nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "preprocessor.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "adt/bitfiddle.h"
  45 #include "adt/error.h"
  46 #include "adt/array.h"
  47
  48 //#define PRINT_TOKENS
  49 #define MAX_LOOKAHEAD 1
  50
  51 typedef struct {
  52         entity_t           *old_entity;
  53         symbol_t           *symbol;
  54         entity_namespace_t  namespc;
  55 } stack_entry_t;
  56
  57 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  58 struct declaration_specifiers_t {
  59         source_position_t  source_position;
  60         storage_class_t    storage_class;
  61         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  62         bool               is_inline    : 1;
  63         bool               thread_local : 1;
  64         attribute_t       *attributes;        /**< list of attributes */
  65         type_t            *type;
  66 };
  67
  68 /**
  69  * An environment for parsing initializers (and compound literals).
  70  */
  71 typedef struct parse_initializer_env_t {
  72         type_t     *type;   /**< the type of the initializer. In case of an
  73                                  array type with unspecified size this gets
  74                                  adjusted to the actual size. */
  75         entity_t   *entity; /**< the variable that is initialized if any */
  76         bool        must_be_constant;
  77 } parse_initializer_env_t;
  78
  79 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  80
  81 /** The current token. */
  82 static token_t              token;
  83 /** The lookahead ring-buffer. */
  84 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  85 /** Position of the next token in the lookahead buffer. */
  86 static size_t               lookahead_bufpos;
  87 static stack_entry_t       *environment_stack = NULL;
  88 static stack_entry_t       *label_stack       = NULL;
  89 static scope_t             *file_scope        = NULL;
  90 static scope_t             *current_scope     = NULL;
  91 /** Point to the current function declaration if inside a function. */
  92 static function_t          *current_function  = NULL;
  93 static entity_t            *current_entity    = NULL;
  94 static switch_statement_t  *current_switch    = NULL;
  95 static statement_t         *current_loop      = NULL;
  96 static statement_t         *current_parent    = NULL;
  97 static ms_try_statement_t  *current_try       = NULL;
  98 static linkage_kind_t       current_linkage;
  99 static goto_statement_t    *goto_first        = NULL;
 100 static goto_statement_t   **goto_anchor       = NULL;
 101 static label_statement_t   *label_first       = NULL;
 102 static label_statement_t  **label_anchor      = NULL;
 103 /** current translation unit. */
 104 static translation_unit_t  *unit              = NULL;
 105 /** true if we are in an __extension__ context. */
 106 static bool                 in_gcc_extension  = false;
 107 static struct obstack       temp_obst;
 108 static entity_t            *anonymous_entity;
 109 static declaration_t      **incomplete_arrays;
 110 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 111
 112
 113 #define PUSH_CURRENT_ENTITY(entity) \
 114         entity_t *const new_current_entity = (entity); \
 115         entity_t *const old_current_entity = current_entity; \
 116         ((void)(current_entity = new_current_entity))
 117 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 118
 119 #define PUSH_PARENT(stmt) \
 120         statement_t *const new_parent = (stmt); \
 121         statement_t *const old_parent = current_parent; \
 122         ((void)(current_parent = new_parent))
 123 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 124
 125 #define PUSH_SCOPE(scope) \
 126         size_t   const top       = environment_top(); \
 127         scope_t *const new_scope = (scope); \
 128         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 129 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 130 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 131
 132 #define PUSH_EXTENSION() \
 133         (void)0; \
 134         bool const old_gcc_extension = in_gcc_extension; \
 135         while (next_if(T___extension__)) { \
 136                 in_gcc_extension = true; \
 137         } \
 138         do {} while (0)
 139 #define POP_EXTENSION() \
 140         ((void)(in_gcc_extension = old_gcc_extension))
 141
 142 /** The token anchor set */
 143 static unsigned short token_anchor_set[T_LAST_TOKEN];
 144
 145 /** The current source position. */
 146 #define HERE (&token.base.source_position)
 147
 148 /** true if we are in GCC mode. */
 149 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 150
 151 static statement_t *parse_compound_statement(bool inside_expression_statement);
 152 static statement_t *parse_statement(void);
 153
 154 static expression_t *parse_subexpression(precedence_t);
 155 static expression_t *parse_expression(void);
 156 static type_t       *parse_typename(void);
 157 static void          parse_externals(void);
 158 static void          parse_external(void);
 159
 160 static void parse_compound_type_entries(compound_t *compound_declaration);
 161
 162 static void check_call_argument(type_t          *expected_type,
 163                                                                 call_argument_t *argument, unsigned pos);
 164
 165 typedef enum declarator_flags_t {
 166         DECL_FLAGS_NONE             = 0,
 167         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 168         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 169         DECL_IS_PARAMETER           = 1U << 2
 170 } declarator_flags_t;
 171
 172 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 173                                   declarator_flags_t flags);
 174
 175 static void semantic_comparison(binary_expression_t *expression);
 176
 177 #define STORAGE_CLASSES       \
 178         STORAGE_CLASSES_NO_EXTERN \
 179         case T_extern:
 180
 181 #define STORAGE_CLASSES_NO_EXTERN \
 182         case T_typedef:         \
 183         case T_static:          \
 184         case T_auto:            \
 185         case T_register:        \
 186         case T__Thread_local:
 187
 188 #define TYPE_QUALIFIERS     \
 189         case T_const:           \
 190         case T_restrict:        \
 191         case T_volatile:        \
 192         case T_inline:          \
 193         case T__forceinline:    \
 194         case T___attribute__:
 195
 196 #define COMPLEX_SPECIFIERS  \
 197         case T__Complex:
 198 #define IMAGINARY_SPECIFIERS \
 199         case T__Imaginary:
 200
 201 #define TYPE_SPECIFIERS       \
 202         case T__Bool:             \
 203         case T___builtin_va_list: \
 204         case T___typeof__:        \
 205         case T__declspec:         \
 206         case T_bool:              \
 207         case T_char:              \
 208         case T_double:            \
 209         case T_enum:              \
 210         case T_float:             \
 211         case T_int:               \
 212         case T_long:              \
 213         case T_short:             \
 214         case T_signed:            \
 215         case T_struct:            \
 216         case T_union:             \
 217         case T_unsigned:          \
 218         case T_void:              \
 219         case T_wchar_t:           \
 220         case T__int8:             \
 221         case T__int16:            \
 222         case T__int32:            \
 223         case T__int64:            \
 224         case T__int128:           \
 225         COMPLEX_SPECIFIERS        \
 226         IMAGINARY_SPECIFIERS
 227
 228 #define DECLARATION_START   \
 229         STORAGE_CLASSES         \
 230         TYPE_QUALIFIERS         \
 231         TYPE_SPECIFIERS
 232
 233 #define DECLARATION_START_NO_EXTERN \
 234         STORAGE_CLASSES_NO_EXTERN       \
 235         TYPE_QUALIFIERS                 \
 236         TYPE_SPECIFIERS
 237
 238 #define EXPRESSION_START              \
 239         case '!':                         \
 240         case '&':                         \
 241         case '(':                         \
 242         case '*':                         \
 243         case '+':                         \
 244         case '-':                         \
 245         case '~':                         \
 246         case T_ANDAND:                    \
 247         case T_CHARACTER_CONSTANT:        \
 248         case T_NUMBER:                    \
 249         case T_MINUSMINUS:                \
 250         case T_PLUSPLUS:                  \
 251         case T_STRING_LITERAL:            \
 252         case T__Alignof:                  \
 253         case T___FUNCDNAME__:             \
 254         case T___FUNCSIG__:               \
 255         case T___PRETTY_FUNCTION__:       \
 256         case T___builtin_classify_type:   \
 257         case T___builtin_constant_p:      \
 258         case T___builtin_isgreater:       \
 259         case T___builtin_isgreaterequal:  \
 260         case T___builtin_isless:          \
 261         case T___builtin_islessequal:     \
 262         case T___builtin_islessgreater:   \
 263         case T___builtin_isunordered:     \
 264         case T___builtin_offsetof:        \
 265         case T___builtin_va_arg:          \
 266         case T___builtin_va_copy:         \
 267         case T___builtin_va_start:        \
 268         case T___func__:                  \
 269         case T___noop:                    \
 270         case T__assume:                   \
 271         case T_delete:                    \
 272         case T_false:                     \
 273         case T_sizeof:                    \
 274         case T_throw:                     \
 275         case T_true:
 276
 277 /**
 278  * Returns the size of a statement node.
 279  *
 280  * @param kind  the statement kind
 281  */
 282 static size_t get_statement_struct_size(statement_kind_t kind)
 283 {
 284         static const size_t sizes[] = {
 285                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 286                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 287                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 288                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 289                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 290                 [STATEMENT_IF]            = sizeof(if_statement_t),
 291                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 292                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 293                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 294                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 295                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 296                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 297                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 298                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 299                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 300                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 301                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 302                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 303                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 304         };
 305         assert((size_t)kind < lengthof(sizes));
 306         assert(sizes[kind] != 0);
 307         return sizes[kind];
 308 }
 309
 310 /**
 311  * Returns the size of an expression node.
 312  *
 313  * @param kind  the expression kind
 314  */
 315 static size_t get_expression_struct_size(expression_kind_t kind)
 316 {
 317         static const size_t sizes[] = {
 318                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 319                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 320                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 321                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 322                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 323                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 325                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 326                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 327                 [EXPR_CALL]                       = sizeof(call_expression_t),
 328                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 329                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 330                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 331                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 332                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 333                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 334                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 335                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 336                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 337                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 338                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 339                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 340                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 341                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 342                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 343                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 344                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 345         };
 346         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 347                 return sizes[EXPR_UNARY_FIRST];
 348         }
 349         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 350                 return sizes[EXPR_BINARY_FIRST];
 351         }
 352         assert((size_t)kind < lengthof(sizes));
 353         assert(sizes[kind] != 0);
 354         return sizes[kind];
 355 }
 356
 357 /**
 358  * Allocate a statement node of given kind and initialize all
 359  * fields with zero. Sets its source position to the position
 360  * of the current token.
 361  */
 362 static statement_t *allocate_statement_zero(statement_kind_t kind)
 363 {
 364         size_t       size = get_statement_struct_size(kind);
 365         statement_t *res  = allocate_ast_zero(size);
 366
 367         res->base.kind            = kind;
 368         res->base.parent          = current_parent;
 369         res->base.source_position = *HERE;
 370         return res;
 371 }
 372
 373 /**
 374  * Allocate an expression node of given kind and initialize all
 375  * fields with zero.
 376  *
 377  * @param kind  the kind of the expression to allocate
 378  */
 379 static expression_t *allocate_expression_zero(expression_kind_t kind)
 380 {
 381         size_t        size = get_expression_struct_size(kind);
 382         expression_t *res  = allocate_ast_zero(size);
 383
 384         res->base.kind            = kind;
 385         res->base.type            = type_error_type;
 386         res->base.source_position = *HERE;
 387         return res;
 388 }
 389
 390 /**
 391  * Creates a new invalid expression at the source position
 392  * of the current token.
 393  */
 394 static expression_t *create_error_expression(void)
 395 {
 396         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 397         expression->base.type = type_error_type;
 398         return expression;
 399 }
 400
 401 /**
 402  * Creates a new invalid statement.
 403  */
 404 static statement_t *create_error_statement(void)
 405 {
 406         return allocate_statement_zero(STATEMENT_ERROR);
 407 }
 408
 409 /**
 410  * Allocate a new empty statement.
 411  */
 412 static statement_t *create_empty_statement(void)
 413 {
 414         return allocate_statement_zero(STATEMENT_EMPTY);
 415 }
 416
 417 /**
 418  * Returns the size of an initializer node.
 419  *
 420  * @param kind  the initializer kind
 421  */
 422 static size_t get_initializer_size(initializer_kind_t kind)
 423 {
 424         static const size_t sizes[] = {
 425                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 426                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 427                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 428                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 429         };
 430         assert((size_t)kind < lengthof(sizes));
 431         assert(sizes[kind] != 0);
 432         return sizes[kind];
 433 }
 434
 435 /**
 436  * Allocate an initializer node of given kind and initialize all
 437  * fields with zero.
 438  */
 439 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 440 {
 441         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 442         result->kind          = kind;
 443
 444         return result;
 445 }
 446
 447 /**
 448  * Returns the index of the top element of the environment stack.
 449  */
 450 static size_t environment_top(void)
 451 {
 452         return ARR_LEN(environment_stack);
 453 }
 454
 455 /**
 456  * Returns the index of the top element of the global label stack.
 457  */
 458 static size_t label_top(void)
 459 {
 460         return ARR_LEN(label_stack);
 461 }
 462
 463 /**
 464  * Return the next token.
 465  */
 466 static inline void next_token(void)
 467 {
 468         token                              = lookahead_buffer[lookahead_bufpos];
 469         lookahead_buffer[lookahead_bufpos] = pp_token;
 470         next_preprocessing_token();
 471
 472         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 473
 474 #ifdef PRINT_TOKENS
 475         print_token(stderr, &token);
 476         fprintf(stderr, "\n");
 477 #endif
 478 }
 479
 480 static inline void eat(token_kind_t const kind)
 481 {
 482         assert(token.kind == kind);
 483         (void)kind;
 484         next_token();
 485 }
 486
 487 static inline bool next_if(token_kind_t const kind)
 488 {
 489         if (token.kind == kind) {
 490                 eat(kind);
 491                 return true;
 492         } else {
 493                 return false;
 494         }
 495 }
 496
 497 /**
 498  * Return the next token with a given lookahead.
 499  */
 500 static inline const token_t *look_ahead(size_t num)
 501 {
 502         assert(0 < num && num <= MAX_LOOKAHEAD);
 503         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 504         return &lookahead_buffer[pos];
 505 }
 506
 507 /**
 508  * Adds a token type to the token type anchor set (a multi-set).
 509  */
 510 static void add_anchor_token(token_kind_t const token_kind)
 511 {
 512         assert(token_kind < T_LAST_TOKEN);
 513         ++token_anchor_set[token_kind];
 514 }
 515
 516 /**
 517  * Remove a token type from the token type anchor set (a multi-set).
 518  */
 519 static void rem_anchor_token(token_kind_t const token_kind)
 520 {
 521         assert(token_kind < T_LAST_TOKEN);
 522         assert(token_anchor_set[token_kind] != 0);
 523         --token_anchor_set[token_kind];
 524 }
 525
 526 /**
 527  * Eat tokens until a matching token type is found.
 528  */
 529 static void eat_until_matching_token(token_kind_t const type)
 530 {
 531         token_kind_t end_token;
 532         switch (type) {
 533                 case '(': end_token = ')';  break;
 534                 case '{': end_token = '}';  break;
 535                 case '[': end_token = ']';  break;
 536                 default:  end_token = type; break;
 537         }
 538
 539         unsigned parenthesis_count = 0;
 540         unsigned brace_count       = 0;
 541         unsigned bracket_count     = 0;
 542         while (token.kind        != end_token ||
 543                parenthesis_count != 0         ||
 544                brace_count       != 0         ||
 545                bracket_count     != 0) {
 546                 switch (token.kind) {
 547                 case T_EOF: return;
 548                 case '(': ++parenthesis_count; break;
 549                 case '{': ++brace_count;       break;
 550                 case '[': ++bracket_count;     break;
 551
 552                 case ')':
 553                         if (parenthesis_count > 0)
 554                                 --parenthesis_count;
 555                         goto check_stop;
 556
 557                 case '}':
 558                         if (brace_count > 0)
 559                                 --brace_count;
 560                         goto check_stop;
 561
 562                 case ']':
 563                         if (bracket_count > 0)
 564                                 --bracket_count;
 565 check_stop:
 566                         if (token.kind        == end_token &&
 567                             parenthesis_count == 0         &&
 568                             brace_count       == 0         &&
 569                             bracket_count     == 0)
 570                                 return;
 571                         break;
 572
 573                 default:
 574                         break;
 575                 }
 576                 next_token();
 577         }
 578 }
 579
 580 /**
 581  * Eat input tokens until an anchor is found.
 582  */
 583 static void eat_until_anchor(void)
 584 {
 585         while (token_anchor_set[token.kind] == 0) {
 586                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 587                         eat_until_matching_token(token.kind);
 588                 next_token();
 589         }
 590 }
 591
 592 /**
 593  * Eat a whole block from input tokens.
 594  */
 595 static void eat_block(void)
 596 {
 597         eat_until_matching_token('{');
 598         next_if('}');
 599 }
 600
 601 /**
 602  * Report a parse error because an expected token was not found.
 603  */
 604 static
 605 #if defined __GNUC__ && __GNUC__ >= 4
 606 __attribute__((sentinel))
 607 #endif
 608 void parse_error_expected(const char *message, ...)
 609 {
 610         if (message != NULL) {
 611                 errorf(HERE, "%s", message);
 612         }
 613         va_list ap;
 614         va_start(ap, message);
 615         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 616         va_end(ap);
 617 }
 618
 619 /**
 620  * Report an incompatible type.
 621  */
 622 static void type_error_incompatible(const char *msg,
 623                 const source_position_t *source_position, type_t *type1, type_t *type2)
 624 {
 625         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 626                msg, type1, type2);
 627 }
 628
 629 static bool skip_till(token_kind_t const expected, char const *const context)
 630 {
 631         if (UNLIKELY(token.kind != expected)) {
 632                 parse_error_expected(context, expected, NULL);
 633                 add_anchor_token(expected);
 634                 eat_until_anchor();
 635                 rem_anchor_token(expected);
 636                 if (token.kind != expected)
 637                         return false;
 638         }
 639         return true;
 640 }
 641
 642 /**
 643  * Expect the current token is the expected token.
 644  * If not, generate an error and skip until the next anchor.
 645  */
 646 static void expect(token_kind_t const expected)
 647 {
 648         if (skip_till(expected, NULL))
 649                 eat(expected);
 650 }
 651
 652 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 653 {
 654         if (!skip_till(T_IDENTIFIER, context))
 655                 return NULL;
 656         symbol_t *const sym = token.base.symbol;
 657         if (pos)
 658                 *pos = *HERE;
 659         eat(T_IDENTIFIER);
 660         return sym;
 661 }
 662
 663 /**
 664  * Push a given scope on the scope stack and make it the
 665  * current scope
 666  */
 667 static scope_t *scope_push(scope_t *new_scope)
 668 {
 669         if (current_scope != NULL) {
 670                 new_scope->depth = current_scope->depth + 1;
 671         }
 672
 673         scope_t *old_scope = current_scope;
 674         current_scope      = new_scope;
 675         return old_scope;
 676 }
 677
 678 /**
 679  * Pop the current scope from the scope stack.
 680  */
 681 static void scope_pop(scope_t *old_scope)
 682 {
 683         current_scope = old_scope;
 684 }
 685
 686 /**
 687  * Search an entity by its symbol in a given namespace.
 688  */
 689 static entity_t *get_entity(const symbol_t *const symbol,
 690                             namespace_tag_t namespc)
 691 {
 692         entity_t *entity = symbol->entity;
 693         for (; entity != NULL; entity = entity->base.symbol_next) {
 694                 if ((namespace_tag_t)entity->base.namespc == namespc)
 695                         return entity;
 696         }
 697
 698         return NULL;
 699 }
 700
 701 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 702  * possible. */
 703 static entity_t *get_tag(symbol_t const *const symbol,
 704                          entity_kind_tag_t const kind)
 705 {
 706         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 707         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 708                 errorf(HERE,
 709                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 710                                 symbol, &entity->base.source_position);
 711                 entity = NULL;
 712         }
 713         return entity;
 714 }
 715
 716 /**
 717  * pushs an entity on the environment stack and links the corresponding symbol
 718  * it.
 719  */
 720 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 721 {
 722         symbol_t           *symbol  = entity->base.symbol;
 723         entity_namespace_t  namespc = entity->base.namespc;
 724         assert(namespc != 0);
 725
 726         /* replace/add entity into entity list of the symbol */
 727         entity_t **anchor;
 728         entity_t  *iter;
 729         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 730                 iter = *anchor;
 731                 if (iter == NULL)
 732                         break;
 733
 734                 /* replace an entry? */
 735                 if (iter->base.namespc == namespc) {
 736                         entity->base.symbol_next = iter->base.symbol_next;
 737                         break;
 738                 }
 739         }
 740         *anchor = entity;
 741
 742         /* remember old declaration */
 743         stack_entry_t entry;
 744         entry.symbol     = symbol;
 745         entry.old_entity = iter;
 746         entry.namespc    = namespc;
 747         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 748 }
 749
 750 /**
 751  * Push an entity on the environment stack.
 752  */
 753 static void environment_push(entity_t *entity)
 754 {
 755         assert(entity->base.source_position.input_name != NULL);
 756         assert(entity->base.parent_scope != NULL);
 757         stack_push(&environment_stack, entity);
 758 }
 759
 760 /**
 761  * Push a declaration on the global label stack.
 762  *
 763  * @param declaration  the declaration
 764  */
 765 static void label_push(entity_t *label)
 766 {
 767         /* we abuse the parameters scope as parent for the labels */
 768         label->base.parent_scope = &current_function->parameters;
 769         stack_push(&label_stack, label);
 770 }
 771
 772 /**
 773  * pops symbols from the environment stack until @p new_top is the top element
 774  */
 775 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 776 {
 777         stack_entry_t *stack = *stack_ptr;
 778         size_t         top   = ARR_LEN(stack);
 779         size_t         i;
 780
 781         assert(new_top <= top);
 782         if (new_top == top)
 783                 return;
 784
 785         for (i = top; i > new_top; --i) {
 786                 stack_entry_t *entry = &stack[i - 1];
 787
 788                 entity_t           *old_entity = entry->old_entity;
 789                 symbol_t           *symbol     = entry->symbol;
 790                 entity_namespace_t  namespc    = entry->namespc;
 791
 792                 /* replace with old_entity/remove */
 793                 entity_t **anchor;
 794                 entity_t  *iter;
 795                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 796                         iter = *anchor;
 797                         assert(iter != NULL);
 798                         /* replace an entry? */
 799                         if (iter->base.namespc == namespc)
 800                                 break;
 801                 }
 802
 803                 /* restore definition from outer scopes (if there was one) */
 804                 if (old_entity != NULL) {
 805                         old_entity->base.symbol_next = iter->base.symbol_next;
 806                         *anchor                      = old_entity;
 807                 } else {
 808                         /* remove entry from list */
 809                         *anchor = iter->base.symbol_next;
 810                 }
 811         }
 812
 813         ARR_SHRINKLEN(*stack_ptr, new_top);
 814 }
 815
 816 /**
 817  * Pop all entries from the environment stack until the new_top
 818  * is reached.
 819  *
 820  * @param new_top  the new stack top
 821  */
 822 static void environment_pop_to(size_t new_top)
 823 {
 824         stack_pop_to(&environment_stack, new_top);
 825 }
 826
 827 /**
 828  * Pop all entries from the global label stack until the new_top
 829  * is reached.
 830  *
 831  * @param new_top  the new stack top
 832  */
 833 static void label_pop_to(size_t new_top)
 834 {
 835         stack_pop_to(&label_stack, new_top);
 836 }
 837
 838 static atomic_type_kind_t get_akind(const type_t *type)
 839 {
 840         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 841                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 842         return type->atomic.akind;
 843 }
 844
 845 /**
 846  * §6.3.1.1:2  Do integer promotion for a given type.
 847  *
 848  * @param type  the type to promote
 849  * @return the promoted type
 850  */
 851 static type_t *promote_integer(type_t *type)
 852 {
 853         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 854                 type = type_int;
 855
 856         return type;
 857 }
 858
 859 /**
 860  * Check if a given expression represents a null pointer constant.
 861  *
 862  * @param expression  the expression to check
 863  */
 864 static bool is_null_pointer_constant(const expression_t *expression)
 865 {
 866         /* skip void* cast */
 867         if (expression->kind == EXPR_UNARY_CAST) {
 868                 type_t *const type = skip_typeref(expression->base.type);
 869                 if (types_compatible(type, type_void_ptr))
 870                         expression = expression->unary.value;
 871         }
 872
 873         type_t *const type = skip_typeref(expression->base.type);
 874         if (!is_type_integer(type))
 875                 return false;
 876         switch (is_constant_expression(expression)) {
 877                 case EXPR_CLASS_ERROR:    return true;
 878                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 879                 default:                  return false;
 880         }
 881 }
 882
 883 /**
 884  * Create an implicit cast expression.
 885  *
 886  * @param expression  the expression to cast
 887  * @param dest_type   the destination type
 888  */
 889 static expression_t *create_implicit_cast(expression_t *expression,
 890                                           type_t *dest_type)
 891 {
 892         type_t *const source_type = expression->base.type;
 893
 894         if (source_type == dest_type)
 895                 return expression;
 896
 897         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 898         cast->unary.value   = expression;
 899         cast->base.type     = dest_type;
 900         cast->base.implicit = true;
 901
 902         return cast;
 903 }
 904
 905 typedef enum assign_error_t {
 906         ASSIGN_SUCCESS,
 907         ASSIGN_ERROR_INCOMPATIBLE,
 908         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 909         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 910         ASSIGN_WARNING_POINTER_FROM_INT,
 911         ASSIGN_WARNING_INT_FROM_POINTER
 912 } assign_error_t;
 913
 914 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)
 915 {
 916         type_t *const orig_type_right = right->base.type;
 917         type_t *const type_left       = skip_typeref(orig_type_left);
 918         type_t *const type_right      = skip_typeref(orig_type_right);
 919
 920         switch (error) {
 921         case ASSIGN_SUCCESS:
 922                 return;
 923         case ASSIGN_ERROR_INCOMPATIBLE:
 924                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 925                 return;
 926
 927         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 928                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 929                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 930
 931                 /* the left type has all qualifiers from the right type */
 932                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 933                 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);
 934                 return;
 935         }
 936
 937         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 938                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 939                 return;
 940
 941         case ASSIGN_WARNING_POINTER_FROM_INT:
 942                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 943                 return;
 944
 945         case ASSIGN_WARNING_INT_FROM_POINTER:
 946                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 947                 return;
 948
 949         default:
 950                 panic("invalid error value");
 951         }
 952 }
 953
 954 /** Implements the rules from §6.5.16.1 */
 955 static assign_error_t semantic_assign(type_t *orig_type_left,
 956                                       const expression_t *const right)
 957 {
 958         type_t *const orig_type_right = right->base.type;
 959         type_t *const type_left       = skip_typeref(orig_type_left);
 960         type_t *const type_right      = skip_typeref(orig_type_right);
 961
 962         if (is_type_pointer(type_left)) {
 963                 if (is_null_pointer_constant(right)) {
 964                         return ASSIGN_SUCCESS;
 965                 } else if (is_type_pointer(type_right)) {
 966                         type_t *points_to_left
 967                                 = skip_typeref(type_left->pointer.points_to);
 968                         type_t *points_to_right
 969                                 = skip_typeref(type_right->pointer.points_to);
 970                         assign_error_t res = ASSIGN_SUCCESS;
 971
 972                         /* the left type has all qualifiers from the right type */
 973                         unsigned missing_qualifiers
 974                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 975                         if (missing_qualifiers != 0) {
 976                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 977                         }
 978
 979                         points_to_left  = get_unqualified_type(points_to_left);
 980                         points_to_right = get_unqualified_type(points_to_right);
 981
 982                         if (is_type_void(points_to_left))
 983                                 return res;
 984
 985                         if (is_type_void(points_to_right)) {
 986                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 987                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 988                         }
 989
 990                         if (!types_compatible(points_to_left, points_to_right)) {
 991                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 992                         }
 993
 994                         return res;
 995                 } else if (is_type_integer(type_right)) {
 996                         return ASSIGN_WARNING_POINTER_FROM_INT;
 997                 }
 998         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 999                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1000                                 && is_type_pointer(type_right))) {
1001                 return ASSIGN_SUCCESS;
1002         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1003                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1004                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1005                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1006                         return ASSIGN_SUCCESS;
1007                 }
1008         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1009                 return ASSIGN_WARNING_INT_FROM_POINTER;
1010         }
1011
1012         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1013                 return ASSIGN_SUCCESS;
1014
1015         return ASSIGN_ERROR_INCOMPATIBLE;
1016 }
1017
1018 static expression_t *parse_constant_expression(void)
1019 {
1020         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1021
1022         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1023                 errorf(&result->base.source_position,
1024                        "expression '%E' is not constant", result);
1025         }
1026
1027         return result;
1028 }
1029
1030 static expression_t *parse_assignment_expression(void)
1031 {
1032         return parse_subexpression(PREC_ASSIGNMENT);
1033 }
1034
1035 static void append_string(string_t const *const s)
1036 {
1037         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1038          * possible, because other tokens are grown there alongside. */
1039         obstack_grow(&ast_obstack, s->begin, s->size);
1040 }
1041
1042 static string_t finish_string(string_encoding_t const enc)
1043 {
1044         obstack_1grow(&ast_obstack, '\0');
1045         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1046         char const *const string = obstack_finish(&ast_obstack);
1047         return (string_t){ string, size, enc };
1048 }
1049
1050 static string_t concat_string_literals(void)
1051 {
1052         assert(token.kind == T_STRING_LITERAL);
1053
1054         string_t result;
1055         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1056                 append_string(&token.literal.string);
1057                 eat(T_STRING_LITERAL);
1058                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1059                 string_encoding_t enc = token.literal.string.encoding;
1060                 do {
1061                         if (token.literal.string.encoding != STRING_ENCODING_CHAR) {
1062                                 enc = token.literal.string.encoding;
1063                         }
1064                         append_string(&token.literal.string);
1065                         eat(T_STRING_LITERAL);
1066                 } while (token.kind == T_STRING_LITERAL);
1067                 result = finish_string(enc);
1068         } else {
1069                 result = token.literal.string;
1070                 eat(T_STRING_LITERAL);
1071         }
1072
1073         return result;
1074 }
1075
1076 static string_t parse_string_literals(char const *const context)
1077 {
1078         if (!skip_till(T_STRING_LITERAL, context))
1079                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1080
1081         source_position_t const pos = *HERE;
1082         string_t          const res = concat_string_literals();
1083
1084         if (res.encoding != STRING_ENCODING_CHAR) {
1085                 errorf(&pos, "expected plain string literal, got wide string literal");
1086         }
1087
1088         return res;
1089 }
1090
1091 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1092 {
1093         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1094         attribute->kind            = kind;
1095         attribute->source_position = *HERE;
1096         return attribute;
1097 }
1098
1099 /**
1100  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1101  *
1102  *  attribute:
1103  *    __attribute__ ( ( attribute-list ) )
1104  *
1105  *  attribute-list:
1106  *    attrib
1107  *    attribute_list , attrib
1108  *
1109  *  attrib:
1110  *    empty
1111  *    any-word
1112  *    any-word ( identifier )
1113  *    any-word ( identifier , nonempty-expr-list )
1114  *    any-word ( expr-list )
1115  *
1116  *  where the "identifier" must not be declared as a type, and
1117  *  "any-word" may be any identifier (including one declared as a
1118  *  type), a reserved word storage class specifier, type specifier or
1119  *  type qualifier.  ??? This still leaves out most reserved keywords
1120  *  (following the old parser), shouldn't we include them, and why not
1121  *  allow identifiers declared as types to start the arguments?
1122  *
1123  *  Matze: this all looks confusing and little systematic, so we're even less
1124  *  strict and parse any list of things which are identifiers or
1125  *  (assignment-)expressions.
1126  */
1127 static attribute_argument_t *parse_attribute_arguments(void)
1128 {
1129         attribute_argument_t  *first  = NULL;
1130         attribute_argument_t **anchor = &first;
1131         if (token.kind != ')') do {
1132                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1133
1134                 /* is it an identifier */
1135                 if (token.kind == T_IDENTIFIER
1136                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1137                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1138                         argument->v.symbol = token.base.symbol;
1139                         eat(T_IDENTIFIER);
1140                 } else {
1141                         /* must be an expression */
1142                         expression_t *expression = parse_assignment_expression();
1143
1144                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1145                         argument->v.expression = expression;
1146                 }
1147
1148                 /* append argument */
1149                 *anchor = argument;
1150                 anchor  = &argument->next;
1151         } while (next_if(','));
1152         expect(')');
1153         return first;
1154 }
1155
1156 static attribute_t *parse_attribute_asm(void)
1157 {
1158         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1159         eat(T_asm);
1160         expect('(');
1161         attribute->a.arguments = parse_attribute_arguments();
1162         return attribute;
1163 }
1164
1165 static attribute_t *parse_attribute_gnu_single(void)
1166 {
1167         /* parse "any-word" */
1168         symbol_t *const symbol = token.base.symbol;
1169         if (symbol == NULL) {
1170                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1171                 return NULL;
1172         }
1173
1174         attribute_kind_t  kind;
1175         char const *const name = symbol->string;
1176         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1177                 if (kind > ATTRIBUTE_GNU_LAST) {
1178                         /* special case for "__const" */
1179                         if (token.kind == T_const) {
1180                                 kind = ATTRIBUTE_GNU_CONST;
1181                                 break;
1182                         }
1183
1184                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1185                         /* TODO: we should still save the attribute in the list... */
1186                         kind = ATTRIBUTE_UNKNOWN;
1187                         break;
1188                 }
1189
1190                 const char *attribute_name = get_attribute_name(kind);
1191                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1192                         break;
1193         }
1194
1195         attribute_t *attribute = allocate_attribute_zero(kind);
1196         next_token();
1197
1198         /* parse arguments */
1199         if (next_if('('))
1200                 attribute->a.arguments = parse_attribute_arguments();
1201
1202         return attribute;
1203 }
1204
1205 static attribute_t *parse_attribute_gnu(void)
1206 {
1207         attribute_t  *first  = NULL;
1208         attribute_t **anchor = &first;
1209
1210         eat(T___attribute__);
1211         add_anchor_token(')');
1212         add_anchor_token(',');
1213         expect('(');
1214         expect('(');
1215
1216         if (token.kind != ')') do {
1217                 attribute_t *attribute = parse_attribute_gnu_single();
1218                 if (attribute) {
1219                         *anchor = attribute;
1220                         anchor  = &attribute->next;
1221                 }
1222         } while (next_if(','));
1223         rem_anchor_token(',');
1224         rem_anchor_token(')');
1225
1226         expect(')');
1227         expect(')');
1228         return first;
1229 }
1230
1231 /** Parse attributes. */
1232 static attribute_t *parse_attributes(attribute_t *first)
1233 {
1234         attribute_t **anchor = &first;
1235         for (;;) {
1236                 while (*anchor != NULL)
1237                         anchor = &(*anchor)->next;
1238
1239                 attribute_t *attribute;
1240                 switch (token.kind) {
1241                 case T___attribute__:
1242                         attribute = parse_attribute_gnu();
1243                         if (attribute == NULL)
1244                                 continue;
1245                         break;
1246
1247                 case T_asm:
1248                         attribute = parse_attribute_asm();
1249                         break;
1250
1251                 case T_cdecl:
1252                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1253                         eat(T_cdecl);
1254                         break;
1255
1256                 case T__fastcall:
1257                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1258                         eat(T__fastcall);
1259                         break;
1260
1261                 case T__forceinline:
1262                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1263                         eat(T__forceinline);
1264                         break;
1265
1266                 case T__stdcall:
1267                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1268                         eat(T__stdcall);
1269                         break;
1270
1271                 case T___thiscall:
1272                         /* TODO record modifier */
1273                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1274                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1275                         eat(T___thiscall);
1276                         break;
1277
1278                 default:
1279                         return first;
1280                 }
1281
1282                 *anchor = attribute;
1283                 anchor  = &attribute->next;
1284         }
1285 }
1286
1287 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1288
1289 static entity_t *determine_lhs_ent(expression_t *const expr,
1290                                    entity_t *lhs_ent)
1291 {
1292         switch (expr->kind) {
1293                 case EXPR_REFERENCE: {
1294                         entity_t *const entity = expr->reference.entity;
1295                         /* we should only find variables as lvalues... */
1296                         if (entity->base.kind != ENTITY_VARIABLE
1297                                         && entity->base.kind != ENTITY_PARAMETER)
1298                                 return NULL;
1299
1300                         return entity;
1301                 }
1302
1303                 case EXPR_ARRAY_ACCESS: {
1304                         expression_t *const ref = expr->array_access.array_ref;
1305                         entity_t     *      ent = NULL;
1306                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1307                                 ent     = determine_lhs_ent(ref, lhs_ent);
1308                                 lhs_ent = ent;
1309                         } else {
1310                                 mark_vars_read(ref, lhs_ent);
1311                         }
1312                         mark_vars_read(expr->array_access.index, lhs_ent);
1313                         return ent;
1314                 }
1315
1316                 case EXPR_SELECT: {
1317                         mark_vars_read(expr->select.compound, lhs_ent);
1318                         if (is_type_compound(skip_typeref(expr->base.type)))
1319                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1320                         return NULL;
1321                 }
1322
1323                 case EXPR_UNARY_DEREFERENCE: {
1324                         expression_t *const val = expr->unary.value;
1325                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1326                                 /* *&x is a NOP */
1327                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1328                         } else {
1329                                 mark_vars_read(val, NULL);
1330                                 return NULL;
1331                         }
1332                 }
1333
1334                 default:
1335                         mark_vars_read(expr, NULL);
1336                         return NULL;
1337         }
1338 }
1339
1340 #define ENT_ANY ((entity_t*)-1)
1341
1342 /**
1343  * Mark declarations, which are read.  This is used to detect variables, which
1344  * are never read.
