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 <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "lexer.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "adt/bitfiddle.h"
  45 #include "adt/error.h"
  46 #include "adt/array.h"
  47
  48 //#define PRINT_TOKENS
  49 #define MAX_LOOKAHEAD 1
  50
  51 typedef struct {
  52         entity_t           *old_entity;
  53         symbol_t           *symbol;
  54         entity_namespace_t  namespc;
  55 } stack_entry_t;
  56
  57 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  58 struct declaration_specifiers_t {
  59         source_position_t  source_position;
  60         storage_class_t    storage_class;
  61         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  62         bool               is_inline    : 1;
  63         bool               thread_local : 1;  /**< GCC __thread */
  64         attribute_t       *attributes;        /**< list of attributes */
  65         type_t            *type;
  66 };
  67
  68 /**
  69  * An environment for parsing initializers (and compound literals).
  70  */
  71 typedef struct parse_initializer_env_t {
  72         type_t     *type;   /**< the type of the initializer. In case of an
  73                                  array type with unspecified size this gets
  74                                  adjusted to the actual size. */
  75         entity_t   *entity; /**< the variable that is initialized if any */
  76         bool        must_be_constant;
  77 } parse_initializer_env_t;
  78
  79 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  80
  81 /** The current token. */
  82 static token_t              token;
  83 /** The lookahead ring-buffer. */
  84 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  85 /** Position of the next token in the lookahead buffer. */
  86 static size_t               lookahead_bufpos;
  87 static stack_entry_t       *environment_stack = NULL;
  88 static stack_entry_t       *label_stack       = NULL;
  89 static scope_t             *file_scope        = NULL;
  90 static scope_t             *current_scope     = NULL;
  91 /** Point to the current function declaration if inside a function. */
  92 static function_t          *current_function  = NULL;
  93 static entity_t            *current_entity    = NULL;
  94 static switch_statement_t  *current_switch    = NULL;
  95 static statement_t         *current_loop      = NULL;
  96 static statement_t         *current_parent    = NULL;
  97 static ms_try_statement_t  *current_try       = NULL;
  98 static linkage_kind_t       current_linkage;
  99 static goto_statement_t    *goto_first        = NULL;
 100 static goto_statement_t   **goto_anchor       = NULL;
 101 static label_statement_t   *label_first       = NULL;
 102 static label_statement_t  **label_anchor      = NULL;
 103 /** current translation unit. */
 104 static translation_unit_t  *unit              = NULL;
 105 /** true if we are in an __extension__ context. */
 106 static bool                 in_gcc_extension  = false;
 107 static struct obstack       temp_obst;
 108 static entity_t            *anonymous_entity;
 109 static declaration_t      **incomplete_arrays;
 110 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 111
 112
 113 #define PUSH_CURRENT_ENTITY(entity) \
 114         entity_t *const new_current_entity = (entity); \
 115         entity_t *const old_current_entity = current_entity; \
 116         ((void)(current_entity = new_current_entity))
 117 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 118
 119 #define PUSH_PARENT(stmt) \
 120         statement_t *const new_parent = (stmt); \
 121         statement_t *const old_parent = current_parent; \
 122         ((void)(current_parent = new_parent))
 123 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 124
 125 #define PUSH_SCOPE(scope) \
 126         size_t   const top       = environment_top(); \
 127         scope_t *const new_scope = (scope); \
 128         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 129 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 130 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 131
 132 #define PUSH_EXTENSION() \
 133         (void)0; \
 134         bool const old_gcc_extension = in_gcc_extension; \
 135         while (next_if(T___extension__)) { \
 136                 in_gcc_extension = true; \
 137         } \
 138         do {} while (0)
 139 #define POP_EXTENSION() \
 140         ((void)(in_gcc_extension = old_gcc_extension))
 141
 142 /** special symbol used for anonymous entities. */
 143 static symbol_t *sym_anonymous = NULL;
 144
 145 /** The token anchor set */
 146 static unsigned short token_anchor_set[T_LAST_TOKEN];
 147
 148 /** The current source position. */
 149 #define HERE (&token.base.source_position)
 150
 151 /** true if we are in GCC mode. */
 152 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 153
 154 static statement_t *parse_compound_statement(bool inside_expression_statement);
 155 static statement_t *parse_statement(void);
 156
 157 static expression_t *parse_subexpression(precedence_t);
 158 static expression_t *parse_expression(void);
 159 static type_t       *parse_typename(void);
 160 static void          parse_externals(void);
 161 static void          parse_external(void);
 162
 163 static void parse_compound_type_entries(compound_t *compound_declaration);
 164
 165 static void check_call_argument(type_t          *expected_type,
 166                                                                 call_argument_t *argument, unsigned pos);
 167
 168 typedef enum declarator_flags_t {
 169         DECL_FLAGS_NONE             = 0,
 170         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 171         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 172         DECL_IS_PARAMETER           = 1U << 2
 173 } declarator_flags_t;
 174
 175 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 176                                   declarator_flags_t flags);
 177
 178 static void semantic_comparison(binary_expression_t *expression);
 179
 180 #define STORAGE_CLASSES       \
 181         STORAGE_CLASSES_NO_EXTERN \
 182         case T_extern:
 183
 184 #define STORAGE_CLASSES_NO_EXTERN \
 185         case T_typedef:         \
 186         case T_static:          \
 187         case T_auto:            \
 188         case T_register:        \
 189         case T___thread:
 190
 191 #define TYPE_QUALIFIERS     \
 192         case T_const:           \
 193         case T_restrict:        \
 194         case T_volatile:        \
 195         case T_inline:          \
 196         case T__forceinline:    \
 197         case T___attribute__:
 198
 199 #define COMPLEX_SPECIFIERS  \
 200         case T__Complex:
 201 #define IMAGINARY_SPECIFIERS \
 202         case T__Imaginary:
 203
 204 #define TYPE_SPECIFIERS       \
 205         case T__Bool:             \
 206         case T___builtin_va_list: \
 207         case T___typeof__:        \
 208         case T__declspec:         \
 209         case T_bool:              \
 210         case T_char:              \
 211         case T_double:            \
 212         case T_enum:              \
 213         case T_float:             \
 214         case T_int:               \
 215         case T_long:              \
 216         case T_short:             \
 217         case T_signed:            \
 218         case T_struct:            \
 219         case T_union:             \
 220         case T_unsigned:          \
 221         case T_void:              \
 222         case T_wchar_t:           \
 223         case T__int8:             \
 224         case T__int16:            \
 225         case T__int32:            \
 226         case T__int64:            \
 227         case T__int128:           \
 228         COMPLEX_SPECIFIERS        \
 229         IMAGINARY_SPECIFIERS
 230
 231 #define DECLARATION_START   \
 232         STORAGE_CLASSES         \
 233         TYPE_QUALIFIERS         \
 234         TYPE_SPECIFIERS
 235
 236 #define DECLARATION_START_NO_EXTERN \
 237         STORAGE_CLASSES_NO_EXTERN       \
 238         TYPE_QUALIFIERS                 \
 239         TYPE_SPECIFIERS
 240
 241 #define EXPRESSION_START              \
 242         case '!':                         \
 243         case '&':                         \
 244         case '(':                         \
 245         case '*':                         \
 246         case '+':                         \
 247         case '-':                         \
 248         case '~':                         \
 249         case T_ANDAND:                    \
 250         case T_CHARACTER_CONSTANT:        \
 251         case T_NUMBER:                    \
 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_value_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 static inline void eat(token_kind_t const kind)
 485 {
 486         assert(token.kind == kind);
 487         (void)kind;
 488         next_token();
 489 }
 490
 491 static inline bool next_if(token_kind_t const kind)
 492 {
 493         if (token.kind == kind) {
 494                 eat(kind);
 495                 return true;
 496         } else {
 497                 return false;
 498         }
 499 }
 500
 501 /**
 502  * Return the next token with a given lookahead.
 503  */
 504 static inline const token_t *look_ahead(size_t num)
 505 {
 506         assert(0 < num && num <= MAX_LOOKAHEAD);
 507         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 508         return &lookahead_buffer[pos];
 509 }
 510
 511 /**
 512  * Adds a token type to the token type anchor set (a multi-set).
 513  */
 514 static void add_anchor_token(token_kind_t const token_kind)
 515 {
 516         assert(token_kind < T_LAST_TOKEN);
 517         ++token_anchor_set[token_kind];
 518 }
 519
 520 /**
 521  * Remove a token type from the token type anchor set (a multi-set).
 522  */
 523 static void rem_anchor_token(token_kind_t const token_kind)
 524 {
 525         assert(token_kind < T_LAST_TOKEN);
 526         assert(token_anchor_set[token_kind] != 0);
 527         --token_anchor_set[token_kind];
 528 }
 529
 530 /**
 531  * Eat tokens until a matching token type is found.
 532  */
 533 static void eat_until_matching_token(token_kind_t const type)
 534 {
 535         token_kind_t end_token;
 536         switch (type) {
 537                 case '(': end_token = ')';  break;
 538                 case '{': end_token = '}';  break;
 539                 case '[': end_token = ']';  break;
 540                 default:  end_token = type; break;
 541         }
 542
 543         unsigned parenthesis_count = 0;
 544         unsigned brace_count       = 0;
 545         unsigned bracket_count     = 0;
 546         while (token.kind        != end_token ||
 547                parenthesis_count != 0         ||
 548                brace_count       != 0         ||
 549                bracket_count     != 0) {
 550                 switch (token.kind) {
 551                 case T_EOF: return;
 552                 case '(': ++parenthesis_count; break;
 553                 case '{': ++brace_count;       break;
 554                 case '[': ++bracket_count;     break;
 555
 556                 case ')':
 557                         if (parenthesis_count > 0)
 558                                 --parenthesis_count;
 559                         goto check_stop;
 560
 561                 case '}':
 562                         if (brace_count > 0)
 563                                 --brace_count;
 564                         goto check_stop;
 565
 566                 case ']':
 567                         if (bracket_count > 0)
 568                                 --bracket_count;
 569 check_stop:
 570                         if (token.kind        == end_token &&
 571                             parenthesis_count == 0         &&
 572                             brace_count       == 0         &&
 573                             bracket_count     == 0)
 574                                 return;
 575                         break;
 576
 577                 default:
 578                         break;
 579                 }
 580                 next_token();
 581         }
 582 }
 583
 584 /**
 585  * Eat input tokens until an anchor is found.
 586  */
 587 static void eat_until_anchor(void)
 588 {
 589         while (token_anchor_set[token.kind] == 0) {
 590                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 591                         eat_until_matching_token(token.kind);
 592                 next_token();
 593         }
 594 }
 595
 596 /**
 597  * Eat a whole block from input tokens.
 598  */
 599 static void eat_block(void)
 600 {
 601         eat_until_matching_token('{');
 602         next_if('}');
 603 }
 604
 605 /**
 606  * Report a parse error because an expected token was not found.
 607  */
 608 static
 609 #if defined __GNUC__ && __GNUC__ >= 4
 610 __attribute__((sentinel))
 611 #endif
 612 void parse_error_expected(const char *message, ...)
 613 {
 614         if (message != NULL) {
 615                 errorf(HERE, "%s", message);
 616         }
 617         va_list ap;
 618         va_start(ap, message);
 619         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 620         va_end(ap);
 621 }
 622
 623 /**
 624  * Report an incompatible type.
 625  */
 626 static void type_error_incompatible(const char *msg,
 627                 const source_position_t *source_position, type_t *type1, type_t *type2)
 628 {
 629         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 630                msg, type1, type2);
 631 }
 632
 633 static bool skip_till(token_kind_t const expected, char const *const context)
 634 {
 635         if (UNLIKELY(token.kind != expected)) {
 636                 parse_error_expected(context, expected, NULL);
 637                 add_anchor_token(expected);
 638                 eat_until_anchor();
 639                 rem_anchor_token(expected);
 640                 if (token.kind != expected)
 641                         return false;
 642         }
 643         return true;
 644 }
 645
 646 /**
 647  * Expect the current token is the expected token.
 648  * If not, generate an error and skip until the next anchor.
 649  */
 650 static void expect(token_kind_t const expected)
 651 {
 652         if (skip_till(expected, NULL))
 653                 eat(expected);
 654 }
 655
 656 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 657 {
 658         if (!skip_till(T_IDENTIFIER, context))
 659                 return NULL;
 660         symbol_t *const sym = token.base.symbol;
 661         if (pos)
 662                 *pos = *HERE;
 663         eat(T_IDENTIFIER);
 664         return sym;
 665 }
 666
 667 /**
 668  * Push a given scope on the scope stack and make it the
 669  * current scope
 670  */
 671 static scope_t *scope_push(scope_t *new_scope)
 672 {
 673         if (current_scope != NULL) {
 674                 new_scope->depth = current_scope->depth + 1;
 675         }
 676
 677         scope_t *old_scope = current_scope;
 678         current_scope      = new_scope;
 679         return old_scope;
 680 }
 681
 682 /**
 683  * Pop the current scope from the scope stack.
 684  */
 685 static void scope_pop(scope_t *old_scope)
 686 {
 687         current_scope = old_scope;
 688 }
 689
 690 /**
 691  * Search an entity by its symbol in a given namespace.
 692  */
 693 static entity_t *get_entity(const symbol_t *const symbol,
 694                             namespace_tag_t namespc)
 695 {
 696         entity_t *entity = symbol->entity;
 697         for (; entity != NULL; entity = entity->base.symbol_next) {
 698                 if ((namespace_tag_t)entity->base.namespc == namespc)
 699                         return entity;
 700         }
 701
 702         return NULL;
 703 }
 704
 705 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 706  * possible. */
 707 static entity_t *get_tag(symbol_t const *const symbol,
 708                          entity_kind_tag_t const kind)
 709 {
 710         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 711         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 712                 errorf(HERE,
 713                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 714                                 symbol, &entity->base.source_position);
 715                 entity = NULL;
 716         }
 717         return entity;
 718 }
 719
 720 /**
 721  * pushs an entity on the environment stack and links the corresponding symbol
 722  * it.
 723  */
 724 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 725 {
 726         symbol_t           *symbol  = entity->base.symbol;
 727         entity_namespace_t  namespc = entity->base.namespc;
 728         assert(namespc != 0);
 729
 730         /* replace/add entity into entity list of the symbol */
 731         entity_t **anchor;
 732         entity_t  *iter;
 733         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 734                 iter = *anchor;
 735                 if (iter == NULL)
 736                         break;
 737
 738                 /* replace an entry? */
 739                 if (iter->base.namespc == namespc) {
 740                         entity->base.symbol_next = iter->base.symbol_next;
 741                         break;
 742                 }
 743         }
 744         *anchor = entity;
 745
 746         /* remember old declaration */
 747         stack_entry_t entry;
 748         entry.symbol     = symbol;
 749         entry.old_entity = iter;
 750         entry.namespc    = namespc;
 751         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 752 }
 753
 754 /**
 755  * Push an entity on the environment stack.
 756  */
 757 static void environment_push(entity_t *entity)
 758 {
 759         assert(entity->base.source_position.input_name != NULL);
 760         assert(entity->base.parent_scope != NULL);
 761         stack_push(&environment_stack, entity);
 762 }
 763
 764 /**
 765  * Push a declaration on the global label stack.
 766  *
 767  * @param declaration  the declaration
 768  */
 769 static void label_push(entity_t *label)
 770 {
 771         /* we abuse the parameters scope as parent for the labels */
 772         label->base.parent_scope = &current_function->parameters;
 773         stack_push(&label_stack, label);
 774 }
 775
 776 /**
 777  * pops symbols from the environment stack until @p new_top is the top element
 778  */
 779 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 780 {
 781         stack_entry_t *stack = *stack_ptr;
 782         size_t         top   = ARR_LEN(stack);
 783         size_t         i;
 784
 785         assert(new_top <= top);
 786         if (new_top == top)
 787                 return;
 788
 789         for (i = top; i > new_top; --i) {
 790                 stack_entry_t *entry = &stack[i - 1];
 791
 792                 entity_t           *old_entity = entry->old_entity;
 793                 symbol_t           *symbol     = entry->symbol;
 794                 entity_namespace_t  namespc    = entry->namespc;
 795
 796                 /* replace with old_entity/remove */
 797                 entity_t **anchor;
 798                 entity_t  *iter;
 799                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 800                         iter = *anchor;
 801                         assert(iter != NULL);
 802                         /* replace an entry? */
 803                         if (iter->base.namespc == namespc)
 804                                 break;
 805                 }
 806
 807                 /* restore definition from outer scopes (if there was one) */
 808                 if (old_entity != NULL) {
 809                         old_entity->base.symbol_next = iter->base.symbol_next;
 810                         *anchor                      = old_entity;
 811                 } else {
 812                         /* remove entry from list */
 813                         *anchor = iter->base.symbol_next;
 814                 }
 815         }
 816
 817         ARR_SHRINKLEN(*stack_ptr, new_top);
 818 }
 819
 820 /**
 821  * Pop all entries from the environment stack until the new_top
 822  * is reached.
 823  *
 824  * @param new_top  the new stack top
 825  */
 826 static void environment_pop_to(size_t new_top)
 827 {
 828         stack_pop_to(&environment_stack, new_top);
 829 }
 830
 831 /**
 832  * Pop all entries from the global label stack until the new_top
 833  * is reached.
 834  *
 835  * @param new_top  the new stack top
 836  */
 837 static void label_pop_to(size_t new_top)
 838 {
 839         stack_pop_to(&label_stack, new_top);
 840 }
 841
 842 static atomic_type_kind_t get_akind(const type_t *type)
 843 {
 844         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 845                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 846         return type->atomic.akind;
 847 }
 848
 849 /**
 850  * §6.3.1.1:2  Do integer promotion for a given type.
 851  *
 852  * @param type  the type to promote
 853  * @return the promoted type
 854  */
 855 static type_t *promote_integer(type_t *type)
 856 {
 857         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 858                 type = type_int;
 859
 860         return type;
 861 }
 862
 863 /**
 864  * Check if a given expression represents a null pointer constant.
 865  *
 866  * @param expression  the expression to check
 867  */
 868 static bool is_null_pointer_constant(const expression_t *expression)
 869 {
 870         /* skip void* cast */
 871         if (expression->kind == EXPR_UNARY_CAST) {
 872                 type_t *const type = skip_typeref(expression->base.type);
 873                 if (types_compatible(type, type_void_ptr))
 874                         expression = expression->unary.value;
 875         }
 876
 877         type_t *const type = skip_typeref(expression->base.type);
 878         if (!is_type_integer(type))
 879                 return false;
 880         switch (is_constant_expression(expression)) {
 881                 case EXPR_CLASS_ERROR:    return true;
 882                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 883                 default:                  return false;
 884         }
 885 }
 886
 887 /**
 888  * Create an implicit cast expression.
 889  *
 890  * @param expression  the expression to cast
 891  * @param dest_type   the destination type
 892  */
 893 static expression_t *create_implicit_cast(expression_t *expression,
 894                                           type_t *dest_type)
 895 {
 896         type_t *const source_type = expression->base.type;
 897
 898         if (source_type == dest_type)
 899                 return expression;
 900
 901         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 902         cast->unary.value   = expression;
 903         cast->base.type     = dest_type;
 904         cast->base.implicit = true;
 905
 906         return cast;
 907 }
 908
 909 typedef enum assign_error_t {
 910         ASSIGN_SUCCESS,
 911         ASSIGN_ERROR_INCOMPATIBLE,
 912         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 913         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 914         ASSIGN_WARNING_POINTER_FROM_INT,
 915         ASSIGN_WARNING_INT_FROM_POINTER
 916 } assign_error_t;
 917
 918 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)
 919 {
 920         type_t *const orig_type_right = right->base.type;
 921         type_t *const type_left       = skip_typeref(orig_type_left);
 922         type_t *const type_right      = skip_typeref(orig_type_right);
 923
 924         switch (error) {
 925         case ASSIGN_SUCCESS:
 926                 return;
 927         case ASSIGN_ERROR_INCOMPATIBLE:
 928                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 929                 return;
 930
 931         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 932                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 933                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 934
 935                 /* the left type has all qualifiers from the right type */
 936                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 937                 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);
 938                 return;
 939         }
 940
 941         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 942                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 943                 return;
 944
 945         case ASSIGN_WARNING_POINTER_FROM_INT:
 946                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 947                 return;
 948
 949         case ASSIGN_WARNING_INT_FROM_POINTER:
 950                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 951                 return;
 952
 953         default:
 954                 panic("invalid error value");
 955         }
 956 }
 957
 958 /** Implements the rules from §6.5.16.1 */
 959 static assign_error_t semantic_assign(type_t *orig_type_left,
 960                                       const expression_t *const right)
 961 {
 962         type_t *const orig_type_right = right->base.type;
 963         type_t *const type_left       = skip_typeref(orig_type_left);
 964         type_t *const type_right      = skip_typeref(orig_type_right);
 965
 966         if (is_type_pointer(type_left)) {
 967                 if (is_null_pointer_constant(right)) {
 968                         return ASSIGN_SUCCESS;
 969                 } else if (is_type_pointer(type_right)) {
 970                         type_t *points_to_left
 971                                 = skip_typeref(type_left->pointer.points_to);
 972                         type_t *points_to_right
 973                                 = skip_typeref(type_right->pointer.points_to);
 974                         assign_error_t res = ASSIGN_SUCCESS;
 975
 976                         /* the left type has all qualifiers from the right type */
 977                         unsigned missing_qualifiers
 978                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 979                         if (missing_qualifiers != 0) {
 980                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 981                         }
 982
 983                         points_to_left  = get_unqualified_type(points_to_left);
 984                         points_to_right = get_unqualified_type(points_to_right);
 985
 986                         if (is_type_void(points_to_left))
 987                                 return res;
 988
 989                         if (is_type_void(points_to_right)) {
 990                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 991                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 992                         }
 993
 994                         if (!types_compatible(points_to_left, points_to_right)) {
 995                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 996                         }
 997
 998                         return res;
 999                 } else if (is_type_integer(type_right)) {
1000                         return ASSIGN_WARNING_POINTER_FROM_INT;
1001                 }
1002         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1003                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1004                                 && is_type_pointer(type_right))) {
1005                 return ASSIGN_SUCCESS;
1006         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1007                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1008                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1009                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1010                         return ASSIGN_SUCCESS;
1011                 }
1012         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1013                 return ASSIGN_WARNING_INT_FROM_POINTER;
1014         }
1015
1016         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1017                 return ASSIGN_SUCCESS;
1018
1019         return ASSIGN_ERROR_INCOMPATIBLE;
1020 }
1021
1022 static expression_t *parse_constant_expression(void)
1023 {
1024         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1025
1026         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1027                 errorf(&result->base.source_position,
1028                        "expression '%E' is not constant", result);
1029         }
1030
1031         return result;
1032 }
1033
1034 static expression_t *parse_assignment_expression(void)
1035 {
1036         return parse_subexpression(PREC_ASSIGNMENT);
1037 }
1038
1039 static void append_string(string_t const *const s)
1040 {
1041         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1042          * possible, because other tokens are grown there alongside. */
1043         obstack_grow(&ast_obstack, s->begin, s->size);
1044 }
1045
1046 static string_t finish_string(string_encoding_t const enc)
1047 {
1048         obstack_1grow(&ast_obstack, '\0');
1049         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1050         char const *const string = obstack_finish(&ast_obstack);
1051         return (string_t){ string, size, enc };
1052 }
1053
1054 static string_t concat_string_literals(void)
1055 {
1056         assert(token.kind == T_STRING_LITERAL);
1057
1058         string_t result;
1059         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1060                 append_string(&token.literal.string);
1061                 eat(T_STRING_LITERAL);
1062                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1063                 string_encoding_t enc = token.literal.string.encoding;
1064                 do {
1065                         if (token.literal.string.encoding != STRING_ENCODING_CHAR) {
1066                                 enc = token.literal.string.encoding;
1067                         }
1068                         append_string(&token.literal.string);
1069                         eat(T_STRING_LITERAL);
1070                 } while (token.kind == T_STRING_LITERAL);
1071                 result = finish_string(enc);
1072         } else {
1073                 result = token.literal.string;
1074                 eat(T_STRING_LITERAL);
1075         }
1076
1077         return result;
1078 }
1079
1080 static string_t parse_string_literals(char const *const context)
1081 {
1082         if (!skip_till(T_STRING_LITERAL, context))
1083                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1084
1085         source_position_t const pos = *HERE;
1086         string_t          const res = concat_string_literals();
1087
1088         if (res.encoding != STRING_ENCODING_CHAR) {
1089                 errorf(&pos, "expected plain string literal, got wide string literal");
1090         }
1091
1092         return res;
1093 }
1094
1095 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1096 {
1097         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1098         attribute->kind            = kind;
1099         attribute->source_position = *HERE;
1100         return attribute;
1101 }
1102
1103 /**
1104  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1105  *
1106  *  attribute:
1107  *    __attribute__ ( ( attribute-list ) )
1108  *
1109  *  attribute-list:
1110  *    attrib
1111  *    attribute_list , attrib
1112  *
1113  *  attrib:
1114  *    empty
1115  *    any-word
1116  *    any-word ( identifier )
1117  *    any-word ( identifier , nonempty-expr-list )
1118  *    any-word ( expr-list )
1119  *
1120  *  where the "identifier" must not be declared as a type, and
1121  *  "any-word" may be any identifier (including one declared as a
1122  *  type), a reserved word storage class specifier, type specifier or
1123  *  type qualifier.  ??? This still leaves out most reserved keywords
1124  *  (following the old parser), shouldn't we include them, and why not
1125  *  allow identifiers declared as types to start the arguments?
1126  *
1127  *  Matze: this all looks confusing and little systematic, so we're even less
1128  *  strict and parse any list of things which are identifiers or
1129  *  (assignment-)expressions.
1130  */
1131 static attribute_argument_t *parse_attribute_arguments(void)
1132 {
1133         attribute_argument_t  *first  = NULL;
1134         attribute_argument_t **anchor = &first;
1135         if (token.kind != ')') do {
1136                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1137
1138                 /* is it an identifier */
1139                 if (token.kind == T_IDENTIFIER
1140                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1141                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1142                         argument->v.symbol = token.base.symbol;
1143                         eat(T_IDENTIFIER);
1144                 } else {
1145                         /* must be an expression */
1146                         expression_t *expression = parse_assignment_expression();
1147
1148                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1149                         argument->v.expression = expression;
1150                 }
1151
1152                 /* append argument */
1153                 *anchor = argument;
1154                 anchor  = &argument->next;
1155         } while (next_if(','));
1156         expect(')');
1157         return first;
1158 }
1159
1160 static attribute_t *parse_attribute_asm(void)
1161 {
1162         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1163         eat(T_asm);
1164         expect('(');
1165         attribute->a.arguments = parse_attribute_arguments();
1166         return attribute;
1167 }
1168
1169 static attribute_t *parse_attribute_gnu_single(void)
1170 {
1171         /* parse "any-word" */
1172         symbol_t *const symbol = token.base.symbol;
1173         if (symbol == NULL) {
1174                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1175                 return NULL;
1176         }
1177
1178         attribute_kind_t  kind;
1179         char const *const name = symbol->string;
1180         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1181                 if (kind > ATTRIBUTE_GNU_LAST) {
1182                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1183                         /* TODO: we should still save the attribute in the list... */
1184                         kind = ATTRIBUTE_UNKNOWN;
1185                         break;
1186                 }
1187
1188                 const char *attribute_name = get_attribute_name(kind);
1189                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1190                         break;
1191         }
1192
1193         attribute_t *attribute = allocate_attribute_zero(kind);
1194         next_token();
1195
1196         /* parse arguments */
1197         if (next_if('('))
1198                 attribute->a.arguments = parse_attribute_arguments();
1199
1200         return attribute;
1201 }
1202
1203 static attribute_t *parse_attribute_gnu(void)
1204 {
1205         attribute_t  *first  = NULL;
1206         attribute_t **anchor = &first;
1207
1208         eat(T___attribute__);
1209         add_anchor_token(')');
1210         add_anchor_token(',');
1211         expect('(');
1212         expect('(');
1213
1214         if (token.kind != ')') do {
1215                 attribute_t *attribute = parse_attribute_gnu_single();
1216                 if (attribute) {
1217                         *anchor = attribute;
1218                         anchor  = &attribute->next;
1219                 }
1220         } while (next_if(','));
1221         rem_anchor_token(',');
1222         rem_anchor_token(')');
1223
1224         expect(')');
1225         expect(')');
1226         return first;
1227 }
1228
1229 /** Parse attributes. */
1230 static attribute_t *parse_attributes(attribute_t *first)
1231 {
1232         attribute_t **anchor = &first;
1233         for (;;) {
1234                 while (*anchor != NULL)
1235                         anchor = &(*anchor)->next;
1236
1237                 attribute_t *attribute;
1238                 switch (token.kind) {
1239                 case T___attribute__:
1240                         attribute = parse_attribute_gnu();
1241                         if (attribute == NULL)
1242                                 continue;
1243                         break;
1244
1245                 case T_asm:
1246                         attribute = parse_attribute_asm();
1247                         break;
1248
1249                 case T_cdecl:
1250                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1251                         eat(T_cdecl);
1252                         break;
1253
1254                 case T__fastcall:
1255                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1256                         eat(T__fastcall);
1257                         break;
1258
1259                 case T__forceinline:
1260                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1261                         eat(T__forceinline);
1262                         break;
1263
1264                 case T__stdcall:
1265                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1266                         eat(T__stdcall);
1267                         break;
1268
1269                 case T___thiscall:
1270                         /* TODO record modifier */
1271                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1272                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1273                         eat(T___thiscall);
1274                         break;
1275
1276                 default:
1277                         return first;
1278                 }
1279
1280                 *anchor = attribute;
1281                 anchor  = &attribute->next;
1282         }
1283 }
1284
1285 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1286
1287 static entity_t *determine_lhs_ent(expression_t *const expr,
1288                                    entity_t *lhs_ent)
1289 {
1290         switch (expr->kind) {
1291                 case EXPR_REFERENCE: {
1292                         entity_t *const entity = expr->reference.entity;
1293                         /* we should only find variables as lvalues... */
1294                         if (entity->base.kind != ENTITY_VARIABLE
1295                                         && entity->base.kind != ENTITY_PARAMETER)
1296                                 return NULL;
1297
1298                         return entity;
1299                 }
1300
1301                 case EXPR_ARRAY_ACCESS: {
1302                         expression_t *const ref = expr->array_access.array_ref;
1303                         entity_t     *      ent = NULL;
1304                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1305                                 ent     = determine_lhs_ent(ref, lhs_ent);
1306                                 lhs_ent = ent;
1307                         } else {
1308                                 mark_vars_read(ref, lhs_ent);
1309                         }
1310                         mark_vars_read(expr->array_access.index, lhs_ent);
1311                         return ent;
1312                 }
1313
1314                 case EXPR_SELECT: {
1315                         mark_vars_read(expr->select.compound, lhs_ent);
1316                         if (is_type_compound(skip_typeref(expr->base.type)))
1317                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1318                         return NULL;
1319                 }
1320
1321                 case EXPR_UNARY_DEREFERENCE: {
1322                         expression_t *const val = expr->unary.value;
1323                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1324                                 /* *&x is a NOP */
1325                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1326                         } else {
1327                                 mark_vars_read(val, NULL);
1328                                 return NULL;
1329                         }
1330                 }
1331
1332                 default:
1333                         mark_vars_read(expr, NULL);
1334                         return NULL;
1335         }
1336 }
1337
1338 #define ENT_ANY ((entity_t*)-1)
1339
1340 /**
1341  * Mark declarations, which are read.  This is used to detect variables, which
1342  * are never read.
1343  * Example:
1344  * x = x + 1;
1345  *   x is not marked as "read", because it is only read to calculate its own new
1346  *   value.
1347  *
1348  * x += y; y += x;
1349  *   x and y are not detected as "not read", because multiple variables are
1350  *   involved.
1351  */
1352 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1353 {
1354         switch (expr->kind) {
1355                 case EXPR_REFERENCE: {
1356                         entity_t *const entity = expr->reference.entity;
1357                         if (entity->kind != ENTITY_VARIABLE
1358                                         && entity->kind != ENTITY_PARAMETER)
1359                                 return;
1360
1361                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1362                                 entity->variable.read = true;
1363                         }
1364                         return;
1365                 }
1366
1367                 case EXPR_CALL:
1368                         // TODO respect pure/const
1369                         mark_vars_read(expr->call.function, NULL);
1370                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1371                                 mark_vars_read(arg->expression, NULL);
1372                         }
1373                         return;
1374
1375                 case EXPR_CONDITIONAL:
1376                         // TODO lhs_decl should depend on whether true/false have an effect
1377                         mark_vars_read(expr->conditional.condition, NULL);
1378                         if (expr->conditional.true_expression != NULL)
1379                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1380                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1381                         return;
1382
1383                 case EXPR_SELECT:
1384                         if (lhs_ent == ENT_ANY
1385                                         && !is_type_compound(skip_typeref(expr->base.type)))
1386                                 lhs_ent = NULL;
1387                         mark_vars_read(expr->select.compound, lhs_ent);
1388                         return;
1389
1390                 case EXPR_ARRAY_ACCESS: {
1391                         mark_vars_read(expr->array_access.index, lhs_ent);
1392                         expression_t *const ref = expr->array_access.array_ref;
1393                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1394                                 if (lhs_ent == ENT_ANY)
1395                                         lhs_ent = NULL;
1396                         }
1397                         mark_vars_read(ref, lhs_ent);
1398                         return;
1399                 }
1400
1401                 case EXPR_VA_ARG:
1402                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1403                         return;
1404
1405                 case EXPR_VA_COPY:
1406                         mark_vars_read(expr->va_copye.src, lhs_ent);
1407                         return;
1408
1409                 case EXPR_UNARY_CAST:
1410                         /* Special case: Use void cast to mark a variable as "read" */
1411                         if (is_type_void(skip_typeref(expr->base.type)))
1412                                 lhs_ent = NULL;
1413                         goto unary;
1414
1415
1416                 case EXPR_UNARY_THROW:
1417                         if (expr->unary.value == NULL)
1418                                 return;
1419                         /* FALLTHROUGH */
1420                 case EXPR_UNARY_DEREFERENCE:
1421                 case EXPR_UNARY_DELETE:
1422                 case EXPR_UNARY_DELETE_ARRAY:
1423                         if (lhs_ent == ENT_ANY)
1424                                 lhs_ent = NULL;
1425                         goto unary;
1426
1427                 case EXPR_UNARY_NEGATE:
1428                 case EXPR_UNARY_PLUS:
1429                 case EXPR_UNARY_BITWISE_NEGATE:
1430                 case EXPR_UNARY_NOT:
1431                 case EXPR_UNARY_TAKE_ADDRESS:
1432                 case EXPR_UNARY_POSTFIX_INCREMENT:
1433                 case EXPR_UNARY_POSTFIX_DECREMENT:
1434                 case EXPR_UNARY_PREFIX_INCREMENT:
1435                 case EXPR_UNARY_PREFIX_DECREMENT:
1436                 case EXPR_UNARY_ASSUME:
1437 unary:
1438                         mark_vars_read(expr->unary.value, lhs_ent);
1439                         return;
1440
1441                 case EXPR_BINARY_ADD:
1442                 case EXPR_BINARY_SUB:
1443                 case EXPR_BINARY_MUL:
1444                 case EXPR_BINARY_DIV:
1445                 case EXPR_BINARY_MOD:
1446                 case EXPR_BINARY_EQUAL:
1447                 case EXPR_BINARY_NOTEQUAL:
1448                 case EXPR_BINARY_LESS:
1449                 case EXPR_BINARY_LESSEQUAL:
1450                 case EXPR_BINARY_GREATER:
1451                 case EXPR_BINARY_GREATEREQUAL:
1452                 case EXPR_BINARY_BITWISE_AND:
1453                 case EXPR_BINARY_BITWISE_OR:
1454                 case EXPR_BINARY_BITWISE_XOR:
1455                 case EXPR_BINARY_LOGICAL_AND:
1456                 case EXPR_BINARY_LOGICAL_OR:
1457                 case EXPR_BINARY_SHIFTLEFT:
1458                 case EXPR_BINARY_SHIFTRIGHT:
1459                 case EXPR_BINARY_COMMA:
1460                 case EXPR_BINARY_ISGREATER:
1461                 case EXPR_BINARY_ISGREATEREQUAL:
1462                 case EXPR_BINARY_ISLESS:
1463                 case EXPR_BINARY_ISLESSEQUAL:
1464                 case EXPR_BINARY_ISLESSGREATER:
1465                 case EXPR_BINARY_ISUNORDERED:
1466                         mark_vars_read(expr->binary.left,  lhs_ent);
1467                         mark_vars_read(expr->binary.right, lhs_ent);
1468                         return;
1469
1470                 case EXPR_BINARY_ASSIGN:
1471                 case EXPR_BINARY_MUL_ASSIGN:
1472                 case EXPR_BINARY_DIV_ASSIGN:
1473                 case EXPR_BINARY_MOD_ASSIGN:
1474                 case EXPR_BINARY_ADD_ASSIGN:
1475                 case EXPR_BINARY_SUB_ASSIGN:
1476                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1477                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1478                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1479                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1480                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1481                         if (lhs_ent == ENT_ANY)
1482                                 lhs_ent = NULL;
1483                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1484                         mark_vars_read(expr->binary.right, lhs_ent);
1485                         return;
1486                 }
1487
1488                 case EXPR_VA_START:
1489                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1490                         return;
1491
1492                 case EXPR_LITERAL_CASES:
1493                 case EXPR_LITERAL_CHARACTER:
1494                 case EXPR_ERROR:
1495                 case EXPR_STRING_LITERAL:
1496                 case EXPR_COMPOUND_LITERAL: // TODO init?
