nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T___FUNCDNAME__:             \
 256         case T___FUNCSIG__:               \
 257         case T___FUNCTION__:              \
 258         case T___PRETTY_FUNCTION__:       \
 259         case T___alignof__:               \
 260         case T___builtin_classify_type:   \
 261         case T___builtin_constant_p:      \
 262         case T___builtin_isgreater:       \
 263         case T___builtin_isgreaterequal:  \
 264         case T___builtin_isless:          \
 265         case T___builtin_islessequal:     \
 266         case T___builtin_islessgreater:   \
 267         case T___builtin_isunordered:     \
 268         case T___builtin_offsetof:        \
 269         case T___builtin_va_arg:          \
 270         case T___builtin_va_copy:         \
 271         case T___builtin_va_start:        \
 272         case T___func__:                  \
 273         case T___noop:                    \
 274         case T__assume:                   \
 275         case T_delete:                    \
 276         case T_false:                     \
 277         case T_sizeof:                    \
 278         case T_throw:                     \
 279         case T_true:
 280
 281 /**
 282  * Returns the size of a statement node.
 283  *
 284  * @param kind  the statement kind
 285  */
 286 static size_t get_statement_struct_size(statement_kind_t kind)
 287 {
 288         static const size_t sizes[] = {
 289                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 290                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 291                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 292                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 293                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 294                 [STATEMENT_IF]            = sizeof(if_statement_t),
 295                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 296                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 297                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 298                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 299                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 300                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 301                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 302                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 303                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 304                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 305                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 306                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 307                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 308                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 309         };
 310         assert((size_t)kind < lengthof(sizes));
 311         assert(sizes[kind] != 0);
 312         return sizes[kind];
 313 }
 314
 315 /**
 316  * Returns the size of an expression node.
 317  *
 318  * @param kind  the expression kind
 319  */
 320 static size_t get_expression_struct_size(expression_kind_t kind)
 321 {
 322         static const size_t sizes[] = {
 323                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 324                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 325                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 326                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 331                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 332                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 333                 [EXPR_CALL]                       = sizeof(call_expression_t),
 334                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 335                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 336                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 337                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 338                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 339                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 340                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 341                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 342                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 343                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 344                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 345                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 346                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 347                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 348                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 349                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 350                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 351         };
 352         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 353                 return sizes[EXPR_UNARY_FIRST];
 354         }
 355         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 356                 return sizes[EXPR_BINARY_FIRST];
 357         }
 358         assert((size_t)kind < lengthof(sizes));
 359         assert(sizes[kind] != 0);
 360         return sizes[kind];
 361 }
 362
 363 /**
 364  * Allocate a statement node of given kind and initialize all
 365  * fields with zero. Sets its source position to the position
 366  * of the current token.
 367  */
 368 static statement_t *allocate_statement_zero(statement_kind_t kind)
 369 {
 370         size_t       size = get_statement_struct_size(kind);
 371         statement_t *res  = allocate_ast_zero(size);
 372
 373         res->base.kind            = kind;
 374         res->base.parent          = current_parent;
 375         res->base.source_position = *HERE;
 376         return res;
 377 }
 378
 379 /**
 380  * Allocate an expression node of given kind and initialize all
 381  * fields with zero.
 382  *
 383  * @param kind  the kind of the expression to allocate
 384  */
 385 static expression_t *allocate_expression_zero(expression_kind_t kind)
 386 {
 387         size_t        size = get_expression_struct_size(kind);
 388         expression_t *res  = allocate_ast_zero(size);
 389
 390         res->base.kind            = kind;
 391         res->base.type            = type_error_type;
 392         res->base.source_position = *HERE;
 393         return res;
 394 }
 395
 396 /**
 397  * Creates a new invalid expression at the source position
 398  * of the current token.
 399  */
 400 static expression_t *create_error_expression(void)
 401 {
 402         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 403         expression->base.type = type_error_type;
 404         return expression;
 405 }
 406
 407 /**
 408  * Creates a new invalid statement.
 409  */
 410 static statement_t *create_error_statement(void)
 411 {
 412         return allocate_statement_zero(STATEMENT_ERROR);
 413 }
 414
 415 /**
 416  * Allocate a new empty statement.
 417  */
 418 static statement_t *create_empty_statement(void)
 419 {
 420         return allocate_statement_zero(STATEMENT_EMPTY);
 421 }
 422
 423 /**
 424  * Returns the size of an initializer node.
 425  *
 426  * @param kind  the initializer kind
 427  */
 428 static size_t get_initializer_size(initializer_kind_t kind)
 429 {
 430         static const size_t sizes[] = {
 431                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 432                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 433                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 434                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 435                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 436         };
 437         assert((size_t)kind < lengthof(sizes));
 438         assert(sizes[kind] != 0);
 439         return sizes[kind];
 440 }
 441
 442 /**
 443  * Allocate an initializer node of given kind and initialize all
 444  * fields with zero.
 445  */
 446 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 447 {
 448         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 449         result->kind          = kind;
 450
 451         return result;
 452 }
 453
 454 /**
 455  * Returns the index of the top element of the environment stack.
 456  */
 457 static size_t environment_top(void)
 458 {
 459         return ARR_LEN(environment_stack);
 460 }
 461
 462 /**
 463  * Returns the index of the top element of the global label stack.
 464  */
 465 static size_t label_top(void)
 466 {
 467         return ARR_LEN(label_stack);
 468 }
 469
 470 /**
 471  * Return the next token.
 472  */
 473 static inline void next_token(void)
 474 {
 475         token                              = lookahead_buffer[lookahead_bufpos];
 476         lookahead_buffer[lookahead_bufpos] = lexer_token;
 477         lexer_next_token();
 478
 479         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 480
 481 #ifdef PRINT_TOKENS
 482         print_token(stderr, &token);
 483         fprintf(stderr, "\n");
 484 #endif
 485 }
 486
 487 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 488
 489 static inline bool next_if(token_kind_t const type)
 490 {
 491         if (token.kind == type) {
 492                 eat(type);
 493                 return true;
 494         } else {
 495                 return false;
 496         }
 497 }
 498
 499 /**
 500  * Return the next token with a given lookahead.
 501  */
 502 static inline const token_t *look_ahead(size_t num)
 503 {
 504         assert(0 < num && num <= MAX_LOOKAHEAD);
 505         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 506         return &lookahead_buffer[pos];
 507 }
 508
 509 /**
 510  * Adds a token type to the token type anchor set (a multi-set).
 511  */
 512 static void add_anchor_token(token_kind_t const token_kind)
 513 {
 514         assert(token_kind < T_LAST_TOKEN);
 515         ++token_anchor_set[token_kind];
 516 }
 517
 518 /**
 519  * Remove a token type from the token type anchor set (a multi-set).
 520  */
 521 static void rem_anchor_token(token_kind_t const token_kind)
 522 {
 523         assert(token_kind < T_LAST_TOKEN);
 524         assert(token_anchor_set[token_kind] != 0);
 525         --token_anchor_set[token_kind];
 526 }
 527
 528 /**
 529  * Eat tokens until a matching token type is found.
 530  */
 531 static void eat_until_matching_token(token_kind_t const type)
 532 {
 533         token_kind_t end_token;
 534         switch (type) {
 535                 case '(': end_token = ')';  break;
 536                 case '{': end_token = '}';  break;
 537                 case '[': end_token = ']';  break;
 538                 default:  end_token = type; break;
 539         }
 540
 541         unsigned parenthesis_count = 0;
 542         unsigned brace_count       = 0;
 543         unsigned bracket_count     = 0;
 544         while (token.kind        != end_token ||
 545                parenthesis_count != 0         ||
 546                brace_count       != 0         ||
 547                bracket_count     != 0) {
 548                 switch (token.kind) {
 549                 case T_EOF: return;
 550                 case '(': ++parenthesis_count; break;
 551                 case '{': ++brace_count;       break;
 552                 case '[': ++bracket_count;     break;
 553
 554                 case ')':
 555                         if (parenthesis_count > 0)
 556                                 --parenthesis_count;
 557                         goto check_stop;
 558
 559                 case '}':
 560                         if (brace_count > 0)
 561                                 --brace_count;
 562                         goto check_stop;
 563
 564                 case ']':
 565                         if (bracket_count > 0)
 566                                 --bracket_count;
 567 check_stop:
 568                         if (token.kind        == end_token &&
 569                             parenthesis_count == 0         &&
 570                             brace_count       == 0         &&
 571                             bracket_count     == 0)
 572                                 return;
 573                         break;
 574
 575                 default:
 576                         break;
 577                 }
 578                 next_token();
 579         }
 580 }
 581
 582 /**
 583  * Eat input tokens until an anchor is found.
 584  */
 585 static void eat_until_anchor(void)
 586 {
 587         while (token_anchor_set[token.kind] == 0) {
 588                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 589                         eat_until_matching_token(token.kind);
 590                 next_token();
 591         }
 592 }
 593
 594 /**
 595  * Eat a whole block from input tokens.
 596  */
 597 static void eat_block(void)
 598 {
 599         eat_until_matching_token('{');
 600         next_if('}');
 601 }
 602
 603 /**
 604  * Report a parse error because an expected token was not found.
 605  */
 606 static
 607 #if defined __GNUC__ && __GNUC__ >= 4
 608 __attribute__((sentinel))
 609 #endif
 610 void parse_error_expected(const char *message, ...)
 611 {
 612         if (message != NULL) {
 613                 errorf(HERE, "%s", message);
 614         }
 615         va_list ap;
 616         va_start(ap, message);
 617         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 618         va_end(ap);
 619 }
 620
 621 /**
 622  * Report an incompatible type.
 623  */
 624 static void type_error_incompatible(const char *msg,
 625                 const source_position_t *source_position, type_t *type1, type_t *type2)
 626 {
 627         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 628                msg, type1, type2);
 629 }
 630
 631 static bool skip_till(token_kind_t const expected, char const *const context)
 632 {
 633         if (UNLIKELY(token.kind != expected)) {
 634                 parse_error_expected(context, expected, NULL);
 635                 add_anchor_token(expected);
 636                 eat_until_anchor();
 637                 rem_anchor_token(expected);
 638                 if (token.kind != expected)
 639                         return false;
 640         }
 641         return true;
 642 }
 643
 644 /**
 645  * Expect the current token is the expected token.
 646  * If not, generate an error and skip until the next anchor.
 647  */
 648 static void expect(token_kind_t const expected)
 649 {
 650         if (skip_till(expected, NULL))
 651                 eat(expected);
 652 }
 653
 654 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 655 {
 656         if (!skip_till(T_IDENTIFIER, context))
 657                 return NULL;
 658         symbol_t *const sym = token.base.symbol;
 659         if (pos)
 660                 *pos = *HERE;
 661         eat(T_IDENTIFIER);
 662         return sym;
 663 }
 664
 665 /**
 666  * Push a given scope on the scope stack and make it the
 667  * current scope
 668  */
 669 static scope_t *scope_push(scope_t *new_scope)
 670 {
 671         if (current_scope != NULL) {
 672                 new_scope->depth = current_scope->depth + 1;
 673         }
 674
 675         scope_t *old_scope = current_scope;
 676         current_scope      = new_scope;
 677         return old_scope;
 678 }
 679
 680 /**
 681  * Pop the current scope from the scope stack.
 682  */
 683 static void scope_pop(scope_t *old_scope)
 684 {
 685         current_scope = old_scope;
 686 }
 687
 688 /**
 689  * Search an entity by its symbol in a given namespace.
 690  */
 691 static entity_t *get_entity(const symbol_t *const symbol,
 692                             namespace_tag_t namespc)
 693 {
 694         entity_t *entity = symbol->entity;
 695         for (; entity != NULL; entity = entity->base.symbol_next) {
 696                 if ((namespace_tag_t)entity->base.namespc == namespc)
 697                         return entity;
 698         }
 699
 700         return NULL;
 701 }
 702
 703 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 704  * possible. */
 705 static entity_t *get_tag(symbol_t const *const symbol,
 706                          entity_kind_tag_t const kind)
 707 {
 708         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 709         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 710                 errorf(HERE,
 711                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 712                                 symbol, &entity->base.source_position);
 713                 entity = NULL;
 714         }
 715         return entity;
 716 }
 717
 718 /**
 719  * pushs an entity on the environment stack and links the corresponding symbol
 720  * it.
 721  */
 722 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 723 {
 724         symbol_t           *symbol  = entity->base.symbol;
 725         entity_namespace_t  namespc = entity->base.namespc;
 726         assert(namespc != 0);
 727
 728         /* replace/add entity into entity list of the symbol */
 729         entity_t **anchor;
 730         entity_t  *iter;
 731         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 732                 iter = *anchor;
 733                 if (iter == NULL)
 734                         break;
 735
 736                 /* replace an entry? */
 737                 if (iter->base.namespc == namespc) {
 738                         entity->base.symbol_next = iter->base.symbol_next;
 739                         break;
 740                 }
 741         }
 742         *anchor = entity;
 743
 744         /* remember old declaration */
 745         stack_entry_t entry;
 746         entry.symbol     = symbol;
 747         entry.old_entity = iter;
 748         entry.namespc    = namespc;
 749         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 750 }
 751
 752 /**
 753  * Push an entity on the environment stack.
 754  */
 755 static void environment_push(entity_t *entity)
 756 {
 757         assert(entity->base.source_position.input_name != NULL);
 758         assert(entity->base.parent_scope != NULL);
 759         stack_push(&environment_stack, entity);
 760 }
 761
 762 /**
 763  * Push a declaration on the global label stack.
 764  *
 765  * @param declaration  the declaration
 766  */
 767 static void label_push(entity_t *label)
 768 {
 769         /* we abuse the parameters scope as parent for the labels */
 770         label->base.parent_scope = &current_function->parameters;
 771         stack_push(&label_stack, label);
 772 }
 773
 774 /**
 775  * pops symbols from the environment stack until @p new_top is the top element
 776  */
 777 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 778 {
 779         stack_entry_t *stack = *stack_ptr;
 780         size_t         top   = ARR_LEN(stack);
 781         size_t         i;
 782
 783         assert(new_top <= top);
 784         if (new_top == top)
 785                 return;
 786
 787         for (i = top; i > new_top; --i) {
 788                 stack_entry_t *entry = &stack[i - 1];
 789
 790                 entity_t           *old_entity = entry->old_entity;
 791                 symbol_t           *symbol     = entry->symbol;
 792                 entity_namespace_t  namespc    = entry->namespc;
 793
 794                 /* replace with old_entity/remove */
 795                 entity_t **anchor;
 796                 entity_t  *iter;
 797                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 798                         iter = *anchor;
 799                         assert(iter != NULL);
 800                         /* replace an entry? */
 801                         if (iter->base.namespc == namespc)
 802                                 break;
 803                 }
 804
 805                 /* restore definition from outer scopes (if there was one) */
 806                 if (old_entity != NULL) {
 807                         old_entity->base.symbol_next = iter->base.symbol_next;
 808                         *anchor                      = old_entity;
 809                 } else {
 810                         /* remove entry from list */
 811                         *anchor = iter->base.symbol_next;
 812                 }
 813         }
 814
 815         ARR_SHRINKLEN(*stack_ptr, new_top);
 816 }
 817
 818 /**
 819  * Pop all entries from the environment stack until the new_top
 820  * is reached.
 821  *
 822  * @param new_top  the new stack top
 823  */
 824 static void environment_pop_to(size_t new_top)
 825 {
 826         stack_pop_to(&environment_stack, new_top);
 827 }
 828
 829 /**
 830  * Pop all entries from the global label stack until the new_top
 831  * is reached.
 832  *
 833  * @param new_top  the new stack top
 834  */
 835 static void label_pop_to(size_t new_top)
 836 {
 837         stack_pop_to(&label_stack, new_top);
 838 }
 839
 840 static atomic_type_kind_t get_akind(const type_t *type)
 841 {
 842         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 843                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 844         return type->atomic.akind;
 845 }
 846
 847 /**
 848  * §6.3.1.1:2  Do integer promotion for a given type.
 849  *
 850  * @param type  the type to promote
 851  * @return the promoted type
 852  */
 853 static type_t *promote_integer(type_t *type)
 854 {
 855         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 856                 type = type_int;
 857
 858         return type;
 859 }
 860
 861 /**
 862  * Check if a given expression represents a null pointer constant.
 863  *
 864  * @param expression  the expression to check
 865  */
 866 static bool is_null_pointer_constant(const expression_t *expression)
 867 {
 868         /* skip void* cast */
 869         if (expression->kind == EXPR_UNARY_CAST) {
 870                 type_t *const type = skip_typeref(expression->base.type);
 871                 if (types_compatible(type, type_void_ptr))
 872                         expression = expression->unary.value;
 873         }
 874
 875         type_t *const type = skip_typeref(expression->base.type);
 876         if (!is_type_integer(type))
 877                 return false;
 878         switch (is_constant_expression(expression)) {
 879                 case EXPR_CLASS_ERROR:    return true;
 880                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 881                 default:                  return false;
 882         }
 883 }
 884
 885 /**
 886  * Create an implicit cast expression.
 887  *
 888  * @param expression  the expression to cast
 889  * @param dest_type   the destination type
 890  */
 891 static expression_t *create_implicit_cast(expression_t *expression,
 892                                           type_t *dest_type)
 893 {
 894         type_t *const source_type = expression->base.type;
 895
 896         if (source_type == dest_type)
 897                 return expression;
 898
 899         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 900         cast->unary.value   = expression;
 901         cast->base.type     = dest_type;
 902         cast->base.implicit = true;
 903
 904         return cast;
 905 }
 906
 907 typedef enum assign_error_t {
 908         ASSIGN_SUCCESS,
 909         ASSIGN_ERROR_INCOMPATIBLE,
 910         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 911         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 912         ASSIGN_WARNING_POINTER_FROM_INT,
 913         ASSIGN_WARNING_INT_FROM_POINTER
 914 } assign_error_t;
 915
 916 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)
 917 {
 918         type_t *const orig_type_right = right->base.type;
 919         type_t *const type_left       = skip_typeref(orig_type_left);
 920         type_t *const type_right      = skip_typeref(orig_type_right);
 921
 922         switch (error) {
 923         case ASSIGN_SUCCESS:
 924                 return;
 925         case ASSIGN_ERROR_INCOMPATIBLE:
 926                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 927                 return;
 928
 929         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 930                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 931                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 932
 933                 /* the left type has all qualifiers from the right type */
 934                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 935                 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);
 936                 return;
 937         }
 938
 939         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 940                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 941                 return;
 942
 943         case ASSIGN_WARNING_POINTER_FROM_INT:
 944                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 945                 return;
 946
 947         case ASSIGN_WARNING_INT_FROM_POINTER:
 948                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 949                 return;
 950
 951         default:
 952                 panic("invalid error value");
 953         }
 954 }
 955
 956 /** Implements the rules from §6.5.16.1 */
 957 static assign_error_t semantic_assign(type_t *orig_type_left,
 958                                       const expression_t *const right)
 959 {
 960         type_t *const orig_type_right = right->base.type;
 961         type_t *const type_left       = skip_typeref(orig_type_left);
 962         type_t *const type_right      = skip_typeref(orig_type_right);
 963
 964         if (is_type_pointer(type_left)) {
 965                 if (is_null_pointer_constant(right)) {
 966                         return ASSIGN_SUCCESS;
 967                 } else if (is_type_pointer(type_right)) {
 968                         type_t *points_to_left
 969                                 = skip_typeref(type_left->pointer.points_to);
 970                         type_t *points_to_right
 971                                 = skip_typeref(type_right->pointer.points_to);
 972                         assign_error_t res = ASSIGN_SUCCESS;
 973
 974                         /* the left type has all qualifiers from the right type */
 975                         unsigned missing_qualifiers
 976                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 977                         if (missing_qualifiers != 0) {
 978                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 979                         }
 980
 981                         points_to_left  = get_unqualified_type(points_to_left);
 982                         points_to_right = get_unqualified_type(points_to_right);
 983
 984                         if (is_type_void(points_to_left))
 985                                 return res;
 986
 987                         if (is_type_void(points_to_right)) {
 988                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 989                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 990                         }
 991
 992                         if (!types_compatible(points_to_left, points_to_right)) {
 993                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 994                         }
 995
 996                         return res;
 997                 } else if (is_type_integer(type_right)) {
 998                         return ASSIGN_WARNING_POINTER_FROM_INT;
 999                 }
1000         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1001                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1002                                 && is_type_pointer(type_right))) {
1003                 return ASSIGN_SUCCESS;
1004         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1005                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1006                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1007                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1008                         return ASSIGN_SUCCESS;
1009                 }
1010         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1011                 return ASSIGN_WARNING_INT_FROM_POINTER;
1012         }
1013
1014         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1015                 return ASSIGN_SUCCESS;
1016
1017         return ASSIGN_ERROR_INCOMPATIBLE;
1018 }
1019
1020 static expression_t *parse_constant_expression(void)
1021 {
1022         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1023
1024         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1025                 errorf(&result->base.source_position,
1026                        "expression '%E' is not constant", result);
1027         }
1028
1029         return result;
1030 }
1031
1032 static expression_t *parse_assignment_expression(void)
1033 {
1034         return parse_subexpression(PREC_ASSIGNMENT);
1035 }
1036
1037 static void append_string(string_t const *const s)
1038 {
1039         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1040          * possible, because other tokens are grown there alongside. */
1041         obstack_grow(&ast_obstack, s->begin, s->size);
1042 }
1043
1044 static string_t finish_string(void)
1045 {
1046         obstack_1grow(&ast_obstack, '\0');
1047         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1048         char const *const string = obstack_finish(&ast_obstack);
1049         return (string_t){ string, size };
1050 }
1051
1052 static string_t concat_string_literals(string_encoding_t *const out_enc)
1053 {
1054         assert(token.kind == T_STRING_LITERAL);
1055
1056         string_t          result;
1057         string_encoding_t enc = token.string.encoding;
1058         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1059                 append_string(&token.string.string);
1060                 eat(T_STRING_LITERAL);
1061                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1062                 do {
1063                         if (token.string.encoding != STRING_ENCODING_CHAR) {
1064                                 enc = token.string.encoding;
1065                         }
1066                         append_string(&token.string.string);
1067                         eat(T_STRING_LITERAL);
1068                 } while (token.kind == T_STRING_LITERAL);
1069                 result = finish_string();
1070         } else {
1071                 result = token.string.string;
1072                 eat(T_STRING_LITERAL);
1073         }
1074
1075         *out_enc = enc;
1076         return result;
1077 }
1078
1079 static string_t parse_string_literals(char const *const context)
1080 {
1081         if (!skip_till(T_STRING_LITERAL, context))
1082                 return (string_t){ "", 0 };
1083
1084         string_encoding_t       enc;
1085         source_position_t const pos = *HERE;
1086         string_t          const res = concat_string_literals(&enc);
1087
1088         if (enc != STRING_ENCODING_CHAR) {
1089                 errorf(&pos, "expected plain string literal, got wide string literal");
1090         }
1091
1092         return res;
1093 }
1094
1095 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1096 {
1097         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1098         attribute->kind            = kind;
1099         attribute->source_position = *HERE;
1100         return attribute;
1101 }
1102
1103 /**
1104  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1105  *
1106  *  attribute:
1107  *    __attribute__ ( ( attribute-list ) )
1108  *
1109  *  attribute-list:
1110  *    attrib
1111  *    attribute_list , attrib
1112  *
1113  *  attrib:
1114  *    empty
1115  *    any-word
1116  *    any-word ( identifier )
1117  *    any-word ( identifier , nonempty-expr-list )
1118  *    any-word ( expr-list )
1119  *
1120  *  where the "identifier" must not be declared as a type, and
1121  *  "any-word" may be any identifier (including one declared as a
1122  *  type), a reserved word storage class specifier, type specifier or
1123  *  type qualifier.  ??? This still leaves out most reserved keywords
1124  *  (following the old parser), shouldn't we include them, and why not
1125  *  allow identifiers declared as types to start the arguments?
1126  *
1127  *  Matze: this all looks confusing and little systematic, so we're even less
1128  *  strict and parse any list of things which are identifiers or
1129  *  (assignment-)expressions.
1130  */
1131 static attribute_argument_t *parse_attribute_arguments(void)
1132 {
1133         attribute_argument_t  *first  = NULL;
1134         attribute_argument_t **anchor = &first;
1135         if (token.kind != ')') do {
1136                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1137
1138                 /* is it an identifier */
1139                 if (token.kind == T_IDENTIFIER
1140                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1141                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1142                         argument->v.symbol = token.base.symbol;
1143                         eat(T_IDENTIFIER);
1144                 } else {
1145                         /* must be an expression */
1146                         expression_t *expression = parse_assignment_expression();
1147
1148                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1149                         argument->v.expression = expression;
1150                 }
1151
1152                 /* append argument */
1153                 *anchor = argument;
1154                 anchor  = &argument->next;
1155         } while (next_if(','));
1156         expect(')');
1157         return first;
1158 }
1159
1160 static attribute_t *parse_attribute_asm(void)
1161 {
1162         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1163         eat(T_asm);
1164         expect('(');
1165         attribute->a.arguments = parse_attribute_arguments();
1166         return attribute;
1167 }
1168
1169 static attribute_t *parse_attribute_gnu_single(void)
1170 {
1171         /* parse "any-word" */
1172         symbol_t *const symbol = token.base.symbol;
1173         if (symbol == NULL) {
1174                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1175                 return NULL;
1176         }
1177
1178         attribute_kind_t  kind;
1179         char const *const name = symbol->string;
1180         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1181                 if (kind > ATTRIBUTE_GNU_LAST) {
1182                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1183                         /* TODO: we should still save the attribute in the list... */
1184                         kind = ATTRIBUTE_UNKNOWN;
1185                         break;
1186                 }
1187
1188                 const char *attribute_name = get_attribute_name(kind);
1189                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1190                         break;
1191         }
1192
1193         attribute_t *attribute = allocate_attribute_zero(kind);
1194         next_token();
1195
1196         /* parse arguments */
1197         if (next_if('('))
1198                 attribute->a.arguments = parse_attribute_arguments();
1199
1200         return attribute;
1201 }
1202
1203 static attribute_t *parse_attribute_gnu(void)
1204 {
1205         attribute_t  *first  = NULL;
1206         attribute_t **anchor = &first;
1207
1208         eat(T___attribute__);
1209         add_anchor_token(')');
1210         add_anchor_token(',');
1211         expect('(');
1212         expect('(');
1213
1214         if (token.kind != ')') do {
1215                 attribute_t *attribute = parse_attribute_gnu_single();
1216                 if (attribute) {
1217                         *anchor = attribute;
1218                         anchor  = &attribute->next;
1219                 }
1220         } while (next_if(','));
1221         rem_anchor_token(',');
1222         rem_anchor_token(')');
1223
1224         expect(')');
1225         expect(')');
1226         return first;
1227 }
1228
1229 /** Parse attributes. */
1230 static attribute_t *parse_attributes(attribute_t *first)
1231 {
1232         attribute_t **anchor = &first;
1233         for (;;) {
1234                 while (*anchor != NULL)
1235                         anchor = &(*anchor)->next;
1236
1237                 attribute_t *attribute;
1238                 switch (token.kind) {
1239                 case T___attribute__:
1240                         attribute = parse_attribute_gnu();
1241                         if (attribute == NULL)
1242                                 continue;
1243                         break;
1244
1245                 case T_asm:
1246                         attribute = parse_attribute_asm();
1247                         break;
1248
1249                 case T_cdecl:
1250                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1251                         eat(T_cdecl);
1252                         break;
1253
1254                 case T__fastcall:
1255                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1256                         eat(T__fastcall);
1257                         break;
1258
1259                 case T__forceinline:
1260                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1261                         eat(T__forceinline);
1262                         break;
1263
1264                 case T__stdcall:
1265                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1266                         eat(T__stdcall);
1267                         break;
1268
1269                 case T___thiscall:
1270                         /* TODO record modifier */
1271                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1272                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1273                         eat(T___thiscall);
1274                         break;
1275
1276                 default:
1277                         return first;
1278                 }
1279
1280                 *anchor = attribute;
1281                 anchor  = &attribute->next;
1282         }
1283 }
1284
1285 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1286
1287 static entity_t *determine_lhs_ent(expression_t *const expr,
1288                                    entity_t *lhs_ent)
1289 {
1290         switch (expr->kind) {
1291                 case EXPR_REFERENCE: {
1292                         entity_t *const entity = expr->reference.entity;
1293                         /* we should only find variables as lvalues... */
1294                         if (entity->base.kind != ENTITY_VARIABLE
1295                                         && entity->base.kind != ENTITY_PARAMETER)
1296                                 return NULL;
1297
1298                         return entity;
1299                 }
1300
1301                 case EXPR_ARRAY_ACCESS: {
1302                         expression_t *const ref = expr->array_access.array_ref;
1303                         entity_t     *      ent = NULL;
1304                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1305                                 ent     = determine_lhs_ent(ref, lhs_ent);
1306                                 lhs_ent = ent;
1307                         } else {
1308                                 mark_vars_read(ref, lhs_ent);
1309                         }
1310                         mark_vars_read(expr->array_access.index, lhs_ent);
1311                         return ent;
1312                 }
1313
1314                 case EXPR_SELECT: {
1315                         mark_vars_read(expr->select.compound, lhs_ent);
1316                         if (is_type_compound(skip_typeref(expr->base.type)))
1317                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1318                         return NULL;
1319                 }
1320
1321                 case EXPR_UNARY_DEREFERENCE: {
1322                         expression_t *const val = expr->unary.value;
1323                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1324                                 /* *&x is a NOP */
1325                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1326                         } else {
1327                                 mark_vars_read(val, NULL);
1328                                 return NULL;
1329                         }
1330                 }
1331
1332                 default:
1333                         mark_vars_read(expr, NULL);
1334                         return NULL;
1335         }
1336 }
1337
1338 #define ENT_ANY ((entity_t*)-1)
1339
1340 /**
1341  * Mark declarations, which are read.  This is used to detect variables, which
1342  * are never read.
1343  * Example:
1344  * x = x + 1;
1345  *   x is not marked as "read", because it is only read to calculate its own new
1346  *   value.
1347  *
1348  * x += y; y += x;
1349  *   x and y are not detected as "not read", because multiple variables are
1350  *   involved.
1351  */
1352 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1353 {
1354         switch (expr->kind) {
1355                 case EXPR_REFERENCE: {
1356                         entity_t *const entity = expr->reference.entity;
1357                         if (entity->kind != ENTITY_VARIABLE
1358                                         && entity->kind != ENTITY_PARAMETER)
1359                                 return;
1360
1361                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1362                                 entity->variable.read = true;
1363                         }
1364                         return;
1365                 }
1366
1367                 case EXPR_CALL:
1368                         // TODO respect pure/const
1369                         mark_vars_read(expr->call.function, NULL);
1370                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1371                                 mark_vars_read(arg->expression, NULL);
1372                         }
1373                         return;
1374
1375                 case EXPR_CONDITIONAL:
1376                         // TODO lhs_decl should depend on whether true/false have an effect
1377                         mark_vars_read(expr->conditional.condition, NULL);
1378                         if (expr->conditional.true_expression != NULL)
1379                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1380                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1381                         return;
1382
1383                 case EXPR_SELECT:
1384                         if (lhs_ent == ENT_ANY
1385                                         && !is_type_compound(skip_typeref(expr->base.type)))
1386                                 lhs_ent = NULL;
1387                         mark_vars_read(expr->select.compound, lhs_ent);
1388                         return;
1389
1390                 case EXPR_ARRAY_ACCESS: {
1391                         mark_vars_read(expr->array_access.index, lhs_ent);
1392                         expression_t *const ref = expr->array_access.array_ref;
1393                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1394                                 if (lhs_ent == ENT_ANY)
1395                                         lhs_ent = NULL;
1396                         }
1397                         mark_vars_read(ref, lhs_ent);
1398                         return;
1399                 }
1400
1401                 case EXPR_VA_ARG:
1402                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1403                         return;
1404
1405                 case EXPR_VA_COPY:
1406                         mark_vars_read(expr->va_copye.src, lhs_ent);
1407                         return;
1408
1409                 case EXPR_UNARY_CAST:
1410                         /* Special case: Use void cast to mark a variable as "read" */
1411                         if (is_type_void(skip_typeref(expr->base.type)))
1412                                 lhs_ent = NULL;
1413                         goto unary;
1414
1415
1416                 case EXPR_UNARY_THROW:
1417                         if (expr->unary.value == NULL)
1418                                 return;
1419                         /* FALLTHROUGH */
1420                 case EXPR_UNARY_DEREFERENCE:
1421                 case EXPR_UNARY_DELETE:
1422                 case EXPR_UNARY_DELETE_ARRAY:
1423                         if (lhs_ent == ENT_ANY)
1424                                 lhs_ent = NULL;
1425                         goto unary;
1426
1427                 case EXPR_UNARY_NEGATE:
1428                 case EXPR_UNARY_PLUS:
1429                 case EXPR_UNARY_BITWISE_NEGATE:
1430                 case EXPR_UNARY_NOT:
1431                 case EXPR_UNARY_TAKE_ADDRESS:
1432                 case EXPR_UNARY_POSTFIX_INCREMENT:
1433                 case EXPR_UNARY_POSTFIX_DECREMENT:
1434                 case EXPR_UNARY_PREFIX_INCREMENT:
1435                 case EXPR_UNARY_PREFIX_DECREMENT:
1436                 case EXPR_UNARY_ASSUME:
1437 unary:
1438                         mark_vars_read(expr->unary.value, lhs_ent);
1439                         return;
1440
1441                 case EXPR_BINARY_ADD:
1442                 case EXPR_BINARY_SUB:
1443                 case EXPR_BINARY_MUL:
1444                 case EXPR_BINARY_DIV:
1445                 case EXPR_BINARY_MOD:
1446                 case EXPR_BINARY_EQUAL:
1447                 case EXPR_BINARY_NOTEQUAL:
1448                 case EXPR_BINARY_LESS:
1449                 case EXPR_BINARY_LESSEQUAL:
1450                 case EXPR_BINARY_GREATER:
1451                 case EXPR_BINARY_GREATEREQUAL:
1452                 case EXPR_BINARY_BITWISE_AND:
1453                 case EXPR_BINARY_BITWISE_OR:
1454                 case EXPR_BINARY_BITWISE_XOR:
1455                 case EXPR_BINARY_LOGICAL_AND:
1456                 case EXPR_BINARY_LOGICAL_OR:
1457                 case EXPR_BINARY_SHIFTLEFT:
1458                 case EXPR_BINARY_SHIFTRIGHT:
1459                 case EXPR_BINARY_COMMA:
1460                 case EXPR_BINARY_ISGREATER:
1461                 case EXPR_BINARY_ISGREATEREQUAL:
1462                 case EXPR_BINARY_ISLESS:
1463                 case EXPR_BINARY_ISLESSEQUAL:
1464                 case EXPR_BINARY_ISLESSGREATER:
1465                 case EXPR_BINARY_ISUNORDERED:
1466                         mark_vars_read(expr->binary.left,  lhs_ent);
1467                         mark_vars_read(expr->binary.right, lhs_ent);
1468                         return;
1469
1470                 case EXPR_BINARY_ASSIGN:
1471                 case EXPR_BINARY_MUL_ASSIGN:
1472                 case EXPR_BINARY_DIV_ASSIGN:
1473                 case EXPR_BINARY_MOD_ASSIGN:
1474                 case EXPR_BINARY_ADD_ASSIGN:
1475                 case EXPR_BINARY_SUB_ASSIGN:
1476                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1477                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1478                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1479                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1480                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1481                         if (lhs_ent == ENT_ANY)
1482                                 lhs_ent = NULL;
1483                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1484                         mark_vars_read(expr->binary.right, lhs_ent);
1485                         return;
1486                 }
1487
1488                 case EXPR_VA_START:
1489                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1490                         return;
1491
1492                 case EXPR_LITERAL_CASES:
1493                 case EXPR_ERROR:
1494                 case EXPR_STRING_LITERAL:
1495                 case EXPR_COMPOUND_LITERAL: // TODO init?