1345  * Example:
1346  * x = x + 1;
1347  *   x is not marked as "read", because it is only read to calculate its own new
1348  *   value.
1349  *
1350  * x += y; y += x;
1351  *   x and y are not detected as "not read", because multiple variables are
1352  *   involved.
1353  */
1354 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1355 {
1356         switch (expr->kind) {
1357                 case EXPR_REFERENCE: {
1358                         entity_t *const entity = expr->reference.entity;
1359                         if (entity->kind != ENTITY_VARIABLE
1360                                         && entity->kind != ENTITY_PARAMETER)
1361                                 return;
1362
1363                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1364                                 entity->variable.read = true;
1365                         }
1366                         return;
1367                 }
1368
1369                 case EXPR_CALL:
1370                         // TODO respect pure/const
1371                         mark_vars_read(expr->call.function, NULL);
1372                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1373                                 mark_vars_read(arg->expression, NULL);
1374                         }
1375                         return;
1376
1377                 case EXPR_CONDITIONAL:
1378                         // TODO lhs_decl should depend on whether true/false have an effect
1379                         mark_vars_read(expr->conditional.condition, NULL);
1380                         if (expr->conditional.true_expression != NULL)
1381                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1382                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1383                         return;
1384
1385                 case EXPR_SELECT:
1386                         if (lhs_ent == ENT_ANY
1387                                         && !is_type_compound(skip_typeref(expr->base.type)))
1388                                 lhs_ent = NULL;
1389                         mark_vars_read(expr->select.compound, lhs_ent);
1390                         return;
1391
1392                 case EXPR_ARRAY_ACCESS: {
1393                         mark_vars_read(expr->array_access.index, lhs_ent);
1394                         expression_t *const ref = expr->array_access.array_ref;
1395                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1396                                 if (lhs_ent == ENT_ANY)
1397                                         lhs_ent = NULL;
1398                         }
1399                         mark_vars_read(ref, lhs_ent);
1400                         return;
1401                 }
1402
1403                 case EXPR_VA_ARG:
1404                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1405                         return;
1406
1407                 case EXPR_VA_COPY:
1408                         mark_vars_read(expr->va_copye.src, lhs_ent);
1409                         return;
1410
1411                 case EXPR_UNARY_CAST:
1412                         /* Special case: Use void cast to mark a variable as "read" */
1413                         if (is_type_void(skip_typeref(expr->base.type)))
1414                                 lhs_ent = NULL;
1415                         goto unary;
1416
1417
1418                 case EXPR_UNARY_THROW:
1419                         if (expr->unary.value == NULL)
1420                                 return;
1421                         /* FALLTHROUGH */
1422                 case EXPR_UNARY_DEREFERENCE:
1423                 case EXPR_UNARY_DELETE:
1424                 case EXPR_UNARY_DELETE_ARRAY:
1425                         if (lhs_ent == ENT_ANY)
1426                                 lhs_ent = NULL;
1427                         goto unary;
1428
1429                 case EXPR_UNARY_NEGATE:
1430                 case EXPR_UNARY_PLUS:
1431                 case EXPR_UNARY_BITWISE_NEGATE:
1432                 case EXPR_UNARY_NOT:
1433                 case EXPR_UNARY_TAKE_ADDRESS:
1434                 case EXPR_UNARY_POSTFIX_INCREMENT:
1435                 case EXPR_UNARY_POSTFIX_DECREMENT:
1436                 case EXPR_UNARY_PREFIX_INCREMENT:
1437                 case EXPR_UNARY_PREFIX_DECREMENT:
1438                 case EXPR_UNARY_ASSUME:
1439 unary:
1440                         mark_vars_read(expr->unary.value, lhs_ent);
1441                         return;
1442
1443                 case EXPR_BINARY_ADD:
1444                 case EXPR_BINARY_SUB:
1445                 case EXPR_BINARY_MUL:
1446                 case EXPR_BINARY_DIV:
1447                 case EXPR_BINARY_MOD:
1448                 case EXPR_BINARY_EQUAL:
1449                 case EXPR_BINARY_NOTEQUAL:
1450                 case EXPR_BINARY_LESS:
1451                 case EXPR_BINARY_LESSEQUAL:
1452                 case EXPR_BINARY_GREATER:
1453                 case EXPR_BINARY_GREATEREQUAL:
1454                 case EXPR_BINARY_BITWISE_AND:
1455                 case EXPR_BINARY_BITWISE_OR:
1456                 case EXPR_BINARY_BITWISE_XOR:
1457                 case EXPR_BINARY_LOGICAL_AND:
1458                 case EXPR_BINARY_LOGICAL_OR:
1459                 case EXPR_BINARY_SHIFTLEFT:
1460                 case EXPR_BINARY_SHIFTRIGHT:
1461                 case EXPR_BINARY_COMMA:
1462                 case EXPR_BINARY_ISGREATER:
1463                 case EXPR_BINARY_ISGREATEREQUAL:
1464                 case EXPR_BINARY_ISLESS:
1465                 case EXPR_BINARY_ISLESSEQUAL:
1466                 case EXPR_BINARY_ISLESSGREATER:
1467                 case EXPR_BINARY_ISUNORDERED:
1468                         mark_vars_read(expr->binary.left,  lhs_ent);
1469                         mark_vars_read(expr->binary.right, lhs_ent);
1470                         return;
1471
1472                 case EXPR_BINARY_ASSIGN:
1473                 case EXPR_BINARY_MUL_ASSIGN:
1474                 case EXPR_BINARY_DIV_ASSIGN:
1475                 case EXPR_BINARY_MOD_ASSIGN:
1476                 case EXPR_BINARY_ADD_ASSIGN:
1477                 case EXPR_BINARY_SUB_ASSIGN:
1478                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1479                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1480                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1481                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1482                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1483                         if (lhs_ent == ENT_ANY)
1484                                 lhs_ent = NULL;
1485                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1486                         mark_vars_read(expr->binary.right, lhs_ent);
1487                         return;
1488                 }
1489
1490                 case EXPR_VA_START:
1491                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1492                         return;
1493
1494                 case EXPR_LITERAL_CASES:
1495                 case EXPR_LITERAL_CHARACTER:
1496                 case EXPR_ERROR:
1497                 case EXPR_STRING_LITERAL:
1498                 case EXPR_COMPOUND_LITERAL: // TODO init?
1499                 case EXPR_SIZEOF:
1500                 case EXPR_CLASSIFY_TYPE:
1501                 case EXPR_ALIGNOF:
1502                 case EXPR_FUNCNAME:
1503                 case EXPR_BUILTIN_CONSTANT_P:
1504                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1505                 case EXPR_OFFSETOF:
1506                 case EXPR_STATEMENT: // TODO
1507                 case EXPR_LABEL_ADDRESS:
1508                 case EXPR_ENUM_CONSTANT:
1509                         return;
1510         }
1511
1512         panic("unhandled expression");
1513 }
1514
1515 static designator_t *parse_designation(void)
1516 {
1517         designator_t  *result = NULL;
1518         designator_t **anchor = &result;
1519
1520         for (;;) {
1521                 designator_t *designator;
1522                 switch (token.kind) {
1523                 case '[':
1524                         designator = allocate_ast_zero(sizeof(designator[0]));
1525                         designator->source_position = *HERE;
1526                         eat('[');
1527                         add_anchor_token(']');
1528                         designator->array_index = parse_constant_expression();
1529                         rem_anchor_token(']');
1530                         expect(']');
1531                         break;
1532                 case '.':
1533                         designator = allocate_ast_zero(sizeof(designator[0]));
1534                         designator->source_position = *HERE;
1535                         eat('.');
1536                         designator->symbol = expect_identifier("while parsing designator", NULL);
1537                         if (!designator->symbol)
1538                                 return NULL;
1539                         break;
1540                 default:
1541                         expect('=');
1542                         return result;
1543                 }
1544
1545                 assert(designator != NULL);
1546                 *anchor = designator;
1547                 anchor  = &designator->next;
1548         }
1549 }
1550
1551 /**
1552  * Build an initializer from a given expression.
1553  */
1554 static initializer_t *initializer_from_expression(type_t *orig_type,
1555                                                   expression_t *expression)
1556 {
1557         /* TODO check that expression is a constant expression */
1558
1559         type_t *const type = skip_typeref(orig_type);
1560
1561         /* §6.7.8.14/15 char array may be initialized by string literals */
1562         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1563                 array_type_t *const array_type   = &type->array;
1564                 type_t       *const element_type = skip_typeref(array_type->element_type);
1565                 switch (expression->string_literal.value.encoding) {
1566                 case STRING_ENCODING_CHAR: {
1567                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1568                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1569                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1570                                 goto make_string_init;
1571                         }
1572                         break;
1573                 }
1574
1575                 case STRING_ENCODING_WIDE: {
1576                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1577                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1578 make_string_init:;
1579                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1580                                 init->value.value = expression;
1581                                 return init;
1582                         }
1583                         break;
1584                 }
1585                 }
1586         }
1587
1588         assign_error_t error = semantic_assign(type, expression);
1589         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1590                 return NULL;
1591         report_assign_error(error, type, expression, "initializer",
1592                             &expression->base.source_position);
1593
1594         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1595         result->value.value = create_implicit_cast(expression, type);
1596
1597         return result;
1598 }
1599
1600 /**
1601  * Parses an scalar initializer.
1602  *
1603  * §6.7.8.11; eat {} without warning
1604  */
1605 static initializer_t *parse_scalar_initializer(type_t *type,
1606                                                bool must_be_constant)
1607 {
1608         /* there might be extra {} hierarchies */
1609         int braces = 0;
1610         if (token.kind == '{') {
1611                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1612                 do {
1613                         eat('{');
1614                         ++braces;
1615                 } while (token.kind == '{');
1616         }
1617
1618         expression_t *expression = parse_assignment_expression();
1619         mark_vars_read(expression, NULL);
1620         if (must_be_constant && !is_linker_constant(expression)) {
1621                 errorf(&expression->base.source_position,
1622                        "initialisation expression '%E' is not constant",
1623                        expression);
1624         }
1625
1626         initializer_t *initializer = initializer_from_expression(type, expression);
1627
1628         if (initializer == NULL) {
1629                 errorf(&expression->base.source_position,
1630                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1631                        expression, expression->base.type, type);
1632                 /* TODO */
1633                 return NULL;
1634         }
1635
1636         bool additional_warning_displayed = false;
1637         while (braces > 0) {
1638                 next_if(',');
1639                 if (token.kind != '}') {
1640                         if (!additional_warning_displayed) {
1641                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1642                                 additional_warning_displayed = true;
1643                         }
1644                 }
1645                 eat_block();
1646                 braces--;
1647         }
1648
1649         return initializer;
1650 }
1651
1652 /**
1653  * An entry in the type path.
1654  */
1655 typedef struct type_path_entry_t type_path_entry_t;
1656 struct type_path_entry_t {
1657         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1658         union {
1659                 size_t         index;          /**< For array types: the current index. */
1660                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1661         } v;
1662 };
1663
1664 /**
1665  * A type path expression a position inside compound or array types.
1666  */
1667 typedef struct type_path_t type_path_t;
1668 struct type_path_t {
1669         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1670         type_t            *top_type;     /**< type of the element the path points */
1671         size_t             max_index;    /**< largest index in outermost array */
1672 };
1673
1674 /**
1675  * Prints a type path for debugging.
1676  */
1677 static __attribute__((unused)) void debug_print_type_path(
1678                 const type_path_t *path)
1679 {
1680         size_t len = ARR_LEN(path->path);
1681
1682         for (size_t i = 0; i < len; ++i) {
1683                 const type_path_entry_t *entry = & path->path[i];
1684
1685                 type_t *type = skip_typeref(entry->type);
1686                 if (is_type_compound(type)) {
1687                         /* in gcc mode structs can have no members */
1688                         if (entry->v.compound_entry == NULL) {
1689                                 assert(i == len-1);
1690                                 continue;
1691                         }
1692                         fprintf(stderr, ".%s",
1693                                 entry->v.compound_entry->base.symbol->string);
1694                 } else if (is_type_array(type)) {
1695                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1696                 } else {
1697                         fprintf(stderr, "-INVALID-");
1698                 }
1699         }
1700         if (path->top_type != NULL) {
1701                 fprintf(stderr, "  (");
1702                 print_type(path->top_type);
1703                 fprintf(stderr, ")");
1704         }
1705 }
1706
1707 /**
1708  * Return the top type path entry, ie. in a path
1709  * (type).a.b returns the b.
1710  */
1711 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1712 {
1713         size_t len = ARR_LEN(path->path);
1714         assert(len > 0);
1715         return &path->path[len-1];
1716 }
1717
1718 /**
1719  * Enlarge the type path by an (empty) element.
1720  */
1721 static type_path_entry_t *append_to_type_path(type_path_t *path)
1722 {
1723         size_t len = ARR_LEN(path->path);
1724         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1725
1726         type_path_entry_t *result = & path->path[len];
1727         memset(result, 0, sizeof(result[0]));
1728         return result;
1729 }
1730
1731 /**
1732  * Descending into a sub-type. Enter the scope of the current top_type.
1733  */
1734 static void descend_into_subtype(type_path_t *path)
1735 {
1736         type_t *orig_top_type = path->top_type;
1737         type_t *top_type      = skip_typeref(orig_top_type);
1738
1739         type_path_entry_t *top = append_to_type_path(path);
1740         top->type              = top_type;
1741
1742         if (is_type_compound(top_type)) {
1743                 compound_t *const compound = top_type->compound.compound;
1744                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1745
1746                 if (entry != NULL) {
1747                         top->v.compound_entry = &entry->declaration;
1748                         path->top_type = entry->declaration.type;
1749                 } else {
1750                         path->top_type = NULL;
1751                 }
1752         } else if (is_type_array(top_type)) {
1753                 top->v.index   = 0;
1754                 path->top_type = top_type->array.element_type;
1755         } else {
1756                 assert(!is_type_valid(top_type));
1757         }
1758 }
1759
1760 /**
1761  * Pop an entry from the given type path, ie. returning from
1762  * (type).a.b to (type).a
1763  */
1764 static void ascend_from_subtype(type_path_t *path)
1765 {
1766         type_path_entry_t *top = get_type_path_top(path);
1767
1768         path->top_type = top->type;
1769
1770         size_t len = ARR_LEN(path->path);
1771         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1772 }
1773
1774 /**
1775  * Pop entries from the given type path until the given
1776  * path level is reached.
1777  */
1778 static void ascend_to(type_path_t *path, size_t top_path_level)
1779 {
1780         size_t len = ARR_LEN(path->path);
1781
1782         while (len > top_path_level) {
1783                 ascend_from_subtype(path);
1784                 len = ARR_LEN(path->path);
1785         }
1786 }
1787
1788 static bool walk_designator(type_path_t *path, const designator_t *designator,
1789                             bool used_in_offsetof)
1790 {
1791         for (; designator != NULL; designator = designator->next) {
1792                 type_path_entry_t *top       = get_type_path_top(path);
1793                 type_t            *orig_type = top->type;
1794
1795                 type_t *type = skip_typeref(orig_type);
1796
1797                 if (designator->symbol != NULL) {
1798                         symbol_t *symbol = designator->symbol;
1799                         if (!is_type_compound(type)) {
1800                                 if (is_type_valid(type)) {
1801                                         errorf(&designator->source_position,
1802                                                "'.%Y' designator used for non-compound type '%T'",
1803                                                symbol, orig_type);
1804                                 }
1805
1806                                 top->type             = type_error_type;
1807                                 top->v.compound_entry = NULL;
1808                                 orig_type             = type_error_type;
1809                         } else {
1810                                 compound_t *compound = type->compound.compound;
1811                                 entity_t   *iter     = compound->members.entities;
1812                                 for (; iter != NULL; iter = iter->base.next) {
1813                                         if (iter->base.symbol == symbol) {
1814                                                 break;
1815                                         }
1816                                 }
1817                                 if (iter == NULL) {
1818                                         errorf(&designator->source_position,
1819                                                "'%T' has no member named '%Y'", orig_type, symbol);
1820                                         return false;
1821                                 }
1822                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1823                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1824                                         errorf(&designator->source_position,
1825                                                    "offsetof designator '%Y' must not specify bitfield",
1826                                                    symbol);
1827                                         return false;
1828                                 }
1829
1830                                 top->type             = orig_type;
1831                                 top->v.compound_entry = &iter->declaration;
1832                                 orig_type             = iter->declaration.type;
1833                         }
1834                 } else {
1835                         expression_t *array_index = designator->array_index;
1836                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1837                                 return true;
1838
1839                         if (!is_type_array(type)) {
1840                                 if (is_type_valid(type)) {
1841                                         errorf(&designator->source_position,
1842                                                "[%E] designator used for non-array type '%T'",
1843                                                array_index, orig_type);
1844                                 }
1845                                 return false;
1846                         }
1847
1848                         long index = fold_constant_to_int(array_index);
1849                         if (!used_in_offsetof) {
1850                                 if (index < 0) {
1851                                         errorf(&designator->source_position,
1852                                                "array index [%E] must be positive", array_index);
1853                                 } else if (type->array.size_constant) {
1854                                         long array_size = type->array.size;
1855                                         if (index >= array_size) {
1856                                                 errorf(&designator->source_position,
1857                                                        "designator [%E] (%d) exceeds array size %d",
1858                                                        array_index, index, array_size);
1859                                         }
1860                                 }
1861                         }
1862
1863                         top->type    = orig_type;
1864                         top->v.index = (size_t) index;
1865                         orig_type    = type->array.element_type;
1866                 }
1867                 path->top_type = orig_type;
1868
1869                 if (designator->next != NULL) {
1870                         descend_into_subtype(path);
1871                 }
1872         }
1873         return true;
1874 }
1875
1876 static void advance_current_object(type_path_t *path, size_t top_path_level)
1877 {
1878         type_path_entry_t *top = get_type_path_top(path);
1879
1880         type_t *type = skip_typeref(top->type);
1881         if (is_type_union(type)) {
1882                 /* in unions only the first element is initialized */
1883                 top->v.compound_entry = NULL;
1884         } else if (is_type_struct(type)) {
1885                 declaration_t *entry = top->v.compound_entry;
1886
1887                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1888                 if (next_entity != NULL) {
1889                         assert(is_declaration(next_entity));
1890                         entry = &next_entity->declaration;
1891                 } else {
1892                         entry = NULL;
1893                 }
1894
1895                 top->v.compound_entry = entry;
1896                 if (entry != NULL) {
1897                         path->top_type = entry->type;
1898                         return;
1899                 }
1900         } else if (is_type_array(type)) {
1901                 assert(is_type_array(type));
1902
1903                 top->v.index++;
1904
1905                 if (!type->array.size_constant || top->v.index < type->array.size) {
1906                         return;
1907                 }
1908         } else {
1909                 assert(!is_type_valid(type));
1910                 return;
1911         }
1912
1913         /* we're past the last member of the current sub-aggregate, try if we
1914          * can ascend in the type hierarchy and continue with another subobject */
1915         size_t len = ARR_LEN(path->path);
1916
1917         if (len > top_path_level) {
1918                 ascend_from_subtype(path);
1919                 advance_current_object(path, top_path_level);
1920         } else {
1921                 path->top_type = NULL;
1922         }
1923 }
1924
1925 /**
1926  * skip any {...} blocks until a closing bracket is reached.
1927  */
1928 static void skip_initializers(void)
1929 {
1930         next_if('{');
1931
1932         while (token.kind != '}') {
1933                 if (token.kind == T_EOF)
1934                         return;
1935                 if (token.kind == '{') {
1936                         eat_block();
1937                         continue;
1938                 }
1939                 next_token();
1940         }
1941 }
1942
1943 static initializer_t *create_empty_initializer(void)
1944 {
1945         static initializer_t empty_initializer
1946                 = { .list = { { INITIALIZER_LIST }, 0 } };
1947         return &empty_initializer;
1948 }
1949
1950 /**
1951  * Parse a part of an initialiser for a struct or union,
1952  */
1953 static initializer_t *parse_sub_initializer(type_path_t *path,
1954                 type_t *outer_type, size_t top_path_level,
1955                 parse_initializer_env_t *env)
1956 {
1957         if (token.kind == '}') {
1958                 /* empty initializer */
1959                 return create_empty_initializer();
1960         }
1961
1962         initializer_t *result = NULL;
1963
1964         type_t *orig_type = path->top_type;
1965         type_t *type      = NULL;
1966
1967         if (orig_type == NULL) {
1968                 /* We are initializing an empty compound. */
1969         } else {
1970                 type = skip_typeref(orig_type);
1971         }
1972
1973         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1974
1975         while (true) {
1976                 designator_t *designator = NULL;
1977                 if (token.kind == '.' || token.kind == '[') {
1978                         designator = parse_designation();
1979                         goto finish_designator;
1980                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1981                         /* GNU-style designator ("identifier: value") */
1982                         designator = allocate_ast_zero(sizeof(designator[0]));
1983                         designator->source_position = *HERE;
1984                         designator->symbol          = token.base.symbol;
1985                         eat(T_IDENTIFIER);
1986                         eat(':');
1987
1988 finish_designator:
1989                         /* reset path to toplevel, evaluate designator from there */
1990                         ascend_to(path, top_path_level);
1991                         if (!walk_designator(path, designator, false)) {
1992                                 /* can't continue after designation error */
1993                                 goto end_error;
1994                         }
1995
1996                         initializer_t *designator_initializer
1997                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1998                         designator_initializer->designator.designator = designator;
1999                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2000
2001                         orig_type = path->top_type;
2002                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2003                 }
2004
2005                 initializer_t *sub;
2006
2007                 if (token.kind == '{') {
2008                         if (type != NULL && is_type_scalar(type)) {
2009                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2010                         } else {
2011                                 if (type == NULL) {
2012                                         if (env->entity != NULL) {
2013                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2014                                         } else {
2015                                                 errorf(HERE, "extra brace group at end of initializer");
2016                                         }
2017                                         eat('{');
2018                                 } else {
2019                                         eat('{');
2020                                         descend_into_subtype(path);
2021                                 }
2022
2023                                 add_anchor_token('}');
2024                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2025                                                             env);
2026                                 rem_anchor_token('}');
2027
2028                                 expect('}');
2029
2030                                 if (!type)
2031                                         goto error_parse_next;
2032
2033                                 ascend_from_subtype(path);
2034                         }
2035                 } else {
2036                         /* must be an expression */
2037                         expression_t *expression = parse_assignment_expression();
2038                         mark_vars_read(expression, NULL);
2039
2040                         if (env->must_be_constant && !is_linker_constant(expression)) {
2041                                 errorf(&expression->base.source_position,
2042                                        "Initialisation expression '%E' is not constant",
2043                                        expression);
2044                         }
2045
2046                         if (type == NULL) {
2047                                 /* we are already outside, ... */
2048                                 if (outer_type == NULL)
2049                                         goto error_parse_next;
2050                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2051                                 if (is_type_compound(outer_type_skip) &&
2052                                                 !outer_type_skip->compound.compound->complete) {
2053                                         goto error_parse_next;
2054                                 }
2055
2056                                 source_position_t const* const pos = &expression->base.source_position;
2057                                 if (env->entity != NULL) {
2058                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2059                                 } else {
2060                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2061                                 }
2062                                 goto error_parse_next;
2063                         }
2064
2065                         /* handle { "string" } special case */
2066                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2067                                 result = initializer_from_expression(outer_type, expression);
2068                                 if (result != NULL) {
2069                                         next_if(',');
2070                                         if (token.kind != '}') {
2071                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2072                                         }
2073                                         /* TODO: eat , ... */
2074                                         goto out;
2075                                 }
2076                         }
2077
2078                         /* descend into subtypes until expression matches type */
2079                         while (true) {
2080                                 orig_type = path->top_type;
2081                                 type      = skip_typeref(orig_type);
2082
2083                                 sub = initializer_from_expression(orig_type, expression);
2084                                 if (sub != NULL) {
2085                                         break;
2086                                 }
2087                                 if (!is_type_valid(type)) {
2088                                         goto end_error;
2089                                 }
2090                                 if (is_type_scalar(type)) {
2091                                         errorf(&expression->base.source_position,
2092                                                         "expression '%E' doesn't match expected type '%T'",
2093                                                         expression, orig_type);
2094                                         goto end_error;
2095                                 }
2096
2097                                 descend_into_subtype(path);
2098                         }
2099                 }
2100
2101                 /* update largest index of top array */
2102                 const type_path_entry_t *first      = &path->path[0];
2103                 type_t                  *first_type = first->type;
2104                 first_type                          = skip_typeref(first_type);
2105                 if (is_type_array(first_type)) {
2106                         size_t index = first->v.index;
2107                         if (index > path->max_index)
2108                                 path->max_index = index;
2109                 }
2110
2111                 /* append to initializers list */
2112                 ARR_APP1(initializer_t*, initializers, sub);
2113
2114 error_parse_next:
2115                 if (!next_if(','))
2116                         break;
2117                 if (token.kind == '}') {
2118                         break;
2119                 }
2120
2121                 if (type != NULL) {
2122                         /* advance to the next declaration if we are not at the end */
2123                         advance_current_object(path, top_path_level);
2124                         orig_type = path->top_type;
2125                         if (orig_type != NULL)
2126                                 type = skip_typeref(orig_type);
2127                         else
2128                                 type = NULL;
2129                 }
2130         }
2131
2132         size_t len  = ARR_LEN(initializers);
2133         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2134         result = allocate_ast_zero(size);
2135         result->kind     = INITIALIZER_LIST;
2136         result->list.len = len;
2137         memcpy(&result->list.initializers, initializers,
2138                len * sizeof(initializers[0]));
2139         goto out;
2140
2141 end_error:
2142         skip_initializers();
2143 out:
2144         DEL_ARR_F(initializers);
2145         ascend_to(path, top_path_level+1);
2146         return result;
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                 entity->compound.attributes = attributes;
2311                 handle_entity_attributes(attributes, entity);
2312         }
2313
2314         return &entity->compound;
2315 }
2316
2317 static void parse_enum_entries(type_t *const enum_type)
2318 {
2319         eat('{');
2320
2321         if (token.kind == '}') {
2322                 errorf(HERE, "empty enum not allowed");
2323                 eat('}');
2324                 return;
2325         }
2326
2327         add_anchor_token('}');
2328         add_anchor_token(',');
2329         do {
2330                 add_anchor_token('=');
2331                 source_position_t pos;
2332                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2333                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2334                 entity->enum_value.enum_type = enum_type;
2335                 rem_anchor_token('=');
2336
2337                 if (next_if('=')) {
2338                         expression_t *value = parse_constant_expression();
2339
2340                         value = create_implicit_cast(value, enum_type);
2341                         entity->enum_value.value = value;
2342
2343                         /* TODO semantic */
2344                 }
2345
2346                 record_entity(entity, false);
2347         } while (next_if(',') && token.kind != '}');
2348         rem_anchor_token(',');
2349         rem_anchor_token('}');
2350
2351         expect('}');
2352 }
2353
2354 static type_t *parse_enum_specifier(void)
2355 {
2356         source_position_t const pos = *HERE;
2357         entity_t               *entity;
2358         symbol_t               *symbol;
2359
2360         eat(T_enum);
2361         switch (token.kind) {
2362                 case T_IDENTIFIER:
2363                         symbol = token.base.symbol;
2364                         entity = get_tag(symbol, ENTITY_ENUM);
2365                         eat(T_IDENTIFIER);
2366
2367                         if (entity != NULL) {
2368                                 if (entity->base.parent_scope != current_scope &&
2369                                                 (token.kind == '{' || token.kind == ';')) {
2370                                         /* we're in an inner scope and have a definition. Shadow
2371                                          * existing definition in outer scope */
2372                                         entity = NULL;
2373                                 } else if (entity->enume.complete && token.kind == '{') {
2374                                         source_position_t const *const ppos = &entity->base.source_position;
2375                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2376                                 }
2377                         }
2378                         break;
2379
2380                 case '{':
2381                         entity = NULL;
2382                         symbol = NULL;
2383                         break;
2384
2385                 default:
2386                         parse_error_expected("while parsing enum type specifier",
2387                                         T_IDENTIFIER, '{', NULL);
2388                         return NULL;
2389         }
2390
2391         if (entity == NULL) {
2392                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2393                 entity->base.parent_scope = current_scope;
2394         }
2395
2396         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2397         type->enumt.enume      = &entity->enume;
2398         type->enumt.base.akind = ATOMIC_TYPE_INT;
2399
2400         if (token.kind == '{') {
2401                 if (symbol != NULL) {
2402                         environment_push(entity);
2403                 }
2404                 append_entity(current_scope, entity);
2405                 entity->enume.complete = true;
2406
2407                 parse_enum_entries(type);
2408                 parse_attributes(NULL);
2409
2410                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2411                 if (symbol == NULL) {
2412                         assert(anonymous_entity == NULL);
2413                         anonymous_entity = entity;
2414                 }
2415         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2416                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2417         }
2418
2419         return type;
2420 }
2421
2422 /**
2423  * if a symbol is a typedef to another type, return true
2424  */
2425 static bool is_typedef_symbol(symbol_t *symbol)
2426 {
2427         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2428         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2429 }
2430
2431 static type_t *parse_typeof(void)
2432 {
2433         eat(T___typeof__);
2434
2435         type_t *type;
2436
2437         add_anchor_token(')');
2438         expect('(');
2439
2440         expression_t *expression  = NULL;
2441
2442         switch (token.kind) {
2443         case T_IDENTIFIER:
2444                 if (is_typedef_symbol(token.base.symbol)) {
2445         DECLARATION_START
2446                         type = parse_typename();
2447                 } else {
2448         default:
2449                         expression = parse_expression();
2450                         type       = revert_automatic_type_conversion(expression);
2451                 }
2452                 break;
2453         }
2454
2455         rem_anchor_token(')');
2456         expect(')');
2457
2458         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2459         typeof_type->typeoft.expression  = expression;
2460         typeof_type->typeoft.typeof_type = type;
2461
2462         return typeof_type;
2463 }
2464
2465 typedef enum specifiers_t {
2466         SPECIFIER_NONE      = 0,
2467         SPECIFIER_SIGNED    = 1 << 0,
2468         SPECIFIER_UNSIGNED  = 1 << 1,
2469         SPECIFIER_LONG      = 1 << 2,
2470         SPECIFIER_INT       = 1 << 3,
2471         SPECIFIER_DOUBLE    = 1 << 4,
2472         SPECIFIER_CHAR      = 1 << 5,
2473         SPECIFIER_WCHAR_T   = 1 << 6,
2474         SPECIFIER_SHORT     = 1 << 7,
2475         SPECIFIER_LONG_LONG = 1 << 8,
2476         SPECIFIER_FLOAT     = 1 << 9,
2477         SPECIFIER_BOOL      = 1 << 10,
2478         SPECIFIER_VOID      = 1 << 11,
2479         SPECIFIER_INT8      = 1 << 12,
2480         SPECIFIER_INT16     = 1 << 13,
2481         SPECIFIER_INT32     = 1 << 14,
2482         SPECIFIER_INT64     = 1 << 15,
2483         SPECIFIER_INT128    = 1 << 16,
2484         SPECIFIER_COMPLEX   = 1 << 17,
2485         SPECIFIER_IMAGINARY = 1 << 18,
2486 } specifiers_t;
2487
2488 static type_t *get_typedef_type(symbol_t *symbol)
2489 {
2490         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2491         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2492                 return NULL;
2493
2494         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2495         type->typedeft.typedefe = &entity->typedefe;
2496
2497         return type;
2498 }
2499
2500 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2501 {
2502         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2503
2504         add_anchor_token(')');
2505         add_anchor_token(',');
2506         expect('(');
2507
2508         do {
2509                 add_anchor_token('=');
2510                 source_position_t pos;
2511                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2512                 rem_anchor_token('=');
2513
2514                 symbol_t **prop = NULL;
2515                 if (prop_sym) {
2516                         if (streq(prop_sym->string, "put")) {
2517                                 prop = &property->put_symbol;
2518                         } else if (streq(prop_sym->string, "get")) {
2519                                 prop = &property->get_symbol;
2520                         } else {
2521                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2522                         }
2523                 }
2524
2525                 add_anchor_token(T_IDENTIFIER);
2526                 expect('=');
2527                 rem_anchor_token(T_IDENTIFIER);
2528
2529                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2530                 if (prop != NULL)
2531                         *prop = sym ? sym : sym_anonymous;
2532         } while (next_if(','));
2533         rem_anchor_token(',');
2534         rem_anchor_token(')');
2535
2536         attribute->a.property = property;
2537
2538         expect(')');
2539         return attribute;
2540 }
2541
2542 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2543 {
2544         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2545         if (next_if(T_restrict)) {
2546                 kind = ATTRIBUTE_MS_RESTRICT;
2547         } else if (token.kind == T_IDENTIFIER) {
2548                 char const *const name = token.base.symbol->string;
2549                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2550                      ++k) {
2551                         const char *attribute_name = get_attribute_name(k);
2552                         if (attribute_name != NULL && streq(attribute_name, name)) {
2553                                 kind = k;
2554                                 break;
2555                         }
2556                 }
2557
2558                 if (kind == ATTRIBUTE_UNKNOWN) {
2559                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2560                 }
2561         } else {
2562                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2563                 return NULL;
2564         }
2565
2566         attribute_t *attribute = allocate_attribute_zero(kind);
2567         eat(T_IDENTIFIER);
2568
2569         if (kind == ATTRIBUTE_MS_PROPERTY) {
2570                 return parse_attribute_ms_property(attribute);
2571         }
2572
2573         /* parse arguments */
2574         if (next_if('('))
2575                 attribute->a.arguments = parse_attribute_arguments();
2576
2577         return attribute;
2578 }
2579
2580 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2581 {
2582         eat(T__declspec);
2583
2584         add_anchor_token(')');
2585         expect('(');
2586         if (token.kind != ')') {
2587                 attribute_t **anchor = &first;
2588                 do {
2589                         while (*anchor != NULL)
2590                                 anchor = &(*anchor)->next;
2591
2592                         attribute_t *attribute
2593                                 = parse_microsoft_extended_decl_modifier_single();
2594                         if (attribute == NULL)
2595                                 break;
2596
2597                         *anchor = attribute;
2598                         anchor  = &attribute->next;
2599                 } while (next_if(','));
2600         }
2601         rem_anchor_token(')');
2602         expect(')');
2603         return first;
2604 }
2605
2606 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2607 {
2608         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2609         if (is_declaration(entity)) {
2610                 entity->declaration.type     = type_error_type;
2611                 entity->declaration.implicit = true;
2612         } else if (kind == ENTITY_TYPEDEF) {
2613                 entity->typedefe.type    = type_error_type;
2614                 entity->typedefe.builtin = true;
2615         }
2616         if (kind != ENTITY_COMPOUND_MEMBER)
2617                 record_entity(entity, false);
2618         return entity;
2619 }
2620
2621 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2622 {
2623         type_t            *type            = NULL;
2624         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2625         unsigned           type_specifiers = 0;
2626         bool               newtype         = false;
2627         bool               saw_error       = false;
2628
2629         memset(specifiers, 0, sizeof(*specifiers));
2630         specifiers->source_position = *HERE;
2631
2632         while (true) {
2633                 specifiers->attributes = parse_attributes(specifiers->attributes);
2634
2635                 switch (token.kind) {
2636                 /* storage class */
2637 #define MATCH_STORAGE_CLASS(token, class)                                  \
2638                 case token:                                                        \
2639                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2640                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2641                         }                                                              \
2642                         specifiers->storage_class = class;                             \
2643                         if (specifiers->thread_local)                                  \
2644                                 goto check_thread_storage_class;                           \
2645                         eat(token); \
2646                         break;
2647
2648                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2649                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2650                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2651                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2652                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2653
2654                 case T__declspec:
2655                         specifiers->attributes
2656                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2657                         break;
2658
2659                 case T__Thread_local:
2660                         if (specifiers->thread_local) {
2661                                 errorf(HERE, "duplicate %K", &token);
2662                         } else {
2663                                 specifiers->thread_local = true;
2664 check_thread_storage_class:
2665                                 switch (specifiers->storage_class) {
2666                                         case STORAGE_CLASS_EXTERN:
2667                                         case STORAGE_CLASS_NONE:
2668                                         case STORAGE_CLASS_STATIC:
2669                                                 break;
2670
2671                                                 char const* wrong;
2672                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2673                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2674                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2675 wrong_thread_storage_class:
2676                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2677                                                 break;
2678                                 }
2679                         }
2680                         next_token();
2681                         break;
2682
2683                 /* type qualifiers */
2684 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2685                 case token:                                                     \
2686                         qualifiers |= qualifier;                                    \
2687                         eat(token); \
2688                         break
2689
2690                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2691                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2692                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2693                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2694                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2695                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2696                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2697                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2698
2699                 /* type specifiers */
2700 #define MATCH_SPECIFIER(token, specifier, name)                         \
2701                 case token:                                                     \
2702                         if (type_specifiers & specifier) {                           \
2703                                 errorf(HERE, "multiple " name " type specifiers given"); \
2704                         } else {                                                    \
2705                                 type_specifiers |= specifier;                           \
2706                         }                                                           \
2707                         eat(token); \
2708                         break
2709
2710                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2711                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2712                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2713                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2714                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2715                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2716                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2717                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2718                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2719                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2720                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2721                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2722                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2723                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2724                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2725                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2726                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2727                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2728
