nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T_WIDE_CHARACTER_CONSTANT:   \
 256         case T_WIDE_STRING_LITERAL:       \
 257         case T___FUNCDNAME__:             \
 258         case T___FUNCSIG__:               \
 259         case T___FUNCTION__:              \
 260         case T___PRETTY_FUNCTION__:       \
 261         case T___alignof__:               \
 262         case T___builtin_classify_type:   \
 263         case T___builtin_constant_p:      \
 264         case T___builtin_isgreater:       \
 265         case T___builtin_isgreaterequal:  \
 266         case T___builtin_isless:          \
 267         case T___builtin_islessequal:     \
 268         case T___builtin_islessgreater:   \
 269         case T___builtin_isunordered:     \
 270         case T___builtin_offsetof:        \
 271         case T___builtin_va_arg:          \
 272         case T___builtin_va_copy:         \
 273         case T___builtin_va_start:        \
 274         case T___func__:                  \
 275         case T___noop:                    \
 276         case T__assume:                   \
 277         case T_delete:                    \
 278         case T_false:                     \
 279         case T_sizeof:                    \
 280         case T_throw:                     \
 281         case T_true:
 282
 283 /**
 284  * Returns the size of a statement node.
 285  *
 286  * @param kind  the statement kind
 287  */
 288 static size_t get_statement_struct_size(statement_kind_t kind)
 289 {
 290         static const size_t sizes[] = {
 291                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 292                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 293                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 294                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 295                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 296                 [STATEMENT_IF]            = sizeof(if_statement_t),
 297                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 298                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 299                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 300                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 301                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 302                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 303                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 304                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 305                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 306                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 307                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 308                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 309                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 310                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 311         };
 312         assert((size_t)kind < lengthof(sizes));
 313         assert(sizes[kind] != 0);
 314         return sizes[kind];
 315 }
 316
 317 /**
 318  * Returns the size of an expression node.
 319  *
 320  * @param kind  the expression kind
 321  */
 322 static size_t get_expression_struct_size(expression_kind_t kind)
 323 {
 324         static const size_t sizes[] = {
 325                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 326                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 327                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 328                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 331                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 332                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 333                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 334                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 335                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 336                 [EXPR_CALL]                       = sizeof(call_expression_t),
 337                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 338                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 339                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 340                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 341                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 342                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 343                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 344                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 345                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 346                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 347                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 348                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 349                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 350                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 351                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 352                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 353                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 354         };
 355         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 356                 return sizes[EXPR_UNARY_FIRST];
 357         }
 358         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 359                 return sizes[EXPR_BINARY_FIRST];
 360         }
 361         assert((size_t)kind < lengthof(sizes));
 362         assert(sizes[kind] != 0);
 363         return sizes[kind];
 364 }
 365
 366 /**
 367  * Allocate a statement node of given kind and initialize all
 368  * fields with zero. Sets its source position to the position
 369  * of the current token.
 370  */
 371 static statement_t *allocate_statement_zero(statement_kind_t kind)
 372 {
 373         size_t       size = get_statement_struct_size(kind);
 374         statement_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.parent          = current_parent;
 378         res->base.source_position = *HERE;
 379         return res;
 380 }
 381
 382 /**
 383  * Allocate an expression node of given kind and initialize all
 384  * fields with zero.
 385  *
 386  * @param kind  the kind of the expression to allocate
 387  */
 388 static expression_t *allocate_expression_zero(expression_kind_t kind)
 389 {
 390         size_t        size = get_expression_struct_size(kind);
 391         expression_t *res  = allocate_ast_zero(size);
 392
 393         res->base.kind            = kind;
 394         res->base.type            = type_error_type;
 395         res->base.source_position = *HERE;
 396         return res;
 397 }
 398
 399 /**
 400  * Creates a new invalid expression at the source position
 401  * of the current token.
 402  */
 403 static expression_t *create_error_expression(void)
 404 {
 405         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 406         expression->base.type = type_error_type;
 407         return expression;
 408 }
 409
 410 /**
 411  * Creates a new invalid statement.
 412  */
 413 static statement_t *create_error_statement(void)
 414 {
 415         return allocate_statement_zero(STATEMENT_ERROR);
 416 }
 417
 418 /**
 419  * Allocate a new empty statement.
 420  */
 421 static statement_t *create_empty_statement(void)
 422 {
 423         return allocate_statement_zero(STATEMENT_EMPTY);
 424 }
 425
 426 /**
 427  * Returns the size of an initializer node.
 428  *
 429  * @param kind  the initializer kind
 430  */
 431 static size_t get_initializer_size(initializer_kind_t kind)
 432 {
 433         static const size_t sizes[] = {
 434                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 435                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 436                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 437                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 438                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 439         };
 440         assert((size_t)kind < lengthof(sizes));
 441         assert(sizes[kind] != 0);
 442         return sizes[kind];
 443 }
 444
 445 /**
 446  * Allocate an initializer node of given kind and initialize all
 447  * fields with zero.
 448  */
 449 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 450 {
 451         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 452         result->kind          = kind;
 453
 454         return result;
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the environment stack.
 459  */
 460 static size_t environment_top(void)
 461 {
 462         return ARR_LEN(environment_stack);
 463 }
 464
 465 /**
 466  * Returns the index of the top element of the global label stack.
 467  */
 468 static size_t label_top(void)
 469 {
 470         return ARR_LEN(label_stack);
 471 }
 472
 473 /**
 474  * Return the next token.
 475  */
 476 static inline void next_token(void)
 477 {
 478         token                              = lookahead_buffer[lookahead_bufpos];
 479         lookahead_buffer[lookahead_bufpos] = lexer_token;
 480         lexer_next_token();
 481
 482         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 483
 484 #ifdef PRINT_TOKENS
 485         print_token(stderr, &token);
 486         fprintf(stderr, "\n");
 487 #endif
 488 }
 489
 490 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 491
 492 static inline bool next_if(token_kind_t const type)
 493 {
 494         if (token.kind == type) {
 495                 eat(type);
 496                 return true;
 497         } else {
 498                 return false;
 499         }
 500 }
 501
 502 /**
 503  * Return the next token with a given lookahead.
 504  */
 505 static inline const token_t *look_ahead(size_t num)
 506 {
 507         assert(0 < num && num <= MAX_LOOKAHEAD);
 508         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 509         return &lookahead_buffer[pos];
 510 }
 511
 512 /**
 513  * Adds a token type to the token type anchor set (a multi-set).
 514  */
 515 static void add_anchor_token(token_kind_t const token_kind)
 516 {
 517         assert(token_kind < T_LAST_TOKEN);
 518         ++token_anchor_set[token_kind];
 519 }
 520
 521 /**
 522  * Remove a token type from the token type anchor set (a multi-set).
 523  */
 524 static void rem_anchor_token(token_kind_t const token_kind)
 525 {
 526         assert(token_kind < T_LAST_TOKEN);
 527         assert(token_anchor_set[token_kind] != 0);
 528         --token_anchor_set[token_kind];
 529 }
 530
 531 /**
 532  * Eat tokens until a matching token type is found.
 533  */
 534 static void eat_until_matching_token(token_kind_t const type)
 535 {
 536         token_kind_t end_token;
 537         switch (type) {
 538                 case '(': end_token = ')';  break;
 539                 case '{': end_token = '}';  break;
 540                 case '[': end_token = ']';  break;
 541                 default:  end_token = type; break;
 542         }
 543
 544         unsigned parenthesis_count = 0;
 545         unsigned brace_count       = 0;
 546         unsigned bracket_count     = 0;
 547         while (token.kind        != end_token ||
 548                parenthesis_count != 0         ||
 549                brace_count       != 0         ||
 550                bracket_count     != 0) {
 551                 switch (token.kind) {
 552                 case T_EOF: return;
 553                 case '(': ++parenthesis_count; break;
 554                 case '{': ++brace_count;       break;
 555                 case '[': ++bracket_count;     break;
 556
 557                 case ')':
 558                         if (parenthesis_count > 0)
 559                                 --parenthesis_count;
 560                         goto check_stop;
 561
 562                 case '}':
 563                         if (brace_count > 0)
 564                                 --brace_count;
 565                         goto check_stop;
 566
 567                 case ']':
 568                         if (bracket_count > 0)
 569                                 --bracket_count;
 570 check_stop:
 571                         if (token.kind        == end_token &&
 572                             parenthesis_count == 0         &&
 573                             brace_count       == 0         &&
 574                             bracket_count     == 0)
 575                                 return;
 576                         break;
 577
 578                 default:
 579                         break;
 580                 }
 581                 next_token();
 582         }
 583 }
 584
 585 /**
 586  * Eat input tokens until an anchor is found.
 587  */
 588 static void eat_until_anchor(void)
 589 {
 590         while (token_anchor_set[token.kind] == 0) {
 591                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 592                         eat_until_matching_token(token.kind);
 593                 next_token();
 594         }
 595 }
 596
 597 /**
 598  * Eat a whole block from input tokens.
 599  */
 600 static void eat_block(void)
 601 {
 602         eat_until_matching_token('{');
 603         next_if('}');
 604 }
 605
 606 /**
 607  * Report a parse error because an expected token was not found.
 608  */
 609 static
 610 #if defined __GNUC__ && __GNUC__ >= 4
 611 __attribute__((sentinel))
 612 #endif
 613 void parse_error_expected(const char *message, ...)
 614 {
 615         if (message != NULL) {
 616                 errorf(HERE, "%s", message);
 617         }
 618         va_list ap;
 619         va_start(ap, message);
 620         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 621         va_end(ap);
 622 }
 623
 624 /**
 625  * Report an incompatible type.
 626  */
 627 static void type_error_incompatible(const char *msg,
 628                 const source_position_t *source_position, type_t *type1, type_t *type2)
 629 {
 630         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 631                msg, type1, type2);
 632 }
 633
 634 /**
 635  * Expect the current token is the expected token.
 636  * If not, generate an error and skip until the next anchor.
 637  */
 638 static void expect(token_kind_t const expected)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(NULL, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return;
 647         }
 648         eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (token.kind != T_IDENTIFIER) {
 654                 parse_error_expected(context, T_IDENTIFIER, NULL);
 655                 add_anchor_token(T_IDENTIFIER);
 656                 eat_until_anchor();
 657                 rem_anchor_token(T_IDENTIFIER);
 658                 if (token.kind != T_IDENTIFIER)
 659                         return NULL;
 660         }
 661         symbol_t *const sym = token.base.symbol;
 662         if (pos)
 663                 *pos = *HERE;
 664         eat(T_IDENTIFIER);
 665         return sym;
 666 }
 667
 668 /**
 669  * Push a given scope on the scope stack and make it the
 670  * current scope
 671  */
 672 static scope_t *scope_push(scope_t *new_scope)
 673 {
 674         if (current_scope != NULL) {
 675                 new_scope->depth = current_scope->depth + 1;
 676         }
 677
 678         scope_t *old_scope = current_scope;
 679         current_scope      = new_scope;
 680         return old_scope;
 681 }
 682
 683 /**
 684  * Pop the current scope from the scope stack.
 685  */
 686 static void scope_pop(scope_t *old_scope)
 687 {
 688         current_scope = old_scope;
 689 }
 690
 691 /**
 692  * Search an entity by its symbol in a given namespace.
 693  */
 694 static entity_t *get_entity(const symbol_t *const symbol,
 695                             namespace_tag_t namespc)
 696 {
 697         entity_t *entity = symbol->entity;
 698         for (; entity != NULL; entity = entity->base.symbol_next) {
 699                 if ((namespace_tag_t)entity->base.namespc == namespc)
 700                         return entity;
 701         }
 702
 703         return NULL;
 704 }
 705
 706 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 707  * possible. */
 708 static entity_t *get_tag(symbol_t const *const symbol,
 709                          entity_kind_tag_t const kind)
 710 {
 711         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 712         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 713                 errorf(HERE,
 714                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 715                                 symbol, &entity->base.source_position);
 716                 entity = NULL;
 717         }
 718         return entity;
 719 }
 720
 721 /**
 722  * pushs an entity on the environment stack and links the corresponding symbol
 723  * it.
 724  */
 725 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 726 {
 727         symbol_t           *symbol  = entity->base.symbol;
 728         entity_namespace_t  namespc = entity->base.namespc;
 729         assert(namespc != 0);
 730
 731         /* replace/add entity into entity list of the symbol */
 732         entity_t **anchor;
 733         entity_t  *iter;
 734         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 735                 iter = *anchor;
 736                 if (iter == NULL)
 737                         break;
 738
 739                 /* replace an entry? */
 740                 if (iter->base.namespc == namespc) {
 741                         entity->base.symbol_next = iter->base.symbol_next;
 742                         break;
 743                 }
 744         }
 745         *anchor = entity;
 746
 747         /* remember old declaration */
 748         stack_entry_t entry;
 749         entry.symbol     = symbol;
 750         entry.old_entity = iter;
 751         entry.namespc    = namespc;
 752         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 753 }
 754
 755 /**
 756  * Push an entity on the environment stack.
 757  */
 758 static void environment_push(entity_t *entity)
 759 {
 760         assert(entity->base.source_position.input_name != NULL);
 761         assert(entity->base.parent_scope != NULL);
 762         stack_push(&environment_stack, entity);
 763 }
 764
 765 /**
 766  * Push a declaration on the global label stack.
 767  *
 768  * @param declaration  the declaration
 769  */
 770 static void label_push(entity_t *label)
 771 {
 772         /* we abuse the parameters scope as parent for the labels */
 773         label->base.parent_scope = &current_function->parameters;
 774         stack_push(&label_stack, label);
 775 }
 776
 777 /**
 778  * pops symbols from the environment stack until @p new_top is the top element
 779  */
 780 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 781 {
 782         stack_entry_t *stack = *stack_ptr;
 783         size_t         top   = ARR_LEN(stack);
 784         size_t         i;
 785
 786         assert(new_top <= top);
 787         if (new_top == top)
 788                 return;
 789
 790         for (i = top; i > new_top; --i) {
 791                 stack_entry_t *entry = &stack[i - 1];
 792
 793                 entity_t           *old_entity = entry->old_entity;
 794                 symbol_t           *symbol     = entry->symbol;
 795                 entity_namespace_t  namespc    = entry->namespc;
 796
 797                 /* replace with old_entity/remove */
 798                 entity_t **anchor;
 799                 entity_t  *iter;
 800                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 801                         iter = *anchor;
 802                         assert(iter != NULL);
 803                         /* replace an entry? */
 804                         if (iter->base.namespc == namespc)
 805                                 break;
 806                 }
 807
 808                 /* restore definition from outer scopes (if there was one) */
 809                 if (old_entity != NULL) {
 810                         old_entity->base.symbol_next = iter->base.symbol_next;
 811                         *anchor                      = old_entity;
 812                 } else {
 813                         /* remove entry from list */
 814                         *anchor = iter->base.symbol_next;
 815                 }
 816         }
 817
 818         ARR_SHRINKLEN(*stack_ptr, new_top);
 819 }
 820
 821 /**
 822  * Pop all entries from the environment stack until the new_top
 823  * is reached.
 824  *
 825  * @param new_top  the new stack top
 826  */
 827 static void environment_pop_to(size_t new_top)
 828 {
 829         stack_pop_to(&environment_stack, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the global label stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void label_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&label_stack, new_top);
 841 }
 842
 843 static atomic_type_kind_t get_akind(const type_t *type)
 844 {
 845         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 846                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 847         return type->atomic.akind;
 848 }
 849
 850 /**
 851  * §6.3.1.1:2  Do integer promotion for a given type.
 852  *
 853  * @param type  the type to promote
 854  * @return the promoted type
 855  */
 856 static type_t *promote_integer(type_t *type)
 857 {
 858         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 859                 type = type_int;
 860
 861         return type;
 862 }
 863
 864 /**
 865  * Check if a given expression represents a null pointer constant.
 866  *
 867  * @param expression  the expression to check
 868  */
 869 static bool is_null_pointer_constant(const expression_t *expression)
 870 {
 871         /* skip void* cast */
 872         if (expression->kind == EXPR_UNARY_CAST) {
 873                 type_t *const type = skip_typeref(expression->base.type);
 874                 if (types_compatible(type, type_void_ptr))
 875                         expression = expression->unary.value;
 876         }
 877
 878         type_t *const type = skip_typeref(expression->base.type);
 879         if (!is_type_integer(type))
 880                 return false;
 881         switch (is_constant_expression(expression)) {
 882                 case EXPR_CLASS_ERROR:    return true;
 883                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 884                 default:                  return false;
 885         }
 886 }
 887
 888 /**
 889  * Create an implicit cast expression.
 890  *
 891  * @param expression  the expression to cast
 892  * @param dest_type   the destination type
 893  */
 894 static expression_t *create_implicit_cast(expression_t *expression,
 895                                           type_t *dest_type)
 896 {
 897         type_t *const source_type = expression->base.type;
 898
 899         if (source_type == dest_type)
 900                 return expression;
 901
 902         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 903         cast->unary.value   = expression;
 904         cast->base.type     = dest_type;
 905         cast->base.implicit = true;
 906
 907         return cast;
 908 }
 909
 910 typedef enum assign_error_t {
 911         ASSIGN_SUCCESS,
 912         ASSIGN_ERROR_INCOMPATIBLE,
 913         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 914         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 915         ASSIGN_WARNING_POINTER_FROM_INT,
 916         ASSIGN_WARNING_INT_FROM_POINTER
 917 } assign_error_t;
 918
 919 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, source_position_t const *const pos)
 920 {
 921         type_t *const orig_type_right = right->base.type;
 922         type_t *const type_left       = skip_typeref(orig_type_left);
 923         type_t *const type_right      = skip_typeref(orig_type_right);
 924
 925         switch (error) {
 926         case ASSIGN_SUCCESS:
 927                 return;
 928         case ASSIGN_ERROR_INCOMPATIBLE:
 929                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 930                 return;
 931
 932         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 933                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 934                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 935
 936                 /* the left type has all qualifiers from the right type */
 937                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 938                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 939                 return;
 940         }
 941
 942         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 943                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_POINTER_FROM_INT:
 947                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         case ASSIGN_WARNING_INT_FROM_POINTER:
 951                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 952                 return;
 953
 954         default:
 955                 panic("invalid error value");
 956         }
 957 }
 958
 959 /** Implements the rules from §6.5.16.1 */
 960 static assign_error_t semantic_assign(type_t *orig_type_left,
 961                                       const expression_t *const right)
 962 {
 963         type_t *const orig_type_right = right->base.type;
 964         type_t *const type_left       = skip_typeref(orig_type_left);
 965         type_t *const type_right      = skip_typeref(orig_type_right);
 966
 967         if (is_type_pointer(type_left)) {
 968                 if (is_null_pointer_constant(right)) {
 969                         return ASSIGN_SUCCESS;
 970                 } else if (is_type_pointer(type_right)) {
 971                         type_t *points_to_left
 972                                 = skip_typeref(type_left->pointer.points_to);
 973                         type_t *points_to_right
 974                                 = skip_typeref(type_right->pointer.points_to);
 975                         assign_error_t res = ASSIGN_SUCCESS;
 976
 977                         /* the left type has all qualifiers from the right type */
 978                         unsigned missing_qualifiers
 979                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 980                         if (missing_qualifiers != 0) {
 981                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 982                         }
 983
 984                         points_to_left  = get_unqualified_type(points_to_left);
 985                         points_to_right = get_unqualified_type(points_to_right);
 986
 987                         if (is_type_void(points_to_left))
 988                                 return res;
 989
 990                         if (is_type_void(points_to_right)) {
 991                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 992                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 993                         }
 994
 995                         if (!types_compatible(points_to_left, points_to_right)) {
 996                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 997                         }
 998
 999                         return res;
1000                 } else if (is_type_integer(type_right)) {
1001                         return ASSIGN_WARNING_POINTER_FROM_INT;
1002                 }
1003         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1004                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1005                                 && is_type_pointer(type_right))) {
1006                 return ASSIGN_SUCCESS;
1007         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1008                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1009                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1010                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1011                         return ASSIGN_SUCCESS;
1012                 }
1013         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1014                 return ASSIGN_WARNING_INT_FROM_POINTER;
1015         }
1016
1017         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1018                 return ASSIGN_SUCCESS;
1019
1020         return ASSIGN_ERROR_INCOMPATIBLE;
1021 }
1022
1023 static expression_t *parse_constant_expression(void)
1024 {
1025         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1026
1027         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1028                 errorf(&result->base.source_position,
1029                        "expression '%E' is not constant", result);
1030         }
1031
1032         return result;
1033 }
1034
1035 static expression_t *parse_assignment_expression(void)
1036 {
1037         return parse_subexpression(PREC_ASSIGNMENT);
1038 }
1039
1040 static void warn_string_concat(const source_position_t *pos)
1041 {
1042         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1043 }
1044
1045 static string_t parse_string_literals(void)
1046 {
1047         assert(token.kind == T_STRING_LITERAL);
1048         string_t result = token.string.string;
1049
1050         eat(T_STRING_LITERAL);
1051
1052         while (token.kind == T_STRING_LITERAL) {
1053                 warn_string_concat(HERE);
1054                 result = concat_strings(&result, &token.string.string);
1055                 eat(T_STRING_LITERAL);
1056         }
1057
1058         return result;
1059 }
1060
1061 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1062 {
1063         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1064         attribute->kind            = kind;
1065         attribute->source_position = *HERE;
1066         return attribute;
1067 }
1068
1069 /**
1070  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1071  *
1072  *  attribute:
1073  *    __attribute__ ( ( attribute-list ) )
1074  *
1075  *  attribute-list:
1076  *    attrib
1077  *    attribute_list , attrib
1078  *
1079  *  attrib:
1080  *    empty
1081  *    any-word
1082  *    any-word ( identifier )
1083  *    any-word ( identifier , nonempty-expr-list )
1084  *    any-word ( expr-list )
1085  *
1086  *  where the "identifier" must not be declared as a type, and
1087  *  "any-word" may be any identifier (including one declared as a
1088  *  type), a reserved word storage class specifier, type specifier or
1089  *  type qualifier.  ??? This still leaves out most reserved keywords
1090  *  (following the old parser), shouldn't we include them, and why not
1091  *  allow identifiers declared as types to start the arguments?
1092  *
1093  *  Matze: this all looks confusing and little systematic, so we're even less
1094  *  strict and parse any list of things which are identifiers or
1095  *  (assignment-)expressions.
1096  */
1097 static attribute_argument_t *parse_attribute_arguments(void)
1098 {
1099         attribute_argument_t  *first  = NULL;
1100         attribute_argument_t **anchor = &first;
1101         if (token.kind != ')') do {
1102                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1103
1104                 /* is it an identifier */
1105                 if (token.kind == T_IDENTIFIER
1106                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1107                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1108                         argument->v.symbol = token.base.symbol;
1109                         eat(T_IDENTIFIER);
1110                 } else {
1111                         /* must be an expression */
1112                         expression_t *expression = parse_assignment_expression();
1113
1114                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1115                         argument->v.expression = expression;
1116                 }
1117
1118                 /* append argument */
1119                 *anchor = argument;
1120                 anchor  = &argument->next;
1121         } while (next_if(','));
1122         expect(')');
1123         return first;
1124 }
1125
1126 static attribute_t *parse_attribute_asm(void)
1127 {
1128         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1129         eat(T_asm);
1130         expect('(');
1131         attribute->a.arguments = parse_attribute_arguments();
1132         return attribute;
1133 }
1134
1135 static attribute_t *parse_attribute_gnu_single(void)
1136 {
1137         /* parse "any-word" */
1138         symbol_t *const symbol = token.base.symbol;
1139         if (symbol == NULL) {
1140                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1141                 return NULL;
1142         }
1143
1144         attribute_kind_t  kind;
1145         char const *const name = symbol->string;
1146         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1147                 if (kind > ATTRIBUTE_GNU_LAST) {
1148                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1149                         /* TODO: we should still save the attribute in the list... */
1150                         kind = ATTRIBUTE_UNKNOWN;
1151                         break;
1152                 }
1153
1154                 const char *attribute_name = get_attribute_name(kind);
1155                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1156                         break;
1157         }
1158
1159         attribute_t *attribute = allocate_attribute_zero(kind);
1160         next_token();
1161
1162         /* parse arguments */
1163         if (next_if('('))
1164                 attribute->a.arguments = parse_attribute_arguments();
1165
1166         return attribute;
1167 }
1168
1169 static attribute_t *parse_attribute_gnu(void)
1170 {
1171         attribute_t  *first  = NULL;
1172         attribute_t **anchor = &first;
1173
1174         eat(T___attribute__);
1175         add_anchor_token(')');
1176         add_anchor_token(',');
1177         expect('(');
1178         expect('(');
1179
1180         if (token.kind != ')') do {
1181                 attribute_t *attribute = parse_attribute_gnu_single();
1182                 if (attribute) {
1183                         *anchor = attribute;
1184                         anchor  = &attribute->next;
1185                 }
1186         } while (next_if(','));
1187         rem_anchor_token(',');
1188         rem_anchor_token(')');
1189
1190         expect(')');
1191         expect(')');
1192         return first;
1193 }
1194
1195 /** Parse attributes. */
1196 static attribute_t *parse_attributes(attribute_t *first)
1197 {
1198         attribute_t **anchor = &first;
1199         for (;;) {
1200                 while (*anchor != NULL)
1201                         anchor = &(*anchor)->next;
1202
1203                 attribute_t *attribute;
1204                 switch (token.kind) {
1205                 case T___attribute__:
1206                         attribute = parse_attribute_gnu();
1207                         if (attribute == NULL)
1208                                 continue;
1209                         break;
1210
1211                 case T_asm:
1212                         attribute = parse_attribute_asm();
1213                         break;
1214
1215                 case T_cdecl:
1216                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1217                         eat(T_cdecl);
1218                         break;
1219
1220                 case T__fastcall:
1221                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1222                         eat(T__fastcall);
1223                         break;
1224
1225                 case T__forceinline:
1226                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1227                         eat(T__forceinline);
1228                         break;
1229
1230                 case T__stdcall:
1231                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1232                         eat(T__stdcall);
1233                         break;
1234
1235                 case T___thiscall:
1236                         /* TODO record modifier */
1237                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1238                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1239                         eat(T___thiscall);
1240                         break;
1241
1242                 default:
1243                         return first;
1244                 }
1245
1246                 *anchor = attribute;
1247                 anchor  = &attribute->next;
1248         }
1249 }
1250
1251 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1252
1253 static entity_t *determine_lhs_ent(expression_t *const expr,
1254                                    entity_t *lhs_ent)
1255 {
1256         switch (expr->kind) {
1257                 case EXPR_REFERENCE: {
1258                         entity_t *const entity = expr->reference.entity;
1259                         /* we should only find variables as lvalues... */
1260                         if (entity->base.kind != ENTITY_VARIABLE
1261                                         && entity->base.kind != ENTITY_PARAMETER)
1262                                 return NULL;
1263
1264                         return entity;
1265                 }
1266
1267                 case EXPR_ARRAY_ACCESS: {
1268                         expression_t *const ref = expr->array_access.array_ref;
1269                         entity_t     *      ent = NULL;
1270                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1271                                 ent     = determine_lhs_ent(ref, lhs_ent);
1272                                 lhs_ent = ent;
1273                         } else {
1274                                 mark_vars_read(ref, lhs_ent);
1275                         }
1276                         mark_vars_read(expr->array_access.index, lhs_ent);
1277                         return ent;
1278                 }
1279
1280                 case EXPR_SELECT: {
1281                         mark_vars_read(expr->select.compound, lhs_ent);
1282                         if (is_type_compound(skip_typeref(expr->base.type)))
1283                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1284                         return NULL;
1285                 }
1286
1287                 case EXPR_UNARY_DEREFERENCE: {
1288                         expression_t *const val = expr->unary.value;
1289                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1290                                 /* *&x is a NOP */
1291                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1292                         } else {
1293                                 mark_vars_read(val, NULL);
1294                                 return NULL;
1295                         }
1296                 }
1297
1298                 default:
1299                         mark_vars_read(expr, NULL);
1300                         return NULL;
1301         }
1302 }
1303
1304 #define ENT_ANY ((entity_t*)-1)
1305
1306 /**
1307  * Mark declarations, which are read.  This is used to detect variables, which
1308  * are never read.
1309  * Example:
1310  * x = x + 1;
1311  *   x is not marked as "read", because it is only read to calculate its own new
1312  *   value.
1313  *
1314  * x += y; y += x;
1315  *   x and y are not detected as "not read", because multiple variables are
1316  *   involved.
1317  */
1318 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1319 {
1320         switch (expr->kind) {
1321                 case EXPR_REFERENCE: {
1322                         entity_t *const entity = expr->reference.entity;
1323                         if (entity->kind != ENTITY_VARIABLE
1324                                         && entity->kind != ENTITY_PARAMETER)
1325                                 return;
1326
1327                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1328                                 entity->variable.read = true;
1329                         }
1330                         return;
1331                 }
1332
1333                 case EXPR_CALL:
1334                         // TODO respect pure/const
1335                         mark_vars_read(expr->call.function, NULL);
1336                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1337                                 mark_vars_read(arg->expression, NULL);
1338                         }
1339                         return;
1340
1341                 case EXPR_CONDITIONAL:
1342                         // TODO lhs_decl should depend on whether true/false have an effect
1343                         mark_vars_read(expr->conditional.condition, NULL);
1344                         if (expr->conditional.true_expression != NULL)
1345                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1346                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1347                         return;
1348
1349                 case EXPR_SELECT:
1350                         if (lhs_ent == ENT_ANY
1351                                         && !is_type_compound(skip_typeref(expr->base.type)))
1352                                 lhs_ent = NULL;
1353                         mark_vars_read(expr->select.compound, lhs_ent);
1354                         return;
1355
1356                 case EXPR_ARRAY_ACCESS: {
1357                         mark_vars_read(expr->array_access.index, lhs_ent);
1358                         expression_t *const ref = expr->array_access.array_ref;
1359                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1360                                 if (lhs_ent == ENT_ANY)
1361                                         lhs_ent = NULL;
1362                         }
1363                         mark_vars_read(ref, lhs_ent);
1364                         return;
1365                 }
1366
1367                 case EXPR_VA_ARG:
1368                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1369                         return;
1370
1371                 case EXPR_VA_COPY:
1372                         mark_vars_read(expr->va_copye.src, lhs_ent);
1373                         return;
1374
1375                 case EXPR_UNARY_CAST:
1376                         /* Special case: Use void cast to mark a variable as "read" */
1377                         if (is_type_void(skip_typeref(expr->base.type)))
1378                                 lhs_ent = NULL;
1379                         goto unary;
1380
1381
1382                 case EXPR_UNARY_THROW:
1383                         if (expr->unary.value == NULL)
1384                                 return;
1385                         /* FALLTHROUGH */
1386                 case EXPR_UNARY_DEREFERENCE:
1387                 case EXPR_UNARY_DELETE:
1388                 case EXPR_UNARY_DELETE_ARRAY:
1389                         if (lhs_ent == ENT_ANY)
1390                                 lhs_ent = NULL;
1391                         goto unary;
1392
1393                 case EXPR_UNARY_NEGATE:
1394                 case EXPR_UNARY_PLUS:
1395                 case EXPR_UNARY_BITWISE_NEGATE:
1396                 case EXPR_UNARY_NOT:
1397                 case EXPR_UNARY_TAKE_ADDRESS:
1398                 case EXPR_UNARY_POSTFIX_INCREMENT:
1399                 case EXPR_UNARY_POSTFIX_DECREMENT:
1400                 case EXPR_UNARY_PREFIX_INCREMENT:
1401                 case EXPR_UNARY_PREFIX_DECREMENT:
1402                 case EXPR_UNARY_ASSUME:
1403 unary:
1404                         mark_vars_read(expr->unary.value, lhs_ent);
1405                         return;
1406
1407                 case EXPR_BINARY_ADD:
1408                 case EXPR_BINARY_SUB:
1409                 case EXPR_BINARY_MUL:
1410                 case EXPR_BINARY_DIV:
1411                 case EXPR_BINARY_MOD:
1412                 case EXPR_BINARY_EQUAL:
1413                 case EXPR_BINARY_NOTEQUAL:
1414                 case EXPR_BINARY_LESS:
1415                 case EXPR_BINARY_LESSEQUAL:
1416                 case EXPR_BINARY_GREATER:
1417                 case EXPR_BINARY_GREATEREQUAL:
1418                 case EXPR_BINARY_BITWISE_AND:
1419                 case EXPR_BINARY_BITWISE_OR:
1420                 case EXPR_BINARY_BITWISE_XOR:
1421                 case EXPR_BINARY_LOGICAL_AND:
1422                 case EXPR_BINARY_LOGICAL_OR:
1423                 case EXPR_BINARY_SHIFTLEFT:
1424                 case EXPR_BINARY_SHIFTRIGHT:
1425                 case EXPR_BINARY_COMMA:
1426                 case EXPR_BINARY_ISGREATER:
1427                 case EXPR_BINARY_ISGREATEREQUAL:
1428                 case EXPR_BINARY_ISLESS:
1429                 case EXPR_BINARY_ISLESSEQUAL:
1430                 case EXPR_BINARY_ISLESSGREATER:
1431                 case EXPR_BINARY_ISUNORDERED:
1432                         mark_vars_read(expr->binary.left,  lhs_ent);
1433                         mark_vars_read(expr->binary.right, lhs_ent);
1434                         return;
1435
1436                 case EXPR_BINARY_ASSIGN:
1437                 case EXPR_BINARY_MUL_ASSIGN:
1438                 case EXPR_BINARY_DIV_ASSIGN:
1439                 case EXPR_BINARY_MOD_ASSIGN:
1440                 case EXPR_BINARY_ADD_ASSIGN:
1441                 case EXPR_BINARY_SUB_ASSIGN:
1442                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1443                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1444                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1445                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1446                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1447                         if (lhs_ent == ENT_ANY)
1448                                 lhs_ent = NULL;
1449                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1450                         mark_vars_read(expr->binary.right, lhs_ent);
1451                         return;
1452                 }
1453
1454                 case EXPR_VA_START:
1455                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1456                         return;
1457
1458                 case EXPR_LITERAL_CASES:
1459                 case EXPR_ERROR:
1460                 case EXPR_STRING_LITERAL:
1461                 case EXPR_WIDE_STRING_LITERAL:
1462                 case EXPR_COMPOUND_LITERAL: // TODO init?
1463                 case EXPR_SIZEOF:
1464                 case EXPR_CLASSIFY_TYPE:
1465                 case EXPR_ALIGNOF:
1466                 case EXPR_FUNCNAME:
1467                 case EXPR_BUILTIN_CONSTANT_P:
1468                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1469                 case EXPR_OFFSETOF:
1470                 case EXPR_STATEMENT: // TODO
1471                 case EXPR_LABEL_ADDRESS:
1472                 case EXPR_ENUM_CONSTANT:
1473                         return;
1474         }
1475
1476         panic("unhandled expression");
1477 }
1478
1479 static designator_t *parse_designation(void)
1480 {
1481         designator_t  *result = NULL;
1482         designator_t **anchor = &result;
1483
1484         for (;;) {
1485                 designator_t *designator;
1486                 switch (token.kind) {
1487                 case '[':
1488                         designator = allocate_ast_zero(sizeof(designator[0]));
1489                         designator->source_position = *HERE;
1490                         eat('[');
1491                         add_anchor_token(']');
1492                         designator->array_index = parse_constant_expression();
1493                         rem_anchor_token(']');
1494                         expect(']');
1495                         break;
1496                 case '.':
1497                         designator = allocate_ast_zero(sizeof(designator[0]));
1498                         designator->source_position = *HERE;
1499                         eat('.');
1500                         designator->symbol = expect_identifier("while parsing designator", NULL);
1501                         if (!designator->symbol)
1502                                 return NULL;
1503                         break;
1504                 default:
1505                         expect('=');
1506                         return result;
1507                 }
1508
1509                 assert(designator != NULL);
1510                 *anchor = designator;
1511                 anchor  = &designator->next;
1512         }
1513 }
1514
1515 static initializer_t *initializer_from_string(array_type_t *const type,
1516                                               const string_t *const string)
1517 {
1518         /* TODO: check len vs. size of array type */
1519         (void) type;
1520
1521         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1522         initializer->string.string = *string;
1523
1524         return initializer;
1525 }
1526
1527 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1528                                                    const string_t *const string)
1529 {
1530         /* TODO: check len vs. size of array type */
1531         (void) type;
1532
1533         initializer_t *const initializer =
1534                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1535         initializer->wide_string.string = *string;
1536
1537         return initializer;
1538 }
1539
1540 /**
1541  * Build an initializer from a given expression.
1542  */
1543 static initializer_t *initializer_from_expression(type_t *orig_type,
1544                                                   expression_t *expression)
1545 {
1546         /* TODO check that expression is a constant expression */
1547
1548         /* §6.7.8.14/15 char array may be initialized by string literals */
1549         type_t *type           = skip_typeref(orig_type);
1550         type_t *expr_type_orig = expression->base.type;
1551         type_t *expr_type      = skip_typeref(expr_type_orig);
1552
1553         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1554                 array_type_t *const array_type   = &type->array;
1555                 type_t       *const element_type = skip_typeref(array_type->element_type);
1556
1557                 if (element_type->kind == TYPE_ATOMIC) {
1558                         atomic_type_kind_t akind = element_type->atomic.akind;
1559                         switch (expression->kind) {
1560                         case EXPR_STRING_LITERAL:
1561                                 if (akind == ATOMIC_TYPE_CHAR
1562                                                 || akind == ATOMIC_TYPE_SCHAR
1563                                                 || akind == ATOMIC_TYPE_UCHAR) {
1564                                         return initializer_from_string(array_type,
1565                                                         &expression->string_literal.value);
1566                                 }
1567                                 break;
1568
1569                         case EXPR_WIDE_STRING_LITERAL: {
1570                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1571                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1572                                         return initializer_from_wide_string(array_type,
1573                                                         &expression->string_literal.value);
1574                                 }
1575                                 break;
1576                         }
1577
1578                         default:
1579                                 break;
1580                         }
1581                 }
1582         }
1583
1584         assign_error_t error = semantic_assign(type, expression);
1585         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1586                 return NULL;
1587         report_assign_error(error, type, expression, "initializer",
1588                             &expression->base.source_position);
1589
1590         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1591         result->value.value = create_implicit_cast(expression, type);
1592
1593         return result;
1594 }
1595
1596 /**
1597  * Parses an scalar initializer.
