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