nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T___FUNCDNAME__:             \
 256         case T___FUNCSIG__:               \
 257         case T___PRETTY_FUNCTION__:       \
 258         case T___alignof__:               \
 259         case T___builtin_classify_type:   \
 260         case T___builtin_constant_p:      \
 261         case T___builtin_isgreater:       \
 262         case T___builtin_isgreaterequal:  \
 263         case T___builtin_isless:          \
 264         case T___builtin_islessequal:     \
 265         case T___builtin_islessgreater:   \
 266         case T___builtin_isunordered:     \
 267         case T___builtin_offsetof:        \
 268         case T___builtin_va_arg:          \
 269         case T___builtin_va_copy:         \
 270         case T___builtin_va_start:        \
 271         case T___func__:                  \
 272         case T___noop:                    \
 273         case T__assume:                   \
 274         case T_delete:                    \
 275         case T_false:                     \
 276         case T_sizeof:                    \
 277         case T_throw:                     \
 278         case T_true:
 279
 280 /**
 281  * Returns the size of a statement node.
 282  *
 283  * @param kind  the statement kind
 284  */
 285 static size_t get_statement_struct_size(statement_kind_t kind)
 286 {
 287         static const size_t sizes[] = {
 288                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 289                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 290                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 291                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 292                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 293                 [STATEMENT_IF]            = sizeof(if_statement_t),
 294                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 295                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 296                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 297                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 298                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 299                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 300                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 301                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 302                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 303                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 304                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 305                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 306                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 307                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 308         };
 309         assert((size_t)kind < lengthof(sizes));
 310         assert(sizes[kind] != 0);
 311         return sizes[kind];
 312 }
 313
 314 /**
 315  * Returns the size of an expression node.
 316  *
 317  * @param kind  the expression kind
 318  */
 319 static size_t get_expression_struct_size(expression_kind_t kind)
 320 {
 321         static const size_t sizes[] = {
 322                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 323                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 324                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 325                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 329                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 330                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 331                 [EXPR_CALL]                       = sizeof(call_expression_t),
 332                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 333                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 334                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 335                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 336                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 337                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 338                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 339                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 340                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 341                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 342                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 343                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 344                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 345                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 346                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 347                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 348                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 349         };
 350         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 351                 return sizes[EXPR_UNARY_FIRST];
 352         }
 353         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 354                 return sizes[EXPR_BINARY_FIRST];
 355         }
 356         assert((size_t)kind < lengthof(sizes));
 357         assert(sizes[kind] != 0);
 358         return sizes[kind];
 359 }
 360
 361 /**
 362  * Allocate a statement node of given kind and initialize all
 363  * fields with zero. Sets its source position to the position
 364  * of the current token.
 365  */
 366 static statement_t *allocate_statement_zero(statement_kind_t kind)
 367 {
 368         size_t       size = get_statement_struct_size(kind);
 369         statement_t *res  = allocate_ast_zero(size);
 370
 371         res->base.kind            = kind;
 372         res->base.parent          = current_parent;
 373         res->base.source_position = *HERE;
 374         return res;
 375 }
 376
 377 /**
 378  * Allocate an expression node of given kind and initialize all
 379  * fields with zero.
 380  *
 381  * @param kind  the kind of the expression to allocate
 382  */
 383 static expression_t *allocate_expression_zero(expression_kind_t kind)
 384 {
 385         size_t        size = get_expression_struct_size(kind);
 386         expression_t *res  = allocate_ast_zero(size);
 387
 388         res->base.kind            = kind;
 389         res->base.type            = type_error_type;
 390         res->base.source_position = *HERE;
 391         return res;
 392 }
 393
 394 /**
 395  * Creates a new invalid expression at the source position
 396  * of the current token.
 397  */
 398 static expression_t *create_error_expression(void)
 399 {
 400         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 401         expression->base.type = type_error_type;
 402         return expression;
 403 }
 404
 405 /**
 406  * Creates a new invalid statement.
 407  */
 408 static statement_t *create_error_statement(void)
 409 {
 410         return allocate_statement_zero(STATEMENT_ERROR);
 411 }
 412
 413 /**
 414  * Allocate a new empty statement.
 415  */
 416 static statement_t *create_empty_statement(void)
 417 {
 418         return allocate_statement_zero(STATEMENT_EMPTY);
 419 }
 420
 421 /**
 422  * Returns the size of an initializer node.
 423  *
 424  * @param kind  the initializer kind
 425  */
 426 static size_t get_initializer_size(initializer_kind_t kind)
 427 {
 428         static const size_t sizes[] = {
 429                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 430                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert((size_t)kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = lexer_token;
 474         lexer_next_token();
 475
 476         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 477
 478 #ifdef PRINT_TOKENS
 479         print_token(stderr, &token);
 480         fprintf(stderr, "\n");
 481 #endif
 482 }
 483
 484 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 485
 486 static inline bool next_if(token_kind_t const type)
 487 {
 488         if (token.kind == type) {
 489                 eat(type);
 490                 return true;
 491         } else {
 492                 return false;
 493         }
 494 }
 495
 496 /**
 497  * Return the next token with a given lookahead.
 498  */
 499 static inline const token_t *look_ahead(size_t num)
 500 {
 501         assert(0 < num && num <= MAX_LOOKAHEAD);
 502         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 503         return &lookahead_buffer[pos];
 504 }
 505
 506 /**
 507  * Adds a token type to the token type anchor set (a multi-set).
 508  */
 509 static void add_anchor_token(token_kind_t const token_kind)
 510 {
 511         assert(token_kind < T_LAST_TOKEN);
 512         ++token_anchor_set[token_kind];
 513 }
 514
 515 /**
 516  * Remove a token type from the token type anchor set (a multi-set).
 517  */
 518 static void rem_anchor_token(token_kind_t const token_kind)
 519 {
 520         assert(token_kind < T_LAST_TOKEN);
 521         assert(token_anchor_set[token_kind] != 0);
 522         --token_anchor_set[token_kind];
 523 }
 524
 525 /**
 526  * Eat tokens until a matching token type is found.
 527  */
 528 static void eat_until_matching_token(token_kind_t const type)
 529 {
 530         token_kind_t end_token;
 531         switch (type) {
 532                 case '(': end_token = ')';  break;
 533                 case '{': end_token = '}';  break;
 534                 case '[': end_token = ']';  break;
 535                 default:  end_token = type; break;
 536         }
 537
 538         unsigned parenthesis_count = 0;
 539         unsigned brace_count       = 0;
 540         unsigned bracket_count     = 0;
 541         while (token.kind        != end_token ||
 542                parenthesis_count != 0         ||
 543                brace_count       != 0         ||
 544                bracket_count     != 0) {
 545                 switch (token.kind) {
 546                 case T_EOF: return;
 547                 case '(': ++parenthesis_count; break;
 548                 case '{': ++brace_count;       break;
 549                 case '[': ++bracket_count;     break;
 550
 551                 case ')':
 552                         if (parenthesis_count > 0)
 553                                 --parenthesis_count;
 554                         goto check_stop;
 555
 556                 case '}':
 557                         if (brace_count > 0)
 558                                 --brace_count;
 559                         goto check_stop;
 560
 561                 case ']':
 562                         if (bracket_count > 0)
 563                                 --bracket_count;
 564 check_stop:
 565                         if (token.kind        == end_token &&
 566                             parenthesis_count == 0         &&
 567                             brace_count       == 0         &&
 568                             bracket_count     == 0)
 569                                 return;
 570                         break;
 571
 572                 default:
 573                         break;
 574                 }
 575                 next_token();
 576         }
 577 }
 578
 579 /**
 580  * Eat input tokens until an anchor is found.
 581  */
 582 static void eat_until_anchor(void)
 583 {
 584         while (token_anchor_set[token.kind] == 0) {
 585                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 586                         eat_until_matching_token(token.kind);
 587                 next_token();
 588         }
 589 }
 590
 591 /**
 592  * Eat a whole block from input tokens.
 593  */
 594 static void eat_block(void)
 595 {
 596         eat_until_matching_token('{');
 597         next_if('}');
 598 }
 599
 600 /**
 601  * Report a parse error because an expected token was not found.
 602  */
 603 static
 604 #if defined __GNUC__ && __GNUC__ >= 4
 605 __attribute__((sentinel))
 606 #endif
 607 void parse_error_expected(const char *message, ...)
 608 {
 609         if (message != NULL) {
 610                 errorf(HERE, "%s", message);
 611         }
 612         va_list ap;
 613         va_start(ap, message);
 614         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 615         va_end(ap);
 616 }
 617
 618 /**
 619  * Report an incompatible type.
 620  */
 621 static void type_error_incompatible(const char *msg,
 622                 const source_position_t *source_position, type_t *type1, type_t *type2)
 623 {
 624         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 625                msg, type1, type2);
 626 }
 627
 628 static bool skip_till(token_kind_t const expected, char const *const context)
 629 {
 630         if (UNLIKELY(token.kind != expected)) {
 631                 parse_error_expected(context, expected, NULL);
 632                 add_anchor_token(expected);
 633                 eat_until_anchor();
 634                 rem_anchor_token(expected);
 635                 if (token.kind != expected)
 636                         return false;
 637         }
 638         return true;
 639 }
 640
 641 /**
 642  * Expect the current token is the expected token.
 643  * If not, generate an error and skip until the next anchor.
 644  */
 645 static void expect(token_kind_t const expected)
 646 {
 647         if (skip_till(expected, NULL))
 648                 eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (!skip_till(T_IDENTIFIER, context))
 654                 return NULL;
 655         symbol_t *const sym = token.base.symbol;
 656         if (pos)
 657                 *pos = *HERE;
 658         eat(T_IDENTIFIER);
 659         return sym;
 660 }
 661
 662 /**
 663  * Push a given scope on the scope stack and make it the
 664  * current scope
 665  */
 666 static scope_t *scope_push(scope_t *new_scope)
 667 {
 668         if (current_scope != NULL) {
 669                 new_scope->depth = current_scope->depth + 1;
 670         }
 671
 672         scope_t *old_scope = current_scope;
 673         current_scope      = new_scope;
 674         return old_scope;
 675 }
 676
 677 /**
 678  * Pop the current scope from the scope stack.
 679  */
 680 static void scope_pop(scope_t *old_scope)
 681 {
 682         current_scope = old_scope;
 683 }
 684
 685 /**
 686  * Search an entity by its symbol in a given namespace.
 687  */
 688 static entity_t *get_entity(const symbol_t *const symbol,
 689                             namespace_tag_t namespc)
 690 {
 691         entity_t *entity = symbol->entity;
 692         for (; entity != NULL; entity = entity->base.symbol_next) {
 693                 if ((namespace_tag_t)entity->base.namespc == namespc)
 694                         return entity;
 695         }
 696
 697         return NULL;
 698 }
 699
 700 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 701  * possible. */
 702 static entity_t *get_tag(symbol_t const *const symbol,
 703                          entity_kind_tag_t const kind)
 704 {
 705         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 706         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 707                 errorf(HERE,
 708                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 709                                 symbol, &entity->base.source_position);
 710                 entity = NULL;
 711         }
 712         return entity;
 713 }
 714
 715 /**
 716  * pushs an entity on the environment stack and links the corresponding symbol
 717  * it.
 718  */
 719 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 720 {
 721         symbol_t           *symbol  = entity->base.symbol;
 722         entity_namespace_t  namespc = entity->base.namespc;
 723         assert(namespc != 0);
 724
 725         /* replace/add entity into entity list of the symbol */
 726         entity_t **anchor;
 727         entity_t  *iter;
 728         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 729                 iter = *anchor;
 730                 if (iter == NULL)
 731                         break;
 732
 733                 /* replace an entry? */
 734                 if (iter->base.namespc == namespc) {
 735                         entity->base.symbol_next = iter->base.symbol_next;
 736                         break;
 737                 }
 738         }
 739         *anchor = entity;
 740
 741         /* remember old declaration */
 742         stack_entry_t entry;
 743         entry.symbol     = symbol;
 744         entry.old_entity = iter;
 745         entry.namespc    = namespc;
 746         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 747 }
 748
 749 /**
 750  * Push an entity on the environment stack.
 751  */
 752 static void environment_push(entity_t *entity)
 753 {
 754         assert(entity->base.source_position.input_name != NULL);
 755         assert(entity->base.parent_scope != NULL);
 756         stack_push(&environment_stack, entity);
 757 }
 758
 759 /**
 760  * Push a declaration on the global label stack.
 761  *
 762  * @param declaration  the declaration
 763  */
 764 static void label_push(entity_t *label)
 765 {
 766         /* we abuse the parameters scope as parent for the labels */
 767         label->base.parent_scope = &current_function->parameters;
 768         stack_push(&label_stack, label);
 769 }
 770
 771 /**
 772  * pops symbols from the environment stack until @p new_top is the top element
 773  */
 774 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 775 {
 776         stack_entry_t *stack = *stack_ptr;
 777         size_t         top   = ARR_LEN(stack);
 778         size_t         i;
 779
 780         assert(new_top <= top);
 781         if (new_top == top)
 782                 return;
 783
 784         for (i = top; i > new_top; --i) {
 785                 stack_entry_t *entry = &stack[i - 1];
 786
 787                 entity_t           *old_entity = entry->old_entity;
 788                 symbol_t           *symbol     = entry->symbol;
 789                 entity_namespace_t  namespc    = entry->namespc;
 790
 791                 /* replace with old_entity/remove */
 792                 entity_t **anchor;
 793                 entity_t  *iter;
 794                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 795                         iter = *anchor;
 796                         assert(iter != NULL);
 797                         /* replace an entry? */
 798                         if (iter->base.namespc == namespc)
 799                                 break;
 800                 }
 801
 802                 /* restore definition from outer scopes (if there was one) */
 803                 if (old_entity != NULL) {
 804                         old_entity->base.symbol_next = iter->base.symbol_next;
 805                         *anchor                      = old_entity;
 806                 } else {
 807                         /* remove entry from list */
 808                         *anchor = iter->base.symbol_next;
 809                 }
 810         }
 811
 812         ARR_SHRINKLEN(*stack_ptr, new_top);
 813 }
 814
 815 /**
 816  * Pop all entries from the environment stack until the new_top
 817  * is reached.
 818  *
 819  * @param new_top  the new stack top
 820  */
 821 static void environment_pop_to(size_t new_top)
 822 {
 823         stack_pop_to(&environment_stack, new_top);
 824 }
 825
 826 /**
 827  * Pop all entries from the global label stack until the new_top
 828  * is reached.
 829  *
 830  * @param new_top  the new stack top
 831  */
 832 static void label_pop_to(size_t new_top)
 833 {
 834         stack_pop_to(&label_stack, new_top);
 835 }
 836
 837 static atomic_type_kind_t get_akind(const type_t *type)
 838 {
 839         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 840                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 841         return type->atomic.akind;
 842 }
 843
 844 /**
 845  * §6.3.1.1:2  Do integer promotion for a given type.
 846  *
 847  * @param type  the type to promote
 848  * @return the promoted type
 849  */
 850 static type_t *promote_integer(type_t *type)
 851 {
 852         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 853                 type = type_int;
 854
 855         return type;
 856 }
 857
 858 /**
 859  * Check if a given expression represents a null pointer constant.
 860  *
 861  * @param expression  the expression to check
 862  */
 863 static bool is_null_pointer_constant(const expression_t *expression)
 864 {
 865         /* skip void* cast */
 866         if (expression->kind == EXPR_UNARY_CAST) {
 867                 type_t *const type = skip_typeref(expression->base.type);
 868                 if (types_compatible(type, type_void_ptr))
 869                         expression = expression->unary.value;
 870         }
 871
 872         type_t *const type = skip_typeref(expression->base.type);
 873         if (!is_type_integer(type))
 874                 return false;
 875         switch (is_constant_expression(expression)) {
 876                 case EXPR_CLASS_ERROR:    return true;
 877                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 878                 default:                  return false;
 879         }
 880 }
 881
 882 /**
 883  * Create an implicit cast expression.
 884  *
 885  * @param expression  the expression to cast
 886  * @param dest_type   the destination type
 887  */
 888 static expression_t *create_implicit_cast(expression_t *expression,
 889                                           type_t *dest_type)
 890 {
 891         type_t *const source_type = expression->base.type;
 892
 893         if (source_type == dest_type)
 894                 return expression;
 895
 896         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 897         cast->unary.value   = expression;
 898         cast->base.type     = dest_type;
 899         cast->base.implicit = true;
 900
 901         return cast;
 902 }
 903
 904 typedef enum assign_error_t {
 905         ASSIGN_SUCCESS,
 906         ASSIGN_ERROR_INCOMPATIBLE,
 907         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 908         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 909         ASSIGN_WARNING_POINTER_FROM_INT,
 910         ASSIGN_WARNING_INT_FROM_POINTER
 911 } assign_error_t;
 912
 913 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, source_position_t const *const pos)
 914 {
 915         type_t *const orig_type_right = right->base.type;
 916         type_t *const type_left       = skip_typeref(orig_type_left);
 917         type_t *const type_right      = skip_typeref(orig_type_right);
 918
 919         switch (error) {
 920         case ASSIGN_SUCCESS:
 921                 return;
 922         case ASSIGN_ERROR_INCOMPATIBLE:
 923                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 924                 return;
 925
 926         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 927                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 928                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 929
 930                 /* the left type has all qualifiers from the right type */
 931                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 932                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 933                 return;
 934         }
 935
 936         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 937                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 938                 return;
 939
 940         case ASSIGN_WARNING_POINTER_FROM_INT:
 941                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 942                 return;
 943
 944         case ASSIGN_WARNING_INT_FROM_POINTER:
 945                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 946                 return;
 947
 948         default:
 949                 panic("invalid error value");
 950         }
 951 }
 952
 953 /** Implements the rules from §6.5.16.1 */
 954 static assign_error_t semantic_assign(type_t *orig_type_left,
 955                                       const expression_t *const right)
 956 {
 957         type_t *const orig_type_right = right->base.type;
 958         type_t *const type_left       = skip_typeref(orig_type_left);
 959         type_t *const type_right      = skip_typeref(orig_type_right);
 960
 961         if (is_type_pointer(type_left)) {
 962                 if (is_null_pointer_constant(right)) {
 963                         return ASSIGN_SUCCESS;
 964                 } else if (is_type_pointer(type_right)) {
 965                         type_t *points_to_left
 966                                 = skip_typeref(type_left->pointer.points_to);
 967                         type_t *points_to_right
 968                                 = skip_typeref(type_right->pointer.points_to);
 969                         assign_error_t res = ASSIGN_SUCCESS;
 970
 971                         /* the left type has all qualifiers from the right type */
 972                         unsigned missing_qualifiers
 973                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 974                         if (missing_qualifiers != 0) {
 975                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 976                         }
 977
 978                         points_to_left  = get_unqualified_type(points_to_left);
 979                         points_to_right = get_unqualified_type(points_to_right);
 980
 981                         if (is_type_void(points_to_left))
 982                                 return res;
 983
 984                         if (is_type_void(points_to_right)) {
 985                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 986                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 987                         }
 988
 989                         if (!types_compatible(points_to_left, points_to_right)) {
 990                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 991                         }
 992
 993                         return res;
 994                 } else if (is_type_integer(type_right)) {
 995                         return ASSIGN_WARNING_POINTER_FROM_INT;
 996                 }
 997         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 998                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 999                                 && is_type_pointer(type_right))) {
1000                 return ASSIGN_SUCCESS;
1001         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1002                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1003                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1004                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1005                         return ASSIGN_SUCCESS;
1006                 }
1007         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1008                 return ASSIGN_WARNING_INT_FROM_POINTER;
1009         }
1010
1011         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1012                 return ASSIGN_SUCCESS;
1013
1014         return ASSIGN_ERROR_INCOMPATIBLE;
1015 }
1016
1017 static expression_t *parse_constant_expression(void)
1018 {
1019         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1020
1021         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1022                 errorf(&result->base.source_position,
1023                        "expression '%E' is not constant", result);
1024         }
1025
1026         return result;
1027 }
1028
1029 static expression_t *parse_assignment_expression(void)
1030 {
1031         return parse_subexpression(PREC_ASSIGNMENT);
1032 }
1033
1034 static void append_string(string_t const *const s)
1035 {
1036         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1037          * possible, because other tokens are grown there alongside. */
1038         obstack_grow(&ast_obstack, s->begin, s->size);
1039 }
1040
1041 static string_t finish_string(void)
1042 {
1043         obstack_1grow(&ast_obstack, '\0');
1044         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1045         char const *const string = obstack_finish(&ast_obstack);
1046         return (string_t){ string, size };
1047 }
1048
1049 static string_t concat_string_literals(string_encoding_t *const out_enc)
1050 {
1051         assert(token.kind == T_STRING_LITERAL);
1052
1053         string_t          result;
1054         string_encoding_t enc = token.string.encoding;
1055         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1056                 append_string(&token.string.string);
1057                 eat(T_STRING_LITERAL);
1058                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1059                 do {
1060                         if (token.string.encoding != STRING_ENCODING_CHAR) {
1061                                 enc = token.string.encoding;
1062                         }
1063                         append_string(&token.string.string);
1064                         eat(T_STRING_LITERAL);
1065                 } while (token.kind == T_STRING_LITERAL);
1066                 result = finish_string();
1067         } else {
1068                 result = token.string.string;
1069                 eat(T_STRING_LITERAL);
1070         }
1071
1072         *out_enc = enc;
1073         return result;
1074 }
1075
1076 static string_t parse_string_literals(char const *const context)
1077 {
1078         if (!skip_till(T_STRING_LITERAL, context))
1079                 return (string_t){ "", 0 };
1080
1081         string_encoding_t       enc;
1082         source_position_t const pos = *HERE;
1083         string_t          const res = concat_string_literals(&enc);
1084
1085         if (enc != STRING_ENCODING_CHAR) {
1086                 errorf(&pos, "expected plain string literal, got wide string literal");
1087         }
1088
1089         return res;
1090 }
1091
1092 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1093 {
1094         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1095         attribute->kind            = kind;
1096         attribute->source_position = *HERE;
1097         return attribute;
1098 }
1099
1100 /**
1101  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1102  *
1103  *  attribute:
1104  *    __attribute__ ( ( attribute-list ) )
1105  *
1106  *  attribute-list:
1107  *    attrib
1108  *    attribute_list , attrib
1109  *
1110  *  attrib:
1111  *    empty
1112  *    any-word
1113  *    any-word ( identifier )
1114  *    any-word ( identifier , nonempty-expr-list )
1115  *    any-word ( expr-list )
1116  *
1117  *  where the "identifier" must not be declared as a type, and
1118  *  "any-word" may be any identifier (including one declared as a
1119  *  type), a reserved word storage class specifier, type specifier or
1120  *  type qualifier.  ??? This still leaves out most reserved keywords
1121  *  (following the old parser), shouldn't we include them, and why not
1122  *  allow identifiers declared as types to start the arguments?
1123  *
1124  *  Matze: this all looks confusing and little systematic, so we're even less
1125  *  strict and parse any list of things which are identifiers or
1126  *  (assignment-)expressions.
1127  */
1128 static attribute_argument_t *parse_attribute_arguments(void)
1129 {
1130         attribute_argument_t  *first  = NULL;
1131         attribute_argument_t **anchor = &first;
1132         if (token.kind != ')') do {
1133                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1134
1135                 /* is it an identifier */
1136                 if (token.kind == T_IDENTIFIER
1137                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1138                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1139                         argument->v.symbol = token.base.symbol;
1140                         eat(T_IDENTIFIER);
1141                 } else {
1142                         /* must be an expression */
1143                         expression_t *expression = parse_assignment_expression();
1144
1145                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1146                         argument->v.expression = expression;
1147                 }
1148
1149                 /* append argument */
1150                 *anchor = argument;
1151                 anchor  = &argument->next;
1152         } while (next_if(','));
1153         expect(')');
1154         return first;
1155 }
1156
1157 static attribute_t *parse_attribute_asm(void)
1158 {
1159         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1160         eat(T_asm);
1161         expect('(');
1162         attribute->a.arguments = parse_attribute_arguments();
1163         return attribute;
1164 }
1165
1166 static attribute_t *parse_attribute_gnu_single(void)
1167 {
1168         /* parse "any-word" */
1169         symbol_t *const symbol = token.base.symbol;
1170         if (symbol == NULL) {
1171                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1172                 return NULL;
1173         }
1174
1175         attribute_kind_t  kind;
1176         char const *const name = symbol->string;
1177         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1178                 if (kind > ATTRIBUTE_GNU_LAST) {
1179                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1180                         /* TODO: we should still save the attribute in the list... */
1181                         kind = ATTRIBUTE_UNKNOWN;
1182                         break;
1183                 }
1184
1185                 const char *attribute_name = get_attribute_name(kind);
1186                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1187                         break;
1188         }
1189
1190         attribute_t *attribute = allocate_attribute_zero(kind);
1191         next_token();
1192
1193         /* parse arguments */
1194         if (next_if('('))
1195                 attribute->a.arguments = parse_attribute_arguments();
1196
1197         return attribute;
1198 }
1199
1200 static attribute_t *parse_attribute_gnu(void)
1201 {
1202         attribute_t  *first  = NULL;
1203         attribute_t **anchor = &first;
1204
1205         eat(T___attribute__);
1206         add_anchor_token(')');
1207         add_anchor_token(',');
1208         expect('(');
1209         expect('(');
1210
1211         if (token.kind != ')') do {
1212                 attribute_t *attribute = parse_attribute_gnu_single();
1213                 if (attribute) {
1214                         *anchor = attribute;
1215                         anchor  = &attribute->next;
1216                 }
1217         } while (next_if(','));
1218         rem_anchor_token(',');
1219         rem_anchor_token(')');
1220
1221         expect(')');
1222         expect(')');
1223         return first;
1224 }
1225
1226 /** Parse attributes. */
1227 static attribute_t *parse_attributes(attribute_t *first)
1228 {
1229         attribute_t **anchor = &first;
1230         for (;;) {
1231                 while (*anchor != NULL)
1232                         anchor = &(*anchor)->next;
1233
1234                 attribute_t *attribute;
1235                 switch (token.kind) {
1236                 case T___attribute__:
1237                         attribute = parse_attribute_gnu();
1238                         if (attribute == NULL)
1239                                 continue;
1240                         break;
1241
1242                 case T_asm:
1243                         attribute = parse_attribute_asm();
1244                         break;
1245
1246                 case T_cdecl:
1247                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1248                         eat(T_cdecl);
1249                         break;
1250
1251                 case T__fastcall:
1252                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1253                         eat(T__fastcall);
1254                         break;
1255
1256                 case T__forceinline:
1257                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1258                         eat(T__forceinline);
1259                         break;
1260
1261                 case T__stdcall:
1262                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1263                         eat(T__stdcall);
1264                         break;
1265
1266                 case T___thiscall:
1267                         /* TODO record modifier */
1268                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1270                         eat(T___thiscall);
1271                         break;
1272
1273                 default:
1274                         return first;
1275                 }
1276
1277                 *anchor = attribute;
1278                 anchor  = &attribute->next;
1279         }
1280 }
1281
1282 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1283
1284 static entity_t *determine_lhs_ent(expression_t *const expr,
1285                                    entity_t *lhs_ent)
1286 {
1287         switch (expr->kind) {
1288                 case EXPR_REFERENCE: {
1289                         entity_t *const entity = expr->reference.entity;
1290                         /* we should only find variables as lvalues... */
1291                         if (entity->base.kind != ENTITY_VARIABLE
1292                                         && entity->base.kind != ENTITY_PARAMETER)
1293                                 return NULL;
1294
1295                         return entity;
1296                 }
1297
1298                 case EXPR_ARRAY_ACCESS: {
1299                         expression_t *const ref = expr->array_access.array_ref;
1300                         entity_t     *      ent = NULL;
1301                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1302                                 ent     = determine_lhs_ent(ref, lhs_ent);
1303                                 lhs_ent = ent;
1304                         } else {
1305                                 mark_vars_read(ref, lhs_ent);
1306                         }
1307                         mark_vars_read(expr->array_access.index, lhs_ent);
1308                         return ent;
1309                 }
1310
1311                 case EXPR_SELECT: {
1312                         mark_vars_read(expr->select.compound, lhs_ent);
1313                         if (is_type_compound(skip_typeref(expr->base.type)))
1314                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1315                         return NULL;
1316                 }
1317
1318                 case EXPR_UNARY_DEREFERENCE: {
1319                         expression_t *const val = expr->unary.value;
1320                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1321                                 /* *&x is a NOP */
1322                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1323                         } else {
1324                                 mark_vars_read(val, NULL);
1325                                 return NULL;
1326                         }
1327                 }
1328
1329                 default:
1330                         mark_vars_read(expr, NULL);
1331                         return NULL;
1332         }
1333 }
1334
1335 #define ENT_ANY ((entity_t*)-1)
1336
1337 /**
1338  * Mark declarations, which are read.  This is used to detect variables, which
1339  * are never read.
1340  * Example:
1341  * x = x + 1;
1342  *   x is not marked as "read", because it is only read to calculate its own new
1343  *   value.
1344  *
1345  * x += y; y += x;
1346  *   x and y are not detected as "not read", because multiple variables are
1347  *   involved.
1348  */
1349 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1350 {
1351         switch (expr->kind) {
1352                 case EXPR_REFERENCE: {
1353                         entity_t *const entity = expr->reference.entity;
1354                         if (entity->kind != ENTITY_VARIABLE
1355                                         && entity->kind != ENTITY_PARAMETER)
1356                                 return;
1357
1358                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1359                                 entity->variable.read = true;
1360                         }
1361                         return;
1362                 }
1363
1364                 case EXPR_CALL:
1365                         // TODO respect pure/const
1366                         mark_vars_read(expr->call.function, NULL);
1367                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1368                                 mark_vars_read(arg->expression, NULL);
1369                         }
1370                         return;
1371
1372                 case EXPR_CONDITIONAL:
1373                         // TODO lhs_decl should depend on whether true/false have an effect
1374                         mark_vars_read(expr->conditional.condition, NULL);
1375                         if (expr->conditional.true_expression != NULL)
1376                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1377                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1378                         return;
1379
1380                 case EXPR_SELECT:
1381                         if (lhs_ent == ENT_ANY
1382                                         && !is_type_compound(skip_typeref(expr->base.type)))
1383                                 lhs_ent = NULL;
1384                         mark_vars_read(expr->select.compound, lhs_ent);
1385                         return;
1386
1387                 case EXPR_ARRAY_ACCESS: {
1388                         mark_vars_read(expr->array_access.index, lhs_ent);
1389                         expression_t *const ref = expr->array_access.array_ref;
1390                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1391                                 if (lhs_ent == ENT_ANY)
1392                                         lhs_ent = NULL;
1393                         }
1394                         mark_vars_read(ref, lhs_ent);
1395                         return;
1396                 }
1397
1398                 case EXPR_VA_ARG:
1399                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1400                         return;
1401
1402                 case EXPR_VA_COPY:
1403                         mark_vars_read(expr->va_copye.src, lhs_ent);
1404                         return;
1405
1406                 case EXPR_UNARY_CAST:
1407                         /* Special case: Use void cast to mark a variable as "read" */
1408                         if (is_type_void(skip_typeref(expr->base.type)))
1409                                 lhs_ent = NULL;
1410                         goto unary;
1411
1412
1413                 case EXPR_UNARY_THROW:
1414                         if (expr->unary.value == NULL)
1415                                 return;
1416                         /* FALLTHROUGH */
1417                 case EXPR_UNARY_DEREFERENCE:
1418                 case EXPR_UNARY_DELETE:
1419                 case EXPR_UNARY_DELETE_ARRAY:
1420                         if (lhs_ent == ENT_ANY)
1421                                 lhs_ent = NULL;
1422                         goto unary;
1423
1424                 case EXPR_UNARY_NEGATE:
1425                 case EXPR_UNARY_PLUS:
1426                 case EXPR_UNARY_BITWISE_NEGATE:
1427                 case EXPR_UNARY_NOT:
1428                 case EXPR_UNARY_TAKE_ADDRESS:
1429                 case EXPR_UNARY_POSTFIX_INCREMENT:
1430                 case EXPR_UNARY_POSTFIX_DECREMENT:
1431                 case EXPR_UNARY_PREFIX_INCREMENT:
1432                 case EXPR_UNARY_PREFIX_DECREMENT:
1433                 case EXPR_UNARY_ASSUME:
1434 unary:
1435                         mark_vars_read(expr->unary.value, lhs_ent);
1436                         return;
1437
1438                 case EXPR_BINARY_ADD:
1439                 case EXPR_BINARY_SUB:
1440                 case EXPR_BINARY_MUL:
1441                 case EXPR_BINARY_DIV:
1442                 case EXPR_BINARY_MOD:
1443                 case EXPR_BINARY_EQUAL:
1444                 case EXPR_BINARY_NOTEQUAL:
1445                 case EXPR_BINARY_LESS:
1446                 case EXPR_BINARY_LESSEQUAL:
1447                 case EXPR_BINARY_GREATER:
1448                 case EXPR_BINARY_GREATEREQUAL:
1449                 case EXPR_BINARY_BITWISE_AND:
1450                 case EXPR_BINARY_BITWISE_OR:
1451                 case EXPR_BINARY_BITWISE_XOR:
1452                 case EXPR_BINARY_LOGICAL_AND:
1453                 case EXPR_BINARY_LOGICAL_OR:
1454                 case EXPR_BINARY_SHIFTLEFT:
1455                 case EXPR_BINARY_SHIFTRIGHT:
1456                 case EXPR_BINARY_COMMA:
1457                 case EXPR_BINARY_ISGREATER:
1458                 case EXPR_BINARY_ISGREATEREQUAL:
1459                 case EXPR_BINARY_ISLESS:
1460                 case EXPR_BINARY_ISLESSEQUAL:
1461                 case EXPR_BINARY_ISLESSGREATER:
1462                 case EXPR_BINARY_ISUNORDERED:
1463                         mark_vars_read(expr->binary.left,  lhs_ent);
1464                         mark_vars_read(expr->binary.right, lhs_ent);
1465                         return;
1466
1467                 case EXPR_BINARY_ASSIGN:
1468                 case EXPR_BINARY_MUL_ASSIGN:
1469                 case EXPR_BINARY_DIV_ASSIGN:
1470                 case EXPR_BINARY_MOD_ASSIGN:
1471                 case EXPR_BINARY_ADD_ASSIGN:
1472                 case EXPR_BINARY_SUB_ASSIGN:
1473                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1474                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1475                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1476                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1478                         if (lhs_ent == ENT_ANY)
1479                                 lhs_ent = NULL;
1480                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1481                         mark_vars_read(expr->binary.right, lhs_ent);
1482                         return;
1483                 }
1484
1485                 case EXPR_VA_START:
1486                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1487                         return;
1488
1489                 case EXPR_LITERAL_CASES:
1490                 case EXPR_LITERAL_CHARACTER:
1491                 case EXPR_ERROR:
1492                 case EXPR_STRING_LITERAL:
1493                 case EXPR_COMPOUND_LITERAL: // TODO init?
1494                 case EXPR_SIZEOF:
1495                 case EXPR_CLASSIFY_TYPE:
1496                 case EXPR_ALIGNOF:
1497                 case EXPR_FUNCNAME:
1498                 case EXPR_BUILTIN_CONSTANT_P:
1499                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1500                 case EXPR_OFFSETOF:
1501                 case EXPR_STATEMENT: // TODO
1502                 case EXPR_LABEL_ADDRESS:
1503                 case EXPR_ENUM_CONSTANT:
1504                         return;
1505         }
1506
1507         panic("unhandled expression");
1508 }
1509
1510 static designator_t *parse_designation(void)
1511 {
1512         designator_t  *result = NULL;
1513         designator_t **anchor = &result;
1514
1515         for (;;) {
1516                 designator_t *designator;
1517                 switch (token.kind) {
1518                 case '[':
1519                         designator = allocate_ast_zero(sizeof(designator[0]));
1520                         designator->source_position = *HERE;
1521                         eat('[');
1522                         add_anchor_token(']');
1523                         designator->array_index = parse_constant_expression();
1524                         rem_anchor_token(']');
1525                         expect(']');
1526                         break;
1527                 case '.':
1528                         designator = allocate_ast_zero(sizeof(designator[0]));
1529                         designator->source_position = *HERE;
1530                         eat('.');
1531                         designator->symbol = expect_identifier("while parsing designator", NULL);
1532                         if (!designator->symbol)
1533                                 return NULL;
1534                         break;
1535                 default:
1536                         expect('=');
1537                         return result;
1538                 }
1539
1540                 assert(designator != NULL);
1541                 *anchor = designator;
1542                 anchor  = &designator->next;
1543         }
1544 }
1545
1546 static initializer_t *initializer_from_string(array_type_t *const type, string_encoding_t const enc, string_t const *const string)
1547 {
1548         /* TODO: check len vs. size of array type */
1549         (void) type;
1550
1551         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1552         initializer->string.encoding = enc;
1553         initializer->string.string   = *string;
1554
1555         return initializer;
1556 }
1557
1558 /**
1559  * Build an initializer from a given expression.
