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 "preprocessor.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;
  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 /** The token anchor set */
 143 static unsigned short token_anchor_set[T_LAST_TOKEN];
 144
 145 /** The current source position. */
 146 #define HERE (&token.base.source_position)
 147
 148 /** true if we are in GCC mode. */
 149 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 150
 151 static statement_t *parse_compound_statement(bool inside_expression_statement);
 152 static statement_t *parse_statement(void);
 153
 154 static expression_t *parse_subexpression(precedence_t);
 155 static expression_t *parse_expression(void);
 156 static type_t       *parse_typename(void);
 157 static void          parse_externals(void);
 158 static void          parse_external(void);
 159
 160 static void parse_compound_type_entries(compound_t *compound_declaration);
 161
 162 static void check_call_argument(type_t          *expected_type,
 163                                                                 call_argument_t *argument, unsigned pos);
 164
 165 typedef enum declarator_flags_t {
 166         DECL_FLAGS_NONE             = 0,
 167         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 168         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 169         DECL_IS_PARAMETER           = 1U << 2
 170 } declarator_flags_t;
 171
 172 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 173                                   declarator_flags_t flags);
 174
 175 static void semantic_comparison(binary_expression_t *expression);
 176
 177 #define STORAGE_CLASSES       \
 178         STORAGE_CLASSES_NO_EXTERN \
 179         case T_extern:
 180
 181 #define STORAGE_CLASSES_NO_EXTERN \
 182         case T_typedef:         \
 183         case T_static:          \
 184         case T_auto:            \
 185         case T_register:        \
 186         case T__Thread_local:
 187
 188 #define TYPE_QUALIFIERS     \
 189         case T_const:           \
 190         case T_restrict:        \
 191         case T_volatile:        \
 192         case T_inline:          \
 193         case T__forceinline:    \
 194         case T___attribute__:
 195
 196 #define COMPLEX_SPECIFIERS  \
 197         case T__Complex:
 198 #define IMAGINARY_SPECIFIERS \
 199         case T__Imaginary:
 200
 201 #define TYPE_SPECIFIERS       \
 202         case T__Bool:             \
 203         case T___builtin_va_list: \
 204         case T___typeof__:        \
 205         case T__declspec:         \
 206         case T_bool:              \
 207         case T_char:              \
 208         case T_double:            \
 209         case T_enum:              \
 210         case T_float:             \
 211         case T_int:               \
 212         case T_long:              \
 213         case T_short:             \
 214         case T_signed:            \
 215         case T_struct:            \
 216         case T_union:             \
 217         case T_unsigned:          \
 218         case T_void:              \
 219         case T_wchar_t:           \
 220         case T__int8:             \
 221         case T__int16:            \
 222         case T__int32:            \
 223         case T__int64:            \
 224         case T__int128:           \
 225         COMPLEX_SPECIFIERS        \
 226         IMAGINARY_SPECIFIERS
 227
 228 #define DECLARATION_START   \
 229         STORAGE_CLASSES         \
 230         TYPE_QUALIFIERS         \
 231         TYPE_SPECIFIERS
 232
 233 #define DECLARATION_START_NO_EXTERN \
 234         STORAGE_CLASSES_NO_EXTERN       \
 235         TYPE_QUALIFIERS                 \
 236         TYPE_SPECIFIERS
 237
 238 #define EXPRESSION_START              \
 239         case '!':                         \
 240         case '&':                         \
 241         case '(':                         \
 242         case '*':                         \
 243         case '+':                         \
 244         case '-':                         \
 245         case '~':                         \
 246         case T_ANDAND:                    \
 247         case T_CHARACTER_CONSTANT:        \
 248         case T_NUMBER:                    \
 249         case T_MINUSMINUS:                \
 250         case T_PLUSPLUS:                  \
 251         case T_STRING_LITERAL:            \
 252         case T__Alignof:                  \
 253         case T___FUNCDNAME__:             \
 254         case T___FUNCSIG__:               \
 255         case T___PRETTY_FUNCTION__:       \
 256         case T___builtin_classify_type:   \
 257         case T___builtin_constant_p:      \
 258         case T___builtin_isgreater:       \
 259         case T___builtin_isgreaterequal:  \
 260         case T___builtin_isless:          \
 261         case T___builtin_islessequal:     \
 262         case T___builtin_islessgreater:   \
 263         case T___builtin_isunordered:     \
 264         case T___builtin_offsetof:        \
 265         case T___builtin_va_arg:          \
 266         case T___builtin_va_copy:         \
 267         case T___builtin_va_start:        \
 268         case T___func__:                  \
 269         case T___noop:                    \
 270         case T__assume:                   \
 271         case T_delete:                    \
 272         case T_false:                     \
 273         case T_sizeof:                    \
 274         case T_throw:                     \
 275         case T_true:
 276
 277 /**
 278  * Returns the size of a statement node.
 279  *
 280  * @param kind  the statement kind
 281  */
 282 static size_t get_statement_struct_size(statement_kind_t kind)
 283 {
 284         static const size_t sizes[] = {
 285                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 286                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 287                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 288                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 289                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 290                 [STATEMENT_IF]            = sizeof(if_statement_t),
 291                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 292                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 293                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 294                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 295                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 296                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 297                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 298                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 299                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 300                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 301                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 302                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 303                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 304                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 305         };
 306         assert((size_t)kind < lengthof(sizes));
 307         assert(sizes[kind] != 0);
 308         return sizes[kind];
 309 }
 310
 311 /**
 312  * Returns the size of an expression node.
 313  *
 314  * @param kind  the expression kind
 315  */
 316 static size_t get_expression_struct_size(expression_kind_t kind)
 317 {
 318         static const size_t sizes[] = {
 319                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 320                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 321                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 322                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 323                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 326                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 327                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 328                 [EXPR_CALL]                       = sizeof(call_expression_t),
 329                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 330                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 331                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 332                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 333                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 334                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 335                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 336                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 337                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 338                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 339                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 340                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 341                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 342                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 343                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 344                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 345                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 346         };
 347         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 348                 return sizes[EXPR_UNARY_FIRST];
 349         }
 350         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 351                 return sizes[EXPR_BINARY_FIRST];
 352         }
 353         assert((size_t)kind < lengthof(sizes));
 354         assert(sizes[kind] != 0);
 355         return sizes[kind];
 356 }
 357
 358 /**
 359  * Allocate a statement node of given kind and initialize all
 360  * fields with zero. Sets its source position to the position
 361  * of the current token.
 362  */
 363 static statement_t *allocate_statement_zero(statement_kind_t kind)
 364 {
 365         size_t       size = get_statement_struct_size(kind);
 366         statement_t *res  = allocate_ast_zero(size);
 367
 368         res->base.kind            = kind;
 369         res->base.parent          = current_parent;
 370         res->base.source_position = *HERE;
 371         return res;
 372 }
 373
 374 /**
 375  * Allocate an expression node of given kind and initialize all
 376  * fields with zero.
 377  *
 378  * @param kind  the kind of the expression to allocate
 379  */
 380 static expression_t *allocate_expression_zero(expression_kind_t kind)
 381 {
 382         size_t        size = get_expression_struct_size(kind);
 383         expression_t *res  = allocate_ast_zero(size);
 384
 385         res->base.kind            = kind;
 386         res->base.type            = type_error_type;
 387         res->base.source_position = *HERE;
 388         return res;
 389 }
 390
 391 /**
 392  * Creates a new invalid expression at the source position
 393  * of the current token.
 394  */
 395 static expression_t *create_error_expression(void)
 396 {
 397         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 398         expression->base.type = type_error_type;
 399         return expression;
 400 }
 401
 402 /**
 403  * Creates a new invalid statement.
 404  */
 405 static statement_t *create_error_statement(void)
 406 {
 407         return allocate_statement_zero(STATEMENT_ERROR);
 408 }
 409
 410 /**
 411  * Allocate a new empty statement.
 412  */
 413 static statement_t *create_empty_statement(void)
 414 {
 415         return allocate_statement_zero(STATEMENT_EMPTY);
 416 }
 417
 418 /**
 419  * Returns the size of an initializer node.
 420  *
 421  * @param kind  the initializer kind
 422  */
 423 static size_t get_initializer_size(initializer_kind_t kind)
 424 {
 425         static const size_t sizes[] = {
 426                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 427                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 428                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 429                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 430         };
 431         assert((size_t)kind < lengthof(sizes));
 432         assert(sizes[kind] != 0);
 433         return sizes[kind];
 434 }
 435
 436 /**
 437  * Allocate an initializer node of given kind and initialize all
 438  * fields with zero.
 439  */
 440 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 441 {
 442         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 443         result->kind          = kind;
 444
 445         return result;
 446 }
 447
 448 /**
 449  * Returns the index of the top element of the environment stack.
 450  */
 451 static size_t environment_top(void)
 452 {
 453         return ARR_LEN(environment_stack);
 454 }
 455
 456 /**
 457  * Returns the index of the top element of the global label stack.
 458  */
 459 static size_t label_top(void)
 460 {
 461         return ARR_LEN(label_stack);
 462 }
 463
 464 /**
 465  * Return the next token.
 466  */
 467 static inline void next_token(void)
 468 {
 469         token                              = lookahead_buffer[lookahead_bufpos];
 470         lookahead_buffer[lookahead_bufpos] = pp_token;
 471         next_preprocessing_token();
 472
 473         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 474
 475 #ifdef PRINT_TOKENS
 476         print_token(stderr, &token);
 477         fprintf(stderr, "\n");
 478 #endif
 479 }
 480
 481 static inline void eat(token_kind_t const kind)
 482 {
 483         assert(token.kind == kind);
 484         (void)kind;
 485         next_token();
 486 }
 487
 488 static inline bool next_if(token_kind_t const kind)
 489 {
 490         if (token.kind == kind) {
 491                 eat(kind);
 492                 return true;
 493         } else {
 494                 return false;
 495         }
 496 }
 497
 498 /**
 499  * Return the next token with a given lookahead.
 500  */
 501 static inline const token_t *look_ahead(size_t num)
 502 {
 503         assert(0 < num && num <= MAX_LOOKAHEAD);
 504         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 505         return &lookahead_buffer[pos];
 506 }
 507
 508 /**
 509  * Adds a token type to the token type anchor set (a multi-set).
 510  */
 511 static void add_anchor_token(token_kind_t const token_kind)
 512 {
 513         assert(token_kind < T_LAST_TOKEN);
 514         ++token_anchor_set[token_kind];
 515 }
 516
 517 /**
 518  * Remove a token type from the token type anchor set (a multi-set).
 519  */
 520 static void rem_anchor_token(token_kind_t const token_kind)
 521 {
 522         assert(token_kind < T_LAST_TOKEN);
 523         assert(token_anchor_set[token_kind] != 0);
 524         --token_anchor_set[token_kind];
 525 }
 526
 527 /**
 528  * Eat tokens until a matching token type is found.
 529  */
 530 static void eat_until_matching_token(token_kind_t const type)
 531 {
 532         token_kind_t end_token;
 533         switch (type) {
 534                 case '(': end_token = ')';  break;
 535                 case '{': end_token = '}';  break;
 536                 case '[': end_token = ']';  break;
 537                 default:  end_token = type; break;
 538         }
 539
 540         unsigned parenthesis_count = 0;
 541         unsigned brace_count       = 0;
 542         unsigned bracket_count     = 0;
 543         while (token.kind        != end_token ||
 544                parenthesis_count != 0         ||
 545                brace_count       != 0         ||
 546                bracket_count     != 0) {
 547                 switch (token.kind) {
 548                 case T_EOF: return;
 549                 case '(': ++parenthesis_count; break;
 550                 case '{': ++brace_count;       break;
 551                 case '[': ++bracket_count;     break;
 552
 553                 case ')':
 554                         if (parenthesis_count > 0)
 555                                 --parenthesis_count;
 556                         goto check_stop;
 557
 558                 case '}':
 559                         if (brace_count > 0)
 560                                 --brace_count;
 561                         goto check_stop;
 562
 563                 case ']':
 564                         if (bracket_count > 0)
 565                                 --bracket_count;
 566 check_stop:
 567                         if (token.kind        == end_token &&
 568                             parenthesis_count == 0         &&
 569                             brace_count       == 0         &&
 570                             bracket_count     == 0)
 571                                 return;
 572                         break;
 573
 574                 default:
 575                         break;
 576                 }
 577                 next_token();
 578         }
 579 }
 580
 581 /**
 582  * Eat input tokens until an anchor is found.
 583  */
 584 static void eat_until_anchor(void)
 585 {
 586         while (token_anchor_set[token.kind] == 0) {
 587                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 588                         eat_until_matching_token(token.kind);
 589                 next_token();
 590         }
 591 }
 592
 593 /**
 594  * Eat a whole block from input tokens.
 595  */
 596 static void eat_block(void)
 597 {
 598         eat_until_matching_token('{');
 599         next_if('}');
 600 }
 601
 602 /**
 603  * Report a parse error because an expected token was not found.
 604  */
 605 static
 606 #if defined __GNUC__ && __GNUC__ >= 4
 607 __attribute__((sentinel))
 608 #endif
 609 void parse_error_expected(const char *message, ...)
 610 {
 611         if (message != NULL) {
 612                 errorf(HERE, "%s", message);
 613         }
 614         va_list ap;
 615         va_start(ap, message);
 616         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 617         va_end(ap);
 618 }
 619
 620 /**
 621  * Report an incompatible type.
 622  */
 623 static void type_error_incompatible(const char *msg,
 624                 const source_position_t *source_position, type_t *type1, type_t *type2)
 625 {
 626         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 627                msg, type1, type2);
 628 }
 629
 630 static bool skip_till(token_kind_t const expected, char const *const context)
 631 {
 632         if (UNLIKELY(token.kind != expected)) {
 633                 parse_error_expected(context, expected, NULL);
 634                 add_anchor_token(expected);
 635                 eat_until_anchor();
 636                 rem_anchor_token(expected);
 637                 if (token.kind != expected)
 638                         return false;
 639         }
 640         return true;
 641 }
 642
 643 /**
 644  * Expect the current token is the expected token.
 645  * If not, generate an error and skip until the next anchor.
 646  */
 647 static void expect(token_kind_t const expected)
 648 {
 649         if (skip_till(expected, NULL))
 650                 eat(expected);
 651 }
 652
 653 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 654 {
 655         if (!skip_till(T_IDENTIFIER, context))
 656                 return NULL;
 657         symbol_t *const sym = token.base.symbol;
 658         if (pos)
 659                 *pos = *HERE;
 660         eat(T_IDENTIFIER);
 661         return sym;
 662 }
 663
 664 /**
 665  * Push a given scope on the scope stack and make it the
 666  * current scope
 667  */
 668 static scope_t *scope_push(scope_t *new_scope)
 669 {
 670         if (current_scope != NULL) {
 671                 new_scope->depth = current_scope->depth + 1;
 672         }
 673
 674         scope_t *old_scope = current_scope;
 675         current_scope      = new_scope;
 676         return old_scope;
 677 }
 678
 679 /**
 680  * Pop the current scope from the scope stack.
 681  */
 682 static void scope_pop(scope_t *old_scope)
 683 {
 684         current_scope = old_scope;
 685 }
 686
 687 /**
 688  * Search an entity by its symbol in a given namespace.
 689  */
 690 static entity_t *get_entity(const symbol_t *const symbol,
 691                             namespace_tag_t namespc)
 692 {
 693         entity_t *entity = symbol->entity;
 694         for (; entity != NULL; entity = entity->base.symbol_next) {
 695                 if ((namespace_tag_t)entity->base.namespc == namespc)
 696                         return entity;
 697         }
 698
 699         return NULL;
 700 }
 701
 702 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 703  * possible. */
 704 static entity_t *get_tag(symbol_t const *const symbol,
 705                          entity_kind_tag_t const kind)
 706 {
 707         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 708         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 709                 errorf(HERE,
 710                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 711                                 symbol, &entity->base.source_position);
 712                 entity = NULL;
 713         }
 714         return entity;
 715 }
 716
 717 /**
 718  * pushs an entity on the environment stack and links the corresponding symbol
 719  * it.
 720  */
 721 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 722 {
 723         symbol_t           *symbol  = entity->base.symbol;
 724         entity_namespace_t  namespc = entity->base.namespc;
 725         assert(namespc != 0);
 726
 727         /* replace/add entity into entity list of the symbol */
 728         entity_t **anchor;
 729         entity_t  *iter;
 730         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 731                 iter = *anchor;
 732                 if (iter == NULL)
 733                         break;
 734
 735                 /* replace an entry? */
 736                 if (iter->base.namespc == namespc) {
 737                         entity->base.symbol_next = iter->base.symbol_next;
 738                         break;
 739                 }
 740         }
 741         *anchor = entity;
 742
 743         /* remember old declaration */
 744         stack_entry_t entry;
 745         entry.symbol     = symbol;
 746         entry.old_entity = iter;
 747         entry.namespc    = namespc;
 748         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 749 }
 750
 751 /**
 752  * Push an entity on the environment stack.
 753  */
 754 static void environment_push(entity_t *entity)
 755 {
 756         assert(entity->base.source_position.input_name != NULL);
 757         assert(entity->base.parent_scope != NULL);
 758         stack_push(&environment_stack, entity);
 759 }
 760
 761 /**
 762  * Push a declaration on the global label stack.
 763  *
 764  * @param declaration  the declaration
 765  */
 766 static void label_push(entity_t *label)
 767 {
 768         /* we abuse the parameters scope as parent for the labels */
 769         label->base.parent_scope = &current_function->parameters;
 770         stack_push(&label_stack, label);
 771 }
 772
 773 /**
 774  * pops symbols from the environment stack until @p new_top is the top element
 775  */
 776 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 777 {
 778         stack_entry_t *stack = *stack_ptr;
 779         size_t         top   = ARR_LEN(stack);
 780         size_t         i;
 781
 782         assert(new_top <= top);
 783         if (new_top == top)
 784                 return;
 785
 786         for (i = top; i > new_top; --i) {
 787                 stack_entry_t *entry = &stack[i - 1];
 788
 789                 entity_t           *old_entity = entry->old_entity;
 790                 symbol_t           *symbol     = entry->symbol;
 791                 entity_namespace_t  namespc    = entry->namespc;
 792
 793                 /* replace with old_entity/remove */
 794                 entity_t **anchor;
 795                 entity_t  *iter;
 796                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 797                         iter = *anchor;
 798                         assert(iter != NULL);
 799                         /* replace an entry? */
 800                         if (iter->base.namespc == namespc)
 801                                 break;
 802                 }
 803
 804                 /* restore definition from outer scopes (if there was one) */
 805                 if (old_entity != NULL) {
 806                         old_entity->base.symbol_next = iter->base.symbol_next;
 807                         *anchor                      = old_entity;
 808                 } else {
 809                         /* remove entry from list */
 810                         *anchor = iter->base.symbol_next;
 811                 }
 812         }
 813
 814         ARR_SHRINKLEN(*stack_ptr, new_top);
 815 }
 816
 817 /**
 818  * Pop all entries from the environment stack until the new_top
 819  * is reached.
 820  *
 821  * @param new_top  the new stack top
 822  */
 823 static void environment_pop_to(size_t new_top)
 824 {
 825         stack_pop_to(&environment_stack, new_top);
 826 }
 827
 828 /**
 829  * Pop all entries from the global label stack until the new_top
 830  * is reached.
 831  *
 832  * @param new_top  the new stack top
 833  */
 834 static void label_pop_to(size_t new_top)
 835 {
 836         stack_pop_to(&label_stack, new_top);
 837 }
 838
 839 static atomic_type_kind_t get_akind(const type_t *type)
 840 {
 841         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 842                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 843         return type->atomic.akind;
 844 }
 845
 846 /**
 847  * §6.3.1.1:2  Do integer promotion for a given type.
 848  *
 849  * @param type  the type to promote
 850  * @return the promoted type
 851  */
 852 static type_t *promote_integer(type_t *type)
 853 {
 854         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 855                 type = type_int;
 856
 857         return type;
 858 }
 859
 860 /**
 861  * Check if a given expression represents a null pointer constant.
 862  *
 863  * @param expression  the expression to check
 864  */
 865 static bool is_null_pointer_constant(const expression_t *expression)
 866 {
 867         /* skip void* cast */
 868         if (expression->kind == EXPR_UNARY_CAST) {
 869                 type_t *const type = skip_typeref(expression->base.type);
 870                 if (types_compatible(type, type_void_ptr))
 871                         expression = expression->unary.value;
 872         }
 873
 874         type_t *const type = skip_typeref(expression->base.type);
 875         if (!is_type_integer(type))
 876                 return false;
 877         switch (is_constant_expression(expression)) {
 878                 case EXPR_CLASS_ERROR:    return true;
 879                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 880                 default:                  return false;
 881         }
 882 }
 883
 884 /**
 885  * Create an implicit cast expression.
 886  *
 887  * @param expression  the expression to cast
 888  * @param dest_type   the destination type
 889  */
 890 static expression_t *create_implicit_cast(expression_t *expression,
 891                                           type_t *dest_type)
 892 {
 893         type_t *const source_type = expression->base.type;
 894
 895         if (source_type == dest_type)
 896                 return expression;
 897
 898         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 899         cast->unary.value   = expression;
 900         cast->base.type     = dest_type;
 901         cast->base.implicit = true;
 902
 903         return cast;
 904 }
 905
 906 typedef enum assign_error_t {
 907         ASSIGN_SUCCESS,
 908         ASSIGN_ERROR_INCOMPATIBLE,
 909         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 910         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 911         ASSIGN_WARNING_POINTER_FROM_INT,
 912         ASSIGN_WARNING_INT_FROM_POINTER
 913 } assign_error_t;
 914
 915 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)
 916 {
 917         type_t *const orig_type_right = right->base.type;
 918         type_t *const type_left       = skip_typeref(orig_type_left);
 919         type_t *const type_right      = skip_typeref(orig_type_right);
 920
 921         switch (error) {
 922         case ASSIGN_SUCCESS:
 923                 return;
 924         case ASSIGN_ERROR_INCOMPATIBLE:
 925                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 926                 return;
 927
 928         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 929                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 930                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 931
 932                 /* the left type has all qualifiers from the right type */
 933                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 934                 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);
 935                 return;
 936         }
 937
 938         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 939                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 940                 return;
 941
 942         case ASSIGN_WARNING_POINTER_FROM_INT:
 943                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_INT_FROM_POINTER:
 947                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         default:
 951                 panic("invalid error value");
 952         }
 953 }
 954
 955 /** Implements the rules from §6.5.16.1 */
 956 static assign_error_t semantic_assign(type_t *orig_type_left,
 957                                       const expression_t *const right)
 958 {
 959         type_t *const orig_type_right = right->base.type;
 960         type_t *const type_left       = skip_typeref(orig_type_left);
 961         type_t *const type_right      = skip_typeref(orig_type_right);
 962
 963         if (is_type_pointer(type_left)) {
 964                 if (is_null_pointer_constant(right)) {
 965                         return ASSIGN_SUCCESS;
 966                 } else if (is_type_pointer(type_right)) {
 967                         type_t *points_to_left
 968                                 = skip_typeref(type_left->pointer.points_to);
 969                         type_t *points_to_right
 970                                 = skip_typeref(type_right->pointer.points_to);
 971                         assign_error_t res = ASSIGN_SUCCESS;
 972
 973                         /* the left type has all qualifiers from the right type */
 974                         unsigned missing_qualifiers
 975                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 976                         if (missing_qualifiers != 0) {
 977                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 978                         }
 979
 980                         points_to_left  = get_unqualified_type(points_to_left);
 981                         points_to_right = get_unqualified_type(points_to_right);
 982
 983                         if (is_type_void(points_to_left))
 984                                 return res;
 985
 986                         if (is_type_void(points_to_right)) {
 987                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 988                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 989                         }
 990
 991                         if (!types_compatible(points_to_left, points_to_right)) {
 992                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 993                         }
 994
 995                         return res;
 996                 } else if (is_type_integer(type_right)) {
 997                         return ASSIGN_WARNING_POINTER_FROM_INT;
 998                 }
 999         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1000                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1001                                 && is_type_pointer(type_right))) {
1002                 return ASSIGN_SUCCESS;
1003         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1004                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1005                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1006                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1007                         return ASSIGN_SUCCESS;
1008                 }
1009         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1010                 return ASSIGN_WARNING_INT_FROM_POINTER;
1011         }
1012
1013         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1014                 return ASSIGN_SUCCESS;
1015
1016         return ASSIGN_ERROR_INCOMPATIBLE;
1017 }
1018
1019 static expression_t *parse_constant_expression(void)
1020 {
1021         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1022
1023         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1024                 errorf(&result->base.source_position,
1025                        "expression '%E' is not constant", result);
1026         }
1027
1028         return result;
1029 }
1030
1031 static expression_t *parse_assignment_expression(void)
1032 {
1033         return parse_subexpression(PREC_ASSIGNMENT);
1034 }
1035
1036 static void append_string(string_t const *const s)
1037 {
1038         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1039          * possible, because other tokens are grown there alongside. */
1040         obstack_grow(&ast_obstack, s->begin, s->size);
1041 }
1042
1043 static string_t finish_string(string_encoding_t const enc)
1044 {
1045         obstack_1grow(&ast_obstack, '\0');
1046         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1047         char const *const string = obstack_finish(&ast_obstack);
1048         return (string_t){ string, size, enc };
1049 }
1050
1051 static string_t concat_string_literals(void)
1052 {
1053         assert(token.kind == T_STRING_LITERAL);
1054
1055         string_t result;
1056         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1057                 append_string(&token.literal.string);
1058                 eat(T_STRING_LITERAL);
1059                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1060                 string_encoding_t enc = token.literal.string.encoding;
1061                 do {
1062                         if (token.literal.string.encoding != STRING_ENCODING_CHAR) {
1063                                 enc = token.literal.string.encoding;
1064                         }
1065                         append_string(&token.literal.string);
1066                         eat(T_STRING_LITERAL);
1067                 } while (token.kind == T_STRING_LITERAL);
1068                 result = finish_string(enc);
1069         } else {
1070                 result = token.literal.string;
1071                 eat(T_STRING_LITERAL);
1072         }
1073
1074         return result;
1075 }
1076
1077 static string_t parse_string_literals(char const *const context)
1078 {
1079         if (!skip_till(T_STRING_LITERAL, context))
1080                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1081
1082         source_position_t const pos = *HERE;
1083         string_t          const res = concat_string_literals();
1084
1085         if (res.encoding != STRING_ENCODING_CHAR) {
1086                 errorf(&pos, "expected plain string literal, got wide string literal");
1087         }
1088
1089         return res;
1090 }
1091
1092 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1093 {
1094         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1095         attribute->kind            = kind;
1096         attribute->source_position = *HERE;
1097         return attribute;
1098 }
1099
1100 /**
1101  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1102  *
1103  *  attribute:
1104  *    __attribute__ ( ( attribute-list ) )
1105  *
1106  *  attribute-list:
1107  *    attrib
1108  *    attribute_list , attrib
1109  *
1110  *  attrib:
1111  *    empty
1112  *    any-word
1113  *    any-word ( identifier )
1114  *    any-word ( identifier , nonempty-expr-list )
1115  *    any-word ( expr-list )
1116  *
1117  *  where the "identifier" must not be declared as a type, and
1118  *  "any-word" may be any identifier (including one declared as a
1119  *  type), a reserved word storage class specifier, type specifier or
1120  *  type qualifier.  ??? This still leaves out most reserved keywords
1121  *  (following the old parser), shouldn't we include them, and why not
1122  *  allow identifiers declared as types to start the arguments?
1123  *
1124  *  Matze: this all looks confusing and little systematic, so we're even less
1125  *  strict and parse any list of things which are identifiers or
1126  *  (assignment-)expressions.
1127  */
1128 static attribute_argument_t *parse_attribute_arguments(void)
1129 {
1130         attribute_argument_t  *first  = NULL;
1131         attribute_argument_t **anchor = &first;
1132         if (token.kind != ')') do {
1133                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1134
1135                 /* is it an identifier */
1136                 if (token.kind == T_IDENTIFIER
1137                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1138                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1139                         argument->v.symbol = token.base.symbol;
1140                         eat(T_IDENTIFIER);
1141                 } else {
1142                         /* must be an expression */
1143                         expression_t *expression = parse_assignment_expression();
1144
1145                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1146                         argument->v.expression = expression;
1147                 }
1148
1149                 /* append argument */
1150                 *anchor = argument;
1151                 anchor  = &argument->next;
1152         } while (next_if(','));
1153         expect(')');
1154         return first;
1155 }
1156
1157 static attribute_t *parse_attribute_asm(void)
1158 {
1159         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1160         eat(T_asm);
1161         expect('(');
1162         attribute->a.arguments = parse_attribute_arguments();
1163         return attribute;
1164 }
1165
1166 static attribute_t *parse_attribute_gnu_single(void)
1167 {
1168         /* parse "any-word" */
1169         symbol_t *const symbol = token.base.symbol;
1170         if (symbol == NULL) {
1171                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1172                 return NULL;
1173         }
1174
1175         attribute_kind_t  kind;
1176         char const *const name = symbol->string;
1177         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1178                 if (kind > ATTRIBUTE_GNU_LAST) {
1179                         /* special case for "__const" */
1180                         if (token.kind == T_const) {
1181                                 kind = ATTRIBUTE_GNU_CONST;
1182                                 break;
1183                         }
1184
1185                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1186                         /* TODO: we should still save the attribute in the list... */
1187                         kind = ATTRIBUTE_UNKNOWN;
1188                         break;
1189                 }
1190
1191                 const char *attribute_name = get_attribute_name(kind);
1192                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1193                         break;
1194         }
1195
1196         attribute_t *attribute = allocate_attribute_zero(kind);
1197         next_token();
1198
1199         /* parse arguments */
1200         if (next_if('('))
1201                 attribute->a.arguments = parse_attribute_arguments();
1202
1203         return attribute;
1204 }
1205
1206 static attribute_t *parse_attribute_gnu(void)
1207 {
1208         attribute_t  *first  = NULL;
1209         attribute_t **anchor = &first;
1210
1211         eat(T___attribute__);
1212         add_anchor_token(')');
1213         add_anchor_token(',');
1214         expect('(');
1215         expect('(');
1216
1217         if (token.kind != ')') do {
1218                 attribute_t *attribute = parse_attribute_gnu_single();
1219                 if (attribute) {
1220                         *anchor = attribute;
1221                         anchor  = &attribute->next;
1222                 }
1223         } while (next_if(','));
1224         rem_anchor_token(',');
1225         rem_anchor_token(')');
1226
1227         expect(')');
1228         expect(')');
1229         return first;
1230 }
1231
1232 /** Parse attributes. */
1233 static attribute_t *parse_attributes(attribute_t *first)
1234 {
1235         attribute_t **anchor = &first;
1236         for (;;) {
1237                 while (*anchor != NULL)
1238                         anchor = &(*anchor)->next;
1239
1240                 attribute_t *attribute;
1241                 switch (token.kind) {
1242                 case T___attribute__:
1243                         attribute = parse_attribute_gnu();
1244                         if (attribute == NULL)
1245                                 continue;
1246                         break;
1247
1248                 case T_asm:
1249                         attribute = parse_attribute_asm();
1250                         break;
1251
1252                 case T_cdecl:
1253                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1254                         eat(T_cdecl);
1255                         break;
1256
1257                 case T__fastcall:
1258                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1259                         eat(T__fastcall);
1260                         break;
1261
1262                 case T__forceinline:
1263                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1264                         eat(T__forceinline);
1265                         break;
1266
1267                 case T__stdcall:
1268                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1269                         eat(T__stdcall);
1270                         break;
1271
1272                 case T___thiscall:
1273                         /* TODO record modifier */
1274                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1275                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1276                         eat(T___thiscall);
1277                         break;
1278
1279                 default:
1280                         return first;
1281                 }
1282
1283                 *anchor = attribute;
1284                 anchor  = &attribute->next;
1285         }
1286 }
1287
1288 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1289
1290 static entity_t *determine_lhs_ent(expression_t *const expr,
1291                                    entity_t *lhs_ent)
1292 {
1293         switch (expr->kind) {
1294                 case EXPR_REFERENCE: {
1295                         entity_t *const entity = expr->reference.entity;
1296                         /* we should only find variables as lvalues... */
1297                         if (entity->base.kind != ENTITY_VARIABLE
1298                                         && entity->base.kind != ENTITY_PARAMETER)
1299                                 return NULL;
1300
1301                         return entity;
1302                 }
1303
1304                 case EXPR_ARRAY_ACCESS: {
1305                         expression_t *const ref = expr->array_access.array_ref;
1306                         entity_t     *      ent = NULL;
1307                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1308                                 ent     = determine_lhs_ent(ref, lhs_ent);
1309                                 lhs_ent = ent;
1310                         } else {
1311                                 mark_vars_read(ref, lhs_ent);
1312                         }
1313                         mark_vars_read(expr->array_access.index, lhs_ent);
1314                         return ent;
1315                 }
1316
1317                 case EXPR_SELECT: {
1318                         mark_vars_read(expr->select.compound, lhs_ent);
1319                         if (is_type_compound(skip_typeref(expr->base.type)))
1320                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1321                         return NULL;
1322                 }
1323
1324                 case EXPR_UNARY_DEREFERENCE: {
1325                         expression_t *const val = expr->unary.value;
1326                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1327                                 /* *&x is a NOP */
1328                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1329                         } else {
1330                                 mark_vars_read(val, NULL);
1331                                 return NULL;
1332                         }
1333                 }
1334
1335                 default:
1336                         mark_vars_read(expr, NULL);
1337                         return NULL;
1338         }
1339 }
1340
1341 #define ENT_ANY ((entity_t*)-1)
1342
1343 /**
1344  * Mark declarations, which are read.  This is used to detect variables, which
1345  * are never read.
1346  * Example:
1347  * x = x + 1;
1348  *   x is not marked as "read", because it is only read to calculate its own new
1349  *   value.
1350  *
1351  * x += y; y += x;
1352  *   x and y are not detected as "not read", because multiple variables are
1353  *   involved.
1354  */
1355 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1356 {
1357         switch (expr->kind) {
1358                 case EXPR_REFERENCE: {
1359                         entity_t *const entity = expr->reference.entity;
1360                         if (entity->kind != ENTITY_VARIABLE
1361                                         && entity->kind != ENTITY_PARAMETER)
1362                                 return;
1363
1364                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1365                                 entity->variable.read = true;
1366                         }
1367                         return;
1368                 }
1369
1370                 case EXPR_CALL:
1371                         // TODO respect pure/const
1372                         mark_vars_read(expr->call.function, NULL);
1373                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1374                                 mark_vars_read(arg->expression, NULL);
1375                         }
1376                         return;
1377
1378                 case EXPR_CONDITIONAL:
1379                         // TODO lhs_decl should depend on whether true/false have an effect
1380                         mark_vars_read(expr->conditional.condition, NULL);
1381                         if (expr->conditional.true_expression != NULL)
1382                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1383                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1384                         return;
1385
1386                 case EXPR_SELECT:
1387                         if (lhs_ent == ENT_ANY
1388                                         && !is_type_compound(skip_typeref(expr->base.type)))
1389                                 lhs_ent = NULL;
1390                         mark_vars_read(expr->select.compound, lhs_ent);
1391                         return;
1392
1393                 case EXPR_ARRAY_ACCESS: {
1394                         mark_vars_read(expr->array_access.index, lhs_ent);
1395                         expression_t *const ref = expr->array_access.array_ref;
1396                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1397                                 if (lhs_ent == ENT_ANY)
1398                                         lhs_ent = NULL;
1399                         }
1400                         mark_vars_read(ref, lhs_ent);
1401                         return;
1402                 }
1403
1404                 case EXPR_VA_ARG:
1405                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1406                         return;
1407
1408                 case EXPR_VA_COPY:
1409                         mark_vars_read(expr->va_copye.src, lhs_ent);
1410                         return;
1411
1412                 case EXPR_UNARY_CAST:
1413                         /* Special case: Use void cast to mark a variable as "read" */
1414                         if (is_type_void(skip_typeref(expr->base.type)))
1415                                 lhs_ent = NULL;
1416                         goto unary;
1417
1418
1419                 case EXPR_UNARY_THROW:
1420                         if (expr->unary.value == NULL)
1421                                 return;
1422                         /* FALLTHROUGH */
1423                 case EXPR_UNARY_DEREFERENCE:
1424                 case EXPR_UNARY_DELETE:
1425                 case EXPR_UNARY_DELETE_ARRAY:
1426                         if (lhs_ent == ENT_ANY)
1427                                 lhs_ent = NULL;
1428                         goto unary;
1429
1430                 case EXPR_UNARY_NEGATE:
1431                 case EXPR_UNARY_PLUS:
1432                 case EXPR_UNARY_BITWISE_NEGATE:
1433                 case EXPR_UNARY_NOT:
1434                 case EXPR_UNARY_TAKE_ADDRESS:
1435                 case EXPR_UNARY_POSTFIX_INCREMENT:
1436                 case EXPR_UNARY_POSTFIX_DECREMENT:
1437                 case EXPR_UNARY_PREFIX_INCREMENT:
1438                 case EXPR_UNARY_PREFIX_DECREMENT:
1439                 case EXPR_UNARY_ASSUME:
1440 unary:
1441                         mark_vars_read(expr->unary.value, lhs_ent);
1442                         return;
1443
1444                 case EXPR_BINARY_ADD:
1445                 case EXPR_BINARY_SUB:
1446                 case EXPR_BINARY_MUL:
1447                 case EXPR_BINARY_DIV:
1448                 case EXPR_BINARY_MOD:
1449                 case EXPR_BINARY_EQUAL:
1450                 case EXPR_BINARY_NOTEQUAL:
1451                 case EXPR_BINARY_LESS:
1452                 case EXPR_BINARY_LESSEQUAL:
1453                 case EXPR_BINARY_GREATER:
1454                 case EXPR_BINARY_GREATEREQUAL:
1455                 case EXPR_BINARY_BITWISE_AND:
1456                 case EXPR_BINARY_BITWISE_OR:
1457                 case EXPR_BINARY_BITWISE_XOR:
1458                 case EXPR_BINARY_LOGICAL_AND:
1459                 case EXPR_BINARY_LOGICAL_OR:
1460                 case EXPR_BINARY_SHIFTLEFT:
1461                 case EXPR_BINARY_SHIFTRIGHT:
1462                 case EXPR_BINARY_COMMA:
1463                 case EXPR_BINARY_ISGREATER:
1464                 case EXPR_BINARY_ISGREATEREQUAL:
1465                 case EXPR_BINARY_ISLESS:
1466                 case EXPR_BINARY_ISLESSEQUAL:
1467                 case EXPR_BINARY_ISLESSGREATER:
1468                 case EXPR_BINARY_ISUNORDERED:
1469                         mark_vars_read(expr->binary.left,  lhs_ent);
1470                         mark_vars_read(expr->binary.right, lhs_ent);
1471                         return;
1472
1473                 case EXPR_BINARY_ASSIGN:
1474                 case EXPR_BINARY_MUL_ASSIGN:
1475                 case EXPR_BINARY_DIV_ASSIGN:
1476                 case EXPR_BINARY_MOD_ASSIGN:
1477                 case EXPR_BINARY_ADD_ASSIGN:
1478                 case EXPR_BINARY_SUB_ASSIGN:
1479                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1480                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1481                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1482                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1483                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1484                         if (lhs_ent == ENT_ANY)
1485                                 lhs_ent = NULL;
1486                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1487                         mark_vars_read(expr->binary.right, lhs_ent);
1488                         return;
1489                 }
1490
1491                 case EXPR_VA_START:
1492                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1493                         return;
1494
1495                 case EXPR_LITERAL_CASES:
1496                 case EXPR_LITERAL_CHARACTER:
1497                 case EXPR_ERROR:
1498                 case EXPR_STRING_LITERAL:
1499                 case EXPR_COMPOUND_LITERAL: // TODO init?