1598  *
1599  * §6.7.8.11; eat {} without warning
1600  */
1601 static initializer_t *parse_scalar_initializer(type_t *type,
1602                                                bool must_be_constant)
1603 {
1604         /* there might be extra {} hierarchies */
1605         int braces = 0;
1606         if (token.kind == '{') {
1607                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1608                 do {
1609                         eat('{');
1610                         ++braces;
1611                 } while (token.kind == '{');
1612         }
1613
1614         expression_t *expression = parse_assignment_expression();
1615         mark_vars_read(expression, NULL);
1616         if (must_be_constant && !is_linker_constant(expression)) {
1617                 errorf(&expression->base.source_position,
1618                        "initialisation expression '%E' is not constant",
1619                        expression);
1620         }
1621
1622         initializer_t *initializer = initializer_from_expression(type, expression);
1623
1624         if (initializer == NULL) {
1625                 errorf(&expression->base.source_position,
1626                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1627                        expression, expression->base.type, type);
1628                 /* TODO */
1629                 return NULL;
1630         }
1631
1632         bool additional_warning_displayed = false;
1633         while (braces > 0) {
1634                 next_if(',');
1635                 if (token.kind != '}') {
1636                         if (!additional_warning_displayed) {
1637                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1638                                 additional_warning_displayed = true;
1639                         }
1640                 }
1641                 eat_block();
1642                 braces--;
1643         }
1644
1645         return initializer;
1646 }
1647
1648 /**
1649  * An entry in the type path.
1650  */
1651 typedef struct type_path_entry_t type_path_entry_t;
1652 struct type_path_entry_t {
1653         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1654         union {
1655                 size_t         index;          /**< For array types: the current index. */
1656                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1657         } v;
1658 };
1659
1660 /**
1661  * A type path expression a position inside compound or array types.
1662  */
1663 typedef struct type_path_t type_path_t;
1664 struct type_path_t {
1665         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1666         type_t            *top_type;     /**< type of the element the path points */
1667         size_t             max_index;    /**< largest index in outermost array */
1668 };
1669
1670 /**
1671  * Prints a type path for debugging.
1672  */
1673 static __attribute__((unused)) void debug_print_type_path(
1674                 const type_path_t *path)
1675 {
1676         size_t len = ARR_LEN(path->path);
1677
1678         for (size_t i = 0; i < len; ++i) {
1679                 const type_path_entry_t *entry = & path->path[i];
1680
1681                 type_t *type = skip_typeref(entry->type);
1682                 if (is_type_compound(type)) {
1683                         /* in gcc mode structs can have no members */
1684                         if (entry->v.compound_entry == NULL) {
1685                                 assert(i == len-1);
1686                                 continue;
1687                         }
1688                         fprintf(stderr, ".%s",
1689                                 entry->v.compound_entry->base.symbol->string);
1690                 } else if (is_type_array(type)) {
1691                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1692                 } else {
1693                         fprintf(stderr, "-INVALID-");
1694                 }
1695         }
1696         if (path->top_type != NULL) {
1697                 fprintf(stderr, "  (");
1698                 print_type(path->top_type);
1699                 fprintf(stderr, ")");
1700         }
1701 }
1702
1703 /**
1704  * Return the top type path entry, ie. in a path
1705  * (type).a.b returns the b.
1706  */
1707 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1708 {
1709         size_t len = ARR_LEN(path->path);
1710         assert(len > 0);
1711         return &path->path[len-1];
1712 }
1713
1714 /**
1715  * Enlarge the type path by an (empty) element.
1716  */
1717 static type_path_entry_t *append_to_type_path(type_path_t *path)
1718 {
1719         size_t len = ARR_LEN(path->path);
1720         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1721
1722         type_path_entry_t *result = & path->path[len];
1723         memset(result, 0, sizeof(result[0]));
1724         return result;
1725 }
1726
1727 /**
1728  * Descending into a sub-type. Enter the scope of the current top_type.
1729  */
1730 static void descend_into_subtype(type_path_t *path)
1731 {
1732         type_t *orig_top_type = path->top_type;
1733         type_t *top_type      = skip_typeref(orig_top_type);
1734
1735         type_path_entry_t *top = append_to_type_path(path);
1736         top->type              = top_type;
1737
1738         if (is_type_compound(top_type)) {
1739                 compound_t *const compound = top_type->compound.compound;
1740                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1741
1742                 if (entry != NULL) {
1743                         top->v.compound_entry = &entry->declaration;
1744                         path->top_type = entry->declaration.type;
1745                 } else {
1746                         path->top_type = NULL;
1747                 }
1748         } else if (is_type_array(top_type)) {
1749                 top->v.index   = 0;
1750                 path->top_type = top_type->array.element_type;
1751         } else {
1752                 assert(!is_type_valid(top_type));
1753         }
1754 }
1755
1756 /**
1757  * Pop an entry from the given type path, ie. returning from
1758  * (type).a.b to (type).a
1759  */
1760 static void ascend_from_subtype(type_path_t *path)
1761 {
1762         type_path_entry_t *top = get_type_path_top(path);
1763
1764         path->top_type = top->type;
1765
1766         size_t len = ARR_LEN(path->path);
1767         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1768 }
1769
1770 /**
1771  * Pop entries from the given type path until the given
1772  * path level is reached.
1773  */
1774 static void ascend_to(type_path_t *path, size_t top_path_level)
1775 {
1776         size_t len = ARR_LEN(path->path);
1777
1778         while (len > top_path_level) {
1779                 ascend_from_subtype(path);
1780                 len = ARR_LEN(path->path);
1781         }
1782 }
1783
1784 static bool walk_designator(type_path_t *path, const designator_t *designator,
1785                             bool used_in_offsetof)
1786 {
1787         for (; designator != NULL; designator = designator->next) {
1788                 type_path_entry_t *top       = get_type_path_top(path);
1789                 type_t            *orig_type = top->type;
1790
1791                 type_t *type = skip_typeref(orig_type);
1792
1793                 if (designator->symbol != NULL) {
1794                         symbol_t *symbol = designator->symbol;
1795                         if (!is_type_compound(type)) {
1796                                 if (is_type_valid(type)) {
1797                                         errorf(&designator->source_position,
1798                                                "'.%Y' designator used for non-compound type '%T'",
1799                                                symbol, orig_type);
1800                                 }
1801
1802                                 top->type             = type_error_type;
1803                                 top->v.compound_entry = NULL;
1804                                 orig_type             = type_error_type;
1805                         } else {
1806                                 compound_t *compound = type->compound.compound;
1807                                 entity_t   *iter     = compound->members.entities;
1808                                 for (; iter != NULL; iter = iter->base.next) {
1809                                         if (iter->base.symbol == symbol) {
1810                                                 break;
1811                                         }
1812                                 }
1813                                 if (iter == NULL) {
1814                                         errorf(&designator->source_position,
1815                                                "'%T' has no member named '%Y'", orig_type, symbol);
1816                                         return false;
1817                                 }
1818                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1819                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1820                                         errorf(&designator->source_position,
1821                                                    "offsetof designator '%Y' must not specify bitfield",
1822                                                    symbol);
1823                                         return false;
1824                                 }
1825
1826                                 top->type             = orig_type;
1827                                 top->v.compound_entry = &iter->declaration;
1828                                 orig_type             = iter->declaration.type;
1829                         }
1830                 } else {
1831                         expression_t *array_index = designator->array_index;
1832                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1833                                 return true;
1834
1835                         if (!is_type_array(type)) {
1836                                 if (is_type_valid(type)) {
1837                                         errorf(&designator->source_position,
1838                                                "[%E] designator used for non-array type '%T'",
1839                                                array_index, orig_type);
1840                                 }
1841                                 return false;
1842                         }
1843
1844                         long index = fold_constant_to_int(array_index);
1845                         if (!used_in_offsetof) {
1846                                 if (index < 0) {
1847                                         errorf(&designator->source_position,
1848                                                "array index [%E] must be positive", array_index);
1849                                 } else if (type->array.size_constant) {
1850                                         long array_size = type->array.size;
1851                                         if (index >= array_size) {
1852                                                 errorf(&designator->source_position,
1853                                                        "designator [%E] (%d) exceeds array size %d",
1854                                                        array_index, index, array_size);
1855                                         }
1856                                 }
1857                         }
1858
1859                         top->type    = orig_type;
1860                         top->v.index = (size_t) index;
1861                         orig_type    = type->array.element_type;
1862                 }
1863                 path->top_type = orig_type;
1864
1865                 if (designator->next != NULL) {
1866                         descend_into_subtype(path);
1867                 }
1868         }
1869         return true;
1870 }
1871
1872 static void advance_current_object(type_path_t *path, size_t top_path_level)
1873 {
1874         type_path_entry_t *top = get_type_path_top(path);
1875
1876         type_t *type = skip_typeref(top->type);
1877         if (is_type_union(type)) {
1878                 /* in unions only the first element is initialized */
1879                 top->v.compound_entry = NULL;
1880         } else if (is_type_struct(type)) {
1881                 declaration_t *entry = top->v.compound_entry;
1882
1883                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1884                 if (next_entity != NULL) {
1885                         assert(is_declaration(next_entity));
1886                         entry = &next_entity->declaration;
1887                 } else {
1888                         entry = NULL;
1889                 }
1890
1891                 top->v.compound_entry = entry;
1892                 if (entry != NULL) {
1893                         path->top_type = entry->type;
1894                         return;
1895                 }
1896         } else if (is_type_array(type)) {
1897                 assert(is_type_array(type));
1898
1899                 top->v.index++;
1900
1901                 if (!type->array.size_constant || top->v.index < type->array.size) {
1902                         return;
1903                 }
1904         } else {
1905                 assert(!is_type_valid(type));
1906                 return;
1907         }
1908
1909         /* we're past the last member of the current sub-aggregate, try if we
1910          * can ascend in the type hierarchy and continue with another subobject */
1911         size_t len = ARR_LEN(path->path);
1912
1913         if (len > top_path_level) {
1914                 ascend_from_subtype(path);
1915                 advance_current_object(path, top_path_level);
1916         } else {
1917                 path->top_type = NULL;
1918         }
1919 }
1920
1921 /**
1922  * skip any {...} blocks until a closing bracket is reached.
1923  */
1924 static void skip_initializers(void)
1925 {
1926         next_if('{');
1927
1928         while (token.kind != '}') {
1929                 if (token.kind == T_EOF)
1930                         return;
1931                 if (token.kind == '{') {
1932                         eat_block();
1933                         continue;
1934                 }
1935                 next_token();
1936         }
1937 }
1938
1939 static initializer_t *create_empty_initializer(void)
1940 {
1941         static initializer_t empty_initializer
1942                 = { .list = { { INITIALIZER_LIST }, 0 } };
1943         return &empty_initializer;
1944 }
1945
1946 /**
1947  * Parse a part of an initialiser for a struct or union,
1948  */
1949 static initializer_t *parse_sub_initializer(type_path_t *path,
1950                 type_t *outer_type, size_t top_path_level,
1951                 parse_initializer_env_t *env)
1952 {
1953         if (token.kind == '}') {
1954                 /* empty initializer */
1955                 return create_empty_initializer();
1956         }
1957
1958         type_t *orig_type = path->top_type;
1959         type_t *type      = NULL;
1960
1961         if (orig_type == NULL) {
1962                 /* We are initializing an empty compound. */
1963         } else {
1964                 type = skip_typeref(orig_type);
1965         }
1966
1967         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1968
1969         while (true) {
1970                 designator_t *designator = NULL;
1971                 if (token.kind == '.' || token.kind == '[') {
1972                         designator = parse_designation();
1973                         goto finish_designator;
1974                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1975                         /* GNU-style designator ("identifier: value") */
1976                         designator = allocate_ast_zero(sizeof(designator[0]));
1977                         designator->source_position = *HERE;
1978                         designator->symbol          = token.base.symbol;
1979                         eat(T_IDENTIFIER);
1980                         eat(':');
1981
1982 finish_designator:
1983                         /* reset path to toplevel, evaluate designator from there */
1984                         ascend_to(path, top_path_level);
1985                         if (!walk_designator(path, designator, false)) {
1986                                 /* can't continue after designation error */
1987                                 goto end_error;
1988                         }
1989
1990                         initializer_t *designator_initializer
1991                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1992                         designator_initializer->designator.designator = designator;
1993                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1994
1995                         orig_type = path->top_type;
1996                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
1997                 }
1998
1999                 initializer_t *sub;
2000
2001                 if (token.kind == '{') {
2002                         if (type != NULL && is_type_scalar(type)) {
2003                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2004                         } else {
2005                                 if (type == NULL) {
2006                                         if (env->entity != NULL) {
2007                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2008                                         } else {
2009                                                 errorf(HERE, "extra brace group at end of initializer");
2010                                         }
2011                                         eat('{');
2012                                 } else {
2013                                         eat('{');
2014                                         descend_into_subtype(path);
2015                                 }
2016
2017                                 add_anchor_token('}');
2018                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2019                                                             env);
2020                                 rem_anchor_token('}');
2021
2022                                 expect('}');
2023
2024                                 if (!type)
2025                                         goto error_parse_next;
2026
2027                                 ascend_from_subtype(path);
2028                         }
2029                 } else {
2030                         /* must be an expression */
2031                         expression_t *expression = parse_assignment_expression();
2032                         mark_vars_read(expression, NULL);
2033
2034                         if (env->must_be_constant && !is_linker_constant(expression)) {
2035                                 errorf(&expression->base.source_position,
2036                                        "Initialisation expression '%E' is not constant",
2037                                        expression);
2038                         }
2039
2040                         if (type == NULL) {
2041                                 /* we are already outside, ... */
2042                                 if (outer_type == NULL)
2043                                         goto error_parse_next;
2044                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2045                                 if (is_type_compound(outer_type_skip) &&
2046                                                 !outer_type_skip->compound.compound->complete) {
2047                                         goto error_parse_next;
2048                                 }
2049
2050                                 source_position_t const* const pos = &expression->base.source_position;
2051                                 if (env->entity != NULL) {
2052                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2053                                 } else {
2054                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2055                                 }
2056                                 goto error_parse_next;
2057                         }
2058
2059                         /* handle { "string" } special case */
2060                         if ((expression->kind == EXPR_STRING_LITERAL
2061                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2062                                         && outer_type != NULL) {
2063                                 sub = initializer_from_expression(outer_type, expression);
2064                                 if (sub != NULL) {
2065                                         next_if(',');
2066                                         if (token.kind != '}') {
2067                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2068                                         }
2069                                         /* TODO: eat , ... */
2070                                         return sub;
2071                                 }
2072                         }
2073
2074                         /* descend into subtypes until expression matches type */
2075                         while (true) {
2076                                 orig_type = path->top_type;
2077                                 type      = skip_typeref(orig_type);
2078
2079                                 sub = initializer_from_expression(orig_type, expression);
2080                                 if (sub != NULL) {
2081                                         break;
2082                                 }
2083                                 if (!is_type_valid(type)) {
2084                                         goto end_error;
2085                                 }
2086                                 if (is_type_scalar(type)) {
2087                                         errorf(&expression->base.source_position,
2088                                                         "expression '%E' doesn't match expected type '%T'",
2089                                                         expression, orig_type);
2090                                         goto end_error;
2091                                 }
2092
2093                                 descend_into_subtype(path);
2094                         }
2095                 }
2096
2097                 /* update largest index of top array */
2098                 const type_path_entry_t *first      = &path->path[0];
2099                 type_t                  *first_type = first->type;
2100                 first_type                          = skip_typeref(first_type);
2101                 if (is_type_array(first_type)) {
2102                         size_t index = first->v.index;
2103                         if (index > path->max_index)
2104                                 path->max_index = index;
2105                 }
2106
2107                 /* append to initializers list */
2108                 ARR_APP1(initializer_t*, initializers, sub);
2109
2110 error_parse_next:
2111                 if (token.kind == '}') {
2112                         break;
2113                 }
2114                 add_anchor_token('}');
2115                 expect(',');
2116                 rem_anchor_token('}');
2117                 if (token.kind == '}') {
2118                         break;
2119                 }
2120
2121                 if (type != NULL) {
2122                         /* advance to the next declaration if we are not at the end */
2123                         advance_current_object(path, top_path_level);
2124                         orig_type = path->top_type;
2125                         if (orig_type != NULL)
2126                                 type = skip_typeref(orig_type);
2127                         else
2128                                 type = NULL;
2129                 }
2130         }
2131
2132         size_t len  = ARR_LEN(initializers);
2133         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2134         initializer_t *result = allocate_ast_zero(size);
2135         result->kind          = INITIALIZER_LIST;
2136         result->list.len      = len;
2137         memcpy(&result->list.initializers, initializers,
2138                len * sizeof(initializers[0]));
2139
2140         DEL_ARR_F(initializers);
2141         ascend_to(path, top_path_level+1);
2142
2143         return result;
2144
2145 end_error:
2146         skip_initializers();
2147         DEL_ARR_F(initializers);
2148         ascend_to(path, top_path_level+1);
2149         return NULL;
2150 }
2151
2152 static expression_t *make_size_literal(size_t value)
2153 {
2154         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2155         literal->base.type    = type_size_t;
2156
2157         char buf[128];
2158         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2159         literal->literal.value = make_string(buf);
2160
2161         return literal;
2162 }
2163
2164 /**
2165  * Parses an initializer. Parsers either a compound literal
2166  * (env->declaration == NULL) or an initializer of a declaration.
2167  */
2168 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2169 {
2170         type_t        *type      = skip_typeref(env->type);
2171         size_t         max_index = 0;
2172         initializer_t *result;
2173
2174         if (is_type_scalar(type)) {
2175                 result = parse_scalar_initializer(type, env->must_be_constant);
2176         } else if (token.kind == '{') {
2177                 eat('{');
2178
2179                 type_path_t path;
2180                 memset(&path, 0, sizeof(path));
2181                 path.top_type = env->type;
2182                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2183
2184                 descend_into_subtype(&path);
2185
2186                 add_anchor_token('}');
2187                 result = parse_sub_initializer(&path, env->type, 1, env);
2188                 rem_anchor_token('}');
2189
2190                 max_index = path.max_index;
2191                 DEL_ARR_F(path.path);
2192
2193                 expect('}');
2194         } else {
2195                 /* parse_scalar_initializer() also works in this case: we simply
2196                  * have an expression without {} around it */
2197                 result = parse_scalar_initializer(type, env->must_be_constant);
2198         }
2199
2200         /* §6.7.8:22 array initializers for arrays with unknown size determine
2201          * the array type size */
2202         if (is_type_array(type) && type->array.size_expression == NULL
2203                         && result != NULL) {
2204                 size_t size;
2205                 switch (result->kind) {
2206                 case INITIALIZER_LIST:
2207                         assert(max_index != 0xdeadbeaf);
2208                         size = max_index + 1;
2209                         break;
2210
2211                 case INITIALIZER_STRING:
2212                         size = result->string.string.size;
2213                         break;
2214
2215                 case INITIALIZER_WIDE_STRING:
2216                         size = result->wide_string.string.size;
2217                         break;
2218
2219                 case INITIALIZER_DESIGNATOR:
2220                 case INITIALIZER_VALUE:
2221                         /* can happen for parse errors */
2222                         size = 0;
2223                         break;
2224
2225                 default:
2226                         internal_errorf(HERE, "invalid initializer type");
2227                 }
2228
2229                 type_t *new_type = duplicate_type(type);
2230
2231                 new_type->array.size_expression   = make_size_literal(size);
2232                 new_type->array.size_constant     = true;
2233                 new_type->array.has_implicit_size = true;
2234                 new_type->array.size              = size;
2235                 env->type = new_type;
2236         }
2237
2238         return result;
2239 }
2240
2241 static void append_entity(scope_t *scope, entity_t *entity)
2242 {
2243         if (scope->last_entity != NULL) {
2244                 scope->last_entity->base.next = entity;
2245         } else {
2246                 scope->entities = entity;
2247         }
2248         entity->base.parent_entity = current_entity;
2249         scope->last_entity         = entity;
2250 }
2251
2252
2253 static compound_t *parse_compound_type_specifier(bool is_struct)
2254 {
2255         source_position_t const pos = *HERE;
2256         eat(is_struct ? T_struct : T_union);
2257
2258         symbol_t    *symbol     = NULL;
2259         entity_t    *entity     = NULL;
2260         attribute_t *attributes = NULL;
2261
2262         if (token.kind == T___attribute__) {
2263                 attributes = parse_attributes(NULL);
2264         }
2265
2266         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2267         if (token.kind == T_IDENTIFIER) {
2268                 /* the compound has a name, check if we have seen it already */
2269                 symbol = token.base.symbol;
2270                 entity = get_tag(symbol, kind);
2271                 eat(T_IDENTIFIER);
2272
2273                 if (entity != NULL) {
2274                         if (entity->base.parent_scope != current_scope &&
2275                             (token.kind == '{' || token.kind == ';')) {
2276                                 /* we're in an inner scope and have a definition. Shadow
2277                                  * existing definition in outer scope */
2278                                 entity = NULL;
2279                         } else if (entity->compound.complete && token.kind == '{') {
2280                                 source_position_t const *const ppos = &entity->base.source_position;
2281                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2282                                 /* clear members in the hope to avoid further errors */
2283                                 entity->compound.members.entities = NULL;
2284                         }
2285                 }
2286         } else if (token.kind != '{') {
2287                 char const *const msg =
2288                         is_struct ? "while parsing struct type specifier" :
2289                                     "while parsing union type specifier";
2290                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2291
2292                 return NULL;
2293         }
2294
2295         if (entity == NULL) {
2296                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2297                 entity->compound.alignment = 1;
2298                 entity->base.parent_scope  = current_scope;
2299                 if (symbol != NULL) {
2300                         environment_push(entity);
2301                 }
2302                 append_entity(current_scope, entity);
2303         }
2304
2305         if (token.kind == '{') {
2306                 parse_compound_type_entries(&entity->compound);
2307
2308                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2309                 if (symbol == NULL) {
2310                         assert(anonymous_entity == NULL);
2311                         anonymous_entity = entity;
2312                 }
2313         }
2314
2315         if (attributes != NULL) {
2316                 handle_entity_attributes(attributes, entity);
2317         }
2318
2319         return &entity->compound;
2320 }
2321
2322 static void parse_enum_entries(type_t *const enum_type)
2323 {
2324         eat('{');
2325
2326         if (token.kind == '}') {
2327                 errorf(HERE, "empty enum not allowed");
2328                 eat('}');
2329                 return;
2330         }
2331
2332         add_anchor_token('}');
2333         add_anchor_token(',');
2334         do {
2335                 add_anchor_token('=');
2336                 source_position_t pos;
2337                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2338                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2339                 entity->enum_value.enum_type = enum_type;
2340                 rem_anchor_token('=');
2341
2342                 if (next_if('=')) {
2343                         expression_t *value = parse_constant_expression();
2344
2345                         value = create_implicit_cast(value, enum_type);
2346                         entity->enum_value.value = value;
2347
2348                         /* TODO semantic */
2349                 }
2350
2351                 record_entity(entity, false);
2352         } while (next_if(',') && token.kind != '}');
2353         rem_anchor_token(',');
2354         rem_anchor_token('}');
2355
2356         expect('}');
2357 }
2358
2359 static type_t *parse_enum_specifier(void)
2360 {
2361         source_position_t const pos = *HERE;
2362         entity_t               *entity;
2363         symbol_t               *symbol;
2364
2365         eat(T_enum);
2366         switch (token.kind) {
2367                 case T_IDENTIFIER:
2368                         symbol = token.base.symbol;
2369                         entity = get_tag(symbol, ENTITY_ENUM);
2370                         eat(T_IDENTIFIER);
2371
2372                         if (entity != NULL) {
2373                                 if (entity->base.parent_scope != current_scope &&
2374                                                 (token.kind == '{' || token.kind == ';')) {
2375                                         /* we're in an inner scope and have a definition. Shadow
2376                                          * existing definition in outer scope */
2377                                         entity = NULL;
2378                                 } else if (entity->enume.complete && token.kind == '{') {
2379                                         source_position_t const *const ppos = &entity->base.source_position;
2380                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2381                                 }
2382                         }
2383                         break;
2384
2385                 case '{':
2386                         entity = NULL;
2387                         symbol = NULL;
2388                         break;
2389
2390                 default:
2391                         parse_error_expected("while parsing enum type specifier",
2392                                         T_IDENTIFIER, '{', NULL);
2393                         return NULL;
2394         }
2395
2396         if (entity == NULL) {
2397                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2398                 entity->base.parent_scope = current_scope;
2399         }
2400
2401         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2402         type->enumt.enume      = &entity->enume;
2403         type->enumt.base.akind = ATOMIC_TYPE_INT;
2404
2405         if (token.kind == '{') {
2406                 if (symbol != NULL) {
2407                         environment_push(entity);
2408                 }
2409                 append_entity(current_scope, entity);
2410                 entity->enume.complete = true;
2411
2412                 parse_enum_entries(type);
2413                 parse_attributes(NULL);
2414
2415                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2416                 if (symbol == NULL) {
2417                         assert(anonymous_entity == NULL);
2418                         anonymous_entity = entity;
2419                 }
2420         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2421                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2422         }
2423
2424         return type;
2425 }
2426
2427 /**
2428  * if a symbol is a typedef to another type, return true
2429  */
2430 static bool is_typedef_symbol(symbol_t *symbol)
2431 {
2432         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2433         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2434 }
2435
2436 static type_t *parse_typeof(void)
2437 {
2438         eat(T___typeof__);
2439
2440         type_t *type;
2441
2442         add_anchor_token(')');
2443         expect('(');
2444
2445         expression_t *expression  = NULL;
2446
2447         switch (token.kind) {
2448         case T_IDENTIFIER:
2449                 if (is_typedef_symbol(token.base.symbol)) {
2450         DECLARATION_START
2451                         type = parse_typename();
2452                 } else {
2453         default:
2454                         expression = parse_expression();
2455                         type       = revert_automatic_type_conversion(expression);
2456                 }
2457                 break;
2458         }
2459
2460         rem_anchor_token(')');
2461         expect(')');
2462
2463         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2464         typeof_type->typeoft.expression  = expression;
2465         typeof_type->typeoft.typeof_type = type;
2466
2467         return typeof_type;
2468 }
2469
2470 typedef enum specifiers_t {
2471         SPECIFIER_SIGNED    = 1 << 0,
2472         SPECIFIER_UNSIGNED  = 1 << 1,
2473         SPECIFIER_LONG      = 1 << 2,
2474         SPECIFIER_INT       = 1 << 3,
2475         SPECIFIER_DOUBLE    = 1 << 4,
2476         SPECIFIER_CHAR      = 1 << 5,
2477         SPECIFIER_WCHAR_T   = 1 << 6,
2478         SPECIFIER_SHORT     = 1 << 7,
2479         SPECIFIER_LONG_LONG = 1 << 8,
2480         SPECIFIER_FLOAT     = 1 << 9,
2481         SPECIFIER_BOOL      = 1 << 10,
2482         SPECIFIER_VOID      = 1 << 11,
2483         SPECIFIER_INT8      = 1 << 12,
2484         SPECIFIER_INT16     = 1 << 13,
2485         SPECIFIER_INT32     = 1 << 14,
2486         SPECIFIER_INT64     = 1 << 15,
2487         SPECIFIER_INT128    = 1 << 16,
2488         SPECIFIER_COMPLEX   = 1 << 17,
2489         SPECIFIER_IMAGINARY = 1 << 18,
2490 } specifiers_t;
2491
2492 static type_t *get_typedef_type(symbol_t *symbol)
2493 {
2494         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2495         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2496                 return NULL;
2497
2498         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2499         type->typedeft.typedefe = &entity->typedefe;
2500
2501         return type;
2502 }
2503
2504 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2505 {
2506         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2507
2508         add_anchor_token(')');
2509         add_anchor_token(',');
2510         expect('(');
2511
2512         do {
2513                 add_anchor_token('=');
2514                 source_position_t pos;
2515                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2516                 rem_anchor_token('=');
2517
2518                 symbol_t **prop = NULL;
2519                 if (prop_sym) {
2520                         if (streq(prop_sym->string, "put")) {
2521                                 prop = &property->put_symbol;
2522                         } else if (streq(prop_sym->string, "get")) {
2523                                 prop = &property->get_symbol;
2524                         } else {
2525                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2526                         }
2527                 }
2528
2529                 add_anchor_token(T_IDENTIFIER);
2530                 expect('=');
2531                 rem_anchor_token(T_IDENTIFIER);
2532
2533                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2534                 if (prop != NULL)
2535                         *prop = sym ? sym : sym_anonymous;
2536         } while (next_if(','));
2537         rem_anchor_token(',');
2538         rem_anchor_token(')');
2539
2540         attribute->a.property = property;
2541
2542         expect(')');
2543         return attribute;
2544 }
2545
2546 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2547 {
2548         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2549         if (next_if(T_restrict)) {
2550                 kind = ATTRIBUTE_MS_RESTRICT;
2551         } else if (token.kind == T_IDENTIFIER) {
2552                 char const *const name = token.base.symbol->string;
2553                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2554                      ++k) {
2555                         const char *attribute_name = get_attribute_name(k);
2556                         if (attribute_name != NULL && streq(attribute_name, name)) {
2557                                 kind = k;
2558                                 break;
2559                         }
2560                 }
2561
2562                 if (kind == ATTRIBUTE_UNKNOWN) {
2563                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2564                 }
2565         } else {
2566                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2567                 return NULL;
2568         }
2569
2570         attribute_t *attribute = allocate_attribute_zero(kind);
2571         eat(T_IDENTIFIER);
2572
2573         if (kind == ATTRIBUTE_MS_PROPERTY) {
2574                 return parse_attribute_ms_property(attribute);
2575         }
2576
2577         /* parse arguments */
2578         if (next_if('('))
2579                 attribute->a.arguments = parse_attribute_arguments();
2580
2581         return attribute;
2582 }
2583
2584 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2585 {
2586         eat(T__declspec);
2587
2588         add_anchor_token(')');
2589         expect('(');
2590         if (token.kind != ')') {
2591                 attribute_t **anchor = &first;
2592                 do {
2593                         while (*anchor != NULL)
2594                                 anchor = &(*anchor)->next;
2595
2596                         attribute_t *attribute
2597                                 = parse_microsoft_extended_decl_modifier_single();
2598                         if (attribute == NULL)
2599                                 break;
2600
2601                         *anchor = attribute;
2602                         anchor  = &attribute->next;
2603                 } while (next_if(','));
2604         }
2605         rem_anchor_token(')');
2606         expect(')');
2607         return first;
2608 }
2609
2610 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2611 {
2612         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2613         if (is_declaration(entity)) {
2614                 entity->declaration.type     = type_error_type;
2615                 entity->declaration.implicit = true;
2616         } else if (kind == ENTITY_TYPEDEF) {
2617                 entity->typedefe.type    = type_error_type;
2618                 entity->typedefe.builtin = true;
2619         }
2620         if (kind != ENTITY_COMPOUND_MEMBER)
2621                 record_entity(entity, false);
2622         return entity;
2623 }
2624
2625 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2626 {
2627         type_t            *type            = NULL;
2628         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2629         unsigned           type_specifiers = 0;
2630         bool               newtype         = false;
2631         bool               saw_error       = false;
2632
2633         memset(specifiers, 0, sizeof(*specifiers));
2634         specifiers->source_position = *HERE;
2635
2636         while (true) {
2637                 specifiers->attributes = parse_attributes(specifiers->attributes);
2638
2639                 switch (token.kind) {
2640                 /* storage class */
2641 #define MATCH_STORAGE_CLASS(token, class)                                  \
2642                 case token:                                                        \
2643                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2644                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2645                         }                                                              \
2646                         specifiers->storage_class = class;                             \
2647                         if (specifiers->thread_local)                                  \
2648                                 goto check_thread_storage_class;                           \
2649                         eat(token); \
2650                         break;
2651
2652                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2653                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2654                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2655                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2656                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2657
2658                 case T__declspec:
2659                         specifiers->attributes
2660                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2661                         break;
2662
2663                 case T___thread:
2664                         if (specifiers->thread_local) {
2665                                 errorf(HERE, "duplicate '__thread'");
2666                         } else {
2667                                 specifiers->thread_local = true;
2668 check_thread_storage_class:
2669                                 switch (specifiers->storage_class) {
2670                                         case STORAGE_CLASS_EXTERN:
2671                                         case STORAGE_CLASS_NONE:
2672                                         case STORAGE_CLASS_STATIC:
2673                                                 break;
2674
2675                                                 char const* wrong;
2676                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2677                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2678                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2679 wrong_thread_storage_class:
2680                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2681                                                 break;
2682                                 }
2683                         }
2684                         next_token();
2685                         break;
2686
2687                 /* type qualifiers */
2688 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2689                 case token:                                                     \
2690                         qualifiers |= qualifier;                                    \
2691                         eat(token); \
2692                         break
2693
2694                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2695                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2696                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2697                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2698                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2699                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2700                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2701                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2702
2703                 /* type specifiers */
2704 #define MATCH_SPECIFIER(token, specifier, name)                         \
2705                 case token:                                                     \
2706                         if (type_specifiers & specifier) {                           \
2707                                 errorf(HERE, "multiple " name " type specifiers given"); \
2708                         } else {                                                    \
2709                                 type_specifiers |= specifier;                           \
2710                         }                                                           \
2711                         eat(token); \
2712                         break
2713
2714                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2715                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2716                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2717                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2718                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2719                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2720                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2721                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2722                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2723                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2724                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2725                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2726                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2727                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2728                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2729                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2730                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2731                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2732
2733                 case T_inline:
2734                         eat(T_inline);
2735                         specifiers->is_inline = true;
2736                         break;
2737
2738 #if 0
2739                 case T__forceinline:
2740                         eat(T__forceinline);
2741                         specifiers->modifiers |= DM_FORCEINLINE;
2742                         break;
2743 #endif
2744
2745                 case T_long:
2746                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2747                                 errorf(HERE, "too many long type specifiers given");
2748                         } else if (type_specifiers & SPECIFIER_LONG) {
2749                                 type_specifiers |= SPECIFIER_LONG_LONG;
2750                         } else {
2751                                 type_specifiers |= SPECIFIER_LONG;
2752                         }
2753                         eat(T_long);
2754                         break;
2755
2756 #define CHECK_DOUBLE_TYPE() \
2757         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2758
2759                 case T_struct:
2760                         CHECK_DOUBLE_TYPE();
2761                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2762
2763                         type->compound.compound = parse_compound_type_specifier(true);
2764                         break;
2765                 case T_union:
2766                         CHECK_DOUBLE_TYPE();
2767                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2768                         type->compound.compound = parse_compound_type_specifier(false);
2769                         break;
2770                 case T_enum:
2771                         CHECK_DOUBLE_TYPE();
2772                         type = parse_enum_specifier();
2773                         break;
2774                 case T___typeof__:
2775                         CHECK_DOUBLE_TYPE();
2776                         type = parse_typeof();
2777                         break;
2778                 case T___builtin_va_list:
2779                         CHECK_DOUBLE_TYPE();