1560  */
1561 static initializer_t *initializer_from_expression(type_t *orig_type,
1562                                                   expression_t *expression)
1563 {
1564         /* TODO check that expression is a constant expression */
1565
1566         type_t *const type = skip_typeref(orig_type);
1567
1568         /* §6.7.8.14/15 char array may be initialized by string literals */
1569         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1570                 array_type_t *const array_type   = &type->array;
1571                 type_t       *const element_type = skip_typeref(array_type->element_type);
1572                 switch (expression->string_literal.encoding) {
1573                 case STRING_ENCODING_CHAR: {
1574                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1575                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1576                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1577                                 goto make_string_init;
1578                         }
1579                         break;
1580                 }
1581
1582                 case STRING_ENCODING_WIDE: {
1583                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1584                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1585 make_string_init:
1586                                 return initializer_from_string(array_type, expression->string_literal.encoding, &expression->string_literal.value);
1587                         }
1588                         break;
1589                 }
1590                 }
1591         }
1592
1593         assign_error_t error = semantic_assign(type, expression);
1594         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1595                 return NULL;
1596         report_assign_error(error, type, expression, "initializer",
1597                             &expression->base.source_position);
1598
1599         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1600         result->value.value = create_implicit_cast(expression, type);
1601
1602         return result;
1603 }
1604
1605 /**
1606  * Parses an scalar initializer.
1607  *
1608  * §6.7.8.11; eat {} without warning
1609  */
1610 static initializer_t *parse_scalar_initializer(type_t *type,
1611                                                bool must_be_constant)
1612 {
1613         /* there might be extra {} hierarchies */
1614         int braces = 0;
1615         if (token.kind == '{') {
1616                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1617                 do {
1618                         eat('{');
1619                         ++braces;
1620                 } while (token.kind == '{');
1621         }
1622
1623         expression_t *expression = parse_assignment_expression();
1624         mark_vars_read(expression, NULL);
1625         if (must_be_constant && !is_linker_constant(expression)) {
1626                 errorf(&expression->base.source_position,
1627                        "initialisation expression '%E' is not constant",
1628                        expression);
1629         }
1630
1631         initializer_t *initializer = initializer_from_expression(type, expression);
1632
1633         if (initializer == NULL) {
1634                 errorf(&expression->base.source_position,
1635                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1636                        expression, expression->base.type, type);
1637                 /* TODO */
1638                 return NULL;
1639         }
1640
1641         bool additional_warning_displayed = false;
1642         while (braces > 0) {
1643                 next_if(',');
1644                 if (token.kind != '}') {
1645                         if (!additional_warning_displayed) {
1646                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1647                                 additional_warning_displayed = true;
1648                         }
1649                 }
1650                 eat_block();
1651                 braces--;
1652         }
1653
1654         return initializer;
1655 }
1656
1657 /**
1658  * An entry in the type path.
1659  */
1660 typedef struct type_path_entry_t type_path_entry_t;
1661 struct type_path_entry_t {
1662         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1663         union {
1664                 size_t         index;          /**< For array types: the current index. */
1665                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1666         } v;
1667 };
1668
1669 /**
1670  * A type path expression a position inside compound or array types.
1671  */
1672 typedef struct type_path_t type_path_t;
1673 struct type_path_t {
1674         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1675         type_t            *top_type;     /**< type of the element the path points */
1676         size_t             max_index;    /**< largest index in outermost array */
1677 };
1678
1679 /**
1680  * Prints a type path for debugging.
1681  */
1682 static __attribute__((unused)) void debug_print_type_path(
1683                 const type_path_t *path)
1684 {
1685         size_t len = ARR_LEN(path->path);
1686
1687         for (size_t i = 0; i < len; ++i) {
1688                 const type_path_entry_t *entry = & path->path[i];
1689
1690                 type_t *type = skip_typeref(entry->type);
1691                 if (is_type_compound(type)) {
1692                         /* in gcc mode structs can have no members */
1693                         if (entry->v.compound_entry == NULL) {
1694                                 assert(i == len-1);
1695                                 continue;
1696                         }
1697                         fprintf(stderr, ".%s",
1698                                 entry->v.compound_entry->base.symbol->string);
1699                 } else if (is_type_array(type)) {
1700                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1701                 } else {
1702                         fprintf(stderr, "-INVALID-");
1703                 }
1704         }
1705         if (path->top_type != NULL) {
1706                 fprintf(stderr, "  (");
1707                 print_type(path->top_type);
1708                 fprintf(stderr, ")");
1709         }
1710 }
1711
1712 /**
1713  * Return the top type path entry, ie. in a path
1714  * (type).a.b returns the b.
1715  */
1716 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1717 {
1718         size_t len = ARR_LEN(path->path);
1719         assert(len > 0);
1720         return &path->path[len-1];
1721 }
1722
1723 /**
1724  * Enlarge the type path by an (empty) element.
1725  */
1726 static type_path_entry_t *append_to_type_path(type_path_t *path)
1727 {
1728         size_t len = ARR_LEN(path->path);
1729         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1730
1731         type_path_entry_t *result = & path->path[len];
1732         memset(result, 0, sizeof(result[0]));
1733         return result;
1734 }
1735
1736 /**
1737  * Descending into a sub-type. Enter the scope of the current top_type.
1738  */
1739 static void descend_into_subtype(type_path_t *path)
1740 {
1741         type_t *orig_top_type = path->top_type;
1742         type_t *top_type      = skip_typeref(orig_top_type);
1743
1744         type_path_entry_t *top = append_to_type_path(path);
1745         top->type              = top_type;
1746
1747         if (is_type_compound(top_type)) {
1748                 compound_t *const compound = top_type->compound.compound;
1749                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1750
1751                 if (entry != NULL) {
1752                         top->v.compound_entry = &entry->declaration;
1753                         path->top_type = entry->declaration.type;
1754                 } else {
1755                         path->top_type = NULL;
1756                 }
1757         } else if (is_type_array(top_type)) {
1758                 top->v.index   = 0;
1759                 path->top_type = top_type->array.element_type;
1760         } else {
1761                 assert(!is_type_valid(top_type));
1762         }
1763 }
1764
1765 /**
1766  * Pop an entry from the given type path, ie. returning from
1767  * (type).a.b to (type).a
1768  */
1769 static void ascend_from_subtype(type_path_t *path)
1770 {
1771         type_path_entry_t *top = get_type_path_top(path);
1772
1773         path->top_type = top->type;
1774
1775         size_t len = ARR_LEN(path->path);
1776         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1777 }
1778
1779 /**
1780  * Pop entries from the given type path until the given
1781  * path level is reached.
1782  */
1783 static void ascend_to(type_path_t *path, size_t top_path_level)
1784 {
1785         size_t len = ARR_LEN(path->path);
1786
1787         while (len > top_path_level) {
1788                 ascend_from_subtype(path);
1789                 len = ARR_LEN(path->path);
1790         }
1791 }
1792
1793 static bool walk_designator(type_path_t *path, const designator_t *designator,
1794                             bool used_in_offsetof)
1795 {
1796         for (; designator != NULL; designator = designator->next) {
1797                 type_path_entry_t *top       = get_type_path_top(path);
1798                 type_t            *orig_type = top->type;
1799
1800                 type_t *type = skip_typeref(orig_type);
1801
1802                 if (designator->symbol != NULL) {
1803                         symbol_t *symbol = designator->symbol;
1804                         if (!is_type_compound(type)) {
1805                                 if (is_type_valid(type)) {
1806                                         errorf(&designator->source_position,
1807                                                "'.%Y' designator used for non-compound type '%T'",
1808                                                symbol, orig_type);
1809                                 }
1810
1811                                 top->type             = type_error_type;
1812                                 top->v.compound_entry = NULL;
1813                                 orig_type             = type_error_type;
1814                         } else {
1815                                 compound_t *compound = type->compound.compound;
1816                                 entity_t   *iter     = compound->members.entities;
1817                                 for (; iter != NULL; iter = iter->base.next) {
1818                                         if (iter->base.symbol == symbol) {
1819                                                 break;
1820                                         }
1821                                 }
1822                                 if (iter == NULL) {
1823                                         errorf(&designator->source_position,
1824                                                "'%T' has no member named '%Y'", orig_type, symbol);
1825                                         return false;
1826                                 }
1827                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1828                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1829                                         errorf(&designator->source_position,
1830                                                    "offsetof designator '%Y' must not specify bitfield",
1831                                                    symbol);
1832                                         return false;
1833                                 }
1834
1835                                 top->type             = orig_type;
1836                                 top->v.compound_entry = &iter->declaration;
1837                                 orig_type             = iter->declaration.type;
1838                         }
1839                 } else {
1840                         expression_t *array_index = designator->array_index;
1841                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1842                                 return true;
1843
1844                         if (!is_type_array(type)) {
1845                                 if (is_type_valid(type)) {
1846                                         errorf(&designator->source_position,
1847                                                "[%E] designator used for non-array type '%T'",
1848                                                array_index, orig_type);
1849                                 }
1850                                 return false;
1851                         }
1852
1853                         long index = fold_constant_to_int(array_index);
1854                         if (!used_in_offsetof) {
1855                                 if (index < 0) {
1856                                         errorf(&designator->source_position,
1857                                                "array index [%E] must be positive", array_index);
1858                                 } else if (type->array.size_constant) {
1859                                         long array_size = type->array.size;
1860                                         if (index >= array_size) {
1861                                                 errorf(&designator->source_position,
1862                                                        "designator [%E] (%d) exceeds array size %d",
1863                                                        array_index, index, array_size);
1864                                         }
1865                                 }
1866                         }
1867
1868                         top->type    = orig_type;
1869                         top->v.index = (size_t) index;
1870                         orig_type    = type->array.element_type;
1871                 }
1872                 path->top_type = orig_type;
1873
1874                 if (designator->next != NULL) {
1875                         descend_into_subtype(path);
1876                 }
1877         }
1878         return true;
1879 }
1880
1881 static void advance_current_object(type_path_t *path, size_t top_path_level)
1882 {
1883         type_path_entry_t *top = get_type_path_top(path);
1884
1885         type_t *type = skip_typeref(top->type);
1886         if (is_type_union(type)) {
1887                 /* in unions only the first element is initialized */
1888                 top->v.compound_entry = NULL;
1889         } else if (is_type_struct(type)) {
1890                 declaration_t *entry = top->v.compound_entry;
1891
1892                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1893                 if (next_entity != NULL) {
1894                         assert(is_declaration(next_entity));
1895                         entry = &next_entity->declaration;
1896                 } else {
1897                         entry = NULL;
1898                 }
1899
1900                 top->v.compound_entry = entry;
1901                 if (entry != NULL) {
1902                         path->top_type = entry->type;
1903                         return;
1904                 }
1905         } else if (is_type_array(type)) {
1906                 assert(is_type_array(type));
1907
1908                 top->v.index++;
1909
1910                 if (!type->array.size_constant || top->v.index < type->array.size) {
1911                         return;
1912                 }
1913         } else {
1914                 assert(!is_type_valid(type));
1915                 return;
1916         }
1917
1918         /* we're past the last member of the current sub-aggregate, try if we
1919          * can ascend in the type hierarchy and continue with another subobject */
1920         size_t len = ARR_LEN(path->path);
1921
1922         if (len > top_path_level) {
1923                 ascend_from_subtype(path);
1924                 advance_current_object(path, top_path_level);
1925         } else {
1926                 path->top_type = NULL;
1927         }
1928 }
1929
1930 /**
1931  * skip any {...} blocks until a closing bracket is reached.
1932  */
1933 static void skip_initializers(void)
1934 {
1935         next_if('{');
1936
1937         while (token.kind != '}') {
1938                 if (token.kind == T_EOF)
1939                         return;
1940                 if (token.kind == '{') {
1941                         eat_block();
1942                         continue;
1943                 }
1944                 next_token();
1945         }
1946 }
1947
1948 static initializer_t *create_empty_initializer(void)
1949 {
1950         static initializer_t empty_initializer
1951                 = { .list = { { INITIALIZER_LIST }, 0 } };
1952         return &empty_initializer;
1953 }
1954
1955 /**
1956  * Parse a part of an initialiser for a struct or union,
1957  */
1958 static initializer_t *parse_sub_initializer(type_path_t *path,
1959                 type_t *outer_type, size_t top_path_level,
1960                 parse_initializer_env_t *env)
1961 {
1962         if (token.kind == '}') {
1963                 /* empty initializer */
1964                 return create_empty_initializer();
1965         }
1966
1967         type_t *orig_type = path->top_type;
1968         type_t *type      = NULL;
1969
1970         if (orig_type == NULL) {
1971                 /* We are initializing an empty compound. */
1972         } else {
1973                 type = skip_typeref(orig_type);
1974         }
1975
1976         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1977
1978         while (true) {
1979                 designator_t *designator = NULL;
1980                 if (token.kind == '.' || token.kind == '[') {
1981                         designator = parse_designation();
1982                         goto finish_designator;
1983                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1984                         /* GNU-style designator ("identifier: value") */
1985                         designator = allocate_ast_zero(sizeof(designator[0]));
1986                         designator->source_position = *HERE;
1987                         designator->symbol          = token.base.symbol;
1988                         eat(T_IDENTIFIER);
1989                         eat(':');
1990
1991 finish_designator:
1992                         /* reset path to toplevel, evaluate designator from there */
1993                         ascend_to(path, top_path_level);
1994                         if (!walk_designator(path, designator, false)) {
1995                                 /* can't continue after designation error */
1996                                 goto end_error;
1997                         }
1998
1999                         initializer_t *designator_initializer
2000                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2001                         designator_initializer->designator.designator = designator;
2002                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2003
2004                         orig_type = path->top_type;
2005                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2006                 }
2007
2008                 initializer_t *sub;
2009
2010                 if (token.kind == '{') {
2011                         if (type != NULL && is_type_scalar(type)) {
2012                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2013                         } else {
2014                                 if (type == NULL) {
2015                                         if (env->entity != NULL) {
2016                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2017                                         } else {
2018                                                 errorf(HERE, "extra brace group at end of initializer");
2019                                         }
2020                                         eat('{');
2021                                 } else {
2022                                         eat('{');
2023                                         descend_into_subtype(path);
2024                                 }
2025
2026                                 add_anchor_token('}');
2027                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2028                                                             env);
2029                                 rem_anchor_token('}');
2030
2031                                 expect('}');
2032
2033                                 if (!type)
2034                                         goto error_parse_next;
2035
2036                                 ascend_from_subtype(path);
2037                         }
2038                 } else {
2039                         /* must be an expression */
2040                         expression_t *expression = parse_assignment_expression();
2041                         mark_vars_read(expression, NULL);
2042
2043                         if (env->must_be_constant && !is_linker_constant(expression)) {
2044                                 errorf(&expression->base.source_position,
2045                                        "Initialisation expression '%E' is not constant",
2046                                        expression);
2047                         }
2048
2049                         if (type == NULL) {
2050                                 /* we are already outside, ... */
2051                                 if (outer_type == NULL)
2052                                         goto error_parse_next;
2053                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2054                                 if (is_type_compound(outer_type_skip) &&
2055                                                 !outer_type_skip->compound.compound->complete) {
2056                                         goto error_parse_next;
2057                                 }
2058
2059                                 source_position_t const* const pos = &expression->base.source_position;
2060                                 if (env->entity != NULL) {
2061                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2062                                 } else {
2063                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2064                                 }
2065                                 goto error_parse_next;
2066                         }
2067
2068                         /* handle { "string" } special case */
2069                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2070                                 sub = initializer_from_expression(outer_type, expression);
2071                                 if (sub != NULL) {
2072                                         next_if(',');
2073                                         if (token.kind != '}') {
2074                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2075                                         }
2076                                         /* TODO: eat , ... */
2077                                         return sub;
2078                                 }
2079                         }
2080
2081                         /* descend into subtypes until expression matches type */
2082                         while (true) {
2083                                 orig_type = path->top_type;
2084                                 type      = skip_typeref(orig_type);
2085
2086                                 sub = initializer_from_expression(orig_type, expression);
2087                                 if (sub != NULL) {
2088                                         break;
2089                                 }
2090                                 if (!is_type_valid(type)) {
2091                                         goto end_error;
2092                                 }
2093                                 if (is_type_scalar(type)) {
2094                                         errorf(&expression->base.source_position,
2095                                                         "expression '%E' doesn't match expected type '%T'",
2096                                                         expression, orig_type);
2097                                         goto end_error;
2098                                 }
2099
2100                                 descend_into_subtype(path);
2101                         }
2102                 }
2103
2104                 /* update largest index of top array */
2105                 const type_path_entry_t *first      = &path->path[0];
2106                 type_t                  *first_type = first->type;
2107                 first_type                          = skip_typeref(first_type);
2108                 if (is_type_array(first_type)) {
2109                         size_t index = first->v.index;
2110                         if (index > path->max_index)
2111                                 path->max_index = index;
2112                 }
2113
2114                 /* append to initializers list */
2115                 ARR_APP1(initializer_t*, initializers, sub);
2116
2117 error_parse_next:
2118                 if (token.kind == '}') {
2119                         break;
2120                 }
2121                 add_anchor_token('}');
2122                 expect(',');
2123                 rem_anchor_token('}');
2124                 if (token.kind == '}') {
2125                         break;
2126                 }
2127
2128                 if (type != NULL) {
2129                         /* advance to the next declaration if we are not at the end */
2130                         advance_current_object(path, top_path_level);
2131                         orig_type = path->top_type;
2132                         if (orig_type != NULL)
2133                                 type = skip_typeref(orig_type);
2134                         else
2135                                 type = NULL;
2136                 }
2137         }
2138
2139         size_t len  = ARR_LEN(initializers);
2140         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2141         initializer_t *result = allocate_ast_zero(size);
2142         result->kind          = INITIALIZER_LIST;
2143         result->list.len      = len;
2144         memcpy(&result->list.initializers, initializers,
2145                len * sizeof(initializers[0]));
2146
2147         DEL_ARR_F(initializers);
2148         ascend_to(path, top_path_level+1);
2149
2150         return result;
2151
2152 end_error:
2153         skip_initializers();
2154         DEL_ARR_F(initializers);
2155         ascend_to(path, top_path_level+1);
2156         return NULL;
2157 }
2158
2159 static expression_t *make_size_literal(size_t value)
2160 {
2161         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2162         literal->base.type    = type_size_t;
2163
2164         char buf[128];
2165         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2166         literal->literal.value = make_string(buf);
2167
2168         return literal;
2169 }
2170
2171 /**
2172  * Parses an initializer. Parsers either a compound literal
2173  * (env->declaration == NULL) or an initializer of a declaration.
2174  */
2175 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2176 {
2177         type_t        *type      = skip_typeref(env->type);
2178         size_t         max_index = 0;
2179         initializer_t *result;
2180
2181         if (is_type_scalar(type)) {
2182                 result = parse_scalar_initializer(type, env->must_be_constant);
2183         } else if (token.kind == '{') {
2184                 eat('{');
2185
2186                 type_path_t path;
2187                 memset(&path, 0, sizeof(path));
2188                 path.top_type = env->type;
2189                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2190
2191                 descend_into_subtype(&path);
2192
2193                 add_anchor_token('}');
2194                 result = parse_sub_initializer(&path, env->type, 1, env);
2195                 rem_anchor_token('}');
2196
2197                 max_index = path.max_index;
2198                 DEL_ARR_F(path.path);
2199
2200                 expect('}');
2201         } else {
2202                 /* parse_scalar_initializer() also works in this case: we simply
2203                  * have an expression without {} around it */
2204                 result = parse_scalar_initializer(type, env->must_be_constant);
2205         }
2206
2207         /* §6.7.8:22 array initializers for arrays with unknown size determine
2208          * the array type size */
2209         if (is_type_array(type) && type->array.size_expression == NULL
2210                         && result != NULL) {
2211                 size_t size;
2212                 switch (result->kind) {
2213                 case INITIALIZER_LIST:
2214                         assert(max_index != 0xdeadbeaf);
2215                         size = max_index + 1;
2216                         break;
2217
2218                 case INITIALIZER_STRING:
2219                         size = get_string_len(result->string.encoding, &result->string.string) + 1;
2220                         break;
2221
2222                 case INITIALIZER_DESIGNATOR:
2223                 case INITIALIZER_VALUE:
2224                         /* can happen for parse errors */
2225                         size = 0;
2226                         break;
2227
2228                 default:
2229                         internal_errorf(HERE, "invalid initializer type");
2230                 }
2231
2232                 type_t *new_type = duplicate_type(type);
2233
2234                 new_type->array.size_expression   = make_size_literal(size);
2235                 new_type->array.size_constant     = true;
2236                 new_type->array.has_implicit_size = true;
2237                 new_type->array.size              = size;
2238                 env->type = new_type;
2239         }
2240
2241         return result;
2242 }
2243
2244 static void append_entity(scope_t *scope, entity_t *entity)
2245 {
2246         if (scope->last_entity != NULL) {
2247                 scope->last_entity->base.next = entity;
2248         } else {
2249                 scope->entities = entity;
2250         }
2251         entity->base.parent_entity = current_entity;
2252         scope->last_entity         = entity;
2253 }
2254
2255
2256 static compound_t *parse_compound_type_specifier(bool is_struct)
2257 {
2258         source_position_t const pos = *HERE;
2259         eat(is_struct ? T_struct : T_union);
2260
2261         symbol_t    *symbol     = NULL;
2262         entity_t    *entity     = NULL;
2263         attribute_t *attributes = NULL;
2264
2265         if (token.kind == T___attribute__) {
2266                 attributes = parse_attributes(NULL);
2267         }
2268
2269         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2270         if (token.kind == T_IDENTIFIER) {
2271                 /* the compound has a name, check if we have seen it already */
2272                 symbol = token.base.symbol;
2273                 entity = get_tag(symbol, kind);
2274                 eat(T_IDENTIFIER);
2275
2276                 if (entity != NULL) {
2277                         if (entity->base.parent_scope != current_scope &&
2278                             (token.kind == '{' || token.kind == ';')) {
2279                                 /* we're in an inner scope and have a definition. Shadow
2280                                  * existing definition in outer scope */
2281                                 entity = NULL;
2282                         } else if (entity->compound.complete && token.kind == '{') {
2283                                 source_position_t const *const ppos = &entity->base.source_position;
2284                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2285                                 /* clear members in the hope to avoid further errors */
2286                                 entity->compound.members.entities = NULL;
2287                         }
2288                 }
2289         } else if (token.kind != '{') {
2290                 char const *const msg =
2291                         is_struct ? "while parsing struct type specifier" :
2292                                     "while parsing union type specifier";
2293                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2294
2295                 return NULL;
2296         }
2297
2298         if (entity == NULL) {
2299                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2300                 entity->compound.alignment = 1;
2301                 entity->base.parent_scope  = current_scope;
2302                 if (symbol != NULL) {
2303                         environment_push(entity);
2304                 }
2305                 append_entity(current_scope, entity);
2306         }
2307
2308         if (token.kind == '{') {
2309                 parse_compound_type_entries(&entity->compound);
2310
2311                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2312                 if (symbol == NULL) {
2313                         assert(anonymous_entity == NULL);
2314                         anonymous_entity = entity;
2315                 }
2316         }
2317
2318         if (attributes != NULL) {
2319                 handle_entity_attributes(attributes, entity);
2320         }
2321
2322         return &entity->compound;
2323 }
2324
2325 static void parse_enum_entries(type_t *const enum_type)
2326 {
2327         eat('{');
2328
2329         if (token.kind == '}') {
2330                 errorf(HERE, "empty enum not allowed");
2331                 eat('}');
2332                 return;
2333         }
2334
2335         add_anchor_token('}');
2336         add_anchor_token(',');
2337         do {
2338                 add_anchor_token('=');
2339                 source_position_t pos;
2340                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2341                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2342                 entity->enum_value.enum_type = enum_type;
2343                 rem_anchor_token('=');
2344
2345                 if (next_if('=')) {
2346                         expression_t *value = parse_constant_expression();
2347
2348                         value = create_implicit_cast(value, enum_type);
2349                         entity->enum_value.value = value;
2350
2351                         /* TODO semantic */
2352                 }
2353
2354                 record_entity(entity, false);
2355         } while (next_if(',') && token.kind != '}');
2356         rem_anchor_token(',');
2357         rem_anchor_token('}');
2358
2359         expect('}');
2360 }
2361
2362 static type_t *parse_enum_specifier(void)
2363 {
2364         source_position_t const pos = *HERE;
2365         entity_t               *entity;
2366         symbol_t               *symbol;
2367
2368         eat(T_enum);
2369         switch (token.kind) {
2370                 case T_IDENTIFIER:
2371                         symbol = token.base.symbol;
2372                         entity = get_tag(symbol, ENTITY_ENUM);
2373                         eat(T_IDENTIFIER);
2374
2375                         if (entity != NULL) {
2376                                 if (entity->base.parent_scope != current_scope &&
2377                                                 (token.kind == '{' || token.kind == ';')) {
2378                                         /* we're in an inner scope and have a definition. Shadow
2379                                          * existing definition in outer scope */
2380                                         entity = NULL;
2381                                 } else if (entity->enume.complete && token.kind == '{') {
2382                                         source_position_t const *const ppos = &entity->base.source_position;
2383                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2384                                 }
2385                         }
2386                         break;
2387
2388                 case '{':
2389                         entity = NULL;
2390                         symbol = NULL;
2391                         break;
2392
2393                 default:
2394                         parse_error_expected("while parsing enum type specifier",
2395                                         T_IDENTIFIER, '{', NULL);
2396                         return NULL;
2397         }
2398
2399         if (entity == NULL) {
2400                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2401                 entity->base.parent_scope = current_scope;
2402         }
2403
2404         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2405         type->enumt.enume      = &entity->enume;
2406         type->enumt.base.akind = ATOMIC_TYPE_INT;
2407
2408         if (token.kind == '{') {
2409                 if (symbol != NULL) {
2410                         environment_push(entity);
2411                 }
2412                 append_entity(current_scope, entity);
2413                 entity->enume.complete = true;
2414
2415                 parse_enum_entries(type);
2416                 parse_attributes(NULL);
2417
2418                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2419                 if (symbol == NULL) {
2420                         assert(anonymous_entity == NULL);
2421                         anonymous_entity = entity;
2422                 }
2423         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2424                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2425         }
2426
2427         return type;
2428 }
2429
2430 /**
2431  * if a symbol is a typedef to another type, return true
2432  */
2433 static bool is_typedef_symbol(symbol_t *symbol)
2434 {
2435         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2436         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2437 }
2438
2439 static type_t *parse_typeof(void)
2440 {
2441         eat(T___typeof__);
2442
2443         type_t *type;
2444
2445         add_anchor_token(')');
2446         expect('(');
2447
2448         expression_t *expression  = NULL;
2449
2450         switch (token.kind) {
2451         case T_IDENTIFIER:
2452                 if (is_typedef_symbol(token.base.symbol)) {
2453         DECLARATION_START
2454                         type = parse_typename();
2455                 } else {
2456         default:
2457                         expression = parse_expression();
2458                         type       = revert_automatic_type_conversion(expression);
2459                 }
2460                 break;
2461         }
2462
2463         rem_anchor_token(')');
2464         expect(')');
2465
2466         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2467         typeof_type->typeoft.expression  = expression;
2468         typeof_type->typeoft.typeof_type = type;
2469
2470         return typeof_type;
2471 }
2472
2473 typedef enum specifiers_t {
2474         SPECIFIER_SIGNED    = 1 << 0,
2475         SPECIFIER_UNSIGNED  = 1 << 1,
2476         SPECIFIER_LONG      = 1 << 2,
2477         SPECIFIER_INT       = 1 << 3,
2478         SPECIFIER_DOUBLE    = 1 << 4,
2479         SPECIFIER_CHAR      = 1 << 5,
2480         SPECIFIER_WCHAR_T   = 1 << 6,
2481         SPECIFIER_SHORT     = 1 << 7,
2482         SPECIFIER_LONG_LONG = 1 << 8,
2483         SPECIFIER_FLOAT     = 1 << 9,
2484         SPECIFIER_BOOL      = 1 << 10,
2485         SPECIFIER_VOID      = 1 << 11,
2486         SPECIFIER_INT8      = 1 << 12,
2487         SPECIFIER_INT16     = 1 << 13,
2488         SPECIFIER_INT32     = 1 << 14,
2489         SPECIFIER_INT64     = 1 << 15,
2490         SPECIFIER_INT128    = 1 << 16,
2491         SPECIFIER_COMPLEX   = 1 << 17,
2492         SPECIFIER_IMAGINARY = 1 << 18,
2493 } specifiers_t;
2494
2495 static type_t *get_typedef_type(symbol_t *symbol)
2496 {
2497         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2498         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2499                 return NULL;
2500
2501         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2502         type->typedeft.typedefe = &entity->typedefe;
2503
2504         return type;
2505 }
2506
2507 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2508 {
2509         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2510
2511         add_anchor_token(')');
2512         add_anchor_token(',');
2513         expect('(');
2514
2515         do {
2516                 add_anchor_token('=');
2517                 source_position_t pos;
2518                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2519                 rem_anchor_token('=');
2520
2521                 symbol_t **prop = NULL;
2522                 if (prop_sym) {
2523                         if (streq(prop_sym->string, "put")) {
2524                                 prop = &property->put_symbol;
2525                         } else if (streq(prop_sym->string, "get")) {
2526                                 prop = &property->get_symbol;
2527                         } else {
2528                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2529                         }
2530                 }
2531
2532                 add_anchor_token(T_IDENTIFIER);
2533                 expect('=');
2534                 rem_anchor_token(T_IDENTIFIER);
2535
2536                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2537                 if (prop != NULL)
2538                         *prop = sym ? sym : sym_anonymous;
2539         } while (next_if(','));
2540         rem_anchor_token(',');
2541         rem_anchor_token(')');
2542
2543         attribute->a.property = property;
2544
2545         expect(')');
2546         return attribute;
2547 }
2548
2549 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2550 {
2551         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2552         if (next_if(T_restrict)) {
2553                 kind = ATTRIBUTE_MS_RESTRICT;
2554         } else if (token.kind == T_IDENTIFIER) {
2555                 char const *const name = token.base.symbol->string;
2556                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2557                      ++k) {
2558                         const char *attribute_name = get_attribute_name(k);
2559                         if (attribute_name != NULL && streq(attribute_name, name)) {
2560                                 kind = k;
2561                                 break;
2562                         }
2563                 }
2564
2565                 if (kind == ATTRIBUTE_UNKNOWN) {
2566                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2567                 }
2568         } else {
2569                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2570                 return NULL;
2571         }
2572
2573         attribute_t *attribute = allocate_attribute_zero(kind);
2574         eat(T_IDENTIFIER);
2575
2576         if (kind == ATTRIBUTE_MS_PROPERTY) {
2577                 return parse_attribute_ms_property(attribute);
2578         }
2579
2580         /* parse arguments */
2581         if (next_if('('))
2582                 attribute->a.arguments = parse_attribute_arguments();
2583
2584         return attribute;
2585 }
2586
2587 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2588 {
2589         eat(T__declspec);
2590
2591         add_anchor_token(')');
2592         expect('(');
2593         if (token.kind != ')') {
2594                 attribute_t **anchor = &first;
2595                 do {
2596                         while (*anchor != NULL)
2597                                 anchor = &(*anchor)->next;
2598
2599                         attribute_t *attribute
2600                                 = parse_microsoft_extended_decl_modifier_single();
2601                         if (attribute == NULL)
2602                                 break;
2603
2604                         *anchor = attribute;
2605                         anchor  = &attribute->next;
2606                 } while (next_if(','));
2607         }
2608         rem_anchor_token(')');
2609         expect(')');
2610         return first;
2611 }
2612
2613 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2614 {
2615         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2616         if (is_declaration(entity)) {
2617                 entity->declaration.type     = type_error_type;
2618                 entity->declaration.implicit = true;
2619         } else if (kind == ENTITY_TYPEDEF) {
2620                 entity->typedefe.type    = type_error_type;
2621                 entity->typedefe.builtin = true;
2622         }
2623         if (kind != ENTITY_COMPOUND_MEMBER)
2624                 record_entity(entity, false);
2625         return entity;
2626 }
2627
2628 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2629 {
2630         type_t            *type            = NULL;
2631         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2632         unsigned           type_specifiers = 0;
2633         bool               newtype         = false;
2634         bool               saw_error       = false;
2635
2636         memset(specifiers, 0, sizeof(*specifiers));
2637         specifiers->source_position = *HERE;
2638
2639         while (true) {
2640                 specifiers->attributes = parse_attributes(specifiers->attributes);
2641
2642                 switch (token.kind) {
2643                 /* storage class */
2644 #define MATCH_STORAGE_CLASS(token, class)                                  \
2645                 case token:                                                        \
2646                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2647                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2648                         }                                                              \
2649                         specifiers->storage_class = class;                             \
2650                         if (specifiers->thread_local)                                  \
2651                                 goto check_thread_storage_class;                           \
2652                         eat(token); \
2653                         break;
2654
2655                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2656                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2657                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2658                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2659                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2660
2661                 case T__declspec:
2662                         specifiers->attributes
2663                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2664                         break;
2665
2666                 case T___thread:
2667                         if (specifiers->thread_local) {
2668                                 errorf(HERE, "duplicate '__thread'");
2669                         } else {
2670                                 specifiers->thread_local = true;
2671 check_thread_storage_class:
2672                                 switch (specifiers->storage_class) {
2673                                         case STORAGE_CLASS_EXTERN:
2674                                         case STORAGE_CLASS_NONE:
2675                                         case STORAGE_CLASS_STATIC:
2676                                                 break;
2677
2678                                                 char const* wrong;
2679                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2680                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2681                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2682 wrong_thread_storage_class:
2683                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2684                                                 break;
2685                                 }
2686                         }
2687                         next_token();
2688                         break;
2689
2690                 /* type qualifiers */
2691 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2692                 case token:                                                     \
2693                         qualifiers |= qualifier;                                    \
2694                         eat(token); \
2695                         break
2696
2697                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2698                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2699                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2700                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2701                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2702                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2703                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2704                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2705
2706                 /* type specifiers */
2707 #define MATCH_SPECIFIER(token, specifier, name)                         \
2708                 case token:                                                     \
2709                         if (type_specifiers & specifier) {                           \
2710                                 errorf(HERE, "multiple " name " type specifiers given"); \
2711                         } else {                                                    \
2712                                 type_specifiers |= specifier;                           \
2713                         }                                                           \
2714                         eat(token); \
2715                         break
2716
2717                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2718                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2719                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2720                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2721                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2722                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2723                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2724                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2725                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2726                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2727                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2728                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2729                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2730                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2731                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2732                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2733                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2734                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2735
2736                 case T_inline:
2737                         eat(T_inline);
2738                         specifiers->is_inline = true;
2739                         break;
2740
2741 #if 0
2742                 case T__forceinline:
2743                         eat(T__forceinline);
2744                         specifiers->modifiers |= DM_FORCEINLINE;
2745                         break;
2746 #endif
2747
2748                 case T_long:
2749                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2750                                 errorf(HERE, "too many long type specifiers given");
2751                         } else if (type_specifiers & SPECIFIER_LONG) {
2752                                 type_specifiers |= SPECIFIER_LONG_LONG;
2753                         } else {
2754                                 type_specifiers |= SPECIFIER_LONG;
2755                         }
2756                         eat(T_long);
2757                         break;
2758
2759 #define CHECK_DOUBLE_TYPE() \
2760         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2761
2762                 case T_struct:
2763                         CHECK_DOUBLE_TYPE();
2764                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2765
2766                         type->compound.compound = parse_compound_type_specifier(true);
2767                         break;
2768                 case T_union:
2769                         CHECK_DOUBLE_TYPE();
2770                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2771                         type->compound.compound = parse_compound_type_specifier(false);
2772                         break;
2773                 case T_enum:
2774                         CHECK_DOUBLE_TYPE();
2775                         type = parse_enum_specifier();
2776                         break;
2777                 case T___typeof__:
2778                         CHECK_DOUBLE_TYPE();
2779                         type = parse_typeof();
2780                         break;
2781                 case T___builtin_va_list:
2782                         CHECK_DOUBLE_TYPE();
2783                         type = duplicate_type(type_valist);
2784                         eat(T___builtin_va_list);
2785                         break;
2786
2787                 case T_IDENTIFIER: {
2788                         /* only parse identifier if we haven't found a type yet */
2789                         if (type != NULL || type_specifiers != 0) {
2790                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2791                                  * declaration, so it doesn't generate errors about expecting '(' or
2792                                  * '{' later on. */
2793                                 switch (look_ahead(1)->kind) {
2794                                         STORAGE_CLASSES
2795                                         TYPE_SPECIFIERS
2796                                         case T_const:
2797                                         case T_restrict:
2798                                         case T_volatile:
2799                                         case T_inline:
2800                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2801                                         case T_IDENTIFIER:
2802                                         case '&':
2803                                         case '*':
2804                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2805                                                 eat(T_IDENTIFIER);
2806                                                 continue;
2807
2808                                         default:
2809                                                 goto finish_specifiers;
2810                                 }
2811                         }
2812
2813                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2814                         if (typedef_type == NULL) {
2815                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2816                                  * declaration, so it doesn't generate 'implicit int' followed by more
2817                                  * errors later on. */
2818                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2819                                 switch (la1_type) {
2820                                         DECLARATION_START
2821                                         case T_IDENTIFIER:
2822                                         case '&':
2823                                         case '*': {
2824                                                 errorf(HERE, "%K does not name a type", &token);
2825
2826                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2827
2828                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2829                                                 type->typedeft.typedefe = &entity->typedefe;
2830
2831                                                 eat(T_IDENTIFIER);
2832                                                 saw_error = true;
2833                                                 continue;
2834                                         }
2835
2836                                         default:
2837                                                 goto finish_specifiers;
2838                                 }
2839                         }
2840
2841                         eat(T_IDENTIFIER);
2842                         type = typedef_type;
2843                         break;
2844                 }
2845
2846                 /* function specifier */
2847                 default:
2848                         goto finish_specifiers;
2849                 }
2850         }
2851
2852 finish_specifiers:
2853         specifiers->attributes = parse_attributes(specifiers->attributes);
2854
2855         if (type == NULL || (saw_error && type_specifiers != 0)) {
2856                 atomic_type_kind_t atomic_type;
2857
2858                 /* match valid basic types */
2859                 switch (type_specifiers) {
2860                 case SPECIFIER_VOID:
2861                         atomic_type = ATOMIC_TYPE_VOID;
2862                         break;
2863                 case SPECIFIER_WCHAR_T:
2864                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2865                         break;
2866                 case SPECIFIER_CHAR:
2867                         atomic_type = ATOMIC_TYPE_CHAR;
2868                         break;
2869                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2870                         atomic_type = ATOMIC_TYPE_SCHAR;
2871                         break;
2872                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2873                         atomic_type = ATOMIC_TYPE_UCHAR;
2874                         break;
2875                 case SPECIFIER_SHORT:
2876                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2877                 case SPECIFIER_SHORT | SPECIFIER_INT:
2878                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2879                         atomic_type = ATOMIC_TYPE_SHORT;
2880                         break;
2881                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2882                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2883                         atomic_type = ATOMIC_TYPE_USHORT;
2884                         break;
2885                 case SPECIFIER_INT:
2886                 case SPECIFIER_SIGNED:
2887                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2888                         atomic_type = ATOMIC_TYPE_INT;
2889                         break;
2890                 case SPECIFIER_UNSIGNED:
2891                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2892                         atomic_type = ATOMIC_TYPE_UINT;
2893                         break;
2894                 case SPECIFIER_LONG:
2895                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2896                 case SPECIFIER_LONG | SPECIFIER_INT:
2897                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2898                         atomic_type = ATOMIC_TYPE_LONG;
2899                         break;
2900                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2901                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2902                         atomic_type = ATOMIC_TYPE_ULONG;
2903                         break;
2904
2905                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2906                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2907                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2908                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2909                         | SPECIFIER_INT:
2910                         atomic_type = ATOMIC_TYPE_LONGLONG;
2911                         goto warn_about_long_long;
2912
2913                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2914                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2915                         | SPECIFIER_INT:
2916                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2917 warn_about_long_long:
2918                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2919                         break;
2920
2921                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2922                         atomic_type = unsigned_int8_type_kind;
2923                         break;
2924
2925                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2926                         atomic_type = unsigned_int16_type_kind;
2927                         break;
2928
2929                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2930                         atomic_type = unsigned_int32_type_kind;
2931                         break;
2932
2933                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2934                         atomic_type = unsigned_int64_type_kind;
2935                         break;
2936
2937                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2938                         atomic_type = unsigned_int128_type_kind;
2939                         break;
2940
2941                 case SPECIFIER_INT8:
2942                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2943                         atomic_type = int8_type_kind;
2944                         break;
2945
2946                 case SPECIFIER_INT16:
2947                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2948                         atomic_type = int16_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_INT32:
2952                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2953                         atomic_type = int32_type_kind;
2954                         break;
2955
2956                 case SPECIFIER_INT64:
2957                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2958                         atomic_type = int64_type_kind;
2959                         break;
2960
2961                 case SPECIFIER_INT128:
2962                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2963                         atomic_type = int128_type_kind;
2964                         break;
2965
2966                 case SPECIFIER_FLOAT:
2967                         atomic_type = ATOMIC_TYPE_FLOAT;
2968                         break;
2969                 case SPECIFIER_DOUBLE:
2970                         atomic_type = ATOMIC_TYPE_DOUBLE;
2971                         break;
2972                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2973                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2974                         break;
2975                 case SPECIFIER_BOOL:
2976                         atomic_type = ATOMIC_TYPE_BOOL;
2977                         break;
2978                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2979                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2980                         atomic_type = ATOMIC_TYPE_FLOAT;
2981                         break;
2982                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2983                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2984                         atomic_type = ATOMIC_TYPE_DOUBLE;
2985                         break;
2986                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2987                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2988                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2989                         break;
2990                 default: {
2991                         /* invalid specifier combination, give an error message */
2992                         source_position_t const* const pos = &specifiers->source_position;
2993                         if (type_specifiers == 0) {
2994                                 if (!saw_error) {
2995                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2996                                         if (!(c_mode & _CXX) && !strict_mode) {
2997                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2998                                                 atomic_type = ATOMIC_TYPE_INT;
2999                                                 break;
3000                                         } else {
3001                                                 errorf(pos, "no type specifiers given in declaration");
3002                                         }
3003                                 }
3004                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3005                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3006                                 errorf(pos, "signed and unsigned specifiers given");
3007                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3008                                 errorf(pos, "only integer types can be signed or unsigned");
3009                         } else {
3010                                 errorf(pos, "multiple datatypes in declaration");
3011                         }
3012                         specifiers->type = type_error_type;
3013                         return;
3014                 }
3015                 }
3016
3017                 if (type_specifiers & SPECIFIER_COMPLEX) {
3018                         type = allocate_type_zero(TYPE_COMPLEX);
3019                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3020                         type = allocate_type_zero(TYPE_IMAGINARY);
3021                 } else {
3022                         type = allocate_type_zero(TYPE_ATOMIC);
3023                 }
3024                 type->atomic.akind = atomic_type;
3025                 newtype = true;
3026         } else if (type_specifiers != 0) {
3027                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3028         }
3029
3030         /* FIXME: check type qualifiers here */
3031         type->base.qualifiers = qualifiers;
3032
3033         if (newtype) {
3034                 type = identify_new_type(type);
3035         } else {
3036                 type = typehash_insert(type);
3037         }
3038
3039         if (specifiers->attributes != NULL)
3040                 type = handle_type_attributes(specifiers->attributes, type);
3041         specifiers->type = type;
3042 }
3043
3044 static type_qualifiers_t parse_type_qualifiers(void)
3045 {
3046         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3047
3048         while (true) {
3049                 switch (token.kind) {
3050                 /* type qualifiers */
3051                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3052                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3053                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3054                 /* microsoft extended type modifiers */
3055                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3056                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3057                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3058                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3059                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3060
3061                 default:
3062                         return qualifiers;
3063                 }
3064         }
3065 }
3066
3067 /**
3068  * Parses an K&R identifier list
3069  */
3070 static void parse_identifier_list(scope_t *scope)
3071 {
3072         assert(token.kind == T_IDENTIFIER);
3073         do {
3074                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3075                 /* a K&R parameter has no type, yet */
3076                 eat(T_IDENTIFIER);
3077
3078                 if (scope != NULL)
3079                         append_entity(scope, entity);
3080         } while (next_if(',') && token.kind == T_IDENTIFIER);
3081 }
3082
3083 static entity_t *parse_parameter(void)
3084 {
3085         declaration_specifiers_t specifiers;
3086         parse_declaration_specifiers(&specifiers);
3087
3088         entity_t *entity = parse_declarator(&specifiers,
3089                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3090         anonymous_entity = NULL;
3091         return entity;
3092 }
3093
3094 static void semantic_parameter_incomplete(const entity_t *entity)
3095 {
3096         assert(entity->kind == ENTITY_PARAMETER);
3097
3098         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3099          *             list in a function declarator that is part of a
3100          *             definition of that function shall not have
3101          *             incomplete type. */
3102         type_t *type = skip_typeref(entity->declaration.type);
3103         if (is_type_incomplete(type)) {
3104                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3105         }
3106 }
3107
3108 static bool has_parameters(void)
3109 {
3110         /* func(void) is not a parameter */
3111         if (look_ahead(1)->kind != ')')
3112                 return true;
3113         if (token.kind == T_IDENTIFIER) {
3114                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3115                 if (entity == NULL)
3116                         return true;
3117                 if (entity->kind != ENTITY_TYPEDEF)
3118                         return true;
3119                 type_t const *const type = skip_typeref(entity->typedefe.type);
3120                 if (!is_type_void(type))
3121                         return true;
3122                 if (c_mode & _CXX) {
3123                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3124                          * is not allowed. */
3125                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3126                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3127                         /* §6.7.5.3:10  Qualification is not allowed here. */
3128                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3129                 }
3130         } else if (token.kind != T_void) {
3131                 return true;
3132         }
3133         next_token();
3134         return false;
3135 }
3136
3137 /**
3138  * Parses function type parameters (and optionally creates variable_t entities
3139  * for them in a scope)
3140  */
3141 static void parse_parameters(function_type_t *type, scope_t *scope)
3142 {
3143         add_anchor_token(')');
3144         eat('(');
3145
3146         if (token.kind == T_IDENTIFIER            &&
3147             !is_typedef_symbol(token.base.symbol) &&
3148             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3149                 type->kr_style_parameters = true;
3150                 parse_identifier_list(scope);
3151         } else if (token.kind == ')') {
3152                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3153                 if (!(c_mode & _CXX))
3154                         type->unspecified_parameters = true;
3155         } else if (has_parameters()) {
3156                 function_parameter_t **anchor = &type->parameters;
3157                 add_anchor_token(',');
3158                 do {
3159                         switch (token.kind) {
3160                         case T_DOTDOTDOT:
3161                                 eat(T_DOTDOTDOT);
3162                                 type->variadic = true;
3163                                 goto parameters_finished;
3164
3165                         case T_IDENTIFIER:
3166                         DECLARATION_START
3167                         {
3168                                 entity_t *entity = parse_parameter();
3169                                 if (entity->kind == ENTITY_TYPEDEF) {
3170                                         errorf(&entity->base.source_position,
3171                                                         "typedef not allowed as function parameter");
3172                                         break;
3173                                 }
3174                                 assert(is_declaration(entity));
3175
3176                                 semantic_parameter_incomplete(entity);
3177
3178                                 function_parameter_t *const parameter =
3179                                         allocate_parameter(entity->declaration.type);
3180
3181                                 if (scope != NULL) {
3182                                         append_entity(scope, entity);
3183                                 }
3184
3185                                 *anchor = parameter;
3186                                 anchor  = &parameter->next;
3187                                 break;
3188                         }
3189
3190                         default:
3191                                 goto parameters_finished;
3192                         }
3193                 } while (next_if(','));
3194 parameters_finished:
3195                 rem_anchor_token(',');
3196         }
3197
3198         rem_anchor_token(')');
3199         expect(')');
3200 }
3201
3202 typedef enum construct_type_kind_t {
3203         CONSTRUCT_POINTER = 1,
3204         CONSTRUCT_REFERENCE,
3205         CONSTRUCT_FUNCTION,
3206         CONSTRUCT_ARRAY
3207 } construct_type_kind_t;
3208
3209 typedef union construct_type_t construct_type_t;
3210
3211 typedef struct construct_type_base_t {
3212         construct_type_kind_t  kind;
3213         source_position_t      pos;
3214         construct_type_t      *next;
3215 } construct_type_base_t;
3216
3217 typedef struct parsed_pointer_t {
3218         construct_type_base_t  base;
3219         type_qualifiers_t      type_qualifiers;
3220         variable_t            *base_variable;  /**< MS __based extension. */
3221 } parsed_pointer_t;
3222
3223 typedef struct parsed_reference_t {
3224         construct_type_base_t base;
3225 } parsed_reference_t;
3226
3227 typedef struct construct_function_type_t {
3228         construct_type_base_t  base;
3229         type_t                *function_type;
3230 } construct_function_type_t;
3231
3232 typedef struct parsed_array_t {
3233         construct_type_base_t  base;
3234         type_qualifiers_t      type_qualifiers;
3235         bool                   is_static;
3236         bool                   is_variable;
3237         expression_t          *size;
3238 } parsed_array_t;
3239
3240 union construct_type_t {
3241         construct_type_kind_t     kind;
3242         construct_type_base_t     base;
3243         parsed_pointer_t          pointer;
3244         parsed_reference_t        reference;
3245         construct_function_type_t function;
3246         parsed_array_t            array;
3247 };
3248
3249 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3250 {
3251         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3252         memset(cons, 0, size);
3253         cons->kind     = kind;
3254         cons->base.pos = *HERE;
3255         return cons;
3256 }
3257
3258 /* §6.7.5.1 */
3259 static construct_type_t *parse_pointer_declarator(void)
3260 {
3261         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3262         eat('*');
3263         cons->pointer.type_qualifiers = parse_type_qualifiers();
3264         //cons->pointer.base_variable   = base_variable;
3265
3266         return cons;
3267 }
3268
3269 /* ISO/IEC 14882:1998(E) §8.3.2 */
3270 static construct_type_t *parse_reference_declarator(void)
3271 {
3272         if (!(c_mode & _CXX))
3273                 errorf(HERE, "references are only available for C++");
3274
3275         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3276         eat('&');
3277
3278         return cons;
3279 }
3280
3281 /* §6.7.5.2 */
3282 static construct_type_t *parse_array_declarator(void)
3283 {
3284         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3285         parsed_array_t   *const array = &cons->array;
3286
3287         eat('[');
3288         add_anchor_token(']');
3289
3290         bool is_static = next_if(T_static);
3291
3292         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3293
3294         if (!is_static)
3295                 is_static = next_if(T_static);
3296
3297         array->type_qualifiers = type_qualifiers;
3298         array->is_static       = is_static;
3299
3300         expression_t *size = NULL;
3301         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3302                 array->is_variable = true;
3303                 eat('*');
3304         } else if (token.kind != ']') {
3305                 size = parse_assignment_expression();
3306
3307                 /* §6.7.5.2:1  Array size must have integer type */
3308                 type_t *const orig_type = size->base.type;
3309                 type_t *const type      = skip_typeref(orig_type);
3310                 if (!is_type_integer(type) && is_type_valid(type)) {
3311                         errorf(&size->base.source_position,
3312                                "array size '%E' must have integer type but has type '%T'",
3313                                size, orig_type);
3314                 }
3315
3316                 array->size = size;
3317                 mark_vars_read(size, NULL);
3318         }
3319
3320         if (is_static && size == NULL)
3321                 errorf(&array->base.pos, "static array parameters require a size");
3322
3323         rem_anchor_token(']');
3324         expect(']');
3325         return cons;
3326 }
3327
3328 /* §6.7.5.3 */
3329 static construct_type_t *parse_function_declarator(scope_t *scope)
3330 {
3331         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3332
3333         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3334         function_type_t *ftype = &type->function;
3335
3336         ftype->linkage            = current_linkage;
3337         ftype->calling_convention = CC_DEFAULT;
3338
3339         parse_parameters(ftype, scope);
3340
3341         cons->function.function_type = type;
3342
3343         return cons;
3344 }
3345
3346 typedef struct parse_declarator_env_t {
3347         bool               may_be_abstract : 1;
3348         bool               must_be_abstract : 1;
3349         decl_modifiers_t   modifiers;
3350         symbol_t          *symbol;
3351         source_position_t  source_position;
3352         scope_t            parameters;
3353         attribute_t       *attributes;
3354 } parse_declarator_env_t;
3355
3356 /* §6.7.5 */
3357 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3358 {
3359         /* construct a single linked list of construct_type_t's which describe
3360          * how to construct the final declarator type */
3361         construct_type_t  *first      = NULL;
3362         construct_type_t **anchor     = &first;
3363
3364         env->attributes = parse_attributes(env->attributes);
3365
3366         for (;;) {
3367                 construct_type_t *type;
3368                 //variable_t       *based = NULL; /* MS __based extension */
3369                 switch (token.kind) {
3370                         case '&':
3371                                 type = parse_reference_declarator();
3372                                 break;
3373
3374                         case T__based: {
3375                                 panic("based not supported anymore");
3376                                 /* FALLTHROUGH */
3377                         }
3378
3379                         case '*':
3380                                 type = parse_pointer_declarator();
3381                                 break;
3382
3383                         default:
3384                                 goto ptr_operator_end;
3385                 }
3386
3387                 *anchor = type;
3388                 anchor  = &type->base.next;
3389
3390                 /* TODO: find out if this is correct */
3391                 env->attributes = parse_attributes(env->attributes);
3392         }
3393
3394 ptr_operator_end: ;
3395         construct_type_t *inner_types = NULL;
3396
3397         switch (token.kind) {
3398         case T_IDENTIFIER:
3399                 if (env->must_be_abstract) {
3400                         errorf(HERE, "no identifier expected in typename");
3401                 } else {
3402                         env->symbol          = token.base.symbol;
3403                         env->source_position = *HERE;
3404                 }
3405                 eat(T_IDENTIFIER);
3406                 break;
3407
3408         case '(': {
3409                 /* Parenthesized declarator or function declarator? */
3410                 token_t const *const la1 = look_ahead(1);
3411                 switch (la1->kind) {
3412                         case T_IDENTIFIER:
3413                                 if (is_typedef_symbol(la1->base.symbol)) {
3414                         case ')':
3415                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3416                                          * interpreted as ``function with no parameter specification'', rather
3417                                          * than redundant parentheses around the omitted identifier. */
3418                         default:
3419                                         /* Function declarator. */
3420                                         if (!env->may_be_abstract) {
3421                                                 errorf(HERE, "function declarator must have a name");
3422                                         }
3423                                 } else {
3424                         case '&':
3425                         case '(':
3426                         case '*':
3427                         case '[':
3428                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3429                                         /* Paranthesized declarator. */
3430                                         eat('(');
3431                                         add_anchor_token(')');
3432                                         inner_types = parse_inner_declarator(env);
3433                                         if (inner_types != NULL) {
3434                                                 /* All later declarators only modify the return type */
3435                                                 env->must_be_abstract = true;
3436                                         }
3437                                         rem_anchor_token(')');
3438                                         expect(')');
3439                                 }
3440                                 break;
3441                 }
3442                 break;
3443         }
3444
3445         default:
3446                 if (env->may_be_abstract)
3447                         break;
3448                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3449                 eat_until_anchor();
3450                 return NULL;
3451         }
3452
3453         construct_type_t **const p = anchor;
3454
3455         for (;;) {
3456                 construct_type_t *type;
3457                 switch (token.kind) {
3458                 case '(': {
3459                         scope_t *scope = NULL;
3460                         if (!env->must_be_abstract) {
3461                                 scope = &env->parameters;
3462                         }
3463
3464                         type = parse_function_declarator(scope);
3465                         break;
3466                 }
3467                 case '[':
3468                         type = parse_array_declarator();
3469                         break;
3470                 default:
3471                         goto declarator_finished;
3472                 }
3473
3474                 /* insert in the middle of the list (at p) */
3475                 type->base.next = *p;
3476                 *p              = type;
3477                 if (anchor == p)
3478                         anchor = &type->base.next;
3479         }
3480
3481 declarator_finished:
3482         /* append inner_types at the end of the list, we don't to set anchor anymore
3483          * as it's not needed anymore */
3484         *anchor = inner_types;
3485
3486         return first;
3487 }
3488
3489 static type_t *construct_declarator_type(construct_type_t *construct_list,
3490                                          type_t *type)
3491 {
3492         construct_type_t *iter = construct_list;
3493         for (; iter != NULL; iter = iter->base.next) {
3494                 source_position_t const* const pos = &iter->base.pos;
3495                 switch (iter->kind) {
3496                 case CONSTRUCT_FUNCTION: {
3497                         construct_function_type_t *function      = &iter->function;
3498                         type_t                    *function_type = function->function_type;
3499
3500                         function_type->function.return_type = type;
3501
3502                         type_t *skipped_return_type = skip_typeref(type);
3503                         /* §6.7.5.3:1 */
3504                         if (is_type_function(skipped_return_type)) {
3505                                 errorf(pos, "function returning function is not allowed");
3506                         } else if (is_type_array(skipped_return_type)) {
3507                                 errorf(pos, "function returning array is not allowed");
3508                         } else {
3509                                 if (skipped_return_type->base.qualifiers != 0) {
3510                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3511                                 }
3512                         }
3513
3514                         /* The function type was constructed earlier.  Freeing it here will
3515                          * destroy other types. */
3516                         type = typehash_insert(function_type);
3517                         continue;
3518                 }
3519
3520                 case CONSTRUCT_POINTER: {
3521                         if (is_type_reference(skip_typeref(type)))
3522                                 errorf(pos, "cannot declare a pointer to reference");
3523
3524                         parsed_pointer_t *pointer = &iter->pointer;
3525                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3526                         continue;
3527                 }
3528
3529                 case CONSTRUCT_REFERENCE:
3530                         if (is_type_reference(skip_typeref(type)))
3531                                 errorf(pos, "cannot declare a reference to reference");
3532
3533                         type = make_reference_type(type);
3534                         continue;
3535
3536                 case CONSTRUCT_ARRAY: {
3537                         if (is_type_reference(skip_typeref(type)))
3538                                 errorf(pos, "cannot declare an array of references");
3539
3540                         parsed_array_t *array      = &iter->array;
3541                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3542
3543                         expression_t *size_expression = array->size;
3544                         if (size_expression != NULL) {
3545                                 size_expression
3546                                         = create_implicit_cast(size_expression, type_size_t);
3547                         }
3548
3549                         array_type->base.qualifiers       = array->type_qualifiers;
3550                         array_type->array.element_type    = type;
3551                         array_type->array.is_static       = array->is_static;
3552                         array_type->array.is_variable     = array->is_variable;
3553                         array_type->array.size_expression = size_expression;
3554
3555                         if (size_expression != NULL) {
3556                                 switch (is_constant_expression(size_expression)) {
3557                                 case EXPR_CLASS_CONSTANT: {
3558                                         long const size = fold_constant_to_int(size_expression);
3559                                         array_type->array.size          = size;
3560                                         array_type->array.size_constant = true;
3561                                         /* §6.7.5.2:1  If the expression is a constant expression,
3562                                          * it shall have a value greater than zero. */
3563                                         if (size < 0) {
3564                                                 errorf(&size_expression->base.source_position,
3565                                                            "size of array must be greater than zero");
3566                                         } else if (size == 0 && !GNU_MODE) {
3567                                                 errorf(&size_expression->base.source_position,
3568                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3569                                         }
3570                                         break;
3571                                 }
3572
3573                                 case EXPR_CLASS_VARIABLE:
3574                                         array_type->array.is_vla = true;
3575                                         break;
3576
3577                                 case EXPR_CLASS_ERROR:
3578                                         break;
3579                                 }
3580                         }
3581
3582                         type_t *skipped_type = skip_typeref(type);
3583                         /* §6.7.5.2:1 */
3584                         if (is_type_incomplete(skipped_type)) {
3585                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3586                         } else if (is_type_function(skipped_type)) {
3587                                 errorf(pos, "array of functions is not allowed");
3588                         }
3589                         type = identify_new_type(array_type);
3590                         continue;
3591                 }
3592                 }
3593                 internal_errorf(pos, "invalid type construction found");
3594         }
3595
3596         return type;
3597 }
3598
3599 static type_t *automatic_type_conversion(type_t *orig_type);
3600
3601 static type_t *semantic_parameter(const source_position_t *pos,
3602                                   type_t *type,
3603                                   const declaration_specifiers_t *specifiers,
3604                                   entity_t const *const param)
3605 {
3606         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3607          *             shall be adjusted to ``qualified pointer to type'',
3608          *             [...]
3609          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3610          *             type'' shall be adjusted to ``pointer to function
3611          *             returning type'', as in 6.3.2.1. */
3612         type = automatic_type_conversion(type);
3613
3614         if (specifiers->is_inline && is_type_valid(type)) {
3615                 errorf(pos, "'%N' declared 'inline'", param);
3616         }
3617
3618         /* §6.9.1:6  The declarations in the declaration list shall contain
3619          *           no storage-class specifier other than register and no
3620          *           initializations. */
3621         if (specifiers->thread_local || (
3622                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3623                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3624            ) {
3625                 errorf(pos, "invalid storage class for '%N'", param);
3626         }
3627
3628         /* delay test for incomplete type, because we might have (void)
3629          * which is legal but incomplete... */
3630
3631         return type;
3632 }
3633
3634 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3635                                   declarator_flags_t flags)
3636 {
3637         parse_declarator_env_t env;
3638         memset(&env, 0, sizeof(env));
3639         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3640
3641         construct_type_t *construct_type = parse_inner_declarator(&env);
3642         type_t           *orig_type      =
3643                 construct_declarator_type(construct_type, specifiers->type);
3644         type_t           *type           = skip_typeref(orig_type);
3645
3646         if (construct_type != NULL) {
3647                 obstack_free(&temp_obst, construct_type);
3648         }
3649
3650         attribute_t *attributes = parse_attributes(env.attributes);
3651         /* append (shared) specifier attribute behind attributes of this
3652          * declarator */
3653         attribute_t **anchor = &attributes;
3654         while (*anchor != NULL)
3655                 anchor = &(*anchor)->next;
3656         *anchor = specifiers->attributes;
3657
3658         entity_t *entity;
3659         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3660                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3661                 entity->typedefe.type = orig_type;
3662
3663                 if (anonymous_entity != NULL) {
3664                         if (is_type_compound(type)) {
3665                                 assert(anonymous_entity->compound.alias == NULL);
3666                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3667                                        anonymous_entity->kind == ENTITY_UNION);
3668                                 anonymous_entity->compound.alias = entity;
3669                                 anonymous_entity = NULL;
3670                         } else if (is_type_enum(type)) {
3671                                 assert(anonymous_entity->enume.alias == NULL);
3672                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3673                                 anonymous_entity->enume.alias = entity;
3674                                 anonymous_entity = NULL;
3675                         }
3676                 }
3677         } else {
3678                 /* create a declaration type entity */
3679                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3680                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3681                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3682
3683                         if (env.symbol != NULL) {
3684                                 if (specifiers->is_inline && is_type_valid(type)) {
3685                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3686                                 }
3687
3688                                 if (specifiers->thread_local ||
3689                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3690                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3691                                 }
3692                         }
3693                 } else if (flags & DECL_IS_PARAMETER) {
3694                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3695                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3696                 } else if (is_type_function(type)) {
3697                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3698                         entity->function.is_inline      = specifiers->is_inline;
3699                         entity->function.elf_visibility = default_visibility;
3700                         entity->function.parameters     = env.parameters;
3701
3702                         if (env.symbol != NULL) {
3703                                 /* this needs fixes for C++ */
3704                                 bool in_function_scope = current_function != NULL;
3705
3706                                 if (specifiers->thread_local || (
3707                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3708                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3709                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3710                                                 )) {
3711                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3712                                 }
3713                         }
3714                 } else {
3715                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3716                         entity->variable.elf_visibility = default_visibility;
3717                         entity->variable.thread_local   = specifiers->thread_local;
3718
3719                         if (env.symbol != NULL) {
3720                                 if (specifiers->is_inline && is_type_valid(type)) {
3721                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3722                                 }
3723
3724                                 bool invalid_storage_class = false;
3725                                 if (current_scope == file_scope) {
3726                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3727                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3728                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3729                                                 invalid_storage_class = true;
3730                                         }
3731                                 } else {
3732                                         if (specifiers->thread_local &&
3733                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3734                                                 invalid_storage_class = true;
3735                                         }
3736                                 }
3737                                 if (invalid_storage_class) {
3738                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3739                                 }
3740                         }
3741                 }
3742
3743                 entity->declaration.type       = orig_type;
3744                 entity->declaration.alignment  = get_type_alignment(orig_type);
3745                 entity->declaration.modifiers  = env.modifiers;
3746                 entity->declaration.attributes = attributes;
3747
3748                 storage_class_t storage_class = specifiers->storage_class;
3749                 entity->declaration.declared_storage_class = storage_class;
3750
3751                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3752                         storage_class = STORAGE_CLASS_AUTO;
3753                 entity->declaration.storage_class = storage_class;
3754         }
3755
3756         if (attributes != NULL) {
3757                 handle_entity_attributes(attributes, entity);
3758         }
3759
3760         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3761                 adapt_special_functions(&entity->function);
3762         }
3763
3764         return entity;
3765 }
3766
3767 static type_t *parse_abstract_declarator(type_t *base_type)
3768 {
3769         parse_declarator_env_t env;
3770         memset(&env, 0, sizeof(env));
3771         env.may_be_abstract = true;
3772         env.must_be_abstract = true;
3773
3774         construct_type_t *construct_type = parse_inner_declarator(&env);
3775
3776         type_t *result = construct_declarator_type(construct_type, base_type);
3777         if (construct_type != NULL) {
3778                 obstack_free(&temp_obst, construct_type);
3779         }
3780         result = handle_type_attributes(env.attributes, result);
3781
3782         return result;
3783 }
3784
3785 /**
3786  * Check if the declaration of main is suspicious.  main should be a
3787  * function with external linkage, returning int, taking either zero
3788  * arguments, two, or three arguments of appropriate types, ie.
3789  *
3790  * int main([ int argc, char **argv [, char **env ] ]).
3791  *
3792  * @param decl    the declaration to check
3793  * @param type    the function type of the declaration
3794  */
3795 static void check_main(const entity_t *entity)
3796 {
3797         const source_position_t *pos = &entity->base.source_position;
3798         if (entity->kind != ENTITY_FUNCTION) {
3799                 warningf(WARN_MAIN, pos, "'main' is not a function");
3800                 return;
3801         }
3802
3803         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3804                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3805         }
3806
3807         type_t *type = skip_typeref(entity->declaration.type);
3808         assert(is_type_function(type));
3809
3810         function_type_t const *const func_type = &type->function;
3811         type_t                *const ret_type  = func_type->return_type;
3812         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3813                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3814         }
3815         const function_parameter_t *parm = func_type->parameters;
3816         if (parm != NULL) {
3817                 type_t *const first_type        = skip_typeref(parm->type);
3818                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3819                 if (!types_compatible(first_type_unqual, type_int)) {
3820                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3821                 }
3822                 parm = parm->next;
3823                 if (parm != NULL) {
3824                         type_t *const second_type = skip_typeref(parm->type);
3825                         type_t *const second_type_unqual
3826                                 = get_unqualified_type(second_type);
3827                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3828                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3829                         }
3830                         parm = parm->next;
3831                         if (parm != NULL) {
3832                                 type_t *const third_type = skip_typeref(parm->type);
3833                                 type_t *const third_type_unqual
3834                                         = get_unqualified_type(third_type);
3835                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3836                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3837                                 }
3838                                 parm = parm->next;
3839                                 if (parm != NULL)
3840                                         goto warn_arg_count;
3841                         }
3842                 } else {
3843 warn_arg_count:
3844                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3845                 }
3846         }
3847 }
3848
3849 static void error_redefined_as_different_kind(const source_position_t *pos,
3850                 const entity_t *old, entity_kind_t new_kind)
3851 {
3852         char              const *const what = get_entity_kind_name(new_kind);
3853         source_position_t const *const ppos = &old->base.source_position;
3854         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3855 }
3856
3857 static bool is_entity_valid(entity_t *const ent)
3858 {
3859         if (is_declaration(ent)) {
3860                 return is_type_valid(skip_typeref(ent->declaration.type));
3861         } else if (ent->kind == ENTITY_TYPEDEF) {
3862                 return is_type_valid(skip_typeref(ent->typedefe.type));
3863         }
3864         return true;
3865 }
3866
3867 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3868 {
3869         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3870                 if (attributes_equal(tattr, attr))
3871                         return true;
3872         }
3873         return false;
3874 }
3875
3876 /**
3877  * test wether new_list contains any attributes not included in old_list
3878  */
3879 static bool has_new_attributes(const attribute_t *old_list,
3880                                const attribute_t *new_list)
3881 {
3882         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3883                 if (!contains_attribute(old_list, attr))
3884                         return true;
3885         }
3886         return false;
3887 }
3888
3889 /**
3890  * Merge in attributes from an attribute list (probably from a previous
3891  * declaration with the same name). Warning: destroys the old structure
3892  * of the attribute list - don't reuse attributes after this call.