1500                 case EXPR_SIZEOF:
1501                 case EXPR_CLASSIFY_TYPE:
1502                 case EXPR_ALIGNOF:
1503                 case EXPR_FUNCNAME:
1504                 case EXPR_BUILTIN_CONSTANT_P:
1505                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1506                 case EXPR_OFFSETOF:
1507                 case EXPR_STATEMENT: // TODO
1508                 case EXPR_LABEL_ADDRESS:
1509                 case EXPR_ENUM_CONSTANT:
1510                         return;
1511         }
1512
1513         panic("unhandled expression");
1514 }
1515
1516 static designator_t *parse_designation(void)
1517 {
1518         designator_t  *result = NULL;
1519         designator_t **anchor = &result;
1520
1521         for (;;) {
1522                 designator_t *designator;
1523                 switch (token.kind) {
1524                 case '[':
1525                         designator = allocate_ast_zero(sizeof(designator[0]));
1526                         designator->source_position = *HERE;
1527                         eat('[');
1528                         add_anchor_token(']');
1529                         designator->array_index = parse_constant_expression();
1530                         rem_anchor_token(']');
1531                         expect(']');
1532                         break;
1533                 case '.':
1534                         designator = allocate_ast_zero(sizeof(designator[0]));
1535                         designator->source_position = *HERE;
1536                         eat('.');
1537                         designator->symbol = expect_identifier("while parsing designator", NULL);
1538                         if (!designator->symbol)
1539                                 return NULL;
1540                         break;
1541                 default:
1542                         expect('=');
1543                         return result;
1544                 }
1545
1546                 assert(designator != NULL);
1547                 *anchor = designator;
1548                 anchor  = &designator->next;
1549         }
1550 }
1551
1552 /**
1553  * Build an initializer from a given expression.
1554  */
1555 static initializer_t *initializer_from_expression(type_t *orig_type,
1556                                                   expression_t *expression)
1557 {
1558         /* TODO check that expression is a constant expression */
1559
1560         type_t *const type = skip_typeref(orig_type);
1561
1562         /* §6.7.8.14/15 char array may be initialized by string literals */
1563         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1564                 array_type_t *const array_type   = &type->array;
1565                 type_t       *const element_type = skip_typeref(array_type->element_type);
1566                 switch (expression->string_literal.value.encoding) {
1567                 case STRING_ENCODING_CHAR: {
1568                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1569                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1570                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1571                                 goto make_string_init;
1572                         }
1573                         break;
1574                 }
1575
1576                 case STRING_ENCODING_WIDE: {
1577                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1578                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1579 make_string_init:;
1580                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1581                                 init->value.value = expression;
1582                                 return init;
1583                         }
1584                         break;
1585                 }
1586                 }
1587         }
1588
1589         assign_error_t error = semantic_assign(type, expression);
1590         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1591                 return NULL;
1592         report_assign_error(error, type, expression, "initializer",
1593                             &expression->base.source_position);
1594
1595         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1596         result->value.value = create_implicit_cast(expression, type);
1597
1598         return result;
1599 }
1600
1601 /**
1602  * Parses an scalar initializer.
1603  *
1604  * §6.7.8.11; eat {} without warning
1605  */
1606 static initializer_t *parse_scalar_initializer(type_t *type,
1607                                                bool must_be_constant)
1608 {
1609         /* there might be extra {} hierarchies */
1610         int braces = 0;
1611         if (token.kind == '{') {
1612                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1613                 do {
1614                         eat('{');
1615                         ++braces;
1616                 } while (token.kind == '{');
1617         }
1618
1619         expression_t *expression = parse_assignment_expression();
1620         mark_vars_read(expression, NULL);
1621         if (must_be_constant && !is_linker_constant(expression)) {
1622                 errorf(&expression->base.source_position,
1623                        "initialisation expression '%E' is not constant",
1624                        expression);
1625         }
1626
1627         initializer_t *initializer = initializer_from_expression(type, expression);
1628
1629         if (initializer == NULL) {
1630                 errorf(&expression->base.source_position,
1631                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1632                        expression, expression->base.type, type);
1633                 /* TODO */
1634                 return NULL;
1635         }
1636
1637         bool additional_warning_displayed = false;
1638         while (braces > 0) {
1639                 next_if(',');
1640                 if (token.kind != '}') {
1641                         if (!additional_warning_displayed) {
1642                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1643                                 additional_warning_displayed = true;
1644                         }
1645                 }
1646                 eat_block();
1647                 braces--;
1648         }
1649
1650         return initializer;
1651 }
1652
1653 /**
1654  * An entry in the type path.
1655  */
1656 typedef struct type_path_entry_t type_path_entry_t;
1657 struct type_path_entry_t {
1658         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1659         union {
1660                 size_t         index;          /**< For array types: the current index. */
1661                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1662         } v;
1663 };
1664
1665 /**
1666  * A type path expression a position inside compound or array types.
1667  */
1668 typedef struct type_path_t type_path_t;
1669 struct type_path_t {
1670         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1671         type_t            *top_type;     /**< type of the element the path points */
1672         size_t             max_index;    /**< largest index in outermost array */
1673 };
1674
1675 /**
1676  * Prints a type path for debugging.
1677  */
1678 static __attribute__((unused)) void debug_print_type_path(
1679                 const type_path_t *path)
1680 {
1681         size_t len = ARR_LEN(path->path);
1682
1683         for (size_t i = 0; i < len; ++i) {
1684                 const type_path_entry_t *entry = & path->path[i];
1685
1686                 type_t *type = skip_typeref(entry->type);
1687                 if (is_type_compound(type)) {
1688                         /* in gcc mode structs can have no members */
1689                         if (entry->v.compound_entry == NULL) {
1690                                 assert(i == len-1);
1691                                 continue;
1692                         }
1693                         fprintf(stderr, ".%s",
1694                                 entry->v.compound_entry->base.symbol->string);
1695                 } else if (is_type_array(type)) {
1696                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1697                 } else {
1698                         fprintf(stderr, "-INVALID-");
1699                 }
1700         }
1701         if (path->top_type != NULL) {
1702                 fprintf(stderr, "  (");
1703                 print_type(path->top_type);
1704                 fprintf(stderr, ")");
1705         }
1706 }
1707
1708 /**
1709  * Return the top type path entry, ie. in a path
1710  * (type).a.b returns the b.
1711  */
1712 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1713 {
1714         size_t len = ARR_LEN(path->path);
1715         assert(len > 0);
1716         return &path->path[len-1];
1717 }
1718
1719 /**
1720  * Enlarge the type path by an (empty) element.
1721  */
1722 static type_path_entry_t *append_to_type_path(type_path_t *path)
1723 {
1724         size_t len = ARR_LEN(path->path);
1725         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1726
1727         type_path_entry_t *result = & path->path[len];
1728         memset(result, 0, sizeof(result[0]));
1729         return result;
1730 }
1731
1732 /**
1733  * Descending into a sub-type. Enter the scope of the current top_type.
1734  */
1735 static void descend_into_subtype(type_path_t *path)
1736 {
1737         type_t *orig_top_type = path->top_type;
1738         type_t *top_type      = skip_typeref(orig_top_type);
1739
1740         type_path_entry_t *top = append_to_type_path(path);
1741         top->type              = top_type;
1742
1743         if (is_type_compound(top_type)) {
1744                 compound_t *const compound = top_type->compound.compound;
1745                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1746
1747                 if (entry != NULL) {
1748                         top->v.compound_entry = &entry->declaration;
1749                         path->top_type = entry->declaration.type;
1750                 } else {
1751                         path->top_type = NULL;
1752                 }
1753         } else if (is_type_array(top_type)) {
1754                 top->v.index   = 0;
1755                 path->top_type = top_type->array.element_type;
1756         } else {
1757                 assert(!is_type_valid(top_type));
1758         }
1759 }
1760
1761 /**
1762  * Pop an entry from the given type path, ie. returning from
1763  * (type).a.b to (type).a
1764  */
1765 static void ascend_from_subtype(type_path_t *path)
1766 {
1767         type_path_entry_t *top = get_type_path_top(path);
1768
1769         path->top_type = top->type;
1770
1771         size_t len = ARR_LEN(path->path);
1772         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1773 }
1774
1775 /**
1776  * Pop entries from the given type path until the given
1777  * path level is reached.
1778  */
1779 static void ascend_to(type_path_t *path, size_t top_path_level)
1780 {
1781         size_t len = ARR_LEN(path->path);
1782
1783         while (len > top_path_level) {
1784                 ascend_from_subtype(path);
1785                 len = ARR_LEN(path->path);
1786         }
1787 }
1788
1789 static bool walk_designator(type_path_t *path, const designator_t *designator,
1790                             bool used_in_offsetof)
1791 {
1792         for (; designator != NULL; designator = designator->next) {
1793                 type_path_entry_t *top       = get_type_path_top(path);
1794                 type_t            *orig_type = top->type;
1795
1796                 type_t *type = skip_typeref(orig_type);
1797
1798                 if (designator->symbol != NULL) {
1799                         symbol_t *symbol = designator->symbol;
1800                         if (!is_type_compound(type)) {
1801                                 if (is_type_valid(type)) {
1802                                         errorf(&designator->source_position,
1803                                                "'.%Y' designator used for non-compound type '%T'",
1804                                                symbol, orig_type);
1805                                 }
1806
1807                                 top->type             = type_error_type;
1808                                 top->v.compound_entry = NULL;
1809                                 orig_type             = type_error_type;
1810                         } else {
1811                                 compound_t *compound = type->compound.compound;
1812                                 entity_t   *iter     = compound->members.entities;
1813                                 for (; iter != NULL; iter = iter->base.next) {
1814                                         if (iter->base.symbol == symbol) {
1815                                                 break;
1816                                         }
1817                                 }
1818                                 if (iter == NULL) {
1819                                         errorf(&designator->source_position,
1820                                                "'%T' has no member named '%Y'", orig_type, symbol);
1821                                         return false;
1822                                 }
1823                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1824                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1825                                         errorf(&designator->source_position,
1826                                                    "offsetof designator '%Y' must not specify bitfield",
1827                                                    symbol);
1828                                         return false;
1829                                 }
1830
1831                                 top->type             = orig_type;
1832                                 top->v.compound_entry = &iter->declaration;
1833                                 orig_type             = iter->declaration.type;
1834                         }
1835                 } else {
1836                         expression_t *array_index = designator->array_index;
1837                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1838                                 return true;
1839
1840                         if (!is_type_array(type)) {
1841                                 if (is_type_valid(type)) {
1842                                         errorf(&designator->source_position,
1843                                                "[%E] designator used for non-array type '%T'",
1844                                                array_index, orig_type);
1845                                 }
1846                                 return false;
1847                         }
1848
1849                         long index = fold_constant_to_int(array_index);
1850                         if (!used_in_offsetof) {
1851                                 if (index < 0) {
1852                                         errorf(&designator->source_position,
1853                                                "array index [%E] must be positive", array_index);
1854                                 } else if (type->array.size_constant) {
1855                                         long array_size = type->array.size;
1856                                         if (index >= array_size) {
1857                                                 errorf(&designator->source_position,
1858                                                        "designator [%E] (%d) exceeds array size %d",
1859                                                        array_index, index, array_size);
1860                                         }
1861                                 }
1862                         }
1863
1864                         top->type    = orig_type;
1865                         top->v.index = (size_t) index;
1866                         orig_type    = type->array.element_type;
1867                 }
1868                 path->top_type = orig_type;
1869
1870                 if (designator->next != NULL) {
1871                         descend_into_subtype(path);
1872                 }
1873         }
1874         return true;
1875 }
1876
1877 static void advance_current_object(type_path_t *path, size_t top_path_level)
1878 {
1879         type_path_entry_t *top = get_type_path_top(path);
1880
1881         type_t *type = skip_typeref(top->type);
1882         if (is_type_union(type)) {
1883                 /* in unions only the first element is initialized */
1884                 top->v.compound_entry = NULL;
1885         } else if (is_type_struct(type)) {
1886                 declaration_t *entry = top->v.compound_entry;
1887
1888                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1889                 if (next_entity != NULL) {
1890                         assert(is_declaration(next_entity));
1891                         entry = &next_entity->declaration;
1892                 } else {
1893                         entry = NULL;
1894                 }
1895
1896                 top->v.compound_entry = entry;
1897                 if (entry != NULL) {
1898                         path->top_type = entry->type;
1899                         return;
1900                 }
1901         } else if (is_type_array(type)) {
1902                 assert(is_type_array(type));
1903
1904                 top->v.index++;
1905
1906                 if (!type->array.size_constant || top->v.index < type->array.size) {
1907                         return;
1908                 }
1909         } else {
1910                 assert(!is_type_valid(type));
1911                 return;
1912         }
1913
1914         /* we're past the last member of the current sub-aggregate, try if we
1915          * can ascend in the type hierarchy and continue with another subobject */
1916         size_t len = ARR_LEN(path->path);
1917
1918         if (len > top_path_level) {
1919                 ascend_from_subtype(path);
1920                 advance_current_object(path, top_path_level);
1921         } else {
1922                 path->top_type = NULL;
1923         }
1924 }
1925
1926 /**
1927  * skip any {...} blocks until a closing bracket is reached.
1928  */
1929 static void skip_initializers(void)
1930 {
1931         next_if('{');
1932
1933         while (token.kind != '}') {
1934                 if (token.kind == T_EOF)
1935                         return;
1936                 if (token.kind == '{') {
1937                         eat_block();
1938                         continue;
1939                 }
1940                 next_token();
1941         }
1942 }
1943
1944 static initializer_t *create_empty_initializer(void)
1945 {
1946         static initializer_t empty_initializer
1947                 = { .list = { { INITIALIZER_LIST }, 0 } };
1948         return &empty_initializer;
1949 }
1950
1951 /**
1952  * Parse a part of an initialiser for a struct or union,
1953  */
1954 static initializer_t *parse_sub_initializer(type_path_t *path,
1955                 type_t *outer_type, size_t top_path_level,
1956                 parse_initializer_env_t *env)
1957 {
1958         if (token.kind == '}') {
1959                 /* empty initializer */
1960                 return create_empty_initializer();
1961         }
1962
1963         initializer_t *result = NULL;
1964
1965         type_t *orig_type = path->top_type;
1966         type_t *type      = NULL;
1967
1968         if (orig_type == NULL) {
1969                 /* We are initializing an empty compound. */
1970         } else {
1971                 type = skip_typeref(orig_type);
1972         }
1973
1974         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1975
1976         while (true) {
1977                 designator_t *designator = NULL;
1978                 if (token.kind == '.' || token.kind == '[') {
1979                         designator = parse_designation();
1980                         goto finish_designator;
1981                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1982                         /* GNU-style designator ("identifier: value") */
1983                         designator = allocate_ast_zero(sizeof(designator[0]));
1984                         designator->source_position = *HERE;
1985                         designator->symbol          = token.base.symbol;
1986                         eat(T_IDENTIFIER);
1987                         eat(':');
1988
1989 finish_designator:
1990                         /* reset path to toplevel, evaluate designator from there */
1991                         ascend_to(path, top_path_level);
1992                         if (!walk_designator(path, designator, false)) {
1993                                 /* can't continue after designation error */
1994                                 goto end_error;
1995                         }
1996
1997                         initializer_t *designator_initializer
1998                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1999                         designator_initializer->designator.designator = designator;
2000                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2001
2002                         orig_type = path->top_type;
2003                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2004                 }
2005
2006                 initializer_t *sub;
2007
2008                 if (token.kind == '{') {
2009                         if (type != NULL && is_type_scalar(type)) {
2010                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2011                         } else {
2012                                 if (type == NULL) {
2013                                         if (env->entity != NULL) {
2014                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2015                                         } else {
2016                                                 errorf(HERE, "extra brace group at end of initializer");
2017                                         }
2018                                         eat('{');
2019                                 } else {
2020                                         eat('{');
2021                                         descend_into_subtype(path);
2022                                 }
2023
2024                                 add_anchor_token('}');
2025                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2026                                                             env);
2027                                 rem_anchor_token('}');
2028
2029                                 expect('}');
2030
2031                                 if (!type)
2032                                         goto error_parse_next;
2033
2034                                 ascend_from_subtype(path);
2035                         }
2036                 } else {
2037                         /* must be an expression */
2038                         expression_t *expression = parse_assignment_expression();
2039                         mark_vars_read(expression, NULL);
2040
2041                         if (env->must_be_constant && !is_linker_constant(expression)) {
2042                                 errorf(&expression->base.source_position,
2043                                        "Initialisation expression '%E' is not constant",
2044                                        expression);
2045                         }
2046
2047                         if (type == NULL) {
2048                                 /* we are already outside, ... */
2049                                 if (outer_type == NULL)
2050                                         goto error_parse_next;
2051                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2052                                 if (is_type_compound(outer_type_skip) &&
2053                                                 !outer_type_skip->compound.compound->complete) {
2054                                         goto error_parse_next;
2055                                 }
2056
2057                                 source_position_t const* const pos = &expression->base.source_position;
2058                                 if (env->entity != NULL) {
2059                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2060                                 } else {
2061                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2062                                 }
2063                                 goto error_parse_next;
2064                         }
2065
2066                         /* handle { "string" } special case */
2067                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2068                                 result = initializer_from_expression(outer_type, expression);
2069                                 if (result != NULL) {
2070                                         next_if(',');
2071                                         if (token.kind != '}') {
2072                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2073                                         }
2074                                         /* TODO: eat , ... */
2075                                         goto out;
2076                                 }
2077                         }
2078
2079                         /* descend into subtypes until expression matches type */
2080                         while (true) {
2081                                 orig_type = path->top_type;
2082                                 type      = skip_typeref(orig_type);
2083
2084                                 sub = initializer_from_expression(orig_type, expression);
2085                                 if (sub != NULL) {
2086                                         break;
2087                                 }
2088                                 if (!is_type_valid(type)) {
2089                                         goto end_error;
2090                                 }
2091                                 if (is_type_scalar(type)) {
2092                                         errorf(&expression->base.source_position,
2093                                                         "expression '%E' doesn't match expected type '%T'",
2094                                                         expression, orig_type);
2095                                         goto end_error;
2096                                 }
2097
2098                                 descend_into_subtype(path);
2099                         }
2100                 }
2101
2102                 /* update largest index of top array */
2103                 const type_path_entry_t *first      = &path->path[0];
2104                 type_t                  *first_type = first->type;
2105                 first_type                          = skip_typeref(first_type);
2106                 if (is_type_array(first_type)) {
2107                         size_t index = first->v.index;
2108                         if (index > path->max_index)
2109                                 path->max_index = index;
2110                 }
2111
2112                 /* append to initializers list */
2113                 ARR_APP1(initializer_t*, initializers, sub);
2114
2115 error_parse_next:
2116                 if (!next_if(','))
2117                         break;
2118                 if (token.kind == '}') {
2119                         break;
2120                 }
2121
2122                 if (type != NULL) {
2123                         /* advance to the next declaration if we are not at the end */
2124                         advance_current_object(path, top_path_level);
2125                         orig_type = path->top_type;
2126                         if (orig_type != NULL)
2127                                 type = skip_typeref(orig_type);
2128                         else
2129                                 type = NULL;
2130                 }
2131         }
2132
2133         size_t len  = ARR_LEN(initializers);
2134         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2135         result = allocate_ast_zero(size);
2136         result->kind     = INITIALIZER_LIST;
2137         result->list.len = len;
2138         memcpy(&result->list.initializers, initializers,
2139                len * sizeof(initializers[0]));
2140         goto out;
2141
2142 end_error:
2143         skip_initializers();
2144 out:
2145         DEL_ARR_F(initializers);
2146         ascend_to(path, top_path_level+1);
2147         return result;
2148 }
2149
2150 static expression_t *make_size_literal(size_t value)
2151 {
2152         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2153         literal->base.type    = type_size_t;
2154
2155         char buf[128];
2156         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2157         literal->literal.value = make_string(buf);
2158
2159         return literal;
2160 }
2161
2162 /**
2163  * Parses an initializer. Parsers either a compound literal
2164  * (env->declaration == NULL) or an initializer of a declaration.
2165  */
2166 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2167 {
2168         type_t        *type      = skip_typeref(env->type);
2169         size_t         max_index = 0;
2170         initializer_t *result;
2171
2172         if (is_type_scalar(type)) {
2173                 result = parse_scalar_initializer(type, env->must_be_constant);
2174         } else if (token.kind == '{') {
2175                 eat('{');
2176
2177                 type_path_t path;
2178                 memset(&path, 0, sizeof(path));
2179                 path.top_type = env->type;
2180                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2181
2182                 descend_into_subtype(&path);
2183
2184                 add_anchor_token('}');
2185                 result = parse_sub_initializer(&path, env->type, 1, env);
2186                 rem_anchor_token('}');
2187
2188                 max_index = path.max_index;
2189                 DEL_ARR_F(path.path);
2190
2191                 expect('}');
2192         } else {
2193                 /* parse_scalar_initializer() also works in this case: we simply
2194                  * have an expression without {} around it */
2195                 result = parse_scalar_initializer(type, env->must_be_constant);
2196         }
2197
2198         /* §6.7.8:22 array initializers for arrays with unknown size determine
2199          * the array type size */
2200         if (is_type_array(type) && type->array.size_expression == NULL
2201                         && result != NULL) {
2202                 size_t size;
2203                 switch (result->kind) {
2204                 case INITIALIZER_LIST:
2205                         assert(max_index != 0xdeadbeaf);
2206                         size = max_index + 1;
2207                         break;
2208
2209                 case INITIALIZER_STRING: {
2210                         size = get_string_len(&get_init_string(result)->value) + 1;
2211                         break;
2212                 }
2213
2214                 case INITIALIZER_DESIGNATOR:
2215                 case INITIALIZER_VALUE:
2216                         /* can happen for parse errors */
2217                         size = 0;
2218                         break;
2219
2220                 default:
2221                         internal_errorf(HERE, "invalid initializer type");
2222                 }
2223
2224                 type_t *new_type = duplicate_type(type);
2225
2226                 new_type->array.size_expression   = make_size_literal(size);
2227                 new_type->array.size_constant     = true;
2228                 new_type->array.has_implicit_size = true;
2229                 new_type->array.size              = size;
2230                 env->type = new_type;
2231         }
2232
2233         return result;
2234 }
2235
2236 static void append_entity(scope_t *scope, entity_t *entity)
2237 {
2238         if (scope->last_entity != NULL) {
2239                 scope->last_entity->base.next = entity;
2240         } else {
2241                 scope->entities = entity;
2242         }
2243         entity->base.parent_entity = current_entity;
2244         scope->last_entity         = entity;
2245 }
2246
2247
2248 static compound_t *parse_compound_type_specifier(bool is_struct)
2249 {
2250         source_position_t const pos = *HERE;
2251         eat(is_struct ? T_struct : T_union);
2252
2253         symbol_t    *symbol     = NULL;
2254         entity_t    *entity     = NULL;
2255         attribute_t *attributes = NULL;
2256
2257         if (token.kind == T___attribute__) {
2258                 attributes = parse_attributes(NULL);
2259         }
2260
2261         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2262         if (token.kind == T_IDENTIFIER) {
2263                 /* the compound has a name, check if we have seen it already */
2264                 symbol = token.base.symbol;
2265                 entity = get_tag(symbol, kind);
2266                 eat(T_IDENTIFIER);
2267
2268                 if (entity != NULL) {
2269                         if (entity->base.parent_scope != current_scope &&
2270                             (token.kind == '{' || token.kind == ';')) {
2271                                 /* we're in an inner scope and have a definition. Shadow
2272                                  * existing definition in outer scope */
2273                                 entity = NULL;
2274                         } else if (entity->compound.complete && token.kind == '{') {
2275                                 source_position_t const *const ppos = &entity->base.source_position;
2276                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2277                                 /* clear members in the hope to avoid further errors */
2278                                 entity->compound.members.entities = NULL;
2279                         }
2280                 }
2281         } else if (token.kind != '{') {
2282                 char const *const msg =
2283                         is_struct ? "while parsing struct type specifier" :
2284                                     "while parsing union type specifier";
2285                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2286
2287                 return NULL;
2288         }
2289
2290         if (entity == NULL) {
2291                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2292                 entity->compound.alignment = 1;
2293                 entity->base.parent_scope  = current_scope;
2294                 if (symbol != NULL) {
2295                         environment_push(entity);
2296                 }
2297                 append_entity(current_scope, entity);
2298         }
2299
2300         if (token.kind == '{') {
2301                 parse_compound_type_entries(&entity->compound);
2302
2303                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2304                 if (symbol == NULL) {
2305                         assert(anonymous_entity == NULL);
2306                         anonymous_entity = entity;
2307                 }
2308         }
2309
2310         if (attributes != NULL) {
2311                 entity->compound.attributes = attributes;
2312                 handle_entity_attributes(attributes, entity);
2313         }
2314
2315         return &entity->compound;
2316 }
2317
2318 static void parse_enum_entries(type_t *const enum_type)
2319 {
2320         eat('{');
2321
2322         if (token.kind == '}') {
2323                 errorf(HERE, "empty enum not allowed");
2324                 eat('}');
2325                 return;
2326         }
2327
2328         add_anchor_token('}');
2329         add_anchor_token(',');
2330         do {
2331                 add_anchor_token('=');
2332                 source_position_t pos;
2333                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2334                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2335                 entity->enum_value.enum_type = enum_type;
2336                 rem_anchor_token('=');
2337
2338                 if (next_if('=')) {
2339                         expression_t *value = parse_constant_expression();
2340
2341                         value = create_implicit_cast(value, enum_type);
2342                         entity->enum_value.value = value;
2343
2344                         /* TODO semantic */
2345                 }
2346
2347                 record_entity(entity, false);
2348         } while (next_if(',') && token.kind != '}');
2349         rem_anchor_token(',');
2350         rem_anchor_token('}');
2351
2352         expect('}');
2353 }
2354
2355 static type_t *parse_enum_specifier(void)
2356 {
2357         source_position_t const pos = *HERE;
2358         entity_t               *entity;
2359         symbol_t               *symbol;
2360
2361         eat(T_enum);
2362         switch (token.kind) {
2363                 case T_IDENTIFIER:
2364                         symbol = token.base.symbol;
2365                         entity = get_tag(symbol, ENTITY_ENUM);
2366                         eat(T_IDENTIFIER);
2367
2368                         if (entity != NULL) {
2369                                 if (entity->base.parent_scope != current_scope &&
2370                                                 (token.kind == '{' || token.kind == ';')) {
2371                                         /* we're in an inner scope and have a definition. Shadow
2372                                          * existing definition in outer scope */
2373                                         entity = NULL;
2374                                 } else if (entity->enume.complete && token.kind == '{') {
2375                                         source_position_t const *const ppos = &entity->base.source_position;
2376                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2377                                 }
2378                         }
2379                         break;
2380
2381                 case '{':
2382                         entity = NULL;
2383                         symbol = NULL;
2384                         break;
2385
2386                 default:
2387                         parse_error_expected("while parsing enum type specifier",
2388                                         T_IDENTIFIER, '{', NULL);
2389                         return NULL;
2390         }
2391
2392         if (entity == NULL) {
2393                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2394                 entity->base.parent_scope = current_scope;
2395         }
2396
2397         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2398         type->enumt.enume      = &entity->enume;
2399         type->enumt.base.akind = ATOMIC_TYPE_INT;
2400
2401         if (token.kind == '{') {
2402                 if (symbol != NULL) {
2403                         environment_push(entity);
2404                 }
2405                 append_entity(current_scope, entity);
2406                 entity->enume.complete = true;
2407
2408                 parse_enum_entries(type);
2409                 parse_attributes(NULL);
2410
2411                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2412                 if (symbol == NULL) {
2413                         assert(anonymous_entity == NULL);
2414                         anonymous_entity = entity;
2415                 }
2416         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2417                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2418         }
2419
2420         return type;
2421 }
2422
2423 /**
2424  * if a symbol is a typedef to another type, return true
2425  */
2426 static bool is_typedef_symbol(symbol_t *symbol)
2427 {
2428         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2429         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2430 }
2431
2432 static type_t *parse_typeof(void)
2433 {
2434         eat(T___typeof__);
2435
2436         type_t *type;
2437
2438         add_anchor_token(')');
2439         expect('(');
2440
2441         expression_t *expression  = NULL;
2442
2443         switch (token.kind) {
2444         case T_IDENTIFIER:
2445                 if (is_typedef_symbol(token.base.symbol)) {
2446         DECLARATION_START
2447                         type = parse_typename();
2448                 } else {
2449         default:
2450                         expression = parse_expression();
2451                         type       = revert_automatic_type_conversion(expression);
2452                 }
2453                 break;
2454         }
2455
2456         rem_anchor_token(')');
2457         expect(')');
2458
2459         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2460         typeof_type->typeoft.expression  = expression;
2461         typeof_type->typeoft.typeof_type = type;
2462
2463         return typeof_type;
2464 }
2465
2466 typedef enum specifiers_t {
2467         SPECIFIER_NONE      = 0,
2468         SPECIFIER_SIGNED    = 1 << 0,
2469         SPECIFIER_UNSIGNED  = 1 << 1,
2470         SPECIFIER_LONG      = 1 << 2,
2471         SPECIFIER_INT       = 1 << 3,
2472         SPECIFIER_DOUBLE    = 1 << 4,
2473         SPECIFIER_CHAR      = 1 << 5,
2474         SPECIFIER_WCHAR_T   = 1 << 6,
2475         SPECIFIER_SHORT     = 1 << 7,
2476         SPECIFIER_LONG_LONG = 1 << 8,
2477         SPECIFIER_FLOAT     = 1 << 9,
2478         SPECIFIER_BOOL      = 1 << 10,
2479         SPECIFIER_VOID      = 1 << 11,
2480         SPECIFIER_INT8      = 1 << 12,
2481         SPECIFIER_INT16     = 1 << 13,
2482         SPECIFIER_INT32     = 1 << 14,
2483         SPECIFIER_INT64     = 1 << 15,
2484         SPECIFIER_INT128    = 1 << 16,
2485         SPECIFIER_COMPLEX   = 1 << 17,
2486         SPECIFIER_IMAGINARY = 1 << 18,
2487 } specifiers_t;
2488
2489 static type_t *get_typedef_type(symbol_t *symbol)
2490 {
2491         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2492         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2493                 return NULL;
2494
2495         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2496         type->typedeft.typedefe = &entity->typedefe;
2497
2498         return type;
2499 }
2500
2501 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2502 {
2503         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2504
2505         add_anchor_token(')');
2506         add_anchor_token(',');
2507         expect('(');
2508
2509         do {
2510                 add_anchor_token('=');
2511                 source_position_t pos;
2512                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2513                 rem_anchor_token('=');
2514
2515                 symbol_t **prop = NULL;
2516                 if (prop_sym) {
2517                         if (streq(prop_sym->string, "put")) {
2518                                 prop = &property->put_symbol;
2519                         } else if (streq(prop_sym->string, "get")) {
2520                                 prop = &property->get_symbol;
2521                         } else {
2522                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2523                         }
2524                 }
2525
2526                 add_anchor_token(T_IDENTIFIER);
2527                 expect('=');
2528                 rem_anchor_token(T_IDENTIFIER);
2529
2530                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2531                 if (prop != NULL)
2532                         *prop = sym ? sym : sym_anonymous;
2533         } while (next_if(','));
2534         rem_anchor_token(',');
2535         rem_anchor_token(')');
2536
2537         attribute->a.property = property;
2538
2539         expect(')');
2540         return attribute;
2541 }
2542
2543 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2544 {
2545         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2546         if (next_if(T_restrict)) {
2547                 kind = ATTRIBUTE_MS_RESTRICT;
2548         } else if (token.kind == T_IDENTIFIER) {
2549                 char const *const name = token.base.symbol->string;
2550                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2551                      ++k) {
2552                         const char *attribute_name = get_attribute_name(k);
2553                         if (attribute_name != NULL && streq(attribute_name, name)) {
2554                                 kind = k;
2555                                 break;
2556                         }
2557                 }
2558
2559                 if (kind == ATTRIBUTE_UNKNOWN) {
2560                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2561                 }
2562         } else {
2563                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2564                 return NULL;
2565         }
2566
2567         attribute_t *attribute = allocate_attribute_zero(kind);
2568         eat(T_IDENTIFIER);
2569
2570         if (kind == ATTRIBUTE_MS_PROPERTY) {
2571                 return parse_attribute_ms_property(attribute);
2572         }
2573
2574         /* parse arguments */
2575         if (next_if('('))
2576                 attribute->a.arguments = parse_attribute_arguments();
2577
2578         return attribute;
2579 }
2580
2581 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2582 {
2583         eat(T__declspec);
2584
2585         add_anchor_token(')');
2586         expect('(');
2587         if (token.kind != ')') {
2588                 attribute_t **anchor = &first;
2589                 do {
2590                         while (*anchor != NULL)
2591                                 anchor = &(*anchor)->next;
2592
2593                         attribute_t *attribute
2594                                 = parse_microsoft_extended_decl_modifier_single();
2595                         if (attribute == NULL)
2596                                 break;
2597
2598                         *anchor = attribute;
2599                         anchor  = &attribute->next;
2600                 } while (next_if(','));
2601         }
2602         rem_anchor_token(')');
2603         expect(')');
2604         return first;
2605 }
2606
2607 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2608 {
2609         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2610         if (is_declaration(entity)) {
2611                 entity->declaration.type     = type_error_type;
2612                 entity->declaration.implicit = true;
2613         } else if (kind == ENTITY_TYPEDEF) {
2614                 entity->typedefe.type    = type_error_type;
2615                 entity->typedefe.builtin = true;
2616         }
2617         if (kind != ENTITY_COMPOUND_MEMBER)
2618                 record_entity(entity, false);
2619         return entity;
2620 }
2621
2622 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2623 {
2624         type_t            *type            = NULL;
2625         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2626         unsigned           type_specifiers = 0;
2627         bool               newtype         = false;
2628         bool               saw_error       = false;
2629
2630         memset(specifiers, 0, sizeof(*specifiers));
2631         specifiers->source_position = *HERE;
2632
2633         while (true) {
2634                 specifiers->attributes = parse_attributes(specifiers->attributes);
2635
2636                 switch (token.kind) {
2637                 /* storage class */
2638 #define MATCH_STORAGE_CLASS(token, class)                                  \
2639                 case token:                                                        \
2640                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2641                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2642                         }                                                              \
2643                         specifiers->storage_class = class;                             \
2644                         if (specifiers->thread_local)                                  \
2645                                 goto check_thread_storage_class;                           \
2646                         eat(token); \
2647                         break;
2648
2649                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2650                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2651                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2652                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2653                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2654
2655                 case T__declspec:
2656                         specifiers->attributes
2657                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2658                         break;
2659
2660                 case T__Thread_local:
2661                         if (specifiers->thread_local) {
2662                                 errorf(HERE, "duplicate %K", &token);
2663                         } else {
2664                                 specifiers->thread_local = true;
2665 check_thread_storage_class:
2666                                 switch (specifiers->storage_class) {
2667                                         case STORAGE_CLASS_EXTERN:
2668                                         case STORAGE_CLASS_NONE:
2669                                         case STORAGE_CLASS_STATIC:
2670                                                 break;
2671
2672                                                 char const* wrong;
2673                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2674                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2675                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2676 wrong_thread_storage_class:
2677                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2678                                                 break;
2679                                 }
2680                         }
2681                         next_token();
2682                         break;
2683
2684                 /* type qualifiers */
2685 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2686                 case token:                                                     \
2687                         qualifiers |= qualifier;                                    \
2688                         eat(token); \
2689                         break
2690
2691                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2692                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2693                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2694                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2695                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2696                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2697                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2698                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2699
2700                 /* type specifiers */
2701 #define MATCH_SPECIFIER(token, specifier, name)                         \
2702                 case token:                                                     \
2703                         if (type_specifiers & specifier) {                           \
2704                                 errorf(HERE, "multiple " name " type specifiers given"); \
2705                         } else {                                                    \
2706                                 type_specifiers |= specifier;                           \
2707                         }                                                           \
2708                         eat(token); \
2709                         break
2710
2711                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2712                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2713                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2714                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2715                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2716                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2717                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2718                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2719                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2720                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2721                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2722                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2723                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2724                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2725                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2726                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2727                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2728                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2729
2730                 case T_inline:
