                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1758
1759                 if (entry != NULL) {
1760                         top->v.compound_entry = &entry->declaration;
1761                         path->top_type = entry->declaration.type;
1762                 } else {
1763                         path->top_type = NULL;
1764                 }
1765         } else if (is_type_array(top_type)) {
1766                 top->v.index   = 0;
1767                 path->top_type = top_type->array.element_type;
1768         } else {
1769                 assert(!is_type_valid(top_type));
1770         }
1771 }
1772
1773 /**
1774  * Pop an entry from the given type path, i.e. returning from
1775  * (type).a.b to (type).a
1776  */
1777 static void ascend_from_subtype(type_path_t *path)
1778 {
1779         type_path_entry_t *top = get_type_path_top(path);
1780
1781         path->top_type = top->type;
1782
1783         size_t len = ARR_LEN(path->path);
1784         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1785 }
1786
1787 /**
1788  * Pop entries from the given type path until the given
1789  * path level is reached.
1790  */
1791 static void ascend_to(type_path_t *path, size_t top_path_level)
1792 {
1793         size_t len = ARR_LEN(path->path);
1794
1795         while (len > top_path_level) {
1796                 ascend_from_subtype(path);
1797                 len = ARR_LEN(path->path);
1798         }
1799 }
1800
1801 static bool walk_designator(type_path_t *path, const designator_t *designator,
1802                             bool used_in_offsetof)
1803 {
1804         for (; designator != NULL; designator = designator->next) {
1805                 type_path_entry_t *top       = get_type_path_top(path);
1806                 type_t            *orig_type = top->type;
1807
1808                 type_t *type = skip_typeref(orig_type);
1809
1810                 if (designator->symbol != NULL) {
1811                         symbol_t *symbol = designator->symbol;
1812                         if (!is_type_compound(type)) {
1813                                 if (is_type_valid(type)) {
1814                                         errorf(&designator->pos,
1815                                                "'.%Y' designator used for non-compound type '%T'",
1816                                                symbol, orig_type);
1817                                 }
1818
1819                                 top->type             = type_error_type;
1820                                 top->v.compound_entry = NULL;
1821                                 orig_type             = type_error_type;
1822                         } else {
1823                                 compound_t *compound = type->compound.compound;
1824                                 entity_t   *iter     = compound->members.entities;
1825                                 for (; iter != NULL; iter = iter->base.next) {
1826                                         if (iter->base.symbol == symbol) {
1827                                                 break;
1828                                         }
1829                                 }
1830                                 if (iter == NULL) {
1831                                         errorf(&designator->pos,
1832                                                "'%T' has no member named '%Y'", orig_type, symbol);
1833                                         return false;
1834                                 }
1835                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1836                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1837                                         errorf(&designator->pos,
1838                                                    "offsetof designator '%Y' must not specify bitfield",
1839                                                    symbol);
1840                                         return false;
1841                                 }
1842
1843                                 top->type             = orig_type;
1844                                 top->v.compound_entry = &iter->declaration;
1845                                 orig_type             = iter->declaration.type;
1846                         }
1847                 } else {
1848                         expression_t *array_index = designator->array_index;
1849                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1850                                 return true;
1851
1852                         if (!is_type_array(type)) {
1853                                 if (is_type_valid(type)) {
1854                                         errorf(&designator->pos,
1855                                                "[%E] designator used for non-array type '%T'",
1856                                                array_index, orig_type);
1857                                 }
1858                                 return false;
1859                         }
1860
1861                         long index = fold_constant_to_int(array_index);
1862                         if (!used_in_offsetof) {
1863                                 if (index < 0) {
1864                                         errorf(&designator->pos,
1865                                                "array index [%E] must be positive", array_index);
1866                                 } else if (type->array.size_constant) {
1867                                         long array_size = type->array.size;
1868                                         if (index >= array_size) {
1869                                                 errorf(&designator->pos,
1870                                                        "designator [%E] (%d) exceeds array size %d",
1871                                                        array_index, index, array_size);
1872                                         }
1873                                 }
1874                         }
1875
1876                         top->type    = orig_type;
1877                         top->v.index = (size_t) index;
1878                         orig_type    = type->array.element_type;
1879                 }
1880                 path->top_type = orig_type;
1881
1882                 if (designator->next != NULL) {
1883                         descend_into_subtype(path);
1884                 }
1885         }
1886         return true;
1887 }
1888
1889 static void advance_current_object(type_path_t *path, size_t top_path_level)
1890 {
1891         type_path_entry_t *top = get_type_path_top(path);
1892
1893         type_t *type = skip_typeref(top->type);
1894         if (is_type_union(type)) {
1895                 /* in unions only the first element is initialized */
1896                 top->v.compound_entry = NULL;
1897         } else if (is_type_struct(type)) {
1898                 declaration_t *entry = top->v.compound_entry;
1899
1900                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1901                 if (next_entity != NULL) {
1902                         assert(is_declaration(next_entity));
1903                         entry = &next_entity->declaration;
1904                 } else {
1905                         entry = NULL;
1906                 }
1907
1908                 top->v.compound_entry = entry;
1909                 if (entry != NULL) {
1910                         path->top_type = entry->type;
1911                         return;
1912                 }
1913         } else if (is_type_array(type)) {
1914                 assert(is_type_array(type));
1915
1916                 top->v.index++;
1917
1918                 if (!type->array.size_constant || top->v.index < type->array.size) {
1919                         return;
1920                 }
1921         } else {
1922                 assert(!is_type_valid(type));
1923                 return;
1924         }
1925
1926         /* we're past the last member of the current sub-aggregate, try if we
1927          * can ascend in the type hierarchy and continue with another subobject */
1928         size_t len = ARR_LEN(path->path);
1929
1930         if (len > top_path_level) {
1931                 ascend_from_subtype(path);
1932                 advance_current_object(path, top_path_level);
1933         } else {
1934                 path->top_type = NULL;
1935         }
1936 }
1937
1938 /**
1939  * skip any {...} blocks until a closing bracket is reached.
1940  */
1941 static void skip_initializers(void)
1942 {
1943         accept('{');
1944
1945         while (token.kind != '}') {
1946                 if (token.kind == T_EOF)
1947                         return;
1948                 if (token.kind == '{') {
1949                         eat_block();
1950                         continue;
1951                 }
1952                 next_token();
1953         }
1954 }
1955
1956 static initializer_t *create_empty_initializer(void)
1957 {
1958         static initializer_t empty_initializer
1959                 = { .list = { { INITIALIZER_LIST }, 0 } };
1960         return &empty_initializer;
1961 }
1962
1963 /**
1964  * Parse a part of an initialiser for a struct or union,
1965  */
1966 static initializer_t *parse_sub_initializer(type_path_t *path,
1967                 type_t *outer_type, size_t top_path_level,
1968                 parse_initializer_env_t *env)
1969 {
1970         if (token.kind == '}') {
1971                 /* empty initializer */
1972                 return create_empty_initializer();
1973         }
1974
1975         initializer_t *result = NULL;
1976
1977         type_t *orig_type = path->top_type;
1978         type_t *type      = NULL;
1979
1980         if (orig_type == NULL) {
1981                 /* We are initializing an empty compound. */
1982         } else {
1983                 type = skip_typeref(orig_type);
1984         }
1985
1986         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1987
1988         while (true) {
1989                 designator_t *designator = NULL;
1990                 if (token.kind == '.' || token.kind == '[') {
1991                         designator = parse_designation();
1992                         goto finish_designator;
1993                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1994                         /* GNU-style designator ("identifier: value") */
1995                         designator         = allocate_ast_zero(sizeof(designator[0]));
1996                         designator->pos    = *HERE;
1997                         designator->symbol = token.base.symbol;
1998                         eat(T_IDENTIFIER);
1999                         eat(':');
2000
2001 finish_designator:
2002                         /* reset path to toplevel, evaluate designator from there */
2003                         ascend_to(path, top_path_level);
2004                         if (!walk_designator(path, designator, false)) {
2005                                 /* can't continue after designation error */
2006                                 goto end_error;
2007                         }
2008
2009                         initializer_t *designator_initializer
2010                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2011                         designator_initializer->designator.designator = designator;
2012                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2013
2014                         orig_type = path->top_type;
2015                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2016                 }
2017
2018                 initializer_t *sub;
2019
2020                 if (token.kind == '{') {
2021                         if (type != NULL && is_type_scalar(type)) {
2022                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2023                         } else {
2024                                 if (type == NULL) {
2025                                         if (env->entity != NULL) {
2026                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2027                                         } else {
2028                                                 errorf(HERE, "extra brace group at end of initializer");
2029                                         }
2030                                         eat('{');
2031                                 } else {
2032                                         eat('{');
2033                                         descend_into_subtype(path);
2034                                 }
2035
2036                                 add_anchor_token('}');
2037                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2038                                                             env);
2039                                 rem_anchor_token('}');
2040
2041                                 expect('}');
2042
2043                                 if (!type)
2044                                         goto error_parse_next;
2045
2046                                 ascend_from_subtype(path);
2047                         }
2048                 } else {
2049                         /* must be an expression */
2050                         expression_t *expression = parse_assignment_expression();
2051                         mark_vars_read(expression, NULL);
2052
2053                         if (env->must_be_constant && !is_linker_constant(expression)) {
2054                                 errorf(&expression->base.pos,
2055                                        "Initialisation expression '%E' is not constant",
2056                                        expression);
2057                         }
2058
2059                         if (type == NULL) {
2060                                 /* we are already outside, ... */
2061                                 if (outer_type == NULL)
2062                                         goto error_parse_next;
2063                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2064                                 if (is_type_compound(outer_type_skip) &&
2065                                                 !outer_type_skip->compound.compound->complete) {
2066                                         goto error_parse_next;
2067                                 }
2068
2069                                 position_t const* const pos = &expression->base.pos;
2070                                 if (env->entity != NULL) {
2071                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2072                                 } else {
2073                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2074                                 }
2075                                 goto error_parse_next;
2076                         }
2077
2078                         /* handle { "string" } special case */
2079                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2080                                 result = initializer_from_expression(outer_type, expression);
2081                                 if (result != NULL) {
2082                                         accept(',');
2083                                         if (token.kind != '}') {
2084                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2085                                         }
2086                                         /* TODO: eat , ... */
2087                                         goto out;
2088                                 }
2089                         }
2090
2091                         /* descend into subtypes until expression matches type */
2092                         while (true) {
2093                                 orig_type = path->top_type;
2094                                 type      = skip_typeref(orig_type);
2095
2096                                 sub = initializer_from_expression(orig_type, expression);
2097                                 if (sub != NULL) {
2098                                         break;
2099                                 }
2100                                 if (!is_type_valid(type)) {
2101                                         goto end_error;
2102                                 }
2103                                 if (is_type_scalar(type)) {
2104                                         errorf(&expression->base.pos,
2105                                                         "expression '%E' doesn't match expected type '%T'",
2106                                                         expression, orig_type);
2107                                         goto end_error;
2108                                 }
2109
2110                                 descend_into_subtype(path);
2111                         }
2112                 }
2113
2114                 /* update largest index of top array */
2115                 const type_path_entry_t *first      = &path->path[0];
2116                 type_t                  *first_type = first->type;
2117                 first_type                          = skip_typeref(first_type);
2118                 if (is_type_array(first_type)) {
2119                         size_t index = first->v.index;
2120                         if (index > path->max_index)
2121                                 path->max_index = index;
2122                 }
2123
2124                 /* append to initializers list */
2125                 ARR_APP1(initializer_t*, initializers, sub);
2126
2127 error_parse_next:
2128                 if (!accept(','))
2129                         break;
2130                 if (token.kind == '}') {
2131                         break;
2132                 }
2133
2134                 if (type != NULL) {
2135                         /* advance to the next declaration if we are not at the end */
2136                         advance_current_object(path, top_path_level);
2137                         orig_type = path->top_type;
2138                         if (orig_type != NULL)
2139                                 type = skip_typeref(orig_type);
2140                         else
2141                                 type = NULL;
2142                 }
2143         }
2144
2145         size_t len  = ARR_LEN(initializers);
2146         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2147         result = allocate_ast_zero(size);
2148         result->kind     = INITIALIZER_LIST;
2149         result->list.len = len;
2150         memcpy(&result->list.initializers, initializers,
2151                len * sizeof(initializers[0]));
2152         goto out;
2153
2154 end_error:
2155         skip_initializers();
2156 out:
2157         DEL_ARR_F(initializers);
2158         ascend_to(path, top_path_level+1);
2159         return result;
2160 }
2161
2162 static expression_t *make_size_literal(size_t value)
2163 {
2164         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2165         literal->base.type    = type_size_t;
2166
2167         char buf[128];
2168         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2169         literal->literal.value = make_string(buf);
2170
2171         return literal;
2172 }
2173
2174 /**
2175  * Parses an initializer. Parsers either a compound literal
2176  * (env->declaration == NULL) or an initializer of a declaration.
2177  */
2178 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2179 {
2180         type_t        *type      = skip_typeref(env->type);
2181         size_t         max_index = 0;
2182         initializer_t *result;
2183
2184         if (is_type_scalar(type)) {
2185                 result = parse_scalar_initializer(type, env->must_be_constant);
2186         } else if (token.kind == '{') {
2187                 eat('{');
2188
2189                 type_path_t path;
2190                 memset(&path, 0, sizeof(path));
2191                 path.top_type = env->type;
2192                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2193
2194                 descend_into_subtype(&path);
2195
2196                 add_anchor_token('}');
2197                 result = parse_sub_initializer(&path, env->type, 1, env);
2198                 rem_anchor_token('}');
2199
2200                 max_index = path.max_index;
2201                 DEL_ARR_F(path.path);
2202
2203                 expect('}');
2204         } else {
2205                 /* parse_scalar_initializer() also works in this case: we simply
2206                  * have an expression without {} around it */
2207                 result = parse_scalar_initializer(type, env->must_be_constant);
2208         }
2209
2210         /* §6.7.8:22 array initializers for arrays with unknown size determine
2211          * the array type size */
2212         if (is_type_array(type) && type->array.size_expression == NULL
2213                         && result != NULL) {
2214                 size_t size;
2215                 switch (result->kind) {
2216                 case INITIALIZER_LIST:
2217                         assert(max_index != 0xdeadbeaf);
2218                         size = max_index + 1;
2219                         break;
2220
2221                 case INITIALIZER_STRING: {
2222                         size = get_string_len(&get_init_string(result)->value) + 1;
2223                         break;
2224                 }
2225
2226                 case INITIALIZER_DESIGNATOR:
2227                 case INITIALIZER_VALUE:
2228                         /* can happen for parse errors */
2229                         size = 0;
2230                         break;
2231
2232                 default:
2233                         internal_errorf(HERE, "invalid initializer type");
2234                 }
2235
2236                 type_t *new_type = duplicate_type(type);
2237
2238                 new_type->array.size_expression   = make_size_literal(size);
2239                 new_type->array.size_constant     = true;
2240                 new_type->array.has_implicit_size = true;
2241                 new_type->array.size              = size;
2242                 env->type = new_type;
2243         }
2244
2245         return result;
2246 }
2247
2248 static void append_entity(scope_t *scope, entity_t *entity)
2249 {
2250         if (scope->last_entity != NULL) {
2251                 scope->last_entity->base.next = entity;
2252         } else {
2253                 scope->entities = entity;
2254         }
2255         entity->base.parent_entity = current_entity;
2256         scope->last_entity         = entity;
2257 }
2258
2259
2260 static compound_t *parse_compound_type_specifier(bool is_struct)
2261 {
2262         position_t const pos = *HERE;
2263         eat(is_struct ? T_struct : T_union);
2264
2265         symbol_t    *symbol     = NULL;
2266         entity_t    *entity     = NULL;
2267         attribute_t *attributes = NULL;
2268
2269         if (token.kind == T___attribute__) {
2270                 attributes = parse_attributes(NULL);
2271         }
2272
2273         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2274         if (token.kind == T_IDENTIFIER) {
2275                 /* the compound has a name, check if we have seen it already */
2276                 symbol = token.base.symbol;
2277                 entity = get_tag(symbol, kind);
2278                 eat(T_IDENTIFIER);
2279
2280                 if (entity != NULL) {
2281                         if (entity->base.parent_scope != current_scope &&
2282                             (token.kind == '{' || token.kind == ';')) {
2283                                 /* we're in an inner scope and have a definition. Shadow
2284                                  * existing definition in outer scope */
2285                                 entity = NULL;
2286                         } else if (entity->compound.complete && token.kind == '{') {
2287                                 position_t const *const ppos = &entity->base.pos;
2288                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2289                                 /* clear members in the hope to avoid further errors */
2290                                 entity->compound.members.entities = NULL;
2291                         }
2292                 }
2293         } else if (token.kind != '{') {
2294                 char const *const msg =
2295                         is_struct ? "while parsing struct type specifier" :
2296                                     "while parsing union type specifier";
2297                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2298
2299                 return NULL;
2300         }
2301
2302         if (entity == NULL) {
2303                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2304                 entity->compound.alignment = 1;
2305                 entity->base.parent_scope  = current_scope;
2306                 if (symbol != NULL) {
2307                         environment_push(entity);
2308                 }
2309                 append_entity(current_scope, entity);
2310         }
2311
2312         if (token.kind == '{') {
2313                 parse_compound_type_entries(&entity->compound);
2314
2315                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2316                 if (symbol == NULL) {
2317                         assert(anonymous_entity == NULL);
2318                         anonymous_entity = entity;
2319                 }
2320         }
2321
2322         if (attributes != NULL) {
2323                 entity->compound.attributes = attributes;
2324                 handle_entity_attributes(attributes, entity);
2325         }
2326
2327         return &entity->compound;
2328 }
2329
2330 static void parse_enum_entries(type_t *const enum_type)
2331 {
2332         eat('{');
2333
2334         if (token.kind == '}') {
2335                 errorf(HERE, "empty enum not allowed");
2336                 eat('}');
2337                 return;
2338         }
2339
2340         add_anchor_token('}');
2341         add_anchor_token(',');
2342         do {
2343                 add_anchor_token('=');
2344                 position_t pos;
2345                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2346                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2347                 entity->enum_value.enum_type = enum_type;
2348                 rem_anchor_token('=');
2349
2350                 if (accept('=')) {
2351                         expression_t *value = parse_constant_expression();
2352
2353                         value = create_implicit_cast(value, enum_type);
2354                         entity->enum_value.value = value;
2355
2356                         /* TODO semantic */
2357                 }
2358
2359                 record_entity(entity, false);
2360         } while (accept(',') && token.kind != '}');
2361         rem_anchor_token(',');
2362         rem_anchor_token('}');
2363
2364         expect('}');
2365 }
2366
2367 static type_t *parse_enum_specifier(void)
2368 {
2369         position_t const pos = *HERE;
2370         entity_t        *entity;
2371         symbol_t        *symbol;
2372
2373         eat(T_enum);
2374         switch (token.kind) {
2375                 case T_IDENTIFIER:
2376                         symbol = token.base.symbol;
2377                         entity = get_tag(symbol, ENTITY_ENUM);
2378                         eat(T_IDENTIFIER);
2379
2380                         if (entity != NULL) {
2381                                 if (entity->base.parent_scope != current_scope &&
2382                                                 (token.kind == '{' || token.kind == ';')) {
2383                                         /* we're in an inner scope and have a definition. Shadow
2384                                          * existing definition in outer scope */
2385                                         entity = NULL;
2386                                 } else if (entity->enume.complete && token.kind == '{') {
2387                                         position_t const *const ppos = &entity->base.pos;
2388                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2389                                 }
2390                         }
2391                         break;
2392
2393                 case '{':
2394                         entity = NULL;
2395                         symbol = NULL;
2396                         break;
2397
2398                 default:
2399                         parse_error_expected("while parsing enum type specifier",
2400                                         T_IDENTIFIER, '{', NULL);
2401                         return NULL;
2402         }
2403
2404         if (entity == NULL) {
2405                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2406                 entity->base.parent_scope = current_scope;
2407         }
2408
2409         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2410         type->enumt.enume      = &entity->enume;
2411         type->enumt.base.akind = ATOMIC_TYPE_INT;
2412
2413         if (token.kind == '{') {
2414                 if (symbol != NULL) {
2415                         environment_push(entity);
2416                 }
2417                 append_entity(current_scope, entity);
2418                 entity->enume.complete = true;
2419
2420                 parse_enum_entries(type);
2421                 parse_attributes(NULL);
2422
2423                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2424                 if (symbol == NULL) {
2425                         assert(anonymous_entity == NULL);
2426                         anonymous_entity = entity;
2427                 }
2428         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2429                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2430         }
2431
2432         return type;
2433 }
2434
2435 /**
2436  * if a symbol is a typedef to another type, return true
2437  */
2438 static bool is_typedef_symbol(symbol_t *symbol)
2439 {
2440         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2441         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2442 }
2443
2444 static type_t *parse_typeof(void)
2445 {
2446         eat(T___typeof__);
2447
2448         type_t *type;
2449
2450         add_anchor_token(')');
2451         expect('(');
2452
2453         expression_t *expression  = NULL;
2454
2455         switch (token.kind) {
2456         case T_IDENTIFIER:
2457                 if (is_typedef_symbol(token.base.symbol)) {
2458         DECLARATION_START
2459                         type = parse_typename();
2460                 } else {
2461         default:
2462                         expression = parse_expression();
2463                         type       = revert_automatic_type_conversion(expression);
2464                 }
2465                 break;
2466         }
2467
2468         rem_anchor_token(')');
2469         expect(')');
2470
2471         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2472         typeof_type->typeoft.expression  = expression;
2473         typeof_type->typeoft.typeof_type = type;
2474
2475         return typeof_type;
2476 }
2477
2478 typedef enum specifiers_t {
2479         SPECIFIER_NONE      = 0,
2480         SPECIFIER_SIGNED    = 1 << 0,
2481         SPECIFIER_UNSIGNED  = 1 << 1,
2482         SPECIFIER_LONG      = 1 << 2,
2483         SPECIFIER_INT       = 1 << 3,
2484         SPECIFIER_DOUBLE    = 1 << 4,
2485         SPECIFIER_CHAR      = 1 << 5,
2486         SPECIFIER_WCHAR_T   = 1 << 6,
2487         SPECIFIER_SHORT     = 1 << 7,
2488         SPECIFIER_LONG_LONG = 1 << 8,
2489         SPECIFIER_FLOAT     = 1 << 9,
2490         SPECIFIER_BOOL      = 1 << 10,
2491         SPECIFIER_VOID      = 1 << 11,
2492         SPECIFIER_INT8      = 1 << 12,
2493         SPECIFIER_INT16     = 1 << 13,
2494         SPECIFIER_INT32     = 1 << 14,
2495         SPECIFIER_INT64     = 1 << 15,
2496         SPECIFIER_INT128    = 1 << 16,
2497         SPECIFIER_COMPLEX   = 1 << 17,
2498         SPECIFIER_IMAGINARY = 1 << 18,
2499 } specifiers_t;
2500
2501 static type_t *get_typedef_type(symbol_t *symbol)
2502 {
2503         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2504         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2505                 return NULL;
2506
2507         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2508         type->typedeft.typedefe = &entity->typedefe;
2509
2510         return type;
2511 }
2512
2513 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2514 {
2515         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2516
2517         add_anchor_token(')');
2518         add_anchor_token(',');
2519         expect('(');
2520
2521         do {
2522                 add_anchor_token('=');
2523                 position_t pos;
2524                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2525                 rem_anchor_token('=');
2526
2527                 symbol_t **prop = NULL;
2528                 if (prop_sym) {
2529                         if (streq(prop_sym->string, "put")) {
2530                                 prop = &property->put_symbol;
2531                         } else if (streq(prop_sym->string, "get")) {
2532                                 prop = &property->get_symbol;
2533                         } else {
2534                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2535                         }
2536                 }
2537
2538                 add_anchor_token(T_IDENTIFIER);
2539                 expect('=');
2540                 rem_anchor_token(T_IDENTIFIER);
2541
2542                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2543                 if (prop != NULL)
2544                         *prop = sym ? sym : sym_anonymous;
2545         } while (accept(','));
2546         rem_anchor_token(',');
2547         rem_anchor_token(')');
2548
2549         attribute->a.property = property;
2550
2551         expect(')');
2552         return attribute;
2553 }
2554
2555 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2556 {
2557         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2558         if (accept(T_restrict)) {
2559                 kind = ATTRIBUTE_MS_RESTRICT;
2560         } else if (token.kind == T_IDENTIFIER) {
2561                 char const *const name = token.base.symbol->string;
2562                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2563                      ++k) {
2564                         const char *attribute_name = get_attribute_name(k);
2565                         if (attribute_name != NULL && streq(attribute_name, name)) {
2566                                 kind = k;
2567                                 break;
2568                         }
2569                 }
2570
2571                 if (kind == ATTRIBUTE_UNKNOWN) {
2572                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2573                 }
2574         } else {
2575                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2576                 return NULL;
2577         }
2578
2579         attribute_t *attribute = allocate_attribute_zero(kind);
2580         eat(T_IDENTIFIER);
2581
2582         if (kind == ATTRIBUTE_MS_PROPERTY) {
2583                 return parse_attribute_ms_property(attribute);
2584         }
2585
2586         /* parse arguments */
2587         if (accept('('))
2588                 attribute->a.arguments = parse_attribute_arguments();
2589
2590         return attribute;
2591 }
2592
2593 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2594 {
2595         eat(T__declspec);
2596
2597         add_anchor_token(')');
2598         expect('(');
2599         if (token.kind != ')') {
2600                 attribute_t **anchor = &first;
2601                 do {
2602                         while (*anchor != NULL)
2603                                 anchor = &(*anchor)->next;
2604
2605                         attribute_t *attribute
2606                                 = parse_microsoft_extended_decl_modifier_single();
2607                         if (attribute == NULL)
2608                                 break;
2609
2610                         *anchor = attribute;
2611                         anchor  = &attribute->next;
2612                 } while (accept(','));
2613         }
2614         rem_anchor_token(')');
2615         expect(')');
2616         return first;
2617 }
2618
2619 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2620 {
2621         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2622         if (is_declaration(entity)) {
2623                 entity->declaration.type     = type_error_type;
2624                 entity->declaration.implicit = true;
2625         } else if (kind == ENTITY_TYPEDEF) {
2626                 entity->typedefe.type    = type_error_type;
2627                 entity->typedefe.builtin = true;
2628         }
2629         if (kind != ENTITY_COMPOUND_MEMBER)
2630                 record_entity(entity, false);
2631         return entity;
2632 }
2633
2634 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2635 {
2636         type_t            *type            = NULL;
2637         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2638         unsigned           type_specifiers = 0;
2639         bool               newtype         = false;
2640         bool               saw_error       = false;
2641
2642         memset(specifiers, 0, sizeof(*specifiers));
2643         specifiers->pos = *HERE;
2644
2645         while (true) {
2646                 specifiers->attributes = parse_attributes(specifiers->attributes);
2647
2648                 switch (token.kind) {
2649                 /* storage class */
2650 #define MATCH_STORAGE_CLASS(token, class)                                  \
2651                 case token:                                                        \
2652                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2653                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2654                         }                                                              \
2655                         specifiers->storage_class = class;                             \
2656                         if (specifiers->thread_local)                                  \
2657                                 goto check_thread_storage_class;                           \
2658                         eat(token); \
2659                         break;
2660
2661                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2662                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2663                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2664                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2665                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2666
2667                 case T__declspec:
2668                         specifiers->attributes
2669                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2670                         break;
2671
2672                 case T__Thread_local:
2673                         if (specifiers->thread_local) {
2674                                 errorf(HERE, "duplicate %K", &token);
2675                         } else {
2676                                 specifiers->thread_local = true;
2677 check_thread_storage_class:
2678                                 switch (specifiers->storage_class) {
2679                                         case STORAGE_CLASS_EXTERN:
2680                                         case STORAGE_CLASS_NONE:
2681                                         case STORAGE_CLASS_STATIC:
2682                                                 break;
2683
2684                                                 char const* wrong;
2685                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2686                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2687                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2688 wrong_thread_storage_class:
2689                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2690                                                 break;
2691                                 }
2692                         }
2693                         next_token();
2694                         break;
2695
2696                 /* type qualifiers */
2697 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2698                 case token:                                                     \
2699                         qualifiers |= qualifier;                                    \
2700                         eat(token); \
2701                         break
2702
2703                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2704                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2705                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2706                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2707                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2708                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2709                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2710                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2711
2712                 /* type specifiers */
2713 #define MATCH_SPECIFIER(token, specifier, name)                         \
2714                 case token:                                                     \
2715                         if (type_specifiers & specifier) {                           \
2716                                 errorf(HERE, "multiple " name " type specifiers given"); \
2717                         } else {                                                    \
2718                                 type_specifiers |= specifier;                           \
2719                         }                                                           \
2720                         eat(token); \
2721                         break
2722
2723                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2724                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2725                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2726                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2727                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2728                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2729                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2730                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2731                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2732                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2733                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2734                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2735                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2736                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2737                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2738                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2739                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2740                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2741
2742                 case T_inline:
2743                         eat(T_inline);
2744                         specifiers->is_inline = true;
2745                         break;
2746
2747 #if 0
2748                 case T__forceinline:
2749                         eat(T__forceinline);
2750                         specifiers->modifiers |= DM_FORCEINLINE;
2751                         break;
2752 #endif
2753
2754                 case T_long:
2755                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2756                                 errorf(HERE, "too many long type specifiers given");
2757                         } else if (type_specifiers & SPECIFIER_LONG) {
2758                                 type_specifiers |= SPECIFIER_LONG_LONG;
2759                         } else {
2760                                 type_specifiers |= SPECIFIER_LONG;
2761                         }
2762                         eat(T_long);
2763                         break;
2764
2765 #define CHECK_DOUBLE_TYPE() \
2766         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2767
2768                 case T_struct:
2769                         CHECK_DOUBLE_TYPE();
2770                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2771
2772                         type->compound.compound = parse_compound_type_specifier(true);
2773                         break;
2774                 case T_union:
2775                         CHECK_DOUBLE_TYPE();
2776                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2777                         type->compound.compound = parse_compound_type_specifier(false);
2778                         break;
2779                 case T_enum:
2780                         CHECK_DOUBLE_TYPE();
2781                         type = parse_enum_specifier();
2782                         break;
2783                 case T___typeof__:
2784                         CHECK_DOUBLE_TYPE();
2785                         type = parse_typeof();
2786                         break;
2787                 case T___builtin_va_list:
2788                         CHECK_DOUBLE_TYPE();
2789                         type = duplicate_type(type_valist);
2790                         eat(T___builtin_va_list);
2791                         break;
2792
2793                 case T_IDENTIFIER: {
2794                         /* only parse identifier if we haven't found a type yet */
2795                         if (type != NULL || type_specifiers != 0) {
2796                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2797                                  * declaration, so it doesn't generate errors about expecting '(' or
2798                                  * '{' later on. */
2799                                 switch (look_ahead(1)->kind) {
2800                                         STORAGE_CLASSES
2801                                         TYPE_SPECIFIERS
2802                                         case T_const:
2803                                         case T_restrict:
2804                                         case T_volatile:
2805                                         case T_inline:
2806                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2807                                         case T_IDENTIFIER:
2808                                         case '&':
2809                                         case '*':
2810                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2811                                                 eat(T_IDENTIFIER);
2812                                                 continue;
2813
2814                                         default:
2815                                                 goto finish_specifiers;
2816                                 }
2817                         }
2818
2819                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2820                         if (typedef_type == NULL) {
2821                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2822                                  * declaration, so it doesn't generate 'implicit int' followed by more
2823                                  * errors later on. */
2824                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2825                                 switch (la1_type) {
2826                                         DECLARATION_START
2827                                         case T_IDENTIFIER:
2828                                         case '&':
2829                                         case '*': {
2830                                                 errorf(HERE, "%K does not name a type", &token);
2831
2832                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2833
2834                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2835                                                 type->typedeft.typedefe = &entity->typedefe;
2836
2837                                                 eat(T_IDENTIFIER);
2838                                                 saw_error = true;
2839                                                 continue;
2840                                         }
2841
2842                                         default:
2843                                                 goto finish_specifiers;