2729                 case T_inline:
2730                         eat(T_inline);
2731                         specifiers->is_inline = true;
2732                         break;
2733
2734 #if 0
2735                 case T__forceinline:
2736                         eat(T__forceinline);
2737                         specifiers->modifiers |= DM_FORCEINLINE;
2738                         break;
2739 #endif
2740
2741                 case T_long:
2742                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2743                                 errorf(HERE, "too many long type specifiers given");
2744                         } else if (type_specifiers & SPECIFIER_LONG) {
2745                                 type_specifiers |= SPECIFIER_LONG_LONG;
2746                         } else {
2747                                 type_specifiers |= SPECIFIER_LONG;
2748                         }
2749                         eat(T_long);
2750                         break;
2751
2752 #define CHECK_DOUBLE_TYPE() \
2753         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2754
2755                 case T_struct:
2756                         CHECK_DOUBLE_TYPE();
2757                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2758
2759                         type->compound.compound = parse_compound_type_specifier(true);
2760                         break;
2761                 case T_union:
2762                         CHECK_DOUBLE_TYPE();
2763                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2764                         type->compound.compound = parse_compound_type_specifier(false);
2765                         break;
2766                 case T_enum:
2767                         CHECK_DOUBLE_TYPE();
2768                         type = parse_enum_specifier();
2769                         break;
2770                 case T___typeof__:
2771                         CHECK_DOUBLE_TYPE();
2772                         type = parse_typeof();
2773                         break;
2774                 case T___builtin_va_list:
2775                         CHECK_DOUBLE_TYPE();
2776                         type = duplicate_type(type_valist);
2777                         eat(T___builtin_va_list);
2778                         break;
2779
2780                 case T_IDENTIFIER: {
2781                         /* only parse identifier if we haven't found a type yet */
2782                         if (type != NULL || type_specifiers != 0) {
2783                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2784                                  * declaration, so it doesn't generate errors about expecting '(' or
2785                                  * '{' later on. */
2786                                 switch (look_ahead(1)->kind) {
2787                                         STORAGE_CLASSES
2788                                         TYPE_SPECIFIERS
2789                                         case T_const:
2790                                         case T_restrict:
2791                                         case T_volatile:
2792                                         case T_inline:
2793                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2794                                         case T_IDENTIFIER:
2795                                         case '&':
2796                                         case '*':
2797                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2798                                                 eat(T_IDENTIFIER);
2799                                                 continue;
2800
2801                                         default:
2802                                                 goto finish_specifiers;
2803                                 }
2804                         }
2805
2806                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2807                         if (typedef_type == NULL) {
2808                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2809                                  * declaration, so it doesn't generate 'implicit int' followed by more
2810                                  * errors later on. */
2811                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2812                                 switch (la1_type) {
2813                                         DECLARATION_START
2814                                         case T_IDENTIFIER:
2815                                         case '&':
2816                                         case '*': {
2817                                                 errorf(HERE, "%K does not name a type", &token);
2818
2819                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2820
2821                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2822                                                 type->typedeft.typedefe = &entity->typedefe;
2823
2824                                                 eat(T_IDENTIFIER);
2825                                                 saw_error = true;
2826                                                 continue;
2827                                         }
2828
2829                                         default:
2830                                                 goto finish_specifiers;
2831                                 }
2832                         }
2833
2834                         eat(T_IDENTIFIER);
2835                         type = typedef_type;
2836                         break;
2837                 }
2838
2839                 /* function specifier */
2840                 default:
2841                         goto finish_specifiers;
2842                 }
2843         }
2844
2845 finish_specifiers:
2846         specifiers->attributes = parse_attributes(specifiers->attributes);
2847
2848         if (type == NULL || (saw_error && type_specifiers != 0)) {
2849                 atomic_type_kind_t atomic_type;
2850
2851                 /* match valid basic types */
2852                 switch (type_specifiers) {
2853                 case SPECIFIER_VOID:
2854                         atomic_type = ATOMIC_TYPE_VOID;
2855                         break;
2856                 case SPECIFIER_WCHAR_T:
2857                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2858                         break;
2859                 case SPECIFIER_CHAR:
2860                         atomic_type = ATOMIC_TYPE_CHAR;
2861                         break;
2862                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2863                         atomic_type = ATOMIC_TYPE_SCHAR;
2864                         break;
2865                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2866                         atomic_type = ATOMIC_TYPE_UCHAR;
2867                         break;
2868                 case SPECIFIER_SHORT:
2869                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2870                 case SPECIFIER_SHORT | SPECIFIER_INT:
2871                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2872                         atomic_type = ATOMIC_TYPE_SHORT;
2873                         break;
2874                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2875                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2876                         atomic_type = ATOMIC_TYPE_USHORT;
2877                         break;
2878                 case SPECIFIER_INT:
2879                 case SPECIFIER_SIGNED:
2880                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2881                         atomic_type = ATOMIC_TYPE_INT;
2882                         break;
2883                 case SPECIFIER_UNSIGNED:
2884                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2885                         atomic_type = ATOMIC_TYPE_UINT;
2886                         break;
2887                 case SPECIFIER_LONG:
2888                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2889                 case SPECIFIER_LONG | SPECIFIER_INT:
2890                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2891                         atomic_type = ATOMIC_TYPE_LONG;
2892                         break;
2893                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2894                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2895                         atomic_type = ATOMIC_TYPE_ULONG;
2896                         break;
2897
2898                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2899                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2900                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2901                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2902                         | SPECIFIER_INT:
2903                         atomic_type = ATOMIC_TYPE_LONGLONG;
2904                         goto warn_about_long_long;
2905
2906                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2908                         | SPECIFIER_INT:
2909                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2910 warn_about_long_long:
2911                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2912                         break;
2913
2914                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2915                         atomic_type = unsigned_int8_type_kind;
2916                         break;
2917
2918                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2919                         atomic_type = unsigned_int16_type_kind;
2920                         break;
2921
2922                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2923                         atomic_type = unsigned_int32_type_kind;
2924                         break;
2925
2926                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2927                         atomic_type = unsigned_int64_type_kind;
2928                         break;
2929
2930                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2931                         atomic_type = unsigned_int128_type_kind;
2932                         break;
2933
2934                 case SPECIFIER_INT8:
2935                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2936                         atomic_type = int8_type_kind;
2937                         break;
2938
2939                 case SPECIFIER_INT16:
2940                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2941                         atomic_type = int16_type_kind;
2942                         break;
2943
2944                 case SPECIFIER_INT32:
2945                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2946                         atomic_type = int32_type_kind;
2947                         break;
2948
2949                 case SPECIFIER_INT64:
2950                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2951                         atomic_type = int64_type_kind;
2952                         break;
2953
2954                 case SPECIFIER_INT128:
2955                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2956                         atomic_type = int128_type_kind;
2957                         break;
2958
2959                 case SPECIFIER_FLOAT:
2960                         atomic_type = ATOMIC_TYPE_FLOAT;
2961                         break;
2962                 case SPECIFIER_DOUBLE:
2963                         atomic_type = ATOMIC_TYPE_DOUBLE;
2964                         break;
2965                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2966                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2967                         break;
2968                 case SPECIFIER_BOOL:
2969                         atomic_type = ATOMIC_TYPE_BOOL;
2970                         break;
2971                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2972                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2973                         atomic_type = ATOMIC_TYPE_FLOAT;
2974                         break;
2975                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2976                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2977                         atomic_type = ATOMIC_TYPE_DOUBLE;
2978                         break;
2979                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2980                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2981                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2982                         break;
2983                 default: {
2984                         /* invalid specifier combination, give an error message */
2985                         source_position_t const* const pos = &specifiers->source_position;
2986                         if (type_specifiers == 0) {
2987                                 if (!saw_error) {
2988                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2989                                         if (!(c_mode & _CXX) && !strict_mode) {
2990                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2991                                                 atomic_type = ATOMIC_TYPE_INT;
2992                                                 break;
2993                                         } else {
2994                                                 errorf(pos, "no type specifiers given in declaration");
2995                                         }
2996                                 }
2997                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
2998                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
2999                                 errorf(pos, "signed and unsigned specifiers given");
3000                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3001                                 errorf(pos, "only integer types can be signed or unsigned");
3002                         } else {
3003                                 errorf(pos, "multiple datatypes in declaration");
3004                         }
3005                         specifiers->type = type_error_type;
3006                         return;
3007                 }
3008                 }
3009
3010                 if (type_specifiers & SPECIFIER_COMPLEX) {
3011                         type = allocate_type_zero(TYPE_COMPLEX);
3012                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3013                         type = allocate_type_zero(TYPE_IMAGINARY);
3014                 } else {
3015                         type = allocate_type_zero(TYPE_ATOMIC);
3016                 }
3017                 type->atomic.akind = atomic_type;
3018                 newtype = true;
3019         } else if (type_specifiers != 0) {
3020                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3021         }
3022
3023         /* FIXME: check type qualifiers here */
3024         type->base.qualifiers = qualifiers;
3025
3026         if (newtype) {
3027                 type = identify_new_type(type);
3028         } else {
3029                 type = typehash_insert(type);
3030         }
3031
3032         if (specifiers->attributes != NULL)
3033                 type = handle_type_attributes(specifiers->attributes, type);
3034         specifiers->type = type;
3035 }
3036
3037 static type_qualifiers_t parse_type_qualifiers(void)
3038 {
3039         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3040
3041         while (true) {
3042                 switch (token.kind) {
3043                 /* type qualifiers */
3044                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3045                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3046                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3047                 /* microsoft extended type modifiers */
3048                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3049                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3050                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3051                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3052                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3053
3054                 default:
3055                         return qualifiers;
3056                 }
3057         }
3058 }
3059
3060 /**
3061  * Parses an K&R identifier list
3062  */
3063 static void parse_identifier_list(scope_t *scope)
3064 {
3065         assert(token.kind == T_IDENTIFIER);
3066         do {
3067                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3068                 /* a K&R parameter has no type, yet */
3069                 eat(T_IDENTIFIER);
3070
3071                 if (scope != NULL)
3072                         append_entity(scope, entity);
3073         } while (next_if(',') && token.kind == T_IDENTIFIER);
3074 }
3075
3076 static entity_t *parse_parameter(void)
3077 {
3078         declaration_specifiers_t specifiers;
3079         parse_declaration_specifiers(&specifiers);
3080
3081         entity_t *entity = parse_declarator(&specifiers,
3082                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3083         anonymous_entity = NULL;
3084         return entity;
3085 }
3086
3087 static void semantic_parameter_incomplete(const entity_t *entity)
3088 {
3089         assert(entity->kind == ENTITY_PARAMETER);
3090
3091         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3092          *             list in a function declarator that is part of a
3093          *             definition of that function shall not have
3094          *             incomplete type. */
3095         type_t *type = skip_typeref(entity->declaration.type);
3096         if (is_type_incomplete(type)) {
3097                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3098         }
3099 }
3100
3101 static bool has_parameters(void)
3102 {
3103         /* func(void) is not a parameter */
3104         if (look_ahead(1)->kind != ')')
3105                 return true;
3106         if (token.kind == T_IDENTIFIER) {
3107                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3108                 if (entity == NULL)
3109                         return true;
3110                 if (entity->kind != ENTITY_TYPEDEF)
3111                         return true;
3112                 type_t const *const type = skip_typeref(entity->typedefe.type);
3113                 if (!is_type_void(type))
3114                         return true;
3115                 if (c_mode & _CXX) {
3116                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3117                          * is not allowed. */
3118                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3119                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3120                         /* §6.7.5.3:10  Qualification is not allowed here. */
3121                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3122                 }
3123         } else if (token.kind != T_void) {
3124                 return true;
3125         }
3126         next_token();
3127         return false;
3128 }
3129
3130 /**
3131  * Parses function type parameters (and optionally creates variable_t entities
3132  * for them in a scope)
3133  */
3134 static void parse_parameters(function_type_t *type, scope_t *scope)
3135 {
3136         add_anchor_token(')');
3137         eat('(');
3138
3139         if (token.kind == T_IDENTIFIER            &&
3140             !is_typedef_symbol(token.base.symbol) &&
3141             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3142                 type->kr_style_parameters = true;
3143                 parse_identifier_list(scope);
3144         } else if (token.kind == ')') {
3145                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3146                 if (!(c_mode & _CXX))
3147                         type->unspecified_parameters = true;
3148         } else if (has_parameters()) {
3149                 function_parameter_t **anchor = &type->parameters;
3150                 add_anchor_token(',');
3151                 do {
3152                         switch (token.kind) {
3153                         case T_DOTDOTDOT:
3154                                 eat(T_DOTDOTDOT);
3155                                 type->variadic = true;
3156                                 goto parameters_finished;
3157
3158                         case T_IDENTIFIER:
3159                         DECLARATION_START
3160                         {
3161                                 entity_t *entity = parse_parameter();
3162                                 if (entity->kind == ENTITY_TYPEDEF) {
3163                                         errorf(&entity->base.source_position,
3164                                                         "typedef not allowed as function parameter");
3165                                         break;
3166                                 }
3167                                 assert(is_declaration(entity));
3168
3169                                 semantic_parameter_incomplete(entity);
3170
3171                                 function_parameter_t *const parameter =
3172                                         allocate_parameter(entity->declaration.type);
3173
3174                                 if (scope != NULL) {
3175                                         append_entity(scope, entity);
3176                                 }
3177
3178                                 *anchor = parameter;
3179                                 anchor  = &parameter->next;
3180                                 break;
3181                         }
3182
3183                         default:
3184                                 goto parameters_finished;
3185                         }
3186                 } while (next_if(','));
3187 parameters_finished:
3188                 rem_anchor_token(',');
3189         }
3190
3191         rem_anchor_token(')');
3192         expect(')');
3193 }
3194
3195 typedef enum construct_type_kind_t {
3196         CONSTRUCT_POINTER = 1,
3197         CONSTRUCT_REFERENCE,
3198         CONSTRUCT_FUNCTION,
3199         CONSTRUCT_ARRAY
3200 } construct_type_kind_t;
3201
3202 typedef union construct_type_t construct_type_t;
3203
3204 typedef struct construct_type_base_t {
3205         construct_type_kind_t  kind;
3206         source_position_t      pos;
3207         construct_type_t      *next;
3208 } construct_type_base_t;
3209
3210 typedef struct parsed_pointer_t {
3211         construct_type_base_t  base;
3212         type_qualifiers_t      type_qualifiers;
3213         variable_t            *base_variable;  /**< MS __based extension. */
3214 } parsed_pointer_t;
3215
3216 typedef struct parsed_reference_t {
3217         construct_type_base_t base;
3218 } parsed_reference_t;
3219
3220 typedef struct construct_function_type_t {
3221         construct_type_base_t  base;
3222         type_t                *function_type;
3223 } construct_function_type_t;
3224
3225 typedef struct parsed_array_t {
3226         construct_type_base_t  base;
3227         type_qualifiers_t      type_qualifiers;
3228         bool                   is_static;
3229         bool                   is_variable;
3230         expression_t          *size;
3231 } parsed_array_t;
3232
3233 union construct_type_t {
3234         construct_type_kind_t     kind;
3235         construct_type_base_t     base;
3236         parsed_pointer_t          pointer;
3237         parsed_reference_t        reference;
3238         construct_function_type_t function;
3239         parsed_array_t            array;
3240 };
3241
3242 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3243 {
3244         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3245         memset(cons, 0, size);
3246         cons->kind     = kind;
3247         cons->base.pos = *HERE;
3248         return cons;
3249 }
3250
3251 /* §6.7.5.1 */
3252 static construct_type_t *parse_pointer_declarator(void)
3253 {
3254         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3255         eat('*');
3256         cons->pointer.type_qualifiers = parse_type_qualifiers();
3257         //cons->pointer.base_variable   = base_variable;
3258
3259         return cons;
3260 }
3261
3262 /* ISO/IEC 14882:1998(E) §8.3.2 */
3263 static construct_type_t *parse_reference_declarator(void)
3264 {
3265         if (!(c_mode & _CXX))
3266                 errorf(HERE, "references are only available for C++");
3267
3268         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3269         eat('&');
3270
3271         return cons;
3272 }
3273
3274 /* §6.7.5.2 */
3275 static construct_type_t *parse_array_declarator(void)
3276 {
3277         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3278         parsed_array_t   *const array = &cons->array;
3279
3280         eat('[');
3281         add_anchor_token(']');
3282
3283         bool is_static = next_if(T_static);
3284
3285         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3286
3287         if (!is_static)
3288                 is_static = next_if(T_static);
3289
3290         array->type_qualifiers = type_qualifiers;
3291         array->is_static       = is_static;
3292
3293         expression_t *size = NULL;
3294         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3295                 array->is_variable = true;
3296                 eat('*');
3297         } else if (token.kind != ']') {
3298                 size = parse_assignment_expression();
3299
3300                 /* §6.7.5.2:1  Array size must have integer type */
3301                 type_t *const orig_type = size->base.type;
3302                 type_t *const type      = skip_typeref(orig_type);
3303                 if (!is_type_integer(type) && is_type_valid(type)) {
3304                         errorf(&size->base.source_position,
3305                                "array size '%E' must have integer type but has type '%T'",
3306                                size, orig_type);
3307                 }
3308
3309                 array->size = size;
3310                 mark_vars_read(size, NULL);
3311         }
3312
3313         if (is_static && size == NULL)
3314                 errorf(&array->base.pos, "static array parameters require a size");
3315
3316         rem_anchor_token(']');
3317         expect(']');
3318         return cons;
3319 }
3320
3321 /* §6.7.5.3 */
3322 static construct_type_t *parse_function_declarator(scope_t *scope)
3323 {
3324         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3325
3326         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3327         function_type_t *ftype = &type->function;
3328
3329         ftype->linkage            = current_linkage;
3330         ftype->calling_convention = CC_DEFAULT;
3331
3332         parse_parameters(ftype, scope);
3333
3334         cons->function.function_type = type;
3335
3336         return cons;
3337 }
3338
3339 typedef struct parse_declarator_env_t {
3340         bool               may_be_abstract : 1;
3341         bool               must_be_abstract : 1;
3342         decl_modifiers_t   modifiers;
3343         symbol_t          *symbol;
3344         source_position_t  source_position;
3345         scope_t            parameters;
3346         attribute_t       *attributes;
3347 } parse_declarator_env_t;
3348
3349 /* §6.7.5 */
3350 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3351 {
3352         /* construct a single linked list of construct_type_t's which describe
3353          * how to construct the final declarator type */
3354         construct_type_t  *first      = NULL;
3355         construct_type_t **anchor     = &first;
3356
3357         env->attributes = parse_attributes(env->attributes);
3358
3359         for (;;) {
3360                 construct_type_t *type;
3361                 //variable_t       *based = NULL; /* MS __based extension */
3362                 switch (token.kind) {
3363                         case '&':
3364                                 type = parse_reference_declarator();
3365                                 break;
3366
3367                         case T__based: {
3368                                 panic("based not supported anymore");
3369                                 /* FALLTHROUGH */
3370                         }
3371
3372                         case '*':
3373                                 type = parse_pointer_declarator();
3374                                 break;
3375
3376                         default:
3377                                 goto ptr_operator_end;
3378                 }
3379
3380                 *anchor = type;
3381                 anchor  = &type->base.next;
3382
3383                 /* TODO: find out if this is correct */
3384                 env->attributes = parse_attributes(env->attributes);
3385         }
3386
3387 ptr_operator_end: ;
3388         construct_type_t *inner_types = NULL;
3389
3390         switch (token.kind) {
3391         case T_IDENTIFIER:
3392                 if (env->must_be_abstract) {
3393                         errorf(HERE, "no identifier expected in typename");
3394                 } else {
3395                         env->symbol          = token.base.symbol;
3396                         env->source_position = *HERE;
3397                 }
3398                 eat(T_IDENTIFIER);
3399                 break;
3400
3401         case '(': {
3402                 /* Parenthesized declarator or function declarator? */
3403                 token_t const *const la1 = look_ahead(1);
3404                 switch (la1->kind) {
3405                         case T_IDENTIFIER:
3406                                 if (is_typedef_symbol(la1->base.symbol)) {
3407                         case ')':
3408                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3409                                          * interpreted as ``function with no parameter specification'', rather
3410                                          * than redundant parentheses around the omitted identifier. */
3411                         default:
3412                                         /* Function declarator. */
3413                                         if (!env->may_be_abstract) {
3414                                                 errorf(HERE, "function declarator must have a name");
3415                                         }
3416                                 } else {
3417                         case '&':
3418                         case '(':
3419                         case '*':
3420                         case '[':
3421                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3422                                         /* Paranthesized declarator. */
3423                                         eat('(');
3424                                         add_anchor_token(')');
3425                                         inner_types = parse_inner_declarator(env);
3426                                         if (inner_types != NULL) {
3427                                                 /* All later declarators only modify the return type */
3428                                                 env->must_be_abstract = true;
3429                                         }
3430                                         rem_anchor_token(')');
3431                                         expect(')');
3432                                 }
3433                                 break;
3434                 }
3435                 break;
3436         }
3437
3438         default:
3439                 if (env->may_be_abstract)
3440                         break;
3441                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3442                 eat_until_anchor();
3443                 return NULL;
3444         }
3445
3446         construct_type_t **const p = anchor;
3447
3448         for (;;) {
3449                 construct_type_t *type;
3450                 switch (token.kind) {
3451                 case '(': {
3452                         scope_t *scope = NULL;
3453                         if (!env->must_be_abstract) {
3454                                 scope = &env->parameters;
3455                         }
3456
3457                         type = parse_function_declarator(scope);
3458                         break;
3459                 }
3460                 case '[':
3461                         type = parse_array_declarator();
3462                         break;
3463                 default:
3464                         goto declarator_finished;
3465                 }
3466
3467                 /* insert in the middle of the list (at p) */
3468                 type->base.next = *p;
3469                 *p              = type;
3470                 if (anchor == p)
3471                         anchor = &type->base.next;
3472         }
3473
3474 declarator_finished:
3475         /* append inner_types at the end of the list, we don't to set anchor anymore
3476          * as it's not needed anymore */
3477         *anchor = inner_types;
3478
3479         return first;
3480 }
3481
3482 static type_t *construct_declarator_type(construct_type_t *construct_list,
3483                                          type_t *type)
3484 {
3485         construct_type_t *iter = construct_list;
3486         for (; iter != NULL; iter = iter->base.next) {
3487                 source_position_t const* const pos = &iter->base.pos;
3488                 switch (iter->kind) {
3489                 case CONSTRUCT_FUNCTION: {
3490                         construct_function_type_t *function      = &iter->function;
3491                         type_t                    *function_type = function->function_type;
3492
3493                         function_type->function.return_type = type;
3494
3495                         type_t *skipped_return_type = skip_typeref(type);
3496                         /* §6.7.5.3:1 */
3497                         if (is_type_function(skipped_return_type)) {
3498                                 errorf(pos, "function returning function is not allowed");
3499                         } else if (is_type_array(skipped_return_type)) {
3500                                 errorf(pos, "function returning array is not allowed");
3501                         } else {
3502                                 if (skipped_return_type->base.qualifiers != 0) {
3503                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3504                                 }
3505                         }
3506
3507                         /* The function type was constructed earlier.  Freeing it here will
3508                          * destroy other types. */
3509                         type = typehash_insert(function_type);
3510                         continue;
3511                 }
3512
3513                 case CONSTRUCT_POINTER: {
3514                         if (is_type_reference(skip_typeref(type)))
3515                                 errorf(pos, "cannot declare a pointer to reference");
3516
3517                         parsed_pointer_t *pointer = &iter->pointer;
3518                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3519                         continue;
3520                 }
3521
3522                 case CONSTRUCT_REFERENCE:
3523                         if (is_type_reference(skip_typeref(type)))
3524                                 errorf(pos, "cannot declare a reference to reference");
3525
3526                         type = make_reference_type(type);
3527                         continue;
3528
3529                 case CONSTRUCT_ARRAY: {
3530                         if (is_type_reference(skip_typeref(type)))
3531                                 errorf(pos, "cannot declare an array of references");
3532
3533                         parsed_array_t *array      = &iter->array;
3534                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3535
3536                         expression_t *size_expression = array->size;
3537                         if (size_expression != NULL) {
3538                                 size_expression
3539                                         = create_implicit_cast(size_expression, type_size_t);
3540                         }
3541
3542                         array_type->base.qualifiers       = array->type_qualifiers;
3543                         array_type->array.element_type    = type;
3544                         array_type->array.is_static       = array->is_static;
3545                         array_type->array.is_variable     = array->is_variable;
3546                         array_type->array.size_expression = size_expression;
3547
3548                         if (size_expression != NULL) {
3549                                 switch (is_constant_expression(size_expression)) {
3550                                 case EXPR_CLASS_CONSTANT: {
3551                                         long const size = fold_constant_to_int(size_expression);
3552                                         array_type->array.size          = size;
3553                                         array_type->array.size_constant = true;
3554                                         /* §6.7.5.2:1  If the expression is a constant expression,
3555                                          * it shall have a value greater than zero. */
3556                                         if (size < 0) {
3557                                                 errorf(&size_expression->base.source_position,
3558                                                            "size of array must be greater than zero");
3559                                         } else if (size == 0 && !GNU_MODE) {
3560                                                 errorf(&size_expression->base.source_position,
3561                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3562                                         }
3563                                         break;
3564                                 }
3565
3566                                 case EXPR_CLASS_VARIABLE:
3567                                         array_type->array.is_vla = true;
3568                                         break;
3569
3570                                 case EXPR_CLASS_ERROR:
3571                                         break;
3572                                 }
3573                         }
3574
3575                         type_t *skipped_type = skip_typeref(type);
3576                         /* §6.7.5.2:1 */
3577                         if (is_type_incomplete(skipped_type)) {
3578                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3579                         } else if (is_type_function(skipped_type)) {
3580                                 errorf(pos, "array of functions is not allowed");
3581                         }
3582                         type = identify_new_type(array_type);
3583                         continue;
3584                 }
3585                 }
3586                 internal_errorf(pos, "invalid type construction found");
3587         }
3588
3589         return type;
3590 }
3591
3592 static type_t *automatic_type_conversion(type_t *orig_type);
3593
3594 static type_t *semantic_parameter(const source_position_t *pos,
3595                                   type_t *type,
3596                                   const declaration_specifiers_t *specifiers,
3597                                   entity_t const *const param)
3598 {
3599         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3600          *             shall be adjusted to ``qualified pointer to type'',
3601          *             [...]
3602          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3603          *             type'' shall be adjusted to ``pointer to function
3604          *             returning type'', as in 6.3.2.1. */
3605         type = automatic_type_conversion(type);
3606
3607         if (specifiers->is_inline && is_type_valid(type)) {
3608                 errorf(pos, "'%N' declared 'inline'", param);
3609         }
3610
3611         /* §6.9.1:6  The declarations in the declaration list shall contain
3612          *           no storage-class specifier other than register and no
3613          *           initializations. */
3614         if (specifiers->thread_local || (
3615                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3616                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3617            ) {
3618                 errorf(pos, "invalid storage class for '%N'", param);
3619         }
3620
3621         /* delay test for incomplete type, because we might have (void)
3622          * which is legal but incomplete... */
3623
3624         return type;
3625 }
3626
3627 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3628                                   declarator_flags_t flags)
3629 {
3630         parse_declarator_env_t env;
3631         memset(&env, 0, sizeof(env));
3632         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3633
3634         construct_type_t *construct_type = parse_inner_declarator(&env);
3635         type_t           *orig_type      =
3636                 construct_declarator_type(construct_type, specifiers->type);
3637         type_t           *type           = skip_typeref(orig_type);
3638
3639         if (construct_type != NULL) {
3640                 obstack_free(&temp_obst, construct_type);
3641         }
3642
3643         attribute_t *attributes = parse_attributes(env.attributes);
3644         /* append (shared) specifier attribute behind attributes of this
3645          * declarator */
3646         attribute_t **anchor = &attributes;
3647         while (*anchor != NULL)
3648                 anchor = &(*anchor)->next;
3649         *anchor = specifiers->attributes;
3650
3651         entity_t *entity;
3652         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3653                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3654                 entity->typedefe.type = orig_type;
3655
3656                 if (anonymous_entity != NULL) {
3657                         if (is_type_compound(type)) {
3658                                 assert(anonymous_entity->compound.alias == NULL);
3659                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3660                                        anonymous_entity->kind == ENTITY_UNION);
3661                                 anonymous_entity->compound.alias = entity;
3662                                 anonymous_entity = NULL;
3663                         } else if (is_type_enum(type)) {
3664                                 assert(anonymous_entity->enume.alias == NULL);
3665                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3666                                 anonymous_entity->enume.alias = entity;
3667                                 anonymous_entity = NULL;
3668                         }
3669                 }
3670         } else {
3671                 /* create a declaration type entity */
3672                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3673                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3674                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3675
3676                         if (env.symbol != NULL) {
3677                                 if (specifiers->is_inline && is_type_valid(type)) {
3678                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3679                                 }
3680
3681                                 if (specifiers->thread_local ||
3682                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3683                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3684                                 }
3685                         }
3686                 } else if (flags & DECL_IS_PARAMETER) {
3687                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3688                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3689                 } else if (is_type_function(type)) {
3690                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3691                         entity->function.is_inline      = specifiers->is_inline;
3692                         entity->function.elf_visibility = default_visibility;
3693                         entity->function.parameters     = env.parameters;
3694
3695                         if (env.symbol != NULL) {
3696                                 /* this needs fixes for C++ */
3697                                 bool in_function_scope = current_function != NULL;
3698
3699                                 if (specifiers->thread_local || (
3700                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3701                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3702                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3703                                                 )) {
3704                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3705                                 }
3706                         }
3707                 } else {
3708                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3709                         entity->variable.elf_visibility = default_visibility;
3710                         entity->variable.thread_local   = specifiers->thread_local;
3711
3712                         if (env.symbol != NULL) {
3713                                 if (specifiers->is_inline && is_type_valid(type)) {
3714                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3715                                 }
3716
3717                                 bool invalid_storage_class = false;
3718                                 if (current_scope == file_scope) {
3719                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3720                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3721                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3722                                                 invalid_storage_class = true;
3723                                         }
3724                                 } else {
3725                                         if (specifiers->thread_local &&
3726                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3727                                                 invalid_storage_class = true;
3728                                         }
3729                                 }
3730                                 if (invalid_storage_class) {
3731                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3732                                 }
3733                         }
3734                 }
3735
3736                 entity->declaration.type       = orig_type;
3737                 entity->declaration.alignment  = get_type_alignment(orig_type);
3738                 entity->declaration.modifiers  = env.modifiers;
3739                 entity->declaration.attributes = attributes;
3740
3741                 storage_class_t storage_class = specifiers->storage_class;
3742                 entity->declaration.declared_storage_class = storage_class;
3743
3744                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3745                         storage_class = STORAGE_CLASS_AUTO;
3746                 entity->declaration.storage_class = storage_class;
3747         }
3748
3749         if (attributes != NULL) {
3750                 handle_entity_attributes(attributes, entity);
3751         }
3752
3753         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3754                 adapt_special_functions(&entity->function);
3755         }
3756
3757         return entity;
3758 }
3759
3760 static type_t *parse_abstract_declarator(type_t *base_type)
3761 {
3762         parse_declarator_env_t env;
3763         memset(&env, 0, sizeof(env));
3764         env.may_be_abstract = true;
3765         env.must_be_abstract = true;
3766
3767         construct_type_t *construct_type = parse_inner_declarator(&env);
3768
3769         type_t *result = construct_declarator_type(construct_type, base_type);
3770         if (construct_type != NULL) {
3771                 obstack_free(&temp_obst, construct_type);
3772         }
3773         result = handle_type_attributes(env.attributes, result);
3774
3775         return result;
3776 }
3777
3778 /**
3779  * Check if the declaration of main is suspicious.  main should be a
3780  * function with external linkage, returning int, taking either zero
3781  * arguments, two, or three arguments of appropriate types, ie.
3782  *
3783  * int main([ int argc, char **argv [, char **env ] ]).
3784  *
3785  * @param decl    the declaration to check
3786  * @param type    the function type of the declaration
3787  */
3788 static void check_main(const entity_t *entity)
3789 {
3790         const source_position_t *pos = &entity->base.source_position;
3791         if (entity->kind != ENTITY_FUNCTION) {
3792                 warningf(WARN_MAIN, pos, "'main' is not a function");
3793                 return;
3794         }
3795
3796         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3797                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3798         }
3799
3800         type_t *type = skip_typeref(entity->declaration.type);
3801         assert(is_type_function(type));
3802
3803         function_type_t const *const func_type = &type->function;
3804         type_t                *const ret_type  = func_type->return_type;
3805         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3806                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3807         }
3808         const function_parameter_t *parm = func_type->parameters;
3809         if (parm != NULL) {
3810                 type_t *const first_type        = skip_typeref(parm->type);
3811                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3812                 if (!types_compatible(first_type_unqual, type_int)) {
3813                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3814                 }
3815                 parm = parm->next;
3816                 if (parm != NULL) {
3817                         type_t *const second_type = skip_typeref(parm->type);
3818                         type_t *const second_type_unqual
3819                                 = get_unqualified_type(second_type);
3820                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3821                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3822                         }
3823                         parm = parm->next;
3824                         if (parm != NULL) {
3825                                 type_t *const third_type = skip_typeref(parm->type);
3826                                 type_t *const third_type_unqual
3827                                         = get_unqualified_type(third_type);
3828                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3829                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3830                                 }
3831                                 parm = parm->next;
3832                                 if (parm != NULL)
3833                                         goto warn_arg_count;
3834                         }
3835                 } else {
3836 warn_arg_count:
3837                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3838                 }
3839         }
3840 }
3841
3842 static void error_redefined_as_different_kind(const source_position_t *pos,
3843                 const entity_t *old, entity_kind_t new_kind)
3844 {
3845         char              const *const what = get_entity_kind_name(new_kind);
3846         source_position_t const *const ppos = &old->base.source_position;
3847         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3848 }
3849
3850 static bool is_entity_valid(entity_t *const ent)
3851 {
3852         if (is_declaration(ent)) {
3853                 return is_type_valid(skip_typeref(ent->declaration.type));
3854         } else if (ent->kind == ENTITY_TYPEDEF) {
3855                 return is_type_valid(skip_typeref(ent->typedefe.type));
3856         }
3857         return true;
3858 }
3859
3860 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3861 {
3862         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3863                 if (attributes_equal(tattr, attr))
3864                         return true;
3865         }
3866         return false;
3867 }
3868
3869 /**
3870  * test wether new_list contains any attributes not included in old_list
3871  */
3872 static bool has_new_attributes(const attribute_t *old_list,
3873                                const attribute_t *new_list)
3874 {
3875         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3876                 if (!contains_attribute(old_list, attr))
3877                         return true;
3878         }
3879         return false;
3880 }
3881
3882 /**
3883  * Merge in attributes from an attribute list (probably from a previous
3884  * declaration with the same name). Warning: destroys the old structure
3885  * of the attribute list - don't reuse attributes after this call.