1496                 case EXPR_SIZEOF:
1497                 case EXPR_CLASSIFY_TYPE:
1498                 case EXPR_ALIGNOF:
1499                 case EXPR_FUNCNAME:
1500                 case EXPR_BUILTIN_CONSTANT_P:
1501                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1502                 case EXPR_OFFSETOF:
1503                 case EXPR_STATEMENT: // TODO
1504                 case EXPR_LABEL_ADDRESS:
1505                 case EXPR_ENUM_CONSTANT:
1506                         return;
1507         }
1508
1509         panic("unhandled expression");
1510 }
1511
1512 static designator_t *parse_designation(void)
1513 {
1514         designator_t  *result = NULL;
1515         designator_t **anchor = &result;
1516
1517         for (;;) {
1518                 designator_t *designator;
1519                 switch (token.kind) {
1520                 case '[':
1521                         designator = allocate_ast_zero(sizeof(designator[0]));
1522                         designator->source_position = *HERE;
1523                         eat('[');
1524                         add_anchor_token(']');
1525                         designator->array_index = parse_constant_expression();
1526                         rem_anchor_token(']');
1527                         expect(']');
1528                         break;
1529                 case '.':
1530                         designator = allocate_ast_zero(sizeof(designator[0]));
1531                         designator->source_position = *HERE;
1532                         eat('.');
1533                         designator->symbol = expect_identifier("while parsing designator", NULL);
1534                         if (!designator->symbol)
1535                                 return NULL;
1536                         break;
1537                 default:
1538                         expect('=');
1539                         return result;
1540                 }
1541
1542                 assert(designator != NULL);
1543                 *anchor = designator;
1544                 anchor  = &designator->next;
1545         }
1546 }
1547
1548 static initializer_t *initializer_from_string(array_type_t *const type,
1549                                               const string_t *const string)
1550 {
1551         /* TODO: check len vs. size of array type */
1552         (void) type;
1553
1554         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1555         initializer->string.string = *string;
1556
1557         return initializer;
1558 }
1559
1560 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1561                                                    const string_t *const string)
1562 {
1563         /* TODO: check len vs. size of array type */
1564         (void) type;
1565
1566         initializer_t *const initializer =
1567                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1568         initializer->wide_string.string = *string;
1569
1570         return initializer;
1571 }
1572
1573 /**
1574  * Build an initializer from a given expression.
1575  */
1576 static initializer_t *initializer_from_expression(type_t *orig_type,
1577                                                   expression_t *expression)
1578 {
1579         /* TODO check that expression is a constant expression */
1580
1581         /* §6.7.8.14/15 char array may be initialized by string literals */
1582         type_t *type           = skip_typeref(orig_type);
1583         type_t *expr_type_orig = expression->base.type;
1584         type_t *expr_type      = skip_typeref(expr_type_orig);
1585
1586         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1587                 array_type_t *const array_type   = &type->array;
1588                 type_t       *const element_type = skip_typeref(array_type->element_type);
1589
1590                 if (element_type->kind == TYPE_ATOMIC && expression->kind == EXPR_STRING_LITERAL) {
1591                         switch (expression->string_literal.encoding) {
1592                         case STRING_ENCODING_CHAR: {
1593                                 atomic_type_kind_t const akind = element_type->atomic.akind;
1594                                 if (akind == ATOMIC_TYPE_CHAR
1595                                                 || akind == ATOMIC_TYPE_SCHAR
1596                                                 || akind == ATOMIC_TYPE_UCHAR) {
1597                                         return initializer_from_string(array_type,
1598                                                         &expression->string_literal.value);
1599                                 }
1600                                 break;
1601                         }
1602
1603                         case STRING_ENCODING_WIDE: {
1604                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1605                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1606                                         return initializer_from_wide_string(array_type,
1607                                                         &expression->string_literal.value);
1608                                 }
1609                                 break;
1610                         }
1611                         }
1612                 }
1613         }
1614
1615         assign_error_t error = semantic_assign(type, expression);
1616         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1617                 return NULL;
1618         report_assign_error(error, type, expression, "initializer",
1619                             &expression->base.source_position);
1620
1621         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1622         result->value.value = create_implicit_cast(expression, type);
1623
1624         return result;
1625 }
1626
1627 /**
1628  * Parses an scalar initializer.
1629  *
1630  * §6.7.8.11; eat {} without warning
1631  */
1632 static initializer_t *parse_scalar_initializer(type_t *type,
1633                                                bool must_be_constant)
1634 {
1635         /* there might be extra {} hierarchies */
1636         int braces = 0;
1637         if (token.kind == '{') {
1638                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1639                 do {
1640                         eat('{');
1641                         ++braces;
1642                 } while (token.kind == '{');
1643         }
1644
1645         expression_t *expression = parse_assignment_expression();
1646         mark_vars_read(expression, NULL);
1647         if (must_be_constant && !is_linker_constant(expression)) {
1648                 errorf(&expression->base.source_position,
1649                        "initialisation expression '%E' is not constant",
1650                        expression);
1651         }
1652
1653         initializer_t *initializer = initializer_from_expression(type, expression);
1654
1655         if (initializer == NULL) {
1656                 errorf(&expression->base.source_position,
1657                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1658                        expression, expression->base.type, type);
1659                 /* TODO */
1660                 return NULL;
1661         }
1662
1663         bool additional_warning_displayed = false;
1664         while (braces > 0) {
1665                 next_if(',');
1666                 if (token.kind != '}') {
1667                         if (!additional_warning_displayed) {
1668                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1669                                 additional_warning_displayed = true;
1670                         }
1671                 }
1672                 eat_block();
1673                 braces--;
1674         }
1675
1676         return initializer;
1677 }
1678
1679 /**
1680  * An entry in the type path.
1681  */
1682 typedef struct type_path_entry_t type_path_entry_t;
1683 struct type_path_entry_t {
1684         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1685         union {
1686                 size_t         index;          /**< For array types: the current index. */
1687                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1688         } v;
1689 };
1690
1691 /**
1692  * A type path expression a position inside compound or array types.
1693  */
1694 typedef struct type_path_t type_path_t;
1695 struct type_path_t {
1696         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1697         type_t            *top_type;     /**< type of the element the path points */
1698         size_t             max_index;    /**< largest index in outermost array */
1699 };
1700
1701 /**
1702  * Prints a type path for debugging.
1703  */
1704 static __attribute__((unused)) void debug_print_type_path(
1705                 const type_path_t *path)
1706 {
1707         size_t len = ARR_LEN(path->path);
1708
1709         for (size_t i = 0; i < len; ++i) {
1710                 const type_path_entry_t *entry = & path->path[i];
1711
1712                 type_t *type = skip_typeref(entry->type);
1713                 if (is_type_compound(type)) {
1714                         /* in gcc mode structs can have no members */
1715                         if (entry->v.compound_entry == NULL) {
1716                                 assert(i == len-1);
1717                                 continue;
1718                         }
1719                         fprintf(stderr, ".%s",
1720                                 entry->v.compound_entry->base.symbol->string);
1721                 } else if (is_type_array(type)) {
1722                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1723                 } else {
1724                         fprintf(stderr, "-INVALID-");
1725                 }
1726         }
1727         if (path->top_type != NULL) {
1728                 fprintf(stderr, "  (");
1729                 print_type(path->top_type);
1730                 fprintf(stderr, ")");
1731         }
1732 }
1733
1734 /**
1735  * Return the top type path entry, ie. in a path
1736  * (type).a.b returns the b.
1737  */
1738 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1739 {
1740         size_t len = ARR_LEN(path->path);
1741         assert(len > 0);
1742         return &path->path[len-1];
1743 }
1744
1745 /**
1746  * Enlarge the type path by an (empty) element.
1747  */
1748 static type_path_entry_t *append_to_type_path(type_path_t *path)
1749 {
1750         size_t len = ARR_LEN(path->path);
1751         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1752
1753         type_path_entry_t *result = & path->path[len];
1754         memset(result, 0, sizeof(result[0]));
1755         return result;
1756 }
1757
1758 /**
1759  * Descending into a sub-type. Enter the scope of the current top_type.
1760  */
1761 static void descend_into_subtype(type_path_t *path)
1762 {
1763         type_t *orig_top_type = path->top_type;
1764         type_t *top_type      = skip_typeref(orig_top_type);
1765
1766         type_path_entry_t *top = append_to_type_path(path);
1767         top->type              = top_type;
1768
1769         if (is_type_compound(top_type)) {
1770                 compound_t *const compound = top_type->compound.compound;
1771                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1772
1773                 if (entry != NULL) {
1774                         top->v.compound_entry = &entry->declaration;
1775                         path->top_type = entry->declaration.type;
1776                 } else {
1777                         path->top_type = NULL;
1778                 }
1779         } else if (is_type_array(top_type)) {
1780                 top->v.index   = 0;
1781                 path->top_type = top_type->array.element_type;
1782         } else {
1783                 assert(!is_type_valid(top_type));
1784         }
1785 }
1786
1787 /**
1788  * Pop an entry from the given type path, ie. returning from
1789  * (type).a.b to (type).a
1790  */
1791 static void ascend_from_subtype(type_path_t *path)
1792 {
1793         type_path_entry_t *top = get_type_path_top(path);
1794
1795         path->top_type = top->type;
1796
1797         size_t len = ARR_LEN(path->path);
1798         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1799 }
1800
1801 /**
1802  * Pop entries from the given type path until the given
1803  * path level is reached.
1804  */
1805 static void ascend_to(type_path_t *path, size_t top_path_level)
1806 {
1807         size_t len = ARR_LEN(path->path);
1808
1809         while (len > top_path_level) {
1810                 ascend_from_subtype(path);
1811                 len = ARR_LEN(path->path);
1812         }
1813 }
1814
1815 static bool walk_designator(type_path_t *path, const designator_t *designator,
1816                             bool used_in_offsetof)
1817 {
1818         for (; designator != NULL; designator = designator->next) {
1819                 type_path_entry_t *top       = get_type_path_top(path);
1820                 type_t            *orig_type = top->type;
1821
1822                 type_t *type = skip_typeref(orig_type);
1823
1824                 if (designator->symbol != NULL) {
1825                         symbol_t *symbol = designator->symbol;
1826                         if (!is_type_compound(type)) {
1827                                 if (is_type_valid(type)) {
1828                                         errorf(&designator->source_position,
1829                                                "'.%Y' designator used for non-compound type '%T'",
1830                                                symbol, orig_type);
1831                                 }
1832
1833                                 top->type             = type_error_type;
1834                                 top->v.compound_entry = NULL;
1835                                 orig_type             = type_error_type;
1836                         } else {
1837                                 compound_t *compound = type->compound.compound;
1838                                 entity_t   *iter     = compound->members.entities;
1839                                 for (; iter != NULL; iter = iter->base.next) {
1840                                         if (iter->base.symbol == symbol) {
1841                                                 break;
1842                                         }
1843                                 }
1844                                 if (iter == NULL) {
1845                                         errorf(&designator->source_position,
1846                                                "'%T' has no member named '%Y'", orig_type, symbol);
1847                                         return false;
1848                                 }
1849                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1850                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1851                                         errorf(&designator->source_position,
1852                                                    "offsetof designator '%Y' must not specify bitfield",
1853                                                    symbol);
1854                                         return false;
1855                                 }
1856
1857                                 top->type             = orig_type;
1858                                 top->v.compound_entry = &iter->declaration;
1859                                 orig_type             = iter->declaration.type;
1860                         }
1861                 } else {
1862                         expression_t *array_index = designator->array_index;
1863                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1864                                 return true;
1865
1866                         if (!is_type_array(type)) {
1867                                 if (is_type_valid(type)) {
1868                                         errorf(&designator->source_position,
1869                                                "[%E] designator used for non-array type '%T'",
1870                                                array_index, orig_type);
1871                                 }
1872                                 return false;
1873                         }
1874
1875                         long index = fold_constant_to_int(array_index);
1876                         if (!used_in_offsetof) {
1877                                 if (index < 0) {
1878                                         errorf(&designator->source_position,
1879                                                "array index [%E] must be positive", array_index);
1880                                 } else if (type->array.size_constant) {
1881                                         long array_size = type->array.size;
1882                                         if (index >= array_size) {
1883                                                 errorf(&designator->source_position,
1884                                                        "designator [%E] (%d) exceeds array size %d",
1885                                                        array_index, index, array_size);
1886                                         }
1887                                 }
1888                         }
1889
1890                         top->type    = orig_type;
1891                         top->v.index = (size_t) index;
1892                         orig_type    = type->array.element_type;
1893                 }
1894                 path->top_type = orig_type;
1895
1896                 if (designator->next != NULL) {
1897                         descend_into_subtype(path);
1898                 }
1899         }
1900         return true;
1901 }
1902
1903 static void advance_current_object(type_path_t *path, size_t top_path_level)
1904 {
1905         type_path_entry_t *top = get_type_path_top(path);
1906
1907         type_t *type = skip_typeref(top->type);
1908         if (is_type_union(type)) {
1909                 /* in unions only the first element is initialized */
1910                 top->v.compound_entry = NULL;
1911         } else if (is_type_struct(type)) {
1912                 declaration_t *entry = top->v.compound_entry;
1913
1914                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1915                 if (next_entity != NULL) {
1916                         assert(is_declaration(next_entity));
1917                         entry = &next_entity->declaration;
1918                 } else {
1919                         entry = NULL;
1920                 }
1921
1922                 top->v.compound_entry = entry;
1923                 if (entry != NULL) {
1924                         path->top_type = entry->type;
1925                         return;
1926                 }
1927         } else if (is_type_array(type)) {
1928                 assert(is_type_array(type));
1929
1930                 top->v.index++;
1931
1932                 if (!type->array.size_constant || top->v.index < type->array.size) {
1933                         return;
1934                 }
1935         } else {
1936                 assert(!is_type_valid(type));
1937                 return;
1938         }
1939
1940         /* we're past the last member of the current sub-aggregate, try if we
1941          * can ascend in the type hierarchy and continue with another subobject */
1942         size_t len = ARR_LEN(path->path);
1943
1944         if (len > top_path_level) {
1945                 ascend_from_subtype(path);
1946                 advance_current_object(path, top_path_level);
1947         } else {
1948                 path->top_type = NULL;
1949         }
1950 }
1951
1952 /**
1953  * skip any {...} blocks until a closing bracket is reached.
1954  */
1955 static void skip_initializers(void)
1956 {
1957         next_if('{');
1958
1959         while (token.kind != '}') {
1960                 if (token.kind == T_EOF)
1961                         return;
1962                 if (token.kind == '{') {
1963                         eat_block();
1964                         continue;
1965                 }
1966                 next_token();
1967         }
1968 }
1969
1970 static initializer_t *create_empty_initializer(void)
1971 {
1972         static initializer_t empty_initializer
1973                 = { .list = { { INITIALIZER_LIST }, 0 } };
1974         return &empty_initializer;
1975 }
1976
1977 /**
1978  * Parse a part of an initialiser for a struct or union,
1979  */
1980 static initializer_t *parse_sub_initializer(type_path_t *path,
1981                 type_t *outer_type, size_t top_path_level,
1982                 parse_initializer_env_t *env)
1983 {
1984         if (token.kind == '}') {
1985                 /* empty initializer */
1986                 return create_empty_initializer();
1987         }
1988
1989         type_t *orig_type = path->top_type;
1990         type_t *type      = NULL;
1991
1992         if (orig_type == NULL) {
1993                 /* We are initializing an empty compound. */
1994         } else {
1995                 type = skip_typeref(orig_type);
1996         }
1997
1998         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1999
2000         while (true) {
2001                 designator_t *designator = NULL;
2002                 if (token.kind == '.' || token.kind == '[') {
2003                         designator = parse_designation();
2004                         goto finish_designator;
2005                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2006                         /* GNU-style designator ("identifier: value") */
2007                         designator = allocate_ast_zero(sizeof(designator[0]));
2008                         designator->source_position = *HERE;
2009                         designator->symbol          = token.base.symbol;
2010                         eat(T_IDENTIFIER);
2011                         eat(':');
2012
2013 finish_designator:
2014                         /* reset path to toplevel, evaluate designator from there */
2015                         ascend_to(path, top_path_level);
2016                         if (!walk_designator(path, designator, false)) {
2017                                 /* can't continue after designation error */
2018                                 goto end_error;
2019                         }
2020
2021                         initializer_t *designator_initializer
2022                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2023                         designator_initializer->designator.designator = designator;
2024                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2025
2026                         orig_type = path->top_type;
2027                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2028                 }
2029
2030                 initializer_t *sub;
2031
2032                 if (token.kind == '{') {
2033                         if (type != NULL && is_type_scalar(type)) {
2034                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2035                         } else {
2036                                 if (type == NULL) {
2037                                         if (env->entity != NULL) {
2038                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2039                                         } else {
2040                                                 errorf(HERE, "extra brace group at end of initializer");
2041                                         }
2042                                         eat('{');
2043                                 } else {
2044                                         eat('{');
2045                                         descend_into_subtype(path);
2046                                 }
2047
2048                                 add_anchor_token('}');
2049                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2050                                                             env);
2051                                 rem_anchor_token('}');
2052
2053                                 expect('}');
2054
2055                                 if (!type)
2056                                         goto error_parse_next;
2057
2058                                 ascend_from_subtype(path);
2059                         }
2060                 } else {
2061                         /* must be an expression */
2062                         expression_t *expression = parse_assignment_expression();
2063                         mark_vars_read(expression, NULL);
2064
2065                         if (env->must_be_constant && !is_linker_constant(expression)) {
2066                                 errorf(&expression->base.source_position,
2067                                        "Initialisation expression '%E' is not constant",
2068                                        expression);
2069                         }
2070
2071                         if (type == NULL) {
2072                                 /* we are already outside, ... */
2073                                 if (outer_type == NULL)
2074                                         goto error_parse_next;
2075                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2076                                 if (is_type_compound(outer_type_skip) &&
2077                                                 !outer_type_skip->compound.compound->complete) {
2078                                         goto error_parse_next;
2079                                 }
2080
2081                                 source_position_t const* const pos = &expression->base.source_position;
2082                                 if (env->entity != NULL) {
2083                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2084                                 } else {
2085                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2086                                 }
2087                                 goto error_parse_next;
2088                         }
2089
2090                         /* handle { "string" } special case */
2091                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2092                                 sub = initializer_from_expression(outer_type, expression);
2093                                 if (sub != NULL) {
2094                                         next_if(',');
2095                                         if (token.kind != '}') {
2096                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2097                                         }
2098                                         /* TODO: eat , ... */
2099                                         return sub;
2100                                 }
2101                         }
2102
2103                         /* descend into subtypes until expression matches type */
2104                         while (true) {
2105                                 orig_type = path->top_type;
2106                                 type      = skip_typeref(orig_type);
2107
2108                                 sub = initializer_from_expression(orig_type, expression);
2109                                 if (sub != NULL) {
2110                                         break;
2111                                 }
2112                                 if (!is_type_valid(type)) {
2113                                         goto end_error;
2114                                 }
2115                                 if (is_type_scalar(type)) {
2116                                         errorf(&expression->base.source_position,
2117                                                         "expression '%E' doesn't match expected type '%T'",
2118                                                         expression, orig_type);
2119                                         goto end_error;
2120                                 }
2121
2122                                 descend_into_subtype(path);
2123                         }
2124                 }
2125
2126                 /* update largest index of top array */
2127                 const type_path_entry_t *first      = &path->path[0];
2128                 type_t                  *first_type = first->type;
2129                 first_type                          = skip_typeref(first_type);
2130                 if (is_type_array(first_type)) {
2131                         size_t index = first->v.index;
2132                         if (index > path->max_index)
2133                                 path->max_index = index;
2134                 }
2135
2136                 /* append to initializers list */
2137                 ARR_APP1(initializer_t*, initializers, sub);
2138
2139 error_parse_next:
2140                 if (token.kind == '}') {
2141                         break;
2142                 }
2143                 add_anchor_token('}');
2144                 expect(',');
2145                 rem_anchor_token('}');
2146                 if (token.kind == '}') {
2147                         break;
2148                 }
2149
2150                 if (type != NULL) {
2151                         /* advance to the next declaration if we are not at the end */
2152                         advance_current_object(path, top_path_level);
2153                         orig_type = path->top_type;
2154                         if (orig_type != NULL)
2155                                 type = skip_typeref(orig_type);
2156                         else
2157                                 type = NULL;
2158                 }
2159         }
2160
2161         size_t len  = ARR_LEN(initializers);
2162         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2163         initializer_t *result = allocate_ast_zero(size);
2164         result->kind          = INITIALIZER_LIST;
2165         result->list.len      = len;
2166         memcpy(&result->list.initializers, initializers,
2167                len * sizeof(initializers[0]));
2168
2169         DEL_ARR_F(initializers);
2170         ascend_to(path, top_path_level+1);
2171
2172         return result;
2173
2174 end_error:
2175         skip_initializers();
2176         DEL_ARR_F(initializers);
2177         ascend_to(path, top_path_level+1);
2178         return NULL;
2179 }
2180
2181 static expression_t *make_size_literal(size_t value)
2182 {
2183         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2184         literal->base.type    = type_size_t;
2185
2186         char buf[128];
2187         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2188         literal->literal.value = make_string(buf);
2189
2190         return literal;
2191 }
2192
2193 /**
2194  * Parses an initializer. Parsers either a compound literal
2195  * (env->declaration == NULL) or an initializer of a declaration.
2196  */
2197 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2198 {
2199         type_t        *type      = skip_typeref(env->type);
2200         size_t         max_index = 0;
2201         initializer_t *result;
2202
2203         if (is_type_scalar(type)) {
2204                 result = parse_scalar_initializer(type, env->must_be_constant);
2205         } else if (token.kind == '{') {
2206                 eat('{');
2207
2208                 type_path_t path;
2209                 memset(&path, 0, sizeof(path));
2210                 path.top_type = env->type;
2211                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2212
2213                 descend_into_subtype(&path);
2214
2215                 add_anchor_token('}');
2216                 result = parse_sub_initializer(&path, env->type, 1, env);
2217                 rem_anchor_token('}');
2218
2219                 max_index = path.max_index;
2220                 DEL_ARR_F(path.path);
2221
2222                 expect('}');
2223         } else {
2224                 /* parse_scalar_initializer() also works in this case: we simply
2225                  * have an expression without {} around it */
2226                 result = parse_scalar_initializer(type, env->must_be_constant);
2227         }
2228
2229         /* §6.7.8:22 array initializers for arrays with unknown size determine
2230          * the array type size */
2231         if (is_type_array(type) && type->array.size_expression == NULL
2232                         && result != NULL) {
2233                 size_t size;
2234                 switch (result->kind) {
2235                 case INITIALIZER_LIST:
2236                         assert(max_index != 0xdeadbeaf);
2237                         size = max_index + 1;
2238                         break;
2239
2240                 case INITIALIZER_STRING:
2241                         size = result->string.string.size + 1;
2242                         break;
2243
2244                 case INITIALIZER_WIDE_STRING:
2245                         size = result->wide_string.string.size;
2246                         break;
2247
2248                 case INITIALIZER_DESIGNATOR:
2249                 case INITIALIZER_VALUE:
2250                         /* can happen for parse errors */
2251                         size = 0;
2252                         break;
2253
2254                 default:
2255                         internal_errorf(HERE, "invalid initializer type");
2256                 }
2257
2258                 type_t *new_type = duplicate_type(type);
2259
2260                 new_type->array.size_expression   = make_size_literal(size);
2261                 new_type->array.size_constant     = true;
2262                 new_type->array.has_implicit_size = true;
2263                 new_type->array.size              = size;
2264                 env->type = new_type;
2265         }
2266
2267         return result;
2268 }
2269
2270 static void append_entity(scope_t *scope, entity_t *entity)
2271 {
2272         if (scope->last_entity != NULL) {
2273                 scope->last_entity->base.next = entity;
2274         } else {
2275                 scope->entities = entity;
2276         }
2277         entity->base.parent_entity = current_entity;
2278         scope->last_entity         = entity;
2279 }
2280
2281
2282 static compound_t *parse_compound_type_specifier(bool is_struct)
2283 {
2284         source_position_t const pos = *HERE;
2285         eat(is_struct ? T_struct : T_union);
2286
2287         symbol_t    *symbol     = NULL;
2288         entity_t    *entity     = NULL;
2289         attribute_t *attributes = NULL;
2290
2291         if (token.kind == T___attribute__) {
2292                 attributes = parse_attributes(NULL);
2293         }
2294
2295         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2296         if (token.kind == T_IDENTIFIER) {
2297                 /* the compound has a name, check if we have seen it already */
2298                 symbol = token.base.symbol;
2299                 entity = get_tag(symbol, kind);
2300                 eat(T_IDENTIFIER);
2301
2302                 if (entity != NULL) {
2303                         if (entity->base.parent_scope != current_scope &&
2304                             (token.kind == '{' || token.kind == ';')) {
2305                                 /* we're in an inner scope and have a definition. Shadow
2306                                  * existing definition in outer scope */
2307                                 entity = NULL;
2308                         } else if (entity->compound.complete && token.kind == '{') {
2309                                 source_position_t const *const ppos = &entity->base.source_position;
2310                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2311                                 /* clear members in the hope to avoid further errors */
2312                                 entity->compound.members.entities = NULL;
2313                         }
2314                 }
2315         } else if (token.kind != '{') {
2316                 char const *const msg =
2317                         is_struct ? "while parsing struct type specifier" :
2318                                     "while parsing union type specifier";
2319                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2320
2321                 return NULL;
2322         }
2323
2324         if (entity == NULL) {
2325                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2326                 entity->compound.alignment = 1;
2327                 entity->base.parent_scope  = current_scope;
2328                 if (symbol != NULL) {
2329                         environment_push(entity);
2330                 }
2331                 append_entity(current_scope, entity);
2332         }
2333
2334         if (token.kind == '{') {
2335                 parse_compound_type_entries(&entity->compound);
2336
2337                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2338                 if (symbol == NULL) {
2339                         assert(anonymous_entity == NULL);
2340                         anonymous_entity = entity;
2341                 }
2342         }
2343
2344         if (attributes != NULL) {
2345                 handle_entity_attributes(attributes, entity);
2346         }
2347
2348         return &entity->compound;
2349 }
2350
2351 static void parse_enum_entries(type_t *const enum_type)
2352 {
2353         eat('{');
2354
2355         if (token.kind == '}') {
2356                 errorf(HERE, "empty enum not allowed");
2357                 eat('}');
2358                 return;
2359         }
2360
2361         add_anchor_token('}');
2362         add_anchor_token(',');
2363         do {
2364                 add_anchor_token('=');
2365                 source_position_t pos;
2366                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2367                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2368                 entity->enum_value.enum_type = enum_type;
2369                 rem_anchor_token('=');
2370
2371                 if (next_if('=')) {
2372                         expression_t *value = parse_constant_expression();
2373
2374                         value = create_implicit_cast(value, enum_type);
2375                         entity->enum_value.value = value;
2376
2377                         /* TODO semantic */
2378                 }
2379
2380                 record_entity(entity, false);
2381         } while (next_if(',') && token.kind != '}');
2382         rem_anchor_token(',');
2383         rem_anchor_token('}');
2384
2385         expect('}');
2386 }
2387
2388 static type_t *parse_enum_specifier(void)
2389 {
2390         source_position_t const pos = *HERE;
2391         entity_t               *entity;
2392         symbol_t               *symbol;
2393
2394         eat(T_enum);
2395         switch (token.kind) {
2396                 case T_IDENTIFIER:
2397                         symbol = token.base.symbol;
2398                         entity = get_tag(symbol, ENTITY_ENUM);
2399                         eat(T_IDENTIFIER);
2400
2401                         if (entity != NULL) {
2402                                 if (entity->base.parent_scope != current_scope &&
2403                                                 (token.kind == '{' || token.kind == ';')) {
2404                                         /* we're in an inner scope and have a definition. Shadow
2405                                          * existing definition in outer scope */
2406                                         entity = NULL;
2407                                 } else if (entity->enume.complete && token.kind == '{') {
2408                                         source_position_t const *const ppos = &entity->base.source_position;
2409                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2410                                 }
2411                         }
2412                         break;
2413
2414                 case '{':
2415                         entity = NULL;
2416                         symbol = NULL;
2417                         break;
2418
2419                 default:
2420                         parse_error_expected("while parsing enum type specifier",
2421                                         T_IDENTIFIER, '{', NULL);
2422                         return NULL;
2423         }
2424
2425         if (entity == NULL) {
2426                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2427                 entity->base.parent_scope = current_scope;
2428         }
2429
2430         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2431         type->enumt.enume      = &entity->enume;
2432         type->enumt.base.akind = ATOMIC_TYPE_INT;
2433
2434         if (token.kind == '{') {
2435                 if (symbol != NULL) {
2436                         environment_push(entity);
2437                 }
2438                 append_entity(current_scope, entity);
2439                 entity->enume.complete = true;
2440
2441                 parse_enum_entries(type);
2442                 parse_attributes(NULL);
2443
2444                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2445                 if (symbol == NULL) {
2446                         assert(anonymous_entity == NULL);
2447                         anonymous_entity = entity;
2448                 }
2449         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2450                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2451         }
2452
2453         return type;
2454 }
2455
2456 /**
2457  * if a symbol is a typedef to another type, return true
2458  */
2459 static bool is_typedef_symbol(symbol_t *symbol)
2460 {
2461         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2462         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2463 }
2464
2465 static type_t *parse_typeof(void)
2466 {
2467         eat(T___typeof__);
2468
2469         type_t *type;
2470
2471         add_anchor_token(')');
2472         expect('(');
2473
2474         expression_t *expression  = NULL;
2475
2476         switch (token.kind) {
2477         case T_IDENTIFIER:
2478                 if (is_typedef_symbol(token.base.symbol)) {
2479         DECLARATION_START
2480                         type = parse_typename();
2481                 } else {
2482         default:
2483                         expression = parse_expression();
2484                         type       = revert_automatic_type_conversion(expression);
2485                 }
2486                 break;
2487         }
2488
2489         rem_anchor_token(')');
2490         expect(')');
2491
2492         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2493         typeof_type->typeoft.expression  = expression;
2494         typeof_type->typeoft.typeof_type = type;
2495
2496         return typeof_type;
2497 }
2498
2499 typedef enum specifiers_t {
2500         SPECIFIER_SIGNED    = 1 << 0,
2501         SPECIFIER_UNSIGNED  = 1 << 1,
2502         SPECIFIER_LONG      = 1 << 2,
2503         SPECIFIER_INT       = 1 << 3,
2504         SPECIFIER_DOUBLE    = 1 << 4,
2505         SPECIFIER_CHAR      = 1 << 5,
2506         SPECIFIER_WCHAR_T   = 1 << 6,
2507         SPECIFIER_SHORT     = 1 << 7,
2508         SPECIFIER_LONG_LONG = 1 << 8,
2509         SPECIFIER_FLOAT     = 1 << 9,
2510         SPECIFIER_BOOL      = 1 << 10,
2511         SPECIFIER_VOID      = 1 << 11,
2512         SPECIFIER_INT8      = 1 << 12,
2513         SPECIFIER_INT16     = 1 << 13,
2514         SPECIFIER_INT32     = 1 << 14,
2515         SPECIFIER_INT64     = 1 << 15,
2516         SPECIFIER_INT128    = 1 << 16,
2517         SPECIFIER_COMPLEX   = 1 << 17,
2518         SPECIFIER_IMAGINARY = 1 << 18,
2519 } specifiers_t;
2520
2521 static type_t *get_typedef_type(symbol_t *symbol)
2522 {
2523         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2524         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2525                 return NULL;
2526
2527         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2528         type->typedeft.typedefe = &entity->typedefe;
2529
2530         return type;
2531 }
2532
2533 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2534 {
2535         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2536
2537         add_anchor_token(')');
2538         add_anchor_token(',');
2539         expect('(');
2540
2541         do {
2542                 add_anchor_token('=');
2543                 source_position_t pos;
2544                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2545                 rem_anchor_token('=');
2546
2547                 symbol_t **prop = NULL;
2548                 if (prop_sym) {
2549                         if (streq(prop_sym->string, "put")) {
2550                                 prop = &property->put_symbol;
2551                         } else if (streq(prop_sym->string, "get")) {
2552                                 prop = &property->get_symbol;
2553                         } else {
2554                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2555                         }
2556                 }
2557
2558                 add_anchor_token(T_IDENTIFIER);
2559                 expect('=');
2560                 rem_anchor_token(T_IDENTIFIER);
2561
2562                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2563                 if (prop != NULL)
2564                         *prop = sym ? sym : sym_anonymous;
2565         } while (next_if(','));
2566         rem_anchor_token(',');
2567         rem_anchor_token(')');
2568
2569         attribute->a.property = property;
2570
2571         expect(')');
2572         return attribute;
2573 }
2574
2575 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2576 {
2577         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2578         if (next_if(T_restrict)) {
2579                 kind = ATTRIBUTE_MS_RESTRICT;
2580         } else if (token.kind == T_IDENTIFIER) {
2581                 char const *const name = token.base.symbol->string;
2582                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2583                      ++k) {
2584                         const char *attribute_name = get_attribute_name(k);
2585                         if (attribute_name != NULL && streq(attribute_name, name)) {
2586                                 kind = k;
2587                                 break;
2588                         }
2589                 }
2590
2591                 if (kind == ATTRIBUTE_UNKNOWN) {
2592                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2593                 }
2594         } else {
2595                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2596                 return NULL;
2597         }
2598
2599         attribute_t *attribute = allocate_attribute_zero(kind);
2600         eat(T_IDENTIFIER);
2601
2602         if (kind == ATTRIBUTE_MS_PROPERTY) {
2603                 return parse_attribute_ms_property(attribute);
2604         }
2605
2606         /* parse arguments */
2607         if (next_if('('))
2608                 attribute->a.arguments = parse_attribute_arguments();
2609
2610         return attribute;
2611 }
2612
2613 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2614 {
2615         eat(T__declspec);
2616
2617         add_anchor_token(')');
2618         expect('(');
2619         if (token.kind != ')') {
2620                 attribute_t **anchor = &first;
2621                 do {
2622                         while (*anchor != NULL)
2623                                 anchor = &(*anchor)->next;
2624
2625                         attribute_t *attribute
2626                                 = parse_microsoft_extended_decl_modifier_single();
2627                         if (attribute == NULL)
2628                                 break;
2629
2630                         *anchor = attribute;
2631                         anchor  = &attribute->next;
2632                 } while (next_if(','));
2633         }
2634         rem_anchor_token(')');
2635         expect(')');
2636         return first;
2637 }
2638
2639 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2640 {
2641         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2642         if (is_declaration(entity)) {
2643                 entity->declaration.type     = type_error_type;
2644                 entity->declaration.implicit = true;
2645         } else if (kind == ENTITY_TYPEDEF) {
2646                 entity->typedefe.type    = type_error_type;
2647                 entity->typedefe.builtin = true;
2648         }
2649         if (kind != ENTITY_COMPOUND_MEMBER)
2650                 record_entity(entity, false);
2651         return entity;
2652 }
2653
2654 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2655 {
2656         type_t            *type            = NULL;
2657         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2658         unsigned           type_specifiers = 0;
2659         bool               newtype         = false;
2660         bool               saw_error       = false;
2661
2662         memset(specifiers, 0, sizeof(*specifiers));
2663         specifiers->source_position = *HERE;
2664
2665         while (true) {
2666                 specifiers->attributes = parse_attributes(specifiers->attributes);
2667
2668                 switch (token.kind) {
2669                 /* storage class */
2670 #define MATCH_STORAGE_CLASS(token, class)                                  \
2671                 case token:                                                        \
2672                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2673                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2674                         }                                                              \
2675                         specifiers->storage_class = class;                             \
2676                         if (specifiers->thread_local)                                  \
2677                                 goto check_thread_storage_class;                           \
2678                         eat(token); \
2679                         break;
2680
2681                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2682                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2683                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2684                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2685                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2686
2687                 case T__declspec:
2688                         specifiers->attributes
2689                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2690                         break;
2691
2692                 case T___thread:
2693                         if (specifiers->thread_local) {
2694                                 errorf(HERE, "duplicate '__thread'");
2695                         } else {
2696                                 specifiers->thread_local = true;
2697 check_thread_storage_class:
2698                                 switch (specifiers->storage_class) {
2699                                         case STORAGE_CLASS_EXTERN:
2700                                         case STORAGE_CLASS_NONE:
2701                                         case STORAGE_CLASS_STATIC:
2702                                                 break;
2703
2704                                                 char const* wrong;
2705                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2706                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2707                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2708 wrong_thread_storage_class:
2709                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2710                                                 break;
2711                                 }
2712                         }
2713                         next_token();
2714                         break;
2715
2716                 /* type qualifiers */
2717 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2718                 case token:                                                     \
2719                         qualifiers |= qualifier;                                    \
2720                         eat(token); \
2721                         break
2722
2723                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2724                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2725                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2726                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2727                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2728                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2729                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2730                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2731
2732                 /* type specifiers */
2733 #define MATCH_SPECIFIER(token, specifier, name)                         \
2734                 case token:                                                     \
2735                         if (type_specifiers & specifier) {                           \
2736                                 errorf(HERE, "multiple " name " type specifiers given"); \
2737                         } else {                                                    \
2738                                 type_specifiers |= specifier;                           \
2739                         }                                                           \
2740                         eat(token); \
2741                         break
2742