2844                                 }
2845                         }
2846
2847                         eat(T_IDENTIFIER);
2848                         type = typedef_type;
2849                         break;
2850                 }
2851
2852                 /* function specifier */
2853                 default:
2854                         goto finish_specifiers;
2855                 }
2856         }
2857
2858 finish_specifiers:
2859         specifiers->attributes = parse_attributes(specifiers->attributes);
2860
2861         if (type == NULL || (saw_error && type_specifiers != 0)) {
2862                 position_t const* const pos = &specifiers->pos;
2863                 atomic_type_kind_t atomic_type;
2864
2865                 /* match valid basic types */
2866                 switch (type_specifiers & ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2867                 case SPECIFIER_VOID:
2868                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2869                                 if (type_specifiers & SPECIFIER_COMPLEX)
2870                                         errorf(pos, "_Complex specifier is invalid for void");
2871                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2872                                         errorf(pos, "_Imaginary specifier is invalid for void");
2873                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2874                         }
2875                         atomic_type = ATOMIC_TYPE_VOID;
2876                         break;
2877                 case SPECIFIER_WCHAR_T:
2878                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2879                         break;
2880                 case SPECIFIER_CHAR:
2881                         atomic_type = ATOMIC_TYPE_CHAR;
2882                         break;
2883                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2884                         atomic_type = ATOMIC_TYPE_SCHAR;
2885                         break;
2886                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2887                         atomic_type = ATOMIC_TYPE_UCHAR;
2888                         break;
2889                 case SPECIFIER_SHORT:
2890                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2891                 case SPECIFIER_SHORT | SPECIFIER_INT:
2892                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2893                         atomic_type = ATOMIC_TYPE_SHORT;
2894                         break;
2895                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2896                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2897                         atomic_type = ATOMIC_TYPE_USHORT;
2898                         break;
2899                 case SPECIFIER_INT:
2900                 case SPECIFIER_SIGNED:
2901                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2902                         atomic_type = ATOMIC_TYPE_INT;
2903                         break;
2904                 case SPECIFIER_UNSIGNED:
2905                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2906                         atomic_type = ATOMIC_TYPE_UINT;
2907                         break;
2908                 case SPECIFIER_LONG:
2909                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2910                 case SPECIFIER_LONG | SPECIFIER_INT:
2911                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2912                         atomic_type = ATOMIC_TYPE_LONG;
2913                         break;
2914                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2915                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2916                         atomic_type = ATOMIC_TYPE_ULONG;
2917                         break;
2918
2919                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2920                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2921                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2922                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2923                         | SPECIFIER_INT:
2924                         atomic_type = ATOMIC_TYPE_LONGLONG;
2925                         goto warn_about_long_long;
2926
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2929                         | SPECIFIER_INT:
2930                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2931 warn_about_long_long:
2932                         warningf(WARN_LONG_LONG, &specifiers->pos, "ISO C90 does not support 'long long'");
2933                         break;
2934
2935                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2936                         atomic_type = unsigned_int8_type_kind;
2937                         break;
2938
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2940                         atomic_type = unsigned_int16_type_kind;
2941                         break;
2942
2943                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2944                         atomic_type = unsigned_int32_type_kind;
2945                         break;
2946
2947                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2948                         atomic_type = unsigned_int64_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2952                         atomic_type = unsigned_int128_type_kind;
2953                         break;
2954
2955                 case SPECIFIER_INT8:
2956                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2957                         atomic_type = int8_type_kind;
2958                         break;
2959
2960                 case SPECIFIER_INT16:
2961                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2962                         atomic_type = int16_type_kind;
2963                         break;
2964
2965                 case SPECIFIER_INT32:
2966                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2967                         atomic_type = int32_type_kind;
2968                         break;
2969
2970                 case SPECIFIER_INT64:
2971                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2972                         atomic_type = int64_type_kind;
2973                         break;
2974
2975                 case SPECIFIER_INT128:
2976                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2977                         atomic_type = int128_type_kind;
2978                         break;
2979
2980                 case SPECIFIER_FLOAT:
2981                         atomic_type = ATOMIC_TYPE_FLOAT;
2982                         break;
2983                 case SPECIFIER_DOUBLE:
2984                         atomic_type = ATOMIC_TYPE_DOUBLE;
2985                         break;
2986                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2987                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2988                         break;
2989                 case SPECIFIER_BOOL:
2990                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2991                                 if (type_specifiers & SPECIFIER_COMPLEX)
2992                                         errorf(pos, "_Complex specifier is invalid for _Bool");
2993                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2994                                         errorf(pos, "_Imaginary specifier is invalid for _Bool");
2995                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2996                         }
2997                         atomic_type = ATOMIC_TYPE_BOOL;
2998                         break;
2999                 default: {
3000                         /* invalid specifier combination, give an error message */
3001                         if (type_specifiers == 0) {
3002                                 if (!saw_error) {
3003                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3004                                         if (!(c_mode & _CXX) && !strict_mode) {
3005                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3006                                                 atomic_type = ATOMIC_TYPE_INT;
3007                                                 break;
3008                                         } else {
3009                                                 errorf(pos, "no type specifiers given in declaration");
3010                                         }
3011                                 }
3012                         } else if (type_specifiers == SPECIFIER_COMPLEX) {
3013                                 warningf(WARN_OTHER, pos, "_Complex requires a type specifier; assuming '_Complex double'");
3014                                 atomic_type = ATOMIC_TYPE_DOUBLE;
3015                                 break;
3016                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3017                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3018                                 errorf(pos, "signed and unsigned specifiers given");
3019                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3020                                 errorf(pos, "only integer types can be signed or unsigned");
3021                         } else {
3022                                 errorf(pos, "multiple datatypes in declaration");
3023                         }
3024                         specifiers->type = type_error_type;
3025                         return;
3026                 }
3027                 }
3028
3029                 if (type_specifiers & SPECIFIER_COMPLEX) {
3030                         type = allocate_type_zero(TYPE_COMPLEX);
3031                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3032                         type = allocate_type_zero(TYPE_IMAGINARY);
3033                 } else {
3034                         type = allocate_type_zero(TYPE_ATOMIC);
3035                 }
3036                 type->atomic.akind = atomic_type;
3037                 newtype = true;
3038         } else if (type_specifiers != 0) {
3039                 errorf(&specifiers->pos, "multiple datatypes in declaration");
3040         }
3041
3042         /* FIXME: check type qualifiers here */
3043         type->base.qualifiers = qualifiers;
3044
3045         if (newtype) {
3046                 type = identify_new_type(type);
3047         } else {
3048                 type = typehash_insert(type);
3049         }
3050
3051         if (specifiers->attributes != NULL)
3052                 type = handle_type_attributes(specifiers->attributes, type);
3053         specifiers->type = type;
3054 }
3055
3056 static type_qualifiers_t parse_type_qualifiers(void)
3057 {
3058         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3059
3060         while (true) {
3061                 switch (token.kind) {
3062                 /* type qualifiers */
3063                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3064                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3065                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3066                 /* microsoft extended type modifiers */
3067                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3068                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3069                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3070                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3071                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3072
3073                 default:
3074                         return qualifiers;
3075                 }
3076         }
3077 }
3078
3079 /**
3080  * Parses an K&R identifier list
3081  */
3082 static void parse_identifier_list(scope_t *scope)
3083 {
3084         assert(token.kind == T_IDENTIFIER);
3085         do {
3086                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3087                 /* a K&R parameter has no type, yet */
3088                 eat(T_IDENTIFIER);
3089
3090                 if (scope != NULL)
3091                         append_entity(scope, entity);
3092         } while (accept(',') && token.kind == T_IDENTIFIER);
3093 }
3094
3095 static entity_t *parse_parameter(void)
3096 {
3097         declaration_specifiers_t specifiers;
3098         parse_declaration_specifiers(&specifiers);
3099
3100         entity_t *entity = parse_declarator(&specifiers,
3101                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3102         anonymous_entity = NULL;
3103         return entity;
3104 }
3105
3106 static void semantic_parameter_incomplete(const entity_t *entity)
3107 {
3108         assert(entity->kind == ENTITY_PARAMETER);
3109
3110         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3111          *             list in a function declarator that is part of a
3112          *             definition of that function shall not have
3113          *             incomplete type. */
3114         type_t *type = skip_typeref(entity->declaration.type);
3115         if (is_type_incomplete(type)) {
3116                 errorf(&entity->base.pos, "'%N' has incomplete type", entity);
3117         }
3118 }
3119
3120 static bool has_parameters(void)
3121 {
3122         /* func(void) is not a parameter */
3123         if (look_ahead(1)->kind != ')')
3124                 return true;
3125         if (token.kind == T_IDENTIFIER) {
3126                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3127                 if (entity == NULL)
3128                         return true;
3129                 if (entity->kind != ENTITY_TYPEDEF)
3130                         return true;
3131                 type_t const *const type = skip_typeref(entity->typedefe.type);
3132                 if (!is_type_void(type))
3133                         return true;
3134                 if (c_mode & _CXX) {
3135                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3136                          * is not allowed. */
3137                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3138                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3139                         /* §6.7.5.3:10  Qualification is not allowed here. */
3140                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3141                 }
3142         } else if (token.kind != T_void) {
3143                 return true;
3144         }
3145         next_token();
3146         return false;
3147 }
3148
3149 /**
3150  * Parses function type parameters (and optionally creates variable_t entities
3151  * for them in a scope)
3152  */
3153 static void parse_parameters(function_type_t *type, scope_t *scope)
3154 {
3155         add_anchor_token(')');
3156         eat('(');
3157
3158         if (token.kind == T_IDENTIFIER            &&
3159             !is_typedef_symbol(token.base.symbol) &&
3160             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3161                 type->kr_style_parameters = true;
3162                 parse_identifier_list(scope);
3163         } else if (token.kind == ')') {
3164                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3165                 if (!(c_mode & _CXX))
3166                         type->unspecified_parameters = true;
3167         } else if (has_parameters()) {
3168                 function_parameter_t **anchor = &type->parameters;
3169                 add_anchor_token(',');
3170                 do {
3171                         switch (token.kind) {
3172                         case T_DOTDOTDOT:
3173                                 eat(T_DOTDOTDOT);
3174                                 type->variadic = true;
3175                                 goto parameters_finished;
3176
3177                         case T_IDENTIFIER:
3178                         DECLARATION_START
3179                         {
3180                                 entity_t *entity = parse_parameter();
3181                                 if (entity->kind == ENTITY_TYPEDEF) {
3182                                         errorf(&entity->base.pos,
3183                                                         "typedef not allowed as function parameter");
3184                                         break;
3185                                 }
3186                                 assert(is_declaration(entity));
3187
3188                                 semantic_parameter_incomplete(entity);
3189
3190                                 function_parameter_t *const parameter =
3191                                         allocate_parameter(entity->declaration.type);
3192
3193                                 if (scope != NULL) {
3194                                         append_entity(scope, entity);
3195                                 }
3196
3197                                 *anchor = parameter;
3198                                 anchor  = &parameter->next;
3199                                 break;
3200                         }
3201
3202                         default:
3203                                 goto parameters_finished;
3204                         }
3205                 } while (accept(','));
3206 parameters_finished:
3207                 rem_anchor_token(',');
3208         }
3209
3210         rem_anchor_token(')');
3211         expect(')');
3212 }
3213
3214 typedef enum construct_type_kind_t {
3215         CONSTRUCT_POINTER = 1,
3216         CONSTRUCT_REFERENCE,
3217         CONSTRUCT_FUNCTION,
3218         CONSTRUCT_ARRAY
3219 } construct_type_kind_t;
3220
3221 typedef union construct_type_t construct_type_t;
3222
3223 typedef struct construct_type_base_t {
3224         construct_type_kind_t kind;
3225         position_t            pos;
3226         construct_type_t     *next;
3227 } construct_type_base_t;
3228
3229 typedef struct parsed_pointer_t {
3230         construct_type_base_t  base;
3231         type_qualifiers_t      type_qualifiers;
3232         variable_t            *base_variable;  /**< MS __based extension. */
3233 } parsed_pointer_t;
3234
3235 typedef struct parsed_reference_t {
3236         construct_type_base_t base;
3237 } parsed_reference_t;
3238
3239 typedef struct construct_function_type_t {
3240         construct_type_base_t  base;
3241         type_t                *function_type;
3242 } construct_function_type_t;
3243
3244 typedef struct parsed_array_t {
3245         construct_type_base_t  base;
3246         type_qualifiers_t      type_qualifiers;
3247         bool                   is_static;
3248         bool                   is_variable;
3249         expression_t          *size;
3250 } parsed_array_t;
3251
3252 union construct_type_t {
3253         construct_type_kind_t     kind;
3254         construct_type_base_t     base;
3255         parsed_pointer_t          pointer;
3256         parsed_reference_t        reference;
3257         construct_function_type_t function;
3258         parsed_array_t            array;
3259 };
3260
3261 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3262 {
3263         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3264         memset(cons, 0, size);
3265         cons->kind     = kind;
3266         cons->base.pos = *HERE;
3267         return cons;
3268 }
3269
3270 /* §6.7.5.1 */
3271 static construct_type_t *parse_pointer_declarator(void)
3272 {
3273         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3274         eat('*');
3275         cons->pointer.type_qualifiers = parse_type_qualifiers();
3276         //cons->pointer.base_variable   = base_variable;
3277
3278         return cons;
3279 }
3280
3281 /* ISO/IEC 14882:1998(E) §8.3.2 */
3282 static construct_type_t *parse_reference_declarator(void)
3283 {
3284         if (!(c_mode & _CXX))
3285                 errorf(HERE, "references are only available for C++");
3286
3287         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3288         eat('&');
3289
3290         return cons;
3291 }
3292
3293 /* §6.7.5.2 */
3294 static construct_type_t *parse_array_declarator(void)
3295 {
3296         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3297         parsed_array_t   *const array = &cons->array;
3298
3299         eat('[');
3300         add_anchor_token(']');
3301
3302         bool is_static = accept(T_static);
3303
3304         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3305
3306         if (!is_static)
3307                 is_static = accept(T_static);
3308
3309         array->type_qualifiers = type_qualifiers;
3310         array->is_static       = is_static;
3311
3312         expression_t *size = NULL;
3313         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3314                 array->is_variable = true;
3315                 eat('*');
3316         } else if (token.kind != ']') {
3317                 size = parse_assignment_expression();
3318
3319                 /* §6.7.5.2:1  Array size must have integer type */
3320                 type_t *const orig_type = size->base.type;
3321                 type_t *const type      = skip_typeref(orig_type);
3322                 if (!is_type_integer(type) && is_type_valid(type)) {
3323                         errorf(&size->base.pos,
3324                                "array size '%E' must have integer type but has type '%T'",
3325                                size, orig_type);
3326                 }
3327
3328                 array->size = size;
3329                 mark_vars_read(size, NULL);
3330         }
3331
3332         if (is_static && size == NULL)
3333                 errorf(&array->base.pos, "static array parameters require a size");
3334
3335         rem_anchor_token(']');
3336         expect(']');
3337         return cons;
3338 }
3339
3340 /* §6.7.5.3 */
3341 static construct_type_t *parse_function_declarator(scope_t *scope)
3342 {
3343         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3344
3345         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3346         function_type_t *ftype = &type->function;
3347
3348         ftype->linkage            = current_linkage;
3349         ftype->calling_convention = CC_DEFAULT;
3350
3351         parse_parameters(ftype, scope);
3352
3353         cons->function.function_type = type;
3354
3355         return cons;
3356 }
3357
3358 typedef struct parse_declarator_env_t {
3359         bool              may_be_abstract : 1;
3360         bool              must_be_abstract : 1;
3361         decl_modifiers_t  modifiers;
3362         symbol_t         *symbol;
3363         position_t        pos;
3364         scope_t           parameters;
3365         attribute_t      *attributes;
3366 } parse_declarator_env_t;
3367
3368 /* §6.7.5 */
3369 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3370 {
3371         /* construct a single linked list of construct_type_t's which describe
3372          * how to construct the final declarator type */
3373         construct_type_t  *first      = NULL;
3374         construct_type_t **anchor     = &first;
3375
3376         env->attributes = parse_attributes(env->attributes);
3377
3378         for (;;) {
3379                 construct_type_t *type;
3380                 //variable_t       *based = NULL; /* MS __based extension */
3381                 switch (token.kind) {
3382                         case '&':
3383                                 type = parse_reference_declarator();
3384                                 break;
3385
3386                         case T__based: {
3387                                 panic("based not supported anymore");
3388                                 /* FALLTHROUGH */
3389                         }
3390
3391                         case '*':
3392                                 type = parse_pointer_declarator();
3393                                 break;
3394
3395                         default:
3396                                 goto ptr_operator_end;
3397                 }
3398
3399                 *anchor = type;
3400                 anchor  = &type->base.next;
3401
3402                 /* TODO: find out if this is correct */
3403                 env->attributes = parse_attributes(env->attributes);
3404         }
3405
3406 ptr_operator_end: ;
3407         construct_type_t *inner_types = NULL;
3408
3409         switch (token.kind) {
3410         case T_IDENTIFIER:
3411                 if (env->must_be_abstract) {
3412                         errorf(HERE, "no identifier expected in typename");
3413                 } else {
3414                         env->symbol = token.base.symbol;
3415                         env->pos    = *HERE;
3416                 }
3417                 eat(T_IDENTIFIER);
3418                 break;
3419
3420         case '(': {
3421                 /* Parenthesized declarator or function declarator? */
3422                 token_t const *const la1 = look_ahead(1);
3423                 switch (la1->kind) {
3424                         case T_IDENTIFIER:
3425                                 if (is_typedef_symbol(la1->base.symbol)) {
3426                         case ')':
3427                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3428                                          * interpreted as ``function with no parameter specification'', rather
3429                                          * than redundant parentheses around the omitted identifier. */
3430                         default:
3431                                         /* Function declarator. */
3432                                         if (!env->may_be_abstract) {
3433                                                 errorf(HERE, "function declarator must have a name");
3434                                         }
3435                                 } else {
3436                         case '&':
3437                         case '(':
3438                         case '*':
3439                         case '[':
3440                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3441                                         /* Paranthesized declarator. */
3442                                         eat('(');
3443                                         add_anchor_token(')');
3444                                         inner_types = parse_inner_declarator(env);
3445                                         if (inner_types != NULL) {
3446                                                 /* All later declarators only modify the return type */
3447                                                 env->must_be_abstract = true;
3448                                         }
3449                                         rem_anchor_token(')');
3450                                         expect(')');
3451                                 }
3452                                 break;
3453                 }
3454                 break;
3455         }
3456
3457         default:
3458                 if (env->may_be_abstract)
3459                         break;
3460                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3461                 eat_until_anchor();
3462                 return NULL;
3463         }
3464
3465         construct_type_t **const p = anchor;
3466
3467         for (;;) {
3468                 construct_type_t *type;
3469                 switch (token.kind) {
3470                 case '(': {
3471                         scope_t *scope = NULL;
3472                         if (!env->must_be_abstract) {
3473                                 scope = &env->parameters;
3474                         }
3475
3476                         type = parse_function_declarator(scope);
3477                         break;
3478                 }
3479                 case '[':
3480                         type = parse_array_declarator();
3481                         break;
3482                 default:
3483                         goto declarator_finished;
3484                 }
3485
3486                 /* insert in the middle of the list (at p) */
3487                 type->base.next = *p;
3488                 *p              = type;
3489                 if (anchor == p)
3490                         anchor = &type->base.next;
3491         }
3492
3493 declarator_finished:
3494         /* append inner_types at the end of the list, we don't to set anchor anymore
3495          * as it's not needed anymore */
3496         *anchor = inner_types;
3497
3498         return first;
3499 }
3500
3501 static type_t *construct_declarator_type(construct_type_t *construct_list,
3502                                          type_t *type)
3503 {
3504         construct_type_t *iter = construct_list;
3505         for (; iter != NULL; iter = iter->base.next) {
3506                 position_t const* const pos = &iter->base.pos;
3507                 switch (iter->kind) {
3508                 case CONSTRUCT_FUNCTION: {
3509                         construct_function_type_t *function      = &iter->function;
3510                         type_t                    *function_type = function->function_type;
3511
3512                         function_type->function.return_type = type;
3513
3514                         type_t *skipped_return_type = skip_typeref(type);
3515                         /* §6.7.5.3:1 */
3516                         if (is_type_function(skipped_return_type)) {
3517                                 errorf(pos, "function returning function is not allowed");
3518                         } else if (is_type_array(skipped_return_type)) {
3519                                 errorf(pos, "function returning array is not allowed");
3520                         } else {
3521                                 if (skipped_return_type->base.qualifiers != 0) {
3522                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3523                                 }
3524                         }
3525
3526                         /* The function type was constructed earlier.  Freeing it here will
3527                          * destroy other types. */
3528                         type = typehash_insert(function_type);
3529                         continue;
3530                 }
3531
3532                 case CONSTRUCT_POINTER: {
3533                         if (is_type_reference(skip_typeref(type)))
3534                                 errorf(pos, "cannot declare a pointer to reference");
3535
3536                         parsed_pointer_t *pointer = &iter->pointer;
3537                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3538                         continue;
3539                 }
3540
3541                 case CONSTRUCT_REFERENCE:
3542                         if (is_type_reference(skip_typeref(type)))
3543                                 errorf(pos, "cannot declare a reference to reference");
3544
3545                         type = make_reference_type(type);
3546                         continue;
3547
3548                 case CONSTRUCT_ARRAY: {
3549                         if (is_type_reference(skip_typeref(type)))
3550                                 errorf(pos, "cannot declare an array of references");
3551
3552                         parsed_array_t *array      = &iter->array;
3553                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3554
3555                         expression_t *size_expression = array->size;
3556                         if (size_expression != NULL) {
3557                                 size_expression
3558                                         = create_implicit_cast(size_expression, type_size_t);
3559                         }
3560
3561                         array_type->base.qualifiers       = array->type_qualifiers;
3562                         array_type->array.element_type    = type;
3563                         array_type->array.is_static       = array->is_static;
3564                         array_type->array.is_variable     = array->is_variable;
3565                         array_type->array.size_expression = size_expression;
3566
3567                         if (size_expression != NULL) {
3568                                 switch (is_constant_expression(size_expression)) {
3569                                 case EXPR_CLASS_CONSTANT: {
3570                                         long const size = fold_constant_to_int(size_expression);
3571                                         array_type->array.size          = size;
3572                                         array_type->array.size_constant = true;
3573                                         /* §6.7.5.2:1  If the expression is a constant expression,
3574                                          * it shall have a value greater than zero. */
3575                                         if (size < 0) {
3576                                                 errorf(&size_expression->base.pos,
3577                                                            "size of array must be greater than zero");
3578                                         } else if (size == 0 && !GNU_MODE) {
3579                                                 errorf(&size_expression->base.pos,
3580                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3581                                         }
3582                                         break;
3583                                 }
3584
3585                                 case EXPR_CLASS_VARIABLE:
3586                                         array_type->array.is_vla = true;
3587                                         break;
3588
3589                                 case EXPR_CLASS_ERROR:
3590                                         break;
3591                                 }
3592                         }
3593
3594                         type_t *skipped_type = skip_typeref(type);
3595                         /* §6.7.5.2:1 */
3596                         if (is_type_incomplete(skipped_type)) {
3597                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3598                         } else if (is_type_function(skipped_type)) {
3599                                 errorf(pos, "array of functions is not allowed");
3600                         }
3601                         type = identify_new_type(array_type);
3602                         continue;
3603                 }
3604                 }
3605                 internal_errorf(pos, "invalid type construction found");
3606         }
3607
3608         return type;
3609 }
3610
3611 static type_t *automatic_type_conversion(type_t *orig_type);
3612
3613 static type_t *semantic_parameter(const position_t *pos, type_t *type,
3614                                   const declaration_specifiers_t *specifiers,
3615                                   entity_t const *const param)
3616 {
3617         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3618          *             shall be adjusted to ``qualified pointer to type'',
3619          *             [...]
3620          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3621          *             type'' shall be adjusted to ``pointer to function
3622          *             returning type'', as in 6.3.2.1. */
3623         type = automatic_type_conversion(type);
3624
3625         if (specifiers->is_inline && is_type_valid(type)) {
3626                 errorf(pos, "'%N' declared 'inline'", param);
3627         }
3628
3629         /* §6.9.1:6  The declarations in the declaration list shall contain
3630          *           no storage-class specifier other than register and no
3631          *           initializations. */
3632         if (specifiers->thread_local || (
3633                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3634                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3635            ) {
3636                 errorf(pos, "invalid storage class for '%N'", param);
3637         }
3638
3639         /* delay test for incomplete type, because we might have (void)
3640          * which is legal but incomplete... */
3641
3642         return type;
3643 }
3644
3645 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3646                                   declarator_flags_t flags)
3647 {
3648         parse_declarator_env_t env;
3649         memset(&env, 0, sizeof(env));
3650         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3651
3652         construct_type_t *construct_type = parse_inner_declarator(&env);
3653         type_t           *orig_type      =
3654                 construct_declarator_type(construct_type, specifiers->type);
3655         type_t           *type           = skip_typeref(orig_type);
3656
3657         if (construct_type != NULL) {
3658                 obstack_free(&temp_obst, construct_type);
3659         }
3660
3661         attribute_t *attributes = parse_attributes(env.attributes);
3662         /* append (shared) specifier attribute behind attributes of this
3663          * declarator */
3664         attribute_t **anchor = &attributes;
3665         while (*anchor != NULL)
3666                 anchor = &(*anchor)->next;
3667         *anchor = specifiers->attributes;
3668
3669         entity_t *entity;
3670         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3671                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.pos);
3672                 entity->typedefe.type = orig_type;
3673
3674                 if (anonymous_entity != NULL) {
3675                         if (is_type_compound(type)) {
3676                                 assert(anonymous_entity->compound.alias == NULL);
3677                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3678                                        anonymous_entity->kind == ENTITY_UNION);
3679                                 anonymous_entity->compound.alias = entity;
3680                                 anonymous_entity = NULL;
3681                         } else if (is_type_enum(type)) {
3682                                 assert(anonymous_entity->enume.alias == NULL);
3683                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3684                                 anonymous_entity->enume.alias = entity;
3685                                 anonymous_entity = NULL;
3686                         }
3687                 }
3688         } else {
3689                 /* create a declaration type entity */
3690                 position_t const *const pos = env.symbol ? &env.pos : &specifiers->pos;
3691                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3692                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3693
3694                         if (env.symbol != NULL) {
3695                                 if (specifiers->is_inline && is_type_valid(type)) {
3696                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3697                                 }
3698
3699                                 if (specifiers->thread_local ||
3700                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3701                                         errorf(&env.pos, "'%N' must have no storage class", entity);
3702                                 }
3703                         }
3704                 } else if (flags & DECL_IS_PARAMETER) {
3705                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3706                         orig_type = semantic_parameter(&env.pos, orig_type, specifiers, entity);
3707                 } else if (is_type_function(type)) {
3708                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3709                         entity->function.is_inline      = specifiers->is_inline;
3710                         entity->function.elf_visibility = default_visibility;
3711                         entity->function.parameters     = env.parameters;
3712
3713                         if (env.symbol != NULL) {
3714                                 /* this needs fixes for C++ */
3715                                 bool in_function_scope = current_function != NULL;
3716
3717                                 if (specifiers->thread_local || (
3718                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3719                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3720                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3721                                                 )) {
3722                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3723                                 }
3724                         }
3725                 } else {
3726                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3727                         entity->variable.elf_visibility = default_visibility;
3728                         entity->variable.thread_local   = specifiers->thread_local;
3729
3730                         if (env.symbol != NULL) {
3731                                 if (specifiers->is_inline && is_type_valid(type)) {
3732                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3733                                 }
3734
3735                                 bool invalid_storage_class = false;
3736                                 if (current_scope == file_scope) {
3737                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3738                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3739                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3740                                                 invalid_storage_class = true;
3741                                         }
3742                                 } else {
3743                                         if (specifiers->thread_local &&
3744                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3745                                                 invalid_storage_class = true;
3746                                         }
3747                                 }
3748                                 if (invalid_storage_class) {
3749                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3750                                 }
3751                         }
3752                 }
3753
3754                 entity->declaration.type       = orig_type;
3755                 entity->declaration.alignment  = get_type_alignment(orig_type);
3756                 entity->declaration.modifiers  = env.modifiers;
3757                 entity->declaration.attributes = attributes;
3758
3759                 storage_class_t storage_class = specifiers->storage_class;
3760                 entity->declaration.declared_storage_class = storage_class;
3761
3762                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3763                         storage_class = STORAGE_CLASS_AUTO;
3764                 entity->declaration.storage_class = storage_class;
3765         }
3766
3767         if (attributes != NULL) {
3768                 handle_entity_attributes(attributes, entity);
3769         }
3770
3771         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3772                 adapt_special_functions(&entity->function);
3773         }
3774
3775         return entity;
3776 }
3777
3778 static type_t *parse_abstract_declarator(type_t *base_type)
3779 {
3780         parse_declarator_env_t env;
3781         memset(&env, 0, sizeof(env));
3782         env.may_be_abstract = true;
3783         env.must_be_abstract = true;
3784
3785         construct_type_t *construct_type = parse_inner_declarator(&env);
3786
3787         type_t *result = construct_declarator_type(construct_type, base_type);
3788         if (construct_type != NULL) {
3789                 obstack_free(&temp_obst, construct_type);
3790         }
3791         result = handle_type_attributes(env.attributes, result);
3792
3793         return result;
3794 }
3795
3796 /**
3797  * Check if the declaration of main is suspicious.  main should be a
3798  * function with external linkage, returning int, taking either zero
3799  * arguments, two, or three arguments of appropriate types, ie.
3800  *
3801  * int main([ int argc, char **argv [, char **env ] ]).
3802  *
3803  * @param decl    the declaration to check
3804  * @param type    the function type of the declaration
3805  */
3806 static void check_main(const entity_t *entity)
3807 {
3808         const position_t *pos = &entity->base.pos;
3809         if (entity->kind != ENTITY_FUNCTION) {
3810                 warningf(WARN_MAIN, pos, "'main' is not a function");
3811                 return;
3812         }
3813
3814         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3815                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3816         }
3817
3818         type_t *type = skip_typeref(entity->declaration.type);
3819         assert(is_type_function(type));
3820
3821         function_type_t const *const func_type = &type->function;
3822         type_t                *const ret_type  = func_type->return_type;
3823         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3824                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3825         }
3826         const function_parameter_t *parm = func_type->parameters;
3827         if (parm != NULL) {
3828                 type_t *const first_type        = skip_typeref(parm->type);
3829                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3830                 if (!types_compatible(first_type_unqual, type_int)) {
3831                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3832                 }
3833                 parm = parm->next;
3834                 if (parm != NULL) {
3835                         type_t *const second_type = skip_typeref(parm->type);
3836                         type_t *const second_type_unqual
3837                                 = get_unqualified_type(second_type);
3838                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3839                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3840                         }
3841                         parm = parm->next;
3842                         if (parm != NULL) {
3843                                 type_t *const third_type = skip_typeref(parm->type);
3844                                 type_t *const third_type_unqual
3845                                         = get_unqualified_type(third_type);
3846                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3847                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3848                                 }
3849                                 parm = parm->next;
3850                                 if (parm != NULL)
3851                                         goto warn_arg_count;
3852                         }
3853                 } else {
3854 warn_arg_count:
3855                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3856                 }
3857         }
3858 }
3859
3860 static void error_redefined_as_different_kind(const position_t *pos,
3861                 const entity_t *old, entity_kind_t new_kind)
3862 {
3863         char       const *const what = get_entity_kind_name(new_kind);
3864         position_t const *const ppos = &old->base.pos;
3865         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3866 }
3867
3868 static bool is_entity_valid(entity_t *const ent)
3869 {
3870         if (is_declaration(ent)) {
3871                 return is_type_valid(skip_typeref(ent->declaration.type));
3872         } else if (ent->kind == ENTITY_TYPEDEF) {
3873                 return is_type_valid(skip_typeref(ent->typedefe.type));
3874         }
3875         return true;
3876 }
3877
3878 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3879 {
3880         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3881                 if (attributes_equal(tattr, attr))
3882                         return true;
3883         }
3884         return false;
3885 }
3886
3887 /**
3888  * Tests whether new_list contains any attributes not included in old_list
3889  */
3890 static bool has_new_attributes(const attribute_t *old_list,
3891                                const attribute_t *new_list)
3892 {
3893         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3894                 if (!contains_attribute(old_list, attr))
3895                         return true;
3896         }
3897         return false;
3898 }
3899
3900 /**
3901  * Merge in attributes from an attribute list (probably from a previous
3902  * declaration with the same name). Warning: destroys the old structure
3903  * of the attribute list - don't reuse attributes after this call.