3886  */
3887 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3888 {
3889         attribute_t *next;
3890         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3891                 next = attr->next;
3892                 if (contains_attribute(decl->attributes, attr))
3893                         continue;
3894
3895                 /* move attribute to new declarations attributes list */
3896                 attr->next       = decl->attributes;
3897                 decl->attributes = attr;
3898         }
3899 }
3900
3901 static bool is_main(entity_t*);
3902
3903 /**
3904  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3905  * for various problems that occur for multiple definitions
3906  */
3907 entity_t *record_entity(entity_t *entity, const bool is_definition)
3908 {
3909         const symbol_t *const    symbol  = entity->base.symbol;
3910         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3911         const source_position_t *pos     = &entity->base.source_position;
3912
3913         /* can happen in error cases */
3914         if (symbol == NULL)
3915                 return entity;
3916
3917         assert(!entity->base.parent_scope);
3918         assert(current_scope);
3919         entity->base.parent_scope = current_scope;
3920
3921         entity_t *const previous_entity = get_entity(symbol, namespc);
3922         /* pushing the same entity twice will break the stack structure */
3923         assert(previous_entity != entity);
3924
3925         if (entity->kind == ENTITY_FUNCTION) {
3926                 type_t *const orig_type = entity->declaration.type;
3927                 type_t *const type      = skip_typeref(orig_type);
3928
3929                 assert(is_type_function(type));
3930                 if (type->function.unspecified_parameters &&
3931                     previous_entity == NULL               &&
3932                     !entity->declaration.implicit) {
3933                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3934                 }
3935
3936                 if (is_main(entity)) {
3937                         check_main(entity);
3938                 }
3939         }
3940
3941         if (is_declaration(entity)                                    &&
3942             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3943             current_scope != file_scope                               &&
3944             !entity->declaration.implicit) {
3945                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3946         }
3947
3948         if (previous_entity != NULL) {
3949                 source_position_t const *const ppos = &previous_entity->base.source_position;
3950
3951                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3952                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3953                         assert(previous_entity->kind == ENTITY_PARAMETER);
3954                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3955                         goto finish;
3956                 }
3957
3958                 if (previous_entity->base.parent_scope == current_scope) {
3959                         if (previous_entity->kind != entity->kind) {
3960                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3961                                         error_redefined_as_different_kind(pos, previous_entity,
3962                                                         entity->kind);
3963                                 }
3964                                 goto finish;
3965                         }
3966                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3967                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3968                                 goto finish;
3969                         }
3970                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3971                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3972                                 type_t *const prev_type
3973                                         = skip_typeref(previous_entity->typedefe.type);
3974                                 if (c_mode & _CXX) {
3975                                         /* C++ allows double typedef if they are identical
3976                                          * (after skipping typedefs) */
3977                                         if (type == prev_type)
3978                                                 goto finish;
3979                                 } else {
3980                                         /* GCC extension: redef in system headers is allowed */
3981                                         if ((pos->is_system_header || ppos->is_system_header) &&
3982                                             types_compatible(type, prev_type))
3983                                                 goto finish;
3984                                 }
3985                                 errorf(pos, "redefinition of '%N' (declared %P)",
3986                                        entity, ppos);
3987                                 goto finish;
3988                         }
3989
3990                         /* at this point we should have only VARIABLES or FUNCTIONS */
3991                         assert(is_declaration(previous_entity) && is_declaration(entity));
3992
3993                         declaration_t *const prev_decl = &previous_entity->declaration;
3994                         declaration_t *const decl      = &entity->declaration;
3995
3996                         /* can happen for K&R style declarations */
3997                         if (prev_decl->type       == NULL             &&
3998                                         previous_entity->kind == ENTITY_PARAMETER &&
3999                                         entity->kind          == ENTITY_PARAMETER) {
4000                                 prev_decl->type                   = decl->type;
4001                                 prev_decl->storage_class          = decl->storage_class;
4002                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4003                                 prev_decl->modifiers              = decl->modifiers;
4004                                 return previous_entity;
4005                         }
4006
4007                         type_t *const type      = skip_typeref(decl->type);
4008                         type_t *const prev_type = skip_typeref(prev_decl->type);
4009
4010                         if (!types_compatible(type, prev_type)) {
4011                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4012                         } else {
4013                                 unsigned old_storage_class = prev_decl->storage_class;
4014
4015                                 if (is_definition                     &&
4016                                                 !prev_decl->used                  &&
4017                                                 !(prev_decl->modifiers & DM_USED) &&
4018                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4019                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4020                                 }
4021
4022                                 storage_class_t new_storage_class = decl->storage_class;
4023
4024                                 /* pretend no storage class means extern for function
4025                                  * declarations (except if the previous declaration is neither
4026                                  * none nor extern) */
4027                                 if (entity->kind == ENTITY_FUNCTION) {
4028                                         /* the previous declaration could have unspecified parameters or
4029                                          * be a typedef, so use the new type */
4030                                         if (prev_type->function.unspecified_parameters || is_definition)
4031                                                 prev_decl->type = type;
4032
4033                                         switch (old_storage_class) {
4034                                                 case STORAGE_CLASS_NONE:
4035                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4036                                                         /* FALLTHROUGH */
4037
4038                                                 case STORAGE_CLASS_EXTERN:
4039                                                         if (is_definition) {
4040                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4041                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4042                                                                 }
4043                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4044                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4045                                                         }
4046                                                         break;
4047
4048                                                 default:
4049                                                         break;
4050                                         }
4051                                 } else if (is_type_incomplete(prev_type)) {
4052                                         prev_decl->type = type;
4053                                 }
4054
4055                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4056                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4057
4058 warn_redundant_declaration: ;
4059                                         bool has_new_attrs
4060                                                 = has_new_attributes(prev_decl->attributes,
4061                                                                      decl->attributes);
4062                                         if (has_new_attrs) {
4063                                                 merge_in_attributes(decl, prev_decl->attributes);
4064                                         } else if (!is_definition        &&
4065                                                         is_type_valid(prev_type) &&
4066                                                         !pos->is_system_header) {
4067                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4068                                         }
4069                                 } else if (current_function == NULL) {
4070                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4071                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4072                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4073                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4074                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4075                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4076                                         } else {
4077                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4078                                                 if (c_mode & _CXX)
4079                                                         goto error_redeclaration;
4080                                                 goto warn_redundant_declaration;
4081                                         }
4082                                 } else if (is_type_valid(prev_type)) {
4083                                         if (old_storage_class == new_storage_class) {
4084 error_redeclaration:
4085                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4086                                         } else {
4087                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4088                                         }
4089                                 }
4090                         }
4091
4092                         prev_decl->modifiers |= decl->modifiers;
4093                         if (entity->kind == ENTITY_FUNCTION) {
4094                                 previous_entity->function.is_inline |= entity->function.is_inline;
4095                         }
4096                         return previous_entity;
4097                 }
4098
4099                 warning_t why;
4100                 if (is_warn_on(why = WARN_SHADOW) ||
4101                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4102                         char const *const what = get_entity_kind_name(previous_entity->kind);
4103                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4104                 }
4105         }
4106
4107         if (entity->kind == ENTITY_FUNCTION) {
4108                 if (is_definition &&
4109                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4110                                 !is_main(entity)) {
4111                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4112                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4113                         } else {
4114                                 goto warn_missing_declaration;
4115                         }
4116                 }
4117         } else if (entity->kind == ENTITY_VARIABLE) {
4118                 if (current_scope                     == file_scope &&
4119                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4120                                 !entity->declaration.implicit) {
4121 warn_missing_declaration:
4122                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4123                 }
4124         }
4125
4126 finish:
4127         environment_push(entity);
4128         append_entity(current_scope, entity);
4129
4130         return entity;
4131 }
4132
4133 static void parser_error_multiple_definition(entity_t *entity,
4134                 const source_position_t *source_position)
4135 {
4136         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4137 }
4138
4139 static bool is_declaration_specifier(const token_t *token)
4140 {
4141         switch (token->kind) {
4142                 DECLARATION_START
4143                         return true;
4144                 case T_IDENTIFIER:
4145                         return is_typedef_symbol(token->base.symbol);
4146
4147                 default:
4148                         return false;
4149         }
4150 }
4151
4152 static void parse_init_declarator_rest(entity_t *entity)
4153 {
4154         type_t *orig_type = type_error_type;
4155
4156         if (entity->base.kind == ENTITY_TYPEDEF) {
4157                 source_position_t const *const pos = &entity->base.source_position;
4158                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4159         } else {
4160                 assert(is_declaration(entity));
4161                 orig_type = entity->declaration.type;
4162         }
4163
4164         type_t *type = skip_typeref(orig_type);
4165
4166         if (entity->kind == ENTITY_VARIABLE
4167                         && entity->variable.initializer != NULL) {
4168                 parser_error_multiple_definition(entity, HERE);
4169         }
4170         eat('=');
4171
4172         declaration_t *const declaration = &entity->declaration;
4173         bool must_be_constant = false;
4174         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4175             entity->base.parent_scope  == file_scope) {
4176                 must_be_constant = true;
4177         }
4178
4179         if (is_type_function(type)) {
4180                 source_position_t const *const pos = &entity->base.source_position;
4181                 errorf(pos, "'%N' is initialized like a variable", entity);
4182                 orig_type = type_error_type;
4183         }
4184
4185         parse_initializer_env_t env;
4186         env.type             = orig_type;
4187         env.must_be_constant = must_be_constant;
4188         env.entity           = entity;
4189
4190         initializer_t *initializer = parse_initializer(&env);
4191
4192         if (entity->kind == ENTITY_VARIABLE) {
4193                 /* §6.7.5:22  array initializers for arrays with unknown size
4194                  * determine the array type size */
4195                 declaration->type            = env.type;
4196                 entity->variable.initializer = initializer;
4197         }
4198 }
4199
4200 /* parse rest of a declaration without any declarator */
4201 static void parse_anonymous_declaration_rest(
4202                 const declaration_specifiers_t *specifiers)
4203 {
4204         eat(';');
4205         anonymous_entity = NULL;
4206
4207         source_position_t const *const pos = &specifiers->source_position;
4208         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4209                         specifiers->thread_local) {
4210                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4211         }
4212
4213         type_t *type = specifiers->type;
4214         switch (type->kind) {
4215                 case TYPE_COMPOUND_STRUCT:
4216                 case TYPE_COMPOUND_UNION: {
4217                         if (type->compound.compound->base.symbol == NULL) {
4218                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4219                         }
4220                         break;
4221                 }
4222
4223                 case TYPE_ENUM:
4224                         break;
4225
4226                 default:
4227                         warningf(WARN_OTHER, pos, "empty declaration");
4228                         break;
4229         }
4230 }
4231
4232 static void check_variable_type_complete(entity_t *ent)
4233 {
4234         if (ent->kind != ENTITY_VARIABLE)
4235                 return;
4236
4237         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4238          *         type for the object shall be complete [...] */
4239         declaration_t *decl = &ent->declaration;
4240         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4241                         decl->storage_class == STORAGE_CLASS_STATIC)
4242                 return;
4243
4244         type_t *const type = skip_typeref(decl->type);
4245         if (!is_type_incomplete(type))
4246                 return;
4247
4248         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4249          * are given length one. */
4250         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4251                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4252                 return;
4253         }
4254
4255         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4256 }
4257
4258
4259 static void parse_declaration_rest(entity_t *ndeclaration,
4260                 const declaration_specifiers_t *specifiers,
4261                 parsed_declaration_func         finished_declaration,
4262                 declarator_flags_t              flags)
4263 {
4264         add_anchor_token(';');
4265         add_anchor_token(',');
4266         while (true) {
4267                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4268
4269                 if (token.kind == '=') {
4270                         parse_init_declarator_rest(entity);
4271                 } else if (entity->kind == ENTITY_VARIABLE) {
4272                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4273                          * [...] where the extern specifier is explicitly used. */
4274                         declaration_t *decl = &entity->declaration;
4275                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4276                             is_type_reference(skip_typeref(decl->type))) {
4277                                 source_position_t const *const pos = &entity->base.source_position;
4278                                 errorf(pos, "reference '%#N' must be initialized", entity);
4279                         }
4280                 }
4281
4282                 check_variable_type_complete(entity);
4283
4284                 if (!next_if(','))
4285                         break;
4286
4287                 add_anchor_token('=');
4288                 ndeclaration = parse_declarator(specifiers, flags);
4289                 rem_anchor_token('=');
4290         }
4291         rem_anchor_token(',');
4292         rem_anchor_token(';');
4293         expect(';');
4294
4295         anonymous_entity = NULL;
4296 }
4297
4298 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4299 {
4300         symbol_t *symbol = entity->base.symbol;
4301         if (symbol == NULL)
4302                 return entity;
4303
4304         assert(entity->base.namespc == NAMESPACE_NORMAL);
4305         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4306         if (previous_entity == NULL
4307                         || previous_entity->base.parent_scope != current_scope) {
4308                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4309                        symbol);
4310                 return entity;
4311         }
4312
4313         if (is_definition) {
4314                 errorf(HERE, "'%N' is initialised", entity);
4315         }
4316
4317         return record_entity(entity, false);
4318 }
4319
4320 static void parse_declaration(parsed_declaration_func finished_declaration,
4321                               declarator_flags_t      flags)
4322 {
4323         add_anchor_token(';');
4324         declaration_specifiers_t specifiers;
4325         parse_declaration_specifiers(&specifiers);
4326         rem_anchor_token(';');
4327
4328         if (token.kind == ';') {
4329                 parse_anonymous_declaration_rest(&specifiers);
4330         } else {
4331                 entity_t *entity = parse_declarator(&specifiers, flags);
4332                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4333         }
4334 }
4335
4336 /* §6.5.2.2:6 */
4337 static type_t *get_default_promoted_type(type_t *orig_type)
4338 {
4339         type_t *result = orig_type;
4340
4341         type_t *type = skip_typeref(orig_type);
4342         if (is_type_integer(type)) {
4343                 result = promote_integer(type);
4344         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4345                 result = type_double;
4346         }
4347
4348         return result;
4349 }
4350
4351 static void parse_kr_declaration_list(entity_t *entity)
4352 {
4353         if (entity->kind != ENTITY_FUNCTION)
4354                 return;
4355
4356         type_t *type = skip_typeref(entity->declaration.type);
4357         assert(is_type_function(type));
4358         if (!type->function.kr_style_parameters)
4359                 return;
4360
4361         add_anchor_token('{');
4362
4363         PUSH_SCOPE(&entity->function.parameters);
4364
4365         entity_t *parameter = entity->function.parameters.entities;
4366         for ( ; parameter != NULL; parameter = parameter->base.next) {
4367                 assert(parameter->base.parent_scope == NULL);
4368                 parameter->base.parent_scope = current_scope;
4369                 environment_push(parameter);
4370         }
4371
4372         /* parse declaration list */
4373         for (;;) {
4374                 switch (token.kind) {
4375                         DECLARATION_START
4376                         /* This covers symbols, which are no type, too, and results in
4377                          * better error messages.  The typical cases are misspelled type
4378                          * names and missing includes. */
4379                         case T_IDENTIFIER:
4380                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4381                                 break;
4382                         default:
4383                                 goto decl_list_end;
4384                 }
4385         }
4386 decl_list_end:
4387
4388         POP_SCOPE();
4389
4390         /* update function type */
4391         type_t *new_type = duplicate_type(type);
4392
4393         function_parameter_t  *parameters = NULL;
4394         function_parameter_t **anchor     = &parameters;
4395
4396         /* did we have an earlier prototype? */
4397         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4398         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4399                 proto_type = NULL;
4400
4401         function_parameter_t *proto_parameter = NULL;
4402         if (proto_type != NULL) {
4403                 type_t *proto_type_type = proto_type->declaration.type;
4404                 proto_parameter         = proto_type_type->function.parameters;
4405                 /* If a K&R function definition has a variadic prototype earlier, then
4406                  * make the function definition variadic, too. This should conform to
4407                  * §6.7.5.3:15 and §6.9.1:8. */
4408                 new_type->function.variadic = proto_type_type->function.variadic;
4409         } else {
4410                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4411                  * prototype */
4412                 new_type->function.unspecified_parameters = true;
4413         }
4414
4415         bool need_incompatible_warning = false;
4416         parameter = entity->function.parameters.entities;
4417         for (; parameter != NULL; parameter = parameter->base.next,
4418                         proto_parameter =
4419                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4420                 if (parameter->kind != ENTITY_PARAMETER)
4421                         continue;
4422
4423                 type_t *parameter_type = parameter->declaration.type;
4424                 if (parameter_type == NULL) {
4425                         source_position_t const* const pos = &parameter->base.source_position;
4426                         if (strict_mode) {
4427                                 errorf(pos, "no type specified for function '%N'", parameter);
4428                                 parameter_type = type_error_type;
4429                         } else {
4430                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4431                                 parameter_type = type_int;
4432                         }
4433                         parameter->declaration.type = parameter_type;
4434                 }
4435
4436                 semantic_parameter_incomplete(parameter);
4437
4438                 /* we need the default promoted types for the function type */
4439                 type_t *not_promoted = parameter_type;
4440                 parameter_type       = get_default_promoted_type(parameter_type);
4441
4442                 /* gcc special: if the type of the prototype matches the unpromoted
4443                  * type don't promote */
4444                 if (!strict_mode && proto_parameter != NULL) {
4445                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4446                         type_t *promo_skip   = skip_typeref(parameter_type);
4447                         type_t *param_skip   = skip_typeref(not_promoted);
4448                         if (!types_compatible(proto_p_type, promo_skip)
4449                                 && types_compatible(proto_p_type, param_skip)) {
4450                                 /* don't promote */
4451                                 need_incompatible_warning = true;
4452                                 parameter_type = not_promoted;
4453                         }
4454                 }
4455                 function_parameter_t *const function_parameter
4456                         = allocate_parameter(parameter_type);
4457
4458                 *anchor = function_parameter;
4459                 anchor  = &function_parameter->next;
4460         }
4461
4462         new_type->function.parameters = parameters;
4463         new_type = identify_new_type(new_type);
4464
4465         if (need_incompatible_warning) {
4466                 symbol_t          const *const sym  = entity->base.symbol;
4467                 source_position_t const *const pos  = &entity->base.source_position;
4468                 source_position_t const *const ppos = &proto_type->base.source_position;
4469                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4470         }
4471         entity->declaration.type = new_type;
4472
4473         rem_anchor_token('{');
4474 }
4475
4476 static bool first_err = true;
4477
4478 /**
4479  * When called with first_err set, prints the name of the current function,
4480  * else does noting.
4481  */
4482 static void print_in_function(void)
4483 {
4484         if (first_err) {
4485                 first_err = false;
4486                 char const *const file = current_function->base.base.source_position.input_name;
4487                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4488         }
4489 }
4490
4491 /**
4492  * Check if all labels are defined in the current function.
4493  * Check if all labels are used in the current function.
4494  */
4495 static void check_labels(void)
4496 {
4497         for (const goto_statement_t *goto_statement = goto_first;
4498             goto_statement != NULL;
4499             goto_statement = goto_statement->next) {
4500                 label_t *label = goto_statement->label;
4501                 if (label->base.source_position.input_name == NULL) {
4502                         print_in_function();
4503                         source_position_t const *const pos = &goto_statement->base.source_position;
4504                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4505                  }
4506         }
4507
4508         if (is_warn_on(WARN_UNUSED_LABEL)) {
4509                 for (const label_statement_t *label_statement = label_first;
4510                          label_statement != NULL;
4511                          label_statement = label_statement->next) {
4512                         label_t *label = label_statement->label;
4513
4514                         if (! label->used) {
4515                                 print_in_function();
4516                                 source_position_t const *const pos = &label_statement->base.source_position;
4517                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4518                         }
4519                 }
4520         }
4521 }
4522
4523 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4524 {
4525         entity_t const *const end = last != NULL ? last->base.next : NULL;
4526         for (; entity != end; entity = entity->base.next) {
4527                 if (!is_declaration(entity))
4528                         continue;
4529
4530                 declaration_t *declaration = &entity->declaration;
4531                 if (declaration->implicit)
4532                         continue;
4533
4534                 if (!declaration->used) {
4535                         print_in_function();
4536                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4537                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4538                         print_in_function();
4539                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4540                 }
4541         }
4542 }
4543
4544 static void check_unused_variables(statement_t *const stmt, void *const env)
4545 {
4546         (void)env;
4547
4548         switch (stmt->kind) {
4549                 case STATEMENT_DECLARATION: {
4550                         declaration_statement_t const *const decls = &stmt->declaration;
4551                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4552                         return;
4553                 }
4554
4555                 case STATEMENT_FOR:
4556                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4557                         return;
4558
4559                 default:
4560                         return;
4561         }
4562 }
4563
4564 /**
4565  * Check declarations of current_function for unused entities.
4566  */
4567 static void check_declarations(void)
4568 {
4569         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4570                 const scope_t *scope = &current_function->parameters;
4571                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4572         }
4573         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4574                 walk_statements(current_function->body, check_unused_variables, 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_DO_WHILE: goto continue_do_while;
4845                                         case STATEMENT_FOR:      goto continue_for;
4846
4847                                         default: break;
4848                                 }
4849                         }
4850
4851                 case STATEMENT_BREAK:
4852                         for (statement_t *parent = stmt;;) {
4853                                 parent = parent->base.parent;
4854                                 if (parent == NULL) /* break not within loop/switch */
4855                                         return;
4856
4857                                 switch (parent->kind) {
4858                                         case STATEMENT_SWITCH:
4859                                         case STATEMENT_DO_WHILE:
4860                                         case STATEMENT_FOR:
4861                                                 last = parent;
4862                                                 next = parent->base.next;
4863                                                 goto found_break_parent;
4864
4865                                         default: break;
4866                                 }
4867                         }
4868 found_break_parent:
4869                         break;
4870
4871                 case STATEMENT_COMPUTED_GOTO: {
4872                         if (!expression_returns(stmt->computed_goto.expression))
4873                                 return;
4874
4875                         statement_t *parent = stmt->base.parent;
4876                         if (parent == NULL) /* top level goto */
4877                                 return;
4878                         next = parent;
4879                         break;
4880                 }
4881
4882                 case STATEMENT_GOTO:
4883                         next = stmt->gotos.label->statement;
4884                         if (next == NULL) /* missing label */
4885                                 return;
4886                         break;
4887
4888                 case STATEMENT_LABEL:
4889                         next = stmt->label.statement;
4890                         break;
4891
4892                 case STATEMENT_CASE_LABEL:
4893                         next = stmt->case_label.statement;
4894                         break;
4895
4896                 case STATEMENT_DO_WHILE:
4897                         next = stmt->do_while.body;
4898                         break;
4899
4900                 case STATEMENT_FOR: {
4901                         for_statement_t *const fors = &stmt->fors;
4902
4903                         if (fors->condition_reachable)
4904                                 return;
4905                         fors->condition_reachable = true;
4906
4907                         expression_t const *const cond = fors->condition;
4908
4909                         int val;
4910                         if (cond == NULL) {
4911                                 val = 1;
4912                         } else if (expression_returns(cond)) {
4913                                 val = determine_truth(cond);
4914                         } else {
4915                                 return;
4916                         }
4917
4918                         if (val >= 0)
4919                                 check_reachable(fors->body);
4920
4921                         if (val > 0)
4922                                 return;
4923
4924                         next = stmt->base.next;
4925                         break;
4926                 }
4927
4928                 case STATEMENT_MS_TRY: {
4929                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4930                         check_reachable(ms_try->try_statement);
4931                         next = ms_try->final_statement;
4932                         break;
4933                 }
4934
4935                 case STATEMENT_LEAVE: {
4936                         statement_t *parent = stmt;
4937                         for (;;) {
4938                                 parent = parent->base.parent;
4939                                 if (parent == NULL) /* __leave not within __try */
4940                                         return;
4941
4942                                 if (parent->kind == STATEMENT_MS_TRY) {
4943                                         last = parent;
4944                                         next = parent->ms_try.final_statement;
4945                                         break;
4946                                 }
4947                         }
4948                         break;
4949                 }
4950
4951                 default:
4952                         panic("invalid statement kind");
4953         }
4954
4955         while (next == NULL) {
4956                 next = last->base.parent;
4957                 if (next == NULL) {
4958                         noreturn_candidate = false;
4959
4960                         type_t *const type = skip_typeref(current_function->base.type);
4961                         assert(is_type_function(type));
4962                         type_t *const ret  = skip_typeref(type->function.return_type);
4963                         if (!is_type_void(ret) &&
4964                             is_type_valid(ret) &&
4965                             !is_main(current_entity)) {
4966                                 source_position_t const *const pos = &stmt->base.source_position;
4967                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4968                         }
4969                         return;
4970                 }
4971
4972                 switch (next->kind) {
4973                         case STATEMENT_ERROR:
4974                         case STATEMENT_EMPTY:
4975                         case STATEMENT_DECLARATION:
4976                         case STATEMENT_EXPRESSION:
4977                         case STATEMENT_ASM:
4978                         case STATEMENT_RETURN:
4979                         case STATEMENT_CONTINUE:
4980                         case STATEMENT_BREAK:
4981                         case STATEMENT_COMPUTED_GOTO:
4982                         case STATEMENT_GOTO:
4983                         case STATEMENT_LEAVE:
4984                                 panic("invalid control flow in function");
4985
4986                         case STATEMENT_COMPOUND:
4987                                 if (next->compound.stmt_expr) {
4988                                         reaches_end = true;
4989                                         return;
4990                                 }
4991                                 /* FALLTHROUGH */
4992                         case STATEMENT_IF:
4993                         case STATEMENT_SWITCH:
4994                         case STATEMENT_LABEL:
4995                         case STATEMENT_CASE_LABEL:
4996                                 last = next;
4997                                 next = next->base.next;
4998                                 break;
4999
5000                         case STATEMENT_DO_WHILE: {
5001 continue_do_while:
5002                                 if (next->base.reachable)
5003                                         return;
5004                                 next->base.reachable = true;
5005
5006                                 do_while_statement_t const *const dw   = &next->do_while;
5007                                 expression_t         const *const cond = dw->condition;
5008
5009                                 if (!expression_returns(cond))
5010                                         return;
5011
5012                                 int const val = determine_truth(cond);
5013
5014                                 if (val >= 0)
5015                                         check_reachable(dw->body);
5016
5017                                 if (val > 0)
5018                                         return;
5019
5020                                 last = next;
5021                                 next = next->base.next;
5022                                 break;
5023                         }
5024
5025                         case STATEMENT_FOR: {
5026 continue_for:;
5027                                 for_statement_t *const fors = &next->fors;
5028
5029                                 fors->step_reachable = true;
5030
5031                                 if (fors->condition_reachable)
5032                                         return;
5033                                 fors->condition_reachable = true;
5034
5035                                 expression_t const *const cond = fors->condition;
5036
5037                                 int val;
5038                                 if (cond == NULL) {
5039                                         val = 1;
5040                                 } else if (expression_returns(cond)) {
5041                                         val = determine_truth(cond);
5042                                 } else {
5043                                         return;
5044                                 }
5045
5046                                 if (val >= 0)
5047                                         check_reachable(fors->body);
5048
5049                                 if (val > 0)
5050                                         return;
5051
5052                                 last = next;
5053                                 next = next->base.next;
5054                                 break;
5055                         }
5056
5057                         case STATEMENT_MS_TRY:
5058                                 last = next;
5059                                 next = next->ms_try.final_statement;
5060                                 break;
5061                 }
5062         }
5063
5064         check_reachable(next);
5065 }
5066
5067 static void check_unreachable(statement_t* const stmt, void *const env)
5068 {
5069         (void)env;
5070
5071         switch (stmt->kind) {
5072                 case STATEMENT_DO_WHILE:
5073                         if (!stmt->base.reachable) {
5074                                 expression_t const *const cond = stmt->do_while.condition;
5075                                 if (determine_truth(cond) >= 0) {
5076                                         source_position_t const *const pos = &cond->base.source_position;
5077                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5078                                 }
5079                         }
5080                         return;
5081
5082                 case STATEMENT_FOR: {
5083                         for_statement_t const* const fors = &stmt->fors;
5084
5085                         // if init and step are unreachable, cond is unreachable, too
5086                         if (!stmt->base.reachable && !fors->step_reachable) {
5087                                 goto warn_unreachable;
5088                         } else {
5089                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5090                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5091                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5092                                 }
5093
5094                                 if (!fors->condition_reachable && fors->condition != NULL) {
5095                                         source_position_t const *const pos = &fors->condition->base.source_position;
5096                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5097                                 }
5098
5099                                 if (!fors->step_reachable && fors->step != NULL) {
5100                                         source_position_t const *const pos = &fors->step->base.source_position;
5101                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5102                                 }
5103                         }
5104                         return;
5105                 }
5106
5107                 case STATEMENT_COMPOUND:
5108                         if (stmt->compound.statements != NULL)
5109                                 return;
5110                         goto warn_unreachable;
5111
5112                 case STATEMENT_DECLARATION: {
5113                         /* Only warn if there is at least one declarator with an initializer.
5114                          * This typically occurs in switch statements. */
5115                         declaration_statement_t const *const decl = &stmt->declaration;
5116                         entity_t                const *      ent  = decl->declarations_begin;
5117                         entity_t                const *const last = decl->declarations_end;
5118                         if (ent != NULL) {
5119                                 for (;; ent = ent->base.next) {
5120                                         if (ent->kind                 == ENTITY_VARIABLE &&
5121                                                         ent->variable.initializer != NULL) {
5122                                                 goto warn_unreachable;
5123                                         }
5124                                         if (ent == last)
5125                                                 return;
5126                                 }
5127                         }
5128                 }
5129
5130                 default:
5131 warn_unreachable:
5132                         if (!stmt->base.reachable) {
5133                                 source_position_t const *const pos = &stmt->base.source_position;
5134                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5135                         }
5136                         return;
5137         }
5138 }
5139
5140 static bool is_main(entity_t *entity)
5141 {
5142         static symbol_t *sym_main = NULL;
5143         if (sym_main == NULL) {
5144                 sym_main = symbol_table_insert("main");
5145         }
5146
5147         if (entity->base.symbol != sym_main)
5148                 return false;
5149         /* must be in outermost scope */
5150         if (entity->base.parent_scope != file_scope)
5151                 return false;
5152
5153         return true;
5154 }
5155
5156 static void prepare_main_collect2(entity_t*);
5157
5158 static void parse_external_declaration(void)
5159 {
5160         /* function-definitions and declarations both start with declaration
5161          * specifiers */
5162         add_anchor_token(';');
5163         declaration_specifiers_t specifiers;
5164         parse_declaration_specifiers(&specifiers);
5165         rem_anchor_token(';');
5166
5167         /* must be a declaration */
5168         if (token.kind == ';') {
5169                 parse_anonymous_declaration_rest(&specifiers);
5170                 return;
5171         }
5172
5173         add_anchor_token(',');
5174         add_anchor_token('=');
5175         add_anchor_token(';');
5176         add_anchor_token('{');
5177
5178         /* declarator is common to both function-definitions and declarations */
5179         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5180
5181         rem_anchor_token('{');
5182         rem_anchor_token(';');
5183         rem_anchor_token('=');
5184         rem_anchor_token(',');
5185
5186         /* must be a declaration */
5187         switch (token.kind) {
5188                 case ',':
5189                 case ';':
5190                 case '=':
5191                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5192                                         DECL_FLAGS_NONE);
5193                         return;
5194         }
5195
5196         /* must be a function definition */
5197         parse_kr_declaration_list(ndeclaration);
5198
5199         if (token.kind != '{') {
5200                 parse_error_expected("while parsing function definition", '{', NULL);
5201                 eat_until_matching_token(';');
5202                 return;
5203         }
5204
5205         assert(is_declaration(ndeclaration));
5206         type_t *const orig_type = ndeclaration->declaration.type;
5207         type_t *      type      = skip_typeref(orig_type);
5208
5209         if (!is_type_function(type)) {
5210                 if (is_type_valid(type)) {
5211                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5212                 }
5213                 eat_block();
5214                 return;
5215         }
5216
5217         source_position_t const *const pos = &ndeclaration->base.source_position;
5218         if (is_typeref(orig_type)) {
5219                 /* §6.9.1:2 */
5220                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5221         }
5222
5223         if (is_type_compound(skip_typeref(type->function.return_type))) {
5224                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5225         }
5226         if (type->function.unspecified_parameters) {
5227                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5228         } else {
5229                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5230         }
5231
5232         /* §6.7.5.3:14 a function definition with () means no
5233          * parameters (and not unspecified parameters) */
5234         if (type->function.unspecified_parameters &&
5235                         type->function.parameters == NULL) {
5236                 type_t *copy                          = duplicate_type(type);
5237                 copy->function.unspecified_parameters = false;
5238                 type                                  = identify_new_type(copy);
5239
5240                 ndeclaration->declaration.type = type;
5241         }
5242
5243         entity_t *const entity = record_entity(ndeclaration, true);
5244         assert(entity->kind == ENTITY_FUNCTION);
5245         assert(ndeclaration->kind == ENTITY_FUNCTION);
5246
5247         function_t *const function = &entity->function;
5248         if (ndeclaration != entity) {
5249                 function->parameters = ndeclaration->function.parameters;
5250         }
5251
5252         PUSH_SCOPE(&function->parameters);
5253
5254         entity_t *parameter = function->parameters.entities;
5255         for (; parameter != NULL; parameter = parameter->base.next) {
5256                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5257                         parameter->base.parent_scope = current_scope;
5258                 }
5259                 assert(parameter->base.parent_scope == NULL
5260                                 || parameter->base.parent_scope == current_scope);
5261                 parameter->base.parent_scope = current_scope;
5262                 if (parameter->base.symbol == NULL) {
5263                         errorf(&parameter->base.source_position, "parameter name omitted");
5264                         continue;
5265                 }
5266                 environment_push(parameter);
5267         }
5268
5269         if (function->body != NULL) {
5270                 parser_error_multiple_definition(entity, HERE);
5271                 eat_block();
5272         } else {
5273                 /* parse function body */
5274                 int         label_stack_top      = label_top();
5275                 function_t *old_current_function = current_function;
5276                 current_function                 = function;
5277                 PUSH_CURRENT_ENTITY(entity);
5278                 PUSH_PARENT(NULL);
5279
5280                 goto_first   = NULL;
5281                 goto_anchor  = &goto_first;
5282                 label_first  = NULL;
5283                 label_anchor = &label_first;
5284
5285                 statement_t *const body = parse_compound_statement(false);
5286                 function->body = body;
5287                 first_err = true;
5288                 check_labels();
5289                 check_declarations();
5290                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5291                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5292                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5293                         noreturn_candidate = true;
5294                         check_reachable(body);
5295                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5296                                 walk_statements(body, check_unreachable, NULL);
5297                         if (noreturn_candidate &&
5298                             !(function->base.modifiers & DM_NORETURN)) {
5299                                 source_position_t const *const pos = &body->base.source_position;
5300                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5301                         }
5302                 }
5303
5304                 if (is_main(entity)) {
5305                         /* Force main to C linkage. */
5306                         type_t *const type = entity->declaration.type;
5307                         assert(is_type_function(type));
5308                         if (type->function.linkage != LINKAGE_C) {
5309                                 type_t *new_type           = duplicate_type(type);
5310                                 new_type->function.linkage = LINKAGE_C;
5311                                 entity->declaration.type   = identify_new_type(new_type);
5312                         }
5313
5314                         if (enable_main_collect2_hack)
5315                                 prepare_main_collect2(entity);
5316                 }
5317
5318                 POP_CURRENT_ENTITY();
5319                 POP_PARENT();
5320                 assert(current_function == function);
5321                 current_function = old_current_function;
5322                 label_pop_to(label_stack_top);
5323         }
5324
5325         POP_SCOPE();
5326 }
5327
5328 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5329 {
5330         entity_t *iter = compound->members.entities;
5331         for (; iter != NULL; iter = iter->base.next) {
5332                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5333                         continue;
5334
5335                 if (iter->base.symbol == symbol) {
5336                         return iter;
5337                 } else if (iter->base.symbol == NULL) {
5338                         /* search in anonymous structs and unions */
5339                         type_t *type = skip_typeref(iter->declaration.type);
5340                         if (is_type_compound(type)) {
5341                                 if (find_compound_entry(type->compound.compound, symbol)
5342                                                 != NULL)
5343                                         return iter;
5344                         }
5345                         continue;
5346                 }
5347         }
5348
5349         return NULL;
5350 }
5351
5352 static void check_deprecated(const source_position_t *source_position,
5353                              const entity_t *entity)
5354 {
5355         if (!is_declaration(entity))
5356                 return;
5357         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5358                 return;
5359
5360         source_position_t const *const epos = &entity->base.source_position;
5361         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5362         if (msg != NULL) {
5363                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5364         } else {
5365                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5366         }
5367 }
5368
5369
5370 static expression_t *create_select(const source_position_t *pos,
5371                                    expression_t *addr,
5372                                    type_qualifiers_t qualifiers,
5373                                                                    entity_t *entry)
5374 {
5375         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5376
5377         check_deprecated(pos, entry);
5378
5379         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5380         select->select.compound       = addr;
5381         select->select.compound_entry = entry;
5382
5383         type_t *entry_type = entry->declaration.type;
5384         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5385
5386         /* bitfields need special treatment */
5387         if (entry->compound_member.bitfield) {
5388                 unsigned bit_size = entry->compound_member.bit_size;
5389                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5390                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5391                         res_type = type_int;
5392                 }
5393         }
5394
5395         /* we always do the auto-type conversions; the & and sizeof parser contains
5396          * code to revert this! */
5397         select->base.type = automatic_type_conversion(res_type);
5398
5399
5400         return select;
5401 }
5402
5403 /**
5404  * Find entry with symbol in compound. Search anonymous structs and unions and
5405  * creates implicit select expressions for them.
