nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T___FUNCDNAME__:             \
 256         case T___FUNCSIG__:               \
 257         case T___PRETTY_FUNCTION__:       \
 258         case T___alignof__:               \
 259         case T___builtin_classify_type:   \
 260         case T___builtin_constant_p:      \
 261         case T___builtin_isgreater:       \
 262         case T___builtin_isgreaterequal:  \
 263         case T___builtin_isless:          \
 264         case T___builtin_islessequal:     \
 265         case T___builtin_islessgreater:   \
 266         case T___builtin_isunordered:     \
 267         case T___builtin_offsetof:        \
 268         case T___builtin_va_arg:          \
 269         case T___builtin_va_copy:         \
 270         case T___builtin_va_start:        \
 271         case T___func__:                  \
 272         case T___noop:                    \
 273         case T__assume:                   \
 274         case T_delete:                    \
 275         case T_false:                     \
 276         case T_sizeof:                    \
 277         case T_throw:                     \
 278         case T_true:
 279
 280 /**
 281  * Returns the size of a statement node.
 282  *
 283  * @param kind  the statement kind
 284  */
 285 static size_t get_statement_struct_size(statement_kind_t kind)
 286 {
 287         static const size_t sizes[] = {
 288                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 289                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 290                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 291                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 292                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 293                 [STATEMENT_IF]            = sizeof(if_statement_t),
 294                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 295                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 296                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 297                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 298                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 299                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 300                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 301                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 302                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 303                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 304                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 305                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 306                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 307                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 308         };
 309         assert((size_t)kind < lengthof(sizes));
 310         assert(sizes[kind] != 0);
 311         return sizes[kind];
 312 }
 313
 314 /**
 315  * Returns the size of an expression node.
 316  *
 317  * @param kind  the expression kind
 318  */
 319 static size_t get_expression_struct_size(expression_kind_t kind)
 320 {
 321         static const size_t sizes[] = {
 322                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 323                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 324                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 325                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 329                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 330                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 331                 [EXPR_CALL]                       = sizeof(call_expression_t),
 332                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 333                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 334                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 335                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 336                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 337                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 338                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 339                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 340                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 341                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 342                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 343                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 344                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 345                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 346                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 347                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 348                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 349         };
 350         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 351                 return sizes[EXPR_UNARY_FIRST];
 352         }
 353         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 354                 return sizes[EXPR_BINARY_FIRST];
 355         }
 356         assert((size_t)kind < lengthof(sizes));
 357         assert(sizes[kind] != 0);
 358         return sizes[kind];
 359 }
 360
 361 /**
 362  * Allocate a statement node of given kind and initialize all
 363  * fields with zero. Sets its source position to the position
 364  * of the current token.
 365  */
 366 static statement_t *allocate_statement_zero(statement_kind_t kind)
 367 {
 368         size_t       size = get_statement_struct_size(kind);
 369         statement_t *res  = allocate_ast_zero(size);
 370
 371         res->base.kind            = kind;
 372         res->base.parent          = current_parent;
 373         res->base.source_position = *HERE;
 374         return res;
 375 }
 376
 377 /**
 378  * Allocate an expression node of given kind and initialize all
 379  * fields with zero.
 380  *
 381  * @param kind  the kind of the expression to allocate
 382  */
 383 static expression_t *allocate_expression_zero(expression_kind_t kind)
 384 {
 385         size_t        size = get_expression_struct_size(kind);
 386         expression_t *res  = allocate_ast_zero(size);
 387
 388         res->base.kind            = kind;
 389         res->base.type            = type_error_type;
 390         res->base.source_position = *HERE;
 391         return res;
 392 }
 393
 394 /**
 395  * Creates a new invalid expression at the source position
 396  * of the current token.
 397  */
 398 static expression_t *create_error_expression(void)
 399 {
 400         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 401         expression->base.type = type_error_type;
 402         return expression;
 403 }
 404
 405 /**
 406  * Creates a new invalid statement.
 407  */
 408 static statement_t *create_error_statement(void)
 409 {
 410         return allocate_statement_zero(STATEMENT_ERROR);
 411 }
 412
 413 /**
 414  * Allocate a new empty statement.
 415  */
 416 static statement_t *create_empty_statement(void)
 417 {
 418         return allocate_statement_zero(STATEMENT_EMPTY);
 419 }
 420
 421 /**
 422  * Returns the size of an initializer node.
 423  *
 424  * @param kind  the initializer kind
 425  */
 426 static size_t get_initializer_size(initializer_kind_t kind)
 427 {
 428         static const size_t sizes[] = {
 429                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 430                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 431                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 432                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 433                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 434         };
 435         assert((size_t)kind < lengthof(sizes));
 436         assert(sizes[kind] != 0);
 437         return sizes[kind];
 438 }
 439
 440 /**
 441  * Allocate an initializer node of given kind and initialize all
 442  * fields with zero.
 443  */
 444 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 445 {
 446         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 447         result->kind          = kind;
 448
 449         return result;
 450 }
 451
 452 /**
 453  * Returns the index of the top element of the environment stack.
 454  */
 455 static size_t environment_top(void)
 456 {
 457         return ARR_LEN(environment_stack);
 458 }
 459
 460 /**
 461  * Returns the index of the top element of the global label stack.
 462  */
 463 static size_t label_top(void)
 464 {
 465         return ARR_LEN(label_stack);
 466 }
 467
 468 /**
 469  * Return the next token.
 470  */
 471 static inline void next_token(void)
 472 {
 473         token                              = lookahead_buffer[lookahead_bufpos];
 474         lookahead_buffer[lookahead_bufpos] = lexer_token;
 475         lexer_next_token();
 476
 477         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 478
 479 #ifdef PRINT_TOKENS
 480         print_token(stderr, &token);
 481         fprintf(stderr, "\n");
 482 #endif
 483 }
 484
 485 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 486
 487 static inline bool next_if(token_kind_t const type)
 488 {
 489         if (token.kind == type) {
 490                 eat(type);
 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(void)
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 };
1048 }
1049
1050 static string_t concat_string_literals(string_encoding_t *const out_enc)
1051 {
1052         assert(token.kind == T_STRING_LITERAL);
1053
1054         string_t          result;
1055         string_encoding_t enc = token.string.encoding;
1056         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1057                 append_string(&token.string.string);
1058                 eat(T_STRING_LITERAL);
1059                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1060                 do {
1061                         if (token.string.encoding != STRING_ENCODING_CHAR) {
1062                                 enc = token.string.encoding;
1063                         }
1064                         append_string(&token.string.string);
1065                         eat(T_STRING_LITERAL);
1066                 } while (token.kind == T_STRING_LITERAL);
1067                 result = finish_string();
1068         } else {
1069                 result = token.string.string;
1070                 eat(T_STRING_LITERAL);
1071         }
1072
1073         *out_enc = enc;
1074         return result;
1075 }
1076
1077 static string_t parse_string_literals(char const *const context)
1078 {
1079         if (!skip_till(T_STRING_LITERAL, context))
1080                 return (string_t){ "", 0 };
1081
1082         string_encoding_t       enc;
1083         source_position_t const pos = *HERE;
1084         string_t          const res = concat_string_literals(&enc);
1085
1086         if (enc != STRING_ENCODING_CHAR) {
1087                 errorf(&pos, "expected plain string literal, got wide string literal");
1088         }
1089
1090         return res;
1091 }
1092
1093 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1094 {
1095         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1096         attribute->kind            = kind;
1097         attribute->source_position = *HERE;
1098         return attribute;
1099 }
1100
1101 /**
1102  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1103  *
1104  *  attribute:
1105  *    __attribute__ ( ( attribute-list ) )
1106  *
1107  *  attribute-list:
1108  *    attrib
1109  *    attribute_list , attrib
1110  *
1111  *  attrib:
1112  *    empty
1113  *    any-word
1114  *    any-word ( identifier )
1115  *    any-word ( identifier , nonempty-expr-list )
1116  *    any-word ( expr-list )
1117  *
1118  *  where the "identifier" must not be declared as a type, and
1119  *  "any-word" may be any identifier (including one declared as a
1120  *  type), a reserved word storage class specifier, type specifier or
1121  *  type qualifier.  ??? This still leaves out most reserved keywords
1122  *  (following the old parser), shouldn't we include them, and why not
1123  *  allow identifiers declared as types to start the arguments?
1124  *
1125  *  Matze: this all looks confusing and little systematic, so we're even less
1126  *  strict and parse any list of things which are identifiers or
1127  *  (assignment-)expressions.
1128  */
1129 static attribute_argument_t *parse_attribute_arguments(void)
1130 {
1131         attribute_argument_t  *first  = NULL;
1132         attribute_argument_t **anchor = &first;
1133         if (token.kind != ')') do {
1134                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1135
1136                 /* is it an identifier */
1137                 if (token.kind == T_IDENTIFIER
1138                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1139                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1140                         argument->v.symbol = token.base.symbol;
1141                         eat(T_IDENTIFIER);
1142                 } else {
1143                         /* must be an expression */
1144                         expression_t *expression = parse_assignment_expression();
1145
1146                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1147                         argument->v.expression = expression;
1148                 }
1149
1150                 /* append argument */
1151                 *anchor = argument;
1152                 anchor  = &argument->next;
1153         } while (next_if(','));
1154         expect(')');
1155         return first;
1156 }
1157
1158 static attribute_t *parse_attribute_asm(void)
1159 {
1160         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1161         eat(T_asm);
1162         expect('(');
1163         attribute->a.arguments = parse_attribute_arguments();
1164         return attribute;
1165 }
1166
1167 static attribute_t *parse_attribute_gnu_single(void)
1168 {
1169         /* parse "any-word" */
1170         symbol_t *const symbol = token.base.symbol;
1171         if (symbol == NULL) {
1172                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1173                 return NULL;
1174         }
1175
1176         attribute_kind_t  kind;
1177         char const *const name = symbol->string;
1178         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1179                 if (kind > ATTRIBUTE_GNU_LAST) {
1180                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1181                         /* TODO: we should still save the attribute in the list... */
1182                         kind = ATTRIBUTE_UNKNOWN;
1183                         break;
1184                 }
1185
1186                 const char *attribute_name = get_attribute_name(kind);
1187                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1188                         break;
1189         }
1190
1191         attribute_t *attribute = allocate_attribute_zero(kind);
1192         next_token();
1193
1194         /* parse arguments */
1195         if (next_if('('))
1196                 attribute->a.arguments = parse_attribute_arguments();
1197
1198         return attribute;
1199 }
1200
1201 static attribute_t *parse_attribute_gnu(void)
1202 {
1203         attribute_t  *first  = NULL;
1204         attribute_t **anchor = &first;
1205
1206         eat(T___attribute__);
1207         add_anchor_token(')');
1208         add_anchor_token(',');
1209         expect('(');
1210         expect('(');
1211
1212         if (token.kind != ')') do {
1213                 attribute_t *attribute = parse_attribute_gnu_single();
1214                 if (attribute) {
1215                         *anchor = attribute;
1216                         anchor  = &attribute->next;
1217                 }
1218         } while (next_if(','));
1219         rem_anchor_token(',');
1220         rem_anchor_token(')');
1221
1222         expect(')');
1223         expect(')');
1224         return first;
1225 }
1226
1227 /** Parse attributes. */
1228 static attribute_t *parse_attributes(attribute_t *first)
1229 {
1230         attribute_t **anchor = &first;
1231         for (;;) {
1232                 while (*anchor != NULL)
1233                         anchor = &(*anchor)->next;
1234
1235                 attribute_t *attribute;
1236                 switch (token.kind) {
1237                 case T___attribute__:
1238                         attribute = parse_attribute_gnu();
1239                         if (attribute == NULL)
1240                                 continue;
1241                         break;
1242
1243                 case T_asm:
1244                         attribute = parse_attribute_asm();
1245                         break;
1246
1247                 case T_cdecl:
1248                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1249                         eat(T_cdecl);
1250                         break;
1251
1252                 case T__fastcall:
1253                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1254                         eat(T__fastcall);
1255                         break;
1256
1257                 case T__forceinline:
1258                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1259                         eat(T__forceinline);
1260                         break;
1261
1262                 case T__stdcall:
1263                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1264                         eat(T__stdcall);
1265                         break;
1266
1267                 case T___thiscall:
1268                         /* TODO record modifier */
1269                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1270                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1271                         eat(T___thiscall);
1272                         break;
1273
1274                 default:
1275                         return first;
1276                 }
1277
1278                 *anchor = attribute;
1279                 anchor  = &attribute->next;
1280         }
1281 }
1282
1283 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1284
1285 static entity_t *determine_lhs_ent(expression_t *const expr,
1286                                    entity_t *lhs_ent)
1287 {
1288         switch (expr->kind) {
1289                 case EXPR_REFERENCE: {
1290                         entity_t *const entity = expr->reference.entity;
1291                         /* we should only find variables as lvalues... */
1292                         if (entity->base.kind != ENTITY_VARIABLE
1293                                         && entity->base.kind != ENTITY_PARAMETER)
1294                                 return NULL;
1295
1296                         return entity;
1297                 }
1298
1299                 case EXPR_ARRAY_ACCESS: {
1300                         expression_t *const ref = expr->array_access.array_ref;
1301                         entity_t     *      ent = NULL;
1302                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1303                                 ent     = determine_lhs_ent(ref, lhs_ent);
1304                                 lhs_ent = ent;
1305                         } else {
1306                                 mark_vars_read(ref, lhs_ent);
1307                         }
1308                         mark_vars_read(expr->array_access.index, lhs_ent);
1309                         return ent;
1310                 }
1311
1312                 case EXPR_SELECT: {
1313                         mark_vars_read(expr->select.compound, lhs_ent);
1314                         if (is_type_compound(skip_typeref(expr->base.type)))
1315                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1316                         return NULL;
1317                 }
1318
1319                 case EXPR_UNARY_DEREFERENCE: {
1320                         expression_t *const val = expr->unary.value;
1321                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1322                                 /* *&x is a NOP */
1323                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1324                         } else {
1325                                 mark_vars_read(val, NULL);
1326                                 return NULL;
1327                         }
1328                 }
1329
1330                 default:
1331                         mark_vars_read(expr, NULL);
1332                         return NULL;
1333         }
1334 }
1335
1336 #define ENT_ANY ((entity_t*)-1)
1337
1338 /**
1339  * Mark declarations, which are read.  This is used to detect variables, which
1340  * are never read.
1341  * Example:
1342  * x = x + 1;
1343  *   x is not marked as "read", because it is only read to calculate its own new
1344  *   value.
1345  *
1346  * x += y; y += x;
1347  *   x and y are not detected as "not read", because multiple variables are
1348  *   involved.
1349  */
1350 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1351 {
1352         switch (expr->kind) {
1353                 case EXPR_REFERENCE: {
1354                         entity_t *const entity = expr->reference.entity;
1355                         if (entity->kind != ENTITY_VARIABLE
1356                                         && entity->kind != ENTITY_PARAMETER)
1357                                 return;
1358
1359                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1360                                 entity->variable.read = true;
1361                         }
1362                         return;
1363                 }
1364
1365                 case EXPR_CALL:
1366                         // TODO respect pure/const
1367                         mark_vars_read(expr->call.function, NULL);
1368                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1369                                 mark_vars_read(arg->expression, NULL);
1370                         }
1371                         return;
1372
1373                 case EXPR_CONDITIONAL:
1374                         // TODO lhs_decl should depend on whether true/false have an effect
1375                         mark_vars_read(expr->conditional.condition, NULL);
1376                         if (expr->conditional.true_expression != NULL)
1377                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1378                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1379                         return;
1380
1381                 case EXPR_SELECT:
1382                         if (lhs_ent == ENT_ANY
1383                                         && !is_type_compound(skip_typeref(expr->base.type)))
1384                                 lhs_ent = NULL;
1385                         mark_vars_read(expr->select.compound, lhs_ent);
1386                         return;
1387
1388                 case EXPR_ARRAY_ACCESS: {
1389                         mark_vars_read(expr->array_access.index, lhs_ent);
1390                         expression_t *const ref = expr->array_access.array_ref;
1391                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1392                                 if (lhs_ent == ENT_ANY)
1393                                         lhs_ent = NULL;
1394                         }
1395                         mark_vars_read(ref, lhs_ent);
1396                         return;
1397                 }
1398
1399                 case EXPR_VA_ARG:
1400                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1401                         return;
1402
1403                 case EXPR_VA_COPY:
1404                         mark_vars_read(expr->va_copye.src, lhs_ent);
1405                         return;
1406
1407                 case EXPR_UNARY_CAST:
1408                         /* Special case: Use void cast to mark a variable as "read" */
1409                         if (is_type_void(skip_typeref(expr->base.type)))
1410                                 lhs_ent = NULL;
1411                         goto unary;
1412
1413
1414                 case EXPR_UNARY_THROW:
1415                         if (expr->unary.value == NULL)
1416                                 return;
1417                         /* FALLTHROUGH */
1418                 case EXPR_UNARY_DEREFERENCE:
1419                 case EXPR_UNARY_DELETE:
1420                 case EXPR_UNARY_DELETE_ARRAY:
1421                         if (lhs_ent == ENT_ANY)
1422                                 lhs_ent = NULL;
1423                         goto unary;
1424
1425                 case EXPR_UNARY_NEGATE:
1426                 case EXPR_UNARY_PLUS:
1427                 case EXPR_UNARY_BITWISE_NEGATE:
1428                 case EXPR_UNARY_NOT:
1429                 case EXPR_UNARY_TAKE_ADDRESS:
1430                 case EXPR_UNARY_POSTFIX_INCREMENT:
1431                 case EXPR_UNARY_POSTFIX_DECREMENT:
1432                 case EXPR_UNARY_PREFIX_INCREMENT:
1433                 case EXPR_UNARY_PREFIX_DECREMENT:
1434                 case EXPR_UNARY_ASSUME:
1435 unary:
1436                         mark_vars_read(expr->unary.value, lhs_ent);
1437                         return;
1438
1439                 case EXPR_BINARY_ADD:
1440                 case EXPR_BINARY_SUB:
1441                 case EXPR_BINARY_MUL:
1442                 case EXPR_BINARY_DIV:
1443                 case EXPR_BINARY_MOD:
1444                 case EXPR_BINARY_EQUAL:
1445                 case EXPR_BINARY_NOTEQUAL:
1446                 case EXPR_BINARY_LESS:
1447                 case EXPR_BINARY_LESSEQUAL:
1448                 case EXPR_BINARY_GREATER:
1449                 case EXPR_BINARY_GREATEREQUAL:
1450                 case EXPR_BINARY_BITWISE_AND:
1451                 case EXPR_BINARY_BITWISE_OR:
1452                 case EXPR_BINARY_BITWISE_XOR:
1453                 case EXPR_BINARY_LOGICAL_AND:
1454                 case EXPR_BINARY_LOGICAL_OR:
1455                 case EXPR_BINARY_SHIFTLEFT:
1456                 case EXPR_BINARY_SHIFTRIGHT:
1457                 case EXPR_BINARY_COMMA:
1458                 case EXPR_BINARY_ISGREATER:
1459                 case EXPR_BINARY_ISGREATEREQUAL:
1460                 case EXPR_BINARY_ISLESS:
1461                 case EXPR_BINARY_ISLESSEQUAL:
1462                 case EXPR_BINARY_ISLESSGREATER:
1463                 case EXPR_BINARY_ISUNORDERED:
1464                         mark_vars_read(expr->binary.left,  lhs_ent);
1465                         mark_vars_read(expr->binary.right, lhs_ent);
1466                         return;
1467
1468                 case EXPR_BINARY_ASSIGN:
1469                 case EXPR_BINARY_MUL_ASSIGN:
1470                 case EXPR_BINARY_DIV_ASSIGN:
1471                 case EXPR_BINARY_MOD_ASSIGN:
1472                 case EXPR_BINARY_ADD_ASSIGN:
1473                 case EXPR_BINARY_SUB_ASSIGN:
1474                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1475                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1476                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1478                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1479                         if (lhs_ent == ENT_ANY)
1480                                 lhs_ent = NULL;
1481                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1482                         mark_vars_read(expr->binary.right, lhs_ent);
1483                         return;
1484                 }
1485
1486                 case EXPR_VA_START:
1487                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1488                         return;
1489
1490                 case EXPR_LITERAL_CASES:
1491                 case EXPR_LITERAL_CHARACTER:
1492                 case EXPR_ERROR:
1493                 case EXPR_STRING_LITERAL:
1494                 case EXPR_COMPOUND_LITERAL: // TODO init?
1495                 case EXPR_SIZEOF:
1496                 case EXPR_CLASSIFY_TYPE:
1497                 case EXPR_ALIGNOF:
1498                 case EXPR_FUNCNAME:
1499                 case EXPR_BUILTIN_CONSTANT_P:
1500                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1501                 case EXPR_OFFSETOF:
1502                 case EXPR_STATEMENT: // TODO
1503                 case EXPR_LABEL_ADDRESS:
1504                 case EXPR_ENUM_CONSTANT:
1505                         return;
1506         }
1507
1508         panic("unhandled expression");
1509 }
1510
1511 static designator_t *parse_designation(void)
1512 {
1513         designator_t  *result = NULL;
1514         designator_t **anchor = &result;
1515
1516         for (;;) {
1517                 designator_t *designator;
1518                 switch (token.kind) {
1519                 case '[':
1520                         designator = allocate_ast_zero(sizeof(designator[0]));
1521                         designator->source_position = *HERE;
1522                         eat('[');
1523                         add_anchor_token(']');
1524                         designator->array_index = parse_constant_expression();
1525                         rem_anchor_token(']');
1526                         expect(']');
1527                         break;
1528                 case '.':
1529                         designator = allocate_ast_zero(sizeof(designator[0]));
1530                         designator->source_position = *HERE;
1531                         eat('.');
1532                         designator->symbol = expect_identifier("while parsing designator", NULL);
1533                         if (!designator->symbol)
1534                                 return NULL;
1535                         break;
1536                 default:
1537                         expect('=');
1538                         return result;
1539                 }
1540
1541                 assert(designator != NULL);
1542                 *anchor = designator;
1543                 anchor  = &designator->next;
1544         }
1545 }
1546
1547 static initializer_t *initializer_from_string(array_type_t *const type,
1548                                               const string_t *const string)
1549 {
1550         /* TODO: check len vs. size of array type */
1551         (void) type;
1552
1553         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1554         initializer->string.string = *string;
1555
1556         return initializer;
1557 }
1558
1559 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1560                                                    const string_t *const string)
1561 {
1562         /* TODO: check len vs. size of array type */
1563         (void) type;
1564
1565         initializer_t *const initializer =
1566                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1567         initializer->wide_string.string = *string;
1568
1569         return initializer;
1570 }
1571
1572 /**
1573  * Build an initializer from a given expression.
1574  */
1575 static initializer_t *initializer_from_expression(type_t *orig_type,
1576                                                   expression_t *expression)
1577 {
1578         /* TODO check that expression is a constant expression */
1579
1580         /* §6.7.8.14/15 char array may be initialized by string literals */
1581         type_t *type           = skip_typeref(orig_type);
1582         type_t *expr_type_orig = expression->base.type;
1583         type_t *expr_type      = skip_typeref(expr_type_orig);
1584
1585         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1586                 array_type_t *const array_type   = &type->array;
1587                 type_t       *const element_type = skip_typeref(array_type->element_type);
1588
1589                 if (element_type->kind == TYPE_ATOMIC && expression->kind == EXPR_STRING_LITERAL) {
1590                         switch (expression->string_literal.encoding) {
1591                         case STRING_ENCODING_CHAR: {
1592                                 atomic_type_kind_t const akind = element_type->atomic.akind;
1593                                 if (akind == ATOMIC_TYPE_CHAR
1594                                                 || akind == ATOMIC_TYPE_SCHAR
1595                                                 || akind == ATOMIC_TYPE_UCHAR) {
1596                                         return initializer_from_string(array_type,
1597                                                         &expression->string_literal.value);
1598                                 }
1599                                 break;
1600                         }
1601
1602                         case STRING_ENCODING_WIDE: {
1603                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1604                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1605                                         return initializer_from_wide_string(array_type,
1606                                                         &expression->string_literal.value);
1607                                 }
1608                                 break;
1609                         }
1610                         }
1611                 }
1612         }
1613
1614         assign_error_t error = semantic_assign(type, expression);
1615         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1616                 return NULL;
1617         report_assign_error(error, type, expression, "initializer",
1618                             &expression->base.source_position);
1619
1620         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1621         result->value.value = create_implicit_cast(expression, type);
1622
1623         return result;
1624 }
1625
1626 /**
1627  * Parses an scalar initializer.
1628  *
1629  * §6.7.8.11; eat {} without warning
1630  */
1631 static initializer_t *parse_scalar_initializer(type_t *type,
1632                                                bool must_be_constant)
1633 {
1634         /* there might be extra {} hierarchies */
1635         int braces = 0;
1636         if (token.kind == '{') {
1637                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1638                 do {
1639                         eat('{');
1640                         ++braces;
1641                 } while (token.kind == '{');
1642         }
1643
1644         expression_t *expression = parse_assignment_expression();
1645         mark_vars_read(expression, NULL);
1646         if (must_be_constant && !is_linker_constant(expression)) {
1647                 errorf(&expression->base.source_position,
1648                        "initialisation expression '%E' is not constant",
1649                        expression);
1650         }
1651
1652         initializer_t *initializer = initializer_from_expression(type, expression);
1653
1654         if (initializer == NULL) {
1655                 errorf(&expression->base.source_position,
1656                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1657                        expression, expression->base.type, type);
1658                 /* TODO */
1659                 return NULL;
1660         }
1661
1662         bool additional_warning_displayed = false;
1663         while (braces > 0) {
1664                 next_if(',');
1665                 if (token.kind != '}') {
1666                         if (!additional_warning_displayed) {
1667                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1668                                 additional_warning_displayed = true;
1669                         }
1670                 }
1671                 eat_block();
1672                 braces--;
1673         }
1674
1675         return initializer;
1676 }
1677
1678 /**
1679  * An entry in the type path.
1680  */
1681 typedef struct type_path_entry_t type_path_entry_t;
1682 struct type_path_entry_t {
1683         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1684         union {
1685                 size_t         index;          /**< For array types: the current index. */
1686                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1687         } v;
1688 };
1689
1690 /**
1691  * A type path expression a position inside compound or array types.
1692  */
1693 typedef struct type_path_t type_path_t;
1694 struct type_path_t {
1695         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1696         type_t            *top_type;     /**< type of the element the path points */
1697         size_t             max_index;    /**< largest index in outermost array */
1698 };
1699
1700 /**
1701  * Prints a type path for debugging.
1702  */
1703 static __attribute__((unused)) void debug_print_type_path(
1704                 const type_path_t *path)
1705 {
1706         size_t len = ARR_LEN(path->path);
1707
1708         for (size_t i = 0; i < len; ++i) {
1709                 const type_path_entry_t *entry = & path->path[i];
1710
1711                 type_t *type = skip_typeref(entry->type);
1712                 if (is_type_compound(type)) {
1713                         /* in gcc mode structs can have no members */
1714                         if (entry->v.compound_entry == NULL) {
1715                                 assert(i == len-1);
1716                                 continue;
1717                         }
1718                         fprintf(stderr, ".%s",
1719                                 entry->v.compound_entry->base.symbol->string);
1720                 } else if (is_type_array(type)) {
1721                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1722                 } else {
1723                         fprintf(stderr, "-INVALID-");
1724                 }
1725         }
1726         if (path->top_type != NULL) {
1727                 fprintf(stderr, "  (");
1728                 print_type(path->top_type);
1729                 fprintf(stderr, ")");
1730         }
1731 }
1732
1733 /**
1734  * Return the top type path entry, ie. in a path
1735  * (type).a.b returns the b.
1736  */
1737 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1738 {
1739         size_t len = ARR_LEN(path->path);
1740         assert(len > 0);
1741         return &path->path[len-1];
1742 }
1743
1744 /**
1745  * Enlarge the type path by an (empty) element.
1746  */
1747 static type_path_entry_t *append_to_type_path(type_path_t *path)
1748 {
1749         size_t len = ARR_LEN(path->path);
1750         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1751
1752         type_path_entry_t *result = & path->path[len];
1753         memset(result, 0, sizeof(result[0]));
1754         return result;
1755 }
1756
1757 /**
1758  * Descending into a sub-type. Enter the scope of the current top_type.
1759  */
1760 static void descend_into_subtype(type_path_t *path)
1761 {
1762         type_t *orig_top_type = path->top_type;
1763         type_t *top_type      = skip_typeref(orig_top_type);
1764
1765         type_path_entry_t *top = append_to_type_path(path);
1766         top->type              = top_type;
1767
1768         if (is_type_compound(top_type)) {
1769                 compound_t *const compound = top_type->compound.compound;
1770                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1771
1772                 if (entry != NULL) {
1773                         top->v.compound_entry = &entry->declaration;
1774                         path->top_type = entry->declaration.type;
1775                 } else {
1776                         path->top_type = NULL;
1777                 }
1778         } else if (is_type_array(top_type)) {
1779                 top->v.index   = 0;
1780                 path->top_type = top_type->array.element_type;
1781         } else {
1782                 assert(!is_type_valid(top_type));
1783         }
1784 }
1785
1786 /**
1787  * Pop an entry from the given type path, ie. returning from
1788  * (type).a.b to (type).a
1789  */
1790 static void ascend_from_subtype(type_path_t *path)
1791 {
1792         type_path_entry_t *top = get_type_path_top(path);
1793
1794         path->top_type = top->type;
1795
1796         size_t len = ARR_LEN(path->path);
1797         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1798 }
1799
1800 /**
1801  * Pop entries from the given type path until the given
1802  * path level is reached.