2743                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2744                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2745                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2746                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2747                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2748                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2749                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2750                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2751                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2752                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2753                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2754                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2755                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2756                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2757                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2758                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2759                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2760                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2761
2762                 case T_inline:
2763                         eat(T_inline);
2764                         specifiers->is_inline = true;
2765                         break;
2766
2767 #if 0
2768                 case T__forceinline:
2769                         eat(T__forceinline);
2770                         specifiers->modifiers |= DM_FORCEINLINE;
2771                         break;
2772 #endif
2773
2774                 case T_long:
2775                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2776                                 errorf(HERE, "too many long type specifiers given");
2777                         } else if (type_specifiers & SPECIFIER_LONG) {
2778                                 type_specifiers |= SPECIFIER_LONG_LONG;
2779                         } else {
2780                                 type_specifiers |= SPECIFIER_LONG;
2781                         }
2782                         eat(T_long);
2783                         break;
2784
2785 #define CHECK_DOUBLE_TYPE() \
2786         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2787
2788                 case T_struct:
2789                         CHECK_DOUBLE_TYPE();
2790                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2791
2792                         type->compound.compound = parse_compound_type_specifier(true);
2793                         break;
2794                 case T_union:
2795                         CHECK_DOUBLE_TYPE();
2796                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2797                         type->compound.compound = parse_compound_type_specifier(false);
2798                         break;
2799                 case T_enum:
2800                         CHECK_DOUBLE_TYPE();
2801                         type = parse_enum_specifier();
2802                         break;
2803                 case T___typeof__:
2804                         CHECK_DOUBLE_TYPE();
2805                         type = parse_typeof();
2806                         break;
2807                 case T___builtin_va_list:
2808                         CHECK_DOUBLE_TYPE();
2809                         type = duplicate_type(type_valist);
2810                         eat(T___builtin_va_list);
2811                         break;
2812
2813                 case T_IDENTIFIER: {
2814                         /* only parse identifier if we haven't found a type yet */
2815                         if (type != NULL || type_specifiers != 0) {
2816                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2817                                  * declaration, so it doesn't generate errors about expecting '(' or
2818                                  * '{' later on. */
2819                                 switch (look_ahead(1)->kind) {
2820                                         STORAGE_CLASSES
2821                                         TYPE_SPECIFIERS
2822                                         case T_const:
2823                                         case T_restrict:
2824                                         case T_volatile:
2825                                         case T_inline:
2826                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2827                                         case T_IDENTIFIER:
2828                                         case '&':
2829                                         case '*':
2830                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2831                                                 eat(T_IDENTIFIER);
2832                                                 continue;
2833
2834                                         default:
2835                                                 goto finish_specifiers;
2836                                 }
2837                         }
2838
2839                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2840                         if (typedef_type == NULL) {
2841                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2842                                  * declaration, so it doesn't generate 'implicit int' followed by more
2843                                  * errors later on. */
2844                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2845                                 switch (la1_type) {
2846                                         DECLARATION_START
2847                                         case T_IDENTIFIER:
2848                                         case '&':
2849                                         case '*': {
2850                                                 errorf(HERE, "%K does not name a type", &token);
2851
2852                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2853
2854                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2855                                                 type->typedeft.typedefe = &entity->typedefe;
2856
2857                                                 eat(T_IDENTIFIER);
2858                                                 saw_error = true;
2859                                                 continue;
2860                                         }
2861
2862                                         default:
2863                                                 goto finish_specifiers;
2864                                 }
2865                         }
2866
2867                         eat(T_IDENTIFIER);
2868                         type = typedef_type;
2869                         break;
2870                 }
2871
2872                 /* function specifier */
2873                 default:
2874                         goto finish_specifiers;
2875                 }
2876         }
2877
2878 finish_specifiers:
2879         specifiers->attributes = parse_attributes(specifiers->attributes);
2880
2881         if (type == NULL || (saw_error && type_specifiers != 0)) {
2882                 atomic_type_kind_t atomic_type;
2883
2884                 /* match valid basic types */
2885                 switch (type_specifiers) {
2886                 case SPECIFIER_VOID:
2887                         atomic_type = ATOMIC_TYPE_VOID;
2888                         break;
2889                 case SPECIFIER_WCHAR_T:
2890                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2891                         break;
2892                 case SPECIFIER_CHAR:
2893                         atomic_type = ATOMIC_TYPE_CHAR;
2894                         break;
2895                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2896                         atomic_type = ATOMIC_TYPE_SCHAR;
2897                         break;
2898                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2899                         atomic_type = ATOMIC_TYPE_UCHAR;
2900                         break;
2901                 case SPECIFIER_SHORT:
2902                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2903                 case SPECIFIER_SHORT | SPECIFIER_INT:
2904                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2905                         atomic_type = ATOMIC_TYPE_SHORT;
2906                         break;
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2908                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2909                         atomic_type = ATOMIC_TYPE_USHORT;
2910                         break;
2911                 case SPECIFIER_INT:
2912                 case SPECIFIER_SIGNED:
2913                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2914                         atomic_type = ATOMIC_TYPE_INT;
2915                         break;
2916                 case SPECIFIER_UNSIGNED:
2917                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2918                         atomic_type = ATOMIC_TYPE_UINT;
2919                         break;
2920                 case SPECIFIER_LONG:
2921                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2922                 case SPECIFIER_LONG | SPECIFIER_INT:
2923                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2924                         atomic_type = ATOMIC_TYPE_LONG;
2925                         break;
2926                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2928                         atomic_type = ATOMIC_TYPE_ULONG;
2929                         break;
2930
2931                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2932                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2933                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2934                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2935                         | SPECIFIER_INT:
2936                         atomic_type = ATOMIC_TYPE_LONGLONG;
2937                         goto warn_about_long_long;
2938
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2940                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2941                         | SPECIFIER_INT:
2942                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2943 warn_about_long_long:
2944                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2945                         break;
2946
2947                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2948                         atomic_type = unsigned_int8_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2952                         atomic_type = unsigned_int16_type_kind;
2953                         break;
2954
2955                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2956                         atomic_type = unsigned_int32_type_kind;
2957                         break;
2958
2959                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2960                         atomic_type = unsigned_int64_type_kind;
2961                         break;
2962
2963                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2964                         atomic_type = unsigned_int128_type_kind;
2965                         break;
2966
2967                 case SPECIFIER_INT8:
2968                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2969                         atomic_type = int8_type_kind;
2970                         break;
2971
2972                 case SPECIFIER_INT16:
2973                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2974                         atomic_type = int16_type_kind;
2975                         break;
2976
2977                 case SPECIFIER_INT32:
2978                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2979                         atomic_type = int32_type_kind;
2980                         break;
2981
2982                 case SPECIFIER_INT64:
2983                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2984                         atomic_type = int64_type_kind;
2985                         break;
2986
2987                 case SPECIFIER_INT128:
2988                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2989                         atomic_type = int128_type_kind;
2990                         break;
2991
2992                 case SPECIFIER_FLOAT:
2993                         atomic_type = ATOMIC_TYPE_FLOAT;
2994                         break;
2995                 case SPECIFIER_DOUBLE:
2996                         atomic_type = ATOMIC_TYPE_DOUBLE;
2997                         break;
2998                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2999                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3000                         break;
3001                 case SPECIFIER_BOOL:
3002                         atomic_type = ATOMIC_TYPE_BOOL;
3003                         break;
3004                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3005                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3006                         atomic_type = ATOMIC_TYPE_FLOAT;
3007                         break;
3008                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3009                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3010                         atomic_type = ATOMIC_TYPE_DOUBLE;
3011                         break;
3012                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3013                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3014                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3015                         break;
3016                 default: {
3017                         /* invalid specifier combination, give an error message */
3018                         source_position_t const* const pos = &specifiers->source_position;
3019                         if (type_specifiers == 0) {
3020                                 if (!saw_error) {
3021                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3022                                         if (!(c_mode & _CXX) && !strict_mode) {
3023                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3024                                                 atomic_type = ATOMIC_TYPE_INT;
3025                                                 break;
3026                                         } else {
3027                                                 errorf(pos, "no type specifiers given in declaration");
3028                                         }
3029                                 }
3030                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3031                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3032                                 errorf(pos, "signed and unsigned specifiers given");
3033                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3034                                 errorf(pos, "only integer types can be signed or unsigned");
3035                         } else {
3036                                 errorf(pos, "multiple datatypes in declaration");
3037                         }
3038                         goto end_error;
3039                 }
3040                 }
3041
3042                 if (type_specifiers & SPECIFIER_COMPLEX) {
3043                         type = allocate_type_zero(TYPE_COMPLEX);
3044                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3045                         type = allocate_type_zero(TYPE_IMAGINARY);
3046                 } else {
3047                         type = allocate_type_zero(TYPE_ATOMIC);
3048                 }
3049                 type->atomic.akind = atomic_type;
3050                 newtype = true;
3051         } else if (type_specifiers != 0) {
3052                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3053         }
3054
3055         /* FIXME: check type qualifiers here */
3056         type->base.qualifiers = qualifiers;
3057
3058         if (newtype) {
3059                 type = identify_new_type(type);
3060         } else {
3061                 type = typehash_insert(type);
3062         }
3063
3064         if (specifiers->attributes != NULL)
3065                 type = handle_type_attributes(specifiers->attributes, type);
3066         specifiers->type = type;
3067         return;
3068
3069 end_error:
3070         specifiers->type = type_error_type;
3071 }
3072
3073 static type_qualifiers_t parse_type_qualifiers(void)
3074 {
3075         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3076
3077         while (true) {
3078                 switch (token.kind) {
3079                 /* type qualifiers */
3080                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3081                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3082                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3083                 /* microsoft extended type modifiers */
3084                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3085                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3086                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3087                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3088                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3089
3090                 default:
3091                         return qualifiers;
3092                 }
3093         }
3094 }
3095
3096 /**
3097  * Parses an K&R identifier list
3098  */
3099 static void parse_identifier_list(scope_t *scope)
3100 {
3101         assert(token.kind == T_IDENTIFIER);
3102         do {
3103                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3104                 /* a K&R parameter has no type, yet */
3105                 eat(T_IDENTIFIER);
3106
3107                 if (scope != NULL)
3108                         append_entity(scope, entity);
3109         } while (next_if(',') && token.kind == T_IDENTIFIER);
3110 }
3111
3112 static entity_t *parse_parameter(void)
3113 {
3114         declaration_specifiers_t specifiers;
3115         parse_declaration_specifiers(&specifiers);
3116
3117         entity_t *entity = parse_declarator(&specifiers,
3118                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3119         anonymous_entity = NULL;
3120         return entity;
3121 }
3122
3123 static void semantic_parameter_incomplete(const entity_t *entity)
3124 {
3125         assert(entity->kind == ENTITY_PARAMETER);
3126
3127         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3128          *             list in a function declarator that is part of a
3129          *             definition of that function shall not have
3130          *             incomplete type. */
3131         type_t *type = skip_typeref(entity->declaration.type);
3132         if (is_type_incomplete(type)) {
3133                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3134         }
3135 }
3136
3137 static bool has_parameters(void)
3138 {
3139         /* func(void) is not a parameter */
3140         if (look_ahead(1)->kind != ')')
3141                 return true;
3142         if (token.kind == T_IDENTIFIER) {
3143                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3144                 if (entity == NULL)
3145                         return true;
3146                 if (entity->kind != ENTITY_TYPEDEF)
3147                         return true;
3148                 type_t const *const type = skip_typeref(entity->typedefe.type);
3149                 if (!is_type_void(type))
3150                         return true;
3151                 if (c_mode & _CXX) {
3152                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3153                          * is not allowed. */
3154                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3155                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3156                         /* §6.7.5.3:10  Qualification is not allowed here. */
3157                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3158                 }
3159         } else if (token.kind != T_void) {
3160                 return true;
3161         }
3162         next_token();
3163         return false;
3164 }
3165
3166 /**
3167  * Parses function type parameters (and optionally creates variable_t entities
3168  * for them in a scope)
3169  */
3170 static void parse_parameters(function_type_t *type, scope_t *scope)
3171 {
3172         add_anchor_token(')');
3173         eat('(');
3174
3175         if (token.kind == T_IDENTIFIER            &&
3176             !is_typedef_symbol(token.base.symbol) &&
3177             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3178                 type->kr_style_parameters = true;
3179                 parse_identifier_list(scope);
3180         } else if (token.kind == ')') {
3181                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3182                 if (!(c_mode & _CXX))
3183                         type->unspecified_parameters = true;
3184         } else if (has_parameters()) {
3185                 function_parameter_t **anchor = &type->parameters;
3186                 add_anchor_token(',');
3187                 do {
3188                         switch (token.kind) {
3189                         case T_DOTDOTDOT:
3190                                 eat(T_DOTDOTDOT);
3191                                 type->variadic = true;
3192                                 goto parameters_finished;
3193
3194                         case T_IDENTIFIER:
3195                         DECLARATION_START
3196                         {
3197                                 entity_t *entity = parse_parameter();
3198                                 if (entity->kind == ENTITY_TYPEDEF) {
3199                                         errorf(&entity->base.source_position,
3200                                                         "typedef not allowed as function parameter");
3201                                         break;
3202                                 }
3203                                 assert(is_declaration(entity));
3204
3205                                 semantic_parameter_incomplete(entity);
3206
3207                                 function_parameter_t *const parameter =
3208                                         allocate_parameter(entity->declaration.type);
3209
3210                                 if (scope != NULL) {
3211                                         append_entity(scope, entity);
3212                                 }
3213
3214                                 *anchor = parameter;
3215                                 anchor  = &parameter->next;
3216                                 break;
3217                         }
3218
3219                         default:
3220                                 goto parameters_finished;
3221                         }
3222                 } while (next_if(','));
3223 parameters_finished:
3224                 rem_anchor_token(',');
3225         }
3226
3227         rem_anchor_token(')');
3228         expect(')');
3229 }
3230
3231 typedef enum construct_type_kind_t {
3232         CONSTRUCT_POINTER = 1,
3233         CONSTRUCT_REFERENCE,
3234         CONSTRUCT_FUNCTION,
3235         CONSTRUCT_ARRAY
3236 } construct_type_kind_t;
3237
3238 typedef union construct_type_t construct_type_t;
3239
3240 typedef struct construct_type_base_t {
3241         construct_type_kind_t  kind;
3242         source_position_t      pos;
3243         construct_type_t      *next;
3244 } construct_type_base_t;
3245
3246 typedef struct parsed_pointer_t {
3247         construct_type_base_t  base;
3248         type_qualifiers_t      type_qualifiers;
3249         variable_t            *base_variable;  /**< MS __based extension. */
3250 } parsed_pointer_t;
3251
3252 typedef struct parsed_reference_t {
3253         construct_type_base_t base;
3254 } parsed_reference_t;
3255
3256 typedef struct construct_function_type_t {
3257         construct_type_base_t  base;
3258         type_t                *function_type;
3259 } construct_function_type_t;
3260
3261 typedef struct parsed_array_t {
3262         construct_type_base_t  base;
3263         type_qualifiers_t      type_qualifiers;
3264         bool                   is_static;
3265         bool                   is_variable;
3266         expression_t          *size;
3267 } parsed_array_t;
3268
3269 union construct_type_t {
3270         construct_type_kind_t     kind;
3271         construct_type_base_t     base;
3272         parsed_pointer_t          pointer;
3273         parsed_reference_t        reference;
3274         construct_function_type_t function;
3275         parsed_array_t            array;
3276 };
3277
3278 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3279 {
3280         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3281         memset(cons, 0, size);
3282         cons->kind     = kind;
3283         cons->base.pos = *HERE;
3284         return cons;
3285 }
3286
3287 /* §6.7.5.1 */
3288 static construct_type_t *parse_pointer_declarator(void)
3289 {
3290         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3291         eat('*');
3292         cons->pointer.type_qualifiers = parse_type_qualifiers();
3293         //cons->pointer.base_variable   = base_variable;
3294
3295         return cons;
3296 }
3297
3298 /* ISO/IEC 14882:1998(E) §8.3.2 */
3299 static construct_type_t *parse_reference_declarator(void)
3300 {
3301         if (!(c_mode & _CXX))
3302                 errorf(HERE, "references are only available for C++");
3303
3304         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3305         eat('&');
3306
3307         return cons;
3308 }
3309
3310 /* §6.7.5.2 */
3311 static construct_type_t *parse_array_declarator(void)
3312 {
3313         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3314         parsed_array_t   *const array = &cons->array;
3315
3316         eat('[');
3317         add_anchor_token(']');
3318
3319         bool is_static = next_if(T_static);
3320
3321         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3322
3323         if (!is_static)
3324                 is_static = next_if(T_static);
3325
3326         array->type_qualifiers = type_qualifiers;
3327         array->is_static       = is_static;
3328
3329         expression_t *size = NULL;
3330         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3331                 array->is_variable = true;
3332                 eat('*');
3333         } else if (token.kind != ']') {
3334                 size = parse_assignment_expression();
3335
3336                 /* §6.7.5.2:1  Array size must have integer type */
3337                 type_t *const orig_type = size->base.type;
3338                 type_t *const type      = skip_typeref(orig_type);
3339                 if (!is_type_integer(type) && is_type_valid(type)) {
3340                         errorf(&size->base.source_position,
3341                                "array size '%E' must have integer type but has type '%T'",
3342                                size, orig_type);
3343                 }
3344
3345                 array->size = size;
3346                 mark_vars_read(size, NULL);
3347         }
3348
3349         if (is_static && size == NULL)
3350                 errorf(&array->base.pos, "static array parameters require a size");
3351
3352         rem_anchor_token(']');
3353         expect(']');
3354         return cons;
3355 }
3356
3357 /* §6.7.5.3 */
3358 static construct_type_t *parse_function_declarator(scope_t *scope)
3359 {
3360         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3361
3362         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3363         function_type_t *ftype = &type->function;
3364
3365         ftype->linkage            = current_linkage;
3366         ftype->calling_convention = CC_DEFAULT;
3367
3368         parse_parameters(ftype, scope);
3369
3370         cons->function.function_type = type;
3371
3372         return cons;
3373 }
3374
3375 typedef struct parse_declarator_env_t {
3376         bool               may_be_abstract : 1;
3377         bool               must_be_abstract : 1;
3378         decl_modifiers_t   modifiers;
3379         symbol_t          *symbol;
3380         source_position_t  source_position;
3381         scope_t            parameters;
3382         attribute_t       *attributes;
3383 } parse_declarator_env_t;
3384
3385 /* §6.7.5 */
3386 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3387 {
3388         /* construct a single linked list of construct_type_t's which describe
3389          * how to construct the final declarator type */
3390         construct_type_t  *first      = NULL;
3391         construct_type_t **anchor     = &first;
3392
3393         env->attributes = parse_attributes(env->attributes);
3394
3395         for (;;) {
3396                 construct_type_t *type;
3397                 //variable_t       *based = NULL; /* MS __based extension */
3398                 switch (token.kind) {
3399                         case '&':
3400                                 type = parse_reference_declarator();
3401                                 break;
3402
3403                         case T__based: {
3404                                 panic("based not supported anymore");
3405                                 /* FALLTHROUGH */
3406                         }
3407
3408                         case '*':
3409                                 type = parse_pointer_declarator();
3410                                 break;
3411
3412                         default:
3413                                 goto ptr_operator_end;
3414                 }
3415
3416                 *anchor = type;
3417                 anchor  = &type->base.next;
3418
3419                 /* TODO: find out if this is correct */
3420                 env->attributes = parse_attributes(env->attributes);
3421         }
3422
3423 ptr_operator_end: ;
3424         construct_type_t *inner_types = NULL;
3425
3426         switch (token.kind) {
3427         case T_IDENTIFIER:
3428                 if (env->must_be_abstract) {
3429                         errorf(HERE, "no identifier expected in typename");
3430                 } else {
3431                         env->symbol          = token.base.symbol;
3432                         env->source_position = *HERE;
3433                 }
3434                 eat(T_IDENTIFIER);
3435                 break;
3436
3437         case '(': {
3438                 /* Parenthesized declarator or function declarator? */
3439                 token_t const *const la1 = look_ahead(1);
3440                 switch (la1->kind) {
3441                         case T_IDENTIFIER:
3442                                 if (is_typedef_symbol(la1->base.symbol)) {
3443                         case ')':
3444                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3445                                          * interpreted as ``function with no parameter specification'', rather
3446                                          * than redundant parentheses around the omitted identifier. */
3447                         default:
3448                                         /* Function declarator. */
3449                                         if (!env->may_be_abstract) {
3450                                                 errorf(HERE, "function declarator must have a name");
3451                                         }
3452                                 } else {
3453                         case '&':
3454                         case '(':
3455                         case '*':
3456                         case '[':
3457                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3458                                         /* Paranthesized declarator. */
3459                                         eat('(');
3460                                         add_anchor_token(')');
3461                                         inner_types = parse_inner_declarator(env);
3462                                         if (inner_types != NULL) {
3463                                                 /* All later declarators only modify the return type */
3464                                                 env->must_be_abstract = true;
3465                                         }
3466                                         rem_anchor_token(')');
3467                                         expect(')');
3468                                 }
3469                                 break;
3470                 }
3471                 break;
3472         }
3473
3474         default:
3475                 if (env->may_be_abstract)
3476                         break;
3477                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3478                 eat_until_anchor();
3479                 return NULL;
3480         }
3481
3482         construct_type_t **const p = anchor;
3483
3484         for (;;) {
3485                 construct_type_t *type;
3486                 switch (token.kind) {
3487                 case '(': {
3488                         scope_t *scope = NULL;
3489                         if (!env->must_be_abstract) {
3490                                 scope = &env->parameters;
3491                         }
3492
3493                         type = parse_function_declarator(scope);
3494                         break;
3495                 }
3496                 case '[':
3497                         type = parse_array_declarator();
3498                         break;
3499                 default:
3500                         goto declarator_finished;
3501                 }
3502
3503                 /* insert in the middle of the list (at p) */
3504                 type->base.next = *p;
3505                 *p              = type;
3506                 if (anchor == p)
3507                         anchor = &type->base.next;
3508         }
3509
3510 declarator_finished:
3511         /* append inner_types at the end of the list, we don't to set anchor anymore
3512          * as it's not needed anymore */
3513         *anchor = inner_types;
3514
3515         return first;
3516 }
3517
3518 static type_t *construct_declarator_type(construct_type_t *construct_list,
3519                                          type_t *type)
3520 {
3521         construct_type_t *iter = construct_list;
3522         for (; iter != NULL; iter = iter->base.next) {
3523                 source_position_t const* const pos = &iter->base.pos;
3524                 switch (iter->kind) {
3525                 case CONSTRUCT_FUNCTION: {
3526                         construct_function_type_t *function      = &iter->function;
3527                         type_t                    *function_type = function->function_type;
3528
3529                         function_type->function.return_type = type;
3530
3531                         type_t *skipped_return_type = skip_typeref(type);
3532                         /* §6.7.5.3:1 */
3533                         if (is_type_function(skipped_return_type)) {
3534                                 errorf(pos, "function returning function is not allowed");
3535                         } else if (is_type_array(skipped_return_type)) {
3536                                 errorf(pos, "function returning array is not allowed");
3537                         } else {
3538                                 if (skipped_return_type->base.qualifiers != 0) {
3539                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3540                                 }
3541                         }
3542
3543                         /* The function type was constructed earlier.  Freeing it here will
3544                          * destroy other types. */
3545                         type = typehash_insert(function_type);
3546                         continue;
3547                 }
3548
3549                 case CONSTRUCT_POINTER: {
3550                         if (is_type_reference(skip_typeref(type)))
3551                                 errorf(pos, "cannot declare a pointer to reference");
3552
3553                         parsed_pointer_t *pointer = &iter->pointer;
3554                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3555                         continue;
3556                 }
3557
3558                 case CONSTRUCT_REFERENCE:
3559                         if (is_type_reference(skip_typeref(type)))
3560                                 errorf(pos, "cannot declare a reference to reference");
3561
3562                         type = make_reference_type(type);
3563                         continue;
3564
3565                 case CONSTRUCT_ARRAY: {
3566                         if (is_type_reference(skip_typeref(type)))
3567                                 errorf(pos, "cannot declare an array of references");
3568
3569                         parsed_array_t *array      = &iter->array;
3570                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3571
3572                         expression_t *size_expression = array->size;
3573                         if (size_expression != NULL) {
3574                                 size_expression
3575                                         = create_implicit_cast(size_expression, type_size_t);
3576                         }
3577
3578                         array_type->base.qualifiers       = array->type_qualifiers;
3579                         array_type->array.element_type    = type;
3580                         array_type->array.is_static       = array->is_static;
3581                         array_type->array.is_variable     = array->is_variable;
3582                         array_type->array.size_expression = size_expression;
3583
3584                         if (size_expression != NULL) {
3585                                 switch (is_constant_expression(size_expression)) {
3586                                 case EXPR_CLASS_CONSTANT: {
3587                                         long const size = fold_constant_to_int(size_expression);
3588                                         array_type->array.size          = size;
3589                                         array_type->array.size_constant = true;
3590                                         /* §6.7.5.2:1  If the expression is a constant expression,
3591                                          * it shall have a value greater than zero. */
3592                                         if (size < 0) {
3593                                                 errorf(&size_expression->base.source_position,
3594                                                            "size of array must be greater than zero");
3595                                         } else if (size == 0 && !GNU_MODE) {
3596                                                 errorf(&size_expression->base.source_position,
3597                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3598                                         }
3599                                         break;
3600                                 }
3601
3602                                 case EXPR_CLASS_VARIABLE:
3603                                         array_type->array.is_vla = true;
3604                                         break;
3605
3606                                 case EXPR_CLASS_ERROR:
3607                                         break;
3608                                 }
3609                         }
3610
3611                         type_t *skipped_type = skip_typeref(type);
3612                         /* §6.7.5.2:1 */
3613                         if (is_type_incomplete(skipped_type)) {
3614                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3615                         } else if (is_type_function(skipped_type)) {
3616                                 errorf(pos, "array of functions is not allowed");
3617                         }
3618                         type = identify_new_type(array_type);
3619                         continue;
3620                 }
3621                 }
3622                 internal_errorf(pos, "invalid type construction found");
3623         }
3624
3625         return type;
3626 }
3627
3628 static type_t *automatic_type_conversion(type_t *orig_type);
3629
3630 static type_t *semantic_parameter(const source_position_t *pos,
3631                                   type_t *type,
3632                                   const declaration_specifiers_t *specifiers,
3633                                   entity_t const *const param)
3634 {
3635         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3636          *             shall be adjusted to ``qualified pointer to type'',
3637          *             [...]
3638          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3639          *             type'' shall be adjusted to ``pointer to function
3640          *             returning type'', as in 6.3.2.1. */
3641         type = automatic_type_conversion(type);
3642
3643         if (specifiers->is_inline && is_type_valid(type)) {
3644                 errorf(pos, "'%N' declared 'inline'", param);
3645         }
3646
3647         /* §6.9.1:6  The declarations in the declaration list shall contain
3648          *           no storage-class specifier other than register and no
3649          *           initializations. */
3650         if (specifiers->thread_local || (
3651                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3652                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3653            ) {
3654                 errorf(pos, "invalid storage class for '%N'", param);
3655         }
3656
3657         /* delay test for incomplete type, because we might have (void)
3658          * which is legal but incomplete... */
3659
3660         return type;
3661 }
3662
3663 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3664                                   declarator_flags_t flags)
3665 {
3666         parse_declarator_env_t env;
3667         memset(&env, 0, sizeof(env));
3668         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3669
3670         construct_type_t *construct_type = parse_inner_declarator(&env);
3671         type_t           *orig_type      =
3672                 construct_declarator_type(construct_type, specifiers->type);
3673         type_t           *type           = skip_typeref(orig_type);
3674
3675         if (construct_type != NULL) {
3676                 obstack_free(&temp_obst, construct_type);
3677         }
3678
3679         attribute_t *attributes = parse_attributes(env.attributes);
3680         /* append (shared) specifier attribute behind attributes of this
3681          * declarator */
3682         attribute_t **anchor = &attributes;
3683         while (*anchor != NULL)
3684                 anchor = &(*anchor)->next;
3685         *anchor = specifiers->attributes;
3686
3687         entity_t *entity;
3688         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3689                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3690                 entity->typedefe.type = orig_type;
3691
3692                 if (anonymous_entity != NULL) {
3693                         if (is_type_compound(type)) {
3694                                 assert(anonymous_entity->compound.alias == NULL);
3695                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3696                                        anonymous_entity->kind == ENTITY_UNION);
3697                                 anonymous_entity->compound.alias = entity;
3698                                 anonymous_entity = NULL;
3699                         } else if (is_type_enum(type)) {
3700                                 assert(anonymous_entity->enume.alias == NULL);
3701                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3702                                 anonymous_entity->enume.alias = entity;
3703                                 anonymous_entity = NULL;
3704                         }
3705                 }
3706         } else {
3707                 /* create a declaration type entity */
3708                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3709                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3710                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3711
3712                         if (env.symbol != NULL) {
3713                                 if (specifiers->is_inline && is_type_valid(type)) {
3714                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3715                                 }
3716
3717                                 if (specifiers->thread_local ||
3718                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3719                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3720                                 }
3721                         }
3722                 } else if (flags & DECL_IS_PARAMETER) {
3723                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3724                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3725                 } else if (is_type_function(type)) {
3726                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3727                         entity->function.is_inline      = specifiers->is_inline;
3728                         entity->function.elf_visibility = default_visibility;
3729                         entity->function.parameters     = env.parameters;
3730
3731                         if (env.symbol != NULL) {
3732                                 /* this needs fixes for C++ */
3733                                 bool in_function_scope = current_function != NULL;
3734
3735                                 if (specifiers->thread_local || (
3736                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3737                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3738                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3739                                                 )) {
3740                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3741                                 }
3742                         }
3743                 } else {
3744                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3745                         entity->variable.elf_visibility = default_visibility;
3746                         entity->variable.thread_local   = specifiers->thread_local;
3747
3748                         if (env.symbol != NULL) {
3749                                 if (specifiers->is_inline && is_type_valid(type)) {
3750                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3751                                 }
3752
3753                                 bool invalid_storage_class = false;
3754                                 if (current_scope == file_scope) {
3755                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3756                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3757                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3758                                                 invalid_storage_class = true;
3759                                         }
3760                                 } else {
3761                                         if (specifiers->thread_local &&
3762                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3763                                                 invalid_storage_class = true;
3764                                         }
3765                                 }
3766                                 if (invalid_storage_class) {
3767                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3768                                 }
3769                         }
3770                 }
3771
3772                 entity->declaration.type       = orig_type;
3773                 entity->declaration.alignment  = get_type_alignment(orig_type);
3774                 entity->declaration.modifiers  = env.modifiers;
3775                 entity->declaration.attributes = attributes;
3776
3777                 storage_class_t storage_class = specifiers->storage_class;
3778                 entity->declaration.declared_storage_class = storage_class;
3779
3780                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3781                         storage_class = STORAGE_CLASS_AUTO;
3782                 entity->declaration.storage_class = storage_class;
3783         }
3784
3785         if (attributes != NULL) {
3786                 handle_entity_attributes(attributes, entity);
3787         }
3788
3789         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3790                 adapt_special_functions(&entity->function);
3791         }
3792
3793         return entity;
3794 }
3795
3796 static type_t *parse_abstract_declarator(type_t *base_type)
3797 {
3798         parse_declarator_env_t env;
3799         memset(&env, 0, sizeof(env));
3800         env.may_be_abstract = true;
3801         env.must_be_abstract = true;
3802
3803         construct_type_t *construct_type = parse_inner_declarator(&env);
3804
3805         type_t *result = construct_declarator_type(construct_type, base_type);
3806         if (construct_type != NULL) {
3807                 obstack_free(&temp_obst, construct_type);
3808         }
3809         result = handle_type_attributes(env.attributes, result);
3810
3811         return result;
3812 }
3813
3814 /**
3815  * Check if the declaration of main is suspicious.  main should be a
3816  * function with external linkage, returning int, taking either zero
3817  * arguments, two, or three arguments of appropriate types, ie.
3818  *
3819  * int main([ int argc, char **argv [, char **env ] ]).
3820  *
3821  * @param decl    the declaration to check
3822  * @param type    the function type of the declaration
3823  */
3824 static void check_main(const entity_t *entity)
3825 {
3826         const source_position_t *pos = &entity->base.source_position;
3827         if (entity->kind != ENTITY_FUNCTION) {
3828                 warningf(WARN_MAIN, pos, "'main' is not a function");
3829                 return;
3830         }
3831
3832         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3833                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3834         }
3835
3836         type_t *type = skip_typeref(entity->declaration.type);
3837         assert(is_type_function(type));
3838
3839         function_type_t const *const func_type = &type->function;
3840         type_t                *const ret_type  = func_type->return_type;
3841         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3842                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3843         }
3844         const function_parameter_t *parm = func_type->parameters;
3845         if (parm != NULL) {
3846                 type_t *const first_type        = skip_typeref(parm->type);
3847                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3848                 if (!types_compatible(first_type_unqual, type_int)) {
3849                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3850                 }
3851                 parm = parm->next;
3852                 if (parm != NULL) {
3853                         type_t *const second_type = skip_typeref(parm->type);
3854                         type_t *const second_type_unqual
3855                                 = get_unqualified_type(second_type);
3856                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3857                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3858                         }
3859                         parm = parm->next;
3860                         if (parm != NULL) {
3861                                 type_t *const third_type = skip_typeref(parm->type);
3862                                 type_t *const third_type_unqual
3863                                         = get_unqualified_type(third_type);
3864                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3865                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3866                                 }
3867                                 parm = parm->next;
3868                                 if (parm != NULL)
3869                                         goto warn_arg_count;
3870                         }
3871                 } else {
3872 warn_arg_count:
3873                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3874                 }
3875         }
3876 }
3877
3878 static void error_redefined_as_different_kind(const source_position_t *pos,
3879                 const entity_t *old, entity_kind_t new_kind)
3880 {
3881         char              const *const what = get_entity_kind_name(new_kind);
3882         source_position_t const *const ppos = &old->base.source_position;
3883         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3884 }
3885
3886 static bool is_entity_valid(entity_t *const ent)
3887 {
3888         if (is_declaration(ent)) {
3889                 return is_type_valid(skip_typeref(ent->declaration.type));
3890         } else if (ent->kind == ENTITY_TYPEDEF) {
3891                 return is_type_valid(skip_typeref(ent->typedefe.type));
3892         }
3893         return true;
3894 }
3895
3896 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3897 {
3898         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3899                 if (attributes_equal(tattr, attr))
3900                         return true;
3901         }
3902         return false;
3903 }
3904
3905 /**
3906  * test wether new_list contains any attributes not included in old_list
3907  */
3908 static bool has_new_attributes(const attribute_t *old_list,
3909                                const attribute_t *new_list)
3910 {
3911         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3912                 if (!contains_attribute(old_list, attr))
3913                         return true;
3914         }
3915         return false;
3916 }
3917
3918 /**
3919  * Merge in attributes from an attribute list (probably from a previous
3920  * declaration with the same name). Warning: destroys the old structure
3921  * of the attribute list - don't reuse attributes after this call.