3893  */
3894 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3895 {
3896         attribute_t *next;
3897         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3898                 next = attr->next;
3899                 if (contains_attribute(decl->attributes, attr))
3900                         continue;
3901
3902                 /* move attribute to new declarations attributes list */
3903                 attr->next       = decl->attributes;
3904                 decl->attributes = attr;
3905         }
3906 }
3907
3908 static bool is_main(entity_t*);
3909
3910 /**
3911  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3912  * for various problems that occur for multiple definitions
3913  */
3914 entity_t *record_entity(entity_t *entity, const bool is_definition)
3915 {
3916         const symbol_t *const    symbol  = entity->base.symbol;
3917         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3918         const source_position_t *pos     = &entity->base.source_position;
3919
3920         /* can happen in error cases */
3921         if (symbol == NULL)
3922                 return entity;
3923
3924         assert(!entity->base.parent_scope);
3925         assert(current_scope);
3926         entity->base.parent_scope = current_scope;
3927
3928         entity_t *const previous_entity = get_entity(symbol, namespc);
3929         /* pushing the same entity twice will break the stack structure */
3930         assert(previous_entity != entity);
3931
3932         if (entity->kind == ENTITY_FUNCTION) {
3933                 type_t *const orig_type = entity->declaration.type;
3934                 type_t *const type      = skip_typeref(orig_type);
3935
3936                 assert(is_type_function(type));
3937                 if (type->function.unspecified_parameters &&
3938                     previous_entity == NULL               &&
3939                     !entity->declaration.implicit) {
3940                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3941                 }
3942
3943                 if (is_main(entity)) {
3944                         check_main(entity);
3945                 }
3946         }
3947
3948         if (is_declaration(entity)                                    &&
3949             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3950             current_scope != file_scope                               &&
3951             !entity->declaration.implicit) {
3952                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3953         }
3954
3955         if (previous_entity != NULL) {
3956                 source_position_t const *const ppos = &previous_entity->base.source_position;
3957
3958                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3959                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3960                         assert(previous_entity->kind == ENTITY_PARAMETER);
3961                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3962                         goto finish;
3963                 }
3964
3965                 if (previous_entity->base.parent_scope == current_scope) {
3966                         if (previous_entity->kind != entity->kind) {
3967                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3968                                         error_redefined_as_different_kind(pos, previous_entity,
3969                                                         entity->kind);
3970                                 }
3971                                 goto finish;
3972                         }
3973                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3974                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3975                                 goto finish;
3976                         }
3977                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3978                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3979                                 type_t *const prev_type
3980                                         = skip_typeref(previous_entity->typedefe.type);
3981                                 if (c_mode & _CXX) {
3982                                         /* C++ allows double typedef if they are identical
3983                                          * (after skipping typedefs) */
3984                                         if (type == prev_type)
3985                                                 goto finish;
3986                                 } else {
3987                                         /* GCC extension: redef in system headers is allowed */
3988                                         if ((pos->is_system_header || ppos->is_system_header) &&
3989                                             types_compatible(type, prev_type))
3990                                                 goto finish;
3991                                 }
3992                                 errorf(pos, "redefinition of '%N' (declared %P)",
3993                                        entity, ppos);
3994                                 goto finish;
3995                         }
3996
3997                         /* at this point we should have only VARIABLES or FUNCTIONS */
3998                         assert(is_declaration(previous_entity) && is_declaration(entity));
3999
4000                         declaration_t *const prev_decl = &previous_entity->declaration;
4001                         declaration_t *const decl      = &entity->declaration;
4002
4003                         /* can happen for K&R style declarations */
4004                         if (prev_decl->type       == NULL             &&
4005                                         previous_entity->kind == ENTITY_PARAMETER &&
4006                                         entity->kind          == ENTITY_PARAMETER) {
4007                                 prev_decl->type                   = decl->type;
4008                                 prev_decl->storage_class          = decl->storage_class;
4009                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4010                                 prev_decl->modifiers              = decl->modifiers;
4011                                 return previous_entity;
4012                         }
4013
4014                         type_t *const type      = skip_typeref(decl->type);
4015                         type_t *const prev_type = skip_typeref(prev_decl->type);
4016
4017                         if (!types_compatible(type, prev_type)) {
4018                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4019                         } else {
4020                                 unsigned old_storage_class = prev_decl->storage_class;
4021
4022                                 if (is_definition                     &&
4023                                                 !prev_decl->used                  &&
4024                                                 !(prev_decl->modifiers & DM_USED) &&
4025                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4026                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4027                                 }
4028
4029                                 storage_class_t new_storage_class = decl->storage_class;
4030
4031                                 /* pretend no storage class means extern for function
4032                                  * declarations (except if the previous declaration is neither
4033                                  * none nor extern) */
4034                                 if (entity->kind == ENTITY_FUNCTION) {
4035                                         /* the previous declaration could have unspecified parameters or
4036                                          * be a typedef, so use the new type */
4037                                         if (prev_type->function.unspecified_parameters || is_definition)
4038                                                 prev_decl->type = type;
4039
4040                                         switch (old_storage_class) {
4041                                                 case STORAGE_CLASS_NONE:
4042                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4043                                                         /* FALLTHROUGH */
4044
4045                                                 case STORAGE_CLASS_EXTERN:
4046                                                         if (is_definition) {
4047                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4048                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4049                                                                 }
4050                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4051                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4052                                                         }
4053                                                         break;
4054
4055                                                 default:
4056                                                         break;
4057                                         }
4058                                 } else if (is_type_incomplete(prev_type)) {
4059                                         prev_decl->type = type;
4060                                 }
4061
4062                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4063                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4064
4065 warn_redundant_declaration: ;
4066                                         bool has_new_attrs
4067                                                 = has_new_attributes(prev_decl->attributes,
4068                                                                      decl->attributes);
4069                                         if (has_new_attrs) {
4070                                                 merge_in_attributes(decl, prev_decl->attributes);
4071                                         } else if (!is_definition        &&
4072                                                         is_type_valid(prev_type) &&
4073                                                         !pos->is_system_header) {
4074                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4075                                         }
4076                                 } else if (current_function == NULL) {
4077                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4078                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4079                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4080                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4081                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4082                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4083                                         } else {
4084                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4085                                                 if (c_mode & _CXX)
4086                                                         goto error_redeclaration;
4087                                                 goto warn_redundant_declaration;
4088                                         }
4089                                 } else if (is_type_valid(prev_type)) {
4090                                         if (old_storage_class == new_storage_class) {
4091 error_redeclaration:
4092                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4093                                         } else {
4094                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4095                                         }
4096                                 }
4097                         }
4098
4099                         prev_decl->modifiers |= decl->modifiers;
4100                         if (entity->kind == ENTITY_FUNCTION) {
4101                                 previous_entity->function.is_inline |= entity->function.is_inline;
4102                         }
4103                         return previous_entity;
4104                 }
4105
4106                 warning_t why;
4107                 if (is_warn_on(why = WARN_SHADOW) ||
4108                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4109                         char const *const what = get_entity_kind_name(previous_entity->kind);
4110                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4111                 }
4112         }
4113
4114         if (entity->kind == ENTITY_FUNCTION) {
4115                 if (is_definition &&
4116                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4117                                 !is_main(entity)) {
4118                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4119                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4120                         } else {
4121                                 goto warn_missing_declaration;
4122                         }
4123                 }
4124         } else if (entity->kind == ENTITY_VARIABLE) {
4125                 if (current_scope                     == file_scope &&
4126                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4127                                 !entity->declaration.implicit) {
4128 warn_missing_declaration:
4129                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4130                 }
4131         }
4132
4133 finish:
4134         environment_push(entity);
4135         append_entity(current_scope, entity);
4136
4137         return entity;
4138 }
4139
4140 static void parser_error_multiple_definition(entity_t *entity,
4141                 const source_position_t *source_position)
4142 {
4143         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4144 }
4145
4146 static bool is_declaration_specifier(const token_t *token)
4147 {
4148         switch (token->kind) {
4149                 DECLARATION_START
4150                         return true;
4151                 case T_IDENTIFIER:
4152                         return is_typedef_symbol(token->base.symbol);
4153
4154                 default:
4155                         return false;
4156         }
4157 }
4158
4159 static void parse_init_declarator_rest(entity_t *entity)
4160 {
4161         type_t *orig_type = type_error_type;
4162
4163         if (entity->base.kind == ENTITY_TYPEDEF) {
4164                 source_position_t const *const pos = &entity->base.source_position;
4165                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4166         } else {
4167                 assert(is_declaration(entity));
4168                 orig_type = entity->declaration.type;
4169         }
4170
4171         type_t *type = skip_typeref(orig_type);
4172
4173         if (entity->kind == ENTITY_VARIABLE
4174                         && entity->variable.initializer != NULL) {
4175                 parser_error_multiple_definition(entity, HERE);
4176         }
4177         eat('=');
4178
4179         declaration_t *const declaration = &entity->declaration;
4180         bool must_be_constant = false;
4181         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4182             entity->base.parent_scope  == file_scope) {
4183                 must_be_constant = true;
4184         }
4185
4186         if (is_type_function(type)) {
4187                 source_position_t const *const pos = &entity->base.source_position;
4188                 errorf(pos, "'%N' is initialized like a variable", entity);
4189                 orig_type = type_error_type;
4190         }
4191
4192         parse_initializer_env_t env;
4193         env.type             = orig_type;
4194         env.must_be_constant = must_be_constant;
4195         env.entity           = entity;
4196
4197         initializer_t *initializer = parse_initializer(&env);
4198
4199         if (entity->kind == ENTITY_VARIABLE) {
4200                 /* §6.7.5:22  array initializers for arrays with unknown size
4201                  * determine the array type size */
4202                 declaration->type            = env.type;
4203                 entity->variable.initializer = initializer;
4204         }
4205 }
4206
4207 /* parse rest of a declaration without any declarator */
4208 static void parse_anonymous_declaration_rest(
4209                 const declaration_specifiers_t *specifiers)
4210 {
4211         eat(';');
4212         anonymous_entity = NULL;
4213
4214         source_position_t const *const pos = &specifiers->source_position;
4215         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4216                         specifiers->thread_local) {
4217                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4218         }
4219
4220         type_t *type = specifiers->type;
4221         switch (type->kind) {
4222                 case TYPE_COMPOUND_STRUCT:
4223                 case TYPE_COMPOUND_UNION: {
4224                         if (type->compound.compound->base.symbol == NULL) {
4225                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4226                         }
4227                         break;
4228                 }
4229
4230                 case TYPE_ENUM:
4231                         break;
4232
4233                 default:
4234                         warningf(WARN_OTHER, pos, "empty declaration");
4235                         break;
4236         }
4237 }
4238
4239 static void check_variable_type_complete(entity_t *ent)
4240 {
4241         if (ent->kind != ENTITY_VARIABLE)
4242                 return;
4243
4244         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4245          *         type for the object shall be complete [...] */
4246         declaration_t *decl = &ent->declaration;
4247         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4248                         decl->storage_class == STORAGE_CLASS_STATIC)
4249                 return;
4250
4251         type_t *const type = skip_typeref(decl->type);
4252         if (!is_type_incomplete(type))
4253                 return;
4254
4255         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4256          * are given length one. */
4257         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4258                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4259                 return;
4260         }
4261
4262         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4263 }
4264
4265
4266 static void parse_declaration_rest(entity_t *ndeclaration,
4267                 const declaration_specifiers_t *specifiers,
4268                 parsed_declaration_func         finished_declaration,
4269                 declarator_flags_t              flags)
4270 {
4271         add_anchor_token(';');
4272         add_anchor_token(',');
4273         while (true) {
4274                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4275
4276                 if (token.kind == '=') {
4277                         parse_init_declarator_rest(entity);
4278                 } else if (entity->kind == ENTITY_VARIABLE) {
4279                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4280                          * [...] where the extern specifier is explicitly used. */
4281                         declaration_t *decl = &entity->declaration;
4282                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4283                             is_type_reference(skip_typeref(decl->type))) {
4284                                 source_position_t const *const pos = &entity->base.source_position;
4285                                 errorf(pos, "reference '%#N' must be initialized", entity);
4286                         }
4287                 }
4288
4289                 check_variable_type_complete(entity);
4290
4291                 if (!next_if(','))
4292                         break;
4293
4294                 add_anchor_token('=');
4295                 ndeclaration = parse_declarator(specifiers, flags);
4296                 rem_anchor_token('=');
4297         }
4298         rem_anchor_token(',');
4299         rem_anchor_token(';');
4300         expect(';');
4301
4302         anonymous_entity = NULL;
4303 }
4304
4305 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4306 {
4307         symbol_t *symbol = entity->base.symbol;
4308         if (symbol == NULL)
4309                 return entity;
4310
4311         assert(entity->base.namespc == NAMESPACE_NORMAL);
4312         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4313         if (previous_entity == NULL
4314                         || previous_entity->base.parent_scope != current_scope) {
4315                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4316                        symbol);
4317                 return entity;
4318         }
4319
4320         if (is_definition) {
4321                 errorf(HERE, "'%N' is initialised", entity);
4322         }
4323
4324         return record_entity(entity, false);
4325 }
4326
4327 static void parse_declaration(parsed_declaration_func finished_declaration,
4328                               declarator_flags_t      flags)
4329 {
4330         add_anchor_token(';');
4331         declaration_specifiers_t specifiers;
4332         parse_declaration_specifiers(&specifiers);
4333         rem_anchor_token(';');
4334
4335         if (token.kind == ';') {
4336                 parse_anonymous_declaration_rest(&specifiers);
4337         } else {
4338                 entity_t *entity = parse_declarator(&specifiers, flags);
4339                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4340         }
4341 }
4342
4343 /* §6.5.2.2:6 */
4344 static type_t *get_default_promoted_type(type_t *orig_type)
4345 {
4346         type_t *result = orig_type;
4347
4348         type_t *type = skip_typeref(orig_type);
4349         if (is_type_integer(type)) {
4350                 result = promote_integer(type);
4351         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4352                 result = type_double;
4353         }
4354
4355         return result;
4356 }
4357
4358 static void parse_kr_declaration_list(entity_t *entity)
4359 {
4360         if (entity->kind != ENTITY_FUNCTION)
4361                 return;
4362
4363         type_t *type = skip_typeref(entity->declaration.type);
4364         assert(is_type_function(type));
4365         if (!type->function.kr_style_parameters)
4366                 return;
4367
4368         add_anchor_token('{');
4369
4370         PUSH_SCOPE(&entity->function.parameters);
4371
4372         entity_t *parameter = entity->function.parameters.entities;
4373         for ( ; parameter != NULL; parameter = parameter->base.next) {
4374                 assert(parameter->base.parent_scope == NULL);
4375                 parameter->base.parent_scope = current_scope;
4376                 environment_push(parameter);
4377         }
4378
4379         /* parse declaration list */
4380         for (;;) {
4381                 switch (token.kind) {
4382                         DECLARATION_START
4383                         /* This covers symbols, which are no type, too, and results in
4384                          * better error messages.  The typical cases are misspelled type
4385                          * names and missing includes. */
4386                         case T_IDENTIFIER:
4387                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4388                                 break;
4389                         default:
4390                                 goto decl_list_end;
4391                 }
4392         }
4393 decl_list_end:
4394
4395         POP_SCOPE();
4396
4397         /* update function type */
4398         type_t *new_type = duplicate_type(type);
4399
4400         function_parameter_t  *parameters = NULL;
4401         function_parameter_t **anchor     = &parameters;
4402
4403         /* did we have an earlier prototype? */
4404         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4405         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4406                 proto_type = NULL;
4407
4408         function_parameter_t *proto_parameter = NULL;
4409         if (proto_type != NULL) {
4410                 type_t *proto_type_type = proto_type->declaration.type;
4411                 proto_parameter         = proto_type_type->function.parameters;
4412                 /* If a K&R function definition has a variadic prototype earlier, then
4413                  * make the function definition variadic, too. This should conform to
4414                  * §6.7.5.3:15 and §6.9.1:8. */
4415                 new_type->function.variadic = proto_type_type->function.variadic;
4416         } else {
4417                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4418                  * prototype */
4419                 new_type->function.unspecified_parameters = true;
4420         }
4421
4422         bool need_incompatible_warning = false;
4423         parameter = entity->function.parameters.entities;
4424         for (; parameter != NULL; parameter = parameter->base.next,
4425                         proto_parameter =
4426                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4427                 if (parameter->kind != ENTITY_PARAMETER)
4428                         continue;
4429
4430                 type_t *parameter_type = parameter->declaration.type;
4431                 if (parameter_type == NULL) {
4432                         source_position_t const* const pos = &parameter->base.source_position;
4433                         if (strict_mode) {
4434                                 errorf(pos, "no type specified for function '%N'", parameter);
4435                                 parameter_type = type_error_type;
4436                         } else {
4437                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4438                                 parameter_type = type_int;
4439                         }
4440                         parameter->declaration.type = parameter_type;
4441                 }
4442
4443                 semantic_parameter_incomplete(parameter);
4444
4445                 /* we need the default promoted types for the function type */
4446                 type_t *not_promoted = parameter_type;
4447                 parameter_type       = get_default_promoted_type(parameter_type);
4448
4449                 /* gcc special: if the type of the prototype matches the unpromoted
4450                  * type don't promote */
4451                 if (!strict_mode && proto_parameter != NULL) {
4452                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4453                         type_t *promo_skip   = skip_typeref(parameter_type);
4454                         type_t *param_skip   = skip_typeref(not_promoted);
4455                         if (!types_compatible(proto_p_type, promo_skip)
4456                                 && types_compatible(proto_p_type, param_skip)) {
4457                                 /* don't promote */
4458                                 need_incompatible_warning = true;
4459                                 parameter_type = not_promoted;
4460                         }
4461                 }
4462                 function_parameter_t *const function_parameter
4463                         = allocate_parameter(parameter_type);
4464
4465                 *anchor = function_parameter;
4466                 anchor  = &function_parameter->next;
4467         }
4468
4469         new_type->function.parameters = parameters;
4470         new_type = identify_new_type(new_type);
4471
4472         if (need_incompatible_warning) {
4473                 symbol_t          const *const sym  = entity->base.symbol;
4474                 source_position_t const *const pos  = &entity->base.source_position;
4475                 source_position_t const *const ppos = &proto_type->base.source_position;
4476                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4477         }
4478         entity->declaration.type = new_type;
4479
4480         rem_anchor_token('{');
4481 }
4482
4483 static bool first_err = true;
4484
4485 /**
4486  * When called with first_err set, prints the name of the current function,
4487  * else does noting.
4488  */
4489 static void print_in_function(void)
4490 {
4491         if (first_err) {
4492                 first_err = false;
4493                 char const *const file = current_function->base.base.source_position.input_name;
4494                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4495         }
4496 }
4497
4498 /**
4499  * Check if all labels are defined in the current function.
4500  * Check if all labels are used in the current function.
4501  */
4502 static void check_labels(void)
4503 {
4504         for (const goto_statement_t *goto_statement = goto_first;
4505             goto_statement != NULL;
4506             goto_statement = goto_statement->next) {
4507                 label_t *label = goto_statement->label;
4508                 if (label->base.source_position.input_name == NULL) {
4509                         print_in_function();
4510                         source_position_t const *const pos = &goto_statement->base.source_position;
4511                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4512                  }
4513         }
4514
4515         if (is_warn_on(WARN_UNUSED_LABEL)) {
4516                 for (const label_statement_t *label_statement = label_first;
4517                          label_statement != NULL;
4518                          label_statement = label_statement->next) {
4519                         label_t *label = label_statement->label;
4520
4521                         if (! label->used) {
4522                                 print_in_function();
4523                                 source_position_t const *const pos = &label_statement->base.source_position;
4524                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4525                         }
4526                 }
4527         }
4528 }
4529
4530 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4531 {
4532         entity_t const *const end = last != NULL ? last->base.next : NULL;
4533         for (; entity != end; entity = entity->base.next) {
4534                 if (!is_declaration(entity))
4535                         continue;
4536
4537                 declaration_t *declaration = &entity->declaration;
4538                 if (declaration->implicit)
4539                         continue;
4540
4541                 if (!declaration->used) {
4542                         print_in_function();
4543                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4544                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4545                         print_in_function();
4546                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4547                 }
4548         }
4549 }
4550
4551 static void check_unused_variables(statement_t *const stmt, void *const env)
4552 {
4553         (void)env;
4554
4555         switch (stmt->kind) {
4556                 case STATEMENT_DECLARATION: {
4557                         declaration_statement_t const *const decls = &stmt->declaration;
4558                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4559                         return;
4560                 }
4561
4562                 case STATEMENT_FOR:
4563                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4564                         return;
4565
4566                 default:
4567                         return;
4568         }
4569 }
4570
4571 /**
4572  * Check declarations of current_function for unused entities.
4573  */
4574 static void check_declarations(void)
4575 {
4576         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4577                 const scope_t *scope = &current_function->parameters;
4578                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4579         }
4580         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4581                 walk_statements(current_function->statement, check_unused_variables,
4582                                 NULL);
4583         }
4584 }
4585
4586 static int determine_truth(expression_t const* const cond)
4587 {
4588         return
4589                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4590                 fold_constant_to_bool(cond)                         ? 1 :
4591                 -1;
4592 }
4593
4594 static void check_reachable(statement_t *);
4595 static bool reaches_end;
4596
4597 static bool expression_returns(expression_t const *const expr)
4598 {
4599         switch (expr->kind) {
4600                 case EXPR_CALL: {
4601                         expression_t const *const func = expr->call.function;
4602                         type_t       const *const type = skip_typeref(func->base.type);
4603                         if (type->kind == TYPE_POINTER) {
4604                                 type_t const *const points_to
4605                                         = skip_typeref(type->pointer.points_to);
4606                                 if (points_to->kind == TYPE_FUNCTION
4607                                     && points_to->function.modifiers & DM_NORETURN)
4608                                         return false;
4609                         }
4610
4611                         if (!expression_returns(func))
4612                                 return false;
4613
4614                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4615                                 if (!expression_returns(arg->expression))
4616                                         return false;
4617                         }
4618
4619                         return true;
4620                 }
4621
4622                 case EXPR_REFERENCE:
4623                 case EXPR_ENUM_CONSTANT:
4624                 case EXPR_LITERAL_CASES:
4625                 case EXPR_LITERAL_CHARACTER:
4626                 case EXPR_STRING_LITERAL:
4627                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4628                 case EXPR_LABEL_ADDRESS:
4629                 case EXPR_CLASSIFY_TYPE:
4630                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4631                 case EXPR_ALIGNOF:
4632                 case EXPR_FUNCNAME:
4633                 case EXPR_BUILTIN_CONSTANT_P:
4634                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4635                 case EXPR_OFFSETOF:
4636                 case EXPR_ERROR:
4637                         return true;
4638
4639                 case EXPR_STATEMENT: {
4640                         bool old_reaches_end = reaches_end;
4641                         reaches_end = false;
4642                         check_reachable(expr->statement.statement);
4643                         bool returns = reaches_end;
4644                         reaches_end = old_reaches_end;
4645                         return returns;
4646                 }
4647
4648                 case EXPR_CONDITIONAL:
4649                         // TODO handle constant expression
4650
4651                         if (!expression_returns(expr->conditional.condition))
4652                                 return false;
4653
4654                         if (expr->conditional.true_expression != NULL
4655                                         && expression_returns(expr->conditional.true_expression))
4656                                 return true;
4657
4658                         return expression_returns(expr->conditional.false_expression);
4659
4660                 case EXPR_SELECT:
4661                         return expression_returns(expr->select.compound);
4662
4663                 case EXPR_ARRAY_ACCESS:
4664                         return
4665                                 expression_returns(expr->array_access.array_ref) &&
4666                                 expression_returns(expr->array_access.index);
4667
4668                 case EXPR_VA_START:
4669                         return expression_returns(expr->va_starte.ap);
4670
4671                 case EXPR_VA_ARG:
4672                         return expression_returns(expr->va_arge.ap);
4673
4674                 case EXPR_VA_COPY:
4675                         return expression_returns(expr->va_copye.src);
4676
4677                 case EXPR_UNARY_CASES_MANDATORY:
4678                         return expression_returns(expr->unary.value);
4679
4680                 case EXPR_UNARY_THROW:
4681                         return false;
4682
4683                 case EXPR_BINARY_CASES:
4684                         // TODO handle constant lhs of && and ||
4685                         return
4686                                 expression_returns(expr->binary.left) &&
4687                                 expression_returns(expr->binary.right);
4688         }
4689
4690         panic("unhandled expression");
4691 }
4692
4693 static bool initializer_returns(initializer_t const *const init)
4694 {
4695         switch (init->kind) {
4696                 case INITIALIZER_VALUE:
4697                         return expression_returns(init->value.value);
4698
4699                 case INITIALIZER_LIST: {
4700                         initializer_t * const*       i       = init->list.initializers;
4701                         initializer_t * const* const end     = i + init->list.len;
4702                         bool                         returns = true;
4703                         for (; i != end; ++i) {
4704                                 if (!initializer_returns(*i))
4705                                         returns = false;
4706                         }
4707                         return returns;
4708                 }
4709
4710                 case INITIALIZER_STRING:
4711                 case INITIALIZER_DESIGNATOR: // designators have no payload
4712                         return true;
4713         }
4714         panic("unhandled initializer");
4715 }
4716
4717 static bool noreturn_candidate;
4718
4719 static void check_reachable(statement_t *const stmt)
4720 {
4721         if (stmt->base.reachable)
4722                 return;
4723         if (stmt->kind != STATEMENT_DO_WHILE)
4724                 stmt->base.reachable = true;
4725
4726         statement_t *last = stmt;
4727         statement_t *next;
4728         switch (stmt->kind) {
4729                 case STATEMENT_ERROR:
4730                 case STATEMENT_EMPTY:
4731                 case STATEMENT_ASM:
4732                         next = stmt->base.next;
4733                         break;
4734
4735                 case STATEMENT_DECLARATION: {
4736                         declaration_statement_t const *const decl = &stmt->declaration;
4737                         entity_t                const *      ent  = decl->declarations_begin;
4738                         entity_t                const *const last_decl = decl->declarations_end;
4739                         if (ent != NULL) {
4740                                 for (;; ent = ent->base.next) {
4741                                         if (ent->kind                 == ENTITY_VARIABLE &&
4742                                             ent->variable.initializer != NULL            &&
4743                                             !initializer_returns(ent->variable.initializer)) {
4744                                                 return;
4745                                         }
4746                                         if (ent == last_decl)
4747                                                 break;
4748                                 }
4749                         }
4750                         next = stmt->base.next;
4751                         break;
4752                 }
4753
4754                 case STATEMENT_COMPOUND:
4755                         next = stmt->compound.statements;
4756                         if (next == NULL)
4757                                 next = stmt->base.next;
4758                         break;
4759
4760                 case STATEMENT_RETURN: {
4761                         expression_t const *const val = stmt->returns.value;
4762                         if (val == NULL || expression_returns(val))
4763                                 noreturn_candidate = false;
4764                         return;
4765                 }
4766
4767                 case STATEMENT_IF: {
4768                         if_statement_t const *const ifs  = &stmt->ifs;
4769                         expression_t   const *const cond = ifs->condition;
4770
4771                         if (!expression_returns(cond))
4772                                 return;
4773
4774                         int const val = determine_truth(cond);
4775
4776                         if (val >= 0)
4777                                 check_reachable(ifs->true_statement);
4778
4779                         if (val > 0)
4780                                 return;
4781
4782                         if (ifs->false_statement != NULL) {
4783                                 check_reachable(ifs->false_statement);
4784                                 return;
4785                         }
4786
4787                         next = stmt->base.next;
4788                         break;
4789                 }
4790
4791                 case STATEMENT_SWITCH: {
4792                         switch_statement_t const *const switchs = &stmt->switchs;
4793                         expression_t       const *const expr    = switchs->expression;
4794
4795                         if (!expression_returns(expr))
4796                                 return;
4797
4798                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4799                                 long                    const val      = fold_constant_to_int(expr);
4800                                 case_label_statement_t *      defaults = NULL;
4801                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4802                                         if (i->expression == NULL) {
4803                                                 defaults = i;
4804                                                 continue;
4805                                         }
4806
4807                                         if (i->first_case <= val && val <= i->last_case) {
4808                                                 check_reachable((statement_t*)i);
4809                                                 return;
4810                                         }
4811                                 }
4812
4813                                 if (defaults != NULL) {
4814                                         check_reachable((statement_t*)defaults);
4815                                         return;
4816                                 }
4817                         } else {
4818                                 bool has_default = false;
4819                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4820                                         if (i->expression == NULL)
4821                                                 has_default = true;
4822
4823                                         check_reachable((statement_t*)i);
4824                                 }
4825
4826                                 if (has_default)
4827                                         return;
4828                         }
4829
4830                         next = stmt->base.next;
4831                         break;
4832                 }
4833
4834                 case STATEMENT_EXPRESSION: {
4835                         /* Check for noreturn function call */
4836                         expression_t const *const expr = stmt->expression.expression;
4837                         if (!expression_returns(expr))
4838                                 return;
4839
4840                         next = stmt->base.next;
4841                         break;
4842                 }
4843
4844                 case STATEMENT_CONTINUE:
4845                         for (statement_t *parent = stmt;;) {
4846                                 parent = parent->base.parent;
4847                                 if (parent == NULL) /* continue not within loop */
4848                                         return;
4849
4850                                 next = parent;
4851                                 switch (parent->kind) {
4852                                         case STATEMENT_WHILE:    goto continue_while;
4853                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4854                                         case STATEMENT_FOR:      goto continue_for;
4855
4856                                         default: break;
4857                                 }
4858                         }
4859
4860                 case STATEMENT_BREAK:
4861                         for (statement_t *parent = stmt;;) {
4862                                 parent = parent->base.parent;
4863                                 if (parent == NULL) /* break not within loop/switch */
4864                                         return;
4865
4866                                 switch (parent->kind) {
4867                                         case STATEMENT_SWITCH:
4868                                         case STATEMENT_WHILE:
4869                                         case STATEMENT_DO_WHILE:
4870                                         case STATEMENT_FOR:
4871                                                 last = parent;
4872                                                 next = parent->base.next;
4873                                                 goto found_break_parent;
4874
4875                                         default: break;
4876                                 }
4877                         }
4878 found_break_parent:
4879                         break;
4880
4881                 case STATEMENT_COMPUTED_GOTO: {
4882                         if (!expression_returns(stmt->computed_goto.expression))
4883                                 return;
4884
4885                         statement_t *parent = stmt->base.parent;
4886                         if (parent == NULL) /* top level goto */
4887                                 return;
4888                         next = parent;
4889                         break;
4890                 }
4891
4892                 case STATEMENT_GOTO:
4893                         next = stmt->gotos.label->statement;
4894                         if (next == NULL) /* missing label */
4895                                 return;
4896                         break;
4897
4898                 case STATEMENT_LABEL:
4899                         next = stmt->label.statement;
4900                         break;
4901
4902                 case STATEMENT_CASE_LABEL:
4903                         next = stmt->case_label.statement;
4904                         break;
4905
4906                 case STATEMENT_WHILE: {
4907                         while_statement_t const *const whiles = &stmt->whiles;
4908                         expression_t      const *const cond   = whiles->condition;
4909
4910                         if (!expression_returns(cond))
4911                                 return;
4912
4913                         int const val = determine_truth(cond);
4914
4915                         if (val >= 0)
4916                                 check_reachable(whiles->body);
4917
4918                         if (val > 0)
4919                                 return;
4920
4921                         next = stmt->base.next;
4922                         break;
4923                 }
4924
4925                 case STATEMENT_DO_WHILE:
4926                         next = stmt->do_while.body;
4927                         break;
4928
4929                 case STATEMENT_FOR: {
4930                         for_statement_t *const fors = &stmt->fors;
4931
4932                         if (fors->condition_reachable)
4933                                 return;
4934                         fors->condition_reachable = true;
4935
4936                         expression_t const *const cond = fors->condition;
4937
4938                         int val;
4939                         if (cond == NULL) {
4940                                 val = 1;
4941                         } else if (expression_returns(cond)) {
4942                                 val = determine_truth(cond);
4943                         } else {
4944                                 return;
4945                         }
4946
4947                         if (val >= 0)
4948                                 check_reachable(fors->body);
4949
4950                         if (val > 0)
4951                                 return;
4952
4953                         next = stmt->base.next;
4954                         break;
4955                 }
4956
4957                 case STATEMENT_MS_TRY: {
4958                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4959                         check_reachable(ms_try->try_statement);
4960                         next = ms_try->final_statement;
4961                         break;
4962                 }
4963
4964                 case STATEMENT_LEAVE: {
4965                         statement_t *parent = stmt;
4966                         for (;;) {
4967                                 parent = parent->base.parent;
4968                                 if (parent == NULL) /* __leave not within __try */
4969                                         return;
4970
4971                                 if (parent->kind == STATEMENT_MS_TRY) {
4972                                         last = parent;
4973                                         next = parent->ms_try.final_statement;
4974                                         break;
4975                                 }
4976                         }
4977                         break;
4978                 }
4979
4980                 default:
4981                         panic("invalid statement kind");
4982         }
4983
4984         while (next == NULL) {
4985                 next = last->base.parent;
4986                 if (next == NULL) {
4987                         noreturn_candidate = false;
4988
4989                         type_t *const type = skip_typeref(current_function->base.type);
4990                         assert(is_type_function(type));
4991                         type_t *const ret  = skip_typeref(type->function.return_type);
4992                         if (!is_type_void(ret) &&
4993                             is_type_valid(ret) &&
4994                             !is_main(current_entity)) {
4995                                 source_position_t const *const pos = &stmt->base.source_position;
4996                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4997                         }
4998                         return;
4999                 }
5000
5001                 switch (next->kind) {
5002                         case STATEMENT_ERROR:
5003                         case STATEMENT_EMPTY:
5004                         case STATEMENT_DECLARATION:
5005                         case STATEMENT_EXPRESSION:
5006                         case STATEMENT_ASM:
5007                         case STATEMENT_RETURN:
5008                         case STATEMENT_CONTINUE:
5009                         case STATEMENT_BREAK:
5010                         case STATEMENT_COMPUTED_GOTO:
5011                         case STATEMENT_GOTO:
5012                         case STATEMENT_LEAVE:
5013                                 panic("invalid control flow in function");
5014
5015                         case STATEMENT_COMPOUND:
5016                                 if (next->compound.stmt_expr) {
5017                                         reaches_end = true;
5018                                         return;
5019                                 }
5020                                 /* FALLTHROUGH */
5021                         case STATEMENT_IF:
5022                         case STATEMENT_SWITCH:
5023                         case STATEMENT_LABEL:
5024                         case STATEMENT_CASE_LABEL:
5025                                 last = next;
5026                                 next = next->base.next;
5027                                 break;
5028
5029                         case STATEMENT_WHILE: {
5030 continue_while:
5031                                 if (next->base.reachable)
5032                                         return;
5033                                 next->base.reachable = true;
5034
5035                                 while_statement_t const *const whiles = &next->whiles;
5036                                 expression_t      const *const cond   = whiles->condition;
5037
5038                                 if (!expression_returns(cond))
5039                                         return;
5040
5041                                 int const val = determine_truth(cond);
5042
5043                                 if (val >= 0)
5044                                         check_reachable(whiles->body);
5045
5046                                 if (val > 0)
5047                                         return;
5048
5049                                 last = next;
5050                                 next = next->base.next;
5051                                 break;
5052                         }
5053
5054                         case STATEMENT_DO_WHILE: {
5055 continue_do_while:
5056                                 if (next->base.reachable)
5057                                         return;
5058                                 next->base.reachable = true;
5059
5060                                 do_while_statement_t const *const dw   = &next->do_while;
5061                                 expression_t         const *const cond = dw->condition;
5062
5063                                 if (!expression_returns(cond))
5064                                         return;
5065
5066                                 int const val = determine_truth(cond);
5067
5068                                 if (val >= 0)
5069                                         check_reachable(dw->body);
5070
5071                                 if (val > 0)
5072                                         return;
5073
5074                                 last = next;
5075                                 next = next->base.next;
5076                                 break;
5077                         }
5078
5079                         case STATEMENT_FOR: {
5080 continue_for:;
5081                                 for_statement_t *const fors = &next->fors;
5082
5083                                 fors->step_reachable = true;
5084
5085                                 if (fors->condition_reachable)
5086                                         return;
5087                                 fors->condition_reachable = true;
5088
5089                                 expression_t const *const cond = fors->condition;
5090
5091                                 int val;
5092                                 if (cond == NULL) {
5093                                         val = 1;
5094                                 } else if (expression_returns(cond)) {
5095                                         val = determine_truth(cond);
5096                                 } else {
5097                                         return;
5098                                 }
5099
5100                                 if (val >= 0)
5101                                         check_reachable(fors->body);
5102
5103                                 if (val > 0)
5104                                         return;
5105
5106                                 last = next;
5107                                 next = next->base.next;
5108                                 break;
5109                         }
5110
5111                         case STATEMENT_MS_TRY:
5112                                 last = next;
5113                                 next = next->ms_try.final_statement;
5114                                 break;
5115                 }
5116         }
5117
5118         check_reachable(next);
5119 }
5120
5121 static void check_unreachable(statement_t* const stmt, void *const env)
5122 {
5123         (void)env;
5124
5125         switch (stmt->kind) {
5126                 case STATEMENT_DO_WHILE:
5127                         if (!stmt->base.reachable) {
5128                                 expression_t const *const cond = stmt->do_while.condition;
5129                                 if (determine_truth(cond) >= 0) {
5130                                         source_position_t const *const pos = &cond->base.source_position;
5131                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5132                                 }
5133                         }
5134                         return;
5135
5136                 case STATEMENT_FOR: {
5137                         for_statement_t const* const fors = &stmt->fors;
5138
5139                         // if init and step are unreachable, cond is unreachable, too
5140                         if (!stmt->base.reachable && !fors->step_reachable) {
5141                                 goto warn_unreachable;
5142                         } else {
5143                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5144                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5145                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5146                                 }
5147
5148                                 if (!fors->condition_reachable && fors->condition != NULL) {
5149                                         source_position_t const *const pos = &fors->condition->base.source_position;
5150                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5151                                 }
5152
5153                                 if (!fors->step_reachable && fors->step != NULL) {
5154                                         source_position_t const *const pos = &fors->step->base.source_position;
5155                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5156                                 }
5157                         }
5158                         return;
5159                 }
5160
5161                 case STATEMENT_COMPOUND:
5162                         if (stmt->compound.statements != NULL)
5163                                 return;
5164                         goto warn_unreachable;
5165
5166                 case STATEMENT_DECLARATION: {
5167                         /* Only warn if there is at least one declarator with an initializer.