1803  */
1804 static void ascend_to(type_path_t *path, size_t top_path_level)
1805 {
1806         size_t len = ARR_LEN(path->path);
1807
1808         while (len > top_path_level) {
1809                 ascend_from_subtype(path);
1810                 len = ARR_LEN(path->path);
1811         }
1812 }
1813
1814 static bool walk_designator(type_path_t *path, const designator_t *designator,
1815                             bool used_in_offsetof)
1816 {
1817         for (; designator != NULL; designator = designator->next) {
1818                 type_path_entry_t *top       = get_type_path_top(path);
1819                 type_t            *orig_type = top->type;
1820
1821                 type_t *type = skip_typeref(orig_type);
1822
1823                 if (designator->symbol != NULL) {
1824                         symbol_t *symbol = designator->symbol;
1825                         if (!is_type_compound(type)) {
1826                                 if (is_type_valid(type)) {
1827                                         errorf(&designator->source_position,
1828                                                "'.%Y' designator used for non-compound type '%T'",
1829                                                symbol, orig_type);
1830                                 }
1831
1832                                 top->type             = type_error_type;
1833                                 top->v.compound_entry = NULL;
1834                                 orig_type             = type_error_type;
1835                         } else {
1836                                 compound_t *compound = type->compound.compound;
1837                                 entity_t   *iter     = compound->members.entities;
1838                                 for (; iter != NULL; iter = iter->base.next) {
1839                                         if (iter->base.symbol == symbol) {
1840                                                 break;
1841                                         }
1842                                 }
1843                                 if (iter == NULL) {
1844                                         errorf(&designator->source_position,
1845                                                "'%T' has no member named '%Y'", orig_type, symbol);
1846                                         return false;
1847                                 }
1848                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1849                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1850                                         errorf(&designator->source_position,
1851                                                    "offsetof designator '%Y' must not specify bitfield",
1852                                                    symbol);
1853                                         return false;
1854                                 }
1855
1856                                 top->type             = orig_type;
1857                                 top->v.compound_entry = &iter->declaration;
1858                                 orig_type             = iter->declaration.type;
1859                         }
1860                 } else {
1861                         expression_t *array_index = designator->array_index;
1862                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1863                                 return true;
1864
1865                         if (!is_type_array(type)) {
1866                                 if (is_type_valid(type)) {
1867                                         errorf(&designator->source_position,
1868                                                "[%E] designator used for non-array type '%T'",
1869                                                array_index, orig_type);
1870                                 }
1871                                 return false;
1872                         }
1873
1874                         long index = fold_constant_to_int(array_index);
1875                         if (!used_in_offsetof) {
1876                                 if (index < 0) {
1877                                         errorf(&designator->source_position,
1878                                                "array index [%E] must be positive", array_index);
1879                                 } else if (type->array.size_constant) {
1880                                         long array_size = type->array.size;
1881                                         if (index >= array_size) {
1882                                                 errorf(&designator->source_position,
1883                                                        "designator [%E] (%d) exceeds array size %d",
1884                                                        array_index, index, array_size);
1885                                         }
1886                                 }
1887                         }
1888
1889                         top->type    = orig_type;
1890                         top->v.index = (size_t) index;
1891                         orig_type    = type->array.element_type;
1892                 }
1893                 path->top_type = orig_type;
1894
1895                 if (designator->next != NULL) {
1896                         descend_into_subtype(path);
1897                 }
1898         }
1899         return true;
1900 }
1901
1902 static void advance_current_object(type_path_t *path, size_t top_path_level)
1903 {
1904         type_path_entry_t *top = get_type_path_top(path);
1905
1906         type_t *type = skip_typeref(top->type);
1907         if (is_type_union(type)) {
1908                 /* in unions only the first element is initialized */
1909                 top->v.compound_entry = NULL;
1910         } else if (is_type_struct(type)) {
1911                 declaration_t *entry = top->v.compound_entry;
1912
1913                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1914                 if (next_entity != NULL) {
1915                         assert(is_declaration(next_entity));
1916                         entry = &next_entity->declaration;
1917                 } else {
1918                         entry = NULL;
1919                 }
1920
1921                 top->v.compound_entry = entry;
1922                 if (entry != NULL) {
1923                         path->top_type = entry->type;
1924                         return;
1925                 }
1926         } else if (is_type_array(type)) {
1927                 assert(is_type_array(type));
1928
1929                 top->v.index++;
1930
1931                 if (!type->array.size_constant || top->v.index < type->array.size) {
1932                         return;
1933                 }
1934         } else {
1935                 assert(!is_type_valid(type));
1936                 return;
1937         }
1938
1939         /* we're past the last member of the current sub-aggregate, try if we
1940          * can ascend in the type hierarchy and continue with another subobject */
1941         size_t len = ARR_LEN(path->path);
1942
1943         if (len > top_path_level) {
1944                 ascend_from_subtype(path);
1945                 advance_current_object(path, top_path_level);
1946         } else {
1947                 path->top_type = NULL;
1948         }
1949 }
1950
1951 /**
1952  * skip any {...} blocks until a closing bracket is reached.
1953  */
1954 static void skip_initializers(void)
1955 {
1956         next_if('{');
1957
1958         while (token.kind != '}') {
1959                 if (token.kind == T_EOF)
1960                         return;
1961                 if (token.kind == '{') {
1962                         eat_block();
1963                         continue;
1964                 }
1965                 next_token();
1966         }
1967 }
1968
1969 static initializer_t *create_empty_initializer(void)
1970 {
1971         static initializer_t empty_initializer
1972                 = { .list = { { INITIALIZER_LIST }, 0 } };
1973         return &empty_initializer;
1974 }
1975
1976 /**
1977  * Parse a part of an initialiser for a struct or union,
1978  */
1979 static initializer_t *parse_sub_initializer(type_path_t *path,
1980                 type_t *outer_type, size_t top_path_level,
1981                 parse_initializer_env_t *env)
1982 {
1983         if (token.kind == '}') {
1984                 /* empty initializer */
1985                 return create_empty_initializer();
1986         }
1987
1988         type_t *orig_type = path->top_type;
1989         type_t *type      = NULL;
1990
1991         if (orig_type == NULL) {
1992                 /* We are initializing an empty compound. */
1993         } else {
1994                 type = skip_typeref(orig_type);
1995         }
1996
1997         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1998
1999         while (true) {
2000                 designator_t *designator = NULL;
2001                 if (token.kind == '.' || token.kind == '[') {
2002                         designator = parse_designation();
2003                         goto finish_designator;
2004                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2005                         /* GNU-style designator ("identifier: value") */
2006                         designator = allocate_ast_zero(sizeof(designator[0]));
2007                         designator->source_position = *HERE;
2008                         designator->symbol          = token.base.symbol;
2009                         eat(T_IDENTIFIER);
2010                         eat(':');
2011
2012 finish_designator:
2013                         /* reset path to toplevel, evaluate designator from there */
2014                         ascend_to(path, top_path_level);
2015                         if (!walk_designator(path, designator, false)) {
2016                                 /* can't continue after designation error */
2017                                 goto end_error;
2018                         }
2019
2020                         initializer_t *designator_initializer
2021                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2022                         designator_initializer->designator.designator = designator;
2023                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2024
2025                         orig_type = path->top_type;
2026                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2027                 }
2028
2029                 initializer_t *sub;
2030
2031                 if (token.kind == '{') {
2032                         if (type != NULL && is_type_scalar(type)) {
2033                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2034                         } else {
2035                                 if (type == NULL) {
2036                                         if (env->entity != NULL) {
2037                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2038                                         } else {
2039                                                 errorf(HERE, "extra brace group at end of initializer");
2040                                         }
2041                                         eat('{');
2042                                 } else {
2043                                         eat('{');
2044                                         descend_into_subtype(path);
2045                                 }
2046
2047                                 add_anchor_token('}');
2048                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2049                                                             env);
2050                                 rem_anchor_token('}');
2051
2052                                 expect('}');
2053
2054                                 if (!type)
2055                                         goto error_parse_next;
2056
2057                                 ascend_from_subtype(path);
2058                         }
2059                 } else {
2060                         /* must be an expression */
2061                         expression_t *expression = parse_assignment_expression();
2062                         mark_vars_read(expression, NULL);
2063
2064                         if (env->must_be_constant && !is_linker_constant(expression)) {
2065                                 errorf(&expression->base.source_position,
2066                                        "Initialisation expression '%E' is not constant",
2067                                        expression);
2068                         }
2069
2070                         if (type == NULL) {
2071                                 /* we are already outside, ... */
2072                                 if (outer_type == NULL)
2073                                         goto error_parse_next;
2074                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2075                                 if (is_type_compound(outer_type_skip) &&
2076                                                 !outer_type_skip->compound.compound->complete) {
2077                                         goto error_parse_next;
2078                                 }
2079
2080                                 source_position_t const* const pos = &expression->base.source_position;
2081                                 if (env->entity != NULL) {
2082                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2083                                 } else {
2084                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2085                                 }
2086                                 goto error_parse_next;
2087                         }
2088
2089                         /* handle { "string" } special case */
2090                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2091                                 sub = initializer_from_expression(outer_type, expression);
2092                                 if (sub != NULL) {
2093                                         next_if(',');
2094                                         if (token.kind != '}') {
2095                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2096                                         }
2097                                         /* TODO: eat , ... */
2098                                         return sub;
2099                                 }
2100                         }
2101
2102                         /* descend into subtypes until expression matches type */
2103                         while (true) {
2104                                 orig_type = path->top_type;
2105                                 type      = skip_typeref(orig_type);
2106
2107                                 sub = initializer_from_expression(orig_type, expression);
2108                                 if (sub != NULL) {
2109                                         break;
2110                                 }
2111                                 if (!is_type_valid(type)) {
2112                                         goto end_error;
2113                                 }
2114                                 if (is_type_scalar(type)) {
2115                                         errorf(&expression->base.source_position,
2116                                                         "expression '%E' doesn't match expected type '%T'",
2117                                                         expression, orig_type);
2118                                         goto end_error;
2119                                 }
2120
2121                                 descend_into_subtype(path);
2122                         }
2123                 }
2124
2125                 /* update largest index of top array */
2126                 const type_path_entry_t *first      = &path->path[0];
2127                 type_t                  *first_type = first->type;
2128                 first_type                          = skip_typeref(first_type);
2129                 if (is_type_array(first_type)) {
2130                         size_t index = first->v.index;
2131                         if (index > path->max_index)
2132                                 path->max_index = index;
2133                 }
2134
2135                 /* append to initializers list */
2136                 ARR_APP1(initializer_t*, initializers, sub);
2137
2138 error_parse_next:
2139                 if (token.kind == '}') {
2140                         break;
2141                 }
2142                 add_anchor_token('}');
2143                 expect(',');
2144                 rem_anchor_token('}');
2145                 if (token.kind == '}') {
2146                         break;
2147                 }
2148
2149                 if (type != NULL) {
2150                         /* advance to the next declaration if we are not at the end */
2151                         advance_current_object(path, top_path_level);
2152                         orig_type = path->top_type;
2153                         if (orig_type != NULL)
2154                                 type = skip_typeref(orig_type);
2155                         else
2156                                 type = NULL;
2157                 }
2158         }
2159
2160         size_t len  = ARR_LEN(initializers);
2161         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2162         initializer_t *result = allocate_ast_zero(size);
2163         result->kind          = INITIALIZER_LIST;
2164         result->list.len      = len;
2165         memcpy(&result->list.initializers, initializers,
2166                len * sizeof(initializers[0]));
2167
2168         DEL_ARR_F(initializers);
2169         ascend_to(path, top_path_level+1);
2170
2171         return result;
2172
2173 end_error:
2174         skip_initializers();
2175         DEL_ARR_F(initializers);
2176         ascend_to(path, top_path_level+1);
2177         return NULL;
2178 }
2179
2180 static expression_t *make_size_literal(size_t value)
2181 {
2182         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2183         literal->base.type    = type_size_t;
2184
2185         char buf[128];
2186         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2187         literal->literal.value = make_string(buf);
2188
2189         return literal;
2190 }
2191
2192 /**
2193  * Parses an initializer. Parsers either a compound literal
2194  * (env->declaration == NULL) or an initializer of a declaration.
2195  */
2196 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2197 {
2198         type_t        *type      = skip_typeref(env->type);
2199         size_t         max_index = 0;
2200         initializer_t *result;
2201
2202         if (is_type_scalar(type)) {
2203                 result = parse_scalar_initializer(type, env->must_be_constant);
2204         } else if (token.kind == '{') {
2205                 eat('{');
2206
2207                 type_path_t path;
2208                 memset(&path, 0, sizeof(path));
2209                 path.top_type = env->type;
2210                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2211
2212                 descend_into_subtype(&path);
2213
2214                 add_anchor_token('}');
2215                 result = parse_sub_initializer(&path, env->type, 1, env);
2216                 rem_anchor_token('}');
2217
2218                 max_index = path.max_index;
2219                 DEL_ARR_F(path.path);
2220
2221                 expect('}');
2222         } else {
2223                 /* parse_scalar_initializer() also works in this case: we simply
2224                  * have an expression without {} around it */
2225                 result = parse_scalar_initializer(type, env->must_be_constant);
2226         }
2227
2228         /* §6.7.8:22 array initializers for arrays with unknown size determine
2229          * the array type size */
2230         if (is_type_array(type) && type->array.size_expression == NULL
2231                         && result != NULL) {
2232                 size_t size;
2233                 switch (result->kind) {
2234                 case INITIALIZER_LIST:
2235                         assert(max_index != 0xdeadbeaf);
2236                         size = max_index + 1;
2237                         break;
2238
2239                 case INITIALIZER_STRING:
2240                         size = result->string.string.size + 1;
2241                         break;
2242
2243                 case INITIALIZER_WIDE_STRING:
2244                         size = result->wide_string.string.size;
2245                         break;
2246
2247                 case INITIALIZER_DESIGNATOR:
2248                 case INITIALIZER_VALUE:
2249                         /* can happen for parse errors */
2250                         size = 0;
2251                         break;
2252
2253                 default:
2254                         internal_errorf(HERE, "invalid initializer type");
2255                 }
2256
2257                 type_t *new_type = duplicate_type(type);
2258
2259                 new_type->array.size_expression   = make_size_literal(size);
2260                 new_type->array.size_constant     = true;
2261                 new_type->array.has_implicit_size = true;
2262                 new_type->array.size              = size;
2263                 env->type = new_type;
2264         }
2265
2266         return result;
2267 }
2268
2269 static void append_entity(scope_t *scope, entity_t *entity)
2270 {
2271         if (scope->last_entity != NULL) {
2272                 scope->last_entity->base.next = entity;
2273         } else {
2274                 scope->entities = entity;
2275         }
2276         entity->base.parent_entity = current_entity;
2277         scope->last_entity         = entity;
2278 }
2279
2280
2281 static compound_t *parse_compound_type_specifier(bool is_struct)
2282 {
2283         source_position_t const pos = *HERE;
2284         eat(is_struct ? T_struct : T_union);
2285
2286         symbol_t    *symbol     = NULL;
2287         entity_t    *entity     = NULL;
2288         attribute_t *attributes = NULL;
2289
2290         if (token.kind == T___attribute__) {
2291                 attributes = parse_attributes(NULL);
2292         }
2293
2294         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2295         if (token.kind == T_IDENTIFIER) {
2296                 /* the compound has a name, check if we have seen it already */
2297                 symbol = token.base.symbol;
2298                 entity = get_tag(symbol, kind);
2299                 eat(T_IDENTIFIER);
2300
2301                 if (entity != NULL) {
2302                         if (entity->base.parent_scope != current_scope &&
2303                             (token.kind == '{' || token.kind == ';')) {
2304                                 /* we're in an inner scope and have a definition. Shadow
2305                                  * existing definition in outer scope */
2306                                 entity = NULL;
2307                         } else if (entity->compound.complete && token.kind == '{') {
2308                                 source_position_t const *const ppos = &entity->base.source_position;
2309                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2310                                 /* clear members in the hope to avoid further errors */
2311                                 entity->compound.members.entities = NULL;
2312                         }
2313                 }
2314         } else if (token.kind != '{') {
2315                 char const *const msg =
2316                         is_struct ? "while parsing struct type specifier" :
2317                                     "while parsing union type specifier";
2318                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2319
2320                 return NULL;
2321         }
2322
2323         if (entity == NULL) {
2324                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2325                 entity->compound.alignment = 1;
2326                 entity->base.parent_scope  = current_scope;
2327                 if (symbol != NULL) {
2328                         environment_push(entity);
2329                 }
2330                 append_entity(current_scope, entity);
2331         }
2332
2333         if (token.kind == '{') {
2334                 parse_compound_type_entries(&entity->compound);
2335
2336                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2337                 if (symbol == NULL) {
2338                         assert(anonymous_entity == NULL);
2339                         anonymous_entity = entity;
2340                 }
2341         }
2342
2343         if (attributes != NULL) {
2344                 handle_entity_attributes(attributes, entity);
2345         }
2346
2347         return &entity->compound;
2348 }
2349
2350 static void parse_enum_entries(type_t *const enum_type)
2351 {
2352         eat('{');
2353
2354         if (token.kind == '}') {
2355                 errorf(HERE, "empty enum not allowed");
2356                 eat('}');
2357                 return;
2358         }
2359
2360         add_anchor_token('}');
2361         add_anchor_token(',');
2362         do {
2363                 add_anchor_token('=');
2364                 source_position_t pos;
2365                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2366                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2367                 entity->enum_value.enum_type = enum_type;
2368                 rem_anchor_token('=');
2369
2370                 if (next_if('=')) {
2371                         expression_t *value = parse_constant_expression();
2372
2373                         value = create_implicit_cast(value, enum_type);
2374                         entity->enum_value.value = value;
2375
2376                         /* TODO semantic */
2377                 }
2378
2379                 record_entity(entity, false);
2380         } while (next_if(',') && token.kind != '}');
2381         rem_anchor_token(',');
2382         rem_anchor_token('}');
2383
2384         expect('}');
2385 }
2386
2387 static type_t *parse_enum_specifier(void)
2388 {
2389         source_position_t const pos = *HERE;
2390         entity_t               *entity;
2391         symbol_t               *symbol;
2392
2393         eat(T_enum);
2394         switch (token.kind) {
2395                 case T_IDENTIFIER:
2396                         symbol = token.base.symbol;
2397                         entity = get_tag(symbol, ENTITY_ENUM);
2398                         eat(T_IDENTIFIER);
2399
2400                         if (entity != NULL) {
2401                                 if (entity->base.parent_scope != current_scope &&
2402                                                 (token.kind == '{' || token.kind == ';')) {
2403                                         /* we're in an inner scope and have a definition. Shadow
2404                                          * existing definition in outer scope */
2405                                         entity = NULL;
2406                                 } else if (entity->enume.complete && token.kind == '{') {
2407                                         source_position_t const *const ppos = &entity->base.source_position;
2408                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2409                                 }
2410                         }
2411                         break;
2412
2413                 case '{':
2414                         entity = NULL;
2415                         symbol = NULL;
2416                         break;
2417
2418                 default:
2419                         parse_error_expected("while parsing enum type specifier",
2420                                         T_IDENTIFIER, '{', NULL);
2421                         return NULL;
2422         }
2423
2424         if (entity == NULL) {
2425                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2426                 entity->base.parent_scope = current_scope;
2427         }
2428
2429         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2430         type->enumt.enume      = &entity->enume;
2431         type->enumt.base.akind = ATOMIC_TYPE_INT;
2432
2433         if (token.kind == '{') {
2434                 if (symbol != NULL) {
2435                         environment_push(entity);
2436                 }
2437                 append_entity(current_scope, entity);
2438                 entity->enume.complete = true;
2439
2440                 parse_enum_entries(type);
2441                 parse_attributes(NULL);
2442
2443                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2444                 if (symbol == NULL) {
2445                         assert(anonymous_entity == NULL);
2446                         anonymous_entity = entity;
2447                 }
2448         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2449                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2450         }
2451
2452         return type;
2453 }
2454
2455 /**
2456  * if a symbol is a typedef to another type, return true
2457  */
2458 static bool is_typedef_symbol(symbol_t *symbol)
2459 {
2460         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2461         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2462 }
2463
2464 static type_t *parse_typeof(void)
2465 {
2466         eat(T___typeof__);
2467
2468         type_t *type;
2469
2470         add_anchor_token(')');
2471         expect('(');
2472
2473         expression_t *expression  = NULL;
2474
2475         switch (token.kind) {
2476         case T_IDENTIFIER:
2477                 if (is_typedef_symbol(token.base.symbol)) {
2478         DECLARATION_START
2479                         type = parse_typename();
2480                 } else {
2481         default:
2482                         expression = parse_expression();
2483                         type       = revert_automatic_type_conversion(expression);
2484                 }
2485                 break;
2486         }
2487
2488         rem_anchor_token(')');
2489         expect(')');
2490
2491         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2492         typeof_type->typeoft.expression  = expression;
2493         typeof_type->typeoft.typeof_type = type;
2494
2495         return typeof_type;
2496 }
2497
2498 typedef enum specifiers_t {
2499         SPECIFIER_SIGNED    = 1 << 0,
2500         SPECIFIER_UNSIGNED  = 1 << 1,
2501         SPECIFIER_LONG      = 1 << 2,
2502         SPECIFIER_INT       = 1 << 3,
2503         SPECIFIER_DOUBLE    = 1 << 4,
2504         SPECIFIER_CHAR      = 1 << 5,
2505         SPECIFIER_WCHAR_T   = 1 << 6,
2506         SPECIFIER_SHORT     = 1 << 7,
2507         SPECIFIER_LONG_LONG = 1 << 8,
2508         SPECIFIER_FLOAT     = 1 << 9,
2509         SPECIFIER_BOOL      = 1 << 10,
2510         SPECIFIER_VOID      = 1 << 11,
2511         SPECIFIER_INT8      = 1 << 12,
2512         SPECIFIER_INT16     = 1 << 13,
2513         SPECIFIER_INT32     = 1 << 14,
2514         SPECIFIER_INT64     = 1 << 15,
2515         SPECIFIER_INT128    = 1 << 16,
2516         SPECIFIER_COMPLEX   = 1 << 17,
2517         SPECIFIER_IMAGINARY = 1 << 18,
2518 } specifiers_t;
2519
2520 static type_t *get_typedef_type(symbol_t *symbol)
2521 {
2522         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2523         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2524                 return NULL;
2525
2526         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2527         type->typedeft.typedefe = &entity->typedefe;
2528
2529         return type;
2530 }
2531
2532 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2533 {
2534         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2535
2536         add_anchor_token(')');
2537         add_anchor_token(',');
2538         expect('(');
2539
2540         do {
2541                 add_anchor_token('=');
2542                 source_position_t pos;
2543                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2544                 rem_anchor_token('=');
2545
2546                 symbol_t **prop = NULL;
2547                 if (prop_sym) {
2548                         if (streq(prop_sym->string, "put")) {
2549                                 prop = &property->put_symbol;
2550                         } else if (streq(prop_sym->string, "get")) {
2551                                 prop = &property->get_symbol;
2552                         } else {
2553                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2554                         }
2555                 }
2556
2557                 add_anchor_token(T_IDENTIFIER);
2558                 expect('=');
2559                 rem_anchor_token(T_IDENTIFIER);
2560
2561                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2562                 if (prop != NULL)
2563                         *prop = sym ? sym : sym_anonymous;
2564         } while (next_if(','));
2565         rem_anchor_token(',');
2566         rem_anchor_token(')');
2567
2568         attribute->a.property = property;
2569
2570         expect(')');
2571         return attribute;
2572 }
2573
2574 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2575 {
2576         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2577         if (next_if(T_restrict)) {
2578                 kind = ATTRIBUTE_MS_RESTRICT;
2579         } else if (token.kind == T_IDENTIFIER) {
2580                 char const *const name = token.base.symbol->string;
2581                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2582                      ++k) {
2583                         const char *attribute_name = get_attribute_name(k);
2584                         if (attribute_name != NULL && streq(attribute_name, name)) {
2585                                 kind = k;
2586                                 break;
2587                         }
2588                 }
2589
2590                 if (kind == ATTRIBUTE_UNKNOWN) {
2591                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2592                 }
2593         } else {
2594                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2595                 return NULL;
2596         }
2597
2598         attribute_t *attribute = allocate_attribute_zero(kind);
2599         eat(T_IDENTIFIER);
2600
2601         if (kind == ATTRIBUTE_MS_PROPERTY) {
2602                 return parse_attribute_ms_property(attribute);
2603         }
2604
2605         /* parse arguments */
2606         if (next_if('('))
2607                 attribute->a.arguments = parse_attribute_arguments();
2608
2609         return attribute;
2610 }
2611
2612 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2613 {
2614         eat(T__declspec);
2615
2616         add_anchor_token(')');
2617         expect('(');
2618         if (token.kind != ')') {
2619                 attribute_t **anchor = &first;
2620                 do {
2621                         while (*anchor != NULL)
2622                                 anchor = &(*anchor)->next;
2623
2624                         attribute_t *attribute
2625                                 = parse_microsoft_extended_decl_modifier_single();
2626                         if (attribute == NULL)
2627                                 break;
2628
2629                         *anchor = attribute;
2630                         anchor  = &attribute->next;
2631                 } while (next_if(','));
2632         }
2633         rem_anchor_token(')');
2634         expect(')');
2635         return first;
2636 }
2637
2638 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2639 {
2640         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2641         if (is_declaration(entity)) {
2642                 entity->declaration.type     = type_error_type;
2643                 entity->declaration.implicit = true;
2644         } else if (kind == ENTITY_TYPEDEF) {
2645                 entity->typedefe.type    = type_error_type;
2646                 entity->typedefe.builtin = true;
2647         }
2648         if (kind != ENTITY_COMPOUND_MEMBER)
2649                 record_entity(entity, false);
2650         return entity;
2651 }
2652
2653 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2654 {
2655         type_t            *type            = NULL;
2656         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2657         unsigned           type_specifiers = 0;
2658         bool               newtype         = false;
2659         bool               saw_error       = false;
2660
2661         memset(specifiers, 0, sizeof(*specifiers));
2662         specifiers->source_position = *HERE;
2663
2664         while (true) {
2665                 specifiers->attributes = parse_attributes(specifiers->attributes);
2666
2667                 switch (token.kind) {
2668                 /* storage class */
2669 #define MATCH_STORAGE_CLASS(token, class)                                  \
2670                 case token:                                                        \
2671                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2672                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2673                         }                                                              \
2674                         specifiers->storage_class = class;                             \
2675                         if (specifiers->thread_local)                                  \
2676                                 goto check_thread_storage_class;                           \
2677                         eat(token); \
2678                         break;
2679
2680                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2681                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2682                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2683                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2684                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2685
2686                 case T__declspec:
2687                         specifiers->attributes
2688                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2689                         break;
2690
2691                 case T___thread:
2692                         if (specifiers->thread_local) {
2693                                 errorf(HERE, "duplicate '__thread'");
2694                         } else {
2695                                 specifiers->thread_local = true;
2696 check_thread_storage_class:
2697                                 switch (specifiers->storage_class) {
2698                                         case STORAGE_CLASS_EXTERN:
2699                                         case STORAGE_CLASS_NONE:
2700                                         case STORAGE_CLASS_STATIC:
2701                                                 break;
2702
2703                                                 char const* wrong;
2704                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2705                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2706                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2707 wrong_thread_storage_class:
2708                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2709                                                 break;
2710                                 }
2711                         }
2712                         next_token();
2713                         break;
2714
2715                 /* type qualifiers */
2716 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2717                 case token:                                                     \
2718                         qualifiers |= qualifier;                                    \
2719                         eat(token); \
2720                         break
2721
2722                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2723                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2724                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2725                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2726                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2727                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2728                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2729                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2730
2731                 /* type specifiers */
2732 #define MATCH_SPECIFIER(token, specifier, name)                         \
2733                 case token:                                                     \
2734                         if (type_specifiers & specifier) {                           \
2735                                 errorf(HERE, "multiple " name " type specifiers given"); \
2736                         } else {                                                    \
2737                                 type_specifiers |= specifier;                           \
2738                         }                                                           \
2739                         eat(token); \
2740                         break
2741
2742                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2743                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2744                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2745                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2746                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2747                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2748                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2749                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2750                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2751                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2752                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2753                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2754                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2755                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2756                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2757                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2758                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2759                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2760
2761                 case T_inline:
2762                         eat(T_inline);
2763                         specifiers->is_inline = true;
2764                         break;
2765
2766 #if 0
2767                 case T__forceinline:
2768                         eat(T__forceinline);
2769                         specifiers->modifiers |= DM_FORCEINLINE;
2770                         break;
2771 #endif
2772
2773                 case T_long:
2774                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2775                                 errorf(HERE, "too many long type specifiers given");
2776                         } else if (type_specifiers & SPECIFIER_LONG) {
2777                                 type_specifiers |= SPECIFIER_LONG_LONG;
2778                         } else {
2779                                 type_specifiers |= SPECIFIER_LONG;
2780                         }
2781                         eat(T_long);
2782                         break;
2783
2784 #define CHECK_DOUBLE_TYPE() \
2785         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2786
2787                 case T_struct:
2788                         CHECK_DOUBLE_TYPE();
2789                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2790
2791                         type->compound.compound = parse_compound_type_specifier(true);
2792                         break;
2793                 case T_union:
2794                         CHECK_DOUBLE_TYPE();
2795                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2796                         type->compound.compound = parse_compound_type_specifier(false);
2797                         break;
2798                 case T_enum:
2799                         CHECK_DOUBLE_TYPE();
2800                         type = parse_enum_specifier();
2801                         break;
2802                 case T___typeof__:
2803                         CHECK_DOUBLE_TYPE();
2804                         type = parse_typeof();
2805                         break;
2806                 case T___builtin_va_list:
2807                         CHECK_DOUBLE_TYPE();
2808                         type = duplicate_type(type_valist);
2809                         eat(T___builtin_va_list);
2810                         break;
2811
2812                 case T_IDENTIFIER: {
2813                         /* only parse identifier if we haven't found a type yet */
2814                         if (type != NULL || type_specifiers != 0) {
2815                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2816                                  * declaration, so it doesn't generate errors about expecting '(' or
2817                                  * '{' later on. */
2818                                 switch (look_ahead(1)->kind) {
2819                                         STORAGE_CLASSES
2820                                         TYPE_SPECIFIERS
2821                                         case T_const:
2822                                         case T_restrict:
2823                                         case T_volatile:
2824                                         case T_inline:
2825                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2826                                         case T_IDENTIFIER:
2827                                         case '&':
2828                                         case '*':
2829                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2830                                                 eat(T_IDENTIFIER);
2831                                                 continue;
2832
2833                                         default:
2834                                                 goto finish_specifiers;
2835                                 }
2836                         }
2837
2838                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2839                         if (typedef_type == NULL) {
2840                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2841                                  * declaration, so it doesn't generate 'implicit int' followed by more
2842                                  * errors later on. */
2843                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2844                                 switch (la1_type) {
2845                                         DECLARATION_START
2846                                         case T_IDENTIFIER:
2847                                         case '&':
2848                                         case '*': {
2849                                                 errorf(HERE, "%K does not name a type", &token);
2850
2851                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2852
2853                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2854                                                 type->typedeft.typedefe = &entity->typedefe;
2855
2856                                                 eat(T_IDENTIFIER);
2857                                                 saw_error = true;
2858                                                 continue;
2859                                         }
2860
2861                                         default:
2862                                                 goto finish_specifiers;
2863                                 }
2864                         }
2865
2866                         eat(T_IDENTIFIER);
2867                         type = typedef_type;
2868                         break;
2869                 }
2870
2871                 /* function specifier */
2872                 default:
2873                         goto finish_specifiers;
2874                 }
2875         }
2876
2877 finish_specifiers:
2878         specifiers->attributes = parse_attributes(specifiers->attributes);
2879
2880         if (type == NULL || (saw_error && type_specifiers != 0)) {
2881                 atomic_type_kind_t atomic_type;
2882
2883                 /* match valid basic types */
2884                 switch (type_specifiers) {
2885                 case SPECIFIER_VOID:
2886                         atomic_type = ATOMIC_TYPE_VOID;
2887                         break;
2888                 case SPECIFIER_WCHAR_T:
2889                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2890                         break;
2891                 case SPECIFIER_CHAR:
2892                         atomic_type = ATOMIC_TYPE_CHAR;
2893                         break;
2894                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2895                         atomic_type = ATOMIC_TYPE_SCHAR;
2896                         break;
2897                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2898                         atomic_type = ATOMIC_TYPE_UCHAR;
2899                         break;
2900                 case SPECIFIER_SHORT:
2901                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2902                 case SPECIFIER_SHORT | SPECIFIER_INT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2904                         atomic_type = ATOMIC_TYPE_SHORT;
2905                         break;
2906                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2908                         atomic_type = ATOMIC_TYPE_USHORT;
2909                         break;
2910                 case SPECIFIER_INT:
2911                 case SPECIFIER_SIGNED:
2912                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2913                         atomic_type = ATOMIC_TYPE_INT;
2914                         break;
2915                 case SPECIFIER_UNSIGNED:
2916                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2917                         atomic_type = ATOMIC_TYPE_UINT;
2918                         break;
2919                 case SPECIFIER_LONG:
2920                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2921                 case SPECIFIER_LONG | SPECIFIER_INT:
2922                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2923                         atomic_type = ATOMIC_TYPE_LONG;
2924                         break;
2925                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2926                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2927                         atomic_type = ATOMIC_TYPE_ULONG;
2928                         break;
2929
2930                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2931                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2932                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2933                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2934                         | SPECIFIER_INT:
2935                         atomic_type = ATOMIC_TYPE_LONGLONG;
2936                         goto warn_about_long_long;
2937
2938                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2940                         | SPECIFIER_INT:
2941                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2942 warn_about_long_long:
2943                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2944                         break;
2945
2946                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2947                         atomic_type = unsigned_int8_type_kind;
2948                         break;
2949
2950                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2951                         atomic_type = unsigned_int16_type_kind;
2952                         break;
2953
2954                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2955                         atomic_type = unsigned_int32_type_kind;
2956                         break;
2957
2958                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2959                         atomic_type = unsigned_int64_type_kind;
2960                         break;
2961
2962                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2963                         atomic_type = unsigned_int128_type_kind;
2964                         break;
2965
2966                 case SPECIFIER_INT8:
2967                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2968                         atomic_type = int8_type_kind;
2969                         break;
2970
2971                 case SPECIFIER_INT16:
2972                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2973                         atomic_type = int16_type_kind;
2974                         break;
2975
2976                 case SPECIFIER_INT32:
2977                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2978                         atomic_type = int32_type_kind;
2979                         break;
2980
2981                 case SPECIFIER_INT64:
2982                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2983                         atomic_type = int64_type_kind;
2984                         break;
2985
2986                 case SPECIFIER_INT128:
2987                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2988                         atomic_type = int128_type_kind;
2989                         break;
2990
2991                 case SPECIFIER_FLOAT:
2992                         atomic_type = ATOMIC_TYPE_FLOAT;
2993                         break;
2994                 case SPECIFIER_DOUBLE:
2995                         atomic_type = ATOMIC_TYPE_DOUBLE;
2996                         break;
2997                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2998                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2999                         break;
3000                 case SPECIFIER_BOOL:
3001                         atomic_type = ATOMIC_TYPE_BOOL;
3002                         break;
3003                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3004                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3005                         atomic_type = ATOMIC_TYPE_FLOAT;
3006                         break;
3007                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3008                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3009                         atomic_type = ATOMIC_TYPE_DOUBLE;
3010                         break;
3011                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3012                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3013                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3014                         break;
3015                 default: {
3016                         /* invalid specifier combination, give an error message */
3017                         source_position_t const* const pos = &specifiers->source_position;
3018                         if (type_specifiers == 0) {
3019                                 if (!saw_error) {
3020                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3021                                         if (!(c_mode & _CXX) && !strict_mode) {
3022                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3023                                                 atomic_type = ATOMIC_TYPE_INT;
3024                                                 break;
3025                                         } else {
3026                                                 errorf(pos, "no type specifiers given in declaration");
3027                                         }
3028                                 }
3029                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3030                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3031                                 errorf(pos, "signed and unsigned specifiers given");
3032                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3033                                 errorf(pos, "only integer types can be signed or unsigned");
3034                         } else {
3035                                 errorf(pos, "multiple datatypes in declaration");
3036                         }
3037                         goto end_error;
3038                 }
3039                 }
3040
3041                 if (type_specifiers & SPECIFIER_COMPLEX) {
3042                         type = allocate_type_zero(TYPE_COMPLEX);
3043                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3044                         type = allocate_type_zero(TYPE_IMAGINARY);
3045                 } else {
3046                         type = allocate_type_zero(TYPE_ATOMIC);
3047                 }
3048                 type->atomic.akind = atomic_type;
3049                 newtype = true;
3050         } else if (type_specifiers != 0) {
3051                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3052         }
3053
3054         /* FIXME: check type qualifiers here */
3055         type->base.qualifiers = qualifiers;
3056
3057         if (newtype) {
3058                 type = identify_new_type(type);
3059         } else {
3060                 type = typehash_insert(type);
3061         }
3062
3063         if (specifiers->attributes != NULL)
3064                 type = handle_type_attributes(specifiers->attributes, type);
3065         specifiers->type = type;
3066         return;
3067
3068 end_error:
3069         specifiers->type = type_error_type;
3070 }
3071
3072 static type_qualifiers_t parse_type_qualifiers(void)
3073 {
3074         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3075
3076         while (true) {
3077                 switch (token.kind) {
3078                 /* type qualifiers */
3079                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3080                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3081                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3082                 /* microsoft extended type modifiers */
3083                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3084                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3085                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3086                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3087                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3088
3089                 default:
3090                         return qualifiers;
3091                 }
3092         }
3093 }
3094
3095 /**
3096  * Parses an K&R identifier list
3097  */
3098 static void parse_identifier_list(scope_t *scope)
3099 {
3100         assert(token.kind == T_IDENTIFIER);
3101         do {
3102                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3103                 /* a K&R parameter has no type, yet */
3104                 eat(T_IDENTIFIER);
3105
3106                 if (scope != NULL)
3107                         append_entity(scope, entity);
3108         } while (next_if(',') && token.kind == T_IDENTIFIER);
3109 }
3110
3111 static entity_t *parse_parameter(void)
3112 {
3113         declaration_specifiers_t specifiers;
3114         parse_declaration_specifiers(&specifiers);
3115
3116         entity_t *entity = parse_declarator(&specifiers,
3117                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3118         anonymous_entity = NULL;
3119         return entity;
3120 }
3121
3122 static void semantic_parameter_incomplete(const entity_t *entity)
3123 {
3124         assert(entity->kind == ENTITY_PARAMETER);
3125
3126         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3127          *             list in a function declarator that is part of a
3128          *             definition of that function shall not have
3129          *             incomplete type. */
3130         type_t *type = skip_typeref(entity->declaration.type);
3131         if (is_type_incomplete(type)) {
3132                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3133         }
3134 }
3135
3136 static bool has_parameters(void)
3137 {
3138         /* func(void) is not a parameter */
3139         if (look_ahead(1)->kind != ')')
3140                 return true;
3141         if (token.kind == T_IDENTIFIER) {
3142                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3143                 if (entity == NULL)
3144                         return true;
3145                 if (entity->kind != ENTITY_TYPEDEF)
3146                         return true;
3147                 type_t const *const type = skip_typeref(entity->typedefe.type);
3148                 if (!is_type_void(type))
3149                         return true;
3150                 if (c_mode & _CXX) {
3151                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3152                          * is not allowed. */
3153                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3154                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3155                         /* §6.7.5.3:10  Qualification is not allowed here. */
3156                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3157                 }
3158         } else if (token.kind != T_void) {
3159                 return true;
3160         }
3161         next_token();
3162         return false;
3163 }
3164
3165 /**
3166  * Parses function type parameters (and optionally creates variable_t entities
3167  * for them in a scope)
3168  */
3169 static void parse_parameters(function_type_t *type, scope_t *scope)
3170 {
3171         add_anchor_token(')');
3172         eat('(');
3173
3174         if (token.kind == T_IDENTIFIER            &&
3175             !is_typedef_symbol(token.base.symbol) &&
3176             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3177                 type->kr_style_parameters = true;
3178                 parse_identifier_list(scope);
3179         } else if (token.kind == ')') {
3180                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3181                 if (!(c_mode & _CXX))
3182                         type->unspecified_parameters = true;
3183         } else if (has_parameters()) {
3184                 function_parameter_t **anchor = &type->parameters;
3185                 add_anchor_token(',');
3186                 do {
3187                         switch (token.kind) {
3188                         case T_DOTDOTDOT:
3189                                 eat(T_DOTDOTDOT);
3190                                 type->variadic = true;
3191                                 goto parameters_finished;
3192
3193                         case T_IDENTIFIER:
3194                         DECLARATION_START
3195                         {
3196                                 entity_t *entity = parse_parameter();
3197                                 if (entity->kind == ENTITY_TYPEDEF) {
3198                                         errorf(&entity->base.source_position,
3199                                                         "typedef not allowed as function parameter");
3200                                         break;
3201                                 }
3202                                 assert(is_declaration(entity));
3203
3204                                 semantic_parameter_incomplete(entity);
3205
3206                                 function_parameter_t *const parameter =
3207                                         allocate_parameter(entity->declaration.type);
3208
3209                                 if (scope != NULL) {
3210                                         append_entity(scope, entity);
3211                                 }
3212
3213                                 *anchor = parameter;
3214                                 anchor  = &parameter->next;
3215                                 break;
3216                         }
3217
3218                         default:
3219                                 goto parameters_finished;
3220                         }
3221                 } while (next_if(','));
3222 parameters_finished:
3223                 rem_anchor_token(',');
3224         }
3225
3226         rem_anchor_token(')');
3227         expect(')');
3228 }
3229
3230 typedef enum construct_type_kind_t {
3231         CONSTRUCT_POINTER = 1,
3232         CONSTRUCT_REFERENCE,
3233         CONSTRUCT_FUNCTION,
3234         CONSTRUCT_ARRAY
3235 } construct_type_kind_t;
3236
3237 typedef union construct_type_t construct_type_t;
3238
3239 typedef struct construct_type_base_t {
3240         construct_type_kind_t  kind;
3241         source_position_t      pos;
3242         construct_type_t      *next;
3243 } construct_type_base_t;
3244
3245 typedef struct parsed_pointer_t {
3246         construct_type_base_t  base;
3247         type_qualifiers_t      type_qualifiers;
3248         variable_t            *base_variable;  /**< MS __based extension. */
3249 } parsed_pointer_t;
3250
3251 typedef struct parsed_reference_t {
3252         construct_type_base_t base;
3253 } parsed_reference_t;
3254
3255 typedef struct construct_function_type_t {
3256         construct_type_base_t  base;
3257         type_t                *function_type;
3258 } construct_function_type_t;
3259
3260 typedef struct parsed_array_t {
3261         construct_type_base_t  base;
3262         type_qualifiers_t      type_qualifiers;
3263         bool                   is_static;
3264         bool                   is_variable;
3265         expression_t          *size;
3266 } parsed_array_t;
3267
3268 union construct_type_t {
3269         construct_type_kind_t     kind;
3270         construct_type_base_t     base;
3271         parsed_pointer_t          pointer;
3272         parsed_reference_t        reference;
3273         construct_function_type_t function;
3274         parsed_array_t            array;
3275 };
3276
3277 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3278 {
3279         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3280         memset(cons, 0, size);
3281         cons->kind     = kind;
3282         cons->base.pos = *HERE;
3283         return cons;
3284 }
3285
3286 /* §6.7.5.1 */
3287 static construct_type_t *parse_pointer_declarator(void)
3288 {
3289         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3290         eat('*');
3291         cons->pointer.type_qualifiers = parse_type_qualifiers();
3292         //cons->pointer.base_variable   = base_variable;
3293
3294         return cons;
3295 }
3296
3297 /* ISO/IEC 14882:1998(E) §8.3.2 */
3298 static construct_type_t *parse_reference_declarator(void)
3299 {
3300         if (!(c_mode & _CXX))
3301                 errorf(HERE, "references are only available for C++");
3302
3303         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3304         eat('&');
3305
3306         return cons;
3307 }
3308
3309 /* §6.7.5.2 */
3310 static construct_type_t *parse_array_declarator(void)
3311 {
3312         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3313         parsed_array_t   *const array = &cons->array;
3314
3315         eat('[');
3316         add_anchor_token(']');
3317
3318         bool is_static = next_if(T_static);
3319
3320         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3321
3322         if (!is_static)
3323                 is_static = next_if(T_static);
3324
3325         array->type_qualifiers = type_qualifiers;
3326         array->is_static       = is_static;
3327
3328         expression_t *size = NULL;
3329         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3330                 array->is_variable = true;
3331                 eat('*');
3332         } else if (token.kind != ']') {
3333                 size = parse_assignment_expression();
3334
3335                 /* §6.7.5.2:1  Array size must have integer type */
3336                 type_t *const orig_type = size->base.type;
3337                 type_t *const type      = skip_typeref(orig_type);
3338                 if (!is_type_integer(type) && is_type_valid(type)) {
3339                         errorf(&size->base.source_position,
3340                                "array size '%E' must have integer type but has type '%T'",
3341                                size, orig_type);
3342                 }
3343
3344                 array->size = size;
3345                 mark_vars_read(size, NULL);
3346         }
3347
3348         if (is_static && size == NULL)
3349                 errorf(&array->base.pos, "static array parameters require a size");
3350
3351         rem_anchor_token(']');
3352         expect(']');
3353         return cons;
3354 }
3355
3356 /* §6.7.5.3 */
3357 static construct_type_t *parse_function_declarator(scope_t *scope)
3358 {
3359         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3360
3361         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3362         function_type_t *ftype = &type->function;
3363
3364         ftype->linkage            = current_linkage;
3365         ftype->calling_convention = CC_DEFAULT;
3366
3367         parse_parameters(ftype, scope);
3368
3369         cons->function.function_type = type;
3370
3371         return cons;
3372 }
3373
3374 typedef struct parse_declarator_env_t {
3375         bool               may_be_abstract : 1;
3376         bool               must_be_abstract : 1;
3377         decl_modifiers_t   modifiers;
3378         symbol_t          *symbol;
3379         source_position_t  source_position;
3380         scope_t            parameters;
3381         attribute_t       *attributes;
3382 } parse_declarator_env_t;
3383
3384 /* §6.7.5 */
3385 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3386 {
3387         /* construct a single linked list of construct_type_t's which describe
3388          * how to construct the final declarator type */
3389         construct_type_t  *first      = NULL;
3390         construct_type_t **anchor     = &first;
3391
3392         env->attributes = parse_attributes(env->attributes);
3393
3394         for (;;) {
3395                 construct_type_t *type;
3396                 //variable_t       *based = NULL; /* MS __based extension */
3397                 switch (token.kind) {
3398                         case '&':
3399                                 type = parse_reference_declarator();
3400                                 break;
3401
3402                         case T__based: {
3403                                 panic("based not supported anymore");
3404                                 /* FALLTHROUGH */
3405                         }
3406
3407                         case '*':
3408                                 type = parse_pointer_declarator();
3409                                 break;
3410
3411                         default:
3412                                 goto ptr_operator_end;
3413                 }
3414
3415                 *anchor = type;
3416                 anchor  = &type->base.next;
3417
3418                 /* TODO: find out if this is correct */
3419                 env->attributes = parse_attributes(env->attributes);
3420         }
3421
3422 ptr_operator_end: ;
3423         construct_type_t *inner_types = NULL;
3424
3425         switch (token.kind) {
3426         case T_IDENTIFIER:
3427                 if (env->must_be_abstract) {
3428                         errorf(HERE, "no identifier expected in typename");
3429                 } else {
3430                         env->symbol          = token.base.symbol;
3431                         env->source_position = *HERE;
3432                 }
3433                 eat(T_IDENTIFIER);
3434                 break;
3435
3436         case '(': {
3437                 /* Parenthesized declarator or function declarator? */
3438                 token_t const *const la1 = look_ahead(1);
3439                 switch (la1->kind) {
3440                         case T_IDENTIFIER:
3441                                 if (is_typedef_symbol(la1->base.symbol)) {
3442                         case ')':
3443                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3444                                          * interpreted as ``function with no parameter specification'', rather
3445                                          * than redundant parentheses around the omitted identifier. */
3446                         default:
3447                                         /* Function declarator. */
3448                                         if (!env->may_be_abstract) {
3449                                                 errorf(HERE, "function declarator must have a name");
3450                                         }
3451                                 } else {
3452                         case '&':
3453                         case '(':
3454                         case '*':
3455                         case '[':
3456                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3457                                         /* Paranthesized declarator. */
3458                                         eat('(');
3459                                         add_anchor_token(')');
3460                                         inner_types = parse_inner_declarator(env);
3461                                         if (inner_types != NULL) {
3462                                                 /* All later declarators only modify the return type */
3463                                                 env->must_be_abstract = true;
3464                                         }
3465                                         rem_anchor_token(')');
3466                                         expect(')');
3467                                 }
3468                                 break;
3469                 }
3470                 break;
3471         }
3472
3473         default:
3474                 if (env->may_be_abstract)
3475                         break;
3476                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3477                 eat_until_anchor();
3478                 return NULL;
3479         }
3480
3481         construct_type_t **const p = anchor;
3482
3483         for (;;) {
3484                 construct_type_t *type;
3485                 switch (token.kind) {
3486                 case '(': {
3487                         scope_t *scope = NULL;
3488                         if (!env->must_be_abstract) {
3489                                 scope = &env->parameters;
3490                         }
3491
3492                         type = parse_function_declarator(scope);
3493                         break;
3494                 }
3495                 case '[':
3496                         type = parse_array_declarator();
3497                         break;
3498                 default:
3499                         goto declarator_finished;
3500                 }
3501
3502                 /* insert in the middle of the list (at p) */
3503                 type->base.next = *p;
3504                 *p              = type;
3505                 if (anchor == p)
3506                         anchor = &type->base.next;
3507         }
3508
3509 declarator_finished:
3510         /* append inner_types at the end of the list, we don't to set anchor anymore
3511          * as it's not needed anymore */
3512         *anchor = inner_types;
3513
3514         return first;
3515 }
3516
3517 static type_t *construct_declarator_type(construct_type_t *construct_list,
3518                                          type_t *type)
3519 {
3520         construct_type_t *iter = construct_list;
3521         for (; iter != NULL; iter = iter->base.next) {
3522                 source_position_t const* const pos = &iter->base.pos;
3523                 switch (iter->kind) {
3524                 case CONSTRUCT_FUNCTION: {
3525                         construct_function_type_t *function      = &iter->function;
3526                         type_t                    *function_type = function->function_type;
3527
3528                         function_type->function.return_type = type;
3529
3530                         type_t *skipped_return_type = skip_typeref(type);
3531                         /* §6.7.5.3:1 */
3532                         if (is_type_function(skipped_return_type)) {
3533                                 errorf(pos, "function returning function is not allowed");
3534                         } else if (is_type_array(skipped_return_type)) {
3535                                 errorf(pos, "function returning array is not allowed");
3536                         } else {
3537                                 if (skipped_return_type->base.qualifiers != 0) {
3538                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3539                                 }
3540                         }
3541
3542                         /* The function type was constructed earlier.  Freeing it here will
3543                          * destroy other types. */
3544                         type = typehash_insert(function_type);
3545                         continue;
3546                 }
3547
3548                 case CONSTRUCT_POINTER: {
3549                         if (is_type_reference(skip_typeref(type)))
3550                                 errorf(pos, "cannot declare a pointer to reference");
3551
3552                         parsed_pointer_t *pointer = &iter->pointer;
3553                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3554                         continue;
3555                 }
3556
3557                 case CONSTRUCT_REFERENCE:
3558                         if (is_type_reference(skip_typeref(type)))
3559                                 errorf(pos, "cannot declare a reference to reference");
3560
3561                         type = make_reference_type(type);
3562                         continue;
3563
3564                 case CONSTRUCT_ARRAY: {
3565                         if (is_type_reference(skip_typeref(type)))
3566                                 errorf(pos, "cannot declare an array of references");
3567
3568                         parsed_array_t *array      = &iter->array;
3569                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3570
3571                         expression_t *size_expression = array->size;
3572                         if (size_expression != NULL) {
3573                                 size_expression
3574                                         = create_implicit_cast(size_expression, type_size_t);
3575                         }
3576
3577                         array_type->base.qualifiers       = array->type_qualifiers;
3578                         array_type->array.element_type    = type;
3579                         array_type->array.is_static       = array->is_static;
3580                         array_type->array.is_variable     = array->is_variable;
3581                         array_type->array.size_expression = size_expression;
3582
3583                         if (size_expression != NULL) {
3584                                 switch (is_constant_expression(size_expression)) {
3585                                 case EXPR_CLASS_CONSTANT: {
3586                                         long const size = fold_constant_to_int(size_expression);
3587                                         array_type->array.size          = size;
3588                                         array_type->array.size_constant = true;
3589                                         /* §6.7.5.2:1  If the expression is a constant expression,
3590                                          * it shall have a value greater than zero. */
3591                                         if (size < 0) {
3592                                                 errorf(&size_expression->base.source_position,
3593                                                            "size of array must be greater than zero");
3594                                         } else if (size == 0 && !GNU_MODE) {
3595                                                 errorf(&size_expression->base.source_position,
3596                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3597                                         }
3598                                         break;
3599                                 }
3600
3601                                 case EXPR_CLASS_VARIABLE:
3602                                         array_type->array.is_vla = true;
3603                                         break;
3604
3605                                 case EXPR_CLASS_ERROR:
3606                                         break;
3607                                 }
3608                         }
3609
3610                         type_t *skipped_type = skip_typeref(type);
3611                         /* §6.7.5.2:1 */
3612                         if (is_type_incomplete(skipped_type)) {
3613                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3614                         } else if (is_type_function(skipped_type)) {
3615                                 errorf(pos, "array of functions is not allowed");
3616                         }
3617                         type = identify_new_type(array_type);
3618                         continue;
3619                 }
3620                 }
3621                 internal_errorf(pos, "invalid type construction found");
3622         }
3623
3624         return type;
3625 }
3626
3627 static type_t *automatic_type_conversion(type_t *orig_type);
3628
3629 static type_t *semantic_parameter(const source_position_t *pos,
3630                                   type_t *type,
3631                                   const declaration_specifiers_t *specifiers,
3632                                   entity_t const *const param)
3633 {
3634         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3635          *             shall be adjusted to ``qualified pointer to type'',
3636          *             [...]
3637          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3638          *             type'' shall be adjusted to ``pointer to function
3639          *             returning type'', as in 6.3.2.1. */
3640         type = automatic_type_conversion(type);
3641
3642         if (specifiers->is_inline && is_type_valid(type)) {
3643                 errorf(pos, "'%N' declared 'inline'", param);
3644         }
3645
3646         /* §6.9.1:6  The declarations in the declaration list shall contain
3647          *           no storage-class specifier other than register and no
3648          *           initializations. */
3649         if (specifiers->thread_local || (
3650                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3651                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3652            ) {
3653                 errorf(pos, "invalid storage class for '%N'", param);
3654         }
3655
3656         /* delay test for incomplete type, because we might have (void)
3657          * which is legal but incomplete... */
3658
3659         return type;
3660 }
3661
3662 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3663                                   declarator_flags_t flags)
3664 {
3665         parse_declarator_env_t env;
3666         memset(&env, 0, sizeof(env));
3667         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3668
3669         construct_type_t *construct_type = parse_inner_declarator(&env);
3670         type_t           *orig_type      =
3671                 construct_declarator_type(construct_type, specifiers->type);
3672         type_t           *type           = skip_typeref(orig_type);
3673
3674         if (construct_type != NULL) {
3675                 obstack_free(&temp_obst, construct_type);
3676         }
3677
3678         attribute_t *attributes = parse_attributes(env.attributes);
3679         /* append (shared) specifier attribute behind attributes of this
3680          * declarator */
3681         attribute_t **anchor = &attributes;
3682         while (*anchor != NULL)
3683                 anchor = &(*anchor)->next;
3684         *anchor = specifiers->attributes;
3685
3686         entity_t *entity;
3687         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3688                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3689                 entity->typedefe.type = orig_type;
3690
3691                 if (anonymous_entity != NULL) {
3692                         if (is_type_compound(type)) {
3693                                 assert(anonymous_entity->compound.alias == NULL);
3694                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3695                                        anonymous_entity->kind == ENTITY_UNION);
3696                                 anonymous_entity->compound.alias = entity;
3697                                 anonymous_entity = NULL;
3698                         } else if (is_type_enum(type)) {
3699                                 assert(anonymous_entity->enume.alias == NULL);
3700                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3701                                 anonymous_entity->enume.alias = entity;
3702                                 anonymous_entity = NULL;
3703                         }
3704                 }
3705         } else {
3706                 /* create a declaration type entity */
3707                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3708                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3709                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3710
3711                         if (env.symbol != NULL) {
3712                                 if (specifiers->is_inline && is_type_valid(type)) {
3713                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3714                                 }
3715
3716                                 if (specifiers->thread_local ||
3717                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3718                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3719                                 }
3720                         }
3721                 } else if (flags & DECL_IS_PARAMETER) {
3722                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3723                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3724                 } else if (is_type_function(type)) {
3725                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3726                         entity->function.is_inline      = specifiers->is_inline;
3727                         entity->function.elf_visibility = default_visibility;
3728                         entity->function.parameters     = env.parameters;
3729
3730                         if (env.symbol != NULL) {
3731                                 /* this needs fixes for C++ */
3732                                 bool in_function_scope = current_function != NULL;
3733
3734                                 if (specifiers->thread_local || (
3735                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3736                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3737                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3738                                                 )) {
3739                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3740                                 }
3741                         }
3742                 } else {
3743                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3744                         entity->variable.elf_visibility = default_visibility;
3745                         entity->variable.thread_local   = specifiers->thread_local;
3746
3747                         if (env.symbol != NULL) {
3748                                 if (specifiers->is_inline && is_type_valid(type)) {
3749                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3750                                 }
3751
3752                                 bool invalid_storage_class = false;
3753                                 if (current_scope == file_scope) {
3754                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3755                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3756                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3757                                                 invalid_storage_class = true;
3758                                         }
3759                                 } else {
3760                                         if (specifiers->thread_local &&
3761                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3762                                                 invalid_storage_class = true;
3763                                         }
3764                                 }
3765                                 if (invalid_storage_class) {
3766                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3767                                 }
3768                         }
3769                 }
3770
3771                 entity->declaration.type       = orig_type;
3772                 entity->declaration.alignment  = get_type_alignment(orig_type);
3773                 entity->declaration.modifiers  = env.modifiers;
3774                 entity->declaration.attributes = attributes;
3775
3776                 storage_class_t storage_class = specifiers->storage_class;
3777                 entity->declaration.declared_storage_class = storage_class;
3778
3779                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3780                         storage_class = STORAGE_CLASS_AUTO;
3781                 entity->declaration.storage_class = storage_class;
3782         }
3783
3784         if (attributes != NULL) {
3785                 handle_entity_attributes(attributes, entity);
3786         }
3787
3788         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3789                 adapt_special_functions(&entity->function);
3790         }
3791
3792         return entity;
3793 }
3794
3795 static type_t *parse_abstract_declarator(type_t *base_type)
3796 {
3797         parse_declarator_env_t env;
3798         memset(&env, 0, sizeof(env));
3799         env.may_be_abstract = true;
3800         env.must_be_abstract = true;
3801
3802         construct_type_t *construct_type = parse_inner_declarator(&env);
3803
3804         type_t *result = construct_declarator_type(construct_type, base_type);
3805         if (construct_type != NULL) {
3806                 obstack_free(&temp_obst, construct_type);
3807         }
3808         result = handle_type_attributes(env.attributes, result);
3809
3810         return result;
3811 }
3812
3813 /**
3814  * Check if the declaration of main is suspicious.  main should be a
3815  * function with external linkage, returning int, taking either zero
3816  * arguments, two, or three arguments of appropriate types, ie.