2731                         eat(T_inline);
2732                         specifiers->is_inline = true;
2733                         break;
2734
2735 #if 0
2736                 case T__forceinline:
2737                         eat(T__forceinline);
2738                         specifiers->modifiers |= DM_FORCEINLINE;
2739                         break;
2740 #endif
2741
2742                 case T_long:
2743                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2744                                 errorf(HERE, "too many long type specifiers given");
2745                         } else if (type_specifiers & SPECIFIER_LONG) {
2746                                 type_specifiers |= SPECIFIER_LONG_LONG;
2747                         } else {
2748                                 type_specifiers |= SPECIFIER_LONG;
2749                         }
2750                         eat(T_long);
2751                         break;
2752
2753 #define CHECK_DOUBLE_TYPE() \
2754         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2755
2756                 case T_struct:
2757                         CHECK_DOUBLE_TYPE();
2758                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2759
2760                         type->compound.compound = parse_compound_type_specifier(true);
2761                         break;
2762                 case T_union:
2763                         CHECK_DOUBLE_TYPE();
2764                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2765                         type->compound.compound = parse_compound_type_specifier(false);
2766                         break;
2767                 case T_enum:
2768                         CHECK_DOUBLE_TYPE();
2769                         type = parse_enum_specifier();
2770                         break;
2771                 case T___typeof__:
2772                         CHECK_DOUBLE_TYPE();
2773                         type = parse_typeof();
2774                         break;
2775                 case T___builtin_va_list:
2776                         CHECK_DOUBLE_TYPE();
2777                         type = duplicate_type(type_valist);
2778                         eat(T___builtin_va_list);
2779                         break;
2780
2781                 case T_IDENTIFIER: {
2782                         /* only parse identifier if we haven't found a type yet */
2783                         if (type != NULL || type_specifiers != 0) {
2784                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2785                                  * declaration, so it doesn't generate errors about expecting '(' or
2786                                  * '{' later on. */
2787                                 switch (look_ahead(1)->kind) {
2788                                         STORAGE_CLASSES
2789                                         TYPE_SPECIFIERS
2790                                         case T_const:
2791                                         case T_restrict:
2792                                         case T_volatile:
2793                                         case T_inline:
2794                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2795                                         case T_IDENTIFIER:
2796                                         case '&':
2797                                         case '*':
2798                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2799                                                 eat(T_IDENTIFIER);
2800                                                 continue;
2801
2802                                         default:
2803                                                 goto finish_specifiers;
2804                                 }
2805                         }
2806
2807                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2808                         if (typedef_type == NULL) {
2809                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2810                                  * declaration, so it doesn't generate 'implicit int' followed by more
2811                                  * errors later on. */
2812                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2813                                 switch (la1_type) {
2814                                         DECLARATION_START
2815                                         case T_IDENTIFIER:
2816                                         case '&':
2817                                         case '*': {
2818                                                 errorf(HERE, "%K does not name a type", &token);
2819
2820                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2821
2822                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2823                                                 type->typedeft.typedefe = &entity->typedefe;
2824
2825                                                 eat(T_IDENTIFIER);
2826                                                 saw_error = true;
2827                                                 continue;
2828                                         }
2829
2830                                         default:
2831                                                 goto finish_specifiers;
2832                                 }
2833                         }
2834
2835                         eat(T_IDENTIFIER);
2836                         type = typedef_type;
2837                         break;
2838                 }
2839
2840                 /* function specifier */
2841                 default:
2842                         goto finish_specifiers;
2843                 }
2844         }
2845
2846 finish_specifiers:
2847         specifiers->attributes = parse_attributes(specifiers->attributes);
2848
2849         if (type == NULL || (saw_error && type_specifiers != 0)) {
2850                 atomic_type_kind_t atomic_type;
2851
2852                 /* match valid basic types */
2853                 switch (type_specifiers) {
2854                 case SPECIFIER_VOID:
2855                         atomic_type = ATOMIC_TYPE_VOID;
2856                         break;
2857                 case SPECIFIER_WCHAR_T:
2858                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2859                         break;
2860                 case SPECIFIER_CHAR:
2861                         atomic_type = ATOMIC_TYPE_CHAR;
2862                         break;
2863                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2864                         atomic_type = ATOMIC_TYPE_SCHAR;
2865                         break;
2866                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2867                         atomic_type = ATOMIC_TYPE_UCHAR;
2868                         break;
2869                 case SPECIFIER_SHORT:
2870                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2871                 case SPECIFIER_SHORT | SPECIFIER_INT:
2872                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2873                         atomic_type = ATOMIC_TYPE_SHORT;
2874                         break;
2875                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2876                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2877                         atomic_type = ATOMIC_TYPE_USHORT;
2878                         break;
2879                 case SPECIFIER_INT:
2880                 case SPECIFIER_SIGNED:
2881                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2882                         atomic_type = ATOMIC_TYPE_INT;
2883                         break;
2884                 case SPECIFIER_UNSIGNED:
2885                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2886                         atomic_type = ATOMIC_TYPE_UINT;
2887                         break;
2888                 case SPECIFIER_LONG:
2889                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2890                 case SPECIFIER_LONG | SPECIFIER_INT:
2891                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2892                         atomic_type = ATOMIC_TYPE_LONG;
2893                         break;
2894                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2895                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2896                         atomic_type = ATOMIC_TYPE_ULONG;
2897                         break;
2898
2899                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2900                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2901                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2902                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2903                         | SPECIFIER_INT:
2904                         atomic_type = ATOMIC_TYPE_LONGLONG;
2905                         goto warn_about_long_long;
2906
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2908                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2909                         | SPECIFIER_INT:
2910                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2911 warn_about_long_long:
2912                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2913                         break;
2914
2915                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2916                         atomic_type = unsigned_int8_type_kind;
2917                         break;
2918
2919                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2920                         atomic_type = unsigned_int16_type_kind;
2921                         break;
2922
2923                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2924                         atomic_type = unsigned_int32_type_kind;
2925                         break;
2926
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2928                         atomic_type = unsigned_int64_type_kind;
2929                         break;
2930
2931                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2932                         atomic_type = unsigned_int128_type_kind;
2933                         break;
2934
2935                 case SPECIFIER_INT8:
2936                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2937                         atomic_type = int8_type_kind;
2938                         break;
2939
2940                 case SPECIFIER_INT16:
2941                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2942                         atomic_type = int16_type_kind;
2943                         break;
2944
2945                 case SPECIFIER_INT32:
2946                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2947                         atomic_type = int32_type_kind;
2948                         break;
2949
2950                 case SPECIFIER_INT64:
2951                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2952                         atomic_type = int64_type_kind;
2953                         break;
2954
2955                 case SPECIFIER_INT128:
2956                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2957                         atomic_type = int128_type_kind;
2958                         break;
2959
2960                 case SPECIFIER_FLOAT:
2961                         atomic_type = ATOMIC_TYPE_FLOAT;
2962                         break;
2963                 case SPECIFIER_DOUBLE:
2964                         atomic_type = ATOMIC_TYPE_DOUBLE;
2965                         break;
2966                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2967                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2968                         break;
2969                 case SPECIFIER_BOOL:
2970                         atomic_type = ATOMIC_TYPE_BOOL;
2971                         break;
2972                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2973                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2974                         atomic_type = ATOMIC_TYPE_FLOAT;
2975                         break;
2976                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2977                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2978                         atomic_type = ATOMIC_TYPE_DOUBLE;
2979                         break;
2980                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2981                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2982                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2983                         break;
2984                 default: {
2985                         /* invalid specifier combination, give an error message */
2986                         source_position_t const* const pos = &specifiers->source_position;
2987                         if (type_specifiers == 0) {
2988                                 if (!saw_error) {
2989                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2990                                         if (!(c_mode & _CXX) && !strict_mode) {
2991                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2992                                                 atomic_type = ATOMIC_TYPE_INT;
2993                                                 break;
2994                                         } else {
2995                                                 errorf(pos, "no type specifiers given in declaration");
2996                                         }
2997                                 }
2998                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
2999                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3000                                 errorf(pos, "signed and unsigned specifiers given");
3001                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3002                                 errorf(pos, "only integer types can be signed or unsigned");
3003                         } else {
3004                                 errorf(pos, "multiple datatypes in declaration");
3005                         }
3006                         specifiers->type = type_error_type;
3007                         return;
3008                 }
3009                 }
3010
3011                 if (type_specifiers & SPECIFIER_COMPLEX) {
3012                         type = allocate_type_zero(TYPE_COMPLEX);
3013                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3014                         type = allocate_type_zero(TYPE_IMAGINARY);
3015                 } else {
3016                         type = allocate_type_zero(TYPE_ATOMIC);
3017                 }
3018                 type->atomic.akind = atomic_type;
3019                 newtype = true;
3020         } else if (type_specifiers != 0) {
3021                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3022         }
3023
3024         /* FIXME: check type qualifiers here */
3025         type->base.qualifiers = qualifiers;
3026
3027         if (newtype) {
3028                 type = identify_new_type(type);
3029         } else {
3030                 type = typehash_insert(type);
3031         }
3032
3033         if (specifiers->attributes != NULL)
3034                 type = handle_type_attributes(specifiers->attributes, type);
3035         specifiers->type = type;
3036 }
3037
3038 static type_qualifiers_t parse_type_qualifiers(void)
3039 {
3040         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3041
3042         while (true) {
3043                 switch (token.kind) {
3044                 /* type qualifiers */
3045                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3046                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3047                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3048                 /* microsoft extended type modifiers */
3049                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3050                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3051                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3052                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3053                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3054
3055                 default:
3056                         return qualifiers;
3057                 }
3058         }
3059 }
3060
3061 /**
3062  * Parses an K&R identifier list
3063  */
3064 static void parse_identifier_list(scope_t *scope)
3065 {
3066         assert(token.kind == T_IDENTIFIER);
3067         do {
3068                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3069                 /* a K&R parameter has no type, yet */
3070                 eat(T_IDENTIFIER);
3071
3072                 if (scope != NULL)
3073                         append_entity(scope, entity);
3074         } while (next_if(',') && token.kind == T_IDENTIFIER);
3075 }
3076
3077 static entity_t *parse_parameter(void)
3078 {
3079         declaration_specifiers_t specifiers;
3080         parse_declaration_specifiers(&specifiers);
3081
3082         entity_t *entity = parse_declarator(&specifiers,
3083                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3084         anonymous_entity = NULL;
3085         return entity;
3086 }
3087
3088 static void semantic_parameter_incomplete(const entity_t *entity)
3089 {
3090         assert(entity->kind == ENTITY_PARAMETER);
3091
3092         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3093          *             list in a function declarator that is part of a
3094          *             definition of that function shall not have
3095          *             incomplete type. */
3096         type_t *type = skip_typeref(entity->declaration.type);
3097         if (is_type_incomplete(type)) {
3098                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3099         }
3100 }
3101
3102 static bool has_parameters(void)
3103 {
3104         /* func(void) is not a parameter */
3105         if (look_ahead(1)->kind != ')')
3106                 return true;
3107         if (token.kind == T_IDENTIFIER) {
3108                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3109                 if (entity == NULL)
3110                         return true;
3111                 if (entity->kind != ENTITY_TYPEDEF)
3112                         return true;
3113                 type_t const *const type = skip_typeref(entity->typedefe.type);
3114                 if (!is_type_void(type))
3115                         return true;
3116                 if (c_mode & _CXX) {
3117                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3118                          * is not allowed. */
3119                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3120                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3121                         /* §6.7.5.3:10  Qualification is not allowed here. */
3122                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3123                 }
3124         } else if (token.kind != T_void) {
3125                 return true;
3126         }
3127         next_token();
3128         return false;
3129 }
3130
3131 /**
3132  * Parses function type parameters (and optionally creates variable_t entities
3133  * for them in a scope)
3134  */
3135 static void parse_parameters(function_type_t *type, scope_t *scope)
3136 {
3137         add_anchor_token(')');
3138         eat('(');
3139
3140         if (token.kind == T_IDENTIFIER            &&
3141             !is_typedef_symbol(token.base.symbol) &&
3142             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3143                 type->kr_style_parameters = true;
3144                 parse_identifier_list(scope);
3145         } else if (token.kind == ')') {
3146                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3147                 if (!(c_mode & _CXX))
3148                         type->unspecified_parameters = true;
3149         } else if (has_parameters()) {
3150                 function_parameter_t **anchor = &type->parameters;
3151                 add_anchor_token(',');
3152                 do {
3153                         switch (token.kind) {
3154                         case T_DOTDOTDOT:
3155                                 eat(T_DOTDOTDOT);
3156                                 type->variadic = true;
3157                                 goto parameters_finished;
3158
3159                         case T_IDENTIFIER:
3160                         DECLARATION_START
3161                         {
3162                                 entity_t *entity = parse_parameter();
3163                                 if (entity->kind == ENTITY_TYPEDEF) {
3164                                         errorf(&entity->base.source_position,
3165                                                         "typedef not allowed as function parameter");
3166                                         break;
3167                                 }
3168                                 assert(is_declaration(entity));
3169
3170                                 semantic_parameter_incomplete(entity);
3171
3172                                 function_parameter_t *const parameter =
3173                                         allocate_parameter(entity->declaration.type);
3174
3175                                 if (scope != NULL) {
3176                                         append_entity(scope, entity);
3177                                 }
3178
3179                                 *anchor = parameter;
3180                                 anchor  = &parameter->next;
3181                                 break;
3182                         }
3183
3184                         default:
3185                                 goto parameters_finished;
3186                         }
3187                 } while (next_if(','));
3188 parameters_finished:
3189                 rem_anchor_token(',');
3190         }
3191
3192         rem_anchor_token(')');
3193         expect(')');
3194 }
3195
3196 typedef enum construct_type_kind_t {
3197         CONSTRUCT_POINTER = 1,
3198         CONSTRUCT_REFERENCE,
3199         CONSTRUCT_FUNCTION,
3200         CONSTRUCT_ARRAY
3201 } construct_type_kind_t;
3202
3203 typedef union construct_type_t construct_type_t;
3204
3205 typedef struct construct_type_base_t {
3206         construct_type_kind_t  kind;
3207         source_position_t      pos;
3208         construct_type_t      *next;
3209 } construct_type_base_t;
3210
3211 typedef struct parsed_pointer_t {
3212         construct_type_base_t  base;
3213         type_qualifiers_t      type_qualifiers;
3214         variable_t            *base_variable;  /**< MS __based extension. */
3215 } parsed_pointer_t;
3216
3217 typedef struct parsed_reference_t {
3218         construct_type_base_t base;
3219 } parsed_reference_t;
3220
3221 typedef struct construct_function_type_t {
3222         construct_type_base_t  base;
3223         type_t                *function_type;
3224 } construct_function_type_t;
3225
3226 typedef struct parsed_array_t {
3227         construct_type_base_t  base;
3228         type_qualifiers_t      type_qualifiers;
3229         bool                   is_static;
3230         bool                   is_variable;
3231         expression_t          *size;
3232 } parsed_array_t;
3233
3234 union construct_type_t {
3235         construct_type_kind_t     kind;
3236         construct_type_base_t     base;
3237         parsed_pointer_t          pointer;
3238         parsed_reference_t        reference;
3239         construct_function_type_t function;
3240         parsed_array_t            array;
3241 };
3242
3243 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3244 {
3245         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3246         memset(cons, 0, size);
3247         cons->kind     = kind;
3248         cons->base.pos = *HERE;
3249         return cons;
3250 }
3251
3252 /* §6.7.5.1 */
3253 static construct_type_t *parse_pointer_declarator(void)
3254 {
3255         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3256         eat('*');
3257         cons->pointer.type_qualifiers = parse_type_qualifiers();
3258         //cons->pointer.base_variable   = base_variable;
3259
3260         return cons;
3261 }
3262
3263 /* ISO/IEC 14882:1998(E) §8.3.2 */
3264 static construct_type_t *parse_reference_declarator(void)
3265 {
3266         if (!(c_mode & _CXX))
3267                 errorf(HERE, "references are only available for C++");
3268
3269         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3270         eat('&');
3271
3272         return cons;
3273 }
3274
3275 /* §6.7.5.2 */
3276 static construct_type_t *parse_array_declarator(void)
3277 {
3278         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3279         parsed_array_t   *const array = &cons->array;
3280
3281         eat('[');
3282         add_anchor_token(']');
3283
3284         bool is_static = next_if(T_static);
3285
3286         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3287
3288         if (!is_static)
3289                 is_static = next_if(T_static);
3290
3291         array->type_qualifiers = type_qualifiers;
3292         array->is_static       = is_static;
3293
3294         expression_t *size = NULL;
3295         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3296                 array->is_variable = true;
3297                 eat('*');
3298         } else if (token.kind != ']') {
3299                 size = parse_assignment_expression();
3300
3301                 /* §6.7.5.2:1  Array size must have integer type */
3302                 type_t *const orig_type = size->base.type;
3303                 type_t *const type      = skip_typeref(orig_type);
3304                 if (!is_type_integer(type) && is_type_valid(type)) {
3305                         errorf(&size->base.source_position,
3306                                "array size '%E' must have integer type but has type '%T'",
3307                                size, orig_type);
3308                 }
3309
3310                 array->size = size;
3311                 mark_vars_read(size, NULL);
3312         }
3313
3314         if (is_static && size == NULL)
3315                 errorf(&array->base.pos, "static array parameters require a size");
3316
3317         rem_anchor_token(']');
3318         expect(']');
3319         return cons;
3320 }
3321
3322 /* §6.7.5.3 */
3323 static construct_type_t *parse_function_declarator(scope_t *scope)
3324 {
3325         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3326
3327         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3328         function_type_t *ftype = &type->function;
3329
3330         ftype->linkage            = current_linkage;
3331         ftype->calling_convention = CC_DEFAULT;
3332
3333         parse_parameters(ftype, scope);
3334
3335         cons->function.function_type = type;
3336
3337         return cons;
3338 }
3339
3340 typedef struct parse_declarator_env_t {
3341         bool               may_be_abstract : 1;
3342         bool               must_be_abstract : 1;
3343         decl_modifiers_t   modifiers;
3344         symbol_t          *symbol;
3345         source_position_t  source_position;
3346         scope_t            parameters;
3347         attribute_t       *attributes;
3348 } parse_declarator_env_t;
3349
3350 /* §6.7.5 */
3351 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3352 {
3353         /* construct a single linked list of construct_type_t's which describe
3354          * how to construct the final declarator type */
3355         construct_type_t  *first      = NULL;
3356         construct_type_t **anchor     = &first;
3357
3358         env->attributes = parse_attributes(env->attributes);
3359
3360         for (;;) {
3361                 construct_type_t *type;
3362                 //variable_t       *based = NULL; /* MS __based extension */
3363                 switch (token.kind) {
3364                         case '&':
3365                                 type = parse_reference_declarator();
3366                                 break;
3367
3368                         case T__based: {
3369                                 panic("based not supported anymore");
3370                                 /* FALLTHROUGH */
3371                         }
3372
3373                         case '*':
3374                                 type = parse_pointer_declarator();
3375                                 break;
3376
3377                         default:
3378                                 goto ptr_operator_end;
3379                 }
3380
3381                 *anchor = type;
3382                 anchor  = &type->base.next;
3383
3384                 /* TODO: find out if this is correct */
3385                 env->attributes = parse_attributes(env->attributes);
3386         }
3387
3388 ptr_operator_end: ;
3389         construct_type_t *inner_types = NULL;
3390
3391         switch (token.kind) {
3392         case T_IDENTIFIER:
3393                 if (env->must_be_abstract) {
3394                         errorf(HERE, "no identifier expected in typename");
3395                 } else {
3396                         env->symbol          = token.base.symbol;
3397                         env->source_position = *HERE;
3398                 }
3399                 eat(T_IDENTIFIER);
3400                 break;
3401
3402         case '(': {
3403                 /* Parenthesized declarator or function declarator? */
3404                 token_t const *const la1 = look_ahead(1);
3405                 switch (la1->kind) {
3406                         case T_IDENTIFIER:
3407                                 if (is_typedef_symbol(la1->base.symbol)) {
3408                         case ')':
3409                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3410                                          * interpreted as ``function with no parameter specification'', rather
3411                                          * than redundant parentheses around the omitted identifier. */
3412                         default:
3413                                         /* Function declarator. */
3414                                         if (!env->may_be_abstract) {
3415                                                 errorf(HERE, "function declarator must have a name");
3416                                         }
3417                                 } else {
3418                         case '&':
3419                         case '(':
3420                         case '*':
3421                         case '[':
3422                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3423                                         /* Paranthesized declarator. */
3424                                         eat('(');
3425                                         add_anchor_token(')');
3426                                         inner_types = parse_inner_declarator(env);
3427                                         if (inner_types != NULL) {
3428                                                 /* All later declarators only modify the return type */
3429                                                 env->must_be_abstract = true;
3430                                         }
3431                                         rem_anchor_token(')');
3432                                         expect(')');
3433                                 }
3434                                 break;
3435                 }
3436                 break;
3437         }
3438
3439         default:
3440                 if (env->may_be_abstract)
3441                         break;
3442                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3443                 eat_until_anchor();
3444                 return NULL;
3445         }
3446
3447         construct_type_t **const p = anchor;
3448
3449         for (;;) {
3450                 construct_type_t *type;
3451                 switch (token.kind) {
3452                 case '(': {
3453                         scope_t *scope = NULL;
3454                         if (!env->must_be_abstract) {
3455                                 scope = &env->parameters;
3456                         }
3457
3458                         type = parse_function_declarator(scope);
3459                         break;
3460                 }
3461                 case '[':
3462                         type = parse_array_declarator();
3463                         break;
3464                 default:
3465                         goto declarator_finished;
3466                 }
3467
3468                 /* insert in the middle of the list (at p) */
3469                 type->base.next = *p;
3470                 *p              = type;
3471                 if (anchor == p)
3472                         anchor = &type->base.next;
3473         }
3474
3475 declarator_finished:
3476         /* append inner_types at the end of the list, we don't to set anchor anymore
3477          * as it's not needed anymore */
3478         *anchor = inner_types;
3479
3480         return first;
3481 }
3482
3483 static type_t *construct_declarator_type(construct_type_t *construct_list,
3484                                          type_t *type)
3485 {
3486         construct_type_t *iter = construct_list;
3487         for (; iter != NULL; iter = iter->base.next) {
3488                 source_position_t const* const pos = &iter->base.pos;
3489                 switch (iter->kind) {
3490                 case CONSTRUCT_FUNCTION: {
3491                         construct_function_type_t *function      = &iter->function;
3492                         type_t                    *function_type = function->function_type;
3493
3494                         function_type->function.return_type = type;
3495
3496                         type_t *skipped_return_type = skip_typeref(type);
3497                         /* §6.7.5.3:1 */
3498                         if (is_type_function(skipped_return_type)) {
3499                                 errorf(pos, "function returning function is not allowed");
3500                         } else if (is_type_array(skipped_return_type)) {
3501                                 errorf(pos, "function returning array is not allowed");
3502                         } else {
3503                                 if (skipped_return_type->base.qualifiers != 0) {
3504                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3505                                 }
3506                         }
3507
3508                         /* The function type was constructed earlier.  Freeing it here will
3509                          * destroy other types. */
3510                         type = typehash_insert(function_type);
3511                         continue;
3512                 }
3513
3514                 case CONSTRUCT_POINTER: {
3515                         if (is_type_reference(skip_typeref(type)))
3516                                 errorf(pos, "cannot declare a pointer to reference");
3517
3518                         parsed_pointer_t *pointer = &iter->pointer;
3519                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3520                         continue;
3521                 }
3522
3523                 case CONSTRUCT_REFERENCE:
3524                         if (is_type_reference(skip_typeref(type)))
3525                                 errorf(pos, "cannot declare a reference to reference");
3526
3527                         type = make_reference_type(type);
3528                         continue;
3529
3530                 case CONSTRUCT_ARRAY: {
3531                         if (is_type_reference(skip_typeref(type)))
3532                                 errorf(pos, "cannot declare an array of references");
3533
3534                         parsed_array_t *array      = &iter->array;
3535                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3536
3537                         expression_t *size_expression = array->size;
3538                         if (size_expression != NULL) {
3539                                 size_expression
3540                                         = create_implicit_cast(size_expression, type_size_t);
3541                         }
3542
3543                         array_type->base.qualifiers       = array->type_qualifiers;
3544                         array_type->array.element_type    = type;
3545                         array_type->array.is_static       = array->is_static;
3546                         array_type->array.is_variable     = array->is_variable;
3547                         array_type->array.size_expression = size_expression;
3548
3549                         if (size_expression != NULL) {
3550                                 switch (is_constant_expression(size_expression)) {
3551                                 case EXPR_CLASS_CONSTANT: {
3552                                         long const size = fold_constant_to_int(size_expression);
3553                                         array_type->array.size          = size;
3554                                         array_type->array.size_constant = true;
3555                                         /* §6.7.5.2:1  If the expression is a constant expression,
3556                                          * it shall have a value greater than zero. */
3557                                         if (size < 0) {
3558                                                 errorf(&size_expression->base.source_position,
3559                                                            "size of array must be greater than zero");
3560                                         } else if (size == 0 && !GNU_MODE) {
3561                                                 errorf(&size_expression->base.source_position,
3562                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3563                                         }
3564                                         break;
3565                                 }
3566
3567                                 case EXPR_CLASS_VARIABLE:
3568                                         array_type->array.is_vla = true;
3569                                         break;
3570
3571                                 case EXPR_CLASS_ERROR:
3572                                         break;
3573                                 }
3574                         }
3575
3576                         type_t *skipped_type = skip_typeref(type);
3577                         /* §6.7.5.2:1 */
3578                         if (is_type_incomplete(skipped_type)) {
3579                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3580                         } else if (is_type_function(skipped_type)) {
3581                                 errorf(pos, "array of functions is not allowed");
3582                         }
3583                         type = identify_new_type(array_type);
3584                         continue;
3585                 }
3586                 }
3587                 internal_errorf(pos, "invalid type construction found");
3588         }
3589
3590         return type;
3591 }
3592
3593 static type_t *automatic_type_conversion(type_t *orig_type);
3594
3595 static type_t *semantic_parameter(const source_position_t *pos,
3596                                   type_t *type,
3597                                   const declaration_specifiers_t *specifiers,
3598                                   entity_t const *const param)
3599 {
3600         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3601          *             shall be adjusted to ``qualified pointer to type'',
3602          *             [...]
3603          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3604          *             type'' shall be adjusted to ``pointer to function
3605          *             returning type'', as in 6.3.2.1. */
3606         type = automatic_type_conversion(type);
3607
3608         if (specifiers->is_inline && is_type_valid(type)) {
3609                 errorf(pos, "'%N' declared 'inline'", param);
3610         }
3611
3612         /* §6.9.1:6  The declarations in the declaration list shall contain
3613          *           no storage-class specifier other than register and no
3614          *           initializations. */
3615         if (specifiers->thread_local || (
3616                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3617                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3618            ) {
3619                 errorf(pos, "invalid storage class for '%N'", param);
3620         }
3621
3622         /* delay test for incomplete type, because we might have (void)
3623          * which is legal but incomplete... */
3624
3625         return type;
3626 }
3627
3628 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3629                                   declarator_flags_t flags)
3630 {
3631         parse_declarator_env_t env;
3632         memset(&env, 0, sizeof(env));
3633         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3634
3635         construct_type_t *construct_type = parse_inner_declarator(&env);
3636         type_t           *orig_type      =
3637                 construct_declarator_type(construct_type, specifiers->type);
3638         type_t           *type           = skip_typeref(orig_type);
3639
3640         if (construct_type != NULL) {
3641                 obstack_free(&temp_obst, construct_type);
3642         }
3643
3644         attribute_t *attributes = parse_attributes(env.attributes);
3645         /* append (shared) specifier attribute behind attributes of this
3646          * declarator */
3647         attribute_t **anchor = &attributes;
3648         while (*anchor != NULL)
3649                 anchor = &(*anchor)->next;
3650         *anchor = specifiers->attributes;
3651
3652         entity_t *entity;
3653         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3654                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3655                 entity->typedefe.type = orig_type;
3656
3657                 if (anonymous_entity != NULL) {
3658                         if (is_type_compound(type)) {
3659                                 assert(anonymous_entity->compound.alias == NULL);
3660                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3661                                        anonymous_entity->kind == ENTITY_UNION);
3662                                 anonymous_entity->compound.alias = entity;
3663                                 anonymous_entity = NULL;
3664                         } else if (is_type_enum(type)) {
3665                                 assert(anonymous_entity->enume.alias == NULL);
3666                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3667                                 anonymous_entity->enume.alias = entity;
3668                                 anonymous_entity = NULL;
3669                         }
3670                 }
3671         } else {
3672                 /* create a declaration type entity */
3673                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3674                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3675                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3676
3677                         if (env.symbol != NULL) {
3678                                 if (specifiers->is_inline && is_type_valid(type)) {
3679                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3680                                 }
3681
3682                                 if (specifiers->thread_local ||
3683                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3684                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3685                                 }
3686                         }
3687                 } else if (flags & DECL_IS_PARAMETER) {
3688                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3689                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3690                 } else if (is_type_function(type)) {
3691                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3692                         entity->function.is_inline      = specifiers->is_inline;
3693                         entity->function.elf_visibility = default_visibility;
3694                         entity->function.parameters     = env.parameters;
3695
3696                         if (env.symbol != NULL) {
3697                                 /* this needs fixes for C++ */
3698                                 bool in_function_scope = current_function != NULL;
3699
3700                                 if (specifiers->thread_local || (
3701                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3702                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3703                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3704                                                 )) {
3705                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3706                                 }
3707                         }
3708                 } else {
3709                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3710                         entity->variable.elf_visibility = default_visibility;
3711                         entity->variable.thread_local   = specifiers->thread_local;
3712
3713                         if (env.symbol != NULL) {
3714                                 if (specifiers->is_inline && is_type_valid(type)) {
3715                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3716                                 }
3717
3718                                 bool invalid_storage_class = false;
3719                                 if (current_scope == file_scope) {
3720                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3721                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3722                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3723                                                 invalid_storage_class = true;
3724                                         }
3725                                 } else {
3726                                         if (specifiers->thread_local &&
3727                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3728                                                 invalid_storage_class = true;
3729                                         }
3730                                 }
3731                                 if (invalid_storage_class) {
3732                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3733                                 }
3734                         }
3735                 }
3736
3737                 entity->declaration.type       = orig_type;
3738                 entity->declaration.alignment  = get_type_alignment(orig_type);
3739                 entity->declaration.modifiers  = env.modifiers;
3740                 entity->declaration.attributes = attributes;
3741
3742                 storage_class_t storage_class = specifiers->storage_class;
3743                 entity->declaration.declared_storage_class = storage_class;
3744
3745                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3746                         storage_class = STORAGE_CLASS_AUTO;
3747                 entity->declaration.storage_class = storage_class;
3748         }
3749
3750         if (attributes != NULL) {
3751                 handle_entity_attributes(attributes, entity);
3752         }
3753
3754         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3755                 adapt_special_functions(&entity->function);
3756         }
3757
3758         return entity;
3759 }
3760
3761 static type_t *parse_abstract_declarator(type_t *base_type)
3762 {
3763         parse_declarator_env_t env;
3764         memset(&env, 0, sizeof(env));
3765         env.may_be_abstract = true;
3766         env.must_be_abstract = true;
3767
3768         construct_type_t *construct_type = parse_inner_declarator(&env);
3769
3770         type_t *result = construct_declarator_type(construct_type, base_type);
3771         if (construct_type != NULL) {
3772                 obstack_free(&temp_obst, construct_type);
3773         }
3774         result = handle_type_attributes(env.attributes, result);
3775
3776         return result;
3777 }
3778
3779 /**
3780  * Check if the declaration of main is suspicious.  main should be a
3781  * function with external linkage, returning int, taking either zero
3782  * arguments, two, or three arguments of appropriate types, ie.
3783  *
3784  * int main([ int argc, char **argv [, char **env ] ]).
3785  *
3786  * @param decl    the declaration to check
3787  * @param type    the function type of the declaration
3788  */
3789 static void check_main(const entity_t *entity)
3790 {
3791         const source_position_t *pos = &entity->base.source_position;
3792         if (entity->kind != ENTITY_FUNCTION) {
3793                 warningf(WARN_MAIN, pos, "'main' is not a function");
3794                 return;
3795         }
3796
3797         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3798                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3799         }
3800
3801         type_t *type = skip_typeref(entity->declaration.type);
3802         assert(is_type_function(type));
3803
3804         function_type_t const *const func_type = &type->function;
3805         type_t                *const ret_type  = func_type->return_type;
3806         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3807                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3808         }
3809         const function_parameter_t *parm = func_type->parameters;
3810         if (parm != NULL) {
3811                 type_t *const first_type        = skip_typeref(parm->type);
3812                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3813                 if (!types_compatible(first_type_unqual, type_int)) {
3814                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3815                 }
3816                 parm = parm->next;
3817                 if (parm != NULL) {
3818                         type_t *const second_type = skip_typeref(parm->type);
3819                         type_t *const second_type_unqual
3820                                 = get_unqualified_type(second_type);
3821                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3822                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3823                         }
3824                         parm = parm->next;
3825                         if (parm != NULL) {
3826                                 type_t *const third_type = skip_typeref(parm->type);
3827                                 type_t *const third_type_unqual
3828                                         = get_unqualified_type(third_type);
3829                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3830                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3831                                 }
3832                                 parm = parm->next;
3833                                 if (parm != NULL)
3834                                         goto warn_arg_count;
3835                         }
3836                 } else {
3837 warn_arg_count:
3838                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3839                 }
3840         }
3841 }
3842
3843 static void error_redefined_as_different_kind(const source_position_t *pos,
3844                 const entity_t *old, entity_kind_t new_kind)
3845 {
3846         char              const *const what = get_entity_kind_name(new_kind);
3847         source_position_t const *const ppos = &old->base.source_position;
3848         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3849 }
3850
3851 static bool is_entity_valid(entity_t *const ent)
3852 {
3853         if (is_declaration(ent)) {
3854                 return is_type_valid(skip_typeref(ent->declaration.type));
3855         } else if (ent->kind == ENTITY_TYPEDEF) {
3856                 return is_type_valid(skip_typeref(ent->typedefe.type));
3857         }
3858         return true;
3859 }
3860
3861 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3862 {
3863         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3864                 if (attributes_equal(tattr, attr))
3865                         return true;
3866         }
3867         return false;
3868 }
3869
3870 /**
3871  * test wether new_list contains any attributes not included in old_list
3872  */
3873 static bool has_new_attributes(const attribute_t *old_list,
3874                                const attribute_t *new_list)
3875 {
3876         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3877                 if (!contains_attribute(old_list, attr))
3878                         return true;
3879         }
3880         return false;
3881 }
3882
3883 /**
3884  * Merge in attributes from an attribute list (probably from a previous
3885  * declaration with the same name). Warning: destroys the old structure
3886  * of the attribute list - don't reuse attributes after this call.