5406  * Returns the adress for the innermost compound.
5407  */
5408 static expression_t *find_create_select(const source_position_t *pos,
5409                                         expression_t *addr,
5410                                         type_qualifiers_t qualifiers,
5411                                         compound_t *compound, symbol_t *symbol)
5412 {
5413         entity_t *iter = compound->members.entities;
5414         for (; iter != NULL; iter = iter->base.next) {
5415                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5416                         continue;
5417
5418                 symbol_t *iter_symbol = iter->base.symbol;
5419                 if (iter_symbol == NULL) {
5420                         type_t *type = iter->declaration.type;
5421                         if (!is_type_compound(type))
5422                                 continue;
5423
5424                         compound_t *sub_compound = type->compound.compound;
5425
5426                         if (find_compound_entry(sub_compound, symbol) == NULL)
5427                                 continue;
5428
5429                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5430                         sub_addr->base.source_position = *pos;
5431                         sub_addr->base.implicit        = true;
5432                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5433                                                   symbol);
5434                 }
5435
5436                 if (iter_symbol == symbol) {
5437                         return create_select(pos, addr, qualifiers, iter);
5438                 }
5439         }
5440
5441         return NULL;
5442 }
5443
5444 static void parse_bitfield_member(entity_t *entity)
5445 {
5446         eat(':');
5447
5448         expression_t *size = parse_constant_expression();
5449         long          size_long;
5450
5451         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5452         type_t *type = entity->declaration.type;
5453         if (!is_type_integer(skip_typeref(type))) {
5454                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5455                            type);
5456         }
5457
5458         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5459                 /* error already reported by parse_constant_expression */
5460                 size_long = get_type_size(type) * 8;
5461         } else {
5462                 size_long = fold_constant_to_int(size);
5463
5464                 const symbol_t *symbol = entity->base.symbol;
5465                 const symbol_t *user_symbol
5466                         = symbol == NULL ? sym_anonymous : symbol;
5467                 unsigned bit_size = get_type_size(type) * 8;
5468                 if (size_long < 0) {
5469                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5470                 } else if (size_long == 0 && symbol != NULL) {
5471                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5472                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5473                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5474                                    user_symbol);
5475                 } else {
5476                         /* hope that people don't invent crazy types with more bits
5477                          * than our struct can hold */
5478                         assert(size_long <
5479                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5480                 }
5481         }
5482
5483         entity->compound_member.bitfield = true;
5484         entity->compound_member.bit_size = (unsigned char)size_long;
5485 }
5486
5487 static void parse_compound_declarators(compound_t *compound,
5488                 const declaration_specifiers_t *specifiers)
5489 {
5490         add_anchor_token(';');
5491         add_anchor_token(',');
5492         do {
5493                 entity_t *entity;
5494
5495                 if (token.kind == ':') {
5496                         /* anonymous bitfield */
5497                         type_t *type = specifiers->type;
5498                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5499                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5500                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5501                         entity->declaration.type                   = type;
5502
5503                         parse_bitfield_member(entity);
5504
5505                         attribute_t  *attributes = parse_attributes(NULL);
5506                         attribute_t **anchor     = &attributes;
5507                         while (*anchor != NULL)
5508                                 anchor = &(*anchor)->next;
5509                         *anchor = specifiers->attributes;
5510                         if (attributes != NULL) {
5511                                 handle_entity_attributes(attributes, entity);
5512                         }
5513                         entity->declaration.attributes = attributes;
5514
5515                         append_entity(&compound->members, entity);
5516                 } else {
5517                         entity = parse_declarator(specifiers,
5518                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5519                         source_position_t const *const pos = &entity->base.source_position;
5520                         if (entity->kind == ENTITY_TYPEDEF) {
5521                                 errorf(pos, "typedef not allowed as compound member");
5522                         } else {
5523                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5524
5525                                 /* make sure we don't define a symbol multiple times */
5526                                 symbol_t *symbol = entity->base.symbol;
5527                                 if (symbol != NULL) {
5528                                         entity_t *prev = find_compound_entry(compound, symbol);
5529                                         if (prev != NULL) {
5530                                                 source_position_t const *const ppos = &prev->base.source_position;
5531                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5532                                         }
5533                                 }
5534
5535                                 if (token.kind == ':') {
5536                                         parse_bitfield_member(entity);
5537
5538                                         attribute_t *attributes = parse_attributes(NULL);
5539                                         handle_entity_attributes(attributes, entity);
5540                                 } else {
5541                                         type_t *orig_type = entity->declaration.type;
5542                                         type_t *type      = skip_typeref(orig_type);
5543                                         if (is_type_function(type)) {
5544                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5545                                         } else if (is_type_incomplete(type)) {
5546                                                 /* §6.7.2.1:16 flexible array member */
5547                                                 if (!is_type_array(type)       ||
5548                                                                 token.kind          != ';' ||
5549                                                                 look_ahead(1)->kind != '}') {
5550                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5551                                                 } else if (compound->members.entities == NULL) {
5552                                                         errorf(pos, "flexible array member in otherwise empty struct");
5553                                                 }
5554                                         }
5555                                 }
5556
5557                                 append_entity(&compound->members, entity);
5558                         }
5559                 }
5560         } while (next_if(','));
5561         rem_anchor_token(',');
5562         rem_anchor_token(';');
5563         expect(';');
5564
5565         anonymous_entity = NULL;
5566 }
5567
5568 static void parse_compound_type_entries(compound_t *compound)
5569 {
5570         eat('{');
5571         add_anchor_token('}');
5572
5573         for (;;) {
5574                 switch (token.kind) {
5575                         DECLARATION_START
5576                         case T___extension__:
5577                         case T_IDENTIFIER: {
5578                                 PUSH_EXTENSION();
5579                                 declaration_specifiers_t specifiers;
5580                                 parse_declaration_specifiers(&specifiers);
5581                                 parse_compound_declarators(compound, &specifiers);
5582                                 POP_EXTENSION();
5583                                 break;
5584                         }
5585
5586                         default:
5587                                 rem_anchor_token('}');
5588                                 expect('}');
5589                                 /* §6.7.2.1:7 */
5590                                 compound->complete = true;
5591                                 return;
5592                 }
5593         }
5594 }
5595
5596 static type_t *parse_typename(void)
5597 {
5598         declaration_specifiers_t specifiers;
5599         parse_declaration_specifiers(&specifiers);
5600         if (specifiers.storage_class != STORAGE_CLASS_NONE
5601                         || specifiers.thread_local) {
5602                 /* TODO: improve error message, user does probably not know what a
5603                  * storage class is...
5604                  */
5605                 errorf(&specifiers.source_position, "typename must not have a storage class");
5606         }
5607
5608         type_t *result = parse_abstract_declarator(specifiers.type);
5609
5610         return result;
5611 }
5612
5613
5614
5615
5616 typedef expression_t* (*parse_expression_function)(void);
5617 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5618
5619 typedef struct expression_parser_function_t expression_parser_function_t;
5620 struct expression_parser_function_t {
5621         parse_expression_function        parser;
5622         precedence_t                     infix_precedence;
5623         parse_expression_infix_function  infix_parser;
5624 };
5625
5626 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5627
5628 static type_t *get_string_type(string_encoding_t const enc)
5629 {
5630         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5631         switch (enc) {
5632         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5633         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5634         }
5635         panic("invalid string encoding");
5636 }
5637
5638 /**
5639  * Parse a string constant.
5640  */
5641 static expression_t *parse_string_literal(void)
5642 {
5643         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5644         expr->string_literal.value = concat_string_literals();
5645         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5646         return expr;
5647 }
5648
5649 /**
5650  * Parse a boolean constant.
5651  */
5652 static expression_t *parse_boolean_literal(bool value)
5653 {
5654         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5655         literal->base.type           = type_bool;
5656         literal->literal.value.begin = value ? "true" : "false";
5657         literal->literal.value.size  = value ? 4 : 5;
5658
5659         eat(value ? T_true : T_false);
5660         return literal;
5661 }
5662
5663 static void warn_traditional_suffix(char const *const suffix)
5664 {
5665         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5666 }
5667
5668 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5669 {
5670         unsigned     spec = SPECIFIER_NONE;
5671         char const  *c    = suffix;
5672         for (;;) {
5673                 specifiers_t add;
5674                 if (*c == 'L' || *c == 'l') {
5675                         add = SPECIFIER_LONG;
5676                         if (*c == c[1]) {
5677                                 add |= SPECIFIER_LONG_LONG;
5678                                 ++c;
5679                         }
5680                 } else if (*c == 'U' || *c == 'u') {
5681                         add = SPECIFIER_UNSIGNED;
5682                 } else {
5683                         break;
5684                 }
5685                 ++c;
5686                 if (spec & add)
5687                         goto error;
5688                 spec |= add;
5689         }
5690
5691         if (*c == '\0') {
5692                 type_t *type;
5693                 switch (spec) {
5694                 case SPECIFIER_NONE:                                            type = type_int;                break;
5695                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5696                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5697                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5698                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5699                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5700                 default: panic("inconsistent suffix");
5701                 }
5702                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5703                         warn_traditional_suffix(suffix);
5704                 }
5705                 expr->base.type = type;
5706                 /* Integer type depends on the size of the number and the size
5707                  * representable by the types. The backend/codegeneration has to
5708                  * determine that. */
5709                 determine_literal_type(&expr->literal);
5710         } else {
5711 error:
5712                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5713         }
5714 }
5715
5716 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5717 {
5718         type_t     *type;
5719         char const *c    = suffix;
5720         switch (*c) {
5721         case 'F':
5722         case 'f': type = type_float;       ++c; break;
5723         case 'L':
5724         case 'l': type = type_long_double; ++c; break;
5725         default:  type = type_double;           break;
5726         }
5727
5728         if (*c == '\0') {
5729                 expr->base.type = type;
5730                 if (suffix[0] != '\0') {
5731                         warn_traditional_suffix(suffix);
5732                 }
5733         } else {
5734                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5735         }
5736 }
5737
5738 static expression_t *parse_number_literal(void)
5739 {
5740         string_t const *const str      = &token.literal.string;
5741         char     const *      i        = str->begin;
5742         unsigned              digits   = 0;
5743         bool                  is_float = false;
5744
5745         /* Parse base prefix. */
5746         unsigned base;
5747         if (*i == '0') {
5748                 switch (*++i) {
5749                 case 'B': case 'b': base =  2; ++i;               break;
5750                 case 'X': case 'x': base = 16; ++i;               break;
5751                 default:            base =  8; digits |= 1U << 0; break;
5752                 }
5753         } else {
5754                 base = 10;
5755         }
5756
5757         /* Parse mantissa. */
5758         for (;; ++i) {
5759                 unsigned digit;
5760                 switch (*i) {
5761                 case '.':
5762                         if (is_float) {
5763                                 errorf(HERE, "multiple decimal points in %K", &token);
5764                                 i = 0;
5765                                 goto done;
5766                         }
5767                         is_float = true;
5768                         if (base == 8)
5769                                 base = 10;
5770                         continue;
5771
5772                 case '0':           digit =  0; break;
5773                 case '1':           digit =  1; break;
5774                 case '2':           digit =  2; break;
5775                 case '3':           digit =  3; break;
5776                 case '4':           digit =  4; break;
5777                 case '5':           digit =  5; break;
5778                 case '6':           digit =  6; break;
5779                 case '7':           digit =  7; break;
5780                 case '8':           digit =  8; break;
5781                 case '9':           digit =  9; break;
5782                 case 'A': case 'a': digit = 10; break;
5783                 case 'B': case 'b': digit = 11; break;
5784                 case 'C': case 'c': digit = 12; break;
5785                 case 'D': case 'd': digit = 13; break;
5786                 case 'E': case 'e': digit = 14; break;
5787                 case 'F': case 'f': digit = 15; break;
5788
5789                 default: goto done_mantissa;
5790                 }
5791
5792                 if (digit >= 10 && base != 16)
5793                         goto done_mantissa;
5794
5795                 digits |= 1U << digit;
5796         }
5797 done_mantissa:
5798
5799         /* Parse exponent. */
5800         switch (base) {
5801         case 2:
5802                 if (is_float)
5803                         errorf(HERE, "binary floating %K not allowed", &token);
5804                 break;
5805
5806         case  8:
5807         case 10:
5808                 if (*i == 'E' || *i == 'e') {
5809                         base = 10;
5810                         goto parse_exponent;
5811                 }
5812                 break;
5813
5814         case 16:
5815                 if (*i == 'P' || *i == 'p') {
5816 parse_exponent:
5817                         ++i;
5818                         is_float = true;
5819
5820                         if (*i == '-' || *i == '+')
5821                                 ++i;
5822
5823                         if (isdigit(*i)) {
5824                                 do {
5825                                         ++i;
5826                                 } while (isdigit(*i));
5827                         } else {
5828                                 errorf(HERE, "exponent of %K has no digits", &token);
5829                         }
5830                 } else if (is_float) {
5831                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5832                         i = 0;
5833                 }
5834                 break;
5835
5836         default:
5837                 panic("invalid base");
5838         }
5839
5840 done:;
5841         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5842         expr->literal.value = *str;
5843
5844         if (i) {
5845                 if (digits == 0) {
5846                         errorf(HERE, "%K has no digits", &token);
5847                 } else if (digits & ~((1U << base) - 1)) {
5848                         errorf(HERE, "invalid digit in %K", &token);
5849                 } else {
5850                         expr->literal.suffix = i;
5851                         if (is_float) {
5852                                 check_floatingpoint_suffix(expr, i);
5853                         } else {
5854                                 check_integer_suffix(expr, i);
5855                         }
5856                 }
5857         }
5858
5859         eat(T_NUMBER);
5860         return expr;
5861 }
5862
5863 /**
5864  * Parse a character constant.
5865  */
5866 static expression_t *parse_character_constant(void)
5867 {
5868         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5869         literal->string_literal.value = token.literal.string;
5870
5871         size_t const size = get_string_len(&token.literal.string);
5872         switch (token.literal.string.encoding) {
5873         case STRING_ENCODING_CHAR:
5874                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5875                 if (size > 1) {
5876                         if (!GNU_MODE && !(c_mode & _C99)) {
5877                                 errorf(HERE, "more than 1 character in character constant");
5878                         } else {
5879                                 literal->base.type = type_int;
5880                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5881                         }
5882                 }
5883                 break;
5884
5885         case STRING_ENCODING_WIDE:
5886                 literal->base.type = type_int;
5887                 if (size > 1) {
5888                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5889                 }
5890                 break;
5891         }
5892
5893         eat(T_CHARACTER_CONSTANT);
5894         return literal;
5895 }
5896
5897 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5898 {
5899         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5900         ntype->function.return_type            = type_int;
5901         ntype->function.unspecified_parameters = true;
5902         ntype->function.linkage                = LINKAGE_C;
5903         type_t *type                           = identify_new_type(ntype);
5904
5905         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5906         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5907         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5908         entity->declaration.type                   = type;
5909         entity->declaration.implicit               = true;
5910
5911         if (current_scope != NULL)
5912                 record_entity(entity, false);
5913
5914         return entity;
5915 }
5916
5917 /**
5918  * Performs automatic type cast as described in §6.3.2.1.
5919  *
5920  * @param orig_type  the original type
5921  */
5922 static type_t *automatic_type_conversion(type_t *orig_type)
5923 {
5924         type_t *type = skip_typeref(orig_type);
5925         if (is_type_array(type)) {
5926                 array_type_t *array_type   = &type->array;
5927                 type_t       *element_type = array_type->element_type;
5928                 unsigned      qualifiers   = array_type->base.qualifiers;
5929
5930                 return make_pointer_type(element_type, qualifiers);
5931         }
5932
5933         if (is_type_function(type)) {
5934                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5935         }
5936
5937         return orig_type;
5938 }
5939
5940 /**
5941  * reverts the automatic casts of array to pointer types and function
5942  * to function-pointer types as defined §6.3.2.1
5943  */
5944 type_t *revert_automatic_type_conversion(const expression_t *expression)
5945 {
5946         switch (expression->kind) {
5947         case EXPR_REFERENCE: {
5948                 entity_t *entity = expression->reference.entity;
5949                 if (is_declaration(entity)) {
5950                         return entity->declaration.type;
5951                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5952                         return entity->enum_value.enum_type;
5953                 } else {
5954                         panic("no declaration or enum in reference");
5955                 }
5956         }
5957
5958         case EXPR_SELECT: {
5959                 entity_t *entity = expression->select.compound_entry;
5960                 assert(is_declaration(entity));
5961                 type_t   *type   = entity->declaration.type;
5962                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5963         }
5964
5965         case EXPR_UNARY_DEREFERENCE: {
5966                 const expression_t *const value = expression->unary.value;
5967                 type_t             *const type  = skip_typeref(value->base.type);
5968                 if (!is_type_pointer(type))
5969                         return type_error_type;
5970                 return type->pointer.points_to;
5971         }
5972
5973         case EXPR_ARRAY_ACCESS: {
5974                 const expression_t *array_ref = expression->array_access.array_ref;
5975                 type_t             *type_left = skip_typeref(array_ref->base.type);
5976                 if (!is_type_pointer(type_left))
5977                         return type_error_type;
5978                 return type_left->pointer.points_to;
5979         }
5980
5981         case EXPR_STRING_LITERAL: {
5982                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
5983                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5984                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5985         }
5986
5987         case EXPR_COMPOUND_LITERAL:
5988                 return expression->compound_literal.type;
5989
5990         default:
5991                 break;
5992         }
5993         return expression->base.type;
5994 }
5995
5996 /**
5997  * Find an entity matching a symbol in a scope.
5998  * Uses current scope if scope is NULL
5999  */
6000 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6001                                namespace_tag_t namespc)
6002 {
6003         if (scope == NULL) {
6004                 return get_entity(symbol, namespc);
6005         }
6006
6007         /* we should optimize here, if scope grows above a certain size we should
6008            construct a hashmap here... */
6009         entity_t *entity = scope->entities;
6010         for ( ; entity != NULL; entity = entity->base.next) {
6011                 if (entity->base.symbol == symbol
6012                     && (namespace_tag_t)entity->base.namespc == namespc)
6013                         break;
6014         }
6015
6016         return entity;
6017 }
6018
6019 static entity_t *parse_qualified_identifier(void)
6020 {
6021         /* namespace containing the symbol */
6022         symbol_t          *symbol;
6023         source_position_t  pos;
6024         const scope_t     *lookup_scope = NULL;
6025
6026         if (next_if(T_COLONCOLON))
6027                 lookup_scope = &unit->scope;
6028
6029         entity_t *entity;
6030         while (true) {
6031                 symbol = expect_identifier("while parsing identifier", &pos);
6032                 if (!symbol)
6033                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6034
6035                 /* lookup entity */
6036                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6037
6038                 if (!next_if(T_COLONCOLON))
6039                         break;
6040
6041                 switch (entity->kind) {
6042                 case ENTITY_NAMESPACE:
6043                         lookup_scope = &entity->namespacee.members;
6044                         break;
6045                 case ENTITY_STRUCT:
6046                 case ENTITY_UNION:
6047                 case ENTITY_CLASS:
6048                         lookup_scope = &entity->compound.members;
6049                         break;
6050                 default:
6051                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6052                                symbol, get_entity_kind_name(entity->kind));
6053
6054                         /* skip further qualifications */
6055                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6056
6057                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6058                 }
6059         }
6060
6061         if (entity == NULL) {
6062                 if (!strict_mode && token.kind == '(') {
6063                         /* an implicitly declared function */
6064                         entity = create_implicit_function(symbol, &pos);
6065                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6066                 } else {
6067                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6068                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6069                 }
6070         }
6071
6072         return entity;
6073 }
6074
6075 static expression_t *parse_reference(void)
6076 {
6077         source_position_t const pos    = *HERE;
6078         entity_t         *const entity = parse_qualified_identifier();
6079
6080         type_t *orig_type;
6081         if (is_declaration(entity)) {
6082                 orig_type = entity->declaration.type;
6083         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6084                 orig_type = entity->enum_value.enum_type;
6085         } else {
6086                 panic("expected declaration or enum value in reference");
6087         }
6088
6089         /* we always do the auto-type conversions; the & and sizeof parser contains
6090          * code to revert this! */
6091         type_t *type = automatic_type_conversion(orig_type);
6092
6093         expression_kind_t kind = EXPR_REFERENCE;
6094         if (entity->kind == ENTITY_ENUM_VALUE)
6095                 kind = EXPR_ENUM_CONSTANT;
6096
6097         expression_t *expression         = allocate_expression_zero(kind);
6098         expression->base.source_position = pos;
6099         expression->base.type            = type;
6100         expression->reference.entity     = entity;
6101
6102         /* this declaration is used */
6103         if (is_declaration(entity)) {
6104                 entity->declaration.used = true;
6105         }
6106
6107         if (entity->base.parent_scope != file_scope
6108                 && (current_function != NULL
6109                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6110                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6111                 /* access of a variable from an outer function */
6112                 entity->variable.address_taken = true;
6113                 current_function->need_closure = true;
6114         }
6115
6116         check_deprecated(&pos, entity);
6117
6118         return expression;
6119 }
6120
6121 static bool semantic_cast(expression_t *cast)
6122 {
6123         expression_t            *expression      = cast->unary.value;
6124         type_t                  *orig_dest_type  = cast->base.type;
6125         type_t                  *orig_type_right = expression->base.type;
6126         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6127         type_t            const *src_type        = skip_typeref(orig_type_right);
6128         source_position_t const *pos             = &cast->base.source_position;
6129
6130         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6131         if (is_type_void(dst_type))
6132                 return true;
6133
6134         /* only integer and pointer can be casted to pointer */
6135         if (is_type_pointer(dst_type)  &&
6136             !is_type_pointer(src_type) &&
6137             !is_type_integer(src_type) &&
6138             is_type_valid(src_type)) {
6139                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6140                 return false;
6141         }
6142
6143         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6144                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6145                 return false;
6146         }
6147
6148         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6149                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6150                 return false;
6151         }
6152
6153         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6154                 type_t *src = skip_typeref(src_type->pointer.points_to);
6155                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6156                 unsigned missing_qualifiers =
6157                         src->base.qualifiers & ~dst->base.qualifiers;
6158                 if (missing_qualifiers != 0) {
6159                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6160                 }
6161         }
6162         return true;
6163 }
6164
6165 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6166 {
6167         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6168         expression->base.source_position = *pos;
6169
6170         parse_initializer_env_t env;
6171         env.type             = type;
6172         env.entity           = NULL;
6173         env.must_be_constant = false;
6174         initializer_t *initializer = parse_initializer(&env);
6175         type = env.type;
6176
6177         expression->compound_literal.initializer = initializer;
6178         expression->compound_literal.type        = type;
6179         expression->base.type                    = automatic_type_conversion(type);
6180
6181         return expression;
6182 }
6183
6184 /**
6185  * Parse a cast expression.
6186  */
6187 static expression_t *parse_cast(void)
6188 {
6189         source_position_t const pos = *HERE;
6190
6191         eat('(');
6192         add_anchor_token(')');
6193
6194         type_t *type = parse_typename();
6195
6196         rem_anchor_token(')');
6197         expect(')');
6198
6199         if (token.kind == '{') {
6200                 return parse_compound_literal(&pos, type);
6201         }
6202
6203         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6204         cast->base.source_position = pos;
6205
6206         expression_t *value = parse_subexpression(PREC_CAST);
6207         cast->base.type   = type;
6208         cast->unary.value = value;
6209
6210         if (! semantic_cast(cast)) {
6211                 /* TODO: record the error in the AST. else it is impossible to detect it */
6212         }
6213
6214         return cast;
6215 }
6216
6217 /**
6218  * Parse a statement expression.
6219  */
6220 static expression_t *parse_statement_expression(void)
6221 {
6222         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6223
6224         eat('(');
6225         add_anchor_token(')');
6226
6227         statement_t *statement          = parse_compound_statement(true);
6228         statement->compound.stmt_expr   = true;
6229         expression->statement.statement = statement;
6230
6231         /* find last statement and use its type */
6232         type_t *type = type_void;
6233         const statement_t *stmt = statement->compound.statements;
6234         if (stmt != NULL) {
6235                 while (stmt->base.next != NULL)
6236                         stmt = stmt->base.next;
6237
6238                 if (stmt->kind == STATEMENT_EXPRESSION) {
6239                         type = stmt->expression.expression->base.type;
6240                 }
6241         } else {
6242                 source_position_t const *const pos = &expression->base.source_position;
6243                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6244         }
6245         expression->base.type = type;
6246
6247         rem_anchor_token(')');
6248         expect(')');
6249         return expression;
6250 }
6251
6252 /**
6253  * Parse a parenthesized expression.
6254  */
6255 static expression_t *parse_parenthesized_expression(void)
6256 {
6257         token_t const* const la1 = look_ahead(1);
6258         switch (la1->kind) {
6259         case '{':
6260                 /* gcc extension: a statement expression */
6261                 return parse_statement_expression();
6262
6263         case T_IDENTIFIER:
6264                 if (is_typedef_symbol(la1->base.symbol)) {
6265         DECLARATION_START
6266                         return parse_cast();
6267                 }
6268         }
6269
6270         eat('(');
6271         add_anchor_token(')');
6272         expression_t *result = parse_expression();
6273         result->base.parenthesized = true;
6274         rem_anchor_token(')');
6275         expect(')');
6276
6277         return result;
6278 }
6279
6280 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6281 {
6282         if (current_function == NULL) {
6283                 errorf(HERE, "'%K' used outside of a function", &token);
6284         }
6285
6286         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6287         expression->base.type     = type_char_ptr;
6288         expression->funcname.kind = kind;
6289
6290         next_token();
6291
6292         return expression;
6293 }
6294
6295 static designator_t *parse_designator(void)
6296 {
6297         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6298         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6299         if (!result->symbol)
6300                 return NULL;
6301
6302         designator_t *last_designator = result;
6303         while (true) {
6304                 if (next_if('.')) {
6305                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6306                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6307                         if (!designator->symbol)
6308                                 return NULL;
6309
6310                         last_designator->next = designator;
6311                         last_designator       = designator;
6312                         continue;
6313                 }
6314                 if (next_if('[')) {
6315                         add_anchor_token(']');
6316                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6317                         designator->source_position = *HERE;
6318                         designator->array_index     = parse_expression();
6319                         rem_anchor_token(']');
6320                         expect(']');
6321                         if (designator->array_index == NULL) {
6322                                 return NULL;
6323                         }
6324
6325                         last_designator->next = designator;
6326                         last_designator       = designator;
6327                         continue;
6328                 }
6329                 break;
6330         }
6331
6332         return result;
6333 }
6334
6335 /**
6336  * Parse the __builtin_offsetof() expression.
6337  */
6338 static expression_t *parse_offsetof(void)
6339 {
6340         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6341         expression->base.type    = type_size_t;
6342
6343         eat(T___builtin_offsetof);
6344
6345         add_anchor_token(')');
6346         add_anchor_token(',');
6347         expect('(');
6348         type_t *type = parse_typename();
6349         rem_anchor_token(',');
6350         expect(',');
6351         designator_t *designator = parse_designator();
6352         rem_anchor_token(')');
6353         expect(')');
6354
6355         expression->offsetofe.type       = type;
6356         expression->offsetofe.designator = designator;
6357
6358         type_path_t path;
6359         memset(&path, 0, sizeof(path));
6360         path.top_type = type;
6361         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6362
6363         descend_into_subtype(&path);
6364
6365         if (!walk_designator(&path, designator, true)) {
6366                 return create_error_expression();
6367         }
6368
6369         DEL_ARR_F(path.path);
6370
6371         return expression;
6372 }
6373
6374 static bool is_last_parameter(expression_t *const param)
6375 {
6376         if (param->kind == EXPR_REFERENCE) {
6377                 entity_t *const entity = param->reference.entity;
6378                 if (entity->kind == ENTITY_PARAMETER &&
6379                     !entity->base.next               &&
6380                     entity->base.parent_scope == &current_function->parameters) {
6381                         return true;
6382                 }
6383         }
6384
6385         if (!is_type_valid(skip_typeref(param->base.type)))
6386                 return true;
6387
6388         return false;
6389 }
6390
6391 /**
6392  * Parses a __builtin_va_start() expression.
6393  */
6394 static expression_t *parse_va_start(void)
6395 {
6396         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6397
6398         eat(T___builtin_va_start);
6399
6400         add_anchor_token(')');
6401         add_anchor_token(',');
6402         expect('(');
6403         expression->va_starte.ap = parse_assignment_expression();
6404         rem_anchor_token(',');
6405         expect(',');
6406         expression_t *const param = parse_assignment_expression();
6407         expression->va_starte.parameter = param;
6408         rem_anchor_token(')');
6409         expect(')');
6410
6411         if (!current_function) {
6412                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6413         } else if (!current_function->base.type->function.variadic) {
6414                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6415         } else if (!is_last_parameter(param)) {
6416                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6417         }
6418
6419         return expression;
6420 }
6421
6422 /**
6423  * Parses a __builtin_va_arg() expression.
6424  */
6425 static expression_t *parse_va_arg(void)
6426 {
6427         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6428
6429         eat(T___builtin_va_arg);
6430
6431         add_anchor_token(')');
6432         add_anchor_token(',');
6433         expect('(');
6434         call_argument_t ap;
6435         ap.expression = parse_assignment_expression();
6436         expression->va_arge.ap = ap.expression;
6437         check_call_argument(type_valist, &ap, 1);
6438
6439         rem_anchor_token(',');
6440         expect(',');
6441         expression->base.type = parse_typename();
6442         rem_anchor_token(')');
6443         expect(')');
6444
6445         return expression;
6446 }
6447
6448 /**
6449  * Parses a __builtin_va_copy() expression.
6450  */
6451 static expression_t *parse_va_copy(void)
6452 {
6453         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6454
6455         eat(T___builtin_va_copy);
6456
6457         add_anchor_token(')');
6458         add_anchor_token(',');
6459         expect('(');
6460         expression_t *dst = parse_assignment_expression();
6461         assign_error_t error = semantic_assign(type_valist, dst);
6462         report_assign_error(error, type_valist, dst, "call argument 1",
6463                             &dst->base.source_position);
6464         expression->va_copye.dst = dst;
6465
6466         rem_anchor_token(',');
6467         expect(',');
6468
6469         call_argument_t src;
6470         src.expression = parse_assignment_expression();
6471         check_call_argument(type_valist, &src, 2);
6472         expression->va_copye.src = src.expression;
6473         rem_anchor_token(')');
6474         expect(')');
6475
6476         return expression;
6477 }
6478
6479 /**
6480  * Parses a __builtin_constant_p() expression.
6481  */
6482 static expression_t *parse_builtin_constant(void)
6483 {
6484         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6485
6486         eat(T___builtin_constant_p);
6487
6488         add_anchor_token(')');
6489         expect('(');
6490         expression->builtin_constant.value = parse_assignment_expression();
6491         rem_anchor_token(')');
6492         expect(')');
6493         expression->base.type = type_int;
6494
6495         return expression;
6496 }
6497
6498 /**
6499  * Parses a __builtin_types_compatible_p() expression.
6500  */
6501 static expression_t *parse_builtin_types_compatible(void)
6502 {
6503         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6504
6505         eat(T___builtin_types_compatible_p);
6506
6507         add_anchor_token(')');
6508         add_anchor_token(',');
6509         expect('(');
6510         expression->builtin_types_compatible.left = parse_typename();
6511         rem_anchor_token(',');
6512         expect(',');
6513         expression->builtin_types_compatible.right = parse_typename();
6514         rem_anchor_token(')');
6515         expect(')');
6516         expression->base.type = type_int;
6517
6518         return expression;
6519 }
6520
6521 /**
6522  * Parses a __builtin_is_*() compare expression.
6523  */
6524 static expression_t *parse_compare_builtin(void)
6525 {
6526         expression_kind_t kind;
6527         switch (token.kind) {
6528         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6529         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6530         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6531         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6532         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6533         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6534         default: internal_errorf(HERE, "invalid compare builtin found");
6535         }
6536         expression_t *const expression = allocate_expression_zero(kind);
6537         next_token();
6538
6539         add_anchor_token(')');
6540         add_anchor_token(',');
6541         expect('(');
6542         expression->binary.left = parse_assignment_expression();
6543         rem_anchor_token(',');
6544         expect(',');
6545         expression->binary.right = parse_assignment_expression();
6546         rem_anchor_token(')');
6547         expect(')');
6548
6549         type_t *const orig_type_left  = expression->binary.left->base.type;
6550         type_t *const orig_type_right = expression->binary.right->base.type;
6551
6552         type_t *const type_left  = skip_typeref(orig_type_left);
6553         type_t *const type_right = skip_typeref(orig_type_right);
6554         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6555                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6556                         type_error_incompatible("invalid operands in comparison",
6557                                 &expression->base.source_position, orig_type_left, orig_type_right);
6558                 }
6559         } else {
6560                 semantic_comparison(&expression->binary);
6561         }
6562
6563         return expression;
6564 }
6565
6566 /**
6567  * Parses a MS assume() expression.
6568  */
6569 static expression_t *parse_assume(void)
6570 {
6571         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6572
6573         eat(T__assume);
6574
6575         add_anchor_token(')');
6576         expect('(');
6577         expression->unary.value = parse_assignment_expression();
6578         rem_anchor_token(')');
6579         expect(')');
6580
6581         expression->base.type = type_void;
6582         return expression;
6583 }
6584
6585 /**
6586  * Return the label for the current symbol or create a new one.
6587  */
6588 static label_t *get_label(char const *const context)
6589 {
6590         assert(current_function != NULL);
6591
6592         symbol_t *const sym = expect_identifier(context, NULL);
6593         if (!sym)
6594                 return NULL;
6595
6596         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6597         /* If we find a local label, we already created the declaration. */
6598         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6599                 if (label->base.parent_scope != current_scope) {
6600                         assert(label->base.parent_scope->depth < current_scope->depth);
6601                         current_function->goto_to_outer = true;
6602                 }
6603         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6604                 /* There is no matching label in the same function, so create a new one. */
6605                 source_position_t const nowhere = { NULL, 0, 0, false };
6606                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6607                 label_push(label);
6608         }
6609
6610         return &label->label;
6611 }
6612
6613 /**
6614  * Parses a GNU && label address expression.
6615  */
6616 static expression_t *parse_label_address(void)
6617 {
6618         source_position_t const source_position = *HERE;
6619         eat(T_ANDAND);
6620
6621         label_t *const label = get_label("while parsing label address");
6622         if (!label)
6623                 return create_error_expression();
6624
6625         label->used          = true;
6626         label->address_taken = true;
6627
6628         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6629         expression->base.source_position = source_position;
6630
6631         /* label address is treated as a void pointer */
6632         expression->base.type           = type_void_ptr;
6633         expression->label_address.label = label;
6634         return expression;
6635 }
6636
6637 /**
6638  * Parse a microsoft __noop expression.
6639  */
6640 static expression_t *parse_noop_expression(void)
6641 {
6642         /* the result is a (int)0 */
6643         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6644         literal->base.type           = type_int;
6645         literal->literal.value.begin = "__noop";
6646         literal->literal.value.size  = 6;
6647
6648         eat(T___noop);
6649
6650         if (token.kind == '(') {
6651                 /* parse arguments */
6652                 eat('(');
6653                 add_anchor_token(')');
6654                 add_anchor_token(',');
6655
6656                 if (token.kind != ')') do {
6657                         (void)parse_assignment_expression();
6658                 } while (next_if(','));
6659
6660                 rem_anchor_token(',');
6661                 rem_anchor_token(')');
6662         }
6663         expect(')');
6664
6665         return literal;
6666 }
6667
6668 /**
6669  * Parses a primary expression.