3922  */
3923 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3924 {
3925         attribute_t *next;
3926         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3927                 next = attr->next;
3928                 if (contains_attribute(decl->attributes, attr))
3929                         continue;
3930
3931                 /* move attribute to new declarations attributes list */
3932                 attr->next       = decl->attributes;
3933                 decl->attributes = attr;
3934         }
3935 }
3936
3937 static bool is_main(entity_t*);
3938
3939 /**
3940  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3941  * for various problems that occur for multiple definitions
3942  */
3943 entity_t *record_entity(entity_t *entity, const bool is_definition)
3944 {
3945         const symbol_t *const    symbol  = entity->base.symbol;
3946         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3947         const source_position_t *pos     = &entity->base.source_position;
3948
3949         /* can happen in error cases */
3950         if (symbol == NULL)
3951                 return entity;
3952
3953         assert(!entity->base.parent_scope);
3954         assert(current_scope);
3955         entity->base.parent_scope = current_scope;
3956
3957         entity_t *const previous_entity = get_entity(symbol, namespc);
3958         /* pushing the same entity twice will break the stack structure */
3959         assert(previous_entity != entity);
3960
3961         if (entity->kind == ENTITY_FUNCTION) {
3962                 type_t *const orig_type = entity->declaration.type;
3963                 type_t *const type      = skip_typeref(orig_type);
3964
3965                 assert(is_type_function(type));
3966                 if (type->function.unspecified_parameters &&
3967                     previous_entity == NULL               &&
3968                     !entity->declaration.implicit) {
3969                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3970                 }
3971
3972                 if (is_main(entity)) {
3973                         check_main(entity);
3974                 }
3975         }
3976
3977         if (is_declaration(entity)                                    &&
3978             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3979             current_scope != file_scope                               &&
3980             !entity->declaration.implicit) {
3981                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3982         }
3983
3984         if (previous_entity != NULL) {
3985                 source_position_t const *const ppos = &previous_entity->base.source_position;
3986
3987                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3988                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3989                         assert(previous_entity->kind == ENTITY_PARAMETER);
3990                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3991                         goto finish;
3992                 }
3993
3994                 if (previous_entity->base.parent_scope == current_scope) {
3995                         if (previous_entity->kind != entity->kind) {
3996                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3997                                         error_redefined_as_different_kind(pos, previous_entity,
3998                                                         entity->kind);
3999                                 }
4000                                 goto finish;
4001                         }
4002                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4003                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4004                                 goto finish;
4005                         }
4006                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4007                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4008                                 type_t *const prev_type
4009                                         = skip_typeref(previous_entity->typedefe.type);
4010                                 if (c_mode & _CXX) {
4011                                         /* C++ allows double typedef if they are identical
4012                                          * (after skipping typedefs) */
4013                                         if (type == prev_type)
4014                                                 goto finish;
4015                                 } else {
4016                                         /* GCC extension: redef in system headers is allowed */
4017                                         if ((pos->is_system_header || ppos->is_system_header) &&
4018                                             types_compatible(type, prev_type))
4019                                                 goto finish;
4020                                 }
4021                                 errorf(pos, "redefinition of '%N' (declared %P)",
4022                                        entity, ppos);
4023                                 goto finish;
4024                         }
4025
4026                         /* at this point we should have only VARIABLES or FUNCTIONS */
4027                         assert(is_declaration(previous_entity) && is_declaration(entity));
4028
4029                         declaration_t *const prev_decl = &previous_entity->declaration;
4030                         declaration_t *const decl      = &entity->declaration;
4031
4032                         /* can happen for K&R style declarations */
4033                         if (prev_decl->type       == NULL             &&
4034                                         previous_entity->kind == ENTITY_PARAMETER &&
4035                                         entity->kind          == ENTITY_PARAMETER) {
4036                                 prev_decl->type                   = decl->type;
4037                                 prev_decl->storage_class          = decl->storage_class;
4038                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4039                                 prev_decl->modifiers              = decl->modifiers;
4040                                 return previous_entity;
4041                         }
4042
4043                         type_t *const type      = skip_typeref(decl->type);
4044                         type_t *const prev_type = skip_typeref(prev_decl->type);
4045
4046                         if (!types_compatible(type, prev_type)) {
4047                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4048                         } else {
4049                                 unsigned old_storage_class = prev_decl->storage_class;
4050
4051                                 if (is_definition                     &&
4052                                                 !prev_decl->used                  &&
4053                                                 !(prev_decl->modifiers & DM_USED) &&
4054                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4055                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4056                                 }
4057
4058                                 storage_class_t new_storage_class = decl->storage_class;
4059
4060                                 /* pretend no storage class means extern for function
4061                                  * declarations (except if the previous declaration is neither
4062                                  * none nor extern) */
4063                                 if (entity->kind == ENTITY_FUNCTION) {
4064                                         /* the previous declaration could have unspecified parameters or
4065                                          * be a typedef, so use the new type */
4066                                         if (prev_type->function.unspecified_parameters || is_definition)
4067                                                 prev_decl->type = type;
4068
4069                                         switch (old_storage_class) {
4070                                                 case STORAGE_CLASS_NONE:
4071                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4072                                                         /* FALLTHROUGH */
4073
4074                                                 case STORAGE_CLASS_EXTERN:
4075                                                         if (is_definition) {
4076                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4077                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4078                                                                 }
4079                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4080                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4081                                                         }
4082                                                         break;
4083
4084                                                 default:
4085                                                         break;
4086                                         }
4087                                 } else if (is_type_incomplete(prev_type)) {
4088                                         prev_decl->type = type;
4089                                 }
4090
4091                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4092                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4093
4094 warn_redundant_declaration: ;
4095                                         bool has_new_attrs
4096                                                 = has_new_attributes(prev_decl->attributes,
4097                                                                      decl->attributes);
4098                                         if (has_new_attrs) {
4099                                                 merge_in_attributes(decl, prev_decl->attributes);
4100                                         } else if (!is_definition        &&
4101                                                         is_type_valid(prev_type) &&
4102                                                         !pos->is_system_header) {
4103                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4104                                         }
4105                                 } else if (current_function == NULL) {
4106                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4107                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4108                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4109                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4110                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4111                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4112                                         } else {
4113                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4114                                                 if (c_mode & _CXX)
4115                                                         goto error_redeclaration;
4116                                                 goto warn_redundant_declaration;
4117                                         }
4118                                 } else if (is_type_valid(prev_type)) {
4119                                         if (old_storage_class == new_storage_class) {
4120 error_redeclaration:
4121                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4122                                         } else {
4123                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4124                                         }
4125                                 }
4126                         }
4127
4128                         prev_decl->modifiers |= decl->modifiers;
4129                         if (entity->kind == ENTITY_FUNCTION) {
4130                                 previous_entity->function.is_inline |= entity->function.is_inline;
4131                         }
4132                         return previous_entity;
4133                 }
4134
4135                 warning_t why;
4136                 if (is_warn_on(why = WARN_SHADOW) ||
4137                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4138                         char const *const what = get_entity_kind_name(previous_entity->kind);
4139                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4140                 }
4141         }
4142
4143         if (entity->kind == ENTITY_FUNCTION) {
4144                 if (is_definition &&
4145                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4146                                 !is_main(entity)) {
4147                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4148                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4149                         } else {
4150                                 goto warn_missing_declaration;
4151                         }
4152                 }
4153         } else if (entity->kind == ENTITY_VARIABLE) {
4154                 if (current_scope                     == file_scope &&
4155                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4156                                 !entity->declaration.implicit) {
4157 warn_missing_declaration:
4158                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4159                 }
4160         }
4161
4162 finish:
4163         environment_push(entity);
4164         append_entity(current_scope, entity);
4165
4166         return entity;
4167 }
4168
4169 static void parser_error_multiple_definition(entity_t *entity,
4170                 const source_position_t *source_position)
4171 {
4172         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4173 }
4174
4175 static bool is_declaration_specifier(const token_t *token)
4176 {
4177         switch (token->kind) {
4178                 DECLARATION_START
4179                         return true;
4180                 case T_IDENTIFIER:
4181                         return is_typedef_symbol(token->base.symbol);
4182
4183                 default:
4184                         return false;
4185         }
4186 }
4187
4188 static void parse_init_declarator_rest(entity_t *entity)
4189 {
4190         type_t *orig_type = type_error_type;
4191
4192         if (entity->base.kind == ENTITY_TYPEDEF) {
4193                 source_position_t const *const pos = &entity->base.source_position;
4194                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4195         } else {
4196                 assert(is_declaration(entity));
4197                 orig_type = entity->declaration.type;
4198         }
4199
4200         type_t *type = skip_typeref(orig_type);
4201
4202         if (entity->kind == ENTITY_VARIABLE
4203                         && entity->variable.initializer != NULL) {
4204                 parser_error_multiple_definition(entity, HERE);
4205         }
4206         eat('=');
4207
4208         declaration_t *const declaration = &entity->declaration;
4209         bool must_be_constant = false;
4210         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4211             entity->base.parent_scope  == file_scope) {
4212                 must_be_constant = true;
4213         }
4214
4215         if (is_type_function(type)) {
4216                 source_position_t const *const pos = &entity->base.source_position;
4217                 errorf(pos, "'%N' is initialized like a variable", entity);
4218                 orig_type = type_error_type;
4219         }
4220
4221         parse_initializer_env_t env;
4222         env.type             = orig_type;
4223         env.must_be_constant = must_be_constant;
4224         env.entity           = entity;
4225
4226         initializer_t *initializer = parse_initializer(&env);
4227
4228         if (entity->kind == ENTITY_VARIABLE) {
4229                 /* §6.7.5:22  array initializers for arrays with unknown size
4230                  * determine the array type size */
4231                 declaration->type            = env.type;
4232                 entity->variable.initializer = initializer;
4233         }
4234 }
4235
4236 /* parse rest of a declaration without any declarator */
4237 static void parse_anonymous_declaration_rest(
4238                 const declaration_specifiers_t *specifiers)
4239 {
4240         eat(';');
4241         anonymous_entity = NULL;
4242
4243         source_position_t const *const pos = &specifiers->source_position;
4244         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4245                         specifiers->thread_local) {
4246                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4247         }
4248
4249         type_t *type = specifiers->type;
4250         switch (type->kind) {
4251                 case TYPE_COMPOUND_STRUCT:
4252                 case TYPE_COMPOUND_UNION: {
4253                         if (type->compound.compound->base.symbol == NULL) {
4254                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4255                         }
4256                         break;
4257                 }
4258
4259                 case TYPE_ENUM:
4260                         break;
4261
4262                 default:
4263                         warningf(WARN_OTHER, pos, "empty declaration");
4264                         break;
4265         }
4266 }
4267
4268 static void check_variable_type_complete(entity_t *ent)
4269 {
4270         if (ent->kind != ENTITY_VARIABLE)
4271                 return;
4272
4273         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4274          *         type for the object shall be complete [...] */
4275         declaration_t *decl = &ent->declaration;
4276         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4277                         decl->storage_class == STORAGE_CLASS_STATIC)
4278                 return;
4279
4280         type_t *const type = skip_typeref(decl->type);
4281         if (!is_type_incomplete(type))
4282                 return;
4283
4284         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4285          * are given length one. */
4286         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4287                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4288                 return;
4289         }
4290
4291         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4292 }
4293
4294
4295 static void parse_declaration_rest(entity_t *ndeclaration,
4296                 const declaration_specifiers_t *specifiers,
4297                 parsed_declaration_func         finished_declaration,
4298                 declarator_flags_t              flags)
4299 {
4300         add_anchor_token(';');
4301         add_anchor_token(',');
4302         while (true) {
4303                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4304
4305                 if (token.kind == '=') {
4306                         parse_init_declarator_rest(entity);
4307                 } else if (entity->kind == ENTITY_VARIABLE) {
4308                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4309                          * [...] where the extern specifier is explicitly used. */
4310                         declaration_t *decl = &entity->declaration;
4311                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4312                             is_type_reference(skip_typeref(decl->type))) {
4313                                 source_position_t const *const pos = &entity->base.source_position;
4314                                 errorf(pos, "reference '%#N' must be initialized", entity);
4315                         }
4316                 }
4317
4318                 check_variable_type_complete(entity);
4319
4320                 if (!next_if(','))
4321                         break;
4322
4323                 add_anchor_token('=');
4324                 ndeclaration = parse_declarator(specifiers, flags);
4325                 rem_anchor_token('=');
4326         }
4327         rem_anchor_token(',');
4328         rem_anchor_token(';');
4329         expect(';');
4330
4331         anonymous_entity = NULL;
4332 }
4333
4334 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4335 {
4336         symbol_t *symbol = entity->base.symbol;
4337         if (symbol == NULL)
4338                 return entity;
4339
4340         assert(entity->base.namespc == NAMESPACE_NORMAL);
4341         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4342         if (previous_entity == NULL
4343                         || previous_entity->base.parent_scope != current_scope) {
4344                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4345                        symbol);
4346                 return entity;
4347         }
4348
4349         if (is_definition) {
4350                 errorf(HERE, "'%N' is initialised", entity);
4351         }
4352
4353         return record_entity(entity, false);
4354 }
4355
4356 static void parse_declaration(parsed_declaration_func finished_declaration,
4357                               declarator_flags_t      flags)
4358 {
4359         add_anchor_token(';');
4360         declaration_specifiers_t specifiers;
4361         parse_declaration_specifiers(&specifiers);
4362         rem_anchor_token(';');
4363
4364         if (token.kind == ';') {
4365                 parse_anonymous_declaration_rest(&specifiers);
4366         } else {
4367                 entity_t *entity = parse_declarator(&specifiers, flags);
4368                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4369         }
4370 }
4371
4372 /* §6.5.2.2:6 */
4373 static type_t *get_default_promoted_type(type_t *orig_type)
4374 {
4375         type_t *result = orig_type;
4376
4377         type_t *type = skip_typeref(orig_type);
4378         if (is_type_integer(type)) {
4379                 result = promote_integer(type);
4380         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4381                 result = type_double;
4382         }
4383
4384         return result;
4385 }
4386
4387 static void parse_kr_declaration_list(entity_t *entity)
4388 {
4389         if (entity->kind != ENTITY_FUNCTION)
4390                 return;
4391
4392         type_t *type = skip_typeref(entity->declaration.type);
4393         assert(is_type_function(type));
4394         if (!type->function.kr_style_parameters)
4395                 return;
4396
4397         add_anchor_token('{');
4398
4399         PUSH_SCOPE(&entity->function.parameters);
4400
4401         entity_t *parameter = entity->function.parameters.entities;
4402         for ( ; parameter != NULL; parameter = parameter->base.next) {
4403                 assert(parameter->base.parent_scope == NULL);
4404                 parameter->base.parent_scope = current_scope;
4405                 environment_push(parameter);
4406         }
4407
4408         /* parse declaration list */
4409         for (;;) {
4410                 switch (token.kind) {
4411                         DECLARATION_START
4412                         /* This covers symbols, which are no type, too, and results in
4413                          * better error messages.  The typical cases are misspelled type
4414                          * names and missing includes. */
4415                         case T_IDENTIFIER:
4416                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4417                                 break;
4418                         default:
4419                                 goto decl_list_end;
4420                 }
4421         }
4422 decl_list_end:
4423
4424         POP_SCOPE();
4425
4426         /* update function type */
4427         type_t *new_type = duplicate_type(type);
4428
4429         function_parameter_t  *parameters = NULL;
4430         function_parameter_t **anchor     = &parameters;
4431
4432         /* did we have an earlier prototype? */
4433         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4434         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4435                 proto_type = NULL;
4436
4437         function_parameter_t *proto_parameter = NULL;
4438         if (proto_type != NULL) {
4439                 type_t *proto_type_type = proto_type->declaration.type;
4440                 proto_parameter         = proto_type_type->function.parameters;
4441                 /* If a K&R function definition has a variadic prototype earlier, then
4442                  * make the function definition variadic, too. This should conform to
4443                  * §6.7.5.3:15 and §6.9.1:8. */
4444                 new_type->function.variadic = proto_type_type->function.variadic;
4445         } else {
4446                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4447                  * prototype */
4448                 new_type->function.unspecified_parameters = true;
4449         }
4450
4451         bool need_incompatible_warning = false;
4452         parameter = entity->function.parameters.entities;
4453         for (; parameter != NULL; parameter = parameter->base.next,
4454                         proto_parameter =
4455                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4456                 if (parameter->kind != ENTITY_PARAMETER)
4457                         continue;
4458
4459                 type_t *parameter_type = parameter->declaration.type;
4460                 if (parameter_type == NULL) {
4461                         source_position_t const* const pos = &parameter->base.source_position;
4462                         if (strict_mode) {
4463                                 errorf(pos, "no type specified for function '%N'", parameter);
4464                                 parameter_type = type_error_type;
4465                         } else {
4466                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4467                                 parameter_type = type_int;
4468                         }
4469                         parameter->declaration.type = parameter_type;
4470                 }
4471
4472                 semantic_parameter_incomplete(parameter);
4473
4474                 /* we need the default promoted types for the function type */
4475                 type_t *not_promoted = parameter_type;
4476                 parameter_type       = get_default_promoted_type(parameter_type);
4477
4478                 /* gcc special: if the type of the prototype matches the unpromoted
4479                  * type don't promote */
4480                 if (!strict_mode && proto_parameter != NULL) {
4481                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4482                         type_t *promo_skip   = skip_typeref(parameter_type);
4483                         type_t *param_skip   = skip_typeref(not_promoted);
4484                         if (!types_compatible(proto_p_type, promo_skip)
4485                                 && types_compatible(proto_p_type, param_skip)) {
4486                                 /* don't promote */
4487                                 need_incompatible_warning = true;
4488                                 parameter_type = not_promoted;
4489                         }
4490                 }
4491                 function_parameter_t *const function_parameter
4492                         = allocate_parameter(parameter_type);
4493
4494                 *anchor = function_parameter;
4495                 anchor  = &function_parameter->next;
4496         }
4497
4498         new_type->function.parameters = parameters;
4499         new_type = identify_new_type(new_type);
4500
4501         if (need_incompatible_warning) {
4502                 symbol_t          const *const sym  = entity->base.symbol;
4503                 source_position_t const *const pos  = &entity->base.source_position;
4504                 source_position_t const *const ppos = &proto_type->base.source_position;
4505                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4506         }
4507         entity->declaration.type = new_type;
4508
4509         rem_anchor_token('{');
4510 }
4511
4512 static bool first_err = true;
4513
4514 /**
4515  * When called with first_err set, prints the name of the current function,
4516  * else does noting.
4517  */
4518 static void print_in_function(void)
4519 {
4520         if (first_err) {
4521                 first_err = false;
4522                 char const *const file = current_function->base.base.source_position.input_name;
4523                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4524         }
4525 }
4526
4527 /**
4528  * Check if all labels are defined in the current function.
4529  * Check if all labels are used in the current function.
4530  */
4531 static void check_labels(void)
4532 {
4533         for (const goto_statement_t *goto_statement = goto_first;
4534             goto_statement != NULL;
4535             goto_statement = goto_statement->next) {
4536                 label_t *label = goto_statement->label;
4537                 if (label->base.source_position.input_name == NULL) {
4538                         print_in_function();
4539                         source_position_t const *const pos = &goto_statement->base.source_position;
4540                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4541                  }
4542         }
4543
4544         if (is_warn_on(WARN_UNUSED_LABEL)) {
4545                 for (const label_statement_t *label_statement = label_first;
4546                          label_statement != NULL;
4547                          label_statement = label_statement->next) {
4548                         label_t *label = label_statement->label;
4549
4550                         if (! label->used) {
4551                                 print_in_function();
4552                                 source_position_t const *const pos = &label_statement->base.source_position;
4553                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4554                         }
4555                 }
4556         }
4557 }
4558
4559 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4560 {
4561         entity_t const *const end = last != NULL ? last->base.next : NULL;
4562         for (; entity != end; entity = entity->base.next) {
4563                 if (!is_declaration(entity))
4564                         continue;
4565
4566                 declaration_t *declaration = &entity->declaration;
4567                 if (declaration->implicit)
4568                         continue;
4569
4570                 if (!declaration->used) {
4571                         print_in_function();
4572                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4573                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4574                         print_in_function();
4575                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4576                 }
4577         }
4578 }
4579
4580 static void check_unused_variables(statement_t *const stmt, void *const env)
4581 {
4582         (void)env;
4583
4584         switch (stmt->kind) {
4585                 case STATEMENT_DECLARATION: {
4586                         declaration_statement_t const *const decls = &stmt->declaration;
4587                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4588                         return;
4589                 }
4590
4591                 case STATEMENT_FOR:
4592                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4593                         return;
4594
4595                 default:
4596                         return;
4597         }
4598 }
4599
4600 /**
4601  * Check declarations of current_function for unused entities.
4602  */
4603 static void check_declarations(void)
4604 {
4605         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4606                 const scope_t *scope = &current_function->parameters;
4607                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4608         }
4609         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4610                 walk_statements(current_function->statement, check_unused_variables,
4611                                 NULL);
4612         }
4613 }
4614
4615 static int determine_truth(expression_t const* const cond)
4616 {
4617         return
4618                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4619                 fold_constant_to_bool(cond)                         ? 1 :
4620                 -1;
4621 }
4622
4623 static void check_reachable(statement_t *);
4624 static bool reaches_end;
4625
4626 static bool expression_returns(expression_t const *const expr)
4627 {
4628         switch (expr->kind) {
4629                 case EXPR_CALL: {
4630                         expression_t const *const func = expr->call.function;
4631                         type_t       const *const type = skip_typeref(func->base.type);
4632                         if (type->kind == TYPE_POINTER) {
4633                                 type_t const *const points_to
4634                                         = skip_typeref(type->pointer.points_to);
4635                                 if (points_to->kind == TYPE_FUNCTION
4636                                     && points_to->function.modifiers & DM_NORETURN)
4637                                         return false;
4638                         }
4639
4640                         if (!expression_returns(func))
4641                                 return false;
4642
4643                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4644                                 if (!expression_returns(arg->expression))
4645                                         return false;
4646                         }
4647
4648                         return true;
4649                 }
4650
4651                 case EXPR_REFERENCE:
4652                 case EXPR_ENUM_CONSTANT:
4653                 case EXPR_LITERAL_CASES:
4654                 case EXPR_STRING_LITERAL:
4655                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4656                 case EXPR_LABEL_ADDRESS:
4657                 case EXPR_CLASSIFY_TYPE:
4658                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4659                 case EXPR_ALIGNOF:
4660                 case EXPR_FUNCNAME:
4661                 case EXPR_BUILTIN_CONSTANT_P:
4662                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4663                 case EXPR_OFFSETOF:
4664                 case EXPR_ERROR:
4665                         return true;
4666
4667                 case EXPR_STATEMENT: {
4668                         bool old_reaches_end = reaches_end;
4669                         reaches_end = false;
4670                         check_reachable(expr->statement.statement);
4671                         bool returns = reaches_end;
4672                         reaches_end = old_reaches_end;
4673                         return returns;
4674                 }
4675
4676                 case EXPR_CONDITIONAL:
4677                         // TODO handle constant expression
4678
4679                         if (!expression_returns(expr->conditional.condition))
4680                                 return false;
4681
4682                         if (expr->conditional.true_expression != NULL
4683                                         && expression_returns(expr->conditional.true_expression))
4684                                 return true;
4685
4686                         return expression_returns(expr->conditional.false_expression);
4687
4688                 case EXPR_SELECT:
4689                         return expression_returns(expr->select.compound);
4690
4691                 case EXPR_ARRAY_ACCESS:
4692                         return
4693                                 expression_returns(expr->array_access.array_ref) &&
4694                                 expression_returns(expr->array_access.index);
4695
4696                 case EXPR_VA_START:
4697                         return expression_returns(expr->va_starte.ap);
4698
4699                 case EXPR_VA_ARG:
4700                         return expression_returns(expr->va_arge.ap);
4701
4702                 case EXPR_VA_COPY:
4703                         return expression_returns(expr->va_copye.src);
4704
4705                 case EXPR_UNARY_CASES_MANDATORY:
4706                         return expression_returns(expr->unary.value);
4707
4708                 case EXPR_UNARY_THROW:
4709                         return false;
4710
4711                 case EXPR_BINARY_CASES:
4712                         // TODO handle constant lhs of && and ||
4713                         return
4714                                 expression_returns(expr->binary.left) &&
4715                                 expression_returns(expr->binary.right);
4716         }
4717
4718         panic("unhandled expression");
4719 }
4720
4721 static bool initializer_returns(initializer_t const *const init)
4722 {
4723         switch (init->kind) {
4724                 case INITIALIZER_VALUE:
4725                         return expression_returns(init->value.value);
4726
4727                 case INITIALIZER_LIST: {
4728                         initializer_t * const*       i       = init->list.initializers;
4729                         initializer_t * const* const end     = i + init->list.len;
4730                         bool                         returns = true;
4731                         for (; i != end; ++i) {
4732                                 if (!initializer_returns(*i))
4733                                         returns = false;
4734                         }
4735                         return returns;
4736                 }
4737
4738                 case INITIALIZER_STRING:
4739                 case INITIALIZER_WIDE_STRING:
4740                 case INITIALIZER_DESIGNATOR: // designators have no payload
4741                         return true;
4742         }
4743         panic("unhandled initializer");
4744 }
4745
4746 static bool noreturn_candidate;
4747
4748 static void check_reachable(statement_t *const stmt)
4749 {
4750         if (stmt->base.reachable)
4751                 return;
4752         if (stmt->kind != STATEMENT_DO_WHILE)
4753                 stmt->base.reachable = true;
4754
4755         statement_t *last = stmt;
4756         statement_t *next;
4757         switch (stmt->kind) {
4758                 case STATEMENT_ERROR:
4759                 case STATEMENT_EMPTY:
4760                 case STATEMENT_ASM:
4761                         next = stmt->base.next;
4762                         break;
4763
4764                 case STATEMENT_DECLARATION: {
4765                         declaration_statement_t const *const decl = &stmt->declaration;
4766                         entity_t                const *      ent  = decl->declarations_begin;
4767                         entity_t                const *const last_decl = decl->declarations_end;
4768                         if (ent != NULL) {
4769                                 for (;; ent = ent->base.next) {
4770                                         if (ent->kind                 == ENTITY_VARIABLE &&
4771                                             ent->variable.initializer != NULL            &&
4772                                             !initializer_returns(ent->variable.initializer)) {
4773                                                 return;
4774                                         }
4775                                         if (ent == last_decl)
4776                                                 break;
4777                                 }
4778                         }
4779                         next = stmt->base.next;
4780                         break;
4781                 }
4782
4783                 case STATEMENT_COMPOUND:
4784                         next = stmt->compound.statements;
4785                         if (next == NULL)
4786                                 next = stmt->base.next;
4787                         break;
4788
4789                 case STATEMENT_RETURN: {
4790                         expression_t const *const val = stmt->returns.value;
4791                         if (val == NULL || expression_returns(val))
4792                                 noreturn_candidate = false;
4793                         return;
4794                 }
4795
4796                 case STATEMENT_IF: {
4797                         if_statement_t const *const ifs  = &stmt->ifs;
4798                         expression_t   const *const cond = ifs->condition;
4799
4800                         if (!expression_returns(cond))
4801                                 return;
4802
4803                         int const val = determine_truth(cond);
4804
4805                         if (val >= 0)
4806                                 check_reachable(ifs->true_statement);
4807
4808                         if (val > 0)
4809                                 return;
4810
4811                         if (ifs->false_statement != NULL) {
4812                                 check_reachable(ifs->false_statement);
4813                                 return;
4814                         }
4815
4816                         next = stmt->base.next;
4817                         break;
4818                 }
4819
4820                 case STATEMENT_SWITCH: {
4821                         switch_statement_t const *const switchs = &stmt->switchs;
4822                         expression_t       const *const expr    = switchs->expression;
4823
4824                         if (!expression_returns(expr))
4825                                 return;
4826
4827                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4828                                 long                    const val      = fold_constant_to_int(expr);
4829                                 case_label_statement_t *      defaults = NULL;
4830                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4831                                         if (i->expression == NULL) {
4832                                                 defaults = i;
4833                                                 continue;
4834                                         }
4835
4836                                         if (i->first_case <= val && val <= i->last_case) {
4837                                                 check_reachable((statement_t*)i);
4838                                                 return;
4839                                         }
4840                                 }
4841
4842                                 if (defaults != NULL) {
4843                                         check_reachable((statement_t*)defaults);
4844                                         return;
4845                                 }
4846                         } else {
4847                                 bool has_default = false;
4848                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4849                                         if (i->expression == NULL)
4850                                                 has_default = true;
4851
4852                                         check_reachable((statement_t*)i);
4853                                 }
4854
4855                                 if (has_default)
4856                                         return;
4857                         }
4858
4859                         next = stmt->base.next;
4860                         break;
4861                 }
4862
4863                 case STATEMENT_EXPRESSION: {
4864                         /* Check for noreturn function call */
4865                         expression_t const *const expr = stmt->expression.expression;
4866                         if (!expression_returns(expr))
4867                                 return;
4868
4869                         next = stmt->base.next;
4870                         break;
4871                 }
4872
4873                 case STATEMENT_CONTINUE:
4874                         for (statement_t *parent = stmt;;) {
4875                                 parent = parent->base.parent;
4876                                 if (parent == NULL) /* continue not within loop */
4877                                         return;
4878
4879                                 next = parent;
4880                                 switch (parent->kind) {
4881                                         case STATEMENT_WHILE:    goto continue_while;
4882                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4883                                         case STATEMENT_FOR:      goto continue_for;
4884
4885                                         default: break;
4886                                 }
4887                         }
4888
4889                 case STATEMENT_BREAK:
4890                         for (statement_t *parent = stmt;;) {
4891                                 parent = parent->base.parent;
4892                                 if (parent == NULL) /* break not within loop/switch */
4893                                         return;
4894
4895                                 switch (parent->kind) {
4896                                         case STATEMENT_SWITCH:
4897                                         case STATEMENT_WHILE:
4898                                         case STATEMENT_DO_WHILE:
4899                                         case STATEMENT_FOR:
4900                                                 last = parent;
4901                                                 next = parent->base.next;
4902                                                 goto found_break_parent;
4903
4904                                         default: break;
4905                                 }
4906                         }
4907 found_break_parent:
4908                         break;
4909
4910                 case STATEMENT_COMPUTED_GOTO: {
4911                         if (!expression_returns(stmt->computed_goto.expression))
4912                                 return;
4913
4914                         statement_t *parent = stmt->base.parent;
4915                         if (parent == NULL) /* top level goto */
4916                                 return;
4917                         next = parent;
4918                         break;
4919                 }
4920
4921                 case STATEMENT_GOTO:
4922                         next = stmt->gotos.label->statement;
4923                         if (next == NULL) /* missing label */
4924                                 return;
4925                         break;
4926
4927                 case STATEMENT_LABEL:
4928                         next = stmt->label.statement;
4929                         break;
4930
4931                 case STATEMENT_CASE_LABEL:
4932                         next = stmt->case_label.statement;
4933                         break;
4934
4935                 case STATEMENT_WHILE: {
4936                         while_statement_t const *const whiles = &stmt->whiles;
4937                         expression_t      const *const cond   = whiles->condition;
4938
4939                         if (!expression_returns(cond))
4940                                 return;
4941
4942                         int const val = determine_truth(cond);
4943
4944                         if (val >= 0)
4945                                 check_reachable(whiles->body);
4946
4947                         if (val > 0)
4948                                 return;
4949
4950                         next = stmt->base.next;
4951                         break;
4952                 }
4953
4954                 case STATEMENT_DO_WHILE:
4955                         next = stmt->do_while.body;
4956                         break;
4957
4958                 case STATEMENT_FOR: {
4959                         for_statement_t *const fors = &stmt->fors;
4960
4961                         if (fors->condition_reachable)
4962                                 return;
4963                         fors->condition_reachable = true;
4964
4965                         expression_t const *const cond = fors->condition;
4966
4967                         int val;
4968                         if (cond == NULL) {
4969                                 val = 1;
4970                         } else if (expression_returns(cond)) {
4971                                 val = determine_truth(cond);
4972                         } else {
4973                                 return;
4974                         }
4975
4976                         if (val >= 0)
4977                                 check_reachable(fors->body);
4978
4979                         if (val > 0)
4980                                 return;
4981
4982                         next = stmt->base.next;
4983                         break;
4984                 }
4985
4986                 case STATEMENT_MS_TRY: {
4987                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4988                         check_reachable(ms_try->try_statement);
4989                         next = ms_try->final_statement;
4990                         break;
4991                 }
4992
4993                 case STATEMENT_LEAVE: {
4994                         statement_t *parent = stmt;
4995                         for (;;) {
4996                                 parent = parent->base.parent;
4997                                 if (parent == NULL) /* __leave not within __try */
4998                                         return;
4999
5000                                 if (parent->kind == STATEMENT_MS_TRY) {
5001                                         last = parent;
5002                                         next = parent->ms_try.final_statement;
5003                                         break;
5004                                 }
5005                         }
5006                         break;
5007                 }
5008
5009                 default:
5010                         panic("invalid statement kind");
5011         }
5012
5013         while (next == NULL) {
5014                 next = last->base.parent;
5015                 if (next == NULL) {
5016                         noreturn_candidate = false;
5017
5018                         type_t *const type = skip_typeref(current_function->base.type);
5019                         assert(is_type_function(type));
5020                         type_t *const ret  = skip_typeref(type->function.return_type);
5021                         if (!is_type_void(ret) &&
5022                             is_type_valid(ret) &&
5023                             !is_main(current_entity)) {
5024                                 source_position_t const *const pos = &stmt->base.source_position;
5025                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5026                         }
5027                         return;
5028                 }
5029
5030                 switch (next->kind) {
5031                         case STATEMENT_ERROR:
5032                         case STATEMENT_EMPTY:
5033                         case STATEMENT_DECLARATION:
5034                         case STATEMENT_EXPRESSION:
5035                         case STATEMENT_ASM:
5036                         case STATEMENT_RETURN:
5037                         case STATEMENT_CONTINUE:
5038                         case STATEMENT_BREAK:
5039                         case STATEMENT_COMPUTED_GOTO:
5040                         case STATEMENT_GOTO:
5041                         case STATEMENT_LEAVE:
5042                                 panic("invalid control flow in function");
5043
5044                         case STATEMENT_COMPOUND:
5045                                 if (next->compound.stmt_expr) {
5046                                         reaches_end = true;
5047                                         return;
5048                                 }
5049                                 /* FALLTHROUGH */
5050                         case STATEMENT_IF:
5051                         case STATEMENT_SWITCH:
5052                         case STATEMENT_LABEL:
5053                         case STATEMENT_CASE_LABEL:
5054                                 last = next;
5055                                 next = next->base.next;
5056                                 break;
5057
5058                         case STATEMENT_WHILE: {
5059 continue_while:
5060                                 if (next->base.reachable)
5061                                         return;
5062                                 next->base.reachable = true;
5063
5064                                 while_statement_t const *const whiles = &next->whiles;
5065                                 expression_t      const *const cond   = whiles->condition;
5066
5067                                 if (!expression_returns(cond))
5068                                         return;
5069
5070                                 int const val = determine_truth(cond);
5071
5072                                 if (val >= 0)
5073                                         check_reachable(whiles->body);
5074
5075                                 if (val > 0)
5076                                         return;
5077
5078                                 last = next;
5079                                 next = next->base.next;
5080                                 break;
5081                         }
5082
5083                         case STATEMENT_DO_WHILE: {
5084 continue_do_while:
5085                                 if (next->base.reachable)
5086                                         return;
5087                                 next->base.reachable = true;
5088
5089                                 do_while_statement_t const *const dw   = &next->do_while;
5090                                 expression_t         const *const cond = dw->condition;
5091
5092                                 if (!expression_returns(cond))
5093                                         return;
5094
5095                                 int const val = determine_truth(cond);
5096
5097                                 if (val >= 0)
5098                                         check_reachable(dw->body);
5099
5100                                 if (val > 0)
5101                                         return;
5102
5103                                 last = next;
5104                                 next = next->base.next;
5105                                 break;
5106                         }
5107
5108                         case STATEMENT_FOR: {
5109 continue_for:;
5110                                 for_statement_t *const fors = &next->fors;
5111
5112                                 fors->step_reachable = true;
5113
5114                                 if (fors->condition_reachable)
5115                                         return;
5116                                 fors->condition_reachable = true;
5117
5118                                 expression_t const *const cond = fors->condition;
5119
5120                                 int val;
5121                                 if (cond == NULL) {
5122                                         val = 1;
5123                                 } else if (expression_returns(cond)) {
5124                                         val = determine_truth(cond);
5125                                 } else {
5126                                         return;
5127                                 }
5128
5129                                 if (val >= 0)
5130                                         check_reachable(fors->body);
5131
5132                                 if (val > 0)
5133                                         return;
5134
5135                                 last = next;
5136                                 next = next->base.next;
5137                                 break;
5138                         }
5139
5140                         case STATEMENT_MS_TRY:
5141                                 last = next;
5142                                 next = next->ms_try.final_statement;
5143                                 break;
5144                 }
5145         }
5146
5147         check_reachable(next);
5148 }
5149
5150 static void check_unreachable(statement_t* const stmt, void *const env)
5151 {
5152         (void)env;
5153
5154         switch (stmt->kind) {
5155                 case STATEMENT_DO_WHILE:
5156                         if (!stmt->base.reachable) {
5157                                 expression_t const *const cond = stmt->do_while.condition;
5158                                 if (determine_truth(cond) >= 0) {
5159                                         source_position_t const *const pos = &cond->base.source_position;
5160                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5161                                 }
5162                         }
5163                         return;
5164
5165                 case STATEMENT_FOR: {
5166                         for_statement_t const* const fors = &stmt->fors;
5167
5168                         // if init and step are unreachable, cond is unreachable, too
5169                         if (!stmt->base.reachable && !fors->step_reachable) {
5170                                 goto warn_unreachable;
5171                         } else {
5172                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5173                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5174                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5175                                 }
5176
5177                                 if (!fors->condition_reachable && fors->condition != NULL) {
5178                                         source_position_t const *const pos = &fors->condition->base.source_position;
5179                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5180                                 }
5181
5182                                 if (!fors->step_reachable && fors->step != NULL) {
5183                                         source_position_t const *const pos = &fors->step->base.source_position;
5184                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5185                                 }
5186                         }
5187                         return;
5188                 }
5189
5190                 case STATEMENT_COMPOUND:
5191                         if (stmt->compound.statements != NULL)
5192                                 return;
5193                         goto warn_unreachable;
5194
5195                 case STATEMENT_DECLARATION: {
5196                         /* Only warn if there is at least one declarator with an initializer.