3887  */
3888 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3889 {
3890         attribute_t *next;
3891         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3892                 next = attr->next;
3893                 if (contains_attribute(decl->attributes, attr))
3894                         continue;
3895
3896                 /* move attribute to new declarations attributes list */
3897                 attr->next       = decl->attributes;
3898                 decl->attributes = attr;
3899         }
3900 }
3901
3902 static bool is_main(entity_t*);
3903
3904 /**
3905  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3906  * for various problems that occur for multiple definitions
3907  */
3908 entity_t *record_entity(entity_t *entity, const bool is_definition)
3909 {
3910         const symbol_t *const    symbol  = entity->base.symbol;
3911         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3912         const source_position_t *pos     = &entity->base.source_position;
3913
3914         /* can happen in error cases */
3915         if (symbol == NULL)
3916                 return entity;
3917
3918         assert(!entity->base.parent_scope);
3919         assert(current_scope);
3920         entity->base.parent_scope = current_scope;
3921
3922         entity_t *const previous_entity = get_entity(symbol, namespc);
3923         /* pushing the same entity twice will break the stack structure */
3924         assert(previous_entity != entity);
3925
3926         if (entity->kind == ENTITY_FUNCTION) {
3927                 type_t *const orig_type = entity->declaration.type;
3928                 type_t *const type      = skip_typeref(orig_type);
3929
3930                 assert(is_type_function(type));
3931                 if (type->function.unspecified_parameters &&
3932                     previous_entity == NULL               &&
3933                     !entity->declaration.implicit) {
3934                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3935                 }
3936
3937                 if (is_main(entity)) {
3938                         check_main(entity);
3939                 }
3940         }
3941
3942         if (is_declaration(entity)                                    &&
3943             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3944             current_scope != file_scope                               &&
3945             !entity->declaration.implicit) {
3946                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3947         }
3948
3949         if (previous_entity != NULL) {
3950                 source_position_t const *const ppos = &previous_entity->base.source_position;
3951
3952                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3953                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3954                         assert(previous_entity->kind == ENTITY_PARAMETER);
3955                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3956                         goto finish;
3957                 }
3958
3959                 if (previous_entity->base.parent_scope == current_scope) {
3960                         if (previous_entity->kind != entity->kind) {
3961                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3962                                         error_redefined_as_different_kind(pos, previous_entity,
3963                                                         entity->kind);
3964                                 }
3965                                 goto finish;
3966                         }
3967                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3968                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3969                                 goto finish;
3970                         }
3971                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3972                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3973                                 type_t *const prev_type
3974                                         = skip_typeref(previous_entity->typedefe.type);
3975                                 if (c_mode & _CXX) {
3976                                         /* C++ allows double typedef if they are identical
3977                                          * (after skipping typedefs) */
3978                                         if (type == prev_type)
3979                                                 goto finish;
3980                                 } else {
3981                                         /* GCC extension: redef in system headers is allowed */
3982                                         if ((pos->is_system_header || ppos->is_system_header) &&
3983                                             types_compatible(type, prev_type))
3984                                                 goto finish;
3985                                 }
3986                                 errorf(pos, "redefinition of '%N' (declared %P)",
3987                                        entity, ppos);
3988                                 goto finish;
3989                         }
3990
3991                         /* at this point we should have only VARIABLES or FUNCTIONS */
3992                         assert(is_declaration(previous_entity) && is_declaration(entity));
3993
3994                         declaration_t *const prev_decl = &previous_entity->declaration;
3995                         declaration_t *const decl      = &entity->declaration;
3996
3997                         /* can happen for K&R style declarations */
3998                         if (prev_decl->type       == NULL             &&
3999                                         previous_entity->kind == ENTITY_PARAMETER &&
4000                                         entity->kind          == ENTITY_PARAMETER) {
4001                                 prev_decl->type                   = decl->type;
4002                                 prev_decl->storage_class          = decl->storage_class;
4003                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4004                                 prev_decl->modifiers              = decl->modifiers;
4005                                 return previous_entity;
4006                         }
4007
4008                         type_t *const type      = skip_typeref(decl->type);
4009                         type_t *const prev_type = skip_typeref(prev_decl->type);
4010
4011                         if (!types_compatible(type, prev_type)) {
4012                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4013                         } else {
4014                                 unsigned old_storage_class = prev_decl->storage_class;
4015
4016                                 if (is_definition                     &&
4017                                                 !prev_decl->used                  &&
4018                                                 !(prev_decl->modifiers & DM_USED) &&
4019                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4020                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4021                                 }
4022
4023                                 storage_class_t new_storage_class = decl->storage_class;
4024
4025                                 /* pretend no storage class means extern for function
4026                                  * declarations (except if the previous declaration is neither
4027                                  * none nor extern) */
4028                                 if (entity->kind == ENTITY_FUNCTION) {
4029                                         /* the previous declaration could have unspecified parameters or
4030                                          * be a typedef, so use the new type */
4031                                         if (prev_type->function.unspecified_parameters || is_definition)
4032                                                 prev_decl->type = type;
4033
4034                                         switch (old_storage_class) {
4035                                                 case STORAGE_CLASS_NONE:
4036                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4037                                                         /* FALLTHROUGH */
4038
4039                                                 case STORAGE_CLASS_EXTERN:
4040                                                         if (is_definition) {
4041                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4042                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4043                                                                 }
4044                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4045                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4046                                                         }
4047                                                         break;
4048
4049                                                 default:
4050                                                         break;
4051                                         }
4052                                 } else if (is_type_incomplete(prev_type)) {
4053                                         prev_decl->type = type;
4054                                 }
4055
4056                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4057                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4058
4059 warn_redundant_declaration: ;
4060                                         bool has_new_attrs
4061                                                 = has_new_attributes(prev_decl->attributes,
4062                                                                      decl->attributes);
4063                                         if (has_new_attrs) {
4064                                                 merge_in_attributes(decl, prev_decl->attributes);
4065                                         } else if (!is_definition        &&
4066                                                         is_type_valid(prev_type) &&
4067                                                         !pos->is_system_header) {
4068                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4069                                         }
4070                                 } else if (current_function == NULL) {
4071                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4072                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4073                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4074                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4075                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4076                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4077                                         } else {
4078                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4079                                                 if (c_mode & _CXX)
4080                                                         goto error_redeclaration;
4081                                                 goto warn_redundant_declaration;
4082                                         }
4083                                 } else if (is_type_valid(prev_type)) {
4084                                         if (old_storage_class == new_storage_class) {
4085 error_redeclaration:
4086                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4087                                         } else {
4088                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4089                                         }
4090                                 }
4091                         }
4092
4093                         prev_decl->modifiers |= decl->modifiers;
4094                         if (entity->kind == ENTITY_FUNCTION) {
4095                                 previous_entity->function.is_inline |= entity->function.is_inline;
4096                         }
4097                         return previous_entity;
4098                 }
4099
4100                 warning_t why;
4101                 if (is_warn_on(why = WARN_SHADOW) ||
4102                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4103                         char const *const what = get_entity_kind_name(previous_entity->kind);
4104                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4105                 }
4106         }
4107
4108         if (entity->kind == ENTITY_FUNCTION) {
4109                 if (is_definition &&
4110                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4111                                 !is_main(entity)) {
4112                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4113                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4114                         } else {
4115                                 goto warn_missing_declaration;
4116                         }
4117                 }
4118         } else if (entity->kind == ENTITY_VARIABLE) {
4119                 if (current_scope                     == file_scope &&
4120                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4121                                 !entity->declaration.implicit) {
4122 warn_missing_declaration:
4123                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4124                 }
4125         }
4126
4127 finish:
4128         environment_push(entity);
4129         append_entity(current_scope, entity);
4130
4131         return entity;
4132 }
4133
4134 static void parser_error_multiple_definition(entity_t *entity,
4135                 const source_position_t *source_position)
4136 {
4137         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4138 }
4139
4140 static bool is_declaration_specifier(const token_t *token)
4141 {
4142         switch (token->kind) {
4143                 DECLARATION_START
4144                         return true;
4145                 case T_IDENTIFIER:
4146                         return is_typedef_symbol(token->base.symbol);
4147
4148                 default:
4149                         return false;
4150         }
4151 }
4152
4153 static void parse_init_declarator_rest(entity_t *entity)
4154 {
4155         type_t *orig_type = type_error_type;
4156
4157         if (entity->base.kind == ENTITY_TYPEDEF) {
4158                 source_position_t const *const pos = &entity->base.source_position;
4159                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4160         } else {
4161                 assert(is_declaration(entity));
4162                 orig_type = entity->declaration.type;
4163         }
4164
4165         type_t *type = skip_typeref(orig_type);
4166
4167         if (entity->kind == ENTITY_VARIABLE
4168                         && entity->variable.initializer != NULL) {
4169                 parser_error_multiple_definition(entity, HERE);
4170         }
4171         eat('=');
4172
4173         declaration_t *const declaration = &entity->declaration;
4174         bool must_be_constant = false;
4175         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4176             entity->base.parent_scope  == file_scope) {
4177                 must_be_constant = true;
4178         }
4179
4180         if (is_type_function(type)) {
4181                 source_position_t const *const pos = &entity->base.source_position;
4182                 errorf(pos, "'%N' is initialized like a variable", entity);
4183                 orig_type = type_error_type;
4184         }
4185
4186         parse_initializer_env_t env;
4187         env.type             = orig_type;
4188         env.must_be_constant = must_be_constant;
4189         env.entity           = entity;
4190
4191         initializer_t *initializer = parse_initializer(&env);
4192
4193         if (entity->kind == ENTITY_VARIABLE) {
4194                 /* §6.7.5:22  array initializers for arrays with unknown size
4195                  * determine the array type size */
4196                 declaration->type            = env.type;
4197                 entity->variable.initializer = initializer;
4198         }
4199 }
4200
4201 /* parse rest of a declaration without any declarator */
4202 static void parse_anonymous_declaration_rest(
4203                 const declaration_specifiers_t *specifiers)
4204 {
4205         eat(';');
4206         anonymous_entity = NULL;
4207
4208         source_position_t const *const pos = &specifiers->source_position;
4209         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4210                         specifiers->thread_local) {
4211                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4212         }
4213
4214         type_t *type = specifiers->type;
4215         switch (type->kind) {
4216                 case TYPE_COMPOUND_STRUCT:
4217                 case TYPE_COMPOUND_UNION: {
4218                         if (type->compound.compound->base.symbol == NULL) {
4219                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4220                         }
4221                         break;
4222                 }
4223
4224                 case TYPE_ENUM:
4225                         break;
4226
4227                 default:
4228                         warningf(WARN_OTHER, pos, "empty declaration");
4229                         break;
4230         }
4231 }
4232
4233 static void check_variable_type_complete(entity_t *ent)
4234 {
4235         if (ent->kind != ENTITY_VARIABLE)
4236                 return;
4237
4238         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4239          *         type for the object shall be complete [...] */
4240         declaration_t *decl = &ent->declaration;
4241         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4242                         decl->storage_class == STORAGE_CLASS_STATIC)
4243                 return;
4244
4245         type_t *const type = skip_typeref(decl->type);
4246         if (!is_type_incomplete(type))
4247                 return;
4248
4249         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4250          * are given length one. */
4251         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4252                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4253                 return;
4254         }
4255
4256         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4257 }
4258
4259
4260 static void parse_declaration_rest(entity_t *ndeclaration,
4261                 const declaration_specifiers_t *specifiers,
4262                 parsed_declaration_func         finished_declaration,
4263                 declarator_flags_t              flags)
4264 {
4265         add_anchor_token(';');
4266         add_anchor_token(',');
4267         while (true) {
4268                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4269
4270                 if (token.kind == '=') {
4271                         parse_init_declarator_rest(entity);
4272                 } else if (entity->kind == ENTITY_VARIABLE) {
4273                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4274                          * [...] where the extern specifier is explicitly used. */
4275                         declaration_t *decl = &entity->declaration;
4276                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4277                             is_type_reference(skip_typeref(decl->type))) {
4278                                 source_position_t const *const pos = &entity->base.source_position;
4279                                 errorf(pos, "reference '%#N' must be initialized", entity);
4280                         }
4281                 }
4282
4283                 check_variable_type_complete(entity);
4284
4285                 if (!next_if(','))
4286                         break;
4287
4288                 add_anchor_token('=');
4289                 ndeclaration = parse_declarator(specifiers, flags);
4290                 rem_anchor_token('=');
4291         }
4292         rem_anchor_token(',');
4293         rem_anchor_token(';');
4294         expect(';');
4295
4296         anonymous_entity = NULL;
4297 }
4298
4299 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4300 {
4301         symbol_t *symbol = entity->base.symbol;
4302         if (symbol == NULL)
4303                 return entity;
4304
4305         assert(entity->base.namespc == NAMESPACE_NORMAL);
4306         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4307         if (previous_entity == NULL
4308                         || previous_entity->base.parent_scope != current_scope) {
4309                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4310                        symbol);
4311                 return entity;
4312         }
4313
4314         if (is_definition) {
4315                 errorf(HERE, "'%N' is initialised", entity);
4316         }
4317
4318         return record_entity(entity, false);
4319 }
4320
4321 static void parse_declaration(parsed_declaration_func finished_declaration,
4322                               declarator_flags_t      flags)
4323 {
4324         add_anchor_token(';');
4325         declaration_specifiers_t specifiers;
4326         parse_declaration_specifiers(&specifiers);
4327         rem_anchor_token(';');
4328
4329         if (token.kind == ';') {
4330                 parse_anonymous_declaration_rest(&specifiers);
4331         } else {
4332                 entity_t *entity = parse_declarator(&specifiers, flags);
4333                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4334         }
4335 }
4336
4337 /* §6.5.2.2:6 */
4338 static type_t *get_default_promoted_type(type_t *orig_type)
4339 {
4340         type_t *result = orig_type;
4341
4342         type_t *type = skip_typeref(orig_type);
4343         if (is_type_integer(type)) {
4344                 result = promote_integer(type);
4345         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4346                 result = type_double;
4347         }
4348
4349         return result;
4350 }
4351
4352 static void parse_kr_declaration_list(entity_t *entity)
4353 {
4354         if (entity->kind != ENTITY_FUNCTION)
4355                 return;
4356
4357         type_t *type = skip_typeref(entity->declaration.type);
4358         assert(is_type_function(type));
4359         if (!type->function.kr_style_parameters)
4360                 return;
4361
4362         add_anchor_token('{');
4363
4364         PUSH_SCOPE(&entity->function.parameters);
4365
4366         entity_t *parameter = entity->function.parameters.entities;
4367         for ( ; parameter != NULL; parameter = parameter->base.next) {
4368                 assert(parameter->base.parent_scope == NULL);
4369                 parameter->base.parent_scope = current_scope;
4370                 environment_push(parameter);
4371         }
4372
4373         /* parse declaration list */
4374         for (;;) {
4375                 switch (token.kind) {
4376                         DECLARATION_START
4377                         /* This covers symbols, which are no type, too, and results in
4378                          * better error messages.  The typical cases are misspelled type
4379                          * names and missing includes. */
4380                         case T_IDENTIFIER:
4381                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4382                                 break;
4383                         default:
4384                                 goto decl_list_end;
4385                 }
4386         }
4387 decl_list_end:
4388
4389         POP_SCOPE();
4390
4391         /* update function type */
4392         type_t *new_type = duplicate_type(type);
4393
4394         function_parameter_t  *parameters = NULL;
4395         function_parameter_t **anchor     = &parameters;
4396
4397         /* did we have an earlier prototype? */
4398         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4399         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4400                 proto_type = NULL;
4401
4402         function_parameter_t *proto_parameter = NULL;
4403         if (proto_type != NULL) {
4404                 type_t *proto_type_type = proto_type->declaration.type;
4405                 proto_parameter         = proto_type_type->function.parameters;
4406                 /* If a K&R function definition has a variadic prototype earlier, then
4407                  * make the function definition variadic, too. This should conform to
4408                  * §6.7.5.3:15 and §6.9.1:8. */
4409                 new_type->function.variadic = proto_type_type->function.variadic;
4410         } else {
4411                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4412                  * prototype */
4413                 new_type->function.unspecified_parameters = true;
4414         }
4415
4416         bool need_incompatible_warning = false;
4417         parameter = entity->function.parameters.entities;
4418         for (; parameter != NULL; parameter = parameter->base.next,
4419                         proto_parameter =
4420                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4421                 if (parameter->kind != ENTITY_PARAMETER)
4422                         continue;
4423
4424                 type_t *parameter_type = parameter->declaration.type;
4425                 if (parameter_type == NULL) {
4426                         source_position_t const* const pos = &parameter->base.source_position;
4427                         if (strict_mode) {
4428                                 errorf(pos, "no type specified for function '%N'", parameter);
4429                                 parameter_type = type_error_type;
4430                         } else {
4431                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4432                                 parameter_type = type_int;
4433                         }
4434                         parameter->declaration.type = parameter_type;
4435                 }
4436
4437                 semantic_parameter_incomplete(parameter);
4438
4439                 /* we need the default promoted types for the function type */
4440                 type_t *not_promoted = parameter_type;
4441                 parameter_type       = get_default_promoted_type(parameter_type);
4442
4443                 /* gcc special: if the type of the prototype matches the unpromoted
4444                  * type don't promote */
4445                 if (!strict_mode && proto_parameter != NULL) {
4446                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4447                         type_t *promo_skip   = skip_typeref(parameter_type);
4448                         type_t *param_skip   = skip_typeref(not_promoted);
4449                         if (!types_compatible(proto_p_type, promo_skip)
4450                                 && types_compatible(proto_p_type, param_skip)) {
4451                                 /* don't promote */
4452                                 need_incompatible_warning = true;
4453                                 parameter_type = not_promoted;
4454                         }
4455                 }
4456                 function_parameter_t *const function_parameter
4457                         = allocate_parameter(parameter_type);
4458
4459                 *anchor = function_parameter;
4460                 anchor  = &function_parameter->next;
4461         }
4462
4463         new_type->function.parameters = parameters;
4464         new_type = identify_new_type(new_type);
4465
4466         if (need_incompatible_warning) {
4467                 symbol_t          const *const sym  = entity->base.symbol;
4468                 source_position_t const *const pos  = &entity->base.source_position;
4469                 source_position_t const *const ppos = &proto_type->base.source_position;
4470                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4471         }
4472         entity->declaration.type = new_type;
4473
4474         rem_anchor_token('{');
4475 }
4476
4477 static bool first_err = true;
4478
4479 /**
4480  * When called with first_err set, prints the name of the current function,
4481  * else does noting.
4482  */
4483 static void print_in_function(void)
4484 {
4485         if (first_err) {
4486                 first_err = false;
4487                 char const *const file = current_function->base.base.source_position.input_name;
4488                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4489         }
4490 }
4491
4492 /**
4493  * Check if all labels are defined in the current function.
4494  * Check if all labels are used in the current function.
4495  */
4496 static void check_labels(void)
4497 {
4498         for (const goto_statement_t *goto_statement = goto_first;
4499             goto_statement != NULL;
4500             goto_statement = goto_statement->next) {
4501                 label_t *label = goto_statement->label;
4502                 if (label->base.source_position.input_name == NULL) {
4503                         print_in_function();
4504                         source_position_t const *const pos = &goto_statement->base.source_position;
4505                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4506                  }
4507         }
4508
4509         if (is_warn_on(WARN_UNUSED_LABEL)) {
4510                 for (const label_statement_t *label_statement = label_first;
4511                          label_statement != NULL;
4512                          label_statement = label_statement->next) {
4513                         label_t *label = label_statement->label;
4514
4515                         if (! label->used) {
4516                                 print_in_function();
4517                                 source_position_t const *const pos = &label_statement->base.source_position;
4518                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4519                         }
4520                 }
4521         }
4522 }
4523
4524 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4525 {
4526         entity_t const *const end = last != NULL ? last->base.next : NULL;
4527         for (; entity != end; entity = entity->base.next) {
4528                 if (!is_declaration(entity))
4529                         continue;
4530
4531                 declaration_t *declaration = &entity->declaration;
4532                 if (declaration->implicit)
4533                         continue;
4534
4535                 if (!declaration->used) {
4536                         print_in_function();
4537                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4538                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4539                         print_in_function();
4540                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4541                 }
4542         }
4543 }
4544
4545 static void check_unused_variables(statement_t *const stmt, void *const env)
4546 {
4547         (void)env;
4548
4549         switch (stmt->kind) {
4550                 case STATEMENT_DECLARATION: {
4551                         declaration_statement_t const *const decls = &stmt->declaration;
4552                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4553                         return;
4554                 }
4555
4556                 case STATEMENT_FOR:
4557                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4558                         return;
4559
4560                 default:
4561                         return;
4562         }
4563 }
4564
4565 /**
4566  * Check declarations of current_function for unused entities.
4567  */
4568 static void check_declarations(void)
4569 {
4570         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4571                 const scope_t *scope = &current_function->parameters;
4572                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4573         }
4574         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4575                 walk_statements(current_function->statement, check_unused_variables,
4576                                 NULL);
4577         }
4578 }
4579
4580 static int determine_truth(expression_t const* const cond)
4581 {
4582         return
4583                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4584                 fold_constant_to_bool(cond)                         ? 1 :
4585                 -1;
4586 }
4587
4588 static void check_reachable(statement_t *);
4589 static bool reaches_end;
4590
4591 static bool expression_returns(expression_t const *const expr)
4592 {
4593         switch (expr->kind) {
4594                 case EXPR_CALL: {
4595                         expression_t const *const func = expr->call.function;
4596                         type_t       const *const type = skip_typeref(func->base.type);
4597                         if (type->kind == TYPE_POINTER) {
4598                                 type_t const *const points_to
4599                                         = skip_typeref(type->pointer.points_to);
4600                                 if (points_to->kind == TYPE_FUNCTION
4601                                     && points_to->function.modifiers & DM_NORETURN)
4602                                         return false;
4603                         }
4604
4605                         if (!expression_returns(func))
4606                                 return false;
4607
4608                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4609                                 if (!expression_returns(arg->expression))
4610                                         return false;
4611                         }
4612
4613                         return true;
4614                 }
4615
4616                 case EXPR_REFERENCE:
4617                 case EXPR_ENUM_CONSTANT:
4618                 case EXPR_LITERAL_CASES:
4619                 case EXPR_LITERAL_CHARACTER:
4620                 case EXPR_STRING_LITERAL:
4621                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4622                 case EXPR_LABEL_ADDRESS:
4623                 case EXPR_CLASSIFY_TYPE:
4624                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4625                 case EXPR_ALIGNOF:
4626                 case EXPR_FUNCNAME:
4627                 case EXPR_BUILTIN_CONSTANT_P:
4628                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4629                 case EXPR_OFFSETOF:
4630                 case EXPR_ERROR:
4631                         return true;
4632
4633                 case EXPR_STATEMENT: {
4634                         bool old_reaches_end = reaches_end;
4635                         reaches_end = false;
4636                         check_reachable(expr->statement.statement);
4637                         bool returns = reaches_end;
4638                         reaches_end = old_reaches_end;
4639                         return returns;
4640                 }
4641
4642                 case EXPR_CONDITIONAL:
4643                         // TODO handle constant expression
4644
4645                         if (!expression_returns(expr->conditional.condition))
4646                                 return false;
4647
4648                         if (expr->conditional.true_expression != NULL
4649                                         && expression_returns(expr->conditional.true_expression))
4650                                 return true;
4651
4652                         return expression_returns(expr->conditional.false_expression);
4653
4654                 case EXPR_SELECT:
4655                         return expression_returns(expr->select.compound);
4656
4657                 case EXPR_ARRAY_ACCESS:
4658                         return
4659                                 expression_returns(expr->array_access.array_ref) &&
4660                                 expression_returns(expr->array_access.index);
4661
4662                 case EXPR_VA_START:
4663                         return expression_returns(expr->va_starte.ap);
4664
4665                 case EXPR_VA_ARG:
4666                         return expression_returns(expr->va_arge.ap);
4667
4668                 case EXPR_VA_COPY:
4669                         return expression_returns(expr->va_copye.src);
4670
4671                 case EXPR_UNARY_CASES_MANDATORY:
4672                         return expression_returns(expr->unary.value);
4673
4674                 case EXPR_UNARY_THROW:
4675                         return false;
4676
4677                 case EXPR_BINARY_CASES:
4678                         // TODO handle constant lhs of && and ||
4679                         return
4680                                 expression_returns(expr->binary.left) &&
4681                                 expression_returns(expr->binary.right);
4682         }
4683
4684         panic("unhandled expression");
4685 }
4686
4687 static bool initializer_returns(initializer_t const *const init)
4688 {
4689         switch (init->kind) {
4690                 case INITIALIZER_VALUE:
4691                         return expression_returns(init->value.value);
4692
4693                 case INITIALIZER_LIST: {
4694                         initializer_t * const*       i       = init->list.initializers;
4695                         initializer_t * const* const end     = i + init->list.len;
4696                         bool                         returns = true;
4697                         for (; i != end; ++i) {
4698                                 if (!initializer_returns(*i))
4699                                         returns = false;
4700                         }
4701                         return returns;
4702                 }
4703
4704                 case INITIALIZER_STRING:
4705                 case INITIALIZER_DESIGNATOR: // designators have no payload
4706                         return true;
4707         }
4708         panic("unhandled initializer");
4709 }
4710
4711 static bool noreturn_candidate;
4712
4713 static void check_reachable(statement_t *const stmt)
4714 {
4715         if (stmt->base.reachable)
4716                 return;
4717         if (stmt->kind != STATEMENT_DO_WHILE)
4718                 stmt->base.reachable = true;
4719
4720         statement_t *last = stmt;
4721         statement_t *next;
4722         switch (stmt->kind) {
4723                 case STATEMENT_ERROR:
4724                 case STATEMENT_EMPTY:
4725                 case STATEMENT_ASM:
4726                         next = stmt->base.next;
4727                         break;
4728
4729                 case STATEMENT_DECLARATION: {
4730                         declaration_statement_t const *const decl = &stmt->declaration;
4731                         entity_t                const *      ent  = decl->declarations_begin;
4732                         entity_t                const *const last_decl = decl->declarations_end;
4733                         if (ent != NULL) {
4734                                 for (;; ent = ent->base.next) {
4735                                         if (ent->kind                 == ENTITY_VARIABLE &&
4736                                             ent->variable.initializer != NULL            &&
4737                                             !initializer_returns(ent->variable.initializer)) {
4738                                                 return;
4739                                         }
4740                                         if (ent == last_decl)
4741                                                 break;
4742                                 }
4743                         }
4744                         next = stmt->base.next;
4745                         break;
4746                 }
4747
4748                 case STATEMENT_COMPOUND:
4749                         next = stmt->compound.statements;
4750                         if (next == NULL)
4751                                 next = stmt->base.next;
4752                         break;
4753
4754                 case STATEMENT_RETURN: {
4755                         expression_t const *const val = stmt->returns.value;
4756                         if (val == NULL || expression_returns(val))
4757                                 noreturn_candidate = false;
4758                         return;
4759                 }
4760
4761                 case STATEMENT_IF: {
4762                         if_statement_t const *const ifs  = &stmt->ifs;
4763                         expression_t   const *const cond = ifs->condition;
4764
4765                         if (!expression_returns(cond))
4766                                 return;
4767
4768                         int const val = determine_truth(cond);
4769
4770                         if (val >= 0)
4771                                 check_reachable(ifs->true_statement);
4772
4773                         if (val > 0)
4774                                 return;
4775
4776                         if (ifs->false_statement != NULL) {
4777                                 check_reachable(ifs->false_statement);
4778                                 return;
4779                         }
4780
4781                         next = stmt->base.next;
4782                         break;
4783                 }
4784
4785                 case STATEMENT_SWITCH: {
4786                         switch_statement_t const *const switchs = &stmt->switchs;
4787                         expression_t       const *const expr    = switchs->expression;
4788
4789                         if (!expression_returns(expr))
4790                                 return;
4791
4792                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4793                                 long                    const val      = fold_constant_to_int(expr);
4794                                 case_label_statement_t *      defaults = NULL;
4795                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4796                                         if (i->expression == NULL) {
4797                                                 defaults = i;
4798                                                 continue;
4799                                         }
4800
4801                                         if (i->first_case <= val && val <= i->last_case) {
4802                                                 check_reachable((statement_t*)i);
4803                                                 return;
4804                                         }
4805                                 }
4806
4807                                 if (defaults != NULL) {
4808                                         check_reachable((statement_t*)defaults);
4809                                         return;
4810                                 }
4811                         } else {
4812                                 bool has_default = false;
4813                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4814                                         if (i->expression == NULL)
4815                                                 has_default = true;
4816
4817                                         check_reachable((statement_t*)i);
4818                                 }
4819
4820                                 if (has_default)
4821                                         return;
4822                         }
4823
4824                         next = stmt->base.next;
4825                         break;
4826                 }
4827
4828                 case STATEMENT_EXPRESSION: {
4829                         /* Check for noreturn function call */
4830                         expression_t const *const expr = stmt->expression.expression;
4831                         if (!expression_returns(expr))
4832                                 return;
4833
4834                         next = stmt->base.next;
4835                         break;
4836                 }
4837
4838                 case STATEMENT_CONTINUE:
4839                         for (statement_t *parent = stmt;;) {
4840                                 parent = parent->base.parent;
4841                                 if (parent == NULL) /* continue not within loop */
4842                                         return;
4843
4844                                 next = parent;
4845                                 switch (parent->kind) {
4846                                         case STATEMENT_WHILE:    goto continue_while;
4847                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4848                                         case STATEMENT_FOR:      goto continue_for;
4849
4850                                         default: break;
4851                                 }
4852                         }
4853
4854                 case STATEMENT_BREAK:
4855                         for (statement_t *parent = stmt;;) {
4856                                 parent = parent->base.parent;
4857                                 if (parent == NULL) /* break not within loop/switch */
4858                                         return;
4859
4860                                 switch (parent->kind) {
4861                                         case STATEMENT_SWITCH:
4862                                         case STATEMENT_WHILE:
4863                                         case STATEMENT_DO_WHILE:
4864                                         case STATEMENT_FOR:
4865                                                 last = parent;
4866                                                 next = parent->base.next;
4867                                                 goto found_break_parent;
4868
4869                                         default: break;
4870                                 }
4871                         }
4872 found_break_parent:
4873                         break;
4874
4875                 case STATEMENT_COMPUTED_GOTO: {
4876                         if (!expression_returns(stmt->computed_goto.expression))
4877                                 return;
4878
4879                         statement_t *parent = stmt->base.parent;
4880                         if (parent == NULL) /* top level goto */
4881                                 return;
4882                         next = parent;
4883                         break;
4884                 }
4885
4886                 case STATEMENT_GOTO:
4887                         next = stmt->gotos.label->statement;
4888                         if (next == NULL) /* missing label */
4889                                 return;
4890                         break;
4891
4892                 case STATEMENT_LABEL:
4893                         next = stmt->label.statement;
4894                         break;
4895
4896                 case STATEMENT_CASE_LABEL:
4897                         next = stmt->case_label.statement;
4898                         break;
4899
4900                 case STATEMENT_WHILE: {
4901                         while_statement_t const *const whiles = &stmt->whiles;
4902                         expression_t      const *const cond   = whiles->condition;
4903
4904                         if (!expression_returns(cond))
4905                                 return;
4906
4907                         int const val = determine_truth(cond);
4908
4909                         if (val >= 0)
4910                                 check_reachable(whiles->body);
4911
4912                         if (val > 0)
4913                                 return;
4914
4915                         next = stmt->base.next;
4916                         break;
4917                 }
4918
4919                 case STATEMENT_DO_WHILE:
4920                         next = stmt->do_while.body;
4921                         break;
4922
4923                 case STATEMENT_FOR: {
4924                         for_statement_t *const fors = &stmt->fors;
4925
4926                         if (fors->condition_reachable)
4927                                 return;
4928                         fors->condition_reachable = true;
4929
4930                         expression_t const *const cond = fors->condition;
4931
4932                         int val;
4933                         if (cond == NULL) {
4934                                 val = 1;
4935                         } else if (expression_returns(cond)) {
4936                                 val = determine_truth(cond);
4937                         } else {
4938                                 return;
4939                         }
4940
4941                         if (val >= 0)
4942                                 check_reachable(fors->body);
4943
4944                         if (val > 0)
4945                                 return;
4946
4947                         next = stmt->base.next;
4948                         break;
4949                 }
4950
4951                 case STATEMENT_MS_TRY: {
4952                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4953                         check_reachable(ms_try->try_statement);
4954                         next = ms_try->final_statement;
4955                         break;
4956                 }
4957
4958                 case STATEMENT_LEAVE: {
4959                         statement_t *parent = stmt;
4960                         for (;;) {
4961                                 parent = parent->base.parent;
4962                                 if (parent == NULL) /* __leave not within __try */
4963                                         return;
4964
4965                                 if (parent->kind == STATEMENT_MS_TRY) {
4966                                         last = parent;
4967                                         next = parent->ms_try.final_statement;
4968                                         break;
4969                                 }
4970                         }
4971                         break;
4972                 }
4973
4974                 default:
4975                         panic("invalid statement kind");
4976         }
4977
4978         while (next == NULL) {
4979                 next = last->base.parent;
4980                 if (next == NULL) {
4981                         noreturn_candidate = false;
4982
4983                         type_t *const type = skip_typeref(current_function->base.type);
4984                         assert(is_type_function(type));
4985                         type_t *const ret  = skip_typeref(type->function.return_type);
4986                         if (!is_type_void(ret) &&
4987                             is_type_valid(ret) &&
4988                             !is_main(current_entity)) {
4989                                 source_position_t const *const pos = &stmt->base.source_position;
4990                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4991                         }
4992                         return;
4993                 }
4994
4995                 switch (next->kind) {
4996                         case STATEMENT_ERROR:
4997                         case STATEMENT_EMPTY:
4998                         case STATEMENT_DECLARATION:
4999                         case STATEMENT_EXPRESSION:
5000                         case STATEMENT_ASM:
5001                         case STATEMENT_RETURN:
5002                         case STATEMENT_CONTINUE:
5003                         case STATEMENT_BREAK:
5004                         case STATEMENT_COMPUTED_GOTO:
5005                         case STATEMENT_GOTO:
5006                         case STATEMENT_LEAVE:
5007                                 panic("invalid control flow in function");
5008
5009                         case STATEMENT_COMPOUND:
5010                                 if (next->compound.stmt_expr) {
5011                                         reaches_end = true;
5012                                         return;
5013                                 }
5014                                 /* FALLTHROUGH */
5015                         case STATEMENT_IF:
5016                         case STATEMENT_SWITCH:
5017                         case STATEMENT_LABEL:
5018                         case STATEMENT_CASE_LABEL:
5019                                 last = next;
5020                                 next = next->base.next;
5021                                 break;
5022
5023                         case STATEMENT_WHILE: {
5024 continue_while:
5025                                 if (next->base.reachable)
5026                                         return;
5027                                 next->base.reachable = true;
5028
5029                                 while_statement_t const *const whiles = &next->whiles;
5030                                 expression_t      const *const cond   = whiles->condition;
5031
5032                                 if (!expression_returns(cond))
5033                                         return;
5034
5035                                 int const val = determine_truth(cond);
5036
5037                                 if (val >= 0)
5038                                         check_reachable(whiles->body);
5039
5040                                 if (val > 0)
5041                                         return;
5042
5043                                 last = next;
5044                                 next = next->base.next;
5045                                 break;
5046                         }
5047
5048                         case STATEMENT_DO_WHILE: {
5049 continue_do_while:
5050                                 if (next->base.reachable)
5051                                         return;
5052                                 next->base.reachable = true;
5053
5054                                 do_while_statement_t const *const dw   = &next->do_while;
5055                                 expression_t         const *const cond = dw->condition;
5056
5057                                 if (!expression_returns(cond))
5058                                         return;
5059
5060                                 int const val = determine_truth(cond);
5061
5062                                 if (val >= 0)
5063                                         check_reachable(dw->body);
5064
5065                                 if (val > 0)
5066                                         return;
5067
5068                                 last = next;
5069                                 next = next->base.next;
5070                                 break;
5071                         }
5072
5073                         case STATEMENT_FOR: {
5074 continue_for:;
5075                                 for_statement_t *const fors = &next->fors;
5076
5077                                 fors->step_reachable = true;
5078
5079                                 if (fors->condition_reachable)
5080                                         return;
5081                                 fors->condition_reachable = true;
5082
5083                                 expression_t const *const cond = fors->condition;
5084
5085                                 int val;
5086                                 if (cond == NULL) {
5087                                         val = 1;
5088                                 } else if (expression_returns(cond)) {
5089                                         val = determine_truth(cond);
5090                                 } else {
5091                                         return;
5092                                 }
5093
5094                                 if (val >= 0)
5095                                         check_reachable(fors->body);
5096
5097                                 if (val > 0)
5098                                         return;
5099
5100                                 last = next;
5101                                 next = next->base.next;
5102                                 break;
5103                         }
5104
5105                         case STATEMENT_MS_TRY:
5106                                 last = next;
5107                                 next = next->ms_try.final_statement;
5108                                 break;
5109                 }
5110         }
5111
5112         check_reachable(next);
5113 }
5114
5115 static void check_unreachable(statement_t* const stmt, void *const env)
5116 {
5117         (void)env;
5118
5119         switch (stmt->kind) {
5120                 case STATEMENT_DO_WHILE:
5121                         if (!stmt->base.reachable) {
5122                                 expression_t const *const cond = stmt->do_while.condition;
5123                                 if (determine_truth(cond) >= 0) {
5124                                         source_position_t const *const pos = &cond->base.source_position;
5125                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5126                                 }
5127                         }
5128                         return;
5129
5130                 case STATEMENT_FOR: {
5131                         for_statement_t const* const fors = &stmt->fors;
5132
5133                         // if init and step are unreachable, cond is unreachable, too
5134                         if (!stmt->base.reachable && !fors->step_reachable) {
5135                                 goto warn_unreachable;
5136                         } else {
5137                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5138                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5139                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5140                                 }
5141
5142                                 if (!fors->condition_reachable && fors->condition != NULL) {
5143                                         source_position_t const *const pos = &fors->condition->base.source_position;
5144                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5145                                 }
5146
5147                                 if (!fors->step_reachable && fors->step != NULL) {
5148                                         source_position_t const *const pos = &fors->step->base.source_position;
5149                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5150                                 }
5151                         }
5152                         return;
5153                 }
5154
5155                 case STATEMENT_COMPOUND:
5156                         if (stmt->compound.statements != NULL)
5157                                 return;
5158                         goto warn_unreachable;
5159
5160                 case STATEMENT_DECLARATION: {
5161                         /* Only warn if there is at least one declarator with an initializer.