6670  */
6671 static expression_t *parse_primary_expression(void)
6672 {
6673         switch (token.kind) {
6674         case T_false:                        return parse_boolean_literal(false);
6675         case T_true:                         return parse_boolean_literal(true);
6676         case T_NUMBER:                       return parse_number_literal();
6677         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6678         case T_STRING_LITERAL:               return parse_string_literal();
6679         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6680         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6681         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6682         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6683         case T___builtin_offsetof:           return parse_offsetof();
6684         case T___builtin_va_start:           return parse_va_start();
6685         case T___builtin_va_arg:             return parse_va_arg();
6686         case T___builtin_va_copy:            return parse_va_copy();
6687         case T___builtin_isgreater:
6688         case T___builtin_isgreaterequal:
6689         case T___builtin_isless:
6690         case T___builtin_islessequal:
6691         case T___builtin_islessgreater:
6692         case T___builtin_isunordered:        return parse_compare_builtin();
6693         case T___builtin_constant_p:         return parse_builtin_constant();
6694         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6695         case T__assume:                      return parse_assume();
6696         case T_ANDAND:
6697                 if (GNU_MODE)
6698                         return parse_label_address();
6699                 break;
6700
6701         case '(':                            return parse_parenthesized_expression();
6702         case T___noop:                       return parse_noop_expression();
6703
6704         /* Gracefully handle type names while parsing expressions. */
6705         case T_COLONCOLON:
6706                 return parse_reference();
6707         case T_IDENTIFIER:
6708                 if (!is_typedef_symbol(token.base.symbol)) {
6709                         return parse_reference();
6710                 }
6711                 /* FALLTHROUGH */
6712         DECLARATION_START {
6713                 source_position_t const  pos = *HERE;
6714                 declaration_specifiers_t specifiers;
6715                 parse_declaration_specifiers(&specifiers);
6716                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6717                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6718                 return create_error_expression();
6719         }
6720         }
6721
6722         errorf(HERE, "unexpected token %K, expected an expression", &token);
6723         eat_until_anchor();
6724         return create_error_expression();
6725 }
6726
6727 static expression_t *parse_array_expression(expression_t *left)
6728 {
6729         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6730         array_access_expression_t *const arr  = &expr->array_access;
6731
6732         eat('[');
6733         add_anchor_token(']');
6734
6735         expression_t *const inside = parse_expression();
6736
6737         type_t *const orig_type_left   = left->base.type;
6738         type_t *const orig_type_inside = inside->base.type;
6739
6740         type_t *const type_left   = skip_typeref(orig_type_left);
6741         type_t *const type_inside = skip_typeref(orig_type_inside);
6742
6743         expression_t *ref;
6744         expression_t *idx;
6745         type_t       *idx_type;
6746         type_t       *res_type;
6747         if (is_type_pointer(type_left)) {
6748                 ref      = left;
6749                 idx      = inside;
6750                 idx_type = type_inside;
6751                 res_type = type_left->pointer.points_to;
6752                 goto check_idx;
6753         } else if (is_type_pointer(type_inside)) {
6754                 arr->flipped = true;
6755                 ref      = inside;
6756                 idx      = left;
6757                 idx_type = type_left;
6758                 res_type = type_inside->pointer.points_to;
6759 check_idx:
6760                 res_type = automatic_type_conversion(res_type);
6761                 if (!is_type_integer(idx_type)) {
6762                         errorf(&idx->base.source_position, "array subscript must have integer type");
6763                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6764                         source_position_t const *const pos = &idx->base.source_position;
6765                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6766                 }
6767         } else {
6768                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6769                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6770                 }
6771                 res_type = type_error_type;
6772                 ref      = left;
6773                 idx      = inside;
6774         }
6775
6776         arr->array_ref = ref;
6777         arr->index     = idx;
6778         arr->base.type = res_type;
6779
6780         rem_anchor_token(']');
6781         expect(']');
6782         return expr;
6783 }
6784
6785 static bool is_bitfield(const expression_t *expression)
6786 {
6787         return expression->kind == EXPR_SELECT
6788                 && expression->select.compound_entry->compound_member.bitfield;
6789 }
6790
6791 static expression_t *parse_typeprop(expression_kind_t const kind)
6792 {
6793         expression_t  *tp_expression = allocate_expression_zero(kind);
6794         tp_expression->base.type     = type_size_t;
6795
6796         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6797
6798         type_t       *orig_type;
6799         expression_t *expression;
6800         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6801                 source_position_t const pos = *HERE;
6802                 eat('(');
6803                 add_anchor_token(')');
6804                 orig_type = parse_typename();
6805                 rem_anchor_token(')');
6806                 expect(')');
6807
6808                 if (token.kind == '{') {
6809                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6810                          * starting with a compound literal */
6811                         expression = parse_compound_literal(&pos, orig_type);
6812                         goto typeprop_expression;
6813                 }
6814         } else {
6815                 expression = parse_subexpression(PREC_UNARY);
6816
6817 typeprop_expression:
6818                 if (is_bitfield(expression)) {
6819                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6820                         errorf(&tp_expression->base.source_position,
6821                                    "operand of %s expression must not be a bitfield", what);
6822                 }
6823
6824                 tp_expression->typeprop.tp_expression = expression;
6825
6826                 orig_type = revert_automatic_type_conversion(expression);
6827                 expression->base.type = orig_type;
6828         }
6829
6830         tp_expression->typeprop.type   = orig_type;
6831         type_t const* const type       = skip_typeref(orig_type);
6832         char   const*       wrong_type = NULL;
6833         if (is_type_incomplete(type)) {
6834                 if (!is_type_void(type) || !GNU_MODE)
6835                         wrong_type = "incomplete";
6836         } else if (type->kind == TYPE_FUNCTION) {
6837                 if (GNU_MODE) {
6838                         /* function types are allowed (and return 1) */
6839                         source_position_t const *const pos  = &tp_expression->base.source_position;
6840                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6841                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6842                 } else {
6843                         wrong_type = "function";
6844                 }
6845         }
6846
6847         if (wrong_type != NULL) {
6848                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6849                 errorf(&tp_expression->base.source_position,
6850                                 "operand of %s expression must not be of %s type '%T'",
6851                                 what, wrong_type, orig_type);
6852         }
6853
6854         return tp_expression;
6855 }
6856
6857 static expression_t *parse_sizeof(void)
6858 {
6859         return parse_typeprop(EXPR_SIZEOF);
6860 }
6861
6862 static expression_t *parse_alignof(void)
6863 {
6864         return parse_typeprop(EXPR_ALIGNOF);
6865 }
6866
6867 static expression_t *parse_select_expression(expression_t *addr)
6868 {
6869         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6870         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6871         source_position_t const pos = *HERE;
6872         next_token();
6873
6874         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6875         if (!symbol)
6876                 return create_error_expression();
6877
6878         type_t *const orig_type = addr->base.type;
6879         type_t *const type      = skip_typeref(orig_type);
6880
6881         type_t *type_left;
6882         bool    saw_error = false;
6883         if (is_type_pointer(type)) {
6884                 if (!select_left_arrow) {
6885                         errorf(&pos,
6886                                "request for member '%Y' in something not a struct or union, but '%T'",
6887                                symbol, orig_type);
6888                         saw_error = true;
6889                 }
6890                 type_left = skip_typeref(type->pointer.points_to);
6891         } else {
6892                 if (select_left_arrow && is_type_valid(type)) {
6893                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6894                         saw_error = true;
6895                 }
6896                 type_left = type;
6897         }
6898
6899         if (!is_type_compound(type_left)) {
6900                 if (is_type_valid(type_left) && !saw_error) {
6901                         errorf(&pos,
6902                                "request for member '%Y' in something not a struct or union, but '%T'",
6903                                symbol, type_left);
6904                 }
6905                 return create_error_expression();
6906         }
6907
6908         compound_t *compound = type_left->compound.compound;
6909         if (!compound->complete) {
6910                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6911                        symbol, type_left);
6912                 return create_error_expression();
6913         }
6914
6915         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6916         expression_t      *result     =
6917                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6918
6919         if (result == NULL) {
6920                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6921                 return create_error_expression();
6922         }
6923
6924         return result;
6925 }
6926
6927 static void check_call_argument(type_t          *expected_type,
6928                                 call_argument_t *argument, unsigned pos)
6929 {
6930         type_t         *expected_type_skip = skip_typeref(expected_type);
6931         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6932         expression_t   *arg_expr           = argument->expression;
6933         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6934
6935         /* handle transparent union gnu extension */
6936         if (is_type_union(expected_type_skip)
6937                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6938                 compound_t *union_decl  = expected_type_skip->compound.compound;
6939                 type_t     *best_type   = NULL;
6940                 entity_t   *entry       = union_decl->members.entities;
6941                 for ( ; entry != NULL; entry = entry->base.next) {
6942                         assert(is_declaration(entry));
6943                         type_t *decl_type = entry->declaration.type;
6944                         error = semantic_assign(decl_type, arg_expr);
6945                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6946                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6947                                 continue;
6948
6949                         if (error == ASSIGN_SUCCESS) {
6950                                 best_type = decl_type;
6951                         } else if (best_type == NULL) {
6952                                 best_type = decl_type;
6953                         }
6954                 }
6955
6956                 if (best_type != NULL) {
6957                         expected_type = best_type;
6958                 }
6959         }
6960
6961         error                = semantic_assign(expected_type, arg_expr);
6962         argument->expression = create_implicit_cast(arg_expr, expected_type);
6963
6964         if (error != ASSIGN_SUCCESS) {
6965                 /* report exact scope in error messages (like "in argument 3") */
6966                 char buf[64];
6967                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6968                 report_assign_error(error, expected_type, arg_expr, buf,
6969                                     &arg_expr->base.source_position);
6970         } else {
6971                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6972                 if (!types_compatible(expected_type_skip, promoted_type) &&
6973                     !types_compatible(expected_type_skip, type_void_ptr) &&
6974                     !types_compatible(type_void_ptr,      promoted_type)) {
6975                         /* Deliberately show the skipped types in this warning */
6976                         source_position_t const *const apos = &arg_expr->base.source_position;
6977                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6978                 }
6979         }
6980 }
6981
6982 /**
6983  * Handle the semantic restrictions of builtin calls
6984  */
6985 static void handle_builtin_argument_restrictions(call_expression_t *call)
6986 {
6987         entity_t *entity = call->function->reference.entity;
6988         switch (entity->function.btk) {
6989         case BUILTIN_FIRM:
6990                 switch (entity->function.b.firm_builtin_kind) {
6991                 case ir_bk_return_address:
6992                 case ir_bk_frame_address: {
6993                         /* argument must be constant */
6994                         call_argument_t *argument = call->arguments;
6995
6996                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6997                                 errorf(&call->base.source_position,
6998                                            "argument of '%Y' must be a constant expression",
6999                                            call->function->reference.entity->base.symbol);
7000                         }
7001                         break;
7002                 }
7003                 case ir_bk_prefetch:
7004                         /* second and third argument must be constant if existent */
7005                         if (call->arguments == NULL)
7006                                 break;
7007                         call_argument_t *rw = call->arguments->next;
7008                         call_argument_t *locality = NULL;
7009
7010                         if (rw != NULL) {
7011                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7012                                         errorf(&call->base.source_position,
7013                                                    "second argument of '%Y' must be a constant expression",
7014                                                    call->function->reference.entity->base.symbol);
7015                                 }
7016                                 locality = rw->next;
7017                         }
7018                         if (locality != NULL) {
7019                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7020                                         errorf(&call->base.source_position,
7021                                                    "third argument of '%Y' must be a constant expression",
7022                                                    call->function->reference.entity->base.symbol);
7023                                 }
7024                                 locality = rw->next;
7025                         }
7026                         break;
7027                 default:
7028                         break;
7029                 }
7030
7031         case BUILTIN_OBJECT_SIZE:
7032                 if (call->arguments == NULL)
7033                         break;
7034
7035                 call_argument_t *arg = call->arguments->next;
7036                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7037                         errorf(&call->base.source_position,
7038                                    "second argument of '%Y' must be a constant expression",
7039                                    call->function->reference.entity->base.symbol);
7040                 }
7041                 break;
7042         default:
7043                 break;
7044         }
7045 }
7046
7047 /**
7048  * Parse a call expression, ie. expression '( ... )'.
7049  *
7050  * @param expression  the function address
7051  */
7052 static expression_t *parse_call_expression(expression_t *expression)
7053 {
7054         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7055         call_expression_t *call   = &result->call;
7056         call->function            = expression;
7057
7058         type_t *const orig_type = expression->base.type;
7059         type_t *const type      = skip_typeref(orig_type);
7060
7061         function_type_t *function_type = NULL;
7062         if (is_type_pointer(type)) {
7063                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7064
7065                 if (is_type_function(to_type)) {
7066                         function_type   = &to_type->function;
7067                         call->base.type = function_type->return_type;
7068                 }
7069         }
7070
7071         if (function_type == NULL && is_type_valid(type)) {
7072                 errorf(HERE,
7073                        "called object '%E' (type '%T') is not a pointer to a function",
7074                        expression, orig_type);
7075         }
7076
7077         /* parse arguments */
7078         eat('(');
7079         add_anchor_token(')');
7080         add_anchor_token(',');
7081
7082         if (token.kind != ')') {
7083                 call_argument_t **anchor = &call->arguments;
7084                 do {
7085                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7086                         argument->expression = parse_assignment_expression();
7087
7088                         *anchor = argument;
7089                         anchor  = &argument->next;
7090                 } while (next_if(','));
7091         }
7092         rem_anchor_token(',');
7093         rem_anchor_token(')');
7094         expect(')');
7095
7096         if (function_type == NULL)
7097                 return result;
7098
7099         /* check type and count of call arguments */
7100         function_parameter_t *parameter = function_type->parameters;
7101         call_argument_t      *argument  = call->arguments;
7102         if (!function_type->unspecified_parameters) {
7103                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7104                                 parameter = parameter->next, argument = argument->next) {
7105                         check_call_argument(parameter->type, argument, ++pos);
7106                 }
7107
7108                 if (parameter != NULL) {
7109                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7110                 } else if (argument != NULL && !function_type->variadic) {
7111                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7112                 }
7113         }
7114
7115         /* do default promotion for other arguments */
7116         for (; argument != NULL; argument = argument->next) {
7117                 type_t *argument_type = argument->expression->base.type;
7118                 if (!is_type_object(skip_typeref(argument_type))) {
7119                         errorf(&argument->expression->base.source_position,
7120                                "call argument '%E' must not be void", argument->expression);
7121                 }
7122
7123                 argument_type = get_default_promoted_type(argument_type);
7124
7125                 argument->expression
7126                         = create_implicit_cast(argument->expression, argument_type);
7127         }
7128
7129         check_format(call);
7130
7131         if (is_type_compound(skip_typeref(function_type->return_type))) {
7132                 source_position_t const *const pos = &expression->base.source_position;
7133                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7134         }
7135
7136         if (expression->kind == EXPR_REFERENCE) {
7137                 reference_expression_t *reference = &expression->reference;
7138                 if (reference->entity->kind == ENTITY_FUNCTION &&
7139                     reference->entity->function.btk != BUILTIN_NONE)
7140                         handle_builtin_argument_restrictions(call);
7141         }
7142
7143         return result;
7144 }
7145
7146 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7147
7148 static bool same_compound_type(const type_t *type1, const type_t *type2)
7149 {
7150         return
7151                 is_type_compound(type1) &&
7152                 type1->kind == type2->kind &&
7153                 type1->compound.compound == type2->compound.compound;
7154 }
7155
7156 static expression_t const *get_reference_address(expression_t const *expr)
7157 {
7158         bool regular_take_address = true;
7159         for (;;) {
7160                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7161                         expr = expr->unary.value;
7162                 } else {
7163                         regular_take_address = false;
7164                 }
7165
7166                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7167                         break;
7168
7169                 expr = expr->unary.value;
7170         }
7171
7172         if (expr->kind != EXPR_REFERENCE)
7173                 return NULL;
7174
7175         /* special case for functions which are automatically converted to a
7176          * pointer to function without an extra TAKE_ADDRESS operation */
7177         if (!regular_take_address &&
7178                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7179                 return NULL;
7180         }
7181
7182         return expr;
7183 }
7184
7185 static void warn_reference_address_as_bool(expression_t const* expr)
7186 {
7187         expr = get_reference_address(expr);
7188         if (expr != NULL) {
7189                 source_position_t const *const pos = &expr->base.source_position;
7190                 entity_t          const *const ent = expr->reference.entity;
7191                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7192         }
7193 }
7194
7195 static void warn_assignment_in_condition(const expression_t *const expr)
7196 {
7197         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7198                 return;
7199         if (expr->base.parenthesized)
7200                 return;
7201         source_position_t const *const pos = &expr->base.source_position;
7202         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7203 }
7204
7205 static void semantic_condition(expression_t const *const expr,
7206                                char const *const context)
7207 {
7208         type_t *const type = skip_typeref(expr->base.type);
7209         if (is_type_scalar(type)) {
7210                 warn_reference_address_as_bool(expr);
7211                 warn_assignment_in_condition(expr);
7212         } else if (is_type_valid(type)) {
7213                 errorf(&expr->base.source_position,
7214                                 "%s must have scalar type", context);
7215         }
7216 }
7217
7218 /**
7219  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7220  *
7221  * @param expression  the conditional expression
7222  */
7223 static expression_t *parse_conditional_expression(expression_t *expression)
7224 {
7225         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7226
7227         conditional_expression_t *conditional = &result->conditional;
7228         conditional->condition                = expression;
7229
7230         eat('?');
7231         add_anchor_token(':');
7232
7233         /* §6.5.15:2  The first operand shall have scalar type. */
7234         semantic_condition(expression, "condition of conditional operator");
7235
7236         expression_t *true_expression = expression;
7237         bool          gnu_cond = false;
7238         if (GNU_MODE && token.kind == ':') {
7239                 gnu_cond = true;
7240         } else {
7241                 true_expression = parse_expression();
7242         }
7243         rem_anchor_token(':');
7244         expect(':');
7245         expression_t *false_expression =
7246                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7247
7248         type_t *const orig_true_type  = true_expression->base.type;
7249         type_t *const orig_false_type = false_expression->base.type;
7250         type_t *const true_type       = skip_typeref(orig_true_type);
7251         type_t *const false_type      = skip_typeref(orig_false_type);
7252
7253         /* 6.5.15.3 */
7254         source_position_t const *const pos = &conditional->base.source_position;
7255         type_t                        *result_type;
7256         if (is_type_void(true_type) || is_type_void(false_type)) {
7257                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7258                 if (true_expression->kind == EXPR_UNARY_THROW) {
7259                         result_type = false_type;
7260                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7261                         result_type = true_type;
7262                 } else {
7263                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7264                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7265                         }
7266                         result_type = type_void;
7267                 }
7268         } else if (is_type_arithmetic(true_type)
7269                    && is_type_arithmetic(false_type)) {
7270                 result_type = semantic_arithmetic(true_type, false_type);
7271         } else if (same_compound_type(true_type, false_type)) {
7272                 /* just take 1 of the 2 types */
7273                 result_type = true_type;
7274         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7275                 type_t *pointer_type;
7276                 type_t *other_type;
7277                 expression_t *other_expression;
7278                 if (is_type_pointer(true_type) &&
7279                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7280                         pointer_type     = true_type;
7281                         other_type       = false_type;
7282                         other_expression = false_expression;
7283                 } else {
7284                         pointer_type     = false_type;
7285                         other_type       = true_type;
7286                         other_expression = true_expression;
7287                 }
7288
7289                 if (is_null_pointer_constant(other_expression)) {
7290                         result_type = pointer_type;
7291                 } else if (is_type_pointer(other_type)) {
7292                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7293                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7294
7295                         type_t *to;
7296                         if (is_type_void(to1) || is_type_void(to2)) {
7297                                 to = type_void;
7298                         } else if (types_compatible(get_unqualified_type(to1),
7299                                                     get_unqualified_type(to2))) {
7300                                 to = to1;
7301                         } else {
7302                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7303                                 to = type_void;
7304                         }
7305
7306                         type_t *const type =
7307                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7308                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7309                 } else if (is_type_integer(other_type)) {
7310                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7311                         result_type = pointer_type;
7312                 } else {
7313                         goto types_incompatible;
7314                 }
7315         } else {
7316 types_incompatible:
7317                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7318                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7319                 }
7320                 result_type = type_error_type;
7321         }
7322
7323         conditional->true_expression
7324                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7325         conditional->false_expression
7326                 = create_implicit_cast(false_expression, result_type);
7327         conditional->base.type = result_type;
7328         return result;
7329 }
7330
7331 /**
7332  * Parse an extension expression.
7333  */
7334 static expression_t *parse_extension(void)
7335 {
7336         PUSH_EXTENSION();
7337         expression_t *expression = parse_subexpression(PREC_UNARY);
7338         POP_EXTENSION();
7339         return expression;
7340 }
7341
7342 /**
7343  * Parse a __builtin_classify_type() expression.
7344  */
7345 static expression_t *parse_builtin_classify_type(void)
7346 {
7347         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7348         result->base.type    = type_int;
7349
7350         eat(T___builtin_classify_type);
7351
7352         add_anchor_token(')');
7353         expect('(');
7354         expression_t *expression = parse_expression();
7355         rem_anchor_token(')');
7356         expect(')');
7357         result->classify_type.type_expression = expression;
7358
7359         return result;
7360 }
7361
7362 /**
7363  * Parse a delete expression
7364  * ISO/IEC 14882:1998(E) §5.3.5
7365  */
7366 static expression_t *parse_delete(void)
7367 {
7368         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7369         result->base.type          = type_void;
7370
7371         eat(T_delete);
7372
7373         if (next_if('[')) {
7374                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7375                 expect(']');
7376         }
7377
7378         expression_t *const value = parse_subexpression(PREC_CAST);
7379         result->unary.value = value;
7380
7381         type_t *const type = skip_typeref(value->base.type);
7382         if (!is_type_pointer(type)) {
7383                 if (is_type_valid(type)) {
7384                         errorf(&value->base.source_position,
7385                                         "operand of delete must have pointer type");
7386                 }
7387         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7388                 source_position_t const *const pos = &value->base.source_position;
7389                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7390         }
7391
7392         return result;
7393 }
7394
7395 /**
7396  * Parse a throw expression
7397  * ISO/IEC 14882:1998(E) §15:1
7398  */
7399 static expression_t *parse_throw(void)
7400 {
7401         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7402         result->base.type          = type_void;
7403
7404         eat(T_throw);
7405
7406         expression_t *value = NULL;
7407         switch (token.kind) {
7408                 EXPRESSION_START {
7409                         value = parse_assignment_expression();
7410                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7411                         type_t *const orig_type = value->base.type;
7412                         type_t *const type      = skip_typeref(orig_type);
7413                         if (is_type_incomplete(type)) {
7414                                 errorf(&value->base.source_position,
7415                                                 "cannot throw object of incomplete type '%T'", orig_type);
7416                         } else if (is_type_pointer(type)) {
7417                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7418                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7419                                         errorf(&value->base.source_position,
7420                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7421                                 }
7422                         }
7423                 }
7424
7425                 default:
7426                         break;
7427         }
7428         result->unary.value = value;
7429
7430         return result;
7431 }
7432
7433 static bool check_pointer_arithmetic(const source_position_t *source_position,
7434                                      type_t *pointer_type,
7435                                      type_t *orig_pointer_type)
7436 {
7437         type_t *points_to = pointer_type->pointer.points_to;
7438         points_to = skip_typeref(points_to);
7439
7440         if (is_type_incomplete(points_to)) {
7441                 if (!GNU_MODE || !is_type_void(points_to)) {
7442                         errorf(source_position,
7443                                "arithmetic with pointer to incomplete type '%T' not allowed",
7444                                orig_pointer_type);
7445                         return false;
7446                 } else {
7447                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7448                 }
7449         } else if (is_type_function(points_to)) {
7450                 if (!GNU_MODE) {
7451                         errorf(source_position,
7452                                "arithmetic with pointer to function type '%T' not allowed",
7453                                orig_pointer_type);
7454                         return false;
7455                 } else {
7456                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7457                 }
7458         }
7459         return true;
7460 }
7461
7462 static bool is_lvalue(const expression_t *expression)
7463 {
7464         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7465         switch (expression->kind) {
7466         case EXPR_ARRAY_ACCESS:
7467         case EXPR_COMPOUND_LITERAL:
7468         case EXPR_REFERENCE:
7469         case EXPR_SELECT:
7470         case EXPR_UNARY_DEREFERENCE:
7471                 return true;
7472
7473         default: {
7474                 type_t *type = skip_typeref(expression->base.type);
7475                 return
7476                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7477                         is_type_reference(type) ||
7478                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7479                          * error before, which maybe prevented properly recognizing it as
7480                          * lvalue. */
7481                         !is_type_valid(type);
7482         }
7483         }
7484 }
7485
7486 static void semantic_incdec(unary_expression_t *expression)
7487 {
7488         type_t *const orig_type = expression->value->base.type;
7489         type_t *const type      = skip_typeref(orig_type);
7490         if (is_type_pointer(type)) {
7491                 if (!check_pointer_arithmetic(&expression->base.source_position,
7492                                               type, orig_type)) {
7493                         return;
7494                 }
7495         } else if (!is_type_real(type) && is_type_valid(type)) {
7496                 /* TODO: improve error message */
7497                 errorf(&expression->base.source_position,
7498                        "operation needs an arithmetic or pointer type");
7499                 return;
7500         }
7501         if (!is_lvalue(expression->value)) {
7502                 /* TODO: improve error message */
7503                 errorf(&expression->base.source_position, "lvalue required as operand");
7504         }
7505         expression->base.type = orig_type;
7506 }
7507
7508 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7509 {
7510         type_t *const res_type = promote_integer(type);
7511         expr->base.type = res_type;
7512         expr->value     = create_implicit_cast(expr->value, res_type);
7513 }
7514
7515 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7516 {
7517         type_t *const orig_type = expression->value->base.type;
7518         type_t *const type      = skip_typeref(orig_type);
7519         if (!is_type_arithmetic(type)) {
7520                 if (is_type_valid(type)) {
7521                         /* TODO: improve error message */
7522                         errorf(&expression->base.source_position,
7523                                 "operation needs an arithmetic type");
7524                 }
7525                 return;
7526         } else if (is_type_integer(type)) {
7527                 promote_unary_int_expr(expression, type);
7528         } else {
7529                 expression->base.type = orig_type;
7530         }
7531 }
7532
7533 static void semantic_unexpr_plus(unary_expression_t *expression)
7534 {
7535         semantic_unexpr_arithmetic(expression);
7536         source_position_t const *const pos = &expression->base.source_position;
7537         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7538 }
7539
7540 static void semantic_not(unary_expression_t *expression)
7541 {
7542         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7543         semantic_condition(expression->value, "operand of !");
7544         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7545 }
7546
7547 static void semantic_unexpr_integer(unary_expression_t *expression)
7548 {
7549         type_t *const orig_type = expression->value->base.type;
7550         type_t *const type      = skip_typeref(orig_type);
7551         if (!is_type_integer(type)) {
7552                 if (is_type_valid(type)) {
7553                         errorf(&expression->base.source_position,
7554                                "operand of ~ must be of integer type");
7555                 }
7556                 return;
7557         }
7558
7559         promote_unary_int_expr(expression, type);
7560 }
7561
7562 static void semantic_dereference(unary_expression_t *expression)
7563 {
7564         type_t *const orig_type = expression->value->base.type;
7565         type_t *const type      = skip_typeref(orig_type);
7566         if (!is_type_pointer(type)) {
7567                 if (is_type_valid(type)) {
7568                         errorf(&expression->base.source_position,
7569                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7570                 }
7571                 return;
7572         }
7573
7574         type_t *result_type   = type->pointer.points_to;
7575         result_type           = automatic_type_conversion(result_type);
7576         expression->base.type = result_type;
7577 }
7578
7579 /**
7580  * Record that an address is taken (expression represents an lvalue).
7581  *
7582  * @param expression       the expression
7583  * @param may_be_register  if true, the expression might be an register
7584  */
7585 static void set_address_taken(expression_t *expression, bool may_be_register)
7586 {
7587         if (expression->kind != EXPR_REFERENCE)
7588                 return;
7589
7590         entity_t *const entity = expression->reference.entity;
7591
7592         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7593                 return;
7594
7595         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7596                         && !may_be_register) {
7597                 source_position_t const *const pos = &expression->base.source_position;
7598                 errorf(pos, "address of register '%N' requested", entity);
7599         }
7600
7601         entity->variable.address_taken = true;
7602 }
7603
7604 /**
7605  * Check the semantic of the address taken expression.
7606  */
7607 static void semantic_take_addr(unary_expression_t *expression)
7608 {
7609         expression_t *value = expression->value;
7610         value->base.type    = revert_automatic_type_conversion(value);
7611
7612         type_t *orig_type = value->base.type;
7613         type_t *type      = skip_typeref(orig_type);
7614         if (!is_type_valid(type))
7615                 return;
7616
7617         /* §6.5.3.2 */
7618         if (!is_lvalue(value)) {
7619                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7620         }
7621         if (is_bitfield(value)) {
7622                 errorf(&expression->base.source_position,
7623                        "'&' not allowed on bitfield");
7624         }
7625
7626         set_address_taken(value, false);
7627
7628         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7629 }
7630
7631 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7632 static expression_t *parse_##unexpression_type(void)                         \
7633 {                                                                            \
7634         expression_t *unary_expression                                           \
7635                 = allocate_expression_zero(unexpression_type);                       \
7636         eat(token_kind);                                                         \
7637         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7638                                                                                  \
7639         sfunc(&unary_expression->unary);                                         \
7640                                                                                  \
7641         return unary_expression;                                                 \
7642 }
7643
7644 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7645                                semantic_unexpr_arithmetic)
7646 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7647                                semantic_unexpr_plus)
7648 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7649                                semantic_not)
7650 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7651                                semantic_dereference)
7652 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7653                                semantic_take_addr)
7654 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7655                                semantic_unexpr_integer)
7656 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7657                                semantic_incdec)
7658 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7659                                semantic_incdec)
7660
7661 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7662                                                sfunc)                         \
7663 static expression_t *parse_##unexpression_type(expression_t *left)            \
7664 {                                                                             \
7665         expression_t *unary_expression                                            \
7666                 = allocate_expression_zero(unexpression_type);                        \
7667         eat(token_kind);                                                          \
7668         unary_expression->unary.value = left;                                     \
7669                                                                                   \
7670         sfunc(&unary_expression->unary);                                          \
7671                                                                               \
7672         return unary_expression;                                                  \
7673 }
7674
7675 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7676                                        EXPR_UNARY_POSTFIX_INCREMENT,
7677                                        semantic_incdec)
7678 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7679                                        EXPR_UNARY_POSTFIX_DECREMENT,
7680                                        semantic_incdec)
7681
7682 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7683 {
7684         /* TODO: handle complex + imaginary types */
7685
7686         type_left  = get_unqualified_type(type_left);
7687         type_right = get_unqualified_type(type_right);
7688
7689         /* §6.3.1.8 Usual arithmetic conversions */
7690         if (type_left == type_long_double || type_right == type_long_double) {
7691                 return type_long_double;
7692         } else if (type_left == type_double || type_right == type_double) {
7693                 return type_double;
7694         } else if (type_left == type_float || type_right == type_float) {
7695                 return type_float;
7696         }
7697
7698         type_left  = promote_integer(type_left);
7699         type_right = promote_integer(type_right);
7700
7701         if (type_left == type_right)
7702                 return type_left;
7703
7704         bool     const signed_left  = is_type_signed(type_left);
7705         bool     const signed_right = is_type_signed(type_right);
7706         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7707         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7708
7709         if (signed_left == signed_right)
7710                 return rank_left >= rank_right ? type_left : type_right;
7711
7712         unsigned           s_rank;
7713         unsigned           u_rank;
7714         atomic_type_kind_t s_akind;
7715         atomic_type_kind_t u_akind;
7716         type_t *s_type;
7717         type_t *u_type;
7718         if (signed_left) {
7719                 s_type = type_left;
7720                 u_type = type_right;
7721         } else {
7722                 s_type = type_right;
7723                 u_type = type_left;
7724         }
7725         s_akind = get_akind(s_type);
7726         u_akind = get_akind(u_type);
7727         s_rank  = get_akind_rank(s_akind);
7728         u_rank  = get_akind_rank(u_akind);
7729
7730         if (u_rank >= s_rank)
7731                 return u_type;
7732
7733         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7734                 return s_type;
7735
7736         switch (s_akind) {
7737         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7738         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7739         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7740
7741         default: panic("invalid atomic type");
7742         }
7743 }
7744
7745 /**
7746  * Check the semantic restrictions for a binary expression.
7747  */
7748 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7749 {
7750         expression_t *const left            = expression->left;
7751         expression_t *const right           = expression->right;
7752         type_t       *const orig_type_left  = left->base.type;
7753         type_t       *const orig_type_right = right->base.type;
7754         type_t       *const type_left       = skip_typeref(orig_type_left);
7755         type_t       *const type_right      = skip_typeref(orig_type_right);
7756
7757         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7758                 /* TODO: improve error message */
7759                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7760                         errorf(&expression->base.source_position,
7761                                "operation needs arithmetic types");
7762                 }
7763                 return;
7764         }
7765
7766         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7767         expression->left      = create_implicit_cast(left, arithmetic_type);
7768         expression->right     = create_implicit_cast(right, arithmetic_type);
7769         expression->base.type = arithmetic_type;
7770 }
7771
7772 static void semantic_binexpr_integer(binary_expression_t *const expression)
7773 {
7774         expression_t *const left            = expression->left;
7775         expression_t *const right           = expression->right;
7776         type_t       *const orig_type_left  = left->base.type;
7777         type_t       *const orig_type_right = right->base.type;
7778         type_t       *const type_left       = skip_typeref(orig_type_left);
7779         type_t       *const type_right      = skip_typeref(orig_type_right);
7780
7781         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7782                 /* TODO: improve error message */
7783                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7784                         errorf(&expression->base.source_position,
7785                                "operation needs integer types");
7786                 }
7787                 return;
7788         }
7789
7790         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7791         expression->left      = create_implicit_cast(left, result_type);
7792         expression->right     = create_implicit_cast(right, result_type);
7793         expression->base.type = result_type;
7794 }
7795
7796 static void warn_div_by_zero(binary_expression_t const *const expression)
7797 {
7798         if (!is_type_integer(expression->base.type))
7799                 return;
7800
7801         expression_t const *const right = expression->right;
7802         /* The type of the right operand can be different for /= */
7803         if (is_type_integer(right->base.type)                    &&
7804             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7805             !fold_constant_to_bool(right)) {
7806                 source_position_t const *const pos = &expression->base.source_position;
7807                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7808         }
7809 }
7810
7811 /**
7812  * Check the semantic restrictions for a div/mod expression.