2780                         type = duplicate_type(type_valist);
2781                         eat(T___builtin_va_list);
2782                         break;
2783
2784                 case T_IDENTIFIER: {
2785                         /* only parse identifier if we haven't found a type yet */
2786                         if (type != NULL || type_specifiers != 0) {
2787                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2788                                  * declaration, so it doesn't generate errors about expecting '(' or
2789                                  * '{' later on. */
2790                                 switch (look_ahead(1)->kind) {
2791                                         STORAGE_CLASSES
2792                                         TYPE_SPECIFIERS
2793                                         case T_const:
2794                                         case T_restrict:
2795                                         case T_volatile:
2796                                         case T_inline:
2797                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2798                                         case T_IDENTIFIER:
2799                                         case '&':
2800                                         case '*':
2801                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2802                                                 eat(T_IDENTIFIER);
2803                                                 continue;
2804
2805                                         default:
2806                                                 goto finish_specifiers;
2807                                 }
2808                         }
2809
2810                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2811                         if (typedef_type == NULL) {
2812                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2813                                  * declaration, so it doesn't generate 'implicit int' followed by more
2814                                  * errors later on. */
2815                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2816                                 switch (la1_type) {
2817                                         DECLARATION_START
2818                                         case T_IDENTIFIER:
2819                                         case '&':
2820                                         case '*': {
2821                                                 errorf(HERE, "%K does not name a type", &token);
2822
2823                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2824
2825                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2826                                                 type->typedeft.typedefe = &entity->typedefe;
2827
2828                                                 eat(T_IDENTIFIER);
2829                                                 saw_error = true;
2830                                                 continue;
2831                                         }
2832
2833                                         default:
2834                                                 goto finish_specifiers;
2835                                 }
2836                         }
2837
2838                         eat(T_IDENTIFIER);
2839                         type = typedef_type;
2840                         break;
2841                 }
2842
2843                 /* function specifier */
2844                 default:
2845                         goto finish_specifiers;
2846                 }
2847         }
2848
2849 finish_specifiers:
2850         specifiers->attributes = parse_attributes(specifiers->attributes);
2851
2852         if (type == NULL || (saw_error && type_specifiers != 0)) {
2853                 atomic_type_kind_t atomic_type;
2854
2855                 /* match valid basic types */
2856                 switch (type_specifiers) {
2857                 case SPECIFIER_VOID:
2858                         atomic_type = ATOMIC_TYPE_VOID;
2859                         break;
2860                 case SPECIFIER_WCHAR_T:
2861                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2862                         break;
2863                 case SPECIFIER_CHAR:
2864                         atomic_type = ATOMIC_TYPE_CHAR;
2865                         break;
2866                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2867                         atomic_type = ATOMIC_TYPE_SCHAR;
2868                         break;
2869                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2870                         atomic_type = ATOMIC_TYPE_UCHAR;
2871                         break;
2872                 case SPECIFIER_SHORT:
2873                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2874                 case SPECIFIER_SHORT | SPECIFIER_INT:
2875                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2876                         atomic_type = ATOMIC_TYPE_SHORT;
2877                         break;
2878                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2879                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2880                         atomic_type = ATOMIC_TYPE_USHORT;
2881                         break;
2882                 case SPECIFIER_INT:
2883                 case SPECIFIER_SIGNED:
2884                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2885                         atomic_type = ATOMIC_TYPE_INT;
2886                         break;
2887                 case SPECIFIER_UNSIGNED:
2888                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2889                         atomic_type = ATOMIC_TYPE_UINT;
2890                         break;
2891                 case SPECIFIER_LONG:
2892                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2893                 case SPECIFIER_LONG | SPECIFIER_INT:
2894                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2895                         atomic_type = ATOMIC_TYPE_LONG;
2896                         break;
2897                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2898                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2899                         atomic_type = ATOMIC_TYPE_ULONG;
2900                         break;
2901
2902                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2903                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2904                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2905                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2906                         | SPECIFIER_INT:
2907                         atomic_type = ATOMIC_TYPE_LONGLONG;
2908                         goto warn_about_long_long;
2909
2910                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2911                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2912                         | SPECIFIER_INT:
2913                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2914 warn_about_long_long:
2915                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2916                         break;
2917
2918                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2919                         atomic_type = unsigned_int8_type_kind;
2920                         break;
2921
2922                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2923                         atomic_type = unsigned_int16_type_kind;
2924                         break;
2925
2926                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2927                         atomic_type = unsigned_int32_type_kind;
2928                         break;
2929
2930                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2931                         atomic_type = unsigned_int64_type_kind;
2932                         break;
2933
2934                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2935                         atomic_type = unsigned_int128_type_kind;
2936                         break;
2937
2938                 case SPECIFIER_INT8:
2939                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2940                         atomic_type = int8_type_kind;
2941                         break;
2942
2943                 case SPECIFIER_INT16:
2944                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2945                         atomic_type = int16_type_kind;
2946                         break;
2947
2948                 case SPECIFIER_INT32:
2949                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2950                         atomic_type = int32_type_kind;
2951                         break;
2952
2953                 case SPECIFIER_INT64:
2954                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2955                         atomic_type = int64_type_kind;
2956                         break;
2957
2958                 case SPECIFIER_INT128:
2959                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2960                         atomic_type = int128_type_kind;
2961                         break;
2962
2963                 case SPECIFIER_FLOAT:
2964                         atomic_type = ATOMIC_TYPE_FLOAT;
2965                         break;
2966                 case SPECIFIER_DOUBLE:
2967                         atomic_type = ATOMIC_TYPE_DOUBLE;
2968                         break;
2969                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2970                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2971                         break;
2972                 case SPECIFIER_BOOL:
2973                         atomic_type = ATOMIC_TYPE_BOOL;
2974                         break;
2975                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2976                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2977                         atomic_type = ATOMIC_TYPE_FLOAT;
2978                         break;
2979                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2980                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2981                         atomic_type = ATOMIC_TYPE_DOUBLE;
2982                         break;
2983                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2984                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2985                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2986                         break;
2987                 default: {
2988                         /* invalid specifier combination, give an error message */
2989                         source_position_t const* const pos = &specifiers->source_position;
2990                         if (type_specifiers == 0) {
2991                                 if (!saw_error) {
2992                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2993                                         if (!(c_mode & _CXX) && !strict_mode) {
2994                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2995                                                 atomic_type = ATOMIC_TYPE_INT;
2996                                                 break;
2997                                         } else {
2998                                                 errorf(pos, "no type specifiers given in declaration");
2999                                         }
3000                                 }
3001                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3002                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3003                                 errorf(pos, "signed and unsigned specifiers given");
3004                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3005                                 errorf(pos, "only integer types can be signed or unsigned");
3006                         } else {
3007                                 errorf(pos, "multiple datatypes in declaration");
3008                         }
3009                         goto end_error;
3010                 }
3011                 }
3012
3013                 if (type_specifiers & SPECIFIER_COMPLEX) {
3014                         type = allocate_type_zero(TYPE_COMPLEX);
3015                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3016                         type = allocate_type_zero(TYPE_IMAGINARY);
3017                 } else {
3018                         type = allocate_type_zero(TYPE_ATOMIC);
3019                 }
3020                 type->atomic.akind = atomic_type;
3021                 newtype = true;
3022         } else if (type_specifiers != 0) {
3023                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3024         }
3025
3026         /* FIXME: check type qualifiers here */
3027         type->base.qualifiers = qualifiers;
3028
3029         if (newtype) {
3030                 type = identify_new_type(type);
3031         } else {
3032                 type = typehash_insert(type);
3033         }
3034
3035         if (specifiers->attributes != NULL)
3036                 type = handle_type_attributes(specifiers->attributes, type);
3037         specifiers->type = type;
3038         return;
3039
3040 end_error:
3041         specifiers->type = type_error_type;
3042 }
3043
3044 static type_qualifiers_t parse_type_qualifiers(void)
3045 {
3046         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3047
3048         while (true) {
3049                 switch (token.kind) {
3050                 /* type qualifiers */
3051                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3052                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3053                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3054                 /* microsoft extended type modifiers */
3055                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3056                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3057                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3058                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3059                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3060
3061                 default:
3062                         return qualifiers;
3063                 }
3064         }
3065 }
3066
3067 /**
3068  * Parses an K&R identifier list
3069  */
3070 static void parse_identifier_list(scope_t *scope)
3071 {
3072         assert(token.kind == T_IDENTIFIER);
3073         do {
3074                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3075                 /* a K&R parameter has no type, yet */
3076                 eat(T_IDENTIFIER);
3077
3078                 if (scope != NULL)
3079                         append_entity(scope, entity);
3080         } while (next_if(',') && token.kind == T_IDENTIFIER);
3081 }
3082
3083 static entity_t *parse_parameter(void)
3084 {
3085         declaration_specifiers_t specifiers;
3086         parse_declaration_specifiers(&specifiers);
3087
3088         entity_t *entity = parse_declarator(&specifiers,
3089                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3090         anonymous_entity = NULL;
3091         return entity;
3092 }
3093
3094 static void semantic_parameter_incomplete(const entity_t *entity)
3095 {
3096         assert(entity->kind == ENTITY_PARAMETER);
3097
3098         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3099          *             list in a function declarator that is part of a
3100          *             definition of that function shall not have
3101          *             incomplete type. */
3102         type_t *type = skip_typeref(entity->declaration.type);
3103         if (is_type_incomplete(type)) {
3104                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3105         }
3106 }
3107
3108 static bool has_parameters(void)
3109 {
3110         /* func(void) is not a parameter */
3111         if (look_ahead(1)->kind != ')')
3112                 return true;
3113         if (token.kind == T_IDENTIFIER) {
3114                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3115                 if (entity == NULL)
3116                         return true;
3117                 if (entity->kind != ENTITY_TYPEDEF)
3118                         return true;
3119                 type_t const *const type = skip_typeref(entity->typedefe.type);
3120                 if (!is_type_void(type))
3121                         return true;
3122                 if (c_mode & _CXX) {
3123                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3124                          * is not allowed. */
3125                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3126                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3127                         /* §6.7.5.3:10  Qualification is not allowed here. */
3128                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3129                 }
3130         } else if (token.kind != T_void) {
3131                 return true;
3132         }
3133         next_token();
3134         return false;
3135 }
3136
3137 /**
3138  * Parses function type parameters (and optionally creates variable_t entities
3139  * for them in a scope)
3140  */
3141 static void parse_parameters(function_type_t *type, scope_t *scope)
3142 {
3143         add_anchor_token(')');
3144         eat('(');
3145
3146         if (token.kind == T_IDENTIFIER            &&
3147             !is_typedef_symbol(token.base.symbol) &&
3148             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3149                 type->kr_style_parameters = true;
3150                 parse_identifier_list(scope);
3151         } else if (token.kind == ')') {
3152                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3153                 if (!(c_mode & _CXX))
3154                         type->unspecified_parameters = true;
3155         } else if (has_parameters()) {
3156                 function_parameter_t **anchor = &type->parameters;
3157                 add_anchor_token(',');
3158                 do {
3159                         switch (token.kind) {
3160                         case T_DOTDOTDOT:
3161                                 eat(T_DOTDOTDOT);
3162                                 type->variadic = true;
3163                                 goto parameters_finished;
3164
3165                         case T_IDENTIFIER:
3166                         DECLARATION_START
3167                         {
3168                                 entity_t *entity = parse_parameter();
3169                                 if (entity->kind == ENTITY_TYPEDEF) {
3170                                         errorf(&entity->base.source_position,
3171                                                         "typedef not allowed as function parameter");
3172                                         break;
3173                                 }
3174                                 assert(is_declaration(entity));
3175
3176                                 semantic_parameter_incomplete(entity);
3177
3178                                 function_parameter_t *const parameter =
3179                                         allocate_parameter(entity->declaration.type);
3180
3181                                 if (scope != NULL) {
3182                                         append_entity(scope, entity);
3183                                 }
3184
3185                                 *anchor = parameter;
3186                                 anchor  = &parameter->next;
3187                                 break;
3188                         }
3189
3190                         default:
3191                                 goto parameters_finished;
3192                         }
3193                 } while (next_if(','));
3194 parameters_finished:
3195                 rem_anchor_token(',');
3196         }
3197
3198         rem_anchor_token(')');
3199         expect(')');
3200 }
3201
3202 typedef enum construct_type_kind_t {
3203         CONSTRUCT_POINTER = 1,
3204         CONSTRUCT_REFERENCE,
3205         CONSTRUCT_FUNCTION,
3206         CONSTRUCT_ARRAY
3207 } construct_type_kind_t;
3208
3209 typedef union construct_type_t construct_type_t;
3210
3211 typedef struct construct_type_base_t {
3212         construct_type_kind_t  kind;
3213         source_position_t      pos;
3214         construct_type_t      *next;
3215 } construct_type_base_t;
3216
3217 typedef struct parsed_pointer_t {
3218         construct_type_base_t  base;
3219         type_qualifiers_t      type_qualifiers;
3220         variable_t            *base_variable;  /**< MS __based extension. */
3221 } parsed_pointer_t;
3222
3223 typedef struct parsed_reference_t {
3224         construct_type_base_t base;
3225 } parsed_reference_t;
3226
3227 typedef struct construct_function_type_t {
3228         construct_type_base_t  base;
3229         type_t                *function_type;
3230 } construct_function_type_t;
3231
3232 typedef struct parsed_array_t {
3233         construct_type_base_t  base;
3234         type_qualifiers_t      type_qualifiers;
3235         bool                   is_static;
3236         bool                   is_variable;
3237         expression_t          *size;
3238 } parsed_array_t;
3239
3240 union construct_type_t {
3241         construct_type_kind_t     kind;
3242         construct_type_base_t     base;
3243         parsed_pointer_t          pointer;
3244         parsed_reference_t        reference;
3245         construct_function_type_t function;
3246         parsed_array_t            array;
3247 };
3248
3249 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3250 {
3251         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3252         memset(cons, 0, size);
3253         cons->kind     = kind;
3254         cons->base.pos = *HERE;
3255         return cons;
3256 }
3257
3258 /* §6.7.5.1 */
3259 static construct_type_t *parse_pointer_declarator(void)
3260 {
3261         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3262         eat('*');
3263         cons->pointer.type_qualifiers = parse_type_qualifiers();
3264         //cons->pointer.base_variable   = base_variable;
3265
3266         return cons;
3267 }
3268
3269 /* ISO/IEC 14882:1998(E) §8.3.2 */
3270 static construct_type_t *parse_reference_declarator(void)
3271 {
3272         if (!(c_mode & _CXX))
3273                 errorf(HERE, "references are only available for C++");
3274
3275         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3276         eat('&');
3277
3278         return cons;
3279 }
3280
3281 /* §6.7.5.2 */
3282 static construct_type_t *parse_array_declarator(void)
3283 {
3284         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3285         parsed_array_t   *const array = &cons->array;
3286
3287         eat('[');
3288         add_anchor_token(']');
3289
3290         bool is_static = next_if(T_static);
3291
3292         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3293
3294         if (!is_static)
3295                 is_static = next_if(T_static);
3296
3297         array->type_qualifiers = type_qualifiers;
3298         array->is_static       = is_static;
3299
3300         expression_t *size = NULL;
3301         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3302                 array->is_variable = true;
3303                 eat('*');
3304         } else if (token.kind != ']') {
3305                 size = parse_assignment_expression();
3306
3307                 /* §6.7.5.2:1  Array size must have integer type */
3308                 type_t *const orig_type = size->base.type;
3309                 type_t *const type      = skip_typeref(orig_type);
3310                 if (!is_type_integer(type) && is_type_valid(type)) {
3311                         errorf(&size->base.source_position,
3312                                "array size '%E' must have integer type but has type '%T'",
3313                                size, orig_type);
3314                 }
3315
3316                 array->size = size;
3317                 mark_vars_read(size, NULL);
3318         }
3319
3320         if (is_static && size == NULL)
3321                 errorf(&array->base.pos, "static array parameters require a size");
3322
3323         rem_anchor_token(']');
3324         expect(']');
3325         return cons;
3326 }
3327
3328 /* §6.7.5.3 */
3329 static construct_type_t *parse_function_declarator(scope_t *scope)
3330 {
3331         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3332
3333         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3334         function_type_t *ftype = &type->function;
3335
3336         ftype->linkage            = current_linkage;
3337         ftype->calling_convention = CC_DEFAULT;
3338
3339         parse_parameters(ftype, scope);
3340
3341         cons->function.function_type = type;
3342
3343         return cons;
3344 }
3345
3346 typedef struct parse_declarator_env_t {
3347         bool               may_be_abstract : 1;
3348         bool               must_be_abstract : 1;
3349         decl_modifiers_t   modifiers;
3350         symbol_t          *symbol;
3351         source_position_t  source_position;
3352         scope_t            parameters;
3353         attribute_t       *attributes;
3354 } parse_declarator_env_t;
3355
3356 /* §6.7.5 */
3357 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3358 {
3359         /* construct a single linked list of construct_type_t's which describe
3360          * how to construct the final declarator type */
3361         construct_type_t  *first      = NULL;
3362         construct_type_t **anchor     = &first;
3363
3364         env->attributes = parse_attributes(env->attributes);
3365
3366         for (;;) {
3367                 construct_type_t *type;
3368                 //variable_t       *based = NULL; /* MS __based extension */
3369                 switch (token.kind) {
3370                         case '&':
3371                                 type = parse_reference_declarator();
3372                                 break;
3373
3374                         case T__based: {
3375                                 panic("based not supported anymore");
3376                                 /* FALLTHROUGH */
3377                         }
3378
3379                         case '*':
3380                                 type = parse_pointer_declarator();
3381                                 break;
3382
3383                         default:
3384                                 goto ptr_operator_end;
3385                 }
3386
3387                 *anchor = type;
3388                 anchor  = &type->base.next;
3389
3390                 /* TODO: find out if this is correct */
3391                 env->attributes = parse_attributes(env->attributes);
3392         }
3393
3394 ptr_operator_end: ;
3395         construct_type_t *inner_types = NULL;
3396
3397         switch (token.kind) {
3398         case T_IDENTIFIER:
3399                 if (env->must_be_abstract) {
3400                         errorf(HERE, "no identifier expected in typename");
3401                 } else {
3402                         env->symbol          = token.base.symbol;
3403                         env->source_position = *HERE;
3404                 }
3405                 eat(T_IDENTIFIER);
3406                 break;
3407
3408         case '(': {
3409                 /* Parenthesized declarator or function declarator? */
3410                 token_t const *const la1 = look_ahead(1);
3411                 switch (la1->kind) {
3412                         case T_IDENTIFIER:
3413                                 if (is_typedef_symbol(la1->base.symbol)) {
3414                         case ')':
3415                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3416                                          * interpreted as ``function with no parameter specification'', rather
3417                                          * than redundant parentheses around the omitted identifier. */
3418                         default:
3419                                         /* Function declarator. */
3420                                         if (!env->may_be_abstract) {
3421                                                 errorf(HERE, "function declarator must have a name");
3422                                         }
3423                                 } else {
3424                         case '&':
3425                         case '(':
3426                         case '*':
3427                         case '[':
3428                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3429                                         /* Paranthesized declarator. */
3430                                         eat('(');
3431                                         add_anchor_token(')');
3432                                         inner_types = parse_inner_declarator(env);
3433                                         if (inner_types != NULL) {
3434                                                 /* All later declarators only modify the return type */
3435                                                 env->must_be_abstract = true;
3436                                         }
3437                                         rem_anchor_token(')');
3438                                         expect(')');
3439                                 }
3440                                 break;
3441                 }
3442                 break;
3443         }
3444
3445         default:
3446                 if (env->may_be_abstract)
3447                         break;
3448                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3449                 eat_until_anchor();
3450                 return NULL;
3451         }
3452
3453         construct_type_t **const p = anchor;
3454
3455         for (;;) {
3456                 construct_type_t *type;
3457                 switch (token.kind) {
3458                 case '(': {
3459                         scope_t *scope = NULL;
3460                         if (!env->must_be_abstract) {
3461                                 scope = &env->parameters;
3462                         }
3463
3464                         type = parse_function_declarator(scope);
3465                         break;
3466                 }
3467                 case '[':
3468                         type = parse_array_declarator();
3469                         break;
3470                 default:
3471                         goto declarator_finished;
3472                 }
3473
3474                 /* insert in the middle of the list (at p) */
3475                 type->base.next = *p;
3476                 *p              = type;
3477                 if (anchor == p)
3478                         anchor = &type->base.next;
3479         }
3480
3481 declarator_finished:
3482         /* append inner_types at the end of the list, we don't to set anchor anymore
3483          * as it's not needed anymore */
3484         *anchor = inner_types;
3485
3486         return first;
3487 }
3488
3489 static type_t *construct_declarator_type(construct_type_t *construct_list,
3490                                          type_t *type)
3491 {
3492         construct_type_t *iter = construct_list;
3493         for (; iter != NULL; iter = iter->base.next) {
3494                 source_position_t const* const pos = &iter->base.pos;
3495                 switch (iter->kind) {
3496                 case CONSTRUCT_FUNCTION: {
3497                         construct_function_type_t *function      = &iter->function;
3498                         type_t                    *function_type = function->function_type;
3499
3500                         function_type->function.return_type = type;
3501
3502                         type_t *skipped_return_type = skip_typeref(type);
3503                         /* §6.7.5.3:1 */
3504                         if (is_type_function(skipped_return_type)) {
3505                                 errorf(pos, "function returning function is not allowed");
3506                         } else if (is_type_array(skipped_return_type)) {
3507                                 errorf(pos, "function returning array is not allowed");
3508                         } else {
3509                                 if (skipped_return_type->base.qualifiers != 0) {
3510                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3511                                 }
3512                         }
3513
3514                         /* The function type was constructed earlier.  Freeing it here will
3515                          * destroy other types. */
3516                         type = typehash_insert(function_type);
3517                         continue;
3518                 }
3519
3520                 case CONSTRUCT_POINTER: {
3521                         if (is_type_reference(skip_typeref(type)))
3522                                 errorf(pos, "cannot declare a pointer to reference");
3523
3524                         parsed_pointer_t *pointer = &iter->pointer;
3525                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3526                         continue;
3527                 }
3528
3529                 case CONSTRUCT_REFERENCE:
3530                         if (is_type_reference(skip_typeref(type)))
3531                                 errorf(pos, "cannot declare a reference to reference");
3532
3533                         type = make_reference_type(type);
3534                         continue;
3535
3536                 case CONSTRUCT_ARRAY: {
3537                         if (is_type_reference(skip_typeref(type)))
3538                                 errorf(pos, "cannot declare an array of references");
3539
3540                         parsed_array_t *array      = &iter->array;
3541                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3542
3543                         expression_t *size_expression = array->size;
3544                         if (size_expression != NULL) {
3545                                 size_expression
3546                                         = create_implicit_cast(size_expression, type_size_t);
3547                         }
3548
3549                         array_type->base.qualifiers       = array->type_qualifiers;
3550                         array_type->array.element_type    = type;
3551                         array_type->array.is_static       = array->is_static;
3552                         array_type->array.is_variable     = array->is_variable;
3553                         array_type->array.size_expression = size_expression;
3554
3555                         if (size_expression != NULL) {
3556                                 switch (is_constant_expression(size_expression)) {
3557                                 case EXPR_CLASS_CONSTANT: {
3558                                         long const size = fold_constant_to_int(size_expression);
3559                                         array_type->array.size          = size;
3560                                         array_type->array.size_constant = true;
3561                                         /* §6.7.5.2:1  If the expression is a constant expression,
3562                                          * it shall have a value greater than zero. */
3563                                         if (size < 0) {
3564                                                 errorf(&size_expression->base.source_position,
3565                                                            "size of array must be greater than zero");
3566                                         } else if (size == 0 && !GNU_MODE) {
3567                                                 errorf(&size_expression->base.source_position,
3568                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3569                                         }
3570                                         break;
3571                                 }
3572
3573                                 case EXPR_CLASS_VARIABLE:
3574                                         array_type->array.is_vla = true;
3575                                         break;
3576
3577                                 case EXPR_CLASS_ERROR:
3578                                         break;
3579                                 }
3580                         }
3581
3582                         type_t *skipped_type = skip_typeref(type);
3583                         /* §6.7.5.2:1 */
3584                         if (is_type_incomplete(skipped_type)) {
3585                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3586                         } else if (is_type_function(skipped_type)) {
3587                                 errorf(pos, "array of functions is not allowed");
3588                         }
3589                         type = identify_new_type(array_type);
3590                         continue;
3591                 }
3592                 }
3593                 internal_errorf(pos, "invalid type construction found");
3594         }
3595
3596         return type;
3597 }
3598
3599 static type_t *automatic_type_conversion(type_t *orig_type);
3600
3601 static type_t *semantic_parameter(const source_position_t *pos,
3602                                   type_t *type,
3603                                   const declaration_specifiers_t *specifiers,
3604                                   entity_t const *const param)
3605 {
3606         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3607          *             shall be adjusted to ``qualified pointer to type'',
3608          *             [...]
3609          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3610          *             type'' shall be adjusted to ``pointer to function
3611          *             returning type'', as in 6.3.2.1. */
3612         type = automatic_type_conversion(type);
3613
3614         if (specifiers->is_inline && is_type_valid(type)) {
3615                 errorf(pos, "'%N' declared 'inline'", param);
3616         }
3617
3618         /* §6.9.1:6  The declarations in the declaration list shall contain
3619          *           no storage-class specifier other than register and no
3620          *           initializations. */
3621         if (specifiers->thread_local || (
3622                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3623                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3624            ) {
3625                 errorf(pos, "invalid storage class for '%N'", param);
3626         }
3627
3628         /* delay test for incomplete type, because we might have (void)
3629          * which is legal but incomplete... */
3630
3631         return type;
3632 }
3633
3634 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3635                                   declarator_flags_t flags)
3636 {
3637         parse_declarator_env_t env;
3638         memset(&env, 0, sizeof(env));
3639         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3640
3641         construct_type_t *construct_type = parse_inner_declarator(&env);
3642         type_t           *orig_type      =
3643                 construct_declarator_type(construct_type, specifiers->type);
3644         type_t           *type           = skip_typeref(orig_type);
3645
3646         if (construct_type != NULL) {
3647                 obstack_free(&temp_obst, construct_type);
3648         }
3649
3650         attribute_t *attributes = parse_attributes(env.attributes);
3651         /* append (shared) specifier attribute behind attributes of this
3652          * declarator */
3653         attribute_t **anchor = &attributes;
3654         while (*anchor != NULL)
3655                 anchor = &(*anchor)->next;
3656         *anchor = specifiers->attributes;
3657
3658         entity_t *entity;
3659         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3660                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3661                 entity->typedefe.type = orig_type;
3662
3663                 if (anonymous_entity != NULL) {
3664                         if (is_type_compound(type)) {
3665                                 assert(anonymous_entity->compound.alias == NULL);
3666                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3667                                        anonymous_entity->kind == ENTITY_UNION);
3668                                 anonymous_entity->compound.alias = entity;
3669                                 anonymous_entity = NULL;
3670                         } else if (is_type_enum(type)) {
3671                                 assert(anonymous_entity->enume.alias == NULL);
3672                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3673                                 anonymous_entity->enume.alias = entity;
3674                                 anonymous_entity = NULL;
3675                         }
3676                 }
3677         } else {
3678                 /* create a declaration type entity */
3679                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3680                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3681                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3682
3683                         if (env.symbol != NULL) {
3684                                 if (specifiers->is_inline && is_type_valid(type)) {
3685                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3686                                 }
3687
3688                                 if (specifiers->thread_local ||
3689                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3690                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3691                                 }
3692                         }
3693                 } else if (flags & DECL_IS_PARAMETER) {
3694                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3695                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3696                 } else if (is_type_function(type)) {
3697                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3698                         entity->function.is_inline      = specifiers->is_inline;
3699                         entity->function.elf_visibility = default_visibility;
3700                         entity->function.parameters     = env.parameters;
3701
3702                         if (env.symbol != NULL) {
3703                                 /* this needs fixes for C++ */
3704                                 bool in_function_scope = current_function != NULL;
3705
3706                                 if (specifiers->thread_local || (
3707                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3708                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3709                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3710                                                 )) {
3711                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3712                                 }
3713                         }
3714                 } else {
3715                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3716                         entity->variable.elf_visibility = default_visibility;
3717                         entity->variable.thread_local   = specifiers->thread_local;
3718
3719                         if (env.symbol != NULL) {
3720                                 if (specifiers->is_inline && is_type_valid(type)) {
3721                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3722                                 }
3723
3724                                 bool invalid_storage_class = false;
3725                                 if (current_scope == file_scope) {
3726                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3727                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3728                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3729                                                 invalid_storage_class = true;
3730                                         }
3731                                 } else {
3732                                         if (specifiers->thread_local &&
3733                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3734                                                 invalid_storage_class = true;
3735                                         }
3736                                 }
3737                                 if (invalid_storage_class) {
3738                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3739                                 }
3740                         }
3741                 }
3742
3743                 entity->declaration.type       = orig_type;
3744                 entity->declaration.alignment  = get_type_alignment(orig_type);
3745                 entity->declaration.modifiers  = env.modifiers;
3746                 entity->declaration.attributes = attributes;
3747
3748                 storage_class_t storage_class = specifiers->storage_class;
3749                 entity->declaration.declared_storage_class = storage_class;
3750
3751                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3752                         storage_class = STORAGE_CLASS_AUTO;
3753                 entity->declaration.storage_class = storage_class;
3754         }
3755
3756         if (attributes != NULL) {
3757                 handle_entity_attributes(attributes, entity);
3758         }
3759
3760         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3761                 adapt_special_functions(&entity->function);
3762         }
3763
3764         return entity;
3765 }
3766
3767 static type_t *parse_abstract_declarator(type_t *base_type)
3768 {
3769         parse_declarator_env_t env;
3770         memset(&env, 0, sizeof(env));
3771         env.may_be_abstract = true;
3772         env.must_be_abstract = true;
3773
3774         construct_type_t *construct_type = parse_inner_declarator(&env);
3775
3776         type_t *result = construct_declarator_type(construct_type, base_type);
3777         if (construct_type != NULL) {
3778                 obstack_free(&temp_obst, construct_type);
3779         }
3780         result = handle_type_attributes(env.attributes, result);
3781
3782         return result;
3783 }
3784
3785 /**
3786  * Check if the declaration of main is suspicious.  main should be a
3787  * function with external linkage, returning int, taking either zero
3788  * arguments, two, or three arguments of appropriate types, ie.
3789  *
3790  * int main([ int argc, char **argv [, char **env ] ]).
3791  *
3792  * @param decl    the declaration to check
3793  * @param type    the function type of the declaration
3794  */
3795 static void check_main(const entity_t *entity)
3796 {
3797         const source_position_t *pos = &entity->base.source_position;
3798         if (entity->kind != ENTITY_FUNCTION) {
3799                 warningf(WARN_MAIN, pos, "'main' is not a function");
3800                 return;
3801         }
3802
3803         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3804                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3805         }
3806
3807         type_t *type = skip_typeref(entity->declaration.type);
3808         assert(is_type_function(type));
3809
3810         function_type_t const *const func_type = &type->function;
3811         type_t                *const ret_type  = func_type->return_type;
3812         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3813                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3814         }
3815         const function_parameter_t *parm = func_type->parameters;
3816         if (parm != NULL) {
3817                 type_t *const first_type        = skip_typeref(parm->type);
3818                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3819                 if (!types_compatible(first_type_unqual, type_int)) {
3820                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3821                 }
3822                 parm = parm->next;
3823                 if (parm != NULL) {
3824                         type_t *const second_type = skip_typeref(parm->type);
3825                         type_t *const second_type_unqual
3826                                 = get_unqualified_type(second_type);
3827                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3828                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3829                         }
3830                         parm = parm->next;
3831                         if (parm != NULL) {
3832                                 type_t *const third_type = skip_typeref(parm->type);
3833                                 type_t *const third_type_unqual
3834                                         = get_unqualified_type(third_type);
3835                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3836                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3837                                 }
3838                                 parm = parm->next;
3839                                 if (parm != NULL)
3840                                         goto warn_arg_count;
3841                         }
3842                 } else {
3843 warn_arg_count:
3844                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3845                 }
3846         }
3847 }
3848
3849 static void error_redefined_as_different_kind(const source_position_t *pos,
3850                 const entity_t *old, entity_kind_t new_kind)
3851 {
3852         char              const *const what = get_entity_kind_name(new_kind);
3853         source_position_t const *const ppos = &old->base.source_position;
3854         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3855 }
3856
3857 static bool is_entity_valid(entity_t *const ent)
3858 {
3859         if (is_declaration(ent)) {
3860                 return is_type_valid(skip_typeref(ent->declaration.type));
3861         } else if (ent->kind == ENTITY_TYPEDEF) {
3862                 return is_type_valid(skip_typeref(ent->typedefe.type));
3863         }
3864         return true;
3865 }
3866
3867 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3868 {
3869         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3870                 if (attributes_equal(tattr, attr))
3871                         return true;
3872         }
3873         return false;
3874 }
3875
3876 /**
3877  * test wether new_list contains any attributes not included in old_list
3878  */
3879 static bool has_new_attributes(const attribute_t *old_list,
3880                                const attribute_t *new_list)
3881 {
3882         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3883                 if (!contains_attribute(old_list, attr))
3884                         return true;
3885         }
3886         return false;
3887 }
3888
3889 /**
3890  * Merge in attributes from an attribute list (probably from a previous
3891  * declaration with the same name). Warning: destroys the old structure
3892  * of the attribute list - don't reuse attributes after this call.