5162                          * This typically occurs in switch statements. */
5163                         declaration_statement_t const *const decl = &stmt->declaration;
5164                         entity_t                const *      ent  = decl->declarations_begin;
5165                         entity_t                const *const last = decl->declarations_end;
5166                         if (ent != NULL) {
5167                                 for (;; ent = ent->base.next) {
5168                                         if (ent->kind                 == ENTITY_VARIABLE &&
5169                                                         ent->variable.initializer != NULL) {
5170                                                 goto warn_unreachable;
5171                                         }
5172                                         if (ent == last)
5173                                                 return;
5174                                 }
5175                         }
5176                 }
5177
5178                 default:
5179 warn_unreachable:
5180                         if (!stmt->base.reachable) {
5181                                 source_position_t const *const pos = &stmt->base.source_position;
5182                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5183                         }
5184                         return;
5185         }
5186 }
5187
5188 static bool is_main(entity_t *entity)
5189 {
5190         static symbol_t *sym_main = NULL;
5191         if (sym_main == NULL) {
5192                 sym_main = symbol_table_insert("main");
5193         }
5194
5195         if (entity->base.symbol != sym_main)
5196                 return false;
5197         /* must be in outermost scope */
5198         if (entity->base.parent_scope != file_scope)
5199                 return false;
5200
5201         return true;
5202 }
5203
5204 static void prepare_main_collect2(entity_t*);
5205
5206 static void parse_external_declaration(void)
5207 {
5208         /* function-definitions and declarations both start with declaration
5209          * specifiers */
5210         add_anchor_token(';');
5211         declaration_specifiers_t specifiers;
5212         parse_declaration_specifiers(&specifiers);
5213         rem_anchor_token(';');
5214
5215         /* must be a declaration */
5216         if (token.kind == ';') {
5217                 parse_anonymous_declaration_rest(&specifiers);
5218                 return;
5219         }
5220
5221         add_anchor_token(',');
5222         add_anchor_token('=');
5223         add_anchor_token(';');
5224         add_anchor_token('{');
5225
5226         /* declarator is common to both function-definitions and declarations */
5227         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5228
5229         rem_anchor_token('{');
5230         rem_anchor_token(';');
5231         rem_anchor_token('=');
5232         rem_anchor_token(',');
5233
5234         /* must be a declaration */
5235         switch (token.kind) {
5236                 case ',':
5237                 case ';':
5238                 case '=':
5239                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5240                                         DECL_FLAGS_NONE);
5241                         return;
5242         }
5243
5244         /* must be a function definition */
5245         parse_kr_declaration_list(ndeclaration);
5246
5247         if (token.kind != '{') {
5248                 parse_error_expected("while parsing function definition", '{', NULL);
5249                 eat_until_matching_token(';');
5250                 return;
5251         }
5252
5253         assert(is_declaration(ndeclaration));
5254         type_t *const orig_type = ndeclaration->declaration.type;
5255         type_t *      type      = skip_typeref(orig_type);
5256
5257         if (!is_type_function(type)) {
5258                 if (is_type_valid(type)) {
5259                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5260                 }
5261                 eat_block();
5262                 return;
5263         }
5264
5265         source_position_t const *const pos = &ndeclaration->base.source_position;
5266         if (is_typeref(orig_type)) {
5267                 /* §6.9.1:2 */
5268                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5269         }
5270
5271         if (is_type_compound(skip_typeref(type->function.return_type))) {
5272                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5273         }
5274         if (type->function.unspecified_parameters) {
5275                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5276         } else {
5277                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5278         }
5279
5280         /* §6.7.5.3:14 a function definition with () means no
5281          * parameters (and not unspecified parameters) */
5282         if (type->function.unspecified_parameters &&
5283                         type->function.parameters == NULL) {
5284                 type_t *copy                          = duplicate_type(type);
5285                 copy->function.unspecified_parameters = false;
5286                 type                                  = identify_new_type(copy);
5287
5288                 ndeclaration->declaration.type = type;
5289         }
5290
5291         entity_t *const entity = record_entity(ndeclaration, true);
5292         assert(entity->kind == ENTITY_FUNCTION);
5293         assert(ndeclaration->kind == ENTITY_FUNCTION);
5294
5295         function_t *const function = &entity->function;
5296         if (ndeclaration != entity) {
5297                 function->parameters = ndeclaration->function.parameters;
5298         }
5299
5300         PUSH_SCOPE(&function->parameters);
5301
5302         entity_t *parameter = function->parameters.entities;
5303         for (; parameter != NULL; parameter = parameter->base.next) {
5304                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5305                         parameter->base.parent_scope = current_scope;
5306                 }
5307                 assert(parameter->base.parent_scope == NULL
5308                                 || parameter->base.parent_scope == current_scope);
5309                 parameter->base.parent_scope = current_scope;
5310                 if (parameter->base.symbol == NULL) {
5311                         errorf(&parameter->base.source_position, "parameter name omitted");
5312                         continue;
5313                 }
5314                 environment_push(parameter);
5315         }
5316
5317         if (function->statement != NULL) {
5318                 parser_error_multiple_definition(entity, HERE);
5319                 eat_block();
5320         } else {
5321                 /* parse function body */
5322                 int         label_stack_top      = label_top();
5323                 function_t *old_current_function = current_function;
5324                 current_function                 = function;
5325                 PUSH_CURRENT_ENTITY(entity);
5326                 PUSH_PARENT(NULL);
5327
5328                 goto_first   = NULL;
5329                 goto_anchor  = &goto_first;
5330                 label_first  = NULL;
5331                 label_anchor = &label_first;
5332
5333                 statement_t *const body = parse_compound_statement(false);
5334                 function->statement = body;
5335                 first_err = true;
5336                 check_labels();
5337                 check_declarations();
5338                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5339                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5340                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5341                         noreturn_candidate = true;
5342                         check_reachable(body);
5343                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5344                                 walk_statements(body, check_unreachable, NULL);
5345                         if (noreturn_candidate &&
5346                             !(function->base.modifiers & DM_NORETURN)) {
5347                                 source_position_t const *const pos = &body->base.source_position;
5348                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5349                         }
5350                 }
5351
5352                 if (is_main(entity)) {
5353                         /* Force main to C linkage. */
5354                         type_t *const type = entity->declaration.type;
5355                         assert(is_type_function(type));
5356                         if (type->function.linkage != LINKAGE_C) {
5357                                 type_t *new_type           = duplicate_type(type);
5358                                 new_type->function.linkage = LINKAGE_C;
5359                                 entity->declaration.type   = identify_new_type(new_type);
5360                         }
5361
5362                         if (enable_main_collect2_hack)
5363                                 prepare_main_collect2(entity);
5364                 }
5365
5366                 POP_CURRENT_ENTITY();
5367                 POP_PARENT();
5368                 assert(current_function == function);
5369                 current_function = old_current_function;
5370                 label_pop_to(label_stack_top);
5371         }
5372
5373         POP_SCOPE();
5374 }
5375
5376 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5377 {
5378         entity_t *iter = compound->members.entities;
5379         for (; iter != NULL; iter = iter->base.next) {
5380                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5381                         continue;
5382
5383                 if (iter->base.symbol == symbol) {
5384                         return iter;
5385                 } else if (iter->base.symbol == NULL) {
5386                         /* search in anonymous structs and unions */
5387                         type_t *type = skip_typeref(iter->declaration.type);
5388                         if (is_type_compound(type)) {
5389                                 if (find_compound_entry(type->compound.compound, symbol)
5390                                                 != NULL)
5391                                         return iter;
5392                         }
5393                         continue;
5394                 }
5395         }
5396
5397         return NULL;
5398 }
5399
5400 static void check_deprecated(const source_position_t *source_position,
5401                              const entity_t *entity)
5402 {
5403         if (!is_declaration(entity))
5404                 return;
5405         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5406                 return;
5407
5408         source_position_t const *const epos = &entity->base.source_position;
5409         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5410         if (msg != NULL) {
5411                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5412         } else {
5413                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5414         }
5415 }
5416
5417
5418 static expression_t *create_select(const source_position_t *pos,
5419                                    expression_t *addr,
5420                                    type_qualifiers_t qualifiers,
5421                                                                    entity_t *entry)
5422 {
5423         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5424
5425         check_deprecated(pos, entry);
5426
5427         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5428         select->select.compound       = addr;
5429         select->select.compound_entry = entry;
5430
5431         type_t *entry_type = entry->declaration.type;
5432         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5433
5434         /* bitfields need special treatment */
5435         if (entry->compound_member.bitfield) {
5436                 unsigned bit_size = entry->compound_member.bit_size;
5437                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5438                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5439                         res_type = type_int;
5440                 }
5441         }
5442
5443         /* we always do the auto-type conversions; the & and sizeof parser contains
5444          * code to revert this! */
5445         select->base.type = automatic_type_conversion(res_type);
5446
5447
5448         return select;
5449 }
5450
5451 /**
5452  * Find entry with symbol in compound. Search anonymous structs and unions and
5453  * creates implicit select expressions for them.
5454  * Returns the adress for the innermost compound.
5455  */
5456 static expression_t *find_create_select(const source_position_t *pos,
5457                                         expression_t *addr,
5458                                         type_qualifiers_t qualifiers,
5459                                         compound_t *compound, symbol_t *symbol)
5460 {
5461         entity_t *iter = compound->members.entities;
5462         for (; iter != NULL; iter = iter->base.next) {
5463                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5464                         continue;
5465
5466                 symbol_t *iter_symbol = iter->base.symbol;
5467                 if (iter_symbol == NULL) {
5468                         type_t *type = iter->declaration.type;
5469                         if (!is_type_compound(type))
5470                                 continue;
5471
5472                         compound_t *sub_compound = type->compound.compound;
5473
5474                         if (find_compound_entry(sub_compound, symbol) == NULL)
5475                                 continue;
5476
5477                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5478                         sub_addr->base.source_position = *pos;
5479                         sub_addr->base.implicit        = true;
5480                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5481                                                   symbol);
5482                 }
5483
5484                 if (iter_symbol == symbol) {
5485                         return create_select(pos, addr, qualifiers, iter);
5486                 }
5487         }
5488
5489         return NULL;
5490 }
5491
5492 static void parse_bitfield_member(entity_t *entity)
5493 {
5494         eat(':');
5495
5496         expression_t *size = parse_constant_expression();
5497         long          size_long;
5498
5499         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5500         type_t *type = entity->declaration.type;
5501         if (!is_type_integer(skip_typeref(type))) {
5502                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5503                            type);
5504         }
5505
5506         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5507                 /* error already reported by parse_constant_expression */
5508                 size_long = get_type_size(type) * 8;
5509         } else {
5510                 size_long = fold_constant_to_int(size);
5511
5512                 const symbol_t *symbol = entity->base.symbol;
5513                 const symbol_t *user_symbol
5514                         = symbol == NULL ? sym_anonymous : symbol;
5515                 unsigned bit_size = get_type_size(type) * 8;
5516                 if (size_long < 0) {
5517                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5518                 } else if (size_long == 0 && symbol != NULL) {
5519                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5520                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5521                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5522                                    user_symbol);
5523                 } else {
5524                         /* hope that people don't invent crazy types with more bits
5525                          * than our struct can hold */
5526                         assert(size_long <
5527                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5528                 }
5529         }
5530
5531         entity->compound_member.bitfield = true;
5532         entity->compound_member.bit_size = (unsigned char)size_long;
5533 }
5534
5535 static void parse_compound_declarators(compound_t *compound,
5536                 const declaration_specifiers_t *specifiers)
5537 {
5538         add_anchor_token(';');
5539         add_anchor_token(',');
5540         do {
5541                 entity_t *entity;
5542
5543                 if (token.kind == ':') {
5544                         /* anonymous bitfield */
5545                         type_t *type = specifiers->type;
5546                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5547                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5548                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5549                         entity->declaration.type                   = type;
5550
5551                         parse_bitfield_member(entity);
5552
5553                         attribute_t  *attributes = parse_attributes(NULL);
5554                         attribute_t **anchor     = &attributes;
5555                         while (*anchor != NULL)
5556                                 anchor = &(*anchor)->next;
5557                         *anchor = specifiers->attributes;
5558                         if (attributes != NULL) {
5559                                 handle_entity_attributes(attributes, entity);
5560                         }
5561                         entity->declaration.attributes = attributes;
5562
5563                         append_entity(&compound->members, entity);
5564                 } else {
5565                         entity = parse_declarator(specifiers,
5566                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5567                         source_position_t const *const pos = &entity->base.source_position;
5568                         if (entity->kind == ENTITY_TYPEDEF) {
5569                                 errorf(pos, "typedef not allowed as compound member");
5570                         } else {
5571                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5572
5573                                 /* make sure we don't define a symbol multiple times */
5574                                 symbol_t *symbol = entity->base.symbol;
5575                                 if (symbol != NULL) {
5576                                         entity_t *prev = find_compound_entry(compound, symbol);
5577                                         if (prev != NULL) {
5578                                                 source_position_t const *const ppos = &prev->base.source_position;
5579                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5580                                         }
5581                                 }
5582
5583                                 if (token.kind == ':') {
5584                                         parse_bitfield_member(entity);
5585
5586                                         attribute_t *attributes = parse_attributes(NULL);
5587                                         handle_entity_attributes(attributes, entity);
5588                                 } else {
5589                                         type_t *orig_type = entity->declaration.type;
5590                                         type_t *type      = skip_typeref(orig_type);
5591                                         if (is_type_function(type)) {
5592                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5593                                         } else if (is_type_incomplete(type)) {
5594                                                 /* §6.7.2.1:16 flexible array member */
5595                                                 if (!is_type_array(type)       ||
5596                                                                 token.kind          != ';' ||
5597                                                                 look_ahead(1)->kind != '}') {
5598                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5599                                                 } else if (compound->members.entities == NULL) {
5600                                                         errorf(pos, "flexible array member in otherwise empty struct");
5601                                                 }
5602                                         }
5603                                 }
5604
5605                                 append_entity(&compound->members, entity);
5606                         }
5607                 }
5608         } while (next_if(','));
5609         rem_anchor_token(',');
5610         rem_anchor_token(';');
5611         expect(';');
5612
5613         anonymous_entity = NULL;
5614 }
5615
5616 static void parse_compound_type_entries(compound_t *compound)
5617 {
5618         eat('{');
5619         add_anchor_token('}');
5620
5621         for (;;) {
5622                 switch (token.kind) {
5623                         DECLARATION_START
5624                         case T___extension__:
5625                         case T_IDENTIFIER: {
5626                                 PUSH_EXTENSION();
5627                                 declaration_specifiers_t specifiers;
5628                                 parse_declaration_specifiers(&specifiers);
5629                                 parse_compound_declarators(compound, &specifiers);
5630                                 POP_EXTENSION();
5631                                 break;
5632                         }
5633
5634                         default:
5635                                 rem_anchor_token('}');
5636                                 expect('}');
5637                                 /* §6.7.2.1:7 */
5638                                 compound->complete = true;
5639                                 return;
5640                 }
5641         }
5642 }
5643
5644 static type_t *parse_typename(void)
5645 {
5646         declaration_specifiers_t specifiers;
5647         parse_declaration_specifiers(&specifiers);
5648         if (specifiers.storage_class != STORAGE_CLASS_NONE
5649                         || specifiers.thread_local) {
5650                 /* TODO: improve error message, user does probably not know what a
5651                  * storage class is...
5652                  */
5653                 errorf(&specifiers.source_position, "typename must not have a storage class");
5654         }
5655
5656         type_t *result = parse_abstract_declarator(specifiers.type);
5657
5658         return result;
5659 }
5660
5661
5662
5663
5664 typedef expression_t* (*parse_expression_function)(void);
5665 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5666
5667 typedef struct expression_parser_function_t expression_parser_function_t;
5668 struct expression_parser_function_t {
5669         parse_expression_function        parser;
5670         precedence_t                     infix_precedence;
5671         parse_expression_infix_function  infix_parser;
5672 };
5673
5674 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5675
5676 static type_t *get_string_type(string_encoding_t const enc)
5677 {
5678         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5679         switch (enc) {
5680         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5681         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5682         }
5683         panic("invalid string encoding");
5684 }
5685
5686 /**
5687  * Parse a string constant.
5688  */
5689 static expression_t *parse_string_literal(void)
5690 {
5691         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5692         expr->string_literal.value = concat_string_literals();
5693         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5694         return expr;
5695 }
5696
5697 /**
5698  * Parse a boolean constant.
5699  */
5700 static expression_t *parse_boolean_literal(bool value)
5701 {
5702         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5703         literal->base.type           = type_bool;
5704         literal->literal.value.begin = value ? "true" : "false";
5705         literal->literal.value.size  = value ? 4 : 5;
5706
5707         eat(value ? T_true : T_false);
5708         return literal;
5709 }
5710
5711 static void warn_traditional_suffix(char const *const suffix)
5712 {
5713         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5714 }
5715
5716 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5717 {
5718         unsigned     spec = SPECIFIER_NONE;
5719         char const  *c    = suffix;
5720         for (;;) {
5721                 specifiers_t add;
5722                 if (*c == 'L' || *c == 'l') {
5723                         add = SPECIFIER_LONG;
5724                         if (*c == c[1]) {
5725                                 add |= SPECIFIER_LONG_LONG;
5726                                 ++c;
5727                         }
5728                 } else if (*c == 'U' || *c == 'u') {
5729                         add = SPECIFIER_UNSIGNED;
5730                 } else {
5731                         break;
5732                 }
5733                 ++c;
5734                 if (spec & add)
5735                         goto error;
5736                 spec |= add;
5737         }
5738
5739         if (*c == '\0') {
5740                 type_t *type;
5741                 switch (spec) {
5742                 case SPECIFIER_NONE:                                            type = type_int;                break;
5743                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5744                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5745                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5746                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5747                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5748                 default: panic("inconsistent suffix");
5749                 }
5750                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5751                         warn_traditional_suffix(suffix);
5752                 }
5753                 expr->base.type = type;
5754                 /* Integer type depends on the size of the number and the size
5755                  * representable by the types. The backend/codegeneration has to
5756                  * determine that. */
5757                 determine_literal_type(&expr->literal);
5758         } else {
5759 error:
5760                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5761         }
5762 }
5763
5764 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5765 {
5766         type_t     *type;
5767         char const *c    = suffix;
5768         switch (*c) {
5769         case 'F':
5770         case 'f': type = type_float;       ++c; break;
5771         case 'L':
5772         case 'l': type = type_long_double; ++c; break;
5773         default:  type = type_double;           break;
5774         }
5775
5776         if (*c == '\0') {
5777                 expr->base.type = type;
5778                 if (suffix[0] != '\0') {
5779                         warn_traditional_suffix(suffix);
5780                 }
5781         } else {
5782                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5783         }
5784 }
5785
5786 static expression_t *parse_number_literal(void)
5787 {
5788         string_t const *const str      = &token.literal.string;
5789         char     const *      i        = str->begin;
5790         unsigned              digits   = 0;
5791         bool                  is_float = false;
5792
5793         /* Parse base prefix. */
5794         unsigned base;
5795         if (*i == '0') {
5796                 switch (*++i) {
5797                 case 'B': case 'b': base =  2; ++i;               break;
5798                 case 'X': case 'x': base = 16; ++i;               break;
5799                 default:            base =  8; digits |= 1U << 0; break;
5800                 }
5801         } else {
5802                 base = 10;
5803         }
5804
5805         /* Parse mantissa. */
5806         for (;; ++i) {
5807                 unsigned digit;
5808                 switch (*i) {
5809                 case '.':
5810                         if (is_float) {
5811                                 errorf(HERE, "multiple decimal points in %K", &token);
5812                                 i = 0;
5813                                 goto done;
5814                         }
5815                         is_float = true;
5816                         if (base == 8)
5817                                 base = 10;
5818                         continue;
5819
5820                 case '0':           digit =  0; break;
5821                 case '1':           digit =  1; break;
5822                 case '2':           digit =  2; break;
5823                 case '3':           digit =  3; break;
5824                 case '4':           digit =  4; break;
5825                 case '5':           digit =  5; break;
5826                 case '6':           digit =  6; break;
5827                 case '7':           digit =  7; break;
5828                 case '8':           digit =  8; break;
5829                 case '9':           digit =  9; break;
5830                 case 'A': case 'a': digit = 10; break;
5831                 case 'B': case 'b': digit = 11; break;
5832                 case 'C': case 'c': digit = 12; break;
5833                 case 'D': case 'd': digit = 13; break;
5834                 case 'E': case 'e': digit = 14; break;
5835                 case 'F': case 'f': digit = 15; break;
5836
5837                 default: goto done_mantissa;
5838                 }
5839
5840                 if (digit >= 10 && base != 16)
5841                         goto done_mantissa;
5842
5843                 digits |= 1U << digit;
5844         }
5845 done_mantissa:
5846
5847         /* Parse exponent. */
5848         switch (base) {
5849         case 2:
5850                 if (is_float)
5851                         errorf(HERE, "binary floating %K not allowed", &token);
5852                 break;
5853
5854         case  8:
5855         case 10:
5856                 if (*i == 'E' || *i == 'e') {
5857                         base = 10;
5858                         goto parse_exponent;
5859                 }
5860                 break;
5861
5862         case 16:
5863                 if (*i == 'P' || *i == 'p') {
5864 parse_exponent:
5865                         ++i;
5866                         is_float = true;
5867
5868                         if (*i == '-' || *i == '+')
5869                                 ++i;
5870
5871                         if (isdigit(*i)) {
5872                                 do {
5873                                         ++i;
5874                                 } while (isdigit(*i));
5875                         } else {
5876                                 errorf(HERE, "exponent of %K has no digits", &token);
5877                         }
5878                 } else if (is_float) {
5879                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5880                         i = 0;
5881                 }
5882                 break;
5883
5884         default:
5885                 panic("invalid base");
5886         }
5887
5888 done:;
5889         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5890         expr->literal.value = *str;
5891
5892         if (i) {
5893                 if (digits == 0) {
5894                         errorf(HERE, "%K has no digits", &token);
5895                 } else if (digits & ~((1U << base) - 1)) {
5896                         errorf(HERE, "invalid digit in %K", &token);
5897                 } else {
5898                         expr->literal.suffix = i;
5899                         if (is_float) {
5900                                 check_floatingpoint_suffix(expr, i);
5901                         } else {
5902                                 check_integer_suffix(expr, i);
5903                         }
5904                 }
5905         }
5906
5907         eat(T_NUMBER);
5908         return expr;
5909 }
5910
5911 /**
5912  * Parse a character constant.
5913  */
5914 static expression_t *parse_character_constant(void)
5915 {
5916         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5917         literal->string_literal.value = token.literal.string;
5918
5919         size_t const size = get_string_len(&token.literal.string);
5920         switch (token.literal.string.encoding) {
5921         case STRING_ENCODING_CHAR:
5922                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5923                 if (size > 1) {
5924                         if (!GNU_MODE && !(c_mode & _C99)) {
5925                                 errorf(HERE, "more than 1 character in character constant");
5926                         } else {
5927                                 literal->base.type = type_int;
5928                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5929                         }
5930                 }
5931                 break;
5932
5933         case STRING_ENCODING_WIDE:
5934                 literal->base.type = type_int;
5935                 if (size > 1) {
5936                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5937                 }
5938                 break;
5939         }
5940
5941         eat(T_CHARACTER_CONSTANT);
5942         return literal;
5943 }
5944
5945 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5946 {
5947         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5948         ntype->function.return_type            = type_int;
5949         ntype->function.unspecified_parameters = true;
5950         ntype->function.linkage                = LINKAGE_C;
5951         type_t *type                           = identify_new_type(ntype);
5952
5953         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5954         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5955         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5956         entity->declaration.type                   = type;
5957         entity->declaration.implicit               = true;
5958
5959         if (current_scope != NULL)
5960                 record_entity(entity, false);
5961
5962         return entity;
5963 }
5964
5965 /**
5966  * Performs automatic type cast as described in §6.3.2.1.
5967  *
5968  * @param orig_type  the original type
5969  */
5970 static type_t *automatic_type_conversion(type_t *orig_type)
5971 {
5972         type_t *type = skip_typeref(orig_type);
5973         if (is_type_array(type)) {
5974                 array_type_t *array_type   = &type->array;
5975                 type_t       *element_type = array_type->element_type;
5976                 unsigned      qualifiers   = array_type->base.qualifiers;
5977
5978                 return make_pointer_type(element_type, qualifiers);
5979         }
5980
5981         if (is_type_function(type)) {
5982                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5983         }
5984
5985         return orig_type;
5986 }
5987
5988 /**
5989  * reverts the automatic casts of array to pointer types and function
5990  * to function-pointer types as defined §6.3.2.1
5991  */
5992 type_t *revert_automatic_type_conversion(const expression_t *expression)
5993 {
5994         switch (expression->kind) {
5995         case EXPR_REFERENCE: {
5996                 entity_t *entity = expression->reference.entity;
5997                 if (is_declaration(entity)) {
5998                         return entity->declaration.type;
5999                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6000                         return entity->enum_value.enum_type;
6001                 } else {
6002                         panic("no declaration or enum in reference");
6003                 }
6004         }
6005
6006         case EXPR_SELECT: {
6007                 entity_t *entity = expression->select.compound_entry;
6008                 assert(is_declaration(entity));
6009                 type_t   *type   = entity->declaration.type;
6010                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6011         }
6012
6013         case EXPR_UNARY_DEREFERENCE: {
6014                 const expression_t *const value = expression->unary.value;
6015                 type_t             *const type  = skip_typeref(value->base.type);
6016                 if (!is_type_pointer(type))
6017                         return type_error_type;
6018                 return type->pointer.points_to;
6019         }
6020
6021         case EXPR_ARRAY_ACCESS: {
6022                 const expression_t *array_ref = expression->array_access.array_ref;
6023                 type_t             *type_left = skip_typeref(array_ref->base.type);
6024                 if (!is_type_pointer(type_left))
6025                         return type_error_type;
6026                 return type_left->pointer.points_to;
6027         }
6028
6029         case EXPR_STRING_LITERAL: {
6030                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
6031                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
6032                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
6033         }
6034
6035         case EXPR_COMPOUND_LITERAL:
6036                 return expression->compound_literal.type;
6037
6038         default:
6039                 break;
6040         }
6041         return expression->base.type;
6042 }
6043
6044 /**
6045  * Find an entity matching a symbol in a scope.
6046  * Uses current scope if scope is NULL
6047  */
6048 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6049                                namespace_tag_t namespc)
6050 {
6051         if (scope == NULL) {
6052                 return get_entity(symbol, namespc);
6053         }
6054
6055         /* we should optimize here, if scope grows above a certain size we should
6056            construct a hashmap here... */
6057         entity_t *entity = scope->entities;
6058         for ( ; entity != NULL; entity = entity->base.next) {
6059                 if (entity->base.symbol == symbol
6060                     && (namespace_tag_t)entity->base.namespc == namespc)
6061                         break;
6062         }
6063
6064         return entity;
6065 }
6066
6067 static entity_t *parse_qualified_identifier(void)
6068 {
6069         /* namespace containing the symbol */
6070         symbol_t          *symbol;
6071         source_position_t  pos;
6072         const scope_t     *lookup_scope = NULL;
6073
6074         if (next_if(T_COLONCOLON))
6075                 lookup_scope = &unit->scope;
6076
6077         entity_t *entity;
6078         while (true) {
6079                 symbol = expect_identifier("while parsing identifier", &pos);
6080                 if (!symbol)
6081                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6082
6083                 /* lookup entity */
6084                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6085
6086                 if (!next_if(T_COLONCOLON))
6087                         break;
6088
6089                 switch (entity->kind) {
6090                 case ENTITY_NAMESPACE:
6091                         lookup_scope = &entity->namespacee.members;
6092                         break;
6093                 case ENTITY_STRUCT:
6094                 case ENTITY_UNION:
6095                 case ENTITY_CLASS:
6096                         lookup_scope = &entity->compound.members;
6097                         break;
6098                 default:
6099                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6100                                symbol, get_entity_kind_name(entity->kind));
6101
6102                         /* skip further qualifications */
6103                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6104
6105                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6106                 }
6107         }
6108
6109         if (entity == NULL) {
6110                 if (!strict_mode && token.kind == '(') {
6111                         /* an implicitly declared function */
6112                         entity = create_implicit_function(symbol, &pos);
6113                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6114                 } else {
6115                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6116                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6117                 }
6118         }
6119
6120         return entity;
6121 }
6122
6123 static expression_t *parse_reference(void)
6124 {
6125         source_position_t const pos    = *HERE;
6126         entity_t         *const entity = parse_qualified_identifier();
6127
6128         type_t *orig_type;
6129         if (is_declaration(entity)) {
6130                 orig_type = entity->declaration.type;
6131         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6132                 orig_type = entity->enum_value.enum_type;
6133         } else {
6134                 panic("expected declaration or enum value in reference");
6135         }
6136
6137         /* we always do the auto-type conversions; the & and sizeof parser contains
6138          * code to revert this! */
6139         type_t *type = automatic_type_conversion(orig_type);
6140
6141         expression_kind_t kind = EXPR_REFERENCE;
6142         if (entity->kind == ENTITY_ENUM_VALUE)
6143                 kind = EXPR_ENUM_CONSTANT;
6144
6145         expression_t *expression         = allocate_expression_zero(kind);
6146         expression->base.source_position = pos;
6147         expression->base.type            = type;
6148         expression->reference.entity     = entity;
6149
6150         /* this declaration is used */
6151         if (is_declaration(entity)) {
6152                 entity->declaration.used = true;
6153         }
6154
6155         if (entity->base.parent_scope != file_scope
6156                 && (current_function != NULL
6157                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6158                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6159                 /* access of a variable from an outer function */
6160                 entity->variable.address_taken = true;
6161                 current_function->need_closure = true;
6162         }
6163
6164         check_deprecated(&pos, entity);
6165
6166         return expression;
6167 }
6168
6169 static bool semantic_cast(expression_t *cast)
6170 {
6171         expression_t            *expression      = cast->unary.value;
6172         type_t                  *orig_dest_type  = cast->base.type;
6173         type_t                  *orig_type_right = expression->base.type;
6174         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6175         type_t            const *src_type        = skip_typeref(orig_type_right);
6176         source_position_t const *pos             = &cast->base.source_position;
6177
6178         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6179         if (is_type_void(dst_type))
6180                 return true;
6181
6182         /* only integer and pointer can be casted to pointer */
6183         if (is_type_pointer(dst_type)  &&
6184             !is_type_pointer(src_type) &&
6185             !is_type_integer(src_type) &&
6186             is_type_valid(src_type)) {
6187                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6188                 return false;
6189         }
6190
6191         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6192                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6193                 return false;
6194         }
6195
6196         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6197                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6198                 return false;
6199         }
6200
6201         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6202                 type_t *src = skip_typeref(src_type->pointer.points_to);
6203                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6204                 unsigned missing_qualifiers =
6205                         src->base.qualifiers & ~dst->base.qualifiers;
6206                 if (missing_qualifiers != 0) {
6207                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6208                 }
6209         }
6210         return true;
6211 }
6212
6213 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6214 {
6215         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6216         expression->base.source_position = *pos;
6217
6218         parse_initializer_env_t env;
6219         env.type             = type;
6220         env.entity           = NULL;
6221         env.must_be_constant = false;
6222         initializer_t *initializer = parse_initializer(&env);
6223         type = env.type;
6224
6225         expression->compound_literal.initializer = initializer;
6226         expression->compound_literal.type        = type;
6227         expression->base.type                    = automatic_type_conversion(type);
6228
6229         return expression;
6230 }
6231
6232 /**
6233  * Parse a cast expression.
6234  */
6235 static expression_t *parse_cast(void)
6236 {
6237         source_position_t const pos = *HERE;
6238
6239         eat('(');
6240         add_anchor_token(')');
6241
6242         type_t *type = parse_typename();
6243
6244         rem_anchor_token(')');
6245         expect(')');
6246
6247         if (token.kind == '{') {
6248                 return parse_compound_literal(&pos, type);
6249         }
6250
6251         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6252         cast->base.source_position = pos;
6253
6254         expression_t *value = parse_subexpression(PREC_CAST);
6255         cast->base.type   = type;
6256         cast->unary.value = value;
6257
6258         if (! semantic_cast(cast)) {
6259                 /* TODO: record the error in the AST. else it is impossible to detect it */
6260         }
6261
6262         return cast;
6263 }
6264
6265 /**
6266  * Parse a statement expression.
6267  */
6268 static expression_t *parse_statement_expression(void)
6269 {
6270         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6271
6272         eat('(');
6273         add_anchor_token(')');
6274
6275         statement_t *statement          = parse_compound_statement(true);
6276         statement->compound.stmt_expr   = true;
6277         expression->statement.statement = statement;
6278
6279         /* find last statement and use its type */
6280         type_t *type = type_void;
6281         const statement_t *stmt = statement->compound.statements;
6282         if (stmt != NULL) {
6283                 while (stmt->base.next != NULL)
6284                         stmt = stmt->base.next;
6285
6286                 if (stmt->kind == STATEMENT_EXPRESSION) {
6287                         type = stmt->expression.expression->base.type;
6288                 }
6289         } else {
6290                 source_position_t const *const pos = &expression->base.source_position;
6291                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6292         }
6293         expression->base.type = type;
6294
6295         rem_anchor_token(')');
6296         expect(')');
6297         return expression;
6298 }
6299
6300 /**
6301  * Parse a parenthesized expression.
6302  */
6303 static expression_t *parse_parenthesized_expression(void)
6304 {
6305         token_t const* const la1 = look_ahead(1);
6306         switch (la1->kind) {
6307         case '{':
6308                 /* gcc extension: a statement expression */
6309                 return parse_statement_expression();
6310
6311         case T_IDENTIFIER:
6312                 if (is_typedef_symbol(la1->base.symbol)) {
6313         DECLARATION_START
6314                         return parse_cast();
6315                 }
6316         }
6317
6318         eat('(');
6319         add_anchor_token(')');
6320         expression_t *result = parse_expression();
6321         result->base.parenthesized = true;
6322         rem_anchor_token(')');
6323         expect(')');
6324
6325         return result;
6326 }
6327
6328 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6329 {
6330         if (current_function == NULL) {
6331                 errorf(HERE, "'%K' used outside of a function", &token);
6332         }
6333
6334         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6335         expression->base.type     = type_char_ptr;
6336         expression->funcname.kind = kind;
6337
6338         next_token();
6339
6340         return expression;
6341 }
6342
6343 static designator_t *parse_designator(void)
6344 {
6345         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6346         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6347         if (!result->symbol)
6348                 return NULL;
6349
6350         designator_t *last_designator = result;
6351         while (true) {
6352                 if (next_if('.')) {
6353                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6354                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6355                         if (!designator->symbol)
6356                                 return NULL;
6357
6358                         last_designator->next = designator;
6359                         last_designator       = designator;
6360                         continue;
6361                 }
6362                 if (next_if('[')) {
6363                         add_anchor_token(']');
6364                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6365                         designator->source_position = *HERE;
6366                         designator->array_index     = parse_expression();
6367                         rem_anchor_token(']');
6368                         expect(']');
6369                         if (designator->array_index == NULL) {
6370                                 return NULL;
6371                         }
6372
6373                         last_designator->next = designator;
6374                         last_designator       = designator;
6375                         continue;
6376                 }
6377                 break;
6378         }
6379
6380         return result;
6381 }
6382
6383 /**
6384  * Parse the __builtin_offsetof() expression.
6385  */
6386 static expression_t *parse_offsetof(void)
6387 {
6388         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6389         expression->base.type    = type_size_t;
6390
6391         eat(T___builtin_offsetof);
6392
6393         add_anchor_token(')');
6394         add_anchor_token(',');
6395         expect('(');
6396         type_t *type = parse_typename();
6397         rem_anchor_token(',');
6398         expect(',');
6399         designator_t *designator = parse_designator();
6400         rem_anchor_token(')');
6401         expect(')');
6402
6403         expression->offsetofe.type       = type;
6404         expression->offsetofe.designator = designator;
6405
6406         type_path_t path;
6407         memset(&path, 0, sizeof(path));
6408         path.top_type = type;
6409         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6410
6411         descend_into_subtype(&path);
6412
6413         if (!walk_designator(&path, designator, true)) {
6414                 return create_error_expression();
6415         }
6416
6417         DEL_ARR_F(path.path);
6418
6419         return expression;
6420 }
6421
6422 static bool is_last_parameter(expression_t *const param)
6423 {
6424         if (param->kind == EXPR_REFERENCE) {
6425                 entity_t *const entity = param->reference.entity;
6426                 if (entity->kind == ENTITY_PARAMETER &&
6427                     !entity->base.next               &&
6428                     entity->base.parent_scope == &current_function->parameters) {
6429                         return true;
6430                 }
6431         }
6432
6433         if (!is_type_valid(skip_typeref(param->base.type)))
6434                 return true;
6435
6436         return false;
6437 }
6438
6439 /**
6440  * Parses a __builtin_va_start() expression.
6441  */
6442 static expression_t *parse_va_start(void)
6443 {
6444         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6445
6446         eat(T___builtin_va_start);
6447
6448         add_anchor_token(')');
6449         add_anchor_token(',');
6450         expect('(');
6451         expression->va_starte.ap = parse_assignment_expression();
6452         rem_anchor_token(',');
6453         expect(',');
6454         expression_t *const param = parse_assignment_expression();
6455         expression->va_starte.parameter = param;
6456         rem_anchor_token(')');
6457         expect(')');
6458
6459         if (!current_function) {
6460                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6461         } else if (!current_function->base.type->function.variadic) {
6462                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6463         } else if (!is_last_parameter(param)) {
6464                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6465         }
6466
6467         return expression;
6468 }
6469
6470 /**
6471  * Parses a __builtin_va_arg() expression.
6472  */
6473 static expression_t *parse_va_arg(void)
6474 {
6475         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6476
6477         eat(T___builtin_va_arg);
6478
6479         add_anchor_token(')');
6480         add_anchor_token(',');
6481         expect('(');
6482         call_argument_t ap;
6483         ap.expression = parse_assignment_expression();
6484         expression->va_arge.ap = ap.expression;
6485         check_call_argument(type_valist, &ap, 1);
6486
6487         rem_anchor_token(',');
6488         expect(',');
6489         expression->base.type = parse_typename();
6490         rem_anchor_token(')');
6491         expect(')');
6492
6493         return expression;
6494 }
6495
6496 /**
6497  * Parses a __builtin_va_copy() expression.
6498  */
6499 static expression_t *parse_va_copy(void)
6500 {
6501         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6502
6503         eat(T___builtin_va_copy);
6504
6505         add_anchor_token(')');
6506         add_anchor_token(',');
6507         expect('(');
6508         expression_t *dst = parse_assignment_expression();
6509         assign_error_t error = semantic_assign(type_valist, dst);
6510         report_assign_error(error, type_valist, dst, "call argument 1",
6511                             &dst->base.source_position);
6512         expression->va_copye.dst = dst;
6513
6514         rem_anchor_token(',');
6515         expect(',');
6516
6517         call_argument_t src;
6518         src.expression = parse_assignment_expression();
6519         check_call_argument(type_valist, &src, 2);
6520         expression->va_copye.src = src.expression;
6521         rem_anchor_token(')');
6522         expect(')');
6523
6524         return expression;
6525 }
6526
6527 /**
6528  * Parses a __builtin_constant_p() expression.
6529  */
6530 static expression_t *parse_builtin_constant(void)
6531 {
6532         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6533
6534         eat(T___builtin_constant_p);
6535
6536         add_anchor_token(')');
6537         expect('(');
6538         expression->builtin_constant.value = parse_assignment_expression();
6539         rem_anchor_token(')');
6540         expect(')');
6541         expression->base.type = type_int;
6542
6543         return expression;
6544 }
6545
6546 /**
6547  * Parses a __builtin_types_compatible_p() expression.
6548  */
6549 static expression_t *parse_builtin_types_compatible(void)
6550 {
6551         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6552
6553         eat(T___builtin_types_compatible_p);
6554
6555         add_anchor_token(')');
6556         add_anchor_token(',');
6557         expect('(');
6558         expression->builtin_types_compatible.left = parse_typename();
6559         rem_anchor_token(',');
6560         expect(',');
6561         expression->builtin_types_compatible.right = parse_typename();
6562         rem_anchor_token(')');
6563         expect(')');
6564         expression->base.type = type_int;
6565
6566         return expression;
6567 }
6568
6569 /**
6570  * Parses a __builtin_is_*() compare expression.