5168                          * This typically occurs in switch statements. */
5169                         declaration_statement_t const *const decl = &stmt->declaration;
5170                         entity_t                const *      ent  = decl->declarations_begin;
5171                         entity_t                const *const last = decl->declarations_end;
5172                         if (ent != NULL) {
5173                                 for (;; ent = ent->base.next) {
5174                                         if (ent->kind                 == ENTITY_VARIABLE &&
5175                                                         ent->variable.initializer != NULL) {
5176                                                 goto warn_unreachable;
5177                                         }
5178                                         if (ent == last)
5179                                                 return;
5180                                 }
5181                         }
5182                 }
5183
5184                 default:
5185 warn_unreachable:
5186                         if (!stmt->base.reachable) {
5187                                 source_position_t const *const pos = &stmt->base.source_position;
5188                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5189                         }
5190                         return;
5191         }
5192 }
5193
5194 static bool is_main(entity_t *entity)
5195 {
5196         static symbol_t *sym_main = NULL;
5197         if (sym_main == NULL) {
5198                 sym_main = symbol_table_insert("main");
5199         }
5200
5201         if (entity->base.symbol != sym_main)
5202                 return false;
5203         /* must be in outermost scope */
5204         if (entity->base.parent_scope != file_scope)
5205                 return false;
5206
5207         return true;
5208 }
5209
5210 static void prepare_main_collect2(entity_t*);
5211
5212 static void parse_external_declaration(void)
5213 {
5214         /* function-definitions and declarations both start with declaration
5215          * specifiers */
5216         add_anchor_token(';');
5217         declaration_specifiers_t specifiers;
5218         parse_declaration_specifiers(&specifiers);
5219         rem_anchor_token(';');
5220
5221         /* must be a declaration */
5222         if (token.kind == ';') {
5223                 parse_anonymous_declaration_rest(&specifiers);
5224                 return;
5225         }
5226
5227         add_anchor_token(',');
5228         add_anchor_token('=');
5229         add_anchor_token(';');
5230         add_anchor_token('{');
5231
5232         /* declarator is common to both function-definitions and declarations */
5233         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5234
5235         rem_anchor_token('{');
5236         rem_anchor_token(';');
5237         rem_anchor_token('=');
5238         rem_anchor_token(',');
5239
5240         /* must be a declaration */
5241         switch (token.kind) {
5242                 case ',':
5243                 case ';':
5244                 case '=':
5245                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5246                                         DECL_FLAGS_NONE);
5247                         return;
5248         }
5249
5250         /* must be a function definition */
5251         parse_kr_declaration_list(ndeclaration);
5252
5253         if (token.kind != '{') {
5254                 parse_error_expected("while parsing function definition", '{', NULL);
5255                 eat_until_matching_token(';');
5256                 return;
5257         }
5258
5259         assert(is_declaration(ndeclaration));
5260         type_t *const orig_type = ndeclaration->declaration.type;
5261         type_t *      type      = skip_typeref(orig_type);
5262
5263         if (!is_type_function(type)) {
5264                 if (is_type_valid(type)) {
5265                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5266                 }
5267                 eat_block();
5268                 return;
5269         }
5270
5271         source_position_t const *const pos = &ndeclaration->base.source_position;
5272         if (is_typeref(orig_type)) {
5273                 /* §6.9.1:2 */
5274                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5275         }
5276
5277         if (is_type_compound(skip_typeref(type->function.return_type))) {
5278                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5279         }
5280         if (type->function.unspecified_parameters) {
5281                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5282         } else {
5283                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5284         }
5285
5286         /* §6.7.5.3:14 a function definition with () means no
5287          * parameters (and not unspecified parameters) */
5288         if (type->function.unspecified_parameters &&
5289                         type->function.parameters == NULL) {
5290                 type_t *copy                          = duplicate_type(type);
5291                 copy->function.unspecified_parameters = false;
5292                 type                                  = identify_new_type(copy);
5293
5294                 ndeclaration->declaration.type = type;
5295         }
5296
5297         entity_t *const entity = record_entity(ndeclaration, true);
5298         assert(entity->kind == ENTITY_FUNCTION);
5299         assert(ndeclaration->kind == ENTITY_FUNCTION);
5300
5301         function_t *const function = &entity->function;
5302         if (ndeclaration != entity) {
5303                 function->parameters = ndeclaration->function.parameters;
5304         }
5305
5306         PUSH_SCOPE(&function->parameters);
5307
5308         entity_t *parameter = function->parameters.entities;
5309         for (; parameter != NULL; parameter = parameter->base.next) {
5310                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5311                         parameter->base.parent_scope = current_scope;
5312                 }
5313                 assert(parameter->base.parent_scope == NULL
5314                                 || parameter->base.parent_scope == current_scope);
5315                 parameter->base.parent_scope = current_scope;
5316                 if (parameter->base.symbol == NULL) {
5317                         errorf(&parameter->base.source_position, "parameter name omitted");
5318                         continue;
5319                 }
5320                 environment_push(parameter);
5321         }
5322
5323         if (function->statement != NULL) {
5324                 parser_error_multiple_definition(entity, HERE);
5325                 eat_block();
5326         } else {
5327                 /* parse function body */
5328                 int         label_stack_top      = label_top();
5329                 function_t *old_current_function = current_function;
5330                 current_function                 = function;
5331                 PUSH_CURRENT_ENTITY(entity);
5332                 PUSH_PARENT(NULL);
5333
5334                 goto_first   = NULL;
5335                 goto_anchor  = &goto_first;
5336                 label_first  = NULL;
5337                 label_anchor = &label_first;
5338
5339                 statement_t *const body = parse_compound_statement(false);
5340                 function->statement = body;
5341                 first_err = true;
5342                 check_labels();
5343                 check_declarations();
5344                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5345                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5346                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5347                         noreturn_candidate = true;
5348                         check_reachable(body);
5349                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5350                                 walk_statements(body, check_unreachable, NULL);
5351                         if (noreturn_candidate &&
5352                             !(function->base.modifiers & DM_NORETURN)) {
5353                                 source_position_t const *const pos = &body->base.source_position;
5354                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5355                         }
5356                 }
5357
5358                 if (is_main(entity)) {
5359                         /* Force main to C linkage. */
5360                         type_t *const type = entity->declaration.type;
5361                         assert(is_type_function(type));
5362                         if (type->function.linkage != LINKAGE_C) {
5363                                 type_t *new_type           = duplicate_type(type);
5364                                 new_type->function.linkage = LINKAGE_C;
5365                                 entity->declaration.type   = identify_new_type(new_type);
5366                         }
5367
5368                         if (enable_main_collect2_hack)
5369                                 prepare_main_collect2(entity);
5370                 }
5371
5372                 POP_CURRENT_ENTITY();
5373                 POP_PARENT();
5374                 assert(current_function == function);
5375                 current_function = old_current_function;
5376                 label_pop_to(label_stack_top);
5377         }
5378
5379         POP_SCOPE();
5380 }
5381
5382 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5383 {
5384         entity_t *iter = compound->members.entities;
5385         for (; iter != NULL; iter = iter->base.next) {
5386                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5387                         continue;
5388
5389                 if (iter->base.symbol == symbol) {
5390                         return iter;
5391                 } else if (iter->base.symbol == NULL) {
5392                         /* search in anonymous structs and unions */
5393                         type_t *type = skip_typeref(iter->declaration.type);
5394                         if (is_type_compound(type)) {
5395                                 if (find_compound_entry(type->compound.compound, symbol)
5396                                                 != NULL)
5397                                         return iter;
5398                         }
5399                         continue;
5400                 }
5401         }
5402
5403         return NULL;
5404 }
5405
5406 static void check_deprecated(const source_position_t *source_position,
5407                              const entity_t *entity)
5408 {
5409         if (!is_declaration(entity))
5410                 return;
5411         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5412                 return;
5413
5414         source_position_t const *const epos = &entity->base.source_position;
5415         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5416         if (msg != NULL) {
5417                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5418         } else {
5419                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5420         }
5421 }
5422
5423
5424 static expression_t *create_select(const source_position_t *pos,
5425                                    expression_t *addr,
5426                                    type_qualifiers_t qualifiers,
5427                                                                    entity_t *entry)
5428 {
5429         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5430
5431         check_deprecated(pos, entry);
5432
5433         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5434         select->select.compound       = addr;
5435         select->select.compound_entry = entry;
5436
5437         type_t *entry_type = entry->declaration.type;
5438         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5439
5440         /* bitfields need special treatment */
5441         if (entry->compound_member.bitfield) {
5442                 unsigned bit_size = entry->compound_member.bit_size;
5443                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5444                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5445                         res_type = type_int;
5446                 }
5447         }
5448
5449         /* we always do the auto-type conversions; the & and sizeof parser contains
5450          * code to revert this! */
5451         select->base.type = automatic_type_conversion(res_type);
5452
5453
5454         return select;
5455 }
5456
5457 /**
5458  * Find entry with symbol in compound. Search anonymous structs and unions and
5459  * creates implicit select expressions for them.
5460  * Returns the adress for the innermost compound.
5461  */
5462 static expression_t *find_create_select(const source_position_t *pos,
5463                                         expression_t *addr,
5464                                         type_qualifiers_t qualifiers,
5465                                         compound_t *compound, symbol_t *symbol)
5466 {
5467         entity_t *iter = compound->members.entities;
5468         for (; iter != NULL; iter = iter->base.next) {
5469                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5470                         continue;
5471
5472                 symbol_t *iter_symbol = iter->base.symbol;
5473                 if (iter_symbol == NULL) {
5474                         type_t *type = iter->declaration.type;
5475                         if (type->kind != TYPE_COMPOUND_STRUCT
5476                                         && type->kind != TYPE_COMPOUND_UNION)
5477                                 continue;
5478
5479                         compound_t *sub_compound = type->compound.compound;
5480
5481                         if (find_compound_entry(sub_compound, symbol) == NULL)
5482                                 continue;
5483
5484                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5485                         sub_addr->base.source_position = *pos;
5486                         sub_addr->base.implicit        = true;
5487                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5488                                                   symbol);
5489                 }
5490
5491                 if (iter_symbol == symbol) {
5492                         return create_select(pos, addr, qualifiers, iter);
5493                 }
5494         }
5495
5496         return NULL;
5497 }
5498
5499 static void parse_bitfield_member(entity_t *entity)
5500 {
5501         eat(':');
5502
5503         expression_t *size = parse_constant_expression();
5504         long          size_long;
5505
5506         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5507         type_t *type = entity->declaration.type;
5508         if (!is_type_integer(skip_typeref(type))) {
5509                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5510                            type);
5511         }
5512
5513         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5514                 /* error already reported by parse_constant_expression */
5515                 size_long = get_type_size(type) * 8;
5516         } else {
5517                 size_long = fold_constant_to_int(size);
5518
5519                 const symbol_t *symbol = entity->base.symbol;
5520                 const symbol_t *user_symbol
5521                         = symbol == NULL ? sym_anonymous : symbol;
5522                 unsigned bit_size = get_type_size(type) * 8;
5523                 if (size_long < 0) {
5524                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5525                 } else if (size_long == 0 && symbol != NULL) {
5526                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5527                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5528                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5529                                    user_symbol);
5530                 } else {
5531                         /* hope that people don't invent crazy types with more bits
5532                          * than our struct can hold */
5533                         assert(size_long <
5534                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5535                 }
5536         }
5537
5538         entity->compound_member.bitfield = true;
5539         entity->compound_member.bit_size = (unsigned char)size_long;
5540 }
5541
5542 static void parse_compound_declarators(compound_t *compound,
5543                 const declaration_specifiers_t *specifiers)
5544 {
5545         add_anchor_token(';');
5546         add_anchor_token(',');
5547         do {
5548                 entity_t *entity;
5549
5550                 if (token.kind == ':') {
5551                         /* anonymous bitfield */
5552                         type_t *type = specifiers->type;
5553                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5554                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5555                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5556                         entity->declaration.type                   = type;
5557
5558                         parse_bitfield_member(entity);
5559
5560                         attribute_t  *attributes = parse_attributes(NULL);
5561                         attribute_t **anchor     = &attributes;
5562                         while (*anchor != NULL)
5563                                 anchor = &(*anchor)->next;
5564                         *anchor = specifiers->attributes;
5565                         if (attributes != NULL) {
5566                                 handle_entity_attributes(attributes, entity);
5567                         }
5568                         entity->declaration.attributes = attributes;
5569
5570                         append_entity(&compound->members, entity);
5571                 } else {
5572                         entity = parse_declarator(specifiers,
5573                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5574                         source_position_t const *const pos = &entity->base.source_position;
5575                         if (entity->kind == ENTITY_TYPEDEF) {
5576                                 errorf(pos, "typedef not allowed as compound member");
5577                         } else {
5578                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5579
5580                                 /* make sure we don't define a symbol multiple times */
5581                                 symbol_t *symbol = entity->base.symbol;
5582                                 if (symbol != NULL) {
5583                                         entity_t *prev = find_compound_entry(compound, symbol);
5584                                         if (prev != NULL) {
5585                                                 source_position_t const *const ppos = &prev->base.source_position;
5586                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5587                                         }
5588                                 }
5589
5590                                 if (token.kind == ':') {
5591                                         parse_bitfield_member(entity);
5592
5593                                         attribute_t *attributes = parse_attributes(NULL);
5594                                         handle_entity_attributes(attributes, entity);
5595                                 } else {
5596                                         type_t *orig_type = entity->declaration.type;
5597                                         type_t *type      = skip_typeref(orig_type);
5598                                         if (is_type_function(type)) {
5599                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5600                                         } else if (is_type_incomplete(type)) {
5601                                                 /* §6.7.2.1:16 flexible array member */
5602                                                 if (!is_type_array(type)       ||
5603                                                                 token.kind          != ';' ||
5604                                                                 look_ahead(1)->kind != '}') {
5605                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5606                                                 } else if (compound->members.entities == NULL) {
5607                                                         errorf(pos, "flexible array member in otherwise empty struct");
5608                                                 }
5609                                         }
5610                                 }
5611
5612                                 append_entity(&compound->members, entity);
5613                         }
5614                 }
5615         } while (next_if(','));
5616         rem_anchor_token(',');
5617         rem_anchor_token(';');
5618         expect(';');
5619
5620         anonymous_entity = NULL;
5621 }
5622
5623 static void parse_compound_type_entries(compound_t *compound)
5624 {
5625         eat('{');
5626         add_anchor_token('}');
5627
5628         for (;;) {
5629                 switch (token.kind) {
5630                         DECLARATION_START
5631                         case T___extension__:
5632                         case T_IDENTIFIER: {
5633                                 PUSH_EXTENSION();
5634                                 declaration_specifiers_t specifiers;
5635                                 parse_declaration_specifiers(&specifiers);
5636                                 parse_compound_declarators(compound, &specifiers);
5637                                 POP_EXTENSION();
5638                                 break;
5639                         }
5640
5641                         default:
5642                                 rem_anchor_token('}');
5643                                 expect('}');
5644                                 /* §6.7.2.1:7 */
5645                                 compound->complete = true;
5646                                 return;
5647                 }
5648         }
5649 }
5650
5651 static type_t *parse_typename(void)
5652 {
5653         declaration_specifiers_t specifiers;
5654         parse_declaration_specifiers(&specifiers);
5655         if (specifiers.storage_class != STORAGE_CLASS_NONE
5656                         || specifiers.thread_local) {
5657                 /* TODO: improve error message, user does probably not know what a
5658                  * storage class is...
5659                  */
5660                 errorf(&specifiers.source_position, "typename must not have a storage class");
5661         }
5662
5663         type_t *result = parse_abstract_declarator(specifiers.type);
5664
5665         return result;
5666 }
5667
5668
5669
5670
5671 typedef expression_t* (*parse_expression_function)(void);
5672 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5673
5674 typedef struct expression_parser_function_t expression_parser_function_t;
5675 struct expression_parser_function_t {
5676         parse_expression_function        parser;
5677         precedence_t                     infix_precedence;
5678         parse_expression_infix_function  infix_parser;
5679 };
5680
5681 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5682
5683 static type_t *get_string_type(string_encoding_t const enc)
5684 {
5685         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5686         switch (enc) {
5687         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5688         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5689         }
5690         panic("invalid string encoding");
5691 }
5692
5693 /**
5694  * Parse a string constant.
5695  */
5696 static expression_t *parse_string_literal(void)
5697 {
5698         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5699         expr->string_literal.value = concat_string_literals(&expr->string_literal.encoding);
5700         expr->base.type            = get_string_type(expr->string_literal.encoding);
5701         return expr;
5702 }
5703
5704 /**
5705  * Parse a boolean constant.
5706  */
5707 static expression_t *parse_boolean_literal(bool value)
5708 {
5709         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5710         literal->base.type           = type_bool;
5711         literal->literal.value.begin = value ? "true" : "false";
5712         literal->literal.value.size  = value ? 4 : 5;
5713
5714         eat(value ? T_true : T_false);
5715         return literal;
5716 }
5717
5718 static void warn_traditional_suffix(void)
5719 {
5720         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5721                  &token.number.suffix);
5722 }
5723
5724 static void check_integer_suffix(void)
5725 {
5726         const string_t *suffix = &token.number.suffix;
5727         if (suffix->size == 0)
5728                 return;
5729
5730         bool not_traditional = false;
5731         const char *c = suffix->begin;
5732         if (*c == 'l' || *c == 'L') {
5733                 ++c;
5734                 if (*c == *(c-1)) {
5735                         not_traditional = true;
5736                         ++c;
5737                         if (*c == 'u' || *c == 'U') {
5738                                 ++c;
5739                         }
5740                 } else if (*c == 'u' || *c == 'U') {
5741                         not_traditional = true;
5742                         ++c;
5743                 }
5744         } else if (*c == 'u' || *c == 'U') {
5745                 not_traditional = true;
5746                 ++c;
5747                 if (*c == 'l' || *c == 'L') {
5748                         ++c;
5749                         if (*c == *(c-1)) {
5750                                 ++c;
5751                         }
5752                 }
5753         }
5754         if (*c != '\0') {
5755                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5756         } else if (not_traditional) {
5757                 warn_traditional_suffix();
5758         }
5759 }
5760
5761 static type_t *check_floatingpoint_suffix(void)
5762 {
5763         const string_t *suffix = &token.number.suffix;
5764         type_t         *type   = type_double;
5765         if (suffix->size == 0)
5766                 return type;
5767
5768         bool not_traditional = false;
5769         const char *c = suffix->begin;
5770         if (*c == 'f' || *c == 'F') {
5771                 ++c;
5772                 type = type_float;
5773         } else if (*c == 'l' || *c == 'L') {
5774                 ++c;
5775                 type = type_long_double;
5776         }
5777         if (*c != '\0') {
5778                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5779         } else if (not_traditional) {
5780                 warn_traditional_suffix();
5781         }
5782
5783         return type;
5784 }
5785
5786 /**
5787  * Parse an integer constant.
5788  */
5789 static expression_t *parse_number_literal(void)
5790 {
5791         expression_kind_t  kind;
5792         type_t            *type;
5793
5794         switch (token.kind) {
5795         case T_INTEGER:
5796                 kind = EXPR_LITERAL_INTEGER;
5797                 check_integer_suffix();
5798                 type = type_int;
5799                 break;
5800
5801         case T_FLOATINGPOINT:
5802                 kind = EXPR_LITERAL_FLOATINGPOINT;
5803                 type = check_floatingpoint_suffix();
5804                 break;
5805
5806         default:
5807                 panic("unexpected token type in parse_number_literal");
5808         }
5809
5810         expression_t *literal = allocate_expression_zero(kind);
5811         literal->base.type      = type;
5812         literal->literal.value  = token.number.number;
5813         literal->literal.suffix = token.number.suffix;
5814         next_token();
5815
5816         /* integer type depends on the size of the number and the size
5817          * representable by the types. The backend/codegeneration has to determine
5818          * that
5819          */
5820         determine_literal_type(&literal->literal);
5821         return literal;
5822 }
5823
5824 /**
5825  * Parse a character constant.
5826  */
5827 static expression_t *parse_character_constant(void)
5828 {
5829         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5830         literal->string_literal.encoding = token.string.encoding;
5831         literal->string_literal.value    = token.string.string;
5832
5833         size_t const size = get_string_len(token.string.encoding, &token.string.string);
5834         switch (token.string.encoding) {
5835         case STRING_ENCODING_CHAR:
5836                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5837                 if (size > 1) {
5838                         if (!GNU_MODE && !(c_mode & _C99)) {
5839                                 errorf(HERE, "more than 1 character in character constant");
5840                         } else {
5841                                 literal->base.type = type_int;
5842                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5843                         }
5844                 }
5845                 break;
5846
5847         case STRING_ENCODING_WIDE:
5848                 literal->base.type = type_int;
5849                 if (size > 1) {
5850                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5851                 }
5852                 break;
5853         }
5854
5855         eat(T_CHARACTER_CONSTANT);
5856         return literal;
5857 }
5858
5859 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5860 {
5861         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5862         ntype->function.return_type            = type_int;
5863         ntype->function.unspecified_parameters = true;
5864         ntype->function.linkage                = LINKAGE_C;
5865         type_t *type                           = identify_new_type(ntype);
5866
5867         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5868         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5869         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5870         entity->declaration.type                   = type;
5871         entity->declaration.implicit               = true;
5872
5873         if (current_scope != NULL)
5874                 record_entity(entity, false);
5875
5876         return entity;
5877 }
5878
5879 /**
5880  * Performs automatic type cast as described in §6.3.2.1.
5881  *
5882  * @param orig_type  the original type
5883  */
5884 static type_t *automatic_type_conversion(type_t *orig_type)
5885 {
5886         type_t *type = skip_typeref(orig_type);
5887         if (is_type_array(type)) {
5888                 array_type_t *array_type   = &type->array;
5889                 type_t       *element_type = array_type->element_type;
5890                 unsigned      qualifiers   = array_type->base.qualifiers;
5891
5892                 return make_pointer_type(element_type, qualifiers);
5893         }
5894
5895         if (is_type_function(type)) {
5896                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5897         }
5898
5899         return orig_type;
5900 }
5901
5902 /**
5903  * reverts the automatic casts of array to pointer types and function
5904  * to function-pointer types as defined §6.3.2.1
5905  */
5906 type_t *revert_automatic_type_conversion(const expression_t *expression)
5907 {
5908         switch (expression->kind) {
5909         case EXPR_REFERENCE: {
5910                 entity_t *entity = expression->reference.entity;
5911                 if (is_declaration(entity)) {
5912                         return entity->declaration.type;
5913                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5914                         return entity->enum_value.enum_type;
5915                 } else {
5916                         panic("no declaration or enum in reference");
5917                 }
5918         }
5919
5920         case EXPR_SELECT: {
5921                 entity_t *entity = expression->select.compound_entry;
5922                 assert(is_declaration(entity));
5923                 type_t   *type   = entity->declaration.type;
5924                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5925         }
5926
5927         case EXPR_UNARY_DEREFERENCE: {
5928                 const expression_t *const value = expression->unary.value;
5929                 type_t             *const type  = skip_typeref(value->base.type);
5930                 if (!is_type_pointer(type))
5931                         return type_error_type;
5932                 return type->pointer.points_to;
5933         }
5934
5935         case EXPR_ARRAY_ACCESS: {
5936                 const expression_t *array_ref = expression->array_access.array_ref;
5937                 type_t             *type_left = skip_typeref(array_ref->base.type);
5938                 if (!is_type_pointer(type_left))
5939                         return type_error_type;
5940                 return type_left->pointer.points_to;
5941         }
5942
5943         case EXPR_STRING_LITERAL: {
5944                 size_t  const size = get_string_len(expression->string_literal.encoding, &expression->string_literal.value) + 1;
5945                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5946                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5947         }
5948
5949         case EXPR_COMPOUND_LITERAL:
5950                 return expression->compound_literal.type;
5951
5952         default:
5953                 break;
5954         }
5955         return expression->base.type;
5956 }
5957
5958 /**
5959  * Find an entity matching a symbol in a scope.
5960  * Uses current scope if scope is NULL
5961  */
5962 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5963                                namespace_tag_t namespc)
5964 {
5965         if (scope == NULL) {
5966                 return get_entity(symbol, namespc);
5967         }
5968
5969         /* we should optimize here, if scope grows above a certain size we should
5970            construct a hashmap here... */
5971         entity_t *entity = scope->entities;
5972         for ( ; entity != NULL; entity = entity->base.next) {
5973                 if (entity->base.symbol == symbol
5974                     && (namespace_tag_t)entity->base.namespc == namespc)
5975                         break;
5976         }
5977
5978         return entity;
5979 }
5980
5981 static entity_t *parse_qualified_identifier(void)
5982 {
5983         /* namespace containing the symbol */
5984         symbol_t          *symbol;
5985         source_position_t  pos;
5986         const scope_t     *lookup_scope = NULL;
5987
5988         if (next_if(T_COLONCOLON))
5989                 lookup_scope = &unit->scope;
5990
5991         entity_t *entity;
5992         while (true) {
5993                 symbol = expect_identifier("while parsing identifier", &pos);
5994                 if (!symbol)
5995                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
5996
5997                 /* lookup entity */
5998                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
5999
6000                 if (!next_if(T_COLONCOLON))
6001                         break;
6002
6003                 switch (entity->kind) {
6004                 case ENTITY_NAMESPACE:
6005                         lookup_scope = &entity->namespacee.members;
6006                         break;
6007                 case ENTITY_STRUCT:
6008                 case ENTITY_UNION:
6009                 case ENTITY_CLASS:
6010                         lookup_scope = &entity->compound.members;
6011                         break;
6012                 default:
6013                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6014                                symbol, get_entity_kind_name(entity->kind));
6015
6016                         /* skip further qualifications */
6017                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6018
6019                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6020                 }
6021         }
6022
6023         if (entity == NULL) {
6024                 if (!strict_mode && token.kind == '(') {
6025                         /* an implicitly declared function */
6026                         entity = create_implicit_function(symbol, &pos);
6027                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6028                 } else {
6029                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6030                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6031                 }
6032         }
6033
6034         return entity;
6035 }
6036
6037 static expression_t *parse_reference(void)
6038 {
6039         source_position_t const pos    = *HERE;
6040         entity_t         *const entity = parse_qualified_identifier();
6041
6042         type_t *orig_type;
6043         if (is_declaration(entity)) {
6044                 orig_type = entity->declaration.type;
6045         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6046                 orig_type = entity->enum_value.enum_type;
6047         } else {
6048                 panic("expected declaration or enum value in reference");
6049         }
6050
6051         /* we always do the auto-type conversions; the & and sizeof parser contains
6052          * code to revert this! */
6053         type_t *type = automatic_type_conversion(orig_type);
6054
6055         expression_kind_t kind = EXPR_REFERENCE;
6056         if (entity->kind == ENTITY_ENUM_VALUE)
6057                 kind = EXPR_ENUM_CONSTANT;
6058
6059         expression_t *expression         = allocate_expression_zero(kind);
6060         expression->base.source_position = pos;
6061         expression->base.type            = type;
6062         expression->reference.entity     = entity;
6063
6064         /* this declaration is used */
6065         if (is_declaration(entity)) {
6066                 entity->declaration.used = true;
6067         }
6068
6069         if (entity->base.parent_scope != file_scope
6070                 && (current_function != NULL
6071                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6072                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6073                 /* access of a variable from an outer function */
6074                 entity->variable.address_taken = true;
6075                 current_function->need_closure = true;
6076         }
6077
6078         check_deprecated(&pos, entity);
6079
6080         return expression;
6081 }
6082
6083 static bool semantic_cast(expression_t *cast)
6084 {
6085         expression_t            *expression      = cast->unary.value;
6086         type_t                  *orig_dest_type  = cast->base.type;
6087         type_t                  *orig_type_right = expression->base.type;
6088         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6089         type_t            const *src_type        = skip_typeref(orig_type_right);
6090         source_position_t const *pos             = &cast->base.source_position;
6091
6092         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6093         if (is_type_void(dst_type))
6094                 return true;
6095
6096         /* only integer and pointer can be casted to pointer */
6097         if (is_type_pointer(dst_type)  &&
6098             !is_type_pointer(src_type) &&
6099             !is_type_integer(src_type) &&
6100             is_type_valid(src_type)) {
6101                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6102                 return false;
6103         }
6104
6105         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6106                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6107                 return false;
6108         }
6109
6110         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6111                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6112                 return false;
6113         }
6114
6115         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6116                 type_t *src = skip_typeref(src_type->pointer.points_to);
6117                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6118                 unsigned missing_qualifiers =
6119                         src->base.qualifiers & ~dst->base.qualifiers;
6120                 if (missing_qualifiers != 0) {
6121                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6122                 }
6123         }
6124         return true;
6125 }
6126
6127 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6128 {
6129         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6130         expression->base.source_position = *pos;
6131
6132         parse_initializer_env_t env;
6133         env.type             = type;
6134         env.entity           = NULL;
6135         env.must_be_constant = false;
6136         initializer_t *initializer = parse_initializer(&env);
6137         type = env.type;
6138
6139         expression->compound_literal.initializer = initializer;
6140         expression->compound_literal.type        = type;
6141         expression->base.type                    = automatic_type_conversion(type);
6142
6143         return expression;
6144 }
6145
6146 /**
6147  * Parse a cast expression.
6148  */
6149 static expression_t *parse_cast(void)
6150 {
6151         source_position_t const pos = *HERE;
6152
6153         eat('(');
6154         add_anchor_token(')');
6155
6156         type_t *type = parse_typename();
6157
6158         rem_anchor_token(')');
6159         expect(')');
6160
6161         if (token.kind == '{') {
6162                 return parse_compound_literal(&pos, type);
6163         }
6164
6165         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6166         cast->base.source_position = pos;
6167
6168         expression_t *value = parse_subexpression(PREC_CAST);
6169         cast->base.type   = type;
6170         cast->unary.value = value;
6171
6172         if (! semantic_cast(cast)) {
6173                 /* TODO: record the error in the AST. else it is impossible to detect it */
6174         }
6175
6176         return cast;
6177 }
6178
6179 /**
6180  * Parse a statement expression.
6181  */
6182 static expression_t *parse_statement_expression(void)
6183 {
6184         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6185
6186         eat('(');
6187         add_anchor_token(')');
6188
6189         statement_t *statement          = parse_compound_statement(true);
6190         statement->compound.stmt_expr   = true;
6191         expression->statement.statement = statement;
6192
6193         /* find last statement and use its type */
6194         type_t *type = type_void;
6195         const statement_t *stmt = statement->compound.statements;
6196         if (stmt != NULL) {
6197                 while (stmt->base.next != NULL)
6198                         stmt = stmt->base.next;
6199
6200                 if (stmt->kind == STATEMENT_EXPRESSION) {
6201                         type = stmt->expression.expression->base.type;
6202                 }
6203         } else {
6204                 source_position_t const *const pos = &expression->base.source_position;
6205                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6206         }
6207         expression->base.type = type;
6208
6209         rem_anchor_token(')');
6210         expect(')');
6211         return expression;
6212 }
6213
6214 /**
6215  * Parse a parenthesized expression.
6216  */
6217 static expression_t *parse_parenthesized_expression(void)
6218 {
6219         token_t const* const la1 = look_ahead(1);
6220         switch (la1->kind) {
6221         case '{':
6222                 /* gcc extension: a statement expression */
6223                 return parse_statement_expression();
6224
6225         case T_IDENTIFIER:
6226                 if (is_typedef_symbol(la1->base.symbol)) {
6227         DECLARATION_START
6228                         return parse_cast();
6229                 }
6230         }
6231
6232         eat('(');
6233         add_anchor_token(')');
6234         expression_t *result = parse_expression();
6235         result->base.parenthesized = true;
6236         rem_anchor_token(')');
6237         expect(')');
6238
6239         return result;
6240 }
6241
6242 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6243 {
6244         if (current_function == NULL) {
6245                 errorf(HERE, "'%K' used outside of a function", &token);
6246         }
6247
6248         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6249         expression->base.type     = type_char_ptr;
6250         expression->funcname.kind = kind;
6251
6252         next_token();
6253
6254         return expression;
6255 }
6256
6257 static designator_t *parse_designator(void)
6258 {
6259         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6260         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6261         if (!result->symbol)
6262                 return NULL;
6263
6264         designator_t *last_designator = result;
6265         while (true) {
6266                 if (next_if('.')) {
6267                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6268                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6269                         if (!designator->symbol)
6270                                 return NULL;
6271
6272                         last_designator->next = designator;
6273                         last_designator       = designator;
6274                         continue;
6275                 }
6276                 if (next_if('[')) {
6277                         add_anchor_token(']');
6278                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6279                         designator->source_position = *HERE;
6280                         designator->array_index     = parse_expression();
6281                         rem_anchor_token(']');
6282                         expect(']');
6283                         if (designator->array_index == NULL) {
6284                                 return NULL;
6285                         }
6286
6287                         last_designator->next = designator;
6288                         last_designator       = designator;
6289                         continue;
6290                 }
6291                 break;
6292         }
6293
6294         return result;
6295 }
6296
6297 /**
6298  * Parse the __builtin_offsetof() expression.
6299  */
6300 static expression_t *parse_offsetof(void)
6301 {
6302         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6303         expression->base.type    = type_size_t;
6304
6305         eat(T___builtin_offsetof);
6306
6307         add_anchor_token(')');
6308         add_anchor_token(',');
6309         expect('(');
6310         type_t *type = parse_typename();
6311         rem_anchor_token(',');
6312         expect(',');
6313         designator_t *designator = parse_designator();
6314         rem_anchor_token(')');
6315         expect(')');
6316
6317         expression->offsetofe.type       = type;
6318         expression->offsetofe.designator = designator;
6319
6320         type_path_t path;
6321         memset(&path, 0, sizeof(path));
6322         path.top_type = type;
6323         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6324
6325         descend_into_subtype(&path);
6326
6327         if (!walk_designator(&path, designator, true)) {
6328                 return create_error_expression();
6329         }
6330
6331         DEL_ARR_F(path.path);
6332
6333         return expression;
6334 }
6335
6336 static bool is_last_parameter(expression_t *const param)
6337 {
6338         if (param->kind == EXPR_REFERENCE) {
6339                 entity_t *const entity = param->reference.entity;
6340                 if (entity->kind == ENTITY_PARAMETER &&
6341                     !entity->base.next               &&
6342                     entity->base.parent_scope == &current_function->parameters) {
6343                         return true;
6344                 }
6345         }
6346
6347         if (!is_type_valid(skip_typeref(param->base.type)))
6348                 return true;
6349
6350         return false;
6351 }
6352
6353 /**
6354  * Parses a __builtin_va_start() expression.
6355  */
6356 static expression_t *parse_va_start(void)
6357 {
6358         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6359
6360         eat(T___builtin_va_start);
6361
6362         add_anchor_token(')');
6363         add_anchor_token(',');
6364         expect('(');
6365         expression->va_starte.ap = parse_assignment_expression();
6366         rem_anchor_token(',');
6367         expect(',');
6368         expression_t *const param = parse_assignment_expression();
6369         expression->va_starte.parameter = param;
6370         rem_anchor_token(')');
6371         expect(')');
6372
6373         if (!current_function) {
6374                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6375         } else if (!current_function->base.type->function.variadic) {
6376                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6377         } else if (!is_last_parameter(param)) {
6378                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6379         }
6380
6381         return expression;
6382 }
6383
6384 /**
6385  * Parses a __builtin_va_arg() expression.
6386  */
6387 static expression_t *parse_va_arg(void)
6388 {
6389         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6390
6391         eat(T___builtin_va_arg);
6392
6393         add_anchor_token(')');
6394         add_anchor_token(',');
6395         expect('(');
6396         call_argument_t ap;
6397         ap.expression = parse_assignment_expression();
6398         expression->va_arge.ap = ap.expression;
6399         check_call_argument(type_valist, &ap, 1);
6400
6401         rem_anchor_token(',');
6402         expect(',');
6403         expression->base.type = parse_typename();
6404         rem_anchor_token(')');
6405         expect(')');
6406
6407         return expression;
6408 }
6409
6410 /**
6411  * Parses a __builtin_va_copy() expression.
6412  */
6413 static expression_t *parse_va_copy(void)
6414 {
6415         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6416
6417         eat(T___builtin_va_copy);
6418
6419         add_anchor_token(')');
6420         add_anchor_token(',');
6421         expect('(');
6422         expression_t *dst = parse_assignment_expression();
6423         assign_error_t error = semantic_assign(type_valist, dst);
6424         report_assign_error(error, type_valist, dst, "call argument 1",
6425                             &dst->base.source_position);
6426         expression->va_copye.dst = dst;
6427
6428         rem_anchor_token(',');
6429         expect(',');
6430
6431         call_argument_t src;
6432         src.expression = parse_assignment_expression();
6433         check_call_argument(type_valist, &src, 2);
6434         expression->va_copye.src = src.expression;
6435         rem_anchor_token(')');
6436         expect(')');
6437
6438         return expression;
6439 }
6440
6441 /**
6442  * Parses a __builtin_constant_p() expression.
6443  */
6444 static expression_t *parse_builtin_constant(void)
6445 {
6446         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6447
6448         eat(T___builtin_constant_p);
6449
6450         add_anchor_token(')');
6451         expect('(');
6452         expression->builtin_constant.value = parse_assignment_expression();
6453         rem_anchor_token(')');
6454         expect(')');
6455         expression->base.type = type_int;
6456
6457         return expression;
6458 }
6459
6460 /**
6461  * Parses a __builtin_types_compatible_p() expression.
6462  */
6463 static expression_t *parse_builtin_types_compatible(void)
6464 {
6465         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6466
6467         eat(T___builtin_types_compatible_p);
6468
6469         add_anchor_token(')');
6470         add_anchor_token(',');
6471         expect('(');
6472         expression->builtin_types_compatible.left = parse_typename();
6473         rem_anchor_token(',');
6474         expect(',');
6475         expression->builtin_types_compatible.right = parse_typename();
6476         rem_anchor_token(')');
6477         expect(')');
6478         expression->base.type = type_int;
6479
6480         return expression;
6481 }
6482
6483 /**
6484  * Parses a __builtin_is_*() compare expression.
6485  */
6486 static expression_t *parse_compare_builtin(void)
6487 {
6488         expression_kind_t kind;
6489         switch (token.kind) {
6490         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6491         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6492         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6493         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6494         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6495         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6496         default: internal_errorf(HERE, "invalid compare builtin found");
6497         }
6498         expression_t *const expression = allocate_expression_zero(kind);
6499         next_token();
6500
6501         add_anchor_token(')');
6502         add_anchor_token(',');
6503         expect('(');
6504         expression->binary.left = parse_assignment_expression();
6505         rem_anchor_token(',');
6506         expect(',');
6507         expression->binary.right = parse_assignment_expression();
6508         rem_anchor_token(')');
6509         expect(')');
6510
6511         type_t *const orig_type_left  = expression->binary.left->base.type;
6512         type_t *const orig_type_right = expression->binary.right->base.type;
6513
6514         type_t *const type_left  = skip_typeref(orig_type_left);
6515         type_t *const type_right = skip_typeref(orig_type_right);
6516         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6517                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6518                         type_error_incompatible("invalid operands in comparison",
6519                                 &expression->base.source_position, orig_type_left, orig_type_right);
6520                 }
6521         } else {
6522                 semantic_comparison(&expression->binary);
6523         }
6524
6525         return expression;
6526 }
6527
6528 /**
6529  * Parses a MS assume() expression.
6530  */
6531 static expression_t *parse_assume(void)
6532 {
6533         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6534
6535         eat(T__assume);
6536
6537         add_anchor_token(')');
6538         expect('(');
6539         expression->unary.value = parse_assignment_expression();
6540         rem_anchor_token(')');
6541         expect(')');
6542
6543         expression->base.type = type_void;
6544         return expression;
6545 }
6546
6547 /**
6548  * Return the label for the current symbol or create a new one.
6549  */
6550 static label_t *get_label(char const *const context)
6551 {
6552         assert(current_function != NULL);
6553
6554         symbol_t *const sym = expect_identifier(context, NULL);
6555         if (!sym)
6556                 return NULL;
6557
6558         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6559         /* If we find a local label, we already created the declaration. */
6560         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6561                 if (label->base.parent_scope != current_scope) {
6562                         assert(label->base.parent_scope->depth < current_scope->depth);
6563                         current_function->goto_to_outer = true;
6564                 }
6565         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6566                 /* There is no matching label in the same function, so create a new one. */
6567                 source_position_t const nowhere = { NULL, 0, 0, false };
6568                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6569                 label_push(label);
6570         }
6571
6572         return &label->label;
6573 }
6574
6575 /**
6576  * Parses a GNU && label address expression.
6577  */
6578 static expression_t *parse_label_address(void)
6579 {
6580         source_position_t const source_position = *HERE;
6581         eat(T_ANDAND);
6582
6583         label_t *const label = get_label("while parsing label address");
6584         if (!label)
6585                 return create_error_expression();
6586
6587         label->used          = true;
6588         label->address_taken = true;
6589
6590         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6591         expression->base.source_position = source_position;
6592
6593         /* label address is treated as a void pointer */
6594         expression->base.type           = type_void_ptr;
6595         expression->label_address.label = label;
6596         return expression;
6597 }
6598
6599 /**
6600  * Parse a microsoft __noop expression.