3904  */
3905 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3906 {
3907         attribute_t *next;
3908         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3909                 next = attr->next;
3910                 if (contains_attribute(decl->attributes, attr))
3911                         continue;
3912
3913                 /* move attribute to new declarations attributes list */
3914                 attr->next       = decl->attributes;
3915                 decl->attributes = attr;
3916         }
3917 }
3918
3919 static bool is_main(entity_t*);
3920
3921 /**
3922  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3923  * for various problems that occur for multiple definitions
3924  */
3925 entity_t *record_entity(entity_t *entity, const bool is_definition)
3926 {
3927         const symbol_t *const symbol  = entity->base.symbol;
3928         const namespace_tag_t namespc = (namespace_tag_t)entity->base.namespc;
3929         const position_t     *pos     = &entity->base.pos;
3930
3931         /* can happen in error cases */
3932         if (symbol == NULL)
3933                 return entity;
3934
3935         assert(!entity->base.parent_scope);
3936         assert(current_scope);
3937         entity->base.parent_scope = current_scope;
3938
3939         entity_t *const previous_entity = get_entity(symbol, namespc);
3940         /* pushing the same entity twice will break the stack structure */
3941         assert(previous_entity != entity);
3942
3943         if (entity->kind == ENTITY_FUNCTION) {
3944                 type_t *const orig_type = entity->declaration.type;
3945                 type_t *const type      = skip_typeref(orig_type);
3946
3947                 assert(is_type_function(type));
3948                 if (type->function.unspecified_parameters &&
3949                     previous_entity == NULL               &&
3950                     !entity->declaration.implicit) {
3951                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3952                 }
3953
3954                 if (is_main(entity)) {
3955                         check_main(entity);
3956                 }
3957         }
3958
3959         if (is_declaration(entity)                                    &&
3960             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3961             current_scope != file_scope                               &&
3962             !entity->declaration.implicit) {
3963                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3964         }
3965
3966         if (previous_entity != NULL) {
3967                 position_t const *const ppos = &previous_entity->base.pos;
3968
3969                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3970                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3971                         assert(previous_entity->kind == ENTITY_PARAMETER);
3972                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3973                         goto finish;
3974                 }
3975
3976                 if (previous_entity->base.parent_scope == current_scope) {
3977                         if (previous_entity->kind != entity->kind) {
3978                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3979                                         error_redefined_as_different_kind(pos, previous_entity,
3980                                                         entity->kind);
3981                                 }
3982                                 goto finish;
3983                         }
3984                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3985                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3986                                 goto finish;
3987                         }
3988                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3989                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3990                                 type_t *const prev_type
3991                                         = skip_typeref(previous_entity->typedefe.type);
3992                                 if (c_mode & _CXX) {
3993                                         /* C++ allows double typedef if they are identical
3994                                          * (after skipping typedefs) */
3995                                         if (type == prev_type)
3996                                                 goto finish;
3997                                 } else {
3998                                         /* GCC extension: redef in system headers is allowed */
3999                                         if ((pos->is_system_header || ppos->is_system_header) &&
4000                                             types_compatible(type, prev_type))
4001                                                 goto finish;
4002                                 }
4003                                 errorf(pos, "redefinition of '%N' (declared %P)",
4004                                        entity, ppos);
4005                                 goto finish;
4006                         }
4007
4008                         /* at this point we should have only VARIABLES or FUNCTIONS */
4009                         assert(is_declaration(previous_entity) && is_declaration(entity));
4010
4011                         declaration_t *const prev_decl = &previous_entity->declaration;
4012                         declaration_t *const decl      = &entity->declaration;
4013
4014                         /* can happen for K&R style declarations */
4015                         if (prev_decl->type       == NULL             &&
4016                                         previous_entity->kind == ENTITY_PARAMETER &&
4017                                         entity->kind          == ENTITY_PARAMETER) {
4018                                 prev_decl->type                   = decl->type;
4019                                 prev_decl->storage_class          = decl->storage_class;
4020                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4021                                 prev_decl->modifiers              = decl->modifiers;
4022                                 return previous_entity;
4023                         }
4024
4025                         type_t *const type      = skip_typeref(decl->type);
4026                         type_t *const prev_type = skip_typeref(prev_decl->type);
4027
4028                         if (!types_compatible(type, prev_type)) {
4029                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4030                         } else {
4031                                 unsigned old_storage_class = prev_decl->storage_class;
4032
4033                                 if (is_definition                     &&
4034                                                 !prev_decl->used                  &&
4035                                                 !(prev_decl->modifiers & DM_USED) &&
4036                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4037                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4038                                 }
4039
4040                                 storage_class_t new_storage_class = decl->storage_class;
4041
4042                                 /* pretend no storage class means extern for function
4043                                  * declarations (except if the previous declaration is neither
4044                                  * none nor extern) */
4045                                 if (entity->kind == ENTITY_FUNCTION) {
4046                                         /* the previous declaration could have unspecified parameters or
4047                                          * be a typedef, so use the new type */
4048                                         if (prev_type->function.unspecified_parameters || is_definition)
4049                                                 prev_decl->type = type;
4050
4051                                         switch (old_storage_class) {
4052                                                 case STORAGE_CLASS_NONE:
4053                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4054                                                         /* FALLTHROUGH */
4055
4056                                                 case STORAGE_CLASS_EXTERN:
4057                                                         if (is_definition) {
4058                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4059                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4060                                                                 }
4061                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4062                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4063                                                         }
4064                                                         break;
4065
4066                                                 default:
4067                                                         break;
4068                                         }
4069                                 } else if (is_type_incomplete(prev_type)) {
4070                                         prev_decl->type = type;
4071                                 }
4072
4073                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4074                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4075
4076 warn_redundant_declaration: ;
4077                                         bool has_new_attrs
4078                                                 = has_new_attributes(prev_decl->attributes,
4079                                                                      decl->attributes);
4080                                         if (has_new_attrs) {
4081                                                 merge_in_attributes(decl, prev_decl->attributes);
4082                                         } else if (!is_definition        &&
4083                                                         is_type_valid(prev_type) &&
4084                                                         !pos->is_system_header) {
4085                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4086                                         }
4087                                 } else if (current_function == NULL) {
4088                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4089                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4090                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4091                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4092                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4093                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4094                                         } else {
4095                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4096                                                 if (c_mode & _CXX)
4097                                                         goto error_redeclaration;
4098                                                 goto warn_redundant_declaration;
4099                                         }
4100                                 } else if (is_type_valid(prev_type)) {
4101                                         if (old_storage_class == new_storage_class) {
4102 error_redeclaration:
4103                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4104                                         } else {
4105                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4106                                         }
4107                                 }
4108                         }
4109
4110                         prev_decl->modifiers |= decl->modifiers;
4111                         if (entity->kind == ENTITY_FUNCTION) {
4112                                 previous_entity->function.is_inline |= entity->function.is_inline;
4113                         }
4114                         return previous_entity;
4115                 }
4116
4117                 warning_t why;
4118                 if (is_warn_on(why = WARN_SHADOW) ||
4119                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4120                         char const *const what = get_entity_kind_name(previous_entity->kind);
4121                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4122                 }
4123         }
4124
4125         if (entity->kind == ENTITY_FUNCTION) {
4126                 if (is_definition &&
4127                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4128                                 !is_main(entity)) {
4129                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4130                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4131                         } else {
4132                                 goto warn_missing_declaration;
4133                         }
4134                 }
4135         } else if (entity->kind == ENTITY_VARIABLE) {
4136                 if (current_scope                     == file_scope &&
4137                     entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4138                     !entity->declaration.implicit) {
4139 warn_missing_declaration:
4140                         if (is_type_valid(skip_typeref(entity->declaration.type)))
4141                                 warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4142                 }
4143         }
4144
4145 finish:
4146         environment_push(entity);
4147         append_entity(current_scope, entity);
4148
4149         return entity;
4150 }
4151
4152 static void parser_error_multiple_definition(entity_t *entity,
4153                                              const position_t *pos)
4154 {
4155         errorf(pos, "redefinition of '%N' (declared %P)", entity, &entity->base.pos);
4156 }
4157
4158 static bool is_declaration_specifier(const token_t *token)
4159 {
4160         switch (token->kind) {
4161                 DECLARATION_START
4162                         return true;
4163                 case T_IDENTIFIER:
4164                         return is_typedef_symbol(token->base.symbol);
4165
4166                 default:
4167                         return false;
4168         }
4169 }
4170
4171 static void parse_init_declarator_rest(entity_t *entity)
4172 {
4173         type_t *orig_type = type_error_type;
4174
4175         if (entity->base.kind == ENTITY_TYPEDEF) {
4176                 position_t const *const pos = &entity->base.pos;
4177                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4178         } else {
4179                 assert(is_declaration(entity));
4180                 orig_type = entity->declaration.type;
4181         }
4182
4183         type_t *type = skip_typeref(orig_type);
4184
4185         if (entity->kind == ENTITY_VARIABLE
4186                         && entity->variable.initializer != NULL) {
4187                 parser_error_multiple_definition(entity, HERE);
4188         }
4189         eat('=');
4190
4191         declaration_t *const declaration = &entity->declaration;
4192         bool must_be_constant = false;
4193         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4194             entity->base.parent_scope  == file_scope) {
4195                 must_be_constant = true;
4196         }
4197
4198         if (is_type_function(type)) {
4199                 position_t const *const pos = &entity->base.pos;
4200                 errorf(pos, "'%N' is initialized like a variable", entity);
4201                 orig_type = type_error_type;
4202         }
4203
4204         parse_initializer_env_t env;
4205         env.type             = orig_type;
4206         env.must_be_constant = must_be_constant;
4207         env.entity           = entity;
4208
4209         initializer_t *initializer = parse_initializer(&env);
4210
4211         if (entity->kind == ENTITY_VARIABLE) {
4212                 /* §6.7.5:22  array initializers for arrays with unknown size
4213                  * determine the array type size */
4214                 declaration->type            = env.type;
4215                 entity->variable.initializer = initializer;
4216         }
4217 }
4218
4219 /* parse rest of a declaration without any declarator */
4220 static void parse_anonymous_declaration_rest(
4221                 const declaration_specifiers_t *specifiers)
4222 {
4223         eat(';');
4224         anonymous_entity = NULL;
4225
4226         position_t const *const pos = &specifiers->pos;
4227         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4228                         specifiers->thread_local) {
4229                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4230         }
4231
4232         type_t *type = specifiers->type;
4233         switch (type->kind) {
4234                 case TYPE_COMPOUND_STRUCT:
4235                 case TYPE_COMPOUND_UNION: {
4236                         if (type->compound.compound->base.symbol == NULL) {
4237                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4238                         }
4239                         break;
4240                 }
4241
4242                 case TYPE_ENUM:
4243                         break;
4244
4245                 default:
4246                         warningf(WARN_OTHER, pos, "empty declaration");
4247                         break;
4248         }
4249 }
4250
4251 static void check_variable_type_complete(entity_t *ent)
4252 {
4253         if (ent->kind != ENTITY_VARIABLE)
4254                 return;
4255
4256         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4257          *         type for the object shall be complete [...] */
4258         declaration_t *decl = &ent->declaration;
4259         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4260                         decl->storage_class == STORAGE_CLASS_STATIC)
4261                 return;
4262
4263         type_t *const type = skip_typeref(decl->type);
4264         if (!is_type_incomplete(type))
4265                 return;
4266
4267         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4268          * are given length one. */
4269         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4270                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4271                 return;
4272         }
4273
4274         errorf(&ent->base.pos, "variable '%#N' has incomplete type", ent);
4275 }
4276
4277
4278 static void parse_declaration_rest(entity_t *ndeclaration,
4279                 const declaration_specifiers_t *specifiers,
4280                 parsed_declaration_func         finished_declaration,
4281                 declarator_flags_t              flags)
4282 {
4283         add_anchor_token(';');
4284         add_anchor_token(',');
4285         while (true) {
4286                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4287
4288                 if (token.kind == '=') {
4289                         parse_init_declarator_rest(entity);
4290                 } else if (entity->kind == ENTITY_VARIABLE) {
4291                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4292                          * [...] where the extern specifier is explicitly used. */
4293                         declaration_t *decl = &entity->declaration;
4294                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4295                             is_type_reference(skip_typeref(decl->type))) {
4296                                 position_t const *const pos = &entity->base.pos;
4297                                 errorf(pos, "reference '%#N' must be initialized", entity);
4298                         }
4299                 }
4300
4301                 check_variable_type_complete(entity);
4302
4303                 if (!accept(','))
4304                         break;
4305
4306                 add_anchor_token('=');
4307                 ndeclaration = parse_declarator(specifiers, flags);
4308                 rem_anchor_token('=');
4309         }
4310         rem_anchor_token(',');
4311         rem_anchor_token(';');
4312         expect(';');
4313
4314         anonymous_entity = NULL;
4315 }
4316
4317 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4318 {
4319         symbol_t *symbol = entity->base.symbol;
4320         if (symbol == NULL)
4321                 return entity;
4322
4323         assert(entity->base.namespc == NAMESPACE_NORMAL);
4324         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4325         if (previous_entity == NULL
4326                         || previous_entity->base.parent_scope != current_scope) {
4327                 errorf(&entity->base.pos, "expected declaration of a function parameter, found '%Y'",
4328                        symbol);
4329                 return entity;
4330         }
4331
4332         if (is_definition) {
4333                 errorf(HERE, "'%N' is initialised", entity);
4334         }
4335
4336         return record_entity(entity, false);
4337 }
4338
4339 static void parse_declaration(parsed_declaration_func finished_declaration,
4340                               declarator_flags_t      flags)
4341 {
4342         add_anchor_token(';');
4343         declaration_specifiers_t specifiers;
4344         parse_declaration_specifiers(&specifiers);
4345         rem_anchor_token(';');
4346
4347         if (token.kind == ';') {
4348                 parse_anonymous_declaration_rest(&specifiers);
4349         } else {
4350                 entity_t *entity = parse_declarator(&specifiers, flags);
4351                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4352         }
4353 }
4354
4355 /* §6.5.2.2:6 */
4356 static type_t *get_default_promoted_type(type_t *orig_type)
4357 {
4358         type_t *result = orig_type;
4359
4360         type_t *type = skip_typeref(orig_type);
4361         if (is_type_integer(type)) {
4362                 result = promote_integer(type);
4363         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4364                 result = type_double;
4365         }
4366
4367         return result;
4368 }
4369
4370 static void parse_kr_declaration_list(entity_t *entity)
4371 {
4372         if (entity->kind != ENTITY_FUNCTION)
4373                 return;
4374
4375         type_t *type = skip_typeref(entity->declaration.type);
4376         assert(is_type_function(type));
4377         if (!type->function.kr_style_parameters)
4378                 return;
4379
4380         add_anchor_token('{');
4381
4382         PUSH_SCOPE(&entity->function.parameters);
4383
4384         entity_t *parameter = entity->function.parameters.entities;
4385         for ( ; parameter != NULL; parameter = parameter->base.next) {
4386                 assert(parameter->base.parent_scope == NULL);
4387                 parameter->base.parent_scope = current_scope;
4388                 environment_push(parameter);
4389         }
4390
4391         /* parse declaration list */
4392         for (;;) {
4393                 switch (token.kind) {
4394                         DECLARATION_START
4395                         /* This covers symbols, which are no type, too, and results in
4396                          * better error messages.  The typical cases are misspelled type
4397                          * names and missing includes. */
4398                         case T_IDENTIFIER:
4399                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4400                                 break;
4401                         default:
4402                                 goto decl_list_end;
4403                 }
4404         }
4405 decl_list_end:
4406
4407         POP_SCOPE();
4408
4409         /* update function type */
4410         type_t *new_type = duplicate_type(type);
4411
4412         function_parameter_t  *parameters = NULL;
4413         function_parameter_t **anchor     = &parameters;
4414
4415         /* did we have an earlier prototype? */
4416         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4417         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4418                 proto_type = NULL;
4419
4420         function_parameter_t *proto_parameter = NULL;
4421         if (proto_type != NULL) {
4422                 type_t *proto_type_type = proto_type->declaration.type;
4423                 proto_parameter         = proto_type_type->function.parameters;
4424                 /* If a K&R function definition has a variadic prototype earlier, then
4425                  * make the function definition variadic, too. This should conform to
4426                  * §6.7.5.3:15 and §6.9.1:8. */
4427                 new_type->function.variadic = proto_type_type->function.variadic;
4428         } else {
4429                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4430                  * prototype */
4431                 new_type->function.unspecified_parameters = true;
4432         }
4433
4434         bool need_incompatible_warning = false;
4435         parameter = entity->function.parameters.entities;
4436         for (; parameter != NULL; parameter = parameter->base.next,
4437                         proto_parameter =
4438                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4439                 if (parameter->kind != ENTITY_PARAMETER)
4440                         continue;
4441
4442                 type_t *parameter_type = parameter->declaration.type;
4443                 if (parameter_type == NULL) {
4444                         position_t const* const pos = &parameter->base.pos;
4445                         if (strict_mode) {
4446                                 errorf(pos, "no type specified for function '%N'", parameter);
4447                                 parameter_type = type_error_type;
4448                         } else {
4449                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4450                                 parameter_type = type_int;
4451                         }
4452                         parameter->declaration.type = parameter_type;
4453                 }
4454
4455                 semantic_parameter_incomplete(parameter);
4456
4457                 /* we need the default promoted types for the function type */
4458                 type_t *not_promoted = parameter_type;
4459                 parameter_type       = get_default_promoted_type(parameter_type);
4460
4461                 /* gcc special: if the type of the prototype matches the unpromoted
4462                  * type don't promote */
4463                 if (!strict_mode && proto_parameter != NULL) {
4464                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4465                         type_t *promo_skip   = skip_typeref(parameter_type);
4466                         type_t *param_skip   = skip_typeref(not_promoted);
4467                         if (!types_compatible(proto_p_type, promo_skip)
4468                                 && types_compatible(proto_p_type, param_skip)) {
4469                                 /* don't promote */
4470                                 need_incompatible_warning = true;
4471                                 parameter_type = not_promoted;
4472                         }
4473                 }
4474                 function_parameter_t *const function_parameter
4475                         = allocate_parameter(parameter_type);
4476
4477                 *anchor = function_parameter;
4478                 anchor  = &function_parameter->next;
4479         }
4480
4481         new_type->function.parameters = parameters;
4482         new_type = identify_new_type(new_type);
4483
4484         if (need_incompatible_warning) {
4485                 symbol_t   const *const sym  = entity->base.symbol;
4486                 position_t const *const pos  = &entity->base.pos;
4487                 position_t const *const ppos = &proto_type->base.pos;
4488                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4489         }
4490         entity->declaration.type = new_type;
4491
4492         rem_anchor_token('{');
4493 }
4494
4495 static bool first_err = true;
4496
4497 /**
4498  * When called with first_err set, prints the name of the current function,
4499  * else does noting.
4500  */
4501 static void print_in_function(void)
4502 {
4503         if (first_err) {
4504                 first_err = false;
4505                 char const *const file = current_function->base.base.pos.input_name;
4506                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4507         }
4508 }
4509
4510 /**
4511  * Check if all labels are defined in the current function.
4512  * Check if all labels are used in the current function.
4513  */
4514 static void check_labels(void)
4515 {
4516         for (const goto_statement_t *goto_statement = goto_first;
4517             goto_statement != NULL;
4518             goto_statement = goto_statement->next) {
4519                 label_t *label = goto_statement->label;
4520                 if (label->base.pos.input_name == NULL) {
4521                         print_in_function();
4522                         position_t const *const pos = &goto_statement->base.pos;
4523                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4524                  }
4525         }
4526
4527         if (is_warn_on(WARN_UNUSED_LABEL)) {
4528                 for (const label_statement_t *label_statement = label_first;
4529                          label_statement != NULL;
4530                          label_statement = label_statement->next) {
4531                         label_t *label = label_statement->label;
4532
4533                         if (! label->used) {
4534                                 print_in_function();
4535                                 position_t const *const pos = &label_statement->base.pos;
4536                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4537                         }
4538                 }
4539         }
4540 }
4541
4542 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4543 {
4544         entity_t const *const end = last != NULL ? last->base.next : NULL;
4545         for (; entity != end; entity = entity->base.next) {
4546                 if (!is_declaration(entity))
4547                         continue;
4548
4549                 declaration_t *declaration = &entity->declaration;
4550                 if (declaration->implicit)
4551                         continue;
4552
4553                 if (!declaration->used) {
4554                         print_in_function();
4555                         warningf(why, &entity->base.pos, "'%N' is unused", entity);
4556                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4557                         print_in_function();
4558                         warningf(why, &entity->base.pos, "'%N' is never read", entity);
4559                 }
4560         }
4561 }
4562
4563 static void check_unused_variables(statement_t *const stmt, void *const env)
4564 {
4565         (void)env;
4566
4567         switch (stmt->kind) {
4568                 case STATEMENT_DECLARATION: {
4569                         declaration_statement_t const *const decls = &stmt->declaration;
4570                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4571                         return;
4572                 }
4573
4574                 case STATEMENT_FOR:
4575                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4576                         return;
4577
4578                 default:
4579                         return;
4580         }
4581 }
4582
4583 /**
4584  * Check declarations of current_function for unused entities.
4585  */
4586 static void check_declarations(void)
4587 {
4588         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4589                 const scope_t *scope = &current_function->parameters;
4590                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4591         }
4592         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4593                 walk_statements(current_function->body, check_unused_variables, NULL);
4594         }
4595 }
4596
4597 static int determine_truth(expression_t const* const cond)
4598 {
4599         return
4600                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4601                 fold_constant_to_bool(cond)                         ? 1 :
4602                 -1;
4603 }
4604
4605 static void check_reachable(statement_t *);
4606 static bool reaches_end;
4607
4608 static bool expression_returns(expression_t const *const expr)
4609 {
4610         switch (expr->kind) {
4611                 case EXPR_CALL: {
4612                         expression_t const *const func = expr->call.function;
4613                         type_t       const *const type = skip_typeref(func->base.type);
4614                         if (type->kind == TYPE_POINTER) {
4615                                 type_t const *const points_to
4616                                         = skip_typeref(type->pointer.points_to);
4617                                 if (points_to->kind == TYPE_FUNCTION
4618                                     && points_to->function.modifiers & DM_NORETURN)
4619                                         return false;
4620                         }
4621
4622                         if (!expression_returns(func))
4623                                 return false;
4624
4625                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4626                                 if (!expression_returns(arg->expression))
4627                                         return false;
4628                         }
4629
4630                         return true;
4631                 }
4632
4633                 case EXPR_REFERENCE:
4634                 case EXPR_ENUM_CONSTANT:
4635                 case EXPR_LITERAL_CASES:
4636                 case EXPR_LITERAL_CHARACTER:
4637                 case EXPR_STRING_LITERAL:
4638                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4639                 case EXPR_LABEL_ADDRESS:
4640                 case EXPR_CLASSIFY_TYPE:
4641                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4642                 case EXPR_ALIGNOF:
4643                 case EXPR_FUNCNAME:
4644                 case EXPR_BUILTIN_CONSTANT_P:
4645                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4646                 case EXPR_OFFSETOF:
4647                 case EXPR_ERROR:
4648                         return true;
4649
4650                 case EXPR_STATEMENT: {
4651                         bool old_reaches_end = reaches_end;
4652                         reaches_end = false;
4653                         check_reachable(expr->statement.statement);
4654                         bool returns = reaches_end;
4655                         reaches_end = old_reaches_end;
4656                         return returns;
4657                 }
4658
4659                 case EXPR_CONDITIONAL:
4660                         // TODO handle constant expression
4661
4662                         if (!expression_returns(expr->conditional.condition))
4663                                 return false;
4664
4665                         if (expr->conditional.true_expression != NULL
4666                                         && expression_returns(expr->conditional.true_expression))
4667                                 return true;
4668
4669                         return expression_returns(expr->conditional.false_expression);
4670
4671                 case EXPR_SELECT:
4672                         return expression_returns(expr->select.compound);
4673
4674                 case EXPR_ARRAY_ACCESS:
4675                         return
4676                                 expression_returns(expr->array_access.array_ref) &&
4677                                 expression_returns(expr->array_access.index);
4678
4679                 case EXPR_VA_START:
4680                         return expression_returns(expr->va_starte.ap);
4681
4682                 case EXPR_VA_ARG:
4683                         return expression_returns(expr->va_arge.ap);
4684
4685                 case EXPR_VA_COPY:
4686                         return expression_returns(expr->va_copye.src);
4687
4688                 case EXPR_UNARY_CASES_MANDATORY:
4689                         return expression_returns(expr->unary.value);
4690
4691                 case EXPR_UNARY_THROW:
4692                         return false;
4693
4694                 case EXPR_BINARY_CASES:
4695                         // TODO handle constant lhs of && and ||
4696                         return
4697                                 expression_returns(expr->binary.left) &&
4698                                 expression_returns(expr->binary.right);
4699         }
4700
4701         panic("unhandled expression");
4702 }
4703
4704 static bool initializer_returns(initializer_t const *const init)
4705 {
4706         switch (init->kind) {
4707                 case INITIALIZER_VALUE:
4708                         return expression_returns(init->value.value);
4709
4710                 case INITIALIZER_LIST: {
4711                         initializer_t * const*       i       = init->list.initializers;
4712                         initializer_t * const* const end     = i + init->list.len;
4713                         bool                         returns = true;
4714                         for (; i != end; ++i) {
4715                                 if (!initializer_returns(*i))
4716                                         returns = false;
4717                         }
4718                         return returns;
4719                 }
4720
4721                 case INITIALIZER_STRING:
4722                 case INITIALIZER_DESIGNATOR: // designators have no payload
4723                         return true;
4724         }
4725         panic("unhandled initializer");
4726 }
4727
4728 static bool noreturn_candidate;
4729
4730 static void check_reachable(statement_t *const stmt)
4731 {
4732         if (stmt->base.reachable)
4733                 return;
4734         if (stmt->kind != STATEMENT_DO_WHILE)
4735                 stmt->base.reachable = true;
4736
4737         statement_t *last = stmt;
4738         statement_t *next;
4739         switch (stmt->kind) {
4740                 case STATEMENT_ERROR:
4741                 case STATEMENT_EMPTY:
4742                 case STATEMENT_ASM:
4743                         next = stmt->base.next;
4744                         break;
4745
4746                 case STATEMENT_DECLARATION: {
4747                         declaration_statement_t const *const decl = &stmt->declaration;
4748                         entity_t                const *      ent  = decl->declarations_begin;
4749                         entity_t                const *const last_decl = decl->declarations_end;
4750                         if (ent != NULL) {
4751                                 for (;; ent = ent->base.next) {
4752                                         if (ent->kind                 == ENTITY_VARIABLE &&
4753                                             ent->variable.initializer != NULL            &&
4754                                             !initializer_returns(ent->variable.initializer)) {
4755                                                 return;
4756                                         }
4757                                         if (ent == last_decl)
4758                                                 break;
4759                                 }
4760                         }
4761                         next = stmt->base.next;
4762                         break;
4763                 }
4764
4765                 case STATEMENT_COMPOUND:
4766                         next = stmt->compound.statements;
4767                         if (next == NULL)
4768                                 next = stmt->base.next;
4769                         break;
4770
4771                 case STATEMENT_RETURN: {
4772                         expression_t const *const val = stmt->returns.value;
4773                         if (val == NULL || expression_returns(val))
4774                                 noreturn_candidate = false;
4775                         return;
4776                 }
4777
4778                 case STATEMENT_IF: {
4779                         if_statement_t const *const ifs  = &stmt->ifs;
4780                         expression_t   const *const cond = ifs->condition;
4781
4782                         if (!expression_returns(cond))
4783                                 return;
4784
4785                         int const val = determine_truth(cond);
4786
4787                         if (val >= 0)
4788                                 check_reachable(ifs->true_statement);
4789
4790                         if (val > 0)
4791                                 return;
4792
4793                         if (ifs->false_statement != NULL) {
4794                                 check_reachable(ifs->false_statement);
4795                                 return;
4796                         }
4797
4798                         next = stmt->base.next;
4799                         break;
4800                 }
4801
4802                 case STATEMENT_SWITCH: {
4803                         switch_statement_t const *const switchs = &stmt->switchs;
4804                         expression_t       const *const expr    = switchs->expression;
4805
4806                         if (!expression_returns(expr))
4807                                 return;
4808
4809                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4810                                 ir_tarval              *const val      = fold_constant_to_tarval(expr);
4811                                 case_label_statement_t *      defaults = NULL;
4812                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4813                                         if (i->expression == NULL) {
4814                                                 defaults = i;
4815                                                 continue;
4816                                         }
4817
4818                                         if (i->first_case == val || i->last_case == val ||
4819                                                 ((tarval_cmp(i->first_case, val) & ir_relation_less_equal)
4820                                             && (tarval_cmp(val, i->last_case) & ir_relation_less_equal))) {
4821                                                 check_reachable((statement_t*)i);
4822                                                 return;
4823                                         }
4824                                 }
4825
4826                                 if (defaults != NULL) {
4827                                         check_reachable((statement_t*)defaults);
4828                                         return;
4829                                 }
4830                         } else {
4831                                 bool has_default = false;
4832                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4833                                         if (i->expression == NULL)
4834                                                 has_default = true;
4835
4836                                         check_reachable((statement_t*)i);
4837                                 }
4838
4839                                 if (has_default)
4840                                         return;
4841                         }
4842
4843                         next = stmt->base.next;
4844                         break;
4845                 }
4846
4847                 case STATEMENT_EXPRESSION: {
4848                         /* Check for noreturn function call */
4849                         expression_t const *const expr = stmt->expression.expression;
4850                         if (!expression_returns(expr))
4851                                 return;
4852
4853                         next = stmt->base.next;
4854                         break;
4855                 }
4856
4857                 case STATEMENT_CONTINUE:
4858                         for (statement_t *parent = stmt;;) {
4859                                 parent = parent->base.parent;
4860                                 if (parent == NULL) /* continue not within loop */
4861                                         return;
4862
4863                                 next = parent;
4864                                 switch (parent->kind) {
4865                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4866                                         case STATEMENT_FOR:      goto continue_for;
4867
4868                                         default: break;
4869                                 }
4870                         }
4871
4872                 case STATEMENT_BREAK:
4873                         for (statement_t *parent = stmt;;) {
4874                                 parent = parent->base.parent;
4875                                 if (parent == NULL) /* break not within loop/switch */
4876                                         return;
4877
4878                                 switch (parent->kind) {
4879                                         case STATEMENT_SWITCH:
4880                                         case STATEMENT_DO_WHILE:
4881                                         case STATEMENT_FOR:
4882                                                 last = parent;
4883                                                 next = parent->base.next;
4884                                                 goto found_break_parent;
4885
4886                                         default: break;
4887                                 }
4888                         }
4889 found_break_parent:
4890                         break;
4891
4892                 case STATEMENT_COMPUTED_GOTO: {
4893                         if (!expression_returns(stmt->computed_goto.expression))
4894                                 return;
4895
4896                         statement_t *parent = stmt->base.parent;
4897                         if (parent == NULL) /* top level goto */
4898                                 return;
4899                         next = parent;
4900                         break;
4901                 }
4902
4903                 case STATEMENT_GOTO:
4904                         next = stmt->gotos.label->statement;
4905                         if (next == NULL) /* missing label */
4906                                 return;
4907                         break;
4908
4909                 case STATEMENT_LABEL:
4910                         next = stmt->label.statement;
4911                         break;
4912
4913                 case STATEMENT_CASE_LABEL:
4914                         next = stmt->case_label.statement;
4915                         break;
4916
4917                 case STATEMENT_DO_WHILE:
4918                         next = stmt->do_while.body;
4919                         break;
4920
4921                 case STATEMENT_FOR: {
4922                         for_statement_t *const fors = &stmt->fors;
4923
4924                         if (fors->condition_reachable)
4925                                 return;
4926                         fors->condition_reachable = true;
4927
4928                         expression_t const *const cond = fors->condition;
4929
4930                         int val;
4931                         if (cond == NULL) {
4932                                 val = 1;
4933                         } else if (expression_returns(cond)) {
4934                                 val = determine_truth(cond);
4935                         } else {
4936                                 return;
4937                         }
4938
4939                         if (val >= 0)
4940                                 check_reachable(fors->body);
4941
4942                         if (val > 0)
4943                                 return;
4944
4945                         next = stmt->base.next;
4946                         break;
4947                 }
4948
4949                 case STATEMENT_MS_TRY: {
4950                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4951                         check_reachable(ms_try->try_statement);
4952                         next = ms_try->final_statement;
4953                         break;
4954                 }
4955
4956                 case STATEMENT_LEAVE: {
4957                         statement_t *parent = stmt;
4958                         for (;;) {
4959                                 parent = parent->base.parent;
4960                                 if (parent == NULL) /* __leave not within __try */
4961                                         return;
4962
4963                                 if (parent->kind == STATEMENT_MS_TRY) {
4964                                         last = parent;
4965                                         next = parent->ms_try.final_statement;
4966                                         break;
4967                                 }
4968                         }
4969                         break;
4970                 }
4971
4972                 default:
4973                         panic("invalid statement kind");
4974         }
4975
4976         while (next == NULL) {
4977                 next = last->base.parent;
4978                 if (next == NULL) {
4979                         noreturn_candidate = false;
4980
4981                         type_t *const type = skip_typeref(current_function->base.type);
4982                         assert(is_type_function(type));
4983                         type_t *const ret  = skip_typeref(type->function.return_type);
4984                         if (!is_type_void(ret) &&
4985                             is_type_valid(ret) &&
4986                             !is_main(current_entity)) {
4987                                 position_t const *const pos = &stmt->base.pos;
4988                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4989                         }
4990                         return;
4991                 }
4992
4993                 switch (next->kind) {
4994                         case STATEMENT_ERROR:
4995                         case STATEMENT_EMPTY:
4996                         case STATEMENT_DECLARATION:
4997                         case STATEMENT_EXPRESSION:
4998                         case STATEMENT_ASM:
4999                         case STATEMENT_RETURN:
5000                         case STATEMENT_CONTINUE:
5001                         case STATEMENT_BREAK:
5002                         case STATEMENT_COMPUTED_GOTO:
5003                         case STATEMENT_GOTO:
5004                         case STATEMENT_LEAVE:
5005                                 panic("invalid control flow in function");
5006
5007                         case STATEMENT_COMPOUND:
5008                                 if (next->compound.stmt_expr) {
5009                                         reaches_end = true;
5010                                         return;
5011                                 }
5012                                 /* FALLTHROUGH */
5013                         case STATEMENT_IF:
5014                         case STATEMENT_SWITCH:
5015                         case STATEMENT_LABEL:
5016                         case STATEMENT_CASE_LABEL:
5017                                 last = next;
5018                                 next = next->base.next;
5019                                 break;
5020
5021                         case STATEMENT_DO_WHILE: {
5022 continue_do_while:
5023                                 if (next->base.reachable)
5024                                         return;
5025                                 next->base.reachable = true;
5026
5027                                 do_while_statement_t const *const dw   = &next->do_while;
5028                                 expression_t         const *const cond = dw->condition;
5029
5030                                 if (!expression_returns(cond))
5031                                         return;
5032
5033                                 int const val = determine_truth(cond);
5034
5035                                 if (val >= 0)
5036                                         check_reachable(dw->body);
5037
5038                                 if (val > 0)
5039                                         return;
5040
5041                                 last = next;
5042                                 next = next->base.next;
5043                                 break;
5044                         }
5045
5046                         case STATEMENT_FOR: {
5047 continue_for:;
5048                                 for_statement_t *const fors = &next->fors;
5049
5050                                 fors->step_reachable = true;
5051
5052                                 if (fors->condition_reachable)
5053                                         return;
5054                                 fors->condition_reachable = true;
5055
5056                                 expression_t const *const cond = fors->condition;
5057
5058                                 int val;
5059                                 if (cond == NULL) {
5060                                         val = 1;
5061                                 } else if (expression_returns(cond)) {
5062                                         val = determine_truth(cond);
5063                                 } else {
5064                                         return;
5065                                 }
5066
5067                                 if (val >= 0)
5068                                         check_reachable(fors->body);
5069
5070                                 if (val > 0)
5071                                         return;
5072
5073                                 last = next;
5074                                 next = next->base.next;
5075                                 break;
5076                         }
5077
5078                         case STATEMENT_MS_TRY:
5079                                 last = next;
5080                                 next = next->ms_try.final_statement;
5081                                 break;
5082                 }
5083         }
5084
5085         check_reachable(next);
5086 }
5087
5088 static void check_unreachable(statement_t* const stmt, void *const env)
5089 {
5090         (void)env;
5091
5092         switch (stmt->kind) {
5093                 case STATEMENT_DO_WHILE:
5094                         if (!stmt->base.reachable) {
5095                                 expression_t const *const cond = stmt->do_while.condition;
5096                                 if (determine_truth(cond) >= 0) {
5097                                         position_t const *const pos = &cond->base.pos;
5098                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5099                                 }
5100                         }
5101                         return;
5102
5103                 case STATEMENT_FOR: {
5104                         for_statement_t const* const fors = &stmt->fors;
5105
5106                         // if init and step are unreachable, cond is unreachable, too
5107                         if (!stmt->base.reachable && !fors->step_reachable) {
5108                                 goto warn_unreachable;
5109                         } else {
5110                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5111                                         position_t const *const pos = &fors->initialisation->base.pos;
5112                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5113                                 }
5114
5115                                 if (!fors->condition_reachable && fors->condition != NULL) {
5116                                         position_t const *const pos = &fors->condition->base.pos;
5117                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5118                                 }
5119
5120                                 if (!fors->step_reachable && fors->step != NULL) {
5121                                         position_t const *const pos = &fors->step->base.pos;
5122                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5123                                 }
5124                         }
5125                         return;
5126                 }
5127
5128                 case STATEMENT_COMPOUND:
5129                         if (stmt->compound.statements != NULL)
5130                                 return;
5131                         goto warn_unreachable;
5132
5133                 case STATEMENT_DECLARATION: {
5134                         /* Only warn if there is at least one declarator with an initializer.