6571  */
6572 static expression_t *parse_compare_builtin(void)
6573 {
6574         expression_kind_t kind;
6575         switch (token.kind) {
6576         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6577         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6578         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6579         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6580         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6581         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6582         default: internal_errorf(HERE, "invalid compare builtin found");
6583         }
6584         expression_t *const expression = allocate_expression_zero(kind);
6585         next_token();
6586
6587         add_anchor_token(')');
6588         add_anchor_token(',');
6589         expect('(');
6590         expression->binary.left = parse_assignment_expression();
6591         rem_anchor_token(',');
6592         expect(',');
6593         expression->binary.right = parse_assignment_expression();
6594         rem_anchor_token(')');
6595         expect(')');
6596
6597         type_t *const orig_type_left  = expression->binary.left->base.type;
6598         type_t *const orig_type_right = expression->binary.right->base.type;
6599
6600         type_t *const type_left  = skip_typeref(orig_type_left);
6601         type_t *const type_right = skip_typeref(orig_type_right);
6602         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6603                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6604                         type_error_incompatible("invalid operands in comparison",
6605                                 &expression->base.source_position, orig_type_left, orig_type_right);
6606                 }
6607         } else {
6608                 semantic_comparison(&expression->binary);
6609         }
6610
6611         return expression;
6612 }
6613
6614 /**
6615  * Parses a MS assume() expression.
6616  */
6617 static expression_t *parse_assume(void)
6618 {
6619         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6620
6621         eat(T__assume);
6622
6623         add_anchor_token(')');
6624         expect('(');
6625         expression->unary.value = parse_assignment_expression();
6626         rem_anchor_token(')');
6627         expect(')');
6628
6629         expression->base.type = type_void;
6630         return expression;
6631 }
6632
6633 /**
6634  * Return the label for the current symbol or create a new one.
6635  */
6636 static label_t *get_label(char const *const context)
6637 {
6638         assert(current_function != NULL);
6639
6640         symbol_t *const sym = expect_identifier(context, NULL);
6641         if (!sym)
6642                 return NULL;
6643
6644         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6645         /* If we find a local label, we already created the declaration. */
6646         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6647                 if (label->base.parent_scope != current_scope) {
6648                         assert(label->base.parent_scope->depth < current_scope->depth);
6649                         current_function->goto_to_outer = true;
6650                 }
6651         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6652                 /* There is no matching label in the same function, so create a new one. */
6653                 source_position_t const nowhere = { NULL, 0, 0, false };
6654                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6655                 label_push(label);
6656         }
6657
6658         return &label->label;
6659 }
6660
6661 /**
6662  * Parses a GNU && label address expression.
6663  */
6664 static expression_t *parse_label_address(void)
6665 {
6666         source_position_t const source_position = *HERE;
6667         eat(T_ANDAND);
6668
6669         label_t *const label = get_label("while parsing label address");
6670         if (!label)
6671                 return create_error_expression();
6672
6673         label->used          = true;
6674         label->address_taken = true;
6675
6676         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6677         expression->base.source_position = source_position;
6678
6679         /* label address is treated as a void pointer */
6680         expression->base.type           = type_void_ptr;
6681         expression->label_address.label = label;
6682         return expression;
6683 }
6684
6685 /**
6686  * Parse a microsoft __noop expression.
6687  */
6688 static expression_t *parse_noop_expression(void)
6689 {
6690         /* the result is a (int)0 */
6691         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6692         literal->base.type           = type_int;
6693         literal->literal.value.begin = "__noop";
6694         literal->literal.value.size  = 6;
6695
6696         eat(T___noop);
6697
6698         if (token.kind == '(') {
6699                 /* parse arguments */
6700                 eat('(');
6701                 add_anchor_token(')');
6702                 add_anchor_token(',');
6703
6704                 if (token.kind != ')') do {
6705                         (void)parse_assignment_expression();
6706                 } while (next_if(','));
6707
6708                 rem_anchor_token(',');
6709                 rem_anchor_token(')');
6710         }
6711         expect(')');
6712
6713         return literal;
6714 }
6715
6716 /**
6717  * Parses a primary expression.
6718  */
6719 static expression_t *parse_primary_expression(void)
6720 {
6721         switch (token.kind) {
6722         case T_false:                        return parse_boolean_literal(false);
6723         case T_true:                         return parse_boolean_literal(true);
6724         case T_NUMBER:                       return parse_number_literal();
6725         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6726         case T_STRING_LITERAL:               return parse_string_literal();
6727         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6728         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6729         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6730         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6731         case T___builtin_offsetof:           return parse_offsetof();
6732         case T___builtin_va_start:           return parse_va_start();
6733         case T___builtin_va_arg:             return parse_va_arg();
6734         case T___builtin_va_copy:            return parse_va_copy();
6735         case T___builtin_isgreater:
6736         case T___builtin_isgreaterequal:
6737         case T___builtin_isless:
6738         case T___builtin_islessequal:
6739         case T___builtin_islessgreater:
6740         case T___builtin_isunordered:        return parse_compare_builtin();
6741         case T___builtin_constant_p:         return parse_builtin_constant();
6742         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6743         case T__assume:                      return parse_assume();
6744         case T_ANDAND:
6745                 if (GNU_MODE)
6746                         return parse_label_address();
6747                 break;
6748
6749         case '(':                            return parse_parenthesized_expression();
6750         case T___noop:                       return parse_noop_expression();
6751
6752         /* Gracefully handle type names while parsing expressions. */
6753         case T_COLONCOLON:
6754                 return parse_reference();
6755         case T_IDENTIFIER:
6756                 if (!is_typedef_symbol(token.base.symbol)) {
6757                         return parse_reference();
6758                 }
6759                 /* FALLTHROUGH */
6760         DECLARATION_START {
6761                 source_position_t const  pos = *HERE;
6762                 declaration_specifiers_t specifiers;
6763                 parse_declaration_specifiers(&specifiers);
6764                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6765                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6766                 return create_error_expression();
6767         }
6768         }
6769
6770         errorf(HERE, "unexpected token %K, expected an expression", &token);
6771         eat_until_anchor();
6772         return create_error_expression();
6773 }
6774
6775 static expression_t *parse_array_expression(expression_t *left)
6776 {
6777         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6778         array_access_expression_t *const arr  = &expr->array_access;
6779
6780         eat('[');
6781         add_anchor_token(']');
6782
6783         expression_t *const inside = parse_expression();
6784
6785         type_t *const orig_type_left   = left->base.type;
6786         type_t *const orig_type_inside = inside->base.type;
6787
6788         type_t *const type_left   = skip_typeref(orig_type_left);
6789         type_t *const type_inside = skip_typeref(orig_type_inside);
6790
6791         expression_t *ref;
6792         expression_t *idx;
6793         type_t       *idx_type;
6794         type_t       *res_type;
6795         if (is_type_pointer(type_left)) {
6796                 ref      = left;
6797                 idx      = inside;
6798                 idx_type = type_inside;
6799                 res_type = type_left->pointer.points_to;
6800                 goto check_idx;
6801         } else if (is_type_pointer(type_inside)) {
6802                 arr->flipped = true;
6803                 ref      = inside;
6804                 idx      = left;
6805                 idx_type = type_left;
6806                 res_type = type_inside->pointer.points_to;
6807 check_idx:
6808                 res_type = automatic_type_conversion(res_type);
6809                 if (!is_type_integer(idx_type)) {
6810                         errorf(&idx->base.source_position, "array subscript must have integer type");
6811                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6812                         source_position_t const *const pos = &idx->base.source_position;
6813                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6814                 }
6815         } else {
6816                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6817                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6818                 }
6819                 res_type = type_error_type;
6820                 ref      = left;
6821                 idx      = inside;
6822         }
6823
6824         arr->array_ref = ref;
6825         arr->index     = idx;
6826         arr->base.type = res_type;
6827
6828         rem_anchor_token(']');
6829         expect(']');
6830         return expr;
6831 }
6832
6833 static bool is_bitfield(const expression_t *expression)
6834 {
6835         return expression->kind == EXPR_SELECT
6836                 && expression->select.compound_entry->compound_member.bitfield;
6837 }
6838
6839 static expression_t *parse_typeprop(expression_kind_t const kind)
6840 {
6841         expression_t  *tp_expression = allocate_expression_zero(kind);
6842         tp_expression->base.type     = type_size_t;
6843
6844         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6845
6846         type_t       *orig_type;
6847         expression_t *expression;
6848         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6849                 source_position_t const pos = *HERE;
6850                 eat('(');
6851                 add_anchor_token(')');
6852                 orig_type = parse_typename();
6853                 rem_anchor_token(')');
6854                 expect(')');
6855
6856                 if (token.kind == '{') {
6857                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6858                          * starting with a compound literal */
6859                         expression = parse_compound_literal(&pos, orig_type);
6860                         goto typeprop_expression;
6861                 }
6862         } else {
6863                 expression = parse_subexpression(PREC_UNARY);
6864
6865 typeprop_expression:
6866                 if (is_bitfield(expression)) {
6867                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6868                         errorf(&tp_expression->base.source_position,
6869                                    "operand of %s expression must not be a bitfield", what);
6870                 }
6871
6872                 tp_expression->typeprop.tp_expression = expression;
6873
6874                 orig_type = revert_automatic_type_conversion(expression);
6875                 expression->base.type = orig_type;
6876         }
6877
6878         tp_expression->typeprop.type   = orig_type;
6879         type_t const* const type       = skip_typeref(orig_type);
6880         char   const*       wrong_type = NULL;
6881         if (is_type_incomplete(type)) {
6882                 if (!is_type_void(type) || !GNU_MODE)
6883                         wrong_type = "incomplete";
6884         } else if (type->kind == TYPE_FUNCTION) {
6885                 if (GNU_MODE) {
6886                         /* function types are allowed (and return 1) */
6887                         source_position_t const *const pos  = &tp_expression->base.source_position;
6888                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6889                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6890                 } else {
6891                         wrong_type = "function";
6892                 }
6893         }
6894
6895         if (wrong_type != NULL) {
6896                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6897                 errorf(&tp_expression->base.source_position,
6898                                 "operand of %s expression must not be of %s type '%T'",
6899                                 what, wrong_type, orig_type);
6900         }
6901
6902         return tp_expression;
6903 }
6904
6905 static expression_t *parse_sizeof(void)
6906 {
6907         return parse_typeprop(EXPR_SIZEOF);
6908 }
6909
6910 static expression_t *parse_alignof(void)
6911 {
6912         return parse_typeprop(EXPR_ALIGNOF);
6913 }
6914
6915 static expression_t *parse_select_expression(expression_t *addr)
6916 {
6917         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6918         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6919         source_position_t const pos = *HERE;
6920         next_token();
6921
6922         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6923         if (!symbol)
6924                 return create_error_expression();
6925
6926         type_t *const orig_type = addr->base.type;
6927         type_t *const type      = skip_typeref(orig_type);
6928
6929         type_t *type_left;
6930         bool    saw_error = false;
6931         if (is_type_pointer(type)) {
6932                 if (!select_left_arrow) {
6933                         errorf(&pos,
6934                                "request for member '%Y' in something not a struct or union, but '%T'",
6935                                symbol, orig_type);
6936                         saw_error = true;
6937                 }
6938                 type_left = skip_typeref(type->pointer.points_to);
6939         } else {
6940                 if (select_left_arrow && is_type_valid(type)) {
6941                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6942                         saw_error = true;
6943                 }
6944                 type_left = type;
6945         }
6946
6947         if (!is_type_compound(type_left)) {
6948                 if (is_type_valid(type_left) && !saw_error) {
6949                         errorf(&pos,
6950                                "request for member '%Y' in something not a struct or union, but '%T'",
6951                                symbol, type_left);
6952                 }
6953                 return create_error_expression();
6954         }
6955
6956         compound_t *compound = type_left->compound.compound;
6957         if (!compound->complete) {
6958                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6959                        symbol, type_left);
6960                 return create_error_expression();
6961         }
6962
6963         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6964         expression_t      *result     =
6965                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6966
6967         if (result == NULL) {
6968                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6969                 return create_error_expression();
6970         }
6971
6972         return result;
6973 }
6974
6975 static void check_call_argument(type_t          *expected_type,
6976                                 call_argument_t *argument, unsigned pos)
6977 {
6978         type_t         *expected_type_skip = skip_typeref(expected_type);
6979         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6980         expression_t   *arg_expr           = argument->expression;
6981         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6982
6983         /* handle transparent union gnu extension */
6984         if (is_type_union(expected_type_skip)
6985                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6986                 compound_t *union_decl  = expected_type_skip->compound.compound;
6987                 type_t     *best_type   = NULL;
6988                 entity_t   *entry       = union_decl->members.entities;
6989                 for ( ; entry != NULL; entry = entry->base.next) {
6990                         assert(is_declaration(entry));
6991                         type_t *decl_type = entry->declaration.type;
6992                         error = semantic_assign(decl_type, arg_expr);
6993                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6994                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6995                                 continue;
6996
6997                         if (error == ASSIGN_SUCCESS) {
6998                                 best_type = decl_type;
6999                         } else if (best_type == NULL) {
7000                                 best_type = decl_type;
7001                         }
7002                 }
7003
7004                 if (best_type != NULL) {
7005                         expected_type = best_type;
7006                 }
7007         }
7008
7009         error                = semantic_assign(expected_type, arg_expr);
7010         argument->expression = create_implicit_cast(arg_expr, expected_type);
7011
7012         if (error != ASSIGN_SUCCESS) {
7013                 /* report exact scope in error messages (like "in argument 3") */
7014                 char buf[64];
7015                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7016                 report_assign_error(error, expected_type, arg_expr, buf,
7017                                     &arg_expr->base.source_position);
7018         } else {
7019                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7020                 if (!types_compatible(expected_type_skip, promoted_type) &&
7021                     !types_compatible(expected_type_skip, type_void_ptr) &&
7022                     !types_compatible(type_void_ptr,      promoted_type)) {
7023                         /* Deliberately show the skipped types in this warning */
7024                         source_position_t const *const apos = &arg_expr->base.source_position;
7025                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7026                 }
7027         }
7028 }
7029
7030 /**
7031  * Handle the semantic restrictions of builtin calls
7032  */
7033 static void handle_builtin_argument_restrictions(call_expression_t *call)
7034 {
7035         entity_t *entity = call->function->reference.entity;
7036         switch (entity->function.btk) {
7037         case BUILTIN_FIRM:
7038                 switch (entity->function.b.firm_builtin_kind) {
7039                 case ir_bk_return_address:
7040                 case ir_bk_frame_address: {
7041                         /* argument must be constant */
7042                         call_argument_t *argument = call->arguments;
7043
7044                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7045                                 errorf(&call->base.source_position,
7046                                            "argument of '%Y' must be a constant expression",
7047                                            call->function->reference.entity->base.symbol);
7048                         }
7049                         break;
7050                 }
7051                 case ir_bk_prefetch:
7052                         /* second and third argument must be constant if existent */
7053                         if (call->arguments == NULL)
7054                                 break;
7055                         call_argument_t *rw = call->arguments->next;
7056                         call_argument_t *locality = NULL;
7057
7058                         if (rw != NULL) {
7059                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7060                                         errorf(&call->base.source_position,
7061                                                    "second argument of '%Y' must be a constant expression",
7062                                                    call->function->reference.entity->base.symbol);
7063                                 }
7064                                 locality = rw->next;
7065                         }
7066                         if (locality != NULL) {
7067                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7068                                         errorf(&call->base.source_position,
7069                                                    "third argument of '%Y' must be a constant expression",
7070                                                    call->function->reference.entity->base.symbol);
7071                                 }
7072                                 locality = rw->next;
7073                         }
7074                         break;
7075                 default:
7076                         break;
7077                 }
7078
7079         case BUILTIN_OBJECT_SIZE:
7080                 if (call->arguments == NULL)
7081                         break;
7082
7083                 call_argument_t *arg = call->arguments->next;
7084                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7085                         errorf(&call->base.source_position,
7086                                    "second argument of '%Y' must be a constant expression",
7087                                    call->function->reference.entity->base.symbol);
7088                 }
7089                 break;
7090         default:
7091                 break;
7092         }
7093 }
7094
7095 /**
7096  * Parse a call expression, ie. expression '( ... )'.
7097  *
7098  * @param expression  the function address
7099  */
7100 static expression_t *parse_call_expression(expression_t *expression)
7101 {
7102         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7103         call_expression_t *call   = &result->call;
7104         call->function            = expression;
7105
7106         type_t *const orig_type = expression->base.type;
7107         type_t *const type      = skip_typeref(orig_type);
7108
7109         function_type_t *function_type = NULL;
7110         if (is_type_pointer(type)) {
7111                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7112
7113                 if (is_type_function(to_type)) {
7114                         function_type   = &to_type->function;
7115                         call->base.type = function_type->return_type;
7116                 }
7117         }
7118
7119         if (function_type == NULL && is_type_valid(type)) {
7120                 errorf(HERE,
7121                        "called object '%E' (type '%T') is not a pointer to a function",
7122                        expression, orig_type);
7123         }
7124
7125         /* parse arguments */
7126         eat('(');
7127         add_anchor_token(')');
7128         add_anchor_token(',');
7129
7130         if (token.kind != ')') {
7131                 call_argument_t **anchor = &call->arguments;
7132                 do {
7133                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7134                         argument->expression = parse_assignment_expression();
7135
7136                         *anchor = argument;
7137                         anchor  = &argument->next;
7138                 } while (next_if(','));
7139         }
7140         rem_anchor_token(',');
7141         rem_anchor_token(')');
7142         expect(')');
7143
7144         if (function_type == NULL)
7145                 return result;
7146
7147         /* check type and count of call arguments */
7148         function_parameter_t *parameter = function_type->parameters;
7149         call_argument_t      *argument  = call->arguments;
7150         if (!function_type->unspecified_parameters) {
7151                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7152                                 parameter = parameter->next, argument = argument->next) {
7153                         check_call_argument(parameter->type, argument, ++pos);
7154                 }
7155
7156                 if (parameter != NULL) {
7157                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7158                 } else if (argument != NULL && !function_type->variadic) {
7159                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7160                 }
7161         }
7162
7163         /* do default promotion for other arguments */
7164         for (; argument != NULL; argument = argument->next) {
7165                 type_t *argument_type = argument->expression->base.type;
7166                 if (!is_type_object(skip_typeref(argument_type))) {
7167                         errorf(&argument->expression->base.source_position,
7168                                "call argument '%E' must not be void", argument->expression);
7169                 }
7170
7171                 argument_type = get_default_promoted_type(argument_type);
7172
7173                 argument->expression
7174                         = create_implicit_cast(argument->expression, argument_type);
7175         }
7176
7177         check_format(call);
7178
7179         if (is_type_compound(skip_typeref(function_type->return_type))) {
7180                 source_position_t const *const pos = &expression->base.source_position;
7181                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7182         }
7183
7184         if (expression->kind == EXPR_REFERENCE) {
7185                 reference_expression_t *reference = &expression->reference;
7186                 if (reference->entity->kind == ENTITY_FUNCTION &&
7187                     reference->entity->function.btk != BUILTIN_NONE)
7188                         handle_builtin_argument_restrictions(call);
7189         }
7190
7191         return result;
7192 }
7193
7194 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7195
7196 static bool same_compound_type(const type_t *type1, const type_t *type2)
7197 {
7198         return
7199                 is_type_compound(type1) &&
7200                 type1->kind == type2->kind &&
7201                 type1->compound.compound == type2->compound.compound;
7202 }
7203
7204 static expression_t const *get_reference_address(expression_t const *expr)
7205 {
7206         bool regular_take_address = true;
7207         for (;;) {
7208                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7209                         expr = expr->unary.value;
7210                 } else {
7211                         regular_take_address = false;
7212                 }
7213
7214                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7215                         break;
7216
7217                 expr = expr->unary.value;
7218         }
7219
7220         if (expr->kind != EXPR_REFERENCE)
7221                 return NULL;
7222
7223         /* special case for functions which are automatically converted to a
7224          * pointer to function without an extra TAKE_ADDRESS operation */
7225         if (!regular_take_address &&
7226                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7227                 return NULL;
7228         }
7229
7230         return expr;
7231 }
7232
7233 static void warn_reference_address_as_bool(expression_t const* expr)
7234 {
7235         expr = get_reference_address(expr);
7236         if (expr != NULL) {
7237                 source_position_t const *const pos = &expr->base.source_position;
7238                 entity_t          const *const ent = expr->reference.entity;
7239                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7240         }
7241 }
7242
7243 static void warn_assignment_in_condition(const expression_t *const expr)
7244 {
7245         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7246                 return;
7247         if (expr->base.parenthesized)
7248                 return;
7249         source_position_t const *const pos = &expr->base.source_position;
7250         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7251 }
7252
7253 static void semantic_condition(expression_t const *const expr,
7254                                char const *const context)
7255 {
7256         type_t *const type = skip_typeref(expr->base.type);
7257         if (is_type_scalar(type)) {
7258                 warn_reference_address_as_bool(expr);
7259                 warn_assignment_in_condition(expr);
7260         } else if (is_type_valid(type)) {
7261                 errorf(&expr->base.source_position,
7262                                 "%s must have scalar type", context);
7263         }
7264 }
7265
7266 /**
7267  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7268  *
7269  * @param expression  the conditional expression
7270  */
7271 static expression_t *parse_conditional_expression(expression_t *expression)
7272 {
7273         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7274
7275         conditional_expression_t *conditional = &result->conditional;
7276         conditional->condition                = expression;
7277
7278         eat('?');
7279         add_anchor_token(':');
7280
7281         /* §6.5.15:2  The first operand shall have scalar type. */
7282         semantic_condition(expression, "condition of conditional operator");
7283
7284         expression_t *true_expression = expression;
7285         bool          gnu_cond = false;
7286         if (GNU_MODE && token.kind == ':') {
7287                 gnu_cond = true;
7288         } else {
7289                 true_expression = parse_expression();
7290         }
7291         rem_anchor_token(':');
7292         expect(':');
7293         expression_t *false_expression =
7294                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7295
7296         type_t *const orig_true_type  = true_expression->base.type;
7297         type_t *const orig_false_type = false_expression->base.type;
7298         type_t *const true_type       = skip_typeref(orig_true_type);
7299         type_t *const false_type      = skip_typeref(orig_false_type);
7300
7301         /* 6.5.15.3 */
7302         source_position_t const *const pos = &conditional->base.source_position;
7303         type_t                        *result_type;
7304         if (is_type_void(true_type) || is_type_void(false_type)) {
7305                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7306                 if (true_expression->kind == EXPR_UNARY_THROW) {
7307                         result_type = false_type;
7308                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7309                         result_type = true_type;
7310                 } else {
7311                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7312                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7313                         }
7314                         result_type = type_void;
7315                 }
7316         } else if (is_type_arithmetic(true_type)
7317                    && is_type_arithmetic(false_type)) {
7318                 result_type = semantic_arithmetic(true_type, false_type);
7319         } else if (same_compound_type(true_type, false_type)) {
7320                 /* just take 1 of the 2 types */
7321                 result_type = true_type;
7322         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7323                 type_t *pointer_type;
7324                 type_t *other_type;
7325                 expression_t *other_expression;
7326                 if (is_type_pointer(true_type) &&
7327                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7328                         pointer_type     = true_type;
7329                         other_type       = false_type;
7330                         other_expression = false_expression;
7331                 } else {
7332                         pointer_type     = false_type;
7333                         other_type       = true_type;
7334                         other_expression = true_expression;
7335                 }
7336
7337                 if (is_null_pointer_constant(other_expression)) {
7338                         result_type = pointer_type;
7339                 } else if (is_type_pointer(other_type)) {
7340                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7341                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7342
7343                         type_t *to;
7344                         if (is_type_void(to1) || is_type_void(to2)) {
7345                                 to = type_void;
7346                         } else if (types_compatible(get_unqualified_type(to1),
7347                                                     get_unqualified_type(to2))) {
7348                                 to = to1;
7349                         } else {
7350                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7351                                 to = type_void;
7352                         }
7353
7354                         type_t *const type =
7355                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7356                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7357                 } else if (is_type_integer(other_type)) {
7358                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7359                         result_type = pointer_type;
7360                 } else {
7361                         goto types_incompatible;
7362                 }
7363         } else {
7364 types_incompatible:
7365                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7366                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7367                 }
7368                 result_type = type_error_type;
7369         }
7370
7371         conditional->true_expression
7372                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7373         conditional->false_expression
7374                 = create_implicit_cast(false_expression, result_type);
7375         conditional->base.type = result_type;
7376         return result;
7377 }
7378
7379 /**
7380  * Parse an extension expression.
7381  */
7382 static expression_t *parse_extension(void)
7383 {
7384         PUSH_EXTENSION();
7385         expression_t *expression = parse_subexpression(PREC_UNARY);
7386         POP_EXTENSION();
7387         return expression;
7388 }
7389
7390 /**
7391  * Parse a __builtin_classify_type() expression.
7392  */
7393 static expression_t *parse_builtin_classify_type(void)
7394 {
7395         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7396         result->base.type    = type_int;
7397
7398         eat(T___builtin_classify_type);
7399
7400         add_anchor_token(')');
7401         expect('(');
7402         expression_t *expression = parse_expression();
7403         rem_anchor_token(')');
7404         expect(')');
7405         result->classify_type.type_expression = expression;
7406
7407         return result;
7408 }
7409
7410 /**
7411  * Parse a delete expression
7412  * ISO/IEC 14882:1998(E) §5.3.5
7413  */
7414 static expression_t *parse_delete(void)
7415 {
7416         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7417         result->base.type          = type_void;
7418
7419         eat(T_delete);
7420
7421         if (next_if('[')) {
7422                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7423                 expect(']');
7424         }
7425
7426         expression_t *const value = parse_subexpression(PREC_CAST);
7427         result->unary.value = value;
7428
7429         type_t *const type = skip_typeref(value->base.type);
7430         if (!is_type_pointer(type)) {
7431                 if (is_type_valid(type)) {
7432                         errorf(&value->base.source_position,
7433                                         "operand of delete must have pointer type");
7434                 }
7435         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7436                 source_position_t const *const pos = &value->base.source_position;
7437                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7438         }
7439
7440         return result;
7441 }
7442
7443 /**
7444  * Parse a throw expression
7445  * ISO/IEC 14882:1998(E) §15:1
7446  */
7447 static expression_t *parse_throw(void)
7448 {
7449         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7450         result->base.type          = type_void;
7451
7452         eat(T_throw);
7453
7454         expression_t *value = NULL;
7455         switch (token.kind) {
7456                 EXPRESSION_START {
7457                         value = parse_assignment_expression();
7458                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7459                         type_t *const orig_type = value->base.type;
7460                         type_t *const type      = skip_typeref(orig_type);
7461                         if (is_type_incomplete(type)) {
7462                                 errorf(&value->base.source_position,
7463                                                 "cannot throw object of incomplete type '%T'", orig_type);
7464                         } else if (is_type_pointer(type)) {
7465                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7466                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7467                                         errorf(&value->base.source_position,
7468                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7469                                 }
7470                         }
7471                 }
7472
7473                 default:
7474                         break;
7475         }
7476         result->unary.value = value;
7477
7478         return result;
7479 }
7480
7481 static bool check_pointer_arithmetic(const source_position_t *source_position,
7482                                      type_t *pointer_type,
7483                                      type_t *orig_pointer_type)
7484 {
7485         type_t *points_to = pointer_type->pointer.points_to;
7486         points_to = skip_typeref(points_to);
7487
7488         if (is_type_incomplete(points_to)) {
7489                 if (!GNU_MODE || !is_type_void(points_to)) {
7490                         errorf(source_position,
7491                                "arithmetic with pointer to incomplete type '%T' not allowed",
7492                                orig_pointer_type);
7493                         return false;
7494                 } else {
7495                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7496                 }
7497         } else if (is_type_function(points_to)) {
7498                 if (!GNU_MODE) {
7499                         errorf(source_position,
7500                                "arithmetic with pointer to function type '%T' not allowed",
7501                                orig_pointer_type);
7502                         return false;
7503                 } else {
7504                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7505                 }
7506         }
7507         return true;
7508 }
7509
7510 static bool is_lvalue(const expression_t *expression)
7511 {
7512         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7513         switch (expression->kind) {
7514         case EXPR_ARRAY_ACCESS:
7515         case EXPR_COMPOUND_LITERAL:
7516         case EXPR_REFERENCE:
7517         case EXPR_SELECT:
7518         case EXPR_UNARY_DEREFERENCE:
7519                 return true;
7520
7521         default: {
7522                 type_t *type = skip_typeref(expression->base.type);
7523                 return
7524                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7525                         is_type_reference(type) ||
7526                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7527                          * error before, which maybe prevented properly recognizing it as
7528                          * lvalue. */
7529                         !is_type_valid(type);
7530         }
7531         }
7532 }
7533
7534 static void semantic_incdec(unary_expression_t *expression)
7535 {
7536         type_t *const orig_type = expression->value->base.type;
7537         type_t *const type      = skip_typeref(orig_type);
7538         if (is_type_pointer(type)) {
7539                 if (!check_pointer_arithmetic(&expression->base.source_position,
7540                                               type, orig_type)) {
7541                         return;
7542                 }
7543         } else if (!is_type_real(type) && is_type_valid(type)) {
7544                 /* TODO: improve error message */
7545                 errorf(&expression->base.source_position,
7546                        "operation needs an arithmetic or pointer type");
7547                 return;
7548         }
7549         if (!is_lvalue(expression->value)) {
7550                 /* TODO: improve error message */
7551                 errorf(&expression->base.source_position, "lvalue required as operand");
7552         }
7553         expression->base.type = orig_type;
7554 }
7555
7556 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7557 {
7558         type_t *const res_type = promote_integer(type);
7559         expr->base.type = res_type;
7560         expr->value     = create_implicit_cast(expr->value, res_type);
7561 }
7562
7563 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7564 {
7565         type_t *const orig_type = expression->value->base.type;
7566         type_t *const type      = skip_typeref(orig_type);
7567         if (!is_type_arithmetic(type)) {
7568                 if (is_type_valid(type)) {
7569                         /* TODO: improve error message */
7570                         errorf(&expression->base.source_position,
7571                                 "operation needs an arithmetic type");
7572                 }
7573                 return;
7574         } else if (is_type_integer(type)) {
7575                 promote_unary_int_expr(expression, type);
7576         } else {
7577                 expression->base.type = orig_type;
7578         }
7579 }
7580
7581 static void semantic_unexpr_plus(unary_expression_t *expression)
7582 {
7583         semantic_unexpr_arithmetic(expression);
7584         source_position_t const *const pos = &expression->base.source_position;
7585         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7586 }
7587
7588 static void semantic_not(unary_expression_t *expression)
7589 {
7590         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7591         semantic_condition(expression->value, "operand of !");
7592         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7593 }
7594
7595 static void semantic_unexpr_integer(unary_expression_t *expression)
7596 {
7597         type_t *const orig_type = expression->value->base.type;
7598         type_t *const type      = skip_typeref(orig_type);
7599         if (!is_type_integer(type)) {
7600                 if (is_type_valid(type)) {
7601                         errorf(&expression->base.source_position,
7602                                "operand of ~ must be of integer type");
7603                 }
7604                 return;
7605         }
7606
7607         promote_unary_int_expr(expression, type);
7608 }
7609
7610 static void semantic_dereference(unary_expression_t *expression)
7611 {
7612         type_t *const orig_type = expression->value->base.type;
7613         type_t *const type      = skip_typeref(orig_type);
7614         if (!is_type_pointer(type)) {
7615                 if (is_type_valid(type)) {
7616                         errorf(&expression->base.source_position,
7617                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7618                 }
7619                 return;
7620         }
7621
7622         type_t *result_type   = type->pointer.points_to;
7623         result_type           = automatic_type_conversion(result_type);
7624         expression->base.type = result_type;
7625 }
7626
7627 /**
7628  * Record that an address is taken (expression represents an lvalue).
7629  *
7630  * @param expression       the expression
7631  * @param may_be_register  if true, the expression might be an register
7632  */
7633 static void set_address_taken(expression_t *expression, bool may_be_register)
7634 {
7635         if (expression->kind != EXPR_REFERENCE)
7636                 return;
7637
7638         entity_t *const entity = expression->reference.entity;
7639
7640         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7641                 return;
7642
7643         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7644                         && !may_be_register) {
7645                 source_position_t const *const pos = &expression->base.source_position;
7646                 errorf(pos, "address of register '%N' requested", entity);
7647         }
7648
7649         entity->variable.address_taken = true;
7650 }
7651
7652 /**
7653  * Check the semantic of the address taken expression.
7654  */
7655 static void semantic_take_addr(unary_expression_t *expression)
7656 {
7657         expression_t *value = expression->value;
7658         value->base.type    = revert_automatic_type_conversion(value);
7659
7660         type_t *orig_type = value->base.type;
7661         type_t *type      = skip_typeref(orig_type);
7662         if (!is_type_valid(type))
7663                 return;
7664
7665         /* §6.5.3.2 */
7666         if (!is_lvalue(value)) {
7667                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7668         }
7669         if (is_bitfield(value)) {
7670                 errorf(&expression->base.source_position,
7671                        "'&' not allowed on bitfield");
7672         }
7673
7674         set_address_taken(value, false);
7675
7676         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7677 }
7678
7679 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7680 static expression_t *parse_##unexpression_type(void)                         \
7681 {                                                                            \
7682         expression_t *unary_expression                                           \
7683                 = allocate_expression_zero(unexpression_type);                       \
7684         eat(token_kind);                                                         \
7685         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7686                                                                                  \
7687         sfunc(&unary_expression->unary);                                         \
7688                                                                                  \
7689         return unary_expression;                                                 \
7690 }
7691
7692 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7693                                semantic_unexpr_arithmetic)
7694 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7695                                semantic_unexpr_plus)
7696 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7697                                semantic_not)
7698 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7699                                semantic_dereference)
7700 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7701                                semantic_take_addr)
7702 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7703                                semantic_unexpr_integer)
7704 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7705                                semantic_incdec)
7706 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7707                                semantic_incdec)
7708
7709 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7710                                                sfunc)                         \
7711 static expression_t *parse_##unexpression_type(expression_t *left)            \
7712 {                                                                             \
7713         expression_t *unary_expression                                            \
7714                 = allocate_expression_zero(unexpression_type);                        \
7715         eat(token_kind);                                                          \
7716         unary_expression->unary.value = left;                                     \
7717                                                                                   \
7718         sfunc(&unary_expression->unary);                                          \
7719                                                                               \
7720         return unary_expression;                                                  \
7721 }
7722
7723 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7724                                        EXPR_UNARY_POSTFIX_INCREMENT,
7725                                        semantic_incdec)
7726 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7727                                        EXPR_UNARY_POSTFIX_DECREMENT,
7728                                        semantic_incdec)
7729
7730 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7731 {
7732         /* TODO: handle complex + imaginary types */
7733
7734         type_left  = get_unqualified_type(type_left);
7735         type_right = get_unqualified_type(type_right);
7736
7737         /* §6.3.1.8 Usual arithmetic conversions */
7738         if (type_left == type_long_double || type_right == type_long_double) {
7739                 return type_long_double;
7740         } else if (type_left == type_double || type_right == type_double) {
7741                 return type_double;
7742         } else if (type_left == type_float || type_right == type_float) {
7743                 return type_float;
7744         }
7745
7746         type_left  = promote_integer(type_left);
7747         type_right = promote_integer(type_right);
7748
7749         if (type_left == type_right)
7750                 return type_left;
7751
7752         bool     const signed_left  = is_type_signed(type_left);
7753         bool     const signed_right = is_type_signed(type_right);
7754         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7755         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7756
7757         if (signed_left == signed_right)
7758                 return rank_left >= rank_right ? type_left : type_right;
7759
7760         unsigned           s_rank;
7761         unsigned           u_rank;
7762         atomic_type_kind_t s_akind;
7763         atomic_type_kind_t u_akind;
7764         type_t *s_type;
7765         type_t *u_type;
7766         if (signed_left) {
7767                 s_type = type_left;
7768                 u_type = type_right;
7769         } else {
7770                 s_type = type_right;
7771                 u_type = type_left;
7772         }
7773         s_akind = get_akind(s_type);
7774         u_akind = get_akind(u_type);
7775         s_rank  = get_akind_rank(s_akind);
7776         u_rank  = get_akind_rank(u_akind);
7777
7778         if (u_rank >= s_rank)
7779                 return u_type;
7780
7781         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7782                 return s_type;
7783
7784         switch (s_akind) {
7785         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7786         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7787         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7788
7789         default: panic("invalid atomic type");
7790         }
7791 }
7792
7793 /**
7794  * Check the semantic restrictions for a binary expression.