1497                 case EXPR_SIZEOF:
1498                 case EXPR_CLASSIFY_TYPE:
1499                 case EXPR_ALIGNOF:
1500                 case EXPR_FUNCNAME:
1501                 case EXPR_BUILTIN_CONSTANT_P:
1502                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1503                 case EXPR_OFFSETOF:
1504                 case EXPR_STATEMENT: // TODO
1505                 case EXPR_LABEL_ADDRESS:
1506                 case EXPR_ENUM_CONSTANT:
1507                         return;
1508         }
1509
1510         panic("unhandled expression");
1511 }
1512
1513 static designator_t *parse_designation(void)
1514 {
1515         designator_t  *result = NULL;
1516         designator_t **anchor = &result;
1517
1518         for (;;) {
1519                 designator_t *designator;
1520                 switch (token.kind) {
1521                 case '[':
1522                         designator = allocate_ast_zero(sizeof(designator[0]));
1523                         designator->source_position = *HERE;
1524                         eat('[');
1525                         add_anchor_token(']');
1526                         designator->array_index = parse_constant_expression();
1527                         rem_anchor_token(']');
1528                         expect(']');
1529                         break;
1530                 case '.':
1531                         designator = allocate_ast_zero(sizeof(designator[0]));
1532                         designator->source_position = *HERE;
1533                         eat('.');
1534                         designator->symbol = expect_identifier("while parsing designator", NULL);
1535                         if (!designator->symbol)
1536                                 return NULL;
1537                         break;
1538                 default:
1539                         expect('=');
1540                         return result;
1541                 }
1542
1543                 assert(designator != NULL);
1544                 *anchor = designator;
1545                 anchor  = &designator->next;
1546         }
1547 }
1548
1549 /**
1550  * Build an initializer from a given expression.
1551  */
1552 static initializer_t *initializer_from_expression(type_t *orig_type,
1553                                                   expression_t *expression)
1554 {
1555         /* TODO check that expression is a constant expression */
1556
1557         type_t *const type = skip_typeref(orig_type);
1558
1559         /* §6.7.8.14/15 char array may be initialized by string literals */
1560         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1561                 array_type_t *const array_type   = &type->array;
1562                 type_t       *const element_type = skip_typeref(array_type->element_type);
1563                 switch (expression->string_literal.value.encoding) {
1564                 case STRING_ENCODING_CHAR: {
1565                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1566                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1567                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1568                                 goto make_string_init;
1569                         }
1570                         break;
1571                 }
1572
1573                 case STRING_ENCODING_WIDE: {
1574                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1575                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1576 make_string_init:;
1577                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1578                                 init->value.value = expression;
1579                                 return init;
1580                         }
1581                         break;
1582                 }
1583                 }
1584         }
1585
1586         assign_error_t error = semantic_assign(type, expression);
1587         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1588                 return NULL;
1589         report_assign_error(error, type, expression, "initializer",
1590                             &expression->base.source_position);
1591
1592         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1593         result->value.value = create_implicit_cast(expression, type);
1594
1595         return result;
1596 }
1597
1598 /**
1599  * Parses an scalar initializer.
1600  *
1601  * §6.7.8.11; eat {} without warning
1602  */
1603 static initializer_t *parse_scalar_initializer(type_t *type,
1604                                                bool must_be_constant)
1605 {
1606         /* there might be extra {} hierarchies */
1607         int braces = 0;
1608         if (token.kind == '{') {
1609                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1610                 do {
1611                         eat('{');
1612                         ++braces;
1613                 } while (token.kind == '{');
1614         }
1615
1616         expression_t *expression = parse_assignment_expression();
1617         mark_vars_read(expression, NULL);
1618         if (must_be_constant && !is_linker_constant(expression)) {
1619                 errorf(&expression->base.source_position,
1620                        "initialisation expression '%E' is not constant",
1621                        expression);
1622         }
1623
1624         initializer_t *initializer = initializer_from_expression(type, expression);
1625
1626         if (initializer == NULL) {
1627                 errorf(&expression->base.source_position,
1628                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1629                        expression, expression->base.type, type);
1630                 /* TODO */
1631                 return NULL;
1632         }
1633
1634         bool additional_warning_displayed = false;
1635         while (braces > 0) {
1636                 next_if(',');
1637                 if (token.kind != '}') {
1638                         if (!additional_warning_displayed) {
1639                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1640                                 additional_warning_displayed = true;
1641                         }
1642                 }
1643                 eat_block();
1644                 braces--;
1645         }
1646
1647         return initializer;
1648 }
1649
1650 /**
1651  * An entry in the type path.
1652  */
1653 typedef struct type_path_entry_t type_path_entry_t;
1654 struct type_path_entry_t {
1655         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1656         union {
1657                 size_t         index;          /**< For array types: the current index. */
1658                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1659         } v;
1660 };
1661
1662 /**
1663  * A type path expression a position inside compound or array types.
1664  */
1665 typedef struct type_path_t type_path_t;
1666 struct type_path_t {
1667         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1668         type_t            *top_type;     /**< type of the element the path points */
1669         size_t             max_index;    /**< largest index in outermost array */
1670 };
1671
1672 /**
1673  * Prints a type path for debugging.
1674  */
1675 static __attribute__((unused)) void debug_print_type_path(
1676                 const type_path_t *path)
1677 {
1678         size_t len = ARR_LEN(path->path);
1679
1680         for (size_t i = 0; i < len; ++i) {
1681                 const type_path_entry_t *entry = & path->path[i];
1682
1683                 type_t *type = skip_typeref(entry->type);
1684                 if (is_type_compound(type)) {
1685                         /* in gcc mode structs can have no members */
1686                         if (entry->v.compound_entry == NULL) {
1687                                 assert(i == len-1);
1688                                 continue;
1689                         }
1690                         fprintf(stderr, ".%s",
1691                                 entry->v.compound_entry->base.symbol->string);
1692                 } else if (is_type_array(type)) {
1693                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1694                 } else {
1695                         fprintf(stderr, "-INVALID-");
1696                 }
1697         }
1698         if (path->top_type != NULL) {
1699                 fprintf(stderr, "  (");
1700                 print_type(path->top_type);
1701                 fprintf(stderr, ")");
1702         }
1703 }
1704
1705 /**
1706  * Return the top type path entry, ie. in a path
1707  * (type).a.b returns the b.
1708  */
1709 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1710 {
1711         size_t len = ARR_LEN(path->path);
1712         assert(len > 0);
1713         return &path->path[len-1];
1714 }
1715
1716 /**
1717  * Enlarge the type path by an (empty) element.
1718  */
1719 static type_path_entry_t *append_to_type_path(type_path_t *path)
1720 {
1721         size_t len = ARR_LEN(path->path);
1722         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1723
1724         type_path_entry_t *result = & path->path[len];
1725         memset(result, 0, sizeof(result[0]));
1726         return result;
1727 }
1728
1729 /**
1730  * Descending into a sub-type. Enter the scope of the current top_type.
1731  */
1732 static void descend_into_subtype(type_path_t *path)
1733 {
1734         type_t *orig_top_type = path->top_type;
1735         type_t *top_type      = skip_typeref(orig_top_type);
1736
1737         type_path_entry_t *top = append_to_type_path(path);
1738         top->type              = top_type;
1739
1740         if (is_type_compound(top_type)) {
1741                 compound_t *const compound = top_type->compound.compound;
1742                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1743
1744                 if (entry != NULL) {
1745                         top->v.compound_entry = &entry->declaration;
1746                         path->top_type = entry->declaration.type;
1747                 } else {
1748                         path->top_type = NULL;
1749                 }
1750         } else if (is_type_array(top_type)) {
1751                 top->v.index   = 0;
1752                 path->top_type = top_type->array.element_type;
1753         } else {
1754                 assert(!is_type_valid(top_type));
1755         }
1756 }
1757
1758 /**
1759  * Pop an entry from the given type path, ie. returning from
1760  * (type).a.b to (type).a
1761  */
1762 static void ascend_from_subtype(type_path_t *path)
1763 {
1764         type_path_entry_t *top = get_type_path_top(path);
1765
1766         path->top_type = top->type;
1767
1768         size_t len = ARR_LEN(path->path);
1769         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1770 }
1771
1772 /**
1773  * Pop entries from the given type path until the given
1774  * path level is reached.
1775  */
1776 static void ascend_to(type_path_t *path, size_t top_path_level)
1777 {
1778         size_t len = ARR_LEN(path->path);
1779
1780         while (len > top_path_level) {
1781                 ascend_from_subtype(path);
1782                 len = ARR_LEN(path->path);
1783         }
1784 }
1785
1786 static bool walk_designator(type_path_t *path, const designator_t *designator,
1787                             bool used_in_offsetof)
1788 {
1789         for (; designator != NULL; designator = designator->next) {
1790                 type_path_entry_t *top       = get_type_path_top(path);
1791                 type_t            *orig_type = top->type;
1792
1793                 type_t *type = skip_typeref(orig_type);
1794
1795                 if (designator->symbol != NULL) {
1796                         symbol_t *symbol = designator->symbol;
1797                         if (!is_type_compound(type)) {
1798                                 if (is_type_valid(type)) {
1799                                         errorf(&designator->source_position,
1800                                                "'.%Y' designator used for non-compound type '%T'",
1801                                                symbol, orig_type);
1802                                 }
1803
1804                                 top->type             = type_error_type;
1805                                 top->v.compound_entry = NULL;
1806                                 orig_type             = type_error_type;
1807                         } else {
1808                                 compound_t *compound = type->compound.compound;
1809                                 entity_t   *iter     = compound->members.entities;
1810                                 for (; iter != NULL; iter = iter->base.next) {
1811                                         if (iter->base.symbol == symbol) {
1812                                                 break;
1813                                         }
1814                                 }
1815                                 if (iter == NULL) {
1816                                         errorf(&designator->source_position,
1817                                                "'%T' has no member named '%Y'", orig_type, symbol);
1818                                         return false;
1819                                 }
1820                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1821                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1822                                         errorf(&designator->source_position,
1823                                                    "offsetof designator '%Y' must not specify bitfield",
1824                                                    symbol);
1825                                         return false;
1826                                 }
1827
1828                                 top->type             = orig_type;
1829                                 top->v.compound_entry = &iter->declaration;
1830                                 orig_type             = iter->declaration.type;
1831                         }
1832                 } else {
1833                         expression_t *array_index = designator->array_index;
1834                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1835                                 return true;
1836
1837                         if (!is_type_array(type)) {
1838                                 if (is_type_valid(type)) {
1839                                         errorf(&designator->source_position,
1840                                                "[%E] designator used for non-array type '%T'",
1841                                                array_index, orig_type);
1842                                 }
1843                                 return false;
1844                         }
1845
1846                         long index = fold_constant_to_int(array_index);
1847                         if (!used_in_offsetof) {
1848                                 if (index < 0) {
1849                                         errorf(&designator->source_position,
1850                                                "array index [%E] must be positive", array_index);
1851                                 } else if (type->array.size_constant) {
1852                                         long array_size = type->array.size;
1853                                         if (index >= array_size) {
1854                                                 errorf(&designator->source_position,
1855                                                        "designator [%E] (%d) exceeds array size %d",
1856                                                        array_index, index, array_size);
1857                                         }
1858                                 }
1859                         }
1860
1861                         top->type    = orig_type;
1862                         top->v.index = (size_t) index;
1863                         orig_type    = type->array.element_type;
1864                 }
1865                 path->top_type = orig_type;
1866
1867                 if (designator->next != NULL) {
1868                         descend_into_subtype(path);
1869                 }
1870         }
1871         return true;
1872 }
1873
1874 static void advance_current_object(type_path_t *path, size_t top_path_level)
1875 {
1876         type_path_entry_t *top = get_type_path_top(path);
1877
1878         type_t *type = skip_typeref(top->type);
1879         if (is_type_union(type)) {
1880                 /* in unions only the first element is initialized */
1881                 top->v.compound_entry = NULL;
1882         } else if (is_type_struct(type)) {
1883                 declaration_t *entry = top->v.compound_entry;
1884
1885                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1886                 if (next_entity != NULL) {
1887                         assert(is_declaration(next_entity));
1888                         entry = &next_entity->declaration;
1889                 } else {
1890                         entry = NULL;
1891                 }
1892
1893                 top->v.compound_entry = entry;
1894                 if (entry != NULL) {
1895                         path->top_type = entry->type;
1896                         return;
1897                 }
1898         } else if (is_type_array(type)) {
1899                 assert(is_type_array(type));
1900
1901                 top->v.index++;
1902
1903                 if (!type->array.size_constant || top->v.index < type->array.size) {
1904                         return;
1905                 }
1906         } else {
1907                 assert(!is_type_valid(type));
1908                 return;
1909         }
1910
1911         /* we're past the last member of the current sub-aggregate, try if we
1912          * can ascend in the type hierarchy and continue with another subobject */
1913         size_t len = ARR_LEN(path->path);
1914
1915         if (len > top_path_level) {
1916                 ascend_from_subtype(path);
1917                 advance_current_object(path, top_path_level);
1918         } else {
1919                 path->top_type = NULL;
1920         }
1921 }
1922
1923 /**
1924  * skip any {...} blocks until a closing bracket is reached.
1925  */
1926 static void skip_initializers(void)
1927 {
1928         next_if('{');
1929
1930         while (token.kind != '}') {
1931                 if (token.kind == T_EOF)
1932                         return;
1933                 if (token.kind == '{') {
1934                         eat_block();
1935                         continue;
1936                 }
1937                 next_token();
1938         }
1939 }
1940
1941 static initializer_t *create_empty_initializer(void)
1942 {
1943         static initializer_t empty_initializer
1944                 = { .list = { { INITIALIZER_LIST }, 0 } };
1945         return &empty_initializer;
1946 }
1947
1948 /**
1949  * Parse a part of an initialiser for a struct or union,
1950  */
1951 static initializer_t *parse_sub_initializer(type_path_t *path,
1952                 type_t *outer_type, size_t top_path_level,
1953                 parse_initializer_env_t *env)
1954 {
1955         if (token.kind == '}') {
1956                 /* empty initializer */
1957                 return create_empty_initializer();
1958         }
1959
1960         type_t *orig_type = path->top_type;
1961         type_t *type      = NULL;
1962
1963         if (orig_type == NULL) {
1964                 /* We are initializing an empty compound. */
1965         } else {
1966                 type = skip_typeref(orig_type);
1967         }
1968
1969         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1970
1971         while (true) {
1972                 designator_t *designator = NULL;
1973                 if (token.kind == '.' || token.kind == '[') {
1974                         designator = parse_designation();
1975                         goto finish_designator;
1976                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1977                         /* GNU-style designator ("identifier: value") */
1978                         designator = allocate_ast_zero(sizeof(designator[0]));
1979                         designator->source_position = *HERE;
1980                         designator->symbol          = token.base.symbol;
1981                         eat(T_IDENTIFIER);
1982                         eat(':');
1983
1984 finish_designator:
1985                         /* reset path to toplevel, evaluate designator from there */
1986                         ascend_to(path, top_path_level);
1987                         if (!walk_designator(path, designator, false)) {
1988                                 /* can't continue after designation error */
1989                                 goto end_error;
1990                         }
1991
1992                         initializer_t *designator_initializer
1993                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1994                         designator_initializer->designator.designator = designator;
1995                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1996
1997                         orig_type = path->top_type;
1998                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
1999                 }
2000
2001                 initializer_t *sub;
2002
2003                 if (token.kind == '{') {
2004                         if (type != NULL && is_type_scalar(type)) {
2005                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2006                         } else {
2007                                 if (type == NULL) {
2008                                         if (env->entity != NULL) {
2009                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2010                                         } else {
2011                                                 errorf(HERE, "extra brace group at end of initializer");
2012                                         }
2013                                         eat('{');
2014                                 } else {
2015                                         eat('{');
2016                                         descend_into_subtype(path);
2017                                 }
2018
2019                                 add_anchor_token('}');
2020                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2021                                                             env);
2022                                 rem_anchor_token('}');
2023
2024                                 expect('}');
2025
2026                                 if (!type)
2027                                         goto error_parse_next;
2028
2029                                 ascend_from_subtype(path);
2030                         }
2031                 } else {
2032                         /* must be an expression */
2033                         expression_t *expression = parse_assignment_expression();
2034                         mark_vars_read(expression, NULL);
2035
2036                         if (env->must_be_constant && !is_linker_constant(expression)) {
2037                                 errorf(&expression->base.source_position,
2038                                        "Initialisation expression '%E' is not constant",
2039                                        expression);
2040                         }
2041
2042                         if (type == NULL) {
2043                                 /* we are already outside, ... */
2044                                 if (outer_type == NULL)
2045                                         goto error_parse_next;
2046                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2047                                 if (is_type_compound(outer_type_skip) &&
2048                                                 !outer_type_skip->compound.compound->complete) {
2049                                         goto error_parse_next;
2050                                 }
2051
2052                                 source_position_t const* const pos = &expression->base.source_position;
2053                                 if (env->entity != NULL) {
2054                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2055                                 } else {
2056                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2057                                 }
2058                                 goto error_parse_next;
2059                         }
2060
2061                         /* handle { "string" } special case */
2062                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2063                                 sub = initializer_from_expression(outer_type, expression);
2064                                 if (sub != NULL) {
2065                                         next_if(',');
2066                                         if (token.kind != '}') {
2067                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2068                                         }
2069                                         /* TODO: eat , ... */
2070                                         return sub;
2071                                 }
2072                         }
2073
2074                         /* descend into subtypes until expression matches type */
2075                         while (true) {
2076                                 orig_type = path->top_type;
2077                                 type      = skip_typeref(orig_type);
2078
2079                                 sub = initializer_from_expression(orig_type, expression);
2080                                 if (sub != NULL) {
2081                                         break;
2082                                 }
2083                                 if (!is_type_valid(type)) {
2084                                         goto end_error;
2085                                 }
2086                                 if (is_type_scalar(type)) {
2087                                         errorf(&expression->base.source_position,
2088                                                         "expression '%E' doesn't match expected type '%T'",
2089                                                         expression, orig_type);
2090                                         goto end_error;
2091                                 }
2092
2093                                 descend_into_subtype(path);
2094                         }
2095                 }
2096
2097                 /* update largest index of top array */
2098                 const type_path_entry_t *first      = &path->path[0];
2099                 type_t                  *first_type = first->type;
2100                 first_type                          = skip_typeref(first_type);
2101                 if (is_type_array(first_type)) {
2102                         size_t index = first->v.index;
2103                         if (index > path->max_index)
2104                                 path->max_index = index;
2105                 }
2106
2107                 /* append to initializers list */
2108                 ARR_APP1(initializer_t*, initializers, sub);
2109
2110 error_parse_next:
2111                 if (token.kind == '}') {
2112                         break;
2113                 }
2114                 add_anchor_token('}');
2115                 expect(',');
2116                 rem_anchor_token('}');
2117                 if (token.kind == '}') {
2118                         break;
2119                 }
2120
2121                 if (type != NULL) {
2122                         /* advance to the next declaration if we are not at the end */
2123                         advance_current_object(path, top_path_level);
2124                         orig_type = path->top_type;
2125                         if (orig_type != NULL)
2126                                 type = skip_typeref(orig_type);
2127                         else
2128                                 type = NULL;
2129                 }
2130         }
2131
2132         size_t len  = ARR_LEN(initializers);
2133         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2134         initializer_t *result = allocate_ast_zero(size);
2135         result->kind          = INITIALIZER_LIST;
2136         result->list.len      = len;
2137         memcpy(&result->list.initializers, initializers,
2138                len * sizeof(initializers[0]));
2139
2140         DEL_ARR_F(initializers);
2141         ascend_to(path, top_path_level+1);
2142
2143         return result;
2144
2145 end_error:
2146         skip_initializers();
2147         DEL_ARR_F(initializers);
2148         ascend_to(path, top_path_level+1);
2149         return NULL;
2150 }
2151
2152 static expression_t *make_size_literal(size_t value)
2153 {
2154         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2155         literal->base.type    = type_size_t;
2156
2157         char buf[128];
2158         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2159         literal->literal.value = make_string(buf);
2160
2161         return literal;
2162 }
2163
2164 /**
2165  * Parses an initializer. Parsers either a compound literal
2166  * (env->declaration == NULL) or an initializer of a declaration.
2167  */
2168 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2169 {
2170         type_t        *type      = skip_typeref(env->type);
2171         size_t         max_index = 0;
2172         initializer_t *result;
2173
2174         if (is_type_scalar(type)) {
2175                 result = parse_scalar_initializer(type, env->must_be_constant);
2176         } else if (token.kind == '{') {
2177                 eat('{');
2178
2179                 type_path_t path;
2180                 memset(&path, 0, sizeof(path));
2181                 path.top_type = env->type;
2182                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2183
2184                 descend_into_subtype(&path);
2185
2186                 add_anchor_token('}');
2187                 result = parse_sub_initializer(&path, env->type, 1, env);
2188                 rem_anchor_token('}');
2189
2190                 max_index = path.max_index;
2191                 DEL_ARR_F(path.path);
2192
2193                 expect('}');
2194         } else {
2195                 /* parse_scalar_initializer() also works in this case: we simply
2196                  * have an expression without {} around it */
2197                 result = parse_scalar_initializer(type, env->must_be_constant);
2198         }
2199
2200         /* §6.7.8:22 array initializers for arrays with unknown size determine
2201          * the array type size */
2202         if (is_type_array(type) && type->array.size_expression == NULL
2203                         && result != NULL) {
2204                 size_t size;
2205                 switch (result->kind) {
2206                 case INITIALIZER_LIST:
2207                         assert(max_index != 0xdeadbeaf);
2208                         size = max_index + 1;
2209                         break;
2210
2211                 case INITIALIZER_STRING: {
2212                         size = get_string_len(&get_init_string(result)->value) + 1;
2213                         break;
2214                 }
2215
2216                 case INITIALIZER_DESIGNATOR:
2217                 case INITIALIZER_VALUE:
2218                         /* can happen for parse errors */
2219                         size = 0;
2220                         break;
2221
2222                 default:
2223                         internal_errorf(HERE, "invalid initializer type");
2224                 }
2225
2226                 type_t *new_type = duplicate_type(type);
2227
2228                 new_type->array.size_expression   = make_size_literal(size);
2229                 new_type->array.size_constant     = true;
2230                 new_type->array.has_implicit_size = true;
2231                 new_type->array.size              = size;
2232                 env->type = new_type;
2233         }
2234
2235         return result;
2236 }
2237
2238 static void append_entity(scope_t *scope, entity_t *entity)
2239 {
2240         if (scope->last_entity != NULL) {
2241                 scope->last_entity->base.next = entity;
2242         } else {
2243                 scope->entities = entity;
2244         }
2245         entity->base.parent_entity = current_entity;
2246         scope->last_entity         = entity;
2247 }
2248
2249
2250 static compound_t *parse_compound_type_specifier(bool is_struct)
2251 {
2252         source_position_t const pos = *HERE;
2253         eat(is_struct ? T_struct : T_union);
2254
2255         symbol_t    *symbol     = NULL;
2256         entity_t    *entity     = NULL;
2257         attribute_t *attributes = NULL;
2258
2259         if (token.kind == T___attribute__) {
2260                 attributes = parse_attributes(NULL);
2261         }
2262
2263         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2264         if (token.kind == T_IDENTIFIER) {
2265                 /* the compound has a name, check if we have seen it already */
2266                 symbol = token.base.symbol;
2267                 entity = get_tag(symbol, kind);
2268                 eat(T_IDENTIFIER);
2269
2270                 if (entity != NULL) {
2271                         if (entity->base.parent_scope != current_scope &&
2272                             (token.kind == '{' || token.kind == ';')) {
2273                                 /* we're in an inner scope and have a definition. Shadow
2274                                  * existing definition in outer scope */
2275                                 entity = NULL;
2276                         } else if (entity->compound.complete && token.kind == '{') {
2277                                 source_position_t const *const ppos = &entity->base.source_position;
2278                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2279                                 /* clear members in the hope to avoid further errors */
2280                                 entity->compound.members.entities = NULL;
2281                         }
2282                 }
2283         } else if (token.kind != '{') {
2284                 char const *const msg =
2285                         is_struct ? "while parsing struct type specifier" :
2286                                     "while parsing union type specifier";
2287                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2288
2289                 return NULL;
2290         }
2291
2292         if (entity == NULL) {
2293                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2294                 entity->compound.alignment = 1;
2295                 entity->base.parent_scope  = current_scope;
2296                 if (symbol != NULL) {
2297                         environment_push(entity);
2298                 }
2299                 append_entity(current_scope, entity);
2300         }
2301
2302         if (token.kind == '{') {
2303                 parse_compound_type_entries(&entity->compound);
2304
2305                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2306                 if (symbol == NULL) {
2307                         assert(anonymous_entity == NULL);
2308                         anonymous_entity = entity;
2309                 }
2310         }
2311
2312         if (attributes != NULL) {
2313                 handle_entity_attributes(attributes, entity);
2314         }
2315
2316         return &entity->compound;
2317 }
2318
2319 static void parse_enum_entries(type_t *const enum_type)
2320 {
2321         eat('{');
2322
2323         if (token.kind == '}') {
2324                 errorf(HERE, "empty enum not allowed");
2325                 eat('}');
2326                 return;
2327         }
2328
2329         add_anchor_token('}');
2330         add_anchor_token(',');
2331         do {
2332                 add_anchor_token('=');
2333                 source_position_t pos;
2334                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2335                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2336                 entity->enum_value.enum_type = enum_type;
2337                 rem_anchor_token('=');
2338
2339                 if (next_if('=')) {
2340                         expression_t *value = parse_constant_expression();
2341
2342                         value = create_implicit_cast(value, enum_type);
2343                         entity->enum_value.value = value;
2344
2345                         /* TODO semantic */
2346                 }
2347
2348                 record_entity(entity, false);
2349         } while (next_if(',') && token.kind != '}');
2350         rem_anchor_token(',');
2351         rem_anchor_token('}');
2352
2353         expect('}');
2354 }
2355
2356 static type_t *parse_enum_specifier(void)
2357 {
2358         source_position_t const pos = *HERE;
2359         entity_t               *entity;
2360         symbol_t               *symbol;
2361
2362         eat(T_enum);
2363         switch (token.kind) {
2364                 case T_IDENTIFIER:
2365                         symbol = token.base.symbol;
2366                         entity = get_tag(symbol, ENTITY_ENUM);
2367                         eat(T_IDENTIFIER);
2368
2369                         if (entity != NULL) {
2370                                 if (entity->base.parent_scope != current_scope &&
2371                                                 (token.kind == '{' || token.kind == ';')) {
2372                                         /* we're in an inner scope and have a definition. Shadow
2373                                          * existing definition in outer scope */
2374                                         entity = NULL;
2375                                 } else if (entity->enume.complete && token.kind == '{') {
2376                                         source_position_t const *const ppos = &entity->base.source_position;
2377                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2378                                 }
2379                         }
2380                         break;
2381
2382                 case '{':
2383                         entity = NULL;
2384                         symbol = NULL;
2385                         break;
2386
2387                 default:
2388                         parse_error_expected("while parsing enum type specifier",
2389                                         T_IDENTIFIER, '{', NULL);
2390                         return NULL;
2391         }
2392
2393         if (entity == NULL) {
2394                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2395                 entity->base.parent_scope = current_scope;
2396         }
2397
2398         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2399         type->enumt.enume      = &entity->enume;
2400         type->enumt.base.akind = ATOMIC_TYPE_INT;
2401
2402         if (token.kind == '{') {
2403                 if (symbol != NULL) {
2404                         environment_push(entity);
2405                 }
2406                 append_entity(current_scope, entity);
2407                 entity->enume.complete = true;
2408
2409                 parse_enum_entries(type);
2410                 parse_attributes(NULL);
2411
2412                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2413                 if (symbol == NULL) {
2414                         assert(anonymous_entity == NULL);
2415                         anonymous_entity = entity;
2416                 }
2417         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2418                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2419         }
2420
2421         return type;
2422 }
2423
2424 /**
2425  * if a symbol is a typedef to another type, return true
2426  */
2427 static bool is_typedef_symbol(symbol_t *symbol)
2428 {
2429         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2430         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2431 }
2432
2433 static type_t *parse_typeof(void)
2434 {
2435         eat(T___typeof__);
2436
2437         type_t *type;
2438
2439         add_anchor_token(')');
2440         expect('(');
2441
2442         expression_t *expression  = NULL;
2443
2444         switch (token.kind) {
2445         case T_IDENTIFIER:
2446                 if (is_typedef_symbol(token.base.symbol)) {
2447         DECLARATION_START
2448                         type = parse_typename();
2449                 } else {
2450         default:
2451                         expression = parse_expression();
2452                         type       = revert_automatic_type_conversion(expression);
2453                 }
2454                 break;
2455         }
2456
2457         rem_anchor_token(')');
2458         expect(')');
2459
2460         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2461         typeof_type->typeoft.expression  = expression;
2462         typeof_type->typeoft.typeof_type = type;
2463
2464         return typeof_type;
2465 }
2466
2467 typedef enum specifiers_t {
2468         SPECIFIER_NONE      = 0,
2469         SPECIFIER_SIGNED    = 1 << 0,
2470         SPECIFIER_UNSIGNED  = 1 << 1,
2471         SPECIFIER_LONG      = 1 << 2,
2472         SPECIFIER_INT       = 1 << 3,
2473         SPECIFIER_DOUBLE    = 1 << 4,
2474         SPECIFIER_CHAR      = 1 << 5,
2475         SPECIFIER_WCHAR_T   = 1 << 6,
2476         SPECIFIER_SHORT     = 1 << 7,
2477         SPECIFIER_LONG_LONG = 1 << 8,
2478         SPECIFIER_FLOAT     = 1 << 9,
2479         SPECIFIER_BOOL      = 1 << 10,
2480         SPECIFIER_VOID      = 1 << 11,
2481         SPECIFIER_INT8      = 1 << 12,
2482         SPECIFIER_INT16     = 1 << 13,
2483         SPECIFIER_INT32     = 1 << 14,
2484         SPECIFIER_INT64     = 1 << 15,
2485         SPECIFIER_INT128    = 1 << 16,
2486         SPECIFIER_COMPLEX   = 1 << 17,
2487         SPECIFIER_IMAGINARY = 1 << 18,
2488 } specifiers_t;
2489
2490 static type_t *get_typedef_type(symbol_t *symbol)
2491 {
2492         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2493         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2494                 return NULL;
2495
2496         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2497         type->typedeft.typedefe = &entity->typedefe;
2498
2499         return type;
2500 }
2501
2502 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2503 {
2504         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2505
2506         add_anchor_token(')');
2507         add_anchor_token(',');
2508         expect('(');
2509
2510         do {
2511                 add_anchor_token('=');
2512                 source_position_t pos;
2513                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2514                 rem_anchor_token('=');
2515
2516                 symbol_t **prop = NULL;
2517                 if (prop_sym) {
2518                         if (streq(prop_sym->string, "put")) {
2519                                 prop = &property->put_symbol;
2520                         } else if (streq(prop_sym->string, "get")) {
2521                                 prop = &property->get_symbol;
2522                         } else {
2523                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2524                         }
2525                 }
2526
2527                 add_anchor_token(T_IDENTIFIER);
2528                 expect('=');
2529                 rem_anchor_token(T_IDENTIFIER);
2530
2531                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2532                 if (prop != NULL)
2533                         *prop = sym ? sym : sym_anonymous;
2534         } while (next_if(','));
2535         rem_anchor_token(',');
2536         rem_anchor_token(')');
2537
2538         attribute->a.property = property;
2539
2540         expect(')');
2541         return attribute;
2542 }
2543
2544 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2545 {
2546         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2547         if (next_if(T_restrict)) {
2548                 kind = ATTRIBUTE_MS_RESTRICT;
2549         } else if (token.kind == T_IDENTIFIER) {
2550                 char const *const name = token.base.symbol->string;
2551                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2552                      ++k) {
2553                         const char *attribute_name = get_attribute_name(k);
2554                         if (attribute_name != NULL && streq(attribute_name, name)) {
2555                                 kind = k;
2556                                 break;
2557                         }
2558                 }
2559
2560                 if (kind == ATTRIBUTE_UNKNOWN) {
2561                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2562                 }
2563         } else {
2564                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2565                 return NULL;
2566         }
2567
2568         attribute_t *attribute = allocate_attribute_zero(kind);
2569         eat(T_IDENTIFIER);
2570
2571         if (kind == ATTRIBUTE_MS_PROPERTY) {
2572                 return parse_attribute_ms_property(attribute);
2573         }
2574
2575         /* parse arguments */
2576         if (next_if('('))
2577                 attribute->a.arguments = parse_attribute_arguments();
2578
2579         return attribute;
2580 }
2581
2582 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2583 {
2584         eat(T__declspec);
2585
2586         add_anchor_token(')');
2587         expect('(');
2588         if (token.kind != ')') {
2589                 attribute_t **anchor = &first;
2590                 do {
2591                         while (*anchor != NULL)
2592                                 anchor = &(*anchor)->next;
2593
2594                         attribute_t *attribute
2595                                 = parse_microsoft_extended_decl_modifier_single();
2596                         if (attribute == NULL)
2597                                 break;
2598
2599                         *anchor = attribute;
2600                         anchor  = &attribute->next;
2601                 } while (next_if(','));
2602         }
2603         rem_anchor_token(')');
2604         expect(')');
2605         return first;
2606 }
2607
2608 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2609 {
2610         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2611         if (is_declaration(entity)) {
2612                 entity->declaration.type     = type_error_type;
2613                 entity->declaration.implicit = true;
2614         } else if (kind == ENTITY_TYPEDEF) {
2615                 entity->typedefe.type    = type_error_type;
2616                 entity->typedefe.builtin = true;
2617         }
2618         if (kind != ENTITY_COMPOUND_MEMBER)
2619                 record_entity(entity, false);
2620         return entity;
2621 }
2622
2623 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2624 {
2625         type_t            *type            = NULL;
2626         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2627         unsigned           type_specifiers = 0;
2628         bool               newtype         = false;
2629         bool               saw_error       = false;
2630
2631         memset(specifiers, 0, sizeof(*specifiers));
2632         specifiers->source_position = *HERE;
2633
2634         while (true) {
2635                 specifiers->attributes = parse_attributes(specifiers->attributes);
2636
2637                 switch (token.kind) {
2638                 /* storage class */
2639 #define MATCH_STORAGE_CLASS(token, class)                                  \
2640                 case token:                                                        \
2641                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2642                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2643                         }                                                              \
2644                         specifiers->storage_class = class;                             \
2645                         if (specifiers->thread_local)                                  \
2646                                 goto check_thread_storage_class;                           \
2647                         eat(token); \
2648                         break;
2649
2650                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2651                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2652                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2653                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2654                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2655
2656                 case T__declspec:
2657                         specifiers->attributes
2658                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2659                         break;
2660
2661                 case T___thread:
2662                         if (specifiers->thread_local) {
2663                                 errorf(HERE, "duplicate '__thread'");
2664                         } else {
2665                                 specifiers->thread_local = true;
2666 check_thread_storage_class:
2667                                 switch (specifiers->storage_class) {
2668                                         case STORAGE_CLASS_EXTERN:
2669                                         case STORAGE_CLASS_NONE:
2670                                         case STORAGE_CLASS_STATIC:
2671                                                 break;
2672
2673                                                 char const* wrong;
2674                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2675                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2676                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2677 wrong_thread_storage_class:
2678                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2679                                                 break;
2680                                 }
2681                         }
2682                         next_token();
2683                         break;
2684
2685                 /* type qualifiers */
2686 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2687                 case token:                                                     \
2688                         qualifiers |= qualifier;                                    \
2689                         eat(token); \
2690                         break
2691
2692                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2693                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2694                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2695                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2696                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2697                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2698                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2699                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2700
2701                 /* type specifiers */
2702 #define MATCH_SPECIFIER(token, specifier, name)                         \
2703                 case token:                                                     \
2704                         if (type_specifiers & specifier) {                           \
2705                                 errorf(HERE, "multiple " name " type specifiers given"); \
2706                         } else {                                                    \
2707                                 type_specifiers |= specifier;                           \
2708                         }                                                           \
2709                         eat(token); \
2710                         break
2711
2712                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2713                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2714                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2715                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2716                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2717                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2718                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2719                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2720                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2721                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2722                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2723                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2724                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2725                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2726                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2727                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2728                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2729                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2730