5135                          * This typically occurs in switch statements. */
5136                         declaration_statement_t const *const decl = &stmt->declaration;
5137                         entity_t                const *      ent  = decl->declarations_begin;
5138                         entity_t                const *const last = decl->declarations_end;
5139                         if (ent != NULL) {
5140                                 for (;; ent = ent->base.next) {
5141                                         if (ent->kind                 == ENTITY_VARIABLE &&
5142                                                         ent->variable.initializer != NULL) {
5143                                                 goto warn_unreachable;
5144                                         }
5145                                         if (ent == last)
5146                                                 return;
5147                                 }
5148                         }
5149                 }
5150
5151                 default:
5152 warn_unreachable:
5153                         if (!stmt->base.reachable) {
5154                                 position_t const *const pos = &stmt->base.pos;
5155                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5156                         }
5157                         return;
5158         }
5159 }
5160
5161 static bool is_main(entity_t *entity)
5162 {
5163         static symbol_t *sym_main = NULL;
5164         if (sym_main == NULL) {
5165                 sym_main = symbol_table_insert("main");
5166         }
5167
5168         if (entity->base.symbol != sym_main)
5169                 return false;
5170         /* must be in outermost scope */
5171         if (entity->base.parent_scope != file_scope)
5172                 return false;
5173
5174         return true;
5175 }
5176
5177 static void prepare_main_collect2(entity_t*);
5178
5179 static void parse_external_declaration(void)
5180 {
5181         /* function-definitions and declarations both start with declaration
5182          * specifiers */
5183         add_anchor_token(';');
5184         declaration_specifiers_t specifiers;
5185         parse_declaration_specifiers(&specifiers);
5186         rem_anchor_token(';');
5187
5188         /* must be a declaration */
5189         if (token.kind == ';') {
5190                 parse_anonymous_declaration_rest(&specifiers);
5191                 return;
5192         }
5193
5194         add_anchor_token(',');
5195         add_anchor_token('=');
5196         add_anchor_token(';');
5197         add_anchor_token('{');
5198
5199         /* declarator is common to both function-definitions and declarations */
5200         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5201
5202         rem_anchor_token('{');
5203         rem_anchor_token(';');
5204         rem_anchor_token('=');
5205         rem_anchor_token(',');
5206
5207         /* must be a declaration */
5208         switch (token.kind) {
5209                 case ',':
5210                 case ';':
5211                 case '=':
5212                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5213                                         DECL_FLAGS_NONE);
5214                         return;
5215         }
5216
5217         /* must be a function definition */
5218         parse_kr_declaration_list(ndeclaration);
5219
5220         if (token.kind != '{') {
5221                 parse_error_expected("while parsing function definition", '{', NULL);
5222                 eat_until_matching_token(';');
5223                 return;
5224         }
5225
5226         assert(is_declaration(ndeclaration));
5227         type_t *const orig_type = ndeclaration->declaration.type;
5228         type_t *      type      = skip_typeref(orig_type);
5229
5230         if (!is_type_function(type)) {
5231                 if (is_type_valid(type)) {
5232                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5233                 }
5234                 eat_block();
5235                 return;
5236         }
5237
5238         position_t const *const pos = &ndeclaration->base.pos;
5239         if (is_typeref(orig_type)) {
5240                 /* §6.9.1:2 */
5241                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5242         }
5243
5244         if (is_type_compound(skip_typeref(type->function.return_type))) {
5245                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5246         }
5247         if (type->function.unspecified_parameters) {
5248                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5249         } else {
5250                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5251         }
5252
5253         /* §6.7.5.3:14 a function definition with () means no
5254          * parameters (and not unspecified parameters) */
5255         if (type->function.unspecified_parameters &&
5256                         type->function.parameters == NULL) {
5257                 type_t *copy                          = duplicate_type(type);
5258                 copy->function.unspecified_parameters = false;
5259                 type                                  = identify_new_type(copy);
5260
5261                 ndeclaration->declaration.type = type;
5262         }
5263
5264         entity_t *const entity = record_entity(ndeclaration, true);
5265         assert(entity->kind == ENTITY_FUNCTION);
5266         assert(ndeclaration->kind == ENTITY_FUNCTION);
5267
5268         function_t *const function = &entity->function;
5269         if (ndeclaration != entity) {
5270                 function->parameters = ndeclaration->function.parameters;
5271         }
5272
5273         PUSH_SCOPE(&function->parameters);
5274
5275         entity_t *parameter = function->parameters.entities;
5276         for (; parameter != NULL; parameter = parameter->base.next) {
5277                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5278                         parameter->base.parent_scope = current_scope;
5279                 }
5280                 assert(parameter->base.parent_scope == NULL
5281                                 || parameter->base.parent_scope == current_scope);
5282                 parameter->base.parent_scope = current_scope;
5283                 if (parameter->base.symbol == NULL) {
5284                         errorf(&parameter->base.pos, "parameter name omitted");
5285                         continue;
5286                 }
5287                 environment_push(parameter);
5288         }
5289
5290         if (function->body != NULL) {
5291                 parser_error_multiple_definition(entity, HERE);
5292                 eat_block();
5293         } else {
5294                 /* parse function body */
5295                 int         label_stack_top      = label_top();
5296                 function_t *old_current_function = current_function;
5297                 current_function                 = function;
5298                 PUSH_CURRENT_ENTITY(entity);
5299                 PUSH_PARENT(NULL);
5300
5301                 goto_first   = NULL;
5302                 goto_anchor  = &goto_first;
5303                 label_first  = NULL;
5304                 label_anchor = &label_first;
5305
5306                 statement_t *const body = parse_compound_statement(false);
5307                 function->body = body;
5308                 first_err = true;
5309                 check_labels();
5310                 check_declarations();
5311                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5312                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5313                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5314                         noreturn_candidate = true;
5315                         check_reachable(body);
5316                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5317                                 walk_statements(body, check_unreachable, NULL);
5318                         if (noreturn_candidate &&
5319                             !(function->base.modifiers & DM_NORETURN)) {
5320                                 position_t const *const pos = &body->base.pos;
5321                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5322                         }
5323                 }
5324
5325                 if (is_main(entity)) {
5326                         /* Force main to C linkage. */
5327                         type_t *const type = entity->declaration.type;
5328                         assert(is_type_function(type));
5329                         if (type->function.linkage != LINKAGE_C) {
5330                                 type_t *new_type           = duplicate_type(type);
5331                                 new_type->function.linkage = LINKAGE_C;
5332                                 entity->declaration.type   = identify_new_type(new_type);
5333                         }
5334
5335                         if (enable_main_collect2_hack)
5336                                 prepare_main_collect2(entity);
5337                 }
5338
5339                 POP_CURRENT_ENTITY();
5340                 POP_PARENT();
5341                 assert(current_function == function);
5342                 current_function = old_current_function;
5343                 label_pop_to(label_stack_top);
5344         }
5345
5346         POP_SCOPE();
5347 }
5348
5349 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5350 {
5351         entity_t *iter = compound->members.entities;
5352         for (; iter != NULL; iter = iter->base.next) {
5353                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5354                         continue;
5355
5356                 if (iter->base.symbol == symbol) {
5357                         return iter;
5358                 } else if (iter->base.symbol == NULL) {
5359                         /* search in anonymous structs and unions */
5360                         type_t *type = skip_typeref(iter->declaration.type);
5361                         if (is_type_compound(type)) {
5362                                 if (find_compound_entry(type->compound.compound, symbol)
5363                                                 != NULL)
5364                                         return iter;
5365                         }
5366                         continue;
5367                 }
5368         }
5369
5370         return NULL;
5371 }
5372
5373 static void check_deprecated(const position_t *pos, const entity_t *entity)
5374 {
5375         if (!is_declaration(entity))
5376                 return;
5377         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5378                 return;
5379
5380         position_t const *const epos = &entity->base.pos;
5381         char       const *const msg  = get_deprecated_string(entity->declaration.attributes);
5382         if (msg != NULL) {
5383                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5384         } else {
5385                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P)", entity, epos);
5386         }
5387 }
5388
5389
5390 static expression_t *create_select(const position_t *pos, expression_t *addr,
5391                                    type_qualifiers_t qualifiers,
5392                                                                    entity_t *entry)
5393 {
5394         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5395
5396         check_deprecated(pos, entry);
5397
5398         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5399         select->select.compound       = addr;
5400         select->select.compound_entry = entry;
5401
5402         type_t *entry_type = entry->declaration.type;
5403         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5404
5405         /* bitfields need special treatment */
5406         if (entry->compound_member.bitfield) {
5407                 unsigned bit_size = entry->compound_member.bit_size;
5408                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5409                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5410                         res_type = type_int;
5411                 }
5412         }
5413
5414         /* we always do the auto-type conversions; the & and sizeof parser contains
5415          * code to revert this! */
5416         select->base.type = automatic_type_conversion(res_type);
5417
5418
5419         return select;
5420 }
5421
5422 /**
5423  * Find entry with symbol in compound. Search anonymous structs and unions and
5424  * creates implicit select expressions for them.
5425  * Returns the adress for the innermost compound.
5426  */
5427 static expression_t *find_create_select(const position_t *pos,
5428                                         expression_t *addr,
5429                                         type_qualifiers_t qualifiers,
5430                                         compound_t *compound, symbol_t *symbol)
5431 {
5432         entity_t *iter = compound->members.entities;
5433         for (; iter != NULL; iter = iter->base.next) {
5434                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5435                         continue;
5436
5437                 symbol_t *iter_symbol = iter->base.symbol;
5438                 if (iter_symbol == NULL) {
5439                         type_t *type = iter->declaration.type;
5440                         if (!is_type_compound(type))
5441                                 continue;
5442
5443                         compound_t *sub_compound = type->compound.compound;
5444
5445                         if (find_compound_entry(sub_compound, symbol) == NULL)
5446                                 continue;
5447
5448                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5449                         sub_addr->base.pos      = *pos;
5450                         sub_addr->base.implicit = true;
5451                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5452                                                   symbol);
5453                 }
5454
5455                 if (iter_symbol == symbol) {
5456                         return create_select(pos, addr, qualifiers, iter);
5457                 }
5458         }
5459
5460         return NULL;
5461 }
5462
5463 static void parse_bitfield_member(entity_t *entity)
5464 {
5465         eat(':');
5466
5467         expression_t *size = parse_constant_expression();
5468         long          size_long;
5469
5470         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5471         type_t *type = entity->declaration.type;
5472         if (!is_type_integer(skip_typeref(type))) {
5473                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5474                            type);
5475         }
5476
5477         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5478                 /* error already reported by parse_constant_expression */
5479                 size_long = get_type_size(type) * 8;
5480         } else {
5481                 size_long = fold_constant_to_int(size);
5482
5483                 const symbol_t *symbol = entity->base.symbol;
5484                 const symbol_t *user_symbol
5485                         = symbol == NULL ? sym_anonymous : symbol;
5486                 unsigned bit_size = get_type_size(type) * 8;
5487                 if (size_long < 0) {
5488                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5489                 } else if (size_long == 0 && symbol != NULL) {
5490                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5491                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5492                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5493                                    user_symbol);
5494                 } else {
5495                         /* hope that people don't invent crazy types with more bits
5496                          * than our struct can hold */
5497                         assert(size_long <
5498                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5499                 }
5500         }
5501
5502         entity->compound_member.bitfield = true;
5503         entity->compound_member.bit_size = (unsigned char)size_long;
5504 }
5505
5506 static void parse_compound_declarators(compound_t *compound,
5507                 const declaration_specifiers_t *specifiers)
5508 {
5509         add_anchor_token(';');
5510         add_anchor_token(',');
5511         do {
5512                 entity_t *entity;
5513
5514                 if (token.kind == ':') {
5515                         /* anonymous bitfield */
5516                         type_t *type = specifiers->type;
5517                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5518                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5519                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5520                         entity->declaration.type                   = type;
5521
5522                         parse_bitfield_member(entity);
5523
5524                         attribute_t  *attributes = parse_attributes(NULL);
5525                         attribute_t **anchor     = &attributes;
5526                         while (*anchor != NULL)
5527                                 anchor = &(*anchor)->next;
5528                         *anchor = specifiers->attributes;
5529                         if (attributes != NULL) {
5530                                 handle_entity_attributes(attributes, entity);
5531                         }
5532                         entity->declaration.attributes = attributes;
5533
5534                         append_entity(&compound->members, entity);
5535                 } else {
5536                         entity = parse_declarator(specifiers,
5537                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5538                         position_t const *const pos = &entity->base.pos;
5539                         if (entity->kind == ENTITY_TYPEDEF) {
5540                                 errorf(pos, "typedef not allowed as compound member");
5541                         } else {
5542                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5543
5544                                 /* make sure we don't define a symbol multiple times */
5545                                 symbol_t *symbol = entity->base.symbol;
5546                                 if (symbol != NULL) {
5547                                         entity_t *prev = find_compound_entry(compound, symbol);
5548                                         if (prev != NULL) {
5549                                                 position_t const *const ppos = &prev->base.pos;
5550                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5551                                         }
5552                                 }
5553
5554                                 if (token.kind == ':') {
5555                                         parse_bitfield_member(entity);
5556
5557                                         attribute_t *attributes = parse_attributes(NULL);
5558                                         handle_entity_attributes(attributes, entity);
5559                                 } else {
5560                                         type_t *orig_type = entity->declaration.type;
5561                                         type_t *type      = skip_typeref(orig_type);
5562                                         if (is_type_function(type)) {
5563                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5564                                         } else if (is_type_incomplete(type)) {
5565                                                 /* §6.7.2.1:16 flexible array member */
5566                                                 if (!is_type_array(type)       ||
5567                                                                 token.kind          != ';' ||
5568                                                                 look_ahead(1)->kind != '}') {
5569                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5570                                                 } else if (compound->members.entities == NULL) {
5571                                                         errorf(pos, "flexible array member in otherwise empty struct");
5572                                                 }
5573                                         }
5574                                 }
5575
5576                                 append_entity(&compound->members, entity);
5577                         }
5578                 }
5579         } while (accept(','));
5580         rem_anchor_token(',');
5581         rem_anchor_token(';');
5582         expect(';');
5583
5584         anonymous_entity = NULL;
5585 }
5586
5587 static void parse_compound_type_entries(compound_t *compound)
5588 {
5589         eat('{');
5590         add_anchor_token('}');
5591
5592         for (;;) {
5593                 switch (token.kind) {
5594                         DECLARATION_START
5595                         case T___extension__:
5596                         case T_IDENTIFIER: {
5597                                 PUSH_EXTENSION();
5598                                 declaration_specifiers_t specifiers;
5599                                 parse_declaration_specifiers(&specifiers);
5600                                 parse_compound_declarators(compound, &specifiers);
5601                                 POP_EXTENSION();
5602                                 break;
5603                         }
5604
5605                         default:
5606                                 rem_anchor_token('}');
5607                                 expect('}');
5608                                 /* §6.7.2.1:7 */
5609                                 compound->complete = true;
5610                                 return;
5611                 }
5612         }
5613 }
5614
5615 static type_t *parse_typename(void)
5616 {
5617         declaration_specifiers_t specifiers;
5618         parse_declaration_specifiers(&specifiers);
5619         if (specifiers.storage_class != STORAGE_CLASS_NONE
5620                         || specifiers.thread_local) {
5621                 /* TODO: improve error message, user does probably not know what a
5622                  * storage class is...
5623                  */
5624                 errorf(&specifiers.pos, "typename must not have a storage class");
5625         }
5626
5627         type_t *result = parse_abstract_declarator(specifiers.type);
5628
5629         return result;
5630 }
5631
5632
5633
5634
5635 typedef expression_t* (*parse_expression_function)(void);
5636 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5637
5638 typedef struct expression_parser_function_t expression_parser_function_t;
5639 struct expression_parser_function_t {
5640         parse_expression_function        parser;
5641         precedence_t                     infix_precedence;
5642         parse_expression_infix_function  infix_parser;
5643 };
5644
5645 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5646
5647 static type_t *get_string_type(string_encoding_t const enc)
5648 {
5649         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5650         switch (enc) {
5651         case STRING_ENCODING_CHAR:
5652         case STRING_ENCODING_UTF8:   return warn ? type_const_char_ptr     : type_char_ptr;
5653         case STRING_ENCODING_CHAR16: return warn ? type_char16_t_const_ptr : type_char16_t_ptr;
5654         case STRING_ENCODING_CHAR32: return warn ? type_char32_t_const_ptr : type_char32_t_ptr;
5655         case STRING_ENCODING_WIDE:   return warn ? type_const_wchar_t_ptr  : type_wchar_t_ptr;
5656         }
5657         panic("invalid string encoding");
5658 }
5659
5660 /**
5661  * Parse a string constant.
5662  */
5663 static expression_t *parse_string_literal(void)
5664 {
5665         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5666         expr->string_literal.value = concat_string_literals();
5667         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5668         return expr;
5669 }
5670
5671 /**
5672  * Parse a boolean constant.
5673  */
5674 static expression_t *parse_boolean_literal(bool value)
5675 {
5676         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5677         literal->base.type           = type_bool;
5678         literal->literal.value.begin = value ? "true" : "false";
5679         literal->literal.value.size  = value ? 4 : 5;
5680
5681         eat(value ? T_true : T_false);
5682         return literal;
5683 }
5684
5685 static void warn_traditional_suffix(char const *const suffix)
5686 {
5687         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5688 }
5689
5690 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5691 {
5692         unsigned     spec = SPECIFIER_NONE;
5693         char const  *c    = suffix;
5694         while (*c != '\0') {
5695                 specifiers_t add;
5696                 switch (*c) {
5697                 case 'L':
5698                 case 'l':
5699                         add = SPECIFIER_LONG;
5700                         if (*c == c[1]) {
5701                                 add |= SPECIFIER_LONG_LONG;
5702                                 ++c;
5703                         }
5704                         break;
5705                 case 'u':
5706                 case 'U':
5707                         add = SPECIFIER_UNSIGNED;
5708                         break;
5709                 case 'i':
5710                 case 'I':
5711                 case 'j':
5712                 case 'J':
5713                         if (!GNU_MODE)
5714                                 goto error;
5715                         add = SPECIFIER_COMPLEX;
5716                         break;
5717
5718                 default:
5719                         goto error;
5720                 }
5721                 ++c;
5722                 if (spec & add)
5723                         goto error;
5724                 spec |= add;
5725         }
5726
5727         if (*c == '\0') {
5728                 type_t *type;
5729                 switch (spec & ~SPECIFIER_COMPLEX) {
5730                 case SPECIFIER_NONE:                                            type = type_int;                break;
5731                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5732                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5733                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5734                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5735                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5736                 default: panic("inconsistent suffix");
5737                 }
5738                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5739                         warn_traditional_suffix(suffix);
5740                 }
5741                 if (spec & SPECIFIER_COMPLEX) {
5742                         assert(type->kind == TYPE_ATOMIC);
5743                         type = make_complex_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
5744                 }
5745                 expr->base.type = type;
5746                 /* Integer type depends on the size of the number and the size
5747                  * representable by the types. The backend/codegeneration has to
5748                  * determine that. */
5749                 determine_literal_type(&expr->literal);
5750         } else {
5751 error:
5752                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5753         }
5754 }
5755
5756 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5757 {
5758         type_t     *type;
5759         char const *c          = suffix;
5760         bool        is_complex = false;
5761 next:
5762         switch (*c) {
5763         case 'F':
5764         case 'f': type = type_float;       ++c; break;
5765         case 'L':
5766         case 'l': type = type_long_double; ++c; break;
5767         case 'i':
5768         case 'I':
5769         case 'j':
5770         case 'J':
5771                 if (!GNU_MODE)
5772                         break;
5773                 is_complex = true;
5774                 ++c;
5775                 goto next;
5776         default:  type = type_double;           break;
5777         }
5778
5779         if (*c == '\0') {
5780                 if (is_complex) {
5781                         assert(type->kind == TYPE_ATOMIC);
5782                         type = make_complex_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
5783                 }
5784
5785                 expr->base.type = type;
5786                 if (suffix[0] != '\0') {
5787                         warn_traditional_suffix(suffix);
5788                 }
5789         } else {
5790                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5791         }
5792 }
5793
5794 static expression_t *parse_number_literal(void)
5795 {
5796         string_t const *const str      = &token.literal.string;
5797         char     const *      i        = str->begin;
5798         unsigned              digits   = 0;
5799         bool                  is_float = false;
5800
5801         /* Parse base prefix. */
5802         unsigned base;
5803         if (*i == '0') {
5804                 switch (*++i) {
5805                 case 'B': case 'b': base =  2; ++i;               break;
5806                 case 'X': case 'x': base = 16; ++i;               break;
5807                 default:            base =  8; digits |= 1U << 0; break;
5808                 }
5809         } else {
5810                 base = 10;
5811         }
5812
5813         /* Parse mantissa. */
5814         for (;; ++i) {
5815                 unsigned digit;
5816                 switch (*i) {
5817                 case '.':
5818                         if (is_float) {
5819                                 errorf(HERE, "multiple decimal points in %K", &token);
5820                                 i = 0;
5821                                 goto done;
5822                         }
5823                         is_float = true;
5824                         if (base == 8)
5825                                 base = 10;
5826                         continue;
5827
5828                 case '0':           digit =  0; break;
5829                 case '1':           digit =  1; break;
5830                 case '2':           digit =  2; break;
5831                 case '3':           digit =  3; break;
5832                 case '4':           digit =  4; break;
5833                 case '5':           digit =  5; break;
5834                 case '6':           digit =  6; break;
5835                 case '7':           digit =  7; break;
5836                 case '8':           digit =  8; break;
5837                 case '9':           digit =  9; break;
5838                 case 'A': case 'a': digit = 10; break;
5839                 case 'B': case 'b': digit = 11; break;
5840                 case 'C': case 'c': digit = 12; break;
5841                 case 'D': case 'd': digit = 13; break;
5842                 case 'E': case 'e': digit = 14; break;
5843                 case 'F': case 'f': digit = 15; break;
5844
5845                 default: goto done_mantissa;
5846                 }
5847
5848                 if (digit >= 10 && base != 16)
5849                         goto done_mantissa;
5850
5851                 digits |= 1U << digit;
5852         }
5853 done_mantissa:
5854
5855         /* Parse exponent. */
5856         switch (base) {
5857         case 2:
5858                 if (is_float)
5859                         errorf(HERE, "binary floating %K not allowed", &token);
5860                 break;
5861
5862         case  8:
5863         case 10:
5864                 if (*i == 'E' || *i == 'e') {
5865                         base = 10;
5866                         goto parse_exponent;
5867                 }
5868                 break;
5869
5870         case 16:
5871                 if (*i == 'P' || *i == 'p') {
5872 parse_exponent:
5873                         ++i;
5874                         is_float = true;
5875
5876                         if (*i == '-' || *i == '+')
5877                                 ++i;
5878
5879                         if (isdigit(*i)) {
5880                                 do {
5881                                         ++i;
5882                                 } while (isdigit(*i));
5883                         } else {
5884                                 errorf(HERE, "exponent of %K has no digits", &token);
5885                         }
5886                 } else if (is_float) {
5887                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5888                         i = 0;
5889                 }
5890                 break;
5891
5892         default:
5893                 panic("invalid base");
5894         }
5895
5896 done:;
5897         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5898         expr->literal.value = *str;
5899
5900         if (i) {
5901                 if (digits == 0) {
5902                         errorf(HERE, "%K has no digits", &token);
5903                 } else if (digits & ~((1U << base) - 1)) {
5904                         errorf(HERE, "invalid digit in %K", &token);
5905                 } else {
5906                         expr->literal.suffix = i;
5907                         if (is_float) {
5908                                 check_floatingpoint_suffix(expr, i);
5909                         } else {
5910                                 check_integer_suffix(expr, i);
5911                         }
5912                 }
5913         }
5914
5915         eat(T_NUMBER);
5916         return expr;
5917 }
5918
5919 /**
5920  * Parse a character constant.
5921  */
5922 static expression_t *parse_character_constant(void)
5923 {
5924         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5925         literal->string_literal.value = token.literal.string;
5926
5927         size_t const size = get_string_len(&token.literal.string);
5928         switch (token.literal.string.encoding) {
5929         case STRING_ENCODING_CHAR:
5930         case STRING_ENCODING_UTF8:
5931                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5932                 if (size > 1) {
5933                         if (!GNU_MODE && !(c_mode & _C99)) {
5934                                 errorf(HERE, "more than 1 character in character constant");
5935                         } else {
5936                                 literal->base.type = type_int;
5937                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5938                         }
5939                 }
5940                 break;
5941
5942         case STRING_ENCODING_CHAR16: literal->base.type = type_char16_t; goto warn_multi;
5943         case STRING_ENCODING_CHAR32: literal->base.type = type_char32_t; goto warn_multi;
5944         case STRING_ENCODING_WIDE:   literal->base.type = type_wchar_t;  goto warn_multi;
5945 warn_multi:
5946                 if (size > 1) {
5947                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5948                 }
5949                 break;
5950         }
5951
5952         eat(T_CHARACTER_CONSTANT);
5953         return literal;
5954 }
5955
5956 static entity_t *create_implicit_function(symbol_t *symbol, position_t const *const pos)
5957 {
5958         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5959         ntype->function.return_type            = type_int;
5960         ntype->function.unspecified_parameters = true;
5961         ntype->function.linkage                = LINKAGE_C;
5962         type_t *type                           = identify_new_type(ntype);
5963
5964         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5965         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5966         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5967         entity->declaration.type                   = type;
5968         entity->declaration.implicit               = true;
5969
5970         if (current_scope != NULL)
5971                 record_entity(entity, false);
5972
5973         return entity;
5974 }
5975
5976 /**
5977  * Performs automatic type cast as described in §6.3.2.1.
5978  *
5979  * @param orig_type  the original type
5980  */
5981 static type_t *automatic_type_conversion(type_t *orig_type)
5982 {
5983         type_t *type = skip_typeref(orig_type);
5984         if (is_type_array(type)) {
5985                 array_type_t *array_type   = &type->array;
5986                 type_t       *element_type = array_type->element_type;
5987                 unsigned      qualifiers   = array_type->base.qualifiers;
5988
5989                 return make_pointer_type(element_type, qualifiers);
5990         }
5991
5992         if (is_type_function(type)) {
5993                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5994         }
5995
5996         return orig_type;
5997 }
5998
5999 /**
6000  * reverts the automatic casts of array to pointer types and function
6001  * to function-pointer types as defined §6.3.2.1
6002  */
6003 type_t *revert_automatic_type_conversion(const expression_t *expression)
6004 {
6005         switch (expression->kind) {
6006         case EXPR_REFERENCE: {
6007                 entity_t *entity = expression->reference.entity;
6008                 if (is_declaration(entity)) {
6009                         return entity->declaration.type;
6010                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6011                         return entity->enum_value.enum_type;
6012                 } else {
6013                         panic("no declaration or enum in reference");
6014                 }
6015         }
6016
6017         case EXPR_SELECT: {
6018                 entity_t *entity = expression->select.compound_entry;
6019                 assert(is_declaration(entity));
6020                 type_t   *type   = entity->declaration.type;
6021                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6022         }
6023
6024         case EXPR_UNARY_DEREFERENCE: {
6025                 const expression_t *const value = expression->unary.value;
6026                 type_t             *const type  = skip_typeref(value->base.type);
6027                 if (!is_type_pointer(type))
6028                         return type_error_type;
6029                 return type->pointer.points_to;
6030         }
6031
6032         case EXPR_ARRAY_ACCESS: {
6033                 const expression_t *array_ref = expression->array_access.array_ref;
6034                 type_t             *type_left = skip_typeref(array_ref->base.type);
6035                 if (!is_type_pointer(type_left))
6036                         return type_error_type;
6037                 return type_left->pointer.points_to;
6038         }
6039
6040         case EXPR_STRING_LITERAL: {
6041                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
6042                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
6043                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
6044         }
6045
6046         case EXPR_COMPOUND_LITERAL:
6047                 return expression->compound_literal.type;
6048
6049         default:
6050                 break;
6051         }
6052         return expression->base.type;
6053 }
6054
6055 /**
6056  * Find an entity matching a symbol in a scope.
6057  * Uses current scope if scope is NULL
6058  */
6059 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6060                                namespace_tag_t namespc)
6061 {
6062         if (scope == NULL) {
6063                 return get_entity(symbol, namespc);
6064         }
6065
6066         /* we should optimize here, if scope grows above a certain size we should
6067            construct a hashmap here... */
6068         entity_t *entity = scope->entities;
6069         for ( ; entity != NULL; entity = entity->base.next) {
6070                 if (entity->base.symbol == symbol
6071                     && (namespace_tag_t)entity->base.namespc == namespc)
6072                         break;
6073         }
6074
6075         return entity;
6076 }
6077
6078 static entity_t *parse_qualified_identifier(void)
6079 {
6080         /* namespace containing the symbol */
6081         symbol_t      *symbol;
6082         position_t     pos;
6083         const scope_t *lookup_scope = NULL;
6084
6085         if (accept(T_COLONCOLON))
6086                 lookup_scope = &unit->scope;
6087
6088         entity_t *entity;
6089         while (true) {
6090                 symbol = expect_identifier("while parsing identifier", &pos);
6091                 if (!symbol)
6092                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6093
6094                 /* lookup entity */
6095                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6096
6097                 if (!accept(T_COLONCOLON))
6098                         break;
6099
6100                 switch (entity->kind) {
6101                 case ENTITY_NAMESPACE:
6102                         lookup_scope = &entity->namespacee.members;
6103                         break;
6104                 case ENTITY_STRUCT:
6105                 case ENTITY_UNION:
6106                 case ENTITY_CLASS:
6107                         lookup_scope = &entity->compound.members;
6108                         break;
6109                 default:
6110                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6111                                symbol, get_entity_kind_name(entity->kind));
6112
6113                         /* skip further qualifications */
6114                         while (accept(T_IDENTIFIER) && accept(T_COLONCOLON)) {}
6115
6116                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6117                 }
6118         }
6119
6120         if (entity == NULL) {
6121                 if (!strict_mode && token.kind == '(') {
6122                         /* an implicitly declared function */
6123                         entity = create_implicit_function(symbol, &pos);
6124                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6125                 } else {
6126                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6127                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6128                 }
6129         }
6130
6131         return entity;
6132 }
6133
6134 static expression_t *parse_reference(void)
6135 {
6136         position_t const pos    = *HERE;
6137         entity_t  *const entity = parse_qualified_identifier();
6138
6139         type_t *orig_type;
6140         if (is_declaration(entity)) {
6141                 orig_type = entity->declaration.type;
6142         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6143                 orig_type = entity->enum_value.enum_type;
6144         } else {
6145                 panic("expected declaration or enum value in reference");
6146         }
6147
6148         /* we always do the auto-type conversions; the & and sizeof parser contains
6149          * code to revert this! */
6150         type_t *type = automatic_type_conversion(orig_type);
6151
6152         expression_kind_t kind = EXPR_REFERENCE;
6153         if (entity->kind == ENTITY_ENUM_VALUE)
6154                 kind = EXPR_ENUM_CONSTANT;
6155
6156         expression_t *expression     = allocate_expression_zero(kind);
6157         expression->base.pos         = pos;
6158         expression->base.type        = type;
6159         expression->reference.entity = entity;
6160
6161         /* this declaration is used */
6162         if (is_declaration(entity)) {
6163                 entity->declaration.used = true;
6164         }
6165
6166         if (entity->base.parent_scope != file_scope
6167                 && (current_function != NULL
6168                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6169                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6170                 /* access of a variable from an outer function */
6171                 entity->variable.address_taken = true;
6172                 current_function->need_closure = true;
6173         }
6174
6175         check_deprecated(&pos, entity);
6176
6177         return expression;
6178 }
6179
6180 static bool semantic_cast(expression_t *cast)
6181 {
6182         expression_t     *expression      = cast->unary.value;
6183         type_t           *orig_dest_type  = cast->base.type;
6184         type_t           *orig_type_right = expression->base.type;
6185         type_t     const *dst_type        = skip_typeref(orig_dest_type);
6186         type_t     const *src_type        = skip_typeref(orig_type_right);
6187         position_t const *pos             = &cast->base.pos;
6188
6189         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation
6190          * than for utility. */
6191         if (is_type_void(dst_type))
6192                 return true;
6193
6194         /* only integer and pointer can be casted to pointer */
6195         if (is_type_pointer(dst_type)  &&
6196             !is_type_pointer(src_type) &&
6197             !is_type_integer(src_type) &&
6198             is_type_valid(src_type)) {
6199                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6200                 return false;
6201         }
6202
6203         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6204                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6205                 return false;
6206         }
6207
6208         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6209                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6210                 return false;
6211         }
6212
6213         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6214                 type_t *src = skip_typeref(src_type->pointer.points_to);
6215                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6216                 unsigned missing_qualifiers =
6217                         src->base.qualifiers & ~dst->base.qualifiers;
6218                 if (missing_qualifiers != 0) {
6219                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6220                 }
6221         }
6222         return true;
6223 }
6224
6225 static void semantic_complex_extract(unary_expression_t *extract)
6226 {
6227         type_t *orig_value_type = extract->value->base.type;
6228         type_t *value_type      = skip_typeref(orig_value_type);
6229         if (!is_type_valid(value_type)) {
6230                 extract->base.type = type_error_type;
6231                 return;
6232         }
6233
6234         type_t *type = value_type;
6235         if (!is_type_complex(type)) {
6236                 if (!is_type_arithmetic(type)) {
6237                         errorf(&extract->base.pos,
6238                                    "%s requires an argument with complex or arithmetic type, got '%T'",
6239                                    extract->base.kind == EXPR_UNARY_IMAG ? "__imag__" : "__real__",
6240                                    orig_value_type);
6241                         extract->base.type = type_error_type;
6242                         return;
6243                 }
6244                 atomic_type_kind_t const akind = get_arithmetic_akind(type);
6245                 type = make_complex_type(akind, TYPE_QUALIFIER_NONE);
6246                 extract->value = create_implicit_cast(extract->value, type);
6247         }
6248         assert(type->kind == TYPE_COMPLEX);
6249         type = make_atomic_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
6250         extract->base.type = type;
6251 }
6252
6253 static expression_t *parse_compound_literal(position_t const *const pos,
6254                                             type_t *type)
6255 {
6256         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6257         expression->base.pos = *pos;
6258         bool global_scope = current_scope == file_scope;
6259
6260         parse_initializer_env_t env;
6261         env.type             = type;
6262         env.entity           = NULL;
6263         env.must_be_constant = global_scope;
6264         initializer_t *initializer = parse_initializer(&env);
6265         type = env.type;
6266
6267         expression->base.type                     = automatic_type_conversion(type);
6268         expression->compound_literal.initializer  = initializer;
6269         expression->compound_literal.type         = type;
6270         expression->compound_literal.global_scope = global_scope;
6271
6272         return expression;
6273 }
6274
6275 /**
6276  * Parse a cast expression.