5197                          * This typically occurs in switch statements. */
5198                         declaration_statement_t const *const decl = &stmt->declaration;
5199                         entity_t                const *      ent  = decl->declarations_begin;
5200                         entity_t                const *const last = decl->declarations_end;
5201                         if (ent != NULL) {
5202                                 for (;; ent = ent->base.next) {
5203                                         if (ent->kind                 == ENTITY_VARIABLE &&
5204                                                         ent->variable.initializer != NULL) {
5205                                                 goto warn_unreachable;
5206                                         }
5207                                         if (ent == last)
5208                                                 return;
5209                                 }
5210                         }
5211                 }
5212
5213                 default:
5214 warn_unreachable:
5215                         if (!stmt->base.reachable) {
5216                                 source_position_t const *const pos = &stmt->base.source_position;
5217                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5218                         }
5219                         return;
5220         }
5221 }
5222
5223 static bool is_main(entity_t *entity)
5224 {
5225         static symbol_t *sym_main = NULL;
5226         if (sym_main == NULL) {
5227                 sym_main = symbol_table_insert("main");
5228         }
5229
5230         if (entity->base.symbol != sym_main)
5231                 return false;
5232         /* must be in outermost scope */
5233         if (entity->base.parent_scope != file_scope)
5234                 return false;
5235
5236         return true;
5237 }
5238
5239 static void prepare_main_collect2(entity_t*);
5240
5241 static void parse_external_declaration(void)
5242 {
5243         /* function-definitions and declarations both start with declaration
5244          * specifiers */
5245         add_anchor_token(';');
5246         declaration_specifiers_t specifiers;
5247         parse_declaration_specifiers(&specifiers);
5248         rem_anchor_token(';');
5249
5250         /* must be a declaration */
5251         if (token.kind == ';') {
5252                 parse_anonymous_declaration_rest(&specifiers);
5253                 return;
5254         }
5255
5256         add_anchor_token(',');
5257         add_anchor_token('=');
5258         add_anchor_token(';');
5259         add_anchor_token('{');
5260
5261         /* declarator is common to both function-definitions and declarations */
5262         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5263
5264         rem_anchor_token('{');
5265         rem_anchor_token(';');
5266         rem_anchor_token('=');
5267         rem_anchor_token(',');
5268
5269         /* must be a declaration */
5270         switch (token.kind) {
5271                 case ',':
5272                 case ';':
5273                 case '=':
5274                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5275                                         DECL_FLAGS_NONE);
5276                         return;
5277         }
5278
5279         /* must be a function definition */
5280         parse_kr_declaration_list(ndeclaration);
5281
5282         if (token.kind != '{') {
5283                 parse_error_expected("while parsing function definition", '{', NULL);
5284                 eat_until_matching_token(';');
5285                 return;
5286         }
5287
5288         assert(is_declaration(ndeclaration));
5289         type_t *const orig_type = ndeclaration->declaration.type;
5290         type_t *      type      = skip_typeref(orig_type);
5291
5292         if (!is_type_function(type)) {
5293                 if (is_type_valid(type)) {
5294                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5295                 }
5296                 eat_block();
5297                 return;
5298         }
5299
5300         source_position_t const *const pos = &ndeclaration->base.source_position;
5301         if (is_typeref(orig_type)) {
5302                 /* §6.9.1:2 */
5303                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5304         }
5305
5306         if (is_type_compound(skip_typeref(type->function.return_type))) {
5307                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5308         }
5309         if (type->function.unspecified_parameters) {
5310                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5311         } else {
5312                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5313         }
5314
5315         /* §6.7.5.3:14 a function definition with () means no
5316          * parameters (and not unspecified parameters) */
5317         if (type->function.unspecified_parameters &&
5318                         type->function.parameters == NULL) {
5319                 type_t *copy                          = duplicate_type(type);
5320                 copy->function.unspecified_parameters = false;
5321                 type                                  = identify_new_type(copy);
5322
5323                 ndeclaration->declaration.type = type;
5324         }
5325
5326         entity_t *const entity = record_entity(ndeclaration, true);
5327         assert(entity->kind == ENTITY_FUNCTION);
5328         assert(ndeclaration->kind == ENTITY_FUNCTION);
5329
5330         function_t *const function = &entity->function;
5331         if (ndeclaration != entity) {
5332                 function->parameters = ndeclaration->function.parameters;
5333         }
5334
5335         PUSH_SCOPE(&function->parameters);
5336
5337         entity_t *parameter = function->parameters.entities;
5338         for (; parameter != NULL; parameter = parameter->base.next) {
5339                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5340                         parameter->base.parent_scope = current_scope;
5341                 }
5342                 assert(parameter->base.parent_scope == NULL
5343                                 || parameter->base.parent_scope == current_scope);
5344                 parameter->base.parent_scope = current_scope;
5345                 if (parameter->base.symbol == NULL) {
5346                         errorf(&parameter->base.source_position, "parameter name omitted");
5347                         continue;
5348                 }
5349                 environment_push(parameter);
5350         }
5351
5352         if (function->statement != NULL) {
5353                 parser_error_multiple_definition(entity, HERE);
5354                 eat_block();
5355         } else {
5356                 /* parse function body */
5357                 int         label_stack_top      = label_top();
5358                 function_t *old_current_function = current_function;
5359                 current_function                 = function;
5360                 PUSH_CURRENT_ENTITY(entity);
5361                 PUSH_PARENT(NULL);
5362
5363                 goto_first   = NULL;
5364                 goto_anchor  = &goto_first;
5365                 label_first  = NULL;
5366                 label_anchor = &label_first;
5367
5368                 statement_t *const body = parse_compound_statement(false);
5369                 function->statement = body;
5370                 first_err = true;
5371                 check_labels();
5372                 check_declarations();
5373                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5374                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5375                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5376                         noreturn_candidate = true;
5377                         check_reachable(body);
5378                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5379                                 walk_statements(body, check_unreachable, NULL);
5380                         if (noreturn_candidate &&
5381                             !(function->base.modifiers & DM_NORETURN)) {
5382                                 source_position_t const *const pos = &body->base.source_position;
5383                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5384                         }
5385                 }
5386
5387                 if (is_main(entity)) {
5388                         /* Force main to C linkage. */
5389                         type_t *const type = entity->declaration.type;
5390                         assert(is_type_function(type));
5391                         if (type->function.linkage != LINKAGE_C) {
5392                                 type_t *new_type           = duplicate_type(type);
5393                                 new_type->function.linkage = LINKAGE_C;
5394                                 entity->declaration.type   = identify_new_type(new_type);
5395                         }
5396
5397                         if (enable_main_collect2_hack)
5398                                 prepare_main_collect2(entity);
5399                 }
5400
5401                 POP_CURRENT_ENTITY();
5402                 POP_PARENT();
5403                 assert(current_function == function);
5404                 current_function = old_current_function;
5405                 label_pop_to(label_stack_top);
5406         }
5407
5408         POP_SCOPE();
5409 }
5410
5411 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5412 {
5413         entity_t *iter = compound->members.entities;
5414         for (; iter != NULL; iter = iter->base.next) {
5415                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5416                         continue;
5417
5418                 if (iter->base.symbol == symbol) {
5419                         return iter;
5420                 } else if (iter->base.symbol == NULL) {
5421                         /* search in anonymous structs and unions */
5422                         type_t *type = skip_typeref(iter->declaration.type);
5423                         if (is_type_compound(type)) {
5424                                 if (find_compound_entry(type->compound.compound, symbol)
5425                                                 != NULL)
5426                                         return iter;
5427                         }
5428                         continue;
5429                 }
5430         }
5431
5432         return NULL;
5433 }
5434
5435 static void check_deprecated(const source_position_t *source_position,
5436                              const entity_t *entity)
5437 {
5438         if (!is_declaration(entity))
5439                 return;
5440         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5441                 return;
5442
5443         source_position_t const *const epos = &entity->base.source_position;
5444         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5445         if (msg != NULL) {
5446                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5447         } else {
5448                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5449         }
5450 }
5451
5452
5453 static expression_t *create_select(const source_position_t *pos,
5454                                    expression_t *addr,
5455                                    type_qualifiers_t qualifiers,
5456                                                                    entity_t *entry)
5457 {
5458         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5459
5460         check_deprecated(pos, entry);
5461
5462         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5463         select->select.compound       = addr;
5464         select->select.compound_entry = entry;
5465
5466         type_t *entry_type = entry->declaration.type;
5467         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5468
5469         /* bitfields need special treatment */
5470         if (entry->compound_member.bitfield) {
5471                 unsigned bit_size = entry->compound_member.bit_size;
5472                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5473                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5474                         res_type = type_int;
5475                 }
5476         }
5477
5478         /* we always do the auto-type conversions; the & and sizeof parser contains
5479          * code to revert this! */
5480         select->base.type = automatic_type_conversion(res_type);
5481
5482
5483         return select;
5484 }
5485
5486 /**
5487  * Find entry with symbol in compound. Search anonymous structs and unions and
5488  * creates implicit select expressions for them.
5489  * Returns the adress for the innermost compound.
5490  */
5491 static expression_t *find_create_select(const source_position_t *pos,
5492                                         expression_t *addr,
5493                                         type_qualifiers_t qualifiers,
5494                                         compound_t *compound, symbol_t *symbol)
5495 {
5496         entity_t *iter = compound->members.entities;
5497         for (; iter != NULL; iter = iter->base.next) {
5498                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5499                         continue;
5500
5501                 symbol_t *iter_symbol = iter->base.symbol;
5502                 if (iter_symbol == NULL) {
5503                         type_t *type = iter->declaration.type;
5504                         if (type->kind != TYPE_COMPOUND_STRUCT
5505                                         && type->kind != TYPE_COMPOUND_UNION)
5506                                 continue;
5507
5508                         compound_t *sub_compound = type->compound.compound;
5509
5510                         if (find_compound_entry(sub_compound, symbol) == NULL)
5511                                 continue;
5512
5513                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5514                         sub_addr->base.source_position = *pos;
5515                         sub_addr->base.implicit        = true;
5516                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5517                                                   symbol);
5518                 }
5519
5520                 if (iter_symbol == symbol) {
5521                         return create_select(pos, addr, qualifiers, iter);
5522                 }
5523         }
5524
5525         return NULL;
5526 }
5527
5528 static void parse_bitfield_member(entity_t *entity)
5529 {
5530         eat(':');
5531
5532         expression_t *size = parse_constant_expression();
5533         long          size_long;
5534
5535         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5536         type_t *type = entity->declaration.type;
5537         if (!is_type_integer(skip_typeref(type))) {
5538                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5539                            type);
5540         }
5541
5542         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5543                 /* error already reported by parse_constant_expression */
5544                 size_long = get_type_size(type) * 8;
5545         } else {
5546                 size_long = fold_constant_to_int(size);
5547
5548                 const symbol_t *symbol = entity->base.symbol;
5549                 const symbol_t *user_symbol
5550                         = symbol == NULL ? sym_anonymous : symbol;
5551                 unsigned bit_size = get_type_size(type) * 8;
5552                 if (size_long < 0) {
5553                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5554                 } else if (size_long == 0 && symbol != NULL) {
5555                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5556                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5557                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5558                                    user_symbol);
5559                 } else {
5560                         /* hope that people don't invent crazy types with more bits
5561                          * than our struct can hold */
5562                         assert(size_long <
5563                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5564                 }
5565         }
5566
5567         entity->compound_member.bitfield = true;
5568         entity->compound_member.bit_size = (unsigned char)size_long;
5569 }
5570
5571 static void parse_compound_declarators(compound_t *compound,
5572                 const declaration_specifiers_t *specifiers)
5573 {
5574         add_anchor_token(';');
5575         add_anchor_token(',');
5576         do {
5577                 entity_t *entity;
5578
5579                 if (token.kind == ':') {
5580                         /* anonymous bitfield */
5581                         type_t *type = specifiers->type;
5582                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5583                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5584                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5585                         entity->declaration.type                   = type;
5586
5587                         parse_bitfield_member(entity);
5588
5589                         attribute_t  *attributes = parse_attributes(NULL);
5590                         attribute_t **anchor     = &attributes;
5591                         while (*anchor != NULL)
5592                                 anchor = &(*anchor)->next;
5593                         *anchor = specifiers->attributes;
5594                         if (attributes != NULL) {
5595                                 handle_entity_attributes(attributes, entity);
5596                         }
5597                         entity->declaration.attributes = attributes;
5598
5599                         append_entity(&compound->members, entity);
5600                 } else {
5601                         entity = parse_declarator(specifiers,
5602                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5603                         source_position_t const *const pos = &entity->base.source_position;
5604                         if (entity->kind == ENTITY_TYPEDEF) {
5605                                 errorf(pos, "typedef not allowed as compound member");
5606                         } else {
5607                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5608
5609                                 /* make sure we don't define a symbol multiple times */
5610                                 symbol_t *symbol = entity->base.symbol;
5611                                 if (symbol != NULL) {
5612                                         entity_t *prev = find_compound_entry(compound, symbol);
5613                                         if (prev != NULL) {
5614                                                 source_position_t const *const ppos = &prev->base.source_position;
5615                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5616                                         }
5617                                 }
5618
5619                                 if (token.kind == ':') {
5620                                         parse_bitfield_member(entity);
5621
5622                                         attribute_t *attributes = parse_attributes(NULL);
5623                                         handle_entity_attributes(attributes, entity);
5624                                 } else {
5625                                         type_t *orig_type = entity->declaration.type;
5626                                         type_t *type      = skip_typeref(orig_type);
5627                                         if (is_type_function(type)) {
5628                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5629                                         } else if (is_type_incomplete(type)) {
5630                                                 /* §6.7.2.1:16 flexible array member */
5631                                                 if (!is_type_array(type)       ||
5632                                                                 token.kind          != ';' ||
5633                                                                 look_ahead(1)->kind != '}') {
5634                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5635                                                 } else if (compound->members.entities == NULL) {
5636                                                         errorf(pos, "flexible array member in otherwise empty struct");
5637                                                 }
5638                                         }
5639                                 }
5640
5641                                 append_entity(&compound->members, entity);
5642                         }
5643                 }
5644         } while (next_if(','));
5645         rem_anchor_token(',');
5646         rem_anchor_token(';');
5647         expect(';');
5648
5649         anonymous_entity = NULL;
5650 }
5651
5652 static void parse_compound_type_entries(compound_t *compound)
5653 {
5654         eat('{');
5655         add_anchor_token('}');
5656
5657         for (;;) {
5658                 switch (token.kind) {
5659                         DECLARATION_START
5660                         case T___extension__:
5661                         case T_IDENTIFIER: {
5662                                 PUSH_EXTENSION();
5663                                 declaration_specifiers_t specifiers;
5664                                 parse_declaration_specifiers(&specifiers);
5665                                 parse_compound_declarators(compound, &specifiers);
5666                                 POP_EXTENSION();
5667                                 break;
5668                         }
5669
5670                         default:
5671                                 rem_anchor_token('}');
5672                                 expect('}');
5673                                 /* §6.7.2.1:7 */
5674                                 compound->complete = true;
5675                                 return;
5676                 }
5677         }
5678 }
5679
5680 static type_t *parse_typename(void)
5681 {
5682         declaration_specifiers_t specifiers;
5683         parse_declaration_specifiers(&specifiers);
5684         if (specifiers.storage_class != STORAGE_CLASS_NONE
5685                         || specifiers.thread_local) {
5686                 /* TODO: improve error message, user does probably not know what a
5687                  * storage class is...
5688                  */
5689                 errorf(&specifiers.source_position, "typename must not have a storage class");
5690         }
5691
5692         type_t *result = parse_abstract_declarator(specifiers.type);
5693
5694         return result;
5695 }
5696
5697
5698
5699
5700 typedef expression_t* (*parse_expression_function)(void);
5701 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5702
5703 typedef struct expression_parser_function_t expression_parser_function_t;
5704 struct expression_parser_function_t {
5705         parse_expression_function        parser;
5706         precedence_t                     infix_precedence;
5707         parse_expression_infix_function  infix_parser;
5708 };
5709
5710 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5711
5712 static type_t *get_string_type(string_encoding_t const enc)
5713 {
5714         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5715         switch (enc) {
5716         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5717         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5718         }
5719         panic("invalid string encoding");
5720 }
5721
5722 /**
5723  * Parse a string constant.
5724  */
5725 static expression_t *parse_string_literal(void)
5726 {
5727         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5728         expr->string_literal.value = concat_string_literals(&expr->string_literal.encoding);
5729         expr->base.type            = get_string_type(expr->string_literal.encoding);
5730         return expr;
5731 }
5732
5733 /**
5734  * Parse a boolean constant.
5735  */
5736 static expression_t *parse_boolean_literal(bool value)
5737 {
5738         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5739         literal->base.type           = type_bool;
5740         literal->literal.value.begin = value ? "true" : "false";
5741         literal->literal.value.size  = value ? 4 : 5;
5742
5743         eat(value ? T_true : T_false);
5744         return literal;
5745 }
5746
5747 static void warn_traditional_suffix(void)
5748 {
5749         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5750                  &token.number.suffix);
5751 }
5752
5753 static void check_integer_suffix(void)
5754 {
5755         const string_t *suffix = &token.number.suffix;
5756         if (suffix->size == 0)
5757                 return;
5758
5759         bool not_traditional = false;
5760         const char *c = suffix->begin;
5761         if (*c == 'l' || *c == 'L') {
5762                 ++c;
5763                 if (*c == *(c-1)) {
5764                         not_traditional = true;
5765                         ++c;
5766                         if (*c == 'u' || *c == 'U') {
5767                                 ++c;
5768                         }
5769                 } else if (*c == 'u' || *c == 'U') {
5770                         not_traditional = true;
5771                         ++c;
5772                 }
5773         } else if (*c == 'u' || *c == 'U') {
5774                 not_traditional = true;
5775                 ++c;
5776                 if (*c == 'l' || *c == 'L') {
5777                         ++c;
5778                         if (*c == *(c-1)) {
5779                                 ++c;
5780                         }
5781                 }
5782         }
5783         if (*c != '\0') {
5784                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5785         } else if (not_traditional) {
5786                 warn_traditional_suffix();
5787         }
5788 }
5789
5790 static type_t *check_floatingpoint_suffix(void)
5791 {
5792         const string_t *suffix = &token.number.suffix;
5793         type_t         *type   = type_double;
5794         if (suffix->size == 0)
5795                 return type;
5796
5797         bool not_traditional = false;
5798         const char *c = suffix->begin;
5799         if (*c == 'f' || *c == 'F') {
5800                 ++c;
5801                 type = type_float;
5802         } else if (*c == 'l' || *c == 'L') {
5803                 ++c;
5804                 type = type_long_double;
5805         }
5806         if (*c != '\0') {
5807                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5808         } else if (not_traditional) {
5809                 warn_traditional_suffix();
5810         }
5811
5812         return type;
5813 }
5814
5815 /**
5816  * Parse an integer constant.
5817  */
5818 static expression_t *parse_number_literal(void)
5819 {
5820         expression_kind_t  kind;
5821         type_t            *type;
5822
5823         switch (token.kind) {
5824         case T_INTEGER:
5825                 kind = EXPR_LITERAL_INTEGER;
5826                 check_integer_suffix();
5827                 type = type_int;
5828                 break;
5829
5830         case T_FLOATINGPOINT:
5831                 kind = EXPR_LITERAL_FLOATINGPOINT;
5832                 type = check_floatingpoint_suffix();
5833                 break;
5834
5835         default:
5836                 panic("unexpected token type in parse_number_literal");
5837         }
5838
5839         expression_t *literal = allocate_expression_zero(kind);
5840         literal->base.type      = type;
5841         literal->literal.value  = token.number.number;
5842         literal->literal.suffix = token.number.suffix;
5843         next_token();
5844
5845         /* integer type depends on the size of the number and the size
5846          * representable by the types. The backend/codegeneration has to determine
5847          * that
5848          */
5849         determine_literal_type(&literal->literal);
5850         return literal;
5851 }
5852
5853 /**
5854  * Parse a character constant.
5855  */
5856 static expression_t *parse_character_constant(void)
5857 {
5858         expression_t *literal;
5859         switch (token.string.encoding) {
5860         case STRING_ENCODING_CHAR: {
5861                 literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5862                 literal->base.type     = c_mode & _CXX ? type_char : type_int;
5863                 literal->literal.value = token.string.string;
5864
5865                 size_t len = literal->literal.value.size;
5866                 if (len > 1) {
5867                         if (!GNU_MODE && !(c_mode & _C99)) {
5868                                 errorf(HERE, "more than 1 character in character constant");
5869                         } else {
5870                                 literal->base.type = type_int;
5871                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5872                         }
5873                 }
5874                 break;
5875         }
5876
5877         case STRING_ENCODING_WIDE: {
5878                 literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5879                 literal->base.type     = type_int;
5880                 literal->literal.value = token.string.string;
5881
5882                 size_t len = wstrlen(&literal->literal.value);
5883                 if (len > 1) {
5884                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5885                 }
5886                 break;
5887         }
5888         }
5889
5890         eat(T_CHARACTER_CONSTANT);
5891         return literal;
5892 }
5893
5894 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5895 {
5896         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5897         ntype->function.return_type            = type_int;
5898         ntype->function.unspecified_parameters = true;
5899         ntype->function.linkage                = LINKAGE_C;
5900         type_t *type                           = identify_new_type(ntype);
5901
5902         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5903         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5904         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5905         entity->declaration.type                   = type;
5906         entity->declaration.implicit               = true;
5907
5908         if (current_scope != NULL)
5909                 record_entity(entity, false);
5910
5911         return entity;
5912 }
5913
5914 /**
5915  * Performs automatic type cast as described in §6.3.2.1.
5916  *
5917  * @param orig_type  the original type
5918  */
5919 static type_t *automatic_type_conversion(type_t *orig_type)
5920 {
5921         type_t *type = skip_typeref(orig_type);
5922         if (is_type_array(type)) {
5923                 array_type_t *array_type   = &type->array;
5924                 type_t       *element_type = array_type->element_type;
5925                 unsigned      qualifiers   = array_type->base.qualifiers;
5926
5927                 return make_pointer_type(element_type, qualifiers);
5928         }
5929
5930         if (is_type_function(type)) {
5931                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5932         }
5933
5934         return orig_type;
5935 }
5936
5937 /**
5938  * reverts the automatic casts of array to pointer types and function
5939  * to function-pointer types as defined §6.3.2.1
5940  */
5941 type_t *revert_automatic_type_conversion(const expression_t *expression)
5942 {
5943         switch (expression->kind) {
5944         case EXPR_REFERENCE: {
5945                 entity_t *entity = expression->reference.entity;
5946                 if (is_declaration(entity)) {
5947                         return entity->declaration.type;
5948                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5949                         return entity->enum_value.enum_type;
5950                 } else {
5951                         panic("no declaration or enum in reference");
5952                 }
5953         }
5954
5955         case EXPR_SELECT: {
5956                 entity_t *entity = expression->select.compound_entry;
5957                 assert(is_declaration(entity));
5958                 type_t   *type   = entity->declaration.type;
5959                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5960         }
5961
5962         case EXPR_UNARY_DEREFERENCE: {
5963                 const expression_t *const value = expression->unary.value;
5964                 type_t             *const type  = skip_typeref(value->base.type);
5965                 if (!is_type_pointer(type))
5966                         return type_error_type;
5967                 return type->pointer.points_to;
5968         }
5969
5970         case EXPR_ARRAY_ACCESS: {
5971                 const expression_t *array_ref = expression->array_access.array_ref;
5972                 type_t             *type_left = skip_typeref(array_ref->base.type);
5973                 if (!is_type_pointer(type_left))
5974                         return type_error_type;
5975                 return type_left->pointer.points_to;
5976         }
5977
5978         case EXPR_STRING_LITERAL: {
5979                 size_t  const size = expression->string_literal.value.size + 1;
5980                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5981                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5982         }
5983
5984         case EXPR_COMPOUND_LITERAL:
5985                 return expression->compound_literal.type;
5986
5987         default:
5988                 break;
5989         }
5990         return expression->base.type;
5991 }
5992
5993 /**
5994  * Find an entity matching a symbol in a scope.
5995  * Uses current scope if scope is NULL
5996  */
5997 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5998                                namespace_tag_t namespc)
5999 {
6000         if (scope == NULL) {
6001                 return get_entity(symbol, namespc);
6002         }
6003
6004         /* we should optimize here, if scope grows above a certain size we should
6005            construct a hashmap here... */
6006         entity_t *entity = scope->entities;
6007         for ( ; entity != NULL; entity = entity->base.next) {
6008                 if (entity->base.symbol == symbol
6009                     && (namespace_tag_t)entity->base.namespc == namespc)
6010                         break;
6011         }
6012
6013         return entity;
6014 }
6015
6016 static entity_t *parse_qualified_identifier(void)
6017 {
6018         /* namespace containing the symbol */
6019         symbol_t          *symbol;
6020         source_position_t  pos;
6021         const scope_t     *lookup_scope = NULL;
6022
6023         if (next_if(T_COLONCOLON))
6024                 lookup_scope = &unit->scope;
6025
6026         entity_t *entity;
6027         while (true) {
6028                 symbol = expect_identifier("while parsing identifier", &pos);
6029                 if (!symbol)
6030                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6031
6032                 /* lookup entity */
6033                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6034
6035                 if (!next_if(T_COLONCOLON))
6036                         break;
6037
6038                 switch (entity->kind) {
6039                 case ENTITY_NAMESPACE:
6040                         lookup_scope = &entity->namespacee.members;
6041                         break;
6042                 case ENTITY_STRUCT:
6043                 case ENTITY_UNION:
6044                 case ENTITY_CLASS:
6045                         lookup_scope = &entity->compound.members;
6046                         break;
6047                 default:
6048                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6049                                symbol, get_entity_kind_name(entity->kind));
6050
6051                         /* skip further qualifications */
6052                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6053
6054                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6055                 }
6056         }
6057
6058         if (entity == NULL) {
6059                 if (!strict_mode && token.kind == '(') {
6060                         /* an implicitly declared function */
6061                         entity = create_implicit_function(symbol, &pos);
6062                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6063                 } else {
6064                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6065                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6066                 }
6067         }
6068
6069         return entity;
6070 }
6071
6072 static expression_t *parse_reference(void)
6073 {
6074         source_position_t const pos    = *HERE;
6075         entity_t         *const entity = parse_qualified_identifier();
6076
6077         type_t *orig_type;
6078         if (is_declaration(entity)) {
6079                 orig_type = entity->declaration.type;
6080         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6081                 orig_type = entity->enum_value.enum_type;
6082         } else {
6083                 panic("expected declaration or enum value in reference");
6084         }
6085
6086         /* we always do the auto-type conversions; the & and sizeof parser contains
6087          * code to revert this! */
6088         type_t *type = automatic_type_conversion(orig_type);
6089
6090         expression_kind_t kind = EXPR_REFERENCE;
6091         if (entity->kind == ENTITY_ENUM_VALUE)
6092                 kind = EXPR_ENUM_CONSTANT;
6093
6094         expression_t *expression         = allocate_expression_zero(kind);
6095         expression->base.source_position = pos;
6096         expression->base.type            = type;
6097         expression->reference.entity     = entity;
6098
6099         /* this declaration is used */
6100         if (is_declaration(entity)) {
6101                 entity->declaration.used = true;
6102         }
6103
6104         if (entity->base.parent_scope != file_scope
6105                 && (current_function != NULL
6106                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6107                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6108                 /* access of a variable from an outer function */
6109                 entity->variable.address_taken = true;
6110                 current_function->need_closure = true;
6111         }
6112
6113         check_deprecated(&pos, entity);
6114
6115         return expression;
6116 }
6117
6118 static bool semantic_cast(expression_t *cast)
6119 {
6120         expression_t            *expression      = cast->unary.value;
6121         type_t                  *orig_dest_type  = cast->base.type;
6122         type_t                  *orig_type_right = expression->base.type;
6123         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6124         type_t            const *src_type        = skip_typeref(orig_type_right);
6125         source_position_t const *pos             = &cast->base.source_position;
6126
6127         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6128         if (is_type_void(dst_type))
6129                 return true;
6130
6131         /* only integer and pointer can be casted to pointer */
6132         if (is_type_pointer(dst_type)  &&
6133             !is_type_pointer(src_type) &&
6134             !is_type_integer(src_type) &&
6135             is_type_valid(src_type)) {
6136                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6137                 return false;
6138         }
6139
6140         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6141                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6142                 return false;
6143         }
6144
6145         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6146                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6147                 return false;
6148         }
6149
6150         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6151                 type_t *src = skip_typeref(src_type->pointer.points_to);
6152                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6153                 unsigned missing_qualifiers =
6154                         src->base.qualifiers & ~dst->base.qualifiers;
6155                 if (missing_qualifiers != 0) {
6156                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6157                 }
6158         }
6159         return true;
6160 }
6161
6162 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6163 {
6164         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6165         expression->base.source_position = *pos;
6166
6167         parse_initializer_env_t env;
6168         env.type             = type;
6169         env.entity           = NULL;
6170         env.must_be_constant = false;
6171         initializer_t *initializer = parse_initializer(&env);
6172         type = env.type;
6173
6174         expression->compound_literal.initializer = initializer;
6175         expression->compound_literal.type        = type;
6176         expression->base.type                    = automatic_type_conversion(type);
6177
6178         return expression;
6179 }
6180
6181 /**
6182  * Parse a cast expression.
6183  */
6184 static expression_t *parse_cast(void)
6185 {
6186         source_position_t const pos = *HERE;
6187
6188         eat('(');
6189         add_anchor_token(')');
6190
6191         type_t *type = parse_typename();
6192
6193         rem_anchor_token(')');
6194         expect(')');
6195
6196         if (token.kind == '{') {
6197                 return parse_compound_literal(&pos, type);
6198         }
6199
6200         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6201         cast->base.source_position = pos;
6202
6203         expression_t *value = parse_subexpression(PREC_CAST);
6204         cast->base.type   = type;
6205         cast->unary.value = value;
6206
6207         if (! semantic_cast(cast)) {
6208                 /* TODO: record the error in the AST. else it is impossible to detect it */
6209         }
6210
6211         return cast;
6212 }
6213
6214 /**
6215  * Parse a statement expression.
6216  */
6217 static expression_t *parse_statement_expression(void)
6218 {
6219         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6220
6221         eat('(');
6222         add_anchor_token(')');
6223
6224         statement_t *statement          = parse_compound_statement(true);
6225         statement->compound.stmt_expr   = true;
6226         expression->statement.statement = statement;
6227
6228         /* find last statement and use its type */
6229         type_t *type = type_void;
6230         const statement_t *stmt = statement->compound.statements;
6231         if (stmt != NULL) {
6232                 while (stmt->base.next != NULL)
6233                         stmt = stmt->base.next;
6234
6235                 if (stmt->kind == STATEMENT_EXPRESSION) {
6236                         type = stmt->expression.expression->base.type;
6237                 }
6238         } else {
6239                 source_position_t const *const pos = &expression->base.source_position;
6240                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6241         }
6242         expression->base.type = type;
6243
6244         rem_anchor_token(')');
6245         expect(')');
6246         return expression;
6247 }
6248
6249 /**
6250  * Parse a parenthesized expression.
6251  */
6252 static expression_t *parse_parenthesized_expression(void)
6253 {
6254         token_t const* const la1 = look_ahead(1);
6255         switch (la1->kind) {
6256         case '{':
6257                 /* gcc extension: a statement expression */
6258                 return parse_statement_expression();
6259
6260         case T_IDENTIFIER:
6261                 if (is_typedef_symbol(la1->base.symbol)) {
6262         DECLARATION_START
6263                         return parse_cast();
6264                 }
6265         }
6266
6267         eat('(');
6268         add_anchor_token(')');
6269         expression_t *result = parse_expression();
6270         result->base.parenthesized = true;
6271         rem_anchor_token(')');
6272         expect(')');
6273
6274         return result;
6275 }
6276
6277 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6278 {
6279         if (current_function == NULL) {
6280                 errorf(HERE, "'%K' used outside of a function", &token);
6281         }
6282
6283         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6284         expression->base.type     = type_char_ptr;
6285         expression->funcname.kind = kind;
6286
6287         next_token();
6288
6289         return expression;
6290 }
6291
6292 static designator_t *parse_designator(void)
6293 {
6294         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6295         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6296         if (!result->symbol)
6297                 return NULL;
6298
6299         designator_t *last_designator = result;
6300         while (true) {
6301                 if (next_if('.')) {
6302                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6303                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6304                         if (!designator->symbol)
6305                                 return NULL;
6306
6307                         last_designator->next = designator;
6308                         last_designator       = designator;
6309                         continue;
6310                 }
6311                 if (next_if('[')) {
6312                         add_anchor_token(']');
6313                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6314                         designator->source_position = *HERE;
6315                         designator->array_index     = parse_expression();
6316                         rem_anchor_token(']');
6317                         expect(']');
6318                         if (designator->array_index == NULL) {
6319                                 return NULL;
6320                         }
6321
6322                         last_designator->next = designator;
6323                         last_designator       = designator;
6324                         continue;
6325                 }
6326                 break;
6327         }
6328
6329         return result;
6330 }
6331
6332 /**
6333  * Parse the __builtin_offsetof() expression.