2731                 case T_inline:
2732                         eat(T_inline);
2733                         specifiers->is_inline = true;
2734                         break;
2735
2736 #if 0
2737                 case T__forceinline:
2738                         eat(T__forceinline);
2739                         specifiers->modifiers |= DM_FORCEINLINE;
2740                         break;
2741 #endif
2742
2743                 case T_long:
2744                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2745                                 errorf(HERE, "too many long type specifiers given");
2746                         } else if (type_specifiers & SPECIFIER_LONG) {
2747                                 type_specifiers |= SPECIFIER_LONG_LONG;
2748                         } else {
2749                                 type_specifiers |= SPECIFIER_LONG;
2750                         }
2751                         eat(T_long);
2752                         break;
2753
2754 #define CHECK_DOUBLE_TYPE() \
2755         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2756
2757                 case T_struct:
2758                         CHECK_DOUBLE_TYPE();
2759                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2760
2761                         type->compound.compound = parse_compound_type_specifier(true);
2762                         break;
2763                 case T_union:
2764                         CHECK_DOUBLE_TYPE();
2765                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2766                         type->compound.compound = parse_compound_type_specifier(false);
2767                         break;
2768                 case T_enum:
2769                         CHECK_DOUBLE_TYPE();
2770                         type = parse_enum_specifier();
2771                         break;
2772                 case T___typeof__:
2773                         CHECK_DOUBLE_TYPE();
2774                         type = parse_typeof();
2775                         break;
2776                 case T___builtin_va_list:
2777                         CHECK_DOUBLE_TYPE();
2778                         type = duplicate_type(type_valist);
2779                         eat(T___builtin_va_list);
2780                         break;
2781
2782                 case T_IDENTIFIER: {
2783                         /* only parse identifier if we haven't found a type yet */
2784                         if (type != NULL || type_specifiers != 0) {
2785                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2786                                  * declaration, so it doesn't generate errors about expecting '(' or
2787                                  * '{' later on. */
2788                                 switch (look_ahead(1)->kind) {
2789                                         STORAGE_CLASSES
2790                                         TYPE_SPECIFIERS
2791                                         case T_const:
2792                                         case T_restrict:
2793                                         case T_volatile:
2794                                         case T_inline:
2795                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2796                                         case T_IDENTIFIER:
2797                                         case '&':
2798                                         case '*':
2799                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2800                                                 eat(T_IDENTIFIER);
2801                                                 continue;
2802
2803                                         default:
2804                                                 goto finish_specifiers;
2805                                 }
2806                         }
2807
2808                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2809                         if (typedef_type == NULL) {
2810                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2811                                  * declaration, so it doesn't generate 'implicit int' followed by more
2812                                  * errors later on. */
2813                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2814                                 switch (la1_type) {
2815                                         DECLARATION_START
2816                                         case T_IDENTIFIER:
2817                                         case '&':
2818                                         case '*': {
2819                                                 errorf(HERE, "%K does not name a type", &token);
2820
2821                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2822
2823                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2824                                                 type->typedeft.typedefe = &entity->typedefe;
2825
2826                                                 eat(T_IDENTIFIER);
2827                                                 saw_error = true;
2828                                                 continue;
2829                                         }
2830
2831                                         default:
2832                                                 goto finish_specifiers;
2833                                 }
2834                         }
2835
2836                         eat(T_IDENTIFIER);
2837                         type = typedef_type;
2838                         break;
2839                 }
2840
2841                 /* function specifier */
2842                 default:
2843                         goto finish_specifiers;
2844                 }
2845         }
2846
2847 finish_specifiers:
2848         specifiers->attributes = parse_attributes(specifiers->attributes);
2849
2850         if (type == NULL || (saw_error && type_specifiers != 0)) {
2851                 atomic_type_kind_t atomic_type;
2852
2853                 /* match valid basic types */
2854                 switch (type_specifiers) {
2855                 case SPECIFIER_VOID:
2856                         atomic_type = ATOMIC_TYPE_VOID;
2857                         break;
2858                 case SPECIFIER_WCHAR_T:
2859                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2860                         break;
2861                 case SPECIFIER_CHAR:
2862                         atomic_type = ATOMIC_TYPE_CHAR;
2863                         break;
2864                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2865                         atomic_type = ATOMIC_TYPE_SCHAR;
2866                         break;
2867                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2868                         atomic_type = ATOMIC_TYPE_UCHAR;
2869                         break;
2870                 case SPECIFIER_SHORT:
2871                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2872                 case SPECIFIER_SHORT | SPECIFIER_INT:
2873                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2874                         atomic_type = ATOMIC_TYPE_SHORT;
2875                         break;
2876                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2877                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2878                         atomic_type = ATOMIC_TYPE_USHORT;
2879                         break;
2880                 case SPECIFIER_INT:
2881                 case SPECIFIER_SIGNED:
2882                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2883                         atomic_type = ATOMIC_TYPE_INT;
2884                         break;
2885                 case SPECIFIER_UNSIGNED:
2886                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2887                         atomic_type = ATOMIC_TYPE_UINT;
2888                         break;
2889                 case SPECIFIER_LONG:
2890                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2891                 case SPECIFIER_LONG | SPECIFIER_INT:
2892                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2893                         atomic_type = ATOMIC_TYPE_LONG;
2894                         break;
2895                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2896                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2897                         atomic_type = ATOMIC_TYPE_ULONG;
2898                         break;
2899
2900                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2901                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2902                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2904                         | SPECIFIER_INT:
2905                         atomic_type = ATOMIC_TYPE_LONGLONG;
2906                         goto warn_about_long_long;
2907
2908                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2909                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2910                         | SPECIFIER_INT:
2911                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2912 warn_about_long_long:
2913                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2914                         break;
2915
2916                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2917                         atomic_type = unsigned_int8_type_kind;
2918                         break;
2919
2920                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2921                         atomic_type = unsigned_int16_type_kind;
2922                         break;
2923
2924                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2925                         atomic_type = unsigned_int32_type_kind;
2926                         break;
2927
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2929                         atomic_type = unsigned_int64_type_kind;
2930                         break;
2931
2932                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2933                         atomic_type = unsigned_int128_type_kind;
2934                         break;
2935
2936                 case SPECIFIER_INT8:
2937                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2938                         atomic_type = int8_type_kind;
2939                         break;
2940
2941                 case SPECIFIER_INT16:
2942                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2943                         atomic_type = int16_type_kind;
2944                         break;
2945
2946                 case SPECIFIER_INT32:
2947                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2948                         atomic_type = int32_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_INT64:
2952                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2953                         atomic_type = int64_type_kind;
2954                         break;
2955
2956                 case SPECIFIER_INT128:
2957                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2958                         atomic_type = int128_type_kind;
2959                         break;
2960
2961                 case SPECIFIER_FLOAT:
2962                         atomic_type = ATOMIC_TYPE_FLOAT;
2963                         break;
2964                 case SPECIFIER_DOUBLE:
2965                         atomic_type = ATOMIC_TYPE_DOUBLE;
2966                         break;
2967                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2968                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2969                         break;
2970                 case SPECIFIER_BOOL:
2971                         atomic_type = ATOMIC_TYPE_BOOL;
2972                         break;
2973                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2974                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2975                         atomic_type = ATOMIC_TYPE_FLOAT;
2976                         break;
2977                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2978                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2979                         atomic_type = ATOMIC_TYPE_DOUBLE;
2980                         break;
2981                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2982                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2983                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2984                         break;
2985                 default: {
2986                         /* invalid specifier combination, give an error message */
2987                         source_position_t const* const pos = &specifiers->source_position;
2988                         if (type_specifiers == 0) {
2989                                 if (!saw_error) {
2990                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2991                                         if (!(c_mode & _CXX) && !strict_mode) {
2992                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2993                                                 atomic_type = ATOMIC_TYPE_INT;
2994                                                 break;
2995                                         } else {
2996                                                 errorf(pos, "no type specifiers given in declaration");
2997                                         }
2998                                 }
2999                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3000                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3001                                 errorf(pos, "signed and unsigned specifiers given");
3002                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3003                                 errorf(pos, "only integer types can be signed or unsigned");
3004                         } else {
3005                                 errorf(pos, "multiple datatypes in declaration");
3006                         }
3007                         specifiers->type = type_error_type;
3008                         return;
3009                 }
3010                 }
3011
3012                 if (type_specifiers & SPECIFIER_COMPLEX) {
3013                         type = allocate_type_zero(TYPE_COMPLEX);
3014                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3015                         type = allocate_type_zero(TYPE_IMAGINARY);
3016                 } else {
3017                         type = allocate_type_zero(TYPE_ATOMIC);
3018                 }
3019                 type->atomic.akind = atomic_type;
3020                 newtype = true;
3021         } else if (type_specifiers != 0) {
3022                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3023         }
3024
3025         /* FIXME: check type qualifiers here */
3026         type->base.qualifiers = qualifiers;
3027
3028         if (newtype) {
3029                 type = identify_new_type(type);
3030         } else {
3031                 type = typehash_insert(type);
3032         }
3033
3034         if (specifiers->attributes != NULL)
3035                 type = handle_type_attributes(specifiers->attributes, type);
3036         specifiers->type = type;
3037 }
3038
3039 static type_qualifiers_t parse_type_qualifiers(void)
3040 {
3041         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3042
3043         while (true) {
3044                 switch (token.kind) {
3045                 /* type qualifiers */
3046                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3047                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3048                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3049                 /* microsoft extended type modifiers */
3050                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3051                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3052                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3053                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3054                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3055
3056                 default:
3057                         return qualifiers;
3058                 }
3059         }
3060 }
3061
3062 /**
3063  * Parses an K&R identifier list
3064  */
3065 static void parse_identifier_list(scope_t *scope)
3066 {
3067         assert(token.kind == T_IDENTIFIER);
3068         do {
3069                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3070                 /* a K&R parameter has no type, yet */
3071                 eat(T_IDENTIFIER);
3072
3073                 if (scope != NULL)
3074                         append_entity(scope, entity);
3075         } while (next_if(',') && token.kind == T_IDENTIFIER);
3076 }
3077
3078 static entity_t *parse_parameter(void)
3079 {
3080         declaration_specifiers_t specifiers;
3081         parse_declaration_specifiers(&specifiers);
3082
3083         entity_t *entity = parse_declarator(&specifiers,
3084                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3085         anonymous_entity = NULL;
3086         return entity;
3087 }
3088
3089 static void semantic_parameter_incomplete(const entity_t *entity)
3090 {
3091         assert(entity->kind == ENTITY_PARAMETER);
3092
3093         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3094          *             list in a function declarator that is part of a
3095          *             definition of that function shall not have
3096          *             incomplete type. */
3097         type_t *type = skip_typeref(entity->declaration.type);
3098         if (is_type_incomplete(type)) {
3099                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3100         }
3101 }
3102
3103 static bool has_parameters(void)
3104 {
3105         /* func(void) is not a parameter */
3106         if (look_ahead(1)->kind != ')')
3107                 return true;
3108         if (token.kind == T_IDENTIFIER) {
3109                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3110                 if (entity == NULL)
3111                         return true;
3112                 if (entity->kind != ENTITY_TYPEDEF)
3113                         return true;
3114                 type_t const *const type = skip_typeref(entity->typedefe.type);
3115                 if (!is_type_void(type))
3116                         return true;
3117                 if (c_mode & _CXX) {
3118                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3119                          * is not allowed. */
3120                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3121                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3122                         /* §6.7.5.3:10  Qualification is not allowed here. */
3123                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3124                 }
3125         } else if (token.kind != T_void) {
3126                 return true;
3127         }
3128         next_token();
3129         return false;
3130 }
3131
3132 /**
3133  * Parses function type parameters (and optionally creates variable_t entities
3134  * for them in a scope)
3135  */
3136 static void parse_parameters(function_type_t *type, scope_t *scope)
3137 {
3138         add_anchor_token(')');
3139         eat('(');
3140
3141         if (token.kind == T_IDENTIFIER            &&
3142             !is_typedef_symbol(token.base.symbol) &&
3143             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3144                 type->kr_style_parameters = true;
3145                 parse_identifier_list(scope);
3146         } else if (token.kind == ')') {
3147                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3148                 if (!(c_mode & _CXX))
3149                         type->unspecified_parameters = true;
3150         } else if (has_parameters()) {
3151                 function_parameter_t **anchor = &type->parameters;
3152                 add_anchor_token(',');
3153                 do {
3154                         switch (token.kind) {
3155                         case T_DOTDOTDOT:
3156                                 eat(T_DOTDOTDOT);
3157                                 type->variadic = true;
3158                                 goto parameters_finished;
3159
3160                         case T_IDENTIFIER:
3161                         DECLARATION_START
3162                         {
3163                                 entity_t *entity = parse_parameter();
3164                                 if (entity->kind == ENTITY_TYPEDEF) {
3165                                         errorf(&entity->base.source_position,
3166                                                         "typedef not allowed as function parameter");
3167                                         break;
3168                                 }
3169                                 assert(is_declaration(entity));
3170
3171                                 semantic_parameter_incomplete(entity);
3172
3173                                 function_parameter_t *const parameter =
3174                                         allocate_parameter(entity->declaration.type);
3175
3176                                 if (scope != NULL) {
3177                                         append_entity(scope, entity);
3178                                 }
3179
3180                                 *anchor = parameter;
3181                                 anchor  = &parameter->next;
3182                                 break;
3183                         }
3184
3185                         default:
3186                                 goto parameters_finished;
3187                         }
3188                 } while (next_if(','));
3189 parameters_finished:
3190                 rem_anchor_token(',');
3191         }
3192
3193         rem_anchor_token(')');
3194         expect(')');
3195 }
3196
3197 typedef enum construct_type_kind_t {
3198         CONSTRUCT_POINTER = 1,
3199         CONSTRUCT_REFERENCE,
3200         CONSTRUCT_FUNCTION,
3201         CONSTRUCT_ARRAY
3202 } construct_type_kind_t;
3203
3204 typedef union construct_type_t construct_type_t;
3205
3206 typedef struct construct_type_base_t {
3207         construct_type_kind_t  kind;
3208         source_position_t      pos;
3209         construct_type_t      *next;
3210 } construct_type_base_t;
3211
3212 typedef struct parsed_pointer_t {
3213         construct_type_base_t  base;
3214         type_qualifiers_t      type_qualifiers;
3215         variable_t            *base_variable;  /**< MS __based extension. */
3216 } parsed_pointer_t;
3217
3218 typedef struct parsed_reference_t {
3219         construct_type_base_t base;
3220 } parsed_reference_t;
3221
3222 typedef struct construct_function_type_t {
3223         construct_type_base_t  base;
3224         type_t                *function_type;
3225 } construct_function_type_t;
3226
3227 typedef struct parsed_array_t {
3228         construct_type_base_t  base;
3229         type_qualifiers_t      type_qualifiers;
3230         bool                   is_static;
3231         bool                   is_variable;
3232         expression_t          *size;
3233 } parsed_array_t;
3234
3235 union construct_type_t {
3236         construct_type_kind_t     kind;
3237         construct_type_base_t     base;
3238         parsed_pointer_t          pointer;
3239         parsed_reference_t        reference;
3240         construct_function_type_t function;
3241         parsed_array_t            array;
3242 };
3243
3244 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3245 {
3246         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3247         memset(cons, 0, size);
3248         cons->kind     = kind;
3249         cons->base.pos = *HERE;
3250         return cons;
3251 }
3252
3253 /* §6.7.5.1 */
3254 static construct_type_t *parse_pointer_declarator(void)
3255 {
3256         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3257         eat('*');
3258         cons->pointer.type_qualifiers = parse_type_qualifiers();
3259         //cons->pointer.base_variable   = base_variable;
3260
3261         return cons;
3262 }
3263
3264 /* ISO/IEC 14882:1998(E) §8.3.2 */
3265 static construct_type_t *parse_reference_declarator(void)
3266 {
3267         if (!(c_mode & _CXX))
3268                 errorf(HERE, "references are only available for C++");
3269
3270         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3271         eat('&');
3272
3273         return cons;
3274 }
3275
3276 /* §6.7.5.2 */
3277 static construct_type_t *parse_array_declarator(void)
3278 {
3279         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3280         parsed_array_t   *const array = &cons->array;
3281
3282         eat('[');
3283         add_anchor_token(']');
3284
3285         bool is_static = next_if(T_static);
3286
3287         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3288
3289         if (!is_static)
3290                 is_static = next_if(T_static);
3291
3292         array->type_qualifiers = type_qualifiers;
3293         array->is_static       = is_static;
3294
3295         expression_t *size = NULL;
3296         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3297                 array->is_variable = true;
3298                 eat('*');
3299         } else if (token.kind != ']') {
3300                 size = parse_assignment_expression();
3301
3302                 /* §6.7.5.2:1  Array size must have integer type */
3303                 type_t *const orig_type = size->base.type;
3304                 type_t *const type      = skip_typeref(orig_type);
3305                 if (!is_type_integer(type) && is_type_valid(type)) {
3306                         errorf(&size->base.source_position,
3307                                "array size '%E' must have integer type but has type '%T'",
3308                                size, orig_type);
3309                 }
3310
3311                 array->size = size;
3312                 mark_vars_read(size, NULL);
3313         }
3314
3315         if (is_static && size == NULL)
3316                 errorf(&array->base.pos, "static array parameters require a size");
3317
3318         rem_anchor_token(']');
3319         expect(']');
3320         return cons;
3321 }
3322
3323 /* §6.7.5.3 */
3324 static construct_type_t *parse_function_declarator(scope_t *scope)
3325 {
3326         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3327
3328         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3329         function_type_t *ftype = &type->function;
3330
3331         ftype->linkage            = current_linkage;
3332         ftype->calling_convention = CC_DEFAULT;
3333
3334         parse_parameters(ftype, scope);
3335
3336         cons->function.function_type = type;
3337
3338         return cons;
3339 }
3340
3341 typedef struct parse_declarator_env_t {
3342         bool               may_be_abstract : 1;
3343         bool               must_be_abstract : 1;
3344         decl_modifiers_t   modifiers;
3345         symbol_t          *symbol;
3346         source_position_t  source_position;
3347         scope_t            parameters;
3348         attribute_t       *attributes;
3349 } parse_declarator_env_t;
3350
3351 /* §6.7.5 */
3352 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3353 {
3354         /* construct a single linked list of construct_type_t's which describe
3355          * how to construct the final declarator type */
3356         construct_type_t  *first      = NULL;
3357         construct_type_t **anchor     = &first;
3358
3359         env->attributes = parse_attributes(env->attributes);
3360
3361         for (;;) {
3362                 construct_type_t *type;
3363                 //variable_t       *based = NULL; /* MS __based extension */
3364                 switch (token.kind) {
3365                         case '&':
3366                                 type = parse_reference_declarator();
3367                                 break;
3368
3369                         case T__based: {
3370                                 panic("based not supported anymore");
3371                                 /* FALLTHROUGH */
3372                         }
3373
3374                         case '*':
3375                                 type = parse_pointer_declarator();
3376                                 break;
3377
3378                         default:
3379                                 goto ptr_operator_end;
3380                 }
3381
3382                 *anchor = type;
3383                 anchor  = &type->base.next;
3384
3385                 /* TODO: find out if this is correct */
3386                 env->attributes = parse_attributes(env->attributes);
3387         }
3388
3389 ptr_operator_end: ;
3390         construct_type_t *inner_types = NULL;
3391
3392         switch (token.kind) {
3393         case T_IDENTIFIER:
3394                 if (env->must_be_abstract) {
3395                         errorf(HERE, "no identifier expected in typename");
3396                 } else {
3397                         env->symbol          = token.base.symbol;
3398                         env->source_position = *HERE;
3399                 }
3400                 eat(T_IDENTIFIER);
3401                 break;
3402
3403         case '(': {
3404                 /* Parenthesized declarator or function declarator? */
3405                 token_t const *const la1 = look_ahead(1);
3406                 switch (la1->kind) {
3407                         case T_IDENTIFIER:
3408                                 if (is_typedef_symbol(la1->base.symbol)) {
3409                         case ')':
3410                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3411                                          * interpreted as ``function with no parameter specification'', rather
3412                                          * than redundant parentheses around the omitted identifier. */
3413                         default:
3414                                         /* Function declarator. */
3415                                         if (!env->may_be_abstract) {
3416                                                 errorf(HERE, "function declarator must have a name");
3417                                         }
3418                                 } else {
3419                         case '&':
3420                         case '(':
3421                         case '*':
3422                         case '[':
3423                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3424                                         /* Paranthesized declarator. */
3425                                         eat('(');
3426                                         add_anchor_token(')');
3427                                         inner_types = parse_inner_declarator(env);
3428                                         if (inner_types != NULL) {
3429                                                 /* All later declarators only modify the return type */
3430                                                 env->must_be_abstract = true;
3431                                         }
3432                                         rem_anchor_token(')');
3433                                         expect(')');
3434                                 }
3435                                 break;
3436                 }
3437                 break;
3438         }
3439
3440         default:
3441                 if (env->may_be_abstract)
3442                         break;
3443                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3444                 eat_until_anchor();
3445                 return NULL;
3446         }
3447
3448         construct_type_t **const p = anchor;
3449
3450         for (;;) {
3451                 construct_type_t *type;
3452                 switch (token.kind) {
3453                 case '(': {
3454                         scope_t *scope = NULL;
3455                         if (!env->must_be_abstract) {
3456                                 scope = &env->parameters;
3457                         }
3458
3459                         type = parse_function_declarator(scope);
3460                         break;
3461                 }
3462                 case '[':
3463                         type = parse_array_declarator();
3464                         break;
3465                 default:
3466                         goto declarator_finished;
3467                 }
3468
3469                 /* insert in the middle of the list (at p) */
3470                 type->base.next = *p;
3471                 *p              = type;
3472                 if (anchor == p)
3473                         anchor = &type->base.next;
3474         }
3475
3476 declarator_finished:
3477         /* append inner_types at the end of the list, we don't to set anchor anymore
3478          * as it's not needed anymore */
3479         *anchor = inner_types;
3480
3481         return first;
3482 }
3483
3484 static type_t *construct_declarator_type(construct_type_t *construct_list,
3485                                          type_t *type)
3486 {
3487         construct_type_t *iter = construct_list;
3488         for (; iter != NULL; iter = iter->base.next) {
3489                 source_position_t const* const pos = &iter->base.pos;
3490                 switch (iter->kind) {
3491                 case CONSTRUCT_FUNCTION: {
3492                         construct_function_type_t *function      = &iter->function;
3493                         type_t                    *function_type = function->function_type;
3494
3495                         function_type->function.return_type = type;
3496
3497                         type_t *skipped_return_type = skip_typeref(type);
3498                         /* §6.7.5.3:1 */
3499                         if (is_type_function(skipped_return_type)) {
3500                                 errorf(pos, "function returning function is not allowed");
3501                         } else if (is_type_array(skipped_return_type)) {
3502                                 errorf(pos, "function returning array is not allowed");
3503                         } else {
3504                                 if (skipped_return_type->base.qualifiers != 0) {
3505                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3506                                 }
3507                         }
3508
3509                         /* The function type was constructed earlier.  Freeing it here will
3510                          * destroy other types. */
3511                         type = typehash_insert(function_type);
3512                         continue;
3513                 }
3514
3515                 case CONSTRUCT_POINTER: {
3516                         if (is_type_reference(skip_typeref(type)))
3517                                 errorf(pos, "cannot declare a pointer to reference");
3518
3519                         parsed_pointer_t *pointer = &iter->pointer;
3520                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3521                         continue;
3522                 }
3523
3524                 case CONSTRUCT_REFERENCE:
3525                         if (is_type_reference(skip_typeref(type)))
3526                                 errorf(pos, "cannot declare a reference to reference");
3527
3528                         type = make_reference_type(type);
3529                         continue;
3530
3531                 case CONSTRUCT_ARRAY: {
3532                         if (is_type_reference(skip_typeref(type)))
3533                                 errorf(pos, "cannot declare an array of references");
3534
3535                         parsed_array_t *array      = &iter->array;
3536                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3537
3538                         expression_t *size_expression = array->size;
3539                         if (size_expression != NULL) {
3540                                 size_expression
3541                                         = create_implicit_cast(size_expression, type_size_t);
3542                         }
3543
3544                         array_type->base.qualifiers       = array->type_qualifiers;
3545                         array_type->array.element_type    = type;
3546                         array_type->array.is_static       = array->is_static;
3547                         array_type->array.is_variable     = array->is_variable;
3548                         array_type->array.size_expression = size_expression;
3549
3550                         if (size_expression != NULL) {
3551                                 switch (is_constant_expression(size_expression)) {
3552                                 case EXPR_CLASS_CONSTANT: {
3553                                         long const size = fold_constant_to_int(size_expression);
3554                                         array_type->array.size          = size;
3555                                         array_type->array.size_constant = true;
3556                                         /* §6.7.5.2:1  If the expression is a constant expression,
3557                                          * it shall have a value greater than zero. */
3558                                         if (size < 0) {
3559                                                 errorf(&size_expression->base.source_position,
3560                                                            "size of array must be greater than zero");
3561                                         } else if (size == 0 && !GNU_MODE) {
3562                                                 errorf(&size_expression->base.source_position,
3563                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3564                                         }
3565                                         break;
3566                                 }
3567
3568                                 case EXPR_CLASS_VARIABLE:
3569                                         array_type->array.is_vla = true;
3570                                         break;
3571
3572                                 case EXPR_CLASS_ERROR:
3573                                         break;
3574                                 }
3575                         }
3576
3577                         type_t *skipped_type = skip_typeref(type);
3578                         /* §6.7.5.2:1 */
3579                         if (is_type_incomplete(skipped_type)) {
3580                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3581                         } else if (is_type_function(skipped_type)) {
3582                                 errorf(pos, "array of functions is not allowed");
3583                         }
3584                         type = identify_new_type(array_type);
3585                         continue;
3586                 }
3587                 }
3588                 internal_errorf(pos, "invalid type construction found");
3589         }
3590
3591         return type;
3592 }
3593
3594 static type_t *automatic_type_conversion(type_t *orig_type);
3595
3596 static type_t *semantic_parameter(const source_position_t *pos,
3597                                   type_t *type,
3598                                   const declaration_specifiers_t *specifiers,
3599                                   entity_t const *const param)
3600 {
3601         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3602          *             shall be adjusted to ``qualified pointer to type'',
3603          *             [...]
3604          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3605          *             type'' shall be adjusted to ``pointer to function
3606          *             returning type'', as in 6.3.2.1. */
3607         type = automatic_type_conversion(type);
3608
3609         if (specifiers->is_inline && is_type_valid(type)) {
3610                 errorf(pos, "'%N' declared 'inline'", param);
3611         }
3612
3613         /* §6.9.1:6  The declarations in the declaration list shall contain
3614          *           no storage-class specifier other than register and no
3615          *           initializations. */
3616         if (specifiers->thread_local || (
3617                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3618                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3619            ) {
3620                 errorf(pos, "invalid storage class for '%N'", param);
3621         }
3622
3623         /* delay test for incomplete type, because we might have (void)
3624          * which is legal but incomplete... */
3625
3626         return type;
3627 }
3628
3629 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3630                                   declarator_flags_t flags)
3631 {
3632         parse_declarator_env_t env;
3633         memset(&env, 0, sizeof(env));
3634         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3635
3636         construct_type_t *construct_type = parse_inner_declarator(&env);
3637         type_t           *orig_type      =
3638                 construct_declarator_type(construct_type, specifiers->type);
3639         type_t           *type           = skip_typeref(orig_type);
3640
3641         if (construct_type != NULL) {
3642                 obstack_free(&temp_obst, construct_type);
3643         }
3644
3645         attribute_t *attributes = parse_attributes(env.attributes);
3646         /* append (shared) specifier attribute behind attributes of this
3647          * declarator */
3648         attribute_t **anchor = &attributes;
3649         while (*anchor != NULL)
3650                 anchor = &(*anchor)->next;
3651         *anchor = specifiers->attributes;
3652
3653         entity_t *entity;
3654         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3655                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3656                 entity->typedefe.type = orig_type;
3657
3658                 if (anonymous_entity != NULL) {
3659                         if (is_type_compound(type)) {
3660                                 assert(anonymous_entity->compound.alias == NULL);
3661                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3662                                        anonymous_entity->kind == ENTITY_UNION);
3663                                 anonymous_entity->compound.alias = entity;
3664                                 anonymous_entity = NULL;
3665                         } else if (is_type_enum(type)) {
3666                                 assert(anonymous_entity->enume.alias == NULL);
3667                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3668                                 anonymous_entity->enume.alias = entity;
3669                                 anonymous_entity = NULL;
3670                         }
3671                 }
3672         } else {
3673                 /* create a declaration type entity */
3674                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3675                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3676                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3677
3678                         if (env.symbol != NULL) {
3679                                 if (specifiers->is_inline && is_type_valid(type)) {
3680                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3681                                 }
3682
3683                                 if (specifiers->thread_local ||
3684                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3685                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3686                                 }
3687                         }
3688                 } else if (flags & DECL_IS_PARAMETER) {
3689                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3690                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3691                 } else if (is_type_function(type)) {
3692                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3693                         entity->function.is_inline      = specifiers->is_inline;
3694                         entity->function.elf_visibility = default_visibility;
3695                         entity->function.parameters     = env.parameters;
3696
3697                         if (env.symbol != NULL) {
3698                                 /* this needs fixes for C++ */
3699                                 bool in_function_scope = current_function != NULL;
3700
3701                                 if (specifiers->thread_local || (
3702                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3703                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3704                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3705                                                 )) {
3706                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3707                                 }
3708                         }
3709                 } else {
3710                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3711                         entity->variable.elf_visibility = default_visibility;
3712                         entity->variable.thread_local   = specifiers->thread_local;
3713
3714                         if (env.symbol != NULL) {
3715                                 if (specifiers->is_inline && is_type_valid(type)) {
3716                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3717                                 }
3718
3719                                 bool invalid_storage_class = false;
3720                                 if (current_scope == file_scope) {
3721                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3722                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3723                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3724                                                 invalid_storage_class = true;
3725                                         }
3726                                 } else {
3727                                         if (specifiers->thread_local &&
3728                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3729                                                 invalid_storage_class = true;
3730                                         }
3731                                 }
3732                                 if (invalid_storage_class) {
3733                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3734                                 }
3735                         }
3736                 }
3737
3738                 entity->declaration.type       = orig_type;
3739                 entity->declaration.alignment  = get_type_alignment(orig_type);
3740                 entity->declaration.modifiers  = env.modifiers;
3741                 entity->declaration.attributes = attributes;
3742
3743                 storage_class_t storage_class = specifiers->storage_class;
3744                 entity->declaration.declared_storage_class = storage_class;
3745
3746                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3747                         storage_class = STORAGE_CLASS_AUTO;
3748                 entity->declaration.storage_class = storage_class;
3749         }
3750
3751         if (attributes != NULL) {
3752                 handle_entity_attributes(attributes, entity);
3753         }
3754
3755         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3756                 adapt_special_functions(&entity->function);
3757         }
3758
3759         return entity;
3760 }
3761
3762 static type_t *parse_abstract_declarator(type_t *base_type)
3763 {
3764         parse_declarator_env_t env;
3765         memset(&env, 0, sizeof(env));
3766         env.may_be_abstract = true;
3767         env.must_be_abstract = true;
3768
3769         construct_type_t *construct_type = parse_inner_declarator(&env);
3770
3771         type_t *result = construct_declarator_type(construct_type, base_type);
3772         if (construct_type != NULL) {
3773                 obstack_free(&temp_obst, construct_type);
3774         }
3775         result = handle_type_attributes(env.attributes, result);
3776
3777         return result;
3778 }
3779
3780 /**
3781  * Check if the declaration of main is suspicious.  main should be a
3782  * function with external linkage, returning int, taking either zero
3783  * arguments, two, or three arguments of appropriate types, ie.
3784  *
3785  * int main([ int argc, char **argv [, char **env ] ]).
3786  *
3787  * @param decl    the declaration to check
3788  * @param type    the function type of the declaration
3789  */
3790 static void check_main(const entity_t *entity)
3791 {
3792         const source_position_t *pos = &entity->base.source_position;
3793         if (entity->kind != ENTITY_FUNCTION) {
3794                 warningf(WARN_MAIN, pos, "'main' is not a function");
3795                 return;
3796         }
3797
3798         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3799                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3800         }
3801
3802         type_t *type = skip_typeref(entity->declaration.type);
3803         assert(is_type_function(type));
3804
3805         function_type_t const *const func_type = &type->function;
3806         type_t                *const ret_type  = func_type->return_type;
3807         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3808                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3809         }
3810         const function_parameter_t *parm = func_type->parameters;
3811         if (parm != NULL) {
3812                 type_t *const first_type        = skip_typeref(parm->type);
3813                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3814                 if (!types_compatible(first_type_unqual, type_int)) {
3815                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3816                 }
3817                 parm = parm->next;
3818                 if (parm != NULL) {
3819                         type_t *const second_type = skip_typeref(parm->type);
3820                         type_t *const second_type_unqual
3821                                 = get_unqualified_type(second_type);
3822                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3823                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3824                         }
3825                         parm = parm->next;
3826                         if (parm != NULL) {
3827                                 type_t *const third_type = skip_typeref(parm->type);
3828                                 type_t *const third_type_unqual
3829                                         = get_unqualified_type(third_type);
3830                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3831                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3832                                 }
3833                                 parm = parm->next;
3834                                 if (parm != NULL)
3835                                         goto warn_arg_count;
3836                         }
3837                 } else {
3838 warn_arg_count:
3839                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3840                 }
3841         }
3842 }
3843
3844 static void error_redefined_as_different_kind(const source_position_t *pos,
3845                 const entity_t *old, entity_kind_t new_kind)
3846 {
3847         char              const *const what = get_entity_kind_name(new_kind);
3848         source_position_t const *const ppos = &old->base.source_position;
3849         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3850 }
3851
3852 static bool is_entity_valid(entity_t *const ent)
3853 {
3854         if (is_declaration(ent)) {
3855                 return is_type_valid(skip_typeref(ent->declaration.type));
3856         } else if (ent->kind == ENTITY_TYPEDEF) {
3857                 return is_type_valid(skip_typeref(ent->typedefe.type));
3858         }
3859         return true;
3860 }
3861
3862 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3863 {
3864         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3865                 if (attributes_equal(tattr, attr))
3866                         return true;
3867         }
3868         return false;
3869 }
3870
3871 /**
3872  * test wether new_list contains any attributes not included in old_list
3873  */
3874 static bool has_new_attributes(const attribute_t *old_list,
3875                                const attribute_t *new_list)
3876 {
3877         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3878                 if (!contains_attribute(old_list, attr))
3879                         return true;
3880         }
3881         return false;
3882 }
3883
3884 /**
3885  * Merge in attributes from an attribute list (probably from a previous
3886  * declaration with the same name). Warning: destroys the old structure
3887  * of the attribute list - don't reuse attributes after this call.