6277  */
6278 static expression_t *parse_cast(void)
6279 {
6280         position_t const pos = *HERE;
6281
6282         eat('(');
6283         add_anchor_token(')');
6284
6285         type_t *type = parse_typename();
6286
6287         rem_anchor_token(')');
6288         expect(')');
6289
6290         if (token.kind == '{') {
6291                 return parse_compound_literal(&pos, type);
6292         }
6293
6294         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6295         cast->base.pos     = pos;
6296
6297         expression_t *value = parse_subexpression(PREC_CAST);
6298         cast->base.type   = type;
6299         cast->unary.value = value;
6300
6301         if (!semantic_cast(cast)) {
6302                 cast->base.type = type_error_type;
6303         }
6304
6305         return cast;
6306 }
6307
6308 static expression_t *parse_complex_extract_expression(void)
6309 {
6310         expression_kind_t kind;
6311         if (token.kind == T___imag__) {
6312                 kind = EXPR_UNARY_IMAG;
6313         } else {
6314                 assert(token.kind == T___real__);
6315                 kind = EXPR_UNARY_REAL;
6316         }
6317         expression_t *extract = allocate_expression_zero(kind);
6318         extract->base.pos = *HERE;
6319         next_token();
6320
6321         extract->unary.value = parse_subexpression(PREC_CAST);
6322         semantic_complex_extract(&extract->unary);
6323         return extract;
6324 }
6325
6326 /**
6327  * Parse a statement expression.
6328  */
6329 static expression_t *parse_statement_expression(void)
6330 {
6331         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6332
6333         eat('(');
6334         add_anchor_token(')');
6335
6336         statement_t *statement          = parse_compound_statement(true);
6337         statement->compound.stmt_expr   = true;
6338         expression->statement.statement = statement;
6339
6340         /* find last statement and use its type */
6341         type_t *type = type_void;
6342         const statement_t *stmt = statement->compound.statements;
6343         if (stmt != NULL) {
6344                 while (stmt->base.next != NULL)
6345                         stmt = stmt->base.next;
6346
6347                 if (stmt->kind == STATEMENT_EXPRESSION) {
6348                         type = stmt->expression.expression->base.type;
6349                 }
6350         } else {
6351                 position_t const *const pos = &expression->base.pos;
6352                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6353         }
6354         expression->base.type = type;
6355
6356         rem_anchor_token(')');
6357         expect(')');
6358         return expression;
6359 }
6360
6361 /**
6362  * Parse a parenthesized expression.
6363  */
6364 static expression_t *parse_parenthesized_expression(void)
6365 {
6366         token_t const* const la1 = look_ahead(1);
6367         switch (la1->kind) {
6368         case '{':
6369                 /* gcc extension: a statement expression */
6370                 return parse_statement_expression();
6371
6372         case T_IDENTIFIER:
6373                 if (is_typedef_symbol(la1->base.symbol)) {
6374         DECLARATION_START
6375                         return parse_cast();
6376                 }
6377         }
6378
6379         eat('(');
6380         add_anchor_token(')');
6381         expression_t *result = parse_expression();
6382         result->base.parenthesized = true;
6383         rem_anchor_token(')');
6384         expect(')');
6385
6386         return result;
6387 }
6388
6389 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6390 {
6391         if (current_function == NULL) {
6392                 errorf(HERE, "%K used outside of a function", &token);
6393         }
6394
6395         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6396         expression->base.type     = type_char_ptr;
6397         expression->funcname.kind = kind;
6398
6399         next_token();
6400
6401         return expression;
6402 }
6403
6404 static designator_t *parse_designator(void)
6405 {
6406         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6407         result->symbol = expect_identifier("while parsing member designator", &result->pos);
6408         if (!result->symbol)
6409                 return NULL;
6410
6411         designator_t *last_designator = result;
6412         while (true) {
6413                 if (accept('.')) {
6414                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6415                         designator->symbol = expect_identifier("while parsing member designator", &designator->pos);
6416                         if (!designator->symbol)
6417                                 return NULL;
6418
6419                         last_designator->next = designator;
6420                         last_designator       = designator;
6421                         continue;
6422                 }
6423                 if (accept('[')) {
6424                         add_anchor_token(']');
6425                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
6426                         designator->pos          = *HERE;
6427                         designator->array_index  = parse_expression();
6428                         rem_anchor_token(']');
6429                         expect(']');
6430                         if (designator->array_index == NULL) {
6431                                 return NULL;
6432                         }
6433
6434                         last_designator->next = designator;
6435                         last_designator       = designator;
6436                         continue;
6437                 }
6438                 break;
6439         }
6440
6441         return result;
6442 }
6443
6444 /**
6445  * Parse the __builtin_offsetof() expression.
6446  */
6447 static expression_t *parse_offsetof(void)
6448 {
6449         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6450         expression->base.type    = type_size_t;
6451
6452         eat(T___builtin_offsetof);
6453
6454         add_anchor_token(')');
6455         add_anchor_token(',');
6456         expect('(');
6457         type_t *type = parse_typename();
6458         rem_anchor_token(',');
6459         expect(',');
6460         designator_t *designator = parse_designator();
6461         rem_anchor_token(')');
6462         expect(')');
6463
6464         expression->offsetofe.type       = type;
6465         expression->offsetofe.designator = designator;
6466
6467         type_path_t path;
6468         memset(&path, 0, sizeof(path));
6469         path.top_type = type;
6470         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6471
6472         descend_into_subtype(&path);
6473
6474         if (!walk_designator(&path, designator, true)) {
6475                 return create_error_expression();
6476         }
6477
6478         DEL_ARR_F(path.path);
6479
6480         return expression;
6481 }
6482
6483 static bool is_last_parameter(expression_t *const param)
6484 {
6485         if (param->kind == EXPR_REFERENCE) {
6486                 entity_t *const entity = param->reference.entity;
6487                 if (entity->kind == ENTITY_PARAMETER &&
6488                     !entity->base.next               &&
6489                     entity->base.parent_scope == &current_function->parameters) {
6490                         return true;
6491                 }
6492         }
6493
6494         if (!is_type_valid(skip_typeref(param->base.type)))
6495                 return true;
6496
6497         return false;
6498 }
6499
6500 /**
6501  * Parses a __builtin_va_start() expression.
6502  */
6503 static expression_t *parse_va_start(void)
6504 {
6505         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6506
6507         eat(T___builtin_va_start);
6508
6509         add_anchor_token(')');
6510         add_anchor_token(',');
6511         expect('(');
6512         expression->va_starte.ap = parse_assignment_expression();
6513         rem_anchor_token(',');
6514         expect(',');
6515         expression_t *const param = parse_assignment_expression();
6516         expression->va_starte.parameter = param;
6517         rem_anchor_token(')');
6518         expect(')');
6519
6520         if (!current_function) {
6521                 errorf(&expression->base.pos, "'va_start' used outside of function");
6522         } else if (!current_function->base.type->function.variadic) {
6523                 errorf(&expression->base.pos, "'va_start' used in non-variadic function");
6524         } else if (!is_last_parameter(param)) {
6525                 errorf(&param->base.pos, "second argument of 'va_start' must be last parameter of the current function");
6526         }
6527
6528         return expression;
6529 }
6530
6531 /**
6532  * Parses a __builtin_va_arg() expression.
6533  */
6534 static expression_t *parse_va_arg(void)
6535 {
6536         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6537
6538         eat(T___builtin_va_arg);
6539
6540         add_anchor_token(')');
6541         add_anchor_token(',');
6542         expect('(');
6543         call_argument_t ap;
6544         ap.expression = parse_assignment_expression();
6545         expression->va_arge.ap = ap.expression;
6546         check_call_argument(type_valist, &ap, 1);
6547
6548         rem_anchor_token(',');
6549         expect(',');
6550         expression->base.type = parse_typename();
6551         rem_anchor_token(')');
6552         expect(')');
6553
6554         return expression;
6555 }
6556
6557 /**
6558  * Parses a __builtin_va_copy() expression.
6559  */
6560 static expression_t *parse_va_copy(void)
6561 {
6562         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6563
6564         eat(T___builtin_va_copy);
6565
6566         add_anchor_token(')');
6567         add_anchor_token(',');
6568         expect('(');
6569         expression_t *dst = parse_assignment_expression();
6570         assign_error_t error = semantic_assign(type_valist, dst);
6571         report_assign_error(error, type_valist, dst, "call argument 1",
6572                             &dst->base.pos);
6573         expression->va_copye.dst = dst;
6574
6575         rem_anchor_token(',');
6576         expect(',');
6577
6578         call_argument_t src;
6579         src.expression = parse_assignment_expression();
6580         check_call_argument(type_valist, &src, 2);
6581         expression->va_copye.src = src.expression;
6582         rem_anchor_token(')');
6583         expect(')');
6584
6585         return expression;
6586 }
6587
6588 /**
6589  * Parses a __builtin_constant_p() expression.
6590  */
6591 static expression_t *parse_builtin_constant(void)
6592 {
6593         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6594
6595         eat(T___builtin_constant_p);
6596
6597         add_anchor_token(')');
6598         expect('(');
6599         expression->builtin_constant.value = parse_assignment_expression();
6600         rem_anchor_token(')');
6601         expect(')');
6602         expression->base.type = type_int;
6603
6604         return expression;
6605 }
6606
6607 /**
6608  * Parses a __builtin_types_compatible_p() expression.
6609  */
6610 static expression_t *parse_builtin_types_compatible(void)
6611 {
6612         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6613
6614         eat(T___builtin_types_compatible_p);
6615
6616         add_anchor_token(')');
6617         add_anchor_token(',');
6618         expect('(');
6619         expression->builtin_types_compatible.left = parse_typename();
6620         rem_anchor_token(',');
6621         expect(',');
6622         expression->builtin_types_compatible.right = parse_typename();
6623         rem_anchor_token(')');
6624         expect(')');
6625         expression->base.type = type_int;
6626
6627         return expression;
6628 }
6629
6630 /**
6631  * Parses a __builtin_is_*() compare expression.
6632  */
6633 static expression_t *parse_compare_builtin(void)
6634 {
6635         expression_kind_t kind;
6636         switch (token.kind) {
6637         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6638         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6639         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6640         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6641         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6642         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6643         default: internal_errorf(HERE, "invalid compare builtin found");
6644         }
6645         expression_t *const expression = allocate_expression_zero(kind);
6646         next_token();
6647
6648         add_anchor_token(')');
6649         add_anchor_token(',');
6650         expect('(');
6651         expression->binary.left = parse_assignment_expression();
6652         rem_anchor_token(',');
6653         expect(',');
6654         expression->binary.right = parse_assignment_expression();
6655         rem_anchor_token(')');
6656         expect(')');
6657
6658         type_t *const orig_type_left  = expression->binary.left->base.type;
6659         type_t *const orig_type_right = expression->binary.right->base.type;
6660
6661         type_t *const type_left  = skip_typeref(orig_type_left);
6662         type_t *const type_right = skip_typeref(orig_type_right);
6663         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6664                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6665                         type_error_incompatible("invalid operands in comparison",
6666                                 &expression->base.pos, orig_type_left, orig_type_right);
6667                 }
6668         } else {
6669                 semantic_comparison(&expression->binary);
6670         }
6671
6672         return expression;
6673 }
6674
6675 /**
6676  * Parses a MS assume() expression.
6677  */
6678 static expression_t *parse_assume(void)
6679 {
6680         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6681
6682         eat(T__assume);
6683
6684         add_anchor_token(')');
6685         expect('(');
6686         expression->unary.value = parse_assignment_expression();
6687         rem_anchor_token(')');
6688         expect(')');
6689
6690         expression->base.type = type_void;
6691         return expression;
6692 }
6693
6694 /**
6695  * Return the label for the current symbol or create a new one.
6696  */
6697 static label_t *get_label(char const *const context)
6698 {
6699         assert(current_function != NULL);
6700
6701         symbol_t *const sym = expect_identifier(context, NULL);
6702         if (!sym)
6703                 return NULL;
6704
6705         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6706         /* If we find a local label, we already created the declaration. */
6707         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6708                 if (label->base.parent_scope != current_scope) {
6709                         assert(label->base.parent_scope->depth < current_scope->depth);
6710                         current_function->goto_to_outer = true;
6711                 }
6712         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6713                 /* There is no matching label in the same function, so create a new one. */
6714                 position_t const nowhere = { NULL, 0, 0, false };
6715                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6716                 label_push(label);
6717         }
6718
6719         return &label->label;
6720 }
6721
6722 /**
6723  * Parses a GNU && label address expression.
6724  */
6725 static expression_t *parse_label_address(void)
6726 {
6727         position_t const pos = *HERE;
6728         eat(T_ANDAND);
6729
6730         label_t *const label = get_label("while parsing label address");
6731         if (!label)
6732                 return create_error_expression();
6733
6734         label->used          = true;
6735         label->address_taken = true;
6736
6737         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6738         expression->base.pos     = pos;
6739
6740         /* label address is treated as a void pointer */
6741         expression->base.type           = type_void_ptr;
6742         expression->label_address.label = label;
6743         return expression;
6744 }
6745
6746 /**
6747  * Parse a microsoft __noop expression.
6748  */
6749 static expression_t *parse_noop_expression(void)
6750 {
6751         /* the result is a (int)0 */
6752         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6753         literal->base.type           = type_int;
6754         literal->literal.value.begin = "__noop";
6755         literal->literal.value.size  = 6;
6756
6757         eat(T___noop);
6758
6759         if (token.kind == '(') {
6760                 /* parse arguments */
6761                 eat('(');
6762                 add_anchor_token(')');
6763                 add_anchor_token(',');
6764
6765                 if (token.kind != ')') do {
6766                         (void)parse_assignment_expression();
6767                 } while (accept(','));
6768
6769                 rem_anchor_token(',');
6770                 rem_anchor_token(')');
6771         }
6772         expect(')');
6773
6774         return literal;
6775 }
6776
6777 /**
6778  * Parses a primary expression.
6779  */
6780 static expression_t *parse_primary_expression(void)
6781 {
6782         switch (token.kind) {
6783         case T_false:                        return parse_boolean_literal(false);
6784         case T_true:                         return parse_boolean_literal(true);
6785         case T_NUMBER:                       return parse_number_literal();
6786         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6787         case T_STRING_LITERAL:               return parse_string_literal();
6788         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6789         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6790         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6791         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6792         case T___builtin_offsetof:           return parse_offsetof();
6793         case T___builtin_va_start:           return parse_va_start();
6794         case T___builtin_va_arg:             return parse_va_arg();
6795         case T___builtin_va_copy:            return parse_va_copy();
6796         case T___builtin_isgreater:
6797         case T___builtin_isgreaterequal:
6798         case T___builtin_isless:
6799         case T___builtin_islessequal:
6800         case T___builtin_islessgreater:
6801         case T___builtin_isunordered:        return parse_compare_builtin();
6802         case T___builtin_constant_p:         return parse_builtin_constant();
6803         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6804         case T__assume:                      return parse_assume();
6805         case T_ANDAND:
6806                 if (GNU_MODE)
6807                         return parse_label_address();
6808                 break;
6809
6810         case '(':                            return parse_parenthesized_expression();
6811         case T___noop:                       return parse_noop_expression();
6812         case T___real__:
6813         case T___imag__:                     return parse_complex_extract_expression();
6814
6815         /* Gracefully handle type names while parsing expressions. */
6816         case T_COLONCOLON:
6817                 return parse_reference();
6818         case T_IDENTIFIER:
6819                 if (!is_typedef_symbol(token.base.symbol)) {
6820                         return parse_reference();
6821                 }
6822                 /* FALLTHROUGH */
6823         DECLARATION_START {
6824                 position_t const pos = *HERE;
6825                 declaration_specifiers_t specifiers;
6826                 parse_declaration_specifiers(&specifiers);
6827                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6828                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6829                 return create_error_expression();
6830         }
6831         }
6832
6833         errorf(HERE, "unexpected token %K, expected an expression", &token);
6834         eat_until_anchor();
6835         return create_error_expression();
6836 }
6837
6838 static expression_t *parse_array_expression(expression_t *left)
6839 {
6840         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6841         array_access_expression_t *const arr  = &expr->array_access;
6842
6843         eat('[');
6844         add_anchor_token(']');
6845
6846         expression_t *const inside = parse_expression();
6847
6848         type_t *const orig_type_left   = left->base.type;
6849         type_t *const orig_type_inside = inside->base.type;
6850
6851         type_t *const type_left   = skip_typeref(orig_type_left);
6852         type_t *const type_inside = skip_typeref(orig_type_inside);
6853
6854         expression_t *ref;
6855         expression_t *idx;
6856         type_t       *idx_type;
6857         type_t       *res_type;
6858         if (is_type_pointer(type_left)) {
6859                 ref      = left;
6860                 idx      = inside;
6861                 idx_type = type_inside;
6862                 res_type = type_left->pointer.points_to;
6863                 goto check_idx;
6864         } else if (is_type_pointer(type_inside)) {
6865                 arr->flipped = true;
6866                 ref      = inside;
6867                 idx      = left;
6868                 idx_type = type_left;
6869                 res_type = type_inside->pointer.points_to;
6870 check_idx:
6871                 res_type = automatic_type_conversion(res_type);
6872                 if (!is_type_integer(idx_type)) {
6873                         if (is_type_valid(idx_type))
6874                                 errorf(&idx->base.pos, "array subscript must have integer type");
6875                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6876                         position_t const *const pos = &idx->base.pos;
6877                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6878                 }
6879         } else {
6880                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6881                         errorf(&expr->base.pos, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6882                 }
6883                 res_type = type_error_type;
6884                 ref      = left;
6885                 idx      = inside;
6886         }
6887
6888         arr->array_ref = ref;
6889         arr->index     = idx;
6890         arr->base.type = res_type;
6891
6892         rem_anchor_token(']');
6893         expect(']');
6894         return expr;
6895 }
6896
6897 static bool is_bitfield(const expression_t *expression)
6898 {
6899         return expression->kind == EXPR_SELECT
6900                 && expression->select.compound_entry->compound_member.bitfield;
6901 }
6902
6903 static expression_t *parse_typeprop(expression_kind_t const kind)
6904 {
6905         expression_t  *tp_expression = allocate_expression_zero(kind);
6906         tp_expression->base.type     = type_size_t;
6907
6908         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6909
6910         type_t       *orig_type;
6911         expression_t *expression;
6912         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6913                 position_t const pos = *HERE;
6914                 eat('(');
6915                 add_anchor_token(')');
6916                 orig_type = parse_typename();
6917                 rem_anchor_token(')');
6918                 expect(')');
6919
6920                 if (token.kind == '{') {
6921                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6922                          * starting with a compound literal */
6923                         expression = parse_compound_literal(&pos, orig_type);
6924                         goto typeprop_expression;
6925                 }
6926         } else {
6927                 expression = parse_subexpression(PREC_UNARY);
6928
6929 typeprop_expression:
6930                 if (is_bitfield(expression)) {
6931                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6932                         errorf(&tp_expression->base.pos,
6933                                    "operand of %s expression must not be a bitfield", what);
6934                 }
6935
6936                 tp_expression->typeprop.tp_expression = expression;
6937
6938                 orig_type = revert_automatic_type_conversion(expression);
6939                 expression->base.type = orig_type;
6940         }
6941
6942         tp_expression->typeprop.type   = orig_type;
6943         type_t const* const type       = skip_typeref(orig_type);
6944         char   const*       wrong_type = NULL;
6945         if (is_type_incomplete(type)) {
6946                 if (!is_type_void(type) || !GNU_MODE)
6947                         wrong_type = "incomplete";
6948         } else if (type->kind == TYPE_FUNCTION) {
6949                 if (GNU_MODE) {
6950                         /* function types are allowed (and return 1) */
6951                         position_t const *const pos  = &tp_expression->base.pos;
6952                         char       const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6953                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6954                 } else {
6955                         wrong_type = "function";
6956                 }
6957         }
6958
6959         if (wrong_type != NULL) {
6960                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6961                 errorf(&tp_expression->base.pos,
6962                                 "operand of %s expression must not be of %s type '%T'",
6963                                 what, wrong_type, orig_type);
6964         }
6965
6966         return tp_expression;
6967 }
6968
6969 static expression_t *parse_sizeof(void)
6970 {
6971         return parse_typeprop(EXPR_SIZEOF);
6972 }
6973
6974 static expression_t *parse_alignof(void)
6975 {
6976         return parse_typeprop(EXPR_ALIGNOF);
6977 }
6978
6979 static expression_t *parse_select_expression(expression_t *addr)
6980 {
6981         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6982         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6983         position_t const pos = *HERE;
6984         next_token();
6985
6986         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6987         if (!symbol)
6988                 return create_error_expression();
6989
6990         type_t *const orig_type = addr->base.type;
6991         type_t *const type      = skip_typeref(orig_type);
6992
6993         type_t *type_left;
6994         bool    saw_error = false;
6995         if (is_type_pointer(type)) {
6996                 if (!select_left_arrow) {
6997                         errorf(&pos,
6998                                "request for member '%Y' in something not a struct or union, but '%T'",
6999                                symbol, orig_type);
7000                         saw_error = true;
7001                 }
7002                 type_left = skip_typeref(type->pointer.points_to);
7003         } else {
7004                 if (select_left_arrow && is_type_valid(type)) {
7005                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7006                         saw_error = true;
7007                 }
7008                 type_left = type;
7009         }
7010
7011         if (!is_type_compound(type_left)) {
7012                 if (is_type_valid(type_left) && !saw_error) {
7013                         errorf(&pos,
7014                                "request for member '%Y' in something not a struct or union, but '%T'",
7015                                symbol, type_left);
7016                 }
7017                 return create_error_expression();
7018         }
7019
7020         compound_t *compound = type_left->compound.compound;
7021         if (!compound->complete) {
7022                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7023                        symbol, type_left);
7024                 return create_error_expression();
7025         }
7026
7027         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7028         expression_t      *result     =
7029                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7030
7031         if (result == NULL) {
7032                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7033                 return create_error_expression();
7034         }
7035
7036         return result;
7037 }
7038
7039 static void check_call_argument(type_t          *expected_type,
7040                                 call_argument_t *argument, unsigned pos)
7041 {
7042         type_t         *expected_type_skip = skip_typeref(expected_type);
7043         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7044         expression_t   *arg_expr           = argument->expression;
7045         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7046
7047         /* handle transparent union gnu extension */
7048         if (is_type_union(expected_type_skip)
7049                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7050                 compound_t *union_decl  = expected_type_skip->compound.compound;
7051                 type_t     *best_type   = NULL;
7052                 entity_t   *entry       = union_decl->members.entities;
7053                 for ( ; entry != NULL; entry = entry->base.next) {
7054                         assert(is_declaration(entry));
7055                         type_t *decl_type = entry->declaration.type;
7056                         error = semantic_assign(decl_type, arg_expr);
7057                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7058                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7059                                 continue;
7060
7061                         if (error == ASSIGN_SUCCESS) {
7062                                 best_type = decl_type;
7063                         } else if (best_type == NULL) {
7064                                 best_type = decl_type;
7065                         }
7066                 }
7067
7068                 if (best_type != NULL) {
7069                         expected_type = best_type;
7070                 }
7071         }
7072
7073         error                = semantic_assign(expected_type, arg_expr);
7074         argument->expression = create_implicit_cast(arg_expr, expected_type);
7075
7076         if (error != ASSIGN_SUCCESS) {
7077                 /* report exact scope in error messages (like "in argument 3") */
7078                 char buf[64];
7079                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7080                 report_assign_error(error, expected_type, arg_expr, buf,
7081                                     &arg_expr->base.pos);
7082         } else {
7083                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7084                 if (!types_compatible(expected_type_skip, promoted_type) &&
7085                     !types_compatible(expected_type_skip, type_void_ptr) &&
7086                     !types_compatible(type_void_ptr,      promoted_type)) {
7087                         /* Deliberately show the skipped types in this warning */
7088                         position_t const *const apos = &arg_expr->base.pos;
7089                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7090                 }
7091         }
7092 }
7093
7094 /**
7095  * Handle the semantic restrictions of builtin calls
7096  */
7097 static void handle_builtin_argument_restrictions(call_expression_t *call)
7098 {
7099         entity_t *entity = call->function->reference.entity;
7100         switch (entity->function.btk) {
7101         case BUILTIN_FIRM:
7102                 switch (entity->function.b.firm_builtin_kind) {
7103                 case ir_bk_return_address:
7104                 case ir_bk_frame_address: {
7105                         /* argument must be constant */
7106                         call_argument_t *argument = call->arguments;
7107
7108                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7109                                 errorf(&call->base.pos,
7110                                            "argument of '%Y' must be a constant expression",
7111                                            call->function->reference.entity->base.symbol);
7112                         }
7113                         break;
7114                 }
7115                 case ir_bk_prefetch:
7116                         /* second and third argument must be constant if existent */
7117                         if (call->arguments == NULL)
7118                                 break;
7119                         call_argument_t *rw = call->arguments->next;
7120                         call_argument_t *locality = NULL;
7121
7122                         if (rw != NULL) {
7123                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7124                                         errorf(&call->base.pos,
7125                                                    "second argument of '%Y' must be a constant expression",
7126                                                    call->function->reference.entity->base.symbol);
7127                                 }
7128                                 locality = rw->next;
7129                         }
7130                         if (locality != NULL) {
7131                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7132                                         errorf(&call->base.pos,
7133                                                    "third argument of '%Y' must be a constant expression",
7134                                                    call->function->reference.entity->base.symbol);
7135                                 }
7136                         }
7137                         break;
7138                 default:
7139                         break;
7140                 }
7141
7142         case BUILTIN_OBJECT_SIZE:
7143                 if (call->arguments == NULL)
7144                         break;
7145
7146                 call_argument_t *arg = call->arguments->next;
7147                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7148                         errorf(&call->base.pos,
7149                                    "second argument of '%Y' must be a constant expression",
7150                                    call->function->reference.entity->base.symbol);
7151                 }
7152                 break;
7153         default:
7154                 break;
7155         }
7156 }
7157
7158 /**
7159  * Parse a call expression, i.e. expression '( ... )'.
7160  *
7161  * @param expression  the function address
7162  */
7163 static expression_t *parse_call_expression(expression_t *expression)
7164 {
7165         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7166         call_expression_t *call   = &result->call;
7167         call->function            = expression;
7168
7169         type_t *const orig_type = expression->base.type;
7170         type_t *const type      = skip_typeref(orig_type);
7171
7172         function_type_t *function_type = NULL;
7173         if (is_type_pointer(type)) {
7174                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7175
7176                 if (is_type_function(to_type)) {
7177                         function_type   = &to_type->function;
7178                         call->base.type = function_type->return_type;
7179                 }
7180         }
7181
7182         if (function_type == NULL && is_type_valid(type)) {
7183                 errorf(HERE,
7184                        "called object '%E' (type '%T') is not a pointer to a function",
7185                        expression, orig_type);
7186         }
7187
7188         /* parse arguments */
7189         eat('(');
7190         add_anchor_token(')');
7191         add_anchor_token(',');
7192
7193         if (token.kind != ')') {
7194                 call_argument_t **anchor = &call->arguments;
7195                 do {
7196                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7197                         argument->expression = parse_assignment_expression();
7198
7199                         *anchor = argument;
7200                         anchor  = &argument->next;
7201                 } while (accept(','));
7202         }
7203         rem_anchor_token(',');
7204         rem_anchor_token(')');
7205         expect(')');
7206
7207         if (function_type == NULL)
7208                 return result;
7209
7210         /* check type and count of call arguments */
7211         function_parameter_t *parameter = function_type->parameters;
7212         call_argument_t      *argument  = call->arguments;
7213         if (!function_type->unspecified_parameters) {
7214                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7215                                 parameter = parameter->next, argument = argument->next) {
7216                         check_call_argument(parameter->type, argument, ++pos);
7217                 }
7218
7219                 if (parameter != NULL) {
7220                         errorf(&expression->base.pos, "too few arguments to function '%E'",
7221                                expression);
7222                 } else if (argument != NULL && !function_type->variadic) {
7223                         errorf(&argument->expression->base.pos,
7224                                "too many arguments to function '%E'", expression);
7225                 }
7226         }
7227
7228         /* do default promotion for other arguments */
7229         for (; argument != NULL; argument = argument->next) {
7230                 type_t *argument_type = argument->expression->base.type;
7231                 if (!is_type_object(skip_typeref(argument_type))) {
7232                         errorf(&argument->expression->base.pos,
7233                                "call argument '%E' must not be void", argument->expression);
7234                 }
7235
7236                 argument_type = get_default_promoted_type(argument_type);
7237
7238                 argument->expression
7239                         = create_implicit_cast(argument->expression, argument_type);
7240         }
7241
7242         check_format(call);
7243
7244         if (is_type_compound(skip_typeref(function_type->return_type))) {
7245                 position_t const *const pos = &expression->base.pos;
7246                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7247         }
7248
7249         if (expression->kind == EXPR_REFERENCE) {
7250                 reference_expression_t *reference = &expression->reference;
7251                 if (reference->entity->kind == ENTITY_FUNCTION &&
7252                     reference->entity->function.btk != BUILTIN_NONE)
7253                         handle_builtin_argument_restrictions(call);
7254         }
7255
7256         return result;
7257 }
7258
7259 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7260
7261 static bool same_compound_type(const type_t *type1, const type_t *type2)
7262 {
7263         return
7264                 is_type_compound(type1) &&
7265                 type1->kind == type2->kind &&
7266                 type1->compound.compound == type2->compound.compound;
7267 }
7268
7269 static expression_t const *get_reference_address(expression_t const *expr)
7270 {
7271         bool regular_take_address = true;
7272         for (;;) {
7273                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7274                         expr = expr->unary.value;
7275                 } else {
7276                         regular_take_address = false;
7277                 }
7278
7279                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7280                         break;
7281
7282                 expr = expr->unary.value;
7283         }
7284
7285         if (expr->kind != EXPR_REFERENCE)
7286                 return NULL;
7287
7288         /* special case for functions which are automatically converted to a
7289          * pointer to function without an extra TAKE_ADDRESS operation */
7290         if (!regular_take_address &&
7291                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7292                 return NULL;
7293         }
7294
7295         return expr;
7296 }
7297
7298 static void warn_reference_address_as_bool(expression_t const* expr)
7299 {
7300         expr = get_reference_address(expr);
7301         if (expr != NULL) {
7302                 position_t const *const pos = &expr->base.pos;
7303                 entity_t   const *const ent = expr->reference.entity;
7304                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7305         }
7306 }
7307
7308 static void warn_assignment_in_condition(const expression_t *const expr)
7309 {
7310         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7311                 return;
7312         if (expr->base.parenthesized)
7313                 return;
7314         position_t const *const pos = &expr->base.pos;
7315         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7316 }
7317
7318 static void semantic_condition(expression_t const *const expr,
7319                                char const *const context)
7320 {
7321         type_t *const type = skip_typeref(expr->base.type);
7322         if (is_type_scalar(type)) {
7323                 warn_reference_address_as_bool(expr);
7324                 warn_assignment_in_condition(expr);
7325         } else if (is_type_valid(type)) {
7326                 errorf(&expr->base.pos, "%s must have scalar type", context);
7327         }
7328 }
7329
7330 /**
7331  * Parse a conditional expression, i.e. 'expression ? ... : ...'.
