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