3888  */
3889 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3890 {
3891         attribute_t *next;
3892         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3893                 next = attr->next;
3894                 if (contains_attribute(decl->attributes, attr))
3895                         continue;
3896
3897                 /* move attribute to new declarations attributes list */
3898                 attr->next       = decl->attributes;
3899                 decl->attributes = attr;
3900         }
3901 }
3902
3903 static bool is_main(entity_t*);
3904
3905 /**
3906  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3907  * for various problems that occur for multiple definitions
3908  */
3909 entity_t *record_entity(entity_t *entity, const bool is_definition)
3910 {
3911         const symbol_t *const    symbol  = entity->base.symbol;
3912         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3913         const source_position_t *pos     = &entity->base.source_position;
3914
3915         /* can happen in error cases */
3916         if (symbol == NULL)
3917                 return entity;
3918
3919         assert(!entity->base.parent_scope);
3920         assert(current_scope);
3921         entity->base.parent_scope = current_scope;
3922
3923         entity_t *const previous_entity = get_entity(symbol, namespc);
3924         /* pushing the same entity twice will break the stack structure */
3925         assert(previous_entity != entity);
3926
3927         if (entity->kind == ENTITY_FUNCTION) {
3928                 type_t *const orig_type = entity->declaration.type;
3929                 type_t *const type      = skip_typeref(orig_type);
3930
3931                 assert(is_type_function(type));
3932                 if (type->function.unspecified_parameters &&
3933                     previous_entity == NULL               &&
3934                     !entity->declaration.implicit) {
3935                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3936                 }
3937
3938                 if (is_main(entity)) {
3939                         check_main(entity);
3940                 }
3941         }
3942
3943         if (is_declaration(entity)                                    &&
3944             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3945             current_scope != file_scope                               &&
3946             !entity->declaration.implicit) {
3947                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3948         }
3949
3950         if (previous_entity != NULL) {
3951                 source_position_t const *const ppos = &previous_entity->base.source_position;
3952
3953                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3954                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3955                         assert(previous_entity->kind == ENTITY_PARAMETER);
3956                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3957                         goto finish;
3958                 }
3959
3960                 if (previous_entity->base.parent_scope == current_scope) {
3961                         if (previous_entity->kind != entity->kind) {
3962                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3963                                         error_redefined_as_different_kind(pos, previous_entity,
3964                                                         entity->kind);
3965                                 }
3966                                 goto finish;
3967                         }
3968                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3969                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3970                                 goto finish;
3971                         }
3972                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3973                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3974                                 type_t *const prev_type
3975                                         = skip_typeref(previous_entity->typedefe.type);
3976                                 if (c_mode & _CXX) {
3977                                         /* C++ allows double typedef if they are identical
3978                                          * (after skipping typedefs) */
3979                                         if (type == prev_type)
3980                                                 goto finish;
3981                                 } else {
3982                                         /* GCC extension: redef in system headers is allowed */
3983                                         if ((pos->is_system_header || ppos->is_system_header) &&
3984                                             types_compatible(type, prev_type))
3985                                                 goto finish;
3986                                 }
3987                                 errorf(pos, "redefinition of '%N' (declared %P)",
3988                                        entity, ppos);
3989                                 goto finish;
3990                         }
3991
3992                         /* at this point we should have only VARIABLES or FUNCTIONS */
3993                         assert(is_declaration(previous_entity) && is_declaration(entity));
3994
3995                         declaration_t *const prev_decl = &previous_entity->declaration;
3996                         declaration_t *const decl      = &entity->declaration;
3997
3998                         /* can happen for K&R style declarations */
3999                         if (prev_decl->type       == NULL             &&
4000                                         previous_entity->kind == ENTITY_PARAMETER &&
4001                                         entity->kind          == ENTITY_PARAMETER) {
4002                                 prev_decl->type                   = decl->type;
4003                                 prev_decl->storage_class          = decl->storage_class;
4004                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4005                                 prev_decl->modifiers              = decl->modifiers;
4006                                 return previous_entity;
4007                         }
4008
4009                         type_t *const type      = skip_typeref(decl->type);
4010                         type_t *const prev_type = skip_typeref(prev_decl->type);
4011
4012                         if (!types_compatible(type, prev_type)) {
4013                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4014                         } else {
4015                                 unsigned old_storage_class = prev_decl->storage_class;
4016
4017                                 if (is_definition                     &&
4018                                                 !prev_decl->used                  &&
4019                                                 !(prev_decl->modifiers & DM_USED) &&
4020                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4021                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4022                                 }
4023
4024                                 storage_class_t new_storage_class = decl->storage_class;
4025
4026                                 /* pretend no storage class means extern for function
4027                                  * declarations (except if the previous declaration is neither
4028                                  * none nor extern) */
4029                                 if (entity->kind == ENTITY_FUNCTION) {
4030                                         /* the previous declaration could have unspecified parameters or
4031                                          * be a typedef, so use the new type */
4032                                         if (prev_type->function.unspecified_parameters || is_definition)
4033                                                 prev_decl->type = type;
4034
4035                                         switch (old_storage_class) {
4036                                                 case STORAGE_CLASS_NONE:
4037                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4038                                                         /* FALLTHROUGH */
4039
4040                                                 case STORAGE_CLASS_EXTERN:
4041                                                         if (is_definition) {
4042                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4043                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4044                                                                 }
4045                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4046                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4047                                                         }
4048                                                         break;
4049
4050                                                 default:
4051                                                         break;
4052                                         }
4053                                 } else if (is_type_incomplete(prev_type)) {
4054                                         prev_decl->type = type;
4055                                 }
4056
4057                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4058                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4059
4060 warn_redundant_declaration: ;
4061                                         bool has_new_attrs
4062                                                 = has_new_attributes(prev_decl->attributes,
4063                                                                      decl->attributes);
4064                                         if (has_new_attrs) {
4065                                                 merge_in_attributes(decl, prev_decl->attributes);
4066                                         } else if (!is_definition        &&
4067                                                         is_type_valid(prev_type) &&
4068                                                         !pos->is_system_header) {
4069                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4070                                         }
4071                                 } else if (current_function == NULL) {
4072                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4073                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4074                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4075                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4076                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4077                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4078                                         } else {
4079                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4080                                                 if (c_mode & _CXX)
4081                                                         goto error_redeclaration;
4082                                                 goto warn_redundant_declaration;
4083                                         }
4084                                 } else if (is_type_valid(prev_type)) {
4085                                         if (old_storage_class == new_storage_class) {
4086 error_redeclaration:
4087                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4088                                         } else {
4089                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4090                                         }
4091                                 }
4092                         }
4093
4094                         prev_decl->modifiers |= decl->modifiers;
4095                         if (entity->kind == ENTITY_FUNCTION) {
4096                                 previous_entity->function.is_inline |= entity->function.is_inline;
4097                         }
4098                         return previous_entity;
4099                 }
4100
4101                 warning_t why;
4102                 if (is_warn_on(why = WARN_SHADOW) ||
4103                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4104                         char const *const what = get_entity_kind_name(previous_entity->kind);
4105                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4106                 }
4107         }
4108
4109         if (entity->kind == ENTITY_FUNCTION) {
4110                 if (is_definition &&
4111                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4112                                 !is_main(entity)) {
4113                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4114                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4115                         } else {
4116                                 goto warn_missing_declaration;
4117                         }
4118                 }
4119         } else if (entity->kind == ENTITY_VARIABLE) {
4120                 if (current_scope                     == file_scope &&
4121                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4122                                 !entity->declaration.implicit) {
4123 warn_missing_declaration:
4124                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4125                 }
4126         }
4127
4128 finish:
4129         environment_push(entity);
4130         append_entity(current_scope, entity);
4131
4132         return entity;
4133 }
4134
4135 static void parser_error_multiple_definition(entity_t *entity,
4136                 const source_position_t *source_position)
4137 {
4138         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4139 }
4140
4141 static bool is_declaration_specifier(const token_t *token)
4142 {
4143         switch (token->kind) {
4144                 DECLARATION_START
4145                         return true;
4146                 case T_IDENTIFIER:
4147                         return is_typedef_symbol(token->base.symbol);
4148
4149                 default:
4150                         return false;
4151         }
4152 }
4153
4154 static void parse_init_declarator_rest(entity_t *entity)
4155 {
4156         type_t *orig_type = type_error_type;
4157
4158         if (entity->base.kind == ENTITY_TYPEDEF) {
4159                 source_position_t const *const pos = &entity->base.source_position;
4160                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4161         } else {
4162                 assert(is_declaration(entity));
4163                 orig_type = entity->declaration.type;
4164         }
4165
4166         type_t *type = skip_typeref(orig_type);
4167
4168         if (entity->kind == ENTITY_VARIABLE
4169                         && entity->variable.initializer != NULL) {
4170                 parser_error_multiple_definition(entity, HERE);
4171         }
4172         eat('=');
4173
4174         declaration_t *const declaration = &entity->declaration;
4175         bool must_be_constant = false;
4176         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4177             entity->base.parent_scope  == file_scope) {
4178                 must_be_constant = true;
4179         }
4180
4181         if (is_type_function(type)) {
4182                 source_position_t const *const pos = &entity->base.source_position;
4183                 errorf(pos, "'%N' is initialized like a variable", entity);
4184                 orig_type = type_error_type;
4185         }
4186
4187         parse_initializer_env_t env;
4188         env.type             = orig_type;
4189         env.must_be_constant = must_be_constant;
4190         env.entity           = entity;
4191
4192         initializer_t *initializer = parse_initializer(&env);
4193
4194         if (entity->kind == ENTITY_VARIABLE) {
4195                 /* §6.7.5:22  array initializers for arrays with unknown size
4196                  * determine the array type size */
4197                 declaration->type            = env.type;
4198                 entity->variable.initializer = initializer;
4199         }
4200 }
4201
4202 /* parse rest of a declaration without any declarator */
4203 static void parse_anonymous_declaration_rest(
4204                 const declaration_specifiers_t *specifiers)
4205 {
4206         eat(';');
4207         anonymous_entity = NULL;
4208
4209         source_position_t const *const pos = &specifiers->source_position;
4210         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4211                         specifiers->thread_local) {
4212                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4213         }
4214
4215         type_t *type = specifiers->type;
4216         switch (type->kind) {
4217                 case TYPE_COMPOUND_STRUCT:
4218                 case TYPE_COMPOUND_UNION: {
4219                         if (type->compound.compound->base.symbol == NULL) {
4220                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4221                         }
4222                         break;
4223                 }
4224
4225                 case TYPE_ENUM:
4226                         break;
4227
4228                 default:
4229                         warningf(WARN_OTHER, pos, "empty declaration");
4230                         break;
4231         }
4232 }
4233
4234 static void check_variable_type_complete(entity_t *ent)
4235 {
4236         if (ent->kind != ENTITY_VARIABLE)
4237                 return;
4238
4239         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4240          *         type for the object shall be complete [...] */
4241         declaration_t *decl = &ent->declaration;
4242         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4243                         decl->storage_class == STORAGE_CLASS_STATIC)
4244                 return;
4245
4246         type_t *const type = skip_typeref(decl->type);
4247         if (!is_type_incomplete(type))
4248                 return;
4249
4250         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4251          * are given length one. */
4252         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4253                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4254                 return;
4255         }
4256
4257         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4258 }
4259
4260
4261 static void parse_declaration_rest(entity_t *ndeclaration,
4262                 const declaration_specifiers_t *specifiers,
4263                 parsed_declaration_func         finished_declaration,
4264                 declarator_flags_t              flags)
4265 {
4266         add_anchor_token(';');
4267         add_anchor_token(',');
4268         while (true) {
4269                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4270
4271                 if (token.kind == '=') {
4272                         parse_init_declarator_rest(entity);
4273                 } else if (entity->kind == ENTITY_VARIABLE) {
4274                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4275                          * [...] where the extern specifier is explicitly used. */
4276                         declaration_t *decl = &entity->declaration;
4277                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4278                             is_type_reference(skip_typeref(decl->type))) {
4279                                 source_position_t const *const pos = &entity->base.source_position;
4280                                 errorf(pos, "reference '%#N' must be initialized", entity);
4281                         }
4282                 }
4283
4284                 check_variable_type_complete(entity);
4285
4286                 if (!next_if(','))
4287                         break;
4288
4289                 add_anchor_token('=');
4290                 ndeclaration = parse_declarator(specifiers, flags);
4291                 rem_anchor_token('=');
4292         }
4293         rem_anchor_token(',');
4294         rem_anchor_token(';');
4295         expect(';');
4296
4297         anonymous_entity = NULL;
4298 }
4299
4300 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4301 {
4302         symbol_t *symbol = entity->base.symbol;
4303         if (symbol == NULL)
4304                 return entity;
4305
4306         assert(entity->base.namespc == NAMESPACE_NORMAL);
4307         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4308         if (previous_entity == NULL
4309                         || previous_entity->base.parent_scope != current_scope) {
4310                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4311                        symbol);
4312                 return entity;
4313         }
4314
4315         if (is_definition) {
4316                 errorf(HERE, "'%N' is initialised", entity);
4317         }
4318
4319         return record_entity(entity, false);
4320 }
4321
4322 static void parse_declaration(parsed_declaration_func finished_declaration,
4323                               declarator_flags_t      flags)
4324 {
4325         add_anchor_token(';');
4326         declaration_specifiers_t specifiers;
4327         parse_declaration_specifiers(&specifiers);
4328         rem_anchor_token(';');
4329
4330         if (token.kind == ';') {
4331                 parse_anonymous_declaration_rest(&specifiers);
4332         } else {
4333                 entity_t *entity = parse_declarator(&specifiers, flags);
4334                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4335         }
4336 }
4337
4338 /* §6.5.2.2:6 */
4339 static type_t *get_default_promoted_type(type_t *orig_type)
4340 {
4341         type_t *result = orig_type;
4342
4343         type_t *type = skip_typeref(orig_type);
4344         if (is_type_integer(type)) {
4345                 result = promote_integer(type);
4346         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4347                 result = type_double;
4348         }
4349
4350         return result;
4351 }
4352
4353 static void parse_kr_declaration_list(entity_t *entity)
4354 {
4355         if (entity->kind != ENTITY_FUNCTION)
4356                 return;
4357
4358         type_t *type = skip_typeref(entity->declaration.type);
4359         assert(is_type_function(type));
4360         if (!type->function.kr_style_parameters)
4361                 return;
4362
4363         add_anchor_token('{');
4364
4365         PUSH_SCOPE(&entity->function.parameters);
4366
4367         entity_t *parameter = entity->function.parameters.entities;
4368         for ( ; parameter != NULL; parameter = parameter->base.next) {
4369                 assert(parameter->base.parent_scope == NULL);
4370                 parameter->base.parent_scope = current_scope;
4371                 environment_push(parameter);
4372         }
4373
4374         /* parse declaration list */
4375         for (;;) {
4376                 switch (token.kind) {
4377                         DECLARATION_START
4378                         /* This covers symbols, which are no type, too, and results in
4379                          * better error messages.  The typical cases are misspelled type
4380                          * names and missing includes. */
4381                         case T_IDENTIFIER:
4382                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4383                                 break;
4384                         default:
4385                                 goto decl_list_end;
4386                 }
4387         }
4388 decl_list_end:
4389
4390         POP_SCOPE();
4391
4392         /* update function type */
4393         type_t *new_type = duplicate_type(type);
4394
4395         function_parameter_t  *parameters = NULL;
4396         function_parameter_t **anchor     = &parameters;
4397
4398         /* did we have an earlier prototype? */
4399         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4400         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4401                 proto_type = NULL;
4402
4403         function_parameter_t *proto_parameter = NULL;
4404         if (proto_type != NULL) {
4405                 type_t *proto_type_type = proto_type->declaration.type;
4406                 proto_parameter         = proto_type_type->function.parameters;
4407                 /* If a K&R function definition has a variadic prototype earlier, then
4408                  * make the function definition variadic, too. This should conform to
4409                  * §6.7.5.3:15 and §6.9.1:8. */
4410                 new_type->function.variadic = proto_type_type->function.variadic;
4411         } else {
4412                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4413                  * prototype */
4414                 new_type->function.unspecified_parameters = true;
4415         }
4416
4417         bool need_incompatible_warning = false;
4418         parameter = entity->function.parameters.entities;
4419         for (; parameter != NULL; parameter = parameter->base.next,
4420                         proto_parameter =
4421                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4422                 if (parameter->kind != ENTITY_PARAMETER)
4423                         continue;
4424
4425                 type_t *parameter_type = parameter->declaration.type;
4426                 if (parameter_type == NULL) {
4427                         source_position_t const* const pos = &parameter->base.source_position;
4428                         if (strict_mode) {
4429                                 errorf(pos, "no type specified for function '%N'", parameter);
4430                                 parameter_type = type_error_type;
4431                         } else {
4432                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4433                                 parameter_type = type_int;
4434                         }
4435                         parameter->declaration.type = parameter_type;
4436                 }
4437
4438                 semantic_parameter_incomplete(parameter);
4439
4440                 /* we need the default promoted types for the function type */
4441                 type_t *not_promoted = parameter_type;
4442                 parameter_type       = get_default_promoted_type(parameter_type);
4443
4444                 /* gcc special: if the type of the prototype matches the unpromoted
4445                  * type don't promote */
4446                 if (!strict_mode && proto_parameter != NULL) {
4447                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4448                         type_t *promo_skip   = skip_typeref(parameter_type);
4449                         type_t *param_skip   = skip_typeref(not_promoted);
4450                         if (!types_compatible(proto_p_type, promo_skip)
4451                                 && types_compatible(proto_p_type, param_skip)) {
4452                                 /* don't promote */
4453                                 need_incompatible_warning = true;
4454                                 parameter_type = not_promoted;
4455                         }
4456                 }
4457                 function_parameter_t *const function_parameter
4458                         = allocate_parameter(parameter_type);
4459
4460                 *anchor = function_parameter;
4461                 anchor  = &function_parameter->next;
4462         }
4463
4464         new_type->function.parameters = parameters;
4465         new_type = identify_new_type(new_type);
4466
4467         if (need_incompatible_warning) {
4468                 symbol_t          const *const sym  = entity->base.symbol;
4469                 source_position_t const *const pos  = &entity->base.source_position;
4470                 source_position_t const *const ppos = &proto_type->base.source_position;
4471                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4472         }
4473         entity->declaration.type = new_type;
4474
4475         rem_anchor_token('{');
4476 }
4477
4478 static bool first_err = true;
4479
4480 /**
4481  * When called with first_err set, prints the name of the current function,
4482  * else does noting.
4483  */
4484 static void print_in_function(void)
4485 {
4486         if (first_err) {
4487                 first_err = false;
4488                 char const *const file = current_function->base.base.source_position.input_name;
4489                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4490         }
4491 }
4492
4493 /**
4494  * Check if all labels are defined in the current function.
4495  * Check if all labels are used in the current function.
4496  */
4497 static void check_labels(void)
4498 {
4499         for (const goto_statement_t *goto_statement = goto_first;
4500             goto_statement != NULL;
4501             goto_statement = goto_statement->next) {
4502                 label_t *label = goto_statement->label;
4503                 if (label->base.source_position.input_name == NULL) {
4504                         print_in_function();
4505                         source_position_t const *const pos = &goto_statement->base.source_position;
4506                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4507                  }
4508         }
4509
4510         if (is_warn_on(WARN_UNUSED_LABEL)) {
4511                 for (const label_statement_t *label_statement = label_first;
4512                          label_statement != NULL;
4513                          label_statement = label_statement->next) {
4514                         label_t *label = label_statement->label;
4515
4516                         if (! label->used) {
4517                                 print_in_function();
4518                                 source_position_t const *const pos = &label_statement->base.source_position;
4519                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4520                         }
4521                 }
4522         }
4523 }
4524
4525 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4526 {
4527         entity_t const *const end = last != NULL ? last->base.next : NULL;
4528         for (; entity != end; entity = entity->base.next) {
4529                 if (!is_declaration(entity))
4530                         continue;
4531
4532                 declaration_t *declaration = &entity->declaration;
4533                 if (declaration->implicit)
4534                         continue;
4535
4536                 if (!declaration->used) {
4537                         print_in_function();
4538                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4539                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4540                         print_in_function();
4541                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4542                 }
4543         }
4544 }
4545
4546 static void check_unused_variables(statement_t *const stmt, void *const env)
4547 {
4548         (void)env;
4549
4550         switch (stmt->kind) {
4551                 case STATEMENT_DECLARATION: {
4552                         declaration_statement_t const *const decls = &stmt->declaration;
4553                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4554                         return;
4555                 }
4556
4557                 case STATEMENT_FOR:
4558                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4559                         return;
4560
4561                 default:
4562                         return;
4563         }
4564 }
4565
4566 /**
4567  * Check declarations of current_function for unused entities.
4568  */
4569 static void check_declarations(void)
4570 {
4571         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4572                 const scope_t *scope = &current_function->parameters;
4573                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4574         }
4575         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4576                 walk_statements(current_function->statement, check_unused_variables,
4577                                 NULL);
4578         }
4579 }
4580
4581 static int determine_truth(expression_t const* const cond)
4582 {
4583         return
4584                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4585                 fold_constant_to_bool(cond)                         ? 1 :
4586                 -1;
4587 }
4588
4589 static void check_reachable(statement_t *);
4590 static bool reaches_end;
4591
4592 static bool expression_returns(expression_t const *const expr)
4593 {
4594         switch (expr->kind) {
4595                 case EXPR_CALL: {
4596                         expression_t const *const func = expr->call.function;
4597                         type_t       const *const type = skip_typeref(func->base.type);
4598                         if (type->kind == TYPE_POINTER) {
4599                                 type_t const *const points_to
4600                                         = skip_typeref(type->pointer.points_to);
4601                                 if (points_to->kind == TYPE_FUNCTION
4602                                     && points_to->function.modifiers & DM_NORETURN)
4603                                         return false;
4604                         }
4605
4606                         if (!expression_returns(func))
4607                                 return false;
4608
4609                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4610                                 if (!expression_returns(arg->expression))
4611                                         return false;
4612                         }
4613
4614                         return true;
4615                 }
4616
4617                 case EXPR_REFERENCE:
4618                 case EXPR_ENUM_CONSTANT:
4619                 case EXPR_LITERAL_CASES:
4620                 case EXPR_LITERAL_CHARACTER:
4621                 case EXPR_STRING_LITERAL:
4622                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4623                 case EXPR_LABEL_ADDRESS:
4624                 case EXPR_CLASSIFY_TYPE:
4625                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4626                 case EXPR_ALIGNOF:
4627                 case EXPR_FUNCNAME:
4628                 case EXPR_BUILTIN_CONSTANT_P:
4629                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4630                 case EXPR_OFFSETOF:
4631                 case EXPR_ERROR:
4632                         return true;
4633
4634                 case EXPR_STATEMENT: {
4635                         bool old_reaches_end = reaches_end;
4636                         reaches_end = false;
4637                         check_reachable(expr->statement.statement);
4638                         bool returns = reaches_end;
4639                         reaches_end = old_reaches_end;
4640                         return returns;
4641                 }
4642
4643                 case EXPR_CONDITIONAL:
4644                         // TODO handle constant expression
4645
4646                         if (!expression_returns(expr->conditional.condition))
4647                                 return false;
4648
4649                         if (expr->conditional.true_expression != NULL
4650                                         && expression_returns(expr->conditional.true_expression))
4651                                 return true;
4652
4653                         return expression_returns(expr->conditional.false_expression);
4654
4655                 case EXPR_SELECT:
4656                         return expression_returns(expr->select.compound);
4657
4658                 case EXPR_ARRAY_ACCESS:
4659                         return
4660                                 expression_returns(expr->array_access.array_ref) &&
4661                                 expression_returns(expr->array_access.index);
4662
4663                 case EXPR_VA_START:
4664                         return expression_returns(expr->va_starte.ap);
4665
4666                 case EXPR_VA_ARG:
4667                         return expression_returns(expr->va_arge.ap);
4668
4669                 case EXPR_VA_COPY:
4670                         return expression_returns(expr->va_copye.src);
4671
4672                 case EXPR_UNARY_CASES_MANDATORY:
4673                         return expression_returns(expr->unary.value);
4674
4675                 case EXPR_UNARY_THROW:
4676                         return false;
4677
4678                 case EXPR_BINARY_CASES:
4679                         // TODO handle constant lhs of && and ||
4680                         return
4681                                 expression_returns(expr->binary.left) &&
4682                                 expression_returns(expr->binary.right);
4683         }
4684
4685         panic("unhandled expression");
4686 }
4687
4688 static bool initializer_returns(initializer_t const *const init)
4689 {
4690         switch (init->kind) {
4691                 case INITIALIZER_VALUE:
4692                         return expression_returns(init->value.value);
4693
4694                 case INITIALIZER_LIST: {
4695                         initializer_t * const*       i       = init->list.initializers;
4696                         initializer_t * const* const end     = i + init->list.len;
4697                         bool                         returns = true;
4698                         for (; i != end; ++i) {
4699                                 if (!initializer_returns(*i))
4700                                         returns = false;
4701                         }
4702                         return returns;
4703                 }
4704
4705                 case INITIALIZER_STRING:
4706                 case INITIALIZER_DESIGNATOR: // designators have no payload
4707                         return true;
4708         }
4709         panic("unhandled initializer");
4710 }
4711
4712 static bool noreturn_candidate;
4713
4714 static void check_reachable(statement_t *const stmt)
4715 {
4716         if (stmt->base.reachable)
4717                 return;
4718         if (stmt->kind != STATEMENT_DO_WHILE)
4719                 stmt->base.reachable = true;
4720
4721         statement_t *last = stmt;
4722         statement_t *next;
4723         switch (stmt->kind) {
4724                 case STATEMENT_ERROR:
4725                 case STATEMENT_EMPTY:
4726                 case STATEMENT_ASM:
4727                         next = stmt->base.next;
4728                         break;
4729
4730                 case STATEMENT_DECLARATION: {
4731                         declaration_statement_t const *const decl = &stmt->declaration;
4732                         entity_t                const *      ent  = decl->declarations_begin;
4733                         entity_t                const *const last_decl = decl->declarations_end;
4734                         if (ent != NULL) {
4735                                 for (;; ent = ent->base.next) {
4736                                         if (ent->kind                 == ENTITY_VARIABLE &&
4737                                             ent->variable.initializer != NULL            &&
4738                                             !initializer_returns(ent->variable.initializer)) {
4739                                                 return;
4740                                         }
4741                                         if (ent == last_decl)
4742                                                 break;
4743                                 }
4744                         }
4745                         next = stmt->base.next;
4746                         break;
4747                 }
4748
4749                 case STATEMENT_COMPOUND:
4750                         next = stmt->compound.statements;
4751                         if (next == NULL)
4752                                 next = stmt->base.next;
4753                         break;
4754
4755                 case STATEMENT_RETURN: {
4756                         expression_t const *const val = stmt->returns.value;
4757                         if (val == NULL || expression_returns(val))
4758                                 noreturn_candidate = false;
4759                         return;
4760                 }
4761
4762                 case STATEMENT_IF: {
4763                         if_statement_t const *const ifs  = &stmt->ifs;
4764                         expression_t   const *const cond = ifs->condition;
4765
4766                         if (!expression_returns(cond))
4767                                 return;
4768
4769                         int const val = determine_truth(cond);
4770
4771                         if (val >= 0)
4772                                 check_reachable(ifs->true_statement);
4773
4774                         if (val > 0)
4775                                 return;
4776
4777                         if (ifs->false_statement != NULL) {
4778                                 check_reachable(ifs->false_statement);
4779                                 return;
4780                         }
4781
4782                         next = stmt->base.next;
4783                         break;
4784                 }
4785
4786                 case STATEMENT_SWITCH: {
4787                         switch_statement_t const *const switchs = &stmt->switchs;
4788                         expression_t       const *const expr    = switchs->expression;
4789
4790                         if (!expression_returns(expr))
4791                                 return;
4792
4793                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4794                                 long                    const val      = fold_constant_to_int(expr);
4795                                 case_label_statement_t *      defaults = NULL;
4796                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4797                                         if (i->expression == NULL) {
4798                                                 defaults = i;
4799                                                 continue;
4800                                         }
4801
4802                                         if (i->first_case <= val && val <= i->last_case) {
4803                                                 check_reachable((statement_t*)i);
4804                                                 return;
4805                                         }
4806                                 }
4807
4808                                 if (defaults != NULL) {
4809                                         check_reachable((statement_t*)defaults);
4810                                         return;
4811                                 }
4812                         } else {
4813                                 bool has_default = false;
4814                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4815                                         if (i->expression == NULL)
4816                                                 has_default = true;
4817
4818                                         check_reachable((statement_t*)i);
4819                                 }
4820
4821                                 if (has_default)
4822                                         return;
4823                         }
4824
4825                         next = stmt->base.next;
4826                         break;
4827                 }
4828
4829                 case STATEMENT_EXPRESSION: {
4830                         /* Check for noreturn function call */
4831                         expression_t const *const expr = stmt->expression.expression;
4832                         if (!expression_returns(expr))
4833                                 return;
4834
4835                         next = stmt->base.next;
4836                         break;
4837                 }
4838
4839                 case STATEMENT_CONTINUE:
4840                         for (statement_t *parent = stmt;;) {
4841                                 parent = parent->base.parent;
4842                                 if (parent == NULL) /* continue not within loop */
4843                                         return;
4844
4845                                 next = parent;
4846                                 switch (parent->kind) {
4847                                         case STATEMENT_WHILE:    goto continue_while;
4848                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4849                                         case STATEMENT_FOR:      goto continue_for;
4850
4851                                         default: break;
4852                                 }
4853                         }
4854
4855                 case STATEMENT_BREAK:
4856                         for (statement_t *parent = stmt;;) {
4857                                 parent = parent->base.parent;
4858                                 if (parent == NULL) /* break not within loop/switch */
4859                                         return;
4860
4861                                 switch (parent->kind) {
4862                                         case STATEMENT_SWITCH:
4863                                         case STATEMENT_WHILE:
4864                                         case STATEMENT_DO_WHILE:
4865                                         case STATEMENT_FOR:
4866                                                 last = parent;
4867                                                 next = parent->base.next;
4868                                                 goto found_break_parent;
4869
4870                                         default: break;
4871                                 }
4872                         }
4873 found_break_parent:
4874                         break;
4875
4876                 case STATEMENT_COMPUTED_GOTO: {
4877                         if (!expression_returns(stmt->computed_goto.expression))
4878                                 return;
4879
4880                         statement_t *parent = stmt->base.parent;
4881                         if (parent == NULL) /* top level goto */
4882                                 return;
4883                         next = parent;
4884                         break;
4885                 }
4886
4887                 case STATEMENT_GOTO:
4888                         next = stmt->gotos.label->statement;
4889                         if (next == NULL) /* missing label */
4890                                 return;
4891                         break;
4892
4893                 case STATEMENT_LABEL:
4894                         next = stmt->label.statement;
4895                         break;
4896
4897                 case STATEMENT_CASE_LABEL:
4898                         next = stmt->case_label.statement;
4899                         break;
4900
4901                 case STATEMENT_WHILE: {
4902                         while_statement_t const *const whiles = &stmt->whiles;
4903                         expression_t      const *const cond   = whiles->condition;
4904
4905                         if (!expression_returns(cond))
4906                                 return;
4907
4908                         int const val = determine_truth(cond);
4909
4910                         if (val >= 0)
4911                                 check_reachable(whiles->body);
4912
4913                         if (val > 0)
4914                                 return;
4915
4916                         next = stmt->base.next;
4917                         break;
4918                 }
4919
4920                 case STATEMENT_DO_WHILE:
4921                         next = stmt->do_while.body;
4922                         break;
4923
4924                 case STATEMENT_FOR: {
4925                         for_statement_t *const fors = &stmt->fors;
4926
4927                         if (fors->condition_reachable)
4928                                 return;
4929                         fors->condition_reachable = true;
4930
4931                         expression_t const *const cond = fors->condition;
4932
4933                         int val;
4934                         if (cond == NULL) {
4935                                 val = 1;
4936                         } else if (expression_returns(cond)) {
4937                                 val = determine_truth(cond);
4938                         } else {
4939                                 return;
4940                         }
4941
4942                         if (val >= 0)
4943                                 check_reachable(fors->body);
4944
4945                         if (val > 0)
4946                                 return;
4947
4948                         next = stmt->base.next;
4949                         break;
4950                 }
4951
4952                 case STATEMENT_MS_TRY: {
4953                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4954                         check_reachable(ms_try->try_statement);
4955                         next = ms_try->final_statement;
4956                         break;
4957                 }
4958
4959                 case STATEMENT_LEAVE: {
4960                         statement_t *parent = stmt;
4961                         for (;;) {
4962                                 parent = parent->base.parent;
4963                                 if (parent == NULL) /* __leave not within __try */
4964                                         return;
4965
4966                                 if (parent->kind == STATEMENT_MS_TRY) {
4967                                         last = parent;
4968                                         next = parent->ms_try.final_statement;
4969                                         break;
4970                                 }
4971                         }
4972                         break;
4973                 }
4974
4975                 default:
4976                         panic("invalid statement kind");
4977         }
4978
4979         while (next == NULL) {
4980                 next = last->base.parent;
4981                 if (next == NULL) {
4982                         noreturn_candidate = false;
4983
4984                         type_t *const type = skip_typeref(current_function->base.type);
4985                         assert(is_type_function(type));
4986                         type_t *const ret  = skip_typeref(type->function.return_type);
4987                         if (!is_type_void(ret) &&
4988                             is_type_valid(ret) &&
4989                             !is_main(current_entity)) {
4990                                 source_position_t const *const pos = &stmt->base.source_position;
4991                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4992                         }
4993                         return;
4994                 }
4995
4996                 switch (next->kind) {
4997                         case STATEMENT_ERROR:
4998                         case STATEMENT_EMPTY:
4999                         case STATEMENT_DECLARATION:
5000                         case STATEMENT_EXPRESSION:
5001                         case STATEMENT_ASM:
5002                         case STATEMENT_RETURN:
5003                         case STATEMENT_CONTINUE:
5004                         case STATEMENT_BREAK:
5005                         case STATEMENT_COMPUTED_GOTO:
5006                         case STATEMENT_GOTO:
5007                         case STATEMENT_LEAVE:
5008                                 panic("invalid control flow in function");
5009
5010                         case STATEMENT_COMPOUND:
5011                                 if (next->compound.stmt_expr) {
5012                                         reaches_end = true;
5013                                         return;
5014                                 }
5015                                 /* FALLTHROUGH */
5016                         case STATEMENT_IF:
5017                         case STATEMENT_SWITCH:
5018                         case STATEMENT_LABEL:
5019                         case STATEMENT_CASE_LABEL:
5020                                 last = next;
5021                                 next = next->base.next;
5022                                 break;
5023
5024                         case STATEMENT_WHILE: {
5025 continue_while:
5026                                 if (next->base.reachable)
5027                                         return;
5028                                 next->base.reachable = true;
5029
5030                                 while_statement_t const *const whiles = &next->whiles;
5031                                 expression_t      const *const cond   = whiles->condition;
5032
5033                                 if (!expression_returns(cond))
5034                                         return;
5035
5036                                 int const val = determine_truth(cond);
5037
5038                                 if (val >= 0)
5039                                         check_reachable(whiles->body);
5040
5041                                 if (val > 0)
5042                                         return;
5043
5044                                 last = next;
5045                                 next = next->base.next;
5046                                 break;
5047                         }
5048
5049                         case STATEMENT_DO_WHILE: {
5050 continue_do_while:
5051                                 if (next->base.reachable)
5052                                         return;
5053                                 next->base.reachable = true;
5054
5055                                 do_while_statement_t const *const dw   = &next->do_while;
5056                                 expression_t         const *const cond = dw->condition;
5057
5058                                 if (!expression_returns(cond))
5059                                         return;
5060
5061                                 int const val = determine_truth(cond);
5062
5063                                 if (val >= 0)
5064                                         check_reachable(dw->body);
5065
5066                                 if (val > 0)
5067                                         return;
5068
5069                                 last = next;
5070                                 next = next->base.next;
5071                                 break;
5072                         }
5073
5074                         case STATEMENT_FOR: {
5075 continue_for:;
5076                                 for_statement_t *const fors = &next->fors;
5077
5078                                 fors->step_reachable = true;
5079
5080                                 if (fors->condition_reachable)
5081                                         return;
5082                                 fors->condition_reachable = true;
5083
5084                                 expression_t const *const cond = fors->condition;
5085
5086                                 int val;
5087                                 if (cond == NULL) {
5088                                         val = 1;
5089                                 } else if (expression_returns(cond)) {
5090                                         val = determine_truth(cond);
5091                                 } else {
5092                                         return;
5093                                 }
5094
5095                                 if (val >= 0)
5096                                         check_reachable(fors->body);
5097
5098                                 if (val > 0)
5099                                         return;
5100
5101                                 last = next;
5102                                 next = next->base.next;
5103                                 break;
5104                         }
5105
5106                         case STATEMENT_MS_TRY:
5107                                 last = next;
5108                                 next = next->ms_try.final_statement;
5109                                 break;
5110                 }
5111         }
5112
5113         check_reachable(next);
5114 }
5115
5116 static void check_unreachable(statement_t* const stmt, void *const env)
5117 {
5118         (void)env;
5119
5120         switch (stmt->kind) {
5121                 case STATEMENT_DO_WHILE:
5122                         if (!stmt->base.reachable) {
5123                                 expression_t const *const cond = stmt->do_while.condition;
5124                                 if (determine_truth(cond) >= 0) {
5125                                         source_position_t const *const pos = &cond->base.source_position;
5126                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5127                                 }
5128                         }
5129                         return;
5130
5131                 case STATEMENT_FOR: {
5132                         for_statement_t const* const fors = &stmt->fors;
5133
5134                         // if init and step are unreachable, cond is unreachable, too
5135                         if (!stmt->base.reachable && !fors->step_reachable) {
5136                                 goto warn_unreachable;
5137                         } else {
5138                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5139                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5140                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5141                                 }
5142
5143                                 if (!fors->condition_reachable && fors->condition != NULL) {
5144                                         source_position_t const *const pos = &fors->condition->base.source_position;
5145                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5146                                 }
5147
5148                                 if (!fors->step_reachable && fors->step != NULL) {
5149                                         source_position_t const *const pos = &fors->step->base.source_position;
5150                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5151                                 }
5152                         }
5153                         return;
5154                 }
5155
5156                 case STATEMENT_COMPOUND:
5157                         if (stmt->compound.statements != NULL)
5158                                 return;
5159                         goto warn_unreachable;
5160
5161                 case STATEMENT_DECLARATION: {
5162                         /* Only warn if there is at least one declarator with an initializer.