3893  */
3894 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3895 {
3896         attribute_t *next;
3897         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3898                 next = attr->next;
3899                 if (contains_attribute(decl->attributes, attr))
3900                         continue;
3901
3902                 /* move attribute to new declarations attributes list */
3903                 attr->next       = decl->attributes;
3904                 decl->attributes = attr;
3905         }
3906 }
3907
3908 static bool is_main(entity_t*);
3909
3910 /**
3911  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3912  * for various problems that occur for multiple definitions
3913  */
3914 entity_t *record_entity(entity_t *entity, const bool is_definition)
3915 {
3916         const symbol_t *const    symbol  = entity->base.symbol;
3917         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3918         const source_position_t *pos     = &entity->base.source_position;
3919
3920         /* can happen in error cases */
3921         if (symbol == NULL)
3922                 return entity;
3923
3924         assert(!entity->base.parent_scope);
3925         assert(current_scope);
3926         entity->base.parent_scope = current_scope;
3927
3928         entity_t *const previous_entity = get_entity(symbol, namespc);
3929         /* pushing the same entity twice will break the stack structure */
3930         assert(previous_entity != entity);
3931
3932         if (entity->kind == ENTITY_FUNCTION) {
3933                 type_t *const orig_type = entity->declaration.type;
3934                 type_t *const type      = skip_typeref(orig_type);
3935
3936                 assert(is_type_function(type));
3937                 if (type->function.unspecified_parameters &&
3938                     previous_entity == NULL               &&
3939                     !entity->declaration.implicit) {
3940                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3941                 }
3942
3943                 if (is_main(entity)) {
3944                         check_main(entity);
3945                 }
3946         }
3947
3948         if (is_declaration(entity)                                    &&
3949             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3950             current_scope != file_scope                               &&
3951             !entity->declaration.implicit) {
3952                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3953         }
3954
3955         if (previous_entity != NULL) {
3956                 source_position_t const *const ppos = &previous_entity->base.source_position;
3957
3958                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3959                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3960                         assert(previous_entity->kind == ENTITY_PARAMETER);
3961                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3962                         goto finish;
3963                 }
3964
3965                 if (previous_entity->base.parent_scope == current_scope) {
3966                         if (previous_entity->kind != entity->kind) {
3967                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3968                                         error_redefined_as_different_kind(pos, previous_entity,
3969                                                         entity->kind);
3970                                 }
3971                                 goto finish;
3972                         }
3973                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3974                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3975                                 goto finish;
3976                         }
3977                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3978                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3979                                 type_t *const prev_type
3980                                         = skip_typeref(previous_entity->typedefe.type);
3981                                 if (c_mode & _CXX) {
3982                                         /* C++ allows double typedef if they are identical
3983                                          * (after skipping typedefs) */
3984                                         if (type == prev_type)
3985                                                 goto finish;
3986                                 } else {
3987                                         /* GCC extension: redef in system headers is allowed */
3988                                         if ((pos->is_system_header || ppos->is_system_header) &&
3989                                             types_compatible(type, prev_type))
3990                                                 goto finish;
3991                                 }
3992                                 errorf(pos, "redefinition of '%N' (declared %P)",
3993                                        entity, ppos);
3994                                 goto finish;
3995                         }
3996
3997                         /* at this point we should have only VARIABLES or FUNCTIONS */
3998                         assert(is_declaration(previous_entity) && is_declaration(entity));
3999
4000                         declaration_t *const prev_decl = &previous_entity->declaration;
4001                         declaration_t *const decl      = &entity->declaration;
4002
4003                         /* can happen for K&R style declarations */
4004                         if (prev_decl->type       == NULL             &&
4005                                         previous_entity->kind == ENTITY_PARAMETER &&
4006                                         entity->kind          == ENTITY_PARAMETER) {
4007                                 prev_decl->type                   = decl->type;
4008                                 prev_decl->storage_class          = decl->storage_class;
4009                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4010                                 prev_decl->modifiers              = decl->modifiers;
4011                                 return previous_entity;
4012                         }
4013
4014                         type_t *const type      = skip_typeref(decl->type);
4015                         type_t *const prev_type = skip_typeref(prev_decl->type);
4016
4017                         if (!types_compatible(type, prev_type)) {
4018                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4019                         } else {
4020                                 unsigned old_storage_class = prev_decl->storage_class;
4021
4022                                 if (is_definition                     &&
4023                                                 !prev_decl->used                  &&
4024                                                 !(prev_decl->modifiers & DM_USED) &&
4025                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4026                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4027                                 }
4028
4029                                 storage_class_t new_storage_class = decl->storage_class;
4030
4031                                 /* pretend no storage class means extern for function
4032                                  * declarations (except if the previous declaration is neither
4033                                  * none nor extern) */
4034                                 if (entity->kind == ENTITY_FUNCTION) {
4035                                         /* the previous declaration could have unspecified parameters or
4036                                          * be a typedef, so use the new type */
4037                                         if (prev_type->function.unspecified_parameters || is_definition)
4038                                                 prev_decl->type = type;
4039
4040                                         switch (old_storage_class) {
4041                                                 case STORAGE_CLASS_NONE:
4042                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4043                                                         /* FALLTHROUGH */
4044
4045                                                 case STORAGE_CLASS_EXTERN:
4046                                                         if (is_definition) {
4047                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4048                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4049                                                                 }
4050                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4051                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4052                                                         }
4053                                                         break;
4054
4055                                                 default:
4056                                                         break;
4057                                         }
4058                                 } else if (is_type_incomplete(prev_type)) {
4059                                         prev_decl->type = type;
4060                                 }
4061
4062                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4063                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4064
4065 warn_redundant_declaration: ;
4066                                         bool has_new_attrs
4067                                                 = has_new_attributes(prev_decl->attributes,
4068                                                                      decl->attributes);
4069                                         if (has_new_attrs) {
4070                                                 merge_in_attributes(decl, prev_decl->attributes);
4071                                         } else if (!is_definition        &&
4072                                                         is_type_valid(prev_type) &&
4073                                                         !pos->is_system_header) {
4074                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4075                                         }
4076                                 } else if (current_function == NULL) {
4077                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4078                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4079                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4080                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4081                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4082                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4083                                         } else {
4084                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4085                                                 if (c_mode & _CXX)
4086                                                         goto error_redeclaration;
4087                                                 goto warn_redundant_declaration;
4088                                         }
4089                                 } else if (is_type_valid(prev_type)) {
4090                                         if (old_storage_class == new_storage_class) {
4091 error_redeclaration:
4092                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4093                                         } else {
4094                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4095                                         }
4096                                 }
4097                         }
4098
4099                         prev_decl->modifiers |= decl->modifiers;
4100                         if (entity->kind == ENTITY_FUNCTION) {
4101                                 previous_entity->function.is_inline |= entity->function.is_inline;
4102                         }
4103                         return previous_entity;
4104                 }
4105
4106                 warning_t why;
4107                 if (is_warn_on(why = WARN_SHADOW) ||
4108                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4109                         char const *const what = get_entity_kind_name(previous_entity->kind);
4110                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4111                 }
4112         }
4113
4114         if (entity->kind == ENTITY_FUNCTION) {
4115                 if (is_definition &&
4116                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4117                                 !is_main(entity)) {
4118                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4119                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4120                         } else {
4121                                 goto warn_missing_declaration;
4122                         }
4123                 }
4124         } else if (entity->kind == ENTITY_VARIABLE) {
4125                 if (current_scope                     == file_scope &&
4126                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4127                                 !entity->declaration.implicit) {
4128 warn_missing_declaration:
4129                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4130                 }
4131         }
4132
4133 finish:
4134         environment_push(entity);
4135         append_entity(current_scope, entity);
4136
4137         return entity;
4138 }
4139
4140 static void parser_error_multiple_definition(entity_t *entity,
4141                 const source_position_t *source_position)
4142 {
4143         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4144 }
4145
4146 static bool is_declaration_specifier(const token_t *token)
4147 {
4148         switch (token->kind) {
4149                 DECLARATION_START
4150                         return true;
4151                 case T_IDENTIFIER:
4152                         return is_typedef_symbol(token->base.symbol);
4153
4154                 default:
4155                         return false;
4156         }
4157 }
4158
4159 static void parse_init_declarator_rest(entity_t *entity)
4160 {
4161         type_t *orig_type = type_error_type;
4162
4163         if (entity->base.kind == ENTITY_TYPEDEF) {
4164                 source_position_t const *const pos = &entity->base.source_position;
4165                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4166         } else {
4167                 assert(is_declaration(entity));
4168                 orig_type = entity->declaration.type;
4169         }
4170
4171         type_t *type = skip_typeref(orig_type);
4172
4173         if (entity->kind == ENTITY_VARIABLE
4174                         && entity->variable.initializer != NULL) {
4175                 parser_error_multiple_definition(entity, HERE);
4176         }
4177         eat('=');
4178
4179         declaration_t *const declaration = &entity->declaration;
4180         bool must_be_constant = false;
4181         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4182             entity->base.parent_scope  == file_scope) {
4183                 must_be_constant = true;
4184         }
4185
4186         if (is_type_function(type)) {
4187                 source_position_t const *const pos = &entity->base.source_position;
4188                 errorf(pos, "'%N' is initialized like a variable", entity);
4189                 orig_type = type_error_type;
4190         }
4191
4192         parse_initializer_env_t env;
4193         env.type             = orig_type;
4194         env.must_be_constant = must_be_constant;
4195         env.entity           = entity;
4196
4197         initializer_t *initializer = parse_initializer(&env);
4198
4199         if (entity->kind == ENTITY_VARIABLE) {
4200                 /* §6.7.5:22  array initializers for arrays with unknown size
4201                  * determine the array type size */
4202                 declaration->type            = env.type;
4203                 entity->variable.initializer = initializer;
4204         }
4205 }
4206
4207 /* parse rest of a declaration without any declarator */
4208 static void parse_anonymous_declaration_rest(
4209                 const declaration_specifiers_t *specifiers)
4210 {
4211         eat(';');
4212         anonymous_entity = NULL;
4213
4214         source_position_t const *const pos = &specifiers->source_position;
4215         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4216                         specifiers->thread_local) {
4217                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4218         }
4219
4220         type_t *type = specifiers->type;
4221         switch (type->kind) {
4222                 case TYPE_COMPOUND_STRUCT:
4223                 case TYPE_COMPOUND_UNION: {
4224                         if (type->compound.compound->base.symbol == NULL) {
4225                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4226                         }
4227                         break;
4228                 }
4229
4230                 case TYPE_ENUM:
4231                         break;
4232
4233                 default:
4234                         warningf(WARN_OTHER, pos, "empty declaration");
4235                         break;
4236         }
4237 }
4238
4239 static void check_variable_type_complete(entity_t *ent)
4240 {
4241         if (ent->kind != ENTITY_VARIABLE)
4242                 return;
4243
4244         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4245          *         type for the object shall be complete [...] */
4246         declaration_t *decl = &ent->declaration;
4247         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4248                         decl->storage_class == STORAGE_CLASS_STATIC)
4249                 return;
4250
4251         type_t *const type = skip_typeref(decl->type);
4252         if (!is_type_incomplete(type))
4253                 return;
4254
4255         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4256          * are given length one. */
4257         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4258                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4259                 return;
4260         }
4261
4262         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4263 }
4264
4265
4266 static void parse_declaration_rest(entity_t *ndeclaration,
4267                 const declaration_specifiers_t *specifiers,
4268                 parsed_declaration_func         finished_declaration,
4269                 declarator_flags_t              flags)
4270 {
4271         add_anchor_token(';');
4272         add_anchor_token(',');
4273         while (true) {
4274                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4275
4276                 if (token.kind == '=') {
4277                         parse_init_declarator_rest(entity);
4278                 } else if (entity->kind == ENTITY_VARIABLE) {
4279                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4280                          * [...] where the extern specifier is explicitly used. */
4281                         declaration_t *decl = &entity->declaration;
4282                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4283                             is_type_reference(skip_typeref(decl->type))) {
4284                                 source_position_t const *const pos = &entity->base.source_position;
4285                                 errorf(pos, "reference '%#N' must be initialized", entity);
4286                         }
4287                 }
4288
4289                 check_variable_type_complete(entity);
4290
4291                 if (!next_if(','))
4292                         break;
4293
4294                 add_anchor_token('=');
4295                 ndeclaration = parse_declarator(specifiers, flags);
4296                 rem_anchor_token('=');
4297         }
4298         rem_anchor_token(',');
4299         rem_anchor_token(';');
4300         expect(';');
4301
4302         anonymous_entity = NULL;
4303 }
4304
4305 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4306 {
4307         symbol_t *symbol = entity->base.symbol;
4308         if (symbol == NULL)
4309                 return entity;
4310
4311         assert(entity->base.namespc == NAMESPACE_NORMAL);
4312         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4313         if (previous_entity == NULL
4314                         || previous_entity->base.parent_scope != current_scope) {
4315                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4316                        symbol);
4317                 return entity;
4318         }
4319
4320         if (is_definition) {
4321                 errorf(HERE, "'%N' is initialised", entity);
4322         }
4323
4324         return record_entity(entity, false);
4325 }
4326
4327 static void parse_declaration(parsed_declaration_func finished_declaration,
4328                               declarator_flags_t      flags)
4329 {
4330         add_anchor_token(';');
4331         declaration_specifiers_t specifiers;
4332         parse_declaration_specifiers(&specifiers);
4333         rem_anchor_token(';');
4334
4335         if (token.kind == ';') {
4336                 parse_anonymous_declaration_rest(&specifiers);
4337         } else {
4338                 entity_t *entity = parse_declarator(&specifiers, flags);
4339                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4340         }
4341 }
4342
4343 /* §6.5.2.2:6 */
4344 static type_t *get_default_promoted_type(type_t *orig_type)
4345 {
4346         type_t *result = orig_type;
4347
4348         type_t *type = skip_typeref(orig_type);
4349         if (is_type_integer(type)) {
4350                 result = promote_integer(type);
4351         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4352                 result = type_double;
4353         }
4354
4355         return result;
4356 }
4357
4358 static void parse_kr_declaration_list(entity_t *entity)
4359 {
4360         if (entity->kind != ENTITY_FUNCTION)
4361                 return;
4362
4363         type_t *type = skip_typeref(entity->declaration.type);
4364         assert(is_type_function(type));
4365         if (!type->function.kr_style_parameters)
4366                 return;
4367
4368         add_anchor_token('{');
4369
4370         PUSH_SCOPE(&entity->function.parameters);
4371
4372         entity_t *parameter = entity->function.parameters.entities;
4373         for ( ; parameter != NULL; parameter = parameter->base.next) {
4374                 assert(parameter->base.parent_scope == NULL);
4375                 parameter->base.parent_scope = current_scope;
4376                 environment_push(parameter);
4377         }
4378
4379         /* parse declaration list */
4380         for (;;) {
4381                 switch (token.kind) {
4382                         DECLARATION_START
4383                         /* This covers symbols, which are no type, too, and results in
4384                          * better error messages.  The typical cases are misspelled type
4385                          * names and missing includes. */
4386                         case T_IDENTIFIER:
4387                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4388                                 break;
4389                         default:
4390                                 goto decl_list_end;
4391                 }
4392         }
4393 decl_list_end:
4394
4395         POP_SCOPE();
4396
4397         /* update function type */
4398         type_t *new_type = duplicate_type(type);
4399
4400         function_parameter_t  *parameters = NULL;
4401         function_parameter_t **anchor     = &parameters;
4402
4403         /* did we have an earlier prototype? */
4404         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4405         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4406                 proto_type = NULL;
4407
4408         function_parameter_t *proto_parameter = NULL;
4409         if (proto_type != NULL) {
4410                 type_t *proto_type_type = proto_type->declaration.type;
4411                 proto_parameter         = proto_type_type->function.parameters;
4412                 /* If a K&R function definition has a variadic prototype earlier, then
4413                  * make the function definition variadic, too. This should conform to
4414                  * §6.7.5.3:15 and §6.9.1:8. */
4415                 new_type->function.variadic = proto_type_type->function.variadic;
4416         } else {
4417                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4418                  * prototype */
4419                 new_type->function.unspecified_parameters = true;
4420         }
4421
4422         bool need_incompatible_warning = false;
4423         parameter = entity->function.parameters.entities;
4424         for (; parameter != NULL; parameter = parameter->base.next,
4425                         proto_parameter =
4426                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4427                 if (parameter->kind != ENTITY_PARAMETER)
4428                         continue;
4429
4430                 type_t *parameter_type = parameter->declaration.type;
4431                 if (parameter_type == NULL) {
4432                         source_position_t const* const pos = &parameter->base.source_position;
4433                         if (strict_mode) {
4434                                 errorf(pos, "no type specified for function '%N'", parameter);
4435                                 parameter_type = type_error_type;
4436                         } else {
4437                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4438                                 parameter_type = type_int;
4439                         }
4440                         parameter->declaration.type = parameter_type;
4441                 }
4442
4443                 semantic_parameter_incomplete(parameter);
4444
4445                 /* we need the default promoted types for the function type */
4446                 type_t *not_promoted = parameter_type;
4447                 parameter_type       = get_default_promoted_type(parameter_type);
4448
4449                 /* gcc special: if the type of the prototype matches the unpromoted
4450                  * type don't promote */
4451                 if (!strict_mode && proto_parameter != NULL) {
4452                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4453                         type_t *promo_skip   = skip_typeref(parameter_type);
4454                         type_t *param_skip   = skip_typeref(not_promoted);
4455                         if (!types_compatible(proto_p_type, promo_skip)
4456                                 && types_compatible(proto_p_type, param_skip)) {
4457                                 /* don't promote */
4458                                 need_incompatible_warning = true;
4459                                 parameter_type = not_promoted;
4460                         }
4461                 }
4462                 function_parameter_t *const function_parameter
4463                         = allocate_parameter(parameter_type);
4464
4465                 *anchor = function_parameter;
4466                 anchor  = &function_parameter->next;
4467         }
4468
4469         new_type->function.parameters = parameters;
4470         new_type = identify_new_type(new_type);
4471
4472         if (need_incompatible_warning) {
4473                 symbol_t          const *const sym  = entity->base.symbol;
4474                 source_position_t const *const pos  = &entity->base.source_position;
4475                 source_position_t const *const ppos = &proto_type->base.source_position;
4476                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4477         }
4478         entity->declaration.type = new_type;
4479
4480         rem_anchor_token('{');
4481 }
4482
4483 static bool first_err = true;
4484
4485 /**
4486  * When called with first_err set, prints the name of the current function,
4487  * else does noting.
4488  */
4489 static void print_in_function(void)
4490 {
4491         if (first_err) {
4492                 first_err = false;
4493                 char const *const file = current_function->base.base.source_position.input_name;
4494                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4495         }
4496 }
4497
4498 /**
4499  * Check if all labels are defined in the current function.
4500  * Check if all labels are used in the current function.
4501  */
4502 static void check_labels(void)
4503 {
4504         for (const goto_statement_t *goto_statement = goto_first;
4505             goto_statement != NULL;
4506             goto_statement = goto_statement->next) {
4507                 label_t *label = goto_statement->label;
4508                 if (label->base.source_position.input_name == NULL) {
4509                         print_in_function();
4510                         source_position_t const *const pos = &goto_statement->base.source_position;
4511                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4512                  }
4513         }
4514
4515         if (is_warn_on(WARN_UNUSED_LABEL)) {
4516                 for (const label_statement_t *label_statement = label_first;
4517                          label_statement != NULL;
4518                          label_statement = label_statement->next) {
4519                         label_t *label = label_statement->label;
4520
4521                         if (! label->used) {
4522                                 print_in_function();
4523                                 source_position_t const *const pos = &label_statement->base.source_position;
4524                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4525                         }
4526                 }
4527         }
4528 }
4529
4530 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4531 {
4532         entity_t const *const end = last != NULL ? last->base.next : NULL;
4533         for (; entity != end; entity = entity->base.next) {
4534                 if (!is_declaration(entity))
4535                         continue;
4536
4537                 declaration_t *declaration = &entity->declaration;
4538                 if (declaration->implicit)
4539                         continue;
4540
4541                 if (!declaration->used) {
4542                         print_in_function();
4543                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4544                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4545                         print_in_function();
4546                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4547                 }
4548         }
4549 }
4550
4551 static void check_unused_variables(statement_t *const stmt, void *const env)
4552 {
4553         (void)env;
4554
4555         switch (stmt->kind) {
4556                 case STATEMENT_DECLARATION: {
4557                         declaration_statement_t const *const decls = &stmt->declaration;
4558                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4559                         return;
4560                 }
4561
4562                 case STATEMENT_FOR:
4563                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4564                         return;
4565
4566                 default:
4567                         return;
4568         }
4569 }
4570
4571 /**
4572  * Check declarations of current_function for unused entities.
4573  */
4574 static void check_declarations(void)
4575 {
4576         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4577                 const scope_t *scope = &current_function->parameters;
4578                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4579         }
4580         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4581                 walk_statements(current_function->statement, check_unused_variables,
4582                                 NULL);
4583         }
4584 }
4585
4586 static int determine_truth(expression_t const* const cond)
4587 {
4588         return
4589                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4590                 fold_constant_to_bool(cond)                         ? 1 :
4591                 -1;
4592 }
4593
4594 static void check_reachable(statement_t *);
4595 static bool reaches_end;
4596
4597 static bool expression_returns(expression_t const *const expr)
4598 {
4599         switch (expr->kind) {
4600                 case EXPR_CALL: {
4601                         expression_t const *const func = expr->call.function;
4602                         type_t       const *const type = skip_typeref(func->base.type);
4603                         if (type->kind == TYPE_POINTER) {
4604                                 type_t const *const points_to
4605                                         = skip_typeref(type->pointer.points_to);
4606                                 if (points_to->kind == TYPE_FUNCTION
4607                                     && points_to->function.modifiers & DM_NORETURN)
4608                                         return false;
4609                         }
4610
4611                         if (!expression_returns(func))
4612                                 return false;
4613
4614                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4615                                 if (!expression_returns(arg->expression))
4616                                         return false;
4617                         }
4618
4619                         return true;
4620                 }
4621
4622                 case EXPR_REFERENCE:
4623                 case EXPR_ENUM_CONSTANT:
4624                 case EXPR_LITERAL_CASES:
4625                 case EXPR_STRING_LITERAL:
4626                 case EXPR_WIDE_STRING_LITERAL:
4627                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4628                 case EXPR_LABEL_ADDRESS:
4629                 case EXPR_CLASSIFY_TYPE:
4630                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4631                 case EXPR_ALIGNOF:
4632                 case EXPR_FUNCNAME:
4633                 case EXPR_BUILTIN_CONSTANT_P:
4634                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4635                 case EXPR_OFFSETOF:
4636                 case EXPR_ERROR:
4637                         return true;
4638
4639                 case EXPR_STATEMENT: {
4640                         bool old_reaches_end = reaches_end;
4641                         reaches_end = false;
4642                         check_reachable(expr->statement.statement);
4643                         bool returns = reaches_end;
4644                         reaches_end = old_reaches_end;
4645                         return returns;
4646                 }
4647
4648                 case EXPR_CONDITIONAL:
4649                         // TODO handle constant expression
4650
4651                         if (!expression_returns(expr->conditional.condition))
4652                                 return false;
4653
4654                         if (expr->conditional.true_expression != NULL
4655                                         && expression_returns(expr->conditional.true_expression))
4656                                 return true;
4657
4658                         return expression_returns(expr->conditional.false_expression);
4659
4660                 case EXPR_SELECT:
4661                         return expression_returns(expr->select.compound);
4662
4663                 case EXPR_ARRAY_ACCESS:
4664                         return
4665                                 expression_returns(expr->array_access.array_ref) &&
4666                                 expression_returns(expr->array_access.index);
4667
4668                 case EXPR_VA_START:
4669                         return expression_returns(expr->va_starte.ap);
4670
4671                 case EXPR_VA_ARG:
4672                         return expression_returns(expr->va_arge.ap);
4673
4674                 case EXPR_VA_COPY:
4675                         return expression_returns(expr->va_copye.src);
4676
4677                 case EXPR_UNARY_CASES_MANDATORY:
4678                         return expression_returns(expr->unary.value);
4679
4680                 case EXPR_UNARY_THROW:
4681                         return false;
4682
4683                 case EXPR_BINARY_CASES:
4684                         // TODO handle constant lhs of && and ||
4685                         return
4686                                 expression_returns(expr->binary.left) &&
4687                                 expression_returns(expr->binary.right);
4688         }
4689
4690         panic("unhandled expression");
4691 }
4692
4693 static bool initializer_returns(initializer_t const *const init)
4694 {
4695         switch (init->kind) {
4696                 case INITIALIZER_VALUE:
4697                         return expression_returns(init->value.value);
4698
4699                 case INITIALIZER_LIST: {
4700                         initializer_t * const*       i       = init->list.initializers;
4701                         initializer_t * const* const end     = i + init->list.len;
4702                         bool                         returns = true;
4703                         for (; i != end; ++i) {
4704                                 if (!initializer_returns(*i))
4705                                         returns = false;
4706                         }
4707                         return returns;
4708                 }
4709
4710                 case INITIALIZER_STRING:
4711                 case INITIALIZER_WIDE_STRING:
4712                 case INITIALIZER_DESIGNATOR: // designators have no payload
4713                         return true;
4714         }
4715         panic("unhandled initializer");
4716 }
4717
4718 static bool noreturn_candidate;
4719
4720 static void check_reachable(statement_t *const stmt)
4721 {
4722         if (stmt->base.reachable)
4723                 return;
4724         if (stmt->kind != STATEMENT_DO_WHILE)
4725                 stmt->base.reachable = true;
4726
4727         statement_t *last = stmt;
4728         statement_t *next;
4729         switch (stmt->kind) {
4730                 case STATEMENT_ERROR:
4731                 case STATEMENT_EMPTY:
4732                 case STATEMENT_ASM:
4733                         next = stmt->base.next;
4734                         break;
4735
4736                 case STATEMENT_DECLARATION: {
4737                         declaration_statement_t const *const decl = &stmt->declaration;
4738                         entity_t                const *      ent  = decl->declarations_begin;
4739                         entity_t                const *const last_decl = decl->declarations_end;
4740                         if (ent != NULL) {
4741                                 for (;; ent = ent->base.next) {
4742                                         if (ent->kind                 == ENTITY_VARIABLE &&
4743                                             ent->variable.initializer != NULL            &&
4744                                             !initializer_returns(ent->variable.initializer)) {
4745                                                 return;
4746                                         }
4747                                         if (ent == last_decl)
4748                                                 break;
4749                                 }
4750                         }
4751                         next = stmt->base.next;
4752                         break;
4753                 }
4754
4755                 case STATEMENT_COMPOUND:
4756                         next = stmt->compound.statements;
4757                         if (next == NULL)
4758                                 next = stmt->base.next;
4759                         break;
4760
4761                 case STATEMENT_RETURN: {
4762                         expression_t const *const val = stmt->returns.value;
4763                         if (val == NULL || expression_returns(val))
4764                                 noreturn_candidate = false;
4765                         return;
4766                 }
4767
4768                 case STATEMENT_IF: {
4769                         if_statement_t const *const ifs  = &stmt->ifs;
4770                         expression_t   const *const cond = ifs->condition;
4771
4772                         if (!expression_returns(cond))
4773                                 return;
4774
4775                         int const val = determine_truth(cond);
4776
4777                         if (val >= 0)
4778                                 check_reachable(ifs->true_statement);
4779
4780                         if (val > 0)
4781                                 return;
4782
4783                         if (ifs->false_statement != NULL) {
4784                                 check_reachable(ifs->false_statement);
4785                                 return;
4786                         }
4787
4788                         next = stmt->base.next;
4789                         break;
4790                 }
4791
4792                 case STATEMENT_SWITCH: {
4793                         switch_statement_t const *const switchs = &stmt->switchs;
4794                         expression_t       const *const expr    = switchs->expression;
4795
4796                         if (!expression_returns(expr))
4797                                 return;
4798
4799                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4800                                 long                    const val      = fold_constant_to_int(expr);
4801                                 case_label_statement_t *      defaults = NULL;
4802                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4803                                         if (i->expression == NULL) {
4804                                                 defaults = i;
4805                                                 continue;
4806                                         }
4807
4808                                         if (i->first_case <= val && val <= i->last_case) {
4809                                                 check_reachable((statement_t*)i);
4810                                                 return;
4811                                         }
4812                                 }
4813
4814                                 if (defaults != NULL) {
4815                                         check_reachable((statement_t*)defaults);
4816                                         return;
4817                                 }
4818                         } else {
4819                                 bool has_default = false;
4820                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4821                                         if (i->expression == NULL)
4822                                                 has_default = true;
4823
4824                                         check_reachable((statement_t*)i);
4825                                 }
4826
4827                                 if (has_default)
4828                                         return;
4829                         }
4830
4831                         next = stmt->base.next;
4832                         break;
4833                 }
4834
4835                 case STATEMENT_EXPRESSION: {
4836                         /* Check for noreturn function call */
4837                         expression_t const *const expr = stmt->expression.expression;
4838                         if (!expression_returns(expr))
4839                                 return;
4840
4841                         next = stmt->base.next;
4842                         break;
4843                 }
4844
4845                 case STATEMENT_CONTINUE:
4846                         for (statement_t *parent = stmt;;) {
4847                                 parent = parent->base.parent;
4848                                 if (parent == NULL) /* continue not within loop */
4849                                         return;
4850
4851                                 next = parent;
4852                                 switch (parent->kind) {
4853                                         case STATEMENT_WHILE:    goto continue_while;
4854                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4855                                         case STATEMENT_FOR:      goto continue_for;
4856
4857                                         default: break;
4858                                 }
4859                         }
4860
4861                 case STATEMENT_BREAK:
4862                         for (statement_t *parent = stmt;;) {
4863                                 parent = parent->base.parent;
4864                                 if (parent == NULL) /* break not within loop/switch */
4865                                         return;
4866
4867                                 switch (parent->kind) {
4868                                         case STATEMENT_SWITCH:
4869                                         case STATEMENT_WHILE:
4870                                         case STATEMENT_DO_WHILE:
4871                                         case STATEMENT_FOR:
4872                                                 last = parent;
4873                                                 next = parent->base.next;
4874                                                 goto found_break_parent;
4875
4876                                         default: break;
4877                                 }
4878                         }
4879 found_break_parent:
4880                         break;
4881
4882                 case STATEMENT_COMPUTED_GOTO: {
4883                         if (!expression_returns(stmt->computed_goto.expression))
4884                                 return;
4885
4886                         statement_t *parent = stmt->base.parent;
4887                         if (parent == NULL) /* top level goto */
4888                                 return;
4889                         next = parent;
4890                         break;
4891                 }
4892
4893                 case STATEMENT_GOTO:
4894                         next = stmt->gotos.label->statement;
4895                         if (next == NULL) /* missing label */
4896                                 return;
4897                         break;
4898
4899                 case STATEMENT_LABEL:
4900                         next = stmt->label.statement;
4901                         break;
4902
4903                 case STATEMENT_CASE_LABEL:
4904                         next = stmt->case_label.statement;
4905                         break;
4906
4907                 case STATEMENT_WHILE: {
4908                         while_statement_t const *const whiles = &stmt->whiles;
4909                         expression_t      const *const cond   = whiles->condition;
4910
4911                         if (!expression_returns(cond))
4912                                 return;
4913
4914                         int const val = determine_truth(cond);
4915
4916                         if (val >= 0)
4917                                 check_reachable(whiles->body);
4918
4919                         if (val > 0)
4920                                 return;
4921
4922                         next = stmt->base.next;
4923                         break;
4924                 }
4925
4926                 case STATEMENT_DO_WHILE:
4927                         next = stmt->do_while.body;
4928                         break;
4929
4930                 case STATEMENT_FOR: {
4931                         for_statement_t *const fors = &stmt->fors;
4932
4933                         if (fors->condition_reachable)
4934                                 return;
4935                         fors->condition_reachable = true;
4936
4937                         expression_t const *const cond = fors->condition;
4938
4939                         int val;
4940                         if (cond == NULL) {
4941                                 val = 1;
4942                         } else if (expression_returns(cond)) {
4943                                 val = determine_truth(cond);
4944                         } else {
4945                                 return;
4946                         }
4947
4948                         if (val >= 0)
4949                                 check_reachable(fors->body);
4950
4951                         if (val > 0)
4952                                 return;
4953
4954                         next = stmt->base.next;
4955                         break;
4956                 }
4957
4958                 case STATEMENT_MS_TRY: {
4959                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4960                         check_reachable(ms_try->try_statement);
4961                         next = ms_try->final_statement;
4962                         break;
4963                 }
4964
4965                 case STATEMENT_LEAVE: {
4966                         statement_t *parent = stmt;
4967                         for (;;) {
4968                                 parent = parent->base.parent;
4969                                 if (parent == NULL) /* __leave not within __try */
4970                                         return;
4971
4972                                 if (parent->kind == STATEMENT_MS_TRY) {
4973                                         last = parent;
4974                                         next = parent->ms_try.final_statement;
4975                                         break;
4976                                 }
4977                         }
4978                         break;
4979                 }
4980
4981                 default:
4982                         panic("invalid statement kind");
4983         }
4984
4985         while (next == NULL) {
4986                 next = last->base.parent;
4987                 if (next == NULL) {
4988                         noreturn_candidate = false;
4989
4990                         type_t *const type = skip_typeref(current_function->base.type);
4991                         assert(is_type_function(type));
4992                         type_t *const ret  = skip_typeref(type->function.return_type);
4993                         if (!is_type_void(ret) &&
4994                             is_type_valid(ret) &&
4995                             !is_main(current_entity)) {
4996                                 source_position_t const *const pos = &stmt->base.source_position;
4997                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4998                         }
4999                         return;
5000                 }
5001
5002                 switch (next->kind) {
5003                         case STATEMENT_ERROR:
5004                         case STATEMENT_EMPTY:
5005                         case STATEMENT_DECLARATION:
5006                         case STATEMENT_EXPRESSION:
5007                         case STATEMENT_ASM:
5008                         case STATEMENT_RETURN:
5009                         case STATEMENT_CONTINUE:
5010                         case STATEMENT_BREAK:
5011                         case STATEMENT_COMPUTED_GOTO:
5012                         case STATEMENT_GOTO:
5013                         case STATEMENT_LEAVE:
5014                                 panic("invalid control flow in function");
5015
5016                         case STATEMENT_COMPOUND:
5017                                 if (next->compound.stmt_expr) {
5018                                         reaches_end = true;
5019                                         return;
5020                                 }
5021                                 /* FALLTHROUGH */
5022                         case STATEMENT_IF:
5023                         case STATEMENT_SWITCH:
5024                         case STATEMENT_LABEL:
5025                         case STATEMENT_CASE_LABEL:
5026                                 last = next;
5027                                 next = next->base.next;
5028                                 break;
5029
5030                         case STATEMENT_WHILE: {
5031 continue_while:
5032                                 if (next->base.reachable)
5033                                         return;
5034                                 next->base.reachable = true;
5035
5036                                 while_statement_t const *const whiles = &next->whiles;
5037                                 expression_t      const *const cond   = whiles->condition;
5038
5039                                 if (!expression_returns(cond))
5040                                         return;
5041
5042                                 int const val = determine_truth(cond);
5043
5044                                 if (val >= 0)
5045                                         check_reachable(whiles->body);
5046
5047                                 if (val > 0)
5048                                         return;
5049
5050                                 last = next;
5051                                 next = next->base.next;
5052                                 break;
5053                         }
5054
5055                         case STATEMENT_DO_WHILE: {
5056 continue_do_while:
5057                                 if (next->base.reachable)
5058                                         return;
5059                                 next->base.reachable = true;
5060
5061                                 do_while_statement_t const *const dw   = &next->do_while;
5062                                 expression_t         const *const cond = dw->condition;
5063
5064                                 if (!expression_returns(cond))
5065                                         return;
5066
5067                                 int const val = determine_truth(cond);
5068
5069                                 if (val >= 0)
5070                                         check_reachable(dw->body);
5071
5072                                 if (val > 0)
5073                                         return;
5074
5075                                 last = next;
5076                                 next = next->base.next;
5077                                 break;
5078                         }
5079
5080                         case STATEMENT_FOR: {
5081 continue_for:;
5082                                 for_statement_t *const fors = &next->fors;
5083
5084                                 fors->step_reachable = true;
5085
5086                                 if (fors->condition_reachable)
5087                                         return;
5088                                 fors->condition_reachable = true;
5089
5090                                 expression_t const *const cond = fors->condition;
5091
5092                                 int val;
5093                                 if (cond == NULL) {
5094                                         val = 1;
5095                                 } else if (expression_returns(cond)) {
5096                                         val = determine_truth(cond);
5097                                 } else {
5098                                         return;
5099                                 }
5100
5101                                 if (val >= 0)
5102                                         check_reachable(fors->body);
5103
5104                                 if (val > 0)
5105                                         return;
5106
5107                                 last = next;
5108                                 next = next->base.next;
5109                                 break;
5110                         }
5111
5112                         case STATEMENT_MS_TRY:
5113                                 last = next;
5114                                 next = next->ms_try.final_statement;
5115                                 break;
5116                 }
5117         }
5118
5119         check_reachable(next);
5120 }
5121
5122 static void check_unreachable(statement_t* const stmt, void *const env)
5123 {
5124         (void)env;
5125
5126         switch (stmt->kind) {
5127                 case STATEMENT_DO_WHILE:
5128                         if (!stmt->base.reachable) {
5129                                 expression_t const *const cond = stmt->do_while.condition;
5130                                 if (determine_truth(cond) >= 0) {
5131                                         source_position_t const *const pos = &cond->base.source_position;
5132                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5133                                 }
5134                         }
5135                         return;
5136
5137                 case STATEMENT_FOR: {
5138                         for_statement_t const* const fors = &stmt->fors;
5139
5140                         // if init and step are unreachable, cond is unreachable, too
5141                         if (!stmt->base.reachable && !fors->step_reachable) {
5142                                 goto warn_unreachable;
5143                         } else {
5144                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5145                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5146                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5147                                 }
5148
5149                                 if (!fors->condition_reachable && fors->condition != NULL) {
5150                                         source_position_t const *const pos = &fors->condition->base.source_position;
5151                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5152                                 }
5153
5154                                 if (!fors->step_reachable && fors->step != NULL) {
5155                                         source_position_t const *const pos = &fors->step->base.source_position;
5156                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5157                                 }
5158                         }
5159                         return;
5160                 }
5161
5162                 case STATEMENT_COMPOUND:
5163                         if (stmt->compound.statements != NULL)
5164                                 return;
5165                         goto warn_unreachable;
5166
5167                 case STATEMENT_DECLARATION: {
5168                         /* Only warn if there is at least one declarator with an initializer.
5169                          * This typically occurs in switch statements. */
5170                         declaration_statement_t const *const decl = &stmt->declaration;
5171                         entity_t                const *      ent  = decl->declarations_begin;
5172                         entity_t                const *const last = decl->declarations_end;
5173                         if (ent != NULL) {
5174                                 for (;; ent = ent->base.next) {
5175                                         if (ent->kind                 == ENTITY_VARIABLE &&
5176                                                         ent->variable.initializer != NULL) {
5177                                                 goto warn_unreachable;
5178                                         }
5179                                         if (ent == last)
5180                                                 return;
5181                                 }
5182                         }
5183                 }
5184
5185                 default:
5186 warn_unreachable:
5187                         if (!stmt->base.reachable) {
5188                                 source_position_t const *const pos = &stmt->base.source_position;
5189                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5190                         }
5191                         return;
5192         }
5193 }
5194
5195 static bool is_main(entity_t *entity)
5196 {
5197         static symbol_t *sym_main = NULL;
5198         if (sym_main == NULL) {
5199                 sym_main = symbol_table_insert("main");
5200         }
5201
5202         if (entity->base.symbol != sym_main)
5203                 return false;
5204         /* must be in outermost scope */
5205         if (entity->base.parent_scope != file_scope)
5206                 return false;
5207
5208         return true;
5209 }
5210
5211 static void prepare_main_collect2(entity_t*);
5212
5213 static void parse_external_declaration(void)
5214 {
5215         /* function-definitions and declarations both start with declaration
5216          * specifiers */
5217         add_anchor_token(';');
5218         declaration_specifiers_t specifiers;
5219         parse_declaration_specifiers(&specifiers);
5220         rem_anchor_token(';');
5221
5222         /* must be a declaration */
5223         if (token.kind == ';') {
5224                 parse_anonymous_declaration_rest(&specifiers);
5225                 return;
5226         }
5227
5228         add_anchor_token(',');
5229         add_anchor_token('=');
5230         add_anchor_token(';');
5231         add_anchor_token('{');
5232
5233         /* declarator is common to both function-definitions and declarations */
5234         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5235
5236         rem_anchor_token('{');
5237         rem_anchor_token(';');
5238         rem_anchor_token('=');
5239         rem_anchor_token(',');
5240
5241         /* must be a declaration */
5242         switch (token.kind) {
5243                 case ',':
5244                 case ';':
5245                 case '=':
5246                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5247                                         DECL_FLAGS_NONE);
5248                         return;
5249         }
5250
5251         /* must be a function definition */
5252         parse_kr_declaration_list(ndeclaration);
5253
5254         if (token.kind != '{') {
5255                 parse_error_expected("while parsing function definition", '{', NULL);
5256                 eat_until_matching_token(';');
5257                 return;
5258         }
5259
5260         assert(is_declaration(ndeclaration));
5261         type_t *const orig_type = ndeclaration->declaration.type;
5262         type_t *      type      = skip_typeref(orig_type);
5263
5264         if (!is_type_function(type)) {
5265                 if (is_type_valid(type)) {
5266                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5267                 }
5268                 eat_block();
5269                 return;
5270         }
5271
5272         source_position_t const *const pos = &ndeclaration->base.source_position;
5273         if (is_typeref(orig_type)) {
5274                 /* §6.9.1:2 */
5275                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5276         }
5277
5278         if (is_type_compound(skip_typeref(type->function.return_type))) {
5279                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5280         }
5281         if (type->function.unspecified_parameters) {
5282                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5283         } else {
5284                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5285         }
5286
5287         /* §6.7.5.3:14 a function definition with () means no
5288          * parameters (and not unspecified parameters) */
5289         if (type->function.unspecified_parameters &&
5290                         type->function.parameters == NULL) {
5291                 type_t *copy                          = duplicate_type(type);
5292                 copy->function.unspecified_parameters = false;
5293                 type                                  = identify_new_type(copy);
5294
5295                 ndeclaration->declaration.type = type;
5296         }
5297
5298         entity_t *const entity = record_entity(ndeclaration, true);
5299         assert(entity->kind == ENTITY_FUNCTION);
5300         assert(ndeclaration->kind == ENTITY_FUNCTION);
5301
5302         function_t *const function = &entity->function;
5303         if (ndeclaration != entity) {
5304                 function->parameters = ndeclaration->function.parameters;
5305         }
5306
5307         PUSH_SCOPE(&function->parameters);
5308
5309         entity_t *parameter = function->parameters.entities;
5310         for (; parameter != NULL; parameter = parameter->base.next) {
5311                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5312                         parameter->base.parent_scope = current_scope;
5313                 }
5314                 assert(parameter->base.parent_scope == NULL
5315                                 || parameter->base.parent_scope == current_scope);
5316                 parameter->base.parent_scope = current_scope;
5317                 if (parameter->base.symbol == NULL) {
5318                         errorf(&parameter->base.source_position, "parameter name omitted");
5319                         continue;
5320                 }
5321                 environment_push(parameter);
5322         }
5323
5324         if (function->statement != NULL) {
5325                 parser_error_multiple_definition(entity, HERE);
5326                 eat_block();
5327         } else {
5328                 /* parse function body */
5329                 int         label_stack_top      = label_top();
5330                 function_t *old_current_function = current_function;
5331                 current_function                 = function;
5332                 PUSH_CURRENT_ENTITY(entity);
5333                 PUSH_PARENT(NULL);
5334
5335                 goto_first   = NULL;
5336                 goto_anchor  = &goto_first;
5337                 label_first  = NULL;
5338                 label_anchor = &label_first;
5339
5340                 statement_t *const body = parse_compound_statement(false);
5341                 function->statement = body;
5342                 first_err = true;
5343                 check_labels();
5344                 check_declarations();
5345                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5346                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5347                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5348                         noreturn_candidate = true;
5349                         check_reachable(body);
5350                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5351                                 walk_statements(body, check_unreachable, NULL);
5352                         if (noreturn_candidate &&
5353                             !(function->base.modifiers & DM_NORETURN)) {
5354                                 source_position_t const *const pos = &body->base.source_position;
5355                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5356                         }
5357                 }
5358
5359                 if (is_main(entity)) {
5360                         /* Force main to C linkage. */
5361                         type_t *const type = entity->declaration.type;
5362                         assert(is_type_function(type));
5363                         if (type->function.linkage != LINKAGE_C) {
5364                                 type_t *new_type           = duplicate_type(type);
5365                                 new_type->function.linkage = LINKAGE_C;
5366                                 entity->declaration.type   = identify_new_type(new_type);
5367                         }
5368
5369                         if (enable_main_collect2_hack)
5370                                 prepare_main_collect2(entity);
5371                 }
5372
5373                 POP_CURRENT_ENTITY();
5374                 POP_PARENT();
5375                 assert(current_function == function);
5376                 current_function = old_current_function;
5377                 label_pop_to(label_stack_top);
5378         }
5379
5380         POP_SCOPE();
5381 }
5382
5383 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5384 {
5385         entity_t *iter = compound->members.entities;
5386         for (; iter != NULL; iter = iter->base.next) {
5387                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5388                         continue;
5389
5390                 if (iter->base.symbol == symbol) {
5391                         return iter;
5392                 } else if (iter->base.symbol == NULL) {
5393                         /* search in anonymous structs and unions */
5394                         type_t *type = skip_typeref(iter->declaration.type);
5395                         if (is_type_compound(type)) {
5396                                 if (find_compound_entry(type->compound.compound, symbol)
5397                                                 != NULL)
5398                                         return iter;
5399                         }
5400                         continue;
5401                 }
5402         }
5403
5404         return NULL;
5405 }
5406
5407 static void check_deprecated(const source_position_t *source_position,
5408                              const entity_t *entity)
5409 {
5410         if (!is_declaration(entity))
5411                 return;
5412         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5413                 return;
5414
5415         source_position_t const *const epos = &entity->base.source_position;
5416         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5417         if (msg != NULL) {
5418                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5419         } else {
5420                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5421         }
5422 }
5423
5424
5425 static expression_t *create_select(const source_position_t *pos,
5426                                    expression_t *addr,
5427                                    type_qualifiers_t qualifiers,
5428                                                                    entity_t *entry)
5429 {
5430         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5431
5432         check_deprecated(pos, entry);
5433
5434         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5435         select->select.compound       = addr;
5436         select->select.compound_entry = entry;
5437
5438         type_t *entry_type = entry->declaration.type;
5439         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5440
5441         /* bitfields need special treatment */
5442         if (entry->compound_member.bitfield) {
5443                 unsigned bit_size = entry->compound_member.bit_size;
5444                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5445                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5446                         res_type = type_int;
5447                 }
5448         }
5449
5450         /* we always do the auto-type conversions; the & and sizeof parser contains
5451          * code to revert this! */
5452         select->base.type = automatic_type_conversion(res_type);
5453
5454
5455         return select;
5456 }
5457
5458 /**
5459  * Find entry with symbol in compound. Search anonymous structs and unions and
5460  * creates implicit select expressions for them.