3817  *
3818  * int main([ int argc, char **argv [, char **env ] ]).
3819  *
3820  * @param decl    the declaration to check
3821  * @param type    the function type of the declaration
3822  */
3823 static void check_main(const entity_t *entity)
3824 {
3825         const source_position_t *pos = &entity->base.source_position;
3826         if (entity->kind != ENTITY_FUNCTION) {
3827                 warningf(WARN_MAIN, pos, "'main' is not a function");
3828                 return;
3829         }
3830
3831         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3832                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3833         }
3834
3835         type_t *type = skip_typeref(entity->declaration.type);
3836         assert(is_type_function(type));
3837
3838         function_type_t const *const func_type = &type->function;
3839         type_t                *const ret_type  = func_type->return_type;
3840         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3841                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3842         }
3843         const function_parameter_t *parm = func_type->parameters;
3844         if (parm != NULL) {
3845                 type_t *const first_type        = skip_typeref(parm->type);
3846                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3847                 if (!types_compatible(first_type_unqual, type_int)) {
3848                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3849                 }
3850                 parm = parm->next;
3851                 if (parm != NULL) {
3852                         type_t *const second_type = skip_typeref(parm->type);
3853                         type_t *const second_type_unqual
3854                                 = get_unqualified_type(second_type);
3855                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3856                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3857                         }
3858                         parm = parm->next;
3859                         if (parm != NULL) {
3860                                 type_t *const third_type = skip_typeref(parm->type);
3861                                 type_t *const third_type_unqual
3862                                         = get_unqualified_type(third_type);
3863                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3864                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3865                                 }
3866                                 parm = parm->next;
3867                                 if (parm != NULL)
3868                                         goto warn_arg_count;
3869                         }
3870                 } else {
3871 warn_arg_count:
3872                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3873                 }
3874         }
3875 }
3876
3877 static void error_redefined_as_different_kind(const source_position_t *pos,
3878                 const entity_t *old, entity_kind_t new_kind)
3879 {
3880         char              const *const what = get_entity_kind_name(new_kind);
3881         source_position_t const *const ppos = &old->base.source_position;
3882         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3883 }
3884
3885 static bool is_entity_valid(entity_t *const ent)
3886 {
3887         if (is_declaration(ent)) {
3888                 return is_type_valid(skip_typeref(ent->declaration.type));
3889         } else if (ent->kind == ENTITY_TYPEDEF) {
3890                 return is_type_valid(skip_typeref(ent->typedefe.type));
3891         }
3892         return true;
3893 }
3894
3895 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3896 {
3897         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3898                 if (attributes_equal(tattr, attr))
3899                         return true;
3900         }
3901         return false;
3902 }
3903
3904 /**
3905  * test wether new_list contains any attributes not included in old_list
3906  */
3907 static bool has_new_attributes(const attribute_t *old_list,
3908                                const attribute_t *new_list)
3909 {
3910         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3911                 if (!contains_attribute(old_list, attr))
3912                         return true;
3913         }
3914         return false;
3915 }
3916
3917 /**
3918  * Merge in attributes from an attribute list (probably from a previous
3919  * declaration with the same name). Warning: destroys the old structure
3920  * of the attribute list - don't reuse attributes after this call.
3921  */
3922 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3923 {
3924         attribute_t *next;
3925         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3926                 next = attr->next;
3927                 if (contains_attribute(decl->attributes, attr))
3928                         continue;
3929
3930                 /* move attribute to new declarations attributes list */
3931                 attr->next       = decl->attributes;
3932                 decl->attributes = attr;
3933         }
3934 }
3935
3936 static bool is_main(entity_t*);
3937
3938 /**
3939  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3940  * for various problems that occur for multiple definitions
3941  */
3942 entity_t *record_entity(entity_t *entity, const bool is_definition)
3943 {
3944         const symbol_t *const    symbol  = entity->base.symbol;
3945         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3946         const source_position_t *pos     = &entity->base.source_position;
3947
3948         /* can happen in error cases */
3949         if (symbol == NULL)
3950                 return entity;
3951
3952         assert(!entity->base.parent_scope);
3953         assert(current_scope);
3954         entity->base.parent_scope = current_scope;
3955
3956         entity_t *const previous_entity = get_entity(symbol, namespc);
3957         /* pushing the same entity twice will break the stack structure */
3958         assert(previous_entity != entity);
3959
3960         if (entity->kind == ENTITY_FUNCTION) {
3961                 type_t *const orig_type = entity->declaration.type;
3962                 type_t *const type      = skip_typeref(orig_type);
3963
3964                 assert(is_type_function(type));
3965                 if (type->function.unspecified_parameters &&
3966                     previous_entity == NULL               &&
3967                     !entity->declaration.implicit) {
3968                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3969                 }
3970
3971                 if (is_main(entity)) {
3972                         check_main(entity);
3973                 }
3974         }
3975
3976         if (is_declaration(entity)                                    &&
3977             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3978             current_scope != file_scope                               &&
3979             !entity->declaration.implicit) {
3980                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3981         }
3982
3983         if (previous_entity != NULL) {
3984                 source_position_t const *const ppos = &previous_entity->base.source_position;
3985
3986                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3987                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3988                         assert(previous_entity->kind == ENTITY_PARAMETER);
3989                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3990                         goto finish;
3991                 }
3992
3993                 if (previous_entity->base.parent_scope == current_scope) {
3994                         if (previous_entity->kind != entity->kind) {
3995                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3996                                         error_redefined_as_different_kind(pos, previous_entity,
3997                                                         entity->kind);
3998                                 }
3999                                 goto finish;
4000                         }
4001                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4002                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4003                                 goto finish;
4004                         }
4005                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4006                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4007                                 type_t *const prev_type
4008                                         = skip_typeref(previous_entity->typedefe.type);
4009                                 if (c_mode & _CXX) {
4010                                         /* C++ allows double typedef if they are identical
4011                                          * (after skipping typedefs) */
4012                                         if (type == prev_type)
4013                                                 goto finish;
4014                                 } else {
4015                                         /* GCC extension: redef in system headers is allowed */
4016                                         if ((pos->is_system_header || ppos->is_system_header) &&
4017                                             types_compatible(type, prev_type))
4018                                                 goto finish;
4019                                 }
4020                                 errorf(pos, "redefinition of '%N' (declared %P)",
4021                                        entity, ppos);
4022                                 goto finish;
4023                         }
4024
4025                         /* at this point we should have only VARIABLES or FUNCTIONS */
4026                         assert(is_declaration(previous_entity) && is_declaration(entity));
4027
4028                         declaration_t *const prev_decl = &previous_entity->declaration;
4029                         declaration_t *const decl      = &entity->declaration;
4030
4031                         /* can happen for K&R style declarations */
4032                         if (prev_decl->type       == NULL             &&
4033                                         previous_entity->kind == ENTITY_PARAMETER &&
4034                                         entity->kind          == ENTITY_PARAMETER) {
4035                                 prev_decl->type                   = decl->type;
4036                                 prev_decl->storage_class          = decl->storage_class;
4037                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4038                                 prev_decl->modifiers              = decl->modifiers;
4039                                 return previous_entity;
4040                         }
4041
4042                         type_t *const type      = skip_typeref(decl->type);
4043                         type_t *const prev_type = skip_typeref(prev_decl->type);
4044
4045                         if (!types_compatible(type, prev_type)) {
4046                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4047                         } else {
4048                                 unsigned old_storage_class = prev_decl->storage_class;
4049
4050                                 if (is_definition                     &&
4051                                                 !prev_decl->used                  &&
4052                                                 !(prev_decl->modifiers & DM_USED) &&
4053                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4054                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4055                                 }
4056
4057                                 storage_class_t new_storage_class = decl->storage_class;
4058
4059                                 /* pretend no storage class means extern for function
4060                                  * declarations (except if the previous declaration is neither
4061                                  * none nor extern) */
4062                                 if (entity->kind == ENTITY_FUNCTION) {
4063                                         /* the previous declaration could have unspecified parameters or
4064                                          * be a typedef, so use the new type */
4065                                         if (prev_type->function.unspecified_parameters || is_definition)
4066                                                 prev_decl->type = type;
4067
4068                                         switch (old_storage_class) {
4069                                                 case STORAGE_CLASS_NONE:
4070                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4071                                                         /* FALLTHROUGH */
4072
4073                                                 case STORAGE_CLASS_EXTERN:
4074                                                         if (is_definition) {
4075                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4076                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4077                                                                 }
4078                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4079                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4080                                                         }
4081                                                         break;
4082
4083                                                 default:
4084                                                         break;
4085                                         }
4086                                 } else if (is_type_incomplete(prev_type)) {
4087                                         prev_decl->type = type;
4088                                 }
4089
4090                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4091                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4092
4093 warn_redundant_declaration: ;
4094                                         bool has_new_attrs
4095                                                 = has_new_attributes(prev_decl->attributes,
4096                                                                      decl->attributes);
4097                                         if (has_new_attrs) {
4098                                                 merge_in_attributes(decl, prev_decl->attributes);
4099                                         } else if (!is_definition        &&
4100                                                         is_type_valid(prev_type) &&
4101                                                         !pos->is_system_header) {
4102                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4103                                         }
4104                                 } else if (current_function == NULL) {
4105                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4106                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4107                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4108                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4109                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4110                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4111                                         } else {
4112                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4113                                                 if (c_mode & _CXX)
4114                                                         goto error_redeclaration;
4115                                                 goto warn_redundant_declaration;
4116                                         }
4117                                 } else if (is_type_valid(prev_type)) {
4118                                         if (old_storage_class == new_storage_class) {
4119 error_redeclaration:
4120                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4121                                         } else {
4122                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4123                                         }
4124                                 }
4125                         }
4126
4127                         prev_decl->modifiers |= decl->modifiers;
4128                         if (entity->kind == ENTITY_FUNCTION) {
4129                                 previous_entity->function.is_inline |= entity->function.is_inline;
4130                         }
4131                         return previous_entity;
4132                 }
4133
4134                 warning_t why;
4135                 if (is_warn_on(why = WARN_SHADOW) ||
4136                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4137                         char const *const what = get_entity_kind_name(previous_entity->kind);
4138                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4139                 }
4140         }
4141
4142         if (entity->kind == ENTITY_FUNCTION) {
4143                 if (is_definition &&
4144                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4145                                 !is_main(entity)) {
4146                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4147                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4148                         } else {
4149                                 goto warn_missing_declaration;
4150                         }
4151                 }
4152         } else if (entity->kind == ENTITY_VARIABLE) {
4153                 if (current_scope                     == file_scope &&
4154                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4155                                 !entity->declaration.implicit) {
4156 warn_missing_declaration:
4157                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4158                 }
4159         }
4160
4161 finish:
4162         environment_push(entity);
4163         append_entity(current_scope, entity);
4164
4165         return entity;
4166 }
4167
4168 static void parser_error_multiple_definition(entity_t *entity,
4169                 const source_position_t *source_position)
4170 {
4171         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4172 }
4173
4174 static bool is_declaration_specifier(const token_t *token)
4175 {
4176         switch (token->kind) {
4177                 DECLARATION_START
4178                         return true;
4179                 case T_IDENTIFIER:
4180                         return is_typedef_symbol(token->base.symbol);
4181
4182                 default:
4183                         return false;
4184         }
4185 }
4186
4187 static void parse_init_declarator_rest(entity_t *entity)
4188 {
4189         type_t *orig_type = type_error_type;
4190
4191         if (entity->base.kind == ENTITY_TYPEDEF) {
4192                 source_position_t const *const pos = &entity->base.source_position;
4193                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4194         } else {
4195                 assert(is_declaration(entity));
4196                 orig_type = entity->declaration.type;
4197         }
4198
4199         type_t *type = skip_typeref(orig_type);
4200
4201         if (entity->kind == ENTITY_VARIABLE
4202                         && entity->variable.initializer != NULL) {
4203                 parser_error_multiple_definition(entity, HERE);
4204         }
4205         eat('=');
4206
4207         declaration_t *const declaration = &entity->declaration;
4208         bool must_be_constant = false;
4209         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4210             entity->base.parent_scope  == file_scope) {
4211                 must_be_constant = true;
4212         }
4213
4214         if (is_type_function(type)) {
4215                 source_position_t const *const pos = &entity->base.source_position;
4216                 errorf(pos, "'%N' is initialized like a variable", entity);
4217                 orig_type = type_error_type;
4218         }
4219
4220         parse_initializer_env_t env;
4221         env.type             = orig_type;
4222         env.must_be_constant = must_be_constant;
4223         env.entity           = entity;
4224
4225         initializer_t *initializer = parse_initializer(&env);
4226
4227         if (entity->kind == ENTITY_VARIABLE) {
4228                 /* §6.7.5:22  array initializers for arrays with unknown size
4229                  * determine the array type size */
4230                 declaration->type            = env.type;
4231                 entity->variable.initializer = initializer;
4232         }
4233 }
4234
4235 /* parse rest of a declaration without any declarator */
4236 static void parse_anonymous_declaration_rest(
4237                 const declaration_specifiers_t *specifiers)
4238 {
4239         eat(';');
4240         anonymous_entity = NULL;
4241
4242         source_position_t const *const pos = &specifiers->source_position;
4243         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4244                         specifiers->thread_local) {
4245                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4246         }
4247
4248         type_t *type = specifiers->type;
4249         switch (type->kind) {
4250                 case TYPE_COMPOUND_STRUCT:
4251                 case TYPE_COMPOUND_UNION: {
4252                         if (type->compound.compound->base.symbol == NULL) {
4253                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4254                         }
4255                         break;
4256                 }
4257
4258                 case TYPE_ENUM:
4259                         break;
4260
4261                 default:
4262                         warningf(WARN_OTHER, pos, "empty declaration");
4263                         break;
4264         }
4265 }
4266
4267 static void check_variable_type_complete(entity_t *ent)
4268 {
4269         if (ent->kind != ENTITY_VARIABLE)
4270                 return;
4271
4272         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4273          *         type for the object shall be complete [...] */
4274         declaration_t *decl = &ent->declaration;
4275         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4276                         decl->storage_class == STORAGE_CLASS_STATIC)
4277                 return;
4278
4279         type_t *const type = skip_typeref(decl->type);
4280         if (!is_type_incomplete(type))
4281                 return;
4282
4283         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4284          * are given length one. */
4285         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4286                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4287                 return;
4288         }
4289
4290         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4291 }
4292
4293
4294 static void parse_declaration_rest(entity_t *ndeclaration,
4295                 const declaration_specifiers_t *specifiers,
4296                 parsed_declaration_func         finished_declaration,
4297                 declarator_flags_t              flags)
4298 {
4299         add_anchor_token(';');
4300         add_anchor_token(',');
4301         while (true) {
4302                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4303
4304                 if (token.kind == '=') {
4305                         parse_init_declarator_rest(entity);
4306                 } else if (entity->kind == ENTITY_VARIABLE) {
4307                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4308                          * [...] where the extern specifier is explicitly used. */
4309                         declaration_t *decl = &entity->declaration;
4310                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4311                             is_type_reference(skip_typeref(decl->type))) {
4312                                 source_position_t const *const pos = &entity->base.source_position;
4313                                 errorf(pos, "reference '%#N' must be initialized", entity);
4314                         }
4315                 }
4316
4317                 check_variable_type_complete(entity);
4318
4319                 if (!next_if(','))
4320                         break;
4321
4322                 add_anchor_token('=');
4323                 ndeclaration = parse_declarator(specifiers, flags);
4324                 rem_anchor_token('=');
4325         }
4326         rem_anchor_token(',');
4327         rem_anchor_token(';');
4328         expect(';');
4329
4330         anonymous_entity = NULL;
4331 }
4332
4333 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4334 {
4335         symbol_t *symbol = entity->base.symbol;
4336         if (symbol == NULL)
4337                 return entity;
4338
4339         assert(entity->base.namespc == NAMESPACE_NORMAL);
4340         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4341         if (previous_entity == NULL
4342                         || previous_entity->base.parent_scope != current_scope) {
4343                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4344                        symbol);
4345                 return entity;
4346         }
4347
4348         if (is_definition) {
4349                 errorf(HERE, "'%N' is initialised", entity);
4350         }
4351
4352         return record_entity(entity, false);
4353 }
4354
4355 static void parse_declaration(parsed_declaration_func finished_declaration,
4356                               declarator_flags_t      flags)
4357 {
4358         add_anchor_token(';');
4359         declaration_specifiers_t specifiers;
4360         parse_declaration_specifiers(&specifiers);
4361         rem_anchor_token(';');
4362
4363         if (token.kind == ';') {
4364                 parse_anonymous_declaration_rest(&specifiers);
4365         } else {
4366                 entity_t *entity = parse_declarator(&specifiers, flags);
4367                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4368         }
4369 }
4370
4371 /* §6.5.2.2:6 */
4372 static type_t *get_default_promoted_type(type_t *orig_type)
4373 {
4374         type_t *result = orig_type;
4375
4376         type_t *type = skip_typeref(orig_type);
4377         if (is_type_integer(type)) {
4378                 result = promote_integer(type);
4379         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4380                 result = type_double;
4381         }
4382
4383         return result;
4384 }
4385
4386 static void parse_kr_declaration_list(entity_t *entity)
4387 {
4388         if (entity->kind != ENTITY_FUNCTION)
4389                 return;
4390
4391         type_t *type = skip_typeref(entity->declaration.type);
4392         assert(is_type_function(type));
4393         if (!type->function.kr_style_parameters)
4394                 return;
4395
4396         add_anchor_token('{');
4397
4398         PUSH_SCOPE(&entity->function.parameters);
4399
4400         entity_t *parameter = entity->function.parameters.entities;
4401         for ( ; parameter != NULL; parameter = parameter->base.next) {
4402                 assert(parameter->base.parent_scope == NULL);
4403                 parameter->base.parent_scope = current_scope;
4404                 environment_push(parameter);
4405         }
4406
4407         /* parse declaration list */
4408         for (;;) {
4409                 switch (token.kind) {
4410                         DECLARATION_START
4411                         /* This covers symbols, which are no type, too, and results in
4412                          * better error messages.  The typical cases are misspelled type
4413                          * names and missing includes. */
4414                         case T_IDENTIFIER:
4415                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4416                                 break;
4417                         default:
4418                                 goto decl_list_end;
4419                 }
4420         }
4421 decl_list_end:
4422
4423         POP_SCOPE();
4424
4425         /* update function type */
4426         type_t *new_type = duplicate_type(type);
4427
4428         function_parameter_t  *parameters = NULL;
4429         function_parameter_t **anchor     = &parameters;
4430
4431         /* did we have an earlier prototype? */
4432         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4433         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4434                 proto_type = NULL;
4435
4436         function_parameter_t *proto_parameter = NULL;
4437         if (proto_type != NULL) {
4438                 type_t *proto_type_type = proto_type->declaration.type;
4439                 proto_parameter         = proto_type_type->function.parameters;
4440                 /* If a K&R function definition has a variadic prototype earlier, then
4441                  * make the function definition variadic, too. This should conform to
4442                  * §6.7.5.3:15 and §6.9.1:8. */
4443                 new_type->function.variadic = proto_type_type->function.variadic;
4444         } else {
4445                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4446                  * prototype */
4447                 new_type->function.unspecified_parameters = true;
4448         }
4449
4450         bool need_incompatible_warning = false;
4451         parameter = entity->function.parameters.entities;
4452         for (; parameter != NULL; parameter = parameter->base.next,
4453                         proto_parameter =
4454                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4455                 if (parameter->kind != ENTITY_PARAMETER)
4456                         continue;
4457
4458                 type_t *parameter_type = parameter->declaration.type;
4459                 if (parameter_type == NULL) {
4460                         source_position_t const* const pos = &parameter->base.source_position;
4461                         if (strict_mode) {
4462                                 errorf(pos, "no type specified for function '%N'", parameter);
4463                                 parameter_type = type_error_type;
4464                         } else {
4465                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4466                                 parameter_type = type_int;
4467                         }
4468                         parameter->declaration.type = parameter_type;
4469                 }
4470
4471                 semantic_parameter_incomplete(parameter);
4472
4473                 /* we need the default promoted types for the function type */
4474                 type_t *not_promoted = parameter_type;
4475                 parameter_type       = get_default_promoted_type(parameter_type);
4476
4477                 /* gcc special: if the type of the prototype matches the unpromoted
4478                  * type don't promote */
4479                 if (!strict_mode && proto_parameter != NULL) {
4480                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4481                         type_t *promo_skip   = skip_typeref(parameter_type);
4482                         type_t *param_skip   = skip_typeref(not_promoted);
4483                         if (!types_compatible(proto_p_type, promo_skip)
4484                                 && types_compatible(proto_p_type, param_skip)) {
4485                                 /* don't promote */
4486                                 need_incompatible_warning = true;
4487                                 parameter_type = not_promoted;
4488                         }
4489                 }
4490                 function_parameter_t *const function_parameter
4491                         = allocate_parameter(parameter_type);
4492
4493                 *anchor = function_parameter;
4494                 anchor  = &function_parameter->next;
4495         }
4496
4497         new_type->function.parameters = parameters;
4498         new_type = identify_new_type(new_type);
4499
4500         if (need_incompatible_warning) {
4501                 symbol_t          const *const sym  = entity->base.symbol;
4502                 source_position_t const *const pos  = &entity->base.source_position;
4503                 source_position_t const *const ppos = &proto_type->base.source_position;
4504                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4505         }
4506         entity->declaration.type = new_type;
4507
4508         rem_anchor_token('{');
4509 }
4510
4511 static bool first_err = true;
4512
4513 /**
4514  * When called with first_err set, prints the name of the current function,
4515  * else does noting.
4516  */
4517 static void print_in_function(void)
4518 {
4519         if (first_err) {
4520                 first_err = false;
4521                 char const *const file = current_function->base.base.source_position.input_name;
4522                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4523         }
4524 }
4525
4526 /**
4527  * Check if all labels are defined in the current function.
4528  * Check if all labels are used in the current function.
4529  */
4530 static void check_labels(void)
4531 {
4532         for (const goto_statement_t *goto_statement = goto_first;
4533             goto_statement != NULL;
4534             goto_statement = goto_statement->next) {
4535                 label_t *label = goto_statement->label;
4536                 if (label->base.source_position.input_name == NULL) {
4537                         print_in_function();
4538                         source_position_t const *const pos = &goto_statement->base.source_position;
4539                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4540                  }
4541         }
4542
4543         if (is_warn_on(WARN_UNUSED_LABEL)) {
4544                 for (const label_statement_t *label_statement = label_first;
4545                          label_statement != NULL;
4546                          label_statement = label_statement->next) {
4547                         label_t *label = label_statement->label;
4548
4549                         if (! label->used) {
4550                                 print_in_function();
4551                                 source_position_t const *const pos = &label_statement->base.source_position;
4552                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4553                         }
4554                 }
4555         }
4556 }
4557
4558 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4559 {
4560         entity_t const *const end = last != NULL ? last->base.next : NULL;
4561         for (; entity != end; entity = entity->base.next) {
4562                 if (!is_declaration(entity))
4563                         continue;
4564
4565                 declaration_t *declaration = &entity->declaration;
4566                 if (declaration->implicit)
4567                         continue;
4568
4569                 if (!declaration->used) {
4570                         print_in_function();
4571                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4572                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4573                         print_in_function();
4574                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4575                 }
4576         }
4577 }
4578
4579 static void check_unused_variables(statement_t *const stmt, void *const env)
4580 {
4581         (void)env;
4582
4583         switch (stmt->kind) {
4584                 case STATEMENT_DECLARATION: {
4585                         declaration_statement_t const *const decls = &stmt->declaration;
4586                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4587                         return;
4588                 }
4589
4590                 case STATEMENT_FOR:
4591                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4592                         return;
4593
4594                 default:
4595                         return;
4596         }
4597 }
4598
4599 /**
4600  * Check declarations of current_function for unused entities.