5163                          * This typically occurs in switch statements. */
5164                         declaration_statement_t const *const decl = &stmt->declaration;
5165                         entity_t                const *      ent  = decl->declarations_begin;
5166                         entity_t                const *const last = decl->declarations_end;
5167                         if (ent != NULL) {
5168                                 for (;; ent = ent->base.next) {
5169                                         if (ent->kind                 == ENTITY_VARIABLE &&
5170                                                         ent->variable.initializer != NULL) {
5171                                                 goto warn_unreachable;
5172                                         }
5173                                         if (ent == last)
5174                                                 return;
5175                                 }
5176                         }
5177                 }
5178
5179                 default:
5180 warn_unreachable:
5181                         if (!stmt->base.reachable) {
5182                                 source_position_t const *const pos = &stmt->base.source_position;
5183                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5184                         }
5185                         return;
5186         }
5187 }
5188
5189 static bool is_main(entity_t *entity)
5190 {
5191         static symbol_t *sym_main = NULL;
5192         if (sym_main == NULL) {
5193                 sym_main = symbol_table_insert("main");
5194         }
5195
5196         if (entity->base.symbol != sym_main)
5197                 return false;
5198         /* must be in outermost scope */
5199         if (entity->base.parent_scope != file_scope)
5200                 return false;
5201
5202         return true;
5203 }
5204
5205 static void prepare_main_collect2(entity_t*);
5206
5207 static void parse_external_declaration(void)
5208 {
5209         /* function-definitions and declarations both start with declaration
5210          * specifiers */
5211         add_anchor_token(';');
5212         declaration_specifiers_t specifiers;
5213         parse_declaration_specifiers(&specifiers);
5214         rem_anchor_token(';');
5215
5216         /* must be a declaration */
5217         if (token.kind == ';') {
5218                 parse_anonymous_declaration_rest(&specifiers);
5219                 return;
5220         }
5221
5222         add_anchor_token(',');
5223         add_anchor_token('=');
5224         add_anchor_token(';');
5225         add_anchor_token('{');
5226
5227         /* declarator is common to both function-definitions and declarations */
5228         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5229
5230         rem_anchor_token('{');
5231         rem_anchor_token(';');
5232         rem_anchor_token('=');
5233         rem_anchor_token(',');
5234
5235         /* must be a declaration */
5236         switch (token.kind) {
5237                 case ',':
5238                 case ';':
5239                 case '=':
5240                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5241                                         DECL_FLAGS_NONE);
5242                         return;
5243         }
5244
5245         /* must be a function definition */
5246         parse_kr_declaration_list(ndeclaration);
5247
5248         if (token.kind != '{') {
5249                 parse_error_expected("while parsing function definition", '{', NULL);
5250                 eat_until_matching_token(';');
5251                 return;
5252         }
5253
5254         assert(is_declaration(ndeclaration));
5255         type_t *const orig_type = ndeclaration->declaration.type;
5256         type_t *      type      = skip_typeref(orig_type);
5257
5258         if (!is_type_function(type)) {
5259                 if (is_type_valid(type)) {
5260                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5261                 }
5262                 eat_block();
5263                 return;
5264         }
5265
5266         source_position_t const *const pos = &ndeclaration->base.source_position;
5267         if (is_typeref(orig_type)) {
5268                 /* §6.9.1:2 */
5269                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5270         }
5271
5272         if (is_type_compound(skip_typeref(type->function.return_type))) {
5273                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5274         }
5275         if (type->function.unspecified_parameters) {
5276                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5277         } else {
5278                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5279         }
5280
5281         /* §6.7.5.3:14 a function definition with () means no
5282          * parameters (and not unspecified parameters) */
5283         if (type->function.unspecified_parameters &&
5284                         type->function.parameters == NULL) {
5285                 type_t *copy                          = duplicate_type(type);
5286                 copy->function.unspecified_parameters = false;
5287                 type                                  = identify_new_type(copy);
5288
5289                 ndeclaration->declaration.type = type;
5290         }
5291
5292         entity_t *const entity = record_entity(ndeclaration, true);
5293         assert(entity->kind == ENTITY_FUNCTION);
5294         assert(ndeclaration->kind == ENTITY_FUNCTION);
5295
5296         function_t *const function = &entity->function;
5297         if (ndeclaration != entity) {
5298                 function->parameters = ndeclaration->function.parameters;
5299         }
5300
5301         PUSH_SCOPE(&function->parameters);
5302
5303         entity_t *parameter = function->parameters.entities;
5304         for (; parameter != NULL; parameter = parameter->base.next) {
5305                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5306                         parameter->base.parent_scope = current_scope;
5307                 }
5308                 assert(parameter->base.parent_scope == NULL
5309                                 || parameter->base.parent_scope == current_scope);
5310                 parameter->base.parent_scope = current_scope;
5311                 if (parameter->base.symbol == NULL) {
5312                         errorf(&parameter->base.source_position, "parameter name omitted");
5313                         continue;
5314                 }
5315                 environment_push(parameter);
5316         }
5317
5318         if (function->statement != NULL) {
5319                 parser_error_multiple_definition(entity, HERE);
5320                 eat_block();
5321         } else {
5322                 /* parse function body */
5323                 int         label_stack_top      = label_top();
5324                 function_t *old_current_function = current_function;
5325                 current_function                 = function;
5326                 PUSH_CURRENT_ENTITY(entity);
5327                 PUSH_PARENT(NULL);
5328
5329                 goto_first   = NULL;
5330                 goto_anchor  = &goto_first;
5331                 label_first  = NULL;
5332                 label_anchor = &label_first;
5333
5334                 statement_t *const body = parse_compound_statement(false);
5335                 function->statement = body;
5336                 first_err = true;
5337                 check_labels();
5338                 check_declarations();
5339                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5340                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5341                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5342                         noreturn_candidate = true;
5343                         check_reachable(body);
5344                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5345                                 walk_statements(body, check_unreachable, NULL);
5346                         if (noreturn_candidate &&
5347                             !(function->base.modifiers & DM_NORETURN)) {
5348                                 source_position_t const *const pos = &body->base.source_position;
5349                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5350                         }
5351                 }
5352
5353                 if (is_main(entity)) {
5354                         /* Force main to C linkage. */
5355                         type_t *const type = entity->declaration.type;
5356                         assert(is_type_function(type));
5357                         if (type->function.linkage != LINKAGE_C) {
5358                                 type_t *new_type           = duplicate_type(type);
5359                                 new_type->function.linkage = LINKAGE_C;
5360                                 entity->declaration.type   = identify_new_type(new_type);
5361                         }
5362
5363                         if (enable_main_collect2_hack)
5364                                 prepare_main_collect2(entity);
5365                 }
5366
5367                 POP_CURRENT_ENTITY();
5368                 POP_PARENT();
5369                 assert(current_function == function);
5370                 current_function = old_current_function;
5371                 label_pop_to(label_stack_top);
5372         }
5373
5374         POP_SCOPE();
5375 }
5376
5377 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5378 {
5379         entity_t *iter = compound->members.entities;
5380         for (; iter != NULL; iter = iter->base.next) {
5381                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5382                         continue;
5383
5384                 if (iter->base.symbol == symbol) {
5385                         return iter;
5386                 } else if (iter->base.symbol == NULL) {
5387                         /* search in anonymous structs and unions */
5388                         type_t *type = skip_typeref(iter->declaration.type);
5389                         if (is_type_compound(type)) {
5390                                 if (find_compound_entry(type->compound.compound, symbol)
5391                                                 != NULL)
5392                                         return iter;
5393                         }
5394                         continue;
5395                 }
5396         }
5397
5398         return NULL;
5399 }
5400
5401 static void check_deprecated(const source_position_t *source_position,
5402                              const entity_t *entity)
5403 {
5404         if (!is_declaration(entity))
5405                 return;
5406         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5407                 return;
5408
5409         source_position_t const *const epos = &entity->base.source_position;
5410         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5411         if (msg != NULL) {
5412                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5413         } else {
5414                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5415         }
5416 }
5417
5418
5419 static expression_t *create_select(const source_position_t *pos,
5420                                    expression_t *addr,
5421                                    type_qualifiers_t qualifiers,
5422                                                                    entity_t *entry)
5423 {
5424         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5425
5426         check_deprecated(pos, entry);
5427
5428         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5429         select->select.compound       = addr;
5430         select->select.compound_entry = entry;
5431
5432         type_t *entry_type = entry->declaration.type;
5433         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5434
5435         /* bitfields need special treatment */
5436         if (entry->compound_member.bitfield) {
5437                 unsigned bit_size = entry->compound_member.bit_size;
5438                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5439                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5440                         res_type = type_int;
5441                 }
5442         }
5443
5444         /* we always do the auto-type conversions; the & and sizeof parser contains
5445          * code to revert this! */
5446         select->base.type = automatic_type_conversion(res_type);
5447
5448
5449         return select;
5450 }
5451
5452 /**
5453  * Find entry with symbol in compound. Search anonymous structs and unions and
5454  * creates implicit select expressions for them.
5455  * Returns the adress for the innermost compound.
5456  */
5457 static expression_t *find_create_select(const source_position_t *pos,
5458                                         expression_t *addr,
5459                                         type_qualifiers_t qualifiers,
5460                                         compound_t *compound, symbol_t *symbol)
5461 {
5462         entity_t *iter = compound->members.entities;
5463         for (; iter != NULL; iter = iter->base.next) {
5464                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5465                         continue;
5466
5467                 symbol_t *iter_symbol = iter->base.symbol;
5468                 if (iter_symbol == NULL) {
5469                         type_t *type = iter->declaration.type;
5470                         if (!is_type_compound(type))
5471                                 continue;
5472
5473                         compound_t *sub_compound = type->compound.compound;
5474
5475                         if (find_compound_entry(sub_compound, symbol) == NULL)
5476                                 continue;
5477
5478                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5479                         sub_addr->base.source_position = *pos;
5480                         sub_addr->base.implicit        = true;
5481                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5482                                                   symbol);
5483                 }
5484
5485                 if (iter_symbol == symbol) {
5486                         return create_select(pos, addr, qualifiers, iter);
5487                 }
5488         }
5489
5490         return NULL;
5491 }
5492
5493 static void parse_bitfield_member(entity_t *entity)
5494 {
5495         eat(':');
5496
5497         expression_t *size = parse_constant_expression();
5498         long          size_long;
5499
5500         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5501         type_t *type = entity->declaration.type;
5502         if (!is_type_integer(skip_typeref(type))) {
5503                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5504                            type);
5505         }
5506
5507         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5508                 /* error already reported by parse_constant_expression */
5509                 size_long = get_type_size(type) * 8;
5510         } else {
5511                 size_long = fold_constant_to_int(size);
5512
5513                 const symbol_t *symbol = entity->base.symbol;
5514                 const symbol_t *user_symbol
5515                         = symbol == NULL ? sym_anonymous : symbol;
5516                 unsigned bit_size = get_type_size(type) * 8;
5517                 if (size_long < 0) {
5518                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5519                 } else if (size_long == 0 && symbol != NULL) {
5520                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5521                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5522                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5523                                    user_symbol);
5524                 } else {
5525                         /* hope that people don't invent crazy types with more bits
5526                          * than our struct can hold */
5527                         assert(size_long <
5528                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5529                 }
5530         }
5531
5532         entity->compound_member.bitfield = true;
5533         entity->compound_member.bit_size = (unsigned char)size_long;
5534 }
5535
5536 static void parse_compound_declarators(compound_t *compound,
5537                 const declaration_specifiers_t *specifiers)
5538 {
5539         add_anchor_token(';');
5540         add_anchor_token(',');
5541         do {
5542                 entity_t *entity;
5543
5544                 if (token.kind == ':') {
5545                         /* anonymous bitfield */
5546                         type_t *type = specifiers->type;
5547                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5548                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5549                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5550                         entity->declaration.type                   = type;
5551
5552                         parse_bitfield_member(entity);
5553
5554                         attribute_t  *attributes = parse_attributes(NULL);
5555                         attribute_t **anchor     = &attributes;
5556                         while (*anchor != NULL)
5557                                 anchor = &(*anchor)->next;
5558                         *anchor = specifiers->attributes;
5559                         if (attributes != NULL) {
5560                                 handle_entity_attributes(attributes, entity);
5561                         }
5562                         entity->declaration.attributes = attributes;
5563
5564                         append_entity(&compound->members, entity);
5565                 } else {
5566                         entity = parse_declarator(specifiers,
5567                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5568                         source_position_t const *const pos = &entity->base.source_position;
5569                         if (entity->kind == ENTITY_TYPEDEF) {
5570                                 errorf(pos, "typedef not allowed as compound member");
5571                         } else {
5572                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5573
5574                                 /* make sure we don't define a symbol multiple times */
5575                                 symbol_t *symbol = entity->base.symbol;
5576                                 if (symbol != NULL) {
5577                                         entity_t *prev = find_compound_entry(compound, symbol);
5578                                         if (prev != NULL) {
5579                                                 source_position_t const *const ppos = &prev->base.source_position;
5580                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5581                                         }
5582                                 }
5583
5584                                 if (token.kind == ':') {
5585                                         parse_bitfield_member(entity);
5586
5587                                         attribute_t *attributes = parse_attributes(NULL);
5588                                         handle_entity_attributes(attributes, entity);
5589                                 } else {
5590                                         type_t *orig_type = entity->declaration.type;
5591                                         type_t *type      = skip_typeref(orig_type);
5592                                         if (is_type_function(type)) {
5593                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5594                                         } else if (is_type_incomplete(type)) {
5595                                                 /* §6.7.2.1:16 flexible array member */
5596                                                 if (!is_type_array(type)       ||
5597                                                                 token.kind          != ';' ||
5598                                                                 look_ahead(1)->kind != '}') {
5599                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5600                                                 } else if (compound->members.entities == NULL) {
5601                                                         errorf(pos, "flexible array member in otherwise empty struct");
5602                                                 }
5603                                         }
5604                                 }
5605
5606                                 append_entity(&compound->members, entity);
5607                         }
5608                 }
5609         } while (next_if(','));
5610         rem_anchor_token(',');
5611         rem_anchor_token(';');
5612         expect(';');
5613
5614         anonymous_entity = NULL;
5615 }
5616
5617 static void parse_compound_type_entries(compound_t *compound)
5618 {
5619         eat('{');
5620         add_anchor_token('}');
5621
5622         for (;;) {
5623                 switch (token.kind) {
5624                         DECLARATION_START
5625                         case T___extension__:
5626                         case T_IDENTIFIER: {
5627                                 PUSH_EXTENSION();
5628                                 declaration_specifiers_t specifiers;
5629                                 parse_declaration_specifiers(&specifiers);
5630                                 parse_compound_declarators(compound, &specifiers);
5631                                 POP_EXTENSION();
5632                                 break;
5633                         }
5634
5635                         default:
5636                                 rem_anchor_token('}');
5637                                 expect('}');
5638                                 /* §6.7.2.1:7 */
5639                                 compound->complete = true;
5640                                 return;
5641                 }
5642         }
5643 }
5644
5645 static type_t *parse_typename(void)
5646 {
5647         declaration_specifiers_t specifiers;
5648         parse_declaration_specifiers(&specifiers);
5649         if (specifiers.storage_class != STORAGE_CLASS_NONE
5650                         || specifiers.thread_local) {
5651                 /* TODO: improve error message, user does probably not know what a
5652                  * storage class is...
5653                  */
5654                 errorf(&specifiers.source_position, "typename must not have a storage class");
5655         }
5656
5657         type_t *result = parse_abstract_declarator(specifiers.type);
5658
5659         return result;
5660 }
5661
5662
5663
5664
5665 typedef expression_t* (*parse_expression_function)(void);
5666 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5667
5668 typedef struct expression_parser_function_t expression_parser_function_t;
5669 struct expression_parser_function_t {
5670         parse_expression_function        parser;
5671         precedence_t                     infix_precedence;
5672         parse_expression_infix_function  infix_parser;
5673 };
5674
5675 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5676
5677 static type_t *get_string_type(string_encoding_t const enc)
5678 {
5679         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5680         switch (enc) {
5681         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5682         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5683         }
5684         panic("invalid string encoding");
5685 }
5686
5687 /**
5688  * Parse a string constant.
5689  */
5690 static expression_t *parse_string_literal(void)
5691 {
5692         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5693         expr->string_literal.value = concat_string_literals();
5694         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5695         return expr;
5696 }
5697
5698 /**
5699  * Parse a boolean constant.
5700  */
5701 static expression_t *parse_boolean_literal(bool value)
5702 {
5703         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5704         literal->base.type           = type_bool;
5705         literal->literal.value.begin = value ? "true" : "false";
5706         literal->literal.value.size  = value ? 4 : 5;
5707
5708         eat(value ? T_true : T_false);
5709         return literal;
5710 }
5711
5712 static void warn_traditional_suffix(char const *const suffix)
5713 {
5714         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5715 }
5716
5717 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5718 {
5719         specifiers_t spec = SPECIFIER_NONE;
5720         char const  *c    = suffix;
5721         for (;;) {
5722                 specifiers_t add;
5723                 if (*c == 'L' || *c == 'l') {
5724                         add = SPECIFIER_LONG;
5725                         if (*c == c[1]) {
5726                                 add |= SPECIFIER_LONG_LONG;
5727                                 ++c;
5728                         }
5729                 } else if (*c == 'U' || *c == 'u') {
5730                         add = SPECIFIER_UNSIGNED;
5731                 } else {
5732                         break;
5733                 }
5734                 ++c;
5735                 if (spec & add)
5736                         goto error;
5737                 spec |= add;
5738         }
5739
5740         if (*c == '\0') {
5741                 type_t *type;
5742                 switch (spec) {
5743                 case SPECIFIER_NONE:                                            type = type_int;                break;
5744                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5745                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5746                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5747                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5748                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5749                 default: panic("inconsistent suffix");
5750                 }
5751                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5752                         warn_traditional_suffix(suffix);
5753                 }
5754                 expr->base.type = type;
5755                 /* Integer type depends on the size of the number and the size
5756                  * representable by the types. The backend/codegeneration has to
5757                  * determine that. */
5758                 determine_literal_type(&expr->literal);
5759         } else {
5760 error:
5761                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5762         }
5763 }
5764
5765 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5766 {
5767         type_t     *type;
5768         char const *c    = suffix;
5769         switch (*c) {
5770         case 'F':
5771         case 'f': type = type_float;       ++c; break;
5772         case 'L':
5773         case 'l': type = type_long_double; ++c; break;
5774         default:  type = type_double;           break;
5775         }
5776
5777         if (*c == '\0') {
5778                 expr->base.type = type;
5779                 if (suffix[0] != '\0') {
5780                         warn_traditional_suffix(suffix);
5781                 }
5782         } else {
5783                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5784         }
5785 }
5786
5787 static expression_t *parse_number_literal(void)
5788 {
5789         string_t const *const str      = &token.literal.string;
5790         char     const *      i        = str->begin;
5791         unsigned              digits   = 0;
5792         bool                  is_float = false;
5793
5794         /* Parse base prefix. */
5795         unsigned base;
5796         if (*i == '0') {
5797                 switch (*++i) {
5798                 case 'B': case 'b': base =  2; ++i;               break;
5799                 case 'X': case 'x': base = 16; ++i;               break;
5800                 default:            base =  8; digits |= 1U << 0; break;
5801                 }
5802         } else {
5803                 base = 10;
5804         }
5805
5806         /* Parse mantissa. */
5807         for (;; ++i) {
5808                 unsigned digit;
5809                 switch (*i) {
5810                 case '.':
5811                         if (is_float) {
5812                                 errorf(HERE, "multiple decimal points in %K", &token);
5813                                 i = 0;
5814                                 goto done;
5815                         }
5816                         is_float = true;
5817                         if (base == 8)
5818                                 base = 10;
5819                         continue;
5820
5821                 case '0':           digit =  0; break;
5822                 case '1':           digit =  1; break;
5823                 case '2':           digit =  2; break;
5824                 case '3':           digit =  3; break;
5825                 case '4':           digit =  4; break;
5826                 case '5':           digit =  5; break;
5827                 case '6':           digit =  6; break;
5828                 case '7':           digit =  7; break;
5829                 case '8':           digit =  8; break;
5830                 case '9':           digit =  9; break;
5831                 case 'A': case 'a': digit = 10; break;
5832                 case 'B': case 'b': digit = 11; break;
5833                 case 'C': case 'c': digit = 12; break;
5834                 case 'D': case 'd': digit = 13; break;
5835                 case 'E': case 'e': digit = 14; break;
5836                 case 'F': case 'f': digit = 15; break;
5837
5838                 default: goto done_mantissa;
5839                 }
5840
5841                 if (digit >= 10 && base != 16)
5842                         goto done_mantissa;
5843
5844                 digits |= 1U << digit;
5845         }
5846 done_mantissa:
5847
5848         /* Parse exponent. */
5849         switch (base) {
5850         case 2:
5851                 if (is_float)
5852                         errorf(HERE, "binary floating %K not allowed", &token);
5853                 break;
5854
5855         case  8:
5856         case 10:
5857                 if (*i == 'E' || *i == 'e') {
5858                         base = 10;
5859                         goto parse_exponent;
5860                 }
5861                 break;
5862
5863         case 16:
5864                 if (*i == 'P' || *i == 'p') {
5865 parse_exponent:
5866                         ++i;
5867                         is_float = true;
5868
5869                         if (*i == '-' || *i == '+')
5870                                 ++i;
5871
5872                         if (isdigit(*i)) {
5873                                 do {
5874                                         ++i;
5875                                 } while (isdigit(*i));
5876                         } else {
5877                                 errorf(HERE, "exponent of %K has no digits", &token);
5878                         }
5879                 } else if (is_float) {
5880                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5881                         i = 0;
5882                 }
5883                 break;
5884
5885         default:
5886                 panic("invalid base");
5887         }
5888
5889 done:;
5890         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5891         expr->literal.value = *str;
5892
5893         if (i) {
5894                 if (digits == 0) {
5895                         errorf(HERE, "%K has no digits", &token);
5896                 } else if (digits & ~((1U << base) - 1)) {
5897                         errorf(HERE, "invalid digit in %K", &token);
5898                 } else {
5899                         expr->literal.suffix = i;
5900                         if (is_float) {
5901                                 check_floatingpoint_suffix(expr, i);
5902                         } else {
5903                                 check_integer_suffix(expr, i);
5904                         }
5905                 }
5906         }
5907
5908         eat(T_NUMBER);
5909         return expr;
5910 }
5911
5912 /**
5913  * Parse a character constant.
5914  */
5915 static expression_t *parse_character_constant(void)
5916 {
5917         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5918         literal->string_literal.value = token.literal.string;
5919
5920         size_t const size = get_string_len(&token.literal.string);
5921         switch (token.literal.string.encoding) {
5922         case STRING_ENCODING_CHAR:
5923                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5924                 if (size > 1) {
5925                         if (!GNU_MODE && !(c_mode & _C99)) {
5926                                 errorf(HERE, "more than 1 character in character constant");
5927                         } else {
5928                                 literal->base.type = type_int;
5929                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5930                         }
5931                 }
5932                 break;
5933
5934         case STRING_ENCODING_WIDE:
5935                 literal->base.type = type_int;
5936                 if (size > 1) {
5937                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5938                 }
5939                 break;
5940         }
5941
5942         eat(T_CHARACTER_CONSTANT);
5943         return literal;
5944 }
5945
5946 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5947 {
5948         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5949         ntype->function.return_type            = type_int;
5950         ntype->function.unspecified_parameters = true;
5951         ntype->function.linkage                = LINKAGE_C;
5952         type_t *type                           = identify_new_type(ntype);
5953
5954         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5955         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5956         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5957         entity->declaration.type                   = type;
5958         entity->declaration.implicit               = true;
5959
5960         if (current_scope != NULL)
5961                 record_entity(entity, false);
5962
5963         return entity;
5964 }
5965
5966 /**
5967  * Performs automatic type cast as described in §6.3.2.1.
5968  *
5969  * @param orig_type  the original type
5970  */
5971 static type_t *automatic_type_conversion(type_t *orig_type)
5972 {
5973         type_t *type = skip_typeref(orig_type);
5974         if (is_type_array(type)) {
5975                 array_type_t *array_type   = &type->array;
5976                 type_t       *element_type = array_type->element_type;
5977                 unsigned      qualifiers   = array_type->base.qualifiers;
5978
5979                 return make_pointer_type(element_type, qualifiers);
5980         }
5981
5982         if (is_type_function(type)) {
5983                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5984         }
5985
5986         return orig_type;
5987 }
5988
5989 /**
5990  * reverts the automatic casts of array to pointer types and function
5991  * to function-pointer types as defined §6.3.2.1
5992  */
5993 type_t *revert_automatic_type_conversion(const expression_t *expression)
5994 {
5995         switch (expression->kind) {
5996         case EXPR_REFERENCE: {
5997                 entity_t *entity = expression->reference.entity;
5998                 if (is_declaration(entity)) {
5999                         return entity->declaration.type;
6000                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6001                         return entity->enum_value.enum_type;
6002                 } else {
6003                         panic("no declaration or enum in reference");
6004                 }
6005         }
6006
6007         case EXPR_SELECT: {
6008                 entity_t *entity = expression->select.compound_entry;
6009                 assert(is_declaration(entity));
6010                 type_t   *type   = entity->declaration.type;
6011                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6012         }
6013
6014         case EXPR_UNARY_DEREFERENCE: {
6015                 const expression_t *const value = expression->unary.value;
6016                 type_t             *const type  = skip_typeref(value->base.type);
6017                 if (!is_type_pointer(type))
6018                         return type_error_type;
6019                 return type->pointer.points_to;
6020         }
6021
6022         case EXPR_ARRAY_ACCESS: {
6023                 const expression_t *array_ref = expression->array_access.array_ref;
6024                 type_t             *type_left = skip_typeref(array_ref->base.type);
6025                 if (!is_type_pointer(type_left))
6026                         return type_error_type;
6027                 return type_left->pointer.points_to;
6028         }
6029
6030         case EXPR_STRING_LITERAL: {
6031                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
6032                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
6033                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
6034         }
6035
6036         case EXPR_COMPOUND_LITERAL:
6037                 return expression->compound_literal.type;
6038
6039         default:
6040                 break;
6041         }
6042         return expression->base.type;
6043 }
6044
6045 /**
6046  * Find an entity matching a symbol in a scope.
6047  * Uses current scope if scope is NULL
6048  */
6049 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6050                                namespace_tag_t namespc)
6051 {
6052         if (scope == NULL) {
6053                 return get_entity(symbol, namespc);
6054         }
6055
6056         /* we should optimize here, if scope grows above a certain size we should
6057            construct a hashmap here... */
6058         entity_t *entity = scope->entities;
6059         for ( ; entity != NULL; entity = entity->base.next) {
6060                 if (entity->base.symbol == symbol
6061                     && (namespace_tag_t)entity->base.namespc == namespc)
6062                         break;
6063         }
6064
6065         return entity;
6066 }
6067
6068 static entity_t *parse_qualified_identifier(void)
6069 {
6070         /* namespace containing the symbol */
6071         symbol_t          *symbol;
6072         source_position_t  pos;
6073         const scope_t     *lookup_scope = NULL;
6074
6075         if (next_if(T_COLONCOLON))
6076                 lookup_scope = &unit->scope;
6077
6078         entity_t *entity;
6079         while (true) {
6080                 symbol = expect_identifier("while parsing identifier", &pos);
6081                 if (!symbol)
6082                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6083
6084                 /* lookup entity */
6085                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6086
6087                 if (!next_if(T_COLONCOLON))
6088                         break;
6089
6090                 switch (entity->kind) {
6091                 case ENTITY_NAMESPACE:
6092                         lookup_scope = &entity->namespacee.members;
6093                         break;
6094                 case ENTITY_STRUCT:
6095                 case ENTITY_UNION:
6096                 case ENTITY_CLASS:
6097                         lookup_scope = &entity->compound.members;
6098                         break;
6099                 default:
6100                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6101                                symbol, get_entity_kind_name(entity->kind));
6102
6103                         /* skip further qualifications */
6104                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6105
6106                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6107                 }
6108         }
6109
6110         if (entity == NULL) {
6111                 if (!strict_mode && token.kind == '(') {
6112                         /* an implicitly declared function */
6113                         entity = create_implicit_function(symbol, &pos);
6114                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6115                 } else {
6116                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6117                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6118                 }
6119         }
6120
6121         return entity;
6122 }
6123
6124 static expression_t *parse_reference(void)
6125 {
6126         source_position_t const pos    = *HERE;
6127         entity_t         *const entity = parse_qualified_identifier();
6128
6129         type_t *orig_type;
6130         if (is_declaration(entity)) {
6131                 orig_type = entity->declaration.type;
6132         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6133                 orig_type = entity->enum_value.enum_type;
6134         } else {
6135                 panic("expected declaration or enum value in reference");
6136         }
6137
6138         /* we always do the auto-type conversions; the & and sizeof parser contains
6139          * code to revert this! */
6140         type_t *type = automatic_type_conversion(orig_type);
6141
6142         expression_kind_t kind = EXPR_REFERENCE;
6143         if (entity->kind == ENTITY_ENUM_VALUE)
6144                 kind = EXPR_ENUM_CONSTANT;
6145
6146         expression_t *expression         = allocate_expression_zero(kind);
6147         expression->base.source_position = pos;
6148         expression->base.type            = type;
6149         expression->reference.entity     = entity;
6150
6151         /* this declaration is used */
6152         if (is_declaration(entity)) {
6153                 entity->declaration.used = true;
6154         }
6155
6156         if (entity->base.parent_scope != file_scope
6157                 && (current_function != NULL
6158                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6159                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6160                 /* access of a variable from an outer function */
6161                 entity->variable.address_taken = true;
6162                 current_function->need_closure = true;
6163         }
6164
6165         check_deprecated(&pos, entity);
6166
6167         return expression;
6168 }
6169
6170 static bool semantic_cast(expression_t *cast)
6171 {
6172         expression_t            *expression      = cast->unary.value;
6173         type_t                  *orig_dest_type  = cast->base.type;
6174         type_t                  *orig_type_right = expression->base.type;
6175         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6176         type_t            const *src_type        = skip_typeref(orig_type_right);
6177         source_position_t const *pos             = &cast->base.source_position;
6178
6179         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6180         if (is_type_void(dst_type))
6181                 return true;
6182
6183         /* only integer and pointer can be casted to pointer */
6184         if (is_type_pointer(dst_type)  &&
6185             !is_type_pointer(src_type) &&
6186             !is_type_integer(src_type) &&
6187             is_type_valid(src_type)) {
6188                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6189                 return false;
6190         }
6191
6192         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6193                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6194                 return false;
6195         }
6196
6197         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6198                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6199                 return false;
6200         }
6201
6202         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6203                 type_t *src = skip_typeref(src_type->pointer.points_to);
6204                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6205                 unsigned missing_qualifiers =
6206                         src->base.qualifiers & ~dst->base.qualifiers;
6207                 if (missing_qualifiers != 0) {
6208                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6209                 }
6210         }
6211         return true;
6212 }
6213
6214 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6215 {
6216         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6217         expression->base.source_position = *pos;
6218
6219         parse_initializer_env_t env;
6220         env.type             = type;
6221         env.entity           = NULL;
6222         env.must_be_constant = false;
6223         initializer_t *initializer = parse_initializer(&env);
6224         type = env.type;
6225
6226         expression->compound_literal.initializer = initializer;
6227         expression->compound_literal.type        = type;
6228         expression->base.type                    = automatic_type_conversion(type);
6229
6230         return expression;
6231 }
6232
6233 /**
6234  * Parse a cast expression.
6235  */
6236 static expression_t *parse_cast(void)
6237 {
6238         source_position_t const pos = *HERE;
6239
6240         eat('(');
6241         add_anchor_token(')');
6242
6243         type_t *type = parse_typename();
6244
6245         rem_anchor_token(')');
6246         expect(')');
6247
6248         if (token.kind == '{') {
6249                 return parse_compound_literal(&pos, type);
6250         }
6251
6252         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6253         cast->base.source_position = pos;
6254
6255         expression_t *value = parse_subexpression(PREC_CAST);
6256         cast->base.type   = type;
6257         cast->unary.value = value;
6258
6259         if (! semantic_cast(cast)) {
6260                 /* TODO: record the error in the AST. else it is impossible to detect it */
6261         }
6262
6263         return cast;
6264 }
6265
6266 /**
6267  * Parse a statement expression.
6268  */
6269 static expression_t *parse_statement_expression(void)
6270 {
6271         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6272
6273         eat('(');
6274         add_anchor_token(')');
6275
6276         statement_t *statement          = parse_compound_statement(true);
6277         statement->compound.stmt_expr   = true;
6278         expression->statement.statement = statement;
6279
6280         /* find last statement and use its type */
6281         type_t *type = type_void;
6282         const statement_t *stmt = statement->compound.statements;
6283         if (stmt != NULL) {
6284                 while (stmt->base.next != NULL)
6285                         stmt = stmt->base.next;
6286
6287                 if (stmt->kind == STATEMENT_EXPRESSION) {
6288                         type = stmt->expression.expression->base.type;
6289                 }
6290         } else {
6291                 source_position_t const *const pos = &expression->base.source_position;
6292                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6293         }
6294         expression->base.type = type;
6295
6296         rem_anchor_token(')');
6297         expect(')');
6298         return expression;
6299 }
6300
6301 /**
6302  * Parse a parenthesized expression.
6303  */
6304 static expression_t *parse_parenthesized_expression(void)
6305 {
6306         token_t const* const la1 = look_ahead(1);
6307         switch (la1->kind) {
6308         case '{':
6309                 /* gcc extension: a statement expression */
6310                 return parse_statement_expression();
6311
6312         case T_IDENTIFIER:
6313                 if (is_typedef_symbol(la1->base.symbol)) {
6314         DECLARATION_START
6315                         return parse_cast();
6316                 }
6317         }
6318
6319         eat('(');
6320         add_anchor_token(')');
6321         expression_t *result = parse_expression();
6322         result->base.parenthesized = true;
6323         rem_anchor_token(')');
6324         expect(')');
6325
6326         return result;
6327 }
6328
6329 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6330 {
6331         if (current_function == NULL) {
6332                 errorf(HERE, "'%K' used outside of a function", &token);
6333         }
6334
6335         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6336         expression->base.type     = type_char_ptr;
6337         expression->funcname.kind = kind;
6338
6339         next_token();
6340
6341         return expression;
6342 }
6343
6344 static designator_t *parse_designator(void)
6345 {
6346         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6347         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6348         if (!result->symbol)
6349                 return NULL;
6350
6351         designator_t *last_designator = result;
6352         while (true) {
6353                 if (next_if('.')) {
6354                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6355                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6356                         if (!designator->symbol)
6357                                 return NULL;
6358
6359                         last_designator->next = designator;
6360                         last_designator       = designator;
6361                         continue;
6362                 }
6363                 if (next_if('[')) {
6364                         add_anchor_token(']');
6365                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6366                         designator->source_position = *HERE;
6367                         designator->array_index     = parse_expression();
6368                         rem_anchor_token(']');
6369                         expect(']');
6370                         if (designator->array_index == NULL) {
6371                                 return NULL;
6372                         }
6373
6374                         last_designator->next = designator;
6375                         last_designator       = designator;
6376                         continue;
6377                 }
6378                 break;
6379         }
6380
6381         return result;
6382 }
6383
6384 /**
6385  * Parse the __builtin_offsetof() expression.
6386  */
6387 static expression_t *parse_offsetof(void)
6388 {
6389         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6390         expression->base.type    = type_size_t;
6391
6392         eat(T___builtin_offsetof);
6393
6394         add_anchor_token(')');
6395         add_anchor_token(',');
6396         expect('(');
6397         type_t *type = parse_typename();
6398         rem_anchor_token(',');
6399         expect(',');
6400         designator_t *designator = parse_designator();
6401         rem_anchor_token(')');
6402         expect(')');
6403
6404         expression->offsetofe.type       = type;
6405         expression->offsetofe.designator = designator;
6406
6407         type_path_t path;
6408         memset(&path, 0, sizeof(path));
6409         path.top_type = type;
6410         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6411
6412         descend_into_subtype(&path);
6413
6414         if (!walk_designator(&path, designator, true)) {
6415                 return create_error_expression();
6416         }
6417
6418         DEL_ARR_F(path.path);
6419
6420         return expression;
6421 }
6422
6423 static bool is_last_parameter(expression_t *const param)
6424 {
6425         if (param->kind == EXPR_REFERENCE) {
6426                 entity_t *const entity = param->reference.entity;
6427                 if (entity->kind == ENTITY_PARAMETER &&
6428                     !entity->base.next               &&
6429                     entity->base.parent_scope == &current_function->parameters) {
6430                         return true;
6431                 }
6432         }
6433
6434         if (!is_type_valid(skip_typeref(param->base.type)))
6435                 return true;
6436
6437         return false;
6438 }
6439
6440 /**
6441  * Parses a __builtin_va_start() expression.
6442  */
6443 static expression_t *parse_va_start(void)
6444 {
6445         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6446
6447         eat(T___builtin_va_start);
6448
6449         add_anchor_token(')');
6450         add_anchor_token(',');
6451         expect('(');
6452         expression->va_starte.ap = parse_assignment_expression();
6453         rem_anchor_token(',');
6454         expect(',');
6455         expression_t *const param = parse_assignment_expression();
6456         expression->va_starte.parameter = param;
6457         rem_anchor_token(')');
6458         expect(')');
6459
6460         if (!current_function) {
6461                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6462         } else if (!current_function->base.type->function.variadic) {
6463                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6464         } else if (!is_last_parameter(param)) {
6465                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6466         }
6467
6468         return expression;
6469 }
6470
6471 /**
6472  * Parses a __builtin_va_arg() expression.
6473  */
6474 static expression_t *parse_va_arg(void)
6475 {
6476         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6477
6478         eat(T___builtin_va_arg);
6479
6480         add_anchor_token(')');
6481         add_anchor_token(',');
6482         expect('(');
6483         call_argument_t ap;
6484         ap.expression = parse_assignment_expression();
6485         expression->va_arge.ap = ap.expression;
6486         check_call_argument(type_valist, &ap, 1);
6487
6488         rem_anchor_token(',');
6489         expect(',');
6490         expression->base.type = parse_typename();
6491         rem_anchor_token(')');
6492         expect(')');
6493
6494         return expression;
6495 }
6496
6497 /**
6498  * Parses a __builtin_va_copy() expression.
6499  */
6500 static expression_t *parse_va_copy(void)
6501 {
6502         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6503
6504         eat(T___builtin_va_copy);
6505
6506         add_anchor_token(')');
6507         add_anchor_token(',');
6508         expect('(');
6509         expression_t *dst = parse_assignment_expression();
6510         assign_error_t error = semantic_assign(type_valist, dst);
6511         report_assign_error(error, type_valist, dst, "call argument 1",
6512                             &dst->base.source_position);
6513         expression->va_copye.dst = dst;
6514
6515         rem_anchor_token(',');
6516         expect(',');
6517
6518         call_argument_t src;
6519         src.expression = parse_assignment_expression();
6520         check_call_argument(type_valist, &src, 2);
6521         expression->va_copye.src = src.expression;
6522         rem_anchor_token(')');
6523         expect(')');
6524
6525         return expression;
6526 }
6527
6528 /**
6529  * Parses a __builtin_constant_p() expression.
6530  */
6531 static expression_t *parse_builtin_constant(void)
6532 {
6533         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6534
6535         eat(T___builtin_constant_p);
6536
6537         add_anchor_token(')');
6538         expect('(');
6539         expression->builtin_constant.value = parse_assignment_expression();
6540         rem_anchor_token(')');
6541         expect(')');
6542         expression->base.type = type_int;
6543
6544         return expression;
6545 }
6546
6547 /**
6548  * Parses a __builtin_types_compatible_p() expression.
6549  */
6550 static expression_t *parse_builtin_types_compatible(void)
6551 {
6552         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6553
6554         eat(T___builtin_types_compatible_p);
6555
6556         add_anchor_token(')');
6557         add_anchor_token(',');
6558         expect('(');
6559         expression->builtin_types_compatible.left = parse_typename();
6560         rem_anchor_token(',');
6561         expect(',');
6562         expression->builtin_types_compatible.right = parse_typename();
6563         rem_anchor_token(')');
6564         expect(')');
6565         expression->base.type = type_int;
6566
6567         return expression;
6568 }
6569
6570 /**
6571  * Parses a __builtin_is_*() compare expression.
6572  */
6573 static expression_t *parse_compare_builtin(void)
6574 {
6575         expression_kind_t kind;
6576         switch (token.kind) {
6577         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6578         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6579         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6580         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6581         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6582         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6583         default: internal_errorf(HERE, "invalid compare builtin found");
6584         }
6585         expression_t *const expression = allocate_expression_zero(kind);
6586         next_token();
6587
6588         add_anchor_token(')');
6589         add_anchor_token(',');
6590         expect('(');
6591         expression->binary.left = parse_assignment_expression();
6592         rem_anchor_token(',');
6593         expect(',');
6594         expression->binary.right = parse_assignment_expression();
6595         rem_anchor_token(')');
6596         expect(')');
6597
6598         type_t *const orig_type_left  = expression->binary.left->base.type;
6599         type_t *const orig_type_right = expression->binary.right->base.type;
6600
6601         type_t *const type_left  = skip_typeref(orig_type_left);
6602         type_t *const type_right = skip_typeref(orig_type_right);
6603         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6604                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6605                         type_error_incompatible("invalid operands in comparison",
6606                                 &expression->base.source_position, orig_type_left, orig_type_right);
6607                 }
6608         } else {
6609                 semantic_comparison(&expression->binary);
6610         }
6611
6612         return expression;
6613 }
6614
6615 /**
6616  * Parses a MS assume() expression.