7813  */
7814 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7815 {
7816         semantic_binexpr_arithmetic(expression);
7817         warn_div_by_zero(expression);
7818 }
7819
7820 static void warn_addsub_in_shift(const expression_t *const expr)
7821 {
7822         if (expr->base.parenthesized)
7823                 return;
7824
7825         char op;
7826         switch (expr->kind) {
7827                 case EXPR_BINARY_ADD: op = '+'; break;
7828                 case EXPR_BINARY_SUB: op = '-'; break;
7829                 default:              return;
7830         }
7831
7832         source_position_t const *const pos = &expr->base.source_position;
7833         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7834 }
7835
7836 static bool semantic_shift(binary_expression_t *expression)
7837 {
7838         expression_t *const left            = expression->left;
7839         expression_t *const right           = expression->right;
7840         type_t       *const orig_type_left  = left->base.type;
7841         type_t       *const orig_type_right = right->base.type;
7842         type_t       *      type_left       = skip_typeref(orig_type_left);
7843         type_t       *      type_right      = skip_typeref(orig_type_right);
7844
7845         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7846                 /* TODO: improve error message */
7847                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7848                         errorf(&expression->base.source_position,
7849                                "operands of shift operation must have integer types");
7850                 }
7851                 return false;
7852         }
7853
7854         type_left = promote_integer(type_left);
7855
7856         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7857                 source_position_t const *const pos   = &right->base.source_position;
7858                 long                     const count = fold_constant_to_int(right);
7859                 if (count < 0) {
7860                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7861                 } else if ((unsigned long)count >=
7862                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7863                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7864                 }
7865         }
7866
7867         type_right        = promote_integer(type_right);
7868         expression->right = create_implicit_cast(right, type_right);
7869
7870         return true;
7871 }
7872
7873 static void semantic_shift_op(binary_expression_t *expression)
7874 {
7875         expression_t *const left  = expression->left;
7876         expression_t *const right = expression->right;
7877
7878         if (!semantic_shift(expression))
7879                 return;
7880
7881         warn_addsub_in_shift(left);
7882         warn_addsub_in_shift(right);
7883
7884         type_t *const orig_type_left = left->base.type;
7885         type_t *      type_left      = skip_typeref(orig_type_left);
7886
7887         type_left             = promote_integer(type_left);
7888         expression->left      = create_implicit_cast(left, type_left);
7889         expression->base.type = type_left;
7890 }
7891
7892 static void semantic_add(binary_expression_t *expression)
7893 {
7894         expression_t *const left            = expression->left;
7895         expression_t *const right           = expression->right;
7896         type_t       *const orig_type_left  = left->base.type;
7897         type_t       *const orig_type_right = right->base.type;
7898         type_t       *const type_left       = skip_typeref(orig_type_left);
7899         type_t       *const type_right      = skip_typeref(orig_type_right);
7900
7901         /* §6.5.6 */
7902         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7903                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7904                 expression->left  = create_implicit_cast(left, arithmetic_type);
7905                 expression->right = create_implicit_cast(right, arithmetic_type);
7906                 expression->base.type = arithmetic_type;
7907         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7908                 check_pointer_arithmetic(&expression->base.source_position,
7909                                          type_left, orig_type_left);
7910                 expression->base.type = type_left;
7911         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7912                 check_pointer_arithmetic(&expression->base.source_position,
7913                                          type_right, orig_type_right);
7914                 expression->base.type = type_right;
7915         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7916                 errorf(&expression->base.source_position,
7917                        "invalid operands to binary + ('%T', '%T')",
7918                        orig_type_left, orig_type_right);
7919         }
7920 }
7921
7922 static void semantic_sub(binary_expression_t *expression)
7923 {
7924         expression_t            *const left            = expression->left;
7925         expression_t            *const right           = expression->right;
7926         type_t                  *const orig_type_left  = left->base.type;
7927         type_t                  *const orig_type_right = right->base.type;
7928         type_t                  *const type_left       = skip_typeref(orig_type_left);
7929         type_t                  *const type_right      = skip_typeref(orig_type_right);
7930         source_position_t const *const pos             = &expression->base.source_position;
7931
7932         /* §5.6.5 */
7933         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7934                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7935                 expression->left        = create_implicit_cast(left, arithmetic_type);
7936                 expression->right       = create_implicit_cast(right, arithmetic_type);
7937                 expression->base.type =  arithmetic_type;
7938         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7939                 check_pointer_arithmetic(&expression->base.source_position,
7940                                          type_left, orig_type_left);
7941                 expression->base.type = type_left;
7942         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7943                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7944                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7945                 if (!types_compatible(unqual_left, unqual_right)) {
7946                         errorf(pos,
7947                                "subtracting pointers to incompatible types '%T' and '%T'",
7948                                orig_type_left, orig_type_right);
7949                 } else if (!is_type_object(unqual_left)) {
7950                         if (!is_type_void(unqual_left)) {
7951                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7952                                        orig_type_left);
7953                         } else {
7954                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7955                         }
7956                 }
7957                 expression->base.type = type_ptrdiff_t;
7958         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7959                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7960                        orig_type_left, orig_type_right);
7961         }
7962 }
7963
7964 static void warn_string_literal_address(expression_t const* expr)
7965 {
7966         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7967                 expr = expr->unary.value;
7968                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7969                         return;
7970                 expr = expr->unary.value;
7971         }
7972
7973         if (expr->kind == EXPR_STRING_LITERAL) {
7974                 source_position_t const *const pos = &expr->base.source_position;
7975                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7976         }
7977 }
7978
7979 static bool maybe_negative(expression_t const *const expr)
7980 {
7981         switch (is_constant_expression(expr)) {
7982                 case EXPR_CLASS_ERROR:    return false;
7983                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7984                 default:                  return true;
7985         }
7986 }
7987
7988 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7989 {
7990         warn_string_literal_address(expr);
7991
7992         expression_t const* const ref = get_reference_address(expr);
7993         if (ref != NULL && is_null_pointer_constant(other)) {
7994                 entity_t const *const ent = ref->reference.entity;
7995                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7996         }
7997
7998         if (!expr->base.parenthesized) {
7999                 switch (expr->base.kind) {
8000                         case EXPR_BINARY_LESS:
8001                         case EXPR_BINARY_GREATER:
8002                         case EXPR_BINARY_LESSEQUAL:
8003                         case EXPR_BINARY_GREATEREQUAL:
8004                         case EXPR_BINARY_NOTEQUAL:
8005                         case EXPR_BINARY_EQUAL:
8006                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8007                                 break;
8008                         default:
8009                                 break;
8010                 }
8011         }
8012 }
8013
8014 /**
8015  * Check the semantics of comparison expressions.
8016  *
8017  * @param expression   The expression to check.
8018  */
8019 static void semantic_comparison(binary_expression_t *expression)
8020 {
8021         source_position_t const *const pos   = &expression->base.source_position;
8022         expression_t            *const left  = expression->left;
8023         expression_t            *const right = expression->right;
8024
8025         warn_comparison(pos, left, right);
8026         warn_comparison(pos, right, left);
8027
8028         type_t *orig_type_left  = left->base.type;
8029         type_t *orig_type_right = right->base.type;
8030         type_t *type_left       = skip_typeref(orig_type_left);
8031         type_t *type_right      = skip_typeref(orig_type_right);
8032
8033         /* TODO non-arithmetic types */
8034         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8035                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8036
8037                 /* test for signed vs unsigned compares */
8038                 if (is_type_integer(arithmetic_type)) {
8039                         bool const signed_left  = is_type_signed(type_left);
8040                         bool const signed_right = is_type_signed(type_right);
8041                         if (signed_left != signed_right) {
8042                                 /* FIXME long long needs better const folding magic */
8043                                 /* TODO check whether constant value can be represented by other type */
8044                                 if ((signed_left  && maybe_negative(left)) ||
8045                                                 (signed_right && maybe_negative(right))) {
8046                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8047                                 }
8048                         }
8049                 }
8050
8051                 expression->left        = create_implicit_cast(left, arithmetic_type);
8052                 expression->right       = create_implicit_cast(right, arithmetic_type);
8053                 expression->base.type   = arithmetic_type;
8054                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8055                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8056                     is_type_float(arithmetic_type)) {
8057                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8058                 }
8059         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8060                 /* TODO check compatibility */
8061         } else if (is_type_pointer(type_left)) {
8062                 expression->right = create_implicit_cast(right, type_left);
8063         } else if (is_type_pointer(type_right)) {
8064                 expression->left = create_implicit_cast(left, type_right);
8065         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8066                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8067         }
8068         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8069 }
8070
8071 /**
8072  * Checks if a compound type has constant fields.
8073  */
8074 static bool has_const_fields(const compound_type_t *type)
8075 {
8076         compound_t *compound = type->compound;
8077         entity_t   *entry    = compound->members.entities;
8078
8079         for (; entry != NULL; entry = entry->base.next) {
8080                 if (!is_declaration(entry))
8081                         continue;
8082
8083                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8084                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8085                         return true;
8086         }
8087
8088         return false;
8089 }
8090
8091 static bool is_valid_assignment_lhs(expression_t const* const left)
8092 {
8093         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8094         type_t *const type_left      = skip_typeref(orig_type_left);
8095
8096         if (!is_lvalue(left)) {
8097                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8098                        left);
8099                 return false;
8100         }
8101
8102         if (left->kind == EXPR_REFERENCE
8103                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8104                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8105                 return false;
8106         }
8107
8108         if (is_type_array(type_left)) {
8109                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8110                 return false;
8111         }
8112         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8113                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8114                        orig_type_left);
8115                 return false;
8116         }
8117         if (is_type_incomplete(type_left)) {
8118                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8119                        left, orig_type_left);
8120                 return false;
8121         }
8122         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8123                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8124                        left, orig_type_left);
8125                 return false;
8126         }
8127
8128         return true;
8129 }
8130
8131 static void semantic_arithmetic_assign(binary_expression_t *expression)
8132 {
8133         expression_t *left            = expression->left;
8134         expression_t *right           = expression->right;
8135         type_t       *orig_type_left  = left->base.type;
8136         type_t       *orig_type_right = right->base.type;
8137
8138         if (!is_valid_assignment_lhs(left))
8139                 return;
8140
8141         type_t *type_left  = skip_typeref(orig_type_left);
8142         type_t *type_right = skip_typeref(orig_type_right);
8143
8144         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8145                 /* TODO: improve error message */
8146                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8147                         errorf(&expression->base.source_position,
8148                                "operation needs arithmetic types");
8149                 }
8150                 return;
8151         }
8152
8153         /* combined instructions are tricky. We can't create an implicit cast on
8154          * the left side, because we need the uncasted form for the store.
8155          * The ast2firm pass has to know that left_type must be right_type
8156          * for the arithmetic operation and create a cast by itself */
8157         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8158         expression->right       = create_implicit_cast(right, arithmetic_type);
8159         expression->base.type   = type_left;
8160 }
8161
8162 static void semantic_divmod_assign(binary_expression_t *expression)
8163 {
8164         semantic_arithmetic_assign(expression);
8165         warn_div_by_zero(expression);
8166 }
8167
8168 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8169 {
8170         expression_t *const left            = expression->left;
8171         expression_t *const right           = expression->right;
8172         type_t       *const orig_type_left  = left->base.type;
8173         type_t       *const orig_type_right = right->base.type;
8174         type_t       *const type_left       = skip_typeref(orig_type_left);
8175         type_t       *const type_right      = skip_typeref(orig_type_right);
8176
8177         if (!is_valid_assignment_lhs(left))
8178                 return;
8179
8180         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8181                 /* combined instructions are tricky. We can't create an implicit cast on
8182                  * the left side, because we need the uncasted form for the store.
8183                  * The ast2firm pass has to know that left_type must be right_type
8184                  * for the arithmetic operation and create a cast by itself */
8185                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8186                 expression->right     = create_implicit_cast(right, arithmetic_type);
8187                 expression->base.type = type_left;
8188         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8189                 check_pointer_arithmetic(&expression->base.source_position,
8190                                          type_left, orig_type_left);
8191                 expression->base.type = type_left;
8192         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8193                 errorf(&expression->base.source_position,
8194                        "incompatible types '%T' and '%T' in assignment",
8195                        orig_type_left, orig_type_right);
8196         }
8197 }
8198
8199 static void semantic_integer_assign(binary_expression_t *expression)
8200 {
8201         expression_t *left            = expression->left;
8202         expression_t *right           = expression->right;
8203         type_t       *orig_type_left  = left->base.type;
8204         type_t       *orig_type_right = right->base.type;
8205
8206         if (!is_valid_assignment_lhs(left))
8207                 return;
8208
8209         type_t *type_left  = skip_typeref(orig_type_left);
8210         type_t *type_right = skip_typeref(orig_type_right);
8211
8212         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8213                 /* TODO: improve error message */
8214                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8215                         errorf(&expression->base.source_position,
8216                                "operation needs integer types");
8217                 }
8218                 return;
8219         }
8220
8221         /* combined instructions are tricky. We can't create an implicit cast on
8222          * the left side, because we need the uncasted form for the store.
8223          * The ast2firm pass has to know that left_type must be right_type
8224          * for the arithmetic operation and create a cast by itself */
8225         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8226         expression->right       = create_implicit_cast(right, arithmetic_type);
8227         expression->base.type   = type_left;
8228 }
8229
8230 static void semantic_shift_assign(binary_expression_t *expression)
8231 {
8232         expression_t *left           = expression->left;
8233
8234         if (!is_valid_assignment_lhs(left))
8235                 return;
8236
8237         if (!semantic_shift(expression))
8238                 return;
8239
8240         expression->base.type = skip_typeref(left->base.type);
8241 }
8242
8243 static void warn_logical_and_within_or(const expression_t *const expr)
8244 {
8245         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8246                 return;
8247         if (expr->base.parenthesized)
8248                 return;
8249         source_position_t const *const pos = &expr->base.source_position;
8250         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8251 }
8252
8253 /**
8254  * Check the semantic restrictions of a logical expression.
8255  */
8256 static void semantic_logical_op(binary_expression_t *expression)
8257 {
8258         /* §6.5.13:2  Each of the operands shall have scalar type.
8259          * §6.5.14:2  Each of the operands shall have scalar type. */
8260         semantic_condition(expression->left,   "left operand of logical operator");
8261         semantic_condition(expression->right, "right operand of logical operator");
8262         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8263                 warn_logical_and_within_or(expression->left);
8264                 warn_logical_and_within_or(expression->right);
8265         }
8266         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8267 }
8268
8269 /**
8270  * Check the semantic restrictions of a binary assign expression.
8271  */
8272 static void semantic_binexpr_assign(binary_expression_t *expression)
8273 {
8274         expression_t *left           = expression->left;
8275         type_t       *orig_type_left = left->base.type;
8276
8277         if (!is_valid_assignment_lhs(left))
8278                 return;
8279
8280         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8281         report_assign_error(error, orig_type_left, expression->right,
8282                         "assignment", &left->base.source_position);
8283         expression->right = create_implicit_cast(expression->right, orig_type_left);
8284         expression->base.type = orig_type_left;
8285 }
8286
8287 /**
8288  * Determine if the outermost operation (or parts thereof) of the given
8289  * expression has no effect in order to generate a warning about this fact.
8290  * Therefore in some cases this only examines some of the operands of the
8291  * expression (see comments in the function and examples below).
8292  * Examples:
8293  *   f() + 23;    // warning, because + has no effect
8294  *   x || f();    // no warning, because x controls execution of f()
8295  *   x ? y : f(); // warning, because y has no effect
8296  *   (void)x;     // no warning to be able to suppress the warning
8297  * This function can NOT be used for an "expression has definitely no effect"-
8298  * analysis. */
8299 static bool expression_has_effect(const expression_t *const expr)
8300 {
8301         switch (expr->kind) {
8302                 case EXPR_ERROR:                      return true; /* do NOT warn */
8303                 case EXPR_REFERENCE:                  return false;
8304                 case EXPR_ENUM_CONSTANT:              return false;
8305                 case EXPR_LABEL_ADDRESS:              return false;
8306
8307                 /* suppress the warning for microsoft __noop operations */
8308                 case EXPR_LITERAL_MS_NOOP:            return true;
8309                 case EXPR_LITERAL_BOOLEAN:
8310                 case EXPR_LITERAL_CHARACTER:
8311                 case EXPR_LITERAL_INTEGER:
8312                 case EXPR_LITERAL_FLOATINGPOINT:
8313                 case EXPR_STRING_LITERAL:             return false;
8314
8315                 case EXPR_CALL: {
8316                         const call_expression_t *const call = &expr->call;
8317                         if (call->function->kind != EXPR_REFERENCE)
8318                                 return true;
8319
8320                         switch (call->function->reference.entity->function.btk) {
8321                                 /* FIXME: which builtins have no effect? */
8322                                 default:                      return true;
8323                         }
8324                 }
8325
8326                 /* Generate the warning if either the left or right hand side of a
8327                  * conditional expression has no effect */
8328                 case EXPR_CONDITIONAL: {
8329                         conditional_expression_t const *const cond = &expr->conditional;
8330                         expression_t             const *const t    = cond->true_expression;
8331                         return
8332                                 (t == NULL || expression_has_effect(t)) &&
8333                                 expression_has_effect(cond->false_expression);
8334                 }
8335
8336                 case EXPR_SELECT:                     return false;
8337                 case EXPR_ARRAY_ACCESS:               return false;
8338                 case EXPR_SIZEOF:                     return false;
8339                 case EXPR_CLASSIFY_TYPE:              return false;
8340                 case EXPR_ALIGNOF:                    return false;
8341
8342                 case EXPR_FUNCNAME:                   return false;
8343                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8344                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8345                 case EXPR_OFFSETOF:                   return false;
8346                 case EXPR_VA_START:                   return true;
8347                 case EXPR_VA_ARG:                     return true;
8348                 case EXPR_VA_COPY:                    return true;
8349                 case EXPR_STATEMENT:                  return true; // TODO
8350                 case EXPR_COMPOUND_LITERAL:           return false;
8351
8352                 case EXPR_UNARY_NEGATE:               return false;
8353                 case EXPR_UNARY_PLUS:                 return false;
8354                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8355                 case EXPR_UNARY_NOT:                  return false;
8356                 case EXPR_UNARY_DEREFERENCE:          return false;
8357                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8358                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8359                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8360                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8361                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8362
8363                 /* Treat void casts as if they have an effect in order to being able to
8364                  * suppress the warning */
8365                 case EXPR_UNARY_CAST: {
8366                         type_t *const type = skip_typeref(expr->base.type);
8367                         return is_type_void(type);
8368                 }
8369
8370                 case EXPR_UNARY_ASSUME:               return true;
8371                 case EXPR_UNARY_DELETE:               return true;
8372                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8373                 case EXPR_UNARY_THROW:                return true;
8374
8375                 case EXPR_BINARY_ADD:                 return false;
8376                 case EXPR_BINARY_SUB:                 return false;
8377                 case EXPR_BINARY_MUL:                 return false;
8378                 case EXPR_BINARY_DIV:                 return false;
8379                 case EXPR_BINARY_MOD:                 return false;
8380                 case EXPR_BINARY_EQUAL:               return false;
8381                 case EXPR_BINARY_NOTEQUAL:            return false;
8382                 case EXPR_BINARY_LESS:                return false;
8383                 case EXPR_BINARY_LESSEQUAL:           return false;
8384                 case EXPR_BINARY_GREATER:             return false;
8385                 case EXPR_BINARY_GREATEREQUAL:        return false;
8386                 case EXPR_BINARY_BITWISE_AND:         return false;
8387                 case EXPR_BINARY_BITWISE_OR:          return false;
8388                 case EXPR_BINARY_BITWISE_XOR:         return false;
8389                 case EXPR_BINARY_SHIFTLEFT:           return false;
8390                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8391                 case EXPR_BINARY_ASSIGN:              return true;
8392                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8393                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8394                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8395                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8396                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8397                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8398                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8399                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8400                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8401                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8402
8403                 /* Only examine the right hand side of && and ||, because the left hand
8404                  * side already has the effect of controlling the execution of the right
8405                  * hand side */
8406                 case EXPR_BINARY_LOGICAL_AND:
8407                 case EXPR_BINARY_LOGICAL_OR:
8408                 /* Only examine the right hand side of a comma expression, because the left
8409                  * hand side has a separate warning */
8410                 case EXPR_BINARY_COMMA:
8411                         return expression_has_effect(expr->binary.right);
8412
8413                 case EXPR_BINARY_ISGREATER:           return false;
8414                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8415                 case EXPR_BINARY_ISLESS:              return false;
8416                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8417                 case EXPR_BINARY_ISLESSGREATER:       return false;
8418                 case EXPR_BINARY_ISUNORDERED:         return false;
8419         }
8420
8421         internal_errorf(HERE, "unexpected expression");
8422 }
8423
8424 static void semantic_comma(binary_expression_t *expression)
8425 {
8426         const expression_t *const left = expression->left;
8427         if (!expression_has_effect(left)) {
8428                 source_position_t const *const pos = &left->base.source_position;
8429                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8430         }
8431         expression->base.type = expression->right->base.type;
8432 }
8433
8434 /**
8435  * @param prec_r precedence of the right operand
8436  */
8437 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8438 static expression_t *parse_##binexpression_type(expression_t *left)          \
8439 {                                                                            \
8440         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8441         binexpr->binary.left  = left;                                            \
8442         eat(token_kind);                                                         \
8443                                                                              \
8444         expression_t *right = parse_subexpression(prec_r);                       \
8445                                                                              \
8446         binexpr->binary.right = right;                                           \
8447         sfunc(&binexpr->binary);                                                 \
8448                                                                              \
8449         return binexpr;                                                          \
8450 }
8451
8452 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8453 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8454 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8455 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8456 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8457 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8458 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8459 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8460 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8461 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8462 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8463 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8464 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8465 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8466 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8467 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8468 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8469 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8470 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8471 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8472 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8473 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8474 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8475 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8476 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8477 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8478 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8479 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8480 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8481 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8482
8483
8484 static expression_t *parse_subexpression(precedence_t precedence)
8485 {
8486         expression_parser_function_t *parser
8487                 = &expression_parsers[token.kind];
8488         expression_t                 *left;
8489
8490         if (parser->parser != NULL) {
8491                 left = parser->parser();
8492         } else {
8493                 left = parse_primary_expression();
8494         }
8495         assert(left != NULL);
8496
8497         while (true) {
8498                 parser = &expression_parsers[token.kind];
8499                 if (parser->infix_parser == NULL)
8500                         break;
8501                 if (parser->infix_precedence < precedence)
8502                         break;
8503
8504                 left = parser->infix_parser(left);
8505
8506                 assert(left != NULL);
8507         }
8508
8509         return left;
8510 }
8511
8512 /**
8513  * Parse an expression.
8514  */
8515 static expression_t *parse_expression(void)
8516 {
8517         return parse_subexpression(PREC_EXPRESSION);
8518 }
8519
8520 /**
8521  * Register a parser for a prefix-like operator.
8522  *
8523  * @param parser      the parser function
8524  * @param token_kind  the token type of the prefix token
8525  */
8526 static void register_expression_parser(parse_expression_function parser,
8527                                        int token_kind)
8528 {
8529         expression_parser_function_t *entry = &expression_parsers[token_kind];
8530
8531         assert(!entry->parser);
8532         entry->parser = parser;
8533 }
8534
8535 /**
8536  * Register a parser for an infix operator with given precedence.
8537  *
8538  * @param parser      the parser function
8539  * @param token_kind  the token type of the infix operator
8540  * @param precedence  the precedence of the operator
8541  */
8542 static void register_infix_parser(parse_expression_infix_function parser,
8543                                   int token_kind, precedence_t precedence)
8544 {
8545         expression_parser_function_t *entry = &expression_parsers[token_kind];
8546
8547         assert(!entry->infix_parser);
8548         entry->infix_parser     = parser;
8549         entry->infix_precedence = precedence;
8550 }
8551
8552 /**
8553  * Initialize the expression parsers.
8554  */
8555 static void init_expression_parsers(void)
8556 {
8557         memset(&expression_parsers, 0, sizeof(expression_parsers));
8558
8559         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8560         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8561         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8562         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8563         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8564         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8565         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8566         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8567         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8568         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8569         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8570         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8571         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8572         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8573         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8574         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8575         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8576         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8577         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8578         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8579         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8580         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8581         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8582         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8583         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8584         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8585         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8586         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8587         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8588         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8589         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8590         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8591         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8592         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8593         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8594         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8595         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8596
8597         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8598         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8599         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8600         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8601         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8602         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8603         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8604         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8605         register_expression_parser(parse_sizeof,                      T_sizeof);
8606         register_expression_parser(parse_alignof,                     T__Alignof);
8607         register_expression_parser(parse_extension,                   T___extension__);
8608         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8609         register_expression_parser(parse_delete,                      T_delete);
8610         register_expression_parser(parse_throw,                       T_throw);
8611 }
8612
8613 /**
8614  * Parse a asm statement arguments specification.
8615  */
8616 static asm_argument_t *parse_asm_arguments(bool is_out)
8617 {
8618         asm_argument_t  *result = NULL;
8619         asm_argument_t **anchor = &result;
8620
8621         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8622                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8623
8624                 if (next_if('[')) {
8625                         add_anchor_token(']');
8626                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8627                         rem_anchor_token(']');
8628                         expect(']');
8629                         if (!argument->symbol)
8630                                 return NULL;
8631                 }
8632
8633                 argument->constraints = parse_string_literals("asm argument");
8634                 add_anchor_token(')');
8635                 expect('(');
8636                 expression_t *expression = parse_expression();
8637                 rem_anchor_token(')');
8638                 if (is_out) {
8639                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8640                          * change size or type representation (e.g. int -> long is ok, but
8641                          * int -> float is not) */
8642                         if (expression->kind == EXPR_UNARY_CAST) {
8643                                 type_t      *const type = expression->base.type;
8644                                 type_kind_t  const kind = type->kind;
8645                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8646                                         unsigned flags;
8647                                         unsigned size;
8648                                         if (kind == TYPE_ATOMIC) {
8649                                                 atomic_type_kind_t const akind = type->atomic.akind;
8650                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8651                                                 size  = get_atomic_type_size(akind);
8652                                         } else {
8653                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8654                                                 size  = get_type_size(type_void_ptr);
8655                                         }
8656
8657                                         do {
8658                                                 expression_t *const value      = expression->unary.value;
8659                                                 type_t       *const value_type = value->base.type;
8660                                                 type_kind_t   const value_kind = value_type->kind;
8661
8662                                                 unsigned value_flags;
8663                                                 unsigned value_size;
8664                                                 if (value_kind == TYPE_ATOMIC) {
8665                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8666                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8667                                                         value_size  = get_atomic_type_size(value_akind);
8668                                                 } else if (value_kind == TYPE_POINTER) {
8669                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8670                                                         value_size  = get_type_size(type_void_ptr);
8671                                                 } else {
8672                                                         break;
8673                                                 }
8674
8675                                                 if (value_flags != flags || value_size != size)
8676                                                         break;
8677
8678                                                 expression = value;
8679                                         } while (expression->kind == EXPR_UNARY_CAST);
8680                                 }
8681                         }
8682
8683                         if (!is_lvalue(expression)) {
8684                                 errorf(&expression->base.source_position,
8685                                        "asm output argument is not an lvalue");
8686                         }
8687
8688                         if (argument->constraints.begin[0] == '=')
8689                                 determine_lhs_ent(expression, NULL);
8690                         else
8691                                 mark_vars_read(expression, NULL);
8692                 } else {
8693                         mark_vars_read(expression, NULL);
8694                 }
8695                 argument->expression = expression;
8696                 expect(')');
8697
8698                 set_address_taken(expression, true);
8699
8700                 *anchor = argument;
8701                 anchor  = &argument->next;
8702
8703                 if (!next_if(','))
8704                         break;
8705         }
8706
8707         return result;
8708 }
8709
8710 /**
8711  * Parse a asm statement clobber specification.
8712  */
8713 static asm_clobber_t *parse_asm_clobbers(void)
8714 {
8715         asm_clobber_t *result  = NULL;
8716         asm_clobber_t **anchor = &result;
8717
8718         while (token.kind == T_STRING_LITERAL) {
8719                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8720                 clobber->clobber       = parse_string_literals(NULL);
8721
8722                 *anchor = clobber;
8723                 anchor  = &clobber->next;
8724
8725                 if (!next_if(','))
8726                         break;
8727         }
8728
8729         return result;
8730 }
8731
8732 /**
8733  * Parse an asm statement.
8734  */
8735 static statement_t *parse_asm_statement(void)
8736 {
8737         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8738         asm_statement_t *asm_statement = &statement->asms;
8739
8740         eat(T_asm);
8741         add_anchor_token(')');
8742         add_anchor_token(':');
8743         add_anchor_token(T_STRING_LITERAL);
8744
8745         if (next_if(T_volatile))
8746                 asm_statement->is_volatile = true;
8747
8748         expect('(');
8749         rem_anchor_token(T_STRING_LITERAL);
8750         asm_statement->asm_text = parse_string_literals("asm statement");
8751
8752         if (next_if(':'))
8753                 asm_statement->outputs = parse_asm_arguments(true);
8754
8755         if (next_if(':'))
8756                 asm_statement->inputs = parse_asm_arguments(false);
8757
8758         rem_anchor_token(':');
8759         if (next_if(':'))
8760                 asm_statement->clobbers = parse_asm_clobbers();
8761
8762         rem_anchor_token(')');
8763         expect(')');
8764         expect(';');
8765
8766         if (asm_statement->outputs == NULL) {
8767                 /* GCC: An 'asm' instruction without any output operands will be treated
8768                  * identically to a volatile 'asm' instruction. */
8769                 asm_statement->is_volatile = true;
8770         }
8771
8772         return statement;
8773 }
8774
8775 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8776 {
8777         statement_t *inner_stmt;
8778         switch (token.kind) {
8779                 case '}':
8780                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8781                         inner_stmt = create_error_statement();
8782                         break;
8783
8784                 case ';':
8785                         if (label->kind == STATEMENT_LABEL) {
8786                                 /* Eat an empty statement here, to avoid the warning about an empty
8787                                  * statement after a label.  label:; is commonly used to have a label
8788                                  * before a closing brace. */
8789                                 inner_stmt = create_empty_statement();
8790                                 eat(';');
8791                                 break;
8792                         }
8793                         /* FALLTHROUGH */
8794
8795                 default:
8796                         inner_stmt = parse_statement();
8797                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8798                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8799                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8800                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8801                         }
8802                         break;
8803         }
8804         return inner_stmt;
8805 }
8806
8807 /**
8808  * Parse a case statement.
8809  */
8810 static statement_t *parse_case_statement(void)
8811 {
8812         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8813         source_position_t *const pos       = &statement->base.source_position;
8814
8815         eat(T_case);
8816         add_anchor_token(':');
8817
8818         expression_t *expression = parse_expression();
8819         type_t *expression_type = expression->base.type;
8820         type_t *skipped         = skip_typeref(expression_type);
8821         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8822                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8823                        expression, expression_type);
8824         }
8825
8826         type_t *type = expression_type;
8827         if (current_switch != NULL) {
8828                 type_t *switch_type = current_switch->expression->base.type;
8829                 if (is_type_valid(switch_type)) {
8830                         expression = create_implicit_cast(expression, switch_type);
8831                 }
8832         }
8833
8834         statement->case_label.expression = expression;
8835         expression_classification_t const expr_class = is_constant_expression(expression);
8836         if (expr_class != EXPR_CLASS_CONSTANT) {
8837                 if (expr_class != EXPR_CLASS_ERROR) {
8838                         errorf(pos, "case label does not reduce to an integer constant");
8839                 }
8840                 statement->case_label.is_bad = true;
8841         } else {
8842                 long const val = fold_constant_to_int(expression);
8843                 statement->case_label.first_case = val;
8844                 statement->case_label.last_case  = val;
8845         }
8846
8847         if (GNU_MODE) {
8848                 if (next_if(T_DOTDOTDOT)) {
8849                         expression_t *end_range = parse_expression();
8850                         expression_type = expression->base.type;
8851                         skipped         = skip_typeref(expression_type);
8852                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8853                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8854                                            expression, expression_type);
8855                         }
8856
8857                         end_range = create_implicit_cast(end_range, type);
8858                         statement->case_label.end_range = end_range;
8859                         expression_classification_t const end_class = is_constant_expression(end_range);
8860                         if (end_class != EXPR_CLASS_CONSTANT) {
8861                                 if (end_class != EXPR_CLASS_ERROR) {
8862                                         errorf(pos, "case range does not reduce to an integer constant");
8863                                 }
8864                                 statement->case_label.is_bad = true;
8865                         } else {
8866                                 long const val = fold_constant_to_int(end_range);
8867                                 statement->case_label.last_case = val;
8868
8869                                 if (val < statement->case_label.first_case) {
8870                                         statement->case_label.is_empty_range = true;
8871                                         warningf(WARN_OTHER, pos, "empty range specified");
8872                                 }
8873                         }
8874                 }
8875         }
8876
8877         PUSH_PARENT(statement);
8878
8879         rem_anchor_token(':');
8880         expect(':');
8881
8882         if (current_switch != NULL) {
8883                 if (! statement->case_label.is_bad) {
8884                         /* Check for duplicate case values */
8885                         case_label_statement_t *c = &statement->case_label;
8886                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8887                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8888                                         continue;
8889
8890                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8891                                         continue;
8892
8893                                 errorf(pos, "duplicate case value (previously used %P)",
8894                                        &l->base.source_position);
8895                                 break;
8896                         }
8897                 }
8898                 /* link all cases into the switch statement */
8899                 if (current_switch->last_case == NULL) {
8900                         current_switch->first_case      = &statement->case_label;
8901                 } else {
8902                         current_switch->last_case->next = &statement->case_label;
8903                 }
8904                 current_switch->last_case = &statement->case_label;
8905         } else {
8906                 errorf(pos, "case label not within a switch statement");
8907         }
8908
8909         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8910
8911         POP_PARENT();
8912         return statement;
8913 }
8914
8915 /**
8916  * Parse a default statement.
8917  */
8918 static statement_t *parse_default_statement(void)
8919 {
8920         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8921
8922         eat(T_default);
8923
8924         PUSH_PARENT(statement);
8925
8926         expect(':');
8927
8928         if (current_switch != NULL) {
8929                 const case_label_statement_t *def_label = current_switch->default_label;
8930                 if (def_label != NULL) {
8931                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8932                 } else {
8933                         current_switch->default_label = &statement->case_label;
8934
8935                         /* link all cases into the switch statement */
8936                         if (current_switch->last_case == NULL) {
8937                                 current_switch->first_case      = &statement->case_label;
8938                         } else {
8939                                 current_switch->last_case->next = &statement->case_label;
8940                         }
8941                         current_switch->last_case = &statement->case_label;
8942                 }
8943         } else {
8944                 errorf(&statement->base.source_position,
8945                         "'default' label not within a switch statement");
8946         }
8947
8948         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8949
8950         POP_PARENT();
8951         return statement;
8952 }
8953
8954 /**
8955  * Parse a label statement.
8956  */
8957 static statement_t *parse_label_statement(void)
8958 {
8959         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8960         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8961         statement->label.label = label;
8962
8963         PUSH_PARENT(statement);
8964
8965         /* if statement is already set then the label is defined twice,
8966          * otherwise it was just mentioned in a goto/local label declaration so far
8967          */
8968         source_position_t const* const pos = &statement->base.source_position;
8969         if (label->statement != NULL) {
8970                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8971         } else {
8972                 label->base.source_position = *pos;
8973                 label->statement            = statement;
8974         }
8975
8976         eat(':');
8977
8978         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8979                 parse_attributes(NULL); // TODO process attributes
8980         }
8981
8982         statement->label.statement = parse_label_inner_statement(statement, "label");
8983
8984         /* remember the labels in a list for later checking */
8985         *label_anchor = &statement->label;
8986         label_anchor  = &statement->label.next;
8987
8988         POP_PARENT();
8989         return statement;
8990 }
8991
8992 static statement_t *parse_inner_statement(void)
8993 {
8994         statement_t *const stmt = parse_statement();
8995         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8996         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8997         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8998                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
8999         }
9000         return stmt;
9001 }
9002
9003 /**
9004  * Parse an expression in parentheses and mark its variables as read.
9005  */
9006 static expression_t *parse_condition(void)
9007 {
9008         add_anchor_token(')');
9009         expect('(');
9010         expression_t *const expr = parse_expression();
9011         mark_vars_read(expr, NULL);
9012         rem_anchor_token(')');
9013         expect(')');
9014         return expr;
9015 }
9016
9017 /**
9018  * Parse an if statement.
9019  */
9020 static statement_t *parse_if(void)
9021 {
9022         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9023
9024         eat(T_if);
9025
9026         PUSH_PARENT(statement);
9027         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9028
9029         add_anchor_token(T_else);
9030
9031         expression_t *const expr = parse_condition();
9032         statement->ifs.condition = expr;
9033         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9034          *             scalar type. */
9035         semantic_condition(expr, "condition of 'if'-statment");
9036
9037         statement_t *const true_stmt = parse_inner_statement();
9038         statement->ifs.true_statement = true_stmt;
9039         rem_anchor_token(T_else);
9040
9041         if (true_stmt->kind == STATEMENT_EMPTY) {
9042                 warningf(WARN_EMPTY_BODY, HERE,
9043                         "suggest braces around empty body in an ‘if’ statement");
9044         }
9045
9046         if (next_if(T_else)) {
9047                 statement->ifs.false_statement = parse_inner_statement();
9048
9049                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9050                         warningf(WARN_EMPTY_BODY, HERE,
9051                                         "suggest braces around empty body in an ‘if’ statement");
9052                 }
9053         } else if (true_stmt->kind == STATEMENT_IF &&
9054                         true_stmt->ifs.false_statement != NULL) {
9055                 source_position_t const *const pos = &true_stmt->base.source_position;
9056                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9057         }
9058
9059         POP_SCOPE();
9060         POP_PARENT();
9061         return statement;
9062 }
9063
9064 /**
9065  * Check that all enums are handled in a switch.
9066  *
9067  * @param statement  the switch statement to check
9068  */
9069 static void check_enum_cases(const switch_statement_t *statement)
9070 {
9071         if (!is_warn_on(WARN_SWITCH_ENUM))
9072                 return;
9073         const type_t *type = skip_typeref(statement->expression->base.type);
9074         if (! is_type_enum(type))
9075                 return;
9076         const enum_type_t *enumt = &type->enumt;
9077
9078         /* if we have a default, no warnings */
9079         if (statement->default_label != NULL)
9080                 return;
9081
9082         /* FIXME: calculation of value should be done while parsing */
9083         /* TODO: quadratic algorithm here. Change to an n log n one */
9084         long            last_value = -1;
9085         const entity_t *entry      = enumt->enume->base.next;
9086         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9087              entry = entry->base.next) {
9088                 const expression_t *expression = entry->enum_value.value;
9089                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9090                 bool                found      = false;
9091                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9092                         if (l->expression == NULL)
9093                                 continue;
9094                         if (l->first_case <= value && value <= l->last_case) {
9095                                 found = true;
9096                                 break;
9097                         }
9098                 }
9099                 if (!found) {
9100                         source_position_t const *const pos = &statement->base.source_position;
9101                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9102                 }
9103                 last_value = value;
9104         }
9105 }
9106
9107 /**
9108  * Parse a switch statement.