4601  */
4602 static void check_declarations(void)
4603 {
4604         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4605                 const scope_t *scope = &current_function->parameters;
4606                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4607         }
4608         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4609                 walk_statements(current_function->statement, check_unused_variables,
4610                                 NULL);
4611         }
4612 }
4613
4614 static int determine_truth(expression_t const* const cond)
4615 {
4616         return
4617                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4618                 fold_constant_to_bool(cond)                         ? 1 :
4619                 -1;
4620 }
4621
4622 static void check_reachable(statement_t *);
4623 static bool reaches_end;
4624
4625 static bool expression_returns(expression_t const *const expr)
4626 {
4627         switch (expr->kind) {
4628                 case EXPR_CALL: {
4629                         expression_t const *const func = expr->call.function;
4630                         type_t       const *const type = skip_typeref(func->base.type);
4631                         if (type->kind == TYPE_POINTER) {
4632                                 type_t const *const points_to
4633                                         = skip_typeref(type->pointer.points_to);
4634                                 if (points_to->kind == TYPE_FUNCTION
4635                                     && points_to->function.modifiers & DM_NORETURN)
4636                                         return false;
4637                         }
4638
4639                         if (!expression_returns(func))
4640                                 return false;
4641
4642                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4643                                 if (!expression_returns(arg->expression))
4644                                         return false;
4645                         }
4646
4647                         return true;
4648                 }
4649
4650                 case EXPR_REFERENCE:
4651                 case EXPR_ENUM_CONSTANT:
4652                 case EXPR_LITERAL_CASES:
4653                 case EXPR_LITERAL_CHARACTER:
4654                 case EXPR_STRING_LITERAL:
4655                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4656                 case EXPR_LABEL_ADDRESS:
4657                 case EXPR_CLASSIFY_TYPE:
4658                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4659                 case EXPR_ALIGNOF:
4660                 case EXPR_FUNCNAME:
4661                 case EXPR_BUILTIN_CONSTANT_P:
4662                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4663                 case EXPR_OFFSETOF:
4664                 case EXPR_ERROR:
4665                         return true;
4666
4667                 case EXPR_STATEMENT: {
4668                         bool old_reaches_end = reaches_end;
4669                         reaches_end = false;
4670                         check_reachable(expr->statement.statement);
4671                         bool returns = reaches_end;
4672                         reaches_end = old_reaches_end;
4673                         return returns;
4674                 }
4675
4676                 case EXPR_CONDITIONAL:
4677                         // TODO handle constant expression
4678
4679                         if (!expression_returns(expr->conditional.condition))
4680                                 return false;
4681
4682                         if (expr->conditional.true_expression != NULL
4683                                         && expression_returns(expr->conditional.true_expression))
4684                                 return true;
4685
4686                         return expression_returns(expr->conditional.false_expression);
4687
4688                 case EXPR_SELECT:
4689                         return expression_returns(expr->select.compound);
4690
4691                 case EXPR_ARRAY_ACCESS:
4692                         return
4693                                 expression_returns(expr->array_access.array_ref) &&
4694                                 expression_returns(expr->array_access.index);
4695
4696                 case EXPR_VA_START:
4697                         return expression_returns(expr->va_starte.ap);
4698
4699                 case EXPR_VA_ARG:
4700                         return expression_returns(expr->va_arge.ap);
4701
4702                 case EXPR_VA_COPY:
4703                         return expression_returns(expr->va_copye.src);
4704
4705                 case EXPR_UNARY_CASES_MANDATORY:
4706                         return expression_returns(expr->unary.value);
4707
4708                 case EXPR_UNARY_THROW:
4709                         return false;
4710
4711                 case EXPR_BINARY_CASES:
4712                         // TODO handle constant lhs of && and ||
4713                         return
4714                                 expression_returns(expr->binary.left) &&
4715                                 expression_returns(expr->binary.right);
4716         }
4717
4718         panic("unhandled expression");
4719 }
4720
4721 static bool initializer_returns(initializer_t const *const init)
4722 {
4723         switch (init->kind) {
4724                 case INITIALIZER_VALUE:
4725                         return expression_returns(init->value.value);
4726
4727                 case INITIALIZER_LIST: {
4728                         initializer_t * const*       i       = init->list.initializers;
4729                         initializer_t * const* const end     = i + init->list.len;
4730                         bool                         returns = true;
4731                         for (; i != end; ++i) {
4732                                 if (!initializer_returns(*i))
4733                                         returns = false;
4734                         }
4735                         return returns;
4736                 }
4737
4738                 case INITIALIZER_STRING:
4739                 case INITIALIZER_WIDE_STRING:
4740                 case INITIALIZER_DESIGNATOR: // designators have no payload
4741                         return true;
4742         }
4743         panic("unhandled initializer");
4744 }
4745
4746 static bool noreturn_candidate;
4747
4748 static void check_reachable(statement_t *const stmt)
4749 {
4750         if (stmt->base.reachable)
4751                 return;
4752         if (stmt->kind != STATEMENT_DO_WHILE)
4753                 stmt->base.reachable = true;
4754
4755         statement_t *last = stmt;
4756         statement_t *next;
4757         switch (stmt->kind) {
4758                 case STATEMENT_ERROR:
4759                 case STATEMENT_EMPTY:
4760                 case STATEMENT_ASM:
4761                         next = stmt->base.next;
4762                         break;
4763
4764                 case STATEMENT_DECLARATION: {
4765                         declaration_statement_t const *const decl = &stmt->declaration;
4766                         entity_t                const *      ent  = decl->declarations_begin;
4767                         entity_t                const *const last_decl = decl->declarations_end;
4768                         if (ent != NULL) {
4769                                 for (;; ent = ent->base.next) {
4770                                         if (ent->kind                 == ENTITY_VARIABLE &&
4771                                             ent->variable.initializer != NULL            &&
4772                                             !initializer_returns(ent->variable.initializer)) {
4773                                                 return;
4774                                         }
4775                                         if (ent == last_decl)
4776                                                 break;
4777                                 }
4778                         }
4779                         next = stmt->base.next;
4780                         break;
4781                 }
4782
4783                 case STATEMENT_COMPOUND:
4784                         next = stmt->compound.statements;
4785                         if (next == NULL)
4786                                 next = stmt->base.next;
4787                         break;
4788
4789                 case STATEMENT_RETURN: {
4790                         expression_t const *const val = stmt->returns.value;
4791                         if (val == NULL || expression_returns(val))
4792                                 noreturn_candidate = false;
4793                         return;
4794                 }
4795
4796                 case STATEMENT_IF: {
4797                         if_statement_t const *const ifs  = &stmt->ifs;
4798                         expression_t   const *const cond = ifs->condition;
4799
4800                         if (!expression_returns(cond))
4801                                 return;
4802
4803                         int const val = determine_truth(cond);
4804
4805                         if (val >= 0)
4806                                 check_reachable(ifs->true_statement);
4807
4808                         if (val > 0)
4809                                 return;
4810
4811                         if (ifs->false_statement != NULL) {
4812                                 check_reachable(ifs->false_statement);
4813                                 return;
4814                         }
4815
4816                         next = stmt->base.next;
4817                         break;
4818                 }
4819
4820                 case STATEMENT_SWITCH: {
4821                         switch_statement_t const *const switchs = &stmt->switchs;
4822                         expression_t       const *const expr    = switchs->expression;
4823
4824                         if (!expression_returns(expr))
4825                                 return;
4826
4827                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4828                                 long                    const val      = fold_constant_to_int(expr);
4829                                 case_label_statement_t *      defaults = NULL;
4830                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4831                                         if (i->expression == NULL) {
4832                                                 defaults = i;
4833                                                 continue;
4834                                         }
4835
4836                                         if (i->first_case <= val && val <= i->last_case) {
4837                                                 check_reachable((statement_t*)i);
4838                                                 return;
4839                                         }
4840                                 }
4841
4842                                 if (defaults != NULL) {
4843                                         check_reachable((statement_t*)defaults);
4844                                         return;
4845                                 }
4846                         } else {
4847                                 bool has_default = false;
4848                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4849                                         if (i->expression == NULL)
4850                                                 has_default = true;
4851
4852                                         check_reachable((statement_t*)i);
4853                                 }
4854
4855                                 if (has_default)
4856                                         return;
4857                         }
4858
4859                         next = stmt->base.next;
4860                         break;
4861                 }
4862
4863                 case STATEMENT_EXPRESSION: {
4864                         /* Check for noreturn function call */
4865                         expression_t const *const expr = stmt->expression.expression;
4866                         if (!expression_returns(expr))
4867                                 return;
4868
4869                         next = stmt->base.next;
4870                         break;
4871                 }
4872
4873                 case STATEMENT_CONTINUE:
4874                         for (statement_t *parent = stmt;;) {
4875                                 parent = parent->base.parent;
4876                                 if (parent == NULL) /* continue not within loop */
4877                                         return;
4878
4879                                 next = parent;
4880                                 switch (parent->kind) {
4881                                         case STATEMENT_WHILE:    goto continue_while;
4882                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4883                                         case STATEMENT_FOR:      goto continue_for;
4884
4885                                         default: break;
4886                                 }
4887                         }
4888
4889                 case STATEMENT_BREAK:
4890                         for (statement_t *parent = stmt;;) {
4891                                 parent = parent->base.parent;
4892                                 if (parent == NULL) /* break not within loop/switch */
4893                                         return;
4894
4895                                 switch (parent->kind) {
4896                                         case STATEMENT_SWITCH:
4897                                         case STATEMENT_WHILE:
4898                                         case STATEMENT_DO_WHILE:
4899                                         case STATEMENT_FOR:
4900                                                 last = parent;
4901                                                 next = parent->base.next;
4902                                                 goto found_break_parent;
4903
4904                                         default: break;
4905                                 }
4906                         }
4907 found_break_parent:
4908                         break;
4909
4910                 case STATEMENT_COMPUTED_GOTO: {
4911                         if (!expression_returns(stmt->computed_goto.expression))
4912                                 return;
4913
4914                         statement_t *parent = stmt->base.parent;
4915                         if (parent == NULL) /* top level goto */
4916                                 return;
4917                         next = parent;
4918                         break;
4919                 }
4920
4921                 case STATEMENT_GOTO:
4922                         next = stmt->gotos.label->statement;
4923                         if (next == NULL) /* missing label */
4924                                 return;
4925                         break;
4926
4927                 case STATEMENT_LABEL:
4928                         next = stmt->label.statement;
4929                         break;
4930
4931                 case STATEMENT_CASE_LABEL:
4932                         next = stmt->case_label.statement;
4933                         break;
4934
4935                 case STATEMENT_WHILE: {
4936                         while_statement_t const *const whiles = &stmt->whiles;
4937                         expression_t      const *const cond   = whiles->condition;
4938
4939                         if (!expression_returns(cond))
4940                                 return;
4941
4942                         int const val = determine_truth(cond);
4943
4944                         if (val >= 0)
4945                                 check_reachable(whiles->body);
4946
4947                         if (val > 0)
4948                                 return;
4949
4950                         next = stmt->base.next;
4951                         break;
4952                 }
4953
4954                 case STATEMENT_DO_WHILE:
4955                         next = stmt->do_while.body;
4956                         break;
4957
4958                 case STATEMENT_FOR: {
4959                         for_statement_t *const fors = &stmt->fors;
4960
4961                         if (fors->condition_reachable)
4962                                 return;
4963                         fors->condition_reachable = true;
4964
4965                         expression_t const *const cond = fors->condition;
4966
4967                         int val;
4968                         if (cond == NULL) {
4969                                 val = 1;
4970                         } else if (expression_returns(cond)) {
4971                                 val = determine_truth(cond);
4972                         } else {
4973                                 return;
4974                         }
4975
4976                         if (val >= 0)
4977                                 check_reachable(fors->body);
4978
4979                         if (val > 0)
4980                                 return;
4981
4982                         next = stmt->base.next;
4983                         break;
4984                 }
4985
4986                 case STATEMENT_MS_TRY: {
4987                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4988                         check_reachable(ms_try->try_statement);
4989                         next = ms_try->final_statement;
4990                         break;
4991                 }
4992
4993                 case STATEMENT_LEAVE: {
4994                         statement_t *parent = stmt;
4995                         for (;;) {
4996                                 parent = parent->base.parent;
4997                                 if (parent == NULL) /* __leave not within __try */
4998                                         return;
4999
5000                                 if (parent->kind == STATEMENT_MS_TRY) {
5001                                         last = parent;
5002                                         next = parent->ms_try.final_statement;
5003                                         break;
5004                                 }
5005                         }
5006                         break;
5007                 }
5008
5009                 default:
5010                         panic("invalid statement kind");
5011         }
5012
5013         while (next == NULL) {
5014                 next = last->base.parent;
5015                 if (next == NULL) {
5016                         noreturn_candidate = false;
5017
5018                         type_t *const type = skip_typeref(current_function->base.type);
5019                         assert(is_type_function(type));
5020                         type_t *const ret  = skip_typeref(type->function.return_type);
5021                         if (!is_type_void(ret) &&
5022                             is_type_valid(ret) &&
5023                             !is_main(current_entity)) {
5024                                 source_position_t const *const pos = &stmt->base.source_position;
5025                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5026                         }
5027                         return;
5028                 }
5029
5030                 switch (next->kind) {
5031                         case STATEMENT_ERROR:
5032                         case STATEMENT_EMPTY:
5033                         case STATEMENT_DECLARATION:
5034                         case STATEMENT_EXPRESSION:
5035                         case STATEMENT_ASM:
5036                         case STATEMENT_RETURN:
5037                         case STATEMENT_CONTINUE:
5038                         case STATEMENT_BREAK:
5039                         case STATEMENT_COMPUTED_GOTO:
5040                         case STATEMENT_GOTO:
5041                         case STATEMENT_LEAVE:
5042                                 panic("invalid control flow in function");
5043
5044                         case STATEMENT_COMPOUND:
5045                                 if (next->compound.stmt_expr) {
5046                                         reaches_end = true;
5047                                         return;
5048                                 }
5049                                 /* FALLTHROUGH */
5050                         case STATEMENT_IF:
5051                         case STATEMENT_SWITCH:
5052                         case STATEMENT_LABEL:
5053                         case STATEMENT_CASE_LABEL:
5054                                 last = next;
5055                                 next = next->base.next;
5056                                 break;
5057
5058                         case STATEMENT_WHILE: {
5059 continue_while:
5060                                 if (next->base.reachable)
5061                                         return;
5062                                 next->base.reachable = true;
5063
5064                                 while_statement_t const *const whiles = &next->whiles;
5065                                 expression_t      const *const cond   = whiles->condition;
5066
5067                                 if (!expression_returns(cond))
5068                                         return;
5069
5070                                 int const val = determine_truth(cond);
5071
5072                                 if (val >= 0)
5073                                         check_reachable(whiles->body);
5074
5075                                 if (val > 0)
5076                                         return;
5077
5078                                 last = next;
5079                                 next = next->base.next;
5080                                 break;
5081                         }
5082
5083                         case STATEMENT_DO_WHILE: {
5084 continue_do_while:
5085                                 if (next->base.reachable)
5086                                         return;
5087                                 next->base.reachable = true;
5088
5089                                 do_while_statement_t const *const dw   = &next->do_while;
5090                                 expression_t         const *const cond = dw->condition;
5091
5092                                 if (!expression_returns(cond))
5093                                         return;
5094
5095                                 int const val = determine_truth(cond);
5096
5097                                 if (val >= 0)
5098                                         check_reachable(dw->body);
5099
5100                                 if (val > 0)
5101                                         return;
5102
5103                                 last = next;
5104                                 next = next->base.next;
5105                                 break;
5106                         }
5107
5108                         case STATEMENT_FOR: {
5109 continue_for:;
5110                                 for_statement_t *const fors = &next->fors;
5111
5112                                 fors->step_reachable = true;
5113
5114                                 if (fors->condition_reachable)
5115                                         return;
5116                                 fors->condition_reachable = true;
5117
5118                                 expression_t const *const cond = fors->condition;
5119
5120                                 int val;
5121                                 if (cond == NULL) {
5122                                         val = 1;
5123                                 } else if (expression_returns(cond)) {
5124                                         val = determine_truth(cond);
5125                                 } else {
5126                                         return;
5127                                 }
5128
5129                                 if (val >= 0)
5130                                         check_reachable(fors->body);
5131
5132                                 if (val > 0)
5133                                         return;
5134
5135                                 last = next;
5136                                 next = next->base.next;
5137                                 break;
5138                         }
5139
5140                         case STATEMENT_MS_TRY:
5141                                 last = next;
5142                                 next = next->ms_try.final_statement;
5143                                 break;
5144                 }
5145         }
5146
5147         check_reachable(next);
5148 }
5149
5150 static void check_unreachable(statement_t* const stmt, void *const env)
5151 {
5152         (void)env;
5153
5154         switch (stmt->kind) {
5155                 case STATEMENT_DO_WHILE:
5156                         if (!stmt->base.reachable) {
5157                                 expression_t const *const cond = stmt->do_while.condition;
5158                                 if (determine_truth(cond) >= 0) {
5159                                         source_position_t const *const pos = &cond->base.source_position;
5160                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5161                                 }
5162                         }
5163                         return;
5164
5165                 case STATEMENT_FOR: {
5166                         for_statement_t const* const fors = &stmt->fors;
5167
5168                         // if init and step are unreachable, cond is unreachable, too
5169                         if (!stmt->base.reachable && !fors->step_reachable) {
5170                                 goto warn_unreachable;
5171                         } else {
5172                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5173                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5174                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5175                                 }
5176
5177                                 if (!fors->condition_reachable && fors->condition != NULL) {
5178                                         source_position_t const *const pos = &fors->condition->base.source_position;
5179                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5180                                 }
5181
5182                                 if (!fors->step_reachable && fors->step != NULL) {
5183                                         source_position_t const *const pos = &fors->step->base.source_position;
5184                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5185                                 }
5186                         }
5187                         return;
5188                 }
5189
5190                 case STATEMENT_COMPOUND:
5191                         if (stmt->compound.statements != NULL)
5192                                 return;
5193                         goto warn_unreachable;
5194
5195                 case STATEMENT_DECLARATION: {
5196                         /* Only warn if there is at least one declarator with an initializer.
5197                          * This typically occurs in switch statements. */
5198                         declaration_statement_t const *const decl = &stmt->declaration;
5199                         entity_t                const *      ent  = decl->declarations_begin;
5200                         entity_t                const *const last = decl->declarations_end;
5201                         if (ent != NULL) {
5202                                 for (;; ent = ent->base.next) {
5203                                         if (ent->kind                 == ENTITY_VARIABLE &&
5204                                                         ent->variable.initializer != NULL) {
5205                                                 goto warn_unreachable;
5206                                         }
5207                                         if (ent == last)
5208                                                 return;
5209                                 }
5210                         }
5211                 }
5212
5213                 default:
5214 warn_unreachable:
5215                         if (!stmt->base.reachable) {
5216                                 source_position_t const *const pos = &stmt->base.source_position;
5217                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5218                         }
5219                         return;
5220         }
5221 }
5222
5223 static bool is_main(entity_t *entity)
5224 {
5225         static symbol_t *sym_main = NULL;
5226         if (sym_main == NULL) {
5227                 sym_main = symbol_table_insert("main");
5228         }
5229
5230         if (entity->base.symbol != sym_main)
5231                 return false;
5232         /* must be in outermost scope */
5233         if (entity->base.parent_scope != file_scope)
5234                 return false;
5235
5236         return true;
5237 }
5238
5239 static void prepare_main_collect2(entity_t*);
5240
5241 static void parse_external_declaration(void)
5242 {
5243         /* function-definitions and declarations both start with declaration
5244          * specifiers */
5245         add_anchor_token(';');
5246         declaration_specifiers_t specifiers;
5247         parse_declaration_specifiers(&specifiers);
5248         rem_anchor_token(';');
5249
5250         /* must be a declaration */
5251         if (token.kind == ';') {
5252                 parse_anonymous_declaration_rest(&specifiers);
5253                 return;
5254         }
5255
5256         add_anchor_token(',');
5257         add_anchor_token('=');
5258         add_anchor_token(';');
5259         add_anchor_token('{');
5260
5261         /* declarator is common to both function-definitions and declarations */
5262         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5263
5264         rem_anchor_token('{');
5265         rem_anchor_token(';');
5266         rem_anchor_token('=');
5267         rem_anchor_token(',');
5268
5269         /* must be a declaration */
5270         switch (token.kind) {
5271                 case ',':
5272                 case ';':
5273                 case '=':
5274                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5275                                         DECL_FLAGS_NONE);
5276                         return;
5277         }
5278
5279         /* must be a function definition */
5280         parse_kr_declaration_list(ndeclaration);
5281
5282         if (token.kind != '{') {
5283                 parse_error_expected("while parsing function definition", '{', NULL);
5284                 eat_until_matching_token(';');
5285                 return;
5286         }
5287
5288         assert(is_declaration(ndeclaration));
5289         type_t *const orig_type = ndeclaration->declaration.type;
5290         type_t *      type      = skip_typeref(orig_type);
5291
5292         if (!is_type_function(type)) {
5293                 if (is_type_valid(type)) {
5294                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5295                 }
5296                 eat_block();
5297                 return;
5298         }
5299
5300         source_position_t const *const pos = &ndeclaration->base.source_position;
5301         if (is_typeref(orig_type)) {
5302                 /* §6.9.1:2 */
5303                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5304         }
5305
5306         if (is_type_compound(skip_typeref(type->function.return_type))) {
5307                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5308         }
5309         if (type->function.unspecified_parameters) {
5310                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5311         } else {
5312                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5313         }
5314
5315         /* §6.7.5.3:14 a function definition with () means no
5316          * parameters (and not unspecified parameters) */
5317         if (type->function.unspecified_parameters &&
5318                         type->function.parameters == NULL) {
5319                 type_t *copy                          = duplicate_type(type);
5320                 copy->function.unspecified_parameters = false;
5321                 type                                  = identify_new_type(copy);
5322
5323                 ndeclaration->declaration.type = type;
5324         }
5325
5326         entity_t *const entity = record_entity(ndeclaration, true);
5327         assert(entity->kind == ENTITY_FUNCTION);
5328         assert(ndeclaration->kind == ENTITY_FUNCTION);
5329
5330         function_t *const function = &entity->function;
5331         if (ndeclaration != entity) {
5332                 function->parameters = ndeclaration->function.parameters;
5333         }
5334
5335         PUSH_SCOPE(&function->parameters);
5336
5337         entity_t *parameter = function->parameters.entities;
5338         for (; parameter != NULL; parameter = parameter->base.next) {
5339                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5340                         parameter->base.parent_scope = current_scope;
5341                 }
5342                 assert(parameter->base.parent_scope == NULL
5343                                 || parameter->base.parent_scope == current_scope);
5344                 parameter->base.parent_scope = current_scope;
5345                 if (parameter->base.symbol == NULL) {
5346                         errorf(&parameter->base.source_position, "parameter name omitted");
5347                         continue;
5348                 }
5349                 environment_push(parameter);
5350         }
5351
5352         if (function->statement != NULL) {
5353                 parser_error_multiple_definition(entity, HERE);
5354                 eat_block();
5355         } else {
5356                 /* parse function body */
5357                 int         label_stack_top      = label_top();
5358                 function_t *old_current_function = current_function;
5359                 current_function                 = function;
5360                 PUSH_CURRENT_ENTITY(entity);
5361                 PUSH_PARENT(NULL);
5362
5363                 goto_first   = NULL;
5364                 goto_anchor  = &goto_first;
5365                 label_first  = NULL;
5366                 label_anchor = &label_first;
5367
5368                 statement_t *const body = parse_compound_statement(false);
5369                 function->statement = body;
5370                 first_err = true;
5371                 check_labels();
5372                 check_declarations();
5373                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5374                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5375                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5376                         noreturn_candidate = true;
5377                         check_reachable(body);
5378                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5379                                 walk_statements(body, check_unreachable, NULL);
5380                         if (noreturn_candidate &&
5381                             !(function->base.modifiers & DM_NORETURN)) {
5382                                 source_position_t const *const pos = &body->base.source_position;
5383                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5384                         }
5385                 }
5386
5387                 if (is_main(entity)) {
5388                         /* Force main to C linkage. */
5389                         type_t *const type = entity->declaration.type;
5390                         assert(is_type_function(type));
5391                         if (type->function.linkage != LINKAGE_C) {
5392                                 type_t *new_type           = duplicate_type(type);
5393                                 new_type->function.linkage = LINKAGE_C;
5394                                 entity->declaration.type   = identify_new_type(new_type);
5395                         }
5396
5397                         if (enable_main_collect2_hack)
5398                                 prepare_main_collect2(entity);
5399                 }
5400
5401                 POP_CURRENT_ENTITY();
5402                 POP_PARENT();
5403                 assert(current_function == function);
5404                 current_function = old_current_function;
5405                 label_pop_to(label_stack_top);
5406         }
5407
5408         POP_SCOPE();
5409 }
5410
5411 static entity_t *find_compound_entry(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                 if (iter->base.symbol == symbol) {
5419                         return iter;
5420                 } else if (iter->base.symbol == NULL) {
5421                         /* search in anonymous structs and unions */
5422                         type_t *type = skip_typeref(iter->declaration.type);
5423                         if (is_type_compound(type)) {
5424                                 if (find_compound_entry(type->compound.compound, symbol)
5425                                                 != NULL)
5426                                         return iter;
5427                         }
5428                         continue;
5429                 }
5430         }
5431
5432         return NULL;
5433 }
5434
5435 static void check_deprecated(const source_position_t *source_position,
5436                              const entity_t *entity)
5437 {
5438         if (!is_declaration(entity))
5439                 return;
5440         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5441                 return;
5442
5443         source_position_t const *const epos = &entity->base.source_position;
5444         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5445         if (msg != NULL) {
5446                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5447         } else {
5448                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5449         }
5450 }
5451
5452
5453 static expression_t *create_select(const source_position_t *pos,
5454                                    expression_t *addr,
5455                                    type_qualifiers_t qualifiers,
5456                                                                    entity_t *entry)
5457 {
5458         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5459
5460         check_deprecated(pos, entry);
5461
5462         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5463         select->select.compound       = addr;
5464         select->select.compound_entry = entry;
5465
5466         type_t *entry_type = entry->declaration.type;
5467         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5468
5469         /* bitfields need special treatment */
5470         if (entry->compound_member.bitfield) {
5471                 unsigned bit_size = entry->compound_member.bit_size;
5472                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5473                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5474                         res_type = type_int;
5475                 }
5476         }
5477
5478         /* we always do the auto-type conversions; the & and sizeof parser contains
5479          * code to revert this! */
5480         select->base.type = automatic_type_conversion(res_type);
5481
5482
5483         return select;
5484 }
5485
5486 /**
5487  * Find entry with symbol in compound. Search anonymous structs and unions and
5488  * creates implicit select expressions for them.
5489  * Returns the adress for the innermost compound.
5490  */
5491 static expression_t *find_create_select(const source_position_t *pos,
5492                                         expression_t *addr,
5493                                         type_qualifiers_t qualifiers,
5494                                         compound_t *compound, symbol_t *symbol)
5495 {
5496         entity_t *iter = compound->members.entities;
5497         for (; iter != NULL; iter = iter->base.next) {
5498                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5499                         continue;
5500
5501                 symbol_t *iter_symbol = iter->base.symbol;
5502                 if (iter_symbol == NULL) {
5503                         type_t *type = iter->declaration.type;
5504                         if (type->kind != TYPE_COMPOUND_STRUCT
5505                                         && type->kind != TYPE_COMPOUND_UNION)
5506                                 continue;
5507
5508                         compound_t *sub_compound = type->compound.compound;
5509
5510                         if (find_compound_entry(sub_compound, symbol) == NULL)
5511                                 continue;
5512
5513                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5514                         sub_addr->base.source_position = *pos;
5515                         sub_addr->base.implicit        = true;
5516                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5517                                                   symbol);
5518                 }
5519
5520                 if (iter_symbol == symbol) {
5521                         return create_select(pos, addr, qualifiers, iter);
5522                 }
5523         }
5524
5525         return NULL;
5526 }
5527
5528 static void parse_bitfield_member(entity_t *entity)
5529 {
5530         eat(':');
5531
5532         expression_t *size = parse_constant_expression();
5533         long          size_long;
5534
5535         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5536         type_t *type = entity->declaration.type;
5537         if (!is_type_integer(skip_typeref(type))) {
5538                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5539                            type);
5540         }
5541
5542         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5543                 /* error already reported by parse_constant_expression */
5544                 size_long = get_type_size(type) * 8;
5545         } else {
5546                 size_long = fold_constant_to_int(size);
5547
5548                 const symbol_t *symbol = entity->base.symbol;
5549                 const symbol_t *user_symbol
5550                         = symbol == NULL ? sym_anonymous : symbol;
5551                 unsigned bit_size = get_type_size(type) * 8;
5552                 if (size_long < 0) {
5553                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5554                 } else if (size_long == 0 && symbol != NULL) {
5555                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5556                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5557                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5558                                    user_symbol);
5559                 } else {
5560                         /* hope that people don't invent crazy types with more bits
5561                          * than our struct can hold */
5562                         assert(size_long <
5563                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5564                 }
5565         }
5566
5567         entity->compound_member.bitfield = true;
5568         entity->compound_member.bit_size = (unsigned char)size_long;
5569 }
5570
5571 static void parse_compound_declarators(compound_t *compound,
5572                 const declaration_specifiers_t *specifiers)
5573 {
5574         add_anchor_token(';');
5575         add_anchor_token(',');
5576         do {
5577                 entity_t *entity;
5578
5579                 if (token.kind == ':') {
5580                         /* anonymous bitfield */
5581                         type_t *type = specifiers->type;
5582                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5583                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5584                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5585                         entity->declaration.type                   = type;
5586
5587                         parse_bitfield_member(entity);
5588
5589                         attribute_t  *attributes = parse_attributes(NULL);
5590                         attribute_t **anchor     = &attributes;
5591                         while (*anchor != NULL)
5592                                 anchor = &(*anchor)->next;
5593                         *anchor = specifiers->attributes;
5594                         if (attributes != NULL) {
5595                                 handle_entity_attributes(attributes, entity);
5596                         }
5597                         entity->declaration.attributes = attributes;
5598
5599                         append_entity(&compound->members, entity);
5600                 } else {
5601                         entity = parse_declarator(specifiers,
5602                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5603                         source_position_t const *const pos = &entity->base.source_position;
5604                         if (entity->kind == ENTITY_TYPEDEF) {
5605                                 errorf(pos, "typedef not allowed as compound member");
5606                         } else {
5607                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5608
5609                                 /* make sure we don't define a symbol multiple times */
5610                                 symbol_t *symbol = entity->base.symbol;
5611                                 if (symbol != NULL) {
5612                                         entity_t *prev = find_compound_entry(compound, symbol);
5613                                         if (prev != NULL) {
5614                                                 source_position_t const *const ppos = &prev->base.source_position;
5615                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5616                                         }
5617                                 }
5618
5619                                 if (token.kind == ':') {
5620                                         parse_bitfield_member(entity);
5621
5622                                         attribute_t *attributes = parse_attributes(NULL);
5623                                         handle_entity_attributes(attributes, entity);
5624                                 } else {
5625                                         type_t *orig_type = entity->declaration.type;
5626                                         type_t *type      = skip_typeref(orig_type);
5627                                         if (is_type_function(type)) {
5628                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5629                                         } else if (is_type_incomplete(type)) {
5630                                                 /* §6.7.2.1:16 flexible array member */
5631                                                 if (!is_type_array(type)       ||
5632                                                                 token.kind          != ';' ||
5633                                                                 look_ahead(1)->kind != '}') {
5634                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5635                                                 } else if (compound->members.entities == NULL) {
5636                                                         errorf(pos, "flexible array member in otherwise empty struct");
5637                                                 }
5638                                         }
5639                                 }
5640
5641                                 append_entity(&compound->members, entity);
5642                         }
5643                 }
5644         } while (next_if(','));
5645         rem_anchor_token(',');
5646         rem_anchor_token(';');
5647         expect(';');
5648
5649         anonymous_entity = NULL;
5650 }
5651
5652 static void parse_compound_type_entries(compound_t *compound)
5653 {
5654         eat('{');
5655         add_anchor_token('}');
5656
5657         for (;;) {
5658                 switch (token.kind) {
5659                         DECLARATION_START
5660                         case T___extension__:
5661                         case T_IDENTIFIER: {
5662                                 PUSH_EXTENSION();
5663                                 declaration_specifiers_t specifiers;
5664                                 parse_declaration_specifiers(&specifiers);
5665                                 parse_compound_declarators(compound, &specifiers);
5666                                 POP_EXTENSION();
5667                                 break;
5668                         }
5669
5670                         default:
5671                                 rem_anchor_token('}');
5672                                 expect('}');
5673                                 /* §6.7.2.1:7 */
5674                                 compound->complete = true;
5675                                 return;
5676                 }
5677         }
5678 }
5679
5680 static type_t *parse_typename(void)
5681 {
5682         declaration_specifiers_t specifiers;
5683         parse_declaration_specifiers(&specifiers);
5684         if (specifiers.storage_class != STORAGE_CLASS_NONE
5685                         || specifiers.thread_local) {
5686                 /* TODO: improve error message, user does probably not know what a
5687                  * storage class is...