6601  */
6602 static expression_t *parse_noop_expression(void)
6603 {
6604         /* the result is a (int)0 */
6605         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6606         literal->base.type           = type_int;
6607         literal->literal.value.begin = "__noop";
6608         literal->literal.value.size  = 6;
6609
6610         eat(T___noop);
6611
6612         if (token.kind == '(') {
6613                 /* parse arguments */
6614                 eat('(');
6615                 add_anchor_token(')');
6616                 add_anchor_token(',');
6617
6618                 if (token.kind != ')') do {
6619                         (void)parse_assignment_expression();
6620                 } while (next_if(','));
6621
6622                 rem_anchor_token(',');
6623                 rem_anchor_token(')');
6624         }
6625         expect(')');
6626
6627         return literal;
6628 }
6629
6630 /**
6631  * Parses a primary expression.
6632  */
6633 static expression_t *parse_primary_expression(void)
6634 {
6635         switch (token.kind) {
6636         case T_false:                        return parse_boolean_literal(false);
6637         case T_true:                         return parse_boolean_literal(true);
6638         case T_INTEGER:
6639         case T_FLOATINGPOINT:                return parse_number_literal();
6640         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6641         case T_STRING_LITERAL:               return parse_string_literal();
6642         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6643         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6644         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6645         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6646         case T___builtin_offsetof:           return parse_offsetof();
6647         case T___builtin_va_start:           return parse_va_start();
6648         case T___builtin_va_arg:             return parse_va_arg();
6649         case T___builtin_va_copy:            return parse_va_copy();
6650         case T___builtin_isgreater:
6651         case T___builtin_isgreaterequal:
6652         case T___builtin_isless:
6653         case T___builtin_islessequal:
6654         case T___builtin_islessgreater:
6655         case T___builtin_isunordered:        return parse_compare_builtin();
6656         case T___builtin_constant_p:         return parse_builtin_constant();
6657         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6658         case T__assume:                      return parse_assume();
6659         case T_ANDAND:
6660                 if (GNU_MODE)
6661                         return parse_label_address();
6662                 break;
6663
6664         case '(':                            return parse_parenthesized_expression();
6665         case T___noop:                       return parse_noop_expression();
6666
6667         /* Gracefully handle type names while parsing expressions. */
6668         case T_COLONCOLON:
6669                 return parse_reference();
6670         case T_IDENTIFIER:
6671                 if (!is_typedef_symbol(token.base.symbol)) {
6672                         return parse_reference();
6673                 }
6674                 /* FALLTHROUGH */
6675         DECLARATION_START {
6676                 source_position_t const  pos = *HERE;
6677                 declaration_specifiers_t specifiers;
6678                 parse_declaration_specifiers(&specifiers);
6679                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6680                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6681                 return create_error_expression();
6682         }
6683         }
6684
6685         errorf(HERE, "unexpected token %K, expected an expression", &token);
6686         eat_until_anchor();
6687         return create_error_expression();
6688 }
6689
6690 static expression_t *parse_array_expression(expression_t *left)
6691 {
6692         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6693         array_access_expression_t *const arr  = &expr->array_access;
6694
6695         eat('[');
6696         add_anchor_token(']');
6697
6698         expression_t *const inside = parse_expression();
6699
6700         type_t *const orig_type_left   = left->base.type;
6701         type_t *const orig_type_inside = inside->base.type;
6702
6703         type_t *const type_left   = skip_typeref(orig_type_left);
6704         type_t *const type_inside = skip_typeref(orig_type_inside);
6705
6706         expression_t *ref;
6707         expression_t *idx;
6708         type_t       *idx_type;
6709         type_t       *res_type;
6710         if (is_type_pointer(type_left)) {
6711                 ref      = left;
6712                 idx      = inside;
6713                 idx_type = type_inside;
6714                 res_type = type_left->pointer.points_to;
6715                 goto check_idx;
6716         } else if (is_type_pointer(type_inside)) {
6717                 arr->flipped = true;
6718                 ref      = inside;
6719                 idx      = left;
6720                 idx_type = type_left;
6721                 res_type = type_inside->pointer.points_to;
6722 check_idx:
6723                 res_type = automatic_type_conversion(res_type);
6724                 if (!is_type_integer(idx_type)) {
6725                         errorf(&idx->base.source_position, "array subscript must have integer type");
6726                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6727                         source_position_t const *const pos = &idx->base.source_position;
6728                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6729                 }
6730         } else {
6731                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6732                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6733                 }
6734                 res_type = type_error_type;
6735                 ref      = left;
6736                 idx      = inside;
6737         }
6738
6739         arr->array_ref = ref;
6740         arr->index     = idx;
6741         arr->base.type = res_type;
6742
6743         rem_anchor_token(']');
6744         expect(']');
6745         return expr;
6746 }
6747
6748 static bool is_bitfield(const expression_t *expression)
6749 {
6750         return expression->kind == EXPR_SELECT
6751                 && expression->select.compound_entry->compound_member.bitfield;
6752 }
6753
6754 static expression_t *parse_typeprop(expression_kind_t const kind)
6755 {
6756         expression_t  *tp_expression = allocate_expression_zero(kind);
6757         tp_expression->base.type     = type_size_t;
6758
6759         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6760
6761         type_t       *orig_type;
6762         expression_t *expression;
6763         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6764                 source_position_t const pos = *HERE;
6765                 eat('(');
6766                 add_anchor_token(')');
6767                 orig_type = parse_typename();
6768                 rem_anchor_token(')');
6769                 expect(')');
6770
6771                 if (token.kind == '{') {
6772                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6773                          * starting with a compound literal */
6774                         expression = parse_compound_literal(&pos, orig_type);
6775                         goto typeprop_expression;
6776                 }
6777         } else {
6778                 expression = parse_subexpression(PREC_UNARY);
6779
6780 typeprop_expression:
6781                 if (is_bitfield(expression)) {
6782                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6783                         errorf(&tp_expression->base.source_position,
6784                                    "operand of %s expression must not be a bitfield", what);
6785                 }
6786
6787                 tp_expression->typeprop.tp_expression = expression;
6788
6789                 orig_type = revert_automatic_type_conversion(expression);
6790                 expression->base.type = orig_type;
6791         }
6792
6793         tp_expression->typeprop.type   = orig_type;
6794         type_t const* const type       = skip_typeref(orig_type);
6795         char   const*       wrong_type = NULL;
6796         if (is_type_incomplete(type)) {
6797                 if (!is_type_void(type) || !GNU_MODE)
6798                         wrong_type = "incomplete";
6799         } else if (type->kind == TYPE_FUNCTION) {
6800                 if (GNU_MODE) {
6801                         /* function types are allowed (and return 1) */
6802                         source_position_t const *const pos  = &tp_expression->base.source_position;
6803                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6804                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6805                 } else {
6806                         wrong_type = "function";
6807                 }
6808         }
6809
6810         if (wrong_type != NULL) {
6811                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6812                 errorf(&tp_expression->base.source_position,
6813                                 "operand of %s expression must not be of %s type '%T'",
6814                                 what, wrong_type, orig_type);
6815         }
6816
6817         return tp_expression;
6818 }
6819
6820 static expression_t *parse_sizeof(void)
6821 {
6822         return parse_typeprop(EXPR_SIZEOF);
6823 }
6824
6825 static expression_t *parse_alignof(void)
6826 {
6827         return parse_typeprop(EXPR_ALIGNOF);
6828 }
6829
6830 static expression_t *parse_select_expression(expression_t *addr)
6831 {
6832         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6833         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6834         source_position_t const pos = *HERE;
6835         next_token();
6836
6837         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6838         if (!symbol)
6839                 return create_error_expression();
6840
6841         type_t *const orig_type = addr->base.type;
6842         type_t *const type      = skip_typeref(orig_type);
6843
6844         type_t *type_left;
6845         bool    saw_error = false;
6846         if (is_type_pointer(type)) {
6847                 if (!select_left_arrow) {
6848                         errorf(&pos,
6849                                "request for member '%Y' in something not a struct or union, but '%T'",
6850                                symbol, orig_type);
6851                         saw_error = true;
6852                 }
6853                 type_left = skip_typeref(type->pointer.points_to);
6854         } else {
6855                 if (select_left_arrow && is_type_valid(type)) {
6856                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6857                         saw_error = true;
6858                 }
6859                 type_left = type;
6860         }
6861
6862         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6863             type_left->kind != TYPE_COMPOUND_UNION) {
6864
6865                 if (is_type_valid(type_left) && !saw_error) {
6866                         errorf(&pos,
6867                                "request for member '%Y' in something not a struct or union, but '%T'",
6868                                symbol, type_left);
6869                 }
6870                 return create_error_expression();
6871         }
6872
6873         compound_t *compound = type_left->compound.compound;
6874         if (!compound->complete) {
6875                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6876                        symbol, type_left);
6877                 return create_error_expression();
6878         }
6879
6880         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6881         expression_t      *result     =
6882                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6883
6884         if (result == NULL) {
6885                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6886                 return create_error_expression();
6887         }
6888
6889         return result;
6890 }
6891
6892 static void check_call_argument(type_t          *expected_type,
6893                                 call_argument_t *argument, unsigned pos)
6894 {
6895         type_t         *expected_type_skip = skip_typeref(expected_type);
6896         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6897         expression_t   *arg_expr           = argument->expression;
6898         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6899
6900         /* handle transparent union gnu extension */
6901         if (is_type_union(expected_type_skip)
6902                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6903                 compound_t *union_decl  = expected_type_skip->compound.compound;
6904                 type_t     *best_type   = NULL;
6905                 entity_t   *entry       = union_decl->members.entities;
6906                 for ( ; entry != NULL; entry = entry->base.next) {
6907                         assert(is_declaration(entry));
6908                         type_t *decl_type = entry->declaration.type;
6909                         error = semantic_assign(decl_type, arg_expr);
6910                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6911                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6912                                 continue;
6913
6914                         if (error == ASSIGN_SUCCESS) {
6915                                 best_type = decl_type;
6916                         } else if (best_type == NULL) {
6917                                 best_type = decl_type;
6918                         }
6919                 }
6920
6921                 if (best_type != NULL) {
6922                         expected_type = best_type;
6923                 }
6924         }
6925
6926         error                = semantic_assign(expected_type, arg_expr);
6927         argument->expression = create_implicit_cast(arg_expr, expected_type);
6928
6929         if (error != ASSIGN_SUCCESS) {
6930                 /* report exact scope in error messages (like "in argument 3") */
6931                 char buf[64];
6932                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6933                 report_assign_error(error, expected_type, arg_expr, buf,
6934                                     &arg_expr->base.source_position);
6935         } else {
6936                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6937                 if (!types_compatible(expected_type_skip, promoted_type) &&
6938                     !types_compatible(expected_type_skip, type_void_ptr) &&
6939                     !types_compatible(type_void_ptr,      promoted_type)) {
6940                         /* Deliberately show the skipped types in this warning */
6941                         source_position_t const *const apos = &arg_expr->base.source_position;
6942                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6943                 }
6944         }
6945 }
6946
6947 /**
6948  * Handle the semantic restrictions of builtin calls
6949  */
6950 static void handle_builtin_argument_restrictions(call_expression_t *call)
6951 {
6952         entity_t *entity = call->function->reference.entity;
6953         switch (entity->function.btk) {
6954         case BUILTIN_FIRM:
6955                 switch (entity->function.b.firm_builtin_kind) {
6956                 case ir_bk_return_address:
6957                 case ir_bk_frame_address: {
6958                         /* argument must be constant */
6959                         call_argument_t *argument = call->arguments;
6960
6961                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6962                                 errorf(&call->base.source_position,
6963                                            "argument of '%Y' must be a constant expression",
6964                                            call->function->reference.entity->base.symbol);
6965                         }
6966                         break;
6967                 }
6968                 case ir_bk_prefetch:
6969                         /* second and third argument must be constant if existent */
6970                         if (call->arguments == NULL)
6971                                 break;
6972                         call_argument_t *rw = call->arguments->next;
6973                         call_argument_t *locality = NULL;
6974
6975                         if (rw != NULL) {
6976                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
6977                                         errorf(&call->base.source_position,
6978                                                    "second argument of '%Y' must be a constant expression",
6979                                                    call->function->reference.entity->base.symbol);
6980                                 }
6981                                 locality = rw->next;
6982                         }
6983                         if (locality != NULL) {
6984                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
6985                                         errorf(&call->base.source_position,
6986                                                    "third argument of '%Y' must be a constant expression",
6987                                                    call->function->reference.entity->base.symbol);
6988                                 }
6989                                 locality = rw->next;
6990                         }
6991                         break;
6992                 default:
6993                         break;
6994                 }
6995
6996         case BUILTIN_OBJECT_SIZE:
6997                 if (call->arguments == NULL)
6998                         break;
6999
7000                 call_argument_t *arg = call->arguments->next;
7001                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7002                         errorf(&call->base.source_position,
7003                                    "second argument of '%Y' must be a constant expression",
7004                                    call->function->reference.entity->base.symbol);
7005                 }
7006                 break;
7007         default:
7008                 break;
7009         }
7010 }
7011
7012 /**
7013  * Parse a call expression, ie. expression '( ... )'.
7014  *
7015  * @param expression  the function address
7016  */
7017 static expression_t *parse_call_expression(expression_t *expression)
7018 {
7019         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7020         call_expression_t *call   = &result->call;
7021         call->function            = expression;
7022
7023         type_t *const orig_type = expression->base.type;
7024         type_t *const type      = skip_typeref(orig_type);
7025
7026         function_type_t *function_type = NULL;
7027         if (is_type_pointer(type)) {
7028                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7029
7030                 if (is_type_function(to_type)) {
7031                         function_type   = &to_type->function;
7032                         call->base.type = function_type->return_type;
7033                 }
7034         }
7035
7036         if (function_type == NULL && is_type_valid(type)) {
7037                 errorf(HERE,
7038                        "called object '%E' (type '%T') is not a pointer to a function",
7039                        expression, orig_type);
7040         }
7041
7042         /* parse arguments */
7043         eat('(');
7044         add_anchor_token(')');
7045         add_anchor_token(',');
7046
7047         if (token.kind != ')') {
7048                 call_argument_t **anchor = &call->arguments;
7049                 do {
7050                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7051                         argument->expression = parse_assignment_expression();
7052
7053                         *anchor = argument;
7054                         anchor  = &argument->next;
7055                 } while (next_if(','));
7056         }
7057         rem_anchor_token(',');
7058         rem_anchor_token(')');
7059         expect(')');
7060
7061         if (function_type == NULL)
7062                 return result;
7063
7064         /* check type and count of call arguments */
7065         function_parameter_t *parameter = function_type->parameters;
7066         call_argument_t      *argument  = call->arguments;
7067         if (!function_type->unspecified_parameters) {
7068                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7069                                 parameter = parameter->next, argument = argument->next) {
7070                         check_call_argument(parameter->type, argument, ++pos);
7071                 }
7072
7073                 if (parameter != NULL) {
7074                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7075                 } else if (argument != NULL && !function_type->variadic) {
7076                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7077                 }
7078         }
7079
7080         /* do default promotion for other arguments */
7081         for (; argument != NULL; argument = argument->next) {
7082                 type_t *argument_type = argument->expression->base.type;
7083                 if (!is_type_object(skip_typeref(argument_type))) {
7084                         errorf(&argument->expression->base.source_position,
7085                                "call argument '%E' must not be void", argument->expression);
7086                 }
7087
7088                 argument_type = get_default_promoted_type(argument_type);
7089
7090                 argument->expression
7091                         = create_implicit_cast(argument->expression, argument_type);
7092         }
7093
7094         check_format(call);
7095
7096         if (is_type_compound(skip_typeref(function_type->return_type))) {
7097                 source_position_t const *const pos = &expression->base.source_position;
7098                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7099         }
7100
7101         if (expression->kind == EXPR_REFERENCE) {
7102                 reference_expression_t *reference = &expression->reference;
7103                 if (reference->entity->kind == ENTITY_FUNCTION &&
7104                     reference->entity->function.btk != BUILTIN_NONE)
7105                         handle_builtin_argument_restrictions(call);
7106         }
7107
7108         return result;
7109 }
7110
7111 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7112
7113 static bool same_compound_type(const type_t *type1, const type_t *type2)
7114 {
7115         return
7116                 is_type_compound(type1) &&
7117                 type1->kind == type2->kind &&
7118                 type1->compound.compound == type2->compound.compound;
7119 }
7120
7121 static expression_t const *get_reference_address(expression_t const *expr)
7122 {
7123         bool regular_take_address = true;
7124         for (;;) {
7125                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7126                         expr = expr->unary.value;
7127                 } else {
7128                         regular_take_address = false;
7129                 }
7130
7131                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7132                         break;
7133
7134                 expr = expr->unary.value;
7135         }
7136
7137         if (expr->kind != EXPR_REFERENCE)
7138                 return NULL;
7139
7140         /* special case for functions which are automatically converted to a
7141          * pointer to function without an extra TAKE_ADDRESS operation */
7142         if (!regular_take_address &&
7143                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7144                 return NULL;
7145         }
7146
7147         return expr;
7148 }
7149
7150 static void warn_reference_address_as_bool(expression_t const* expr)
7151 {
7152         expr = get_reference_address(expr);
7153         if (expr != NULL) {
7154                 source_position_t const *const pos = &expr->base.source_position;
7155                 entity_t          const *const ent = expr->reference.entity;
7156                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7157         }
7158 }
7159
7160 static void warn_assignment_in_condition(const expression_t *const expr)
7161 {
7162         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7163                 return;
7164         if (expr->base.parenthesized)
7165                 return;
7166         source_position_t const *const pos = &expr->base.source_position;
7167         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7168 }
7169
7170 static void semantic_condition(expression_t const *const expr,
7171                                char const *const context)
7172 {
7173         type_t *const type = skip_typeref(expr->base.type);
7174         if (is_type_scalar(type)) {
7175                 warn_reference_address_as_bool(expr);
7176                 warn_assignment_in_condition(expr);
7177         } else if (is_type_valid(type)) {
7178                 errorf(&expr->base.source_position,
7179                                 "%s must have scalar type", context);
7180         }
7181 }
7182
7183 /**
7184  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7185  *
7186  * @param expression  the conditional expression
7187  */
7188 static expression_t *parse_conditional_expression(expression_t *expression)
7189 {
7190         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7191
7192         conditional_expression_t *conditional = &result->conditional;
7193         conditional->condition                = expression;
7194
7195         eat('?');
7196         add_anchor_token(':');
7197
7198         /* §6.5.15:2  The first operand shall have scalar type. */
7199         semantic_condition(expression, "condition of conditional operator");
7200
7201         expression_t *true_expression = expression;
7202         bool          gnu_cond = false;
7203         if (GNU_MODE && token.kind == ':') {
7204                 gnu_cond = true;
7205         } else {
7206                 true_expression = parse_expression();
7207         }
7208         rem_anchor_token(':');
7209         expect(':');
7210         expression_t *false_expression =
7211                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7212
7213         type_t *const orig_true_type  = true_expression->base.type;
7214         type_t *const orig_false_type = false_expression->base.type;
7215         type_t *const true_type       = skip_typeref(orig_true_type);
7216         type_t *const false_type      = skip_typeref(orig_false_type);
7217
7218         /* 6.5.15.3 */
7219         source_position_t const *const pos = &conditional->base.source_position;
7220         type_t                        *result_type;
7221         if (is_type_void(true_type) || is_type_void(false_type)) {
7222                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7223                 if (true_expression->kind == EXPR_UNARY_THROW) {
7224                         result_type = false_type;
7225                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7226                         result_type = true_type;
7227                 } else {
7228                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7229                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7230                         }
7231                         result_type = type_void;
7232                 }
7233         } else if (is_type_arithmetic(true_type)
7234                    && is_type_arithmetic(false_type)) {
7235                 result_type = semantic_arithmetic(true_type, false_type);
7236         } else if (same_compound_type(true_type, false_type)) {
7237                 /* just take 1 of the 2 types */
7238                 result_type = true_type;
7239         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7240                 type_t *pointer_type;
7241                 type_t *other_type;
7242                 expression_t *other_expression;
7243                 if (is_type_pointer(true_type) &&
7244                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7245                         pointer_type     = true_type;
7246                         other_type       = false_type;
7247                         other_expression = false_expression;
7248                 } else {
7249                         pointer_type     = false_type;
7250                         other_type       = true_type;
7251                         other_expression = true_expression;
7252                 }
7253
7254                 if (is_null_pointer_constant(other_expression)) {
7255                         result_type = pointer_type;
7256                 } else if (is_type_pointer(other_type)) {
7257                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7258                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7259
7260                         type_t *to;
7261                         if (is_type_void(to1) || is_type_void(to2)) {
7262                                 to = type_void;
7263                         } else if (types_compatible(get_unqualified_type(to1),
7264                                                     get_unqualified_type(to2))) {
7265                                 to = to1;
7266                         } else {
7267                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7268                                 to = type_void;
7269                         }
7270
7271                         type_t *const type =
7272                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7273                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7274                 } else if (is_type_integer(other_type)) {
7275                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7276                         result_type = pointer_type;
7277                 } else {
7278                         goto types_incompatible;
7279                 }
7280         } else {
7281 types_incompatible:
7282                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7283                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7284                 }
7285                 result_type = type_error_type;
7286         }
7287
7288         conditional->true_expression
7289                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7290         conditional->false_expression
7291                 = create_implicit_cast(false_expression, result_type);
7292         conditional->base.type = result_type;
7293         return result;
7294 }
7295
7296 /**
7297  * Parse an extension expression.
7298  */
7299 static expression_t *parse_extension(void)
7300 {
7301         PUSH_EXTENSION();
7302         expression_t *expression = parse_subexpression(PREC_UNARY);
7303         POP_EXTENSION();
7304         return expression;
7305 }
7306
7307 /**
7308  * Parse a __builtin_classify_type() expression.
7309  */
7310 static expression_t *parse_builtin_classify_type(void)
7311 {
7312         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7313         result->base.type    = type_int;
7314
7315         eat(T___builtin_classify_type);
7316
7317         add_anchor_token(')');
7318         expect('(');
7319         expression_t *expression = parse_expression();
7320         rem_anchor_token(')');
7321         expect(')');
7322         result->classify_type.type_expression = expression;
7323
7324         return result;
7325 }
7326
7327 /**
7328  * Parse a delete expression
7329  * ISO/IEC 14882:1998(E) §5.3.5
7330  */
7331 static expression_t *parse_delete(void)
7332 {
7333         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7334         result->base.type          = type_void;
7335
7336         eat(T_delete);
7337
7338         if (next_if('[')) {
7339                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7340                 expect(']');
7341         }
7342
7343         expression_t *const value = parse_subexpression(PREC_CAST);
7344         result->unary.value = value;
7345
7346         type_t *const type = skip_typeref(value->base.type);
7347         if (!is_type_pointer(type)) {
7348                 if (is_type_valid(type)) {
7349                         errorf(&value->base.source_position,
7350                                         "operand of delete must have pointer type");
7351                 }
7352         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7353                 source_position_t const *const pos = &value->base.source_position;
7354                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7355         }
7356
7357         return result;
7358 }
7359
7360 /**
7361  * Parse a throw expression
7362  * ISO/IEC 14882:1998(E) §15:1
7363  */
7364 static expression_t *parse_throw(void)
7365 {
7366         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7367         result->base.type          = type_void;
7368
7369         eat(T_throw);
7370
7371         expression_t *value = NULL;
7372         switch (token.kind) {
7373                 EXPRESSION_START {
7374                         value = parse_assignment_expression();
7375                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7376                         type_t *const orig_type = value->base.type;
7377                         type_t *const type      = skip_typeref(orig_type);
7378                         if (is_type_incomplete(type)) {
7379                                 errorf(&value->base.source_position,
7380                                                 "cannot throw object of incomplete type '%T'", orig_type);
7381                         } else if (is_type_pointer(type)) {
7382                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7383                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7384                                         errorf(&value->base.source_position,
7385                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7386                                 }
7387                         }
7388                 }
7389
7390                 default:
7391                         break;
7392         }
7393         result->unary.value = value;
7394
7395         return result;
7396 }
7397
7398 static bool check_pointer_arithmetic(const source_position_t *source_position,
7399                                      type_t *pointer_type,
7400                                      type_t *orig_pointer_type)
7401 {
7402         type_t *points_to = pointer_type->pointer.points_to;
7403         points_to = skip_typeref(points_to);
7404
7405         if (is_type_incomplete(points_to)) {
7406                 if (!GNU_MODE || !is_type_void(points_to)) {
7407                         errorf(source_position,
7408                                "arithmetic with pointer to incomplete type '%T' not allowed",
7409                                orig_pointer_type);
7410                         return false;
7411                 } else {
7412                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7413                 }
7414         } else if (is_type_function(points_to)) {
7415                 if (!GNU_MODE) {
7416                         errorf(source_position,
7417                                "arithmetic with pointer to function type '%T' not allowed",
7418                                orig_pointer_type);
7419                         return false;
7420                 } else {
7421                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7422                 }
7423         }
7424         return true;
7425 }
7426
7427 static bool is_lvalue(const expression_t *expression)
7428 {
7429         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7430         switch (expression->kind) {
7431         case EXPR_ARRAY_ACCESS:
7432         case EXPR_COMPOUND_LITERAL:
7433         case EXPR_REFERENCE:
7434         case EXPR_SELECT:
7435         case EXPR_UNARY_DEREFERENCE:
7436                 return true;
7437
7438         default: {
7439                 type_t *type = skip_typeref(expression->base.type);
7440                 return
7441                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7442                         is_type_reference(type) ||
7443                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7444                          * error before, which maybe prevented properly recognizing it as
7445                          * lvalue. */
7446                         !is_type_valid(type);
7447         }
7448         }
7449 }
7450
7451 static void semantic_incdec(unary_expression_t *expression)
7452 {
7453         type_t *const orig_type = expression->value->base.type;
7454         type_t *const type      = skip_typeref(orig_type);
7455         if (is_type_pointer(type)) {
7456                 if (!check_pointer_arithmetic(&expression->base.source_position,
7457                                               type, orig_type)) {
7458                         return;
7459                 }
7460         } else if (!is_type_real(type) && is_type_valid(type)) {
7461                 /* TODO: improve error message */
7462                 errorf(&expression->base.source_position,
7463                        "operation needs an arithmetic or pointer type");
7464                 return;
7465         }
7466         if (!is_lvalue(expression->value)) {
7467                 /* TODO: improve error message */
7468                 errorf(&expression->base.source_position, "lvalue required as operand");
7469         }
7470         expression->base.type = orig_type;
7471 }
7472
7473 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7474 {
7475         type_t *const res_type = promote_integer(type);
7476         expr->base.type = res_type;
7477         expr->value     = create_implicit_cast(expr->value, res_type);
7478 }
7479
7480 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7481 {
7482         type_t *const orig_type = expression->value->base.type;
7483         type_t *const type      = skip_typeref(orig_type);
7484         if (!is_type_arithmetic(type)) {
7485                 if (is_type_valid(type)) {
7486                         /* TODO: improve error message */
7487                         errorf(&expression->base.source_position,
7488                                 "operation needs an arithmetic type");
7489                 }
7490                 return;
7491         } else if (is_type_integer(type)) {
7492                 promote_unary_int_expr(expression, type);
7493         } else {
7494                 expression->base.type = orig_type;
7495         }
7496 }
7497
7498 static void semantic_unexpr_plus(unary_expression_t *expression)
7499 {
7500         semantic_unexpr_arithmetic(expression);
7501         source_position_t const *const pos = &expression->base.source_position;
7502         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7503 }
7504
7505 static void semantic_not(unary_expression_t *expression)
7506 {
7507         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7508         semantic_condition(expression->value, "operand of !");
7509         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7510 }
7511
7512 static void semantic_unexpr_integer(unary_expression_t *expression)
7513 {
7514         type_t *const orig_type = expression->value->base.type;
7515         type_t *const type      = skip_typeref(orig_type);
7516         if (!is_type_integer(type)) {
7517                 if (is_type_valid(type)) {
7518                         errorf(&expression->base.source_position,
7519                                "operand of ~ must be of integer type");
7520                 }
7521                 return;
7522         }
7523
7524         promote_unary_int_expr(expression, type);
7525 }
7526
7527 static void semantic_dereference(unary_expression_t *expression)
7528 {
7529         type_t *const orig_type = expression->value->base.type;
7530         type_t *const type      = skip_typeref(orig_type);
7531         if (!is_type_pointer(type)) {
7532                 if (is_type_valid(type)) {
7533                         errorf(&expression->base.source_position,
7534                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7535                 }
7536                 return;
7537         }
7538
7539         type_t *result_type   = type->pointer.points_to;
7540         result_type           = automatic_type_conversion(result_type);
7541         expression->base.type = result_type;
7542 }
7543
7544 /**
7545  * Record that an address is taken (expression represents an lvalue).
7546  *
7547  * @param expression       the expression
7548  * @param may_be_register  if true, the expression might be an register
7549  */
7550 static void set_address_taken(expression_t *expression, bool may_be_register)
7551 {
7552         if (expression->kind != EXPR_REFERENCE)
7553                 return;
7554
7555         entity_t *const entity = expression->reference.entity;
7556
7557         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7558                 return;
7559
7560         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7561                         && !may_be_register) {
7562                 source_position_t const *const pos = &expression->base.source_position;
7563                 errorf(pos, "address of register '%N' requested", entity);
7564         }
7565
7566         entity->variable.address_taken = true;
7567 }
7568
7569 /**
7570  * Check the semantic of the address taken expression.
7571  */
7572 static void semantic_take_addr(unary_expression_t *expression)
7573 {
7574         expression_t *value = expression->value;
7575         value->base.type    = revert_automatic_type_conversion(value);
7576
7577         type_t *orig_type = value->base.type;
7578         type_t *type      = skip_typeref(orig_type);
7579         if (!is_type_valid(type))
7580                 return;
7581
7582         /* §6.5.3.2 */
7583         if (!is_lvalue(value)) {
7584                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7585         }
7586         if (is_bitfield(value)) {
7587                 errorf(&expression->base.source_position,
7588                        "'&' not allowed on bitfield");
7589         }
7590
7591         set_address_taken(value, false);
7592
7593         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7594 }
7595
7596 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7597 static expression_t *parse_##unexpression_type(void)                         \
7598 {                                                                            \
7599         expression_t *unary_expression                                           \
7600                 = allocate_expression_zero(unexpression_type);                       \
7601         eat(token_kind);                                                         \
7602         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7603                                                                                  \
7604         sfunc(&unary_expression->unary);                                         \
7605                                                                                  \
7606         return unary_expression;                                                 \
7607 }
7608
7609 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7610                                semantic_unexpr_arithmetic)
7611 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7612                                semantic_unexpr_plus)
7613 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7614                                semantic_not)
7615 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7616                                semantic_dereference)
7617 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7618                                semantic_take_addr)
7619 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7620                                semantic_unexpr_integer)
7621 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7622                                semantic_incdec)
7623 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7624                                semantic_incdec)
7625
7626 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7627                                                sfunc)                         \
7628 static expression_t *parse_##unexpression_type(expression_t *left)            \
7629 {                                                                             \
7630         expression_t *unary_expression                                            \
7631                 = allocate_expression_zero(unexpression_type);                        \
7632         eat(token_kind);                                                          \
7633         unary_expression->unary.value = left;                                     \
7634                                                                                   \
7635         sfunc(&unary_expression->unary);                                          \
7636                                                                               \
7637         return unary_expression;                                                  \
7638 }
7639
7640 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7641                                        EXPR_UNARY_POSTFIX_INCREMENT,
7642                                        semantic_incdec)
7643 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7644                                        EXPR_UNARY_POSTFIX_DECREMENT,
7645                                        semantic_incdec)
7646
7647 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7648 {
7649         /* TODO: handle complex + imaginary types */
7650
7651         type_left  = get_unqualified_type(type_left);
7652         type_right = get_unqualified_type(type_right);
7653
7654         /* §6.3.1.8 Usual arithmetic conversions */
7655         if (type_left == type_long_double || type_right == type_long_double) {
7656                 return type_long_double;
7657         } else if (type_left == type_double || type_right == type_double) {
7658                 return type_double;
7659         } else if (type_left == type_float || type_right == type_float) {
7660                 return type_float;
7661         }
7662
7663         type_left  = promote_integer(type_left);
7664         type_right = promote_integer(type_right);
7665
7666         if (type_left == type_right)
7667                 return type_left;
7668
7669         bool     const signed_left  = is_type_signed(type_left);
7670         bool     const signed_right = is_type_signed(type_right);
7671         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7672         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7673
7674         if (signed_left == signed_right)
7675                 return rank_left >= rank_right ? type_left : type_right;
7676
7677         unsigned           s_rank;
7678         unsigned           u_rank;
7679         atomic_type_kind_t s_akind;
7680         atomic_type_kind_t u_akind;
7681         type_t *s_type;
7682         type_t *u_type;
7683         if (signed_left) {
7684                 s_type = type_left;
7685                 u_type = type_right;
7686         } else {
7687                 s_type = type_right;
7688                 u_type = type_left;
7689         }
7690         s_akind = get_akind(s_type);
7691         u_akind = get_akind(u_type);
7692         s_rank  = get_akind_rank(s_akind);
7693         u_rank  = get_akind_rank(u_akind);
7694
7695         if (u_rank >= s_rank)
7696                 return u_type;
7697
7698         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7699                 return s_type;
7700
7701         switch (s_akind) {
7702         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7703         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7704         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7705
7706         default: panic("invalid atomic type");
7707         }
7708 }
7709
7710 /**
7711  * Check the semantic restrictions for a binary expression.
7712  */
7713 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7714 {
7715         expression_t *const left            = expression->left;
7716         expression_t *const right           = expression->right;
7717         type_t       *const orig_type_left  = left->base.type;
7718         type_t       *const orig_type_right = right->base.type;
7719         type_t       *const type_left       = skip_typeref(orig_type_left);
7720         type_t       *const type_right      = skip_typeref(orig_type_right);
7721
7722         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7723                 /* TODO: improve error message */
7724                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7725                         errorf(&expression->base.source_position,
7726                                "operation needs arithmetic types");
7727                 }
7728                 return;
7729         }
7730
7731         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7732         expression->left      = create_implicit_cast(left, arithmetic_type);
7733         expression->right     = create_implicit_cast(right, arithmetic_type);
7734         expression->base.type = arithmetic_type;
7735 }
7736
7737 static void semantic_binexpr_integer(binary_expression_t *const expression)
7738 {
7739         expression_t *const left            = expression->left;
7740         expression_t *const right           = expression->right;
7741         type_t       *const orig_type_left  = left->base.type;
7742         type_t       *const orig_type_right = right->base.type;
7743         type_t       *const type_left       = skip_typeref(orig_type_left);
7744         type_t       *const type_right      = skip_typeref(orig_type_right);
7745
7746         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7747                 /* TODO: improve error message */
7748                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7749                         errorf(&expression->base.source_position,
7750                                "operation needs integer types");
7751                 }
7752                 return;
7753         }
7754
7755         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7756         expression->left      = create_implicit_cast(left, result_type);
7757         expression->right     = create_implicit_cast(right, result_type);
7758         expression->base.type = result_type;
7759 }
7760
7761 static void warn_div_by_zero(binary_expression_t const *const expression)
7762 {
7763         if (!is_type_integer(expression->base.type))
7764                 return;
7765
7766         expression_t const *const right = expression->right;
7767         /* The type of the right operand can be different for /= */
7768         if (is_type_integer(right->base.type)                    &&
7769             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7770             !fold_constant_to_bool(right)) {
7771                 source_position_t const *const pos = &expression->base.source_position;
7772                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7773         }
7774 }
7775
7776 /**
7777  * Check the semantic restrictions for a div/mod expression.