9109  */
9110 static statement_t *parse_switch(void)
9111 {
9112         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9113
9114         eat(T_switch);
9115
9116         PUSH_PARENT(statement);
9117         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9118
9119         expression_t *const expr = parse_condition();
9120         type_t       *      type = skip_typeref(expr->base.type);
9121         if (is_type_integer(type)) {
9122                 type = promote_integer(type);
9123                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9124                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9125                 }
9126         } else if (is_type_valid(type)) {
9127                 errorf(&expr->base.source_position,
9128                        "switch quantity is not an integer, but '%T'", type);
9129                 type = type_error_type;
9130         }
9131         statement->switchs.expression = create_implicit_cast(expr, type);
9132
9133         switch_statement_t *rem = current_switch;
9134         current_switch          = &statement->switchs;
9135         statement->switchs.body = parse_inner_statement();
9136         current_switch          = rem;
9137
9138         if (statement->switchs.default_label == NULL) {
9139                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9140         }
9141         check_enum_cases(&statement->switchs);
9142
9143         POP_SCOPE();
9144         POP_PARENT();
9145         return statement;
9146 }
9147
9148 static statement_t *parse_loop_body(statement_t *const loop)
9149 {
9150         statement_t *const rem = current_loop;
9151         current_loop = loop;
9152
9153         statement_t *const body = parse_inner_statement();
9154
9155         current_loop = rem;
9156         return body;
9157 }
9158
9159 /**
9160  * Parse a while statement.
9161  */
9162 static statement_t *parse_while(void)
9163 {
9164         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9165
9166         eat(T_while);
9167
9168         PUSH_PARENT(statement);
9169         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9170
9171         expression_t *const cond = parse_condition();
9172         statement->fors.condition = cond;
9173         /* §6.8.5:2    The controlling expression of an iteration statement shall
9174          *             have scalar type. */
9175         semantic_condition(cond, "condition of 'while'-statement");
9176
9177         statement->fors.body = parse_loop_body(statement);
9178
9179         POP_SCOPE();
9180         POP_PARENT();
9181         return statement;
9182 }
9183
9184 /**
9185  * Parse a do statement.
9186  */
9187 static statement_t *parse_do(void)
9188 {
9189         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9190
9191         eat(T_do);
9192
9193         PUSH_PARENT(statement);
9194         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9195
9196         add_anchor_token(T_while);
9197         statement->do_while.body = parse_loop_body(statement);
9198         rem_anchor_token(T_while);
9199
9200         expect(T_while);
9201         expression_t *const cond = parse_condition();
9202         statement->do_while.condition = cond;
9203         /* §6.8.5:2    The controlling expression of an iteration statement shall
9204          *             have scalar type. */
9205         semantic_condition(cond, "condition of 'do-while'-statement");
9206         expect(';');
9207
9208         POP_SCOPE();
9209         POP_PARENT();
9210         return statement;
9211 }
9212
9213 /**
9214  * Parse a for statement.
9215  */
9216 static statement_t *parse_for(void)
9217 {
9218         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9219
9220         eat(T_for);
9221
9222         PUSH_PARENT(statement);
9223         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9224
9225         add_anchor_token(')');
9226         expect('(');
9227
9228         PUSH_EXTENSION();
9229
9230         if (next_if(';')) {
9231         } else if (is_declaration_specifier(&token)) {
9232                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9233         } else {
9234                 add_anchor_token(';');
9235                 expression_t *const init = parse_expression();
9236                 statement->fors.initialisation = init;
9237                 mark_vars_read(init, ENT_ANY);
9238                 if (!expression_has_effect(init)) {
9239                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9240                 }
9241                 rem_anchor_token(';');
9242                 expect(';');
9243         }
9244
9245         POP_EXTENSION();
9246
9247         if (token.kind != ';') {
9248                 add_anchor_token(';');
9249                 expression_t *const cond = parse_expression();
9250                 statement->fors.condition = cond;
9251                 /* §6.8.5:2    The controlling expression of an iteration statement
9252                  *             shall have scalar type. */
9253                 semantic_condition(cond, "condition of 'for'-statement");
9254                 mark_vars_read(cond, NULL);
9255                 rem_anchor_token(';');
9256         }
9257         expect(';');
9258         if (token.kind != ')') {
9259                 expression_t *const step = parse_expression();
9260                 statement->fors.step = step;
9261                 mark_vars_read(step, ENT_ANY);
9262                 if (!expression_has_effect(step)) {
9263                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9264                 }
9265         }
9266         rem_anchor_token(')');
9267         expect(')');
9268         statement->fors.body = parse_loop_body(statement);
9269
9270         POP_SCOPE();
9271         POP_PARENT();
9272         return statement;
9273 }
9274
9275 /**
9276  * Parse a goto statement.
9277  */
9278 static statement_t *parse_goto(void)
9279 {
9280         statement_t *statement;
9281         if (GNU_MODE && look_ahead(1)->kind == '*') {
9282                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9283                 eat(T_goto);
9284                 eat('*');
9285
9286                 expression_t *expression = parse_expression();
9287                 mark_vars_read(expression, NULL);
9288
9289                 /* Argh: although documentation says the expression must be of type void*,
9290                  * gcc accepts anything that can be casted into void* without error */
9291                 type_t *type = expression->base.type;
9292
9293                 if (type != type_error_type) {
9294                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9295                                 errorf(&expression->base.source_position,
9296                                         "cannot convert to a pointer type");
9297                         } else if (type != type_void_ptr) {
9298                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9299                         }
9300                         expression = create_implicit_cast(expression, type_void_ptr);
9301                 }
9302
9303                 statement->computed_goto.expression = expression;
9304         } else {
9305                 statement = allocate_statement_zero(STATEMENT_GOTO);
9306                 eat(T_goto);
9307
9308                 label_t *const label = get_label("while parsing goto");
9309                 if (label) {
9310                         label->used            = true;
9311                         statement->gotos.label = label;
9312
9313                         /* remember the goto's in a list for later checking */
9314                         *goto_anchor = &statement->gotos;
9315                         goto_anchor  = &statement->gotos.next;
9316                 } else {
9317                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9318                 }
9319         }
9320
9321         expect(';');
9322         return statement;
9323 }
9324
9325 /**
9326  * Parse a continue statement.
9327  */
9328 static statement_t *parse_continue(void)
9329 {
9330         if (current_loop == NULL) {
9331                 errorf(HERE, "continue statement not within loop");
9332         }
9333
9334         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9335
9336         eat(T_continue);
9337         expect(';');
9338         return statement;
9339 }
9340
9341 /**
9342  * Parse a break statement.
9343  */
9344 static statement_t *parse_break(void)
9345 {
9346         if (current_switch == NULL && current_loop == NULL) {
9347                 errorf(HERE, "break statement not within loop or switch");
9348         }
9349
9350         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9351
9352         eat(T_break);
9353         expect(';');
9354         return statement;
9355 }
9356
9357 /**
9358  * Parse a __leave statement.
9359  */
9360 static statement_t *parse_leave_statement(void)
9361 {
9362         if (current_try == NULL) {
9363                 errorf(HERE, "__leave statement not within __try");
9364         }
9365
9366         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9367
9368         eat(T___leave);
9369         expect(';');
9370         return statement;
9371 }
9372
9373 /**
9374  * Check if a given entity represents a local variable.
9375  */
9376 static bool is_local_variable(const entity_t *entity)
9377 {
9378         if (entity->kind != ENTITY_VARIABLE)
9379                 return false;
9380
9381         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9382         case STORAGE_CLASS_AUTO:
9383         case STORAGE_CLASS_REGISTER: {
9384                 const type_t *type = skip_typeref(entity->declaration.type);
9385                 if (is_type_function(type)) {
9386                         return false;
9387                 } else {
9388                         return true;
9389                 }
9390         }
9391         default:
9392                 return false;
9393         }
9394 }
9395
9396 /**
9397  * Check if a given expression represents a local variable.
9398  */
9399 static bool expression_is_local_variable(const expression_t *expression)
9400 {
9401         if (expression->base.kind != EXPR_REFERENCE) {
9402                 return false;
9403         }
9404         const entity_t *entity = expression->reference.entity;
9405         return is_local_variable(entity);
9406 }
9407
9408 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9409 {
9410         if (c_mode & _CXX || strict_mode) {
9411                 errorf(pos, msg);
9412         } else {
9413                 warningf(WARN_OTHER, pos, msg);
9414         }
9415 }
9416
9417 /**
9418  * Parse a return statement.
9419  */
9420 static statement_t *parse_return(void)
9421 {
9422         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9423         eat(T_return);
9424
9425         expression_t *return_value = NULL;
9426         if (token.kind != ';') {
9427                 return_value = parse_expression();
9428                 mark_vars_read(return_value, NULL);
9429         }
9430
9431         const type_t *const func_type = skip_typeref(current_function->base.type);
9432         assert(is_type_function(func_type));
9433         type_t *const return_type = skip_typeref(func_type->function.return_type);
9434
9435         source_position_t const *const pos = &statement->base.source_position;
9436         if (return_value != NULL) {
9437                 type_t *return_value_type = skip_typeref(return_value->base.type);
9438
9439                 if (is_type_void(return_type)) {
9440                         if (!is_type_void(return_value_type)) {
9441                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9442                                 /* Only warn in C mode, because GCC does the same */
9443                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9444                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9445                                 /* Only warn in C mode, because GCC does the same */
9446                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9447                         }
9448                 } else {
9449                         assign_error_t error = semantic_assign(return_type, return_value);
9450                         report_assign_error(error, return_type, return_value, "'return'",
9451                                             pos);
9452                 }
9453                 return_value = create_implicit_cast(return_value, return_type);
9454                 /* check for returning address of a local var */
9455                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9456                         const expression_t *expression = return_value->unary.value;
9457                         if (expression_is_local_variable(expression)) {
9458                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9459                         }
9460                 }
9461         } else if (!is_type_void(return_type)) {
9462                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9463                 err_or_warn(pos, "'return' without value, in function returning non-void");
9464         }
9465         statement->returns.value = return_value;
9466
9467         expect(';');
9468         return statement;
9469 }
9470
9471 /**
9472  * Parse a declaration statement.
9473  */
9474 static statement_t *parse_declaration_statement(void)
9475 {
9476         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9477
9478         entity_t *before = current_scope->last_entity;
9479         if (GNU_MODE) {
9480                 parse_external_declaration();
9481         } else {
9482                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9483         }
9484
9485         declaration_statement_t *const decl  = &statement->declaration;
9486         entity_t                *const begin =
9487                 before != NULL ? before->base.next : current_scope->entities;
9488         decl->declarations_begin = begin;
9489         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9490
9491         return statement;
9492 }
9493
9494 /**
9495  * Parse an expression statement, ie. expr ';'.
9496  */
9497 static statement_t *parse_expression_statement(void)
9498 {
9499         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9500
9501         expression_t *const expr         = parse_expression();
9502         statement->expression.expression = expr;
9503         mark_vars_read(expr, ENT_ANY);
9504
9505         expect(';');
9506         return statement;
9507 }
9508
9509 /**
9510  * Parse a microsoft __try { } __finally { } or
9511  * __try{ } __except() { }
9512  */
9513 static statement_t *parse_ms_try_statment(void)
9514 {
9515         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9516         eat(T___try);
9517
9518         PUSH_PARENT(statement);
9519
9520         ms_try_statement_t *rem = current_try;
9521         current_try = &statement->ms_try;
9522         statement->ms_try.try_statement = parse_compound_statement(false);
9523         current_try = rem;
9524
9525         POP_PARENT();
9526
9527         if (next_if(T___except)) {
9528                 expression_t *const expr = parse_condition();
9529                 type_t       *      type = skip_typeref(expr->base.type);
9530                 if (is_type_integer(type)) {
9531                         type = promote_integer(type);
9532                 } else if (is_type_valid(type)) {
9533                         errorf(&expr->base.source_position,
9534                                "__expect expression is not an integer, but '%T'", type);
9535                         type = type_error_type;
9536                 }
9537                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9538         } else if (!next_if(T__finally)) {
9539                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9540         }
9541         statement->ms_try.final_statement = parse_compound_statement(false);
9542         return statement;
9543 }
9544
9545 static statement_t *parse_empty_statement(void)
9546 {
9547         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9548         statement_t *const statement = create_empty_statement();
9549         eat(';');
9550         return statement;
9551 }
9552
9553 static statement_t *parse_local_label_declaration(void)
9554 {
9555         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9556
9557         eat(T___label__);
9558
9559         entity_t *begin   = NULL;
9560         entity_t *end     = NULL;
9561         entity_t **anchor = &begin;
9562         add_anchor_token(';');
9563         add_anchor_token(',');
9564         do {
9565                 source_position_t pos;
9566                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9567                 if (symbol) {
9568                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9569                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9570                                 source_position_t const *const ppos = &entity->base.source_position;
9571                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9572                         } else {
9573                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9574                                 entity->base.parent_scope = current_scope;
9575
9576                                 *anchor = entity;
9577                                 anchor  = &entity->base.next;
9578                                 end     = entity;
9579
9580                                 environment_push(entity);
9581                         }
9582                 }
9583         } while (next_if(','));
9584         rem_anchor_token(',');
9585         rem_anchor_token(';');
9586         expect(';');
9587         statement->declaration.declarations_begin = begin;
9588         statement->declaration.declarations_end   = end;
9589         return statement;
9590 }
9591
9592 static void parse_namespace_definition(void)
9593 {
9594         eat(T_namespace);
9595
9596         entity_t *entity = NULL;
9597         symbol_t *symbol = NULL;
9598
9599         if (token.kind == T_IDENTIFIER) {
9600                 symbol = token.base.symbol;
9601                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9602                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9603                         entity = NULL;
9604                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9605                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9606                         }
9607                 }
9608                 eat(T_IDENTIFIER);
9609         }
9610
9611         if (entity == NULL) {
9612                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9613                 entity->base.parent_scope = current_scope;
9614         }
9615
9616         if (token.kind == '=') {
9617                 /* TODO: parse namespace alias */
9618                 panic("namespace alias definition not supported yet");
9619         }
9620
9621         environment_push(entity);
9622         append_entity(current_scope, entity);
9623
9624         PUSH_SCOPE(&entity->namespacee.members);
9625         PUSH_CURRENT_ENTITY(entity);
9626
9627         add_anchor_token('}');
9628         expect('{');
9629         parse_externals();
9630         rem_anchor_token('}');
9631         expect('}');
9632
9633         POP_CURRENT_ENTITY();
9634         POP_SCOPE();
9635 }
9636
9637 /**
9638  * Parse a statement.
9639  * There's also parse_statement() which additionally checks for
9640  * "statement has no effect" warnings
9641  */
9642 static statement_t *intern_parse_statement(void)
9643 {
9644         /* declaration or statement */
9645         statement_t *statement;
9646         switch (token.kind) {
9647         case T_IDENTIFIER: {
9648                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9649                 if (la1_type == ':') {
9650                         statement = parse_label_statement();
9651                 } else if (is_typedef_symbol(token.base.symbol)) {
9652                         statement = parse_declaration_statement();
9653                 } else {
9654                         /* it's an identifier, the grammar says this must be an
9655                          * expression statement. However it is common that users mistype
9656                          * declaration types, so we guess a bit here to improve robustness
9657                          * for incorrect programs */
9658                         switch (la1_type) {
9659                         case '&':
9660                         case '*':
9661                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9662                         default:
9663                                         statement = parse_expression_statement();
9664                                 } else {
9665                         DECLARATION_START
9666                         case T_IDENTIFIER:
9667                                         statement = parse_declaration_statement();
9668                                 }
9669                                 break;
9670                         }
9671                 }
9672                 break;
9673         }
9674
9675         case T___extension__: {
9676                 /* This can be a prefix to a declaration or an expression statement.
9677                  * We simply eat it now and parse the rest with tail recursion. */
9678                 PUSH_EXTENSION();
9679                 statement = intern_parse_statement();
9680                 POP_EXTENSION();
9681                 break;
9682         }
9683
9684         DECLARATION_START
9685                 statement = parse_declaration_statement();
9686                 break;
9687
9688         case T___label__:
9689                 statement = parse_local_label_declaration();
9690                 break;
9691
9692         case ';':         statement = parse_empty_statement();         break;
9693         case '{':         statement = parse_compound_statement(false); break;
9694         case T___leave:   statement = parse_leave_statement();         break;
9695         case T___try:     statement = parse_ms_try_statment();         break;
9696         case T_asm:       statement = parse_asm_statement();           break;
9697         case T_break:     statement = parse_break();                   break;
9698         case T_case:      statement = parse_case_statement();          break;
9699         case T_continue:  statement = parse_continue();                break;
9700         case T_default:   statement = parse_default_statement();       break;
9701         case T_do:        statement = parse_do();                      break;
9702         case T_for:       statement = parse_for();                     break;
9703         case T_goto:      statement = parse_goto();                    break;
9704         case T_if:        statement = parse_if();                      break;
9705         case T_return:    statement = parse_return();                  break;
9706         case T_switch:    statement = parse_switch();                  break;
9707         case T_while:     statement = parse_while();                   break;
9708
9709         EXPRESSION_START
9710                 statement = parse_expression_statement();
9711                 break;
9712
9713         default:
9714                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9715                 statement = create_error_statement();
9716                 eat_until_anchor();
9717                 break;
9718         }
9719
9720         return statement;
9721 }
9722
9723 /**
9724  * parse a statement and emits "statement has no effect" warning if needed
9725  * (This is really a wrapper around intern_parse_statement with check for 1
9726  *  single warning. It is needed, because for statement expressions we have
9727  *  to avoid the warning on the last statement)
9728  */
9729 static statement_t *parse_statement(void)
9730 {
9731         statement_t *statement = intern_parse_statement();
9732
9733         if (statement->kind == STATEMENT_EXPRESSION) {
9734                 expression_t *expression = statement->expression.expression;
9735                 if (!expression_has_effect(expression)) {
9736                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9737                 }
9738         }
9739
9740         return statement;
9741 }
9742
9743 /**
9744  * Parse a compound statement.
9745  */
9746 static statement_t *parse_compound_statement(bool inside_expression_statement)
9747 {
9748         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9749
9750         PUSH_PARENT(statement);
9751         PUSH_SCOPE(&statement->compound.scope);
9752
9753         eat('{');
9754         add_anchor_token('}');
9755         /* tokens, which can start a statement */
9756         /* TODO MS, __builtin_FOO */
9757         add_anchor_token('!');
9758         add_anchor_token('&');
9759         add_anchor_token('(');
9760         add_anchor_token('*');
9761         add_anchor_token('+');
9762         add_anchor_token('-');
9763         add_anchor_token(';');
9764         add_anchor_token('{');
9765         add_anchor_token('~');
9766         add_anchor_token(T_CHARACTER_CONSTANT);
9767         add_anchor_token(T_COLONCOLON);
9768         add_anchor_token(T_IDENTIFIER);
9769         add_anchor_token(T_MINUSMINUS);
9770         add_anchor_token(T_NUMBER);
9771         add_anchor_token(T_PLUSPLUS);
9772         add_anchor_token(T_STRING_LITERAL);
9773         add_anchor_token(T__Alignof);
9774         add_anchor_token(T__Bool);
9775         add_anchor_token(T__Complex);
9776         add_anchor_token(T__Imaginary);
9777         add_anchor_token(T__Thread_local);
9778         add_anchor_token(T___PRETTY_FUNCTION__);
9779         add_anchor_token(T___attribute__);
9780         add_anchor_token(T___builtin_va_start);
9781         add_anchor_token(T___extension__);
9782         add_anchor_token(T___func__);
9783         add_anchor_token(T___imag__);
9784         add_anchor_token(T___label__);
9785         add_anchor_token(T___real__);
9786         add_anchor_token(T_asm);
9787         add_anchor_token(T_auto);
9788         add_anchor_token(T_bool);
9789         add_anchor_token(T_break);
9790         add_anchor_token(T_case);
9791         add_anchor_token(T_char);
9792         add_anchor_token(T_class);
9793         add_anchor_token(T_const);
9794         add_anchor_token(T_const_cast);
9795         add_anchor_token(T_continue);
9796         add_anchor_token(T_default);
9797         add_anchor_token(T_delete);
9798         add_anchor_token(T_double);
9799         add_anchor_token(T_do);
9800         add_anchor_token(T_dynamic_cast);
9801         add_anchor_token(T_enum);
9802         add_anchor_token(T_extern);
9803         add_anchor_token(T_false);
9804         add_anchor_token(T_float);
9805         add_anchor_token(T_for);
9806         add_anchor_token(T_goto);
9807         add_anchor_token(T_if);
9808         add_anchor_token(T_inline);
9809         add_anchor_token(T_int);
9810         add_anchor_token(T_long);
9811         add_anchor_token(T_new);
9812         add_anchor_token(T_operator);
9813         add_anchor_token(T_register);
9814         add_anchor_token(T_reinterpret_cast);
9815         add_anchor_token(T_restrict);
9816         add_anchor_token(T_return);
9817         add_anchor_token(T_short);
9818         add_anchor_token(T_signed);
9819         add_anchor_token(T_sizeof);
9820         add_anchor_token(T_static);
9821         add_anchor_token(T_static_cast);
9822         add_anchor_token(T_struct);
9823         add_anchor_token(T_switch);
9824         add_anchor_token(T_template);
9825         add_anchor_token(T_this);
9826         add_anchor_token(T_throw);
9827         add_anchor_token(T_true);
9828         add_anchor_token(T_try);
9829         add_anchor_token(T_typedef);
9830         add_anchor_token(T_typeid);
9831         add_anchor_token(T_typename);
9832         add_anchor_token(T_typeof);
9833         add_anchor_token(T_union);
9834         add_anchor_token(T_unsigned);
9835         add_anchor_token(T_using);
9836         add_anchor_token(T_void);
9837         add_anchor_token(T_volatile);
9838         add_anchor_token(T_wchar_t);
9839         add_anchor_token(T_while);
9840
9841         statement_t **anchor            = &statement->compound.statements;
9842         bool          only_decls_so_far = true;
9843         while (token.kind != '}' && token.kind != T_EOF) {
9844                 statement_t *sub_statement = intern_parse_statement();
9845                 if (sub_statement->kind == STATEMENT_ERROR) {
9846                         break;
9847                 }
9848
9849                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9850                         only_decls_so_far = false;
9851                 } else if (!only_decls_so_far) {
9852                         source_position_t const *const pos = &sub_statement->base.source_position;
9853                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9854                 }
9855
9856                 *anchor = sub_statement;
9857                 anchor  = &sub_statement->base.next;
9858         }
9859         expect('}');
9860
9861         /* look over all statements again to produce no effect warnings */
9862         if (is_warn_on(WARN_UNUSED_VALUE)) {
9863                 statement_t *sub_statement = statement->compound.statements;
9864                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9865                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9866                                 continue;
9867                         /* don't emit a warning for the last expression in an expression
9868                          * statement as it has always an effect */
9869                         if (inside_expression_statement && sub_statement->base.next == NULL)
9870                                 continue;
9871
9872                         expression_t *expression = sub_statement->expression.expression;
9873                         if (!expression_has_effect(expression)) {
9874                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9875                         }
9876                 }
9877         }
9878
9879         rem_anchor_token(T_while);
9880         rem_anchor_token(T_wchar_t);
9881         rem_anchor_token(T_volatile);
9882         rem_anchor_token(T_void);
9883         rem_anchor_token(T_using);
9884         rem_anchor_token(T_unsigned);
9885         rem_anchor_token(T_union);
9886         rem_anchor_token(T_typeof);
9887         rem_anchor_token(T_typename);
9888         rem_anchor_token(T_typeid);
9889         rem_anchor_token(T_typedef);
9890         rem_anchor_token(T_try);
9891         rem_anchor_token(T_true);
9892         rem_anchor_token(T_throw);
9893         rem_anchor_token(T_this);
9894         rem_anchor_token(T_template);
9895         rem_anchor_token(T_switch);
9896         rem_anchor_token(T_struct);
9897         rem_anchor_token(T_static_cast);
9898         rem_anchor_token(T_static);
9899         rem_anchor_token(T_sizeof);
9900         rem_anchor_token(T_signed);
9901         rem_anchor_token(T_short);
9902         rem_anchor_token(T_return);
9903         rem_anchor_token(T_restrict);
9904         rem_anchor_token(T_reinterpret_cast);
9905         rem_anchor_token(T_register);
9906         rem_anchor_token(T_operator);
9907         rem_anchor_token(T_new);
9908         rem_anchor_token(T_long);
9909         rem_anchor_token(T_int);
9910         rem_anchor_token(T_inline);
9911         rem_anchor_token(T_if);
9912         rem_anchor_token(T_goto);
9913         rem_anchor_token(T_for);
9914         rem_anchor_token(T_float);
9915         rem_anchor_token(T_false);
9916         rem_anchor_token(T_extern);
9917         rem_anchor_token(T_enum);
9918         rem_anchor_token(T_dynamic_cast);
9919         rem_anchor_token(T_do);
9920         rem_anchor_token(T_double);
9921         rem_anchor_token(T_delete);
9922         rem_anchor_token(T_default);
9923         rem_anchor_token(T_continue);
9924         rem_anchor_token(T_const_cast);
9925         rem_anchor_token(T_const);
9926         rem_anchor_token(T_class);
9927         rem_anchor_token(T_char);
9928         rem_anchor_token(T_case);
9929         rem_anchor_token(T_break);
9930         rem_anchor_token(T_bool);
9931         rem_anchor_token(T_auto);
9932         rem_anchor_token(T_asm);
9933         rem_anchor_token(T___real__);
9934         rem_anchor_token(T___label__);
9935         rem_anchor_token(T___imag__);
9936         rem_anchor_token(T___func__);
9937         rem_anchor_token(T___extension__);
9938         rem_anchor_token(T___builtin_va_start);
9939         rem_anchor_token(T___attribute__);
9940         rem_anchor_token(T___PRETTY_FUNCTION__);
9941         rem_anchor_token(T__Thread_local);
9942         rem_anchor_token(T__Imaginary);
9943         rem_anchor_token(T__Complex);
9944         rem_anchor_token(T__Bool);
9945         rem_anchor_token(T__Alignof);
9946         rem_anchor_token(T_STRING_LITERAL);
9947         rem_anchor_token(T_PLUSPLUS);
9948         rem_anchor_token(T_NUMBER);
9949         rem_anchor_token(T_MINUSMINUS);
9950         rem_anchor_token(T_IDENTIFIER);
9951         rem_anchor_token(T_COLONCOLON);
9952         rem_anchor_token(T_CHARACTER_CONSTANT);
9953         rem_anchor_token('~');
9954         rem_anchor_token('{');
9955         rem_anchor_token(';');
9956         rem_anchor_token('-');
9957         rem_anchor_token('+');
9958         rem_anchor_token('*');
9959         rem_anchor_token('(');
9960         rem_anchor_token('&');
9961         rem_anchor_token('!');
9962         rem_anchor_token('}');
9963
9964         POP_SCOPE();
9965         POP_PARENT();
9966         return statement;
9967 }
9968
9969 /**
9970  * Check for unused global static functions and variables
9971  */
9972 static void check_unused_globals(void)
9973 {
9974         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9975                 return;
9976
9977         for (const entity_t *entity = file_scope->entities; entity != NULL;
9978              entity = entity->base.next) {
9979                 if (!is_declaration(entity))
9980                         continue;
9981
9982                 const declaration_t *declaration = &entity->declaration;
9983                 if (declaration->used                  ||
9984                     declaration->modifiers & DM_UNUSED ||
9985                     declaration->modifiers & DM_USED   ||
9986                     declaration->storage_class != STORAGE_CLASS_STATIC)
9987                         continue;
9988
9989                 warning_t   why;
9990                 char const *s;
9991                 if (entity->kind == ENTITY_FUNCTION) {
9992                         /* inhibit warning for static inline functions */
9993                         if (entity->function.is_inline)
9994                                 continue;
9995
9996                         why = WARN_UNUSED_FUNCTION;
9997                         s   = entity->function.body != NULL ? "defined" : "declared";
9998                 } else {
9999                         why = WARN_UNUSED_VARIABLE;
10000                         s   = "defined";
10001                 }
10002
10003                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10004         }
10005 }
10006
10007 static void parse_global_asm(void)
10008 {
10009         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10010
10011         eat(T_asm);
10012         add_anchor_token(';');
10013         add_anchor_token(')');
10014         add_anchor_token(T_STRING_LITERAL);
10015         expect('(');
10016
10017         rem_anchor_token(T_STRING_LITERAL);
10018         statement->asms.asm_text = parse_string_literals("global asm");
10019         statement->base.next     = unit->global_asm;
10020         unit->global_asm         = statement;
10021
10022         rem_anchor_token(')');
10023         expect(')');
10024         rem_anchor_token(';');
10025         expect(';');
10026 }
10027
10028 static void parse_linkage_specification(void)
10029 {
10030         eat(T_extern);
10031
10032         source_position_t const pos     = *HERE;
10033         char const       *const linkage = parse_string_literals(NULL).begin;
10034
10035         linkage_kind_t old_linkage = current_linkage;
10036         linkage_kind_t new_linkage;
10037         if (streq(linkage, "C")) {
10038                 new_linkage = LINKAGE_C;
10039         } else if (streq(linkage, "C++")) {
10040                 new_linkage = LINKAGE_CXX;
10041         } else {
10042                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10043                 new_linkage = LINKAGE_C;
10044         }
10045         current_linkage = new_linkage;
10046
10047         if (next_if('{')) {
10048                 parse_externals();
10049                 expect('}');
10050         } else {
10051                 parse_external();
10052         }
10053
10054         assert(current_linkage == new_linkage);
10055         current_linkage = old_linkage;
10056 }
10057
10058 static void parse_external(void)
10059 {
10060         switch (token.kind) {
10061                 case T_extern:
10062                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10063                                 parse_linkage_specification();
10064                         } else {
10065                 DECLARATION_START_NO_EXTERN
10066                 case T_IDENTIFIER:
10067                 case T___extension__:
10068                 /* tokens below are for implicit int */
10069                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10070                               implicit int) */
10071                 case '*':  /* * x; -> int* x; */
10072                 case '(':  /* (x); -> int (x); */
10073                                 PUSH_EXTENSION();
10074                                 parse_external_declaration();
10075                                 POP_EXTENSION();
10076                         }
10077                         return;
10078
10079                 case T_asm:
10080                         parse_global_asm();
10081                         return;
10082
10083                 case T_namespace:
10084                         parse_namespace_definition();
10085                         return;
10086
10087                 case ';':
10088                         if (!strict_mode) {
10089                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10090                                 eat(';');
10091                                 return;
10092                         }
10093                         /* FALLTHROUGH */
10094
10095                 default:
10096                         errorf(HERE, "stray %K outside of function", &token);
10097                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10098                                 eat_until_matching_token(token.kind);
10099                         next_token();
10100                         return;
10101         }
10102 }
10103
10104 static void parse_externals(void)
10105 {
10106         add_anchor_token('}');
10107         add_anchor_token(T_EOF);
10108
10109 #ifndef NDEBUG
10110         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10111         unsigned short token_anchor_copy[T_LAST_TOKEN];
10112         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10113 #endif
10114
10115         while (token.kind != T_EOF && token.kind != '}') {
10116 #ifndef NDEBUG
10117                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10118                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10119                         if (count != 0) {
10120                                 /* the anchor set and its copy differs */
10121                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10122                         }
10123                 }
10124                 if (in_gcc_extension) {
10125                         /* an gcc extension scope was not closed */
10126                         internal_errorf(HERE, "Leaked __extension__");
10127                 }
10128 #endif
10129
10130                 parse_external();
10131         }
10132
10133         rem_anchor_token(T_EOF);
10134         rem_anchor_token('}');
10135 }
10136
10137 /**
10138  * Parse a translation unit.
10139  */
10140 static void parse_translation_unit(void)
10141 {
10142         add_anchor_token(T_EOF);
10143
10144         while (true) {
10145                 parse_externals();
10146
10147                 if (token.kind == T_EOF)
10148                         break;
10149
10150                 errorf(HERE, "stray %K outside of function", &token);
10151                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10152                         eat_until_matching_token(token.kind);
10153                 next_token();
10154         }
10155 }
10156
10157 void set_default_visibility(elf_visibility_tag_t visibility)
10158 {
10159         default_visibility = visibility;
10160 }
10161
10162 /**
10163  * Parse the input.
10164  *
10165  * @return  the translation unit or NULL if errors occurred.
10166  */
10167 void start_parsing(void)
10168 {
10169         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10170         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10171
10172         print_to_file(stderr);
10173
10174         assert(unit == NULL);
10175         unit = allocate_ast_zero(sizeof(unit[0]));
10176
10177         assert(file_scope == NULL);
10178         file_scope = &unit->scope;
10179
10180         assert(current_scope == NULL);
10181         scope_push(&unit->scope);
10182
10183         create_gnu_builtins();
10184         if (c_mode & _MS)
10185                 create_microsoft_intrinsics();
10186 }
10187
10188 translation_unit_t *finish_parsing(void)
10189 {
10190         assert(current_scope == &unit->scope);
10191         scope_pop(NULL);
10192
10193         assert(file_scope == &unit->scope);
10194         check_unused_globals();
10195         file_scope = NULL;
10196
10197         DEL_ARR_F(environment_stack);
10198         DEL_ARR_F(label_stack);
10199
10200         translation_unit_t *result = unit;
10201         unit = NULL;
10202         return result;
10203 }
10204
10205 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10206  * are given length one. */
10207 static void complete_incomplete_arrays(void)
10208 {
10209         size_t n = ARR_LEN(incomplete_arrays);
10210         for (size_t i = 0; i != n; ++i) {
10211                 declaration_t *const decl = incomplete_arrays[i];
10212                 type_t        *const type = skip_typeref(decl->type);
10213
10214                 if (!is_type_incomplete(type))
10215                         continue;
10216
10217                 source_position_t const *const pos = &decl->base.source_position;
10218                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10219
10220                 type_t *const new_type = duplicate_type(type);
10221                 new_type->array.size_constant     = true;
10222                 new_type->array.has_implicit_size = true;
10223                 new_type->array.size              = 1;
10224
10225                 type_t *const result = identify_new_type(new_type);
10226
10227                 decl->type = result;
10228         }
10229 }
10230
10231 static void prepare_main_collect2(entity_t *const entity)
10232 {
10233         PUSH_SCOPE(&entity->function.body->compound.scope);
10234
10235         // create call to __main
10236         symbol_t *symbol         = symbol_table_insert("__main");
10237         entity_t *subsubmain_ent
10238                 = create_implicit_function(symbol, &builtin_source_position);
10239
10240         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10241         type_t       *ftype       = subsubmain_ent->declaration.type;
10242         ref->base.source_position = builtin_source_position;
10243         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10244         ref->reference.entity     = subsubmain_ent;
10245
10246         expression_t *call = allocate_expression_zero(EXPR_CALL);
10247         call->base.source_position = builtin_source_position;
10248         call->base.type            = type_void;
10249         call->call.function        = ref;
10250
10251         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10252         expr_statement->base.source_position  = builtin_source_position;
10253         expr_statement->expression.expression = call;
10254
10255         statement_t *const body = entity->function.body;
10256         assert(body->kind == STATEMENT_COMPOUND);
10257         compound_statement_t *compounds = &body->compound;
10258
10259         expr_statement->base.next = compounds->statements;
10260         compounds->statements     = expr_statement;
10261
10262         POP_SCOPE();
10263 }
10264
10265 void parse(void)
10266 {
10267         lookahead_bufpos = 0;
10268         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10269                 next_token();
10270         }
10271         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10272         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10273         parse_translation_unit();
10274         complete_incomplete_arrays();
10275         DEL_ARR_F(incomplete_arrays);
10276         incomplete_arrays = NULL;
10277 }
10278
10279 /**
10280  * Initialize the parser.
10281  */
10282 void init_parser(void)
10283 {
10284         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10285
10286         init_expression_parsers();
10287         obstack_init(&temp_obst);
10288 }
10289
10290 /**
10291  * Terminate the parser.
10292  */
10293 void exit_parser(void)
10294 {
10295         obstack_free(&temp_obst, NULL);
10296 }