5688                  */
5689                 errorf(&specifiers.source_position, "typename must not have a storage class");
5690         }
5691
5692         type_t *result = parse_abstract_declarator(specifiers.type);
5693
5694         return result;
5695 }
5696
5697
5698
5699
5700 typedef expression_t* (*parse_expression_function)(void);
5701 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5702
5703 typedef struct expression_parser_function_t expression_parser_function_t;
5704 struct expression_parser_function_t {
5705         parse_expression_function        parser;
5706         precedence_t                     infix_precedence;
5707         parse_expression_infix_function  infix_parser;
5708 };
5709
5710 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5711
5712 static type_t *get_string_type(string_encoding_t const enc)
5713 {
5714         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5715         switch (enc) {
5716         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5717         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5718         }
5719         panic("invalid string encoding");
5720 }
5721
5722 /**
5723  * Parse a string constant.
5724  */
5725 static expression_t *parse_string_literal(void)
5726 {
5727         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5728         expr->string_literal.value = concat_string_literals(&expr->string_literal.encoding);
5729         expr->base.type            = get_string_type(expr->string_literal.encoding);
5730         return expr;
5731 }
5732
5733 /**
5734  * Parse a boolean constant.
5735  */
5736 static expression_t *parse_boolean_literal(bool value)
5737 {
5738         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5739         literal->base.type           = type_bool;
5740         literal->literal.value.begin = value ? "true" : "false";
5741         literal->literal.value.size  = value ? 4 : 5;
5742
5743         eat(value ? T_true : T_false);
5744         return literal;
5745 }
5746
5747 static void warn_traditional_suffix(void)
5748 {
5749         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5750                  &token.number.suffix);
5751 }
5752
5753 static void check_integer_suffix(void)
5754 {
5755         const string_t *suffix = &token.number.suffix;
5756         if (suffix->size == 0)
5757                 return;
5758
5759         bool not_traditional = false;
5760         const char *c = suffix->begin;
5761         if (*c == 'l' || *c == 'L') {
5762                 ++c;
5763                 if (*c == *(c-1)) {
5764                         not_traditional = true;
5765                         ++c;
5766                         if (*c == 'u' || *c == 'U') {
5767                                 ++c;
5768                         }
5769                 } else if (*c == 'u' || *c == 'U') {
5770                         not_traditional = true;
5771                         ++c;
5772                 }
5773         } else if (*c == 'u' || *c == 'U') {
5774                 not_traditional = true;
5775                 ++c;
5776                 if (*c == 'l' || *c == 'L') {
5777                         ++c;
5778                         if (*c == *(c-1)) {
5779                                 ++c;
5780                         }
5781                 }
5782         }
5783         if (*c != '\0') {
5784                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5785         } else if (not_traditional) {
5786                 warn_traditional_suffix();
5787         }
5788 }
5789
5790 static type_t *check_floatingpoint_suffix(void)
5791 {
5792         const string_t *suffix = &token.number.suffix;
5793         type_t         *type   = type_double;
5794         if (suffix->size == 0)
5795                 return type;
5796
5797         bool not_traditional = false;
5798         const char *c = suffix->begin;
5799         if (*c == 'f' || *c == 'F') {
5800                 ++c;
5801                 type = type_float;
5802         } else if (*c == 'l' || *c == 'L') {
5803                 ++c;
5804                 type = type_long_double;
5805         }
5806         if (*c != '\0') {
5807                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5808         } else if (not_traditional) {
5809                 warn_traditional_suffix();
5810         }
5811
5812         return type;
5813 }
5814
5815 /**
5816  * Parse an integer constant.
5817  */
5818 static expression_t *parse_number_literal(void)
5819 {
5820         expression_kind_t  kind;
5821         type_t            *type;
5822
5823         switch (token.kind) {
5824         case T_INTEGER:
5825                 kind = EXPR_LITERAL_INTEGER;
5826                 check_integer_suffix();
5827                 type = type_int;
5828                 break;
5829
5830         case T_FLOATINGPOINT:
5831                 kind = EXPR_LITERAL_FLOATINGPOINT;
5832                 type = check_floatingpoint_suffix();
5833                 break;
5834
5835         default:
5836                 panic("unexpected token type in parse_number_literal");
5837         }
5838
5839         expression_t *literal = allocate_expression_zero(kind);
5840         literal->base.type      = type;
5841         literal->literal.value  = token.number.number;
5842         literal->literal.suffix = token.number.suffix;
5843         next_token();
5844
5845         /* integer type depends on the size of the number and the size
5846          * representable by the types. The backend/codegeneration has to determine
5847          * that
5848          */
5849         determine_literal_type(&literal->literal);
5850         return literal;
5851 }
5852
5853 /**
5854  * Parse a character constant.
5855  */
5856 static expression_t *parse_character_constant(void)
5857 {
5858         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5859         literal->string_literal.encoding = token.string.encoding;
5860         literal->string_literal.value    = token.string.string;
5861
5862         switch (token.string.encoding) {
5863         case STRING_ENCODING_CHAR:
5864                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5865                 if (literal->string_literal.value.size > 1) {
5866                         if (!GNU_MODE && !(c_mode & _C99)) {
5867                                 errorf(HERE, "more than 1 character in character constant");
5868                         } else {
5869                                 literal->base.type = type_int;
5870                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5871                         }
5872                 }
5873                 break;
5874
5875         case STRING_ENCODING_WIDE:
5876                 literal->base.type = type_int;
5877                 if (wstrlen(&literal->string_literal.value) > 1) {
5878                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5879                 }
5880                 break;
5881         }
5882
5883         eat(T_CHARACTER_CONSTANT);
5884         return literal;
5885 }
5886
5887 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5888 {
5889         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5890         ntype->function.return_type            = type_int;
5891         ntype->function.unspecified_parameters = true;
5892         ntype->function.linkage                = LINKAGE_C;
5893         type_t *type                           = identify_new_type(ntype);
5894
5895         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5896         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5897         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5898         entity->declaration.type                   = type;
5899         entity->declaration.implicit               = true;
5900
5901         if (current_scope != NULL)
5902                 record_entity(entity, false);
5903
5904         return entity;
5905 }
5906
5907 /**
5908  * Performs automatic type cast as described in §6.3.2.1.
5909  *
5910  * @param orig_type  the original type
5911  */
5912 static type_t *automatic_type_conversion(type_t *orig_type)
5913 {
5914         type_t *type = skip_typeref(orig_type);
5915         if (is_type_array(type)) {
5916                 array_type_t *array_type   = &type->array;
5917                 type_t       *element_type = array_type->element_type;
5918                 unsigned      qualifiers   = array_type->base.qualifiers;
5919
5920                 return make_pointer_type(element_type, qualifiers);
5921         }
5922
5923         if (is_type_function(type)) {
5924                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5925         }
5926
5927         return orig_type;
5928 }
5929
5930 /**
5931  * reverts the automatic casts of array to pointer types and function
5932  * to function-pointer types as defined §6.3.2.1
5933  */
5934 type_t *revert_automatic_type_conversion(const expression_t *expression)
5935 {
5936         switch (expression->kind) {
5937         case EXPR_REFERENCE: {
5938                 entity_t *entity = expression->reference.entity;
5939                 if (is_declaration(entity)) {
5940                         return entity->declaration.type;
5941                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5942                         return entity->enum_value.enum_type;
5943                 } else {
5944                         panic("no declaration or enum in reference");
5945                 }
5946         }
5947
5948         case EXPR_SELECT: {
5949                 entity_t *entity = expression->select.compound_entry;
5950                 assert(is_declaration(entity));
5951                 type_t   *type   = entity->declaration.type;
5952                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5953         }
5954
5955         case EXPR_UNARY_DEREFERENCE: {
5956                 const expression_t *const value = expression->unary.value;
5957                 type_t             *const type  = skip_typeref(value->base.type);
5958                 if (!is_type_pointer(type))
5959                         return type_error_type;
5960                 return type->pointer.points_to;
5961         }
5962
5963         case EXPR_ARRAY_ACCESS: {
5964                 const expression_t *array_ref = expression->array_access.array_ref;
5965                 type_t             *type_left = skip_typeref(array_ref->base.type);
5966                 if (!is_type_pointer(type_left))
5967                         return type_error_type;
5968                 return type_left->pointer.points_to;
5969         }
5970
5971         case EXPR_STRING_LITERAL: {
5972                 size_t  const size = expression->string_literal.value.size + 1;
5973                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5974                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5975         }
5976
5977         case EXPR_COMPOUND_LITERAL:
5978                 return expression->compound_literal.type;
5979
5980         default:
5981                 break;
5982         }
5983         return expression->base.type;
5984 }
5985
5986 /**
5987  * Find an entity matching a symbol in a scope.
5988  * Uses current scope if scope is NULL
5989  */
5990 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5991                                namespace_tag_t namespc)
5992 {
5993         if (scope == NULL) {
5994                 return get_entity(symbol, namespc);
5995         }
5996
5997         /* we should optimize here, if scope grows above a certain size we should
5998            construct a hashmap here... */
5999         entity_t *entity = scope->entities;
6000         for ( ; entity != NULL; entity = entity->base.next) {
6001                 if (entity->base.symbol == symbol
6002                     && (namespace_tag_t)entity->base.namespc == namespc)
6003                         break;
6004         }
6005
6006         return entity;
6007 }
6008
6009 static entity_t *parse_qualified_identifier(void)
6010 {
6011         /* namespace containing the symbol */
6012         symbol_t          *symbol;
6013         source_position_t  pos;
6014         const scope_t     *lookup_scope = NULL;
6015
6016         if (next_if(T_COLONCOLON))
6017                 lookup_scope = &unit->scope;
6018
6019         entity_t *entity;
6020         while (true) {
6021                 symbol = expect_identifier("while parsing identifier", &pos);
6022                 if (!symbol)
6023                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6024
6025                 /* lookup entity */
6026                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6027
6028                 if (!next_if(T_COLONCOLON))
6029                         break;
6030
6031                 switch (entity->kind) {
6032                 case ENTITY_NAMESPACE:
6033                         lookup_scope = &entity->namespacee.members;
6034                         break;
6035                 case ENTITY_STRUCT:
6036                 case ENTITY_UNION:
6037                 case ENTITY_CLASS:
6038                         lookup_scope = &entity->compound.members;
6039                         break;
6040                 default:
6041                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6042                                symbol, get_entity_kind_name(entity->kind));
6043
6044                         /* skip further qualifications */
6045                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6046
6047                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6048                 }
6049         }
6050
6051         if (entity == NULL) {
6052                 if (!strict_mode && token.kind == '(') {
6053                         /* an implicitly declared function */
6054                         entity = create_implicit_function(symbol, &pos);
6055                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6056                 } else {
6057                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6058                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6059                 }
6060         }
6061
6062         return entity;
6063 }
6064
6065 static expression_t *parse_reference(void)
6066 {
6067         source_position_t const pos    = *HERE;
6068         entity_t         *const entity = parse_qualified_identifier();
6069
6070         type_t *orig_type;
6071         if (is_declaration(entity)) {
6072                 orig_type = entity->declaration.type;
6073         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6074                 orig_type = entity->enum_value.enum_type;
6075         } else {
6076                 panic("expected declaration or enum value in reference");
6077         }
6078
6079         /* we always do the auto-type conversions; the & and sizeof parser contains
6080          * code to revert this! */
6081         type_t *type = automatic_type_conversion(orig_type);
6082
6083         expression_kind_t kind = EXPR_REFERENCE;
6084         if (entity->kind == ENTITY_ENUM_VALUE)
6085                 kind = EXPR_ENUM_CONSTANT;
6086
6087         expression_t *expression         = allocate_expression_zero(kind);
6088         expression->base.source_position = pos;
6089         expression->base.type            = type;
6090         expression->reference.entity     = entity;
6091
6092         /* this declaration is used */
6093         if (is_declaration(entity)) {
6094                 entity->declaration.used = true;
6095         }
6096
6097         if (entity->base.parent_scope != file_scope
6098                 && (current_function != NULL
6099                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6100                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6101                 /* access of a variable from an outer function */
6102                 entity->variable.address_taken = true;
6103                 current_function->need_closure = true;
6104         }
6105
6106         check_deprecated(&pos, entity);
6107
6108         return expression;
6109 }
6110
6111 static bool semantic_cast(expression_t *cast)
6112 {
6113         expression_t            *expression      = cast->unary.value;
6114         type_t                  *orig_dest_type  = cast->base.type;
6115         type_t                  *orig_type_right = expression->base.type;
6116         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6117         type_t            const *src_type        = skip_typeref(orig_type_right);
6118         source_position_t const *pos             = &cast->base.source_position;
6119
6120         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6121         if (is_type_void(dst_type))
6122                 return true;
6123
6124         /* only integer and pointer can be casted to pointer */
6125         if (is_type_pointer(dst_type)  &&
6126             !is_type_pointer(src_type) &&
6127             !is_type_integer(src_type) &&
6128             is_type_valid(src_type)) {
6129                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6130                 return false;
6131         }
6132
6133         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6134                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6135                 return false;
6136         }
6137
6138         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6139                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6140                 return false;
6141         }
6142
6143         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6144                 type_t *src = skip_typeref(src_type->pointer.points_to);
6145                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6146                 unsigned missing_qualifiers =
6147                         src->base.qualifiers & ~dst->base.qualifiers;
6148                 if (missing_qualifiers != 0) {
6149                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6150                 }
6151         }
6152         return true;
6153 }
6154
6155 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6156 {
6157         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6158         expression->base.source_position = *pos;
6159
6160         parse_initializer_env_t env;
6161         env.type             = type;
6162         env.entity           = NULL;
6163         env.must_be_constant = false;
6164         initializer_t *initializer = parse_initializer(&env);
6165         type = env.type;
6166
6167         expression->compound_literal.initializer = initializer;
6168         expression->compound_literal.type        = type;
6169         expression->base.type                    = automatic_type_conversion(type);
6170
6171         return expression;
6172 }
6173
6174 /**
6175  * Parse a cast expression.
6176  */
6177 static expression_t *parse_cast(void)
6178 {
6179         source_position_t const pos = *HERE;
6180
6181         eat('(');
6182         add_anchor_token(')');
6183
6184         type_t *type = parse_typename();
6185
6186         rem_anchor_token(')');
6187         expect(')');
6188
6189         if (token.kind == '{') {
6190                 return parse_compound_literal(&pos, type);
6191         }
6192
6193         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6194         cast->base.source_position = pos;
6195
6196         expression_t *value = parse_subexpression(PREC_CAST);
6197         cast->base.type   = type;
6198         cast->unary.value = value;
6199
6200         if (! semantic_cast(cast)) {
6201                 /* TODO: record the error in the AST. else it is impossible to detect it */
6202         }
6203
6204         return cast;
6205 }
6206
6207 /**
6208  * Parse a statement expression.
6209  */
6210 static expression_t *parse_statement_expression(void)
6211 {
6212         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6213
6214         eat('(');
6215         add_anchor_token(')');
6216
6217         statement_t *statement          = parse_compound_statement(true);
6218         statement->compound.stmt_expr   = true;
6219         expression->statement.statement = statement;
6220
6221         /* find last statement and use its type */
6222         type_t *type = type_void;
6223         const statement_t *stmt = statement->compound.statements;
6224         if (stmt != NULL) {
6225                 while (stmt->base.next != NULL)
6226                         stmt = stmt->base.next;
6227
6228                 if (stmt->kind == STATEMENT_EXPRESSION) {
6229                         type = stmt->expression.expression->base.type;
6230                 }
6231         } else {
6232                 source_position_t const *const pos = &expression->base.source_position;
6233                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6234         }
6235         expression->base.type = type;
6236
6237         rem_anchor_token(')');
6238         expect(')');
6239         return expression;
6240 }
6241
6242 /**
6243  * Parse a parenthesized expression.
6244  */
6245 static expression_t *parse_parenthesized_expression(void)
6246 {
6247         token_t const* const la1 = look_ahead(1);
6248         switch (la1->kind) {
6249         case '{':
6250                 /* gcc extension: a statement expression */
6251                 return parse_statement_expression();
6252
6253         case T_IDENTIFIER:
6254                 if (is_typedef_symbol(la1->base.symbol)) {
6255         DECLARATION_START
6256                         return parse_cast();
6257                 }
6258         }
6259
6260         eat('(');
6261         add_anchor_token(')');
6262         expression_t *result = parse_expression();
6263         result->base.parenthesized = true;
6264         rem_anchor_token(')');
6265         expect(')');
6266
6267         return result;
6268 }
6269
6270 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6271 {
6272         if (current_function == NULL) {
6273                 errorf(HERE, "'%K' used outside of a function", &token);
6274         }
6275
6276         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6277         expression->base.type     = type_char_ptr;
6278         expression->funcname.kind = kind;
6279
6280         next_token();
6281
6282         return expression;
6283 }
6284
6285 static designator_t *parse_designator(void)
6286 {
6287         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6288         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6289         if (!result->symbol)
6290                 return NULL;
6291
6292         designator_t *last_designator = result;
6293         while (true) {
6294                 if (next_if('.')) {
6295                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6296                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6297                         if (!designator->symbol)
6298                                 return NULL;
6299
6300                         last_designator->next = designator;
6301                         last_designator       = designator;
6302                         continue;
6303                 }
6304                 if (next_if('[')) {
6305                         add_anchor_token(']');
6306                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6307                         designator->source_position = *HERE;
6308                         designator->array_index     = parse_expression();
6309                         rem_anchor_token(']');
6310                         expect(']');
6311                         if (designator->array_index == NULL) {
6312                                 return NULL;
6313                         }
6314
6315                         last_designator->next = designator;
6316                         last_designator       = designator;
6317                         continue;
6318                 }
6319                 break;
6320         }
6321
6322         return result;
6323 }
6324
6325 /**
6326  * Parse the __builtin_offsetof() expression.
6327  */
6328 static expression_t *parse_offsetof(void)
6329 {
6330         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6331         expression->base.type    = type_size_t;
6332
6333         eat(T___builtin_offsetof);
6334
6335         add_anchor_token(')');
6336         add_anchor_token(',');
6337         expect('(');
6338         type_t *type = parse_typename();
6339         rem_anchor_token(',');
6340         expect(',');
6341         designator_t *designator = parse_designator();
6342         rem_anchor_token(')');
6343         expect(')');
6344
6345         expression->offsetofe.type       = type;
6346         expression->offsetofe.designator = designator;
6347
6348         type_path_t path;
6349         memset(&path, 0, sizeof(path));
6350         path.top_type = type;
6351         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6352
6353         descend_into_subtype(&path);
6354
6355         if (!walk_designator(&path, designator, true)) {
6356                 return create_error_expression();
6357         }
6358
6359         DEL_ARR_F(path.path);
6360
6361         return expression;
6362 }
6363
6364 static bool is_last_parameter(expression_t *const param)
6365 {
6366         if (param->kind == EXPR_REFERENCE) {
6367                 entity_t *const entity = param->reference.entity;
6368                 if (entity->kind == ENTITY_PARAMETER &&
6369                     !entity->base.next               &&
6370                     entity->base.parent_scope == &current_function->parameters) {
6371                         return true;
6372                 }
6373         }
6374
6375         if (!is_type_valid(skip_typeref(param->base.type)))
6376                 return true;
6377
6378         return false;
6379 }
6380
6381 /**
6382  * Parses a __builtin_va_start() expression.
6383  */
6384 static expression_t *parse_va_start(void)
6385 {
6386         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6387
6388         eat(T___builtin_va_start);
6389
6390         add_anchor_token(')');
6391         add_anchor_token(',');
6392         expect('(');
6393         expression->va_starte.ap = parse_assignment_expression();
6394         rem_anchor_token(',');
6395         expect(',');
6396         expression_t *const param = parse_assignment_expression();
6397         expression->va_starte.parameter = param;
6398         rem_anchor_token(')');
6399         expect(')');
6400
6401         if (!current_function) {
6402                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6403         } else if (!current_function->base.type->function.variadic) {
6404                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6405         } else if (!is_last_parameter(param)) {
6406                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6407         }
6408
6409         return expression;
6410 }
6411
6412 /**
6413  * Parses a __builtin_va_arg() expression.
6414  */
6415 static expression_t *parse_va_arg(void)
6416 {
6417         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6418
6419         eat(T___builtin_va_arg);
6420
6421         add_anchor_token(')');
6422         add_anchor_token(',');
6423         expect('(');
6424         call_argument_t ap;
6425         ap.expression = parse_assignment_expression();
6426         expression->va_arge.ap = ap.expression;
6427         check_call_argument(type_valist, &ap, 1);
6428
6429         rem_anchor_token(',');
6430         expect(',');
6431         expression->base.type = parse_typename();
6432         rem_anchor_token(')');
6433         expect(')');
6434
6435         return expression;
6436 }
6437
6438 /**
6439  * Parses a __builtin_va_copy() expression.
6440  */
6441 static expression_t *parse_va_copy(void)
6442 {
6443         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6444
6445         eat(T___builtin_va_copy);
6446
6447         add_anchor_token(')');
6448         add_anchor_token(',');
6449         expect('(');
6450         expression_t *dst = parse_assignment_expression();
6451         assign_error_t error = semantic_assign(type_valist, dst);
6452         report_assign_error(error, type_valist, dst, "call argument 1",
6453                             &dst->base.source_position);
6454         expression->va_copye.dst = dst;
6455
6456         rem_anchor_token(',');
6457         expect(',');
6458
6459         call_argument_t src;
6460         src.expression = parse_assignment_expression();
6461         check_call_argument(type_valist, &src, 2);
6462         expression->va_copye.src = src.expression;
6463         rem_anchor_token(')');
6464         expect(')');
6465
6466         return expression;
6467 }
6468
6469 /**
6470  * Parses a __builtin_constant_p() expression.
6471  */
6472 static expression_t *parse_builtin_constant(void)
6473 {
6474         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6475
6476         eat(T___builtin_constant_p);
6477
6478         add_anchor_token(')');
6479         expect('(');
6480         expression->builtin_constant.value = parse_assignment_expression();
6481         rem_anchor_token(')');
6482         expect(')');
6483         expression->base.type = type_int;
6484
6485         return expression;
6486 }
6487
6488 /**
6489  * Parses a __builtin_types_compatible_p() expression.
6490  */
6491 static expression_t *parse_builtin_types_compatible(void)
6492 {
6493         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6494
6495         eat(T___builtin_types_compatible_p);
6496
6497         add_anchor_token(')');
6498         add_anchor_token(',');
6499         expect('(');
6500         expression->builtin_types_compatible.left = parse_typename();
6501         rem_anchor_token(',');
6502         expect(',');
6503         expression->builtin_types_compatible.right = parse_typename();
6504         rem_anchor_token(')');
6505         expect(')');
6506         expression->base.type = type_int;
6507
6508         return expression;
6509 }
6510
6511 /**
6512  * Parses a __builtin_is_*() compare expression.
6513  */
6514 static expression_t *parse_compare_builtin(void)
6515 {
6516         expression_kind_t kind;
6517         switch (token.kind) {
6518         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6519         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6520         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6521         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6522         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6523         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6524         default: internal_errorf(HERE, "invalid compare builtin found");
6525         }
6526         expression_t *const expression = allocate_expression_zero(kind);
6527         next_token();
6528
6529         add_anchor_token(')');
6530         add_anchor_token(',');
6531         expect('(');
6532         expression->binary.left = parse_assignment_expression();
6533         rem_anchor_token(',');
6534         expect(',');
6535         expression->binary.right = parse_assignment_expression();
6536         rem_anchor_token(')');
6537         expect(')');
6538
6539         type_t *const orig_type_left  = expression->binary.left->base.type;
6540         type_t *const orig_type_right = expression->binary.right->base.type;
6541
6542         type_t *const type_left  = skip_typeref(orig_type_left);
6543         type_t *const type_right = skip_typeref(orig_type_right);
6544         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6545                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6546                         type_error_incompatible("invalid operands in comparison",
6547                                 &expression->base.source_position, orig_type_left, orig_type_right);
6548                 }
6549         } else {
6550                 semantic_comparison(&expression->binary);
6551         }
6552
6553         return expression;
6554 }
6555
6556 /**
6557  * Parses a MS assume() expression.
6558  */
6559 static expression_t *parse_assume(void)
6560 {
6561         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6562
6563         eat(T__assume);
6564
6565         add_anchor_token(')');
6566         expect('(');
6567         expression->unary.value = parse_assignment_expression();
6568         rem_anchor_token(')');
6569         expect(')');
6570
6571         expression->base.type = type_void;
6572         return expression;
6573 }
6574
6575 /**
6576  * Return the label for the current symbol or create a new one.
6577  */
6578 static label_t *get_label(char const *const context)
6579 {
6580         assert(current_function != NULL);
6581
6582         symbol_t *const sym = expect_identifier(context, NULL);
6583         if (!sym)
6584                 return NULL;
6585
6586         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6587         /* If we find a local label, we already created the declaration. */
6588         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6589                 if (label->base.parent_scope != current_scope) {
6590                         assert(label->base.parent_scope->depth < current_scope->depth);
6591                         current_function->goto_to_outer = true;
6592                 }
6593         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6594                 /* There is no matching label in the same function, so create a new one. */
6595                 source_position_t const nowhere = { NULL, 0, 0, false };
6596                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6597                 label_push(label);
6598         }
6599
6600         return &label->label;
6601 }
6602
6603 /**
6604  * Parses a GNU && label address expression.
6605  */
6606 static expression_t *parse_label_address(void)
6607 {
6608         source_position_t const source_position = *HERE;
6609         eat(T_ANDAND);
6610
6611         label_t *const label = get_label("while parsing label address");
6612         if (!label)
6613                 return create_error_expression();
6614
6615         label->used          = true;
6616         label->address_taken = true;
6617
6618         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6619         expression->base.source_position = source_position;
6620
6621         /* label address is treated as a void pointer */
6622         expression->base.type           = type_void_ptr;
6623         expression->label_address.label = label;
6624         return expression;
6625 }
6626
6627 /**
6628  * Parse a microsoft __noop expression.
6629  */
6630 static expression_t *parse_noop_expression(void)
6631 {
6632         /* the result is a (int)0 */
6633         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6634         literal->base.type           = type_int;
6635         literal->literal.value.begin = "__noop";
6636         literal->literal.value.size  = 6;
6637
6638         eat(T___noop);
6639
6640         if (token.kind == '(') {
6641                 /* parse arguments */
6642                 eat('(');
6643                 add_anchor_token(')');
6644                 add_anchor_token(',');
6645
6646                 if (token.kind != ')') do {
6647                         (void)parse_assignment_expression();
6648                 } while (next_if(','));
6649
6650                 rem_anchor_token(',');
6651                 rem_anchor_token(')');
6652         }
6653         expect(')');
6654
6655         return literal;
6656 }
6657
6658 /**
6659  * Parses a primary expression.