6617  */
6618 static expression_t *parse_assume(void)
6619 {
6620         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6621
6622         eat(T__assume);
6623
6624         add_anchor_token(')');
6625         expect('(');
6626         expression->unary.value = parse_assignment_expression();
6627         rem_anchor_token(')');
6628         expect(')');
6629
6630         expression->base.type = type_void;
6631         return expression;
6632 }
6633
6634 /**
6635  * Return the label for the current symbol or create a new one.
6636  */
6637 static label_t *get_label(char const *const context)
6638 {
6639         assert(current_function != NULL);
6640
6641         symbol_t *const sym = expect_identifier(context, NULL);
6642         if (!sym)
6643                 return NULL;
6644
6645         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6646         /* If we find a local label, we already created the declaration. */
6647         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6648                 if (label->base.parent_scope != current_scope) {
6649                         assert(label->base.parent_scope->depth < current_scope->depth);
6650                         current_function->goto_to_outer = true;
6651                 }
6652         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6653                 /* There is no matching label in the same function, so create a new one. */
6654                 source_position_t const nowhere = { NULL, 0, 0, false };
6655                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6656                 label_push(label);
6657         }
6658
6659         return &label->label;
6660 }
6661
6662 /**
6663  * Parses a GNU && label address expression.
6664  */
6665 static expression_t *parse_label_address(void)
6666 {
6667         source_position_t const source_position = *HERE;
6668         eat(T_ANDAND);
6669
6670         label_t *const label = get_label("while parsing label address");
6671         if (!label)
6672                 return create_error_expression();
6673
6674         label->used          = true;
6675         label->address_taken = true;
6676
6677         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6678         expression->base.source_position = source_position;
6679
6680         /* label address is treated as a void pointer */
6681         expression->base.type           = type_void_ptr;
6682         expression->label_address.label = label;
6683         return expression;
6684 }
6685
6686 /**
6687  * Parse a microsoft __noop expression.
6688  */
6689 static expression_t *parse_noop_expression(void)
6690 {
6691         /* the result is a (int)0 */
6692         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6693         literal->base.type           = type_int;
6694         literal->literal.value.begin = "__noop";
6695         literal->literal.value.size  = 6;
6696
6697         eat(T___noop);
6698
6699         if (token.kind == '(') {
6700                 /* parse arguments */
6701                 eat('(');
6702                 add_anchor_token(')');
6703                 add_anchor_token(',');
6704
6705                 if (token.kind != ')') do {
6706                         (void)parse_assignment_expression();
6707                 } while (next_if(','));
6708
6709                 rem_anchor_token(',');
6710                 rem_anchor_token(')');
6711         }
6712         expect(')');
6713
6714         return literal;
6715 }
6716
6717 /**
6718  * Parses a primary expression.
6719  */
6720 static expression_t *parse_primary_expression(void)
6721 {
6722         switch (token.kind) {
6723         case T_false:                        return parse_boolean_literal(false);
6724         case T_true:                         return parse_boolean_literal(true);
6725         case T_NUMBER:                       return parse_number_literal();
6726         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6727         case T_STRING_LITERAL:               return parse_string_literal();
6728         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6729         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6730         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6731         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6732         case T___builtin_offsetof:           return parse_offsetof();
6733         case T___builtin_va_start:           return parse_va_start();
6734         case T___builtin_va_arg:             return parse_va_arg();
6735         case T___builtin_va_copy:            return parse_va_copy();
6736         case T___builtin_isgreater:
6737         case T___builtin_isgreaterequal:
6738         case T___builtin_isless:
6739         case T___builtin_islessequal:
6740         case T___builtin_islessgreater:
6741         case T___builtin_isunordered:        return parse_compare_builtin();
6742         case T___builtin_constant_p:         return parse_builtin_constant();
6743         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6744         case T__assume:                      return parse_assume();
6745         case T_ANDAND:
6746                 if (GNU_MODE)
6747                         return parse_label_address();
6748                 break;
6749
6750         case '(':                            return parse_parenthesized_expression();
6751         case T___noop:                       return parse_noop_expression();
6752
6753         /* Gracefully handle type names while parsing expressions. */
6754         case T_COLONCOLON:
6755                 return parse_reference();
6756         case T_IDENTIFIER:
6757                 if (!is_typedef_symbol(token.base.symbol)) {
6758                         return parse_reference();
6759                 }
6760                 /* FALLTHROUGH */
6761         DECLARATION_START {
6762                 source_position_t const  pos = *HERE;
6763                 declaration_specifiers_t specifiers;
6764                 parse_declaration_specifiers(&specifiers);
6765                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6766                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6767                 return create_error_expression();
6768         }
6769         }
6770
6771         errorf(HERE, "unexpected token %K, expected an expression", &token);
6772         eat_until_anchor();
6773         return create_error_expression();
6774 }
6775
6776 static expression_t *parse_array_expression(expression_t *left)
6777 {
6778         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6779         array_access_expression_t *const arr  = &expr->array_access;
6780
6781         eat('[');
6782         add_anchor_token(']');
6783
6784         expression_t *const inside = parse_expression();
6785
6786         type_t *const orig_type_left   = left->base.type;
6787         type_t *const orig_type_inside = inside->base.type;
6788
6789         type_t *const type_left   = skip_typeref(orig_type_left);
6790         type_t *const type_inside = skip_typeref(orig_type_inside);
6791
6792         expression_t *ref;
6793         expression_t *idx;
6794         type_t       *idx_type;
6795         type_t       *res_type;
6796         if (is_type_pointer(type_left)) {
6797                 ref      = left;
6798                 idx      = inside;
6799                 idx_type = type_inside;
6800                 res_type = type_left->pointer.points_to;
6801                 goto check_idx;
6802         } else if (is_type_pointer(type_inside)) {
6803                 arr->flipped = true;
6804                 ref      = inside;
6805                 idx      = left;
6806                 idx_type = type_left;
6807                 res_type = type_inside->pointer.points_to;
6808 check_idx:
6809                 res_type = automatic_type_conversion(res_type);
6810                 if (!is_type_integer(idx_type)) {
6811                         errorf(&idx->base.source_position, "array subscript must have integer type");
6812                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6813                         source_position_t const *const pos = &idx->base.source_position;
6814                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6815                 }
6816         } else {
6817                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6818                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6819                 }
6820                 res_type = type_error_type;
6821                 ref      = left;
6822                 idx      = inside;
6823         }
6824
6825         arr->array_ref = ref;
6826         arr->index     = idx;
6827         arr->base.type = res_type;
6828
6829         rem_anchor_token(']');
6830         expect(']');
6831         return expr;
6832 }
6833
6834 static bool is_bitfield(const expression_t *expression)
6835 {
6836         return expression->kind == EXPR_SELECT
6837                 && expression->select.compound_entry->compound_member.bitfield;
6838 }
6839
6840 static expression_t *parse_typeprop(expression_kind_t const kind)
6841 {
6842         expression_t  *tp_expression = allocate_expression_zero(kind);
6843         tp_expression->base.type     = type_size_t;
6844
6845         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6846
6847         type_t       *orig_type;
6848         expression_t *expression;
6849         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6850                 source_position_t const pos = *HERE;
6851                 eat('(');
6852                 add_anchor_token(')');
6853                 orig_type = parse_typename();
6854                 rem_anchor_token(')');
6855                 expect(')');
6856
6857                 if (token.kind == '{') {
6858                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6859                          * starting with a compound literal */
6860                         expression = parse_compound_literal(&pos, orig_type);
6861                         goto typeprop_expression;
6862                 }
6863         } else {
6864                 expression = parse_subexpression(PREC_UNARY);
6865
6866 typeprop_expression:
6867                 if (is_bitfield(expression)) {
6868                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6869                         errorf(&tp_expression->base.source_position,
6870                                    "operand of %s expression must not be a bitfield", what);
6871                 }
6872
6873                 tp_expression->typeprop.tp_expression = expression;
6874
6875                 orig_type = revert_automatic_type_conversion(expression);
6876                 expression->base.type = orig_type;
6877         }
6878
6879         tp_expression->typeprop.type   = orig_type;
6880         type_t const* const type       = skip_typeref(orig_type);
6881         char   const*       wrong_type = NULL;
6882         if (is_type_incomplete(type)) {
6883                 if (!is_type_void(type) || !GNU_MODE)
6884                         wrong_type = "incomplete";
6885         } else if (type->kind == TYPE_FUNCTION) {
6886                 if (GNU_MODE) {
6887                         /* function types are allowed (and return 1) */
6888                         source_position_t const *const pos  = &tp_expression->base.source_position;
6889                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6890                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6891                 } else {
6892                         wrong_type = "function";
6893                 }
6894         }
6895
6896         if (wrong_type != NULL) {
6897                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6898                 errorf(&tp_expression->base.source_position,
6899                                 "operand of %s expression must not be of %s type '%T'",
6900                                 what, wrong_type, orig_type);
6901         }
6902
6903         return tp_expression;
6904 }
6905
6906 static expression_t *parse_sizeof(void)
6907 {
6908         return parse_typeprop(EXPR_SIZEOF);
6909 }
6910
6911 static expression_t *parse_alignof(void)
6912 {
6913         return parse_typeprop(EXPR_ALIGNOF);
6914 }
6915
6916 static expression_t *parse_select_expression(expression_t *addr)
6917 {
6918         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6919         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6920         source_position_t const pos = *HERE;
6921         next_token();
6922
6923         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6924         if (!symbol)
6925                 return create_error_expression();
6926
6927         type_t *const orig_type = addr->base.type;
6928         type_t *const type      = skip_typeref(orig_type);
6929
6930         type_t *type_left;
6931         bool    saw_error = false;
6932         if (is_type_pointer(type)) {
6933                 if (!select_left_arrow) {
6934                         errorf(&pos,
6935                                "request for member '%Y' in something not a struct or union, but '%T'",
6936                                symbol, orig_type);
6937                         saw_error = true;
6938                 }
6939                 type_left = skip_typeref(type->pointer.points_to);
6940         } else {
6941                 if (select_left_arrow && is_type_valid(type)) {
6942                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6943                         saw_error = true;
6944                 }
6945                 type_left = type;
6946         }
6947
6948         if (!is_type_compound(type_left)) {
6949                 if (is_type_valid(type_left) && !saw_error) {
6950                         errorf(&pos,
6951                                "request for member '%Y' in something not a struct or union, but '%T'",
6952                                symbol, type_left);
6953                 }
6954                 return create_error_expression();
6955         }
6956
6957         compound_t *compound = type_left->compound.compound;
6958         if (!compound->complete) {
6959                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6960                        symbol, type_left);
6961                 return create_error_expression();
6962         }
6963
6964         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6965         expression_t      *result     =
6966                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6967
6968         if (result == NULL) {
6969                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6970                 return create_error_expression();
6971         }
6972
6973         return result;
6974 }
6975
6976 static void check_call_argument(type_t          *expected_type,
6977                                 call_argument_t *argument, unsigned pos)
6978 {
6979         type_t         *expected_type_skip = skip_typeref(expected_type);
6980         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6981         expression_t   *arg_expr           = argument->expression;
6982         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6983
6984         /* handle transparent union gnu extension */
6985         if (is_type_union(expected_type_skip)
6986                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6987                 compound_t *union_decl  = expected_type_skip->compound.compound;
6988                 type_t     *best_type   = NULL;
6989                 entity_t   *entry       = union_decl->members.entities;
6990                 for ( ; entry != NULL; entry = entry->base.next) {
6991                         assert(is_declaration(entry));
6992                         type_t *decl_type = entry->declaration.type;
6993                         error = semantic_assign(decl_type, arg_expr);
6994                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6995                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6996                                 continue;
6997
6998                         if (error == ASSIGN_SUCCESS) {
6999                                 best_type = decl_type;
7000                         } else if (best_type == NULL) {
7001                                 best_type = decl_type;
7002                         }
7003                 }
7004
7005                 if (best_type != NULL) {
7006                         expected_type = best_type;
7007                 }
7008         }
7009
7010         error                = semantic_assign(expected_type, arg_expr);
7011         argument->expression = create_implicit_cast(arg_expr, expected_type);
7012
7013         if (error != ASSIGN_SUCCESS) {
7014                 /* report exact scope in error messages (like "in argument 3") */
7015                 char buf[64];
7016                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7017                 report_assign_error(error, expected_type, arg_expr, buf,
7018                                     &arg_expr->base.source_position);
7019         } else {
7020                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7021                 if (!types_compatible(expected_type_skip, promoted_type) &&
7022                     !types_compatible(expected_type_skip, type_void_ptr) &&
7023                     !types_compatible(type_void_ptr,      promoted_type)) {
7024                         /* Deliberately show the skipped types in this warning */
7025                         source_position_t const *const apos = &arg_expr->base.source_position;
7026                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7027                 }
7028         }
7029 }
7030
7031 /**
7032  * Handle the semantic restrictions of builtin calls
7033  */
7034 static void handle_builtin_argument_restrictions(call_expression_t *call)
7035 {
7036         entity_t *entity = call->function->reference.entity;
7037         switch (entity->function.btk) {
7038         case BUILTIN_FIRM:
7039                 switch (entity->function.b.firm_builtin_kind) {
7040                 case ir_bk_return_address:
7041                 case ir_bk_frame_address: {
7042                         /* argument must be constant */
7043                         call_argument_t *argument = call->arguments;
7044
7045                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7046                                 errorf(&call->base.source_position,
7047                                            "argument of '%Y' must be a constant expression",
7048                                            call->function->reference.entity->base.symbol);
7049                         }
7050                         break;
7051                 }
7052                 case ir_bk_prefetch:
7053                         /* second and third argument must be constant if existent */
7054                         if (call->arguments == NULL)
7055                                 break;
7056                         call_argument_t *rw = call->arguments->next;
7057                         call_argument_t *locality = NULL;
7058
7059                         if (rw != NULL) {
7060                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7061                                         errorf(&call->base.source_position,
7062                                                    "second argument of '%Y' must be a constant expression",
7063                                                    call->function->reference.entity->base.symbol);
7064                                 }
7065                                 locality = rw->next;
7066                         }
7067                         if (locality != NULL) {
7068                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7069                                         errorf(&call->base.source_position,
7070                                                    "third argument of '%Y' must be a constant expression",
7071                                                    call->function->reference.entity->base.symbol);
7072                                 }
7073                                 locality = rw->next;
7074                         }
7075                         break;
7076                 default:
7077                         break;
7078                 }
7079
7080         case BUILTIN_OBJECT_SIZE:
7081                 if (call->arguments == NULL)
7082                         break;
7083
7084                 call_argument_t *arg = call->arguments->next;
7085                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7086                         errorf(&call->base.source_position,
7087                                    "second argument of '%Y' must be a constant expression",
7088                                    call->function->reference.entity->base.symbol);
7089                 }
7090                 break;
7091         default:
7092                 break;
7093         }
7094 }
7095
7096 /**
7097  * Parse a call expression, ie. expression '( ... )'.
7098  *
7099  * @param expression  the function address
7100  */
7101 static expression_t *parse_call_expression(expression_t *expression)
7102 {
7103         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7104         call_expression_t *call   = &result->call;
7105         call->function            = expression;
7106
7107         type_t *const orig_type = expression->base.type;
7108         type_t *const type      = skip_typeref(orig_type);
7109
7110         function_type_t *function_type = NULL;
7111         if (is_type_pointer(type)) {
7112                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7113
7114                 if (is_type_function(to_type)) {
7115                         function_type   = &to_type->function;
7116                         call->base.type = function_type->return_type;
7117                 }
7118         }
7119
7120         if (function_type == NULL && is_type_valid(type)) {
7121                 errorf(HERE,
7122                        "called object '%E' (type '%T') is not a pointer to a function",
7123                        expression, orig_type);
7124         }
7125
7126         /* parse arguments */
7127         eat('(');
7128         add_anchor_token(')');
7129         add_anchor_token(',');
7130
7131         if (token.kind != ')') {
7132                 call_argument_t **anchor = &call->arguments;
7133                 do {
7134                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7135                         argument->expression = parse_assignment_expression();
7136
7137                         *anchor = argument;
7138                         anchor  = &argument->next;
7139                 } while (next_if(','));
7140         }
7141         rem_anchor_token(',');
7142         rem_anchor_token(')');
7143         expect(')');
7144
7145         if (function_type == NULL)
7146                 return result;
7147
7148         /* check type and count of call arguments */
7149         function_parameter_t *parameter = function_type->parameters;
7150         call_argument_t      *argument  = call->arguments;
7151         if (!function_type->unspecified_parameters) {
7152                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7153                                 parameter = parameter->next, argument = argument->next) {
7154                         check_call_argument(parameter->type, argument, ++pos);
7155                 }
7156
7157                 if (parameter != NULL) {
7158                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7159                 } else if (argument != NULL && !function_type->variadic) {
7160                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7161                 }
7162         }
7163
7164         /* do default promotion for other arguments */
7165         for (; argument != NULL; argument = argument->next) {
7166                 type_t *argument_type = argument->expression->base.type;
7167                 if (!is_type_object(skip_typeref(argument_type))) {
7168                         errorf(&argument->expression->base.source_position,
7169                                "call argument '%E' must not be void", argument->expression);
7170                 }
7171
7172                 argument_type = get_default_promoted_type(argument_type);
7173
7174                 argument->expression
7175                         = create_implicit_cast(argument->expression, argument_type);
7176         }
7177
7178         check_format(call);
7179
7180         if (is_type_compound(skip_typeref(function_type->return_type))) {
7181                 source_position_t const *const pos = &expression->base.source_position;
7182                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7183         }
7184
7185         if (expression->kind == EXPR_REFERENCE) {
7186                 reference_expression_t *reference = &expression->reference;
7187                 if (reference->entity->kind == ENTITY_FUNCTION &&
7188                     reference->entity->function.btk != BUILTIN_NONE)
7189                         handle_builtin_argument_restrictions(call);
7190         }
7191
7192         return result;
7193 }
7194
7195 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7196
7197 static bool same_compound_type(const type_t *type1, const type_t *type2)
7198 {
7199         return
7200                 is_type_compound(type1) &&
7201                 type1->kind == type2->kind &&
7202                 type1->compound.compound == type2->compound.compound;
7203 }
7204
7205 static expression_t const *get_reference_address(expression_t const *expr)
7206 {
7207         bool regular_take_address = true;
7208         for (;;) {
7209                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7210                         expr = expr->unary.value;
7211                 } else {
7212                         regular_take_address = false;
7213                 }
7214
7215                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7216                         break;
7217
7218                 expr = expr->unary.value;
7219         }
7220
7221         if (expr->kind != EXPR_REFERENCE)
7222                 return NULL;
7223
7224         /* special case for functions which are automatically converted to a
7225          * pointer to function without an extra TAKE_ADDRESS operation */
7226         if (!regular_take_address &&
7227                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7228                 return NULL;
7229         }
7230
7231         return expr;
7232 }
7233
7234 static void warn_reference_address_as_bool(expression_t const* expr)
7235 {
7236         expr = get_reference_address(expr);
7237         if (expr != NULL) {
7238                 source_position_t const *const pos = &expr->base.source_position;
7239                 entity_t          const *const ent = expr->reference.entity;
7240                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7241         }
7242 }
7243
7244 static void warn_assignment_in_condition(const expression_t *const expr)
7245 {
7246         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7247                 return;
7248         if (expr->base.parenthesized)
7249                 return;
7250         source_position_t const *const pos = &expr->base.source_position;
7251         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7252 }
7253
7254 static void semantic_condition(expression_t const *const expr,
7255                                char const *const context)
7256 {
7257         type_t *const type = skip_typeref(expr->base.type);
7258         if (is_type_scalar(type)) {
7259                 warn_reference_address_as_bool(expr);
7260                 warn_assignment_in_condition(expr);
7261         } else if (is_type_valid(type)) {
7262                 errorf(&expr->base.source_position,
7263                                 "%s must have scalar type", context);
7264         }
7265 }
7266
7267 /**
7268  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7269  *
7270  * @param expression  the conditional expression
7271  */
7272 static expression_t *parse_conditional_expression(expression_t *expression)
7273 {
7274         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7275
7276         conditional_expression_t *conditional = &result->conditional;
7277         conditional->condition                = expression;
7278
7279         eat('?');
7280         add_anchor_token(':');
7281
7282         /* §6.5.15:2  The first operand shall have scalar type. */
7283         semantic_condition(expression, "condition of conditional operator");
7284
7285         expression_t *true_expression = expression;
7286         bool          gnu_cond = false;
7287         if (GNU_MODE && token.kind == ':') {
7288                 gnu_cond = true;
7289         } else {
7290                 true_expression = parse_expression();
7291         }
7292         rem_anchor_token(':');
7293         expect(':');
7294         expression_t *false_expression =
7295                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7296
7297         type_t *const orig_true_type  = true_expression->base.type;
7298         type_t *const orig_false_type = false_expression->base.type;
7299         type_t *const true_type       = skip_typeref(orig_true_type);
7300         type_t *const false_type      = skip_typeref(orig_false_type);
7301
7302         /* 6.5.15.3 */
7303         source_position_t const *const pos = &conditional->base.source_position;
7304         type_t                        *result_type;
7305         if (is_type_void(true_type) || is_type_void(false_type)) {
7306                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7307                 if (true_expression->kind == EXPR_UNARY_THROW) {
7308                         result_type = false_type;
7309                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7310                         result_type = true_type;
7311                 } else {
7312                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7313                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7314                         }
7315                         result_type = type_void;
7316                 }
7317         } else if (is_type_arithmetic(true_type)
7318                    && is_type_arithmetic(false_type)) {
7319                 result_type = semantic_arithmetic(true_type, false_type);
7320         } else if (same_compound_type(true_type, false_type)) {
7321                 /* just take 1 of the 2 types */
7322                 result_type = true_type;
7323         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7324                 type_t *pointer_type;
7325                 type_t *other_type;
7326                 expression_t *other_expression;
7327                 if (is_type_pointer(true_type) &&
7328                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7329                         pointer_type     = true_type;
7330                         other_type       = false_type;
7331                         other_expression = false_expression;
7332                 } else {
7333                         pointer_type     = false_type;
7334                         other_type       = true_type;
7335                         other_expression = true_expression;
7336                 }
7337
7338                 if (is_null_pointer_constant(other_expression)) {
7339                         result_type = pointer_type;
7340                 } else if (is_type_pointer(other_type)) {
7341                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7342                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7343
7344                         type_t *to;
7345                         if (is_type_void(to1) || is_type_void(to2)) {
7346                                 to = type_void;
7347                         } else if (types_compatible(get_unqualified_type(to1),
7348                                                     get_unqualified_type(to2))) {
7349                                 to = to1;
7350                         } else {
7351                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7352                                 to = type_void;
7353                         }
7354
7355                         type_t *const type =
7356                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7357                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7358                 } else if (is_type_integer(other_type)) {
7359                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7360                         result_type = pointer_type;
7361                 } else {
7362                         goto types_incompatible;
7363                 }
7364         } else {
7365 types_incompatible:
7366                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7367                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7368                 }
7369                 result_type = type_error_type;
7370         }
7371
7372         conditional->true_expression
7373                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7374         conditional->false_expression
7375                 = create_implicit_cast(false_expression, result_type);
7376         conditional->base.type = result_type;
7377         return result;
7378 }
7379
7380 /**
7381  * Parse an extension expression.
7382  */
7383 static expression_t *parse_extension(void)
7384 {
7385         PUSH_EXTENSION();
7386         expression_t *expression = parse_subexpression(PREC_UNARY);
7387         POP_EXTENSION();
7388         return expression;
7389 }
7390
7391 /**
7392  * Parse a __builtin_classify_type() expression.
7393  */
7394 static expression_t *parse_builtin_classify_type(void)
7395 {
7396         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7397         result->base.type    = type_int;
7398
7399         eat(T___builtin_classify_type);
7400
7401         add_anchor_token(')');
7402         expect('(');
7403         expression_t *expression = parse_expression();
7404         rem_anchor_token(')');
7405         expect(')');
7406         result->classify_type.type_expression = expression;
7407
7408         return result;
7409 }
7410
7411 /**
7412  * Parse a delete expression
7413  * ISO/IEC 14882:1998(E) §5.3.5
7414  */
7415 static expression_t *parse_delete(void)
7416 {
7417         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7418         result->base.type          = type_void;
7419
7420         eat(T_delete);
7421
7422         if (next_if('[')) {
7423                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7424                 expect(']');
7425         }
7426
7427         expression_t *const value = parse_subexpression(PREC_CAST);
7428         result->unary.value = value;
7429
7430         type_t *const type = skip_typeref(value->base.type);
7431         if (!is_type_pointer(type)) {
7432                 if (is_type_valid(type)) {
7433                         errorf(&value->base.source_position,
7434                                         "operand of delete must have pointer type");
7435                 }
7436         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7437                 source_position_t const *const pos = &value->base.source_position;
7438                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7439         }
7440
7441         return result;
7442 }
7443
7444 /**
7445  * Parse a throw expression
7446  * ISO/IEC 14882:1998(E) §15:1
7447  */
7448 static expression_t *parse_throw(void)
7449 {
7450         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7451         result->base.type          = type_void;
7452
7453         eat(T_throw);
7454
7455         expression_t *value = NULL;
7456         switch (token.kind) {
7457                 EXPRESSION_START {
7458                         value = parse_assignment_expression();
7459                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7460                         type_t *const orig_type = value->base.type;
7461                         type_t *const type      = skip_typeref(orig_type);
7462                         if (is_type_incomplete(type)) {
7463                                 errorf(&value->base.source_position,
7464                                                 "cannot throw object of incomplete type '%T'", orig_type);
7465                         } else if (is_type_pointer(type)) {
7466                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7467                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7468                                         errorf(&value->base.source_position,
7469                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7470                                 }
7471                         }
7472                 }
7473
7474                 default:
7475                         break;
7476         }
7477         result->unary.value = value;
7478
7479         return result;
7480 }
7481
7482 static bool check_pointer_arithmetic(const source_position_t *source_position,
7483                                      type_t *pointer_type,
7484                                      type_t *orig_pointer_type)
7485 {
7486         type_t *points_to = pointer_type->pointer.points_to;
7487         points_to = skip_typeref(points_to);
7488
7489         if (is_type_incomplete(points_to)) {
7490                 if (!GNU_MODE || !is_type_void(points_to)) {
7491                         errorf(source_position,
7492                                "arithmetic with pointer to incomplete type '%T' not allowed",
7493                                orig_pointer_type);
7494                         return false;
7495                 } else {
7496                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7497                 }
7498         } else if (is_type_function(points_to)) {
7499                 if (!GNU_MODE) {
7500                         errorf(source_position,
7501                                "arithmetic with pointer to function type '%T' not allowed",
7502                                orig_pointer_type);
7503                         return false;
7504                 } else {
7505                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7506                 }
7507         }
7508         return true;
7509 }
7510
7511 static bool is_lvalue(const expression_t *expression)
7512 {
7513         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7514         switch (expression->kind) {
7515         case EXPR_ARRAY_ACCESS:
7516         case EXPR_COMPOUND_LITERAL:
7517         case EXPR_REFERENCE:
7518         case EXPR_SELECT:
7519         case EXPR_UNARY_DEREFERENCE:
7520                 return true;
7521
7522         default: {
7523                 type_t *type = skip_typeref(expression->base.type);
7524                 return
7525                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7526                         is_type_reference(type) ||
7527                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7528                          * error before, which maybe prevented properly recognizing it as
7529                          * lvalue. */
7530                         !is_type_valid(type);
7531         }
7532         }
7533 }
7534
7535 static void semantic_incdec(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 (!check_pointer_arithmetic(&expression->base.source_position,
7541                                               type, orig_type)) {
7542                         return;
7543                 }
7544         } else if (!is_type_real(type) && is_type_valid(type)) {
7545                 /* TODO: improve error message */
7546                 errorf(&expression->base.source_position,
7547                        "operation needs an arithmetic or pointer type");
7548                 return;
7549         }
7550         if (!is_lvalue(expression->value)) {
7551                 /* TODO: improve error message */
7552                 errorf(&expression->base.source_position, "lvalue required as operand");
7553         }
7554         expression->base.type = orig_type;
7555 }
7556
7557 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7558 {
7559         type_t *const res_type = promote_integer(type);
7560         expr->base.type = res_type;
7561         expr->value     = create_implicit_cast(expr->value, res_type);
7562 }
7563
7564 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7565 {
7566         type_t *const orig_type = expression->value->base.type;
7567         type_t *const type      = skip_typeref(orig_type);
7568         if (!is_type_arithmetic(type)) {
7569                 if (is_type_valid(type)) {
7570                         /* TODO: improve error message */
7571                         errorf(&expression->base.source_position,
7572                                 "operation needs an arithmetic type");
7573                 }
7574                 return;
7575         } else if (is_type_integer(type)) {
7576                 promote_unary_int_expr(expression, type);
7577         } else {
7578                 expression->base.type = orig_type;
7579         }
7580 }
7581
7582 static void semantic_unexpr_plus(unary_expression_t *expression)
7583 {
7584         semantic_unexpr_arithmetic(expression);
7585         source_position_t const *const pos = &expression->base.source_position;
7586         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7587 }
7588
7589 static void semantic_not(unary_expression_t *expression)
7590 {
7591         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7592         semantic_condition(expression->value, "operand of !");
7593         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7594 }
7595
7596 static void semantic_unexpr_integer(unary_expression_t *expression)
7597 {
7598         type_t *const orig_type = expression->value->base.type;
7599         type_t *const type      = skip_typeref(orig_type);
7600         if (!is_type_integer(type)) {
7601                 if (is_type_valid(type)) {
7602                         errorf(&expression->base.source_position,
7603                                "operand of ~ must be of integer type");
7604                 }
7605                 return;
7606         }
7607
7608         promote_unary_int_expr(expression, type);
7609 }
7610
7611 static void semantic_dereference(unary_expression_t *expression)
7612 {
7613         type_t *const orig_type = expression->value->base.type;
7614         type_t *const type      = skip_typeref(orig_type);
7615         if (!is_type_pointer(type)) {
7616                 if (is_type_valid(type)) {
7617                         errorf(&expression->base.source_position,
7618                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7619                 }
7620                 return;
7621         }
7622
7623         type_t *result_type   = type->pointer.points_to;
7624         result_type           = automatic_type_conversion(result_type);
7625         expression->base.type = result_type;
7626 }
7627
7628 /**
7629  * Record that an address is taken (expression represents an lvalue).
7630  *
7631  * @param expression       the expression
7632  * @param may_be_register  if true, the expression might be an register
7633  */
7634 static void set_address_taken(expression_t *expression, bool may_be_register)
7635 {
7636         if (expression->kind != EXPR_REFERENCE)
7637                 return;
7638
7639         entity_t *const entity = expression->reference.entity;
7640
7641         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7642                 return;
7643
7644         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7645                         && !may_be_register) {
7646                 source_position_t const *const pos = &expression->base.source_position;
7647                 errorf(pos, "address of register '%N' requested", entity);
7648         }
7649
7650         entity->variable.address_taken = true;
7651 }
7652
7653 /**
7654  * Check the semantic of the address taken expression.
7655  */
7656 static void semantic_take_addr(unary_expression_t *expression)
7657 {
7658         expression_t *value = expression->value;
7659         value->base.type    = revert_automatic_type_conversion(value);
7660
7661         type_t *orig_type = value->base.type;
7662         type_t *type      = skip_typeref(orig_type);
7663         if (!is_type_valid(type))
7664                 return;
7665
7666         /* §6.5.3.2 */
7667         if (!is_lvalue(value)) {
7668                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7669         }
7670         if (is_bitfield(value)) {
7671                 errorf(&expression->base.source_position,
7672                        "'&' not allowed on bitfield");
7673         }
7674
7675         set_address_taken(value, false);
7676
7677         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7678 }
7679
7680 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7681 static expression_t *parse_##unexpression_type(void)                         \
7682 {                                                                            \
7683         expression_t *unary_expression                                           \
7684                 = allocate_expression_zero(unexpression_type);                       \
7685         eat(token_kind);                                                         \
7686         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7687                                                                                  \
7688         sfunc(&unary_expression->unary);                                         \
7689                                                                                  \
7690         return unary_expression;                                                 \
7691 }
7692
7693 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7694                                semantic_unexpr_arithmetic)
7695 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7696                                semantic_unexpr_plus)
7697 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7698                                semantic_not)
7699 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7700                                semantic_dereference)
7701 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7702                                semantic_take_addr)
7703 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7704                                semantic_unexpr_integer)
7705 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7706                                semantic_incdec)
7707 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7708                                semantic_incdec)
7709
7710 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7711                                                sfunc)                         \
7712 static expression_t *parse_##unexpression_type(expression_t *left)            \
7713 {                                                                             \
7714         expression_t *unary_expression                                            \
7715                 = allocate_expression_zero(unexpression_type);                        \
7716         eat(token_kind);                                                          \
7717         unary_expression->unary.value = left;                                     \
7718                                                                                   \
7719         sfunc(&unary_expression->unary);                                          \
7720                                                                               \
7721         return unary_expression;                                                  \
7722 }
7723
7724 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7725                                        EXPR_UNARY_POSTFIX_INCREMENT,
7726                                        semantic_incdec)
7727 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7728                                        EXPR_UNARY_POSTFIX_DECREMENT,
7729                                        semantic_incdec)
7730
7731 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7732 {
7733         /* TODO: handle complex + imaginary types */
7734
7735         type_left  = get_unqualified_type(type_left);
7736         type_right = get_unqualified_type(type_right);
7737
7738         /* §6.3.1.8 Usual arithmetic conversions */
7739         if (type_left == type_long_double || type_right == type_long_double) {
7740                 return type_long_double;
7741         } else if (type_left == type_double || type_right == type_double) {
7742                 return type_double;
7743         } else if (type_left == type_float || type_right == type_float) {
7744                 return type_float;
7745         }
7746
7747         type_left  = promote_integer(type_left);
7748         type_right = promote_integer(type_right);
7749
7750         if (type_left == type_right)
7751                 return type_left;
7752
7753         bool     const signed_left  = is_type_signed(type_left);
7754         bool     const signed_right = is_type_signed(type_right);
7755         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7756         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7757
7758         if (signed_left == signed_right)
7759                 return rank_left >= rank_right ? type_left : type_right;
7760
7761         unsigned           s_rank;
7762         unsigned           u_rank;
7763         atomic_type_kind_t s_akind;
7764         atomic_type_kind_t u_akind;
7765         type_t *s_type;
7766         type_t *u_type;
7767         if (signed_left) {
7768                 s_type = type_left;
7769                 u_type = type_right;
7770         } else {
7771                 s_type = type_right;
7772                 u_type = type_left;
7773         }
7774         s_akind = get_akind(s_type);
7775         u_akind = get_akind(u_type);
7776         s_rank  = get_akind_rank(s_akind);
7777         u_rank  = get_akind_rank(u_akind);
7778
7779         if (u_rank >= s_rank)
7780                 return u_type;
7781
7782         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7783                 return s_type;
7784
7785         switch (s_akind) {
7786         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7787         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7788         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7789
7790         default: panic("invalid atomic type");
7791         }
7792 }
7793
7794 /**
7795  * Check the semantic restrictions for a binary expression.
7796  */
7797 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7798 {
7799         expression_t *const left            = expression->left;
7800         expression_t *const right           = expression->right;
7801         type_t       *const orig_type_left  = left->base.type;
7802         type_t       *const orig_type_right = right->base.type;
7803         type_t       *const type_left       = skip_typeref(orig_type_left);
7804         type_t       *const type_right      = skip_typeref(orig_type_right);
7805
7806         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7807                 /* TODO: improve error message */
7808                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7809                         errorf(&expression->base.source_position,
7810                                "operation needs arithmetic types");
7811                 }
7812                 return;
7813         }
7814
7815         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7816         expression->left      = create_implicit_cast(left, arithmetic_type);
7817         expression->right     = create_implicit_cast(right, arithmetic_type);
7818         expression->base.type = arithmetic_type;
7819 }
7820
7821 static void semantic_binexpr_integer(binary_expression_t *const expression)
7822 {
7823         expression_t *const left            = expression->left;
7824         expression_t *const right           = expression->right;
7825         type_t       *const orig_type_left  = left->base.type;
7826         type_t       *const orig_type_right = right->base.type;
7827         type_t       *const type_left       = skip_typeref(orig_type_left);
7828         type_t       *const type_right      = skip_typeref(orig_type_right);
7829
7830         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7831                 /* TODO: improve error message */
7832                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7833                         errorf(&expression->base.source_position,
7834                                "operation needs integer types");
7835                 }
7836                 return;
7837         }
7838
7839         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7840         expression->left      = create_implicit_cast(left, result_type);
7841         expression->right     = create_implicit_cast(right, result_type);
7842         expression->base.type = result_type;
7843 }
7844
7845 static void warn_div_by_zero(binary_expression_t const *const expression)
7846 {
7847         if (!is_type_integer(expression->base.type))
7848                 return;
7849
7850         expression_t const *const right = expression->right;
7851         /* The type of the right operand can be different for /= */
7852         if (is_type_integer(right->base.type)                    &&
7853             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7854             !fold_constant_to_bool(right)) {
7855                 source_position_t const *const pos = &expression->base.source_position;
7856                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7857         }
7858 }
7859
7860 /**
7861  * Check the semantic restrictions for a div/mod expression.