7332  *
7333  * @param expression  the conditional expression
7334  */
7335 static expression_t *parse_conditional_expression(expression_t *expression)
7336 {
7337         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7338
7339         conditional_expression_t *conditional = &result->conditional;
7340         conditional->condition                = expression;
7341
7342         eat('?');
7343         add_anchor_token(':');
7344
7345         /* §6.5.15:2  The first operand shall have scalar type. */
7346         semantic_condition(expression, "condition of conditional operator");
7347
7348         expression_t *true_expression = expression;
7349         bool          gnu_cond = false;
7350         if (GNU_MODE && token.kind == ':') {
7351                 gnu_cond = true;
7352         } else {
7353                 true_expression = parse_expression();
7354         }
7355         rem_anchor_token(':');
7356         expect(':');
7357         expression_t *false_expression =
7358                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7359
7360         type_t *const orig_true_type  = true_expression->base.type;
7361         type_t *const orig_false_type = false_expression->base.type;
7362         type_t *const true_type       = skip_typeref(orig_true_type);
7363         type_t *const false_type      = skip_typeref(orig_false_type);
7364
7365         /* 6.5.15.3 */
7366         position_t const *const pos = &conditional->base.pos;
7367         type_t                 *result_type;
7368         if (is_type_void(true_type) || is_type_void(false_type)) {
7369                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7370                 if (true_expression->kind == EXPR_UNARY_THROW) {
7371                         result_type = false_type;
7372                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7373                         result_type = true_type;
7374                 } else {
7375                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7376                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7377                         }
7378                         result_type = type_void;
7379                 }
7380         } else if (is_type_arithmetic(true_type)
7381                    && is_type_arithmetic(false_type)) {
7382                 result_type = semantic_arithmetic(true_type, false_type);
7383         } else if (same_compound_type(true_type, false_type)) {
7384                 /* just take 1 of the 2 types */
7385                 result_type = true_type;
7386         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7387                 type_t *pointer_type;
7388                 type_t *other_type;
7389                 expression_t *other_expression;
7390                 if (is_type_pointer(true_type) &&
7391                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7392                         pointer_type     = true_type;
7393                         other_type       = false_type;
7394                         other_expression = false_expression;
7395                 } else {
7396                         pointer_type     = false_type;
7397                         other_type       = true_type;
7398                         other_expression = true_expression;
7399                 }
7400
7401                 if (is_null_pointer_constant(other_expression)) {
7402                         result_type = pointer_type;
7403                 } else if (is_type_pointer(other_type)) {
7404                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7405                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7406
7407                         type_t *to;
7408                         if (is_type_void(to1) || is_type_void(to2)) {
7409                                 to = type_void;
7410                         } else if (types_compatible(get_unqualified_type(to1),
7411                                                     get_unqualified_type(to2))) {
7412                                 to = to1;
7413                         } else {
7414                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7415                                 to = type_void;
7416                         }
7417
7418                         type_t *const type =
7419                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7420                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7421                 } else if (is_type_integer(other_type)) {
7422                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7423                         result_type = pointer_type;
7424                 } else {
7425                         goto types_incompatible;
7426                 }
7427         } else {
7428 types_incompatible:
7429                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7430                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7431                 }
7432                 result_type = type_error_type;
7433         }
7434
7435         conditional->true_expression
7436                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7437         conditional->false_expression
7438                 = create_implicit_cast(false_expression, result_type);
7439         conditional->base.type = result_type;
7440         return result;
7441 }
7442
7443 /**
7444  * Parse an extension expression.
7445  */
7446 static expression_t *parse_extension(void)
7447 {
7448         PUSH_EXTENSION();
7449         expression_t *expression = parse_subexpression(PREC_UNARY);
7450         POP_EXTENSION();
7451         return expression;
7452 }
7453
7454 /**
7455  * Parse a __builtin_classify_type() expression.
7456  */
7457 static expression_t *parse_builtin_classify_type(void)
7458 {
7459         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7460         result->base.type    = type_int;
7461
7462         eat(T___builtin_classify_type);
7463
7464         add_anchor_token(')');
7465         expect('(');
7466         expression_t *expression = parse_expression();
7467         rem_anchor_token(')');
7468         expect(')');
7469         result->classify_type.type_expression = expression;
7470
7471         return result;
7472 }
7473
7474 /**
7475  * Parse a delete expression
7476  * ISO/IEC 14882:1998(E) §5.3.5
7477  */
7478 static expression_t *parse_delete(void)
7479 {
7480         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7481         result->base.type          = type_void;
7482
7483         eat(T_delete);
7484
7485         if (accept('[')) {
7486                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7487                 expect(']');
7488         }
7489
7490         expression_t *const value = parse_subexpression(PREC_CAST);
7491         result->unary.value = value;
7492
7493         type_t *const type = skip_typeref(value->base.type);
7494         if (!is_type_pointer(type)) {
7495                 if (is_type_valid(type)) {
7496                         errorf(&value->base.pos,
7497                                         "operand of delete must have pointer type");
7498                 }
7499         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7500                 position_t const *const pos = &value->base.pos;
7501                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7502         }
7503
7504         return result;
7505 }
7506
7507 /**
7508  * Parse a throw expression
7509  * ISO/IEC 14882:1998(E) §15:1
7510  */
7511 static expression_t *parse_throw(void)
7512 {
7513         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7514         result->base.type          = type_void;
7515
7516         eat(T_throw);
7517
7518         expression_t *value = NULL;
7519         switch (token.kind) {
7520                 EXPRESSION_START {
7521                         value = parse_assignment_expression();
7522                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7523                         type_t *const orig_type = value->base.type;
7524                         type_t *const type      = skip_typeref(orig_type);
7525                         if (is_type_incomplete(type)) {
7526                                 errorf(&value->base.pos,
7527                                                 "cannot throw object of incomplete type '%T'", orig_type);
7528                         } else if (is_type_pointer(type)) {
7529                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7530                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7531                                         errorf(&value->base.pos,
7532                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7533                                 }
7534                         }
7535                 }
7536
7537                 default:
7538                         break;
7539         }
7540         result->unary.value = value;
7541
7542         return result;
7543 }
7544
7545 static bool check_pointer_arithmetic(const position_t *pos,
7546                                      type_t *pointer_type,
7547                                      type_t *orig_pointer_type)
7548 {
7549         type_t *points_to = pointer_type->pointer.points_to;
7550         points_to = skip_typeref(points_to);
7551
7552         if (is_type_incomplete(points_to)) {
7553                 if (!GNU_MODE || !is_type_void(points_to)) {
7554                         errorf(pos,
7555                                "arithmetic with pointer to incomplete type '%T' not allowed",
7556                                orig_pointer_type);
7557                         return false;
7558                 } else {
7559                         warningf(WARN_POINTER_ARITH, pos, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7560                 }
7561         } else if (is_type_function(points_to)) {
7562                 if (!GNU_MODE) {
7563                         errorf(pos,
7564                                "arithmetic with pointer to function type '%T' not allowed",
7565                                orig_pointer_type);
7566                         return false;
7567                 } else {
7568                         warningf(WARN_POINTER_ARITH, pos,
7569                                  "pointer to a function '%T' used in arithmetic",
7570                                  orig_pointer_type);
7571                 }
7572         }
7573         return true;
7574 }
7575
7576 static bool is_lvalue(const expression_t *expression)
7577 {
7578         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7579         switch (expression->kind) {
7580         case EXPR_ARRAY_ACCESS:
7581         case EXPR_COMPOUND_LITERAL:
7582         case EXPR_REFERENCE:
7583         case EXPR_SELECT:
7584         case EXPR_UNARY_DEREFERENCE:
7585                 return true;
7586
7587         default: {
7588                 type_t *type = skip_typeref(expression->base.type);
7589                 return
7590                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7591                         is_type_reference(type) ||
7592                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7593                          * error before, which maybe prevented properly recognizing it as
7594                          * lvalue. */
7595                         !is_type_valid(type);
7596         }
7597         }
7598 }
7599
7600 static void semantic_incdec(unary_expression_t *expression)
7601 {
7602         type_t *orig_type = expression->value->base.type;
7603         type_t *type      = skip_typeref(orig_type);
7604         if (is_type_pointer(type)) {
7605                 if (!check_pointer_arithmetic(&expression->base.pos, type, orig_type)) {
7606                         return;
7607                 }
7608         } else if (!is_type_real(type) &&
7609                    (!GNU_MODE || !is_type_complex(type)) && is_type_valid(type)) {
7610                 /* TODO: improve error message */
7611                 errorf(&expression->base.pos,
7612                        "operation needs an arithmetic or pointer type");
7613                 orig_type = type = type_error_type;
7614         }
7615         if (!is_lvalue(expression->value)) {
7616                 /* TODO: improve error message */
7617                 errorf(&expression->base.pos, "lvalue required as operand");
7618         }
7619         expression->base.type = orig_type;
7620 }
7621
7622 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7623 {
7624         atomic_type_kind_t akind = get_arithmetic_akind(type);
7625         type_t *res_type;
7626         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT)) {
7627                 if (type->kind == TYPE_COMPLEX)
7628                         res_type = make_complex_type(ATOMIC_TYPE_INT, TYPE_QUALIFIER_NONE);
7629                 else
7630                         res_type = type_int;
7631         } else {
7632                 res_type = type;
7633         }
7634         expr->base.type = res_type;
7635         expr->value     = create_implicit_cast(expr->value, res_type);
7636 }
7637
7638 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7639 {
7640         type_t *const orig_type = expression->value->base.type;
7641         type_t *const type      = skip_typeref(orig_type);
7642         if (!is_type_arithmetic(type)) {
7643                 if (is_type_valid(type)) {
7644                         position_t const *const pos = &expression->base.pos;
7645                         errorf(pos, "operand of unary expression must have arithmetic type, but is '%T'", orig_type);
7646                 }
7647                 return;
7648         } else if (is_type_integer(type)) {
7649                 promote_unary_int_expr(expression, type);
7650         } else {
7651                 expression->base.type = orig_type;
7652         }
7653 }
7654
7655 static void semantic_unexpr_plus(unary_expression_t *expression)
7656 {
7657         semantic_unexpr_arithmetic(expression);
7658         position_t const *const pos = &expression->base.pos;
7659         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7660 }
7661
7662 static void semantic_not(unary_expression_t *expression)
7663 {
7664         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7665         semantic_condition(expression->value, "operand of !");
7666         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7667 }
7668
7669 static void semantic_complement(unary_expression_t *expression)
7670 {
7671         type_t *const orig_type = expression->value->base.type;
7672         type_t *const type      = skip_typeref(orig_type);
7673         if (!is_type_integer(type) && (!GNU_MODE || !is_type_complex(type))) {
7674                 if (is_type_valid(type)) {
7675                         errorf(&expression->base.pos, "operand of ~ must be of integer type");
7676                 }
7677                 return;
7678         }
7679
7680         if (is_type_integer(type)) {
7681                 promote_unary_int_expr(expression, type);
7682         } else {
7683                 expression->base.type = orig_type;
7684         }
7685 }
7686
7687 static void semantic_dereference(unary_expression_t *expression)
7688 {
7689         type_t *const orig_type = expression->value->base.type;
7690         type_t *const type      = skip_typeref(orig_type);
7691         if (!is_type_pointer(type)) {
7692                 if (is_type_valid(type)) {
7693                         errorf(&expression->base.pos,
7694                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7695                 }
7696                 return;
7697         }
7698
7699         type_t *result_type   = type->pointer.points_to;
7700         result_type           = automatic_type_conversion(result_type);
7701         expression->base.type = result_type;
7702 }
7703
7704 /**
7705  * Record that an address is taken (expression represents an lvalue).
7706  *
7707  * @param expression       the expression
7708  * @param may_be_register  if true, the expression might be an register
7709  */
7710 static void set_address_taken(expression_t *expression, bool may_be_register)
7711 {
7712         if (expression->kind != EXPR_REFERENCE)
7713                 return;
7714
7715         entity_t *const entity = expression->reference.entity;
7716
7717         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7718                 return;
7719
7720         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7721                         && !may_be_register) {
7722                 position_t const *const pos = &expression->base.pos;
7723                 errorf(pos, "address of register '%N' requested", entity);
7724         }
7725
7726         entity->variable.address_taken = true;
7727 }
7728
7729 /**
7730  * Check the semantic of the address taken expression.
7731  */
7732 static void semantic_take_addr(unary_expression_t *expression)
7733 {
7734         expression_t *value = expression->value;
7735         value->base.type    = revert_automatic_type_conversion(value);
7736
7737         type_t *orig_type = value->base.type;
7738         type_t *type      = skip_typeref(orig_type);
7739         if (!is_type_valid(type))
7740                 return;
7741
7742         /* §6.5.3.2 */
7743         if (!is_lvalue(value)) {
7744                 errorf(&expression->base.pos, "'&' requires an lvalue");
7745         }
7746         if (is_bitfield(value)) {
7747                 errorf(&expression->base.pos, "'&' not allowed on bitfield");
7748         }
7749
7750         set_address_taken(value, false);
7751
7752         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7753 }
7754
7755 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7756 static expression_t *parse_##unexpression_type(void)                         \
7757 {                                                                            \
7758         expression_t *unary_expression                                           \
7759                 = allocate_expression_zero(unexpression_type);                       \
7760         eat(token_kind);                                                         \
7761         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7762                                                                                  \
7763         sfunc(&unary_expression->unary);                                         \
7764                                                                                  \
7765         return unary_expression;                                                 \
7766 }
7767
7768 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7769                                semantic_unexpr_arithmetic)
7770 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7771                                semantic_unexpr_plus)
7772 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7773                                semantic_not)
7774 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7775                                semantic_dereference)
7776 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7777                                semantic_take_addr)
7778 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_COMPLEMENT,
7779                                semantic_complement)
7780 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7781                                semantic_incdec)
7782 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7783                                semantic_incdec)
7784
7785 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7786                                                sfunc)                         \
7787 static expression_t *parse_##unexpression_type(expression_t *left)            \
7788 {                                                                             \
7789         expression_t *unary_expression                                            \
7790                 = allocate_expression_zero(unexpression_type);                        \
7791         eat(token_kind);                                                          \
7792         unary_expression->unary.value = left;                                     \
7793                                                                                   \
7794         sfunc(&unary_expression->unary);                                          \
7795                                                                               \
7796         return unary_expression;                                                  \
7797 }
7798
7799 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7800                                        EXPR_UNARY_POSTFIX_INCREMENT,
7801                                        semantic_incdec)
7802 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7803                                        EXPR_UNARY_POSTFIX_DECREMENT,
7804                                        semantic_incdec)
7805
7806 static atomic_type_kind_t semantic_arithmetic_(atomic_type_kind_t kind_left,
7807                                                atomic_type_kind_t kind_right)
7808 {
7809         /* §6.3.1.8 Usual arithmetic conversions */
7810         if (kind_left == ATOMIC_TYPE_LONG_DOUBLE
7811          || kind_right == ATOMIC_TYPE_LONG_DOUBLE) {
7812                 return ATOMIC_TYPE_LONG_DOUBLE;
7813         } else if (kind_left == ATOMIC_TYPE_DOUBLE
7814                 || kind_right == ATOMIC_TYPE_DOUBLE) {
7815             return ATOMIC_TYPE_DOUBLE;
7816         } else if (kind_left == ATOMIC_TYPE_FLOAT
7817                 || kind_right == ATOMIC_TYPE_FLOAT) {
7818                 return ATOMIC_TYPE_FLOAT;
7819         }
7820
7821         unsigned       rank_left  = get_akind_rank(kind_left);
7822         unsigned       rank_right = get_akind_rank(kind_right);
7823         unsigned const rank_int   = get_akind_rank(ATOMIC_TYPE_INT);
7824         if (rank_left < rank_int) {
7825                 kind_left = ATOMIC_TYPE_INT;
7826                 rank_left = rank_int;
7827         }
7828         if (rank_right < rank_int) {
7829                 kind_right = ATOMIC_TYPE_INT;
7830                 rank_right = rank_int;
7831         }
7832         if (kind_left == kind_right)
7833                 return kind_left;
7834
7835         bool const signed_left  = is_akind_signed(kind_left);
7836         bool const signed_right = is_akind_signed(kind_right);
7837         if (signed_left == signed_right)
7838                 return rank_left >= rank_right ? kind_left : kind_right;
7839
7840         unsigned           s_rank;
7841         unsigned           u_rank;
7842         atomic_type_kind_t s_kind;
7843         atomic_type_kind_t u_kind;
7844         if (signed_left) {
7845                 s_kind = kind_left;
7846                 s_rank = rank_left;
7847                 u_kind = kind_right;
7848                 u_rank = rank_right;
7849         } else {
7850                 s_kind = kind_right;
7851                 s_rank = rank_right;
7852                 u_kind = kind_left;
7853                 u_rank = rank_left;
7854         }
7855         if (u_rank >= s_rank)
7856                 return u_kind;
7857         if (get_atomic_type_size(s_kind) > get_atomic_type_size(u_kind))
7858                 return s_kind;
7859
7860         switch (s_kind) {
7861         case ATOMIC_TYPE_INT:      return ATOMIC_TYPE_UINT;
7862         case ATOMIC_TYPE_LONG:     return ATOMIC_TYPE_ULONG;
7863         case ATOMIC_TYPE_LONGLONG: return ATOMIC_TYPE_ULONGLONG;
7864         default: panic("invalid atomic type");
7865         }
7866 }
7867
7868 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7869 {
7870         atomic_type_kind_t kind_left  = get_arithmetic_akind(type_left);
7871         atomic_type_kind_t kind_right = get_arithmetic_akind(type_right);
7872         atomic_type_kind_t kind_res   = semantic_arithmetic_(kind_left, kind_right);
7873
7874         if (type_left->kind == TYPE_COMPLEX || type_right->kind == TYPE_COMPLEX) {
7875                 return make_complex_type(kind_res, TYPE_QUALIFIER_NONE);
7876         }
7877         return make_atomic_type(kind_res, TYPE_QUALIFIER_NONE);
7878 }
7879
7880 /**
7881  * Check the semantic restrictions for a binary expression.
7882  */
7883 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7884 {
7885         expression_t *const left            = expression->left;
7886         expression_t *const right           = expression->right;
7887         type_t       *const orig_type_left  = left->base.type;
7888         type_t       *const orig_type_right = right->base.type;
7889         type_t       *const type_left       = skip_typeref(orig_type_left);
7890         type_t       *const type_right      = skip_typeref(orig_type_right);
7891
7892         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7893                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7894                         position_t const *const pos = &expression->base.pos;
7895                         errorf(pos, "operands of binary expression must have arithmetic types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7896                 }
7897                 return;
7898         }
7899
7900         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7901         expression->left      = create_implicit_cast(left, arithmetic_type);
7902         expression->right     = create_implicit_cast(right, arithmetic_type);
7903         expression->base.type = arithmetic_type;
7904 }
7905
7906 static void semantic_binexpr_integer(binary_expression_t *const expression)
7907 {
7908         expression_t *const left            = expression->left;
7909         expression_t *const right           = expression->right;
7910         type_t       *const orig_type_left  = left->base.type;
7911         type_t       *const orig_type_right = right->base.type;
7912         type_t       *const type_left       = skip_typeref(orig_type_left);
7913         type_t       *const type_right      = skip_typeref(orig_type_right);
7914
7915         if (!is_type_integer(type_left) || !is_type_integer(type_right)
7916           || is_type_complex(type_left) || is_type_complex(type_right)) {
7917                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7918                         position_t const *const pos = &expression->base.pos;
7919                         errorf(pos, "operands of binary expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7920                 }
7921                 return;
7922         }
7923
7924         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7925         expression->left      = create_implicit_cast(left, result_type);
7926         expression->right     = create_implicit_cast(right, result_type);
7927         expression->base.type = result_type;
7928 }
7929
7930 static void warn_div_by_zero(binary_expression_t const *const expression)
7931 {
7932         if (!is_type_integer(expression->base.type))
7933                 return;
7934
7935         expression_t const *const right = expression->right;
7936         /* The type of the right operand can be different for /= */
7937         if (is_type_integer(skip_typeref(right->base.type))      &&
7938             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7939             !fold_constant_to_bool(right)) {
7940                 position_t const *const pos = &expression->base.pos;
7941                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7942         }
7943 }
7944
7945 /**
7946  * Check the semantic restrictions for a div expression.
7947  */
7948 static void semantic_div(binary_expression_t *expression)
7949 {
7950         semantic_binexpr_arithmetic(expression);
7951         warn_div_by_zero(expression);
7952 }
7953
7954 /**
7955  * Check the semantic restrictions for a mod expression.
7956  */
7957 static void semantic_mod(binary_expression_t *expression)
7958 {
7959         semantic_binexpr_integer(expression);
7960         warn_div_by_zero(expression);
7961 }
7962
7963 static void warn_addsub_in_shift(const expression_t *const expr)
7964 {
7965         if (expr->base.parenthesized)
7966                 return;
7967
7968         char op;
7969         switch (expr->kind) {
7970                 case EXPR_BINARY_ADD: op = '+'; break;
7971                 case EXPR_BINARY_SUB: op = '-'; break;
7972                 default:              return;
7973         }
7974
7975         position_t const *const pos = &expr->base.pos;
7976         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7977 }
7978
7979 static bool semantic_shift(binary_expression_t *expression)
7980 {
7981         expression_t *const left            = expression->left;
7982         expression_t *const right           = expression->right;
7983         type_t       *const orig_type_left  = left->base.type;
7984         type_t       *const orig_type_right = right->base.type;
7985         type_t       *      type_left       = skip_typeref(orig_type_left);
7986         type_t       *      type_right      = skip_typeref(orig_type_right);
7987
7988         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7989                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7990                         position_t const *const pos = &expression->base.pos;
7991                         errorf(pos, "operands of shift expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7992                 }
7993                 return false;
7994         }
7995
7996         type_left = promote_integer(type_left);
7997
7998         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7999                 position_t const *const pos   = &right->base.pos;
8000                 long              const count = fold_constant_to_int(right);
8001                 if (count < 0) {
8002                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
8003                 } else if ((unsigned long)count >=
8004                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8005                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8006                 }
8007         }
8008
8009         type_right        = promote_integer(type_right);
8010         expression->right = create_implicit_cast(right, type_right);
8011
8012         return true;
8013 }
8014
8015 static void semantic_shift_op(binary_expression_t *expression)
8016 {
8017         expression_t *const left  = expression->left;
8018         expression_t *const right = expression->right;
8019
8020         if (!semantic_shift(expression))
8021                 return;
8022
8023         warn_addsub_in_shift(left);
8024         warn_addsub_in_shift(right);
8025
8026         type_t *const orig_type_left = left->base.type;
8027         type_t *      type_left      = skip_typeref(orig_type_left);
8028
8029         type_left             = promote_integer(type_left);
8030         expression->left      = create_implicit_cast(left, type_left);
8031         expression->base.type = type_left;
8032 }
8033
8034 static void semantic_add(binary_expression_t *expression)
8035 {
8036         expression_t *const left            = expression->left;
8037         expression_t *const right           = expression->right;
8038         type_t       *const orig_type_left  = left->base.type;
8039         type_t       *const orig_type_right = right->base.type;
8040         type_t       *const type_left       = skip_typeref(orig_type_left);
8041         type_t       *const type_right      = skip_typeref(orig_type_right);
8042
8043         /* §6.5.6 */
8044         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8045                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8046                 expression->left  = create_implicit_cast(left, arithmetic_type);
8047                 expression->right = create_implicit_cast(right, arithmetic_type);
8048                 expression->base.type = arithmetic_type;
8049         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8050                 check_pointer_arithmetic(&expression->base.pos, type_left,
8051                                          orig_type_left);
8052                 expression->base.type = type_left;
8053         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8054                 check_pointer_arithmetic(&expression->base.pos, type_right,
8055                                          orig_type_right);
8056                 expression->base.type = type_right;
8057         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8058                 errorf(&expression->base.pos,
8059                        "invalid operands to binary + ('%T', '%T')",
8060                        orig_type_left, orig_type_right);
8061         }
8062 }
8063
8064 static void semantic_sub(binary_expression_t *expression)
8065 {
8066         expression_t     *const left            = expression->left;
8067         expression_t     *const right           = expression->right;
8068         type_t           *const orig_type_left  = left->base.type;
8069         type_t           *const orig_type_right = right->base.type;
8070         type_t           *const type_left       = skip_typeref(orig_type_left);
8071         type_t           *const type_right      = skip_typeref(orig_type_right);
8072         position_t const *const pos             = &expression->base.pos;
8073
8074         /* §5.6.5 */
8075         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8076                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8077                 expression->left        = create_implicit_cast(left, arithmetic_type);
8078                 expression->right       = create_implicit_cast(right, arithmetic_type);
8079                 expression->base.type =  arithmetic_type;
8080         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8081                 check_pointer_arithmetic(&expression->base.pos, type_left,
8082                                          orig_type_left);
8083                 expression->base.type = type_left;
8084         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8085                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8086                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8087                 if (!types_compatible(unqual_left, unqual_right)) {
8088                         errorf(pos,
8089                                "subtracting pointers to incompatible types '%T' and '%T'",
8090                                orig_type_left, orig_type_right);
8091                 } else if (!is_type_object(unqual_left)) {
8092                         if (!is_type_void(unqual_left)) {
8093                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8094                                        orig_type_left);
8095                         } else {
8096                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8097                         }
8098                 }
8099                 expression->base.type = type_ptrdiff_t;
8100         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8101                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8102                        orig_type_left, orig_type_right);
8103         }
8104 }
8105
8106 static void warn_string_literal_address(expression_t const* expr)
8107 {
8108         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8109                 expr = expr->unary.value;
8110                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8111                         return;
8112                 expr = expr->unary.value;
8113         }
8114
8115         if (expr->kind == EXPR_STRING_LITERAL) {
8116                 position_t const *const pos = &expr->base.pos;
8117                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8118         }
8119 }
8120
8121 static bool maybe_negative(expression_t const *const expr)
8122 {
8123         switch (is_constant_expression(expr)) {
8124                 case EXPR_CLASS_ERROR:    return false;
8125                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8126                 default:                  return true;
8127         }
8128 }
8129
8130 static void warn_comparison(position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8131 {
8132         warn_string_literal_address(expr);
8133
8134         expression_t const* const ref = get_reference_address(expr);
8135         if (ref != NULL && is_null_pointer_constant(other)) {
8136                 entity_t const *const ent = ref->reference.entity;
8137                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8138         }
8139
8140         if (!expr->base.parenthesized) {
8141                 switch (expr->base.kind) {
8142                         case EXPR_BINARY_LESS:
8143                         case EXPR_BINARY_GREATER:
8144                         case EXPR_BINARY_LESSEQUAL:
8145                         case EXPR_BINARY_GREATEREQUAL:
8146                         case EXPR_BINARY_NOTEQUAL:
8147                         case EXPR_BINARY_EQUAL:
8148                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8149                                 break;
8150                         default:
8151                                 break;
8152                 }
8153         }
8154 }
8155
8156 /**
8157  * Check the semantics of comparison expressions.
8158  *
8159  * @param expression   The expression to check.
8160  */
8161 static void semantic_comparison(binary_expression_t *expression)
8162 {
8163         position_t const *const pos   = &expression->base.pos;
8164         expression_t     *const left  = expression->left;
8165         expression_t     *const right = expression->right;
8166
8167         warn_comparison(pos, left, right);
8168         warn_comparison(pos, right, left);
8169
8170         type_t *orig_type_left  = left->base.type;
8171         type_t *orig_type_right = right->base.type;
8172         type_t *type_left       = skip_typeref(orig_type_left);
8173         type_t *type_right      = skip_typeref(orig_type_right);
8174
8175         /* TODO non-arithmetic types */
8176         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8177                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8178
8179                 /* test for signed vs unsigned compares */
8180                 if (is_type_integer(arithmetic_type)) {
8181                         bool const signed_left  = is_type_signed(type_left);
8182                         bool const signed_right = is_type_signed(type_right);
8183                         if (signed_left != signed_right) {
8184                                 /* FIXME long long needs better const folding magic */
8185                                 /* TODO check whether constant value can be represented by other type */
8186                                 if ((signed_left  && maybe_negative(left)) ||
8187                                                 (signed_right && maybe_negative(right))) {
8188                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8189                                 }
8190                         }
8191                 }
8192
8193                 expression->left        = create_implicit_cast(left, arithmetic_type);
8194                 expression->right       = create_implicit_cast(right, arithmetic_type);
8195                 expression->base.type   = arithmetic_type;
8196                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8197                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8198                     is_type_float(arithmetic_type)) {
8199                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8200                 }
8201         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8202                 /* TODO check compatibility */
8203         } else if (is_type_pointer(type_left)) {
8204                 expression->right = create_implicit_cast(right, type_left);
8205         } else if (is_type_pointer(type_right)) {
8206                 expression->left = create_implicit_cast(left, type_right);
8207         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8208                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8209         }
8210         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8211 }
8212
8213 /**
8214  * Checks if a compound type has constant fields.
8215  */
8216 static bool has_const_fields(const compound_type_t *type)
8217 {
8218         compound_t *compound = type->compound;
8219         entity_t   *entry    = compound->members.entities;
8220
8221         for (; entry != NULL; entry = entry->base.next) {
8222                 if (!is_declaration(entry))
8223                         continue;
8224
8225                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8226                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8227                         return true;
8228         }
8229
8230         return false;
8231 }
8232
8233 static bool is_valid_assignment_lhs(expression_t const* const left)
8234 {
8235         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8236         type_t *const type_left      = skip_typeref(orig_type_left);
8237
8238         if (!is_lvalue(left)) {
8239                 errorf(&left->base.pos,
8240                        "left hand side '%E' of assignment is not an lvalue", left);
8241                 return false;
8242         }
8243
8244         if (left->kind == EXPR_REFERENCE
8245                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8246                 errorf(&left->base.pos, "cannot assign to function '%E'", left);
8247                 return false;
8248         }
8249
8250         if (is_type_array(type_left)) {
8251                 errorf(&left->base.pos, "cannot assign to array '%E'", left);
8252                 return false;
8253         }
8254         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8255                 errorf(&left->base.pos,
8256                        "assignment to read-only location '%E' (type '%T')", left,
8257                        orig_type_left);
8258                 return false;
8259         }
8260         if (is_type_incomplete(type_left)) {
8261                 errorf(&left->base.pos, "left-hand side '%E' of assignment has incomplete type '%T'",
8262                        left, orig_type_left);
8263                 return false;
8264         }
8265         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8266                 errorf(&left->base.pos, "cannot assign to '%E' because compound type '%T' has read-only fields",
8267                        left, orig_type_left);
8268                 return false;
8269         }
8270
8271         return true;
8272 }
8273
8274 static void semantic_arithmetic_assign(binary_expression_t *expression)
8275 {
8276         expression_t *left            = expression->left;
8277         expression_t *right           = expression->right;
8278         type_t       *orig_type_left  = left->base.type;
8279         type_t       *orig_type_right = right->base.type;
8280
8281         if (!is_valid_assignment_lhs(left))
8282                 return;
8283
8284         type_t *type_left  = skip_typeref(orig_type_left);
8285         type_t *type_right = skip_typeref(orig_type_right);
8286
8287         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8288                 /* TODO: improve error message */
8289                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8290                         errorf(&expression->base.pos, "operation needs arithmetic types");
8291                 }
8292                 return;
8293         }
8294
8295         /* combined instructions are tricky. We can't create an implicit cast on
8296          * the left side, because we need the uncasted form for the store.
8297          * The ast2firm pass has to know that left_type must be right_type
8298          * for the arithmetic operation and create a cast by itself */
8299         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8300         expression->right       = create_implicit_cast(right, arithmetic_type);
8301         expression->base.type   = type_left;
8302 }
8303
8304 static void semantic_divmod_assign(binary_expression_t *expression)
8305 {
8306         semantic_arithmetic_assign(expression);
8307         warn_div_by_zero(expression);
8308 }
8309
8310 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8311 {
8312         expression_t *const left            = expression->left;
8313         expression_t *const right           = expression->right;
8314         type_t       *const orig_type_left  = left->base.type;
8315         type_t       *const orig_type_right = right->base.type;
8316         type_t       *const type_left       = skip_typeref(orig_type_left);
8317         type_t       *const type_right      = skip_typeref(orig_type_right);
8318
8319         if (!is_valid_assignment_lhs(left))
8320                 return;
8321
8322         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8323                 /* combined instructions are tricky. We can't create an implicit cast on
8324                  * the left side, because we need the uncasted form for the store.