5461  * Returns the adress for the innermost compound.
5462  */
5463 static expression_t *find_create_select(const source_position_t *pos,
5464                                         expression_t *addr,
5465                                         type_qualifiers_t qualifiers,
5466                                         compound_t *compound, symbol_t *symbol)
5467 {
5468         entity_t *iter = compound->members.entities;
5469         for (; iter != NULL; iter = iter->base.next) {
5470                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5471                         continue;
5472
5473                 symbol_t *iter_symbol = iter->base.symbol;
5474                 if (iter_symbol == NULL) {
5475                         type_t *type = iter->declaration.type;
5476                         if (type->kind != TYPE_COMPOUND_STRUCT
5477                                         && type->kind != TYPE_COMPOUND_UNION)
5478                                 continue;
5479
5480                         compound_t *sub_compound = type->compound.compound;
5481
5482                         if (find_compound_entry(sub_compound, symbol) == NULL)
5483                                 continue;
5484
5485                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5486                         sub_addr->base.source_position = *pos;
5487                         sub_addr->base.implicit        = true;
5488                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5489                                                   symbol);
5490                 }
5491
5492                 if (iter_symbol == symbol) {
5493                         return create_select(pos, addr, qualifiers, iter);
5494                 }
5495         }
5496
5497         return NULL;
5498 }
5499
5500 static void parse_bitfield_member(entity_t *entity)
5501 {
5502         eat(':');
5503
5504         expression_t *size = parse_constant_expression();
5505         long          size_long;
5506
5507         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5508         type_t *type = entity->declaration.type;
5509         if (!is_type_integer(skip_typeref(type))) {
5510                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5511                            type);
5512         }
5513
5514         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5515                 /* error already reported by parse_constant_expression */
5516                 size_long = get_type_size(type) * 8;
5517         } else {
5518                 size_long = fold_constant_to_int(size);
5519
5520                 const symbol_t *symbol = entity->base.symbol;
5521                 const symbol_t *user_symbol
5522                         = symbol == NULL ? sym_anonymous : symbol;
5523                 unsigned bit_size = get_type_size(type) * 8;
5524                 if (size_long < 0) {
5525                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5526                 } else if (size_long == 0 && symbol != NULL) {
5527                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5528                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5529                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5530                                    user_symbol);
5531                 } else {
5532                         /* hope that people don't invent crazy types with more bits
5533                          * than our struct can hold */
5534                         assert(size_long <
5535                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5536                 }
5537         }
5538
5539         entity->compound_member.bitfield = true;
5540         entity->compound_member.bit_size = (unsigned char)size_long;
5541 }
5542
5543 static void parse_compound_declarators(compound_t *compound,
5544                 const declaration_specifiers_t *specifiers)
5545 {
5546         add_anchor_token(';');
5547         add_anchor_token(',');
5548         do {
5549                 entity_t *entity;
5550
5551                 if (token.kind == ':') {
5552                         /* anonymous bitfield */
5553                         type_t *type = specifiers->type;
5554                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5555                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5556                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5557                         entity->declaration.type                   = type;
5558
5559                         parse_bitfield_member(entity);
5560
5561                         attribute_t  *attributes = parse_attributes(NULL);
5562                         attribute_t **anchor     = &attributes;
5563                         while (*anchor != NULL)
5564                                 anchor = &(*anchor)->next;
5565                         *anchor = specifiers->attributes;
5566                         if (attributes != NULL) {
5567                                 handle_entity_attributes(attributes, entity);
5568                         }
5569                         entity->declaration.attributes = attributes;
5570
5571                         append_entity(&compound->members, entity);
5572                 } else {
5573                         entity = parse_declarator(specifiers,
5574                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5575                         source_position_t const *const pos = &entity->base.source_position;
5576                         if (entity->kind == ENTITY_TYPEDEF) {
5577                                 errorf(pos, "typedef not allowed as compound member");
5578                         } else {
5579                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5580
5581                                 /* make sure we don't define a symbol multiple times */
5582                                 symbol_t *symbol = entity->base.symbol;
5583                                 if (symbol != NULL) {
5584                                         entity_t *prev = find_compound_entry(compound, symbol);
5585                                         if (prev != NULL) {
5586                                                 source_position_t const *const ppos = &prev->base.source_position;
5587                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5588                                         }
5589                                 }
5590
5591                                 if (token.kind == ':') {
5592                                         parse_bitfield_member(entity);
5593
5594                                         attribute_t *attributes = parse_attributes(NULL);
5595                                         handle_entity_attributes(attributes, entity);
5596                                 } else {
5597                                         type_t *orig_type = entity->declaration.type;
5598                                         type_t *type      = skip_typeref(orig_type);
5599                                         if (is_type_function(type)) {
5600                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5601                                         } else if (is_type_incomplete(type)) {
5602                                                 /* §6.7.2.1:16 flexible array member */
5603                                                 if (!is_type_array(type)       ||
5604                                                                 token.kind          != ';' ||
5605                                                                 look_ahead(1)->kind != '}') {
5606                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5607                                                 } else if (compound->members.entities == NULL) {
5608                                                         errorf(pos, "flexible array member in otherwise empty struct");
5609                                                 }
5610                                         }
5611                                 }
5612
5613                                 append_entity(&compound->members, entity);
5614                         }
5615                 }
5616         } while (next_if(','));
5617         rem_anchor_token(',');
5618         rem_anchor_token(';');
5619         expect(';');
5620
5621         anonymous_entity = NULL;
5622 }
5623
5624 static void parse_compound_type_entries(compound_t *compound)
5625 {
5626         eat('{');
5627         add_anchor_token('}');
5628
5629         for (;;) {
5630                 switch (token.kind) {
5631                         DECLARATION_START
5632                         case T___extension__:
5633                         case T_IDENTIFIER: {
5634                                 PUSH_EXTENSION();
5635                                 declaration_specifiers_t specifiers;
5636                                 parse_declaration_specifiers(&specifiers);
5637                                 parse_compound_declarators(compound, &specifiers);
5638                                 POP_EXTENSION();
5639                                 break;
5640                         }
5641
5642                         default:
5643                                 rem_anchor_token('}');
5644                                 expect('}');
5645                                 /* §6.7.2.1:7 */
5646                                 compound->complete = true;
5647                                 return;
5648                 }
5649         }
5650 }
5651
5652 static type_t *parse_typename(void)
5653 {
5654         declaration_specifiers_t specifiers;
5655         parse_declaration_specifiers(&specifiers);
5656         if (specifiers.storage_class != STORAGE_CLASS_NONE
5657                         || specifiers.thread_local) {
5658                 /* TODO: improve error message, user does probably not know what a
5659                  * storage class is...
5660                  */
5661                 errorf(&specifiers.source_position, "typename must not have a storage class");
5662         }
5663
5664         type_t *result = parse_abstract_declarator(specifiers.type);
5665
5666         return result;
5667 }
5668
5669
5670
5671
5672 typedef expression_t* (*parse_expression_function)(void);
5673 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5674
5675 typedef struct expression_parser_function_t expression_parser_function_t;
5676 struct expression_parser_function_t {
5677         parse_expression_function        parser;
5678         precedence_t                     infix_precedence;
5679         parse_expression_infix_function  infix_parser;
5680 };
5681
5682 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5683
5684 static type_t *get_string_type(void)
5685 {
5686         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5687 }
5688
5689 static type_t *get_wide_string_type(void)
5690 {
5691         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5692 }
5693
5694 /**
5695  * Parse a string constant.
5696  */
5697 static expression_t *parse_string_literal(void)
5698 {
5699         source_position_t begin   = *HERE;
5700         string_t          res     = token.string.string;
5701         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5702
5703         next_token();
5704         while (token.kind == T_STRING_LITERAL
5705                         || token.kind == T_WIDE_STRING_LITERAL) {
5706                 warn_string_concat(HERE);
5707                 res = concat_strings(&res, &token.string.string);
5708                 next_token();
5709                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5710         }
5711
5712         expression_t *literal;
5713         if (is_wide) {
5714                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5715                 literal->base.type = get_wide_string_type();
5716         } else {
5717                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5718                 literal->base.type = get_string_type();
5719         }
5720         literal->base.source_position = begin;
5721         literal->literal.value        = res;
5722
5723         return literal;
5724 }
5725
5726 /**
5727  * Parse a boolean constant.
5728  */
5729 static expression_t *parse_boolean_literal(bool value)
5730 {
5731         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5732         literal->base.type           = type_bool;
5733         literal->literal.value.begin = value ? "true" : "false";
5734         literal->literal.value.size  = value ? 4 : 5;
5735
5736         eat(value ? T_true : T_false);
5737         return literal;
5738 }
5739
5740 static void warn_traditional_suffix(void)
5741 {
5742         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5743                  &token.number.suffix);
5744 }
5745
5746 static void check_integer_suffix(void)
5747 {
5748         const string_t *suffix = &token.number.suffix;
5749         if (suffix->size == 0)
5750                 return;
5751
5752         bool not_traditional = false;
5753         const char *c = suffix->begin;
5754         if (*c == 'l' || *c == 'L') {
5755                 ++c;
5756                 if (*c == *(c-1)) {
5757                         not_traditional = true;
5758                         ++c;
5759                         if (*c == 'u' || *c == 'U') {
5760                                 ++c;
5761                         }
5762                 } else if (*c == 'u' || *c == 'U') {
5763                         not_traditional = true;
5764                         ++c;
5765                 }
5766         } else if (*c == 'u' || *c == 'U') {
5767                 not_traditional = true;
5768                 ++c;
5769                 if (*c == 'l' || *c == 'L') {
5770                         ++c;
5771                         if (*c == *(c-1)) {
5772                                 ++c;
5773                         }
5774                 }
5775         }
5776         if (*c != '\0') {
5777                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5778         } else if (not_traditional) {
5779                 warn_traditional_suffix();
5780         }
5781 }
5782
5783 static type_t *check_floatingpoint_suffix(void)
5784 {
5785         const string_t *suffix = &token.number.suffix;
5786         type_t         *type   = type_double;
5787         if (suffix->size == 0)
5788                 return type;
5789
5790         bool not_traditional = false;
5791         const char *c = suffix->begin;
5792         if (*c == 'f' || *c == 'F') {
5793                 ++c;
5794                 type = type_float;
5795         } else if (*c == 'l' || *c == 'L') {
5796                 ++c;
5797                 type = type_long_double;
5798         }
5799         if (*c != '\0') {
5800                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5801         } else if (not_traditional) {
5802                 warn_traditional_suffix();
5803         }
5804
5805         return type;
5806 }
5807
5808 /**
5809  * Parse an integer constant.
5810  */
5811 static expression_t *parse_number_literal(void)
5812 {
5813         expression_kind_t  kind;
5814         type_t            *type;
5815
5816         switch (token.kind) {
5817         case T_INTEGER:
5818                 kind = EXPR_LITERAL_INTEGER;
5819                 check_integer_suffix();
5820                 type = type_int;
5821                 break;
5822
5823         case T_FLOATINGPOINT:
5824                 kind = EXPR_LITERAL_FLOATINGPOINT;
5825                 type = check_floatingpoint_suffix();
5826                 break;
5827
5828         default:
5829                 panic("unexpected token type in parse_number_literal");
5830         }
5831
5832         expression_t *literal = allocate_expression_zero(kind);
5833         literal->base.type      = type;
5834         literal->literal.value  = token.number.number;
5835         literal->literal.suffix = token.number.suffix;
5836         next_token();
5837
5838         /* integer type depends on the size of the number and the size
5839          * representable by the types. The backend/codegeneration has to determine
5840          * that
5841          */
5842         determine_literal_type(&literal->literal);
5843         return literal;
5844 }
5845
5846 /**
5847  * Parse a character constant.
5848  */
5849 static expression_t *parse_character_constant(void)
5850 {
5851         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5852         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5853         literal->literal.value = token.string.string;
5854
5855         size_t len = literal->literal.value.size;
5856         if (len > 1) {
5857                 if (!GNU_MODE && !(c_mode & _C99)) {
5858                         errorf(HERE, "more than 1 character in character constant");
5859                 } else {
5860                         literal->base.type = type_int;
5861                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5862                 }
5863         }
5864
5865         eat(T_CHARACTER_CONSTANT);
5866         return literal;
5867 }
5868
5869 /**
5870  * Parse a wide character constant.
5871  */
5872 static expression_t *parse_wide_character_constant(void)
5873 {
5874         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5875         literal->base.type     = type_int;
5876         literal->literal.value = token.string.string;
5877
5878         size_t len = wstrlen(&literal->literal.value);
5879         if (len > 1) {
5880                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5881         }
5882
5883         eat(T_WIDE_CHARACTER_CONSTANT);
5884         return literal;
5885 }
5886
5887 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5888 {
5889         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5890         ntype->function.return_type            = type_int;
5891         ntype->function.unspecified_parameters = true;
5892         ntype->function.linkage                = LINKAGE_C;
5893         type_t *type                           = identify_new_type(ntype);
5894
5895         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5896         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5897         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5898         entity->declaration.type                   = type;
5899         entity->declaration.implicit               = true;
5900
5901         if (current_scope != NULL)
5902                 record_entity(entity, false);
5903
5904         return entity;
5905 }
5906
5907 /**
5908  * Performs automatic type cast as described in §6.3.2.1.
5909  *
5910  * @param orig_type  the original type
5911  */
5912 static type_t *automatic_type_conversion(type_t *orig_type)
5913 {
5914         type_t *type = skip_typeref(orig_type);
5915         if (is_type_array(type)) {
5916                 array_type_t *array_type   = &type->array;
5917                 type_t       *element_type = array_type->element_type;
5918                 unsigned      qualifiers   = array_type->base.qualifiers;
5919
5920                 return make_pointer_type(element_type, qualifiers);
5921         }
5922
5923         if (is_type_function(type)) {
5924                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5925         }
5926
5927         return orig_type;
5928 }
5929
5930 /**
5931  * reverts the automatic casts of array to pointer types and function
5932  * to function-pointer types as defined §6.3.2.1
5933  */
5934 type_t *revert_automatic_type_conversion(const expression_t *expression)
5935 {
5936         switch (expression->kind) {
5937         case EXPR_REFERENCE: {
5938                 entity_t *entity = expression->reference.entity;
5939                 if (is_declaration(entity)) {
5940                         return entity->declaration.type;
5941                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5942                         return entity->enum_value.enum_type;
5943                 } else {
5944                         panic("no declaration or enum in reference");
5945                 }
5946         }
5947
5948         case EXPR_SELECT: {
5949                 entity_t *entity = expression->select.compound_entry;
5950                 assert(is_declaration(entity));
5951                 type_t   *type   = entity->declaration.type;
5952                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5953         }
5954
5955         case EXPR_UNARY_DEREFERENCE: {
5956                 const expression_t *const value = expression->unary.value;
5957                 type_t             *const type  = skip_typeref(value->base.type);
5958                 if (!is_type_pointer(type))
5959                         return type_error_type;
5960                 return type->pointer.points_to;
5961         }
5962
5963         case EXPR_ARRAY_ACCESS: {
5964                 const expression_t *array_ref = expression->array_access.array_ref;
5965                 type_t             *type_left = skip_typeref(array_ref->base.type);
5966                 if (!is_type_pointer(type_left))
5967                         return type_error_type;
5968                 return type_left->pointer.points_to;
5969         }
5970
5971         case EXPR_STRING_LITERAL: {
5972                 size_t size = expression->string_literal.value.size;
5973                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
5974         }
5975
5976         case EXPR_WIDE_STRING_LITERAL: {
5977                 size_t size = wstrlen(&expression->string_literal.value);
5978                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
5979         }
5980
5981         case EXPR_COMPOUND_LITERAL:
5982                 return expression->compound_literal.type;
5983
5984         default:
5985                 break;
5986         }
5987         return expression->base.type;
5988 }
5989
5990 /**
5991  * Find an entity matching a symbol in a scope.
5992  * Uses current scope if scope is NULL
5993  */
5994 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5995                                namespace_tag_t namespc)
5996 {
5997         if (scope == NULL) {
5998                 return get_entity(symbol, namespc);
5999         }
6000
6001         /* we should optimize here, if scope grows above a certain size we should
6002            construct a hashmap here... */
6003         entity_t *entity = scope->entities;
6004         for ( ; entity != NULL; entity = entity->base.next) {
6005                 if (entity->base.symbol == symbol
6006                     && (namespace_tag_t)entity->base.namespc == namespc)
6007                         break;
6008         }
6009
6010         return entity;
6011 }
6012
6013 static entity_t *parse_qualified_identifier(void)
6014 {
6015         /* namespace containing the symbol */
6016         symbol_t          *symbol;
6017         source_position_t  pos;
6018         const scope_t     *lookup_scope = NULL;
6019
6020         if (next_if(T_COLONCOLON))
6021                 lookup_scope = &unit->scope;
6022
6023         entity_t *entity;
6024         while (true) {
6025                 symbol = expect_identifier("while parsing identifier", &pos);
6026                 if (!symbol)
6027                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6028
6029                 /* lookup entity */
6030                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6031
6032                 if (!next_if(T_COLONCOLON))
6033                         break;
6034
6035                 switch (entity->kind) {
6036                 case ENTITY_NAMESPACE:
6037                         lookup_scope = &entity->namespacee.members;
6038                         break;
6039                 case ENTITY_STRUCT:
6040                 case ENTITY_UNION:
6041                 case ENTITY_CLASS:
6042                         lookup_scope = &entity->compound.members;
6043                         break;
6044                 default:
6045                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6046                                symbol, get_entity_kind_name(entity->kind));
6047
6048                         /* skip further qualifications */
6049                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6050
6051                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6052                 }
6053         }
6054
6055         if (entity == NULL) {
6056                 if (!strict_mode && token.kind == '(') {
6057                         /* an implicitly declared function */
6058                         entity = create_implicit_function(symbol, &pos);
6059                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6060                 } else {
6061                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6062                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6063                 }
6064         }
6065
6066         return entity;
6067 }
6068
6069 static expression_t *parse_reference(void)
6070 {
6071         source_position_t const pos    = *HERE;
6072         entity_t         *const entity = parse_qualified_identifier();
6073
6074         type_t *orig_type;
6075         if (is_declaration(entity)) {
6076                 orig_type = entity->declaration.type;
6077         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6078                 orig_type = entity->enum_value.enum_type;
6079         } else {
6080                 panic("expected declaration or enum value in reference");
6081         }
6082
6083         /* we always do the auto-type conversions; the & and sizeof parser contains
6084          * code to revert this! */
6085         type_t *type = automatic_type_conversion(orig_type);
6086
6087         expression_kind_t kind = EXPR_REFERENCE;
6088         if (entity->kind == ENTITY_ENUM_VALUE)
6089                 kind = EXPR_ENUM_CONSTANT;
6090
6091         expression_t *expression         = allocate_expression_zero(kind);
6092         expression->base.source_position = pos;
6093         expression->base.type            = type;
6094         expression->reference.entity     = entity;
6095
6096         /* this declaration is used */
6097         if (is_declaration(entity)) {
6098                 entity->declaration.used = true;
6099         }
6100
6101         if (entity->base.parent_scope != file_scope
6102                 && (current_function != NULL
6103                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6104                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6105                 /* access of a variable from an outer function */
6106                 entity->variable.address_taken = true;
6107                 current_function->need_closure = true;
6108         }
6109
6110         check_deprecated(&pos, entity);
6111
6112         return expression;
6113 }
6114
6115 static bool semantic_cast(expression_t *cast)
6116 {
6117         expression_t            *expression      = cast->unary.value;
6118         type_t                  *orig_dest_type  = cast->base.type;
6119         type_t                  *orig_type_right = expression->base.type;
6120         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6121         type_t            const *src_type        = skip_typeref(orig_type_right);
6122         source_position_t const *pos             = &cast->base.source_position;
6123
6124         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6125         if (is_type_void(dst_type))
6126                 return true;
6127
6128         /* only integer and pointer can be casted to pointer */
6129         if (is_type_pointer(dst_type)  &&
6130             !is_type_pointer(src_type) &&
6131             !is_type_integer(src_type) &&
6132             is_type_valid(src_type)) {
6133                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6134                 return false;
6135         }
6136
6137         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6138                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6139                 return false;
6140         }
6141
6142         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6143                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6144                 return false;
6145         }
6146
6147         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6148                 type_t *src = skip_typeref(src_type->pointer.points_to);
6149                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6150                 unsigned missing_qualifiers =
6151                         src->base.qualifiers & ~dst->base.qualifiers;
6152                 if (missing_qualifiers != 0) {
6153                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6154                 }
6155         }
6156         return true;
6157 }
6158
6159 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6160 {
6161         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6162         expression->base.source_position = *pos;
6163
6164         parse_initializer_env_t env;
6165         env.type             = type;
6166         env.entity           = NULL;
6167         env.must_be_constant = false;
6168         initializer_t *initializer = parse_initializer(&env);
6169         type = env.type;
6170
6171         expression->compound_literal.initializer = initializer;
6172         expression->compound_literal.type        = type;
6173         expression->base.type                    = automatic_type_conversion(type);
6174
6175         return expression;
6176 }
6177
6178 /**
6179  * Parse a cast expression.
6180  */
6181 static expression_t *parse_cast(void)
6182 {
6183         source_position_t const pos = *HERE;
6184
6185         eat('(');
6186         add_anchor_token(')');
6187
6188         type_t *type = parse_typename();
6189
6190         rem_anchor_token(')');
6191         expect(')');
6192
6193         if (token.kind == '{') {
6194                 return parse_compound_literal(&pos, type);
6195         }
6196
6197         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6198         cast->base.source_position = pos;
6199
6200         expression_t *value = parse_subexpression(PREC_CAST);
6201         cast->base.type   = type;
6202         cast->unary.value = value;
6203
6204         if (! semantic_cast(cast)) {
6205                 /* TODO: record the error in the AST. else it is impossible to detect it */
6206         }
6207
6208         return cast;
6209 }
6210
6211 /**
6212  * Parse a statement expression.
6213  */
6214 static expression_t *parse_statement_expression(void)
6215 {
6216         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6217
6218         eat('(');
6219         add_anchor_token(')');
6220
6221         statement_t *statement          = parse_compound_statement(true);
6222         statement->compound.stmt_expr   = true;
6223         expression->statement.statement = statement;
6224
6225         /* find last statement and use its type */
6226         type_t *type = type_void;
6227         const statement_t *stmt = statement->compound.statements;
6228         if (stmt != NULL) {
6229                 while (stmt->base.next != NULL)
6230                         stmt = stmt->base.next;
6231
6232                 if (stmt->kind == STATEMENT_EXPRESSION) {
6233                         type = stmt->expression.expression->base.type;
6234                 }
6235         } else {
6236                 source_position_t const *const pos = &expression->base.source_position;
6237                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6238         }
6239         expression->base.type = type;
6240
6241         rem_anchor_token(')');
6242         expect(')');
6243         return expression;
6244 }
6245
6246 /**
6247  * Parse a parenthesized expression.
6248  */
6249 static expression_t *parse_parenthesized_expression(void)
6250 {
6251         token_t const* const la1 = look_ahead(1);
6252         switch (la1->kind) {
6253         case '{':
6254                 /* gcc extension: a statement expression */
6255                 return parse_statement_expression();
6256
6257         case T_IDENTIFIER:
6258                 if (is_typedef_symbol(la1->base.symbol)) {
6259         DECLARATION_START
6260                         return parse_cast();
6261                 }
6262         }
6263
6264         eat('(');
6265         add_anchor_token(')');
6266         expression_t *result = parse_expression();
6267         result->base.parenthesized = true;
6268         rem_anchor_token(')');
6269         expect(')');
6270
6271         return result;
6272 }
6273
6274 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6275 {
6276         if (current_function == NULL) {
6277                 errorf(HERE, "'%K' used outside of a function", &token);
6278         }
6279
6280         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6281         expression->base.type     = type_char_ptr;
6282         expression->funcname.kind = kind;
6283
6284         next_token();
6285
6286         return expression;
6287 }
6288
6289 static designator_t *parse_designator(void)
6290 {
6291         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6292         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6293         if (!result->symbol)
6294                 return NULL;
6295
6296         designator_t *last_designator = result;
6297         while (true) {
6298                 if (next_if('.')) {
6299                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6300                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6301                         if (!designator->symbol)
6302                                 return NULL;
6303
6304                         last_designator->next = designator;
6305                         last_designator       = designator;
6306                         continue;
6307                 }
6308                 if (next_if('[')) {
6309                         add_anchor_token(']');
6310                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6311                         designator->source_position = *HERE;
6312                         designator->array_index     = parse_expression();
6313                         rem_anchor_token(']');
6314                         expect(']');
6315                         if (designator->array_index == NULL) {
6316                                 return NULL;
6317                         }
6318
6319                         last_designator->next = designator;
6320                         last_designator       = designator;
6321                         continue;
6322                 }
6323                 break;
6324         }
6325
6326         return result;
6327 }
6328
6329 /**
6330  * Parse the __builtin_offsetof() expression.
6331  */
6332 static expression_t *parse_offsetof(void)
6333 {
6334         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6335         expression->base.type    = type_size_t;
6336
6337         eat(T___builtin_offsetof);
6338
6339         add_anchor_token(')');
6340         add_anchor_token(',');
6341         expect('(');
6342         type_t *type = parse_typename();
6343         rem_anchor_token(',');
6344         expect(',');
6345         designator_t *designator = parse_designator();
6346         rem_anchor_token(')');
6347         expect(')');
6348
6349         expression->offsetofe.type       = type;
6350         expression->offsetofe.designator = designator;
6351
6352         type_path_t path;
6353         memset(&path, 0, sizeof(path));
6354         path.top_type = type;
6355         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6356
6357         descend_into_subtype(&path);
6358
6359         if (!walk_designator(&path, designator, true)) {
6360                 return create_error_expression();
6361         }
6362
6363         DEL_ARR_F(path.path);
6364
6365         return expression;
6366 }
6367
6368 static bool is_last_parameter(expression_t *const param)
6369 {
6370         if (param->kind == EXPR_REFERENCE) {
6371                 entity_t *const entity = param->reference.entity;
6372                 if (entity->kind == ENTITY_PARAMETER &&
6373                     !entity->base.next               &&
6374                     entity->base.parent_scope == &current_function->parameters) {
6375                         return true;
6376                 }
6377         }
6378
6379         if (!is_type_valid(skip_typeref(param->base.type)))
6380                 return true;
6381
6382         return false;
6383 }
6384
6385 /**
6386  * Parses a __builtin_va_start() expression.
6387  */
6388 static expression_t *parse_va_start(void)
6389 {
6390         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6391
6392         eat(T___builtin_va_start);
6393
6394         add_anchor_token(')');
6395         add_anchor_token(',');
6396         expect('(');
6397         expression->va_starte.ap = parse_assignment_expression();
6398         rem_anchor_token(',');
6399         expect(',');
6400         expression_t *const param = parse_assignment_expression();
6401         expression->va_starte.parameter = param;
6402         rem_anchor_token(')');
6403         expect(')');
6404
6405         if (!current_function) {
6406                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6407         } else if (!current_function->base.type->function.variadic) {
6408                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6409         } else if (!is_last_parameter(param)) {
6410                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6411         }
6412
6413         return expression;
6414 }
6415
6416 /**
6417  * Parses a __builtin_va_arg() expression.
6418  */
6419 static expression_t *parse_va_arg(void)
6420 {
6421         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6422
6423         eat(T___builtin_va_arg);
6424
6425         add_anchor_token(')');
6426         add_anchor_token(',');
6427         expect('(');
6428         call_argument_t ap;
6429         ap.expression = parse_assignment_expression();
6430         expression->va_arge.ap = ap.expression;
6431         check_call_argument(type_valist, &ap, 1);
6432
6433         rem_anchor_token(',');
6434         expect(',');
6435         expression->base.type = parse_typename();
6436         rem_anchor_token(')');
6437         expect(')');
6438
6439         return expression;
6440 }
6441
6442 /**
6443  * Parses a __builtin_va_copy() expression.
6444  */
6445 static expression_t *parse_va_copy(void)
6446 {
6447         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6448
6449         eat(T___builtin_va_copy);
6450
6451         add_anchor_token(')');
6452         add_anchor_token(',');
6453         expect('(');
6454         expression_t *dst = parse_assignment_expression();
6455         assign_error_t error = semantic_assign(type_valist, dst);
6456         report_assign_error(error, type_valist, dst, "call argument 1",
6457                             &dst->base.source_position);
6458         expression->va_copye.dst = dst;
6459
6460         rem_anchor_token(',');
6461         expect(',');
6462
6463         call_argument_t src;
6464         src.expression = parse_assignment_expression();
6465         check_call_argument(type_valist, &src, 2);
6466         expression->va_copye.src = src.expression;
6467         rem_anchor_token(')');
6468         expect(')');
6469
6470         return expression;
6471 }
6472
6473 /**
6474  * Parses a __builtin_constant_p() expression.
6475  */
6476 static expression_t *parse_builtin_constant(void)
6477 {
6478         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6479
6480         eat(T___builtin_constant_p);
6481
6482         add_anchor_token(')');
6483         expect('(');
6484         expression->builtin_constant.value = parse_assignment_expression();
6485         rem_anchor_token(')');
6486         expect(')');
6487         expression->base.type = type_int;
6488
6489         return expression;
6490 }
6491
6492 /**
6493  * Parses a __builtin_types_compatible_p() expression.
6494  */
6495 static expression_t *parse_builtin_types_compatible(void)
6496 {
6497         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6498
6499         eat(T___builtin_types_compatible_p);
6500
6501         add_anchor_token(')');
6502         add_anchor_token(',');
6503         expect('(');
6504         expression->builtin_types_compatible.left = parse_typename();
6505         rem_anchor_token(',');
6506         expect(',');
6507         expression->builtin_types_compatible.right = parse_typename();
6508         rem_anchor_token(')');
6509         expect(')');
6510         expression->base.type = type_int;
6511
6512         return expression;
6513 }
6514
6515 /**
6516  * Parses a __builtin_is_*() compare expression.
6517  */
6518 static expression_t *parse_compare_builtin(void)
6519 {
6520         expression_kind_t kind;
6521         switch (token.kind) {
6522         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6523         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6524         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6525         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6526         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6527         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6528         default: internal_errorf(HERE, "invalid compare builtin found");
6529         }
6530         expression_t *const expression = allocate_expression_zero(kind);
6531         next_token();
6532
6533         add_anchor_token(')');
6534         add_anchor_token(',');
6535         expect('(');
6536         expression->binary.left = parse_assignment_expression();
6537         rem_anchor_token(',');
6538         expect(',');
6539         expression->binary.right = parse_assignment_expression();
6540         rem_anchor_token(')');
6541         expect(')');
6542
6543         type_t *const orig_type_left  = expression->binary.left->base.type;
6544         type_t *const orig_type_right = expression->binary.right->base.type;
6545
6546         type_t *const type_left  = skip_typeref(orig_type_left);
6547         type_t *const type_right = skip_typeref(orig_type_right);
6548         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6549                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6550                         type_error_incompatible("invalid operands in comparison",
6551                                 &expression->base.source_position, orig_type_left, orig_type_right);
6552                 }
6553         } else {
6554                 semantic_comparison(&expression->binary);
6555         }
6556
6557         return expression;
6558 }
6559
6560 /**
6561  * Parses a MS assume() expression.
6562  */
6563 static expression_t *parse_assume(void)
6564 {
6565         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6566
6567         eat(T__assume);
6568
6569         add_anchor_token(')');
6570         expect('(');
6571         expression->unary.value = parse_assignment_expression();
6572         rem_anchor_token(')');
6573         expect(')');
6574
6575         expression->base.type = type_void;
6576         return expression;
6577 }
6578
6579 /**
6580  * Return the label for the current symbol or create a new one.
6581  */
6582 static label_t *get_label(char const *const context)
6583 {
6584         assert(current_function != NULL);
6585
6586         symbol_t *const sym = expect_identifier(context, NULL);
6587         if (!sym)
6588                 return NULL;
6589
6590         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6591         /* If we find a local label, we already created the declaration. */
6592         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6593                 if (label->base.parent_scope != current_scope) {
6594                         assert(label->base.parent_scope->depth < current_scope->depth);
6595                         current_function->goto_to_outer = true;
6596                 }
6597         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6598                 /* There is no matching label in the same function, so create a new one. */
6599                 source_position_t const nowhere = { NULL, 0, 0, false };
6600                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6601                 label_push(label);
6602         }
6603
6604         return &label->label;
6605 }
6606
6607 /**
6608  * Parses a GNU && label address expression.
6609  */
6610 static expression_t *parse_label_address(void)
6611 {
6612         source_position_t const source_position = *HERE;
6613         eat(T_ANDAND);
6614
6615         label_t *const label = get_label("while parsing label address");
6616         if (!label)
6617                 return create_error_expression();
6618
6619         label->used          = true;
6620         label->address_taken = true;
6621
6622         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6623         expression->base.source_position = source_position;
6624
6625         /* label address is treated as a void pointer */
6626         expression->base.type           = type_void_ptr;
6627         expression->label_address.label = label;
6628         return expression;
6629 }
6630
6631 /**
6632  * Parse a microsoft __noop expression.