6660  */
6661 static expression_t *parse_primary_expression(void)
6662 {
6663         switch (token.kind) {
6664         case T_false:                        return parse_boolean_literal(false);
6665         case T_true:                         return parse_boolean_literal(true);
6666         case T_INTEGER:
6667         case T_FLOATINGPOINT:                return parse_number_literal();
6668         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6669         case T_STRING_LITERAL:               return parse_string_literal();
6670         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6671         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6672         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6673         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6674         case T___builtin_offsetof:           return parse_offsetof();
6675         case T___builtin_va_start:           return parse_va_start();
6676         case T___builtin_va_arg:             return parse_va_arg();
6677         case T___builtin_va_copy:            return parse_va_copy();
6678         case T___builtin_isgreater:
6679         case T___builtin_isgreaterequal:
6680         case T___builtin_isless:
6681         case T___builtin_islessequal:
6682         case T___builtin_islessgreater:
6683         case T___builtin_isunordered:        return parse_compare_builtin();
6684         case T___builtin_constant_p:         return parse_builtin_constant();
6685         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6686         case T__assume:                      return parse_assume();
6687         case T_ANDAND:
6688                 if (GNU_MODE)
6689                         return parse_label_address();
6690                 break;
6691
6692         case '(':                            return parse_parenthesized_expression();
6693         case T___noop:                       return parse_noop_expression();
6694
6695         /* Gracefully handle type names while parsing expressions. */
6696         case T_COLONCOLON:
6697                 return parse_reference();
6698         case T_IDENTIFIER:
6699                 if (!is_typedef_symbol(token.base.symbol)) {
6700                         return parse_reference();
6701                 }
6702                 /* FALLTHROUGH */
6703         DECLARATION_START {
6704                 source_position_t const  pos = *HERE;
6705                 declaration_specifiers_t specifiers;
6706                 parse_declaration_specifiers(&specifiers);
6707                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6708                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6709                 return create_error_expression();
6710         }
6711         }
6712
6713         errorf(HERE, "unexpected token %K, expected an expression", &token);
6714         eat_until_anchor();
6715         return create_error_expression();
6716 }
6717
6718 static expression_t *parse_array_expression(expression_t *left)
6719 {
6720         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6721         array_access_expression_t *const arr  = &expr->array_access;
6722
6723         eat('[');
6724         add_anchor_token(']');
6725
6726         expression_t *const inside = parse_expression();
6727
6728         type_t *const orig_type_left   = left->base.type;
6729         type_t *const orig_type_inside = inside->base.type;
6730
6731         type_t *const type_left   = skip_typeref(orig_type_left);
6732         type_t *const type_inside = skip_typeref(orig_type_inside);
6733
6734         expression_t *ref;
6735         expression_t *idx;
6736         type_t       *idx_type;
6737         type_t       *res_type;
6738         if (is_type_pointer(type_left)) {
6739                 ref      = left;
6740                 idx      = inside;
6741                 idx_type = type_inside;
6742                 res_type = type_left->pointer.points_to;
6743                 goto check_idx;
6744         } else if (is_type_pointer(type_inside)) {
6745                 arr->flipped = true;
6746                 ref      = inside;
6747                 idx      = left;
6748                 idx_type = type_left;
6749                 res_type = type_inside->pointer.points_to;
6750 check_idx:
6751                 res_type = automatic_type_conversion(res_type);
6752                 if (!is_type_integer(idx_type)) {
6753                         errorf(&idx->base.source_position, "array subscript must have integer type");
6754                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6755                         source_position_t const *const pos = &idx->base.source_position;
6756                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6757                 }
6758         } else {
6759                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6760                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6761                 }
6762                 res_type = type_error_type;
6763                 ref      = left;
6764                 idx      = inside;
6765         }
6766
6767         arr->array_ref = ref;
6768         arr->index     = idx;
6769         arr->base.type = res_type;
6770
6771         rem_anchor_token(']');
6772         expect(']');
6773         return expr;
6774 }
6775
6776 static bool is_bitfield(const expression_t *expression)
6777 {
6778         return expression->kind == EXPR_SELECT
6779                 && expression->select.compound_entry->compound_member.bitfield;
6780 }
6781
6782 static expression_t *parse_typeprop(expression_kind_t const kind)
6783 {
6784         expression_t  *tp_expression = allocate_expression_zero(kind);
6785         tp_expression->base.type     = type_size_t;
6786
6787         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6788
6789         type_t       *orig_type;
6790         expression_t *expression;
6791         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6792                 source_position_t const pos = *HERE;
6793                 eat('(');
6794                 add_anchor_token(')');
6795                 orig_type = parse_typename();
6796                 rem_anchor_token(')');
6797                 expect(')');
6798
6799                 if (token.kind == '{') {
6800                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6801                          * starting with a compound literal */
6802                         expression = parse_compound_literal(&pos, orig_type);
6803                         goto typeprop_expression;
6804                 }
6805         } else {
6806                 expression = parse_subexpression(PREC_UNARY);
6807
6808 typeprop_expression:
6809                 if (is_bitfield(expression)) {
6810                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6811                         errorf(&tp_expression->base.source_position,
6812                                    "operand of %s expression must not be a bitfield", what);
6813                 }
6814
6815                 tp_expression->typeprop.tp_expression = expression;
6816
6817                 orig_type = revert_automatic_type_conversion(expression);
6818                 expression->base.type = orig_type;
6819         }
6820
6821         tp_expression->typeprop.type   = orig_type;
6822         type_t const* const type       = skip_typeref(orig_type);
6823         char   const*       wrong_type = NULL;
6824         if (is_type_incomplete(type)) {
6825                 if (!is_type_void(type) || !GNU_MODE)
6826                         wrong_type = "incomplete";
6827         } else if (type->kind == TYPE_FUNCTION) {
6828                 if (GNU_MODE) {
6829                         /* function types are allowed (and return 1) */
6830                         source_position_t const *const pos  = &tp_expression->base.source_position;
6831                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6832                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6833                 } else {
6834                         wrong_type = "function";
6835                 }
6836         }
6837
6838         if (wrong_type != NULL) {
6839                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6840                 errorf(&tp_expression->base.source_position,
6841                                 "operand of %s expression must not be of %s type '%T'",
6842                                 what, wrong_type, orig_type);
6843         }
6844
6845         return tp_expression;
6846 }
6847
6848 static expression_t *parse_sizeof(void)
6849 {
6850         return parse_typeprop(EXPR_SIZEOF);
6851 }
6852
6853 static expression_t *parse_alignof(void)
6854 {
6855         return parse_typeprop(EXPR_ALIGNOF);
6856 }
6857
6858 static expression_t *parse_select_expression(expression_t *addr)
6859 {
6860         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6861         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6862         source_position_t const pos = *HERE;
6863         next_token();
6864
6865         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6866         if (!symbol)
6867                 return create_error_expression();
6868
6869         type_t *const orig_type = addr->base.type;
6870         type_t *const type      = skip_typeref(orig_type);
6871
6872         type_t *type_left;
6873         bool    saw_error = false;
6874         if (is_type_pointer(type)) {
6875                 if (!select_left_arrow) {
6876                         errorf(&pos,
6877                                "request for member '%Y' in something not a struct or union, but '%T'",
6878                                symbol, orig_type);
6879                         saw_error = true;
6880                 }
6881                 type_left = skip_typeref(type->pointer.points_to);
6882         } else {
6883                 if (select_left_arrow && is_type_valid(type)) {
6884                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6885                         saw_error = true;
6886                 }
6887                 type_left = type;
6888         }
6889
6890         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6891             type_left->kind != TYPE_COMPOUND_UNION) {
6892
6893                 if (is_type_valid(type_left) && !saw_error) {
6894                         errorf(&pos,
6895                                "request for member '%Y' in something not a struct or union, but '%T'",
6896                                symbol, type_left);
6897                 }
6898                 return create_error_expression();
6899         }
6900
6901         compound_t *compound = type_left->compound.compound;
6902         if (!compound->complete) {
6903                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6904                        symbol, type_left);
6905                 return create_error_expression();
6906         }
6907
6908         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6909         expression_t      *result     =
6910                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6911
6912         if (result == NULL) {
6913                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6914                 return create_error_expression();
6915         }
6916
6917         return result;
6918 }
6919
6920 static void check_call_argument(type_t          *expected_type,
6921                                 call_argument_t *argument, unsigned pos)
6922 {
6923         type_t         *expected_type_skip = skip_typeref(expected_type);
6924         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6925         expression_t   *arg_expr           = argument->expression;
6926         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6927
6928         /* handle transparent union gnu extension */
6929         if (is_type_union(expected_type_skip)
6930                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6931                 compound_t *union_decl  = expected_type_skip->compound.compound;
6932                 type_t     *best_type   = NULL;
6933                 entity_t   *entry       = union_decl->members.entities;
6934                 for ( ; entry != NULL; entry = entry->base.next) {
6935                         assert(is_declaration(entry));
6936                         type_t *decl_type = entry->declaration.type;
6937                         error = semantic_assign(decl_type, arg_expr);
6938                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6939                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6940                                 continue;
6941
6942                         if (error == ASSIGN_SUCCESS) {
6943                                 best_type = decl_type;
6944                         } else if (best_type == NULL) {
6945                                 best_type = decl_type;
6946                         }
6947                 }
6948
6949                 if (best_type != NULL) {
6950                         expected_type = best_type;
6951                 }
6952         }
6953
6954         error                = semantic_assign(expected_type, arg_expr);
6955         argument->expression = create_implicit_cast(arg_expr, expected_type);
6956
6957         if (error != ASSIGN_SUCCESS) {
6958                 /* report exact scope in error messages (like "in argument 3") */
6959                 char buf[64];
6960                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6961                 report_assign_error(error, expected_type, arg_expr, buf,
6962                                     &arg_expr->base.source_position);
6963         } else {
6964                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6965                 if (!types_compatible(expected_type_skip, promoted_type) &&
6966                     !types_compatible(expected_type_skip, type_void_ptr) &&
6967                     !types_compatible(type_void_ptr,      promoted_type)) {
6968                         /* Deliberately show the skipped types in this warning */
6969                         source_position_t const *const apos = &arg_expr->base.source_position;
6970                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6971                 }
6972         }
6973 }
6974
6975 /**
6976  * Handle the semantic restrictions of builtin calls
6977  */
6978 static void handle_builtin_argument_restrictions(call_expression_t *call)
6979 {
6980         entity_t *entity = call->function->reference.entity;
6981         switch (entity->function.btk) {
6982         case BUILTIN_FIRM:
6983                 switch (entity->function.b.firm_builtin_kind) {
6984                 case ir_bk_return_address:
6985                 case ir_bk_frame_address: {
6986                         /* argument must be constant */
6987                         call_argument_t *argument = call->arguments;
6988
6989                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6990                                 errorf(&call->base.source_position,
6991                                            "argument of '%Y' must be a constant expression",
6992                                            call->function->reference.entity->base.symbol);
6993                         }
6994                         break;
6995                 }
6996                 case ir_bk_prefetch:
6997                         /* second and third argument must be constant if existent */
6998                         if (call->arguments == NULL)
6999                                 break;
7000                         call_argument_t *rw = call->arguments->next;
7001                         call_argument_t *locality = NULL;
7002
7003                         if (rw != NULL) {
7004                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7005                                         errorf(&call->base.source_position,
7006                                                    "second argument of '%Y' must be a constant expression",
7007                                                    call->function->reference.entity->base.symbol);
7008                                 }
7009                                 locality = rw->next;
7010                         }
7011                         if (locality != NULL) {
7012                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7013                                         errorf(&call->base.source_position,
7014                                                    "third argument of '%Y' must be a constant expression",
7015                                                    call->function->reference.entity->base.symbol);
7016                                 }
7017                                 locality = rw->next;
7018                         }
7019                         break;
7020                 default:
7021                         break;
7022                 }
7023
7024         case BUILTIN_OBJECT_SIZE:
7025                 if (call->arguments == NULL)
7026                         break;
7027
7028                 call_argument_t *arg = call->arguments->next;
7029                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7030                         errorf(&call->base.source_position,
7031                                    "second argument of '%Y' must be a constant expression",
7032                                    call->function->reference.entity->base.symbol);
7033                 }
7034                 break;
7035         default:
7036                 break;
7037         }
7038 }
7039
7040 /**
7041  * Parse a call expression, ie. expression '( ... )'.
7042  *
7043  * @param expression  the function address
7044  */
7045 static expression_t *parse_call_expression(expression_t *expression)
7046 {
7047         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7048         call_expression_t *call   = &result->call;
7049         call->function            = expression;
7050
7051         type_t *const orig_type = expression->base.type;
7052         type_t *const type      = skip_typeref(orig_type);
7053
7054         function_type_t *function_type = NULL;
7055         if (is_type_pointer(type)) {
7056                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7057
7058                 if (is_type_function(to_type)) {
7059                         function_type   = &to_type->function;
7060                         call->base.type = function_type->return_type;
7061                 }
7062         }
7063
7064         if (function_type == NULL && is_type_valid(type)) {
7065                 errorf(HERE,
7066                        "called object '%E' (type '%T') is not a pointer to a function",
7067                        expression, orig_type);
7068         }
7069
7070         /* parse arguments */
7071         eat('(');
7072         add_anchor_token(')');
7073         add_anchor_token(',');
7074
7075         if (token.kind != ')') {
7076                 call_argument_t **anchor = &call->arguments;
7077                 do {
7078                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7079                         argument->expression = parse_assignment_expression();
7080
7081                         *anchor = argument;
7082                         anchor  = &argument->next;
7083                 } while (next_if(','));
7084         }
7085         rem_anchor_token(',');
7086         rem_anchor_token(')');
7087         expect(')');
7088
7089         if (function_type == NULL)
7090                 return result;
7091
7092         /* check type and count of call arguments */
7093         function_parameter_t *parameter = function_type->parameters;
7094         call_argument_t      *argument  = call->arguments;
7095         if (!function_type->unspecified_parameters) {
7096                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7097                                 parameter = parameter->next, argument = argument->next) {
7098                         check_call_argument(parameter->type, argument, ++pos);
7099                 }
7100
7101                 if (parameter != NULL) {
7102                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7103                 } else if (argument != NULL && !function_type->variadic) {
7104                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7105                 }
7106         }
7107
7108         /* do default promotion for other arguments */
7109         for (; argument != NULL; argument = argument->next) {
7110                 type_t *argument_type = argument->expression->base.type;
7111                 if (!is_type_object(skip_typeref(argument_type))) {
7112                         errorf(&argument->expression->base.source_position,
7113                                "call argument '%E' must not be void", argument->expression);
7114                 }
7115
7116                 argument_type = get_default_promoted_type(argument_type);
7117
7118                 argument->expression
7119                         = create_implicit_cast(argument->expression, argument_type);
7120         }
7121
7122         check_format(call);
7123
7124         if (is_type_compound(skip_typeref(function_type->return_type))) {
7125                 source_position_t const *const pos = &expression->base.source_position;
7126                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7127         }
7128
7129         if (expression->kind == EXPR_REFERENCE) {
7130                 reference_expression_t *reference = &expression->reference;
7131                 if (reference->entity->kind == ENTITY_FUNCTION &&
7132                     reference->entity->function.btk != BUILTIN_NONE)
7133                         handle_builtin_argument_restrictions(call);
7134         }
7135
7136         return result;
7137 }
7138
7139 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7140
7141 static bool same_compound_type(const type_t *type1, const type_t *type2)
7142 {
7143         return
7144                 is_type_compound(type1) &&
7145                 type1->kind == type2->kind &&
7146                 type1->compound.compound == type2->compound.compound;
7147 }
7148
7149 static expression_t const *get_reference_address(expression_t const *expr)
7150 {
7151         bool regular_take_address = true;
7152         for (;;) {
7153                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7154                         expr = expr->unary.value;
7155                 } else {
7156                         regular_take_address = false;
7157                 }
7158
7159                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7160                         break;
7161
7162                 expr = expr->unary.value;
7163         }
7164
7165         if (expr->kind != EXPR_REFERENCE)
7166                 return NULL;
7167
7168         /* special case for functions which are automatically converted to a
7169          * pointer to function without an extra TAKE_ADDRESS operation */
7170         if (!regular_take_address &&
7171                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7172                 return NULL;
7173         }
7174
7175         return expr;
7176 }
7177
7178 static void warn_reference_address_as_bool(expression_t const* expr)
7179 {
7180         expr = get_reference_address(expr);
7181         if (expr != NULL) {
7182                 source_position_t const *const pos = &expr->base.source_position;
7183                 entity_t          const *const ent = expr->reference.entity;
7184                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7185         }
7186 }
7187
7188 static void warn_assignment_in_condition(const expression_t *const expr)
7189 {
7190         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7191                 return;
7192         if (expr->base.parenthesized)
7193                 return;
7194         source_position_t const *const pos = &expr->base.source_position;
7195         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7196 }
7197
7198 static void semantic_condition(expression_t const *const expr,
7199                                char const *const context)
7200 {
7201         type_t *const type = skip_typeref(expr->base.type);
7202         if (is_type_scalar(type)) {
7203                 warn_reference_address_as_bool(expr);
7204                 warn_assignment_in_condition(expr);
7205         } else if (is_type_valid(type)) {
7206                 errorf(&expr->base.source_position,
7207                                 "%s must have scalar type", context);
7208         }
7209 }
7210
7211 /**
7212  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7213  *
7214  * @param expression  the conditional expression
7215  */
7216 static expression_t *parse_conditional_expression(expression_t *expression)
7217 {
7218         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7219
7220         conditional_expression_t *conditional = &result->conditional;
7221         conditional->condition                = expression;
7222
7223         eat('?');
7224         add_anchor_token(':');
7225
7226         /* §6.5.15:2  The first operand shall have scalar type. */
7227         semantic_condition(expression, "condition of conditional operator");
7228
7229         expression_t *true_expression = expression;
7230         bool          gnu_cond = false;
7231         if (GNU_MODE && token.kind == ':') {
7232                 gnu_cond = true;
7233         } else {
7234                 true_expression = parse_expression();
7235         }
7236         rem_anchor_token(':');
7237         expect(':');
7238         expression_t *false_expression =
7239                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7240
7241         type_t *const orig_true_type  = true_expression->base.type;
7242         type_t *const orig_false_type = false_expression->base.type;
7243         type_t *const true_type       = skip_typeref(orig_true_type);
7244         type_t *const false_type      = skip_typeref(orig_false_type);
7245
7246         /* 6.5.15.3 */
7247         source_position_t const *const pos = &conditional->base.source_position;
7248         type_t                        *result_type;
7249         if (is_type_void(true_type) || is_type_void(false_type)) {
7250                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7251                 if (true_expression->kind == EXPR_UNARY_THROW) {
7252                         result_type = false_type;
7253                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7254                         result_type = true_type;
7255                 } else {
7256                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7257                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7258                         }
7259                         result_type = type_void;
7260                 }
7261         } else if (is_type_arithmetic(true_type)
7262                    && is_type_arithmetic(false_type)) {
7263                 result_type = semantic_arithmetic(true_type, false_type);
7264         } else if (same_compound_type(true_type, false_type)) {
7265                 /* just take 1 of the 2 types */
7266                 result_type = true_type;
7267         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7268                 type_t *pointer_type;
7269                 type_t *other_type;
7270                 expression_t *other_expression;
7271                 if (is_type_pointer(true_type) &&
7272                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7273                         pointer_type     = true_type;
7274                         other_type       = false_type;
7275                         other_expression = false_expression;
7276                 } else {
7277                         pointer_type     = false_type;
7278                         other_type       = true_type;
7279                         other_expression = true_expression;
7280                 }
7281
7282                 if (is_null_pointer_constant(other_expression)) {
7283                         result_type = pointer_type;
7284                 } else if (is_type_pointer(other_type)) {
7285                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7286                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7287
7288                         type_t *to;
7289                         if (is_type_void(to1) || is_type_void(to2)) {
7290                                 to = type_void;
7291                         } else if (types_compatible(get_unqualified_type(to1),
7292                                                     get_unqualified_type(to2))) {
7293                                 to = to1;
7294                         } else {
7295                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7296                                 to = type_void;
7297                         }
7298
7299                         type_t *const type =
7300                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7301                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7302                 } else if (is_type_integer(other_type)) {
7303                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7304                         result_type = pointer_type;
7305                 } else {
7306                         goto types_incompatible;
7307                 }
7308         } else {
7309 types_incompatible:
7310                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7311                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7312                 }
7313                 result_type = type_error_type;
7314         }
7315
7316         conditional->true_expression
7317                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7318         conditional->false_expression
7319                 = create_implicit_cast(false_expression, result_type);
7320         conditional->base.type = result_type;
7321         return result;
7322 }
7323
7324 /**
7325  * Parse an extension expression.
7326  */
7327 static expression_t *parse_extension(void)
7328 {
7329         PUSH_EXTENSION();
7330         expression_t *expression = parse_subexpression(PREC_UNARY);
7331         POP_EXTENSION();
7332         return expression;
7333 }
7334
7335 /**
7336  * Parse a __builtin_classify_type() expression.
7337  */
7338 static expression_t *parse_builtin_classify_type(void)
7339 {
7340         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7341         result->base.type    = type_int;
7342
7343         eat(T___builtin_classify_type);
7344
7345         add_anchor_token(')');
7346         expect('(');
7347         expression_t *expression = parse_expression();
7348         rem_anchor_token(')');
7349         expect(')');
7350         result->classify_type.type_expression = expression;
7351
7352         return result;
7353 }
7354
7355 /**
7356  * Parse a delete expression
7357  * ISO/IEC 14882:1998(E) §5.3.5
7358  */
7359 static expression_t *parse_delete(void)
7360 {
7361         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7362         result->base.type          = type_void;
7363
7364         eat(T_delete);
7365
7366         if (next_if('[')) {
7367                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7368                 expect(']');
7369         }
7370
7371         expression_t *const value = parse_subexpression(PREC_CAST);
7372         result->unary.value = value;
7373
7374         type_t *const type = skip_typeref(value->base.type);
7375         if (!is_type_pointer(type)) {
7376                 if (is_type_valid(type)) {
7377                         errorf(&value->base.source_position,
7378                                         "operand of delete must have pointer type");
7379                 }
7380         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7381                 source_position_t const *const pos = &value->base.source_position;
7382                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7383         }
7384
7385         return result;
7386 }
7387
7388 /**
7389  * Parse a throw expression
7390  * ISO/IEC 14882:1998(E) §15:1
7391  */
7392 static expression_t *parse_throw(void)
7393 {
7394         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7395         result->base.type          = type_void;
7396
7397         eat(T_throw);
7398
7399         expression_t *value = NULL;
7400         switch (token.kind) {
7401                 EXPRESSION_START {
7402                         value = parse_assignment_expression();
7403                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7404                         type_t *const orig_type = value->base.type;
7405                         type_t *const type      = skip_typeref(orig_type);
7406                         if (is_type_incomplete(type)) {
7407                                 errorf(&value->base.source_position,
7408                                                 "cannot throw object of incomplete type '%T'", orig_type);
7409                         } else if (is_type_pointer(type)) {
7410                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7411                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7412                                         errorf(&value->base.source_position,
7413                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7414                                 }
7415                         }
7416                 }
7417
7418                 default:
7419                         break;
7420         }
7421         result->unary.value = value;
7422
7423         return result;
7424 }
7425
7426 static bool check_pointer_arithmetic(const source_position_t *source_position,
7427                                      type_t *pointer_type,
7428                                      type_t *orig_pointer_type)
7429 {
7430         type_t *points_to = pointer_type->pointer.points_to;
7431         points_to = skip_typeref(points_to);
7432
7433         if (is_type_incomplete(points_to)) {
7434                 if (!GNU_MODE || !is_type_void(points_to)) {
7435                         errorf(source_position,
7436                                "arithmetic with pointer to incomplete type '%T' not allowed",
7437                                orig_pointer_type);
7438                         return false;
7439                 } else {
7440                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7441                 }
7442         } else if (is_type_function(points_to)) {
7443                 if (!GNU_MODE) {
7444                         errorf(source_position,
7445                                "arithmetic with pointer to function type '%T' not allowed",
7446                                orig_pointer_type);
7447                         return false;
7448                 } else {
7449                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7450                 }
7451         }
7452         return true;
7453 }
7454
7455 static bool is_lvalue(const expression_t *expression)
7456 {
7457         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7458         switch (expression->kind) {
7459         case EXPR_ARRAY_ACCESS:
7460         case EXPR_COMPOUND_LITERAL:
7461         case EXPR_REFERENCE:
7462         case EXPR_SELECT:
7463         case EXPR_UNARY_DEREFERENCE:
7464                 return true;
7465
7466         default: {
7467                 type_t *type = skip_typeref(expression->base.type);
7468                 return
7469                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7470                         is_type_reference(type) ||
7471                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7472                          * error before, which maybe prevented properly recognizing it as
7473                          * lvalue. */
7474                         !is_type_valid(type);
7475         }
7476         }
7477 }
7478
7479 static void semantic_incdec(unary_expression_t *expression)
7480 {
7481         type_t *const orig_type = expression->value->base.type;
7482         type_t *const type      = skip_typeref(orig_type);
7483         if (is_type_pointer(type)) {
7484                 if (!check_pointer_arithmetic(&expression->base.source_position,
7485                                               type, orig_type)) {
7486                         return;
7487                 }
7488         } else if (!is_type_real(type) && is_type_valid(type)) {
7489                 /* TODO: improve error message */
7490                 errorf(&expression->base.source_position,
7491                        "operation needs an arithmetic or pointer type");
7492                 return;
7493         }
7494         if (!is_lvalue(expression->value)) {
7495                 /* TODO: improve error message */
7496                 errorf(&expression->base.source_position, "lvalue required as operand");
7497         }
7498         expression->base.type = orig_type;
7499 }
7500
7501 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7502 {
7503         type_t *const res_type = promote_integer(type);
7504         expr->base.type = res_type;
7505         expr->value     = create_implicit_cast(expr->value, res_type);
7506 }
7507
7508 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7509 {
7510         type_t *const orig_type = expression->value->base.type;
7511         type_t *const type      = skip_typeref(orig_type);
7512         if (!is_type_arithmetic(type)) {
7513                 if (is_type_valid(type)) {
7514                         /* TODO: improve error message */
7515                         errorf(&expression->base.source_position,
7516                                 "operation needs an arithmetic type");
7517                 }
7518                 return;
7519         } else if (is_type_integer(type)) {
7520                 promote_unary_int_expr(expression, type);
7521         } else {
7522                 expression->base.type = orig_type;
7523         }
7524 }
7525
7526 static void semantic_unexpr_plus(unary_expression_t *expression)
7527 {
7528         semantic_unexpr_arithmetic(expression);
7529         source_position_t const *const pos = &expression->base.source_position;
7530         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7531 }
7532
7533 static void semantic_not(unary_expression_t *expression)
7534 {
7535         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7536         semantic_condition(expression->value, "operand of !");
7537         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7538 }
7539
7540 static void semantic_unexpr_integer(unary_expression_t *expression)
7541 {
7542         type_t *const orig_type = expression->value->base.type;
7543         type_t *const type      = skip_typeref(orig_type);
7544         if (!is_type_integer(type)) {
7545                 if (is_type_valid(type)) {
7546                         errorf(&expression->base.source_position,
7547                                "operand of ~ must be of integer type");
7548                 }
7549                 return;
7550         }
7551
7552         promote_unary_int_expr(expression, type);
7553 }
7554
7555 static void semantic_dereference(unary_expression_t *expression)
7556 {
7557         type_t *const orig_type = expression->value->base.type;
7558         type_t *const type      = skip_typeref(orig_type);
7559         if (!is_type_pointer(type)) {
7560                 if (is_type_valid(type)) {
7561                         errorf(&expression->base.source_position,
7562                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7563                 }
7564                 return;
7565         }
7566
7567         type_t *result_type   = type->pointer.points_to;
7568         result_type           = automatic_type_conversion(result_type);
7569         expression->base.type = result_type;
7570 }
7571
7572 /**
7573  * Record that an address is taken (expression represents an lvalue).
7574  *
7575  * @param expression       the expression
7576  * @param may_be_register  if true, the expression might be an register
7577  */
7578 static void set_address_taken(expression_t *expression, bool may_be_register)
7579 {
7580         if (expression->kind != EXPR_REFERENCE)
7581                 return;
7582
7583         entity_t *const entity = expression->reference.entity;
7584
7585         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7586                 return;
7587
7588         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7589                         && !may_be_register) {
7590                 source_position_t const *const pos = &expression->base.source_position;
7591                 errorf(pos, "address of register '%N' requested", entity);
7592         }
7593
7594         entity->variable.address_taken = true;
7595 }
7596
7597 /**
7598  * Check the semantic of the address taken expression.
7599  */
7600 static void semantic_take_addr(unary_expression_t *expression)
7601 {
7602         expression_t *value = expression->value;
7603         value->base.type    = revert_automatic_type_conversion(value);
7604
7605         type_t *orig_type = value->base.type;
7606         type_t *type      = skip_typeref(orig_type);
7607         if (!is_type_valid(type))
7608                 return;
7609
7610         /* §6.5.3.2 */
7611         if (!is_lvalue(value)) {
7612                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7613         }
7614         if (is_bitfield(value)) {
7615                 errorf(&expression->base.source_position,
7616                        "'&' not allowed on bitfield");
7617         }
7618
7619         set_address_taken(value, false);
7620
7621         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7622 }
7623
7624 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7625 static expression_t *parse_##unexpression_type(void)                         \
7626 {                                                                            \
7627         expression_t *unary_expression                                           \
7628                 = allocate_expression_zero(unexpression_type);                       \
7629         eat(token_kind);                                                         \
7630         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7631                                                                                  \
7632         sfunc(&unary_expression->unary);                                         \
7633                                                                                  \
7634         return unary_expression;                                                 \
7635 }
7636
7637 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7638                                semantic_unexpr_arithmetic)
7639 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7640                                semantic_unexpr_plus)
7641 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7642                                semantic_not)
7643 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7644                                semantic_dereference)
7645 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7646                                semantic_take_addr)
7647 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7648                                semantic_unexpr_integer)
7649 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7650                                semantic_incdec)
7651 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7652                                semantic_incdec)
7653
7654 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7655                                                sfunc)                         \
7656 static expression_t *parse_##unexpression_type(expression_t *left)            \
7657 {                                                                             \
7658         expression_t *unary_expression                                            \
7659                 = allocate_expression_zero(unexpression_type);                        \
7660         eat(token_kind);                                                          \
7661         unary_expression->unary.value = left;                                     \
7662                                                                                   \
7663         sfunc(&unary_expression->unary);                                          \
7664                                                                               \
7665         return unary_expression;                                                  \
7666 }
7667
7668 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7669                                        EXPR_UNARY_POSTFIX_INCREMENT,
7670                                        semantic_incdec)
7671 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7672                                        EXPR_UNARY_POSTFIX_DECREMENT,
7673                                        semantic_incdec)
7674
7675 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7676 {
7677         /* TODO: handle complex + imaginary types */
7678
7679         type_left  = get_unqualified_type(type_left);
7680         type_right = get_unqualified_type(type_right);
7681
7682         /* §6.3.1.8 Usual arithmetic conversions */
7683         if (type_left == type_long_double || type_right == type_long_double) {
7684                 return type_long_double;
7685         } else if (type_left == type_double || type_right == type_double) {
7686                 return type_double;
7687         } else if (type_left == type_float || type_right == type_float) {
7688                 return type_float;
7689         }
7690
7691         type_left  = promote_integer(type_left);
7692         type_right = promote_integer(type_right);
7693
7694         if (type_left == type_right)
7695                 return type_left;
7696
7697         bool     const signed_left  = is_type_signed(type_left);
7698         bool     const signed_right = is_type_signed(type_right);
7699         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7700         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7701
7702         if (signed_left == signed_right)
7703                 return rank_left >= rank_right ? type_left : type_right;
7704
7705         unsigned           s_rank;
7706         unsigned           u_rank;
7707         atomic_type_kind_t s_akind;
7708         atomic_type_kind_t u_akind;
7709         type_t *s_type;
7710         type_t *u_type;
7711         if (signed_left) {
7712                 s_type = type_left;
7713                 u_type = type_right;
7714         } else {
7715                 s_type = type_right;
7716                 u_type = type_left;
7717         }
7718         s_akind = get_akind(s_type);
7719         u_akind = get_akind(u_type);
7720         s_rank  = get_akind_rank(s_akind);
7721         u_rank  = get_akind_rank(u_akind);
7722
7723         if (u_rank >= s_rank)
7724                 return u_type;
7725
7726         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7727                 return s_type;
7728
7729         switch (s_akind) {
7730         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7731         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7732         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7733
7734         default: panic("invalid atomic type");
7735         }
7736 }
7737
7738 /**
7739  * Check the semantic restrictions for a binary expression.