7795  */
7796 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7797 {
7798         expression_t *const left            = expression->left;
7799         expression_t *const right           = expression->right;
7800         type_t       *const orig_type_left  = left->base.type;
7801         type_t       *const orig_type_right = right->base.type;
7802         type_t       *const type_left       = skip_typeref(orig_type_left);
7803         type_t       *const type_right      = skip_typeref(orig_type_right);
7804
7805         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7806                 /* TODO: improve error message */
7807                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7808                         errorf(&expression->base.source_position,
7809                                "operation needs arithmetic types");
7810                 }
7811                 return;
7812         }
7813
7814         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7815         expression->left      = create_implicit_cast(left, arithmetic_type);
7816         expression->right     = create_implicit_cast(right, arithmetic_type);
7817         expression->base.type = arithmetic_type;
7818 }
7819
7820 static void semantic_binexpr_integer(binary_expression_t *const expression)
7821 {
7822         expression_t *const left            = expression->left;
7823         expression_t *const right           = expression->right;
7824         type_t       *const orig_type_left  = left->base.type;
7825         type_t       *const orig_type_right = right->base.type;
7826         type_t       *const type_left       = skip_typeref(orig_type_left);
7827         type_t       *const type_right      = skip_typeref(orig_type_right);
7828
7829         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7830                 /* TODO: improve error message */
7831                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7832                         errorf(&expression->base.source_position,
7833                                "operation needs integer types");
7834                 }
7835                 return;
7836         }
7837
7838         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7839         expression->left      = create_implicit_cast(left, result_type);
7840         expression->right     = create_implicit_cast(right, result_type);
7841         expression->base.type = result_type;
7842 }
7843
7844 static void warn_div_by_zero(binary_expression_t const *const expression)
7845 {
7846         if (!is_type_integer(expression->base.type))
7847                 return;
7848
7849         expression_t const *const right = expression->right;
7850         /* The type of the right operand can be different for /= */
7851         if (is_type_integer(right->base.type)                    &&
7852             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7853             !fold_constant_to_bool(right)) {
7854                 source_position_t const *const pos = &expression->base.source_position;
7855                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7856         }
7857 }
7858
7859 /**
7860  * Check the semantic restrictions for a div/mod expression.
7861  */
7862 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7863 {
7864         semantic_binexpr_arithmetic(expression);
7865         warn_div_by_zero(expression);
7866 }
7867
7868 static void warn_addsub_in_shift(const expression_t *const expr)
7869 {
7870         if (expr->base.parenthesized)
7871                 return;
7872
7873         char op;
7874         switch (expr->kind) {
7875                 case EXPR_BINARY_ADD: op = '+'; break;
7876                 case EXPR_BINARY_SUB: op = '-'; break;
7877                 default:              return;
7878         }
7879
7880         source_position_t const *const pos = &expr->base.source_position;
7881         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7882 }
7883
7884 static bool semantic_shift(binary_expression_t *expression)
7885 {
7886         expression_t *const left            = expression->left;
7887         expression_t *const right           = expression->right;
7888         type_t       *const orig_type_left  = left->base.type;
7889         type_t       *const orig_type_right = right->base.type;
7890         type_t       *      type_left       = skip_typeref(orig_type_left);
7891         type_t       *      type_right      = skip_typeref(orig_type_right);
7892
7893         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7894                 /* TODO: improve error message */
7895                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7896                         errorf(&expression->base.source_position,
7897                                "operands of shift operation must have integer types");
7898                 }
7899                 return false;
7900         }
7901
7902         type_left = promote_integer(type_left);
7903
7904         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7905                 source_position_t const *const pos   = &right->base.source_position;
7906                 long                     const count = fold_constant_to_int(right);
7907                 if (count < 0) {
7908                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7909                 } else if ((unsigned long)count >=
7910                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7911                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7912                 }
7913         }
7914
7915         type_right        = promote_integer(type_right);
7916         expression->right = create_implicit_cast(right, type_right);
7917
7918         return true;
7919 }
7920
7921 static void semantic_shift_op(binary_expression_t *expression)
7922 {
7923         expression_t *const left  = expression->left;
7924         expression_t *const right = expression->right;
7925
7926         if (!semantic_shift(expression))
7927                 return;
7928
7929         warn_addsub_in_shift(left);
7930         warn_addsub_in_shift(right);
7931
7932         type_t *const orig_type_left = left->base.type;
7933         type_t *      type_left      = skip_typeref(orig_type_left);
7934
7935         type_left             = promote_integer(type_left);
7936         expression->left      = create_implicit_cast(left, type_left);
7937         expression->base.type = type_left;
7938 }
7939
7940 static void semantic_add(binary_expression_t *expression)
7941 {
7942         expression_t *const left            = expression->left;
7943         expression_t *const right           = expression->right;
7944         type_t       *const orig_type_left  = left->base.type;
7945         type_t       *const orig_type_right = right->base.type;
7946         type_t       *const type_left       = skip_typeref(orig_type_left);
7947         type_t       *const type_right      = skip_typeref(orig_type_right);
7948
7949         /* §6.5.6 */
7950         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7951                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7952                 expression->left  = create_implicit_cast(left, arithmetic_type);
7953                 expression->right = create_implicit_cast(right, arithmetic_type);
7954                 expression->base.type = arithmetic_type;
7955         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7956                 check_pointer_arithmetic(&expression->base.source_position,
7957                                          type_left, orig_type_left);
7958                 expression->base.type = type_left;
7959         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7960                 check_pointer_arithmetic(&expression->base.source_position,
7961                                          type_right, orig_type_right);
7962                 expression->base.type = type_right;
7963         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7964                 errorf(&expression->base.source_position,
7965                        "invalid operands to binary + ('%T', '%T')",
7966                        orig_type_left, orig_type_right);
7967         }
7968 }
7969
7970 static void semantic_sub(binary_expression_t *expression)
7971 {
7972         expression_t            *const left            = expression->left;
7973         expression_t            *const right           = expression->right;
7974         type_t                  *const orig_type_left  = left->base.type;
7975         type_t                  *const orig_type_right = right->base.type;
7976         type_t                  *const type_left       = skip_typeref(orig_type_left);
7977         type_t                  *const type_right      = skip_typeref(orig_type_right);
7978         source_position_t const *const pos             = &expression->base.source_position;
7979
7980         /* §5.6.5 */
7981         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7982                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7983                 expression->left        = create_implicit_cast(left, arithmetic_type);
7984                 expression->right       = create_implicit_cast(right, arithmetic_type);
7985                 expression->base.type =  arithmetic_type;
7986         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7987                 check_pointer_arithmetic(&expression->base.source_position,
7988                                          type_left, orig_type_left);
7989                 expression->base.type = type_left;
7990         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7991                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7992                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7993                 if (!types_compatible(unqual_left, unqual_right)) {
7994                         errorf(pos,
7995                                "subtracting pointers to incompatible types '%T' and '%T'",
7996                                orig_type_left, orig_type_right);
7997                 } else if (!is_type_object(unqual_left)) {
7998                         if (!is_type_void(unqual_left)) {
7999                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8000                                        orig_type_left);
8001                         } else {
8002                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8003                         }
8004                 }
8005                 expression->base.type = type_ptrdiff_t;
8006         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8007                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8008                        orig_type_left, orig_type_right);
8009         }
8010 }
8011
8012 static void warn_string_literal_address(expression_t const* expr)
8013 {
8014         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8015                 expr = expr->unary.value;
8016                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8017                         return;
8018                 expr = expr->unary.value;
8019         }
8020
8021         if (expr->kind == EXPR_STRING_LITERAL) {
8022                 source_position_t const *const pos = &expr->base.source_position;
8023                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8024         }
8025 }
8026
8027 static bool maybe_negative(expression_t const *const expr)
8028 {
8029         switch (is_constant_expression(expr)) {
8030                 case EXPR_CLASS_ERROR:    return false;
8031                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8032                 default:                  return true;
8033         }
8034 }
8035
8036 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8037 {
8038         warn_string_literal_address(expr);
8039
8040         expression_t const* const ref = get_reference_address(expr);
8041         if (ref != NULL && is_null_pointer_constant(other)) {
8042                 entity_t const *const ent = ref->reference.entity;
8043                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8044         }
8045
8046         if (!expr->base.parenthesized) {
8047                 switch (expr->base.kind) {
8048                         case EXPR_BINARY_LESS:
8049                         case EXPR_BINARY_GREATER:
8050                         case EXPR_BINARY_LESSEQUAL:
8051                         case EXPR_BINARY_GREATEREQUAL:
8052                         case EXPR_BINARY_NOTEQUAL:
8053                         case EXPR_BINARY_EQUAL:
8054                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8055                                 break;
8056                         default:
8057                                 break;
8058                 }
8059         }
8060 }
8061
8062 /**
8063  * Check the semantics of comparison expressions.
8064  *
8065  * @param expression   The expression to check.
8066  */
8067 static void semantic_comparison(binary_expression_t *expression)
8068 {
8069         source_position_t const *const pos   = &expression->base.source_position;
8070         expression_t            *const left  = expression->left;
8071         expression_t            *const right = expression->right;
8072
8073         warn_comparison(pos, left, right);
8074         warn_comparison(pos, right, left);
8075
8076         type_t *orig_type_left  = left->base.type;
8077         type_t *orig_type_right = right->base.type;
8078         type_t *type_left       = skip_typeref(orig_type_left);
8079         type_t *type_right      = skip_typeref(orig_type_right);
8080
8081         /* TODO non-arithmetic types */
8082         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8083                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8084
8085                 /* test for signed vs unsigned compares */
8086                 if (is_type_integer(arithmetic_type)) {
8087                         bool const signed_left  = is_type_signed(type_left);
8088                         bool const signed_right = is_type_signed(type_right);
8089                         if (signed_left != signed_right) {
8090                                 /* FIXME long long needs better const folding magic */
8091                                 /* TODO check whether constant value can be represented by other type */
8092                                 if ((signed_left  && maybe_negative(left)) ||
8093                                                 (signed_right && maybe_negative(right))) {
8094                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8095                                 }
8096                         }
8097                 }
8098
8099                 expression->left        = create_implicit_cast(left, arithmetic_type);
8100                 expression->right       = create_implicit_cast(right, arithmetic_type);
8101                 expression->base.type   = arithmetic_type;
8102                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8103                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8104                     is_type_float(arithmetic_type)) {
8105                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8106                 }
8107         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8108                 /* TODO check compatibility */
8109         } else if (is_type_pointer(type_left)) {
8110                 expression->right = create_implicit_cast(right, type_left);
8111         } else if (is_type_pointer(type_right)) {
8112                 expression->left = create_implicit_cast(left, type_right);
8113         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8114                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8115         }
8116         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8117 }
8118
8119 /**
8120  * Checks if a compound type has constant fields.
8121  */
8122 static bool has_const_fields(const compound_type_t *type)
8123 {
8124         compound_t *compound = type->compound;
8125         entity_t   *entry    = compound->members.entities;
8126
8127         for (; entry != NULL; entry = entry->base.next) {
8128                 if (!is_declaration(entry))
8129                         continue;
8130
8131                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8132                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8133                         return true;
8134         }
8135
8136         return false;
8137 }
8138
8139 static bool is_valid_assignment_lhs(expression_t const* const left)
8140 {
8141         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8142         type_t *const type_left      = skip_typeref(orig_type_left);
8143
8144         if (!is_lvalue(left)) {
8145                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8146                        left);
8147                 return false;
8148         }
8149
8150         if (left->kind == EXPR_REFERENCE
8151                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8152                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8153                 return false;
8154         }
8155
8156         if (is_type_array(type_left)) {
8157                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8158                 return false;
8159         }
8160         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8161                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8162                        orig_type_left);
8163                 return false;
8164         }
8165         if (is_type_incomplete(type_left)) {
8166                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8167                        left, orig_type_left);
8168                 return false;
8169         }
8170         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8171                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8172                        left, orig_type_left);
8173                 return false;
8174         }
8175
8176         return true;
8177 }
8178
8179 static void semantic_arithmetic_assign(binary_expression_t *expression)
8180 {
8181         expression_t *left            = expression->left;
8182         expression_t *right           = expression->right;
8183         type_t       *orig_type_left  = left->base.type;
8184         type_t       *orig_type_right = right->base.type;
8185
8186         if (!is_valid_assignment_lhs(left))
8187                 return;
8188
8189         type_t *type_left  = skip_typeref(orig_type_left);
8190         type_t *type_right = skip_typeref(orig_type_right);
8191
8192         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8193                 /* TODO: improve error message */
8194                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8195                         errorf(&expression->base.source_position,
8196                                "operation needs arithmetic types");
8197                 }
8198                 return;
8199         }
8200
8201         /* combined instructions are tricky. We can't create an implicit cast on
8202          * the left side, because we need the uncasted form for the store.
8203          * The ast2firm pass has to know that left_type must be right_type
8204          * for the arithmetic operation and create a cast by itself */
8205         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8206         expression->right       = create_implicit_cast(right, arithmetic_type);
8207         expression->base.type   = type_left;
8208 }
8209
8210 static void semantic_divmod_assign(binary_expression_t *expression)
8211 {
8212         semantic_arithmetic_assign(expression);
8213         warn_div_by_zero(expression);
8214 }
8215
8216 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8217 {
8218         expression_t *const left            = expression->left;
8219         expression_t *const right           = expression->right;
8220         type_t       *const orig_type_left  = left->base.type;
8221         type_t       *const orig_type_right = right->base.type;
8222         type_t       *const type_left       = skip_typeref(orig_type_left);
8223         type_t       *const type_right      = skip_typeref(orig_type_right);
8224
8225         if (!is_valid_assignment_lhs(left))
8226                 return;
8227
8228         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8229                 /* combined instructions are tricky. We can't create an implicit cast on
8230                  * the left side, because we need the uncasted form for the store.
8231                  * The ast2firm pass has to know that left_type must be right_type
8232                  * for the arithmetic operation and create a cast by itself */
8233                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8234                 expression->right     = create_implicit_cast(right, arithmetic_type);
8235                 expression->base.type = type_left;
8236         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8237                 check_pointer_arithmetic(&expression->base.source_position,
8238                                          type_left, orig_type_left);
8239                 expression->base.type = type_left;
8240         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8241                 errorf(&expression->base.source_position,
8242                        "incompatible types '%T' and '%T' in assignment",
8243                        orig_type_left, orig_type_right);
8244         }
8245 }
8246
8247 static void semantic_integer_assign(binary_expression_t *expression)
8248 {
8249         expression_t *left            = expression->left;
8250         expression_t *right           = expression->right;
8251         type_t       *orig_type_left  = left->base.type;
8252         type_t       *orig_type_right = right->base.type;
8253
8254         if (!is_valid_assignment_lhs(left))
8255                 return;
8256
8257         type_t *type_left  = skip_typeref(orig_type_left);
8258         type_t *type_right = skip_typeref(orig_type_right);
8259
8260         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8261                 /* TODO: improve error message */
8262                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8263                         errorf(&expression->base.source_position,
8264                                "operation needs integer types");
8265                 }
8266                 return;
8267         }
8268
8269         /* combined instructions are tricky. We can't create an implicit cast on
8270          * the left side, because we need the uncasted form for the store.
8271          * The ast2firm pass has to know that left_type must be right_type
8272          * for the arithmetic operation and create a cast by itself */
8273         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8274         expression->right       = create_implicit_cast(right, arithmetic_type);
8275         expression->base.type   = type_left;
8276 }
8277
8278 static void semantic_shift_assign(binary_expression_t *expression)
8279 {
8280         expression_t *left           = expression->left;
8281
8282         if (!is_valid_assignment_lhs(left))
8283                 return;
8284
8285         if (!semantic_shift(expression))
8286                 return;
8287
8288         expression->base.type = skip_typeref(left->base.type);
8289 }
8290
8291 static void warn_logical_and_within_or(const expression_t *const expr)
8292 {
8293         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8294                 return;
8295         if (expr->base.parenthesized)
8296                 return;
8297         source_position_t const *const pos = &expr->base.source_position;
8298         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8299 }
8300
8301 /**
8302  * Check the semantic restrictions of a logical expression.
8303  */
8304 static void semantic_logical_op(binary_expression_t *expression)
8305 {
8306         /* §6.5.13:2  Each of the operands shall have scalar type.
8307          * §6.5.14:2  Each of the operands shall have scalar type. */
8308         semantic_condition(expression->left,   "left operand of logical operator");
8309         semantic_condition(expression->right, "right operand of logical operator");
8310         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8311                 warn_logical_and_within_or(expression->left);
8312                 warn_logical_and_within_or(expression->right);
8313         }
8314         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8315 }
8316
8317 /**
8318  * Check the semantic restrictions of a binary assign expression.
8319  */
8320 static void semantic_binexpr_assign(binary_expression_t *expression)
8321 {
8322         expression_t *left           = expression->left;
8323         type_t       *orig_type_left = left->base.type;
8324
8325         if (!is_valid_assignment_lhs(left))
8326                 return;
8327
8328         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8329         report_assign_error(error, orig_type_left, expression->right,
8330                         "assignment", &left->base.source_position);
8331         expression->right = create_implicit_cast(expression->right, orig_type_left);
8332         expression->base.type = orig_type_left;
8333 }
8334
8335 /**
8336  * Determine if the outermost operation (or parts thereof) of the given
8337  * expression has no effect in order to generate a warning about this fact.
8338  * Therefore in some cases this only examines some of the operands of the
8339  * expression (see comments in the function and examples below).
8340  * Examples:
8341  *   f() + 23;    // warning, because + has no effect
8342  *   x || f();    // no warning, because x controls execution of f()
8343  *   x ? y : f(); // warning, because y has no effect
8344  *   (void)x;     // no warning to be able to suppress the warning
8345  * This function can NOT be used for an "expression has definitely no effect"-
8346  * analysis. */
8347 static bool expression_has_effect(const expression_t *const expr)
8348 {
8349         switch (expr->kind) {
8350                 case EXPR_ERROR:                      return true; /* do NOT warn */
8351                 case EXPR_REFERENCE:                  return false;
8352                 case EXPR_ENUM_CONSTANT:              return false;
8353                 case EXPR_LABEL_ADDRESS:              return false;
8354
8355                 /* suppress the warning for microsoft __noop operations */
8356                 case EXPR_LITERAL_MS_NOOP:            return true;
8357                 case EXPR_LITERAL_BOOLEAN:
8358                 case EXPR_LITERAL_CHARACTER:
8359                 case EXPR_LITERAL_INTEGER:
8360                 case EXPR_LITERAL_FLOATINGPOINT:
8361                 case EXPR_STRING_LITERAL:             return false;
8362
8363                 case EXPR_CALL: {
8364                         const call_expression_t *const call = &expr->call;
8365                         if (call->function->kind != EXPR_REFERENCE)
8366                                 return true;
8367
8368                         switch (call->function->reference.entity->function.btk) {
8369                                 /* FIXME: which builtins have no effect? */
8370                                 default:                      return true;
8371                         }
8372                 }
8373
8374                 /* Generate the warning if either the left or right hand side of a
8375                  * conditional expression has no effect */
8376                 case EXPR_CONDITIONAL: {
8377                         conditional_expression_t const *const cond = &expr->conditional;
8378                         expression_t             const *const t    = cond->true_expression;
8379                         return
8380                                 (t == NULL || expression_has_effect(t)) &&
8381                                 expression_has_effect(cond->false_expression);
8382                 }
8383
8384                 case EXPR_SELECT:                     return false;
8385                 case EXPR_ARRAY_ACCESS:               return false;
8386                 case EXPR_SIZEOF:                     return false;
8387                 case EXPR_CLASSIFY_TYPE:              return false;
8388                 case EXPR_ALIGNOF:                    return false;
8389
8390                 case EXPR_FUNCNAME:                   return false;
8391                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8392                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8393                 case EXPR_OFFSETOF:                   return false;
8394                 case EXPR_VA_START:                   return true;
8395                 case EXPR_VA_ARG:                     return true;
8396                 case EXPR_VA_COPY:                    return true;
8397                 case EXPR_STATEMENT:                  return true; // TODO
8398                 case EXPR_COMPOUND_LITERAL:           return false;
8399
8400                 case EXPR_UNARY_NEGATE:               return false;
8401                 case EXPR_UNARY_PLUS:                 return false;
8402                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8403                 case EXPR_UNARY_NOT:                  return false;
8404                 case EXPR_UNARY_DEREFERENCE:          return false;
8405                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8406                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8407                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8408                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8409                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8410
8411                 /* Treat void casts as if they have an effect in order to being able to
8412                  * suppress the warning */
8413                 case EXPR_UNARY_CAST: {
8414                         type_t *const type = skip_typeref(expr->base.type);
8415                         return is_type_void(type);
8416                 }
8417
8418                 case EXPR_UNARY_ASSUME:               return true;
8419                 case EXPR_UNARY_DELETE:               return true;
8420                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8421                 case EXPR_UNARY_THROW:                return true;
8422
8423                 case EXPR_BINARY_ADD:                 return false;
8424                 case EXPR_BINARY_SUB:                 return false;
8425                 case EXPR_BINARY_MUL:                 return false;
8426                 case EXPR_BINARY_DIV:                 return false;
8427                 case EXPR_BINARY_MOD:                 return false;
8428                 case EXPR_BINARY_EQUAL:               return false;
8429                 case EXPR_BINARY_NOTEQUAL:            return false;
8430                 case EXPR_BINARY_LESS:                return false;
8431                 case EXPR_BINARY_LESSEQUAL:           return false;
8432                 case EXPR_BINARY_GREATER:             return false;
8433                 case EXPR_BINARY_GREATEREQUAL:        return false;
8434                 case EXPR_BINARY_BITWISE_AND:         return false;
8435                 case EXPR_BINARY_BITWISE_OR:          return false;
8436                 case EXPR_BINARY_BITWISE_XOR:         return false;
8437                 case EXPR_BINARY_SHIFTLEFT:           return false;
8438                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8439                 case EXPR_BINARY_ASSIGN:              return true;
8440                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8441                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8442                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8443                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8444                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8445                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8446                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8447                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8448                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8449                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8450
8451                 /* Only examine the right hand side of && and ||, because the left hand
8452                  * side already has the effect of controlling the execution of the right
8453                  * hand side */
8454                 case EXPR_BINARY_LOGICAL_AND:
8455                 case EXPR_BINARY_LOGICAL_OR:
8456                 /* Only examine the right hand side of a comma expression, because the left
8457                  * hand side has a separate warning */
8458                 case EXPR_BINARY_COMMA:
8459                         return expression_has_effect(expr->binary.right);
8460
8461                 case EXPR_BINARY_ISGREATER:           return false;
8462                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8463                 case EXPR_BINARY_ISLESS:              return false;
8464                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8465                 case EXPR_BINARY_ISLESSGREATER:       return false;
8466                 case EXPR_BINARY_ISUNORDERED:         return false;
8467         }
8468
8469         internal_errorf(HERE, "unexpected expression");
8470 }
8471
8472 static void semantic_comma(binary_expression_t *expression)
8473 {
8474         const expression_t *const left = expression->left;
8475         if (!expression_has_effect(left)) {
8476                 source_position_t const *const pos = &left->base.source_position;
8477                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8478         }
8479         expression->base.type = expression->right->base.type;
8480 }
8481
8482 /**
8483  * @param prec_r precedence of the right operand
8484  */
8485 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8486 static expression_t *parse_##binexpression_type(expression_t *left)          \
8487 {                                                                            \
8488         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8489         binexpr->binary.left  = left;                                            \
8490         eat(token_kind);                                                         \
8491                                                                              \
8492         expression_t *right = parse_subexpression(prec_r);                       \
8493                                                                              \
8494         binexpr->binary.right = right;                                           \
8495         sfunc(&binexpr->binary);                                                 \
8496                                                                              \
8497         return binexpr;                                                          \
8498 }
8499
8500 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8501 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8502 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8503 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8504 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8505 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8506 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8507 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8508 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8509 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8510 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8511 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8512 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8513 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8514 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8515 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8516 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8517 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8518 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8519 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8520 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8521 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8522 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8523 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8524 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8525 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8526 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8527 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8528 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8529 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8530
8531
8532 static expression_t *parse_subexpression(precedence_t precedence)
8533 {
8534         expression_parser_function_t *parser
8535                 = &expression_parsers[token.kind];
8536         expression_t                 *left;
8537
8538         if (parser->parser != NULL) {
8539                 left = parser->parser();
8540         } else {
8541                 left = parse_primary_expression();
8542         }
8543         assert(left != NULL);
8544
8545         while (true) {
8546                 parser = &expression_parsers[token.kind];
8547                 if (parser->infix_parser == NULL)
8548                         break;
8549                 if (parser->infix_precedence < precedence)
8550                         break;
8551
8552                 left = parser->infix_parser(left);
8553
8554                 assert(left != NULL);
8555         }
8556
8557         return left;
8558 }
8559
8560 /**
8561  * Parse an expression.
8562  */
8563 static expression_t *parse_expression(void)
8564 {
8565         return parse_subexpression(PREC_EXPRESSION);
8566 }
8567
8568 /**
8569  * Register a parser for a prefix-like operator.
8570  *
8571  * @param parser      the parser function
8572  * @param token_kind  the token type of the prefix token
8573  */
8574 static void register_expression_parser(parse_expression_function parser,
8575                                        int token_kind)
8576 {
8577         expression_parser_function_t *entry = &expression_parsers[token_kind];
8578
8579         assert(!entry->parser);
8580         entry->parser = parser;
8581 }
8582
8583 /**
8584  * Register a parser for an infix operator with given precedence.
8585  *
8586  * @param parser      the parser function
8587  * @param token_kind  the token type of the infix operator
8588  * @param precedence  the precedence of the operator
8589  */
8590 static void register_infix_parser(parse_expression_infix_function parser,
8591                                   int token_kind, precedence_t precedence)
8592 {
8593         expression_parser_function_t *entry = &expression_parsers[token_kind];
8594
8595         assert(!entry->infix_parser);
8596         entry->infix_parser     = parser;
8597         entry->infix_precedence = precedence;
8598 }
8599
8600 /**
8601  * Initialize the expression parsers.
8602  */
8603 static void init_expression_parsers(void)
8604 {
8605         memset(&expression_parsers, 0, sizeof(expression_parsers));
8606
8607         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8608         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8609         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8610         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8611         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8612         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8613         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8614         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8615         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8616         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8617         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8618         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8619         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8620         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8621         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8622         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8623         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8624         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8625         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8626         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8627         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8628         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8629         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8630         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8631         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8632         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8633         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8634         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8635         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8636         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8637         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8638         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8639         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8640         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8641         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8642         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8643         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8644
8645         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8646         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8647         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8648         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8649         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8650         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8651         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8652         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8653         register_expression_parser(parse_sizeof,                      T_sizeof);
8654         register_expression_parser(parse_alignof,                     T__Alignof);
8655         register_expression_parser(parse_extension,                   T___extension__);
8656         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8657         register_expression_parser(parse_delete,                      T_delete);
8658         register_expression_parser(parse_throw,                       T_throw);
8659 }
8660
8661 /**
8662  * Parse a asm statement arguments specification.
8663  */
8664 static asm_argument_t *parse_asm_arguments(bool is_out)
8665 {
8666         asm_argument_t  *result = NULL;
8667         asm_argument_t **anchor = &result;
8668
8669         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8670                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8671
8672                 if (next_if('[')) {
8673                         add_anchor_token(']');
8674                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8675                         rem_anchor_token(']');
8676                         expect(']');
8677                         if (!argument->symbol)
8678                                 return NULL;
8679                 }
8680
8681                 argument->constraints = parse_string_literals("asm argument");
8682                 add_anchor_token(')');
8683                 expect('(');
8684                 expression_t *expression = parse_expression();
8685                 rem_anchor_token(')');
8686                 if (is_out) {
8687                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8688                          * change size or type representation (e.g. int -> long is ok, but
8689                          * int -> float is not) */
8690                         if (expression->kind == EXPR_UNARY_CAST) {
8691                                 type_t      *const type = expression->base.type;
8692                                 type_kind_t  const kind = type->kind;
8693                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8694                                         unsigned flags;
8695                                         unsigned size;
8696                                         if (kind == TYPE_ATOMIC) {
8697                                                 atomic_type_kind_t const akind = type->atomic.akind;
8698                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8699                                                 size  = get_atomic_type_size(akind);
8700                                         } else {
8701                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8702                                                 size  = get_type_size(type_void_ptr);
8703                                         }
8704
8705                                         do {
8706                                                 expression_t *const value      = expression->unary.value;
8707                                                 type_t       *const value_type = value->base.type;
8708                                                 type_kind_t   const value_kind = value_type->kind;
8709
8710                                                 unsigned value_flags;
8711                                                 unsigned value_size;
8712                                                 if (value_kind == TYPE_ATOMIC) {
8713                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8714                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8715                                                         value_size  = get_atomic_type_size(value_akind);
8716                                                 } else if (value_kind == TYPE_POINTER) {
8717                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8718                                                         value_size  = get_type_size(type_void_ptr);
8719                                                 } else {
8720                                                         break;
8721                                                 }
8722
8723                                                 if (value_flags != flags || value_size != size)
8724                                                         break;
8725
8726                                                 expression = value;
8727                                         } while (expression->kind == EXPR_UNARY_CAST);
8728                                 }
8729                         }
8730
8731                         if (!is_lvalue(expression)) {
8732                                 errorf(&expression->base.source_position,
8733                                        "asm output argument is not an lvalue");
8734                         }
8735
8736                         if (argument->constraints.begin[0] == '=')
8737                                 determine_lhs_ent(expression, NULL);
8738                         else
8739                                 mark_vars_read(expression, NULL);
8740                 } else {
8741                         mark_vars_read(expression, NULL);
8742                 }
8743                 argument->expression = expression;
8744                 expect(')');
8745
8746                 set_address_taken(expression, true);
8747
8748                 *anchor = argument;
8749                 anchor  = &argument->next;
8750
8751                 if (!next_if(','))
8752                         break;
8753         }
8754
8755         return result;
8756 }
8757
8758 /**
8759  * Parse a asm statement clobber specification.
8760  */
8761 static asm_clobber_t *parse_asm_clobbers(void)
8762 {
8763         asm_clobber_t *result  = NULL;
8764         asm_clobber_t **anchor = &result;
8765
8766         while (token.kind == T_STRING_LITERAL) {
8767                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8768                 clobber->clobber       = parse_string_literals(NULL);
8769
8770                 *anchor = clobber;
8771                 anchor  = &clobber->next;
8772
8773                 if (!next_if(','))
8774                         break;
8775         }
8776
8777         return result;
8778 }
8779
8780 /**
8781  * Parse an asm statement.
8782  */
8783 static statement_t *parse_asm_statement(void)
8784 {
8785         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8786         asm_statement_t *asm_statement = &statement->asms;
8787
8788         eat(T_asm);
8789         add_anchor_token(')');
8790         add_anchor_token(':');
8791         add_anchor_token(T_STRING_LITERAL);
8792
8793         if (next_if(T_volatile))
8794                 asm_statement->is_volatile = true;
8795
8796         expect('(');
8797         rem_anchor_token(T_STRING_LITERAL);
8798         asm_statement->asm_text = parse_string_literals("asm statement");
8799
8800         if (next_if(':'))
8801                 asm_statement->outputs = parse_asm_arguments(true);
8802
8803         if (next_if(':'))
8804                 asm_statement->inputs = parse_asm_arguments(false);
8805
8806         rem_anchor_token(':');
8807         if (next_if(':'))
8808                 asm_statement->clobbers = parse_asm_clobbers();
8809
8810         rem_anchor_token(')');
8811         expect(')');
8812         expect(';');
8813
8814         if (asm_statement->outputs == NULL) {
8815                 /* GCC: An 'asm' instruction without any output operands will be treated
8816                  * identically to a volatile 'asm' instruction. */
8817                 asm_statement->is_volatile = true;
8818         }
8819
8820         return statement;
8821 }
8822
8823 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8824 {
8825         statement_t *inner_stmt;
8826         switch (token.kind) {
8827                 case '}':
8828                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8829                         inner_stmt = create_error_statement();
8830                         break;
8831
8832                 case ';':
8833                         if (label->kind == STATEMENT_LABEL) {
8834                                 /* Eat an empty statement here, to avoid the warning about an empty
8835                                  * statement after a label.  label:; is commonly used to have a label
8836                                  * before a closing brace. */
8837                                 inner_stmt = create_empty_statement();
8838                                 eat(';');
8839                                 break;
8840                         }
8841                         /* FALLTHROUGH */
8842
8843                 default:
8844                         inner_stmt = parse_statement();
8845                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8846                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8847                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8848                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8849                         }
8850                         break;
8851         }
8852         return inner_stmt;
8853 }
8854
8855 /**
8856  * Parse a case statement.
8857  */
8858 static statement_t *parse_case_statement(void)
8859 {
8860         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8861         source_position_t *const pos       = &statement->base.source_position;
8862
8863         eat(T_case);
8864         add_anchor_token(':');
8865
8866         expression_t *expression = parse_expression();
8867         type_t *expression_type = expression->base.type;
8868         type_t *skipped         = skip_typeref(expression_type);
8869         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8870                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8871                        expression, expression_type);
8872         }
8873
8874         type_t *type = expression_type;
8875         if (current_switch != NULL) {
8876                 type_t *switch_type = current_switch->expression->base.type;
8877                 if (is_type_valid(switch_type)) {
8878                         expression = create_implicit_cast(expression, switch_type);
8879                 }
8880         }
8881
8882         statement->case_label.expression = expression;
8883         expression_classification_t const expr_class = is_constant_expression(expression);
8884         if (expr_class != EXPR_CLASS_CONSTANT) {
8885                 if (expr_class != EXPR_CLASS_ERROR) {
8886                         errorf(pos, "case label does not reduce to an integer constant");
8887                 }
8888                 statement->case_label.is_bad = true;
8889         } else {
8890                 long const val = fold_constant_to_int(expression);
8891                 statement->case_label.first_case = val;
8892                 statement->case_label.last_case  = val;
8893         }
8894
8895         if (GNU_MODE) {
8896                 if (next_if(T_DOTDOTDOT)) {
8897                         expression_t *end_range = parse_expression();
8898                         expression_type = expression->base.type;
8899                         skipped         = skip_typeref(expression_type);
8900                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8901                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8902                                            expression, expression_type);
8903                         }
8904
8905                         end_range = create_implicit_cast(end_range, type);
8906                         statement->case_label.end_range = end_range;
8907                         expression_classification_t const end_class = is_constant_expression(end_range);
8908                         if (end_class != EXPR_CLASS_CONSTANT) {
8909                                 if (end_class != EXPR_CLASS_ERROR) {
8910                                         errorf(pos, "case range does not reduce to an integer constant");
8911                                 }
8912                                 statement->case_label.is_bad = true;
8913                         } else {
8914                                 long const val = fold_constant_to_int(end_range);
8915                                 statement->case_label.last_case = val;
8916
8917                                 if (val < statement->case_label.first_case) {
8918                                         statement->case_label.is_empty_range = true;
8919                                         warningf(WARN_OTHER, pos, "empty range specified");
8920                                 }
8921                         }
8922                 }
8923         }
8924
8925         PUSH_PARENT(statement);
8926
8927         rem_anchor_token(':');
8928         expect(':');
8929
8930         if (current_switch != NULL) {
8931                 if (! statement->case_label.is_bad) {
8932                         /* Check for duplicate case values */
8933                         case_label_statement_t *c = &statement->case_label;
8934                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8935                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8936                                         continue;
8937
8938                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8939                                         continue;
8940
8941                                 errorf(pos, "duplicate case value (previously used %P)",
8942                                        &l->base.source_position);
8943                                 break;
8944                         }
8945                 }
8946                 /* link all cases into the switch statement */
8947                 if (current_switch->last_case == NULL) {
8948                         current_switch->first_case      = &statement->case_label;
8949                 } else {
8950                         current_switch->last_case->next = &statement->case_label;
8951                 }
8952                 current_switch->last_case = &statement->case_label;
8953         } else {
8954                 errorf(pos, "case label not within a switch statement");
8955         }
8956
8957         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8958
8959         POP_PARENT();
8960         return statement;
8961 }
8962
8963 /**
8964  * Parse a default statement.
8965  */
8966 static statement_t *parse_default_statement(void)
8967 {
8968         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8969
8970         eat(T_default);
8971
8972         PUSH_PARENT(statement);
8973
8974         expect(':');
8975
8976         if (current_switch != NULL) {
8977                 const case_label_statement_t *def_label = current_switch->default_label;
8978                 if (def_label != NULL) {
8979                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8980                 } else {
8981                         current_switch->default_label = &statement->case_label;
8982
8983                         /* link all cases into the switch statement */
8984                         if (current_switch->last_case == NULL) {
8985                                 current_switch->first_case      = &statement->case_label;
8986                         } else {
8987                                 current_switch->last_case->next = &statement->case_label;
8988                         }
8989                         current_switch->last_case = &statement->case_label;
8990                 }
8991         } else {
8992                 errorf(&statement->base.source_position,
8993                         "'default' label not within a switch statement");
8994         }
8995
8996         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8997
8998         POP_PARENT();
8999         return statement;
9000 }
9001
9002 /**
9003  * Parse a label statement.
9004  */
9005 static statement_t *parse_label_statement(void)
9006 {
9007         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9008         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9009         statement->label.label = label;
9010
9011         PUSH_PARENT(statement);
9012
9013         /* if statement is already set then the label is defined twice,
9014          * otherwise it was just mentioned in a goto/local label declaration so far
9015          */
9016         source_position_t const* const pos = &statement->base.source_position;
9017         if (label->statement != NULL) {
9018                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9019         } else {
9020                 label->base.source_position = *pos;
9021                 label->statement            = statement;
9022         }
9023
9024         eat(':');
9025
9026         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9027                 parse_attributes(NULL); // TODO process attributes
9028         }
9029
9030         statement->label.statement = parse_label_inner_statement(statement, "label");
9031
9032         /* remember the labels in a list for later checking */
9033         *label_anchor = &statement->label;
9034         label_anchor  = &statement->label.next;
9035
9036         POP_PARENT();
9037         return statement;
9038 }
9039
9040 static statement_t *parse_inner_statement(void)
9041 {
9042         statement_t *const stmt = parse_statement();
9043         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9044         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9045         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9046                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9047         }
9048         return stmt;
9049 }
9050
9051 /**
9052  * Parse an expression in parentheses and mark its variables as read.
9053  */
9054 static expression_t *parse_condition(void)
9055 {
9056         add_anchor_token(')');
9057         expect('(');
9058         expression_t *const expr = parse_expression();
9059         mark_vars_read(expr, NULL);
9060         rem_anchor_token(')');
9061         expect(')');
9062         return expr;
9063 }
9064
9065 /**
9066  * Parse an if statement.