6334  */
6335 static expression_t *parse_offsetof(void)
6336 {
6337         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6338         expression->base.type    = type_size_t;
6339
6340         eat(T___builtin_offsetof);
6341
6342         add_anchor_token(')');
6343         add_anchor_token(',');
6344         expect('(');
6345         type_t *type = parse_typename();
6346         rem_anchor_token(',');
6347         expect(',');
6348         designator_t *designator = parse_designator();
6349         rem_anchor_token(')');
6350         expect(')');
6351
6352         expression->offsetofe.type       = type;
6353         expression->offsetofe.designator = designator;
6354
6355         type_path_t path;
6356         memset(&path, 0, sizeof(path));
6357         path.top_type = type;
6358         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6359
6360         descend_into_subtype(&path);
6361
6362         if (!walk_designator(&path, designator, true)) {
6363                 return create_error_expression();
6364         }
6365
6366         DEL_ARR_F(path.path);
6367
6368         return expression;
6369 }
6370
6371 static bool is_last_parameter(expression_t *const param)
6372 {
6373         if (param->kind == EXPR_REFERENCE) {
6374                 entity_t *const entity = param->reference.entity;
6375                 if (entity->kind == ENTITY_PARAMETER &&
6376                     !entity->base.next               &&
6377                     entity->base.parent_scope == &current_function->parameters) {
6378                         return true;
6379                 }
6380         }
6381
6382         if (!is_type_valid(skip_typeref(param->base.type)))
6383                 return true;
6384
6385         return false;
6386 }
6387
6388 /**
6389  * Parses a __builtin_va_start() expression.
6390  */
6391 static expression_t *parse_va_start(void)
6392 {
6393         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6394
6395         eat(T___builtin_va_start);
6396
6397         add_anchor_token(')');
6398         add_anchor_token(',');
6399         expect('(');
6400         expression->va_starte.ap = parse_assignment_expression();
6401         rem_anchor_token(',');
6402         expect(',');
6403         expression_t *const param = parse_assignment_expression();
6404         expression->va_starte.parameter = param;
6405         rem_anchor_token(')');
6406         expect(')');
6407
6408         if (!current_function) {
6409                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6410         } else if (!current_function->base.type->function.variadic) {
6411                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6412         } else if (!is_last_parameter(param)) {
6413                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6414         }
6415
6416         return expression;
6417 }
6418
6419 /**
6420  * Parses a __builtin_va_arg() expression.
6421  */
6422 static expression_t *parse_va_arg(void)
6423 {
6424         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6425
6426         eat(T___builtin_va_arg);
6427
6428         add_anchor_token(')');
6429         add_anchor_token(',');
6430         expect('(');
6431         call_argument_t ap;
6432         ap.expression = parse_assignment_expression();
6433         expression->va_arge.ap = ap.expression;
6434         check_call_argument(type_valist, &ap, 1);
6435
6436         rem_anchor_token(',');
6437         expect(',');
6438         expression->base.type = parse_typename();
6439         rem_anchor_token(')');
6440         expect(')');
6441
6442         return expression;
6443 }
6444
6445 /**
6446  * Parses a __builtin_va_copy() expression.
6447  */
6448 static expression_t *parse_va_copy(void)
6449 {
6450         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6451
6452         eat(T___builtin_va_copy);
6453
6454         add_anchor_token(')');
6455         add_anchor_token(',');
6456         expect('(');
6457         expression_t *dst = parse_assignment_expression();
6458         assign_error_t error = semantic_assign(type_valist, dst);
6459         report_assign_error(error, type_valist, dst, "call argument 1",
6460                             &dst->base.source_position);
6461         expression->va_copye.dst = dst;
6462
6463         rem_anchor_token(',');
6464         expect(',');
6465
6466         call_argument_t src;
6467         src.expression = parse_assignment_expression();
6468         check_call_argument(type_valist, &src, 2);
6469         expression->va_copye.src = src.expression;
6470         rem_anchor_token(')');
6471         expect(')');
6472
6473         return expression;
6474 }
6475
6476 /**
6477  * Parses a __builtin_constant_p() expression.
6478  */
6479 static expression_t *parse_builtin_constant(void)
6480 {
6481         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6482
6483         eat(T___builtin_constant_p);
6484
6485         add_anchor_token(')');
6486         expect('(');
6487         expression->builtin_constant.value = parse_assignment_expression();
6488         rem_anchor_token(')');
6489         expect(')');
6490         expression->base.type = type_int;
6491
6492         return expression;
6493 }
6494
6495 /**
6496  * Parses a __builtin_types_compatible_p() expression.
6497  */
6498 static expression_t *parse_builtin_types_compatible(void)
6499 {
6500         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6501
6502         eat(T___builtin_types_compatible_p);
6503
6504         add_anchor_token(')');
6505         add_anchor_token(',');
6506         expect('(');
6507         expression->builtin_types_compatible.left = parse_typename();
6508         rem_anchor_token(',');
6509         expect(',');
6510         expression->builtin_types_compatible.right = parse_typename();
6511         rem_anchor_token(')');
6512         expect(')');
6513         expression->base.type = type_int;
6514
6515         return expression;
6516 }
6517
6518 /**
6519  * Parses a __builtin_is_*() compare expression.
6520  */
6521 static expression_t *parse_compare_builtin(void)
6522 {
6523         expression_kind_t kind;
6524         switch (token.kind) {
6525         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6526         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6527         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6528         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6529         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6530         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6531         default: internal_errorf(HERE, "invalid compare builtin found");
6532         }
6533         expression_t *const expression = allocate_expression_zero(kind);
6534         next_token();
6535
6536         add_anchor_token(')');
6537         add_anchor_token(',');
6538         expect('(');
6539         expression->binary.left = parse_assignment_expression();
6540         rem_anchor_token(',');
6541         expect(',');
6542         expression->binary.right = parse_assignment_expression();
6543         rem_anchor_token(')');
6544         expect(')');
6545
6546         type_t *const orig_type_left  = expression->binary.left->base.type;
6547         type_t *const orig_type_right = expression->binary.right->base.type;
6548
6549         type_t *const type_left  = skip_typeref(orig_type_left);
6550         type_t *const type_right = skip_typeref(orig_type_right);
6551         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6552                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6553                         type_error_incompatible("invalid operands in comparison",
6554                                 &expression->base.source_position, orig_type_left, orig_type_right);
6555                 }
6556         } else {
6557                 semantic_comparison(&expression->binary);
6558         }
6559
6560         return expression;
6561 }
6562
6563 /**
6564  * Parses a MS assume() expression.
6565  */
6566 static expression_t *parse_assume(void)
6567 {
6568         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6569
6570         eat(T__assume);
6571
6572         add_anchor_token(')');
6573         expect('(');
6574         expression->unary.value = parse_assignment_expression();
6575         rem_anchor_token(')');
6576         expect(')');
6577
6578         expression->base.type = type_void;
6579         return expression;
6580 }
6581
6582 /**
6583  * Return the label for the current symbol or create a new one.
6584  */
6585 static label_t *get_label(char const *const context)
6586 {
6587         assert(current_function != NULL);
6588
6589         symbol_t *const sym = expect_identifier(context, NULL);
6590         if (!sym)
6591                 return NULL;
6592
6593         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6594         /* If we find a local label, we already created the declaration. */
6595         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6596                 if (label->base.parent_scope != current_scope) {
6597                         assert(label->base.parent_scope->depth < current_scope->depth);
6598                         current_function->goto_to_outer = true;
6599                 }
6600         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6601                 /* There is no matching label in the same function, so create a new one. */
6602                 source_position_t const nowhere = { NULL, 0, 0, false };
6603                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6604                 label_push(label);
6605         }
6606
6607         return &label->label;
6608 }
6609
6610 /**
6611  * Parses a GNU && label address expression.
6612  */
6613 static expression_t *parse_label_address(void)
6614 {
6615         source_position_t const source_position = *HERE;
6616         eat(T_ANDAND);
6617
6618         label_t *const label = get_label("while parsing label address");
6619         if (!label)
6620                 return create_error_expression();
6621
6622         label->used          = true;
6623         label->address_taken = true;
6624
6625         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6626         expression->base.source_position = source_position;
6627
6628         /* label address is treated as a void pointer */
6629         expression->base.type           = type_void_ptr;
6630         expression->label_address.label = label;
6631         return expression;
6632 }
6633
6634 /**
6635  * Parse a microsoft __noop expression.
6636  */
6637 static expression_t *parse_noop_expression(void)
6638 {
6639         /* the result is a (int)0 */
6640         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6641         literal->base.type           = type_int;
6642         literal->literal.value.begin = "__noop";
6643         literal->literal.value.size  = 6;
6644
6645         eat(T___noop);
6646
6647         if (token.kind == '(') {
6648                 /* parse arguments */
6649                 eat('(');
6650                 add_anchor_token(')');
6651                 add_anchor_token(',');
6652
6653                 if (token.kind != ')') do {
6654                         (void)parse_assignment_expression();
6655                 } while (next_if(','));
6656
6657                 rem_anchor_token(',');
6658                 rem_anchor_token(')');
6659         }
6660         expect(')');
6661
6662         return literal;
6663 }
6664
6665 /**
6666  * Parses a primary expression.
6667  */
6668 static expression_t *parse_primary_expression(void)
6669 {
6670         switch (token.kind) {
6671         case T_false:                        return parse_boolean_literal(false);
6672         case T_true:                         return parse_boolean_literal(true);
6673         case T_INTEGER:
6674         case T_FLOATINGPOINT:                return parse_number_literal();
6675         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6676         case T_STRING_LITERAL:               return parse_string_literal();
6677         case T___FUNCTION__:
6678         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6679         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6680         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6681         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6682         case T___builtin_offsetof:           return parse_offsetof();
6683         case T___builtin_va_start:           return parse_va_start();
6684         case T___builtin_va_arg:             return parse_va_arg();
6685         case T___builtin_va_copy:            return parse_va_copy();
6686         case T___builtin_isgreater:
6687         case T___builtin_isgreaterequal:
6688         case T___builtin_isless:
6689         case T___builtin_islessequal:
6690         case T___builtin_islessgreater:
6691         case T___builtin_isunordered:        return parse_compare_builtin();
6692         case T___builtin_constant_p:         return parse_builtin_constant();
6693         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6694         case T__assume:                      return parse_assume();
6695         case T_ANDAND:
6696                 if (GNU_MODE)
6697                         return parse_label_address();
6698                 break;
6699
6700         case '(':                            return parse_parenthesized_expression();
6701         case T___noop:                       return parse_noop_expression();
6702
6703         /* Gracefully handle type names while parsing expressions. */
6704         case T_COLONCOLON:
6705                 return parse_reference();
6706         case T_IDENTIFIER:
6707                 if (!is_typedef_symbol(token.base.symbol)) {
6708                         return parse_reference();
6709                 }
6710                 /* FALLTHROUGH */
6711         DECLARATION_START {
6712                 source_position_t const  pos = *HERE;
6713                 declaration_specifiers_t specifiers;
6714                 parse_declaration_specifiers(&specifiers);
6715                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6716                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6717                 return create_error_expression();
6718         }
6719         }
6720
6721         errorf(HERE, "unexpected token %K, expected an expression", &token);
6722         eat_until_anchor();
6723         return create_error_expression();
6724 }
6725
6726 static expression_t *parse_array_expression(expression_t *left)
6727 {
6728         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6729         array_access_expression_t *const arr  = &expr->array_access;
6730
6731         eat('[');
6732         add_anchor_token(']');
6733
6734         expression_t *const inside = parse_expression();
6735
6736         type_t *const orig_type_left   = left->base.type;
6737         type_t *const orig_type_inside = inside->base.type;
6738
6739         type_t *const type_left   = skip_typeref(orig_type_left);
6740         type_t *const type_inside = skip_typeref(orig_type_inside);
6741
6742         expression_t *ref;
6743         expression_t *idx;
6744         type_t       *idx_type;
6745         type_t       *res_type;
6746         if (is_type_pointer(type_left)) {
6747                 ref      = left;
6748                 idx      = inside;
6749                 idx_type = type_inside;
6750                 res_type = type_left->pointer.points_to;
6751                 goto check_idx;
6752         } else if (is_type_pointer(type_inside)) {
6753                 arr->flipped = true;
6754                 ref      = inside;
6755                 idx      = left;
6756                 idx_type = type_left;
6757                 res_type = type_inside->pointer.points_to;
6758 check_idx:
6759                 res_type = automatic_type_conversion(res_type);
6760                 if (!is_type_integer(idx_type)) {
6761                         errorf(&idx->base.source_position, "array subscript must have integer type");
6762                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6763                         source_position_t const *const pos = &idx->base.source_position;
6764                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6765                 }
6766         } else {
6767                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6768                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6769                 }
6770                 res_type = type_error_type;
6771                 ref      = left;
6772                 idx      = inside;
6773         }
6774
6775         arr->array_ref = ref;
6776         arr->index     = idx;
6777         arr->base.type = res_type;
6778
6779         rem_anchor_token(']');
6780         expect(']');
6781         return expr;
6782 }
6783
6784 static bool is_bitfield(const expression_t *expression)
6785 {
6786         return expression->kind == EXPR_SELECT
6787                 && expression->select.compound_entry->compound_member.bitfield;
6788 }
6789
6790 static expression_t *parse_typeprop(expression_kind_t const kind)
6791 {
6792         expression_t  *tp_expression = allocate_expression_zero(kind);
6793         tp_expression->base.type     = type_size_t;
6794
6795         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6796
6797         type_t       *orig_type;
6798         expression_t *expression;
6799         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6800                 source_position_t const pos = *HERE;
6801                 eat('(');
6802                 add_anchor_token(')');
6803                 orig_type = parse_typename();
6804                 rem_anchor_token(')');
6805                 expect(')');
6806
6807                 if (token.kind == '{') {
6808                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6809                          * starting with a compound literal */
6810                         expression = parse_compound_literal(&pos, orig_type);
6811                         goto typeprop_expression;
6812                 }
6813         } else {
6814                 expression = parse_subexpression(PREC_UNARY);
6815
6816 typeprop_expression:
6817                 if (is_bitfield(expression)) {
6818                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6819                         errorf(&tp_expression->base.source_position,
6820                                    "operand of %s expression must not be a bitfield", what);
6821                 }
6822
6823                 tp_expression->typeprop.tp_expression = expression;
6824
6825                 orig_type = revert_automatic_type_conversion(expression);
6826                 expression->base.type = orig_type;
6827         }
6828
6829         tp_expression->typeprop.type   = orig_type;
6830         type_t const* const type       = skip_typeref(orig_type);
6831         char   const*       wrong_type = NULL;
6832         if (is_type_incomplete(type)) {
6833                 if (!is_type_void(type) || !GNU_MODE)
6834                         wrong_type = "incomplete";
6835         } else if (type->kind == TYPE_FUNCTION) {
6836                 if (GNU_MODE) {
6837                         /* function types are allowed (and return 1) */
6838                         source_position_t const *const pos  = &tp_expression->base.source_position;
6839                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6840                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6841                 } else {
6842                         wrong_type = "function";
6843                 }
6844         }
6845
6846         if (wrong_type != NULL) {
6847                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6848                 errorf(&tp_expression->base.source_position,
6849                                 "operand of %s expression must not be of %s type '%T'",
6850                                 what, wrong_type, orig_type);
6851         }
6852
6853         return tp_expression;
6854 }
6855
6856 static expression_t *parse_sizeof(void)
6857 {
6858         return parse_typeprop(EXPR_SIZEOF);
6859 }
6860
6861 static expression_t *parse_alignof(void)
6862 {
6863         return parse_typeprop(EXPR_ALIGNOF);
6864 }
6865
6866 static expression_t *parse_select_expression(expression_t *addr)
6867 {
6868         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6869         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6870         source_position_t const pos = *HERE;
6871         next_token();
6872
6873         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6874         if (!symbol)
6875                 return create_error_expression();
6876
6877         type_t *const orig_type = addr->base.type;
6878         type_t *const type      = skip_typeref(orig_type);
6879
6880         type_t *type_left;
6881         bool    saw_error = false;
6882         if (is_type_pointer(type)) {
6883                 if (!select_left_arrow) {
6884                         errorf(&pos,
6885                                "request for member '%Y' in something not a struct or union, but '%T'",
6886                                symbol, orig_type);
6887                         saw_error = true;
6888                 }
6889                 type_left = skip_typeref(type->pointer.points_to);
6890         } else {
6891                 if (select_left_arrow && is_type_valid(type)) {
6892                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6893                         saw_error = true;
6894                 }
6895                 type_left = type;
6896         }
6897
6898         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6899             type_left->kind != TYPE_COMPOUND_UNION) {
6900
6901                 if (is_type_valid(type_left) && !saw_error) {
6902                         errorf(&pos,
6903                                "request for member '%Y' in something not a struct or union, but '%T'",
6904                                symbol, type_left);
6905                 }
6906                 return create_error_expression();
6907         }
6908
6909         compound_t *compound = type_left->compound.compound;
6910         if (!compound->complete) {
6911                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6912                        symbol, type_left);
6913                 return create_error_expression();
6914         }
6915
6916         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6917         expression_t      *result     =
6918                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6919
6920         if (result == NULL) {
6921                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6922                 return create_error_expression();
6923         }
6924
6925         return result;
6926 }
6927
6928 static void check_call_argument(type_t          *expected_type,
6929                                 call_argument_t *argument, unsigned pos)
6930 {
6931         type_t         *expected_type_skip = skip_typeref(expected_type);
6932         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6933         expression_t   *arg_expr           = argument->expression;
6934         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6935
6936         /* handle transparent union gnu extension */
6937         if (is_type_union(expected_type_skip)
6938                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6939                 compound_t *union_decl  = expected_type_skip->compound.compound;
6940                 type_t     *best_type   = NULL;
6941                 entity_t   *entry       = union_decl->members.entities;
6942                 for ( ; entry != NULL; entry = entry->base.next) {
6943                         assert(is_declaration(entry));
6944                         type_t *decl_type = entry->declaration.type;
6945                         error = semantic_assign(decl_type, arg_expr);
6946                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6947                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6948                                 continue;
6949
6950                         if (error == ASSIGN_SUCCESS) {
6951                                 best_type = decl_type;
6952                         } else if (best_type == NULL) {
6953                                 best_type = decl_type;
6954                         }
6955                 }
6956
6957                 if (best_type != NULL) {
6958                         expected_type = best_type;
6959                 }
6960         }
6961
6962         error                = semantic_assign(expected_type, arg_expr);
6963         argument->expression = create_implicit_cast(arg_expr, expected_type);
6964
6965         if (error != ASSIGN_SUCCESS) {
6966                 /* report exact scope in error messages (like "in argument 3") */
6967                 char buf[64];
6968                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6969                 report_assign_error(error, expected_type, arg_expr, buf,
6970                                     &arg_expr->base.source_position);
6971         } else {
6972                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6973                 if (!types_compatible(expected_type_skip, promoted_type) &&
6974                     !types_compatible(expected_type_skip, type_void_ptr) &&
6975                     !types_compatible(type_void_ptr,      promoted_type)) {
6976                         /* Deliberately show the skipped types in this warning */
6977                         source_position_t const *const apos = &arg_expr->base.source_position;
6978                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6979                 }
6980         }
6981 }
6982
6983 /**
6984  * Handle the semantic restrictions of builtin calls
6985  */
6986 static void handle_builtin_argument_restrictions(call_expression_t *call)
6987 {
6988         entity_t *entity = call->function->reference.entity;
6989         switch (entity->function.btk) {
6990         case BUILTIN_FIRM:
6991                 switch (entity->function.b.firm_builtin_kind) {
6992                 case ir_bk_return_address:
6993                 case ir_bk_frame_address: {
6994                         /* argument must be constant */
6995                         call_argument_t *argument = call->arguments;
6996
6997                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6998                                 errorf(&call->base.source_position,
6999                                            "argument of '%Y' must be a constant expression",
7000                                            call->function->reference.entity->base.symbol);
7001                         }
7002                         break;
7003                 }
7004                 case ir_bk_prefetch:
7005                         /* second and third argument must be constant if existent */
7006                         if (call->arguments == NULL)
7007                                 break;
7008                         call_argument_t *rw = call->arguments->next;
7009                         call_argument_t *locality = NULL;
7010
7011                         if (rw != NULL) {
7012                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7013                                         errorf(&call->base.source_position,
7014                                                    "second argument of '%Y' must be a constant expression",
7015                                                    call->function->reference.entity->base.symbol);
7016                                 }
7017                                 locality = rw->next;
7018                         }
7019                         if (locality != NULL) {
7020                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7021                                         errorf(&call->base.source_position,
7022                                                    "third argument of '%Y' must be a constant expression",
7023                                                    call->function->reference.entity->base.symbol);
7024                                 }
7025                                 locality = rw->next;
7026                         }
7027                         break;
7028                 default:
7029                         break;
7030                 }
7031
7032         case BUILTIN_OBJECT_SIZE:
7033                 if (call->arguments == NULL)
7034                         break;
7035
7036                 call_argument_t *arg = call->arguments->next;
7037                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7038                         errorf(&call->base.source_position,
7039                                    "second argument of '%Y' must be a constant expression",
7040                                    call->function->reference.entity->base.symbol);
7041                 }
7042                 break;
7043         default:
7044                 break;
7045         }
7046 }
7047
7048 /**
7049  * Parse a call expression, ie. expression '( ... )'.
7050  *
7051  * @param expression  the function address
7052  */
7053 static expression_t *parse_call_expression(expression_t *expression)
7054 {
7055         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7056         call_expression_t *call   = &result->call;
7057         call->function            = expression;
7058
7059         type_t *const orig_type = expression->base.type;
7060         type_t *const type      = skip_typeref(orig_type);
7061
7062         function_type_t *function_type = NULL;
7063         if (is_type_pointer(type)) {
7064                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7065
7066                 if (is_type_function(to_type)) {
7067                         function_type   = &to_type->function;
7068                         call->base.type = function_type->return_type;
7069                 }
7070         }
7071
7072         if (function_type == NULL && is_type_valid(type)) {
7073                 errorf(HERE,
7074                        "called object '%E' (type '%T') is not a pointer to a function",
7075                        expression, orig_type);
7076         }
7077
7078         /* parse arguments */
7079         eat('(');
7080         add_anchor_token(')');
7081         add_anchor_token(',');
7082
7083         if (token.kind != ')') {
7084                 call_argument_t **anchor = &call->arguments;
7085                 do {
7086                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7087                         argument->expression = parse_assignment_expression();
7088
7089                         *anchor = argument;
7090                         anchor  = &argument->next;
7091                 } while (next_if(','));
7092         }
7093         rem_anchor_token(',');
7094         rem_anchor_token(')');
7095         expect(')');
7096
7097         if (function_type == NULL)
7098                 return result;
7099
7100         /* check type and count of call arguments */
7101         function_parameter_t *parameter = function_type->parameters;
7102         call_argument_t      *argument  = call->arguments;
7103         if (!function_type->unspecified_parameters) {
7104                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7105                                 parameter = parameter->next, argument = argument->next) {
7106                         check_call_argument(parameter->type, argument, ++pos);
7107                 }
7108
7109                 if (parameter != NULL) {
7110                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7111                 } else if (argument != NULL && !function_type->variadic) {
7112                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7113                 }
7114         }
7115
7116         /* do default promotion for other arguments */
7117         for (; argument != NULL; argument = argument->next) {
7118                 type_t *argument_type = argument->expression->base.type;
7119                 if (!is_type_object(skip_typeref(argument_type))) {
7120                         errorf(&argument->expression->base.source_position,
7121                                "call argument '%E' must not be void", argument->expression);
7122                 }
7123
7124                 argument_type = get_default_promoted_type(argument_type);
7125
7126                 argument->expression
7127                         = create_implicit_cast(argument->expression, argument_type);
7128         }
7129
7130         check_format(call);
7131
7132         if (is_type_compound(skip_typeref(function_type->return_type))) {
7133                 source_position_t const *const pos = &expression->base.source_position;
7134                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7135         }
7136
7137         if (expression->kind == EXPR_REFERENCE) {
7138                 reference_expression_t *reference = &expression->reference;
7139                 if (reference->entity->kind == ENTITY_FUNCTION &&
7140                     reference->entity->function.btk != BUILTIN_NONE)
7141                         handle_builtin_argument_restrictions(call);
7142         }
7143
7144         return result;
7145 }
7146
7147 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7148
7149 static bool same_compound_type(const type_t *type1, const type_t *type2)
7150 {
7151         return
7152                 is_type_compound(type1) &&
7153                 type1->kind == type2->kind &&
7154                 type1->compound.compound == type2->compound.compound;
7155 }
7156
7157 static expression_t const *get_reference_address(expression_t const *expr)
7158 {
7159         bool regular_take_address = true;
7160         for (;;) {
7161                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7162                         expr = expr->unary.value;
7163                 } else {
7164                         regular_take_address = false;
7165                 }
7166
7167                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7168                         break;
7169
7170                 expr = expr->unary.value;
7171         }
7172
7173         if (expr->kind != EXPR_REFERENCE)
7174                 return NULL;
7175
7176         /* special case for functions which are automatically converted to a
7177          * pointer to function without an extra TAKE_ADDRESS operation */
7178         if (!regular_take_address &&
7179                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7180                 return NULL;
7181         }
7182
7183         return expr;
7184 }
7185
7186 static void warn_reference_address_as_bool(expression_t const* expr)
7187 {
7188         expr = get_reference_address(expr);
7189         if (expr != NULL) {
7190                 source_position_t const *const pos = &expr->base.source_position;
7191                 entity_t          const *const ent = expr->reference.entity;
7192                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7193         }
7194 }
7195
7196 static void warn_assignment_in_condition(const expression_t *const expr)
7197 {
7198         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7199                 return;
7200         if (expr->base.parenthesized)
7201                 return;
7202         source_position_t const *const pos = &expr->base.source_position;
7203         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7204 }
7205
7206 static void semantic_condition(expression_t const *const expr,
7207                                char const *const context)
7208 {
7209         type_t *const type = skip_typeref(expr->base.type);
7210         if (is_type_scalar(type)) {
7211                 warn_reference_address_as_bool(expr);
7212                 warn_assignment_in_condition(expr);
7213         } else if (is_type_valid(type)) {
7214                 errorf(&expr->base.source_position,
7215                                 "%s must have scalar type", context);
7216         }
7217 }
7218
7219 /**
7220  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7221  *
7222  * @param expression  the conditional expression
7223  */
7224 static expression_t *parse_conditional_expression(expression_t *expression)
7225 {
7226         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7227
7228         conditional_expression_t *conditional = &result->conditional;
7229         conditional->condition                = expression;
7230
7231         eat('?');
7232         add_anchor_token(':');
7233
7234         /* §6.5.15:2  The first operand shall have scalar type. */
7235         semantic_condition(expression, "condition of conditional operator");
7236
7237         expression_t *true_expression = expression;
7238         bool          gnu_cond = false;
7239         if (GNU_MODE && token.kind == ':') {
7240                 gnu_cond = true;
7241         } else {
7242                 true_expression = parse_expression();
7243         }
7244         rem_anchor_token(':');
7245         expect(':');
7246         expression_t *false_expression =
7247                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7248
7249         type_t *const orig_true_type  = true_expression->base.type;
7250         type_t *const orig_false_type = false_expression->base.type;
7251         type_t *const true_type       = skip_typeref(orig_true_type);
7252         type_t *const false_type      = skip_typeref(orig_false_type);
7253
7254         /* 6.5.15.3 */
7255         source_position_t const *const pos = &conditional->base.source_position;
7256         type_t                        *result_type;
7257         if (is_type_void(true_type) || is_type_void(false_type)) {
7258                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7259                 if (true_expression->kind == EXPR_UNARY_THROW) {
7260                         result_type = false_type;
7261                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7262                         result_type = true_type;
7263                 } else {
7264                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7265                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7266                         }
7267                         result_type = type_void;
7268                 }
7269         } else if (is_type_arithmetic(true_type)
7270                    && is_type_arithmetic(false_type)) {
7271                 result_type = semantic_arithmetic(true_type, false_type);
7272         } else if (same_compound_type(true_type, false_type)) {
7273                 /* just take 1 of the 2 types */
7274                 result_type = true_type;
7275         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7276                 type_t *pointer_type;
7277                 type_t *other_type;
7278                 expression_t *other_expression;
7279                 if (is_type_pointer(true_type) &&
7280                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7281                         pointer_type     = true_type;
7282                         other_type       = false_type;
7283                         other_expression = false_expression;
7284                 } else {
7285                         pointer_type     = false_type;
7286                         other_type       = true_type;
7287                         other_expression = true_expression;
7288                 }
7289
7290                 if (is_null_pointer_constant(other_expression)) {
7291                         result_type = pointer_type;
7292                 } else if (is_type_pointer(other_type)) {
7293                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7294                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7295
7296                         type_t *to;
7297                         if (is_type_void(to1) || is_type_void(to2)) {
7298                                 to = type_void;
7299                         } else if (types_compatible(get_unqualified_type(to1),
7300                                                     get_unqualified_type(to2))) {
7301                                 to = to1;
7302                         } else {
7303                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7304                                 to = type_void;
7305                         }
7306
7307                         type_t *const type =
7308                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7309                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7310                 } else if (is_type_integer(other_type)) {
7311                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7312                         result_type = pointer_type;
7313                 } else {
7314                         goto types_incompatible;
7315                 }
7316         } else {
7317 types_incompatible:
7318                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7319                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7320                 }
7321                 result_type = type_error_type;
7322         }
7323
7324         conditional->true_expression
7325                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7326         conditional->false_expression
7327                 = create_implicit_cast(false_expression, result_type);
7328         conditional->base.type = result_type;
7329         return result;
7330 }
7331
7332 /**
7333  * Parse an extension expression.
7334  */
7335 static expression_t *parse_extension(void)
7336 {
7337         PUSH_EXTENSION();
7338         expression_t *expression = parse_subexpression(PREC_UNARY);
7339         POP_EXTENSION();
7340         return expression;
7341 }
7342
7343 /**
7344  * Parse a __builtin_classify_type() expression.
7345  */
7346 static expression_t *parse_builtin_classify_type(void)
7347 {
7348         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7349         result->base.type    = type_int;
7350
7351         eat(T___builtin_classify_type);
7352
7353         add_anchor_token(')');
7354         expect('(');
7355         expression_t *expression = parse_expression();
7356         rem_anchor_token(')');
7357         expect(')');
7358         result->classify_type.type_expression = expression;
7359
7360         return result;
7361 }
7362
7363 /**
7364  * Parse a delete expression
7365  * ISO/IEC 14882:1998(E) §5.3.5
7366  */
7367 static expression_t *parse_delete(void)
7368 {
7369         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7370         result->base.type          = type_void;
7371
7372         eat(T_delete);
7373
7374         if (next_if('[')) {
7375                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7376                 expect(']');
7377         }
7378
7379         expression_t *const value = parse_subexpression(PREC_CAST);
7380         result->unary.value = value;
7381
7382         type_t *const type = skip_typeref(value->base.type);
7383         if (!is_type_pointer(type)) {
7384                 if (is_type_valid(type)) {
7385                         errorf(&value->base.source_position,
7386                                         "operand of delete must have pointer type");
7387                 }
7388         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7389                 source_position_t const *const pos = &value->base.source_position;
7390                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7391         }
7392
7393         return result;
7394 }
7395
7396 /**
7397  * Parse a throw expression
7398  * ISO/IEC 14882:1998(E) §15:1
7399  */
7400 static expression_t *parse_throw(void)
7401 {
7402         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7403         result->base.type          = type_void;
7404
7405         eat(T_throw);
7406
7407         expression_t *value = NULL;
7408         switch (token.kind) {
7409                 EXPRESSION_START {
7410                         value = parse_assignment_expression();
7411                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7412                         type_t *const orig_type = value->base.type;
7413                         type_t *const type      = skip_typeref(orig_type);
7414                         if (is_type_incomplete(type)) {
7415                                 errorf(&value->base.source_position,
7416                                                 "cannot throw object of incomplete type '%T'", orig_type);
7417                         } else if (is_type_pointer(type)) {
7418                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7419                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7420                                         errorf(&value->base.source_position,
7421                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7422                                 }
7423                         }
7424                 }
7425
7426                 default:
7427                         break;
7428         }
7429         result->unary.value = value;
7430
7431         return result;
7432 }
7433
7434 static bool check_pointer_arithmetic(const source_position_t *source_position,
7435                                      type_t *pointer_type,
7436                                      type_t *orig_pointer_type)
7437 {
7438         type_t *points_to = pointer_type->pointer.points_to;
7439         points_to = skip_typeref(points_to);
7440
7441         if (is_type_incomplete(points_to)) {
7442                 if (!GNU_MODE || !is_type_void(points_to)) {
7443                         errorf(source_position,
7444                                "arithmetic with pointer to incomplete type '%T' not allowed",
7445                                orig_pointer_type);
7446                         return false;
7447                 } else {
7448                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7449                 }
7450         } else if (is_type_function(points_to)) {
7451                 if (!GNU_MODE) {
7452                         errorf(source_position,
7453                                "arithmetic with pointer to function type '%T' not allowed",
7454                                orig_pointer_type);
7455                         return false;
7456                 } else {
7457                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7458                 }
7459         }
7460         return true;
7461 }
7462
7463 static bool is_lvalue(const expression_t *expression)
7464 {
7465         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7466         switch (expression->kind) {
7467         case EXPR_ARRAY_ACCESS:
7468         case EXPR_COMPOUND_LITERAL:
7469         case EXPR_REFERENCE:
7470         case EXPR_SELECT:
7471         case EXPR_UNARY_DEREFERENCE:
7472                 return true;
7473
7474         default: {
7475                 type_t *type = skip_typeref(expression->base.type);
7476                 return
7477                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7478                         is_type_reference(type) ||
7479                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7480                          * error before, which maybe prevented properly recognizing it as
7481                          * lvalue. */
7482                         !is_type_valid(type);
7483         }
7484         }
7485 }
7486
7487 static void semantic_incdec(unary_expression_t *expression)
7488 {
7489         type_t *const orig_type = expression->value->base.type;
7490         type_t *const type      = skip_typeref(orig_type);
7491         if (is_type_pointer(type)) {
7492                 if (!check_pointer_arithmetic(&expression->base.source_position,
7493                                               type, orig_type)) {
7494                         return;
7495                 }
7496         } else if (!is_type_real(type) && is_type_valid(type)) {
7497                 /* TODO: improve error message */
7498                 errorf(&expression->base.source_position,
7499                        "operation needs an arithmetic or pointer type");
7500                 return;
7501         }
7502         if (!is_lvalue(expression->value)) {
7503                 /* TODO: improve error message */
7504                 errorf(&expression->base.source_position, "lvalue required as operand");
7505         }
7506         expression->base.type = orig_type;
7507 }
7508
7509 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7510 {
7511         type_t *const res_type = promote_integer(type);
7512         expr->base.type = res_type;
7513         expr->value     = create_implicit_cast(expr->value, res_type);
7514 }
7515
7516 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7517 {
7518         type_t *const orig_type = expression->value->base.type;
7519         type_t *const type      = skip_typeref(orig_type);
7520         if (!is_type_arithmetic(type)) {
7521                 if (is_type_valid(type)) {
7522                         /* TODO: improve error message */
7523                         errorf(&expression->base.source_position,
7524                                 "operation needs an arithmetic type");
7525                 }
7526                 return;
7527         } else if (is_type_integer(type)) {
7528                 promote_unary_int_expr(expression, type);
7529         } else {
7530                 expression->base.type = orig_type;
7531         }
7532 }
7533
7534 static void semantic_unexpr_plus(unary_expression_t *expression)
7535 {
7536         semantic_unexpr_arithmetic(expression);
7537         source_position_t const *const pos = &expression->base.source_position;
7538         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7539 }
7540
7541 static void semantic_not(unary_expression_t *expression)
7542 {
7543         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7544         semantic_condition(expression->value, "operand of !");
7545         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7546 }
7547
7548 static void semantic_unexpr_integer(unary_expression_t *expression)
7549 {
7550         type_t *const orig_type = expression->value->base.type;
7551         type_t *const type      = skip_typeref(orig_type);
7552         if (!is_type_integer(type)) {
7553                 if (is_type_valid(type)) {
7554                         errorf(&expression->base.source_position,
7555                                "operand of ~ must be of integer type");
7556                 }
7557                 return;
7558         }
7559
7560         promote_unary_int_expr(expression, type);
7561 }
7562
7563 static void semantic_dereference(unary_expression_t *expression)
7564 {
7565         type_t *const orig_type = expression->value->base.type;
7566         type_t *const type      = skip_typeref(orig_type);
7567         if (!is_type_pointer(type)) {
7568                 if (is_type_valid(type)) {
7569                         errorf(&expression->base.source_position,
7570                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7571                 }
7572                 return;
7573         }
7574
7575         type_t *result_type   = type->pointer.points_to;
7576         result_type           = automatic_type_conversion(result_type);
7577         expression->base.type = result_type;
7578 }
7579
7580 /**
7581  * Record that an address is taken (expression represents an lvalue).