7778  */
7779 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7780 {
7781         semantic_binexpr_arithmetic(expression);
7782         warn_div_by_zero(expression);
7783 }
7784
7785 static void warn_addsub_in_shift(const expression_t *const expr)
7786 {
7787         if (expr->base.parenthesized)
7788                 return;
7789
7790         char op;
7791         switch (expr->kind) {
7792                 case EXPR_BINARY_ADD: op = '+'; break;
7793                 case EXPR_BINARY_SUB: op = '-'; break;
7794                 default:              return;
7795         }
7796
7797         source_position_t const *const pos = &expr->base.source_position;
7798         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7799 }
7800
7801 static bool semantic_shift(binary_expression_t *expression)
7802 {
7803         expression_t *const left            = expression->left;
7804         expression_t *const right           = expression->right;
7805         type_t       *const orig_type_left  = left->base.type;
7806         type_t       *const orig_type_right = right->base.type;
7807         type_t       *      type_left       = skip_typeref(orig_type_left);
7808         type_t       *      type_right      = skip_typeref(orig_type_right);
7809
7810         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7811                 /* TODO: improve error message */
7812                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7813                         errorf(&expression->base.source_position,
7814                                "operands of shift operation must have integer types");
7815                 }
7816                 return false;
7817         }
7818
7819         type_left = promote_integer(type_left);
7820
7821         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7822                 source_position_t const *const pos   = &right->base.source_position;
7823                 long                     const count = fold_constant_to_int(right);
7824                 if (count < 0) {
7825                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7826                 } else if ((unsigned long)count >=
7827                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7828                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7829                 }
7830         }
7831
7832         type_right        = promote_integer(type_right);
7833         expression->right = create_implicit_cast(right, type_right);
7834
7835         return true;
7836 }
7837
7838 static void semantic_shift_op(binary_expression_t *expression)
7839 {
7840         expression_t *const left  = expression->left;
7841         expression_t *const right = expression->right;
7842
7843         if (!semantic_shift(expression))
7844                 return;
7845
7846         warn_addsub_in_shift(left);
7847         warn_addsub_in_shift(right);
7848
7849         type_t *const orig_type_left = left->base.type;
7850         type_t *      type_left      = skip_typeref(orig_type_left);
7851
7852         type_left             = promote_integer(type_left);
7853         expression->left      = create_implicit_cast(left, type_left);
7854         expression->base.type = type_left;
7855 }
7856
7857 static void semantic_add(binary_expression_t *expression)
7858 {
7859         expression_t *const left            = expression->left;
7860         expression_t *const right           = expression->right;
7861         type_t       *const orig_type_left  = left->base.type;
7862         type_t       *const orig_type_right = right->base.type;
7863         type_t       *const type_left       = skip_typeref(orig_type_left);
7864         type_t       *const type_right      = skip_typeref(orig_type_right);
7865
7866         /* §6.5.6 */
7867         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7868                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7869                 expression->left  = create_implicit_cast(left, arithmetic_type);
7870                 expression->right = create_implicit_cast(right, arithmetic_type);
7871                 expression->base.type = arithmetic_type;
7872         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7873                 check_pointer_arithmetic(&expression->base.source_position,
7874                                          type_left, orig_type_left);
7875                 expression->base.type = type_left;
7876         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7877                 check_pointer_arithmetic(&expression->base.source_position,
7878                                          type_right, orig_type_right);
7879                 expression->base.type = type_right;
7880         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7881                 errorf(&expression->base.source_position,
7882                        "invalid operands to binary + ('%T', '%T')",
7883                        orig_type_left, orig_type_right);
7884         }
7885 }
7886
7887 static void semantic_sub(binary_expression_t *expression)
7888 {
7889         expression_t            *const left            = expression->left;
7890         expression_t            *const right           = expression->right;
7891         type_t                  *const orig_type_left  = left->base.type;
7892         type_t                  *const orig_type_right = right->base.type;
7893         type_t                  *const type_left       = skip_typeref(orig_type_left);
7894         type_t                  *const type_right      = skip_typeref(orig_type_right);
7895         source_position_t const *const pos             = &expression->base.source_position;
7896
7897         /* §5.6.5 */
7898         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7899                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7900                 expression->left        = create_implicit_cast(left, arithmetic_type);
7901                 expression->right       = create_implicit_cast(right, arithmetic_type);
7902                 expression->base.type =  arithmetic_type;
7903         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7904                 check_pointer_arithmetic(&expression->base.source_position,
7905                                          type_left, orig_type_left);
7906                 expression->base.type = type_left;
7907         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7908                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7909                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7910                 if (!types_compatible(unqual_left, unqual_right)) {
7911                         errorf(pos,
7912                                "subtracting pointers to incompatible types '%T' and '%T'",
7913                                orig_type_left, orig_type_right);
7914                 } else if (!is_type_object(unqual_left)) {
7915                         if (!is_type_void(unqual_left)) {
7916                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7917                                        orig_type_left);
7918                         } else {
7919                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7920                         }
7921                 }
7922                 expression->base.type = type_ptrdiff_t;
7923         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7924                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7925                        orig_type_left, orig_type_right);
7926         }
7927 }
7928
7929 static void warn_string_literal_address(expression_t const* expr)
7930 {
7931         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7932                 expr = expr->unary.value;
7933                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7934                         return;
7935                 expr = expr->unary.value;
7936         }
7937
7938         if (expr->kind == EXPR_STRING_LITERAL) {
7939                 source_position_t const *const pos = &expr->base.source_position;
7940                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7941         }
7942 }
7943
7944 static bool maybe_negative(expression_t const *const expr)
7945 {
7946         switch (is_constant_expression(expr)) {
7947                 case EXPR_CLASS_ERROR:    return false;
7948                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7949                 default:                  return true;
7950         }
7951 }
7952
7953 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7954 {
7955         warn_string_literal_address(expr);
7956
7957         expression_t const* const ref = get_reference_address(expr);
7958         if (ref != NULL && is_null_pointer_constant(other)) {
7959                 entity_t const *const ent = ref->reference.entity;
7960                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7961         }
7962
7963         if (!expr->base.parenthesized) {
7964                 switch (expr->base.kind) {
7965                         case EXPR_BINARY_LESS:
7966                         case EXPR_BINARY_GREATER:
7967                         case EXPR_BINARY_LESSEQUAL:
7968                         case EXPR_BINARY_GREATEREQUAL:
7969                         case EXPR_BINARY_NOTEQUAL:
7970                         case EXPR_BINARY_EQUAL:
7971                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
7972                                 break;
7973                         default:
7974                                 break;
7975                 }
7976         }
7977 }
7978
7979 /**
7980  * Check the semantics of comparison expressions.
7981  *
7982  * @param expression   The expression to check.
7983  */
7984 static void semantic_comparison(binary_expression_t *expression)
7985 {
7986         source_position_t const *const pos   = &expression->base.source_position;
7987         expression_t            *const left  = expression->left;
7988         expression_t            *const right = expression->right;
7989
7990         warn_comparison(pos, left, right);
7991         warn_comparison(pos, right, left);
7992
7993         type_t *orig_type_left  = left->base.type;
7994         type_t *orig_type_right = right->base.type;
7995         type_t *type_left       = skip_typeref(orig_type_left);
7996         type_t *type_right      = skip_typeref(orig_type_right);
7997
7998         /* TODO non-arithmetic types */
7999         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8000                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8001
8002                 /* test for signed vs unsigned compares */
8003                 if (is_type_integer(arithmetic_type)) {
8004                         bool const signed_left  = is_type_signed(type_left);
8005                         bool const signed_right = is_type_signed(type_right);
8006                         if (signed_left != signed_right) {
8007                                 /* FIXME long long needs better const folding magic */
8008                                 /* TODO check whether constant value can be represented by other type */
8009                                 if ((signed_left  && maybe_negative(left)) ||
8010                                                 (signed_right && maybe_negative(right))) {
8011                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8012                                 }
8013                         }
8014                 }
8015
8016                 expression->left        = create_implicit_cast(left, arithmetic_type);
8017                 expression->right       = create_implicit_cast(right, arithmetic_type);
8018                 expression->base.type   = arithmetic_type;
8019                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8020                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8021                     is_type_float(arithmetic_type)) {
8022                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8023                 }
8024         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8025                 /* TODO check compatibility */
8026         } else if (is_type_pointer(type_left)) {
8027                 expression->right = create_implicit_cast(right, type_left);
8028         } else if (is_type_pointer(type_right)) {
8029                 expression->left = create_implicit_cast(left, type_right);
8030         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8031                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8032         }
8033         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8034 }
8035
8036 /**
8037  * Checks if a compound type has constant fields.
8038  */
8039 static bool has_const_fields(const compound_type_t *type)
8040 {
8041         compound_t *compound = type->compound;
8042         entity_t   *entry    = compound->members.entities;
8043
8044         for (; entry != NULL; entry = entry->base.next) {
8045                 if (!is_declaration(entry))
8046                         continue;
8047
8048                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8049                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8050                         return true;
8051         }
8052
8053         return false;
8054 }
8055
8056 static bool is_valid_assignment_lhs(expression_t const* const left)
8057 {
8058         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8059         type_t *const type_left      = skip_typeref(orig_type_left);
8060
8061         if (!is_lvalue(left)) {
8062                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8063                        left);
8064                 return false;
8065         }
8066
8067         if (left->kind == EXPR_REFERENCE
8068                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8069                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8070                 return false;
8071         }
8072
8073         if (is_type_array(type_left)) {
8074                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8075                 return false;
8076         }
8077         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8078                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8079                        orig_type_left);
8080                 return false;
8081         }
8082         if (is_type_incomplete(type_left)) {
8083                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8084                        left, orig_type_left);
8085                 return false;
8086         }
8087         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8088                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8089                        left, orig_type_left);
8090                 return false;
8091         }
8092
8093         return true;
8094 }
8095
8096 static void semantic_arithmetic_assign(binary_expression_t *expression)
8097 {
8098         expression_t *left            = expression->left;
8099         expression_t *right           = expression->right;
8100         type_t       *orig_type_left  = left->base.type;
8101         type_t       *orig_type_right = right->base.type;
8102
8103         if (!is_valid_assignment_lhs(left))
8104                 return;
8105
8106         type_t *type_left  = skip_typeref(orig_type_left);
8107         type_t *type_right = skip_typeref(orig_type_right);
8108
8109         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8110                 /* TODO: improve error message */
8111                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8112                         errorf(&expression->base.source_position,
8113                                "operation needs arithmetic types");
8114                 }
8115                 return;
8116         }
8117
8118         /* combined instructions are tricky. We can't create an implicit cast on
8119          * the left side, because we need the uncasted form for the store.
8120          * The ast2firm pass has to know that left_type must be right_type
8121          * for the arithmetic operation and create a cast by itself */
8122         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8123         expression->right       = create_implicit_cast(right, arithmetic_type);
8124         expression->base.type   = type_left;
8125 }
8126
8127 static void semantic_divmod_assign(binary_expression_t *expression)
8128 {
8129         semantic_arithmetic_assign(expression);
8130         warn_div_by_zero(expression);
8131 }
8132
8133 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8134 {
8135         expression_t *const left            = expression->left;
8136         expression_t *const right           = expression->right;
8137         type_t       *const orig_type_left  = left->base.type;
8138         type_t       *const orig_type_right = right->base.type;
8139         type_t       *const type_left       = skip_typeref(orig_type_left);
8140         type_t       *const type_right      = skip_typeref(orig_type_right);
8141
8142         if (!is_valid_assignment_lhs(left))
8143                 return;
8144
8145         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8146                 /* combined instructions are tricky. We can't create an implicit cast on
8147                  * the left side, because we need the uncasted form for the store.
8148                  * The ast2firm pass has to know that left_type must be right_type
8149                  * for the arithmetic operation and create a cast by itself */
8150                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8151                 expression->right     = create_implicit_cast(right, arithmetic_type);
8152                 expression->base.type = type_left;
8153         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8154                 check_pointer_arithmetic(&expression->base.source_position,
8155                                          type_left, orig_type_left);
8156                 expression->base.type = type_left;
8157         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8158                 errorf(&expression->base.source_position,
8159                        "incompatible types '%T' and '%T' in assignment",
8160                        orig_type_left, orig_type_right);
8161         }
8162 }
8163
8164 static void semantic_integer_assign(binary_expression_t *expression)
8165 {
8166         expression_t *left            = expression->left;
8167         expression_t *right           = expression->right;
8168         type_t       *orig_type_left  = left->base.type;
8169         type_t       *orig_type_right = right->base.type;
8170
8171         if (!is_valid_assignment_lhs(left))
8172                 return;
8173
8174         type_t *type_left  = skip_typeref(orig_type_left);
8175         type_t *type_right = skip_typeref(orig_type_right);
8176
8177         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8178                 /* TODO: improve error message */
8179                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8180                         errorf(&expression->base.source_position,
8181                                "operation needs integer types");
8182                 }
8183                 return;
8184         }
8185
8186         /* combined instructions are tricky. We can't create an implicit cast on
8187          * the left side, because we need the uncasted form for the store.
8188          * The ast2firm pass has to know that left_type must be right_type
8189          * for the arithmetic operation and create a cast by itself */
8190         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8191         expression->right       = create_implicit_cast(right, arithmetic_type);
8192         expression->base.type   = type_left;
8193 }
8194
8195 static void semantic_shift_assign(binary_expression_t *expression)
8196 {
8197         expression_t *left           = expression->left;
8198
8199         if (!is_valid_assignment_lhs(left))
8200                 return;
8201
8202         if (!semantic_shift(expression))
8203                 return;
8204
8205         expression->base.type = skip_typeref(left->base.type);
8206 }
8207
8208 static void warn_logical_and_within_or(const expression_t *const expr)
8209 {
8210         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8211                 return;
8212         if (expr->base.parenthesized)
8213                 return;
8214         source_position_t const *const pos = &expr->base.source_position;
8215         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8216 }
8217
8218 /**
8219  * Check the semantic restrictions of a logical expression.
8220  */
8221 static void semantic_logical_op(binary_expression_t *expression)
8222 {
8223         /* §6.5.13:2  Each of the operands shall have scalar type.
8224          * §6.5.14:2  Each of the operands shall have scalar type. */
8225         semantic_condition(expression->left,   "left operand of logical operator");
8226         semantic_condition(expression->right, "right operand of logical operator");
8227         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8228                 warn_logical_and_within_or(expression->left);
8229                 warn_logical_and_within_or(expression->right);
8230         }
8231         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8232 }
8233
8234 /**
8235  * Check the semantic restrictions of a binary assign expression.
8236  */
8237 static void semantic_binexpr_assign(binary_expression_t *expression)
8238 {
8239         expression_t *left           = expression->left;
8240         type_t       *orig_type_left = left->base.type;
8241
8242         if (!is_valid_assignment_lhs(left))
8243                 return;
8244
8245         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8246         report_assign_error(error, orig_type_left, expression->right,
8247                         "assignment", &left->base.source_position);
8248         expression->right = create_implicit_cast(expression->right, orig_type_left);
8249         expression->base.type = orig_type_left;
8250 }
8251
8252 /**
8253  * Determine if the outermost operation (or parts thereof) of the given
8254  * expression has no effect in order to generate a warning about this fact.
8255  * Therefore in some cases this only examines some of the operands of the
8256  * expression (see comments in the function and examples below).
8257  * Examples:
8258  *   f() + 23;    // warning, because + has no effect
8259  *   x || f();    // no warning, because x controls execution of f()
8260  *   x ? y : f(); // warning, because y has no effect
8261  *   (void)x;     // no warning to be able to suppress the warning
8262  * This function can NOT be used for an "expression has definitely no effect"-
8263  * analysis. */
8264 static bool expression_has_effect(const expression_t *const expr)
8265 {
8266         switch (expr->kind) {
8267                 case EXPR_ERROR:                      return true; /* do NOT warn */
8268                 case EXPR_REFERENCE:                  return false;
8269                 case EXPR_ENUM_CONSTANT:              return false;
8270                 case EXPR_LABEL_ADDRESS:              return false;
8271
8272                 /* suppress the warning for microsoft __noop operations */
8273                 case EXPR_LITERAL_MS_NOOP:            return true;
8274                 case EXPR_LITERAL_BOOLEAN:
8275                 case EXPR_LITERAL_CHARACTER:
8276                 case EXPR_LITERAL_INTEGER:
8277                 case EXPR_LITERAL_FLOATINGPOINT:
8278                 case EXPR_STRING_LITERAL:             return false;
8279
8280                 case EXPR_CALL: {
8281                         const call_expression_t *const call = &expr->call;
8282                         if (call->function->kind != EXPR_REFERENCE)
8283                                 return true;
8284
8285                         switch (call->function->reference.entity->function.btk) {
8286                                 /* FIXME: which builtins have no effect? */
8287                                 default:                      return true;
8288                         }
8289                 }
8290
8291                 /* Generate the warning if either the left or right hand side of a
8292                  * conditional expression has no effect */
8293                 case EXPR_CONDITIONAL: {
8294                         conditional_expression_t const *const cond = &expr->conditional;
8295                         expression_t             const *const t    = cond->true_expression;
8296                         return
8297                                 (t == NULL || expression_has_effect(t)) &&
8298                                 expression_has_effect(cond->false_expression);
8299                 }
8300
8301                 case EXPR_SELECT:                     return false;
8302                 case EXPR_ARRAY_ACCESS:               return false;
8303                 case EXPR_SIZEOF:                     return false;
8304                 case EXPR_CLASSIFY_TYPE:              return false;
8305                 case EXPR_ALIGNOF:                    return false;
8306
8307                 case EXPR_FUNCNAME:                   return false;
8308                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8309                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8310                 case EXPR_OFFSETOF:                   return false;
8311                 case EXPR_VA_START:                   return true;
8312                 case EXPR_VA_ARG:                     return true;
8313                 case EXPR_VA_COPY:                    return true;
8314                 case EXPR_STATEMENT:                  return true; // TODO
8315                 case EXPR_COMPOUND_LITERAL:           return false;
8316
8317                 case EXPR_UNARY_NEGATE:               return false;
8318                 case EXPR_UNARY_PLUS:                 return false;
8319                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8320                 case EXPR_UNARY_NOT:                  return false;
8321                 case EXPR_UNARY_DEREFERENCE:          return false;
8322                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8323                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8324                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8325                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8326                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8327
8328                 /* Treat void casts as if they have an effect in order to being able to
8329                  * suppress the warning */
8330                 case EXPR_UNARY_CAST: {
8331                         type_t *const type = skip_typeref(expr->base.type);
8332                         return is_type_void(type);
8333                 }
8334
8335                 case EXPR_UNARY_ASSUME:               return true;
8336                 case EXPR_UNARY_DELETE:               return true;
8337                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8338                 case EXPR_UNARY_THROW:                return true;
8339
8340                 case EXPR_BINARY_ADD:                 return false;
8341                 case EXPR_BINARY_SUB:                 return false;
8342                 case EXPR_BINARY_MUL:                 return false;
8343                 case EXPR_BINARY_DIV:                 return false;
8344                 case EXPR_BINARY_MOD:                 return false;
8345                 case EXPR_BINARY_EQUAL:               return false;
8346                 case EXPR_BINARY_NOTEQUAL:            return false;
8347                 case EXPR_BINARY_LESS:                return false;
8348                 case EXPR_BINARY_LESSEQUAL:           return false;
8349                 case EXPR_BINARY_GREATER:             return false;
8350                 case EXPR_BINARY_GREATEREQUAL:        return false;
8351                 case EXPR_BINARY_BITWISE_AND:         return false;
8352                 case EXPR_BINARY_BITWISE_OR:          return false;
8353                 case EXPR_BINARY_BITWISE_XOR:         return false;
8354                 case EXPR_BINARY_SHIFTLEFT:           return false;
8355                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8356                 case EXPR_BINARY_ASSIGN:              return true;
8357                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8358                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8359                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8360                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8361                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8362                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8363                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8364                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8365                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8366                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8367
8368                 /* Only examine the right hand side of && and ||, because the left hand
8369                  * side already has the effect of controlling the execution of the right
8370                  * hand side */
8371                 case EXPR_BINARY_LOGICAL_AND:
8372                 case EXPR_BINARY_LOGICAL_OR:
8373                 /* Only examine the right hand side of a comma expression, because the left
8374                  * hand side has a separate warning */
8375                 case EXPR_BINARY_COMMA:
8376                         return expression_has_effect(expr->binary.right);
8377
8378                 case EXPR_BINARY_ISGREATER:           return false;
8379                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8380                 case EXPR_BINARY_ISLESS:              return false;
8381                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8382                 case EXPR_BINARY_ISLESSGREATER:       return false;
8383                 case EXPR_BINARY_ISUNORDERED:         return false;
8384         }
8385
8386         internal_errorf(HERE, "unexpected expression");
8387 }
8388
8389 static void semantic_comma(binary_expression_t *expression)
8390 {
8391         const expression_t *const left = expression->left;
8392         if (!expression_has_effect(left)) {
8393                 source_position_t const *const pos = &left->base.source_position;
8394                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8395         }
8396         expression->base.type = expression->right->base.type;
8397 }
8398
8399 /**
8400  * @param prec_r precedence of the right operand
8401  */
8402 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8403 static expression_t *parse_##binexpression_type(expression_t *left)          \
8404 {                                                                            \
8405         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8406         binexpr->binary.left  = left;                                            \
8407         eat(token_kind);                                                         \
8408                                                                              \
8409         expression_t *right = parse_subexpression(prec_r);                       \
8410                                                                              \
8411         binexpr->binary.right = right;                                           \
8412         sfunc(&binexpr->binary);                                                 \
8413                                                                              \
8414         return binexpr;                                                          \
8415 }
8416
8417 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8418 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8419 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8420 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8421 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8422 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8423 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8424 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8425 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8426 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8427 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8428 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8429 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8430 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8431 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8432 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8433 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8434 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8435 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8436 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8437 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8438 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8439 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8440 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8441 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8442 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8443 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8444 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8445 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8446 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8447
8448
8449 static expression_t *parse_subexpression(precedence_t precedence)
8450 {
8451         expression_parser_function_t *parser
8452                 = &expression_parsers[token.kind];
8453         expression_t                 *left;
8454
8455         if (parser->parser != NULL) {
8456                 left = parser->parser();
8457         } else {
8458                 left = parse_primary_expression();
8459         }
8460         assert(left != NULL);
8461
8462         while (true) {
8463                 parser = &expression_parsers[token.kind];
8464                 if (parser->infix_parser == NULL)
8465                         break;
8466                 if (parser->infix_precedence < precedence)
8467                         break;
8468
8469                 left = parser->infix_parser(left);
8470
8471                 assert(left != NULL);
8472         }
8473
8474         return left;
8475 }
8476
8477 /**
8478  * Parse an expression.
8479  */
8480 static expression_t *parse_expression(void)
8481 {
8482         return parse_subexpression(PREC_EXPRESSION);
8483 }
8484
8485 /**
8486  * Register a parser for a prefix-like operator.
8487  *
8488  * @param parser      the parser function
8489  * @param token_kind  the token type of the prefix token
8490  */
8491 static void register_expression_parser(parse_expression_function parser,
8492                                        int token_kind)
8493 {
8494         expression_parser_function_t *entry = &expression_parsers[token_kind];
8495
8496         assert(!entry->parser);
8497         entry->parser = parser;
8498 }
8499
8500 /**
8501  * Register a parser for an infix operator with given precedence.
8502  *
8503  * @param parser      the parser function
8504  * @param token_kind  the token type of the infix operator
8505  * @param precedence  the precedence of the operator
8506  */
8507 static void register_infix_parser(parse_expression_infix_function parser,
8508                                   int token_kind, precedence_t precedence)
8509 {
8510         expression_parser_function_t *entry = &expression_parsers[token_kind];
8511
8512         assert(!entry->infix_parser);
8513         entry->infix_parser     = parser;
8514         entry->infix_precedence = precedence;
8515 }
8516
8517 /**
8518  * Initialize the expression parsers.
8519  */
8520 static void init_expression_parsers(void)
8521 {
8522         memset(&expression_parsers, 0, sizeof(expression_parsers));
8523
8524         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8525         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8526         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8527         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8528         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8529         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8530         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8531         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8532         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8533         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8534         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8535         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8536         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8537         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8538         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8539         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8540         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8541         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8542         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8543         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8544         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8545         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8546         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8547         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8548         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8549         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8550         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8551         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8552         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8553         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8554         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8555         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8556         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8557         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8558         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8559         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8560         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8561
8562         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8563         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8564         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8565         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8566         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8567         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8568         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8569         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8570         register_expression_parser(parse_sizeof,                      T_sizeof);
8571         register_expression_parser(parse_alignof,                     T___alignof__);
8572         register_expression_parser(parse_extension,                   T___extension__);
8573         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8574         register_expression_parser(parse_delete,                      T_delete);
8575         register_expression_parser(parse_throw,                       T_throw);
8576 }
8577
8578 /**
8579  * Parse a asm statement arguments specification.
8580  */
8581 static asm_argument_t *parse_asm_arguments(bool is_out)
8582 {
8583         asm_argument_t  *result = NULL;
8584         asm_argument_t **anchor = &result;
8585
8586         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8587                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8588
8589                 if (next_if('[')) {
8590                         add_anchor_token(']');
8591                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8592                         rem_anchor_token(']');
8593                         expect(']');
8594                         if (!argument->symbol)
8595                                 return NULL;
8596                 }
8597
8598                 argument->constraints = parse_string_literals("asm argument");
8599                 add_anchor_token(')');
8600                 expect('(');
8601                 expression_t *expression = parse_expression();
8602                 rem_anchor_token(')');
8603                 if (is_out) {
8604                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8605                          * change size or type representation (e.g. int -> long is ok, but
8606                          * int -> float is not) */
8607                         if (expression->kind == EXPR_UNARY_CAST) {
8608                                 type_t      *const type = expression->base.type;
8609                                 type_kind_t  const kind = type->kind;
8610                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8611                                         unsigned flags;
8612                                         unsigned size;
8613                                         if (kind == TYPE_ATOMIC) {
8614                                                 atomic_type_kind_t const akind = type->atomic.akind;
8615                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8616                                                 size  = get_atomic_type_size(akind);
8617                                         } else {
8618                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8619                                                 size  = get_type_size(type_void_ptr);
8620                                         }
8621
8622                                         do {
8623                                                 expression_t *const value      = expression->unary.value;
8624                                                 type_t       *const value_type = value->base.type;
8625                                                 type_kind_t   const value_kind = value_type->kind;
8626
8627                                                 unsigned value_flags;
8628                                                 unsigned value_size;
8629                                                 if (value_kind == TYPE_ATOMIC) {
8630                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8631                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8632                                                         value_size  = get_atomic_type_size(value_akind);
8633                                                 } else if (value_kind == TYPE_POINTER) {
8634                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8635                                                         value_size  = get_type_size(type_void_ptr);
8636                                                 } else {
8637                                                         break;
8638                                                 }
8639
8640                                                 if (value_flags != flags || value_size != size)
8641                                                         break;
8642
8643                                                 expression = value;
8644                                         } while (expression->kind == EXPR_UNARY_CAST);
8645                                 }
8646                         }
8647
8648                         if (!is_lvalue(expression)) {
8649                                 errorf(&expression->base.source_position,
8650                                        "asm output argument is not an lvalue");
8651                         }
8652
8653                         if (argument->constraints.begin[0] == '=')
8654                                 determine_lhs_ent(expression, NULL);
8655                         else
8656                                 mark_vars_read(expression, NULL);
8657                 } else {
8658                         mark_vars_read(expression, NULL);
8659                 }
8660                 argument->expression = expression;
8661                 expect(')');
8662
8663                 set_address_taken(expression, true);
8664
8665                 *anchor = argument;
8666                 anchor  = &argument->next;
8667
8668                 if (!next_if(','))
8669                         break;
8670         }
8671
8672         return result;
8673 }
8674
8675 /**
8676  * Parse a asm statement clobber specification.
8677  */
8678 static asm_clobber_t *parse_asm_clobbers(void)
8679 {
8680         asm_clobber_t *result  = NULL;
8681         asm_clobber_t **anchor = &result;
8682
8683         while (token.kind == T_STRING_LITERAL) {
8684                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8685                 clobber->clobber       = parse_string_literals(NULL);
8686
8687                 *anchor = clobber;
8688                 anchor  = &clobber->next;
8689
8690                 if (!next_if(','))
8691                         break;
8692         }
8693
8694         return result;
8695 }
8696
8697 /**
8698  * Parse an asm statement.
8699  */
8700 static statement_t *parse_asm_statement(void)
8701 {
8702         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8703         asm_statement_t *asm_statement = &statement->asms;
8704
8705         eat(T_asm);
8706         add_anchor_token(')');
8707         add_anchor_token(':');
8708         add_anchor_token(T_STRING_LITERAL);
8709
8710         if (next_if(T_volatile))
8711                 asm_statement->is_volatile = true;
8712
8713         expect('(');
8714         rem_anchor_token(T_STRING_LITERAL);
8715         asm_statement->asm_text = parse_string_literals("asm statement");
8716
8717         if (next_if(':'))
8718                 asm_statement->outputs = parse_asm_arguments(true);
8719
8720         if (next_if(':'))
8721                 asm_statement->inputs = parse_asm_arguments(false);
8722
8723         rem_anchor_token(':');
8724         if (next_if(':'))
8725                 asm_statement->clobbers = parse_asm_clobbers();
8726
8727         rem_anchor_token(')');
8728         expect(')');
8729         expect(';');
8730
8731         if (asm_statement->outputs == NULL) {
8732                 /* GCC: An 'asm' instruction without any output operands will be treated
8733                  * identically to a volatile 'asm' instruction. */
8734                 asm_statement->is_volatile = true;
8735         }
8736
8737         return statement;
8738 }
8739
8740 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8741 {
8742         statement_t *inner_stmt;
8743         switch (token.kind) {
8744                 case '}':
8745                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8746                         inner_stmt = create_error_statement();
8747                         break;
8748
8749                 case ';':
8750                         if (label->kind == STATEMENT_LABEL) {
8751                                 /* Eat an empty statement here, to avoid the warning about an empty
8752                                  * statement after a label.  label:; is commonly used to have a label
8753                                  * before a closing brace. */
8754                                 inner_stmt = create_empty_statement();
8755                                 eat(';');
8756                                 break;
8757                         }
8758                         /* FALLTHROUGH */
8759
8760                 default:
8761                         inner_stmt = parse_statement();
8762                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8763                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8764                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8765                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8766                         }
8767                         break;
8768         }
8769         return inner_stmt;
8770 }
8771
8772 /**
8773  * Parse a case statement.
8774  */
8775 static statement_t *parse_case_statement(void)
8776 {
8777         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8778         source_position_t *const pos       = &statement->base.source_position;
8779
8780         eat(T_case);
8781         add_anchor_token(':');
8782
8783         expression_t *expression = parse_expression();
8784         type_t *expression_type = expression->base.type;
8785         type_t *skipped         = skip_typeref(expression_type);
8786         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8787                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8788                        expression, expression_type);
8789         }
8790
8791         type_t *type = expression_type;
8792         if (current_switch != NULL) {
8793                 type_t *switch_type = current_switch->expression->base.type;
8794                 if (is_type_valid(switch_type)) {
8795                         expression = create_implicit_cast(expression, switch_type);
8796                 }
8797         }
8798
8799         statement->case_label.expression = expression;
8800         expression_classification_t const expr_class = is_constant_expression(expression);
8801         if (expr_class != EXPR_CLASS_CONSTANT) {
8802                 if (expr_class != EXPR_CLASS_ERROR) {
8803                         errorf(pos, "case label does not reduce to an integer constant");
8804                 }
8805                 statement->case_label.is_bad = true;
8806         } else {
8807                 long const val = fold_constant_to_int(expression);
8808                 statement->case_label.first_case = val;
8809                 statement->case_label.last_case  = val;
8810         }
8811
8812         if (GNU_MODE) {
8813                 if (next_if(T_DOTDOTDOT)) {
8814                         expression_t *end_range = parse_expression();
8815                         expression_type = expression->base.type;
8816                         skipped         = skip_typeref(expression_type);
8817                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8818                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8819                                            expression, expression_type);
8820                         }
8821
8822                         end_range = create_implicit_cast(end_range, type);
8823                         statement->case_label.end_range = end_range;
8824                         expression_classification_t const end_class = is_constant_expression(end_range);
8825                         if (end_class != EXPR_CLASS_CONSTANT) {
8826                                 if (end_class != EXPR_CLASS_ERROR) {
8827                                         errorf(pos, "case range does not reduce to an integer constant");
8828                                 }
8829                                 statement->case_label.is_bad = true;
8830                         } else {
8831                                 long const val = fold_constant_to_int(end_range);
8832                                 statement->case_label.last_case = val;
8833
8834                                 if (val < statement->case_label.first_case) {
8835                                         statement->case_label.is_empty_range = true;
8836                                         warningf(WARN_OTHER, pos, "empty range specified");
8837                                 }
8838                         }
8839                 }
8840         }
8841
8842         PUSH_PARENT(statement);
8843
8844         rem_anchor_token(':');
8845         expect(':');
8846
8847         if (current_switch != NULL) {
8848                 if (! statement->case_label.is_bad) {
8849                         /* Check for duplicate case values */
8850                         case_label_statement_t *c = &statement->case_label;
8851                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8852                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8853                                         continue;
8854
8855                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8856                                         continue;
8857
8858                                 errorf(pos, "duplicate case value (previously used %P)",
8859                                        &l->base.source_position);
8860                                 break;
8861                         }
8862                 }
8863                 /* link all cases into the switch statement */
8864                 if (current_switch->last_case == NULL) {
8865                         current_switch->first_case      = &statement->case_label;
8866                 } else {
8867                         current_switch->last_case->next = &statement->case_label;
8868                 }
8869                 current_switch->last_case = &statement->case_label;
8870         } else {
8871                 errorf(pos, "case label not within a switch statement");
8872         }
8873
8874         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8875
8876         POP_PARENT();
8877         return statement;
8878 }
8879
8880 /**
8881  * Parse a default statement.
8882  */
8883 static statement_t *parse_default_statement(void)
8884 {
8885         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8886
8887         eat(T_default);
8888
8889         PUSH_PARENT(statement);
8890
8891         expect(':');
8892
8893         if (current_switch != NULL) {
8894                 const case_label_statement_t *def_label = current_switch->default_label;
8895                 if (def_label != NULL) {
8896                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8897                 } else {
8898                         current_switch->default_label = &statement->case_label;
8899
8900                         /* link all cases into the switch statement */
8901                         if (current_switch->last_case == NULL) {
8902                                 current_switch->first_case      = &statement->case_label;
8903                         } else {
8904                                 current_switch->last_case->next = &statement->case_label;
8905                         }
8906                         current_switch->last_case = &statement->case_label;
8907                 }
8908         } else {
8909                 errorf(&statement->base.source_position,
8910                         "'default' label not within a switch statement");
8911         }
8912
8913         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8914
8915         POP_PARENT();
8916         return statement;
8917 }
8918
8919 /**
8920  * Parse a label statement.
8921  */
8922 static statement_t *parse_label_statement(void)
8923 {
8924         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8925         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8926         statement->label.label = label;
8927
8928         PUSH_PARENT(statement);
8929
8930         /* if statement is already set then the label is defined twice,
8931          * otherwise it was just mentioned in a goto/local label declaration so far
8932          */
8933         source_position_t const* const pos = &statement->base.source_position;
8934         if (label->statement != NULL) {
8935                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8936         } else {
8937                 label->base.source_position = *pos;
8938                 label->statement            = statement;
8939         }
8940
8941         eat(':');
8942
8943         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8944                 parse_attributes(NULL); // TODO process attributes
8945         }
8946
8947         statement->label.statement = parse_label_inner_statement(statement, "label");
8948
8949         /* remember the labels in a list for later checking */
8950         *label_anchor = &statement->label;
8951         label_anchor  = &statement->label.next;
8952
8953         POP_PARENT();
8954         return statement;
8955 }
8956
8957 static statement_t *parse_inner_statement(void)
8958 {
8959         statement_t *const stmt = parse_statement();
8960         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8961         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8962         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8963                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
8964         }
8965         return stmt;
8966 }
8967
8968 /**
8969  * Parse an expression in parentheses and mark its variables as read.
8970  */
8971 static expression_t *parse_condition(void)
8972 {
8973         add_anchor_token(')');
8974         expect('(');
8975         expression_t *const expr = parse_expression();
8976         mark_vars_read(expr, NULL);
8977         rem_anchor_token(')');
8978         expect(')');
8979         return expr;
8980 }
8981
8982 /**
8983  * Parse an if statement.
8984  */
8985 static statement_t *parse_if(void)
8986 {
8987         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
8988
8989         eat(T_if);
8990
8991         PUSH_PARENT(statement);
8992         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
8993
8994         add_anchor_token(T_else);
8995
8996         expression_t *const expr = parse_condition();
8997         statement->ifs.condition = expr;
8998         /* §6.8.4.1:1  The controlling expression of an if statement shall have
8999          *             scalar type. */
9000         semantic_condition(expr, "condition of 'if'-statment");
9001
9002         statement_t *const true_stmt = parse_inner_statement();
9003         statement->ifs.true_statement = true_stmt;
9004         rem_anchor_token(T_else);
9005
9006         if (true_stmt->kind == STATEMENT_EMPTY) {
9007                 warningf(WARN_EMPTY_BODY, HERE,
9008                         "suggest braces around empty body in an ‘if’ statement");
9009         }
9010
9011         if (next_if(T_else)) {
9012                 statement->ifs.false_statement = parse_inner_statement();
9013
9014                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9015                         warningf(WARN_EMPTY_BODY, HERE,
9016                                         "suggest braces around empty body in an ‘if’ statement");
9017                 }
9018         } else if (true_stmt->kind == STATEMENT_IF &&
9019                         true_stmt->ifs.false_statement != NULL) {
9020                 source_position_t const *const pos = &true_stmt->base.source_position;
9021                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9022         }
9023
9024         POP_SCOPE();
9025         POP_PARENT();
9026         return statement;
9027 }
9028
9029 /**
9030  * Check that all enums are handled in a switch.