8325                  * The ast2firm pass has to know that left_type must be right_type
8326                  * for the arithmetic operation and create a cast by itself */
8327                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8328                 expression->right     = create_implicit_cast(right, arithmetic_type);
8329                 expression->base.type = type_left;
8330         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8331                 check_pointer_arithmetic(&expression->base.pos, type_left,
8332                                          orig_type_left);
8333                 expression->base.type = type_left;
8334         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8335                 errorf(&expression->base.pos,
8336                        "incompatible types '%T' and '%T' in assignment",
8337                        orig_type_left, orig_type_right);
8338         }
8339 }
8340
8341 static void semantic_integer_assign(binary_expression_t *expression)
8342 {
8343         expression_t *left            = expression->left;
8344         expression_t *right           = expression->right;
8345         type_t       *orig_type_left  = left->base.type;
8346         type_t       *orig_type_right = right->base.type;
8347
8348         if (!is_valid_assignment_lhs(left))
8349                 return;
8350
8351         type_t *type_left  = skip_typeref(orig_type_left);
8352         type_t *type_right = skip_typeref(orig_type_right);
8353
8354         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8355                 /* TODO: improve error message */
8356                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8357                         errorf(&expression->base.pos, "operation needs integer types");
8358                 }
8359                 return;
8360         }
8361
8362         /* combined instructions are tricky. We can't create an implicit cast on
8363          * the left side, because we need the uncasted form for the store.
8364          * The ast2firm pass has to know that left_type must be right_type
8365          * for the arithmetic operation and create a cast by itself */
8366         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8367         expression->right       = create_implicit_cast(right, arithmetic_type);
8368         expression->base.type   = type_left;
8369 }
8370
8371 static void semantic_shift_assign(binary_expression_t *expression)
8372 {
8373         expression_t *left           = expression->left;
8374
8375         if (!is_valid_assignment_lhs(left))
8376                 return;
8377
8378         if (!semantic_shift(expression))
8379                 return;
8380
8381         expression->base.type = skip_typeref(left->base.type);
8382 }
8383
8384 static void warn_logical_and_within_or(const expression_t *const expr)
8385 {
8386         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8387                 return;
8388         if (expr->base.parenthesized)
8389                 return;
8390         position_t const *const pos = &expr->base.pos;
8391         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8392 }
8393
8394 /**
8395  * Check the semantic restrictions of a logical expression.
8396  */
8397 static void semantic_logical_op(binary_expression_t *expression)
8398 {
8399         /* §6.5.13:2  Each of the operands shall have scalar type.
8400          * §6.5.14:2  Each of the operands shall have scalar type. */
8401         semantic_condition(expression->left,   "left operand of logical operator");
8402         semantic_condition(expression->right, "right operand of logical operator");
8403         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8404                 warn_logical_and_within_or(expression->left);
8405                 warn_logical_and_within_or(expression->right);
8406         }
8407         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8408 }
8409
8410 /**
8411  * Check the semantic restrictions of a binary assign expression.
8412  */
8413 static void semantic_binexpr_assign(binary_expression_t *expression)
8414 {
8415         expression_t *left           = expression->left;
8416         type_t       *orig_type_left = left->base.type;
8417
8418         if (!is_valid_assignment_lhs(left))
8419                 return;
8420
8421         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8422         report_assign_error(error, orig_type_left, expression->right,
8423                             "assignment", &left->base.pos);
8424         expression->right = create_implicit_cast(expression->right, orig_type_left);
8425         expression->base.type = orig_type_left;
8426 }
8427
8428 /**
8429  * Determine if the outermost operation (or parts thereof) of the given
8430  * expression has no effect in order to generate a warning about this fact.
8431  * Therefore in some cases this only examines some of the operands of the
8432  * expression (see comments in the function and examples below).
8433  * Examples:
8434  *   f() + 23;    // warning, because + has no effect
8435  *   x || f();    // no warning, because x controls execution of f()
8436  *   x ? y : f(); // warning, because y has no effect
8437  *   (void)x;     // no warning to be able to suppress the warning
8438  * This function can NOT be used for an "expression has definitely no effect"-
8439  * analysis. */
8440 static bool expression_has_effect(const expression_t *const expr)
8441 {
8442         switch (expr->kind) {
8443                 case EXPR_ERROR:                      return true; /* do NOT warn */
8444                 case EXPR_REFERENCE:                  return false;
8445                 case EXPR_ENUM_CONSTANT:              return false;
8446                 case EXPR_LABEL_ADDRESS:              return false;
8447
8448                 /* suppress the warning for microsoft __noop operations */
8449                 case EXPR_LITERAL_MS_NOOP:            return true;
8450                 case EXPR_LITERAL_BOOLEAN:
8451                 case EXPR_LITERAL_CHARACTER:
8452                 case EXPR_LITERAL_INTEGER:
8453                 case EXPR_LITERAL_FLOATINGPOINT:
8454                 case EXPR_STRING_LITERAL:             return false;
8455
8456                 case EXPR_CALL: {
8457                         const call_expression_t *const call = &expr->call;
8458                         if (call->function->kind != EXPR_REFERENCE)
8459                                 return true;
8460
8461                         switch (call->function->reference.entity->function.btk) {
8462                                 /* FIXME: which builtins have no effect? */
8463                                 default:                      return true;
8464                         }
8465                 }
8466
8467                 /* Generate the warning if either the left or right hand side of a
8468                  * conditional expression has no effect */
8469                 case EXPR_CONDITIONAL: {
8470                         conditional_expression_t const *const cond = &expr->conditional;
8471                         expression_t             const *const t    = cond->true_expression;
8472                         return
8473                                 (t == NULL || expression_has_effect(t)) &&
8474                                 expression_has_effect(cond->false_expression);
8475                 }
8476
8477                 case EXPR_SELECT:                     return false;
8478                 case EXPR_ARRAY_ACCESS:               return false;
8479                 case EXPR_SIZEOF:                     return false;
8480                 case EXPR_CLASSIFY_TYPE:              return false;
8481                 case EXPR_ALIGNOF:                    return false;
8482
8483                 case EXPR_FUNCNAME:                   return false;
8484                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8485                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8486                 case EXPR_OFFSETOF:                   return false;
8487                 case EXPR_VA_START:                   return true;
8488                 case EXPR_VA_ARG:                     return true;
8489                 case EXPR_VA_COPY:                    return true;
8490                 case EXPR_STATEMENT:                  return true; // TODO
8491                 case EXPR_COMPOUND_LITERAL:           return false;
8492
8493                 case EXPR_UNARY_NEGATE:               return false;
8494                 case EXPR_UNARY_PLUS:                 return false;
8495                 case EXPR_UNARY_COMPLEMENT:           return false;
8496                 case EXPR_UNARY_NOT:                  return false;
8497                 case EXPR_UNARY_DEREFERENCE:          return false;
8498                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8499                 case EXPR_UNARY_REAL:                 return false;
8500                 case EXPR_UNARY_IMAG:                 return false;
8501                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8502                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8503                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8504                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8505
8506                 /* Treat void casts as if they have an effect in order to being able to
8507                  * suppress the warning */
8508                 case EXPR_UNARY_CAST: {
8509                         type_t *const type = skip_typeref(expr->base.type);
8510                         return is_type_void(type);
8511                 }
8512
8513                 case EXPR_UNARY_ASSUME:               return true;
8514                 case EXPR_UNARY_DELETE:               return true;
8515                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8516                 case EXPR_UNARY_THROW:                return true;
8517
8518                 case EXPR_BINARY_ADD:                 return false;
8519                 case EXPR_BINARY_SUB:                 return false;
8520                 case EXPR_BINARY_MUL:                 return false;
8521                 case EXPR_BINARY_DIV:                 return false;
8522                 case EXPR_BINARY_MOD:                 return false;
8523                 case EXPR_BINARY_EQUAL:               return false;
8524                 case EXPR_BINARY_NOTEQUAL:            return false;
8525                 case EXPR_BINARY_LESS:                return false;
8526                 case EXPR_BINARY_LESSEQUAL:           return false;
8527                 case EXPR_BINARY_GREATER:             return false;
8528                 case EXPR_BINARY_GREATEREQUAL:        return false;
8529                 case EXPR_BINARY_BITWISE_AND:         return false;
8530                 case EXPR_BINARY_BITWISE_OR:          return false;
8531                 case EXPR_BINARY_BITWISE_XOR:         return false;
8532                 case EXPR_BINARY_SHIFTLEFT:           return false;
8533                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8534                 case EXPR_BINARY_ASSIGN:              return true;
8535                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8536                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8537                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8538                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8539                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8540                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8541                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8542                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8543                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8544                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8545
8546                 /* Only examine the right hand side of && and ||, because the left hand
8547                  * side already has the effect of controlling the execution of the right
8548                  * hand side */
8549                 case EXPR_BINARY_LOGICAL_AND:
8550                 case EXPR_BINARY_LOGICAL_OR:
8551                 /* Only examine the right hand side of a comma expression, because the left
8552                  * hand side has a separate warning */
8553                 case EXPR_BINARY_COMMA:
8554                         return expression_has_effect(expr->binary.right);
8555
8556                 case EXPR_BINARY_ISGREATER:           return false;
8557                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8558                 case EXPR_BINARY_ISLESS:              return false;
8559                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8560                 case EXPR_BINARY_ISLESSGREATER:       return false;
8561                 case EXPR_BINARY_ISUNORDERED:         return false;
8562         }
8563
8564         internal_errorf(HERE, "unexpected expression");
8565 }
8566
8567 static void semantic_comma(binary_expression_t *expression)
8568 {
8569         const expression_t *const left = expression->left;
8570         if (!expression_has_effect(left)) {
8571                 position_t const *const pos = &left->base.pos;
8572                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8573         }
8574         expression->base.type = expression->right->base.type;
8575 }
8576
8577 /**
8578  * @param prec_r precedence of the right operand
8579  */
8580 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8581 static expression_t *parse_##binexpression_type(expression_t *left)          \
8582 {                                                                            \
8583         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8584         binexpr->binary.left  = left;                                            \
8585         eat(token_kind);                                                         \
8586                                                                              \
8587         expression_t *right = parse_subexpression(prec_r);                       \
8588                                                                              \
8589         binexpr->binary.right = right;                                           \
8590         sfunc(&binexpr->binary);                                                 \
8591                                                                              \
8592         return binexpr;                                                          \
8593 }
8594
8595 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8596 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_div)
8597 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_mod)
8598 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8599 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8600 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8601 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8602 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8603 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8604 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8605 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8606 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8607 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8608 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8609 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8610 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8611 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8612 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8613 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8614 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8615 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8616 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8617 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8618 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8619 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8620 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8621 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8622 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8623 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8624 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8625
8626
8627 static expression_t *parse_subexpression(precedence_t precedence)
8628 {
8629         expression_parser_function_t *parser
8630                 = &expression_parsers[token.kind];
8631         expression_t                 *left;
8632
8633         if (parser->parser != NULL) {
8634                 left = parser->parser();
8635         } else {
8636                 left = parse_primary_expression();
8637         }
8638         assert(left != NULL);
8639
8640         while (true) {
8641                 parser = &expression_parsers[token.kind];
8642                 if (parser->infix_parser == NULL)
8643                         break;
8644                 if (parser->infix_precedence < precedence)
8645                         break;
8646
8647                 left = parser->infix_parser(left);
8648
8649                 assert(left != NULL);
8650         }
8651
8652         return left;
8653 }
8654
8655 /**
8656  * Parse an expression.
8657  */
8658 static expression_t *parse_expression(void)
8659 {
8660         return parse_subexpression(PREC_EXPRESSION);
8661 }
8662
8663 /**
8664  * Register a parser for a prefix-like operator.
8665  *
8666  * @param parser      the parser function
8667  * @param token_kind  the token type of the prefix token
8668  */
8669 static void register_expression_parser(parse_expression_function parser,
8670                                        int token_kind)
8671 {
8672         expression_parser_function_t *entry = &expression_parsers[token_kind];
8673
8674         assert(!entry->parser);
8675         entry->parser = parser;
8676 }
8677
8678 /**
8679  * Register a parser for an infix operator with given precedence.
8680  *
8681  * @param parser      the parser function
8682  * @param token_kind  the token type of the infix operator
8683  * @param precedence  the precedence of the operator
8684  */
8685 static void register_infix_parser(parse_expression_infix_function parser,
8686                                   int token_kind, precedence_t precedence)
8687 {
8688         expression_parser_function_t *entry = &expression_parsers[token_kind];
8689
8690         assert(!entry->infix_parser);
8691         entry->infix_parser     = parser;
8692         entry->infix_precedence = precedence;
8693 }
8694
8695 /**
8696  * Initialize the expression parsers.
8697  */
8698 static void init_expression_parsers(void)
8699 {
8700         memset(&expression_parsers, 0, sizeof(expression_parsers));
8701
8702         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8703         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8704         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8705         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8706         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8707         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8708         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8709         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8710         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8711         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8712         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8713         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8714         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8715         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8716         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8717         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8718         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8719         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8720         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8721         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8722         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8723         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8724         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8725         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8726         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8727         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8728         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8729         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8730         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8731         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8732         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8733         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8734         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8735         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8736         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8737         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8738         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8739
8740         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8741         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8742         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8743         register_expression_parser(parse_EXPR_UNARY_COMPLEMENT,       '~');
8744         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8745         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8746         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8747         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8748         register_expression_parser(parse_sizeof,                      T_sizeof);
8749         register_expression_parser(parse_alignof,                     T__Alignof);
8750         register_expression_parser(parse_extension,                   T___extension__);
8751         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8752         register_expression_parser(parse_delete,                      T_delete);
8753         register_expression_parser(parse_throw,                       T_throw);
8754 }
8755
8756 /**
8757  * Parse a asm statement arguments specification.
8758  */
8759 static void parse_asm_arguments(asm_argument_t **anchor, bool const is_out)
8760 {
8761         if (token.kind == T_STRING_LITERAL || token.kind == '[') {
8762                 add_anchor_token(',');
8763                 do {
8764                         asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8765
8766                         add_anchor_token(')');
8767                         add_anchor_token('(');
8768                         add_anchor_token(T_STRING_LITERAL);
8769
8770                         if (accept('[')) {
8771                                 add_anchor_token(']');
8772                                 argument->symbol = expect_identifier("while parsing asm argument", NULL);
8773                                 rem_anchor_token(']');
8774                                 expect(']');
8775                         }
8776
8777                         rem_anchor_token(T_STRING_LITERAL);
8778                         argument->constraints = parse_string_literals("asm argument");
8779                         rem_anchor_token('(');
8780                         expect('(');
8781                         expression_t *expression = parse_expression();
8782                         if (is_out) {
8783                                 /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8784                                  * change size or type representation (e.g. int -> long is ok, but
8785                                  * int -> float is not) */
8786                                 if (expression->kind == EXPR_UNARY_CAST) {
8787                                         type_t      *const type = expression->base.type;
8788                                         type_kind_t  const kind = type->kind;
8789                                         if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8790                                                 unsigned flags;
8791                                                 unsigned size;
8792                                                 if (kind == TYPE_ATOMIC) {
8793                                                         atomic_type_kind_t const akind = type->atomic.akind;
8794                                                         flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8795                                                         size  = get_atomic_type_size(akind);
8796                                                 } else {
8797                                                         flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8798                                                         size  = get_type_size(type_void_ptr);
8799                                                 }
8800
8801                                                 do {
8802                                                         expression_t *const value      = expression->unary.value;
8803                                                         type_t       *const value_type = value->base.type;
8804                                                         type_kind_t   const value_kind = value_type->kind;
8805
8806                                                         unsigned value_flags;
8807                                                         unsigned value_size;
8808                                                         if (value_kind == TYPE_ATOMIC) {
8809                                                                 atomic_type_kind_t const value_akind = value_type->atomic.akind;
8810                                                                 value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8811                                                                 value_size  = get_atomic_type_size(value_akind);
8812                                                         } else if (value_kind == TYPE_POINTER) {
8813                                                                 value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8814                                                                 value_size  = get_type_size(type_void_ptr);
8815                                                         } else {
8816                                                                 break;
8817                                                         }
8818
8819                                                         if (value_flags != flags || value_size != size)
8820                                                                 break;
8821
8822                                                         expression = value;
8823                                                 } while (expression->kind == EXPR_UNARY_CAST);
8824                                         }
8825                                 }
8826
8827                                 if (!is_lvalue(expression))
8828                                         errorf(&expression->base.pos,
8829                                                "asm output argument is not an lvalue");
8830
8831                                 if (argument->constraints.begin[0] == '=')
8832                                         determine_lhs_ent(expression, NULL);
8833                                 else
8834                                         mark_vars_read(expression, NULL);
8835                         } else {
8836                                 mark_vars_read(expression, NULL);
8837                         }
8838                         argument->expression = expression;
8839                         rem_anchor_token(')');
8840                         expect(')');
8841
8842                         set_address_taken(expression, true);
8843
8844                         *anchor = argument;
8845                         anchor  = &argument->next;
8846                 } while (accept(','));
8847                 rem_anchor_token(',');
8848         }
8849 }
8850
8851 /**
8852  * Parse a asm statement clobber specification.
8853  */
8854 static void parse_asm_clobbers(asm_clobber_t **anchor)
8855 {
8856         if (token.kind == T_STRING_LITERAL) {
8857                 add_anchor_token(',');
8858                 do {
8859                         asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8860                         clobber->clobber       = parse_string_literals(NULL);
8861
8862                         *anchor = clobber;
8863                         anchor  = &clobber->next;
8864                 } while (accept(','));
8865                 rem_anchor_token(',');
8866         }
8867 }
8868
8869 static void parse_asm_labels(asm_label_t **anchor)
8870 {
8871         if (token.kind == T_IDENTIFIER) {
8872                 add_anchor_token(',');
8873                 do {
8874                         label_t *const label = get_label("while parsing 'asm goto' labels");
8875                         if (label) {
8876                                 asm_label_t *const asm_label = allocate_ast_zero(sizeof(*asm_label));
8877                                 asm_label->label = label;
8878
8879                                 *anchor = asm_label;
8880                                 anchor  = &asm_label->next;
8881                         }
8882                 } while (accept(','));
8883                 rem_anchor_token(',');
8884         }
8885 }
8886
8887 /**
8888  * Parse an asm statement.
8889  */
8890 static statement_t *parse_asm_statement(void)
8891 {
8892         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8893         asm_statement_t *asm_statement = &statement->asms;
8894
8895         eat(T_asm);
8896         add_anchor_token(')');
8897         add_anchor_token(':');
8898         add_anchor_token(T_STRING_LITERAL);
8899
8900         if (accept(T_volatile))
8901                 asm_statement->is_volatile = true;
8902
8903         bool const asm_goto = accept(T_goto);
8904
8905         expect('(');
8906         rem_anchor_token(T_STRING_LITERAL);
8907         asm_statement->asm_text = parse_string_literals("asm statement");
8908
8909         if (accept(':')) parse_asm_arguments(&asm_statement->outputs, true);
8910         if (accept(':')) parse_asm_arguments(&asm_statement->inputs, false);
8911         if (accept(':')) parse_asm_clobbers( &asm_statement->clobbers);
8912
8913         rem_anchor_token(':');
8914         if (accept(':')) {
8915                 if (!asm_goto)
8916                         warningf(WARN_OTHER, &statement->base.pos, "assembler statement with labels should be 'asm goto'");
8917                 parse_asm_labels(&asm_statement->labels);
8918                 if (asm_statement->labels)
8919                         errorf(&statement->base.pos, "'asm goto' not supported");
8920         } else {
8921                 if (asm_goto)
8922                         warningf(WARN_OTHER, &statement->base.pos, "'asm goto' without labels");
8923         }
8924
8925         rem_anchor_token(')');
8926         expect(')');
8927         expect(';');
8928
8929         if (asm_statement->outputs == NULL) {
8930                 /* GCC: An 'asm' instruction without any output operands will be treated
8931                  * identically to a volatile 'asm' instruction. */
8932                 asm_statement->is_volatile = true;
8933         }
8934
8935         return statement;
8936 }
8937
8938 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8939 {
8940         statement_t *inner_stmt;
8941         switch (token.kind) {
8942                 case '}':
8943                         errorf(&label->base.pos, "%s at end of compound statement", label_kind);
8944                         inner_stmt = create_error_statement();
8945                         break;
8946
8947                 case ';':
8948                         if (label->kind == STATEMENT_LABEL) {
8949                                 /* Eat an empty statement here, to avoid the warning about an empty
8950                                  * statement after a label.  label:; is commonly used to have a label
8951                                  * before a closing brace. */
8952                                 inner_stmt = create_empty_statement();
8953                                 eat(';');
8954                                 break;
8955                         }
8956                         /* FALLTHROUGH */
8957
8958                 default:
8959                         inner_stmt = parse_statement();
8960                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8961                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8962                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8963                                 errorf(&inner_stmt->base.pos, "declaration after %s", label_kind);
8964                         }
8965                         break;
8966         }
8967         return inner_stmt;
8968 }
8969
8970 /**
8971  * Parse a case statement.
8972  */
8973 static statement_t *parse_case_statement(void)
8974 {
8975         statement_t *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8976         position_t  *const pos       = &statement->base.pos;
8977
8978         eat(T_case);
8979         add_anchor_token(':');
8980
8981         expression_t *expression = parse_expression();
8982         type_t *expression_type = expression->base.type;
8983         type_t *skipped         = skip_typeref(expression_type);
8984         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8985                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8986                        expression, expression_type);
8987         }
8988
8989         type_t *type = expression_type;
8990         if (current_switch != NULL) {
8991                 type_t *switch_type = current_switch->expression->base.type;
8992                 if (is_type_valid(skip_typeref(switch_type))) {
8993                         expression = create_implicit_cast(expression, switch_type);
8994                 }
8995         }
8996
8997         statement->case_label.expression = expression;
8998         expression_classification_t const expr_class = is_constant_expression(expression);
8999         if (expr_class != EXPR_CLASS_CONSTANT) {
9000                 if (expr_class != EXPR_CLASS_ERROR) {
9001                         errorf(pos, "case label does not reduce to an integer constant");
9002                 }
9003                 statement->case_label.is_bad = true;
9004         } else {
9005                 ir_tarval *val = fold_constant_to_tarval(expression);
9006                 statement->case_label.first_case = val;
9007                 statement->case_label.last_case  = val;
9008         }
9009
9010         if (GNU_MODE) {
9011                 if (accept(T_DOTDOTDOT)) {
9012                         expression_t *end_range = parse_expression();
9013                         expression_type = expression->base.type;
9014                         skipped         = skip_typeref(expression_type);
9015                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9016                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9017                                            expression, expression_type);
9018                         }
9019
9020                         end_range = create_implicit_cast(end_range, type);
9021                         statement->case_label.end_range = end_range;
9022                         expression_classification_t const end_class = is_constant_expression(end_range);
9023                         if (end_class != EXPR_CLASS_CONSTANT) {
9024                                 if (end_class != EXPR_CLASS_ERROR) {
9025                                         errorf(pos, "case range does not reduce to an integer constant");
9026                                 }
9027                                 statement->case_label.is_bad = true;
9028                         } else {
9029                                 ir_tarval *val = fold_constant_to_tarval(end_range);
9030                                 statement->case_label.last_case = val;
9031
9032                                 if (tarval_cmp(val, statement->case_label.first_case)
9033                                     == ir_relation_less) {
9034                                         statement->case_label.is_empty_range = true;
9035                                         warningf(WARN_OTHER, pos, "empty range specified");
9036                                 }
9037                         }
9038                 }
9039         }
9040
9041         PUSH_PARENT(statement);
9042
9043         rem_anchor_token(':');
9044         expect(':');
9045
9046         if (current_switch != NULL) {
9047                 if (! statement->case_label.is_bad) {
9048                         /* Check for duplicate case values */
9049                         case_label_statement_t *c = &statement->case_label;
9050                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9051                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9052                                         continue;
9053
9054                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9055                                         continue;
9056
9057                                 errorf(pos, "duplicate case value (previously used %P)",
9058                                        &l->base.pos);
9059                                 break;
9060                         }
9061                 }
9062                 /* link all cases into the switch statement */
9063                 if (current_switch->last_case == NULL) {
9064                         current_switch->first_case      = &statement->case_label;
9065                 } else {
9066                         current_switch->last_case->next = &statement->case_label;
9067                 }
9068                 current_switch->last_case = &statement->case_label;
9069         } else {
9070                 errorf(pos, "case label not within a switch statement");
9071         }
9072
9073         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9074
9075         POP_PARENT();
9076         return statement;
9077 }
9078
9079 /**
9080  * Parse a default statement.
9081  */
9082 static statement_t *parse_default_statement(void)
9083 {
9084         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9085
9086         eat(T_default);
9087
9088         PUSH_PARENT(statement);
9089
9090         expect(':');
9091
9092         if (current_switch != NULL) {
9093                 const case_label_statement_t *def_label = current_switch->default_label;
9094                 if (def_label != NULL) {
9095                         errorf(&statement->base.pos, "multiple default labels in one switch (previous declared %P)", &def_label->base.pos);
9096                 } else {
9097                         current_switch->default_label = &statement->case_label;
9098
9099                         /* link all cases into the switch statement */
9100                         if (current_switch->last_case == NULL) {
9101                                 current_switch->first_case      = &statement->case_label;
9102                         } else {
9103                                 current_switch->last_case->next = &statement->case_label;
9104                         }
9105                         current_switch->last_case = &statement->case_label;
9106                 }
9107         } else {
9108                 errorf(&statement->base.pos,
9109                        "'default' label not within a switch statement");
9110         }
9111
9112         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9113
9114         POP_PARENT();
9115         return statement;
9116 }
9117
9118 /**
9119  * Parse a label statement.
9120  */
9121 static statement_t *parse_label_statement(void)
9122 {
9123         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9124         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9125         statement->label.label = label;
9126
9127         PUSH_PARENT(statement);
9128
9129         /* if statement is already set then the label is defined twice,
9130          * otherwise it was just mentioned in a goto/local label declaration so far
9131          */
9132         position_t const* const pos = &statement->base.pos;
9133         if (label->statement != NULL) {
9134                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.pos);
9135         } else {
9136                 label->base.pos  = *pos;
9137                 label->statement = statement;
9138                 label->n_users  += 1;
9139         }
9140
9141         eat(':');
9142
9143         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9144                 parse_attributes(NULL); // TODO process attributes
9145         }
9146
9147         statement->label.statement = parse_label_inner_statement(statement, "label");
9148
9149         /* remember the labels in a list for later checking */
9150         *label_anchor = &statement->label;
9151         label_anchor  = &statement->label.next;
9152
9153         POP_PARENT();
9154         return statement;
9155 }
9156
9157 static statement_t *parse_inner_statement(void)
9158 {
9159         statement_t *const stmt = parse_statement();
9160         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9161         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9162         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9163                 errorf(&stmt->base.pos, "declaration as inner statement, use {}");
9164         }
9165         return stmt;
9166 }
9167
9168 /**
9169  * Parse an expression in parentheses and mark its variables as read.
9170  */
9171 static expression_t *parse_condition(void)
9172 {
9173         add_anchor_token(')');
9174         expect('(');
9175         expression_t *const expr = parse_expression();
9176         mark_vars_read(expr, NULL);
9177         rem_anchor_token(')');
9178         expect(')');
9179         return expr;
9180 }
9181
9182 /**
9183  * Parse an if statement.
9184  */
9185 static statement_t *parse_if(void)
9186 {
9187         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9188
9189         eat(T_if);
9190
9191         PUSH_PARENT(statement);
9192         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9193
9194         add_anchor_token(T_else);
9195
9196         expression_t *const expr = parse_condition();
9197         statement->ifs.condition = expr;
9198         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9199          *             scalar type. */
9200         semantic_condition(expr, "condition of 'if'-statment");
9201
9202         statement_t *const true_stmt = parse_inner_statement();
9203         statement->ifs.true_statement = true_stmt;
9204         rem_anchor_token(T_else);
9205
9206         if (true_stmt->kind == STATEMENT_EMPTY) {
9207                 warningf(WARN_EMPTY_BODY, HERE,
9208                         "suggest braces around empty body in an ‘if’ statement");
9209         }
9210
9211         if (accept(T_else)) {
9212                 statement->ifs.false_statement = parse_inner_statement();
9213
9214                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9215                         warningf(WARN_EMPTY_BODY, HERE,
9216                                         "suggest braces around empty body in an ‘if’ statement");
9217                 }
9218         } else if (true_stmt->kind == STATEMENT_IF &&
9219                         true_stmt->ifs.false_statement != NULL) {
9220                 position_t const *const pos = &true_stmt->base.pos;
9221                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9222         }
9223
9224         POP_SCOPE();
9225         POP_PARENT();
9226         return statement;
9227 }
9228
9229 /**
9230  * Check that all enums are handled in a switch.
9231  *
9232  * @param statement  the switch statement to check
9233  */
9234 static void check_enum_cases(const switch_statement_t *statement)
9235 {
9236         if (!is_warn_on(WARN_SWITCH_ENUM))
9237                 return;
9238         type_t *type = skip_typeref(statement->expression->base.type);
9239         if (! is_type_enum(type))
9240                 return;
9241         enum_type_t *enumt = &type->enumt;
9242
9243         /* if we have a default, no warnings */
9244         if (statement->default_label != NULL)
9245                 return;
9246
9247         determine_enum_values(enumt);
9248
9249         /* FIXME: calculation of value should be done while parsing */
9250         /* TODO: quadratic algorithm here. Change to an n log n one */
9251         const entity_t *entry = enumt->enume->base.next;
9252         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9253              entry = entry->base.next) {
9254                 ir_tarval *value = entry->enum_value.tv;
9255                 bool       found = false;
9256                 for (const case_label_statement_t *l = statement->first_case; l != NULL;
9257                      l = l->next) {
9258                         if (l->expression == NULL)
9259                                 continue;
9260                         if (l->first_case == l->last_case && l->first_case != value)
9261                                 continue;
9262                         if ((tarval_cmp(l->first_case, value) & ir_relation_less_equal)
9263                          && (tarval_cmp(value, l->last_case) & ir_relation_less_equal)) {
9264                                 found = true;
9265                                 break;
9266                         }
9267                 }
9268                 if (!found) {
9269                         position_t const *const pos = &statement->base.pos;
9270                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9271                 }
9272         }
9273 }
9274
9275 /**
9276  * Parse a switch statement.
9277  */
9278 static statement_t *parse_switch(void)
9279 {
9280         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9281
9282         eat(T_switch);
9283
9284         PUSH_PARENT(statement);
9285         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9286
9287         expression_t *const expr = parse_condition();
9288         type_t       *      type = skip_typeref(expr->base.type);
9289         if (is_type_integer(type)) {
9290                 type = promote_integer(type);
9291                 if (get_akind_rank(get_arithmetic_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9292                         warningf(WARN_TRADITIONAL, &expr->base.pos,
9293                                  "'%T' switch expression not converted to '%T' in ISO C",
9294                                  type, type_int);
9295                 }
9296         } else if (is_type_valid(type)) {
9297                 errorf(&expr->base.pos, "switch quantity is not an integer, but '%T'",
9298                        type);
9299                 type = type_error_type;
9300         }
9301         statement->switchs.expression = create_implicit_cast(expr, type);
9302
9303         switch_statement_t *rem = current_switch;
9304         current_switch          = &statement->switchs;
9305         statement->switchs.body = parse_inner_statement();
9306         current_switch          = rem;
9307
9308         if (statement->switchs.default_label == NULL) {
9309                 warningf(WARN_SWITCH_DEFAULT, &statement->base.pos, "switch has no default case");
9310         }
9311         check_enum_cases(&statement->switchs);
9312
9313         POP_SCOPE();
9314         POP_PARENT();
9315         return statement;
9316 }
9317
9318 static statement_t *parse_loop_body(statement_t *const loop)
9319 {
9320         statement_t *const rem = current_loop;
9321         current_loop = loop;
9322
9323         statement_t *const body = parse_inner_statement();
9324
9325         current_loop = rem;
9326         return body;
9327 }
9328
9329 /**
9330  * Parse a while statement.
9331  */
9332 static statement_t *parse_while(void)
9333 {
9334         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9335
9336         eat(T_while);
9337
9338         PUSH_PARENT(statement);
9339         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9340
9341         expression_t *const cond = parse_condition();
9342         statement->fors.condition = cond;
9343         /* §6.8.5:2    The controlling expression of an iteration statement shall
9344          *             have scalar type. */
9345         semantic_condition(cond, "condition of 'while'-statement");
9346
9347         statement->fors.body = parse_loop_body(statement);
9348
9349         POP_SCOPE();
9350         POP_PARENT();
9351         return statement;
9352 }
9353
9354 /**
9355  * Parse a do statement.
9356  */
9357 static statement_t *parse_do(void)
9358 {
9359         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9360
9361         eat(T_do);
9362
9363         PUSH_PARENT(statement);
9364         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9365
9366         add_anchor_token(T_while);
9367         statement->do_while.body = parse_loop_body(statement);
9368         rem_anchor_token(T_while);
9369
9370         expect(T_while);
9371         expression_t *const cond = parse_condition();
9372         statement->do_while.condition = cond;
9373         /* §6.8.5:2    The controlling expression of an iteration statement shall
9374          *             have scalar type. */
9375         semantic_condition(cond, "condition of 'do-while'-statement");
9376         expect(';');
9377
9378         POP_SCOPE();
9379         POP_PARENT();
9380         return statement;
9381 }
9382
9383 /**
9384  * Parse a for statement.