7582  *
7583  * @param expression       the expression
7584  * @param may_be_register  if true, the expression might be an register
7585  */
7586 static void set_address_taken(expression_t *expression, bool may_be_register)
7587 {
7588         if (expression->kind != EXPR_REFERENCE)
7589                 return;
7590
7591         entity_t *const entity = expression->reference.entity;
7592
7593         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7594                 return;
7595
7596         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7597                         && !may_be_register) {
7598                 source_position_t const *const pos = &expression->base.source_position;
7599                 errorf(pos, "address of register '%N' requested", entity);
7600         }
7601
7602         entity->variable.address_taken = true;
7603 }
7604
7605 /**
7606  * Check the semantic of the address taken expression.
7607  */
7608 static void semantic_take_addr(unary_expression_t *expression)
7609 {
7610         expression_t *value = expression->value;
7611         value->base.type    = revert_automatic_type_conversion(value);
7612
7613         type_t *orig_type = value->base.type;
7614         type_t *type      = skip_typeref(orig_type);
7615         if (!is_type_valid(type))
7616                 return;
7617
7618         /* §6.5.3.2 */
7619         if (!is_lvalue(value)) {
7620                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7621         }
7622         if (is_bitfield(value)) {
7623                 errorf(&expression->base.source_position,
7624                        "'&' not allowed on bitfield");
7625         }
7626
7627         set_address_taken(value, false);
7628
7629         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7630 }
7631
7632 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7633 static expression_t *parse_##unexpression_type(void)                         \
7634 {                                                                            \
7635         expression_t *unary_expression                                           \
7636                 = allocate_expression_zero(unexpression_type);                       \
7637         eat(token_kind);                                                         \
7638         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7639                                                                                  \
7640         sfunc(&unary_expression->unary);                                         \
7641                                                                                  \
7642         return unary_expression;                                                 \
7643 }
7644
7645 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7646                                semantic_unexpr_arithmetic)
7647 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7648                                semantic_unexpr_plus)
7649 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7650                                semantic_not)
7651 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7652                                semantic_dereference)
7653 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7654                                semantic_take_addr)
7655 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7656                                semantic_unexpr_integer)
7657 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7658                                semantic_incdec)
7659 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7660                                semantic_incdec)
7661
7662 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7663                                                sfunc)                         \
7664 static expression_t *parse_##unexpression_type(expression_t *left)            \
7665 {                                                                             \
7666         expression_t *unary_expression                                            \
7667                 = allocate_expression_zero(unexpression_type);                        \
7668         eat(token_kind);                                                          \
7669         unary_expression->unary.value = left;                                     \
7670                                                                                   \
7671         sfunc(&unary_expression->unary);                                          \
7672                                                                               \
7673         return unary_expression;                                                  \
7674 }
7675
7676 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7677                                        EXPR_UNARY_POSTFIX_INCREMENT,
7678                                        semantic_incdec)
7679 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7680                                        EXPR_UNARY_POSTFIX_DECREMENT,
7681                                        semantic_incdec)
7682
7683 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7684 {
7685         /* TODO: handle complex + imaginary types */
7686
7687         type_left  = get_unqualified_type(type_left);
7688         type_right = get_unqualified_type(type_right);
7689
7690         /* §6.3.1.8 Usual arithmetic conversions */
7691         if (type_left == type_long_double || type_right == type_long_double) {
7692                 return type_long_double;
7693         } else if (type_left == type_double || type_right == type_double) {
7694                 return type_double;
7695         } else if (type_left == type_float || type_right == type_float) {
7696                 return type_float;
7697         }
7698
7699         type_left  = promote_integer(type_left);
7700         type_right = promote_integer(type_right);
7701
7702         if (type_left == type_right)
7703                 return type_left;
7704
7705         bool     const signed_left  = is_type_signed(type_left);
7706         bool     const signed_right = is_type_signed(type_right);
7707         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7708         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7709
7710         if (signed_left == signed_right)
7711                 return rank_left >= rank_right ? type_left : type_right;
7712
7713         unsigned           s_rank;
7714         unsigned           u_rank;
7715         atomic_type_kind_t s_akind;
7716         atomic_type_kind_t u_akind;
7717         type_t *s_type;
7718         type_t *u_type;
7719         if (signed_left) {
7720                 s_type = type_left;
7721                 u_type = type_right;
7722         } else {
7723                 s_type = type_right;
7724                 u_type = type_left;
7725         }
7726         s_akind = get_akind(s_type);
7727         u_akind = get_akind(u_type);
7728         s_rank  = get_akind_rank(s_akind);
7729         u_rank  = get_akind_rank(u_akind);
7730
7731         if (u_rank >= s_rank)
7732                 return u_type;
7733
7734         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7735                 return s_type;
7736
7737         switch (s_akind) {
7738         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7739         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7740         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7741
7742         default: panic("invalid atomic type");
7743         }
7744 }
7745
7746 /**
7747  * Check the semantic restrictions for a binary expression.
7748  */
7749 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7750 {
7751         expression_t *const left            = expression->left;
7752         expression_t *const right           = expression->right;
7753         type_t       *const orig_type_left  = left->base.type;
7754         type_t       *const orig_type_right = right->base.type;
7755         type_t       *const type_left       = skip_typeref(orig_type_left);
7756         type_t       *const type_right      = skip_typeref(orig_type_right);
7757
7758         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7759                 /* TODO: improve error message */
7760                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7761                         errorf(&expression->base.source_position,
7762                                "operation needs arithmetic types");
7763                 }
7764                 return;
7765         }
7766
7767         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7768         expression->left      = create_implicit_cast(left, arithmetic_type);
7769         expression->right     = create_implicit_cast(right, arithmetic_type);
7770         expression->base.type = arithmetic_type;
7771 }
7772
7773 static void semantic_binexpr_integer(binary_expression_t *const expression)
7774 {
7775         expression_t *const left            = expression->left;
7776         expression_t *const right           = expression->right;
7777         type_t       *const orig_type_left  = left->base.type;
7778         type_t       *const orig_type_right = right->base.type;
7779         type_t       *const type_left       = skip_typeref(orig_type_left);
7780         type_t       *const type_right      = skip_typeref(orig_type_right);
7781
7782         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7783                 /* TODO: improve error message */
7784                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7785                         errorf(&expression->base.source_position,
7786                                "operation needs integer types");
7787                 }
7788                 return;
7789         }
7790
7791         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7792         expression->left      = create_implicit_cast(left, result_type);
7793         expression->right     = create_implicit_cast(right, result_type);
7794         expression->base.type = result_type;
7795 }
7796
7797 static void warn_div_by_zero(binary_expression_t const *const expression)
7798 {
7799         if (!is_type_integer(expression->base.type))
7800                 return;
7801
7802         expression_t const *const right = expression->right;
7803         /* The type of the right operand can be different for /= */
7804         if (is_type_integer(right->base.type)                    &&
7805             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7806             !fold_constant_to_bool(right)) {
7807                 source_position_t const *const pos = &expression->base.source_position;
7808                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7809         }
7810 }
7811
7812 /**
7813  * Check the semantic restrictions for a div/mod expression.
7814  */
7815 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7816 {
7817         semantic_binexpr_arithmetic(expression);
7818         warn_div_by_zero(expression);
7819 }
7820
7821 static void warn_addsub_in_shift(const expression_t *const expr)
7822 {
7823         if (expr->base.parenthesized)
7824                 return;
7825
7826         char op;
7827         switch (expr->kind) {
7828                 case EXPR_BINARY_ADD: op = '+'; break;
7829                 case EXPR_BINARY_SUB: op = '-'; break;
7830                 default:              return;
7831         }
7832
7833         source_position_t const *const pos = &expr->base.source_position;
7834         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7835 }
7836
7837 static bool semantic_shift(binary_expression_t *expression)
7838 {
7839         expression_t *const left            = expression->left;
7840         expression_t *const right           = expression->right;
7841         type_t       *const orig_type_left  = left->base.type;
7842         type_t       *const orig_type_right = right->base.type;
7843         type_t       *      type_left       = skip_typeref(orig_type_left);
7844         type_t       *      type_right      = skip_typeref(orig_type_right);
7845
7846         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7847                 /* TODO: improve error message */
7848                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7849                         errorf(&expression->base.source_position,
7850                                "operands of shift operation must have integer types");
7851                 }
7852                 return false;
7853         }
7854
7855         type_left = promote_integer(type_left);
7856
7857         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7858                 source_position_t const *const pos   = &right->base.source_position;
7859                 long                     const count = fold_constant_to_int(right);
7860                 if (count < 0) {
7861                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7862                 } else if ((unsigned long)count >=
7863                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7864                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7865                 }
7866         }
7867
7868         type_right        = promote_integer(type_right);
7869         expression->right = create_implicit_cast(right, type_right);
7870
7871         return true;
7872 }
7873
7874 static void semantic_shift_op(binary_expression_t *expression)
7875 {
7876         expression_t *const left  = expression->left;
7877         expression_t *const right = expression->right;
7878
7879         if (!semantic_shift(expression))
7880                 return;
7881
7882         warn_addsub_in_shift(left);
7883         warn_addsub_in_shift(right);
7884
7885         type_t *const orig_type_left = left->base.type;
7886         type_t *      type_left      = skip_typeref(orig_type_left);
7887
7888         type_left             = promote_integer(type_left);
7889         expression->left      = create_implicit_cast(left, type_left);
7890         expression->base.type = type_left;
7891 }
7892
7893 static void semantic_add(binary_expression_t *expression)
7894 {
7895         expression_t *const left            = expression->left;
7896         expression_t *const right           = expression->right;
7897         type_t       *const orig_type_left  = left->base.type;
7898         type_t       *const orig_type_right = right->base.type;
7899         type_t       *const type_left       = skip_typeref(orig_type_left);
7900         type_t       *const type_right      = skip_typeref(orig_type_right);
7901
7902         /* §6.5.6 */
7903         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7904                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7905                 expression->left  = create_implicit_cast(left, arithmetic_type);
7906                 expression->right = create_implicit_cast(right, arithmetic_type);
7907                 expression->base.type = arithmetic_type;
7908         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7909                 check_pointer_arithmetic(&expression->base.source_position,
7910                                          type_left, orig_type_left);
7911                 expression->base.type = type_left;
7912         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7913                 check_pointer_arithmetic(&expression->base.source_position,
7914                                          type_right, orig_type_right);
7915                 expression->base.type = type_right;
7916         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7917                 errorf(&expression->base.source_position,
7918                        "invalid operands to binary + ('%T', '%T')",
7919                        orig_type_left, orig_type_right);
7920         }
7921 }
7922
7923 static void semantic_sub(binary_expression_t *expression)
7924 {
7925         expression_t            *const left            = expression->left;
7926         expression_t            *const right           = expression->right;
7927         type_t                  *const orig_type_left  = left->base.type;
7928         type_t                  *const orig_type_right = right->base.type;
7929         type_t                  *const type_left       = skip_typeref(orig_type_left);
7930         type_t                  *const type_right      = skip_typeref(orig_type_right);
7931         source_position_t const *const pos             = &expression->base.source_position;
7932
7933         /* §5.6.5 */
7934         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7935                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7936                 expression->left        = create_implicit_cast(left, arithmetic_type);
7937                 expression->right       = create_implicit_cast(right, arithmetic_type);
7938                 expression->base.type =  arithmetic_type;
7939         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7940                 check_pointer_arithmetic(&expression->base.source_position,
7941                                          type_left, orig_type_left);
7942                 expression->base.type = type_left;
7943         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7944                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7945                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7946                 if (!types_compatible(unqual_left, unqual_right)) {
7947                         errorf(pos,
7948                                "subtracting pointers to incompatible types '%T' and '%T'",
7949                                orig_type_left, orig_type_right);
7950                 } else if (!is_type_object(unqual_left)) {
7951                         if (!is_type_void(unqual_left)) {
7952                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7953                                        orig_type_left);
7954                         } else {
7955                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7956                         }
7957                 }
7958                 expression->base.type = type_ptrdiff_t;
7959         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7960                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7961                        orig_type_left, orig_type_right);
7962         }
7963 }
7964
7965 static void warn_string_literal_address(expression_t const* expr)
7966 {
7967         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7968                 expr = expr->unary.value;
7969                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7970                         return;
7971                 expr = expr->unary.value;
7972         }
7973
7974         if (expr->kind == EXPR_STRING_LITERAL) {
7975                 source_position_t const *const pos = &expr->base.source_position;
7976                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7977         }
7978 }
7979
7980 static bool maybe_negative(expression_t const *const expr)
7981 {
7982         switch (is_constant_expression(expr)) {
7983                 case EXPR_CLASS_ERROR:    return false;
7984                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7985                 default:                  return true;
7986         }
7987 }
7988
7989 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7990 {
7991         warn_string_literal_address(expr);
7992
7993         expression_t const* const ref = get_reference_address(expr);
7994         if (ref != NULL && is_null_pointer_constant(other)) {
7995                 entity_t const *const ent = ref->reference.entity;
7996                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7997         }
7998
7999         if (!expr->base.parenthesized) {
8000                 switch (expr->base.kind) {
8001                         case EXPR_BINARY_LESS:
8002                         case EXPR_BINARY_GREATER:
8003                         case EXPR_BINARY_LESSEQUAL:
8004                         case EXPR_BINARY_GREATEREQUAL:
8005                         case EXPR_BINARY_NOTEQUAL:
8006                         case EXPR_BINARY_EQUAL:
8007                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8008                                 break;
8009                         default:
8010                                 break;
8011                 }
8012         }
8013 }
8014
8015 /**
8016  * Check the semantics of comparison expressions.
8017  *
8018  * @param expression   The expression to check.
8019  */
8020 static void semantic_comparison(binary_expression_t *expression)
8021 {
8022         source_position_t const *const pos   = &expression->base.source_position;
8023         expression_t            *const left  = expression->left;
8024         expression_t            *const right = expression->right;
8025
8026         warn_comparison(pos, left, right);
8027         warn_comparison(pos, right, left);
8028
8029         type_t *orig_type_left  = left->base.type;
8030         type_t *orig_type_right = right->base.type;
8031         type_t *type_left       = skip_typeref(orig_type_left);
8032         type_t *type_right      = skip_typeref(orig_type_right);
8033
8034         /* TODO non-arithmetic types */
8035         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8036                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8037
8038                 /* test for signed vs unsigned compares */
8039                 if (is_type_integer(arithmetic_type)) {
8040                         bool const signed_left  = is_type_signed(type_left);
8041                         bool const signed_right = is_type_signed(type_right);
8042                         if (signed_left != signed_right) {
8043                                 /* FIXME long long needs better const folding magic */
8044                                 /* TODO check whether constant value can be represented by other type */
8045                                 if ((signed_left  && maybe_negative(left)) ||
8046                                                 (signed_right && maybe_negative(right))) {
8047                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8048                                 }
8049                         }
8050                 }
8051
8052                 expression->left        = create_implicit_cast(left, arithmetic_type);
8053                 expression->right       = create_implicit_cast(right, arithmetic_type);
8054                 expression->base.type   = arithmetic_type;
8055                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8056                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8057                     is_type_float(arithmetic_type)) {
8058                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8059                 }
8060         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8061                 /* TODO check compatibility */
8062         } else if (is_type_pointer(type_left)) {
8063                 expression->right = create_implicit_cast(right, type_left);
8064         } else if (is_type_pointer(type_right)) {
8065                 expression->left = create_implicit_cast(left, type_right);
8066         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8067                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8068         }
8069         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8070 }
8071
8072 /**
8073  * Checks if a compound type has constant fields.
8074  */
8075 static bool has_const_fields(const compound_type_t *type)
8076 {
8077         compound_t *compound = type->compound;
8078         entity_t   *entry    = compound->members.entities;
8079
8080         for (; entry != NULL; entry = entry->base.next) {
8081                 if (!is_declaration(entry))
8082                         continue;
8083
8084                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8085                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8086                         return true;
8087         }
8088
8089         return false;
8090 }
8091
8092 static bool is_valid_assignment_lhs(expression_t const* const left)
8093 {
8094         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8095         type_t *const type_left      = skip_typeref(orig_type_left);
8096
8097         if (!is_lvalue(left)) {
8098                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8099                        left);
8100                 return false;
8101         }
8102
8103         if (left->kind == EXPR_REFERENCE
8104                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8105                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8106                 return false;
8107         }
8108
8109         if (is_type_array(type_left)) {
8110                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8111                 return false;
8112         }
8113         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8114                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8115                        orig_type_left);
8116                 return false;
8117         }
8118         if (is_type_incomplete(type_left)) {
8119                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8120                        left, orig_type_left);
8121                 return false;
8122         }
8123         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8124                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8125                        left, orig_type_left);
8126                 return false;
8127         }
8128
8129         return true;
8130 }
8131
8132 static void semantic_arithmetic_assign(binary_expression_t *expression)
8133 {
8134         expression_t *left            = expression->left;
8135         expression_t *right           = expression->right;
8136         type_t       *orig_type_left  = left->base.type;
8137         type_t       *orig_type_right = right->base.type;
8138
8139         if (!is_valid_assignment_lhs(left))
8140                 return;
8141
8142         type_t *type_left  = skip_typeref(orig_type_left);
8143         type_t *type_right = skip_typeref(orig_type_right);
8144
8145         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8146                 /* TODO: improve error message */
8147                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8148                         errorf(&expression->base.source_position,
8149                                "operation needs arithmetic types");
8150                 }
8151                 return;
8152         }
8153
8154         /* combined instructions are tricky. We can't create an implicit cast on
8155          * the left side, because we need the uncasted form for the store.
8156          * The ast2firm pass has to know that left_type must be right_type
8157          * for the arithmetic operation and create a cast by itself */
8158         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8159         expression->right       = create_implicit_cast(right, arithmetic_type);
8160         expression->base.type   = type_left;
8161 }
8162
8163 static void semantic_divmod_assign(binary_expression_t *expression)
8164 {
8165         semantic_arithmetic_assign(expression);
8166         warn_div_by_zero(expression);
8167 }
8168
8169 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8170 {
8171         expression_t *const left            = expression->left;
8172         expression_t *const right           = expression->right;
8173         type_t       *const orig_type_left  = left->base.type;
8174         type_t       *const orig_type_right = right->base.type;
8175         type_t       *const type_left       = skip_typeref(orig_type_left);
8176         type_t       *const type_right      = skip_typeref(orig_type_right);
8177
8178         if (!is_valid_assignment_lhs(left))
8179                 return;
8180
8181         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8182                 /* combined instructions are tricky. We can't create an implicit cast on
8183                  * the left side, because we need the uncasted form for the store.
8184                  * The ast2firm pass has to know that left_type must be right_type
8185                  * for the arithmetic operation and create a cast by itself */
8186                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8187                 expression->right     = create_implicit_cast(right, arithmetic_type);
8188                 expression->base.type = type_left;
8189         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8190                 check_pointer_arithmetic(&expression->base.source_position,
8191                                          type_left, orig_type_left);
8192                 expression->base.type = type_left;
8193         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8194                 errorf(&expression->base.source_position,
8195                        "incompatible types '%T' and '%T' in assignment",
8196                        orig_type_left, orig_type_right);
8197         }
8198 }
8199
8200 static void semantic_integer_assign(binary_expression_t *expression)
8201 {
8202         expression_t *left            = expression->left;
8203         expression_t *right           = expression->right;
8204         type_t       *orig_type_left  = left->base.type;
8205         type_t       *orig_type_right = right->base.type;
8206
8207         if (!is_valid_assignment_lhs(left))
8208                 return;
8209
8210         type_t *type_left  = skip_typeref(orig_type_left);
8211         type_t *type_right = skip_typeref(orig_type_right);
8212
8213         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8214                 /* TODO: improve error message */
8215                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8216                         errorf(&expression->base.source_position,
8217                                "operation needs integer types");
8218                 }
8219                 return;
8220         }
8221
8222         /* combined instructions are tricky. We can't create an implicit cast on
8223          * the left side, because we need the uncasted form for the store.
8224          * The ast2firm pass has to know that left_type must be right_type
8225          * for the arithmetic operation and create a cast by itself */
8226         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8227         expression->right       = create_implicit_cast(right, arithmetic_type);
8228         expression->base.type   = type_left;
8229 }
8230
8231 static void semantic_shift_assign(binary_expression_t *expression)
8232 {
8233         expression_t *left           = expression->left;
8234
8235         if (!is_valid_assignment_lhs(left))
8236                 return;
8237
8238         if (!semantic_shift(expression))
8239                 return;
8240
8241         expression->base.type = skip_typeref(left->base.type);
8242 }
8243
8244 static void warn_logical_and_within_or(const expression_t *const expr)
8245 {
8246         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8247                 return;
8248         if (expr->base.parenthesized)
8249                 return;
8250         source_position_t const *const pos = &expr->base.source_position;
8251         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8252 }
8253
8254 /**
8255  * Check the semantic restrictions of a logical expression.
8256  */
8257 static void semantic_logical_op(binary_expression_t *expression)
8258 {
8259         /* §6.5.13:2  Each of the operands shall have scalar type.
8260          * §6.5.14:2  Each of the operands shall have scalar type. */
8261         semantic_condition(expression->left,   "left operand of logical operator");
8262         semantic_condition(expression->right, "right operand of logical operator");
8263         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8264                 warn_logical_and_within_or(expression->left);
8265                 warn_logical_and_within_or(expression->right);
8266         }
8267         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8268 }
8269
8270 /**
8271  * Check the semantic restrictions of a binary assign expression.
8272  */
8273 static void semantic_binexpr_assign(binary_expression_t *expression)
8274 {
8275         expression_t *left           = expression->left;
8276         type_t       *orig_type_left = left->base.type;
8277
8278         if (!is_valid_assignment_lhs(left))
8279                 return;
8280
8281         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8282         report_assign_error(error, orig_type_left, expression->right,
8283                         "assignment", &left->base.source_position);
8284         expression->right = create_implicit_cast(expression->right, orig_type_left);
8285         expression->base.type = orig_type_left;
8286 }
8287
8288 /**
8289  * Determine if the outermost operation (or parts thereof) of the given
8290  * expression has no effect in order to generate a warning about this fact.
8291  * Therefore in some cases this only examines some of the operands of the
8292  * expression (see comments in the function and examples below).
8293  * Examples:
8294  *   f() + 23;    // warning, because + has no effect
8295  *   x || f();    // no warning, because x controls execution of f()
8296  *   x ? y : f(); // warning, because y has no effect
8297  *   (void)x;     // no warning to be able to suppress the warning
8298  * This function can NOT be used for an "expression has definitely no effect"-
8299  * analysis. */
8300 static bool expression_has_effect(const expression_t *const expr)
8301 {
8302         switch (expr->kind) {
8303                 case EXPR_ERROR:                      return true; /* do NOT warn */
8304                 case EXPR_REFERENCE:                  return false;
8305                 case EXPR_ENUM_CONSTANT:              return false;
8306                 case EXPR_LABEL_ADDRESS:              return false;
8307
8308                 /* suppress the warning for microsoft __noop operations */
8309                 case EXPR_LITERAL_MS_NOOP:            return true;
8310                 case EXPR_LITERAL_BOOLEAN:
8311                 case EXPR_LITERAL_CHARACTER:
8312                 case EXPR_LITERAL_WIDE_CHARACTER:
8313                 case EXPR_LITERAL_INTEGER:
8314                 case EXPR_LITERAL_FLOATINGPOINT:
8315                 case EXPR_STRING_LITERAL:             return false;
8316
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("asm argument");
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(NULL);
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         add_anchor_token(')');
8751         add_anchor_token(':');
8752         add_anchor_token(T_STRING_LITERAL);
8753
8754         if (next_if(T_volatile))
8755                 asm_statement->is_volatile = true;
8756
8757         expect('(');
8758         rem_anchor_token(T_STRING_LITERAL);
8759         asm_statement->asm_text = parse_string_literals("asm statement");
8760
8761         if (next_if(':'))
8762                 asm_statement->outputs = parse_asm_arguments(true);
8763
8764         if (next_if(':'))
8765                 asm_statement->inputs = parse_asm_arguments(false);
8766
8767         rem_anchor_token(':');
8768         if (next_if(':'))
8769                 asm_statement->clobbers = parse_asm_clobbers();
8770
8771         rem_anchor_token(')');
8772         expect(')');
8773         expect(';');
8774
8775         if (asm_statement->outputs == NULL) {
8776                 /* GCC: An 'asm' instruction without any output operands will be treated
8777                  * identically to a volatile 'asm' instruction. */
8778                 asm_statement->is_volatile = true;
8779         }
8780
8781         return statement;
8782 }
8783
8784 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8785 {
8786         statement_t *inner_stmt;
8787         switch (token.kind) {
8788                 case '}':
8789                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8790                         inner_stmt = create_error_statement();
8791                         break;
8792
8793                 case ';':
8794                         if (label->kind == STATEMENT_LABEL) {
8795                                 /* Eat an empty statement here, to avoid the warning about an empty
8796                                  * statement after a label.  label:; is commonly used to have a label
8797                                  * before a closing brace. */
8798                                 inner_stmt = create_empty_statement();
8799                                 eat(';');
8800                                 break;
8801                         }
8802                         /* FALLTHROUGH */
8803
8804                 default:
8805                         inner_stmt = parse_statement();
8806                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8807                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8808                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8809                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8810                         }
8811                         break;
8812         }
8813         return inner_stmt;
8814 }
8815
8816 /**
8817  * Parse a case statement.
8818  */
8819 static statement_t *parse_case_statement(void)
8820 {
8821         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8822         source_position_t *const pos       = &statement->base.source_position;
8823
8824         eat(T_case);
8825         add_anchor_token(':');
8826
8827         expression_t *expression = parse_expression();
8828         type_t *expression_type = expression->base.type;
8829         type_t *skipped         = skip_typeref(expression_type);
8830         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8831                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8832                        expression, expression_type);
8833         }
8834
8835         type_t *type = expression_type;
8836         if (current_switch != NULL) {
8837                 type_t *switch_type = current_switch->expression->base.type;
8838                 if (is_type_valid(switch_type)) {
8839                         expression = create_implicit_cast(expression, switch_type);
8840                 }
8841         }
8842
8843         statement->case_label.expression = expression;
8844         expression_classification_t const expr_class = is_constant_expression(expression);
8845         if (expr_class != EXPR_CLASS_CONSTANT) {
8846                 if (expr_class != EXPR_CLASS_ERROR) {
8847                         errorf(pos, "case label does not reduce to an integer constant");
8848                 }
8849                 statement->case_label.is_bad = true;
8850         } else {
8851                 long const val = fold_constant_to_int(expression);
8852                 statement->case_label.first_case = val;
8853                 statement->case_label.last_case  = val;
8854         }
8855
8856         if (GNU_MODE) {
8857                 if (next_if(T_DOTDOTDOT)) {
8858                         expression_t *end_range = parse_expression();
8859                         expression_type = expression->base.type;
8860                         skipped         = skip_typeref(expression_type);
8861                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8862                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8863                                            expression, expression_type);
8864                         }
8865
8866                         end_range = create_implicit_cast(end_range, type);
8867                         statement->case_label.end_range = end_range;
8868                         expression_classification_t const end_class = is_constant_expression(end_range);
8869                         if (end_class != EXPR_CLASS_CONSTANT) {
8870                                 if (end_class != EXPR_CLASS_ERROR) {
8871                                         errorf(pos, "case range does not reduce to an integer constant");
8872                                 }
8873                                 statement->case_label.is_bad = true;
8874                         } else {
8875                                 long const val = fold_constant_to_int(end_range);
8876                                 statement->case_label.last_case = val;
8877
8878                                 if (val < statement->case_label.first_case) {
8879                                         statement->case_label.is_empty_range = true;
8880                                         warningf(WARN_OTHER, pos, "empty range specified");
8881                                 }
8882                         }
8883                 }
8884         }
8885
8886         PUSH_PARENT(statement);
8887
8888         rem_anchor_token(':');
8889         expect(':');
8890
8891         if (current_switch != NULL) {
8892                 if (! statement->case_label.is_bad) {
8893                         /* Check for duplicate case values */
8894                         case_label_statement_t *c = &statement->case_label;
8895                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8896                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8897                                         continue;
8898
8899                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8900                                         continue;
8901
8902                                 errorf(pos, "duplicate case value (previously used %P)",
8903                                        &l->base.source_position);
8904                                 break;
8905                         }
8906                 }
8907                 /* link all cases into the switch statement */
8908                 if (current_switch->last_case == NULL) {
8909                         current_switch->first_case      = &statement->case_label;
8910                 } else {
8911                         current_switch->last_case->next = &statement->case_label;
8912                 }
8913                 current_switch->last_case = &statement->case_label;
8914         } else {
8915                 errorf(pos, "case label not within a switch statement");
8916         }
8917
8918         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8919
8920         POP_PARENT();
8921         return statement;
8922 }
8923
8924 /**
8925  * Parse a default statement.
8926  */
8927 static statement_t *parse_default_statement(void)
8928 {
8929         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8930
8931         eat(T_default);
8932
8933         PUSH_PARENT(statement);
8934
8935         expect(':');
8936
8937         if (current_switch != NULL) {
8938                 const case_label_statement_t *def_label = current_switch->default_label;
8939                 if (def_label != NULL) {
8940                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8941                 } else {
8942                         current_switch->default_label = &statement->case_label;
8943
8944                         /* link all cases into the switch statement */
8945                         if (current_switch->last_case == NULL) {
8946                                 current_switch->first_case      = &statement->case_label;
8947                         } else {
8948                                 current_switch->last_case->next = &statement->case_label;
8949                         }
8950                         current_switch->last_case = &statement->case_label;
8951                 }
8952         } else {
8953                 errorf(&statement->base.source_position,
8954                         "'default' label not within a switch statement");
8955         }
8956
8957         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8958
8959         POP_PARENT();
8960         return statement;
8961 }
8962
8963 /**
8964  * Parse a label statement.
8965  */
8966 static statement_t *parse_label_statement(void)
8967 {
8968         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8969         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8970         statement->label.label = label;
8971
8972         PUSH_PARENT(statement);
8973
8974         /* if statement is already set then the label is defined twice,
8975          * otherwise it was just mentioned in a goto/local label declaration so far
8976          */
8977         source_position_t const* const pos = &statement->base.source_position;
8978         if (label->statement != NULL) {
8979                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8980         } else {
8981                 label->base.source_position = *pos;
8982                 label->statement            = statement;
8983         }
8984
8985         eat(':');
8986
8987         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8988                 parse_attributes(NULL); // TODO process attributes
8989         }
8990
8991         statement->label.statement = parse_label_inner_statement(statement, "label");
8992
8993         /* remember the labels in a list for later checking */
8994         *label_anchor = &statement->label;
8995         label_anchor  = &statement->label.next;
8996
8997         POP_PARENT();
8998         return statement;
8999 }
9000
9001 static statement_t *parse_inner_statement(void)
9002 {
9003         statement_t *const stmt = parse_statement();
9004         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9005         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9006         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9007                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9008         }
9009         return stmt;
9010 }
9011
9012 /**
9013  * Parse an expression in parentheses and mark its variables as read.
9014  */
9015 static expression_t *parse_condition(void)
9016 {
9017         add_anchor_token(')');
9018         expect('(');
9019         expression_t *const expr = parse_expression();
9020         mark_vars_read(expr, NULL);
9021         rem_anchor_token(')');
9022         expect(')');
9023         return expr;
9024 }
9025
9026 /**
9027  * Parse an if statement.
9028  */
9029 static statement_t *parse_if(void)
9030 {
9031         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9032
9033         eat(T_if);
9034
9035         PUSH_PARENT(statement);
9036         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9037
9038         add_anchor_token(T_else);
9039
9040         expression_t *const expr = parse_condition();
9041         statement->ifs.condition = expr;
9042         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9043          *             scalar type. */
9044         semantic_condition(expr, "condition of 'if'-statment");
9045
9046         statement_t *const true_stmt = parse_inner_statement();
9047         statement->ifs.true_statement = true_stmt;
9048         rem_anchor_token(T_else);
9049
9050         if (true_stmt->kind == STATEMENT_EMPTY) {
9051                 warningf(WARN_EMPTY_BODY, HERE,
9052                         "suggest braces around empty body in an ‘if’ statement");
9053         }
9054
9055         if (next_if(T_else)) {
9056                 statement->ifs.false_statement = parse_inner_statement();
9057
9058                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9059                         warningf(WARN_EMPTY_BODY, HERE,
9060                                         "suggest braces around empty body in an ‘if’ statement");
9061                 }
9062         } else if (true_stmt->kind == STATEMENT_IF &&
9063                         true_stmt->ifs.false_statement != NULL) {
9064                 source_position_t const *const pos = &true_stmt->base.source_position;
9065                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9066         }
9067
9068         POP_SCOPE();
9069         POP_PARENT();
9070         return statement;
9071 }
9072
9073 /**
9074  * Check that all enums are handled in a switch.
9075  *
9076  * @param statement  the switch statement to check
9077  */
9078 static void check_enum_cases(const switch_statement_t *statement)
9079 {
9080         if (!is_warn_on(WARN_SWITCH_ENUM))
9081                 return;
9082         const type_t *type = skip_typeref(statement->expression->base.type);
9083         if (! is_type_enum(type))
9084                 return;
9085         const enum_type_t *enumt = &type->enumt;
9086
9087         /* if we have a default, no warnings */
9088         if (statement->default_label != NULL)
9089                 return;
9090
9091         /* FIXME: calculation of value should be done while parsing */
9092         /* TODO: quadratic algorithm here. Change to an n log n one */
9093         long            last_value = -1;
9094         const entity_t *entry      = enumt->enume->base.next;
9095         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9096              entry = entry->base.next) {
9097                 const expression_t *expression = entry->enum_value.value;
9098                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9099                 bool                found      = false;
9100                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9101                         if (l->expression == NULL)
9102                                 continue;
9103                         if (l->first_case <= value && value <= l->last_case) {
9104                                 found = true;
9105                                 break;
9106                         }
9107                 }
9108                 if (!found) {
9109                         source_position_t const *const pos = &statement->base.source_position;
9110                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9111                 }
9112                 last_value = value;
9113         }
9114 }
9115
9116 /**
9117  * Parse a switch statement.