9031  *
9032  * @param statement  the switch statement to check
9033  */
9034 static void check_enum_cases(const switch_statement_t *statement)
9035 {
9036         if (!is_warn_on(WARN_SWITCH_ENUM))
9037                 return;
9038         const type_t *type = skip_typeref(statement->expression->base.type);
9039         if (! is_type_enum(type))
9040                 return;
9041         const enum_type_t *enumt = &type->enumt;
9042
9043         /* if we have a default, no warnings */
9044         if (statement->default_label != NULL)
9045                 return;
9046
9047         /* FIXME: calculation of value should be done while parsing */
9048         /* TODO: quadratic algorithm here. Change to an n log n one */
9049         long            last_value = -1;
9050         const entity_t *entry      = enumt->enume->base.next;
9051         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9052              entry = entry->base.next) {
9053                 const expression_t *expression = entry->enum_value.value;
9054                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9055                 bool                found      = false;
9056                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9057                         if (l->expression == NULL)
9058                                 continue;
9059                         if (l->first_case <= value && value <= l->last_case) {
9060                                 found = true;
9061                                 break;
9062                         }
9063                 }
9064                 if (!found) {
9065                         source_position_t const *const pos = &statement->base.source_position;
9066                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9067                 }
9068                 last_value = value;
9069         }
9070 }
9071
9072 /**
9073  * Parse a switch statement.
9074  */
9075 static statement_t *parse_switch(void)
9076 {
9077         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9078
9079         eat(T_switch);
9080
9081         PUSH_PARENT(statement);
9082         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9083
9084         expression_t *const expr = parse_condition();
9085         type_t       *      type = skip_typeref(expr->base.type);
9086         if (is_type_integer(type)) {
9087                 type = promote_integer(type);
9088                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9089                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9090                 }
9091         } else if (is_type_valid(type)) {
9092                 errorf(&expr->base.source_position,
9093                        "switch quantity is not an integer, but '%T'", type);
9094                 type = type_error_type;
9095         }
9096         statement->switchs.expression = create_implicit_cast(expr, type);
9097
9098         switch_statement_t *rem = current_switch;
9099         current_switch          = &statement->switchs;
9100         statement->switchs.body = parse_inner_statement();
9101         current_switch          = rem;
9102
9103         if (statement->switchs.default_label == NULL) {
9104                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9105         }
9106         check_enum_cases(&statement->switchs);
9107
9108         POP_SCOPE();
9109         POP_PARENT();
9110         return statement;
9111 }
9112
9113 static statement_t *parse_loop_body(statement_t *const loop)
9114 {
9115         statement_t *const rem = current_loop;
9116         current_loop = loop;
9117
9118         statement_t *const body = parse_inner_statement();
9119
9120         current_loop = rem;
9121         return body;
9122 }
9123
9124 /**
9125  * Parse a while statement.
9126  */
9127 static statement_t *parse_while(void)
9128 {
9129         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9130
9131         eat(T_while);
9132
9133         PUSH_PARENT(statement);
9134         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9135
9136         expression_t *const cond = parse_condition();
9137         statement->whiles.condition = cond;
9138         /* §6.8.5:2    The controlling expression of an iteration statement shall
9139          *             have scalar type. */
9140         semantic_condition(cond, "condition of 'while'-statement");
9141
9142         statement->whiles.body = parse_loop_body(statement);
9143
9144         POP_SCOPE();
9145         POP_PARENT();
9146         return statement;
9147 }
9148
9149 /**
9150  * Parse a do statement.
9151  */
9152 static statement_t *parse_do(void)
9153 {
9154         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9155
9156         eat(T_do);
9157
9158         PUSH_PARENT(statement);
9159         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9160
9161         add_anchor_token(T_while);
9162         statement->do_while.body = parse_loop_body(statement);
9163         rem_anchor_token(T_while);
9164
9165         expect(T_while);
9166         expression_t *const cond = parse_condition();
9167         statement->do_while.condition = cond;
9168         /* §6.8.5:2    The controlling expression of an iteration statement shall
9169          *             have scalar type. */
9170         semantic_condition(cond, "condition of 'do-while'-statement");
9171         expect(';');
9172
9173         POP_SCOPE();
9174         POP_PARENT();
9175         return statement;
9176 }
9177
9178 /**
9179  * Parse a for statement.
9180  */
9181 static statement_t *parse_for(void)
9182 {
9183         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9184
9185         eat(T_for);
9186
9187         PUSH_PARENT(statement);
9188         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9189
9190         add_anchor_token(')');
9191         expect('(');
9192
9193         PUSH_EXTENSION();
9194
9195         if (next_if(';')) {
9196         } else if (is_declaration_specifier(&token)) {
9197                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9198         } else {
9199                 add_anchor_token(';');
9200                 expression_t *const init = parse_expression();
9201                 statement->fors.initialisation = init;
9202                 mark_vars_read(init, ENT_ANY);
9203                 if (!expression_has_effect(init)) {
9204                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9205                 }
9206                 rem_anchor_token(';');
9207                 expect(';');
9208         }
9209
9210         POP_EXTENSION();
9211
9212         if (token.kind != ';') {
9213                 add_anchor_token(';');
9214                 expression_t *const cond = parse_expression();
9215                 statement->fors.condition = cond;
9216                 /* §6.8.5:2    The controlling expression of an iteration statement
9217                  *             shall have scalar type. */
9218                 semantic_condition(cond, "condition of 'for'-statement");
9219                 mark_vars_read(cond, NULL);
9220                 rem_anchor_token(';');
9221         }
9222         expect(';');
9223         if (token.kind != ')') {
9224                 expression_t *const step = parse_expression();
9225                 statement->fors.step = step;
9226                 mark_vars_read(step, ENT_ANY);
9227                 if (!expression_has_effect(step)) {
9228                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9229                 }
9230         }
9231         rem_anchor_token(')');
9232         expect(')');
9233         statement->fors.body = parse_loop_body(statement);
9234
9235         POP_SCOPE();
9236         POP_PARENT();
9237         return statement;
9238 }
9239
9240 /**
9241  * Parse a goto statement.
9242  */
9243 static statement_t *parse_goto(void)
9244 {
9245         statement_t *statement;
9246         if (GNU_MODE && look_ahead(1)->kind == '*') {
9247                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9248                 eat(T_goto);
9249                 eat('*');
9250
9251                 expression_t *expression = parse_expression();
9252                 mark_vars_read(expression, NULL);
9253
9254                 /* Argh: although documentation says the expression must be of type void*,
9255                  * gcc accepts anything that can be casted into void* without error */
9256                 type_t *type = expression->base.type;
9257
9258                 if (type != type_error_type) {
9259                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9260                                 errorf(&expression->base.source_position,
9261                                         "cannot convert to a pointer type");
9262                         } else if (type != type_void_ptr) {
9263                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9264                         }
9265                         expression = create_implicit_cast(expression, type_void_ptr);
9266                 }
9267
9268                 statement->computed_goto.expression = expression;
9269         } else {
9270                 statement = allocate_statement_zero(STATEMENT_GOTO);
9271                 eat(T_goto);
9272
9273                 label_t *const label = get_label("while parsing goto");
9274                 if (label) {
9275                         label->used            = true;
9276                         statement->gotos.label = label;
9277
9278                         /* remember the goto's in a list for later checking */
9279                         *goto_anchor = &statement->gotos;
9280                         goto_anchor  = &statement->gotos.next;
9281                 } else {
9282                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9283                 }
9284         }
9285
9286         expect(';');
9287         return statement;
9288 }
9289
9290 /**
9291  * Parse a continue statement.
9292  */
9293 static statement_t *parse_continue(void)
9294 {
9295         if (current_loop == NULL) {
9296                 errorf(HERE, "continue statement not within loop");
9297         }
9298
9299         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9300
9301         eat(T_continue);
9302         expect(';');
9303         return statement;
9304 }
9305
9306 /**
9307  * Parse a break statement.
9308  */
9309 static statement_t *parse_break(void)
9310 {
9311         if (current_switch == NULL && current_loop == NULL) {
9312                 errorf(HERE, "break statement not within loop or switch");
9313         }
9314
9315         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9316
9317         eat(T_break);
9318         expect(';');
9319         return statement;
9320 }
9321
9322 /**
9323  * Parse a __leave statement.
9324  */
9325 static statement_t *parse_leave_statement(void)
9326 {
9327         if (current_try == NULL) {
9328                 errorf(HERE, "__leave statement not within __try");
9329         }
9330
9331         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9332
9333         eat(T___leave);
9334         expect(';');
9335         return statement;
9336 }
9337
9338 /**
9339  * Check if a given entity represents a local variable.
9340  */
9341 static bool is_local_variable(const entity_t *entity)
9342 {
9343         if (entity->kind != ENTITY_VARIABLE)
9344                 return false;
9345
9346         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9347         case STORAGE_CLASS_AUTO:
9348         case STORAGE_CLASS_REGISTER: {
9349                 const type_t *type = skip_typeref(entity->declaration.type);
9350                 if (is_type_function(type)) {
9351                         return false;
9352                 } else {
9353                         return true;
9354                 }
9355         }
9356         default:
9357                 return false;
9358         }
9359 }
9360
9361 /**
9362  * Check if a given expression represents a local variable.
9363  */
9364 static bool expression_is_local_variable(const expression_t *expression)
9365 {
9366         if (expression->base.kind != EXPR_REFERENCE) {
9367                 return false;
9368         }
9369         const entity_t *entity = expression->reference.entity;
9370         return is_local_variable(entity);
9371 }
9372
9373 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9374 {
9375         if (c_mode & _CXX || strict_mode) {
9376                 errorf(pos, msg);
9377         } else {
9378                 warningf(WARN_OTHER, pos, msg);
9379         }
9380 }
9381
9382 /**
9383  * Parse a return statement.
9384  */
9385 static statement_t *parse_return(void)
9386 {
9387         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9388         eat(T_return);
9389
9390         expression_t *return_value = NULL;
9391         if (token.kind != ';') {
9392                 return_value = parse_expression();
9393                 mark_vars_read(return_value, NULL);
9394         }
9395
9396         const type_t *const func_type = skip_typeref(current_function->base.type);
9397         assert(is_type_function(func_type));
9398         type_t *const return_type = skip_typeref(func_type->function.return_type);
9399
9400         source_position_t const *const pos = &statement->base.source_position;
9401         if (return_value != NULL) {
9402                 type_t *return_value_type = skip_typeref(return_value->base.type);
9403
9404                 if (is_type_void(return_type)) {
9405                         if (!is_type_void(return_value_type)) {
9406                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9407                                 /* Only warn in C mode, because GCC does the same */
9408                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9409                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9410                                 /* Only warn in C mode, because GCC does the same */
9411                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9412                         }
9413                 } else {
9414                         assign_error_t error = semantic_assign(return_type, return_value);
9415                         report_assign_error(error, return_type, return_value, "'return'",
9416                                             pos);
9417                 }
9418                 return_value = create_implicit_cast(return_value, return_type);
9419                 /* check for returning address of a local var */
9420                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9421                         const expression_t *expression = return_value->unary.value;
9422                         if (expression_is_local_variable(expression)) {
9423                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9424                         }
9425                 }
9426         } else if (!is_type_void(return_type)) {
9427                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9428                 err_or_warn(pos, "'return' without value, in function returning non-void");
9429         }
9430         statement->returns.value = return_value;
9431
9432         expect(';');
9433         return statement;
9434 }
9435
9436 /**
9437  * Parse a declaration statement.
9438  */
9439 static statement_t *parse_declaration_statement(void)
9440 {
9441         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9442
9443         entity_t *before = current_scope->last_entity;
9444         if (GNU_MODE) {
9445                 parse_external_declaration();
9446         } else {
9447                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9448         }
9449
9450         declaration_statement_t *const decl  = &statement->declaration;
9451         entity_t                *const begin =
9452                 before != NULL ? before->base.next : current_scope->entities;
9453         decl->declarations_begin = begin;
9454         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9455
9456         return statement;
9457 }
9458
9459 /**
9460  * Parse an expression statement, ie. expr ';'.
9461  */
9462 static statement_t *parse_expression_statement(void)
9463 {
9464         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9465
9466         expression_t *const expr         = parse_expression();
9467         statement->expression.expression = expr;
9468         mark_vars_read(expr, ENT_ANY);
9469
9470         expect(';');
9471         return statement;
9472 }
9473
9474 /**
9475  * Parse a microsoft __try { } __finally { } or
9476  * __try{ } __except() { }
9477  */
9478 static statement_t *parse_ms_try_statment(void)
9479 {
9480         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9481         eat(T___try);
9482
9483         PUSH_PARENT(statement);
9484
9485         ms_try_statement_t *rem = current_try;
9486         current_try = &statement->ms_try;
9487         statement->ms_try.try_statement = parse_compound_statement(false);
9488         current_try = rem;
9489
9490         POP_PARENT();
9491
9492         if (next_if(T___except)) {
9493                 expression_t *const expr = parse_condition();
9494                 type_t       *      type = skip_typeref(expr->base.type);
9495                 if (is_type_integer(type)) {
9496                         type = promote_integer(type);
9497                 } else if (is_type_valid(type)) {
9498                         errorf(&expr->base.source_position,
9499                                "__expect expression is not an integer, but '%T'", type);
9500                         type = type_error_type;
9501                 }
9502                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9503         } else if (!next_if(T__finally)) {
9504                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9505         }
9506         statement->ms_try.final_statement = parse_compound_statement(false);
9507         return statement;
9508 }
9509
9510 static statement_t *parse_empty_statement(void)
9511 {
9512         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9513         statement_t *const statement = create_empty_statement();
9514         eat(';');
9515         return statement;
9516 }
9517
9518 static statement_t *parse_local_label_declaration(void)
9519 {
9520         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9521
9522         eat(T___label__);
9523
9524         entity_t *begin   = NULL;
9525         entity_t *end     = NULL;
9526         entity_t **anchor = &begin;
9527         add_anchor_token(';');
9528         add_anchor_token(',');
9529         do {
9530                 source_position_t pos;
9531                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9532                 if (symbol) {
9533                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9534                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9535                                 source_position_t const *const ppos = &entity->base.source_position;
9536                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9537                         } else {
9538                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9539                                 entity->base.parent_scope = current_scope;
9540
9541                                 *anchor = entity;
9542                                 anchor  = &entity->base.next;
9543                                 end     = entity;
9544
9545                                 environment_push(entity);
9546                         }
9547                 }
9548         } while (next_if(','));
9549         rem_anchor_token(',');
9550         rem_anchor_token(';');
9551         expect(';');
9552         statement->declaration.declarations_begin = begin;
9553         statement->declaration.declarations_end   = end;
9554         return statement;
9555 }
9556
9557 static void parse_namespace_definition(void)
9558 {
9559         eat(T_namespace);
9560
9561         entity_t *entity = NULL;
9562         symbol_t *symbol = NULL;
9563
9564         if (token.kind == T_IDENTIFIER) {
9565                 symbol = token.base.symbol;
9566                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9567                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9568                         entity = NULL;
9569                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9570                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9571                         }
9572                 }
9573                 eat(T_IDENTIFIER);
9574         }
9575
9576         if (entity == NULL) {
9577                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9578                 entity->base.parent_scope = current_scope;
9579         }
9580
9581         if (token.kind == '=') {
9582                 /* TODO: parse namespace alias */
9583                 panic("namespace alias definition not supported yet");
9584         }
9585
9586         environment_push(entity);
9587         append_entity(current_scope, entity);
9588
9589         PUSH_SCOPE(&entity->namespacee.members);
9590         PUSH_CURRENT_ENTITY(entity);
9591
9592         add_anchor_token('}');
9593         expect('{');
9594         parse_externals();
9595         rem_anchor_token('}');
9596         expect('}');
9597
9598         POP_CURRENT_ENTITY();
9599         POP_SCOPE();
9600 }
9601
9602 /**
9603  * Parse a statement.
9604  * There's also parse_statement() which additionally checks for
9605  * "statement has no effect" warnings
9606  */
9607 static statement_t *intern_parse_statement(void)
9608 {
9609         /* declaration or statement */
9610         statement_t *statement;
9611         switch (token.kind) {
9612         case T_IDENTIFIER: {
9613                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9614                 if (la1_type == ':') {
9615                         statement = parse_label_statement();
9616                 } else if (is_typedef_symbol(token.base.symbol)) {
9617                         statement = parse_declaration_statement();
9618                 } else {
9619                         /* it's an identifier, the grammar says this must be an
9620                          * expression statement. However it is common that users mistype
9621                          * declaration types, so we guess a bit here to improve robustness
9622                          * for incorrect programs */
9623                         switch (la1_type) {
9624                         case '&':
9625                         case '*':
9626                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9627                         default:
9628                                         statement = parse_expression_statement();
9629                                 } else {
9630                         DECLARATION_START
9631                         case T_IDENTIFIER:
9632                                         statement = parse_declaration_statement();
9633                                 }
9634                                 break;
9635                         }
9636                 }
9637                 break;
9638         }
9639
9640         case T___extension__: {
9641                 /* This can be a prefix to a declaration or an expression statement.
9642                  * We simply eat it now and parse the rest with tail recursion. */
9643                 PUSH_EXTENSION();
9644                 statement = intern_parse_statement();
9645                 POP_EXTENSION();
9646                 break;
9647         }
9648
9649         DECLARATION_START
9650                 statement = parse_declaration_statement();
9651                 break;
9652
9653         case T___label__:
9654                 statement = parse_local_label_declaration();
9655                 break;
9656
9657         case ';':         statement = parse_empty_statement();         break;
9658         case '{':         statement = parse_compound_statement(false); break;
9659         case T___leave:   statement = parse_leave_statement();         break;
9660         case T___try:     statement = parse_ms_try_statment();         break;
9661         case T_asm:       statement = parse_asm_statement();           break;
9662         case T_break:     statement = parse_break();                   break;
9663         case T_case:      statement = parse_case_statement();          break;
9664         case T_continue:  statement = parse_continue();                break;
9665         case T_default:   statement = parse_default_statement();       break;
9666         case T_do:        statement = parse_do();                      break;
9667         case T_for:       statement = parse_for();                     break;
9668         case T_goto:      statement = parse_goto();                    break;
9669         case T_if:        statement = parse_if();                      break;
9670         case T_return:    statement = parse_return();                  break;
9671         case T_switch:    statement = parse_switch();                  break;
9672         case T_while:     statement = parse_while();                   break;
9673
9674         EXPRESSION_START
9675                 statement = parse_expression_statement();
9676                 break;
9677
9678         default:
9679                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9680                 statement = create_error_statement();
9681                 eat_until_anchor();
9682                 break;
9683         }
9684
9685         return statement;
9686 }
9687
9688 /**
9689  * parse a statement and emits "statement has no effect" warning if needed
9690  * (This is really a wrapper around intern_parse_statement with check for 1
9691  *  single warning. It is needed, because for statement expressions we have
9692  *  to avoid the warning on the last statement)
9693  */
9694 static statement_t *parse_statement(void)
9695 {
9696         statement_t *statement = intern_parse_statement();
9697
9698         if (statement->kind == STATEMENT_EXPRESSION) {
9699                 expression_t *expression = statement->expression.expression;
9700                 if (!expression_has_effect(expression)) {
9701                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9702                 }
9703         }
9704
9705         return statement;
9706 }
9707
9708 /**
9709  * Parse a compound statement.
9710  */
9711 static statement_t *parse_compound_statement(bool inside_expression_statement)
9712 {
9713         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9714
9715         PUSH_PARENT(statement);
9716         PUSH_SCOPE(&statement->compound.scope);
9717
9718         eat('{');
9719         add_anchor_token('}');
9720         /* tokens, which can start a statement */
9721         /* TODO MS, __builtin_FOO */
9722         add_anchor_token('!');
9723         add_anchor_token('&');
9724         add_anchor_token('(');
9725         add_anchor_token('*');
9726         add_anchor_token('+');
9727         add_anchor_token('-');
9728         add_anchor_token(';');
9729         add_anchor_token('{');
9730         add_anchor_token('~');
9731         add_anchor_token(T_CHARACTER_CONSTANT);
9732         add_anchor_token(T_COLONCOLON);
9733         add_anchor_token(T_FLOATINGPOINT);
9734         add_anchor_token(T_IDENTIFIER);
9735         add_anchor_token(T_INTEGER);
9736         add_anchor_token(T_MINUSMINUS);
9737         add_anchor_token(T_PLUSPLUS);
9738         add_anchor_token(T_STRING_LITERAL);
9739         add_anchor_token(T__Bool);
9740         add_anchor_token(T__Complex);
9741         add_anchor_token(T__Imaginary);
9742         add_anchor_token(T___PRETTY_FUNCTION__);
9743         add_anchor_token(T___alignof__);
9744         add_anchor_token(T___attribute__);
9745         add_anchor_token(T___builtin_va_start);
9746         add_anchor_token(T___extension__);
9747         add_anchor_token(T___func__);
9748         add_anchor_token(T___imag__);
9749         add_anchor_token(T___label__);
9750         add_anchor_token(T___real__);
9751         add_anchor_token(T___thread);
9752         add_anchor_token(T_asm);
9753         add_anchor_token(T_auto);
9754         add_anchor_token(T_bool);
9755         add_anchor_token(T_break);
9756         add_anchor_token(T_case);
9757         add_anchor_token(T_char);
9758         add_anchor_token(T_class);
9759         add_anchor_token(T_const);
9760         add_anchor_token(T_const_cast);
9761         add_anchor_token(T_continue);
9762         add_anchor_token(T_default);
9763         add_anchor_token(T_delete);
9764         add_anchor_token(T_double);
9765         add_anchor_token(T_do);
9766         add_anchor_token(T_dynamic_cast);
9767         add_anchor_token(T_enum);
9768         add_anchor_token(T_extern);
9769         add_anchor_token(T_false);
9770         add_anchor_token(T_float);
9771         add_anchor_token(T_for);
9772         add_anchor_token(T_goto);
9773         add_anchor_token(T_if);
9774         add_anchor_token(T_inline);
9775         add_anchor_token(T_int);
9776         add_anchor_token(T_long);
9777         add_anchor_token(T_new);
9778         add_anchor_token(T_operator);
9779         add_anchor_token(T_register);
9780         add_anchor_token(T_reinterpret_cast);
9781         add_anchor_token(T_restrict);
9782         add_anchor_token(T_return);
9783         add_anchor_token(T_short);
9784         add_anchor_token(T_signed);
9785         add_anchor_token(T_sizeof);
9786         add_anchor_token(T_static);
9787         add_anchor_token(T_static_cast);
9788         add_anchor_token(T_struct);
9789         add_anchor_token(T_switch);
9790         add_anchor_token(T_template);
9791         add_anchor_token(T_this);
9792         add_anchor_token(T_throw);
9793         add_anchor_token(T_true);
9794         add_anchor_token(T_try);
9795         add_anchor_token(T_typedef);
9796         add_anchor_token(T_typeid);
9797         add_anchor_token(T_typename);
9798         add_anchor_token(T_typeof);
9799         add_anchor_token(T_union);
9800         add_anchor_token(T_unsigned);
9801         add_anchor_token(T_using);
9802         add_anchor_token(T_void);
9803         add_anchor_token(T_volatile);
9804         add_anchor_token(T_wchar_t);
9805         add_anchor_token(T_while);
9806
9807         statement_t **anchor            = &statement->compound.statements;
9808         bool          only_decls_so_far = true;
9809         while (token.kind != '}' && token.kind != T_EOF) {
9810                 statement_t *sub_statement = intern_parse_statement();
9811                 if (sub_statement->kind == STATEMENT_ERROR) {
9812                         break;
9813                 }
9814
9815                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9816                         only_decls_so_far = false;
9817                 } else if (!only_decls_so_far) {
9818                         source_position_t const *const pos = &sub_statement->base.source_position;
9819                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9820                 }
9821
9822                 *anchor = sub_statement;
9823                 anchor  = &sub_statement->base.next;
9824         }
9825         expect('}');
9826
9827         /* look over all statements again to produce no effect warnings */
9828         if (is_warn_on(WARN_UNUSED_VALUE)) {
9829                 statement_t *sub_statement = statement->compound.statements;
9830                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9831                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9832                                 continue;
9833                         /* don't emit a warning for the last expression in an expression
9834                          * statement as it has always an effect */
9835                         if (inside_expression_statement && sub_statement->base.next == NULL)
9836                                 continue;
9837
9838                         expression_t *expression = sub_statement->expression.expression;
9839                         if (!expression_has_effect(expression)) {
9840                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9841                         }
9842                 }
9843         }
9844
9845         rem_anchor_token(T_while);
9846         rem_anchor_token(T_wchar_t);
9847         rem_anchor_token(T_volatile);
9848         rem_anchor_token(T_void);
9849         rem_anchor_token(T_using);
9850         rem_anchor_token(T_unsigned);
9851         rem_anchor_token(T_union);
9852         rem_anchor_token(T_typeof);
9853         rem_anchor_token(T_typename);
9854         rem_anchor_token(T_typeid);
9855         rem_anchor_token(T_typedef);
9856         rem_anchor_token(T_try);
9857         rem_anchor_token(T_true);
9858         rem_anchor_token(T_throw);
9859         rem_anchor_token(T_this);
9860         rem_anchor_token(T_template);
9861         rem_anchor_token(T_switch);
9862         rem_anchor_token(T_struct);
9863         rem_anchor_token(T_static_cast);
9864         rem_anchor_token(T_static);
9865         rem_anchor_token(T_sizeof);
9866         rem_anchor_token(T_signed);
9867         rem_anchor_token(T_short);
9868         rem_anchor_token(T_return);
9869         rem_anchor_token(T_restrict);
9870         rem_anchor_token(T_reinterpret_cast);
9871         rem_anchor_token(T_register);
9872         rem_anchor_token(T_operator);
9873         rem_anchor_token(T_new);
9874         rem_anchor_token(T_long);
9875         rem_anchor_token(T_int);
9876         rem_anchor_token(T_inline);
9877         rem_anchor_token(T_if);
9878         rem_anchor_token(T_goto);
9879         rem_anchor_token(T_for);
9880         rem_anchor_token(T_float);
9881         rem_anchor_token(T_false);
9882         rem_anchor_token(T_extern);
9883         rem_anchor_token(T_enum);
9884         rem_anchor_token(T_dynamic_cast);
9885         rem_anchor_token(T_do);
9886         rem_anchor_token(T_double);
9887         rem_anchor_token(T_delete);
9888         rem_anchor_token(T_default);
9889         rem_anchor_token(T_continue);
9890         rem_anchor_token(T_const_cast);
9891         rem_anchor_token(T_const);
9892         rem_anchor_token(T_class);
9893         rem_anchor_token(T_char);
9894         rem_anchor_token(T_case);
9895         rem_anchor_token(T_break);
9896         rem_anchor_token(T_bool);
9897         rem_anchor_token(T_auto);
9898         rem_anchor_token(T_asm);
9899         rem_anchor_token(T___thread);
9900         rem_anchor_token(T___real__);
9901         rem_anchor_token(T___label__);
9902         rem_anchor_token(T___imag__);
9903         rem_anchor_token(T___func__);
9904         rem_anchor_token(T___extension__);
9905         rem_anchor_token(T___builtin_va_start);
9906         rem_anchor_token(T___attribute__);
9907         rem_anchor_token(T___alignof__);
9908         rem_anchor_token(T___PRETTY_FUNCTION__);
9909         rem_anchor_token(T__Imaginary);
9910         rem_anchor_token(T__Complex);
9911         rem_anchor_token(T__Bool);
9912         rem_anchor_token(T_STRING_LITERAL);
9913         rem_anchor_token(T_PLUSPLUS);
9914         rem_anchor_token(T_MINUSMINUS);
9915         rem_anchor_token(T_INTEGER);
9916         rem_anchor_token(T_IDENTIFIER);
9917         rem_anchor_token(T_FLOATINGPOINT);
9918         rem_anchor_token(T_COLONCOLON);
9919         rem_anchor_token(T_CHARACTER_CONSTANT);
9920         rem_anchor_token('~');
9921         rem_anchor_token('{');
9922         rem_anchor_token(';');
9923         rem_anchor_token('-');
9924         rem_anchor_token('+');
9925         rem_anchor_token('*');
9926         rem_anchor_token('(');
9927         rem_anchor_token('&');
9928         rem_anchor_token('!');
9929         rem_anchor_token('}');
9930
9931         POP_SCOPE();
9932         POP_PARENT();
9933         return statement;
9934 }
9935
9936 /**
9937  * Check for unused global static functions and variables
9938  */
9939 static void check_unused_globals(void)
9940 {
9941         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9942                 return;
9943
9944         for (const entity_t *entity = file_scope->entities; entity != NULL;
9945              entity = entity->base.next) {
9946                 if (!is_declaration(entity))
9947                         continue;
9948
9949                 const declaration_t *declaration = &entity->declaration;
9950                 if (declaration->used                  ||
9951                     declaration->modifiers & DM_UNUSED ||
9952                     declaration->modifiers & DM_USED   ||
9953                     declaration->storage_class != STORAGE_CLASS_STATIC)
9954                         continue;
9955
9956                 warning_t   why;
9957                 char const *s;
9958                 if (entity->kind == ENTITY_FUNCTION) {
9959                         /* inhibit warning for static inline functions */
9960                         if (entity->function.is_inline)
9961                                 continue;
9962
9963                         why = WARN_UNUSED_FUNCTION;
9964                         s   = entity->function.statement != NULL ? "defined" : "declared";
9965                 } else {
9966                         why = WARN_UNUSED_VARIABLE;
9967                         s   = "defined";
9968                 }
9969
9970                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
9971         }
9972 }
9973
9974 static void parse_global_asm(void)
9975 {
9976         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
9977
9978         eat(T_asm);
9979         add_anchor_token(';');
9980         add_anchor_token(')');
9981         add_anchor_token(T_STRING_LITERAL);
9982         expect('(');
9983
9984         rem_anchor_token(T_STRING_LITERAL);
9985         statement->asms.asm_text = parse_string_literals("global asm");
9986         statement->base.next     = unit->global_asm;
9987         unit->global_asm         = statement;
9988
9989         rem_anchor_token(')');
9990         expect(')');
9991         rem_anchor_token(';');
9992         expect(';');
9993 }
9994
9995 static void parse_linkage_specification(void)
9996 {
9997         eat(T_extern);
9998
9999         source_position_t const pos     = *HERE;
10000         char const       *const linkage = parse_string_literals(NULL).begin;
10001
10002         linkage_kind_t old_linkage = current_linkage;
10003         linkage_kind_t new_linkage;
10004         if (streq(linkage, "C")) {
10005                 new_linkage = LINKAGE_C;
10006         } else if (streq(linkage, "C++")) {
10007                 new_linkage = LINKAGE_CXX;
10008         } else {
10009                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10010                 new_linkage = LINKAGE_C;
10011         }
10012         current_linkage = new_linkage;
10013
10014         if (next_if('{')) {
10015                 parse_externals();
10016                 expect('}');
10017         } else {
10018                 parse_external();
10019         }
10020
10021         assert(current_linkage == new_linkage);
10022         current_linkage = old_linkage;
10023 }
10024
10025 static void parse_external(void)
10026 {
10027         switch (token.kind) {
10028                 case T_extern:
10029                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10030                                 parse_linkage_specification();
10031                         } else {
10032                 DECLARATION_START_NO_EXTERN
10033                 case T_IDENTIFIER:
10034                 case T___extension__:
10035                 /* tokens below are for implicit int */
10036                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10037                               implicit int) */
10038                 case '*':  /* * x; -> int* x; */
10039                 case '(':  /* (x); -> int (x); */
10040                                 PUSH_EXTENSION();
10041                                 parse_external_declaration();
10042                                 POP_EXTENSION();
10043                         }
10044                         return;
10045
10046                 case T_asm:
10047                         parse_global_asm();
10048                         return;
10049
10050                 case T_namespace:
10051                         parse_namespace_definition();
10052                         return;
10053
10054                 case ';':
10055                         if (!strict_mode) {
10056                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10057                                 eat(';');
10058                                 return;
10059                         }
10060                         /* FALLTHROUGH */
10061
10062                 default:
10063                         errorf(HERE, "stray %K outside of function", &token);
10064                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10065                                 eat_until_matching_token(token.kind);
10066                         next_token();
10067                         return;
10068         }
10069 }
10070
10071 static void parse_externals(void)
10072 {
10073         add_anchor_token('}');
10074         add_anchor_token(T_EOF);
10075
10076 #ifndef NDEBUG
10077         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10078         unsigned short token_anchor_copy[T_LAST_TOKEN];
10079         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10080 #endif
10081
10082         while (token.kind != T_EOF && token.kind != '}') {
10083 #ifndef NDEBUG
10084                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10085                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10086                         if (count != 0) {
10087                                 /* the anchor set and its copy differs */
10088                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10089                         }
10090                 }
10091                 if (in_gcc_extension) {
10092                         /* an gcc extension scope was not closed */
10093                         internal_errorf(HERE, "Leaked __extension__");
10094                 }
10095 #endif
10096
10097                 parse_external();
10098         }
10099
10100         rem_anchor_token(T_EOF);
10101         rem_anchor_token('}');
10102 }
10103
10104 /**
10105  * Parse a translation unit.
10106  */
10107 static void parse_translation_unit(void)
10108 {
10109         add_anchor_token(T_EOF);
10110
10111         while (true) {
10112                 parse_externals();
10113
10114                 if (token.kind == T_EOF)
10115                         break;
10116
10117                 errorf(HERE, "stray %K outside of function", &token);
10118                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10119                         eat_until_matching_token(token.kind);
10120                 next_token();
10121         }
10122 }
10123
10124 void set_default_visibility(elf_visibility_tag_t visibility)
10125 {
10126         default_visibility = visibility;
10127 }
10128
10129 /**
10130  * Parse the input.
10131  *
10132  * @return  the translation unit or NULL if errors occurred.
10133  */
10134 void start_parsing(void)
10135 {
10136         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10137         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10138         error_count       = 0;
10139         warning_count     = 0;
10140
10141         print_to_file(stderr);
10142
10143         assert(unit == NULL);
10144         unit = allocate_ast_zero(sizeof(unit[0]));
10145
10146         assert(file_scope == NULL);
10147         file_scope = &unit->scope;
10148
10149         assert(current_scope == NULL);
10150         scope_push(&unit->scope);
10151
10152         create_gnu_builtins();
10153         if (c_mode & _MS)
10154                 create_microsoft_intrinsics();
10155 }
10156
10157 translation_unit_t *finish_parsing(void)
10158 {
10159         assert(current_scope == &unit->scope);
10160         scope_pop(NULL);
10161
10162         assert(file_scope == &unit->scope);
10163         check_unused_globals();
10164         file_scope = NULL;
10165
10166         DEL_ARR_F(environment_stack);
10167         DEL_ARR_F(label_stack);
10168
10169         translation_unit_t *result = unit;
10170         unit = NULL;
10171         return result;
10172 }
10173
10174 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10175  * are given length one. */
10176 static void complete_incomplete_arrays(void)
10177 {
10178         size_t n = ARR_LEN(incomplete_arrays);
10179         for (size_t i = 0; i != n; ++i) {
10180                 declaration_t *const decl = incomplete_arrays[i];
10181                 type_t        *const type = skip_typeref(decl->type);
10182
10183                 if (!is_type_incomplete(type))
10184                         continue;
10185
10186                 source_position_t const *const pos = &decl->base.source_position;
10187                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10188
10189                 type_t *const new_type = duplicate_type(type);
10190                 new_type->array.size_constant     = true;
10191                 new_type->array.has_implicit_size = true;
10192                 new_type->array.size              = 1;
10193
10194                 type_t *const result = identify_new_type(new_type);
10195
10196                 decl->type = result;
10197         }
10198 }
10199
10200 static void prepare_main_collect2(entity_t *const entity)
10201 {
10202         PUSH_SCOPE(&entity->function.statement->compound.scope);
10203
10204         // create call to __main
10205         symbol_t *symbol         = symbol_table_insert("__main");
10206         entity_t *subsubmain_ent
10207                 = create_implicit_function(symbol, &builtin_source_position);
10208
10209         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10210         type_t       *ftype       = subsubmain_ent->declaration.type;
10211         ref->base.source_position = builtin_source_position;
10212         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10213         ref->reference.entity     = subsubmain_ent;
10214
10215         expression_t *call = allocate_expression_zero(EXPR_CALL);
10216         call->base.source_position = builtin_source_position;
10217         call->base.type            = type_void;
10218         call->call.function        = ref;
10219
10220         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10221         expr_statement->base.source_position  = builtin_source_position;
10222         expr_statement->expression.expression = call;
10223
10224         statement_t *statement = entity->function.statement;
10225         assert(statement->kind == STATEMENT_COMPOUND);
10226         compound_statement_t *compounds = &statement->compound;
10227
10228         expr_statement->base.next = compounds->statements;
10229         compounds->statements     = expr_statement;
10230
10231         POP_SCOPE();
10232 }
10233
10234 void parse(void)
10235 {
10236         lookahead_bufpos = 0;
10237         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10238                 next_token();
10239         }
10240         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10241         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10242         parse_translation_unit();
10243         complete_incomplete_arrays();
10244         DEL_ARR_F(incomplete_arrays);
10245         incomplete_arrays = NULL;
10246 }
10247
10248 /**
10249  * Initialize the parser.
10250  */
10251 void init_parser(void)
10252 {
10253         sym_anonymous = symbol_table_insert("<anonymous>");
10254
10255         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10256
10257         init_expression_parsers();
10258         obstack_init(&temp_obst);
10259 }
10260
10261 /**
10262  * Terminate the parser.
10263  */
10264 void exit_parser(void)
10265 {
10266         obstack_free(&temp_obst, NULL);
10267 }