7862  */
7863 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7864 {
7865         semantic_binexpr_arithmetic(expression);
7866         warn_div_by_zero(expression);
7867 }
7868
7869 static void warn_addsub_in_shift(const expression_t *const expr)
7870 {
7871         if (expr->base.parenthesized)
7872                 return;
7873
7874         char op;
7875         switch (expr->kind) {
7876                 case EXPR_BINARY_ADD: op = '+'; break;
7877                 case EXPR_BINARY_SUB: op = '-'; break;
7878                 default:              return;
7879         }
7880
7881         source_position_t const *const pos = &expr->base.source_position;
7882         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7883 }
7884
7885 static bool semantic_shift(binary_expression_t *expression)
7886 {
7887         expression_t *const left            = expression->left;
7888         expression_t *const right           = expression->right;
7889         type_t       *const orig_type_left  = left->base.type;
7890         type_t       *const orig_type_right = right->base.type;
7891         type_t       *      type_left       = skip_typeref(orig_type_left);
7892         type_t       *      type_right      = skip_typeref(orig_type_right);
7893
7894         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7895                 /* TODO: improve error message */
7896                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7897                         errorf(&expression->base.source_position,
7898                                "operands of shift operation must have integer types");
7899                 }
7900                 return false;
7901         }
7902
7903         type_left = promote_integer(type_left);
7904
7905         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7906                 source_position_t const *const pos   = &right->base.source_position;
7907                 long                     const count = fold_constant_to_int(right);
7908                 if (count < 0) {
7909                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7910                 } else if ((unsigned long)count >=
7911                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7912                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7913                 }
7914         }
7915
7916         type_right        = promote_integer(type_right);
7917         expression->right = create_implicit_cast(right, type_right);
7918
7919         return true;
7920 }
7921
7922 static void semantic_shift_op(binary_expression_t *expression)
7923 {
7924         expression_t *const left  = expression->left;
7925         expression_t *const right = expression->right;
7926
7927         if (!semantic_shift(expression))
7928                 return;
7929
7930         warn_addsub_in_shift(left);
7931         warn_addsub_in_shift(right);
7932
7933         type_t *const orig_type_left = left->base.type;
7934         type_t *      type_left      = skip_typeref(orig_type_left);
7935
7936         type_left             = promote_integer(type_left);
7937         expression->left      = create_implicit_cast(left, type_left);
7938         expression->base.type = type_left;
7939 }
7940
7941 static void semantic_add(binary_expression_t *expression)
7942 {
7943         expression_t *const left            = expression->left;
7944         expression_t *const right           = expression->right;
7945         type_t       *const orig_type_left  = left->base.type;
7946         type_t       *const orig_type_right = right->base.type;
7947         type_t       *const type_left       = skip_typeref(orig_type_left);
7948         type_t       *const type_right      = skip_typeref(orig_type_right);
7949
7950         /* §6.5.6 */
7951         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7952                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7953                 expression->left  = create_implicit_cast(left, arithmetic_type);
7954                 expression->right = create_implicit_cast(right, arithmetic_type);
7955                 expression->base.type = arithmetic_type;
7956         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7957                 check_pointer_arithmetic(&expression->base.source_position,
7958                                          type_left, orig_type_left);
7959                 expression->base.type = type_left;
7960         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7961                 check_pointer_arithmetic(&expression->base.source_position,
7962                                          type_right, orig_type_right);
7963                 expression->base.type = type_right;
7964         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7965                 errorf(&expression->base.source_position,
7966                        "invalid operands to binary + ('%T', '%T')",
7967                        orig_type_left, orig_type_right);
7968         }
7969 }
7970
7971 static void semantic_sub(binary_expression_t *expression)
7972 {
7973         expression_t            *const left            = expression->left;
7974         expression_t            *const right           = expression->right;
7975         type_t                  *const orig_type_left  = left->base.type;
7976         type_t                  *const orig_type_right = right->base.type;
7977         type_t                  *const type_left       = skip_typeref(orig_type_left);
7978         type_t                  *const type_right      = skip_typeref(orig_type_right);
7979         source_position_t const *const pos             = &expression->base.source_position;
7980
7981         /* §5.6.5 */
7982         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7983                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7984                 expression->left        = create_implicit_cast(left, arithmetic_type);
7985                 expression->right       = create_implicit_cast(right, arithmetic_type);
7986                 expression->base.type =  arithmetic_type;
7987         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7988                 check_pointer_arithmetic(&expression->base.source_position,
7989                                          type_left, orig_type_left);
7990                 expression->base.type = type_left;
7991         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7992                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7993                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7994                 if (!types_compatible(unqual_left, unqual_right)) {
7995                         errorf(pos,
7996                                "subtracting pointers to incompatible types '%T' and '%T'",
7997                                orig_type_left, orig_type_right);
7998                 } else if (!is_type_object(unqual_left)) {
7999                         if (!is_type_void(unqual_left)) {
8000                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8001                                        orig_type_left);
8002                         } else {
8003                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8004                         }
8005                 }
8006                 expression->base.type = type_ptrdiff_t;
8007         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8008                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8009                        orig_type_left, orig_type_right);
8010         }
8011 }
8012
8013 static void warn_string_literal_address(expression_t const* expr)
8014 {
8015         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8016                 expr = expr->unary.value;
8017                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8018                         return;
8019                 expr = expr->unary.value;
8020         }
8021
8022         if (expr->kind == EXPR_STRING_LITERAL) {
8023                 source_position_t const *const pos = &expr->base.source_position;
8024                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8025         }
8026 }
8027
8028 static bool maybe_negative(expression_t const *const expr)
8029 {
8030         switch (is_constant_expression(expr)) {
8031                 case EXPR_CLASS_ERROR:    return false;
8032                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8033                 default:                  return true;
8034         }
8035 }
8036
8037 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8038 {
8039         warn_string_literal_address(expr);
8040
8041         expression_t const* const ref = get_reference_address(expr);
8042         if (ref != NULL && is_null_pointer_constant(other)) {
8043                 entity_t const *const ent = ref->reference.entity;
8044                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8045         }
8046
8047         if (!expr->base.parenthesized) {
8048                 switch (expr->base.kind) {
8049                         case EXPR_BINARY_LESS:
8050                         case EXPR_BINARY_GREATER:
8051                         case EXPR_BINARY_LESSEQUAL:
8052                         case EXPR_BINARY_GREATEREQUAL:
8053                         case EXPR_BINARY_NOTEQUAL:
8054                         case EXPR_BINARY_EQUAL:
8055                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8056                                 break;
8057                         default:
8058                                 break;
8059                 }
8060         }
8061 }
8062
8063 /**
8064  * Check the semantics of comparison expressions.
8065  *
8066  * @param expression   The expression to check.
8067  */
8068 static void semantic_comparison(binary_expression_t *expression)
8069 {
8070         source_position_t const *const pos   = &expression->base.source_position;
8071         expression_t            *const left  = expression->left;
8072         expression_t            *const right = expression->right;
8073
8074         warn_comparison(pos, left, right);
8075         warn_comparison(pos, right, left);
8076
8077         type_t *orig_type_left  = left->base.type;
8078         type_t *orig_type_right = right->base.type;
8079         type_t *type_left       = skip_typeref(orig_type_left);
8080         type_t *type_right      = skip_typeref(orig_type_right);
8081
8082         /* TODO non-arithmetic types */
8083         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8084                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8085
8086                 /* test for signed vs unsigned compares */
8087                 if (is_type_integer(arithmetic_type)) {
8088                         bool const signed_left  = is_type_signed(type_left);
8089                         bool const signed_right = is_type_signed(type_right);
8090                         if (signed_left != signed_right) {
8091                                 /* FIXME long long needs better const folding magic */
8092                                 /* TODO check whether constant value can be represented by other type */
8093                                 if ((signed_left  && maybe_negative(left)) ||
8094                                                 (signed_right && maybe_negative(right))) {
8095                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8096                                 }
8097                         }
8098                 }
8099
8100                 expression->left        = create_implicit_cast(left, arithmetic_type);
8101                 expression->right       = create_implicit_cast(right, arithmetic_type);
8102                 expression->base.type   = arithmetic_type;
8103                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8104                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8105                     is_type_float(arithmetic_type)) {
8106                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8107                 }
8108         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8109                 /* TODO check compatibility */
8110         } else if (is_type_pointer(type_left)) {
8111                 expression->right = create_implicit_cast(right, type_left);
8112         } else if (is_type_pointer(type_right)) {
8113                 expression->left = create_implicit_cast(left, type_right);
8114         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8115                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8116         }
8117         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8118 }
8119
8120 /**
8121  * Checks if a compound type has constant fields.
8122  */
8123 static bool has_const_fields(const compound_type_t *type)
8124 {
8125         compound_t *compound = type->compound;
8126         entity_t   *entry    = compound->members.entities;
8127
8128         for (; entry != NULL; entry = entry->base.next) {
8129                 if (!is_declaration(entry))
8130                         continue;
8131
8132                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8133                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8134                         return true;
8135         }
8136
8137         return false;
8138 }
8139
8140 static bool is_valid_assignment_lhs(expression_t const* const left)
8141 {
8142         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8143         type_t *const type_left      = skip_typeref(orig_type_left);
8144
8145         if (!is_lvalue(left)) {
8146                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8147                        left);
8148                 return false;
8149         }
8150
8151         if (left->kind == EXPR_REFERENCE
8152                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8153                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8154                 return false;
8155         }
8156
8157         if (is_type_array(type_left)) {
8158                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8159                 return false;
8160         }
8161         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8162                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8163                        orig_type_left);
8164                 return false;
8165         }
8166         if (is_type_incomplete(type_left)) {
8167                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8168                        left, orig_type_left);
8169                 return false;
8170         }
8171         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8172                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8173                        left, orig_type_left);
8174                 return false;
8175         }
8176
8177         return true;
8178 }
8179
8180 static void semantic_arithmetic_assign(binary_expression_t *expression)
8181 {
8182         expression_t *left            = expression->left;
8183         expression_t *right           = expression->right;
8184         type_t       *orig_type_left  = left->base.type;
8185         type_t       *orig_type_right = right->base.type;
8186
8187         if (!is_valid_assignment_lhs(left))
8188                 return;
8189
8190         type_t *type_left  = skip_typeref(orig_type_left);
8191         type_t *type_right = skip_typeref(orig_type_right);
8192
8193         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8194                 /* TODO: improve error message */
8195                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8196                         errorf(&expression->base.source_position,
8197                                "operation needs arithmetic types");
8198                 }
8199                 return;
8200         }
8201
8202         /* combined instructions are tricky. We can't create an implicit cast on
8203          * the left side, because we need the uncasted form for the store.
8204          * The ast2firm pass has to know that left_type must be right_type
8205          * for the arithmetic operation and create a cast by itself */
8206         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8207         expression->right       = create_implicit_cast(right, arithmetic_type);
8208         expression->base.type   = type_left;
8209 }
8210
8211 static void semantic_divmod_assign(binary_expression_t *expression)
8212 {
8213         semantic_arithmetic_assign(expression);
8214         warn_div_by_zero(expression);
8215 }
8216
8217 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8218 {
8219         expression_t *const left            = expression->left;
8220         expression_t *const right           = expression->right;
8221         type_t       *const orig_type_left  = left->base.type;
8222         type_t       *const orig_type_right = right->base.type;
8223         type_t       *const type_left       = skip_typeref(orig_type_left);
8224         type_t       *const type_right      = skip_typeref(orig_type_right);
8225
8226         if (!is_valid_assignment_lhs(left))
8227                 return;
8228
8229         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8230                 /* combined instructions are tricky. We can't create an implicit cast on
8231                  * the left side, because we need the uncasted form for the store.
8232                  * The ast2firm pass has to know that left_type must be right_type
8233                  * for the arithmetic operation and create a cast by itself */
8234                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8235                 expression->right     = create_implicit_cast(right, arithmetic_type);
8236                 expression->base.type = type_left;
8237         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8238                 check_pointer_arithmetic(&expression->base.source_position,
8239                                          type_left, orig_type_left);
8240                 expression->base.type = type_left;
8241         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8242                 errorf(&expression->base.source_position,
8243                        "incompatible types '%T' and '%T' in assignment",
8244                        orig_type_left, orig_type_right);
8245         }
8246 }
8247
8248 static void semantic_integer_assign(binary_expression_t *expression)
8249 {
8250         expression_t *left            = expression->left;
8251         expression_t *right           = expression->right;
8252         type_t       *orig_type_left  = left->base.type;
8253         type_t       *orig_type_right = right->base.type;
8254
8255         if (!is_valid_assignment_lhs(left))
8256                 return;
8257
8258         type_t *type_left  = skip_typeref(orig_type_left);
8259         type_t *type_right = skip_typeref(orig_type_right);
8260
8261         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8262                 /* TODO: improve error message */
8263                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8264                         errorf(&expression->base.source_position,
8265                                "operation needs integer types");
8266                 }
8267                 return;
8268         }
8269
8270         /* combined instructions are tricky. We can't create an implicit cast on
8271          * the left side, because we need the uncasted form for the store.
8272          * The ast2firm pass has to know that left_type must be right_type
8273          * for the arithmetic operation and create a cast by itself */
8274         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8275         expression->right       = create_implicit_cast(right, arithmetic_type);
8276         expression->base.type   = type_left;
8277 }
8278
8279 static void semantic_shift_assign(binary_expression_t *expression)
8280 {
8281         expression_t *left           = expression->left;
8282
8283         if (!is_valid_assignment_lhs(left))
8284                 return;
8285
8286         if (!semantic_shift(expression))
8287                 return;
8288
8289         expression->base.type = skip_typeref(left->base.type);
8290 }
8291
8292 static void warn_logical_and_within_or(const expression_t *const expr)
8293 {
8294         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8295                 return;
8296         if (expr->base.parenthesized)
8297                 return;
8298         source_position_t const *const pos = &expr->base.source_position;
8299         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8300 }
8301
8302 /**
8303  * Check the semantic restrictions of a logical expression.
8304  */
8305 static void semantic_logical_op(binary_expression_t *expression)
8306 {
8307         /* §6.5.13:2  Each of the operands shall have scalar type.
8308          * §6.5.14:2  Each of the operands shall have scalar type. */
8309         semantic_condition(expression->left,   "left operand of logical operator");
8310         semantic_condition(expression->right, "right operand of logical operator");
8311         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8312                 warn_logical_and_within_or(expression->left);
8313                 warn_logical_and_within_or(expression->right);
8314         }
8315         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8316 }
8317
8318 /**
8319  * Check the semantic restrictions of a binary assign expression.
8320  */
8321 static void semantic_binexpr_assign(binary_expression_t *expression)
8322 {
8323         expression_t *left           = expression->left;
8324         type_t       *orig_type_left = left->base.type;
8325
8326         if (!is_valid_assignment_lhs(left))
8327                 return;
8328
8329         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8330         report_assign_error(error, orig_type_left, expression->right,
8331                         "assignment", &left->base.source_position);
8332         expression->right = create_implicit_cast(expression->right, orig_type_left);
8333         expression->base.type = orig_type_left;
8334 }
8335
8336 /**
8337  * Determine if the outermost operation (or parts thereof) of the given
8338  * expression has no effect in order to generate a warning about this fact.
8339  * Therefore in some cases this only examines some of the operands of the
8340  * expression (see comments in the function and examples below).
8341  * Examples:
8342  *   f() + 23;    // warning, because + has no effect
8343  *   x || f();    // no warning, because x controls execution of f()
8344  *   x ? y : f(); // warning, because y has no effect
8345  *   (void)x;     // no warning to be able to suppress the warning
8346  * This function can NOT be used for an "expression has definitely no effect"-
8347  * analysis. */
8348 static bool expression_has_effect(const expression_t *const expr)
8349 {
8350         switch (expr->kind) {
8351                 case EXPR_ERROR:                      return true; /* do NOT warn */
8352                 case EXPR_REFERENCE:                  return false;
8353                 case EXPR_ENUM_CONSTANT:              return false;
8354                 case EXPR_LABEL_ADDRESS:              return false;
8355
8356                 /* suppress the warning for microsoft __noop operations */
8357                 case EXPR_LITERAL_MS_NOOP:            return true;
8358                 case EXPR_LITERAL_BOOLEAN:
8359                 case EXPR_LITERAL_CHARACTER:
8360                 case EXPR_LITERAL_INTEGER:
8361                 case EXPR_LITERAL_FLOATINGPOINT:
8362                 case EXPR_STRING_LITERAL:             return false;
8363
8364                 case EXPR_CALL: {
8365                         const call_expression_t *const call = &expr->call;
8366                         if (call->function->kind != EXPR_REFERENCE)
8367                                 return true;
8368
8369                         switch (call->function->reference.entity->function.btk) {
8370                                 /* FIXME: which builtins have no effect? */
8371                                 default:                      return true;
8372                         }
8373                 }
8374
8375                 /* Generate the warning if either the left or right hand side of a
8376                  * conditional expression has no effect */
8377                 case EXPR_CONDITIONAL: {
8378                         conditional_expression_t const *const cond = &expr->conditional;
8379                         expression_t             const *const t    = cond->true_expression;
8380                         return
8381                                 (t == NULL || expression_has_effect(t)) &&
8382                                 expression_has_effect(cond->false_expression);
8383                 }
8384
8385                 case EXPR_SELECT:                     return false;
8386                 case EXPR_ARRAY_ACCESS:               return false;
8387                 case EXPR_SIZEOF:                     return false;
8388                 case EXPR_CLASSIFY_TYPE:              return false;
8389                 case EXPR_ALIGNOF:                    return false;
8390
8391                 case EXPR_FUNCNAME:                   return false;
8392                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8393                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8394                 case EXPR_OFFSETOF:                   return false;
8395                 case EXPR_VA_START:                   return true;
8396                 case EXPR_VA_ARG:                     return true;
8397                 case EXPR_VA_COPY:                    return true;
8398                 case EXPR_STATEMENT:                  return true; // TODO
8399                 case EXPR_COMPOUND_LITERAL:           return false;
8400
8401                 case EXPR_UNARY_NEGATE:               return false;
8402                 case EXPR_UNARY_PLUS:                 return false;
8403                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8404                 case EXPR_UNARY_NOT:                  return false;
8405                 case EXPR_UNARY_DEREFERENCE:          return false;
8406                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8407                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8408                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8409                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8410                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8411
8412                 /* Treat void casts as if they have an effect in order to being able to
8413                  * suppress the warning */
8414                 case EXPR_UNARY_CAST: {
8415                         type_t *const type = skip_typeref(expr->base.type);
8416                         return is_type_void(type);
8417                 }
8418
8419                 case EXPR_UNARY_ASSUME:               return true;
8420                 case EXPR_UNARY_DELETE:               return true;
8421                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8422                 case EXPR_UNARY_THROW:                return true;
8423
8424                 case EXPR_BINARY_ADD:                 return false;
8425                 case EXPR_BINARY_SUB:                 return false;
8426                 case EXPR_BINARY_MUL:                 return false;
8427                 case EXPR_BINARY_DIV:                 return false;
8428                 case EXPR_BINARY_MOD:                 return false;
8429                 case EXPR_BINARY_EQUAL:               return false;
8430                 case EXPR_BINARY_NOTEQUAL:            return false;
8431                 case EXPR_BINARY_LESS:                return false;
8432                 case EXPR_BINARY_LESSEQUAL:           return false;
8433                 case EXPR_BINARY_GREATER:             return false;
8434                 case EXPR_BINARY_GREATEREQUAL:        return false;
8435                 case EXPR_BINARY_BITWISE_AND:         return false;
8436                 case EXPR_BINARY_BITWISE_OR:          return false;
8437                 case EXPR_BINARY_BITWISE_XOR:         return false;
8438                 case EXPR_BINARY_SHIFTLEFT:           return false;
8439                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8440                 case EXPR_BINARY_ASSIGN:              return true;
8441                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8442                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8443                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8444                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8445                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8446                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8447                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8448                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8449                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8450                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8451
8452                 /* Only examine the right hand side of && and ||, because the left hand
8453                  * side already has the effect of controlling the execution of the right
8454                  * hand side */
8455                 case EXPR_BINARY_LOGICAL_AND:
8456                 case EXPR_BINARY_LOGICAL_OR:
8457                 /* Only examine the right hand side of a comma expression, because the left
8458                  * hand side has a separate warning */
8459                 case EXPR_BINARY_COMMA:
8460                         return expression_has_effect(expr->binary.right);
8461
8462                 case EXPR_BINARY_ISGREATER:           return false;
8463                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8464                 case EXPR_BINARY_ISLESS:              return false;
8465                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8466                 case EXPR_BINARY_ISLESSGREATER:       return false;
8467                 case EXPR_BINARY_ISUNORDERED:         return false;
8468         }
8469
8470         internal_errorf(HERE, "unexpected expression");
8471 }
8472
8473 static void semantic_comma(binary_expression_t *expression)
8474 {
8475         const expression_t *const left = expression->left;
8476         if (!expression_has_effect(left)) {
8477                 source_position_t const *const pos = &left->base.source_position;
8478                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8479         }
8480         expression->base.type = expression->right->base.type;
8481 }
8482
8483 /**
8484  * @param prec_r precedence of the right operand
8485  */
8486 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8487 static expression_t *parse_##binexpression_type(expression_t *left)          \
8488 {                                                                            \
8489         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8490         binexpr->binary.left  = left;                                            \
8491         eat(token_kind);                                                         \
8492                                                                              \
8493         expression_t *right = parse_subexpression(prec_r);                       \
8494                                                                              \
8495         binexpr->binary.right = right;                                           \
8496         sfunc(&binexpr->binary);                                                 \
8497                                                                              \
8498         return binexpr;                                                          \
8499 }
8500
8501 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8502 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8503 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8504 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8505 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8506 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8507 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8508 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8509 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8510 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8511 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8512 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8513 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8514 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8515 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8516 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8517 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8518 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8519 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8520 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8521 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8522 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8523 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8524 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8525 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8526 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8527 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8528 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8529 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8530 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8531
8532
8533 static expression_t *parse_subexpression(precedence_t precedence)
8534 {
8535         expression_parser_function_t *parser
8536                 = &expression_parsers[token.kind];
8537         expression_t                 *left;
8538
8539         if (parser->parser != NULL) {
8540                 left = parser->parser();
8541         } else {
8542                 left = parse_primary_expression();
8543         }
8544         assert(left != NULL);
8545
8546         while (true) {
8547                 parser = &expression_parsers[token.kind];
8548                 if (parser->infix_parser == NULL)
8549                         break;
8550                 if (parser->infix_precedence < precedence)
8551                         break;
8552
8553                 left = parser->infix_parser(left);
8554
8555                 assert(left != NULL);
8556         }
8557
8558         return left;
8559 }
8560
8561 /**
8562  * Parse an expression.
8563  */
8564 static expression_t *parse_expression(void)
8565 {
8566         return parse_subexpression(PREC_EXPRESSION);
8567 }
8568
8569 /**
8570  * Register a parser for a prefix-like operator.
8571  *
8572  * @param parser      the parser function
8573  * @param token_kind  the token type of the prefix token
8574  */
8575 static void register_expression_parser(parse_expression_function parser,
8576                                        int token_kind)
8577 {
8578         expression_parser_function_t *entry = &expression_parsers[token_kind];
8579
8580         assert(!entry->parser);
8581         entry->parser = parser;
8582 }
8583
8584 /**
8585  * Register a parser for an infix operator with given precedence.
8586  *
8587  * @param parser      the parser function
8588  * @param token_kind  the token type of the infix operator
8589  * @param precedence  the precedence of the operator
8590  */
8591 static void register_infix_parser(parse_expression_infix_function parser,
8592                                   int token_kind, precedence_t precedence)
8593 {
8594         expression_parser_function_t *entry = &expression_parsers[token_kind];
8595
8596         assert(!entry->infix_parser);
8597         entry->infix_parser     = parser;
8598         entry->infix_precedence = precedence;
8599 }
8600
8601 /**
8602  * Initialize the expression parsers.
8603  */
8604 static void init_expression_parsers(void)
8605 {
8606         memset(&expression_parsers, 0, sizeof(expression_parsers));
8607
8608         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8609         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8610         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8611         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8612         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8613         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8614         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8615         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8616         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8617         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8618         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8619         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8620         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8621         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8622         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8623         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8624         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8625         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8626         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8627         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8628         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8629         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8630         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8631         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8632         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8633         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8634         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8635         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8636         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8637         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8638         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8639         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8640         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8641         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8642         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8643         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8644         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8645
8646         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8647         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8648         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8649         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8650         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8651         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8652         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8653         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8654         register_expression_parser(parse_sizeof,                      T_sizeof);
8655         register_expression_parser(parse_alignof,                     T___alignof__);
8656         register_expression_parser(parse_extension,                   T___extension__);
8657         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8658         register_expression_parser(parse_delete,                      T_delete);
8659         register_expression_parser(parse_throw,                       T_throw);
8660 }
8661
8662 /**
8663  * Parse a asm statement arguments specification.
8664  */
8665 static asm_argument_t *parse_asm_arguments(bool is_out)
8666 {
8667         asm_argument_t  *result = NULL;
8668         asm_argument_t **anchor = &result;
8669
8670         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8671                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8672
8673                 if (next_if('[')) {
8674                         add_anchor_token(']');
8675                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8676                         rem_anchor_token(']');
8677                         expect(']');
8678                         if (!argument->symbol)
8679                                 return NULL;
8680                 }
8681
8682                 argument->constraints = parse_string_literals("asm argument");
8683                 add_anchor_token(')');
8684                 expect('(');
8685                 expression_t *expression = parse_expression();
8686                 rem_anchor_token(')');
8687                 if (is_out) {
8688                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8689                          * change size or type representation (e.g. int -> long is ok, but
8690                          * int -> float is not) */
8691                         if (expression->kind == EXPR_UNARY_CAST) {
8692                                 type_t      *const type = expression->base.type;
8693                                 type_kind_t  const kind = type->kind;
8694                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8695                                         unsigned flags;
8696                                         unsigned size;
8697                                         if (kind == TYPE_ATOMIC) {
8698                                                 atomic_type_kind_t const akind = type->atomic.akind;
8699                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8700                                                 size  = get_atomic_type_size(akind);
8701                                         } else {
8702                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8703                                                 size  = get_type_size(type_void_ptr);
8704                                         }
8705
8706                                         do {
8707                                                 expression_t *const value      = expression->unary.value;
8708                                                 type_t       *const value_type = value->base.type;
8709                                                 type_kind_t   const value_kind = value_type->kind;
8710
8711                                                 unsigned value_flags;
8712                                                 unsigned value_size;
8713                                                 if (value_kind == TYPE_ATOMIC) {
8714                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8715                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8716                                                         value_size  = get_atomic_type_size(value_akind);
8717                                                 } else if (value_kind == TYPE_POINTER) {
8718                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8719                                                         value_size  = get_type_size(type_void_ptr);
8720                                                 } else {
8721                                                         break;
8722                                                 }
8723
8724                                                 if (value_flags != flags || value_size != size)
8725                                                         break;
8726
8727                                                 expression = value;
8728                                         } while (expression->kind == EXPR_UNARY_CAST);
8729                                 }
8730                         }
8731
8732                         if (!is_lvalue(expression)) {
8733                                 errorf(&expression->base.source_position,
8734                                        "asm output argument is not an lvalue");
8735                         }
8736
8737                         if (argument->constraints.begin[0] == '=')
8738                                 determine_lhs_ent(expression, NULL);
8739                         else
8740                                 mark_vars_read(expression, NULL);
8741                 } else {
8742                         mark_vars_read(expression, NULL);
8743                 }
8744                 argument->expression = expression;
8745                 expect(')');
8746
8747                 set_address_taken(expression, true);
8748
8749                 *anchor = argument;
8750                 anchor  = &argument->next;
8751
8752                 if (!next_if(','))
8753                         break;
8754         }
8755
8756         return result;
8757 }
8758
8759 /**
8760  * Parse a asm statement clobber specification.
8761  */
8762 static asm_clobber_t *parse_asm_clobbers(void)
8763 {
8764         asm_clobber_t *result  = NULL;
8765         asm_clobber_t **anchor = &result;
8766
8767         while (token.kind == T_STRING_LITERAL) {
8768                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8769                 clobber->clobber       = parse_string_literals(NULL);
8770
8771                 *anchor = clobber;
8772                 anchor  = &clobber->next;
8773
8774                 if (!next_if(','))
8775                         break;
8776         }
8777
8778         return result;
8779 }
8780
8781 /**
8782  * Parse an asm statement.
8783  */
8784 static statement_t *parse_asm_statement(void)
8785 {
8786         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8787         asm_statement_t *asm_statement = &statement->asms;
8788
8789         eat(T_asm);
8790         add_anchor_token(')');
8791         add_anchor_token(':');
8792         add_anchor_token(T_STRING_LITERAL);
8793
8794         if (next_if(T_volatile))
8795                 asm_statement->is_volatile = true;
8796
8797         expect('(');
8798         rem_anchor_token(T_STRING_LITERAL);
8799         asm_statement->asm_text = parse_string_literals("asm statement");
8800
8801         if (next_if(':'))
8802                 asm_statement->outputs = parse_asm_arguments(true);
8803
8804         if (next_if(':'))
8805                 asm_statement->inputs = parse_asm_arguments(false);
8806
8807         rem_anchor_token(':');
8808         if (next_if(':'))
8809                 asm_statement->clobbers = parse_asm_clobbers();
8810
8811         rem_anchor_token(')');
8812         expect(')');
8813         expect(';');
8814
8815         if (asm_statement->outputs == NULL) {
8816                 /* GCC: An 'asm' instruction without any output operands will be treated
8817                  * identically to a volatile 'asm' instruction. */
8818                 asm_statement->is_volatile = true;
8819         }
8820
8821         return statement;
8822 }
8823
8824 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8825 {
8826         statement_t *inner_stmt;
8827         switch (token.kind) {
8828                 case '}':
8829                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8830                         inner_stmt = create_error_statement();
8831                         break;
8832
8833                 case ';':
8834                         if (label->kind == STATEMENT_LABEL) {
8835                                 /* Eat an empty statement here, to avoid the warning about an empty
8836                                  * statement after a label.  label:; is commonly used to have a label
8837                                  * before a closing brace. */
8838                                 inner_stmt = create_empty_statement();
8839                                 eat(';');
8840                                 break;
8841                         }
8842                         /* FALLTHROUGH */
8843
8844                 default:
8845                         inner_stmt = parse_statement();
8846                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8847                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8848                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8849                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8850                         }
8851                         break;
8852         }
8853         return inner_stmt;
8854 }
8855
8856 /**
8857  * Parse a case statement.
8858  */
8859 static statement_t *parse_case_statement(void)
8860 {
8861         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8862         source_position_t *const pos       = &statement->base.source_position;
8863
8864         eat(T_case);
8865         add_anchor_token(':');
8866
8867         expression_t *expression = parse_expression();
8868         type_t *expression_type = expression->base.type;
8869         type_t *skipped         = skip_typeref(expression_type);
8870         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8871                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8872                        expression, expression_type);
8873         }
8874
8875         type_t *type = expression_type;
8876         if (current_switch != NULL) {
8877                 type_t *switch_type = current_switch->expression->base.type;
8878                 if (is_type_valid(switch_type)) {
8879                         expression = create_implicit_cast(expression, switch_type);
8880                 }
8881         }
8882
8883         statement->case_label.expression = expression;
8884         expression_classification_t const expr_class = is_constant_expression(expression);
8885         if (expr_class != EXPR_CLASS_CONSTANT) {
8886                 if (expr_class != EXPR_CLASS_ERROR) {
8887                         errorf(pos, "case label does not reduce to an integer constant");
8888                 }
8889                 statement->case_label.is_bad = true;
8890         } else {
8891                 long const val = fold_constant_to_int(expression);
8892                 statement->case_label.first_case = val;
8893                 statement->case_label.last_case  = val;
8894         }
8895
8896         if (GNU_MODE) {
8897                 if (next_if(T_DOTDOTDOT)) {
8898                         expression_t *end_range = parse_expression();
8899                         expression_type = expression->base.type;
8900                         skipped         = skip_typeref(expression_type);
8901                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8902                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8903                                            expression, expression_type);
8904                         }
8905
8906                         end_range = create_implicit_cast(end_range, type);
8907                         statement->case_label.end_range = end_range;
8908                         expression_classification_t const end_class = is_constant_expression(end_range);
8909                         if (end_class != EXPR_CLASS_CONSTANT) {
8910                                 if (end_class != EXPR_CLASS_ERROR) {
8911                                         errorf(pos, "case range does not reduce to an integer constant");
8912                                 }
8913                                 statement->case_label.is_bad = true;
8914                         } else {
8915                                 long const val = fold_constant_to_int(end_range);
8916                                 statement->case_label.last_case = val;
8917
8918                                 if (val < statement->case_label.first_case) {
8919                                         statement->case_label.is_empty_range = true;
8920                                         warningf(WARN_OTHER, pos, "empty range specified");
8921                                 }
8922                         }
8923                 }
8924         }
8925
8926         PUSH_PARENT(statement);
8927
8928         rem_anchor_token(':');
8929         expect(':');
8930
8931         if (current_switch != NULL) {
8932                 if (! statement->case_label.is_bad) {
8933                         /* Check for duplicate case values */
8934                         case_label_statement_t *c = &statement->case_label;
8935                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8936                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8937                                         continue;
8938
8939                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8940                                         continue;
8941
8942                                 errorf(pos, "duplicate case value (previously used %P)",
8943                                        &l->base.source_position);
8944                                 break;
8945                         }
8946                 }
8947                 /* link all cases into the switch statement */
8948                 if (current_switch->last_case == NULL) {
8949                         current_switch->first_case      = &statement->case_label;
8950                 } else {
8951                         current_switch->last_case->next = &statement->case_label;
8952                 }
8953                 current_switch->last_case = &statement->case_label;
8954         } else {
8955                 errorf(pos, "case label not within a switch statement");
8956         }
8957
8958         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8959
8960         POP_PARENT();
8961         return statement;
8962 }
8963
8964 /**
8965  * Parse a default statement.
8966  */
8967 static statement_t *parse_default_statement(void)
8968 {
8969         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8970
8971         eat(T_default);
8972
8973         PUSH_PARENT(statement);
8974
8975         expect(':');
8976
8977         if (current_switch != NULL) {
8978                 const case_label_statement_t *def_label = current_switch->default_label;
8979                 if (def_label != NULL) {
8980                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8981                 } else {
8982                         current_switch->default_label = &statement->case_label;
8983
8984                         /* link all cases into the switch statement */
8985                         if (current_switch->last_case == NULL) {
8986                                 current_switch->first_case      = &statement->case_label;
8987                         } else {
8988                                 current_switch->last_case->next = &statement->case_label;
8989                         }
8990                         current_switch->last_case = &statement->case_label;
8991                 }
8992         } else {
8993                 errorf(&statement->base.source_position,
8994                         "'default' label not within a switch statement");
8995         }
8996
8997         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8998
8999         POP_PARENT();
9000         return statement;
9001 }
9002
9003 /**
9004  * Parse a label statement.
9005  */
9006 static statement_t *parse_label_statement(void)
9007 {
9008         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9009         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9010         statement->label.label = label;
9011
9012         PUSH_PARENT(statement);
9013
9014         /* if statement is already set then the label is defined twice,
9015          * otherwise it was just mentioned in a goto/local label declaration so far
9016          */
9017         source_position_t const* const pos = &statement->base.source_position;
9018         if (label->statement != NULL) {
9019                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9020         } else {
9021                 label->base.source_position = *pos;
9022                 label->statement            = statement;
9023         }
9024
9025         eat(':');
9026
9027         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9028                 parse_attributes(NULL); // TODO process attributes
9029         }
9030
9031         statement->label.statement = parse_label_inner_statement(statement, "label");
9032
9033         /* remember the labels in a list for later checking */
9034         *label_anchor = &statement->label;
9035         label_anchor  = &statement->label.next;
9036
9037         POP_PARENT();
9038         return statement;
9039 }
9040
9041 static statement_t *parse_inner_statement(void)
9042 {
9043         statement_t *const stmt = parse_statement();
9044         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9045         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9046         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9047                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9048         }
9049         return stmt;
9050 }
9051
9052 /**
9053  * Parse an expression in parentheses and mark its variables as read.
9054  */
9055 static expression_t *parse_condition(void)
9056 {
9057         add_anchor_token(')');
9058         expect('(');
9059         expression_t *const expr = parse_expression();
9060         mark_vars_read(expr, NULL);
9061         rem_anchor_token(')');
9062         expect(')');
9063         return expr;
9064 }
9065
9066 /**
9067  * Parse an if statement.
9068  */
9069 static statement_t *parse_if(void)
9070 {
9071         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9072
9073         eat(T_if);
9074
9075         PUSH_PARENT(statement);
9076         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9077
9078         add_anchor_token(T_else);
9079
9080         expression_t *const expr = parse_condition();
9081         statement->ifs.condition = expr;
9082         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9083          *             scalar type. */
9084         semantic_condition(expr, "condition of 'if'-statment");
9085
9086         statement_t *const true_stmt = parse_inner_statement();
9087         statement->ifs.true_statement = true_stmt;
9088         rem_anchor_token(T_else);
9089
9090         if (true_stmt->kind == STATEMENT_EMPTY) {
9091                 warningf(WARN_EMPTY_BODY, HERE,
9092                         "suggest braces around empty body in an ‘if’ statement");
9093         }
9094
9095         if (next_if(T_else)) {
9096                 statement->ifs.false_statement = parse_inner_statement();
9097
9098                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9099                         warningf(WARN_EMPTY_BODY, HERE,
9100                                         "suggest braces around empty body in an ‘if’ statement");
9101                 }
9102         } else if (true_stmt->kind == STATEMENT_IF &&
9103                         true_stmt->ifs.false_statement != NULL) {
9104                 source_position_t const *const pos = &true_stmt->base.source_position;
9105                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9106         }
9107
9108         POP_SCOPE();
9109         POP_PARENT();
9110         return statement;
9111 }
9112
9113 /**
9114  * Check that all enums are handled in a switch.