6633  */
6634 static expression_t *parse_noop_expression(void)
6635 {
6636         /* the result is a (int)0 */
6637         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6638         literal->base.type           = type_int;
6639         literal->literal.value.begin = "__noop";
6640         literal->literal.value.size  = 6;
6641
6642         eat(T___noop);
6643
6644         if (token.kind == '(') {
6645                 /* parse arguments */
6646                 eat('(');
6647                 add_anchor_token(')');
6648                 add_anchor_token(',');
6649
6650                 if (token.kind != ')') do {
6651                         (void)parse_assignment_expression();
6652                 } while (next_if(','));
6653
6654                 rem_anchor_token(',');
6655                 rem_anchor_token(')');
6656         }
6657         expect(')');
6658
6659         return literal;
6660 }
6661
6662 /**
6663  * Parses a primary expression.
6664  */
6665 static expression_t *parse_primary_expression(void)
6666 {
6667         switch (token.kind) {
6668         case T_false:                        return parse_boolean_literal(false);
6669         case T_true:                         return parse_boolean_literal(true);
6670         case T_INTEGER:
6671         case T_FLOATINGPOINT:                return parse_number_literal();
6672         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6673         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6674         case T_STRING_LITERAL:
6675         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6676         case T___FUNCTION__:
6677         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6678         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6679         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6680         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6681         case T___builtin_offsetof:           return parse_offsetof();
6682         case T___builtin_va_start:           return parse_va_start();
6683         case T___builtin_va_arg:             return parse_va_arg();
6684         case T___builtin_va_copy:            return parse_va_copy();
6685         case T___builtin_isgreater:
6686         case T___builtin_isgreaterequal:
6687         case T___builtin_isless:
6688         case T___builtin_islessequal:
6689         case T___builtin_islessgreater:
6690         case T___builtin_isunordered:        return parse_compare_builtin();
6691         case T___builtin_constant_p:         return parse_builtin_constant();
6692         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6693         case T__assume:                      return parse_assume();
6694         case T_ANDAND:
6695                 if (GNU_MODE)
6696                         return parse_label_address();
6697                 break;
6698
6699         case '(':                            return parse_parenthesized_expression();
6700         case T___noop:                       return parse_noop_expression();
6701
6702         /* Gracefully handle type names while parsing expressions. */
6703         case T_COLONCOLON:
6704                 return parse_reference();
6705         case T_IDENTIFIER:
6706                 if (!is_typedef_symbol(token.base.symbol)) {
6707                         return parse_reference();
6708                 }
6709                 /* FALLTHROUGH */
6710         DECLARATION_START {
6711                 source_position_t const  pos = *HERE;
6712                 declaration_specifiers_t specifiers;
6713                 parse_declaration_specifiers(&specifiers);
6714                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6715                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6716                 return create_error_expression();
6717         }
6718         }
6719
6720         errorf(HERE, "unexpected token %K, expected an expression", &token);
6721         eat_until_anchor();
6722         return create_error_expression();
6723 }
6724
6725 static expression_t *parse_array_expression(expression_t *left)
6726 {
6727         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6728         array_access_expression_t *const arr  = &expr->array_access;
6729
6730         eat('[');
6731         add_anchor_token(']');
6732
6733         expression_t *const inside = parse_expression();
6734
6735         type_t *const orig_type_left   = left->base.type;
6736         type_t *const orig_type_inside = inside->base.type;
6737
6738         type_t *const type_left   = skip_typeref(orig_type_left);
6739         type_t *const type_inside = skip_typeref(orig_type_inside);
6740
6741         expression_t *ref;
6742         expression_t *idx;
6743         type_t       *idx_type;
6744         type_t       *res_type;
6745         if (is_type_pointer(type_left)) {
6746                 ref      = left;
6747                 idx      = inside;
6748                 idx_type = type_inside;
6749                 res_type = type_left->pointer.points_to;
6750                 goto check_idx;
6751         } else if (is_type_pointer(type_inside)) {
6752                 arr->flipped = true;
6753                 ref      = inside;
6754                 idx      = left;
6755                 idx_type = type_left;
6756                 res_type = type_inside->pointer.points_to;
6757 check_idx:
6758                 res_type = automatic_type_conversion(res_type);
6759                 if (!is_type_integer(idx_type)) {
6760                         errorf(&idx->base.source_position, "array subscript must have integer type");
6761                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6762                         source_position_t const *const pos = &idx->base.source_position;
6763                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6764                 }
6765         } else {
6766                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6767                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6768                 }
6769                 res_type = type_error_type;
6770                 ref      = left;
6771                 idx      = inside;
6772         }
6773
6774         arr->array_ref = ref;
6775         arr->index     = idx;
6776         arr->base.type = res_type;
6777
6778         rem_anchor_token(']');
6779         expect(']');
6780         return expr;
6781 }
6782
6783 static bool is_bitfield(const expression_t *expression)
6784 {
6785         return expression->kind == EXPR_SELECT
6786                 && expression->select.compound_entry->compound_member.bitfield;
6787 }
6788
6789 static expression_t *parse_typeprop(expression_kind_t const kind)
6790 {
6791         expression_t  *tp_expression = allocate_expression_zero(kind);
6792         tp_expression->base.type     = type_size_t;
6793
6794         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6795
6796         type_t       *orig_type;
6797         expression_t *expression;
6798         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6799                 source_position_t const pos = *HERE;
6800                 eat('(');
6801                 add_anchor_token(')');
6802                 orig_type = parse_typename();
6803                 rem_anchor_token(')');
6804                 expect(')');
6805
6806                 if (token.kind == '{') {
6807                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6808                          * starting with a compound literal */
6809                         expression = parse_compound_literal(&pos, orig_type);
6810                         goto typeprop_expression;
6811                 }
6812         } else {
6813                 expression = parse_subexpression(PREC_UNARY);
6814
6815 typeprop_expression:
6816                 if (is_bitfield(expression)) {
6817                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6818                         errorf(&tp_expression->base.source_position,
6819                                    "operand of %s expression must not be a bitfield", what);
6820                 }
6821
6822                 tp_expression->typeprop.tp_expression = expression;
6823
6824                 orig_type = revert_automatic_type_conversion(expression);
6825                 expression->base.type = orig_type;
6826         }
6827
6828         tp_expression->typeprop.type   = orig_type;
6829         type_t const* const type       = skip_typeref(orig_type);
6830         char   const*       wrong_type = NULL;
6831         if (is_type_incomplete(type)) {
6832                 if (!is_type_void(type) || !GNU_MODE)
6833                         wrong_type = "incomplete";
6834         } else if (type->kind == TYPE_FUNCTION) {
6835                 if (GNU_MODE) {
6836                         /* function types are allowed (and return 1) */
6837                         source_position_t const *const pos  = &tp_expression->base.source_position;
6838                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6839                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6840                 } else {
6841                         wrong_type = "function";
6842                 }
6843         }
6844
6845         if (wrong_type != NULL) {
6846                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6847                 errorf(&tp_expression->base.source_position,
6848                                 "operand of %s expression must not be of %s type '%T'",
6849                                 what, wrong_type, orig_type);
6850         }
6851
6852         return tp_expression;
6853 }
6854
6855 static expression_t *parse_sizeof(void)
6856 {
6857         return parse_typeprop(EXPR_SIZEOF);
6858 }
6859
6860 static expression_t *parse_alignof(void)
6861 {
6862         return parse_typeprop(EXPR_ALIGNOF);
6863 }
6864
6865 static expression_t *parse_select_expression(expression_t *addr)
6866 {
6867         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6868         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6869         source_position_t const pos = *HERE;
6870         next_token();
6871
6872         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6873         if (!symbol)
6874                 return create_error_expression();
6875
6876         type_t *const orig_type = addr->base.type;
6877         type_t *const type      = skip_typeref(orig_type);
6878
6879         type_t *type_left;
6880         bool    saw_error = false;
6881         if (is_type_pointer(type)) {
6882                 if (!select_left_arrow) {
6883                         errorf(&pos,
6884                                "request for member '%Y' in something not a struct or union, but '%T'",
6885                                symbol, orig_type);
6886                         saw_error = true;
6887                 }
6888                 type_left = skip_typeref(type->pointer.points_to);
6889         } else {
6890                 if (select_left_arrow && is_type_valid(type)) {
6891                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6892                         saw_error = true;
6893                 }
6894                 type_left = type;
6895         }
6896
6897         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6898             type_left->kind != TYPE_COMPOUND_UNION) {
6899
6900                 if (is_type_valid(type_left) && !saw_error) {
6901                         errorf(&pos,
6902                                "request for member '%Y' in something not a struct or union, but '%T'",
6903                                symbol, type_left);
6904                 }
6905                 return create_error_expression();
6906         }
6907
6908         compound_t *compound = type_left->compound.compound;
6909         if (!compound->complete) {
6910                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6911                        symbol, type_left);
6912                 return create_error_expression();
6913         }
6914
6915         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6916         expression_t      *result     =
6917                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6918
6919         if (result == NULL) {
6920                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6921                 return create_error_expression();
6922         }
6923
6924         return result;
6925 }
6926
6927 static void check_call_argument(type_t          *expected_type,
6928                                 call_argument_t *argument, unsigned pos)
6929 {
6930         type_t         *expected_type_skip = skip_typeref(expected_type);
6931         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6932         expression_t   *arg_expr           = argument->expression;
6933         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6934
6935         /* handle transparent union gnu extension */
6936         if (is_type_union(expected_type_skip)
6937                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6938                 compound_t *union_decl  = expected_type_skip->compound.compound;
6939                 type_t     *best_type   = NULL;
6940                 entity_t   *entry       = union_decl->members.entities;
6941                 for ( ; entry != NULL; entry = entry->base.next) {
6942                         assert(is_declaration(entry));
6943                         type_t *decl_type = entry->declaration.type;
6944                         error = semantic_assign(decl_type, arg_expr);
6945                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6946                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6947                                 continue;
6948
6949                         if (error == ASSIGN_SUCCESS) {
6950                                 best_type = decl_type;
6951                         } else if (best_type == NULL) {
6952                                 best_type = decl_type;
6953                         }
6954                 }
6955
6956                 if (best_type != NULL) {
6957                         expected_type = best_type;
6958                 }
6959         }
6960
6961         error                = semantic_assign(expected_type, arg_expr);
6962         argument->expression = create_implicit_cast(arg_expr, expected_type);
6963
6964         if (error != ASSIGN_SUCCESS) {
6965                 /* report exact scope in error messages (like "in argument 3") */
6966                 char buf[64];
6967                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6968                 report_assign_error(error, expected_type, arg_expr, buf,
6969                                     &arg_expr->base.source_position);
6970         } else {
6971                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6972                 if (!types_compatible(expected_type_skip, promoted_type) &&
6973                     !types_compatible(expected_type_skip, type_void_ptr) &&
6974                     !types_compatible(type_void_ptr,      promoted_type)) {
6975                         /* Deliberately show the skipped types in this warning */
6976                         source_position_t const *const apos = &arg_expr->base.source_position;
6977                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6978                 }
6979         }
6980 }
6981
6982 /**
6983  * Handle the semantic restrictions of builtin calls
6984  */
6985 static void handle_builtin_argument_restrictions(call_expression_t *call)
6986 {
6987         entity_t *entity = call->function->reference.entity;
6988         switch (entity->function.btk) {
6989         case BUILTIN_FIRM:
6990                 switch (entity->function.b.firm_builtin_kind) {
6991                 case ir_bk_return_address:
6992                 case ir_bk_frame_address: {
6993                         /* argument must be constant */
6994                         call_argument_t *argument = call->arguments;
6995
6996                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6997                                 errorf(&call->base.source_position,
6998                                            "argument of '%Y' must be a constant expression",
6999                                            call->function->reference.entity->base.symbol);
7000                         }
7001                         break;
7002                 }
7003                 case ir_bk_prefetch:
7004                         /* second and third argument must be constant if existent */
7005                         if (call->arguments == NULL)
7006                                 break;
7007                         call_argument_t *rw = call->arguments->next;
7008                         call_argument_t *locality = NULL;
7009
7010                         if (rw != NULL) {
7011                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7012                                         errorf(&call->base.source_position,
7013                                                    "second argument of '%Y' must be a constant expression",
7014                                                    call->function->reference.entity->base.symbol);
7015                                 }
7016                                 locality = rw->next;
7017                         }
7018                         if (locality != NULL) {
7019                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7020                                         errorf(&call->base.source_position,
7021                                                    "third argument of '%Y' must be a constant expression",
7022                                                    call->function->reference.entity->base.symbol);
7023                                 }
7024                                 locality = rw->next;
7025                         }
7026                         break;
7027                 default:
7028                         break;
7029                 }
7030
7031         case BUILTIN_OBJECT_SIZE:
7032                 if (call->arguments == NULL)
7033                         break;
7034
7035                 call_argument_t *arg = call->arguments->next;
7036                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7037                         errorf(&call->base.source_position,
7038                                    "second argument of '%Y' must be a constant expression",
7039                                    call->function->reference.entity->base.symbol);
7040                 }
7041                 break;
7042         default:
7043                 break;
7044         }
7045 }
7046
7047 /**
7048  * Parse a call expression, ie. expression '( ... )'.
7049  *
7050  * @param expression  the function address
7051  */
7052 static expression_t *parse_call_expression(expression_t *expression)
7053 {
7054         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7055         call_expression_t *call   = &result->call;
7056         call->function            = expression;
7057
7058         type_t *const orig_type = expression->base.type;
7059         type_t *const type      = skip_typeref(orig_type);
7060
7061         function_type_t *function_type = NULL;
7062         if (is_type_pointer(type)) {
7063                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7064
7065                 if (is_type_function(to_type)) {
7066                         function_type   = &to_type->function;
7067                         call->base.type = function_type->return_type;
7068                 }
7069         }
7070
7071         if (function_type == NULL && is_type_valid(type)) {
7072                 errorf(HERE,
7073                        "called object '%E' (type '%T') is not a pointer to a function",
7074                        expression, orig_type);
7075         }
7076
7077         /* parse arguments */
7078         eat('(');
7079         add_anchor_token(')');
7080         add_anchor_token(',');
7081
7082         if (token.kind != ')') {
7083                 call_argument_t **anchor = &call->arguments;
7084                 do {
7085                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7086                         argument->expression = parse_assignment_expression();
7087
7088                         *anchor = argument;
7089                         anchor  = &argument->next;
7090                 } while (next_if(','));
7091         }
7092         rem_anchor_token(',');
7093         rem_anchor_token(')');
7094         expect(')');
7095
7096         if (function_type == NULL)
7097                 return result;
7098
7099         /* check type and count of call arguments */
7100         function_parameter_t *parameter = function_type->parameters;
7101         call_argument_t      *argument  = call->arguments;
7102         if (!function_type->unspecified_parameters) {
7103                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7104                                 parameter = parameter->next, argument = argument->next) {
7105                         check_call_argument(parameter->type, argument, ++pos);
7106                 }
7107
7108                 if (parameter != NULL) {
7109                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7110                 } else if (argument != NULL && !function_type->variadic) {
7111                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7112                 }
7113         }
7114
7115         /* do default promotion for other arguments */
7116         for (; argument != NULL; argument = argument->next) {
7117                 type_t *argument_type = argument->expression->base.type;
7118                 if (!is_type_object(skip_typeref(argument_type))) {
7119                         errorf(&argument->expression->base.source_position,
7120                                "call argument '%E' must not be void", argument->expression);
7121                 }
7122
7123                 argument_type = get_default_promoted_type(argument_type);
7124
7125                 argument->expression
7126                         = create_implicit_cast(argument->expression, argument_type);
7127         }
7128
7129         check_format(call);
7130
7131         if (is_type_compound(skip_typeref(function_type->return_type))) {
7132                 source_position_t const *const pos = &expression->base.source_position;
7133                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7134         }
7135
7136         if (expression->kind == EXPR_REFERENCE) {
7137                 reference_expression_t *reference = &expression->reference;
7138                 if (reference->entity->kind == ENTITY_FUNCTION &&
7139                     reference->entity->function.btk != BUILTIN_NONE)
7140                         handle_builtin_argument_restrictions(call);
7141         }
7142
7143         return result;
7144 }
7145
7146 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7147
7148 static bool same_compound_type(const type_t *type1, const type_t *type2)
7149 {
7150         return
7151                 is_type_compound(type1) &&
7152                 type1->kind == type2->kind &&
7153                 type1->compound.compound == type2->compound.compound;
7154 }
7155
7156 static expression_t const *get_reference_address(expression_t const *expr)
7157 {
7158         bool regular_take_address = true;
7159         for (;;) {
7160                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7161                         expr = expr->unary.value;
7162                 } else {
7163                         regular_take_address = false;
7164                 }
7165
7166                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7167                         break;
7168
7169                 expr = expr->unary.value;
7170         }
7171
7172         if (expr->kind != EXPR_REFERENCE)
7173                 return NULL;
7174
7175         /* special case for functions which are automatically converted to a
7176          * pointer to function without an extra TAKE_ADDRESS operation */
7177         if (!regular_take_address &&
7178                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7179                 return NULL;
7180         }
7181
7182         return expr;
7183 }
7184
7185 static void warn_reference_address_as_bool(expression_t const* expr)
7186 {
7187         expr = get_reference_address(expr);
7188         if (expr != NULL) {
7189                 source_position_t const *const pos = &expr->base.source_position;
7190                 entity_t          const *const ent = expr->reference.entity;
7191                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7192         }
7193 }
7194
7195 static void warn_assignment_in_condition(const expression_t *const expr)
7196 {
7197         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7198                 return;
7199         if (expr->base.parenthesized)
7200                 return;
7201         source_position_t const *const pos = &expr->base.source_position;
7202         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7203 }
7204
7205 static void semantic_condition(expression_t const *const expr,
7206                                char const *const context)
7207 {
7208         type_t *const type = skip_typeref(expr->base.type);
7209         if (is_type_scalar(type)) {
7210                 warn_reference_address_as_bool(expr);
7211                 warn_assignment_in_condition(expr);
7212         } else if (is_type_valid(type)) {
7213                 errorf(&expr->base.source_position,
7214                                 "%s must have scalar type", context);
7215         }
7216 }
7217
7218 /**
7219  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7220  *
7221  * @param expression  the conditional expression
7222  */
7223 static expression_t *parse_conditional_expression(expression_t *expression)
7224 {
7225         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7226
7227         conditional_expression_t *conditional = &result->conditional;
7228         conditional->condition                = expression;
7229
7230         eat('?');
7231         add_anchor_token(':');
7232
7233         /* §6.5.15:2  The first operand shall have scalar type. */
7234         semantic_condition(expression, "condition of conditional operator");
7235
7236         expression_t *true_expression = expression;
7237         bool          gnu_cond = false;
7238         if (GNU_MODE && token.kind == ':') {
7239                 gnu_cond = true;
7240         } else {
7241                 true_expression = parse_expression();
7242         }
7243         rem_anchor_token(':');
7244         expect(':');
7245         expression_t *false_expression =
7246                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7247
7248         type_t *const orig_true_type  = true_expression->base.type;
7249         type_t *const orig_false_type = false_expression->base.type;
7250         type_t *const true_type       = skip_typeref(orig_true_type);
7251         type_t *const false_type      = skip_typeref(orig_false_type);
7252
7253         /* 6.5.15.3 */
7254         source_position_t const *const pos = &conditional->base.source_position;
7255         type_t                        *result_type;
7256         if (is_type_void(true_type) || is_type_void(false_type)) {
7257                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7258                 if (true_expression->kind == EXPR_UNARY_THROW) {
7259                         result_type = false_type;
7260                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7261                         result_type = true_type;
7262                 } else {
7263                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7264                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7265                         }
7266                         result_type = type_void;
7267                 }
7268         } else if (is_type_arithmetic(true_type)
7269                    && is_type_arithmetic(false_type)) {
7270                 result_type = semantic_arithmetic(true_type, false_type);
7271         } else if (same_compound_type(true_type, false_type)) {
7272                 /* just take 1 of the 2 types */
7273                 result_type = true_type;
7274         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7275                 type_t *pointer_type;
7276                 type_t *other_type;
7277                 expression_t *other_expression;
7278                 if (is_type_pointer(true_type) &&
7279                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7280                         pointer_type     = true_type;
7281                         other_type       = false_type;
7282                         other_expression = false_expression;
7283                 } else {
7284                         pointer_type     = false_type;
7285                         other_type       = true_type;
7286                         other_expression = true_expression;
7287                 }
7288
7289                 if (is_null_pointer_constant(other_expression)) {
7290                         result_type = pointer_type;
7291                 } else if (is_type_pointer(other_type)) {
7292                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7293                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7294
7295                         type_t *to;
7296                         if (is_type_void(to1) || is_type_void(to2)) {
7297                                 to = type_void;
7298                         } else if (types_compatible(get_unqualified_type(to1),
7299                                                     get_unqualified_type(to2))) {
7300                                 to = to1;
7301                         } else {
7302                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7303                                 to = type_void;
7304                         }
7305
7306                         type_t *const type =
7307                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7308                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7309                 } else if (is_type_integer(other_type)) {
7310                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7311                         result_type = pointer_type;
7312                 } else {
7313                         goto types_incompatible;
7314                 }
7315         } else {
7316 types_incompatible:
7317                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7318                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7319                 }
7320                 result_type = type_error_type;
7321         }
7322
7323         conditional->true_expression
7324                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7325         conditional->false_expression
7326                 = create_implicit_cast(false_expression, result_type);
7327         conditional->base.type = result_type;
7328         return result;
7329 }
7330
7331 /**
7332  * Parse an extension expression.
7333  */
7334 static expression_t *parse_extension(void)
7335 {
7336         PUSH_EXTENSION();
7337         expression_t *expression = parse_subexpression(PREC_UNARY);
7338         POP_EXTENSION();
7339         return expression;
7340 }
7341
7342 /**
7343  * Parse a __builtin_classify_type() expression.
7344  */
7345 static expression_t *parse_builtin_classify_type(void)
7346 {
7347         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7348         result->base.type    = type_int;
7349
7350         eat(T___builtin_classify_type);
7351
7352         add_anchor_token(')');
7353         expect('(');
7354         expression_t *expression = parse_expression();
7355         rem_anchor_token(')');
7356         expect(')');
7357         result->classify_type.type_expression = expression;
7358
7359         return result;
7360 }
7361
7362 /**
7363  * Parse a delete expression
7364  * ISO/IEC 14882:1998(E) §5.3.5
7365  */
7366 static expression_t *parse_delete(void)
7367 {
7368         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7369         result->base.type          = type_void;
7370
7371         eat(T_delete);
7372
7373         if (next_if('[')) {
7374                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7375                 expect(']');
7376         }
7377
7378         expression_t *const value = parse_subexpression(PREC_CAST);
7379         result->unary.value = value;
7380
7381         type_t *const type = skip_typeref(value->base.type);
7382         if (!is_type_pointer(type)) {
7383                 if (is_type_valid(type)) {
7384                         errorf(&value->base.source_position,
7385                                         "operand of delete must have pointer type");
7386                 }
7387         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7388                 source_position_t const *const pos = &value->base.source_position;
7389                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7390         }
7391
7392         return result;
7393 }
7394
7395 /**
7396  * Parse a throw expression
7397  * ISO/IEC 14882:1998(E) §15:1
7398  */
7399 static expression_t *parse_throw(void)
7400 {
7401         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7402         result->base.type          = type_void;
7403
7404         eat(T_throw);
7405
7406         expression_t *value = NULL;
7407         switch (token.kind) {
7408                 EXPRESSION_START {
7409                         value = parse_assignment_expression();
7410                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7411                         type_t *const orig_type = value->base.type;
7412                         type_t *const type      = skip_typeref(orig_type);
7413                         if (is_type_incomplete(type)) {
7414                                 errorf(&value->base.source_position,
7415                                                 "cannot throw object of incomplete type '%T'", orig_type);
7416                         } else if (is_type_pointer(type)) {
7417                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7418                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7419                                         errorf(&value->base.source_position,
7420                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7421                                 }
7422                         }
7423                 }
7424
7425                 default:
7426                         break;
7427         }
7428         result->unary.value = value;
7429
7430         return result;
7431 }
7432
7433 static bool check_pointer_arithmetic(const source_position_t *source_position,
7434                                      type_t *pointer_type,
7435                                      type_t *orig_pointer_type)
7436 {
7437         type_t *points_to = pointer_type->pointer.points_to;
7438         points_to = skip_typeref(points_to);
7439
7440         if (is_type_incomplete(points_to)) {
7441                 if (!GNU_MODE || !is_type_void(points_to)) {
7442                         errorf(source_position,
7443                                "arithmetic with pointer to incomplete type '%T' not allowed",
7444                                orig_pointer_type);
7445                         return false;
7446                 } else {
7447                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7448                 }
7449         } else if (is_type_function(points_to)) {
7450                 if (!GNU_MODE) {
7451                         errorf(source_position,
7452                                "arithmetic with pointer to function type '%T' not allowed",
7453                                orig_pointer_type);
7454                         return false;
7455                 } else {
7456                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7457                 }
7458         }
7459         return true;
7460 }
7461
7462 static bool is_lvalue(const expression_t *expression)
7463 {
7464         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7465         switch (expression->kind) {
7466         case EXPR_ARRAY_ACCESS:
7467         case EXPR_COMPOUND_LITERAL:
7468         case EXPR_REFERENCE:
7469         case EXPR_SELECT:
7470         case EXPR_UNARY_DEREFERENCE:
7471                 return true;
7472
7473         default: {
7474                 type_t *type = skip_typeref(expression->base.type);
7475                 return
7476                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7477                         is_type_reference(type) ||
7478                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7479                          * error before, which maybe prevented properly recognizing it as
7480                          * lvalue. */
7481                         !is_type_valid(type);
7482         }
7483         }
7484 }
7485
7486 static void semantic_incdec(unary_expression_t *expression)
7487 {
7488         type_t *const orig_type = expression->value->base.type;
7489         type_t *const type      = skip_typeref(orig_type);
7490         if (is_type_pointer(type)) {
7491                 if (!check_pointer_arithmetic(&expression->base.source_position,
7492                                               type, orig_type)) {
7493                         return;
7494                 }
7495         } else if (!is_type_real(type) && is_type_valid(type)) {
7496                 /* TODO: improve error message */
7497                 errorf(&expression->base.source_position,
7498                        "operation needs an arithmetic or pointer type");
7499                 return;
7500         }
7501         if (!is_lvalue(expression->value)) {
7502                 /* TODO: improve error message */
7503                 errorf(&expression->base.source_position, "lvalue required as operand");
7504         }
7505         expression->base.type = orig_type;
7506 }
7507
7508 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7509 {
7510         type_t *const res_type = promote_integer(type);
7511         expr->base.type = res_type;
7512         expr->value     = create_implicit_cast(expr->value, res_type);
7513 }
7514
7515 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7516 {
7517         type_t *const orig_type = expression->value->base.type;
7518         type_t *const type      = skip_typeref(orig_type);
7519         if (!is_type_arithmetic(type)) {
7520                 if (is_type_valid(type)) {
7521                         /* TODO: improve error message */
7522                         errorf(&expression->base.source_position,
7523                                 "operation needs an arithmetic type");
7524                 }
7525                 return;
7526         } else if (is_type_integer(type)) {
7527                 promote_unary_int_expr(expression, type);
7528         } else {
7529                 expression->base.type = orig_type;
7530         }
7531 }
7532
7533 static void semantic_unexpr_plus(unary_expression_t *expression)
7534 {
7535         semantic_unexpr_arithmetic(expression);
7536         source_position_t const *const pos = &expression->base.source_position;
7537         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7538 }
7539
7540 static void semantic_not(unary_expression_t *expression)
7541 {
7542         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7543         semantic_condition(expression->value, "operand of !");
7544         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7545 }
7546
7547 static void semantic_unexpr_integer(unary_expression_t *expression)
7548 {
7549         type_t *const orig_type = expression->value->base.type;
7550         type_t *const type      = skip_typeref(orig_type);
7551         if (!is_type_integer(type)) {
7552                 if (is_type_valid(type)) {
7553                         errorf(&expression->base.source_position,
7554                                "operand of ~ must be of integer type");
7555                 }
7556                 return;
7557         }
7558
7559         promote_unary_int_expr(expression, type);
7560 }
7561
7562 static void semantic_dereference(unary_expression_t *expression)
7563 {
7564         type_t *const orig_type = expression->value->base.type;
7565         type_t *const type      = skip_typeref(orig_type);
7566         if (!is_type_pointer(type)) {
7567                 if (is_type_valid(type)) {
7568                         errorf(&expression->base.source_position,
7569                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7570                 }
7571                 return;
7572         }
7573
7574         type_t *result_type   = type->pointer.points_to;
7575         result_type           = automatic_type_conversion(result_type);
7576         expression->base.type = result_type;
7577 }
7578
7579 /**
7580  * Record that an address is taken (expression represents an lvalue).
7581  *
7582  * @param expression       the expression
7583  * @param may_be_register  if true, the expression might be an register
7584  */
7585 static void set_address_taken(expression_t *expression, bool may_be_register)
7586 {
7587         if (expression->kind != EXPR_REFERENCE)
7588                 return;
7589
7590         entity_t *const entity = expression->reference.entity;
7591
7592         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7593                 return;
7594
7595         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7596                         && !may_be_register) {
7597                 source_position_t const *const pos = &expression->base.source_position;
7598                 errorf(pos, "address of register '%N' requested", entity);
7599         }
7600
7601         entity->variable.address_taken = true;
7602 }
7603
7604 /**
7605  * Check the semantic of the address taken expression.
7606  */
7607 static void semantic_take_addr(unary_expression_t *expression)
7608 {
7609         expression_t *value = expression->value;
7610         value->base.type    = revert_automatic_type_conversion(value);
7611
7612         type_t *orig_type = value->base.type;
7613         type_t *type      = skip_typeref(orig_type);
7614         if (!is_type_valid(type))
7615                 return;
7616
7617         /* §6.5.3.2 */
7618         if (!is_lvalue(value)) {
7619                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7620         }
7621         if (is_bitfield(value)) {
7622                 errorf(&expression->base.source_position,
7623                        "'&' not allowed on bitfield");
7624         }
7625
7626         set_address_taken(value, false);
7627
7628         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7629 }
7630
7631 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7632 static expression_t *parse_##unexpression_type(void)                         \
7633 {                                                                            \
7634         expression_t *unary_expression                                           \
7635                 = allocate_expression_zero(unexpression_type);                       \
7636         eat(token_kind);                                                         \
7637         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7638                                                                                  \
7639         sfunc(&unary_expression->unary);                                         \
7640                                                                                  \
7641         return unary_expression;                                                 \
7642 }
7643
7644 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7645                                semantic_unexpr_arithmetic)
7646 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7647                                semantic_unexpr_plus)
7648 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7649                                semantic_not)
7650 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7651                                semantic_dereference)
7652 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7653                                semantic_take_addr)
7654 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7655                                semantic_unexpr_integer)
7656 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7657                                semantic_incdec)
7658 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7659                                semantic_incdec)
7660
7661 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7662                                                sfunc)                         \
7663 static expression_t *parse_##unexpression_type(expression_t *left)            \
7664 {                                                                             \
7665         expression_t *unary_expression                                            \
7666                 = allocate_expression_zero(unexpression_type);                        \
7667         eat(token_kind);                                                          \
7668         unary_expression->unary.value = left;                                     \
7669                                                                                   \
7670         sfunc(&unary_expression->unary);                                          \
7671                                                                               \
7672         return unary_expression;                                                  \
7673 }
7674
7675 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7676                                        EXPR_UNARY_POSTFIX_INCREMENT,
7677                                        semantic_incdec)
7678 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7679                                        EXPR_UNARY_POSTFIX_DECREMENT,
7680                                        semantic_incdec)
7681
7682 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7683 {
7684         /* TODO: handle complex + imaginary types */
7685
7686         type_left  = get_unqualified_type(type_left);
7687         type_right = get_unqualified_type(type_right);
7688
7689         /* §6.3.1.8 Usual arithmetic conversions */
7690         if (type_left == type_long_double || type_right == type_long_double) {
7691                 return type_long_double;
7692         } else if (type_left == type_double || type_right == type_double) {
7693                 return type_double;
7694         } else if (type_left == type_float || type_right == type_float) {
7695                 return type_float;
7696         }
7697
7698         type_left  = promote_integer(type_left);
7699         type_right = promote_integer(type_right);
7700
7701         if (type_left == type_right)
7702                 return type_left;
7703
7704         bool     const signed_left  = is_type_signed(type_left);
7705         bool     const signed_right = is_type_signed(type_right);
7706         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7707         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7708
7709         if (signed_left == signed_right)
7710                 return rank_left >= rank_right ? type_left : type_right;
7711
7712         unsigned           s_rank;
7713         unsigned           u_rank;
7714         atomic_type_kind_t s_akind;
7715         atomic_type_kind_t u_akind;
7716         type_t *s_type;
7717         type_t *u_type;
7718         if (signed_left) {
7719                 s_type = type_left;
7720                 u_type = type_right;
7721         } else {
7722                 s_type = type_right;
7723                 u_type = type_left;
7724         }
7725         s_akind = get_akind(s_type);
7726         u_akind = get_akind(u_type);
7727         s_rank  = get_akind_rank(s_akind);
7728         u_rank  = get_akind_rank(u_akind);
7729
7730         if (u_rank >= s_rank)
7731                 return u_type;
7732
7733         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7734                 return s_type;
7735
7736         switch (s_akind) {
7737         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7738         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7739         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7740
7741         default: panic("invalid atomic type");
7742         }
7743 }
7744
7745 /**
7746  * Check the semantic restrictions for a binary expression.
7747  */
7748 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7749 {
7750         expression_t *const left            = expression->left;
7751         expression_t *const right           = expression->right;
7752         type_t       *const orig_type_left  = left->base.type;
7753         type_t       *const orig_type_right = right->base.type;
7754         type_t       *const type_left       = skip_typeref(orig_type_left);
7755         type_t       *const type_right      = skip_typeref(orig_type_right);
7756
7757         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7758                 /* TODO: improve error message */
7759                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7760                         errorf(&expression->base.source_position,
7761                                "operation needs arithmetic types");
7762                 }
7763                 return;
7764         }
7765
7766         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7767         expression->left      = create_implicit_cast(left, arithmetic_type);
7768         expression->right     = create_implicit_cast(right, arithmetic_type);
7769         expression->base.type = arithmetic_type;
7770 }
7771
7772 static void semantic_binexpr_integer(binary_expression_t *const expression)
7773 {
7774         expression_t *const left            = expression->left;
7775         expression_t *const right           = expression->right;
7776         type_t       *const orig_type_left  = left->base.type;
7777         type_t       *const orig_type_right = right->base.type;
7778         type_t       *const type_left       = skip_typeref(orig_type_left);
7779         type_t       *const type_right      = skip_typeref(orig_type_right);
7780
7781         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7782                 /* TODO: improve error message */
7783                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7784                         errorf(&expression->base.source_position,
7785                                "operation needs integer types");
7786                 }
7787                 return;
7788         }
7789
7790         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7791         expression->left      = create_implicit_cast(left, result_type);
7792         expression->right     = create_implicit_cast(right, result_type);
7793         expression->base.type = result_type;
7794 }
7795
7796 static void warn_div_by_zero(binary_expression_t const *const expression)
7797 {
7798         if (!is_type_integer(expression->base.type))
7799                 return;
7800
7801         expression_t const *const right = expression->right;
7802         /* The type of the right operand can be different for /= */
7803         if (is_type_integer(right->base.type)                    &&
7804             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7805             !fold_constant_to_bool(right)) {
7806                 source_position_t const *const pos = &expression->base.source_position;
7807                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7808         }
7809 }
7810
7811 /**
7812  * Check the semantic restrictions for a div/mod expression.