9118  */
9119 static statement_t *parse_switch(void)
9120 {
9121         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9122
9123         eat(T_switch);
9124
9125         PUSH_PARENT(statement);
9126         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9127
9128         expression_t *const expr = parse_condition();
9129         type_t       *      type = skip_typeref(expr->base.type);
9130         if (is_type_integer(type)) {
9131                 type = promote_integer(type);
9132                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9133                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9134                 }
9135         } else if (is_type_valid(type)) {
9136                 errorf(&expr->base.source_position,
9137                        "switch quantity is not an integer, but '%T'", type);
9138                 type = type_error_type;
9139         }
9140         statement->switchs.expression = create_implicit_cast(expr, type);
9141
9142         switch_statement_t *rem = current_switch;
9143         current_switch          = &statement->switchs;
9144         statement->switchs.body = parse_inner_statement();
9145         current_switch          = rem;
9146
9147         if (statement->switchs.default_label == NULL) {
9148                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9149         }
9150         check_enum_cases(&statement->switchs);
9151
9152         POP_SCOPE();
9153         POP_PARENT();
9154         return statement;
9155 }
9156
9157 static statement_t *parse_loop_body(statement_t *const loop)
9158 {
9159         statement_t *const rem = current_loop;
9160         current_loop = loop;
9161
9162         statement_t *const body = parse_inner_statement();
9163
9164         current_loop = rem;
9165         return body;
9166 }
9167
9168 /**
9169  * Parse a while statement.
9170  */
9171 static statement_t *parse_while(void)
9172 {
9173         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9174
9175         eat(T_while);
9176
9177         PUSH_PARENT(statement);
9178         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9179
9180         expression_t *const cond = parse_condition();
9181         statement->whiles.condition = cond;
9182         /* §6.8.5:2    The controlling expression of an iteration statement shall
9183          *             have scalar type. */
9184         semantic_condition(cond, "condition of 'while'-statement");
9185
9186         statement->whiles.body = parse_loop_body(statement);
9187
9188         POP_SCOPE();
9189         POP_PARENT();
9190         return statement;
9191 }
9192
9193 /**
9194  * Parse a do statement.
9195  */
9196 static statement_t *parse_do(void)
9197 {
9198         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9199
9200         eat(T_do);
9201
9202         PUSH_PARENT(statement);
9203         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9204
9205         add_anchor_token(T_while);
9206         statement->do_while.body = parse_loop_body(statement);
9207         rem_anchor_token(T_while);
9208
9209         expect(T_while);
9210         expression_t *const cond = parse_condition();
9211         statement->do_while.condition = cond;
9212         /* §6.8.5:2    The controlling expression of an iteration statement shall
9213          *             have scalar type. */
9214         semantic_condition(cond, "condition of 'do-while'-statement");
9215         expect(';');
9216
9217         POP_SCOPE();
9218         POP_PARENT();
9219         return statement;
9220 }
9221
9222 /**
9223  * Parse a for statement.
9224  */
9225 static statement_t *parse_for(void)
9226 {
9227         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9228
9229         eat(T_for);
9230
9231         PUSH_PARENT(statement);
9232         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9233
9234         add_anchor_token(')');
9235         expect('(');
9236
9237         PUSH_EXTENSION();
9238
9239         if (next_if(';')) {
9240         } else if (is_declaration_specifier(&token)) {
9241                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9242         } else {
9243                 add_anchor_token(';');
9244                 expression_t *const init = parse_expression();
9245                 statement->fors.initialisation = init;
9246                 mark_vars_read(init, ENT_ANY);
9247                 if (!expression_has_effect(init)) {
9248                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9249                 }
9250                 rem_anchor_token(';');
9251                 expect(';');
9252         }
9253
9254         POP_EXTENSION();
9255
9256         if (token.kind != ';') {
9257                 add_anchor_token(';');
9258                 expression_t *const cond = parse_expression();
9259                 statement->fors.condition = cond;
9260                 /* §6.8.5:2    The controlling expression of an iteration statement
9261                  *             shall have scalar type. */
9262                 semantic_condition(cond, "condition of 'for'-statement");
9263                 mark_vars_read(cond, NULL);
9264                 rem_anchor_token(';');
9265         }
9266         expect(';');
9267         if (token.kind != ')') {
9268                 expression_t *const step = parse_expression();
9269                 statement->fors.step = step;
9270                 mark_vars_read(step, ENT_ANY);
9271                 if (!expression_has_effect(step)) {
9272                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9273                 }
9274         }
9275         rem_anchor_token(')');
9276         expect(')');
9277         statement->fors.body = parse_loop_body(statement);
9278
9279         POP_SCOPE();
9280         POP_PARENT();
9281         return statement;
9282 }
9283
9284 /**
9285  * Parse a goto statement.
9286  */
9287 static statement_t *parse_goto(void)
9288 {
9289         statement_t *statement;
9290         if (GNU_MODE && look_ahead(1)->kind == '*') {
9291                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9292                 eat(T_goto);
9293                 eat('*');
9294
9295                 expression_t *expression = parse_expression();
9296                 mark_vars_read(expression, NULL);
9297
9298                 /* Argh: although documentation says the expression must be of type void*,
9299                  * gcc accepts anything that can be casted into void* without error */
9300                 type_t *type = expression->base.type;
9301
9302                 if (type != type_error_type) {
9303                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9304                                 errorf(&expression->base.source_position,
9305                                         "cannot convert to a pointer type");
9306                         } else if (type != type_void_ptr) {
9307                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9308                         }
9309                         expression = create_implicit_cast(expression, type_void_ptr);
9310                 }
9311
9312                 statement->computed_goto.expression = expression;
9313         } else {
9314                 statement = allocate_statement_zero(STATEMENT_GOTO);
9315                 eat(T_goto);
9316
9317                 label_t *const label = get_label("while parsing goto");
9318                 if (label) {
9319                         label->used            = true;
9320                         statement->gotos.label = label;
9321
9322                         /* remember the goto's in a list for later checking */
9323                         *goto_anchor = &statement->gotos;
9324                         goto_anchor  = &statement->gotos.next;
9325                 } else {
9326                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9327                 }
9328         }
9329
9330         expect(';');
9331         return statement;
9332 }
9333
9334 /**
9335  * Parse a continue statement.
9336  */
9337 static statement_t *parse_continue(void)
9338 {
9339         if (current_loop == NULL) {
9340                 errorf(HERE, "continue statement not within loop");
9341         }
9342
9343         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9344
9345         eat(T_continue);
9346         expect(';');
9347         return statement;
9348 }
9349
9350 /**
9351  * Parse a break statement.
9352  */
9353 static statement_t *parse_break(void)
9354 {
9355         if (current_switch == NULL && current_loop == NULL) {
9356                 errorf(HERE, "break statement not within loop or switch");
9357         }
9358
9359         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9360
9361         eat(T_break);
9362         expect(';');
9363         return statement;
9364 }
9365
9366 /**
9367  * Parse a __leave statement.
9368  */
9369 static statement_t *parse_leave_statement(void)
9370 {
9371         if (current_try == NULL) {
9372                 errorf(HERE, "__leave statement not within __try");
9373         }
9374
9375         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9376
9377         eat(T___leave);
9378         expect(';');
9379         return statement;
9380 }
9381
9382 /**
9383  * Check if a given entity represents a local variable.
9384  */
9385 static bool is_local_variable(const entity_t *entity)
9386 {
9387         if (entity->kind != ENTITY_VARIABLE)
9388                 return false;
9389
9390         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9391         case STORAGE_CLASS_AUTO:
9392         case STORAGE_CLASS_REGISTER: {
9393                 const type_t *type = skip_typeref(entity->declaration.type);
9394                 if (is_type_function(type)) {
9395                         return false;
9396                 } else {
9397                         return true;
9398                 }
9399         }
9400         default:
9401                 return false;
9402         }
9403 }
9404
9405 /**
9406  * Check if a given expression represents a local variable.
9407  */
9408 static bool expression_is_local_variable(const expression_t *expression)
9409 {
9410         if (expression->base.kind != EXPR_REFERENCE) {
9411                 return false;
9412         }
9413         const entity_t *entity = expression->reference.entity;
9414         return is_local_variable(entity);
9415 }
9416
9417 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9418 {
9419         if (c_mode & _CXX || strict_mode) {
9420                 errorf(pos, msg);
9421         } else {
9422                 warningf(WARN_OTHER, pos, msg);
9423         }
9424 }
9425
9426 /**
9427  * Parse a return statement.
9428  */
9429 static statement_t *parse_return(void)
9430 {
9431         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9432         eat(T_return);
9433
9434         expression_t *return_value = NULL;
9435         if (token.kind != ';') {
9436                 return_value = parse_expression();
9437                 mark_vars_read(return_value, NULL);
9438         }
9439
9440         const type_t *const func_type = skip_typeref(current_function->base.type);
9441         assert(is_type_function(func_type));
9442         type_t *const return_type = skip_typeref(func_type->function.return_type);
9443
9444         source_position_t const *const pos = &statement->base.source_position;
9445         if (return_value != NULL) {
9446                 type_t *return_value_type = skip_typeref(return_value->base.type);
9447
9448                 if (is_type_void(return_type)) {
9449                         if (!is_type_void(return_value_type)) {
9450                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9451                                 /* Only warn in C mode, because GCC does the same */
9452                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9453                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9454                                 /* Only warn in C mode, because GCC does the same */
9455                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9456                         }
9457                 } else {
9458                         assign_error_t error = semantic_assign(return_type, return_value);
9459                         report_assign_error(error, return_type, return_value, "'return'",
9460                                             pos);
9461                 }
9462                 return_value = create_implicit_cast(return_value, return_type);
9463                 /* check for returning address of a local var */
9464                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9465                         const expression_t *expression = return_value->unary.value;
9466                         if (expression_is_local_variable(expression)) {
9467                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9468                         }
9469                 }
9470         } else if (!is_type_void(return_type)) {
9471                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9472                 err_or_warn(pos, "'return' without value, in function returning non-void");
9473         }
9474         statement->returns.value = return_value;
9475
9476         expect(';');
9477         return statement;
9478 }
9479
9480 /**
9481  * Parse a declaration statement.
9482  */
9483 static statement_t *parse_declaration_statement(void)
9484 {
9485         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9486
9487         entity_t *before = current_scope->last_entity;
9488         if (GNU_MODE) {
9489                 parse_external_declaration();
9490         } else {
9491                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9492         }
9493
9494         declaration_statement_t *const decl  = &statement->declaration;
9495         entity_t                *const begin =
9496                 before != NULL ? before->base.next : current_scope->entities;
9497         decl->declarations_begin = begin;
9498         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9499
9500         return statement;
9501 }
9502
9503 /**
9504  * Parse an expression statement, ie. expr ';'.
9505  */
9506 static statement_t *parse_expression_statement(void)
9507 {
9508         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9509
9510         expression_t *const expr         = parse_expression();
9511         statement->expression.expression = expr;
9512         mark_vars_read(expr, ENT_ANY);
9513
9514         expect(';');
9515         return statement;
9516 }
9517
9518 /**
9519  * Parse a microsoft __try { } __finally { } or
9520  * __try{ } __except() { }
9521  */
9522 static statement_t *parse_ms_try_statment(void)
9523 {
9524         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9525         eat(T___try);
9526
9527         PUSH_PARENT(statement);
9528
9529         ms_try_statement_t *rem = current_try;
9530         current_try = &statement->ms_try;
9531         statement->ms_try.try_statement = parse_compound_statement(false);
9532         current_try = rem;
9533
9534         POP_PARENT();
9535
9536         if (next_if(T___except)) {
9537                 expression_t *const expr = parse_condition();
9538                 type_t       *      type = skip_typeref(expr->base.type);
9539                 if (is_type_integer(type)) {
9540                         type = promote_integer(type);
9541                 } else if (is_type_valid(type)) {
9542                         errorf(&expr->base.source_position,
9543                                "__expect expression is not an integer, but '%T'", type);
9544                         type = type_error_type;
9545                 }
9546                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9547         } else if (!next_if(T__finally)) {
9548                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9549         }
9550         statement->ms_try.final_statement = parse_compound_statement(false);
9551         return statement;
9552 }
9553
9554 static statement_t *parse_empty_statement(void)
9555 {
9556         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9557         statement_t *const statement = create_empty_statement();
9558         eat(';');
9559         return statement;
9560 }
9561
9562 static statement_t *parse_local_label_declaration(void)
9563 {
9564         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9565
9566         eat(T___label__);
9567
9568         entity_t *begin   = NULL;
9569         entity_t *end     = NULL;
9570         entity_t **anchor = &begin;
9571         add_anchor_token(';');
9572         add_anchor_token(',');
9573         do {
9574                 source_position_t pos;
9575                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9576                 if (symbol) {
9577                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9578                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9579                                 source_position_t const *const ppos = &entity->base.source_position;
9580                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9581                         } else {
9582                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9583                                 entity->base.parent_scope = current_scope;
9584
9585                                 *anchor = entity;
9586                                 anchor  = &entity->base.next;
9587                                 end     = entity;
9588
9589                                 environment_push(entity);
9590                         }
9591                 }
9592         } while (next_if(','));
9593         rem_anchor_token(',');
9594         rem_anchor_token(';');
9595         expect(';');
9596         statement->declaration.declarations_begin = begin;
9597         statement->declaration.declarations_end   = end;
9598         return statement;
9599 }
9600
9601 static void parse_namespace_definition(void)
9602 {
9603         eat(T_namespace);
9604
9605         entity_t *entity = NULL;
9606         symbol_t *symbol = NULL;
9607
9608         if (token.kind == T_IDENTIFIER) {
9609                 symbol = token.base.symbol;
9610                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9611                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9612                         entity = NULL;
9613                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9614                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9615                         }
9616                 }
9617                 eat(T_IDENTIFIER);
9618         }
9619
9620         if (entity == NULL) {
9621                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9622                 entity->base.parent_scope = current_scope;
9623         }
9624
9625         if (token.kind == '=') {
9626                 /* TODO: parse namespace alias */
9627                 panic("namespace alias definition not supported yet");
9628         }
9629
9630         environment_push(entity);
9631         append_entity(current_scope, entity);
9632
9633         PUSH_SCOPE(&entity->namespacee.members);
9634         PUSH_CURRENT_ENTITY(entity);
9635
9636         add_anchor_token('}');
9637         expect('{');
9638         parse_externals();
9639         rem_anchor_token('}');
9640         expect('}');
9641
9642         POP_CURRENT_ENTITY();
9643         POP_SCOPE();
9644 }
9645
9646 /**
9647  * Parse a statement.
9648  * There's also parse_statement() which additionally checks for
9649  * "statement has no effect" warnings
9650  */
9651 static statement_t *intern_parse_statement(void)
9652 {
9653         /* declaration or statement */
9654         statement_t *statement;
9655         switch (token.kind) {
9656         case T_IDENTIFIER: {
9657                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9658                 if (la1_type == ':') {
9659                         statement = parse_label_statement();
9660                 } else if (is_typedef_symbol(token.base.symbol)) {
9661                         statement = parse_declaration_statement();
9662                 } else {
9663                         /* it's an identifier, the grammar says this must be an
9664                          * expression statement. However it is common that users mistype
9665                          * declaration types, so we guess a bit here to improve robustness
9666                          * for incorrect programs */
9667                         switch (la1_type) {
9668                         case '&':
9669                         case '*':
9670                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9671                         default:
9672                                         statement = parse_expression_statement();
9673                                 } else {
9674                         DECLARATION_START
9675                         case T_IDENTIFIER:
9676                                         statement = parse_declaration_statement();
9677                                 }
9678                                 break;
9679                         }
9680                 }
9681                 break;
9682         }
9683
9684         case T___extension__: {
9685                 /* This can be a prefix to a declaration or an expression statement.
9686                  * We simply eat it now and parse the rest with tail recursion. */
9687                 PUSH_EXTENSION();
9688                 statement = intern_parse_statement();
9689                 POP_EXTENSION();
9690                 break;
9691         }
9692
9693         DECLARATION_START
9694                 statement = parse_declaration_statement();
9695                 break;
9696
9697         case T___label__:
9698                 statement = parse_local_label_declaration();
9699                 break;
9700
9701         case ';':         statement = parse_empty_statement();         break;
9702         case '{':         statement = parse_compound_statement(false); break;
9703         case T___leave:   statement = parse_leave_statement();         break;
9704         case T___try:     statement = parse_ms_try_statment();         break;
9705         case T_asm:       statement = parse_asm_statement();           break;
9706         case T_break:     statement = parse_break();                   break;
9707         case T_case:      statement = parse_case_statement();          break;
9708         case T_continue:  statement = parse_continue();                break;
9709         case T_default:   statement = parse_default_statement();       break;
9710         case T_do:        statement = parse_do();                      break;
9711         case T_for:       statement = parse_for();                     break;
9712         case T_goto:      statement = parse_goto();                    break;
9713         case T_if:        statement = parse_if();                      break;
9714         case T_return:    statement = parse_return();                  break;
9715         case T_switch:    statement = parse_switch();                  break;
9716         case T_while:     statement = parse_while();                   break;
9717
9718         EXPRESSION_START
9719                 statement = parse_expression_statement();
9720                 break;
9721
9722         default:
9723                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9724                 statement = create_error_statement();
9725                 eat_until_anchor();
9726                 break;
9727         }
9728
9729         return statement;
9730 }
9731
9732 /**
9733  * parse a statement and emits "statement has no effect" warning if needed
9734  * (This is really a wrapper around intern_parse_statement with check for 1
9735  *  single warning. It is needed, because for statement expressions we have
9736  *  to avoid the warning on the last statement)
9737  */
9738 static statement_t *parse_statement(void)
9739 {
9740         statement_t *statement = intern_parse_statement();
9741
9742         if (statement->kind == STATEMENT_EXPRESSION) {
9743                 expression_t *expression = statement->expression.expression;
9744                 if (!expression_has_effect(expression)) {
9745                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9746                 }
9747         }
9748
9749         return statement;
9750 }
9751
9752 /**
9753  * Parse a compound statement.
9754  */
9755 static statement_t *parse_compound_statement(bool inside_expression_statement)
9756 {
9757         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9758
9759         PUSH_PARENT(statement);
9760         PUSH_SCOPE(&statement->compound.scope);
9761
9762         eat('{');
9763         add_anchor_token('}');
9764         /* tokens, which can start a statement */
9765         /* TODO MS, __builtin_FOO */
9766         add_anchor_token('!');
9767         add_anchor_token('&');
9768         add_anchor_token('(');
9769         add_anchor_token('*');
9770         add_anchor_token('+');
9771         add_anchor_token('-');
9772         add_anchor_token(';');
9773         add_anchor_token('{');
9774         add_anchor_token('~');
9775         add_anchor_token(T_CHARACTER_CONSTANT);
9776         add_anchor_token(T_COLONCOLON);
9777         add_anchor_token(T_FLOATINGPOINT);
9778         add_anchor_token(T_IDENTIFIER);
9779         add_anchor_token(T_INTEGER);
9780         add_anchor_token(T_MINUSMINUS);
9781         add_anchor_token(T_PLUSPLUS);
9782         add_anchor_token(T_STRING_LITERAL);
9783         add_anchor_token(T__Bool);
9784         add_anchor_token(T__Complex);
9785         add_anchor_token(T__Imaginary);
9786         add_anchor_token(T___FUNCTION__);
9787         add_anchor_token(T___PRETTY_FUNCTION__);
9788         add_anchor_token(T___alignof__);
9789         add_anchor_token(T___attribute__);
9790         add_anchor_token(T___builtin_va_start);
9791         add_anchor_token(T___extension__);
9792         add_anchor_token(T___func__);
9793         add_anchor_token(T___imag__);
9794         add_anchor_token(T___label__);
9795         add_anchor_token(T___real__);
9796         add_anchor_token(T___thread);
9797         add_anchor_token(T_asm);
9798         add_anchor_token(T_auto);
9799         add_anchor_token(T_bool);
9800         add_anchor_token(T_break);
9801         add_anchor_token(T_case);
9802         add_anchor_token(T_char);
9803         add_anchor_token(T_class);
9804         add_anchor_token(T_const);
9805         add_anchor_token(T_const_cast);
9806         add_anchor_token(T_continue);
9807         add_anchor_token(T_default);
9808         add_anchor_token(T_delete);
9809         add_anchor_token(T_double);
9810         add_anchor_token(T_do);
9811         add_anchor_token(T_dynamic_cast);
9812         add_anchor_token(T_enum);
9813         add_anchor_token(T_extern);
9814         add_anchor_token(T_false);
9815         add_anchor_token(T_float);
9816         add_anchor_token(T_for);
9817         add_anchor_token(T_goto);
9818         add_anchor_token(T_if);
9819         add_anchor_token(T_inline);
9820         add_anchor_token(T_int);
9821         add_anchor_token(T_long);
9822         add_anchor_token(T_new);
9823         add_anchor_token(T_operator);
9824         add_anchor_token(T_register);
9825         add_anchor_token(T_reinterpret_cast);
9826         add_anchor_token(T_restrict);
9827         add_anchor_token(T_return);
9828         add_anchor_token(T_short);
9829         add_anchor_token(T_signed);
9830         add_anchor_token(T_sizeof);
9831         add_anchor_token(T_static);
9832         add_anchor_token(T_static_cast);
9833         add_anchor_token(T_struct);
9834         add_anchor_token(T_switch);
9835         add_anchor_token(T_template);
9836         add_anchor_token(T_this);
9837         add_anchor_token(T_throw);
9838         add_anchor_token(T_true);
9839         add_anchor_token(T_try);
9840         add_anchor_token(T_typedef);
9841         add_anchor_token(T_typeid);
9842         add_anchor_token(T_typename);
9843         add_anchor_token(T_typeof);
9844         add_anchor_token(T_union);
9845         add_anchor_token(T_unsigned);
9846         add_anchor_token(T_using);
9847         add_anchor_token(T_void);
9848         add_anchor_token(T_volatile);
9849         add_anchor_token(T_wchar_t);
9850         add_anchor_token(T_while);
9851
9852         statement_t **anchor            = &statement->compound.statements;
9853         bool          only_decls_so_far = true;
9854         while (token.kind != '}' && token.kind != T_EOF) {
9855                 statement_t *sub_statement = intern_parse_statement();
9856                 if (sub_statement->kind == STATEMENT_ERROR) {
9857                         break;
9858                 }
9859
9860                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9861                         only_decls_so_far = false;
9862                 } else if (!only_decls_so_far) {
9863                         source_position_t const *const pos = &sub_statement->base.source_position;
9864                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9865                 }
9866
9867                 *anchor = sub_statement;
9868                 anchor  = &sub_statement->base.next;
9869         }
9870         expect('}');
9871
9872         /* look over all statements again to produce no effect warnings */
9873         if (is_warn_on(WARN_UNUSED_VALUE)) {
9874                 statement_t *sub_statement = statement->compound.statements;
9875                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9876                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9877                                 continue;
9878                         /* don't emit a warning for the last expression in an expression
9879                          * statement as it has always an effect */
9880                         if (inside_expression_statement && sub_statement->base.next == NULL)
9881                                 continue;
9882
9883                         expression_t *expression = sub_statement->expression.expression;
9884                         if (!expression_has_effect(expression)) {
9885                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9886                         }
9887                 }
9888         }
9889
9890         rem_anchor_token(T_while);
9891         rem_anchor_token(T_wchar_t);
9892         rem_anchor_token(T_volatile);
9893         rem_anchor_token(T_void);
9894         rem_anchor_token(T_using);
9895         rem_anchor_token(T_unsigned);
9896         rem_anchor_token(T_union);
9897         rem_anchor_token(T_typeof);
9898         rem_anchor_token(T_typename);
9899         rem_anchor_token(T_typeid);
9900         rem_anchor_token(T_typedef);
9901         rem_anchor_token(T_try);
9902         rem_anchor_token(T_true);
9903         rem_anchor_token(T_throw);
9904         rem_anchor_token(T_this);
9905         rem_anchor_token(T_template);
9906         rem_anchor_token(T_switch);
9907         rem_anchor_token(T_struct);
9908         rem_anchor_token(T_static_cast);
9909         rem_anchor_token(T_static);
9910         rem_anchor_token(T_sizeof);
9911         rem_anchor_token(T_signed);
9912         rem_anchor_token(T_short);
9913         rem_anchor_token(T_return);
9914         rem_anchor_token(T_restrict);
9915         rem_anchor_token(T_reinterpret_cast);
9916         rem_anchor_token(T_register);
9917         rem_anchor_token(T_operator);
9918         rem_anchor_token(T_new);
9919         rem_anchor_token(T_long);
9920         rem_anchor_token(T_int);
9921         rem_anchor_token(T_inline);
9922         rem_anchor_token(T_if);
9923         rem_anchor_token(T_goto);
9924         rem_anchor_token(T_for);
9925         rem_anchor_token(T_float);
9926         rem_anchor_token(T_false);
9927         rem_anchor_token(T_extern);
9928         rem_anchor_token(T_enum);
9929         rem_anchor_token(T_dynamic_cast);
9930         rem_anchor_token(T_do);
9931         rem_anchor_token(T_double);
9932         rem_anchor_token(T_delete);
9933         rem_anchor_token(T_default);
9934         rem_anchor_token(T_continue);
9935         rem_anchor_token(T_const_cast);
9936         rem_anchor_token(T_const);
9937         rem_anchor_token(T_class);
9938         rem_anchor_token(T_char);
9939         rem_anchor_token(T_case);
9940         rem_anchor_token(T_break);
9941         rem_anchor_token(T_bool);
9942         rem_anchor_token(T_auto);
9943         rem_anchor_token(T_asm);
9944         rem_anchor_token(T___thread);
9945         rem_anchor_token(T___real__);
9946         rem_anchor_token(T___label__);
9947         rem_anchor_token(T___imag__);
9948         rem_anchor_token(T___func__);
9949         rem_anchor_token(T___extension__);
9950         rem_anchor_token(T___builtin_va_start);
9951         rem_anchor_token(T___attribute__);
9952         rem_anchor_token(T___alignof__);
9953         rem_anchor_token(T___PRETTY_FUNCTION__);
9954         rem_anchor_token(T___FUNCTION__);
9955         rem_anchor_token(T__Imaginary);
9956         rem_anchor_token(T__Complex);
9957         rem_anchor_token(T__Bool);
9958         rem_anchor_token(T_STRING_LITERAL);
9959         rem_anchor_token(T_PLUSPLUS);
9960         rem_anchor_token(T_MINUSMINUS);
9961         rem_anchor_token(T_INTEGER);
9962         rem_anchor_token(T_IDENTIFIER);
9963         rem_anchor_token(T_FLOATINGPOINT);
9964         rem_anchor_token(T_COLONCOLON);
9965         rem_anchor_token(T_CHARACTER_CONSTANT);
9966         rem_anchor_token('~');
9967         rem_anchor_token('{');
9968         rem_anchor_token(';');
9969         rem_anchor_token('-');
9970         rem_anchor_token('+');
9971         rem_anchor_token('*');
9972         rem_anchor_token('(');
9973         rem_anchor_token('&');
9974         rem_anchor_token('!');
9975         rem_anchor_token('}');
9976
9977         POP_SCOPE();
9978         POP_PARENT();
9979         return statement;
9980 }
9981
9982 /**
9983  * Check for unused global static functions and variables
9984  */
9985 static void check_unused_globals(void)
9986 {
9987         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9988                 return;
9989
9990         for (const entity_t *entity = file_scope->entities; entity != NULL;
9991              entity = entity->base.next) {
9992                 if (!is_declaration(entity))
9993                         continue;
9994
9995                 const declaration_t *declaration = &entity->declaration;
9996                 if (declaration->used                  ||
9997                     declaration->modifiers & DM_UNUSED ||
9998                     declaration->modifiers & DM_USED   ||
9999                     declaration->storage_class != STORAGE_CLASS_STATIC)
10000                         continue;
10001
10002                 warning_t   why;
10003                 char const *s;
10004                 if (entity->kind == ENTITY_FUNCTION) {
10005                         /* inhibit warning for static inline functions */
10006                         if (entity->function.is_inline)
10007                                 continue;
10008
10009                         why = WARN_UNUSED_FUNCTION;
10010                         s   = entity->function.statement != NULL ? "defined" : "declared";
10011                 } else {
10012                         why = WARN_UNUSED_VARIABLE;
10013                         s   = "defined";
10014                 }
10015
10016                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10017         }
10018 }
10019
10020 static void parse_global_asm(void)
10021 {
10022         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10023
10024         eat(T_asm);
10025         add_anchor_token(';');
10026         add_anchor_token(')');
10027         add_anchor_token(T_STRING_LITERAL);
10028         expect('(');
10029
10030         rem_anchor_token(T_STRING_LITERAL);
10031         statement->asms.asm_text = parse_string_literals("global asm");
10032         statement->base.next     = unit->global_asm;
10033         unit->global_asm         = statement;
10034
10035         rem_anchor_token(')');
10036         expect(')');
10037         rem_anchor_token(';');
10038         expect(';');
10039 }
10040
10041 static void parse_linkage_specification(void)
10042 {
10043         eat(T_extern);
10044
10045         source_position_t const pos     = *HERE;
10046         char const       *const linkage = parse_string_literals(NULL).begin;
10047
10048         linkage_kind_t old_linkage = current_linkage;
10049         linkage_kind_t new_linkage;
10050         if (streq(linkage, "C")) {
10051                 new_linkage = LINKAGE_C;
10052         } else if (streq(linkage, "C++")) {
10053                 new_linkage = LINKAGE_CXX;
10054         } else {
10055                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10056                 new_linkage = LINKAGE_C;
10057         }
10058         current_linkage = new_linkage;
10059
10060         if (next_if('{')) {
10061                 parse_externals();
10062                 expect('}');
10063         } else {
10064                 parse_external();
10065         }
10066
10067         assert(current_linkage == new_linkage);
10068         current_linkage = old_linkage;
10069 }
10070
10071 static void parse_external(void)
10072 {
10073         switch (token.kind) {
10074                 case T_extern:
10075                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10076                                 parse_linkage_specification();
10077                         } else {
10078                 DECLARATION_START_NO_EXTERN
10079                 case T_IDENTIFIER:
10080                 case T___extension__:
10081                 /* tokens below are for implicit int */
10082                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10083                               implicit int) */
10084                 case '*':  /* * x; -> int* x; */
10085                 case '(':  /* (x); -> int (x); */
10086                                 PUSH_EXTENSION();
10087                                 parse_external_declaration();
10088                                 POP_EXTENSION();
10089                         }
10090                         return;
10091
10092                 case T_asm:
10093                         parse_global_asm();
10094                         return;
10095
10096                 case T_namespace:
10097                         parse_namespace_definition();
10098                         return;
10099
10100                 case ';':
10101                         if (!strict_mode) {
10102                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10103                                 eat(';');
10104                                 return;
10105                         }
10106                         /* FALLTHROUGH */
10107
10108                 default:
10109                         errorf(HERE, "stray %K outside of function", &token);
10110                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10111                                 eat_until_matching_token(token.kind);
10112                         next_token();
10113                         return;
10114         }
10115 }
10116
10117 static void parse_externals(void)
10118 {
10119         add_anchor_token('}');
10120         add_anchor_token(T_EOF);
10121
10122 #ifndef NDEBUG
10123         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10124         unsigned short token_anchor_copy[T_LAST_TOKEN];
10125         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10126 #endif
10127
10128         while (token.kind != T_EOF && token.kind != '}') {
10129 #ifndef NDEBUG
10130                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10131                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10132                         if (count != 0) {
10133                                 /* the anchor set and its copy differs */
10134                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10135                         }
10136                 }
10137                 if (in_gcc_extension) {
10138                         /* an gcc extension scope was not closed */
10139                         internal_errorf(HERE, "Leaked __extension__");
10140                 }
10141 #endif
10142
10143                 parse_external();
10144         }
10145
10146         rem_anchor_token(T_EOF);
10147         rem_anchor_token('}');
10148 }
10149
10150 /**
10151  * Parse a translation unit.
10152  */
10153 static void parse_translation_unit(void)
10154 {
10155         add_anchor_token(T_EOF);
10156
10157         while (true) {
10158                 parse_externals();
10159
10160                 if (token.kind == T_EOF)
10161                         break;
10162
10163                 errorf(HERE, "stray %K outside of function", &token);
10164                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10165                         eat_until_matching_token(token.kind);
10166                 next_token();
10167         }
10168 }
10169
10170 void set_default_visibility(elf_visibility_tag_t visibility)
10171 {
10172         default_visibility = visibility;
10173 }
10174
10175 /**
10176  * Parse the input.
10177  *
10178  * @return  the translation unit or NULL if errors occurred.
10179  */
10180 void start_parsing(void)
10181 {
10182         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10183         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10184         diagnostic_count  = 0;
10185         error_count       = 0;
10186         warning_count     = 0;
10187
10188         print_to_file(stderr);
10189
10190         assert(unit == NULL);
10191         unit = allocate_ast_zero(sizeof(unit[0]));
10192
10193         assert(file_scope == NULL);
10194         file_scope = &unit->scope;
10195
10196         assert(current_scope == NULL);
10197         scope_push(&unit->scope);
10198
10199         create_gnu_builtins();
10200         if (c_mode & _MS)
10201                 create_microsoft_intrinsics();
10202 }
10203
10204 translation_unit_t *finish_parsing(void)
10205 {
10206         assert(current_scope == &unit->scope);
10207         scope_pop(NULL);
10208
10209         assert(file_scope == &unit->scope);
10210         check_unused_globals();
10211         file_scope = NULL;
10212
10213         DEL_ARR_F(environment_stack);
10214         DEL_ARR_F(label_stack);
10215
10216         translation_unit_t *result = unit;
10217         unit = NULL;
10218         return result;
10219 }
10220
10221 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10222  * are given length one. */
10223 static void complete_incomplete_arrays(void)
10224 {
10225         size_t n = ARR_LEN(incomplete_arrays);
10226         for (size_t i = 0; i != n; ++i) {
10227                 declaration_t *const decl = incomplete_arrays[i];
10228                 type_t        *const type = skip_typeref(decl->type);
10229
10230                 if (!is_type_incomplete(type))
10231                         continue;
10232
10233                 source_position_t const *const pos = &decl->base.source_position;
10234                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10235
10236                 type_t *const new_type = duplicate_type(type);
10237                 new_type->array.size_constant     = true;
10238                 new_type->array.has_implicit_size = true;
10239                 new_type->array.size              = 1;
10240
10241                 type_t *const result = identify_new_type(new_type);
10242
10243                 decl->type = result;
10244         }
10245 }
10246
10247 static void prepare_main_collect2(entity_t *const entity)
10248 {
10249         PUSH_SCOPE(&entity->function.statement->compound.scope);
10250
10251         // create call to __main
10252         symbol_t *symbol         = symbol_table_insert("__main");
10253         entity_t *subsubmain_ent
10254                 = create_implicit_function(symbol, &builtin_source_position);
10255
10256         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10257         type_t       *ftype       = subsubmain_ent->declaration.type;
10258         ref->base.source_position = builtin_source_position;
10259         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10260         ref->reference.entity     = subsubmain_ent;
10261
10262         expression_t *call = allocate_expression_zero(EXPR_CALL);
10263         call->base.source_position = builtin_source_position;
10264         call->base.type            = type_void;
10265         call->call.function        = ref;
10266
10267         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10268         expr_statement->base.source_position  = builtin_source_position;
10269         expr_statement->expression.expression = call;
10270
10271         statement_t *statement = entity->function.statement;
10272         assert(statement->kind == STATEMENT_COMPOUND);
10273         compound_statement_t *compounds = &statement->compound;
10274
10275         expr_statement->base.next = compounds->statements;
10276         compounds->statements     = expr_statement;
10277
10278         POP_SCOPE();
10279 }
10280
10281 void parse(void)
10282 {
10283         lookahead_bufpos = 0;
10284         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10285                 next_token();
10286         }
10287         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10288         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10289         parse_translation_unit();
10290         complete_incomplete_arrays();
10291         DEL_ARR_F(incomplete_arrays);
10292         incomplete_arrays = NULL;
10293 }
10294
10295 /**
10296  * Initialize the parser.
10297  */
10298 void init_parser(void)
10299 {
10300         sym_anonymous = symbol_table_insert("<anonymous>");
10301
10302         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10303
10304         init_expression_parsers();
10305         obstack_init(&temp_obst);
10306 }
10307
10308 /**
10309  * Terminate the parser.
10310  */
10311 void exit_parser(void)
10312 {
10313         obstack_free(&temp_obst, NULL);
10314 }