9385  */
9386 static statement_t *parse_for(void)
9387 {
9388         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9389
9390         eat(T_for);
9391
9392         PUSH_PARENT(statement);
9393         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9394
9395         add_anchor_token(')');
9396         expect('(');
9397
9398         PUSH_EXTENSION();
9399
9400         if (accept(';')) {
9401         } else if (is_declaration_specifier(&token)) {
9402                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9403         } else {
9404                 add_anchor_token(';');
9405                 expression_t *const init = parse_expression();
9406                 statement->fors.initialisation = init;
9407                 mark_vars_read(init, ENT_ANY);
9408                 if (!expression_has_effect(init)) {
9409                         warningf(WARN_UNUSED_VALUE, &init->base.pos, "initialisation of 'for'-statement has no effect");
9410                 }
9411                 rem_anchor_token(';');
9412                 expect(';');
9413         }
9414
9415         POP_EXTENSION();
9416
9417         if (token.kind != ';') {
9418                 add_anchor_token(';');
9419                 expression_t *const cond = parse_expression();
9420                 statement->fors.condition = cond;
9421                 /* §6.8.5:2    The controlling expression of an iteration statement
9422                  *             shall have scalar type. */
9423                 semantic_condition(cond, "condition of 'for'-statement");
9424                 mark_vars_read(cond, NULL);
9425                 rem_anchor_token(';');
9426         }
9427         expect(';');
9428         if (token.kind != ')') {
9429                 expression_t *const step = parse_expression();
9430                 statement->fors.step = step;
9431                 mark_vars_read(step, ENT_ANY);
9432                 if (!expression_has_effect(step)) {
9433                         warningf(WARN_UNUSED_VALUE, &step->base.pos, "step of 'for'-statement has no effect");
9434                 }
9435         }
9436         rem_anchor_token(')');
9437         expect(')');
9438         statement->fors.body = parse_loop_body(statement);
9439
9440         POP_SCOPE();
9441         POP_PARENT();
9442         return statement;
9443 }
9444
9445 /**
9446  * Parse a goto statement.
9447  */
9448 static statement_t *parse_goto(void)
9449 {
9450         statement_t *statement;
9451         if (GNU_MODE && look_ahead(1)->kind == '*') {
9452                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9453                 eat(T_goto);
9454                 eat('*');
9455
9456                 expression_t *expression = parse_expression();
9457                 mark_vars_read(expression, NULL);
9458
9459                 /* Argh: although documentation says the expression must be of type void*,
9460                  * gcc accepts anything that can be casted into void* without error */
9461                 type_t *type = expression->base.type;
9462
9463                 if (type != type_error_type) {
9464                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9465                                 errorf(&expression->base.pos, "cannot convert to a pointer type");
9466                         } else if (type != type_void_ptr) {
9467                                 warningf(WARN_OTHER, &expression->base.pos, "type of computed goto expression should be 'void*' not '%T'", type);
9468                         }
9469                         expression = create_implicit_cast(expression, type_void_ptr);
9470                 }
9471
9472                 statement->computed_goto.expression = expression;
9473         } else {
9474                 statement = allocate_statement_zero(STATEMENT_GOTO);
9475                 eat(T_goto);
9476
9477                 label_t *const label = get_label("while parsing goto");
9478                 if (label) {
9479                         label->n_users        += 1;
9480                         label->used            = true;
9481                         statement->gotos.label = label;
9482
9483                         /* remember the goto's in a list for later checking */
9484                         *goto_anchor = &statement->gotos;
9485                         goto_anchor  = &statement->gotos.next;
9486                 } else {
9487                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_position)->label;
9488                 }
9489         }
9490
9491         expect(';');
9492         return statement;
9493 }
9494
9495 /**
9496  * Parse a continue statement.
9497  */
9498 static statement_t *parse_continue(void)
9499 {
9500         if (current_loop == NULL) {
9501                 errorf(HERE, "continue statement not within loop");
9502         }
9503
9504         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9505
9506         eat(T_continue);
9507         expect(';');
9508         return statement;
9509 }
9510
9511 /**
9512  * Parse a break statement.
9513  */
9514 static statement_t *parse_break(void)
9515 {
9516         if (current_switch == NULL && current_loop == NULL) {
9517                 errorf(HERE, "break statement not within loop or switch");
9518         }
9519
9520         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9521
9522         eat(T_break);
9523         expect(';');
9524         return statement;
9525 }
9526
9527 /**
9528  * Parse a __leave statement.
9529  */
9530 static statement_t *parse_leave_statement(void)
9531 {
9532         if (current_try == NULL) {
9533                 errorf(HERE, "__leave statement not within __try");
9534         }
9535
9536         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9537
9538         eat(T___leave);
9539         expect(';');
9540         return statement;
9541 }
9542
9543 /**
9544  * Check if a given entity represents a local variable.
9545  */
9546 static bool is_local_variable(const entity_t *entity)
9547 {
9548         if (entity->kind != ENTITY_VARIABLE)
9549                 return false;
9550
9551         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9552         case STORAGE_CLASS_AUTO:
9553         case STORAGE_CLASS_REGISTER: {
9554                 const type_t *type = skip_typeref(entity->declaration.type);
9555                 if (is_type_function(type)) {
9556                         return false;
9557                 } else {
9558                         return true;
9559                 }
9560         }
9561         default:
9562                 return false;
9563         }
9564 }
9565
9566 /**
9567  * Check if a given expression represents a local variable.
9568  */
9569 static bool expression_is_local_variable(const expression_t *expression)
9570 {
9571         if (expression->base.kind != EXPR_REFERENCE) {
9572                 return false;
9573         }
9574         const entity_t *entity = expression->reference.entity;
9575         return is_local_variable(entity);
9576 }
9577
9578 static void err_or_warn(position_t const *const pos, char const *const msg)
9579 {
9580         if (c_mode & _CXX || strict_mode) {
9581                 errorf(pos, msg);
9582         } else {
9583                 warningf(WARN_OTHER, pos, msg);
9584         }
9585 }
9586
9587 /**
9588  * Parse a return statement.
9589  */
9590 static statement_t *parse_return(void)
9591 {
9592         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9593         eat(T_return);
9594
9595         expression_t *return_value = NULL;
9596         if (token.kind != ';') {
9597                 return_value = parse_expression();
9598                 mark_vars_read(return_value, NULL);
9599         }
9600
9601         const type_t *const func_type = skip_typeref(current_function->base.type);
9602         assert(is_type_function(func_type));
9603         type_t *const return_type = skip_typeref(func_type->function.return_type);
9604
9605         position_t const *const pos = &statement->base.pos;
9606         if (return_value != NULL) {
9607                 type_t *return_value_type = skip_typeref(return_value->base.type);
9608
9609                 if (is_type_void(return_type)) {
9610                         if (!is_type_void(return_value_type)) {
9611                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9612                                 /* Only warn in C mode, because GCC does the same */
9613                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9614                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9615                                 /* Only warn in C mode, because GCC does the same */
9616                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9617                         }
9618                 } else {
9619                         assign_error_t error = semantic_assign(return_type, return_value);
9620                         report_assign_error(error, return_type, return_value, "'return'",
9621                                             pos);
9622                 }
9623                 return_value = create_implicit_cast(return_value, return_type);
9624                 /* check for returning address of a local var */
9625                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9626                         const expression_t *expression = return_value->unary.value;
9627                         if (expression_is_local_variable(expression)) {
9628                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9629                         }
9630                 }
9631         } else if (!is_type_void(return_type)) {
9632                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9633                 err_or_warn(pos, "'return' without value, in function returning non-void");
9634         }
9635         statement->returns.value = return_value;
9636
9637         expect(';');
9638         return statement;
9639 }
9640
9641 /**
9642  * Parse a declaration statement.
9643  */
9644 static statement_t *parse_declaration_statement(void)
9645 {
9646         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9647
9648         entity_t *before = current_scope->last_entity;
9649         if (GNU_MODE) {
9650                 parse_external_declaration();
9651         } else {
9652                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9653         }
9654
9655         declaration_statement_t *const decl  = &statement->declaration;
9656         entity_t                *const begin =
9657                 before != NULL ? before->base.next : current_scope->entities;
9658         decl->declarations_begin = begin;
9659         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9660
9661         return statement;
9662 }
9663
9664 /**
9665  * Parse an expression statement, i.e. expr ';'.
9666  */
9667 static statement_t *parse_expression_statement(void)
9668 {
9669         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9670
9671         expression_t *const expr         = parse_expression();
9672         statement->expression.expression = expr;
9673         mark_vars_read(expr, ENT_ANY);
9674
9675         expect(';');
9676         return statement;
9677 }
9678
9679 /**
9680  * Parse a microsoft __try { } __finally { } or
9681  * __try{ } __except() { }
9682  */
9683 static statement_t *parse_ms_try_statment(void)
9684 {
9685         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9686         eat(T___try);
9687
9688         PUSH_PARENT(statement);
9689
9690         ms_try_statement_t *rem = current_try;
9691         current_try = &statement->ms_try;
9692         statement->ms_try.try_statement = parse_compound_statement(false);
9693         current_try = rem;
9694
9695         POP_PARENT();
9696
9697         if (accept(T___except)) {
9698                 expression_t *const expr = parse_condition();
9699                 type_t       *      type = skip_typeref(expr->base.type);
9700                 if (is_type_integer(type)) {
9701                         type = promote_integer(type);
9702                 } else if (is_type_valid(type)) {
9703                         errorf(&expr->base.pos,
9704                                "__expect expression is not an integer, but '%T'", type);
9705                         type = type_error_type;
9706                 }
9707                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9708         } else if (!accept(T__finally)) {
9709                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9710         }
9711         statement->ms_try.final_statement = parse_compound_statement(false);
9712         return statement;
9713 }
9714
9715 static statement_t *parse_empty_statement(void)
9716 {
9717         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9718         statement_t *const statement = create_empty_statement();
9719         eat(';');
9720         return statement;
9721 }
9722
9723 static statement_t *parse_local_label_declaration(void)
9724 {
9725         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9726
9727         eat(T___label__);
9728
9729         entity_t *begin   = NULL;
9730         entity_t *end     = NULL;
9731         entity_t **anchor = &begin;
9732         add_anchor_token(';');
9733         add_anchor_token(',');
9734         do {
9735                 position_t pos;
9736                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9737                 if (symbol) {
9738                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9739                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9740                                 position_t const *const ppos = &entity->base.pos;
9741                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9742                         } else {
9743                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9744                                 entity->base.parent_scope = current_scope;
9745
9746                                 *anchor = entity;
9747                                 anchor  = &entity->base.next;
9748                                 end     = entity;
9749
9750                                 environment_push(entity);
9751                         }
9752                 }
9753         } while (accept(','));
9754         rem_anchor_token(',');
9755         rem_anchor_token(';');
9756         expect(';');
9757         statement->declaration.declarations_begin = begin;
9758         statement->declaration.declarations_end   = end;
9759         return statement;
9760 }
9761
9762 static void parse_namespace_definition(void)
9763 {
9764         eat(T_namespace);
9765
9766         entity_t *entity = NULL;
9767         symbol_t *symbol = NULL;
9768
9769         if (token.kind == T_IDENTIFIER) {
9770                 symbol = token.base.symbol;
9771                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9772                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9773                         entity = NULL;
9774                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9775                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9776                         }
9777                 }
9778                 eat(T_IDENTIFIER);
9779         }
9780
9781         if (entity == NULL) {
9782                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9783                 entity->base.parent_scope = current_scope;
9784         }
9785
9786         if (token.kind == '=') {
9787                 /* TODO: parse namespace alias */
9788                 panic("namespace alias definition not supported yet");
9789         }
9790
9791         environment_push(entity);
9792         append_entity(current_scope, entity);
9793
9794         PUSH_SCOPE(&entity->namespacee.members);
9795         PUSH_CURRENT_ENTITY(entity);
9796
9797         add_anchor_token('}');
9798         expect('{');
9799         parse_externals();
9800         rem_anchor_token('}');
9801         expect('}');
9802
9803         POP_CURRENT_ENTITY();
9804         POP_SCOPE();
9805 }
9806
9807 /**
9808  * Parse a statement.
9809  * There's also parse_statement() which additionally checks for
9810  * "statement has no effect" warnings
9811  */
9812 static statement_t *intern_parse_statement(void)
9813 {
9814         /* declaration or statement */
9815         statement_t *statement;
9816         switch (token.kind) {
9817         case T_IDENTIFIER: {
9818                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9819                 if (la1_type == ':') {
9820                         statement = parse_label_statement();
9821                 } else if (is_typedef_symbol(token.base.symbol)) {
9822                         statement = parse_declaration_statement();
9823                 } else {
9824                         /* it's an identifier, the grammar says this must be an
9825                          * expression statement. However it is common that users mistype
9826                          * declaration types, so we guess a bit here to improve robustness
9827                          * for incorrect programs */
9828                         switch (la1_type) {
9829                         case '&':
9830                         case '*':
9831                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9832                         default:
9833                                         statement = parse_expression_statement();
9834                                 } else {
9835                         DECLARATION_START
9836                         case T_IDENTIFIER:
9837                                         statement = parse_declaration_statement();
9838                                 }
9839                                 break;
9840                         }
9841                 }
9842                 break;
9843         }
9844
9845         case T___extension__: {
9846                 /* This can be a prefix to a declaration or an expression statement.
9847                  * We simply eat it now and parse the rest with tail recursion. */
9848                 PUSH_EXTENSION();
9849                 statement = intern_parse_statement();
9850                 POP_EXTENSION();
9851                 break;
9852         }
9853
9854         DECLARATION_START
9855                 statement = parse_declaration_statement();
9856                 break;
9857
9858         case T___label__:
9859                 statement = parse_local_label_declaration();
9860                 break;
9861
9862         case ';':         statement = parse_empty_statement();         break;
9863         case '{':         statement = parse_compound_statement(false); break;
9864         case T___leave:   statement = parse_leave_statement();         break;
9865         case T___try:     statement = parse_ms_try_statment();         break;
9866         case T_asm:       statement = parse_asm_statement();           break;
9867         case T_break:     statement = parse_break();                   break;
9868         case T_case:      statement = parse_case_statement();          break;
9869         case T_continue:  statement = parse_continue();                break;
9870         case T_default:   statement = parse_default_statement();       break;
9871         case T_do:        statement = parse_do();                      break;
9872         case T_for:       statement = parse_for();                     break;
9873         case T_goto:      statement = parse_goto();                    break;
9874         case T_if:        statement = parse_if();                      break;
9875         case T_return:    statement = parse_return();                  break;
9876         case T_switch:    statement = parse_switch();                  break;
9877         case T_while:     statement = parse_while();                   break;
9878
9879         EXPRESSION_START
9880                 statement = parse_expression_statement();
9881                 break;
9882
9883         default:
9884                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9885                 statement = create_error_statement();
9886                 eat_until_anchor();
9887                 break;
9888         }
9889
9890         return statement;
9891 }
9892
9893 /**
9894  * parse a statement and emits "statement has no effect" warning if needed
9895  * (This is really a wrapper around intern_parse_statement with check for 1
9896  *  single warning. It is needed, because for statement expressions we have
9897  *  to avoid the warning on the last statement)
9898  */
9899 static statement_t *parse_statement(void)
9900 {
9901         statement_t *statement = intern_parse_statement();
9902
9903         if (statement->kind == STATEMENT_EXPRESSION) {
9904                 expression_t *expression = statement->expression.expression;
9905                 if (!expression_has_effect(expression)) {
9906                         warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9907                                  "statement has no effect");
9908                 }
9909         }
9910
9911         return statement;
9912 }
9913
9914 /**
9915  * Parse a compound statement.
9916  */
9917 static statement_t *parse_compound_statement(bool inside_expression_statement)
9918 {
9919         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9920
9921         PUSH_PARENT(statement);
9922         PUSH_SCOPE(&statement->compound.scope);
9923
9924         eat('{');
9925         add_anchor_token('}');
9926         /* tokens, which can start a statement */
9927         /* TODO MS, __builtin_FOO */
9928         add_anchor_token('!');
9929         add_anchor_token('&');
9930         add_anchor_token('(');
9931         add_anchor_token('*');
9932         add_anchor_token('+');
9933         add_anchor_token('-');
9934         add_anchor_token(';');
9935         add_anchor_token('{');
9936         add_anchor_token('~');
9937         add_anchor_token(T_CHARACTER_CONSTANT);
9938         add_anchor_token(T_COLONCOLON);
9939         add_anchor_token(T_IDENTIFIER);
9940         add_anchor_token(T_MINUSMINUS);
9941         add_anchor_token(T_NUMBER);
9942         add_anchor_token(T_PLUSPLUS);
9943         add_anchor_token(T_STRING_LITERAL);
9944         add_anchor_token(T__Alignof);
9945         add_anchor_token(T__Bool);
9946         add_anchor_token(T__Complex);
9947         add_anchor_token(T__Imaginary);
9948         add_anchor_token(T__Thread_local);
9949         add_anchor_token(T___PRETTY_FUNCTION__);
9950         add_anchor_token(T___attribute__);
9951         add_anchor_token(T___builtin_va_start);
9952         add_anchor_token(T___extension__);
9953         add_anchor_token(T___func__);
9954         add_anchor_token(T___imag__);
9955         add_anchor_token(T___label__);
9956         add_anchor_token(T___real__);
9957         add_anchor_token(T_asm);
9958         add_anchor_token(T_auto);
9959         add_anchor_token(T_bool);
9960         add_anchor_token(T_break);
9961         add_anchor_token(T_case);
9962         add_anchor_token(T_char);
9963         add_anchor_token(T_class);
9964         add_anchor_token(T_const);
9965         add_anchor_token(T_const_cast);
9966         add_anchor_token(T_continue);
9967         add_anchor_token(T_default);
9968         add_anchor_token(T_delete);
9969         add_anchor_token(T_double);
9970         add_anchor_token(T_do);
9971         add_anchor_token(T_dynamic_cast);
9972         add_anchor_token(T_enum);
9973         add_anchor_token(T_extern);
9974         add_anchor_token(T_false);
9975         add_anchor_token(T_float);
9976         add_anchor_token(T_for);
9977         add_anchor_token(T_goto);
9978         add_anchor_token(T_if);
9979         add_anchor_token(T_inline);
9980         add_anchor_token(T_int);
9981         add_anchor_token(T_long);
9982         add_anchor_token(T_new);
9983         add_anchor_token(T_operator);
9984         add_anchor_token(T_register);
9985         add_anchor_token(T_reinterpret_cast);
9986         add_anchor_token(T_restrict);
9987         add_anchor_token(T_return);
9988         add_anchor_token(T_short);
9989         add_anchor_token(T_signed);
9990         add_anchor_token(T_sizeof);
9991         add_anchor_token(T_static);
9992         add_anchor_token(T_static_cast);
9993         add_anchor_token(T_struct);
9994         add_anchor_token(T_switch);
9995         add_anchor_token(T_template);
9996         add_anchor_token(T_this);
9997         add_anchor_token(T_throw);
9998         add_anchor_token(T_true);
9999         add_anchor_token(T_try);
10000         add_anchor_token(T_typedef);
10001         add_anchor_token(T_typeid);
10002         add_anchor_token(T_typename);
10003         add_anchor_token(T_typeof);
10004         add_anchor_token(T_union);
10005         add_anchor_token(T_unsigned);
10006         add_anchor_token(T_using);
10007         add_anchor_token(T_void);
10008         add_anchor_token(T_volatile);
10009         add_anchor_token(T_wchar_t);
10010         add_anchor_token(T_while);
10011
10012         statement_t **anchor            = &statement->compound.statements;
10013         bool          only_decls_so_far = true;
10014         while (token.kind != '}' && token.kind != T_EOF) {
10015                 statement_t *sub_statement = intern_parse_statement();
10016                 if (sub_statement->kind == STATEMENT_ERROR) {
10017                         break;
10018                 }
10019
10020                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10021                         only_decls_so_far = false;
10022                 } else if (!only_decls_so_far) {
10023                         position_t const *const pos = &sub_statement->base.pos;
10024                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10025                 }
10026
10027                 *anchor = sub_statement;
10028                 anchor  = &sub_statement->base.next;
10029         }
10030         expect('}');
10031
10032         /* look over all statements again to produce no effect warnings */
10033         if (is_warn_on(WARN_UNUSED_VALUE)) {
10034                 statement_t *sub_statement = statement->compound.statements;
10035                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10036                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10037                                 continue;
10038                         /* don't emit a warning for the last expression in an expression
10039                          * statement as it has always an effect */
10040                         if (inside_expression_statement && sub_statement->base.next == NULL)
10041                                 continue;
10042
10043                         expression_t *expression = sub_statement->expression.expression;
10044                         if (!expression_has_effect(expression)) {
10045                                 warningf(WARN_UNUSED_VALUE, &expression->base.pos,
10046                                          "statement has no effect");
10047                         }
10048                 }
10049         }
10050
10051         rem_anchor_token(T_while);
10052         rem_anchor_token(T_wchar_t);
10053         rem_anchor_token(T_volatile);
10054         rem_anchor_token(T_void);
10055         rem_anchor_token(T_using);
10056         rem_anchor_token(T_unsigned);
10057         rem_anchor_token(T_union);
10058         rem_anchor_token(T_typeof);
10059         rem_anchor_token(T_typename);
10060         rem_anchor_token(T_typeid);
10061         rem_anchor_token(T_typedef);
10062         rem_anchor_token(T_try);
10063         rem_anchor_token(T_true);
10064         rem_anchor_token(T_throw);
10065         rem_anchor_token(T_this);
10066         rem_anchor_token(T_template);
10067         rem_anchor_token(T_switch);
10068         rem_anchor_token(T_struct);
10069         rem_anchor_token(T_static_cast);
10070         rem_anchor_token(T_static);
10071         rem_anchor_token(T_sizeof);
10072         rem_anchor_token(T_signed);
10073         rem_anchor_token(T_short);
10074         rem_anchor_token(T_return);
10075         rem_anchor_token(T_restrict);
10076         rem_anchor_token(T_reinterpret_cast);
10077         rem_anchor_token(T_register);
10078         rem_anchor_token(T_operator);
10079         rem_anchor_token(T_new);
10080         rem_anchor_token(T_long);
10081         rem_anchor_token(T_int);
10082         rem_anchor_token(T_inline);
10083         rem_anchor_token(T_if);
10084         rem_anchor_token(T_goto);
10085         rem_anchor_token(T_for);
10086         rem_anchor_token(T_float);
10087         rem_anchor_token(T_false);
10088         rem_anchor_token(T_extern);
10089         rem_anchor_token(T_enum);
10090         rem_anchor_token(T_dynamic_cast);
10091         rem_anchor_token(T_do);
10092         rem_anchor_token(T_double);
10093         rem_anchor_token(T_delete);
10094         rem_anchor_token(T_default);
10095         rem_anchor_token(T_continue);
10096         rem_anchor_token(T_const_cast);
10097         rem_anchor_token(T_const);
10098         rem_anchor_token(T_class);
10099         rem_anchor_token(T_char);
10100         rem_anchor_token(T_case);
10101         rem_anchor_token(T_break);
10102         rem_anchor_token(T_bool);
10103         rem_anchor_token(T_auto);
10104         rem_anchor_token(T_asm);
10105         rem_anchor_token(T___real__);
10106         rem_anchor_token(T___label__);
10107         rem_anchor_token(T___imag__);
10108         rem_anchor_token(T___func__);
10109         rem_anchor_token(T___extension__);
10110         rem_anchor_token(T___builtin_va_start);
10111         rem_anchor_token(T___attribute__);
10112         rem_anchor_token(T___PRETTY_FUNCTION__);
10113         rem_anchor_token(T__Thread_local);
10114         rem_anchor_token(T__Imaginary);
10115         rem_anchor_token(T__Complex);
10116         rem_anchor_token(T__Bool);
10117         rem_anchor_token(T__Alignof);
10118         rem_anchor_token(T_STRING_LITERAL);
10119         rem_anchor_token(T_PLUSPLUS);
10120         rem_anchor_token(T_NUMBER);
10121         rem_anchor_token(T_MINUSMINUS);
10122         rem_anchor_token(T_IDENTIFIER);
10123         rem_anchor_token(T_COLONCOLON);
10124         rem_anchor_token(T_CHARACTER_CONSTANT);
10125         rem_anchor_token('~');
10126         rem_anchor_token('{');
10127         rem_anchor_token(';');
10128         rem_anchor_token('-');
10129         rem_anchor_token('+');
10130         rem_anchor_token('*');
10131         rem_anchor_token('(');
10132         rem_anchor_token('&');
10133         rem_anchor_token('!');
10134         rem_anchor_token('}');
10135
10136         POP_SCOPE();
10137         POP_PARENT();
10138         return statement;
10139 }
10140
10141 /**
10142  * Check for unused global static functions and variables
10143  */
10144 static void check_unused_globals(void)
10145 {
10146         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10147                 return;
10148
10149         for (const entity_t *entity = file_scope->entities; entity != NULL;
10150              entity = entity->base.next) {
10151                 if (!is_declaration(entity))
10152                         continue;
10153
10154                 const declaration_t *declaration = &entity->declaration;
10155                 if (declaration->used                  ||
10156                     declaration->modifiers & DM_UNUSED ||
10157                     declaration->modifiers & DM_USED   ||
10158                     declaration->storage_class != STORAGE_CLASS_STATIC)
10159                         continue;
10160
10161                 warning_t   why;
10162                 char const *s;
10163                 if (entity->kind == ENTITY_FUNCTION) {
10164                         /* inhibit warning for static inline functions */
10165                         if (entity->function.is_inline)
10166                                 continue;
10167
10168                         why = WARN_UNUSED_FUNCTION;
10169                         s   = entity->function.body != NULL ? "defined" : "declared";
10170                 } else {
10171                         why = WARN_UNUSED_VARIABLE;
10172                         s   = "defined";
10173                 }
10174
10175                 warningf(why, &declaration->base.pos, "'%#N' %s but not used", entity, s);
10176         }
10177 }
10178
10179 static void parse_global_asm(void)
10180 {
10181         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10182
10183         eat(T_asm);
10184         add_anchor_token(';');
10185         add_anchor_token(')');
10186         add_anchor_token(T_STRING_LITERAL);
10187         expect('(');
10188
10189         rem_anchor_token(T_STRING_LITERAL);
10190         statement->asms.asm_text = parse_string_literals("global asm");
10191         statement->base.next     = unit->global_asm;
10192         unit->global_asm         = statement;
10193
10194         rem_anchor_token(')');
10195         expect(')');
10196         rem_anchor_token(';');
10197         expect(';');
10198 }
10199
10200 static void parse_linkage_specification(void)
10201 {
10202         eat(T_extern);
10203
10204         position_t  const pos     = *HERE;
10205         char const *const linkage = parse_string_literals(NULL).begin;
10206
10207         linkage_kind_t old_linkage = current_linkage;
10208         linkage_kind_t new_linkage;
10209         if (streq(linkage, "C")) {
10210                 new_linkage = LINKAGE_C;
10211         } else if (streq(linkage, "C++")) {
10212                 new_linkage = LINKAGE_CXX;
10213         } else {
10214                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10215                 new_linkage = LINKAGE_C;
10216         }
10217         current_linkage = new_linkage;
10218
10219         if (accept('{')) {
10220                 parse_externals();
10221                 expect('}');
10222         } else {
10223                 parse_external();
10224         }
10225
10226         assert(current_linkage == new_linkage);
10227         current_linkage = old_linkage;
10228 }
10229
10230 static void parse_external(void)
10231 {
10232         switch (token.kind) {
10233                 case T_extern:
10234                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10235                                 parse_linkage_specification();
10236                         } else {
10237                 DECLARATION_START_NO_EXTERN
10238                 case T_IDENTIFIER:
10239                 case T___extension__:
10240                 /* tokens below are for implicit int */
10241                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10242                               implicit int) */
10243                 case '*':  /* * x; -> int* x; */
10244                 case '(':  /* (x); -> int (x); */
10245                                 PUSH_EXTENSION();
10246                                 parse_external_declaration();
10247                                 POP_EXTENSION();
10248                         }
10249                         return;
10250
10251                 case T_asm:
10252                         parse_global_asm();
10253                         return;
10254
10255                 case T_namespace:
10256                         parse_namespace_definition();
10257                         return;
10258
10259                 case ';':
10260                         if (!strict_mode) {
10261                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10262                                 eat(';');
10263                                 return;
10264                         }
10265                         /* FALLTHROUGH */
10266
10267                 default:
10268                         errorf(HERE, "stray %K outside of function", &token);
10269                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10270                                 eat_until_matching_token(token.kind);
10271                         next_token();
10272                         return;
10273         }
10274 }
10275
10276 static void parse_externals(void)
10277 {
10278         add_anchor_token('}');
10279         add_anchor_token(T_EOF);
10280
10281 #ifndef NDEBUG
10282         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10283         unsigned short token_anchor_copy[T_LAST_TOKEN];
10284         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10285 #endif
10286
10287         while (token.kind != T_EOF && token.kind != '}') {
10288 #ifndef NDEBUG
10289                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10290                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10291                         if (count != 0) {
10292                                 /* the anchor set and its copy differs */
10293                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10294                         }
10295                 }
10296                 if (in_gcc_extension) {
10297                         /* an gcc extension scope was not closed */
10298                         internal_errorf(HERE, "Leaked __extension__");
10299                 }
10300 #endif
10301
10302                 parse_external();
10303         }
10304
10305         rem_anchor_token(T_EOF);
10306         rem_anchor_token('}');
10307 }
10308
10309 /**
10310  * Parse a translation unit.
10311  */
10312 static void parse_translation_unit(void)
10313 {
10314         add_anchor_token(T_EOF);
10315
10316         while (true) {
10317                 parse_externals();
10318
10319                 if (token.kind == T_EOF)
10320                         break;
10321
10322                 errorf(HERE, "stray %K outside of function", &token);
10323                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10324                         eat_until_matching_token(token.kind);
10325                 next_token();
10326         }
10327 }
10328
10329 void set_default_visibility(elf_visibility_tag_t visibility)
10330 {
10331         default_visibility = visibility;
10332 }
10333
10334 /**
10335  * Parse the input.
10336  *
10337  * @return  the translation unit or NULL if errors occurred.
10338  */
10339 void start_parsing(void)
10340 {
10341         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10342         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10343
10344         print_to_file(stderr);
10345
10346         assert(unit == NULL);
10347         unit = allocate_ast_zero(sizeof(unit[0]));
10348
10349         assert(file_scope == NULL);
10350         file_scope = &unit->scope;
10351
10352         assert(current_scope == NULL);
10353         scope_push(&unit->scope);
10354
10355         create_gnu_builtins();
10356         if (c_mode & _MS)
10357                 create_microsoft_intrinsics();
10358 }
10359
10360 translation_unit_t *finish_parsing(void)
10361 {
10362         assert(current_scope == &unit->scope);
10363         scope_pop(NULL);
10364
10365         assert(file_scope == &unit->scope);
10366         check_unused_globals();
10367         file_scope = NULL;
10368
10369         DEL_ARR_F(environment_stack);
10370         DEL_ARR_F(label_stack);
10371
10372         translation_unit_t *result = unit;
10373         unit = NULL;
10374         return result;
10375 }
10376
10377 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10378  * are given length one. */
10379 static void complete_incomplete_arrays(void)
10380 {
10381         size_t n = ARR_LEN(incomplete_arrays);
10382         for (size_t i = 0; i != n; ++i) {
10383                 declaration_t *const decl = incomplete_arrays[i];
10384                 type_t        *const type = skip_typeref(decl->type);
10385
10386                 if (!is_type_incomplete(type))
10387                         continue;
10388
10389                 position_t const *const pos = &decl->base.pos;
10390                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10391
10392                 type_t *const new_type = duplicate_type(type);
10393                 new_type->array.size_constant     = true;
10394                 new_type->array.has_implicit_size = true;
10395                 new_type->array.size              = 1;
10396
10397                 type_t *const result = identify_new_type(new_type);
10398
10399                 decl->type = result;
10400         }
10401 }
10402
10403 static void prepare_main_collect2(entity_t *const entity)
10404 {
10405         PUSH_SCOPE(&entity->function.body->compound.scope);
10406
10407         // create call to __main
10408         symbol_t *symbol         = symbol_table_insert("__main");
10409         entity_t *subsubmain_ent
10410                 = create_implicit_function(symbol, &builtin_position);
10411
10412         expression_t *ref     = allocate_expression_zero(EXPR_REFERENCE);
10413         type_t       *ftype   = subsubmain_ent->declaration.type;
10414         ref->base.pos         = builtin_position;
10415         ref->base.type        = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10416         ref->reference.entity = subsubmain_ent;
10417
10418         expression_t *call  = allocate_expression_zero(EXPR_CALL);
10419         call->base.pos      = builtin_position;
10420         call->base.type     = type_void;
10421         call->call.function = ref;
10422
10423         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10424         expr_statement->base.pos              = builtin_position;
10425         expr_statement->expression.expression = call;
10426
10427         statement_t *const body = entity->function.body;
10428         assert(body->kind == STATEMENT_COMPOUND);
10429         compound_statement_t *compounds = &body->compound;
10430
10431         expr_statement->base.next = compounds->statements;
10432         compounds->statements     = expr_statement;
10433
10434         POP_SCOPE();
10435 }
10436
10437 void parse(void)
10438 {
10439         lookahead_bufpos = 0;
10440         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10441                 next_token();
10442         }
10443         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10444         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10445         parse_translation_unit();
10446         complete_incomplete_arrays();
10447         DEL_ARR_F(incomplete_arrays);
10448         incomplete_arrays = NULL;
10449 }
10450
10451 /**
10452  * Initialize the parser.
10453  */
10454 void init_parser(void)
10455 {
10456         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10457
10458         init_expression_parsers();
10459         obstack_init(&temp_obst);
10460 }
10461
10462 /**
10463  * Terminate the parser.
10464  */
10465 void exit_parser(void)
10466 {
10467         obstack_free(&temp_obst, NULL);
10468 }