7813  */
7814 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7815 {
7816         semantic_binexpr_arithmetic(expression);
7817         warn_div_by_zero(expression);
7818 }
7819
7820 static void warn_addsub_in_shift(const expression_t *const expr)
7821 {
7822         if (expr->base.parenthesized)
7823                 return;
7824
7825         char op;
7826         switch (expr->kind) {
7827                 case EXPR_BINARY_ADD: op = '+'; break;
7828                 case EXPR_BINARY_SUB: op = '-'; break;
7829                 default:              return;
7830         }
7831
7832         source_position_t const *const pos = &expr->base.source_position;
7833         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7834 }
7835
7836 static bool semantic_shift(binary_expression_t *expression)
7837 {
7838         expression_t *const left            = expression->left;
7839         expression_t *const right           = expression->right;
7840         type_t       *const orig_type_left  = left->base.type;
7841         type_t       *const orig_type_right = right->base.type;
7842         type_t       *      type_left       = skip_typeref(orig_type_left);
7843         type_t       *      type_right      = skip_typeref(orig_type_right);
7844
7845         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7846                 /* TODO: improve error message */
7847                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7848                         errorf(&expression->base.source_position,
7849                                "operands of shift operation must have integer types");
7850                 }
7851                 return false;
7852         }
7853
7854         type_left = promote_integer(type_left);
7855
7856         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7857                 source_position_t const *const pos   = &right->base.source_position;
7858                 long                     const count = fold_constant_to_int(right);
7859                 if (count < 0) {
7860                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7861                 } else if ((unsigned long)count >=
7862                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7863                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7864                 }
7865         }
7866
7867         type_right        = promote_integer(type_right);
7868         expression->right = create_implicit_cast(right, type_right);
7869
7870         return true;
7871 }
7872
7873 static void semantic_shift_op(binary_expression_t *expression)
7874 {
7875         expression_t *const left  = expression->left;
7876         expression_t *const right = expression->right;
7877
7878         if (!semantic_shift(expression))
7879                 return;
7880
7881         warn_addsub_in_shift(left);
7882         warn_addsub_in_shift(right);
7883
7884         type_t *const orig_type_left = left->base.type;
7885         type_t *      type_left      = skip_typeref(orig_type_left);
7886
7887         type_left             = promote_integer(type_left);
7888         expression->left      = create_implicit_cast(left, type_left);
7889         expression->base.type = type_left;
7890 }
7891
7892 static void semantic_add(binary_expression_t *expression)
7893 {
7894         expression_t *const left            = expression->left;
7895         expression_t *const right           = expression->right;
7896         type_t       *const orig_type_left  = left->base.type;
7897         type_t       *const orig_type_right = right->base.type;
7898         type_t       *const type_left       = skip_typeref(orig_type_left);
7899         type_t       *const type_right      = skip_typeref(orig_type_right);
7900
7901         /* §6.5.6 */
7902         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7903                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7904                 expression->left  = create_implicit_cast(left, arithmetic_type);
7905                 expression->right = create_implicit_cast(right, arithmetic_type);
7906                 expression->base.type = arithmetic_type;
7907         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7908                 check_pointer_arithmetic(&expression->base.source_position,
7909                                          type_left, orig_type_left);
7910                 expression->base.type = type_left;
7911         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7912                 check_pointer_arithmetic(&expression->base.source_position,
7913                                          type_right, orig_type_right);
7914                 expression->base.type = type_right;
7915         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7916                 errorf(&expression->base.source_position,
7917                        "invalid operands to binary + ('%T', '%T')",
7918                        orig_type_left, orig_type_right);
7919         }
7920 }
7921
7922 static void semantic_sub(binary_expression_t *expression)
7923 {
7924         expression_t            *const left            = expression->left;
7925         expression_t            *const right           = expression->right;
7926         type_t                  *const orig_type_left  = left->base.type;
7927         type_t                  *const orig_type_right = right->base.type;
7928         type_t                  *const type_left       = skip_typeref(orig_type_left);
7929         type_t                  *const type_right      = skip_typeref(orig_type_right);
7930         source_position_t const *const pos             = &expression->base.source_position;
7931
7932         /* §5.6.5 */
7933         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7934                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7935                 expression->left        = create_implicit_cast(left, arithmetic_type);
7936                 expression->right       = create_implicit_cast(right, arithmetic_type);
7937                 expression->base.type =  arithmetic_type;
7938         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7939                 check_pointer_arithmetic(&expression->base.source_position,
7940                                          type_left, orig_type_left);
7941                 expression->base.type = type_left;
7942         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7943                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7944                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7945                 if (!types_compatible(unqual_left, unqual_right)) {
7946                         errorf(pos,
7947                                "subtracting pointers to incompatible types '%T' and '%T'",
7948                                orig_type_left, orig_type_right);
7949                 } else if (!is_type_object(unqual_left)) {
7950                         if (!is_type_void(unqual_left)) {
7951                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7952                                        orig_type_left);
7953                         } else {
7954                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7955                         }
7956                 }
7957                 expression->base.type = type_ptrdiff_t;
7958         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7959                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7960                        orig_type_left, orig_type_right);
7961         }
7962 }
7963
7964 static void warn_string_literal_address(expression_t const* expr)
7965 {
7966         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7967                 expr = expr->unary.value;
7968                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7969                         return;
7970                 expr = expr->unary.value;
7971         }
7972
7973         if (expr->kind == EXPR_STRING_LITERAL
7974                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
7975                 source_position_t const *const pos = &expr->base.source_position;
7976                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7977         }
7978 }
7979
7980 static bool maybe_negative(expression_t const *const expr)
7981 {
7982         switch (is_constant_expression(expr)) {
7983                 case EXPR_CLASS_ERROR:    return false;
7984                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7985                 default:                  return true;
7986         }
7987 }
7988
7989 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7990 {
7991         warn_string_literal_address(expr);
7992
7993         expression_t const* const ref = get_reference_address(expr);
7994         if (ref != NULL && is_null_pointer_constant(other)) {
7995                 entity_t const *const ent = ref->reference.entity;
7996                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7997         }
7998
7999         if (!expr->base.parenthesized) {
8000                 switch (expr->base.kind) {
8001                         case EXPR_BINARY_LESS:
8002                         case EXPR_BINARY_GREATER:
8003                         case EXPR_BINARY_LESSEQUAL:
8004                         case EXPR_BINARY_GREATEREQUAL:
8005                         case EXPR_BINARY_NOTEQUAL:
8006                         case EXPR_BINARY_EQUAL:
8007                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8008                                 break;
8009                         default:
8010                                 break;
8011                 }
8012         }
8013 }
8014
8015 /**
8016  * Check the semantics of comparison expressions.
8017  *
8018  * @param expression   The expression to check.
8019  */
8020 static void semantic_comparison(binary_expression_t *expression)
8021 {
8022         source_position_t const *const pos   = &expression->base.source_position;
8023         expression_t            *const left  = expression->left;
8024         expression_t            *const right = expression->right;
8025
8026         warn_comparison(pos, left, right);
8027         warn_comparison(pos, right, left);
8028
8029         type_t *orig_type_left  = left->base.type;
8030         type_t *orig_type_right = right->base.type;
8031         type_t *type_left       = skip_typeref(orig_type_left);
8032         type_t *type_right      = skip_typeref(orig_type_right);
8033
8034         /* TODO non-arithmetic types */
8035         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8036                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8037
8038                 /* test for signed vs unsigned compares */
8039                 if (is_type_integer(arithmetic_type)) {
8040                         bool const signed_left  = is_type_signed(type_left);
8041                         bool const signed_right = is_type_signed(type_right);
8042                         if (signed_left != signed_right) {
8043                                 /* FIXME long long needs better const folding magic */
8044                                 /* TODO check whether constant value can be represented by other type */
8045                                 if ((signed_left  && maybe_negative(left)) ||
8046                                                 (signed_right && maybe_negative(right))) {
8047                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8048                                 }
8049                         }
8050                 }
8051
8052                 expression->left        = create_implicit_cast(left, arithmetic_type);
8053                 expression->right       = create_implicit_cast(right, arithmetic_type);
8054                 expression->base.type   = arithmetic_type;
8055                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8056                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8057                     is_type_float(arithmetic_type)) {
8058                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8059                 }
8060         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8061                 /* TODO check compatibility */
8062         } else if (is_type_pointer(type_left)) {
8063                 expression->right = create_implicit_cast(right, type_left);
8064         } else if (is_type_pointer(type_right)) {
8065                 expression->left = create_implicit_cast(left, type_right);
8066         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8067                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8068         }
8069         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8070 }
8071
8072 /**
8073  * Checks if a compound type has constant fields.
8074  */
8075 static bool has_const_fields(const compound_type_t *type)
8076 {
8077         compound_t *compound = type->compound;
8078         entity_t   *entry    = compound->members.entities;
8079
8080         for (; entry != NULL; entry = entry->base.next) {
8081                 if (!is_declaration(entry))
8082                         continue;
8083
8084                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8085                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8086                         return true;
8087         }
8088
8089         return false;
8090 }
8091
8092 static bool is_valid_assignment_lhs(expression_t const* const left)
8093 {
8094         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8095         type_t *const type_left      = skip_typeref(orig_type_left);
8096
8097         if (!is_lvalue(left)) {
8098                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8099                        left);
8100                 return false;
8101         }
8102
8103         if (left->kind == EXPR_REFERENCE
8104                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8105                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8106                 return false;
8107         }
8108
8109         if (is_type_array(type_left)) {
8110                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8111                 return false;
8112         }
8113         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8114                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8115                        orig_type_left);
8116                 return false;
8117         }
8118         if (is_type_incomplete(type_left)) {
8119                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8120                        left, orig_type_left);
8121                 return false;
8122         }
8123         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8124                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8125                        left, orig_type_left);
8126                 return false;
8127         }
8128
8129         return true;
8130 }
8131
8132 static void semantic_arithmetic_assign(binary_expression_t *expression)
8133 {
8134         expression_t *left            = expression->left;
8135         expression_t *right           = expression->right;
8136         type_t       *orig_type_left  = left->base.type;
8137         type_t       *orig_type_right = right->base.type;
8138
8139         if (!is_valid_assignment_lhs(left))
8140                 return;
8141
8142         type_t *type_left  = skip_typeref(orig_type_left);
8143         type_t *type_right = skip_typeref(orig_type_right);
8144
8145         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8146                 /* TODO: improve error message */
8147                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8148                         errorf(&expression->base.source_position,
8149                                "operation needs arithmetic types");
8150                 }
8151                 return;
8152         }
8153
8154         /* combined instructions are tricky. We can't create an implicit cast on
8155          * the left side, because we need the uncasted form for the store.
8156          * The ast2firm pass has to know that left_type must be right_type
8157          * for the arithmetic operation and create a cast by itself */
8158         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8159         expression->right       = create_implicit_cast(right, arithmetic_type);
8160         expression->base.type   = type_left;
8161 }
8162
8163 static void semantic_divmod_assign(binary_expression_t *expression)
8164 {
8165         semantic_arithmetic_assign(expression);
8166         warn_div_by_zero(expression);
8167 }
8168
8169 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8170 {
8171         expression_t *const left            = expression->left;
8172         expression_t *const right           = expression->right;
8173         type_t       *const orig_type_left  = left->base.type;
8174         type_t       *const orig_type_right = right->base.type;
8175         type_t       *const type_left       = skip_typeref(orig_type_left);
8176         type_t       *const type_right      = skip_typeref(orig_type_right);
8177
8178         if (!is_valid_assignment_lhs(left))
8179                 return;
8180
8181         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8182                 /* combined instructions are tricky. We can't create an implicit cast on
8183                  * the left side, because we need the uncasted form for the store.
8184                  * The ast2firm pass has to know that left_type must be right_type
8185                  * for the arithmetic operation and create a cast by itself */
8186                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8187                 expression->right     = create_implicit_cast(right, arithmetic_type);
8188                 expression->base.type = type_left;
8189         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8190                 check_pointer_arithmetic(&expression->base.source_position,
8191                                          type_left, orig_type_left);
8192                 expression->base.type = type_left;
8193         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8194                 errorf(&expression->base.source_position,
8195                        "incompatible types '%T' and '%T' in assignment",
8196                        orig_type_left, orig_type_right);
8197         }
8198 }
8199
8200 static void semantic_integer_assign(binary_expression_t *expression)
8201 {
8202         expression_t *left            = expression->left;
8203         expression_t *right           = expression->right;
8204         type_t       *orig_type_left  = left->base.type;
8205         type_t       *orig_type_right = right->base.type;
8206
8207         if (!is_valid_assignment_lhs(left))
8208                 return;
8209
8210         type_t *type_left  = skip_typeref(orig_type_left);
8211         type_t *type_right = skip_typeref(orig_type_right);
8212
8213         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8214                 /* TODO: improve error message */
8215                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8216                         errorf(&expression->base.source_position,
8217                                "operation needs integer types");
8218                 }
8219                 return;
8220         }
8221
8222         /* combined instructions are tricky. We can't create an implicit cast on
8223          * the left side, because we need the uncasted form for the store.
8224          * The ast2firm pass has to know that left_type must be right_type
8225          * for the arithmetic operation and create a cast by itself */
8226         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8227         expression->right       = create_implicit_cast(right, arithmetic_type);
8228         expression->base.type   = type_left;
8229 }
8230
8231 static void semantic_shift_assign(binary_expression_t *expression)
8232 {
8233         expression_t *left           = expression->left;
8234
8235         if (!is_valid_assignment_lhs(left))
8236                 return;
8237
8238         if (!semantic_shift(expression))
8239                 return;
8240
8241         expression->base.type = skip_typeref(left->base.type);
8242 }
8243
8244 static void warn_logical_and_within_or(const expression_t *const expr)
8245 {
8246         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8247                 return;
8248         if (expr->base.parenthesized)
8249                 return;
8250         source_position_t const *const pos = &expr->base.source_position;
8251         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8252 }
8253
8254 /**
8255  * Check the semantic restrictions of a logical expression.
8256  */
8257 static void semantic_logical_op(binary_expression_t *expression)
8258 {
8259         /* §6.5.13:2  Each of the operands shall have scalar type.
8260          * §6.5.14:2  Each of the operands shall have scalar type. */
8261         semantic_condition(expression->left,   "left operand of logical operator");
8262         semantic_condition(expression->right, "right operand of logical operator");
8263         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8264                 warn_logical_and_within_or(expression->left);
8265                 warn_logical_and_within_or(expression->right);
8266         }
8267         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8268 }
8269
8270 /**
8271  * Check the semantic restrictions of a binary assign expression.
8272  */
8273 static void semantic_binexpr_assign(binary_expression_t *expression)
8274 {
8275         expression_t *left           = expression->left;
8276         type_t       *orig_type_left = left->base.type;
8277
8278         if (!is_valid_assignment_lhs(left))
8279                 return;
8280
8281         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8282         report_assign_error(error, orig_type_left, expression->right,
8283                         "assignment", &left->base.source_position);
8284         expression->right = create_implicit_cast(expression->right, orig_type_left);
8285         expression->base.type = orig_type_left;
8286 }
8287
8288 /**
8289  * Determine if the outermost operation (or parts thereof) of the given
8290  * expression has no effect in order to generate a warning about this fact.
8291  * Therefore in some cases this only examines some of the operands of the
8292  * expression (see comments in the function and examples below).
8293  * Examples:
8294  *   f() + 23;    // warning, because + has no effect
8295  *   x || f();    // no warning, because x controls execution of f()
8296  *   x ? y : f(); // warning, because y has no effect
8297  *   (void)x;     // no warning to be able to suppress the warning
8298  * This function can NOT be used for an "expression has definitely no effect"-
8299  * analysis. */
8300 static bool expression_has_effect(const expression_t *const expr)
8301 {
8302         switch (expr->kind) {
8303                 case EXPR_ERROR:                      return true; /* do NOT warn */
8304                 case EXPR_REFERENCE:                  return false;
8305                 case EXPR_ENUM_CONSTANT:              return false;
8306                 case EXPR_LABEL_ADDRESS:              return false;
8307
8308                 /* suppress the warning for microsoft __noop operations */
8309                 case EXPR_LITERAL_MS_NOOP:            return true;
8310                 case EXPR_LITERAL_BOOLEAN:
8311                 case EXPR_LITERAL_CHARACTER:
8312                 case EXPR_LITERAL_WIDE_CHARACTER:
8313                 case EXPR_LITERAL_INTEGER:
8314                 case EXPR_LITERAL_FLOATINGPOINT:
8315                 case EXPR_STRING_LITERAL:             return false;
8316                 case EXPR_WIDE_STRING_LITERAL:        return false;
8317
8318                 case EXPR_CALL: {
8319                         const call_expression_t *const call = &expr->call;
8320                         if (call->function->kind != EXPR_REFERENCE)
8321                                 return true;
8322
8323                         switch (call->function->reference.entity->function.btk) {
8324                                 /* FIXME: which builtins have no effect? */
8325                                 default:                      return true;
8326                         }
8327                 }
8328
8329                 /* Generate the warning if either the left or right hand side of a
8330                  * conditional expression has no effect */
8331                 case EXPR_CONDITIONAL: {
8332                         conditional_expression_t const *const cond = &expr->conditional;
8333                         expression_t             const *const t    = cond->true_expression;
8334                         return
8335                                 (t == NULL || expression_has_effect(t)) &&
8336                                 expression_has_effect(cond->false_expression);
8337                 }
8338
8339                 case EXPR_SELECT:                     return false;
8340                 case EXPR_ARRAY_ACCESS:               return false;
8341                 case EXPR_SIZEOF:                     return false;
8342                 case EXPR_CLASSIFY_TYPE:              return false;
8343                 case EXPR_ALIGNOF:                    return false;
8344
8345                 case EXPR_FUNCNAME:                   return false;
8346                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8347                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8348                 case EXPR_OFFSETOF:                   return false;
8349                 case EXPR_VA_START:                   return true;
8350                 case EXPR_VA_ARG:                     return true;
8351                 case EXPR_VA_COPY:                    return true;
8352                 case EXPR_STATEMENT:                  return true; // TODO
8353                 case EXPR_COMPOUND_LITERAL:           return false;
8354
8355                 case EXPR_UNARY_NEGATE:               return false;
8356                 case EXPR_UNARY_PLUS:                 return false;
8357                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8358                 case EXPR_UNARY_NOT:                  return false;
8359                 case EXPR_UNARY_DEREFERENCE:          return false;
8360                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8361                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8362                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8363                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8364                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8365
8366                 /* Treat void casts as if they have an effect in order to being able to
8367                  * suppress the warning */
8368                 case EXPR_UNARY_CAST: {
8369                         type_t *const type = skip_typeref(expr->base.type);
8370                         return is_type_void(type);
8371                 }
8372
8373                 case EXPR_UNARY_ASSUME:               return true;
8374                 case EXPR_UNARY_DELETE:               return true;
8375                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8376                 case EXPR_UNARY_THROW:                return true;
8377
8378                 case EXPR_BINARY_ADD:                 return false;
8379                 case EXPR_BINARY_SUB:                 return false;
8380                 case EXPR_BINARY_MUL:                 return false;
8381                 case EXPR_BINARY_DIV:                 return false;
8382                 case EXPR_BINARY_MOD:                 return false;
8383                 case EXPR_BINARY_EQUAL:               return false;
8384                 case EXPR_BINARY_NOTEQUAL:            return false;
8385                 case EXPR_BINARY_LESS:                return false;
8386                 case EXPR_BINARY_LESSEQUAL:           return false;
8387                 case EXPR_BINARY_GREATER:             return false;
8388                 case EXPR_BINARY_GREATEREQUAL:        return false;
8389                 case EXPR_BINARY_BITWISE_AND:         return false;
8390                 case EXPR_BINARY_BITWISE_OR:          return false;
8391                 case EXPR_BINARY_BITWISE_XOR:         return false;
8392                 case EXPR_BINARY_SHIFTLEFT:           return false;
8393                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8394                 case EXPR_BINARY_ASSIGN:              return true;
8395                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8396                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8397                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8398                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8399                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8400                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8401                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8402                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8403                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8404                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8405
8406                 /* Only examine the right hand side of && and ||, because the left hand
8407                  * side already has the effect of controlling the execution of the right
8408                  * hand side */
8409                 case EXPR_BINARY_LOGICAL_AND:
8410                 case EXPR_BINARY_LOGICAL_OR:
8411                 /* Only examine the right hand side of a comma expression, because the left
8412                  * hand side has a separate warning */
8413                 case EXPR_BINARY_COMMA:
8414                         return expression_has_effect(expr->binary.right);
8415
8416                 case EXPR_BINARY_ISGREATER:           return false;
8417                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8418                 case EXPR_BINARY_ISLESS:              return false;
8419                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8420                 case EXPR_BINARY_ISLESSGREATER:       return false;
8421                 case EXPR_BINARY_ISUNORDERED:         return false;
8422         }
8423
8424         internal_errorf(HERE, "unexpected expression");
8425 }
8426
8427 static void semantic_comma(binary_expression_t *expression)
8428 {
8429         const expression_t *const left = expression->left;
8430         if (!expression_has_effect(left)) {
8431                 source_position_t const *const pos = &left->base.source_position;
8432                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8433         }
8434         expression->base.type = expression->right->base.type;
8435 }
8436
8437 /**
8438  * @param prec_r precedence of the right operand
8439  */
8440 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8441 static expression_t *parse_##binexpression_type(expression_t *left)          \
8442 {                                                                            \
8443         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8444         binexpr->binary.left  = left;                                            \
8445         eat(token_kind);                                                         \
8446                                                                              \
8447         expression_t *right = parse_subexpression(prec_r);                       \
8448                                                                              \
8449         binexpr->binary.right = right;                                           \
8450         sfunc(&binexpr->binary);                                                 \
8451                                                                              \
8452         return binexpr;                                                          \
8453 }
8454
8455 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8456 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8457 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8458 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8459 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8460 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8461 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8462 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8463 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8464 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8465 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8466 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8467 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8468 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8469 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8470 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8471 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8472 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8473 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8474 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8475 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8476 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8477 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8478 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8479 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8480 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8481 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8482 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8483 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8484 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8485
8486
8487 static expression_t *parse_subexpression(precedence_t precedence)
8488 {
8489         expression_parser_function_t *parser
8490                 = &expression_parsers[token.kind];
8491         expression_t                 *left;
8492
8493         if (parser->parser != NULL) {
8494                 left = parser->parser();
8495         } else {
8496                 left = parse_primary_expression();
8497         }
8498         assert(left != NULL);
8499
8500         while (true) {
8501                 parser = &expression_parsers[token.kind];
8502                 if (parser->infix_parser == NULL)
8503                         break;
8504                 if (parser->infix_precedence < precedence)
8505                         break;
8506
8507                 left = parser->infix_parser(left);
8508
8509                 assert(left != NULL);
8510         }
8511
8512         return left;
8513 }
8514
8515 /**
8516  * Parse an expression.
8517  */
8518 static expression_t *parse_expression(void)
8519 {
8520         return parse_subexpression(PREC_EXPRESSION);
8521 }
8522
8523 /**
8524  * Register a parser for a prefix-like operator.
8525  *
8526  * @param parser      the parser function
8527  * @param token_kind  the token type of the prefix token
8528  */
8529 static void register_expression_parser(parse_expression_function parser,
8530                                        int token_kind)
8531 {
8532         expression_parser_function_t *entry = &expression_parsers[token_kind];
8533
8534         if (entry->parser != NULL) {
8535                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8536                 panic("trying to register multiple expression parsers for a token");
8537         }
8538         entry->parser = parser;
8539 }
8540
8541 /**
8542  * Register a parser for an infix operator with given precedence.
8543  *
8544  * @param parser      the parser function
8545  * @param token_kind  the token type of the infix operator
8546  * @param precedence  the precedence of the operator
8547  */
8548 static void register_infix_parser(parse_expression_infix_function parser,
8549                                   int token_kind, precedence_t precedence)
8550 {
8551         expression_parser_function_t *entry = &expression_parsers[token_kind];
8552
8553         if (entry->infix_parser != NULL) {
8554                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8555                 panic("trying to register multiple infix expression parsers for a "
8556                       "token");
8557         }
8558         entry->infix_parser     = parser;
8559         entry->infix_precedence = precedence;
8560 }
8561
8562 /**
8563  * Initialize the expression parsers.
8564  */
8565 static void init_expression_parsers(void)
8566 {
8567         memset(&expression_parsers, 0, sizeof(expression_parsers));
8568
8569         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8570         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8571         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8572         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8573         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8574         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8575         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8576         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8577         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8578         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8579         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8580         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8581         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8582         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8583         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8584         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8585         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8586         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8587         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8588         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8589         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8590         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8591         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8592         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8593         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8594         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8595         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8596         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8597         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8598         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8599         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8600         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8601         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8602         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8603         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8604         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8605         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8606
8607         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8608         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8609         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8610         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8611         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8612         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8613         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8614         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8615         register_expression_parser(parse_sizeof,                      T_sizeof);
8616         register_expression_parser(parse_alignof,                     T___alignof__);
8617         register_expression_parser(parse_extension,                   T___extension__);
8618         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8619         register_expression_parser(parse_delete,                      T_delete);
8620         register_expression_parser(parse_throw,                       T_throw);
8621 }
8622
8623 /**
8624  * Parse a asm statement arguments specification.
8625  */
8626 static asm_argument_t *parse_asm_arguments(bool is_out)
8627 {
8628         asm_argument_t  *result = NULL;
8629         asm_argument_t **anchor = &result;
8630
8631         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8632                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8633
8634                 if (next_if('[')) {
8635                         add_anchor_token(']');
8636                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8637                         rem_anchor_token(']');
8638                         expect(']');
8639                         if (!argument->symbol)
8640                                 return NULL;
8641                 }
8642
8643                 argument->constraints = parse_string_literals();
8644                 add_anchor_token(')');
8645                 expect('(');
8646                 expression_t *expression = parse_expression();
8647                 rem_anchor_token(')');
8648                 if (is_out) {
8649                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8650                          * change size or type representation (e.g. int -> long is ok, but
8651                          * int -> float is not) */
8652                         if (expression->kind == EXPR_UNARY_CAST) {
8653                                 type_t      *const type = expression->base.type;
8654                                 type_kind_t  const kind = type->kind;
8655                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8656                                         unsigned flags;
8657                                         unsigned size;
8658                                         if (kind == TYPE_ATOMIC) {
8659                                                 atomic_type_kind_t const akind = type->atomic.akind;
8660                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8661                                                 size  = get_atomic_type_size(akind);
8662                                         } else {
8663                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8664                                                 size  = get_type_size(type_void_ptr);
8665                                         }
8666
8667                                         do {
8668                                                 expression_t *const value      = expression->unary.value;
8669                                                 type_t       *const value_type = value->base.type;
8670                                                 type_kind_t   const value_kind = value_type->kind;
8671
8672                                                 unsigned value_flags;
8673                                                 unsigned value_size;
8674                                                 if (value_kind == TYPE_ATOMIC) {
8675                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8676                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8677                                                         value_size  = get_atomic_type_size(value_akind);
8678                                                 } else if (value_kind == TYPE_POINTER) {
8679                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8680                                                         value_size  = get_type_size(type_void_ptr);
8681                                                 } else {
8682                                                         break;
8683                                                 }
8684
8685                                                 if (value_flags != flags || value_size != size)
8686                                                         break;
8687
8688                                                 expression = value;
8689                                         } while (expression->kind == EXPR_UNARY_CAST);
8690                                 }
8691                         }
8692
8693                         if (!is_lvalue(expression)) {
8694                                 errorf(&expression->base.source_position,
8695                                        "asm output argument is not an lvalue");
8696                         }
8697
8698                         if (argument->constraints.begin[0] == '=')
8699                                 determine_lhs_ent(expression, NULL);
8700                         else
8701                                 mark_vars_read(expression, NULL);
8702                 } else {
8703                         mark_vars_read(expression, NULL);
8704                 }
8705                 argument->expression = expression;
8706                 expect(')');
8707
8708                 set_address_taken(expression, true);
8709
8710                 *anchor = argument;
8711                 anchor  = &argument->next;
8712
8713                 if (!next_if(','))
8714                         break;
8715         }
8716
8717         return result;
8718 }
8719
8720 /**
8721  * Parse a asm statement clobber specification.
8722  */
8723 static asm_clobber_t *parse_asm_clobbers(void)
8724 {
8725         asm_clobber_t *result  = NULL;
8726         asm_clobber_t **anchor = &result;
8727
8728         while (token.kind == T_STRING_LITERAL) {
8729                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8730                 clobber->clobber       = parse_string_literals();
8731
8732                 *anchor = clobber;
8733                 anchor  = &clobber->next;
8734
8735                 if (!next_if(','))
8736                         break;
8737         }
8738
8739         return result;
8740 }
8741
8742 /**
8743  * Parse an asm statement.
8744  */
8745 static statement_t *parse_asm_statement(void)
8746 {
8747         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8748         asm_statement_t *asm_statement = &statement->asms;
8749
8750         eat(T_asm);
8751
8752         if (next_if(T_volatile))
8753                 asm_statement->is_volatile = true;
8754
8755         expect('(');
8756         add_anchor_token(')');
8757         if (token.kind != T_STRING_LITERAL) {
8758                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8759                 goto end_of_asm;
8760         }
8761         asm_statement->asm_text = parse_string_literals();
8762
8763         add_anchor_token(':');
8764         if (!next_if(':')) {
8765                 rem_anchor_token(':');
8766                 goto end_of_asm;
8767         }
8768
8769         asm_statement->outputs = parse_asm_arguments(true);
8770         if (!next_if(':')) {
8771                 rem_anchor_token(':');
8772                 goto end_of_asm;
8773         }
8774
8775         asm_statement->inputs = parse_asm_arguments(false);
8776         if (!next_if(':')) {
8777                 rem_anchor_token(':');
8778                 goto end_of_asm;
8779         }
8780         rem_anchor_token(':');
8781
8782         asm_statement->clobbers = parse_asm_clobbers();
8783
8784 end_of_asm:
8785         rem_anchor_token(')');
8786         expect(')');
8787         expect(';');
8788
8789         if (asm_statement->outputs == NULL) {
8790                 /* GCC: An 'asm' instruction without any output operands will be treated
8791                  * identically to a volatile 'asm' instruction. */
8792                 asm_statement->is_volatile = true;
8793         }
8794
8795         return statement;
8796 }
8797
8798 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8799 {
8800         statement_t *inner_stmt;
8801         switch (token.kind) {
8802                 case '}':
8803                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8804                         inner_stmt = create_error_statement();
8805                         break;
8806
8807                 case ';':
8808                         if (label->kind == STATEMENT_LABEL) {
8809                                 /* Eat an empty statement here, to avoid the warning about an empty
8810                                  * statement after a label.  label:; is commonly used to have a label
8811                                  * before a closing brace. */
8812                                 inner_stmt = create_empty_statement();
8813                                 eat(';');
8814                                 break;
8815                         }
8816                         /* FALLTHROUGH */
8817
8818                 default:
8819                         inner_stmt = parse_statement();
8820                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8821                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8822                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8823                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8824                         }
8825                         break;
8826         }
8827         return inner_stmt;
8828 }
8829
8830 /**
8831  * Parse a case statement.
8832  */
8833 static statement_t *parse_case_statement(void)
8834 {
8835         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8836         source_position_t *const pos       = &statement->base.source_position;
8837
8838         eat(T_case);
8839         add_anchor_token(':');
8840
8841         expression_t *expression = parse_expression();
8842         type_t *expression_type = expression->base.type;
8843         type_t *skipped         = skip_typeref(expression_type);
8844         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8845                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8846                        expression, expression_type);
8847         }
8848
8849         type_t *type = expression_type;
8850         if (current_switch != NULL) {
8851                 type_t *switch_type = current_switch->expression->base.type;
8852                 if (is_type_valid(switch_type)) {
8853                         expression = create_implicit_cast(expression, switch_type);
8854                 }
8855         }
8856
8857         statement->case_label.expression = expression;
8858         expression_classification_t const expr_class = is_constant_expression(expression);
8859         if (expr_class != EXPR_CLASS_CONSTANT) {
8860                 if (expr_class != EXPR_CLASS_ERROR) {
8861                         errorf(pos, "case label does not reduce to an integer constant");
8862                 }
8863                 statement->case_label.is_bad = true;
8864         } else {
8865                 long const val = fold_constant_to_int(expression);
8866                 statement->case_label.first_case = val;
8867                 statement->case_label.last_case  = val;
8868         }
8869
8870         if (GNU_MODE) {
8871                 if (next_if(T_DOTDOTDOT)) {
8872                         expression_t *end_range = parse_expression();
8873                         expression_type = expression->base.type;
8874                         skipped         = skip_typeref(expression_type);
8875                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8876                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8877                                            expression, expression_type);
8878                         }
8879
8880                         end_range = create_implicit_cast(end_range, type);
8881                         statement->case_label.end_range = end_range;
8882                         expression_classification_t const end_class = is_constant_expression(end_range);
8883                         if (end_class != EXPR_CLASS_CONSTANT) {
8884                                 if (end_class != EXPR_CLASS_ERROR) {
8885                                         errorf(pos, "case range does not reduce to an integer constant");
8886                                 }
8887                                 statement->case_label.is_bad = true;
8888                         } else {
8889                                 long const val = fold_constant_to_int(end_range);
8890                                 statement->case_label.last_case = val;
8891
8892                                 if (val < statement->case_label.first_case) {
8893                                         statement->case_label.is_empty_range = true;
8894                                         warningf(WARN_OTHER, pos, "empty range specified");
8895                                 }
8896                         }
8897                 }
8898         }
8899
8900         PUSH_PARENT(statement);
8901
8902         rem_anchor_token(':');
8903         expect(':');
8904
8905         if (current_switch != NULL) {
8906                 if (! statement->case_label.is_bad) {
8907                         /* Check for duplicate case values */
8908                         case_label_statement_t *c = &statement->case_label;
8909                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8910                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8911                                         continue;
8912
8913                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8914                                         continue;
8915
8916                                 errorf(pos, "duplicate case value (previously used %P)",
8917                                        &l->base.source_position);
8918                                 break;
8919                         }
8920                 }
8921                 /* link all cases into the switch statement */
8922                 if (current_switch->last_case == NULL) {
8923                         current_switch->first_case      = &statement->case_label;
8924                 } else {
8925                         current_switch->last_case->next = &statement->case_label;
8926                 }
8927                 current_switch->last_case = &statement->case_label;
8928         } else {
8929                 errorf(pos, "case label not within a switch statement");
8930         }
8931
8932         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8933
8934         POP_PARENT();
8935         return statement;
8936 }
8937
8938 /**
8939  * Parse a default statement.
8940  */
8941 static statement_t *parse_default_statement(void)
8942 {
8943         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8944
8945         eat(T_default);
8946
8947         PUSH_PARENT(statement);
8948
8949         expect(':');
8950
8951         if (current_switch != NULL) {
8952                 const case_label_statement_t *def_label = current_switch->default_label;
8953                 if (def_label != NULL) {
8954                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8955                 } else {
8956                         current_switch->default_label = &statement->case_label;
8957
8958                         /* link all cases into the switch statement */
8959                         if (current_switch->last_case == NULL) {
8960                                 current_switch->first_case      = &statement->case_label;
8961                         } else {
8962                                 current_switch->last_case->next = &statement->case_label;
8963                         }
8964                         current_switch->last_case = &statement->case_label;
8965                 }
8966         } else {
8967                 errorf(&statement->base.source_position,
8968                         "'default' label not within a switch statement");
8969         }
8970
8971         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8972
8973         POP_PARENT();
8974         return statement;
8975 }
8976
8977 /**
8978  * Parse a label statement.
8979  */
8980 static statement_t *parse_label_statement(void)
8981 {
8982         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8983         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8984         statement->label.label = label;
8985
8986         PUSH_PARENT(statement);
8987
8988         /* if statement is already set then the label is defined twice,
8989          * otherwise it was just mentioned in a goto/local label declaration so far
8990          */
8991         source_position_t const* const pos = &statement->base.source_position;
8992         if (label->statement != NULL) {
8993                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8994         } else {
8995                 label->base.source_position = *pos;
8996                 label->statement            = statement;
8997         }
8998
8999         eat(':');
9000
9001         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9002                 parse_attributes(NULL); // TODO process attributes
9003         }
9004
9005         statement->label.statement = parse_label_inner_statement(statement, "label");
9006
9007         /* remember the labels in a list for later checking */
9008         *label_anchor = &statement->label;
9009         label_anchor  = &statement->label.next;
9010
9011         POP_PARENT();
9012         return statement;
9013 }
9014
9015 static statement_t *parse_inner_statement(void)
9016 {
9017         statement_t *const stmt = parse_statement();
9018         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9019         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9020         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9021                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9022         }
9023         return stmt;
9024 }
9025
9026 /**
9027  * Parse an expression in parentheses and mark its variables as read.
9028  */
9029 static expression_t *parse_condition(void)
9030 {
9031         add_anchor_token(')');
9032         expect('(');
9033         expression_t *const expr = parse_expression();
9034         mark_vars_read(expr, NULL);
9035         rem_anchor_token(')');
9036         expect(')');
9037         return expr;
9038 }
9039
9040 /**
9041  * Parse an if statement.
9042  */
9043 static statement_t *parse_if(void)
9044 {
9045         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9046
9047         eat(T_if);
9048
9049         PUSH_PARENT(statement);
9050         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9051
9052         add_anchor_token(T_else);
9053
9054         expression_t *const expr = parse_condition();
9055         statement->ifs.condition = expr;
9056         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9057          *             scalar type. */
9058         semantic_condition(expr, "condition of 'if'-statment");
9059
9060         statement_t *const true_stmt = parse_inner_statement();
9061         statement->ifs.true_statement = true_stmt;
9062         rem_anchor_token(T_else);
9063
9064         if (true_stmt->kind == STATEMENT_EMPTY) {
9065                 warningf(WARN_EMPTY_BODY, HERE,
9066                         "suggest braces around empty body in an ‘if’ statement");
9067         }
9068
9069         if (next_if(T_else)) {
9070                 statement->ifs.false_statement = parse_inner_statement();
9071
9072                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9073                         warningf(WARN_EMPTY_BODY, HERE,
9074                                         "suggest braces around empty body in an ‘if’ statement");
9075                 }
9076         } else if (true_stmt->kind == STATEMENT_IF &&
9077                         true_stmt->ifs.false_statement != NULL) {
9078                 source_position_t const *const pos = &true_stmt->base.source_position;
9079                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9080         }
9081
9082         POP_SCOPE();
9083         POP_PARENT();
9084         return statement;
9085 }
9086
9087 /**
9088  * Check that all enums are handled in a switch.
9089  *
9090  * @param statement  the switch statement to check
9091  */
9092 static void check_enum_cases(const switch_statement_t *statement)
9093 {
9094         if (!is_warn_on(WARN_SWITCH_ENUM))
9095                 return;
9096         const type_t *type = skip_typeref(statement->expression->base.type);
9097         if (! is_type_enum(type))
9098                 return;
9099         const enum_type_t *enumt = &type->enumt;
9100
9101         /* if we have a default, no warnings */
9102         if (statement->default_label != NULL)
9103                 return;
9104
9105         /* FIXME: calculation of value should be done while parsing */
9106         /* TODO: quadratic algorithm here. Change to an n log n one */
9107         long            last_value = -1;
9108         const entity_t *entry      = enumt->enume->base.next;
9109         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9110              entry = entry->base.next) {
9111                 const expression_t *expression = entry->enum_value.value;
9112                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9113                 bool                found      = false;
9114                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9115                         if (l->expression == NULL)
9116                                 continue;
9117                         if (l->first_case <= value && value <= l->last_case) {
9118                                 found = true;
9119                                 break;
9120                         }
9121                 }
9122                 if (!found) {
9123                         source_position_t const *const pos = &statement->base.source_position;
9124                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9125                 }
9126                 last_value = value;
9127         }
9128 }
9129
9130 /**
9131  * Parse a switch statement.