9115  *
9116  * @param statement  the switch statement to check
9117  */
9118 static void check_enum_cases(const switch_statement_t *statement)
9119 {
9120         if (!is_warn_on(WARN_SWITCH_ENUM))
9121                 return;
9122         const type_t *type = skip_typeref(statement->expression->base.type);
9123         if (! is_type_enum(type))
9124                 return;
9125         const enum_type_t *enumt = &type->enumt;
9126
9127         /* if we have a default, no warnings */
9128         if (statement->default_label != NULL)
9129                 return;
9130
9131         /* FIXME: calculation of value should be done while parsing */
9132         /* TODO: quadratic algorithm here. Change to an n log n one */
9133         long            last_value = -1;
9134         const entity_t *entry      = enumt->enume->base.next;
9135         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9136              entry = entry->base.next) {
9137                 const expression_t *expression = entry->enum_value.value;
9138                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9139                 bool                found      = false;
9140                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9141                         if (l->expression == NULL)
9142                                 continue;
9143                         if (l->first_case <= value && value <= l->last_case) {
9144                                 found = true;
9145                                 break;
9146                         }
9147                 }
9148                 if (!found) {
9149                         source_position_t const *const pos = &statement->base.source_position;
9150                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9151                 }
9152                 last_value = value;
9153         }
9154 }
9155
9156 /**
9157  * Parse a switch statement.
9158  */
9159 static statement_t *parse_switch(void)
9160 {
9161         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9162
9163         eat(T_switch);
9164
9165         PUSH_PARENT(statement);
9166         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9167
9168         expression_t *const expr = parse_condition();
9169         type_t       *      type = skip_typeref(expr->base.type);
9170         if (is_type_integer(type)) {
9171                 type = promote_integer(type);
9172                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9173                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9174                 }
9175         } else if (is_type_valid(type)) {
9176                 errorf(&expr->base.source_position,
9177                        "switch quantity is not an integer, but '%T'", type);
9178                 type = type_error_type;
9179         }
9180         statement->switchs.expression = create_implicit_cast(expr, type);
9181
9182         switch_statement_t *rem = current_switch;
9183         current_switch          = &statement->switchs;
9184         statement->switchs.body = parse_inner_statement();
9185         current_switch          = rem;
9186
9187         if (statement->switchs.default_label == NULL) {
9188                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9189         }
9190         check_enum_cases(&statement->switchs);
9191
9192         POP_SCOPE();
9193         POP_PARENT();
9194         return statement;
9195 }
9196
9197 static statement_t *parse_loop_body(statement_t *const loop)
9198 {
9199         statement_t *const rem = current_loop;
9200         current_loop = loop;
9201
9202         statement_t *const body = parse_inner_statement();
9203
9204         current_loop = rem;
9205         return body;
9206 }
9207
9208 /**
9209  * Parse a while statement.
9210  */
9211 static statement_t *parse_while(void)
9212 {
9213         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9214
9215         eat(T_while);
9216
9217         PUSH_PARENT(statement);
9218         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9219
9220         expression_t *const cond = parse_condition();
9221         statement->whiles.condition = cond;
9222         /* §6.8.5:2    The controlling expression of an iteration statement shall
9223          *             have scalar type. */
9224         semantic_condition(cond, "condition of 'while'-statement");
9225
9226         statement->whiles.body = parse_loop_body(statement);
9227
9228         POP_SCOPE();
9229         POP_PARENT();
9230         return statement;
9231 }
9232
9233 /**
9234  * Parse a do statement.
9235  */
9236 static statement_t *parse_do(void)
9237 {
9238         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9239
9240         eat(T_do);
9241
9242         PUSH_PARENT(statement);
9243         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9244
9245         add_anchor_token(T_while);
9246         statement->do_while.body = parse_loop_body(statement);
9247         rem_anchor_token(T_while);
9248
9249         expect(T_while);
9250         expression_t *const cond = parse_condition();
9251         statement->do_while.condition = cond;
9252         /* §6.8.5:2    The controlling expression of an iteration statement shall
9253          *             have scalar type. */
9254         semantic_condition(cond, "condition of 'do-while'-statement");
9255         expect(';');
9256
9257         POP_SCOPE();
9258         POP_PARENT();
9259         return statement;
9260 }
9261
9262 /**
9263  * Parse a for statement.
9264  */
9265 static statement_t *parse_for(void)
9266 {
9267         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9268
9269         eat(T_for);
9270
9271         PUSH_PARENT(statement);
9272         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9273
9274         add_anchor_token(')');
9275         expect('(');
9276
9277         PUSH_EXTENSION();
9278
9279         if (next_if(';')) {
9280         } else if (is_declaration_specifier(&token)) {
9281                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9282         } else {
9283                 add_anchor_token(';');
9284                 expression_t *const init = parse_expression();
9285                 statement->fors.initialisation = init;
9286                 mark_vars_read(init, ENT_ANY);
9287                 if (!expression_has_effect(init)) {
9288                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9289                 }
9290                 rem_anchor_token(';');
9291                 expect(';');
9292         }
9293
9294         POP_EXTENSION();
9295
9296         if (token.kind != ';') {
9297                 add_anchor_token(';');
9298                 expression_t *const cond = parse_expression();
9299                 statement->fors.condition = cond;
9300                 /* §6.8.5:2    The controlling expression of an iteration statement
9301                  *             shall have scalar type. */
9302                 semantic_condition(cond, "condition of 'for'-statement");
9303                 mark_vars_read(cond, NULL);
9304                 rem_anchor_token(';');
9305         }
9306         expect(';');
9307         if (token.kind != ')') {
9308                 expression_t *const step = parse_expression();
9309                 statement->fors.step = step;
9310                 mark_vars_read(step, ENT_ANY);
9311                 if (!expression_has_effect(step)) {
9312                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9313                 }
9314         }
9315         rem_anchor_token(')');
9316         expect(')');
9317         statement->fors.body = parse_loop_body(statement);
9318
9319         POP_SCOPE();
9320         POP_PARENT();
9321         return statement;
9322 }
9323
9324 /**
9325  * Parse a goto statement.
9326  */
9327 static statement_t *parse_goto(void)
9328 {
9329         statement_t *statement;
9330         if (GNU_MODE && look_ahead(1)->kind == '*') {
9331                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9332                 eat(T_goto);
9333                 eat('*');
9334
9335                 expression_t *expression = parse_expression();
9336                 mark_vars_read(expression, NULL);
9337
9338                 /* Argh: although documentation says the expression must be of type void*,
9339                  * gcc accepts anything that can be casted into void* without error */
9340                 type_t *type = expression->base.type;
9341
9342                 if (type != type_error_type) {
9343                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9344                                 errorf(&expression->base.source_position,
9345                                         "cannot convert to a pointer type");
9346                         } else if (type != type_void_ptr) {
9347                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9348                         }
9349                         expression = create_implicit_cast(expression, type_void_ptr);
9350                 }
9351
9352                 statement->computed_goto.expression = expression;
9353         } else {
9354                 statement = allocate_statement_zero(STATEMENT_GOTO);
9355                 eat(T_goto);
9356
9357                 label_t *const label = get_label("while parsing goto");
9358                 if (label) {
9359                         label->used            = true;
9360                         statement->gotos.label = label;
9361
9362                         /* remember the goto's in a list for later checking */
9363                         *goto_anchor = &statement->gotos;
9364                         goto_anchor  = &statement->gotos.next;
9365                 } else {
9366                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9367                 }
9368         }
9369
9370         expect(';');
9371         return statement;
9372 }
9373
9374 /**
9375  * Parse a continue statement.
9376  */
9377 static statement_t *parse_continue(void)
9378 {
9379         if (current_loop == NULL) {
9380                 errorf(HERE, "continue statement not within loop");
9381         }
9382
9383         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9384
9385         eat(T_continue);
9386         expect(';');
9387         return statement;
9388 }
9389
9390 /**
9391  * Parse a break statement.
9392  */
9393 static statement_t *parse_break(void)
9394 {
9395         if (current_switch == NULL && current_loop == NULL) {
9396                 errorf(HERE, "break statement not within loop or switch");
9397         }
9398
9399         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9400
9401         eat(T_break);
9402         expect(';');
9403         return statement;
9404 }
9405
9406 /**
9407  * Parse a __leave statement.
9408  */
9409 static statement_t *parse_leave_statement(void)
9410 {
9411         if (current_try == NULL) {
9412                 errorf(HERE, "__leave statement not within __try");
9413         }
9414
9415         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9416
9417         eat(T___leave);
9418         expect(';');
9419         return statement;
9420 }
9421
9422 /**
9423  * Check if a given entity represents a local variable.
9424  */
9425 static bool is_local_variable(const entity_t *entity)
9426 {
9427         if (entity->kind != ENTITY_VARIABLE)
9428                 return false;
9429
9430         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9431         case STORAGE_CLASS_AUTO:
9432         case STORAGE_CLASS_REGISTER: {
9433                 const type_t *type = skip_typeref(entity->declaration.type);
9434                 if (is_type_function(type)) {
9435                         return false;
9436                 } else {
9437                         return true;
9438                 }
9439         }
9440         default:
9441                 return false;
9442         }
9443 }
9444
9445 /**
9446  * Check if a given expression represents a local variable.
9447  */
9448 static bool expression_is_local_variable(const expression_t *expression)
9449 {
9450         if (expression->base.kind != EXPR_REFERENCE) {
9451                 return false;
9452         }
9453         const entity_t *entity = expression->reference.entity;
9454         return is_local_variable(entity);
9455 }
9456
9457 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9458 {
9459         if (c_mode & _CXX || strict_mode) {
9460                 errorf(pos, msg);
9461         } else {
9462                 warningf(WARN_OTHER, pos, msg);
9463         }
9464 }
9465
9466 /**
9467  * Parse a return statement.
9468  */
9469 static statement_t *parse_return(void)
9470 {
9471         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9472         eat(T_return);
9473
9474         expression_t *return_value = NULL;
9475         if (token.kind != ';') {
9476                 return_value = parse_expression();
9477                 mark_vars_read(return_value, NULL);
9478         }
9479
9480         const type_t *const func_type = skip_typeref(current_function->base.type);
9481         assert(is_type_function(func_type));
9482         type_t *const return_type = skip_typeref(func_type->function.return_type);
9483
9484         source_position_t const *const pos = &statement->base.source_position;
9485         if (return_value != NULL) {
9486                 type_t *return_value_type = skip_typeref(return_value->base.type);
9487
9488                 if (is_type_void(return_type)) {
9489                         if (!is_type_void(return_value_type)) {
9490                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9491                                 /* Only warn in C mode, because GCC does the same */
9492                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9493                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9494                                 /* Only warn in C mode, because GCC does the same */
9495                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9496                         }
9497                 } else {
9498                         assign_error_t error = semantic_assign(return_type, return_value);
9499                         report_assign_error(error, return_type, return_value, "'return'",
9500                                             pos);
9501                 }
9502                 return_value = create_implicit_cast(return_value, return_type);
9503                 /* check for returning address of a local var */
9504                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9505                         const expression_t *expression = return_value->unary.value;
9506                         if (expression_is_local_variable(expression)) {
9507                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9508                         }
9509                 }
9510         } else if (!is_type_void(return_type)) {
9511                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9512                 err_or_warn(pos, "'return' without value, in function returning non-void");
9513         }
9514         statement->returns.value = return_value;
9515
9516         expect(';');
9517         return statement;
9518 }
9519
9520 /**
9521  * Parse a declaration statement.
9522  */
9523 static statement_t *parse_declaration_statement(void)
9524 {
9525         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9526
9527         entity_t *before = current_scope->last_entity;
9528         if (GNU_MODE) {
9529                 parse_external_declaration();
9530         } else {
9531                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9532         }
9533
9534         declaration_statement_t *const decl  = &statement->declaration;
9535         entity_t                *const begin =
9536                 before != NULL ? before->base.next : current_scope->entities;
9537         decl->declarations_begin = begin;
9538         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9539
9540         return statement;
9541 }
9542
9543 /**
9544  * Parse an expression statement, ie. expr ';'.
9545  */
9546 static statement_t *parse_expression_statement(void)
9547 {
9548         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9549
9550         expression_t *const expr         = parse_expression();
9551         statement->expression.expression = expr;
9552         mark_vars_read(expr, ENT_ANY);
9553
9554         expect(';');
9555         return statement;
9556 }
9557
9558 /**
9559  * Parse a microsoft __try { } __finally { } or
9560  * __try{ } __except() { }
9561  */
9562 static statement_t *parse_ms_try_statment(void)
9563 {
9564         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9565         eat(T___try);
9566
9567         PUSH_PARENT(statement);
9568
9569         ms_try_statement_t *rem = current_try;
9570         current_try = &statement->ms_try;
9571         statement->ms_try.try_statement = parse_compound_statement(false);
9572         current_try = rem;
9573
9574         POP_PARENT();
9575
9576         if (next_if(T___except)) {
9577                 expression_t *const expr = parse_condition();
9578                 type_t       *      type = skip_typeref(expr->base.type);
9579                 if (is_type_integer(type)) {
9580                         type = promote_integer(type);
9581                 } else if (is_type_valid(type)) {
9582                         errorf(&expr->base.source_position,
9583                                "__expect expression is not an integer, but '%T'", type);
9584                         type = type_error_type;
9585                 }
9586                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9587         } else if (!next_if(T__finally)) {
9588                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9589         }
9590         statement->ms_try.final_statement = parse_compound_statement(false);
9591         return statement;
9592 }
9593
9594 static statement_t *parse_empty_statement(void)
9595 {
9596         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9597         statement_t *const statement = create_empty_statement();
9598         eat(';');
9599         return statement;
9600 }
9601
9602 static statement_t *parse_local_label_declaration(void)
9603 {
9604         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9605
9606         eat(T___label__);
9607
9608         entity_t *begin   = NULL;
9609         entity_t *end     = NULL;
9610         entity_t **anchor = &begin;
9611         add_anchor_token(';');
9612         add_anchor_token(',');
9613         do {
9614                 source_position_t pos;
9615                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9616                 if (symbol) {
9617                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9618                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9619                                 source_position_t const *const ppos = &entity->base.source_position;
9620                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9621                         } else {
9622                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9623                                 entity->base.parent_scope = current_scope;
9624
9625                                 *anchor = entity;
9626                                 anchor  = &entity->base.next;
9627                                 end     = entity;
9628
9629                                 environment_push(entity);
9630                         }
9631                 }
9632         } while (next_if(','));
9633         rem_anchor_token(',');
9634         rem_anchor_token(';');
9635         expect(';');
9636         statement->declaration.declarations_begin = begin;
9637         statement->declaration.declarations_end   = end;
9638         return statement;
9639 }
9640
9641 static void parse_namespace_definition(void)
9642 {
9643         eat(T_namespace);
9644
9645         entity_t *entity = NULL;
9646         symbol_t *symbol = NULL;
9647
9648         if (token.kind == T_IDENTIFIER) {
9649                 symbol = token.base.symbol;
9650                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9651                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9652                         entity = NULL;
9653                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9654                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9655                         }
9656                 }
9657                 eat(T_IDENTIFIER);
9658         }
9659
9660         if (entity == NULL) {
9661                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9662                 entity->base.parent_scope = current_scope;
9663         }
9664
9665         if (token.kind == '=') {
9666                 /* TODO: parse namespace alias */
9667                 panic("namespace alias definition not supported yet");
9668         }
9669
9670         environment_push(entity);
9671         append_entity(current_scope, entity);
9672
9673         PUSH_SCOPE(&entity->namespacee.members);
9674         PUSH_CURRENT_ENTITY(entity);
9675
9676         add_anchor_token('}');
9677         expect('{');
9678         parse_externals();
9679         rem_anchor_token('}');
9680         expect('}');
9681
9682         POP_CURRENT_ENTITY();
9683         POP_SCOPE();
9684 }
9685
9686 /**
9687  * Parse a statement.
9688  * There's also parse_statement() which additionally checks for
9689  * "statement has no effect" warnings
9690  */
9691 static statement_t *intern_parse_statement(void)
9692 {
9693         /* declaration or statement */
9694         statement_t *statement;
9695         switch (token.kind) {
9696         case T_IDENTIFIER: {
9697                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9698                 if (la1_type == ':') {
9699                         statement = parse_label_statement();
9700                 } else if (is_typedef_symbol(token.base.symbol)) {
9701                         statement = parse_declaration_statement();
9702                 } else {
9703                         /* it's an identifier, the grammar says this must be an
9704                          * expression statement. However it is common that users mistype
9705                          * declaration types, so we guess a bit here to improve robustness
9706                          * for incorrect programs */
9707                         switch (la1_type) {
9708                         case '&':
9709                         case '*':
9710                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9711                         default:
9712                                         statement = parse_expression_statement();
9713                                 } else {
9714                         DECLARATION_START
9715                         case T_IDENTIFIER:
9716                                         statement = parse_declaration_statement();
9717                                 }
9718                                 break;
9719                         }
9720                 }
9721                 break;
9722         }
9723
9724         case T___extension__: {
9725                 /* This can be a prefix to a declaration or an expression statement.
9726                  * We simply eat it now and parse the rest with tail recursion. */
9727                 PUSH_EXTENSION();
9728                 statement = intern_parse_statement();
9729                 POP_EXTENSION();
9730                 break;
9731         }
9732
9733         DECLARATION_START
9734                 statement = parse_declaration_statement();
9735                 break;
9736
9737         case T___label__:
9738                 statement = parse_local_label_declaration();
9739                 break;
9740
9741         case ';':         statement = parse_empty_statement();         break;
9742         case '{':         statement = parse_compound_statement(false); break;
9743         case T___leave:   statement = parse_leave_statement();         break;
9744         case T___try:     statement = parse_ms_try_statment();         break;
9745         case T_asm:       statement = parse_asm_statement();           break;
9746         case T_break:     statement = parse_break();                   break;
9747         case T_case:      statement = parse_case_statement();          break;
9748         case T_continue:  statement = parse_continue();                break;
9749         case T_default:   statement = parse_default_statement();       break;
9750         case T_do:        statement = parse_do();                      break;
9751         case T_for:       statement = parse_for();                     break;
9752         case T_goto:      statement = parse_goto();                    break;
9753         case T_if:        statement = parse_if();                      break;
9754         case T_return:    statement = parse_return();                  break;
9755         case T_switch:    statement = parse_switch();                  break;
9756         case T_while:     statement = parse_while();                   break;
9757
9758         EXPRESSION_START
9759                 statement = parse_expression_statement();
9760                 break;
9761
9762         default:
9763                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9764                 statement = create_error_statement();
9765                 eat_until_anchor();
9766                 break;
9767         }
9768
9769         return statement;
9770 }
9771
9772 /**
9773  * parse a statement and emits "statement has no effect" warning if needed
9774  * (This is really a wrapper around intern_parse_statement with check for 1
9775  *  single warning. It is needed, because for statement expressions we have
9776  *  to avoid the warning on the last statement)
9777  */
9778 static statement_t *parse_statement(void)
9779 {
9780         statement_t *statement = intern_parse_statement();
9781
9782         if (statement->kind == STATEMENT_EXPRESSION) {
9783                 expression_t *expression = statement->expression.expression;
9784                 if (!expression_has_effect(expression)) {
9785                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9786                 }
9787         }
9788
9789         return statement;
9790 }
9791
9792 /**
9793  * Parse a compound statement.
9794  */
9795 static statement_t *parse_compound_statement(bool inside_expression_statement)
9796 {
9797         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9798
9799         PUSH_PARENT(statement);
9800         PUSH_SCOPE(&statement->compound.scope);
9801
9802         eat('{');
9803         add_anchor_token('}');
9804         /* tokens, which can start a statement */
9805         /* TODO MS, __builtin_FOO */
9806         add_anchor_token('!');
9807         add_anchor_token('&');
9808         add_anchor_token('(');
9809         add_anchor_token('*');
9810         add_anchor_token('+');
9811         add_anchor_token('-');
9812         add_anchor_token(';');
9813         add_anchor_token('{');
9814         add_anchor_token('~');
9815         add_anchor_token(T_CHARACTER_CONSTANT);
9816         add_anchor_token(T_COLONCOLON);
9817         add_anchor_token(T_IDENTIFIER);
9818         add_anchor_token(T_MINUSMINUS);
9819         add_anchor_token(T_NUMBER);
9820         add_anchor_token(T_PLUSPLUS);
9821         add_anchor_token(T_STRING_LITERAL);
9822         add_anchor_token(T__Bool);
9823         add_anchor_token(T__Complex);
9824         add_anchor_token(T__Imaginary);
9825         add_anchor_token(T___PRETTY_FUNCTION__);
9826         add_anchor_token(T___alignof__);
9827         add_anchor_token(T___attribute__);
9828         add_anchor_token(T___builtin_va_start);
9829         add_anchor_token(T___extension__);
9830         add_anchor_token(T___func__);
9831         add_anchor_token(T___imag__);
9832         add_anchor_token(T___label__);
9833         add_anchor_token(T___real__);
9834         add_anchor_token(T___thread);
9835         add_anchor_token(T_asm);
9836         add_anchor_token(T_auto);
9837         add_anchor_token(T_bool);
9838         add_anchor_token(T_break);
9839         add_anchor_token(T_case);
9840         add_anchor_token(T_char);
9841         add_anchor_token(T_class);
9842         add_anchor_token(T_const);
9843         add_anchor_token(T_const_cast);
9844         add_anchor_token(T_continue);
9845         add_anchor_token(T_default);
9846         add_anchor_token(T_delete);
9847         add_anchor_token(T_double);
9848         add_anchor_token(T_do);
9849         add_anchor_token(T_dynamic_cast);
9850         add_anchor_token(T_enum);
9851         add_anchor_token(T_extern);
9852         add_anchor_token(T_false);
9853         add_anchor_token(T_float);
9854         add_anchor_token(T_for);
9855         add_anchor_token(T_goto);
9856         add_anchor_token(T_if);
9857         add_anchor_token(T_inline);
9858         add_anchor_token(T_int);
9859         add_anchor_token(T_long);
9860         add_anchor_token(T_new);
9861         add_anchor_token(T_operator);
9862         add_anchor_token(T_register);
9863         add_anchor_token(T_reinterpret_cast);
9864         add_anchor_token(T_restrict);
9865         add_anchor_token(T_return);
9866         add_anchor_token(T_short);
9867         add_anchor_token(T_signed);
9868         add_anchor_token(T_sizeof);
9869         add_anchor_token(T_static);
9870         add_anchor_token(T_static_cast);
9871         add_anchor_token(T_struct);
9872         add_anchor_token(T_switch);
9873         add_anchor_token(T_template);
9874         add_anchor_token(T_this);
9875         add_anchor_token(T_throw);
9876         add_anchor_token(T_true);
9877         add_anchor_token(T_try);
9878         add_anchor_token(T_typedef);
9879         add_anchor_token(T_typeid);
9880         add_anchor_token(T_typename);
9881         add_anchor_token(T_typeof);
9882         add_anchor_token(T_union);
9883         add_anchor_token(T_unsigned);
9884         add_anchor_token(T_using);
9885         add_anchor_token(T_void);
9886         add_anchor_token(T_volatile);
9887         add_anchor_token(T_wchar_t);
9888         add_anchor_token(T_while);
9889
9890         statement_t **anchor            = &statement->compound.statements;
9891         bool          only_decls_so_far = true;
9892         while (token.kind != '}' && token.kind != T_EOF) {
9893                 statement_t *sub_statement = intern_parse_statement();
9894                 if (sub_statement->kind == STATEMENT_ERROR) {
9895                         break;
9896                 }
9897
9898                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9899                         only_decls_so_far = false;
9900                 } else if (!only_decls_so_far) {
9901                         source_position_t const *const pos = &sub_statement->base.source_position;
9902                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9903                 }
9904
9905                 *anchor = sub_statement;
9906                 anchor  = &sub_statement->base.next;
9907         }
9908         expect('}');
9909
9910         /* look over all statements again to produce no effect warnings */
9911         if (is_warn_on(WARN_UNUSED_VALUE)) {
9912                 statement_t *sub_statement = statement->compound.statements;
9913                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9914                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9915                                 continue;
9916                         /* don't emit a warning for the last expression in an expression
9917                          * statement as it has always an effect */
9918                         if (inside_expression_statement && sub_statement->base.next == NULL)
9919                                 continue;
9920
9921                         expression_t *expression = sub_statement->expression.expression;
9922                         if (!expression_has_effect(expression)) {
9923                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9924                         }
9925                 }
9926         }
9927
9928         rem_anchor_token(T_while);
9929         rem_anchor_token(T_wchar_t);
9930         rem_anchor_token(T_volatile);
9931         rem_anchor_token(T_void);
9932         rem_anchor_token(T_using);
9933         rem_anchor_token(T_unsigned);
9934         rem_anchor_token(T_union);
9935         rem_anchor_token(T_typeof);
9936         rem_anchor_token(T_typename);
9937         rem_anchor_token(T_typeid);
9938         rem_anchor_token(T_typedef);
9939         rem_anchor_token(T_try);
9940         rem_anchor_token(T_true);
9941         rem_anchor_token(T_throw);
9942         rem_anchor_token(T_this);
9943         rem_anchor_token(T_template);
9944         rem_anchor_token(T_switch);
9945         rem_anchor_token(T_struct);
9946         rem_anchor_token(T_static_cast);
9947         rem_anchor_token(T_static);
9948         rem_anchor_token(T_sizeof);
9949         rem_anchor_token(T_signed);
9950         rem_anchor_token(T_short);
9951         rem_anchor_token(T_return);
9952         rem_anchor_token(T_restrict);
9953         rem_anchor_token(T_reinterpret_cast);
9954         rem_anchor_token(T_register);
9955         rem_anchor_token(T_operator);
9956         rem_anchor_token(T_new);
9957         rem_anchor_token(T_long);
9958         rem_anchor_token(T_int);
9959         rem_anchor_token(T_inline);
9960         rem_anchor_token(T_if);
9961         rem_anchor_token(T_goto);
9962         rem_anchor_token(T_for);
9963         rem_anchor_token(T_float);
9964         rem_anchor_token(T_false);
9965         rem_anchor_token(T_extern);
9966         rem_anchor_token(T_enum);
9967         rem_anchor_token(T_dynamic_cast);
9968         rem_anchor_token(T_do);
9969         rem_anchor_token(T_double);
9970         rem_anchor_token(T_delete);
9971         rem_anchor_token(T_default);
9972         rem_anchor_token(T_continue);
9973         rem_anchor_token(T_const_cast);
9974         rem_anchor_token(T_const);
9975         rem_anchor_token(T_class);
9976         rem_anchor_token(T_char);
9977         rem_anchor_token(T_case);
9978         rem_anchor_token(T_break);
9979         rem_anchor_token(T_bool);
9980         rem_anchor_token(T_auto);
9981         rem_anchor_token(T_asm);
9982         rem_anchor_token(T___thread);
9983         rem_anchor_token(T___real__);
9984         rem_anchor_token(T___label__);
9985         rem_anchor_token(T___imag__);
9986         rem_anchor_token(T___func__);
9987         rem_anchor_token(T___extension__);
9988         rem_anchor_token(T___builtin_va_start);
9989         rem_anchor_token(T___attribute__);
9990         rem_anchor_token(T___alignof__);
9991         rem_anchor_token(T___PRETTY_FUNCTION__);
9992         rem_anchor_token(T__Imaginary);
9993         rem_anchor_token(T__Complex);
9994         rem_anchor_token(T__Bool);
9995         rem_anchor_token(T_STRING_LITERAL);
9996         rem_anchor_token(T_PLUSPLUS);
9997         rem_anchor_token(T_NUMBER);
9998         rem_anchor_token(T_MINUSMINUS);
9999         rem_anchor_token(T_IDENTIFIER);
10000         rem_anchor_token(T_COLONCOLON);
10001         rem_anchor_token(T_CHARACTER_CONSTANT);
10002         rem_anchor_token('~');
10003         rem_anchor_token('{');
10004         rem_anchor_token(';');
10005         rem_anchor_token('-');
10006         rem_anchor_token('+');
10007         rem_anchor_token('*');
10008         rem_anchor_token('(');
10009         rem_anchor_token('&');
10010         rem_anchor_token('!');
10011         rem_anchor_token('}');
10012
10013         POP_SCOPE();
10014         POP_PARENT();
10015         return statement;
10016 }
10017
10018 /**
10019  * Check for unused global static functions and variables
10020  */
10021 static void check_unused_globals(void)
10022 {
10023         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10024                 return;
10025
10026         for (const entity_t *entity = file_scope->entities; entity != NULL;
10027              entity = entity->base.next) {
10028                 if (!is_declaration(entity))
10029                         continue;
10030
10031                 const declaration_t *declaration = &entity->declaration;
10032                 if (declaration->used                  ||
10033                     declaration->modifiers & DM_UNUSED ||
10034                     declaration->modifiers & DM_USED   ||
10035                     declaration->storage_class != STORAGE_CLASS_STATIC)
10036                         continue;
10037
10038                 warning_t   why;
10039                 char const *s;
10040                 if (entity->kind == ENTITY_FUNCTION) {
10041                         /* inhibit warning for static inline functions */
10042                         if (entity->function.is_inline)
10043                                 continue;
10044
10045                         why = WARN_UNUSED_FUNCTION;
10046                         s   = entity->function.statement != NULL ? "defined" : "declared";
10047                 } else {
10048                         why = WARN_UNUSED_VARIABLE;
10049                         s   = "defined";
10050                 }
10051
10052                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10053         }
10054 }
10055
10056 static void parse_global_asm(void)
10057 {
10058         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10059
10060         eat(T_asm);
10061         add_anchor_token(';');
10062         add_anchor_token(')');
10063         add_anchor_token(T_STRING_LITERAL);
10064         expect('(');
10065
10066         rem_anchor_token(T_STRING_LITERAL);
10067         statement->asms.asm_text = parse_string_literals("global asm");
10068         statement->base.next     = unit->global_asm;
10069         unit->global_asm         = statement;
10070
10071         rem_anchor_token(')');
10072         expect(')');
10073         rem_anchor_token(';');
10074         expect(';');
10075 }
10076
10077 static void parse_linkage_specification(void)
10078 {
10079         eat(T_extern);
10080
10081         source_position_t const pos     = *HERE;
10082         char const       *const linkage = parse_string_literals(NULL).begin;
10083
10084         linkage_kind_t old_linkage = current_linkage;
10085         linkage_kind_t new_linkage;
10086         if (streq(linkage, "C")) {
10087                 new_linkage = LINKAGE_C;
10088         } else if (streq(linkage, "C++")) {
10089                 new_linkage = LINKAGE_CXX;
10090         } else {
10091                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10092                 new_linkage = LINKAGE_C;
10093         }
10094         current_linkage = new_linkage;
10095
10096         if (next_if('{')) {
10097                 parse_externals();
10098                 expect('}');
10099         } else {
10100                 parse_external();
10101         }
10102
10103         assert(current_linkage == new_linkage);
10104         current_linkage = old_linkage;
10105 }
10106
10107 static void parse_external(void)
10108 {
10109         switch (token.kind) {
10110                 case T_extern:
10111                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10112                                 parse_linkage_specification();
10113                         } else {
10114                 DECLARATION_START_NO_EXTERN
10115                 case T_IDENTIFIER:
10116                 case T___extension__:
10117                 /* tokens below are for implicit int */
10118                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10119                               implicit int) */
10120                 case '*':  /* * x; -> int* x; */
10121                 case '(':  /* (x); -> int (x); */
10122                                 PUSH_EXTENSION();
10123                                 parse_external_declaration();
10124                                 POP_EXTENSION();
10125                         }
10126                         return;
10127
10128                 case T_asm:
10129                         parse_global_asm();
10130                         return;
10131
10132                 case T_namespace:
10133                         parse_namespace_definition();
10134                         return;
10135
10136                 case ';':
10137                         if (!strict_mode) {
10138                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10139                                 eat(';');
10140                                 return;
10141                         }
10142                         /* FALLTHROUGH */
10143
10144                 default:
10145                         errorf(HERE, "stray %K outside of function", &token);
10146                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10147                                 eat_until_matching_token(token.kind);
10148                         next_token();
10149                         return;
10150         }
10151 }
10152
10153 static void parse_externals(void)
10154 {
10155         add_anchor_token('}');
10156         add_anchor_token(T_EOF);
10157
10158 #ifndef NDEBUG
10159         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10160         unsigned short token_anchor_copy[T_LAST_TOKEN];
10161         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10162 #endif
10163
10164         while (token.kind != T_EOF && token.kind != '}') {
10165 #ifndef NDEBUG
10166                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10167                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10168                         if (count != 0) {
10169                                 /* the anchor set and its copy differs */
10170                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10171                         }
10172                 }
10173                 if (in_gcc_extension) {
10174                         /* an gcc extension scope was not closed */
10175                         internal_errorf(HERE, "Leaked __extension__");
10176                 }
10177 #endif
10178
10179                 parse_external();
10180         }
10181
10182         rem_anchor_token(T_EOF);
10183         rem_anchor_token('}');
10184 }
10185
10186 /**
10187  * Parse a translation unit.
10188  */
10189 static void parse_translation_unit(void)
10190 {
10191         add_anchor_token(T_EOF);
10192
10193         while (true) {
10194                 parse_externals();
10195
10196                 if (token.kind == T_EOF)
10197                         break;
10198
10199                 errorf(HERE, "stray %K outside of function", &token);
10200                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10201                         eat_until_matching_token(token.kind);
10202                 next_token();
10203         }
10204 }
10205
10206 void set_default_visibility(elf_visibility_tag_t visibility)
10207 {
10208         default_visibility = visibility;
10209 }
10210
10211 /**
10212  * Parse the input.
10213  *
10214  * @return  the translation unit or NULL if errors occurred.
10215  */
10216 void start_parsing(void)
10217 {
10218         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10219         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10220         error_count       = 0;
10221         warning_count     = 0;
10222
10223         print_to_file(stderr);
10224
10225         assert(unit == NULL);
10226         unit = allocate_ast_zero(sizeof(unit[0]));
10227
10228         assert(file_scope == NULL);
10229         file_scope = &unit->scope;
10230
10231         assert(current_scope == NULL);
10232         scope_push(&unit->scope);
10233
10234         create_gnu_builtins();
10235         if (c_mode & _MS)
10236                 create_microsoft_intrinsics();
10237 }
10238
10239 translation_unit_t *finish_parsing(void)
10240 {
10241         assert(current_scope == &unit->scope);
10242         scope_pop(NULL);
10243
10244         assert(file_scope == &unit->scope);
10245         check_unused_globals();
10246         file_scope = NULL;
10247
10248         DEL_ARR_F(environment_stack);
10249         DEL_ARR_F(label_stack);
10250
10251         translation_unit_t *result = unit;
10252         unit = NULL;
10253         return result;
10254 }
10255
10256 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10257  * are given length one. */
10258 static void complete_incomplete_arrays(void)
10259 {
10260         size_t n = ARR_LEN(incomplete_arrays);
10261         for (size_t i = 0; i != n; ++i) {
10262                 declaration_t *const decl = incomplete_arrays[i];
10263                 type_t        *const type = skip_typeref(decl->type);
10264
10265                 if (!is_type_incomplete(type))
10266                         continue;
10267
10268                 source_position_t const *const pos = &decl->base.source_position;
10269                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10270
10271                 type_t *const new_type = duplicate_type(type);
10272                 new_type->array.size_constant     = true;
10273                 new_type->array.has_implicit_size = true;
10274                 new_type->array.size              = 1;
10275
10276                 type_t *const result = identify_new_type(new_type);
10277
10278                 decl->type = result;
10279         }
10280 }
10281
10282 static void prepare_main_collect2(entity_t *const entity)
10283 {
10284         PUSH_SCOPE(&entity->function.statement->compound.scope);
10285
10286         // create call to __main
10287         symbol_t *symbol         = symbol_table_insert("__main");
10288         entity_t *subsubmain_ent
10289                 = create_implicit_function(symbol, &builtin_source_position);
10290
10291         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10292         type_t       *ftype       = subsubmain_ent->declaration.type;
10293         ref->base.source_position = builtin_source_position;
10294         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10295         ref->reference.entity     = subsubmain_ent;
10296
10297         expression_t *call = allocate_expression_zero(EXPR_CALL);
10298         call->base.source_position = builtin_source_position;
10299         call->base.type            = type_void;
10300         call->call.function        = ref;
10301
10302         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10303         expr_statement->base.source_position  = builtin_source_position;
10304         expr_statement->expression.expression = call;
10305
10306         statement_t *statement = entity->function.statement;
10307         assert(statement->kind == STATEMENT_COMPOUND);
10308         compound_statement_t *compounds = &statement->compound;
10309
10310         expr_statement->base.next = compounds->statements;
10311         compounds->statements     = expr_statement;
10312
10313         POP_SCOPE();
10314 }
10315
10316 void parse(void)
10317 {
10318         lookahead_bufpos = 0;
10319         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10320                 next_token();
10321         }
10322         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10323         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10324         parse_translation_unit();
10325         complete_incomplete_arrays();
10326         DEL_ARR_F(incomplete_arrays);
10327         incomplete_arrays = NULL;
10328 }
10329
10330 /**
10331  * Initialize the parser.
10332  */
10333 void init_parser(void)
10334 {
10335         sym_anonymous = symbol_table_insert("<anonymous>");
10336
10337         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10338
10339         init_expression_parsers();
10340         obstack_init(&temp_obst);
10341 }
10342
10343 /**
10344  * Terminate the parser.
10345  */
10346 void exit_parser(void)
10347 {
10348         obstack_free(&temp_obst, NULL);
10349 }