9067  */
9068 static statement_t *parse_if(void)
9069 {
9070         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9071
9072         eat(T_if);
9073
9074         PUSH_PARENT(statement);
9075         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9076
9077         add_anchor_token(T_else);
9078
9079         expression_t *const expr = parse_condition();
9080         statement->ifs.condition = expr;
9081         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9082          *             scalar type. */
9083         semantic_condition(expr, "condition of 'if'-statment");
9084
9085         statement_t *const true_stmt = parse_inner_statement();
9086         statement->ifs.true_statement = true_stmt;
9087         rem_anchor_token(T_else);
9088
9089         if (true_stmt->kind == STATEMENT_EMPTY) {
9090                 warningf(WARN_EMPTY_BODY, HERE,
9091                         "suggest braces around empty body in an ‘if’ statement");
9092         }
9093
9094         if (next_if(T_else)) {
9095                 statement->ifs.false_statement = parse_inner_statement();
9096
9097                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9098                         warningf(WARN_EMPTY_BODY, HERE,
9099                                         "suggest braces around empty body in an ‘if’ statement");
9100                 }
9101         } else if (true_stmt->kind == STATEMENT_IF &&
9102                         true_stmt->ifs.false_statement != NULL) {
9103                 source_position_t const *const pos = &true_stmt->base.source_position;
9104                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9105         }
9106
9107         POP_SCOPE();
9108         POP_PARENT();
9109         return statement;
9110 }
9111
9112 /**
9113  * Check that all enums are handled in a switch.
9114  *
9115  * @param statement  the switch statement to check
9116  */
9117 static void check_enum_cases(const switch_statement_t *statement)
9118 {
9119         if (!is_warn_on(WARN_SWITCH_ENUM))
9120                 return;
9121         const type_t *type = skip_typeref(statement->expression->base.type);
9122         if (! is_type_enum(type))
9123                 return;
9124         const enum_type_t *enumt = &type->enumt;
9125
9126         /* if we have a default, no warnings */
9127         if (statement->default_label != NULL)
9128                 return;
9129
9130         /* FIXME: calculation of value should be done while parsing */
9131         /* TODO: quadratic algorithm here. Change to an n log n one */
9132         long            last_value = -1;
9133         const entity_t *entry      = enumt->enume->base.next;
9134         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9135              entry = entry->base.next) {
9136                 const expression_t *expression = entry->enum_value.value;
9137                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9138                 bool                found      = false;
9139                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9140                         if (l->expression == NULL)
9141                                 continue;
9142                         if (l->first_case <= value && value <= l->last_case) {
9143                                 found = true;
9144                                 break;
9145                         }
9146                 }
9147                 if (!found) {
9148                         source_position_t const *const pos = &statement->base.source_position;
9149                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9150                 }
9151                 last_value = value;
9152         }
9153 }
9154
9155 /**
9156  * Parse a switch statement.
9157  */
9158 static statement_t *parse_switch(void)
9159 {
9160         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9161
9162         eat(T_switch);
9163
9164         PUSH_PARENT(statement);
9165         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9166
9167         expression_t *const expr = parse_condition();
9168         type_t       *      type = skip_typeref(expr->base.type);
9169         if (is_type_integer(type)) {
9170                 type = promote_integer(type);
9171                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9172                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9173                 }
9174         } else if (is_type_valid(type)) {
9175                 errorf(&expr->base.source_position,
9176                        "switch quantity is not an integer, but '%T'", type);
9177                 type = type_error_type;
9178         }
9179         statement->switchs.expression = create_implicit_cast(expr, type);
9180
9181         switch_statement_t *rem = current_switch;
9182         current_switch          = &statement->switchs;
9183         statement->switchs.body = parse_inner_statement();
9184         current_switch          = rem;
9185
9186         if (statement->switchs.default_label == NULL) {
9187                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9188         }
9189         check_enum_cases(&statement->switchs);
9190
9191         POP_SCOPE();
9192         POP_PARENT();
9193         return statement;
9194 }
9195
9196 static statement_t *parse_loop_body(statement_t *const loop)
9197 {
9198         statement_t *const rem = current_loop;
9199         current_loop = loop;
9200
9201         statement_t *const body = parse_inner_statement();
9202
9203         current_loop = rem;
9204         return body;
9205 }
9206
9207 /**
9208  * Parse a while statement.
9209  */
9210 static statement_t *parse_while(void)
9211 {
9212         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9213
9214         eat(T_while);
9215
9216         PUSH_PARENT(statement);
9217         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9218
9219         expression_t *const cond = parse_condition();
9220         statement->whiles.condition = cond;
9221         /* §6.8.5:2    The controlling expression of an iteration statement shall
9222          *             have scalar type. */
9223         semantic_condition(cond, "condition of 'while'-statement");
9224
9225         statement->whiles.body = parse_loop_body(statement);
9226
9227         POP_SCOPE();
9228         POP_PARENT();
9229         return statement;
9230 }
9231
9232 /**
9233  * Parse a do statement.
9234  */
9235 static statement_t *parse_do(void)
9236 {
9237         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9238
9239         eat(T_do);
9240
9241         PUSH_PARENT(statement);
9242         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9243
9244         add_anchor_token(T_while);
9245         statement->do_while.body = parse_loop_body(statement);
9246         rem_anchor_token(T_while);
9247
9248         expect(T_while);
9249         expression_t *const cond = parse_condition();
9250         statement->do_while.condition = cond;
9251         /* §6.8.5:2    The controlling expression of an iteration statement shall
9252          *             have scalar type. */
9253         semantic_condition(cond, "condition of 'do-while'-statement");
9254         expect(';');
9255
9256         POP_SCOPE();
9257         POP_PARENT();
9258         return statement;
9259 }
9260
9261 /**
9262  * Parse a for statement.
9263  */
9264 static statement_t *parse_for(void)
9265 {
9266         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9267
9268         eat(T_for);
9269
9270         PUSH_PARENT(statement);
9271         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9272
9273         add_anchor_token(')');
9274         expect('(');
9275
9276         PUSH_EXTENSION();
9277
9278         if (next_if(';')) {
9279         } else if (is_declaration_specifier(&token)) {
9280                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9281         } else {
9282                 add_anchor_token(';');
9283                 expression_t *const init = parse_expression();
9284                 statement->fors.initialisation = init;
9285                 mark_vars_read(init, ENT_ANY);
9286                 if (!expression_has_effect(init)) {
9287                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9288                 }
9289                 rem_anchor_token(';');
9290                 expect(';');
9291         }
9292
9293         POP_EXTENSION();
9294
9295         if (token.kind != ';') {
9296                 add_anchor_token(';');
9297                 expression_t *const cond = parse_expression();
9298                 statement->fors.condition = cond;
9299                 /* §6.8.5:2    The controlling expression of an iteration statement
9300                  *             shall have scalar type. */
9301                 semantic_condition(cond, "condition of 'for'-statement");
9302                 mark_vars_read(cond, NULL);
9303                 rem_anchor_token(';');
9304         }
9305         expect(';');
9306         if (token.kind != ')') {
9307                 expression_t *const step = parse_expression();
9308                 statement->fors.step = step;
9309                 mark_vars_read(step, ENT_ANY);
9310                 if (!expression_has_effect(step)) {
9311                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9312                 }
9313         }
9314         rem_anchor_token(')');
9315         expect(')');
9316         statement->fors.body = parse_loop_body(statement);
9317
9318         POP_SCOPE();
9319         POP_PARENT();
9320         return statement;
9321 }
9322
9323 /**
9324  * Parse a goto statement.
9325  */
9326 static statement_t *parse_goto(void)
9327 {
9328         statement_t *statement;
9329         if (GNU_MODE && look_ahead(1)->kind == '*') {
9330                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9331                 eat(T_goto);
9332                 eat('*');
9333
9334                 expression_t *expression = parse_expression();
9335                 mark_vars_read(expression, NULL);
9336
9337                 /* Argh: although documentation says the expression must be of type void*,
9338                  * gcc accepts anything that can be casted into void* without error */
9339                 type_t *type = expression->base.type;
9340
9341                 if (type != type_error_type) {
9342                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9343                                 errorf(&expression->base.source_position,
9344                                         "cannot convert to a pointer type");
9345                         } else if (type != type_void_ptr) {
9346                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9347                         }
9348                         expression = create_implicit_cast(expression, type_void_ptr);
9349                 }
9350
9351                 statement->computed_goto.expression = expression;
9352         } else {
9353                 statement = allocate_statement_zero(STATEMENT_GOTO);
9354                 eat(T_goto);
9355
9356                 label_t *const label = get_label("while parsing goto");
9357                 if (label) {
9358                         label->used            = true;
9359                         statement->gotos.label = label;
9360
9361                         /* remember the goto's in a list for later checking */
9362                         *goto_anchor = &statement->gotos;
9363                         goto_anchor  = &statement->gotos.next;
9364                 } else {
9365                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9366                 }
9367         }
9368
9369         expect(';');
9370         return statement;
9371 }
9372
9373 /**
9374  * Parse a continue statement.
9375  */
9376 static statement_t *parse_continue(void)
9377 {
9378         if (current_loop == NULL) {
9379                 errorf(HERE, "continue statement not within loop");
9380         }
9381
9382         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9383
9384         eat(T_continue);
9385         expect(';');
9386         return statement;
9387 }
9388
9389 /**
9390  * Parse a break statement.
9391  */
9392 static statement_t *parse_break(void)
9393 {
9394         if (current_switch == NULL && current_loop == NULL) {
9395                 errorf(HERE, "break statement not within loop or switch");
9396         }
9397
9398         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9399
9400         eat(T_break);
9401         expect(';');
9402         return statement;
9403 }
9404
9405 /**
9406  * Parse a __leave statement.
9407  */
9408 static statement_t *parse_leave_statement(void)
9409 {
9410         if (current_try == NULL) {
9411                 errorf(HERE, "__leave statement not within __try");
9412         }
9413
9414         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9415
9416         eat(T___leave);
9417         expect(';');
9418         return statement;
9419 }
9420
9421 /**
9422  * Check if a given entity represents a local variable.
9423  */
9424 static bool is_local_variable(const entity_t *entity)
9425 {
9426         if (entity->kind != ENTITY_VARIABLE)
9427                 return false;
9428
9429         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9430         case STORAGE_CLASS_AUTO:
9431         case STORAGE_CLASS_REGISTER: {
9432                 const type_t *type = skip_typeref(entity->declaration.type);
9433                 if (is_type_function(type)) {
9434                         return false;
9435                 } else {
9436                         return true;
9437                 }
9438         }
9439         default:
9440                 return false;
9441         }
9442 }
9443
9444 /**
9445  * Check if a given expression represents a local variable.
9446  */
9447 static bool expression_is_local_variable(const expression_t *expression)
9448 {
9449         if (expression->base.kind != EXPR_REFERENCE) {
9450                 return false;
9451         }
9452         const entity_t *entity = expression->reference.entity;
9453         return is_local_variable(entity);
9454 }
9455
9456 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9457 {
9458         if (c_mode & _CXX || strict_mode) {
9459                 errorf(pos, msg);
9460         } else {
9461                 warningf(WARN_OTHER, pos, msg);
9462         }
9463 }
9464
9465 /**
9466  * Parse a return statement.
9467  */
9468 static statement_t *parse_return(void)
9469 {
9470         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9471         eat(T_return);
9472
9473         expression_t *return_value = NULL;
9474         if (token.kind != ';') {
9475                 return_value = parse_expression();
9476                 mark_vars_read(return_value, NULL);
9477         }
9478
9479         const type_t *const func_type = skip_typeref(current_function->base.type);
9480         assert(is_type_function(func_type));
9481         type_t *const return_type = skip_typeref(func_type->function.return_type);
9482
9483         source_position_t const *const pos = &statement->base.source_position;
9484         if (return_value != NULL) {
9485                 type_t *return_value_type = skip_typeref(return_value->base.type);
9486
9487                 if (is_type_void(return_type)) {
9488                         if (!is_type_void(return_value_type)) {
9489                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9490                                 /* Only warn in C mode, because GCC does the same */
9491                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9492                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9493                                 /* Only warn in C mode, because GCC does the same */
9494                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9495                         }
9496                 } else {
9497                         assign_error_t error = semantic_assign(return_type, return_value);
9498                         report_assign_error(error, return_type, return_value, "'return'",
9499                                             pos);
9500                 }
9501                 return_value = create_implicit_cast(return_value, return_type);
9502                 /* check for returning address of a local var */
9503                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9504                         const expression_t *expression = return_value->unary.value;
9505                         if (expression_is_local_variable(expression)) {
9506                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9507                         }
9508                 }
9509         } else if (!is_type_void(return_type)) {
9510                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9511                 err_or_warn(pos, "'return' without value, in function returning non-void");
9512         }
9513         statement->returns.value = return_value;
9514
9515         expect(';');
9516         return statement;
9517 }
9518
9519 /**
9520  * Parse a declaration statement.
9521  */
9522 static statement_t *parse_declaration_statement(void)
9523 {
9524         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9525
9526         entity_t *before = current_scope->last_entity;
9527         if (GNU_MODE) {
9528                 parse_external_declaration();
9529         } else {
9530                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9531         }
9532
9533         declaration_statement_t *const decl  = &statement->declaration;
9534         entity_t                *const begin =
9535                 before != NULL ? before->base.next : current_scope->entities;
9536         decl->declarations_begin = begin;
9537         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9538
9539         return statement;
9540 }
9541
9542 /**
9543  * Parse an expression statement, ie. expr ';'.
9544  */
9545 static statement_t *parse_expression_statement(void)
9546 {
9547         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9548
9549         expression_t *const expr         = parse_expression();
9550         statement->expression.expression = expr;
9551         mark_vars_read(expr, ENT_ANY);
9552
9553         expect(';');
9554         return statement;
9555 }
9556
9557 /**
9558  * Parse a microsoft __try { } __finally { } or
9559  * __try{ } __except() { }
9560  */
9561 static statement_t *parse_ms_try_statment(void)
9562 {
9563         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9564         eat(T___try);
9565
9566         PUSH_PARENT(statement);
9567
9568         ms_try_statement_t *rem = current_try;
9569         current_try = &statement->ms_try;
9570         statement->ms_try.try_statement = parse_compound_statement(false);
9571         current_try = rem;
9572
9573         POP_PARENT();
9574
9575         if (next_if(T___except)) {
9576                 expression_t *const expr = parse_condition();
9577                 type_t       *      type = skip_typeref(expr->base.type);
9578                 if (is_type_integer(type)) {
9579                         type = promote_integer(type);
9580                 } else if (is_type_valid(type)) {
9581                         errorf(&expr->base.source_position,
9582                                "__expect expression is not an integer, but '%T'", type);
9583                         type = type_error_type;
9584                 }
9585                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9586         } else if (!next_if(T__finally)) {
9587                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9588         }
9589         statement->ms_try.final_statement = parse_compound_statement(false);
9590         return statement;
9591 }
9592
9593 static statement_t *parse_empty_statement(void)
9594 {
9595         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9596         statement_t *const statement = create_empty_statement();
9597         eat(';');
9598         return statement;
9599 }
9600
9601 static statement_t *parse_local_label_declaration(void)
9602 {
9603         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9604
9605         eat(T___label__);
9606
9607         entity_t *begin   = NULL;
9608         entity_t *end     = NULL;
9609         entity_t **anchor = &begin;
9610         add_anchor_token(';');
9611         add_anchor_token(',');
9612         do {
9613                 source_position_t pos;
9614                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9615                 if (symbol) {
9616                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9617                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9618                                 source_position_t const *const ppos = &entity->base.source_position;
9619                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9620                         } else {
9621                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9622                                 entity->base.parent_scope = current_scope;
9623
9624                                 *anchor = entity;
9625                                 anchor  = &entity->base.next;
9626                                 end     = entity;
9627
9628                                 environment_push(entity);
9629                         }
9630                 }
9631         } while (next_if(','));
9632         rem_anchor_token(',');
9633         rem_anchor_token(';');
9634         expect(';');
9635         statement->declaration.declarations_begin = begin;
9636         statement->declaration.declarations_end   = end;
9637         return statement;
9638 }
9639
9640 static void parse_namespace_definition(void)
9641 {
9642         eat(T_namespace);
9643
9644         entity_t *entity = NULL;
9645         symbol_t *symbol = NULL;
9646
9647         if (token.kind == T_IDENTIFIER) {
9648                 symbol = token.base.symbol;
9649                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9650                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9651                         entity = NULL;
9652                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9653                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9654                         }
9655                 }
9656                 eat(T_IDENTIFIER);
9657         }
9658
9659         if (entity == NULL) {
9660                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9661                 entity->base.parent_scope = current_scope;
9662         }
9663
9664         if (token.kind == '=') {
9665                 /* TODO: parse namespace alias */
9666                 panic("namespace alias definition not supported yet");
9667         }
9668
9669         environment_push(entity);
9670         append_entity(current_scope, entity);
9671
9672         PUSH_SCOPE(&entity->namespacee.members);
9673         PUSH_CURRENT_ENTITY(entity);
9674
9675         add_anchor_token('}');
9676         expect('{');
9677         parse_externals();
9678         rem_anchor_token('}');
9679         expect('}');
9680
9681         POP_CURRENT_ENTITY();
9682         POP_SCOPE();
9683 }
9684
9685 /**
9686  * Parse a statement.
9687  * There's also parse_statement() which additionally checks for
9688  * "statement has no effect" warnings
9689  */
9690 static statement_t *intern_parse_statement(void)
9691 {
9692         /* declaration or statement */
9693         statement_t *statement;
9694         switch (token.kind) {
9695         case T_IDENTIFIER: {
9696                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9697                 if (la1_type == ':') {
9698                         statement = parse_label_statement();
9699                 } else if (is_typedef_symbol(token.base.symbol)) {
9700                         statement = parse_declaration_statement();
9701                 } else {
9702                         /* it's an identifier, the grammar says this must be an
9703                          * expression statement. However it is common that users mistype
9704                          * declaration types, so we guess a bit here to improve robustness
9705                          * for incorrect programs */
9706                         switch (la1_type) {
9707                         case '&':
9708                         case '*':
9709                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9710                         default:
9711                                         statement = parse_expression_statement();
9712                                 } else {
9713                         DECLARATION_START
9714                         case T_IDENTIFIER:
9715                                         statement = parse_declaration_statement();
9716                                 }
9717                                 break;
9718                         }
9719                 }
9720                 break;
9721         }
9722
9723         case T___extension__: {
9724                 /* This can be a prefix to a declaration or an expression statement.
9725                  * We simply eat it now and parse the rest with tail recursion. */
9726                 PUSH_EXTENSION();
9727                 statement = intern_parse_statement();
9728                 POP_EXTENSION();
9729                 break;
9730         }
9731
9732         DECLARATION_START
9733                 statement = parse_declaration_statement();
9734                 break;
9735
9736         case T___label__:
9737                 statement = parse_local_label_declaration();
9738                 break;
9739
9740         case ';':         statement = parse_empty_statement();         break;
9741         case '{':         statement = parse_compound_statement(false); break;
9742         case T___leave:   statement = parse_leave_statement();         break;
9743         case T___try:     statement = parse_ms_try_statment();         break;
9744         case T_asm:       statement = parse_asm_statement();           break;
9745         case T_break:     statement = parse_break();                   break;
9746         case T_case:      statement = parse_case_statement();          break;
9747         case T_continue:  statement = parse_continue();                break;
9748         case T_default:   statement = parse_default_statement();       break;
9749         case T_do:        statement = parse_do();                      break;
9750         case T_for:       statement = parse_for();                     break;
9751         case T_goto:      statement = parse_goto();                    break;
9752         case T_if:        statement = parse_if();                      break;
9753         case T_return:    statement = parse_return();                  break;
9754         case T_switch:    statement = parse_switch();                  break;
9755         case T_while:     statement = parse_while();                   break;
9756
9757         EXPRESSION_START
9758                 statement = parse_expression_statement();
9759                 break;
9760
9761         default:
9762                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9763                 statement = create_error_statement();
9764                 eat_until_anchor();
9765                 break;
9766         }
9767
9768         return statement;
9769 }
9770
9771 /**
9772  * parse a statement and emits "statement has no effect" warning if needed
9773  * (This is really a wrapper around intern_parse_statement with check for 1
9774  *  single warning. It is needed, because for statement expressions we have
9775  *  to avoid the warning on the last statement)
9776  */
9777 static statement_t *parse_statement(void)
9778 {
9779         statement_t *statement = intern_parse_statement();
9780
9781         if (statement->kind == STATEMENT_EXPRESSION) {
9782                 expression_t *expression = statement->expression.expression;
9783                 if (!expression_has_effect(expression)) {
9784                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9785                 }
9786         }
9787
9788         return statement;
9789 }
9790
9791 /**
9792  * Parse a compound statement.
9793  */
9794 static statement_t *parse_compound_statement(bool inside_expression_statement)
9795 {
9796         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9797
9798         PUSH_PARENT(statement);
9799         PUSH_SCOPE(&statement->compound.scope);
9800
9801         eat('{');
9802         add_anchor_token('}');
9803         /* tokens, which can start a statement */
9804         /* TODO MS, __builtin_FOO */
9805         add_anchor_token('!');
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(T_CHARACTER_CONSTANT);
9815         add_anchor_token(T_COLONCOLON);
9816         add_anchor_token(T_IDENTIFIER);
9817         add_anchor_token(T_MINUSMINUS);
9818         add_anchor_token(T_NUMBER);
9819         add_anchor_token(T_PLUSPLUS);
9820         add_anchor_token(T_STRING_LITERAL);
9821         add_anchor_token(T__Alignof);
9822         add_anchor_token(T__Bool);
9823         add_anchor_token(T__Complex);
9824         add_anchor_token(T__Imaginary);
9825         add_anchor_token(T__Thread_local);
9826         add_anchor_token(T___PRETTY_FUNCTION__);
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_asm);
9835         add_anchor_token(T_auto);
9836         add_anchor_token(T_bool);
9837         add_anchor_token(T_break);
9838         add_anchor_token(T_case);
9839         add_anchor_token(T_char);
9840         add_anchor_token(T_class);
9841         add_anchor_token(T_const);
9842         add_anchor_token(T_const_cast);
9843         add_anchor_token(T_continue);
9844         add_anchor_token(T_default);
9845         add_anchor_token(T_delete);
9846         add_anchor_token(T_double);
9847         add_anchor_token(T_do);
9848         add_anchor_token(T_dynamic_cast);
9849         add_anchor_token(T_enum);
9850         add_anchor_token(T_extern);
9851         add_anchor_token(T_false);
9852         add_anchor_token(T_float);
9853         add_anchor_token(T_for);
9854         add_anchor_token(T_goto);
9855         add_anchor_token(T_if);
9856         add_anchor_token(T_inline);
9857         add_anchor_token(T_int);
9858         add_anchor_token(T_long);
9859         add_anchor_token(T_new);
9860         add_anchor_token(T_operator);
9861         add_anchor_token(T_register);
9862         add_anchor_token(T_reinterpret_cast);
9863         add_anchor_token(T_restrict);
9864         add_anchor_token(T_return);
9865         add_anchor_token(T_short);
9866         add_anchor_token(T_signed);
9867         add_anchor_token(T_sizeof);
9868         add_anchor_token(T_static);
9869         add_anchor_token(T_static_cast);
9870         add_anchor_token(T_struct);
9871         add_anchor_token(T_switch);
9872         add_anchor_token(T_template);
9873         add_anchor_token(T_this);
9874         add_anchor_token(T_throw);
9875         add_anchor_token(T_true);
9876         add_anchor_token(T_try);
9877         add_anchor_token(T_typedef);
9878         add_anchor_token(T_typeid);
9879         add_anchor_token(T_typename);
9880         add_anchor_token(T_typeof);
9881         add_anchor_token(T_union);
9882         add_anchor_token(T_unsigned);
9883         add_anchor_token(T_using);
9884         add_anchor_token(T_void);
9885         add_anchor_token(T_volatile);
9886         add_anchor_token(T_wchar_t);
9887         add_anchor_token(T_while);
9888
9889         statement_t **anchor            = &statement->compound.statements;
9890         bool          only_decls_so_far = true;
9891         while (token.kind != '}' && token.kind != T_EOF) {
9892                 statement_t *sub_statement = intern_parse_statement();
9893                 if (sub_statement->kind == STATEMENT_ERROR) {
9894                         break;
9895                 }
9896
9897                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9898                         only_decls_so_far = false;
9899                 } else if (!only_decls_so_far) {
9900                         source_position_t const *const pos = &sub_statement->base.source_position;
9901                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9902                 }
9903
9904                 *anchor = sub_statement;
9905                 anchor  = &sub_statement->base.next;
9906         }
9907         expect('}');
9908
9909         /* look over all statements again to produce no effect warnings */
9910         if (is_warn_on(WARN_UNUSED_VALUE)) {
9911                 statement_t *sub_statement = statement->compound.statements;
9912                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9913                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9914                                 continue;
9915                         /* don't emit a warning for the last expression in an expression
9916                          * statement as it has always an effect */
9917                         if (inside_expression_statement && sub_statement->base.next == NULL)
9918                                 continue;
9919
9920                         expression_t *expression = sub_statement->expression.expression;
9921                         if (!expression_has_effect(expression)) {
9922                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9923                         }
9924                 }
9925         }
9926
9927         rem_anchor_token(T_while);
9928         rem_anchor_token(T_wchar_t);
9929         rem_anchor_token(T_volatile);
9930         rem_anchor_token(T_void);
9931         rem_anchor_token(T_using);
9932         rem_anchor_token(T_unsigned);
9933         rem_anchor_token(T_union);
9934         rem_anchor_token(T_typeof);
9935         rem_anchor_token(T_typename);
9936         rem_anchor_token(T_typeid);
9937         rem_anchor_token(T_typedef);
9938         rem_anchor_token(T_try);
9939         rem_anchor_token(T_true);
9940         rem_anchor_token(T_throw);
9941         rem_anchor_token(T_this);
9942         rem_anchor_token(T_template);
9943         rem_anchor_token(T_switch);
9944         rem_anchor_token(T_struct);
9945         rem_anchor_token(T_static_cast);
9946         rem_anchor_token(T_static);
9947         rem_anchor_token(T_sizeof);
9948         rem_anchor_token(T_signed);
9949         rem_anchor_token(T_short);
9950         rem_anchor_token(T_return);
9951         rem_anchor_token(T_restrict);
9952         rem_anchor_token(T_reinterpret_cast);
9953         rem_anchor_token(T_register);
9954         rem_anchor_token(T_operator);
9955         rem_anchor_token(T_new);
9956         rem_anchor_token(T_long);
9957         rem_anchor_token(T_int);
9958         rem_anchor_token(T_inline);
9959         rem_anchor_token(T_if);
9960         rem_anchor_token(T_goto);
9961         rem_anchor_token(T_for);
9962         rem_anchor_token(T_float);
9963         rem_anchor_token(T_false);
9964         rem_anchor_token(T_extern);
9965         rem_anchor_token(T_enum);
9966         rem_anchor_token(T_dynamic_cast);
9967         rem_anchor_token(T_do);
9968         rem_anchor_token(T_double);
9969         rem_anchor_token(T_delete);
9970         rem_anchor_token(T_default);
9971         rem_anchor_token(T_continue);
9972         rem_anchor_token(T_const_cast);
9973         rem_anchor_token(T_const);
9974         rem_anchor_token(T_class);
9975         rem_anchor_token(T_char);
9976         rem_anchor_token(T_case);
9977         rem_anchor_token(T_break);
9978         rem_anchor_token(T_bool);
9979         rem_anchor_token(T_auto);
9980         rem_anchor_token(T_asm);
9981         rem_anchor_token(T___real__);
9982         rem_anchor_token(T___label__);
9983         rem_anchor_token(T___imag__);
9984         rem_anchor_token(T___func__);
9985         rem_anchor_token(T___extension__);
9986         rem_anchor_token(T___builtin_va_start);
9987         rem_anchor_token(T___attribute__);
9988         rem_anchor_token(T___PRETTY_FUNCTION__);
9989         rem_anchor_token(T__Thread_local);
9990         rem_anchor_token(T__Imaginary);
9991         rem_anchor_token(T__Complex);
9992         rem_anchor_token(T__Bool);
9993         rem_anchor_token(T__Alignof);
9994         rem_anchor_token(T_STRING_LITERAL);
9995         rem_anchor_token(T_PLUSPLUS);
9996         rem_anchor_token(T_NUMBER);
9997         rem_anchor_token(T_MINUSMINUS);
9998         rem_anchor_token(T_IDENTIFIER);
9999         rem_anchor_token(T_COLONCOLON);
10000         rem_anchor_token(T_CHARACTER_CONSTANT);
10001         rem_anchor_token('~');
10002         rem_anchor_token('{');
10003         rem_anchor_token(';');
10004         rem_anchor_token('-');
10005         rem_anchor_token('+');
10006         rem_anchor_token('*');
10007         rem_anchor_token('(');
10008         rem_anchor_token('&');
10009         rem_anchor_token('!');
10010         rem_anchor_token('}');
10011
10012         POP_SCOPE();
10013         POP_PARENT();
10014         return statement;
10015 }
10016
10017 /**
10018  * Check for unused global static functions and variables
10019  */
10020 static void check_unused_globals(void)
10021 {
10022         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10023                 return;
10024
10025         for (const entity_t *entity = file_scope->entities; entity != NULL;
10026              entity = entity->base.next) {
10027                 if (!is_declaration(entity))
10028                         continue;
10029
10030                 const declaration_t *declaration = &entity->declaration;
10031                 if (declaration->used                  ||
10032                     declaration->modifiers & DM_UNUSED ||
10033                     declaration->modifiers & DM_USED   ||
10034                     declaration->storage_class != STORAGE_CLASS_STATIC)
10035                         continue;
10036
10037                 warning_t   why;
10038                 char const *s;
10039                 if (entity->kind == ENTITY_FUNCTION) {
10040                         /* inhibit warning for static inline functions */
10041                         if (entity->function.is_inline)
10042                                 continue;
10043
10044                         why = WARN_UNUSED_FUNCTION;
10045                         s   = entity->function.statement != NULL ? "defined" : "declared";
10046                 } else {
10047                         why = WARN_UNUSED_VARIABLE;
10048                         s   = "defined";
10049                 }
10050
10051                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10052         }
10053 }
10054
10055 static void parse_global_asm(void)
10056 {
10057         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10058
10059         eat(T_asm);
10060         add_anchor_token(';');
10061         add_anchor_token(')');
10062         add_anchor_token(T_STRING_LITERAL);
10063         expect('(');
10064
10065         rem_anchor_token(T_STRING_LITERAL);
10066         statement->asms.asm_text = parse_string_literals("global asm");
10067         statement->base.next     = unit->global_asm;
10068         unit->global_asm         = statement;
10069
10070         rem_anchor_token(')');
10071         expect(')');
10072         rem_anchor_token(';');
10073         expect(';');
10074 }
10075
10076 static void parse_linkage_specification(void)
10077 {
10078         eat(T_extern);
10079
10080         source_position_t const pos     = *HERE;
10081         char const       *const linkage = parse_string_literals(NULL).begin;
10082
10083         linkage_kind_t old_linkage = current_linkage;
10084         linkage_kind_t new_linkage;
10085         if (streq(linkage, "C")) {
10086                 new_linkage = LINKAGE_C;
10087         } else if (streq(linkage, "C++")) {
10088                 new_linkage = LINKAGE_CXX;
10089         } else {
10090                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10091                 new_linkage = LINKAGE_C;
10092         }
10093         current_linkage = new_linkage;
10094
10095         if (next_if('{')) {
10096                 parse_externals();
10097                 expect('}');
10098         } else {
10099                 parse_external();
10100         }
10101
10102         assert(current_linkage == new_linkage);
10103         current_linkage = old_linkage;
10104 }
10105
10106 static void parse_external(void)
10107 {
10108         switch (token.kind) {
10109                 case T_extern:
10110                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10111                                 parse_linkage_specification();
10112                         } else {
10113                 DECLARATION_START_NO_EXTERN
10114                 case T_IDENTIFIER:
10115                 case T___extension__:
10116                 /* tokens below are for implicit int */
10117                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10118                               implicit int) */
10119                 case '*':  /* * x; -> int* x; */
10120                 case '(':  /* (x); -> int (x); */
10121                                 PUSH_EXTENSION();
10122                                 parse_external_declaration();
10123                                 POP_EXTENSION();
10124                         }
10125                         return;
10126
10127                 case T_asm:
10128                         parse_global_asm();
10129                         return;
10130
10131                 case T_namespace:
10132                         parse_namespace_definition();
10133                         return;
10134
10135                 case ';':
10136                         if (!strict_mode) {
10137                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10138                                 eat(';');
10139                                 return;
10140                         }
10141                         /* FALLTHROUGH */
10142
10143                 default:
10144                         errorf(HERE, "stray %K outside of function", &token);
10145                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10146                                 eat_until_matching_token(token.kind);
10147                         next_token();
10148                         return;
10149         }
10150 }
10151
10152 static void parse_externals(void)
10153 {
10154         add_anchor_token('}');
10155         add_anchor_token(T_EOF);
10156
10157 #ifndef NDEBUG
10158         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10159         unsigned short token_anchor_copy[T_LAST_TOKEN];
10160         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10161 #endif
10162
10163         while (token.kind != T_EOF && token.kind != '}') {
10164 #ifndef NDEBUG
10165                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10166                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10167                         if (count != 0) {
10168                                 /* the anchor set and its copy differs */
10169                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10170                         }
10171                 }
10172                 if (in_gcc_extension) {
10173                         /* an gcc extension scope was not closed */
10174                         internal_errorf(HERE, "Leaked __extension__");
10175                 }
10176 #endif
10177
10178                 parse_external();
10179         }
10180
10181         rem_anchor_token(T_EOF);
10182         rem_anchor_token('}');
10183 }
10184
10185 /**
10186  * Parse a translation unit.
10187  */
10188 static void parse_translation_unit(void)
10189 {
10190         add_anchor_token(T_EOF);
10191
10192         while (true) {
10193                 parse_externals();
10194
10195                 if (token.kind == T_EOF)
10196                         break;
10197
10198                 errorf(HERE, "stray %K outside of function", &token);
10199                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10200                         eat_until_matching_token(token.kind);
10201                 next_token();
10202         }
10203 }
10204
10205 void set_default_visibility(elf_visibility_tag_t visibility)
10206 {
10207         default_visibility = visibility;
10208 }
10209
10210 /**
10211  * Parse the input.
10212  *
10213  * @return  the translation unit or NULL if errors occurred.
10214  */
10215 void start_parsing(void)
10216 {
10217         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10218         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10219
10220         print_to_file(stderr);
10221
10222         assert(unit == NULL);
10223         unit = allocate_ast_zero(sizeof(unit[0]));
10224
10225         assert(file_scope == NULL);
10226         file_scope = &unit->scope;
10227
10228         assert(current_scope == NULL);
10229         scope_push(&unit->scope);
10230
10231         create_gnu_builtins();
10232         if (c_mode & _MS)
10233                 create_microsoft_intrinsics();
10234 }
10235
10236 translation_unit_t *finish_parsing(void)
10237 {
10238         assert(current_scope == &unit->scope);
10239         scope_pop(NULL);
10240
10241         assert(file_scope == &unit->scope);
10242         check_unused_globals();
10243         file_scope = NULL;
10244
10245         DEL_ARR_F(environment_stack);
10246         DEL_ARR_F(label_stack);
10247
10248         translation_unit_t *result = unit;
10249         unit = NULL;
10250         return result;
10251 }
10252
10253 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10254  * are given length one. */
10255 static void complete_incomplete_arrays(void)
10256 {
10257         size_t n = ARR_LEN(incomplete_arrays);
10258         for (size_t i = 0; i != n; ++i) {
10259                 declaration_t *const decl = incomplete_arrays[i];
10260                 type_t        *const type = skip_typeref(decl->type);
10261
10262                 if (!is_type_incomplete(type))
10263                         continue;
10264
10265                 source_position_t const *const pos = &decl->base.source_position;
10266                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10267
10268                 type_t *const new_type = duplicate_type(type);
10269                 new_type->array.size_constant     = true;
10270                 new_type->array.has_implicit_size = true;
10271                 new_type->array.size              = 1;
10272
10273                 type_t *const result = identify_new_type(new_type);
10274
10275                 decl->type = result;
10276         }
10277 }
10278
10279 static void prepare_main_collect2(entity_t *const entity)
10280 {
10281         PUSH_SCOPE(&entity->function.statement->compound.scope);
10282
10283         // create call to __main
10284         symbol_t *symbol         = symbol_table_insert("__main");
10285         entity_t *subsubmain_ent
10286                 = create_implicit_function(symbol, &builtin_source_position);
10287
10288         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10289         type_t       *ftype       = subsubmain_ent->declaration.type;
10290         ref->base.source_position = builtin_source_position;
10291         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10292         ref->reference.entity     = subsubmain_ent;
10293
10294         expression_t *call = allocate_expression_zero(EXPR_CALL);
10295         call->base.source_position = builtin_source_position;
10296         call->base.type            = type_void;
10297         call->call.function        = ref;
10298
10299         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10300         expr_statement->base.source_position  = builtin_source_position;
10301         expr_statement->expression.expression = call;
10302
10303         statement_t *statement = entity->function.statement;
10304         assert(statement->kind == STATEMENT_COMPOUND);
10305         compound_statement_t *compounds = &statement->compound;
10306
10307         expr_statement->base.next = compounds->statements;
10308         compounds->statements     = expr_statement;
10309
10310         POP_SCOPE();
10311 }
10312
10313 void parse(void)
10314 {
10315         lookahead_bufpos = 0;
10316         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10317                 next_token();
10318         }
10319         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10320         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10321         parse_translation_unit();
10322         complete_incomplete_arrays();
10323         DEL_ARR_F(incomplete_arrays);
10324         incomplete_arrays = NULL;
10325 }
10326
10327 /**
10328  * Initialize the parser.
10329  */
10330 void init_parser(void)
10331 {
10332         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10333
10334         init_expression_parsers();
10335         obstack_init(&temp_obst);
10336 }
10337
10338 /**
10339  * Terminate the parser.
10340  */
10341 void exit_parser(void)
10342 {
10343         obstack_free(&temp_obst, NULL);
10344 }