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