9132  */
9133 static statement_t *parse_switch(void)
9134 {
9135         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9136
9137         eat(T_switch);
9138
9139         PUSH_PARENT(statement);
9140         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9141
9142         expression_t *const expr = parse_condition();
9143         type_t       *      type = skip_typeref(expr->base.type);
9144         if (is_type_integer(type)) {
9145                 type = promote_integer(type);
9146                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9147                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9148                 }
9149         } else if (is_type_valid(type)) {
9150                 errorf(&expr->base.source_position,
9151                        "switch quantity is not an integer, but '%T'", type);
9152                 type = type_error_type;
9153         }
9154         statement->switchs.expression = create_implicit_cast(expr, type);
9155
9156         switch_statement_t *rem = current_switch;
9157         current_switch          = &statement->switchs;
9158         statement->switchs.body = parse_inner_statement();
9159         current_switch          = rem;
9160
9161         if (statement->switchs.default_label == NULL) {
9162                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9163         }
9164         check_enum_cases(&statement->switchs);
9165
9166         POP_SCOPE();
9167         POP_PARENT();
9168         return statement;
9169 }
9170
9171 static statement_t *parse_loop_body(statement_t *const loop)
9172 {
9173         statement_t *const rem = current_loop;
9174         current_loop = loop;
9175
9176         statement_t *const body = parse_inner_statement();
9177
9178         current_loop = rem;
9179         return body;
9180 }
9181
9182 /**
9183  * Parse a while statement.
9184  */
9185 static statement_t *parse_while(void)
9186 {
9187         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9188
9189         eat(T_while);
9190
9191         PUSH_PARENT(statement);
9192         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9193
9194         expression_t *const cond = parse_condition();
9195         statement->whiles.condition = cond;
9196         /* §6.8.5:2    The controlling expression of an iteration statement shall
9197          *             have scalar type. */
9198         semantic_condition(cond, "condition of 'while'-statement");
9199
9200         statement->whiles.body = parse_loop_body(statement);
9201
9202         POP_SCOPE();
9203         POP_PARENT();
9204         return statement;
9205 }
9206
9207 /**
9208  * Parse a do statement.
9209  */
9210 static statement_t *parse_do(void)
9211 {
9212         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9213
9214         eat(T_do);
9215
9216         PUSH_PARENT(statement);
9217         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9218
9219         add_anchor_token(T_while);
9220         statement->do_while.body = parse_loop_body(statement);
9221         rem_anchor_token(T_while);
9222
9223         expect(T_while);
9224         expression_t *const cond = parse_condition();
9225         statement->do_while.condition = cond;
9226         /* §6.8.5:2    The controlling expression of an iteration statement shall
9227          *             have scalar type. */
9228         semantic_condition(cond, "condition of 'do-while'-statement");
9229         expect(';');
9230
9231         POP_SCOPE();
9232         POP_PARENT();
9233         return statement;
9234 }
9235
9236 /**
9237  * Parse a for statement.
9238  */
9239 static statement_t *parse_for(void)
9240 {
9241         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9242
9243         eat(T_for);
9244
9245         PUSH_PARENT(statement);
9246         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9247
9248         add_anchor_token(')');
9249         expect('(');
9250
9251         PUSH_EXTENSION();
9252
9253         if (next_if(';')) {
9254         } else if (is_declaration_specifier(&token)) {
9255                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9256         } else {
9257                 add_anchor_token(';');
9258                 expression_t *const init = parse_expression();
9259                 statement->fors.initialisation = init;
9260                 mark_vars_read(init, ENT_ANY);
9261                 if (!expression_has_effect(init)) {
9262                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9263                 }
9264                 rem_anchor_token(';');
9265                 expect(';');
9266         }
9267
9268         POP_EXTENSION();
9269
9270         if (token.kind != ';') {
9271                 add_anchor_token(';');
9272                 expression_t *const cond = parse_expression();
9273                 statement->fors.condition = cond;
9274                 /* §6.8.5:2    The controlling expression of an iteration statement
9275                  *             shall have scalar type. */
9276                 semantic_condition(cond, "condition of 'for'-statement");
9277                 mark_vars_read(cond, NULL);
9278                 rem_anchor_token(';');
9279         }
9280         expect(';');
9281         if (token.kind != ')') {
9282                 expression_t *const step = parse_expression();
9283                 statement->fors.step = step;
9284                 mark_vars_read(step, ENT_ANY);
9285                 if (!expression_has_effect(step)) {
9286                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9287                 }
9288         }
9289         rem_anchor_token(')');
9290         expect(')');
9291         statement->fors.body = parse_loop_body(statement);
9292
9293         POP_SCOPE();
9294         POP_PARENT();
9295         return statement;
9296 }
9297
9298 /**
9299  * Parse a goto statement.
9300  */
9301 static statement_t *parse_goto(void)
9302 {
9303         statement_t *statement;
9304         if (GNU_MODE && look_ahead(1)->kind == '*') {
9305                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9306                 eat(T_goto);
9307                 eat('*');
9308
9309                 expression_t *expression = parse_expression();
9310                 mark_vars_read(expression, NULL);
9311
9312                 /* Argh: although documentation says the expression must be of type void*,
9313                  * gcc accepts anything that can be casted into void* without error */
9314                 type_t *type = expression->base.type;
9315
9316                 if (type != type_error_type) {
9317                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9318                                 errorf(&expression->base.source_position,
9319                                         "cannot convert to a pointer type");
9320                         } else if (type != type_void_ptr) {
9321                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9322                         }
9323                         expression = create_implicit_cast(expression, type_void_ptr);
9324                 }
9325
9326                 statement->computed_goto.expression = expression;
9327         } else {
9328                 statement = allocate_statement_zero(STATEMENT_GOTO);
9329                 eat(T_goto);
9330
9331                 label_t *const label = get_label("while parsing goto");
9332                 if (label) {
9333                         label->used            = true;
9334                         statement->gotos.label = label;
9335
9336                         /* remember the goto's in a list for later checking */
9337                         *goto_anchor = &statement->gotos;
9338                         goto_anchor  = &statement->gotos.next;
9339                 } else {
9340                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9341                 }
9342         }
9343
9344         expect(';');
9345         return statement;
9346 }
9347
9348 /**
9349  * Parse a continue statement.
9350  */
9351 static statement_t *parse_continue(void)
9352 {
9353         if (current_loop == NULL) {
9354                 errorf(HERE, "continue statement not within loop");
9355         }
9356
9357         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9358
9359         eat(T_continue);
9360         expect(';');
9361         return statement;
9362 }
9363
9364 /**
9365  * Parse a break statement.
9366  */
9367 static statement_t *parse_break(void)
9368 {
9369         if (current_switch == NULL && current_loop == NULL) {
9370                 errorf(HERE, "break statement not within loop or switch");
9371         }
9372
9373         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9374
9375         eat(T_break);
9376         expect(';');
9377         return statement;
9378 }
9379
9380 /**
9381  * Parse a __leave statement.
9382  */
9383 static statement_t *parse_leave_statement(void)
9384 {
9385         if (current_try == NULL) {
9386                 errorf(HERE, "__leave statement not within __try");
9387         }
9388
9389         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9390
9391         eat(T___leave);
9392         expect(';');
9393         return statement;
9394 }
9395
9396 /**
9397  * Check if a given entity represents a local variable.
9398  */
9399 static bool is_local_variable(const entity_t *entity)
9400 {
9401         if (entity->kind != ENTITY_VARIABLE)
9402                 return false;
9403
9404         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9405         case STORAGE_CLASS_AUTO:
9406         case STORAGE_CLASS_REGISTER: {
9407                 const type_t *type = skip_typeref(entity->declaration.type);
9408                 if (is_type_function(type)) {
9409                         return false;
9410                 } else {
9411                         return true;
9412                 }
9413         }
9414         default:
9415                 return false;
9416         }
9417 }
9418
9419 /**
9420  * Check if a given expression represents a local variable.
9421  */
9422 static bool expression_is_local_variable(const expression_t *expression)
9423 {
9424         if (expression->base.kind != EXPR_REFERENCE) {
9425                 return false;
9426         }
9427         const entity_t *entity = expression->reference.entity;
9428         return is_local_variable(entity);
9429 }
9430
9431 /**
9432  * Check if a given expression represents a local variable and
9433  * return its declaration then, else return NULL.
9434  */
9435 entity_t *expression_is_variable(const expression_t *expression)
9436 {
9437         if (expression->base.kind != EXPR_REFERENCE) {
9438                 return NULL;
9439         }
9440         entity_t *entity = expression->reference.entity;
9441         if (entity->kind != ENTITY_VARIABLE)
9442                 return NULL;
9443
9444         return entity;
9445 }
9446
9447 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9448 {
9449         if (c_mode & _CXX || strict_mode) {
9450                 errorf(pos, msg);
9451         } else {
9452                 warningf(WARN_OTHER, pos, msg);
9453         }
9454 }
9455
9456 /**
9457  * Parse a return statement.
9458  */
9459 static statement_t *parse_return(void)
9460 {
9461         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9462         eat(T_return);
9463
9464         expression_t *return_value = NULL;
9465         if (token.kind != ';') {
9466                 return_value = parse_expression();
9467                 mark_vars_read(return_value, NULL);
9468         }
9469
9470         const type_t *const func_type = skip_typeref(current_function->base.type);
9471         assert(is_type_function(func_type));
9472         type_t *const return_type = skip_typeref(func_type->function.return_type);
9473
9474         source_position_t const *const pos = &statement->base.source_position;
9475         if (return_value != NULL) {
9476                 type_t *return_value_type = skip_typeref(return_value->base.type);
9477
9478                 if (is_type_void(return_type)) {
9479                         if (!is_type_void(return_value_type)) {
9480                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9481                                 /* Only warn in C mode, because GCC does the same */
9482                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9483                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9484                                 /* Only warn in C mode, because GCC does the same */
9485                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9486                         }
9487                 } else {
9488                         assign_error_t error = semantic_assign(return_type, return_value);
9489                         report_assign_error(error, return_type, return_value, "'return'",
9490                                             pos);
9491                 }
9492                 return_value = create_implicit_cast(return_value, return_type);
9493                 /* check for returning address of a local var */
9494                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9495                         const expression_t *expression = return_value->unary.value;
9496                         if (expression_is_local_variable(expression)) {
9497                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9498                         }
9499                 }
9500         } else if (!is_type_void(return_type)) {
9501                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9502                 err_or_warn(pos, "'return' without value, in function returning non-void");
9503         }
9504         statement->returns.value = return_value;
9505
9506         expect(';');
9507         return statement;
9508 }
9509
9510 /**
9511  * Parse a declaration statement.
9512  */
9513 static statement_t *parse_declaration_statement(void)
9514 {
9515         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9516
9517         entity_t *before = current_scope->last_entity;
9518         if (GNU_MODE) {
9519                 parse_external_declaration();
9520         } else {
9521                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9522         }
9523
9524         declaration_statement_t *const decl  = &statement->declaration;
9525         entity_t                *const begin =
9526                 before != NULL ? before->base.next : current_scope->entities;
9527         decl->declarations_begin = begin;
9528         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9529
9530         return statement;
9531 }
9532
9533 /**
9534  * Parse an expression statement, ie. expr ';'.
9535  */
9536 static statement_t *parse_expression_statement(void)
9537 {
9538         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9539
9540         expression_t *const expr         = parse_expression();
9541         statement->expression.expression = expr;
9542         mark_vars_read(expr, ENT_ANY);
9543
9544         expect(';');
9545         return statement;
9546 }
9547
9548 /**
9549  * Parse a microsoft __try { } __finally { } or
9550  * __try{ } __except() { }
9551  */
9552 static statement_t *parse_ms_try_statment(void)
9553 {
9554         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9555         eat(T___try);
9556
9557         PUSH_PARENT(statement);
9558
9559         ms_try_statement_t *rem = current_try;
9560         current_try = &statement->ms_try;
9561         statement->ms_try.try_statement = parse_compound_statement(false);
9562         current_try = rem;
9563
9564         POP_PARENT();
9565
9566         if (next_if(T___except)) {
9567                 expression_t *const expr = parse_condition();
9568                 type_t       *      type = skip_typeref(expr->base.type);
9569                 if (is_type_integer(type)) {
9570                         type = promote_integer(type);
9571                 } else if (is_type_valid(type)) {
9572                         errorf(&expr->base.source_position,
9573                                "__expect expression is not an integer, but '%T'", type);
9574                         type = type_error_type;
9575                 }
9576                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9577         } else if (!next_if(T__finally)) {
9578                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9579         }
9580         statement->ms_try.final_statement = parse_compound_statement(false);
9581         return statement;
9582 }
9583
9584 static statement_t *parse_empty_statement(void)
9585 {
9586         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9587         statement_t *const statement = create_empty_statement();
9588         eat(';');
9589         return statement;
9590 }
9591
9592 static statement_t *parse_local_label_declaration(void)
9593 {
9594         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9595
9596         eat(T___label__);
9597
9598         entity_t *begin   = NULL;
9599         entity_t *end     = NULL;
9600         entity_t **anchor = &begin;
9601         add_anchor_token(';');
9602         add_anchor_token(',');
9603         do {
9604                 source_position_t pos;
9605                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9606                 if (symbol) {
9607                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9608                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9609                                 source_position_t const *const ppos = &entity->base.source_position;
9610                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9611                         } else {
9612                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9613                                 entity->base.parent_scope = current_scope;
9614
9615                                 *anchor = entity;
9616                                 anchor  = &entity->base.next;
9617                                 end     = entity;
9618
9619                                 environment_push(entity);
9620                         }
9621                 }
9622         } while (next_if(','));
9623         rem_anchor_token(',');
9624         rem_anchor_token(';');
9625         expect(';');
9626         statement->declaration.declarations_begin = begin;
9627         statement->declaration.declarations_end   = end;
9628         return statement;
9629 }
9630
9631 static void parse_namespace_definition(void)
9632 {
9633         eat(T_namespace);
9634
9635         entity_t *entity = NULL;
9636         symbol_t *symbol = NULL;
9637
9638         if (token.kind == T_IDENTIFIER) {
9639                 symbol = token.base.symbol;
9640                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9641                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9642                         entity = NULL;
9643                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9644                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9645                         }
9646                 }
9647                 eat(T_IDENTIFIER);
9648         }
9649
9650         if (entity == NULL) {
9651                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9652                 entity->base.parent_scope = current_scope;
9653         }
9654
9655         if (token.kind == '=') {
9656                 /* TODO: parse namespace alias */
9657                 panic("namespace alias definition not supported yet");
9658         }
9659
9660         environment_push(entity);
9661         append_entity(current_scope, entity);
9662
9663         PUSH_SCOPE(&entity->namespacee.members);
9664         PUSH_CURRENT_ENTITY(entity);
9665
9666         add_anchor_token('}');
9667         expect('{');
9668         parse_externals();
9669         rem_anchor_token('}');
9670         expect('}');
9671
9672         POP_CURRENT_ENTITY();
9673         POP_SCOPE();
9674 }
9675
9676 /**
9677  * Parse a statement.
9678  * There's also parse_statement() which additionally checks for
9679  * "statement has no effect" warnings
9680  */
9681 static statement_t *intern_parse_statement(void)
9682 {
9683         /* declaration or statement */
9684         statement_t *statement;
9685         switch (token.kind) {
9686         case T_IDENTIFIER: {
9687                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9688                 if (la1_type == ':') {
9689                         statement = parse_label_statement();
9690                 } else if (is_typedef_symbol(token.base.symbol)) {
9691                         statement = parse_declaration_statement();
9692                 } else {
9693                         /* it's an identifier, the grammar says this must be an
9694                          * expression statement. However it is common that users mistype
9695                          * declaration types, so we guess a bit here to improve robustness
9696                          * for incorrect programs */
9697                         switch (la1_type) {
9698                         case '&':
9699                         case '*':
9700                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9701                         default:
9702                                         statement = parse_expression_statement();
9703                                 } else {
9704                         DECLARATION_START
9705                         case T_IDENTIFIER:
9706                                         statement = parse_declaration_statement();
9707                                 }
9708                                 break;
9709                         }
9710                 }
9711                 break;
9712         }
9713
9714         case T___extension__: {
9715                 /* This can be a prefix to a declaration or an expression statement.
9716                  * We simply eat it now and parse the rest with tail recursion. */
9717                 PUSH_EXTENSION();
9718                 statement = intern_parse_statement();
9719                 POP_EXTENSION();
9720                 break;
9721         }
9722
9723         DECLARATION_START
9724                 statement = parse_declaration_statement();
9725                 break;
9726
9727         case T___label__:
9728                 statement = parse_local_label_declaration();
9729                 break;
9730
9731         case ';':         statement = parse_empty_statement();         break;
9732         case '{':         statement = parse_compound_statement(false); break;
9733         case T___leave:   statement = parse_leave_statement();         break;
9734         case T___try:     statement = parse_ms_try_statment();         break;
9735         case T_asm:       statement = parse_asm_statement();           break;
9736         case T_break:     statement = parse_break();                   break;
9737         case T_case:      statement = parse_case_statement();          break;
9738         case T_continue:  statement = parse_continue();                break;
9739         case T_default:   statement = parse_default_statement();       break;
9740         case T_do:        statement = parse_do();                      break;
9741         case T_for:       statement = parse_for();                     break;
9742         case T_goto:      statement = parse_goto();                    break;
9743         case T_if:        statement = parse_if();                      break;
9744         case T_return:    statement = parse_return();                  break;
9745         case T_switch:    statement = parse_switch();                  break;
9746         case T_while:     statement = parse_while();                   break;
9747
9748         EXPRESSION_START
9749                 statement = parse_expression_statement();
9750                 break;
9751
9752         default:
9753                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9754                 statement = create_error_statement();
9755                 eat_until_anchor();
9756                 break;
9757         }
9758
9759         return statement;
9760 }
9761
9762 /**
9763  * parse a statement and emits "statement has no effect" warning if needed
9764  * (This is really a wrapper around intern_parse_statement with check for 1
9765  *  single warning. It is needed, because for statement expressions we have
9766  *  to avoid the warning on the last statement)
9767  */
9768 static statement_t *parse_statement(void)
9769 {
9770         statement_t *statement = intern_parse_statement();
9771
9772         if (statement->kind == STATEMENT_EXPRESSION) {
9773                 expression_t *expression = statement->expression.expression;
9774                 if (!expression_has_effect(expression)) {
9775                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9776                 }
9777         }
9778
9779         return statement;
9780 }
9781
9782 /**
9783  * Parse a compound statement.
9784  */
9785 static statement_t *parse_compound_statement(bool inside_expression_statement)
9786 {
9787         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9788
9789         PUSH_PARENT(statement);
9790         PUSH_SCOPE(&statement->compound.scope);
9791
9792         eat('{');
9793         add_anchor_token('}');
9794         /* tokens, which can start a statement */
9795         /* TODO MS, __builtin_FOO */
9796         add_anchor_token('!');
9797         add_anchor_token('&');
9798         add_anchor_token('(');
9799         add_anchor_token('*');
9800         add_anchor_token('+');
9801         add_anchor_token('-');
9802         add_anchor_token(';');
9803         add_anchor_token('{');
9804         add_anchor_token('~');
9805         add_anchor_token(T_CHARACTER_CONSTANT);
9806         add_anchor_token(T_COLONCOLON);
9807         add_anchor_token(T_FLOATINGPOINT);
9808         add_anchor_token(T_IDENTIFIER);
9809         add_anchor_token(T_INTEGER);
9810         add_anchor_token(T_MINUSMINUS);
9811         add_anchor_token(T_PLUSPLUS);
9812         add_anchor_token(T_STRING_LITERAL);
9813         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9814         add_anchor_token(T_WIDE_STRING_LITERAL);
9815         add_anchor_token(T__Bool);
9816         add_anchor_token(T__Complex);
9817         add_anchor_token(T__Imaginary);
9818         add_anchor_token(T___FUNCTION__);
9819         add_anchor_token(T___PRETTY_FUNCTION__);
9820         add_anchor_token(T___alignof__);
9821         add_anchor_token(T___attribute__);
9822         add_anchor_token(T___builtin_va_start);
9823         add_anchor_token(T___extension__);
9824         add_anchor_token(T___func__);
9825         add_anchor_token(T___imag__);
9826         add_anchor_token(T___label__);
9827         add_anchor_token(T___real__);
9828         add_anchor_token(T___thread);
9829         add_anchor_token(T_asm);
9830         add_anchor_token(T_auto);
9831         add_anchor_token(T_bool);
9832         add_anchor_token(T_break);
9833         add_anchor_token(T_case);
9834         add_anchor_token(T_char);
9835         add_anchor_token(T_class);
9836         add_anchor_token(T_const);
9837         add_anchor_token(T_const_cast);
9838         add_anchor_token(T_continue);
9839         add_anchor_token(T_default);
9840         add_anchor_token(T_delete);
9841         add_anchor_token(T_double);
9842         add_anchor_token(T_do);
9843         add_anchor_token(T_dynamic_cast);
9844         add_anchor_token(T_enum);
9845         add_anchor_token(T_extern);
9846         add_anchor_token(T_false);
9847         add_anchor_token(T_float);
9848         add_anchor_token(T_for);
9849         add_anchor_token(T_goto);
9850         add_anchor_token(T_if);
9851         add_anchor_token(T_inline);
9852         add_anchor_token(T_int);
9853         add_anchor_token(T_long);
9854         add_anchor_token(T_new);
9855         add_anchor_token(T_operator);
9856         add_anchor_token(T_register);
9857         add_anchor_token(T_reinterpret_cast);
9858         add_anchor_token(T_restrict);
9859         add_anchor_token(T_return);
9860         add_anchor_token(T_short);
9861         add_anchor_token(T_signed);
9862         add_anchor_token(T_sizeof);
9863         add_anchor_token(T_static);
9864         add_anchor_token(T_static_cast);
9865         add_anchor_token(T_struct);
9866         add_anchor_token(T_switch);
9867         add_anchor_token(T_template);
9868         add_anchor_token(T_this);
9869         add_anchor_token(T_throw);
9870         add_anchor_token(T_true);
9871         add_anchor_token(T_try);
9872         add_anchor_token(T_typedef);
9873         add_anchor_token(T_typeid);
9874         add_anchor_token(T_typename);
9875         add_anchor_token(T_typeof);
9876         add_anchor_token(T_union);
9877         add_anchor_token(T_unsigned);
9878         add_anchor_token(T_using);
9879         add_anchor_token(T_void);
9880         add_anchor_token(T_volatile);
9881         add_anchor_token(T_wchar_t);
9882         add_anchor_token(T_while);
9883
9884         statement_t **anchor            = &statement->compound.statements;
9885         bool          only_decls_so_far = true;
9886         while (token.kind != '}' && token.kind != T_EOF) {
9887                 statement_t *sub_statement = intern_parse_statement();
9888                 if (sub_statement->kind == STATEMENT_ERROR) {
9889                         break;
9890                 }
9891
9892                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9893                         only_decls_so_far = false;
9894                 } else if (!only_decls_so_far) {
9895                         source_position_t const *const pos = &sub_statement->base.source_position;
9896                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9897                 }
9898
9899                 *anchor = sub_statement;
9900                 anchor  = &sub_statement->base.next;
9901         }
9902         expect('}');
9903
9904         /* look over all statements again to produce no effect warnings */
9905         if (is_warn_on(WARN_UNUSED_VALUE)) {
9906                 statement_t *sub_statement = statement->compound.statements;
9907                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9908                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9909                                 continue;
9910                         /* don't emit a warning for the last expression in an expression
9911                          * statement as it has always an effect */
9912                         if (inside_expression_statement && sub_statement->base.next == NULL)
9913                                 continue;
9914
9915                         expression_t *expression = sub_statement->expression.expression;
9916                         if (!expression_has_effect(expression)) {
9917                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9918                         }
9919                 }
9920         }
9921
9922         rem_anchor_token(T_while);
9923         rem_anchor_token(T_wchar_t);
9924         rem_anchor_token(T_volatile);
9925         rem_anchor_token(T_void);
9926         rem_anchor_token(T_using);
9927         rem_anchor_token(T_unsigned);
9928         rem_anchor_token(T_union);
9929         rem_anchor_token(T_typeof);
9930         rem_anchor_token(T_typename);
9931         rem_anchor_token(T_typeid);
9932         rem_anchor_token(T_typedef);
9933         rem_anchor_token(T_try);
9934         rem_anchor_token(T_true);
9935         rem_anchor_token(T_throw);
9936         rem_anchor_token(T_this);
9937         rem_anchor_token(T_template);
9938         rem_anchor_token(T_switch);
9939         rem_anchor_token(T_struct);
9940         rem_anchor_token(T_static_cast);
9941         rem_anchor_token(T_static);
9942         rem_anchor_token(T_sizeof);
9943         rem_anchor_token(T_signed);
9944         rem_anchor_token(T_short);
9945         rem_anchor_token(T_return);
9946         rem_anchor_token(T_restrict);
9947         rem_anchor_token(T_reinterpret_cast);
9948         rem_anchor_token(T_register);
9949         rem_anchor_token(T_operator);
9950         rem_anchor_token(T_new);
9951         rem_anchor_token(T_long);
9952         rem_anchor_token(T_int);
9953         rem_anchor_token(T_inline);
9954         rem_anchor_token(T_if);
9955         rem_anchor_token(T_goto);
9956         rem_anchor_token(T_for);
9957         rem_anchor_token(T_float);
9958         rem_anchor_token(T_false);
9959         rem_anchor_token(T_extern);
9960         rem_anchor_token(T_enum);
9961         rem_anchor_token(T_dynamic_cast);
9962         rem_anchor_token(T_do);
9963         rem_anchor_token(T_double);
9964         rem_anchor_token(T_delete);
9965         rem_anchor_token(T_default);
9966         rem_anchor_token(T_continue);
9967         rem_anchor_token(T_const_cast);
9968         rem_anchor_token(T_const);
9969         rem_anchor_token(T_class);
9970         rem_anchor_token(T_char);
9971         rem_anchor_token(T_case);
9972         rem_anchor_token(T_break);
9973         rem_anchor_token(T_bool);
9974         rem_anchor_token(T_auto);
9975         rem_anchor_token(T_asm);
9976         rem_anchor_token(T___thread);
9977         rem_anchor_token(T___real__);
9978         rem_anchor_token(T___label__);
9979         rem_anchor_token(T___imag__);
9980         rem_anchor_token(T___func__);
9981         rem_anchor_token(T___extension__);
9982         rem_anchor_token(T___builtin_va_start);
9983         rem_anchor_token(T___attribute__);
9984         rem_anchor_token(T___alignof__);
9985         rem_anchor_token(T___PRETTY_FUNCTION__);
9986         rem_anchor_token(T___FUNCTION__);
9987         rem_anchor_token(T__Imaginary);
9988         rem_anchor_token(T__Complex);
9989         rem_anchor_token(T__Bool);
9990         rem_anchor_token(T_WIDE_STRING_LITERAL);
9991         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9992         rem_anchor_token(T_STRING_LITERAL);
9993         rem_anchor_token(T_PLUSPLUS);
9994         rem_anchor_token(T_MINUSMINUS);
9995         rem_anchor_token(T_INTEGER);
9996         rem_anchor_token(T_IDENTIFIER);
9997         rem_anchor_token(T_FLOATINGPOINT);
9998         rem_anchor_token(T_COLONCOLON);
9999         rem_anchor_token(T_CHARACTER_CONSTANT);
10000         rem_anchor_token('~');
10001         rem_anchor_token('{');
10002         rem_anchor_token(';');
10003         rem_anchor_token('-');
10004         rem_anchor_token('+');
10005         rem_anchor_token('*');
10006         rem_anchor_token('(');
10007         rem_anchor_token('&');
10008         rem_anchor_token('!');
10009         rem_anchor_token('}');
10010
10011         POP_SCOPE();
10012         POP_PARENT();
10013         return statement;
10014 }
10015
10016 /**
10017  * Check for unused global static functions and variables
10018  */
10019 static void check_unused_globals(void)
10020 {
10021         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10022                 return;
10023
10024         for (const entity_t *entity = file_scope->entities; entity != NULL;
10025              entity = entity->base.next) {
10026                 if (!is_declaration(entity))
10027                         continue;
10028
10029                 const declaration_t *declaration = &entity->declaration;
10030                 if (declaration->used                  ||
10031                     declaration->modifiers & DM_UNUSED ||
10032                     declaration->modifiers & DM_USED   ||
10033                     declaration->storage_class != STORAGE_CLASS_STATIC)
10034                         continue;
10035
10036                 warning_t   why;
10037                 char const *s;
10038                 if (entity->kind == ENTITY_FUNCTION) {
10039                         /* inhibit warning for static inline functions */
10040                         if (entity->function.is_inline)
10041                                 continue;
10042
10043                         why = WARN_UNUSED_FUNCTION;
10044                         s   = entity->function.statement != NULL ? "defined" : "declared";
10045                 } else {
10046                         why = WARN_UNUSED_VARIABLE;
10047                         s   = "defined";
10048                 }
10049
10050                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10051         }
10052 }
10053
10054 static void parse_global_asm(void)
10055 {
10056         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10057
10058         eat(T_asm);
10059         add_anchor_token(';');
10060         add_anchor_token(')');
10061         add_anchor_token(T_STRING_LITERAL);
10062         expect('(');
10063
10064         rem_anchor_token(T_STRING_LITERAL);
10065         statement->asms.asm_text = parse_string_literals();
10066         statement->base.next     = unit->global_asm;
10067         unit->global_asm         = statement;
10068
10069         rem_anchor_token(')');
10070         expect(')');
10071         rem_anchor_token(';');
10072         expect(';');
10073 }
10074
10075 static void parse_linkage_specification(void)
10076 {
10077         eat(T_extern);
10078
10079         source_position_t const pos     = *HERE;
10080         char const       *const linkage = parse_string_literals().begin;
10081
10082         linkage_kind_t old_linkage = current_linkage;
10083         linkage_kind_t new_linkage;
10084         if (streq(linkage, "C")) {
10085                 new_linkage = LINKAGE_C;
10086         } else if (streq(linkage, "C++")) {
10087                 new_linkage = LINKAGE_CXX;
10088         } else {
10089                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10090                 new_linkage = LINKAGE_C;
10091         }
10092         current_linkage = new_linkage;
10093
10094         if (next_if('{')) {
10095                 parse_externals();
10096                 expect('}');
10097         } else {
10098                 parse_external();
10099         }
10100
10101         assert(current_linkage == new_linkage);
10102         current_linkage = old_linkage;
10103 }
10104
10105 static void parse_external(void)
10106 {
10107         switch (token.kind) {
10108                 case T_extern:
10109                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10110                                 parse_linkage_specification();
10111                         } else {
10112                 DECLARATION_START_NO_EXTERN
10113                 case T_IDENTIFIER:
10114                 case T___extension__:
10115                 /* tokens below are for implicit int */
10116                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10117                               implicit int) */
10118                 case '*':  /* * x; -> int* x; */
10119                 case '(':  /* (x); -> int (x); */
10120                                 PUSH_EXTENSION();
10121                                 parse_external_declaration();
10122                                 POP_EXTENSION();
10123                         }
10124                         return;
10125
10126                 case T_asm:
10127                         parse_global_asm();
10128                         return;
10129
10130                 case T_namespace:
10131                         parse_namespace_definition();
10132                         return;
10133
10134                 case ';':
10135                         if (!strict_mode) {
10136                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10137                                 eat(';');
10138                                 return;
10139                         }
10140                         /* FALLTHROUGH */
10141
10142                 default:
10143                         errorf(HERE, "stray %K outside of function", &token);
10144                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10145                                 eat_until_matching_token(token.kind);
10146                         next_token();
10147                         return;
10148         }
10149 }
10150
10151 static void parse_externals(void)
10152 {
10153         add_anchor_token('}');
10154         add_anchor_token(T_EOF);
10155
10156 #ifndef NDEBUG
10157         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10158         unsigned short token_anchor_copy[T_LAST_TOKEN];
10159         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10160 #endif
10161
10162         while (token.kind != T_EOF && token.kind != '}') {
10163 #ifndef NDEBUG
10164                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10165                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10166                         if (count != 0) {
10167                                 /* the anchor set and its copy differs */
10168                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10169                         }
10170                 }
10171                 if (in_gcc_extension) {
10172                         /* an gcc extension scope was not closed */
10173                         internal_errorf(HERE, "Leaked __extension__");
10174                 }
10175 #endif
10176
10177                 parse_external();
10178         }
10179
10180         rem_anchor_token(T_EOF);
10181         rem_anchor_token('}');
10182 }
10183
10184 /**
10185  * Parse a translation unit.
10186  */
10187 static void parse_translation_unit(void)
10188 {
10189         add_anchor_token(T_EOF);
10190
10191         while (true) {
10192                 parse_externals();
10193
10194                 if (token.kind == T_EOF)
10195                         break;
10196
10197                 errorf(HERE, "stray %K outside of function", &token);
10198                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10199                         eat_until_matching_token(token.kind);
10200                 next_token();
10201         }
10202 }
10203
10204 void set_default_visibility(elf_visibility_tag_t visibility)
10205 {
10206         default_visibility = visibility;
10207 }
10208
10209 /**
10210  * Parse the input.
10211  *
10212  * @return  the translation unit or NULL if errors occurred.
10213  */
10214 void start_parsing(void)
10215 {
10216         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10217         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10218         diagnostic_count  = 0;
10219         error_count       = 0;
10220         warning_count     = 0;
10221
10222         print_to_file(stderr);
10223
10224         assert(unit == NULL);
10225         unit = allocate_ast_zero(sizeof(unit[0]));
10226
10227         assert(file_scope == NULL);
10228         file_scope = &unit->scope;
10229
10230         assert(current_scope == NULL);
10231         scope_push(&unit->scope);
10232
10233         create_gnu_builtins();
10234         if (c_mode & _MS)
10235                 create_microsoft_intrinsics();
10236 }
10237
10238 translation_unit_t *finish_parsing(void)
10239 {
10240         assert(current_scope == &unit->scope);
10241         scope_pop(NULL);
10242
10243         assert(file_scope == &unit->scope);
10244         check_unused_globals();
10245         file_scope = NULL;
10246
10247         DEL_ARR_F(environment_stack);
10248         DEL_ARR_F(label_stack);
10249
10250         translation_unit_t *result = unit;
10251         unit = NULL;
10252         return result;
10253 }
10254
10255 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10256  * are given length one. */
10257 static void complete_incomplete_arrays(void)
10258 {
10259         size_t n = ARR_LEN(incomplete_arrays);
10260         for (size_t i = 0; i != n; ++i) {
10261                 declaration_t *const decl = incomplete_arrays[i];
10262                 type_t        *const type = skip_typeref(decl->type);
10263
10264                 if (!is_type_incomplete(type))
10265                         continue;
10266
10267                 source_position_t const *const pos = &decl->base.source_position;
10268                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10269
10270                 type_t *const new_type = duplicate_type(type);
10271                 new_type->array.size_constant     = true;
10272                 new_type->array.has_implicit_size = true;
10273                 new_type->array.size              = 1;
10274
10275                 type_t *const result = identify_new_type(new_type);
10276
10277                 decl->type = result;
10278         }
10279 }
10280
10281 static void prepare_main_collect2(entity_t *const entity)
10282 {
10283         PUSH_SCOPE(&entity->function.statement->compound.scope);
10284
10285         // create call to __main
10286         symbol_t *symbol         = symbol_table_insert("__main");
10287         entity_t *subsubmain_ent
10288                 = create_implicit_function(symbol, &builtin_source_position);
10289
10290         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10291         type_t       *ftype       = subsubmain_ent->declaration.type;
10292         ref->base.source_position = builtin_source_position;
10293         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10294         ref->reference.entity     = subsubmain_ent;
10295
10296         expression_t *call = allocate_expression_zero(EXPR_CALL);
10297         call->base.source_position = builtin_source_position;
10298         call->base.type            = type_void;
10299         call->call.function        = ref;
10300
10301         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10302         expr_statement->base.source_position  = builtin_source_position;
10303         expr_statement->expression.expression = call;
10304
10305         statement_t *statement = entity->function.statement;
10306         assert(statement->kind == STATEMENT_COMPOUND);
10307         compound_statement_t *compounds = &statement->compound;
10308
10309         expr_statement->base.next = compounds->statements;
10310         compounds->statements     = expr_statement;
10311
10312         POP_SCOPE();
10313 }
10314
10315 void parse(void)
10316 {
10317         lookahead_bufpos = 0;
10318         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10319                 next_token();
10320         }
10321         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10322         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10323         parse_translation_unit();
10324         complete_incomplete_arrays();
10325         DEL_ARR_F(incomplete_arrays);
10326         incomplete_arrays = NULL;
10327 }
10328
10329 /**
10330  * Initialize the parser.
10331  */
10332 void init_parser(void)
10333 {
10334         sym_anonymous = symbol_table_insert("<anonymous>");
10335
10336         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10337
10338         init_expression_parsers();
10339         obstack_init(&temp_obst);
10340 }
10341
10342 /**
10343  * Terminate the parser.
10344  */
10345 void exit_parser(void)
10346 {
10347         obstack_free(&temp_obst, NULL);
10348 }