7740  */
7741 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7742 {
7743         expression_t *const left            = expression->left;
7744         expression_t *const right           = expression->right;
7745         type_t       *const orig_type_left  = left->base.type;
7746         type_t       *const orig_type_right = right->base.type;
7747         type_t       *const type_left       = skip_typeref(orig_type_left);
7748         type_t       *const type_right      = skip_typeref(orig_type_right);
7749
7750         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7751                 /* TODO: improve error message */
7752                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7753                         errorf(&expression->base.source_position,
7754                                "operation needs arithmetic types");
7755                 }
7756                 return;
7757         }
7758
7759         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7760         expression->left      = create_implicit_cast(left, arithmetic_type);
7761         expression->right     = create_implicit_cast(right, arithmetic_type);
7762         expression->base.type = arithmetic_type;
7763 }
7764
7765 static void semantic_binexpr_integer(binary_expression_t *const expression)
7766 {
7767         expression_t *const left            = expression->left;
7768         expression_t *const right           = expression->right;
7769         type_t       *const orig_type_left  = left->base.type;
7770         type_t       *const orig_type_right = right->base.type;
7771         type_t       *const type_left       = skip_typeref(orig_type_left);
7772         type_t       *const type_right      = skip_typeref(orig_type_right);
7773
7774         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7775                 /* TODO: improve error message */
7776                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7777                         errorf(&expression->base.source_position,
7778                                "operation needs integer types");
7779                 }
7780                 return;
7781         }
7782
7783         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7784         expression->left      = create_implicit_cast(left, result_type);
7785         expression->right     = create_implicit_cast(right, result_type);
7786         expression->base.type = result_type;
7787 }
7788
7789 static void warn_div_by_zero(binary_expression_t const *const expression)
7790 {
7791         if (!is_type_integer(expression->base.type))
7792                 return;
7793
7794         expression_t const *const right = expression->right;
7795         /* The type of the right operand can be different for /= */
7796         if (is_type_integer(right->base.type)                    &&
7797             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7798             !fold_constant_to_bool(right)) {
7799                 source_position_t const *const pos = &expression->base.source_position;
7800                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7801         }
7802 }
7803
7804 /**
7805  * Check the semantic restrictions for a div/mod expression.
7806  */
7807 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7808 {
7809         semantic_binexpr_arithmetic(expression);
7810         warn_div_by_zero(expression);
7811 }
7812
7813 static void warn_addsub_in_shift(const expression_t *const expr)
7814 {
7815         if (expr->base.parenthesized)
7816                 return;
7817
7818         char op;
7819         switch (expr->kind) {
7820                 case EXPR_BINARY_ADD: op = '+'; break;
7821                 case EXPR_BINARY_SUB: op = '-'; break;
7822                 default:              return;
7823         }
7824
7825         source_position_t const *const pos = &expr->base.source_position;
7826         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7827 }
7828
7829 static bool semantic_shift(binary_expression_t *expression)
7830 {
7831         expression_t *const left            = expression->left;
7832         expression_t *const right           = expression->right;
7833         type_t       *const orig_type_left  = left->base.type;
7834         type_t       *const orig_type_right = right->base.type;
7835         type_t       *      type_left       = skip_typeref(orig_type_left);
7836         type_t       *      type_right      = skip_typeref(orig_type_right);
7837
7838         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7839                 /* TODO: improve error message */
7840                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7841                         errorf(&expression->base.source_position,
7842                                "operands of shift operation must have integer types");
7843                 }
7844                 return false;
7845         }
7846
7847         type_left = promote_integer(type_left);
7848
7849         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7850                 source_position_t const *const pos   = &right->base.source_position;
7851                 long                     const count = fold_constant_to_int(right);
7852                 if (count < 0) {
7853                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7854                 } else if ((unsigned long)count >=
7855                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7856                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7857                 }
7858         }
7859
7860         type_right        = promote_integer(type_right);
7861         expression->right = create_implicit_cast(right, type_right);
7862
7863         return true;
7864 }
7865
7866 static void semantic_shift_op(binary_expression_t *expression)
7867 {
7868         expression_t *const left  = expression->left;
7869         expression_t *const right = expression->right;
7870
7871         if (!semantic_shift(expression))
7872                 return;
7873
7874         warn_addsub_in_shift(left);
7875         warn_addsub_in_shift(right);
7876
7877         type_t *const orig_type_left = left->base.type;
7878         type_t *      type_left      = skip_typeref(orig_type_left);
7879
7880         type_left             = promote_integer(type_left);
7881         expression->left      = create_implicit_cast(left, type_left);
7882         expression->base.type = type_left;
7883 }
7884
7885 static void semantic_add(binary_expression_t *expression)
7886 {
7887         expression_t *const left            = expression->left;
7888         expression_t *const right           = expression->right;
7889         type_t       *const orig_type_left  = left->base.type;
7890         type_t       *const orig_type_right = right->base.type;
7891         type_t       *const type_left       = skip_typeref(orig_type_left);
7892         type_t       *const type_right      = skip_typeref(orig_type_right);
7893
7894         /* §6.5.6 */
7895         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7896                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7897                 expression->left  = create_implicit_cast(left, arithmetic_type);
7898                 expression->right = create_implicit_cast(right, arithmetic_type);
7899                 expression->base.type = arithmetic_type;
7900         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7901                 check_pointer_arithmetic(&expression->base.source_position,
7902                                          type_left, orig_type_left);
7903                 expression->base.type = type_left;
7904         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7905                 check_pointer_arithmetic(&expression->base.source_position,
7906                                          type_right, orig_type_right);
7907                 expression->base.type = type_right;
7908         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7909                 errorf(&expression->base.source_position,
7910                        "invalid operands to binary + ('%T', '%T')",
7911                        orig_type_left, orig_type_right);
7912         }
7913 }
7914
7915 static void semantic_sub(binary_expression_t *expression)
7916 {
7917         expression_t            *const left            = expression->left;
7918         expression_t            *const right           = expression->right;
7919         type_t                  *const orig_type_left  = left->base.type;
7920         type_t                  *const orig_type_right = right->base.type;
7921         type_t                  *const type_left       = skip_typeref(orig_type_left);
7922         type_t                  *const type_right      = skip_typeref(orig_type_right);
7923         source_position_t const *const pos             = &expression->base.source_position;
7924
7925         /* §5.6.5 */
7926         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7927                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7928                 expression->left        = create_implicit_cast(left, arithmetic_type);
7929                 expression->right       = create_implicit_cast(right, arithmetic_type);
7930                 expression->base.type =  arithmetic_type;
7931         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7932                 check_pointer_arithmetic(&expression->base.source_position,
7933                                          type_left, orig_type_left);
7934                 expression->base.type = type_left;
7935         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7936                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7937                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7938                 if (!types_compatible(unqual_left, unqual_right)) {
7939                         errorf(pos,
7940                                "subtracting pointers to incompatible types '%T' and '%T'",
7941                                orig_type_left, orig_type_right);
7942                 } else if (!is_type_object(unqual_left)) {
7943                         if (!is_type_void(unqual_left)) {
7944                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7945                                        orig_type_left);
7946                         } else {
7947                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7948                         }
7949                 }
7950                 expression->base.type = type_ptrdiff_t;
7951         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7952                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7953                        orig_type_left, orig_type_right);
7954         }
7955 }
7956
7957 static void warn_string_literal_address(expression_t const* expr)
7958 {
7959         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7960                 expr = expr->unary.value;
7961                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7962                         return;
7963                 expr = expr->unary.value;
7964         }
7965
7966         if (expr->kind == EXPR_STRING_LITERAL) {
7967                 source_position_t const *const pos = &expr->base.source_position;
7968                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7969         }
7970 }
7971
7972 static bool maybe_negative(expression_t const *const expr)
7973 {
7974         switch (is_constant_expression(expr)) {
7975                 case EXPR_CLASS_ERROR:    return false;
7976                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7977                 default:                  return true;
7978         }
7979 }
7980
7981 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7982 {
7983         warn_string_literal_address(expr);
7984
7985         expression_t const* const ref = get_reference_address(expr);
7986         if (ref != NULL && is_null_pointer_constant(other)) {
7987                 entity_t const *const ent = ref->reference.entity;
7988                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7989         }
7990
7991         if (!expr->base.parenthesized) {
7992                 switch (expr->base.kind) {
7993                         case EXPR_BINARY_LESS:
7994                         case EXPR_BINARY_GREATER:
7995                         case EXPR_BINARY_LESSEQUAL:
7996                         case EXPR_BINARY_GREATEREQUAL:
7997                         case EXPR_BINARY_NOTEQUAL:
7998                         case EXPR_BINARY_EQUAL:
7999                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8000                                 break;
8001                         default:
8002                                 break;
8003                 }
8004         }
8005 }
8006
8007 /**
8008  * Check the semantics of comparison expressions.
8009  *
8010  * @param expression   The expression to check.
8011  */
8012 static void semantic_comparison(binary_expression_t *expression)
8013 {
8014         source_position_t const *const pos   = &expression->base.source_position;
8015         expression_t            *const left  = expression->left;
8016         expression_t            *const right = expression->right;
8017
8018         warn_comparison(pos, left, right);
8019         warn_comparison(pos, right, left);
8020
8021         type_t *orig_type_left  = left->base.type;
8022         type_t *orig_type_right = right->base.type;
8023         type_t *type_left       = skip_typeref(orig_type_left);
8024         type_t *type_right      = skip_typeref(orig_type_right);
8025
8026         /* TODO non-arithmetic types */
8027         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8028                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8029
8030                 /* test for signed vs unsigned compares */
8031                 if (is_type_integer(arithmetic_type)) {
8032                         bool const signed_left  = is_type_signed(type_left);
8033                         bool const signed_right = is_type_signed(type_right);
8034                         if (signed_left != signed_right) {
8035                                 /* FIXME long long needs better const folding magic */
8036                                 /* TODO check whether constant value can be represented by other type */
8037                                 if ((signed_left  && maybe_negative(left)) ||
8038                                                 (signed_right && maybe_negative(right))) {
8039                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8040                                 }
8041                         }
8042                 }
8043
8044                 expression->left        = create_implicit_cast(left, arithmetic_type);
8045                 expression->right       = create_implicit_cast(right, arithmetic_type);
8046                 expression->base.type   = arithmetic_type;
8047                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8048                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8049                     is_type_float(arithmetic_type)) {
8050                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8051                 }
8052         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8053                 /* TODO check compatibility */
8054         } else if (is_type_pointer(type_left)) {
8055                 expression->right = create_implicit_cast(right, type_left);
8056         } else if (is_type_pointer(type_right)) {
8057                 expression->left = create_implicit_cast(left, type_right);
8058         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8059                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8060         }
8061         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8062 }
8063
8064 /**
8065  * Checks if a compound type has constant fields.
8066  */
8067 static bool has_const_fields(const compound_type_t *type)
8068 {
8069         compound_t *compound = type->compound;
8070         entity_t   *entry    = compound->members.entities;
8071
8072         for (; entry != NULL; entry = entry->base.next) {
8073                 if (!is_declaration(entry))
8074                         continue;
8075
8076                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8077                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8078                         return true;
8079         }
8080
8081         return false;
8082 }
8083
8084 static bool is_valid_assignment_lhs(expression_t const* const left)
8085 {
8086         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8087         type_t *const type_left      = skip_typeref(orig_type_left);
8088
8089         if (!is_lvalue(left)) {
8090                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8091                        left);
8092                 return false;
8093         }
8094
8095         if (left->kind == EXPR_REFERENCE
8096                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8097                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8098                 return false;
8099         }
8100
8101         if (is_type_array(type_left)) {
8102                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8103                 return false;
8104         }
8105         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8106                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8107                        orig_type_left);
8108                 return false;
8109         }
8110         if (is_type_incomplete(type_left)) {
8111                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8112                        left, orig_type_left);
8113                 return false;
8114         }
8115         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8116                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8117                        left, orig_type_left);
8118                 return false;
8119         }
8120
8121         return true;
8122 }
8123
8124 static void semantic_arithmetic_assign(binary_expression_t *expression)
8125 {
8126         expression_t *left            = expression->left;
8127         expression_t *right           = expression->right;
8128         type_t       *orig_type_left  = left->base.type;
8129         type_t       *orig_type_right = right->base.type;
8130
8131         if (!is_valid_assignment_lhs(left))
8132                 return;
8133
8134         type_t *type_left  = skip_typeref(orig_type_left);
8135         type_t *type_right = skip_typeref(orig_type_right);
8136
8137         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8138                 /* TODO: improve error message */
8139                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8140                         errorf(&expression->base.source_position,
8141                                "operation needs arithmetic types");
8142                 }
8143                 return;
8144         }
8145
8146         /* combined instructions are tricky. We can't create an implicit cast on
8147          * the left side, because we need the uncasted form for the store.
8148          * The ast2firm pass has to know that left_type must be right_type
8149          * for the arithmetic operation and create a cast by itself */
8150         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8151         expression->right       = create_implicit_cast(right, arithmetic_type);
8152         expression->base.type   = type_left;
8153 }
8154
8155 static void semantic_divmod_assign(binary_expression_t *expression)
8156 {
8157         semantic_arithmetic_assign(expression);
8158         warn_div_by_zero(expression);
8159 }
8160
8161 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8162 {
8163         expression_t *const left            = expression->left;
8164         expression_t *const right           = expression->right;
8165         type_t       *const orig_type_left  = left->base.type;
8166         type_t       *const orig_type_right = right->base.type;
8167         type_t       *const type_left       = skip_typeref(orig_type_left);
8168         type_t       *const type_right      = skip_typeref(orig_type_right);
8169
8170         if (!is_valid_assignment_lhs(left))
8171                 return;
8172
8173         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8174                 /* combined instructions are tricky. We can't create an implicit cast on
8175                  * the left side, because we need the uncasted form for the store.
8176                  * The ast2firm pass has to know that left_type must be right_type
8177                  * for the arithmetic operation and create a cast by itself */
8178                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8179                 expression->right     = create_implicit_cast(right, arithmetic_type);
8180                 expression->base.type = type_left;
8181         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8182                 check_pointer_arithmetic(&expression->base.source_position,
8183                                          type_left, orig_type_left);
8184                 expression->base.type = type_left;
8185         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8186                 errorf(&expression->base.source_position,
8187                        "incompatible types '%T' and '%T' in assignment",
8188                        orig_type_left, orig_type_right);
8189         }
8190 }
8191
8192 static void semantic_integer_assign(binary_expression_t *expression)
8193 {
8194         expression_t *left            = expression->left;
8195         expression_t *right           = expression->right;
8196         type_t       *orig_type_left  = left->base.type;
8197         type_t       *orig_type_right = right->base.type;
8198
8199         if (!is_valid_assignment_lhs(left))
8200                 return;
8201
8202         type_t *type_left  = skip_typeref(orig_type_left);
8203         type_t *type_right = skip_typeref(orig_type_right);
8204
8205         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8206                 /* TODO: improve error message */
8207                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8208                         errorf(&expression->base.source_position,
8209                                "operation needs integer types");
8210                 }
8211                 return;
8212         }
8213
8214         /* combined instructions are tricky. We can't create an implicit cast on
8215          * the left side, because we need the uncasted form for the store.
8216          * The ast2firm pass has to know that left_type must be right_type
8217          * for the arithmetic operation and create a cast by itself */
8218         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8219         expression->right       = create_implicit_cast(right, arithmetic_type);
8220         expression->base.type   = type_left;
8221 }
8222
8223 static void semantic_shift_assign(binary_expression_t *expression)
8224 {
8225         expression_t *left           = expression->left;
8226
8227         if (!is_valid_assignment_lhs(left))
8228                 return;
8229
8230         if (!semantic_shift(expression))
8231                 return;
8232
8233         expression->base.type = skip_typeref(left->base.type);
8234 }
8235
8236 static void warn_logical_and_within_or(const expression_t *const expr)
8237 {
8238         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8239                 return;
8240         if (expr->base.parenthesized)
8241                 return;
8242         source_position_t const *const pos = &expr->base.source_position;
8243         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8244 }
8245
8246 /**
8247  * Check the semantic restrictions of a logical expression.
8248  */
8249 static void semantic_logical_op(binary_expression_t *expression)
8250 {
8251         /* §6.5.13:2  Each of the operands shall have scalar type.
8252          * §6.5.14:2  Each of the operands shall have scalar type. */
8253         semantic_condition(expression->left,   "left operand of logical operator");
8254         semantic_condition(expression->right, "right operand of logical operator");
8255         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8256                 warn_logical_and_within_or(expression->left);
8257                 warn_logical_and_within_or(expression->right);
8258         }
8259         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8260 }
8261
8262 /**
8263  * Check the semantic restrictions of a binary assign expression.
8264  */
8265 static void semantic_binexpr_assign(binary_expression_t *expression)
8266 {
8267         expression_t *left           = expression->left;
8268         type_t       *orig_type_left = left->base.type;
8269
8270         if (!is_valid_assignment_lhs(left))
8271                 return;
8272
8273         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8274         report_assign_error(error, orig_type_left, expression->right,
8275                         "assignment", &left->base.source_position);
8276         expression->right = create_implicit_cast(expression->right, orig_type_left);
8277         expression->base.type = orig_type_left;
8278 }
8279
8280 /**
8281  * Determine if the outermost operation (or parts thereof) of the given
8282  * expression has no effect in order to generate a warning about this fact.
8283  * Therefore in some cases this only examines some of the operands of the
8284  * expression (see comments in the function and examples below).
8285  * Examples:
8286  *   f() + 23;    // warning, because + has no effect
8287  *   x || f();    // no warning, because x controls execution of f()
8288  *   x ? y : f(); // warning, because y has no effect
8289  *   (void)x;     // no warning to be able to suppress the warning
8290  * This function can NOT be used for an "expression has definitely no effect"-
8291  * analysis. */
8292 static bool expression_has_effect(const expression_t *const expr)
8293 {
8294         switch (expr->kind) {
8295                 case EXPR_ERROR:                      return true; /* do NOT warn */
8296                 case EXPR_REFERENCE:                  return false;
8297                 case EXPR_ENUM_CONSTANT:              return false;
8298                 case EXPR_LABEL_ADDRESS:              return false;
8299
8300                 /* suppress the warning for microsoft __noop operations */
8301                 case EXPR_LITERAL_MS_NOOP:            return true;
8302                 case EXPR_LITERAL_BOOLEAN:
8303                 case EXPR_LITERAL_CHARACTER:
8304                 case EXPR_LITERAL_INTEGER:
8305                 case EXPR_LITERAL_FLOATINGPOINT:
8306                 case EXPR_STRING_LITERAL:             return false;
8307
8308                 case EXPR_CALL: {
8309                         const call_expression_t *const call = &expr->call;
8310                         if (call->function->kind != EXPR_REFERENCE)
8311                                 return true;
8312
8313                         switch (call->function->reference.entity->function.btk) {
8314                                 /* FIXME: which builtins have no effect? */
8315                                 default:                      return true;
8316                         }
8317                 }
8318
8319                 /* Generate the warning if either the left or right hand side of a
8320                  * conditional expression has no effect */
8321                 case EXPR_CONDITIONAL: {
8322                         conditional_expression_t const *const cond = &expr->conditional;
8323                         expression_t             const *const t    = cond->true_expression;
8324                         return
8325                                 (t == NULL || expression_has_effect(t)) &&
8326                                 expression_has_effect(cond->false_expression);
8327                 }
8328
8329                 case EXPR_SELECT:                     return false;
8330                 case EXPR_ARRAY_ACCESS:               return false;
8331                 case EXPR_SIZEOF:                     return false;
8332                 case EXPR_CLASSIFY_TYPE:              return false;
8333                 case EXPR_ALIGNOF:                    return false;
8334
8335                 case EXPR_FUNCNAME:                   return false;
8336                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8337                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8338                 case EXPR_OFFSETOF:                   return false;
8339                 case EXPR_VA_START:                   return true;
8340                 case EXPR_VA_ARG:                     return true;
8341                 case EXPR_VA_COPY:                    return true;
8342                 case EXPR_STATEMENT:                  return true; // TODO
8343                 case EXPR_COMPOUND_LITERAL:           return false;
8344
8345                 case EXPR_UNARY_NEGATE:               return false;
8346                 case EXPR_UNARY_PLUS:                 return false;
8347                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8348                 case EXPR_UNARY_NOT:                  return false;
8349                 case EXPR_UNARY_DEREFERENCE:          return false;
8350                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8351                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8352                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8353                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8354                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8355
8356                 /* Treat void casts as if they have an effect in order to being able to
8357                  * suppress the warning */
8358                 case EXPR_UNARY_CAST: {
8359                         type_t *const type = skip_typeref(expr->base.type);
8360                         return is_type_void(type);
8361                 }
8362
8363                 case EXPR_UNARY_ASSUME:               return true;
8364                 case EXPR_UNARY_DELETE:               return true;
8365                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8366                 case EXPR_UNARY_THROW:                return true;
8367
8368                 case EXPR_BINARY_ADD:                 return false;
8369                 case EXPR_BINARY_SUB:                 return false;
8370                 case EXPR_BINARY_MUL:                 return false;
8371                 case EXPR_BINARY_DIV:                 return false;
8372                 case EXPR_BINARY_MOD:                 return false;
8373                 case EXPR_BINARY_EQUAL:               return false;
8374                 case EXPR_BINARY_NOTEQUAL:            return false;
8375                 case EXPR_BINARY_LESS:                return false;
8376                 case EXPR_BINARY_LESSEQUAL:           return false;
8377                 case EXPR_BINARY_GREATER:             return false;
8378                 case EXPR_BINARY_GREATEREQUAL:        return false;
8379                 case EXPR_BINARY_BITWISE_AND:         return false;
8380                 case EXPR_BINARY_BITWISE_OR:          return false;
8381                 case EXPR_BINARY_BITWISE_XOR:         return false;
8382                 case EXPR_BINARY_SHIFTLEFT:           return false;
8383                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8384                 case EXPR_BINARY_ASSIGN:              return true;
8385                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8386                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8387                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8388                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8389                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8390                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8391                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8392                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8393                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8394                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8395
8396                 /* Only examine the right hand side of && and ||, because the left hand
8397                  * side already has the effect of controlling the execution of the right
8398                  * hand side */
8399                 case EXPR_BINARY_LOGICAL_AND:
8400                 case EXPR_BINARY_LOGICAL_OR:
8401                 /* Only examine the right hand side of a comma expression, because the left
8402                  * hand side has a separate warning */
8403                 case EXPR_BINARY_COMMA:
8404                         return expression_has_effect(expr->binary.right);
8405
8406                 case EXPR_BINARY_ISGREATER:           return false;
8407                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8408                 case EXPR_BINARY_ISLESS:              return false;
8409                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8410                 case EXPR_BINARY_ISLESSGREATER:       return false;
8411                 case EXPR_BINARY_ISUNORDERED:         return false;
8412         }
8413
8414         internal_errorf(HERE, "unexpected expression");
8415 }
8416
8417 static void semantic_comma(binary_expression_t *expression)
8418 {
8419         const expression_t *const left = expression->left;
8420         if (!expression_has_effect(left)) {
8421                 source_position_t const *const pos = &left->base.source_position;
8422                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8423         }
8424         expression->base.type = expression->right->base.type;
8425 }
8426
8427 /**
8428  * @param prec_r precedence of the right operand
8429  */
8430 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8431 static expression_t *parse_##binexpression_type(expression_t *left)          \
8432 {                                                                            \
8433         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8434         binexpr->binary.left  = left;                                            \
8435         eat(token_kind);                                                         \
8436                                                                              \
8437         expression_t *right = parse_subexpression(prec_r);                       \
8438                                                                              \
8439         binexpr->binary.right = right;                                           \
8440         sfunc(&binexpr->binary);                                                 \
8441                                                                              \
8442         return binexpr;                                                          \
8443 }
8444
8445 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8446 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8447 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8448 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8449 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8450 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8451 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8452 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8453 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8454 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8455 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8456 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8457 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8458 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8459 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8460 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8461 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8462 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8463 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8464 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8465 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8466 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8467 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8468 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8469 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8470 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8471 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8472 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8473 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8474 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8475
8476
8477 static expression_t *parse_subexpression(precedence_t precedence)
8478 {
8479         expression_parser_function_t *parser
8480                 = &expression_parsers[token.kind];
8481         expression_t                 *left;
8482
8483         if (parser->parser != NULL) {
8484                 left = parser->parser();
8485         } else {
8486                 left = parse_primary_expression();
8487         }
8488         assert(left != NULL);
8489
8490         while (true) {
8491                 parser = &expression_parsers[token.kind];
8492                 if (parser->infix_parser == NULL)
8493                         break;
8494                 if (parser->infix_precedence < precedence)
8495                         break;
8496
8497                 left = parser->infix_parser(left);
8498
8499                 assert(left != NULL);
8500         }
8501
8502         return left;
8503 }
8504
8505 /**
8506  * Parse an expression.
8507  */
8508 static expression_t *parse_expression(void)
8509 {
8510         return parse_subexpression(PREC_EXPRESSION);
8511 }
8512
8513 /**
8514  * Register a parser for a prefix-like operator.
8515  *
8516  * @param parser      the parser function
8517  * @param token_kind  the token type of the prefix token
8518  */
8519 static void register_expression_parser(parse_expression_function parser,
8520                                        int token_kind)
8521 {
8522         expression_parser_function_t *entry = &expression_parsers[token_kind];
8523
8524         assert(!entry->parser);
8525         entry->parser = parser;
8526 }
8527
8528 /**
8529  * Register a parser for an infix operator with given precedence.
8530  *
8531  * @param parser      the parser function
8532  * @param token_kind  the token type of the infix operator
8533  * @param precedence  the precedence of the operator
8534  */
8535 static void register_infix_parser(parse_expression_infix_function parser,
8536                                   int token_kind, precedence_t precedence)
8537 {
8538         expression_parser_function_t *entry = &expression_parsers[token_kind];
8539
8540         assert(!entry->infix_parser);
8541         entry->infix_parser     = parser;
8542         entry->infix_precedence = precedence;
8543 }
8544
8545 /**
8546  * Initialize the expression parsers.
8547  */
8548 static void init_expression_parsers(void)
8549 {
8550         memset(&expression_parsers, 0, sizeof(expression_parsers));
8551
8552         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8553         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8554         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8555         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8556         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8557         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8558         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8559         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8560         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8561         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8562         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8563         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8564         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8565         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8566         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8567         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8568         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8569         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8570         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8571         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8572         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8573         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8574         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8575         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8576         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8577         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8578         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8579         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8580         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8581         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8582         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8583         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8584         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8585         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8586         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8587         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8588         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8589
8590         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8591         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8592         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8593         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8594         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8595         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8596         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8597         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8598         register_expression_parser(parse_sizeof,                      T_sizeof);
8599         register_expression_parser(parse_alignof,                     T___alignof__);
8600         register_expression_parser(parse_extension,                   T___extension__);
8601         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8602         register_expression_parser(parse_delete,                      T_delete);
8603         register_expression_parser(parse_throw,                       T_throw);
8604 }
8605
8606 /**
8607  * Parse a asm statement arguments specification.
8608  */
8609 static asm_argument_t *parse_asm_arguments(bool is_out)
8610 {
8611         asm_argument_t  *result = NULL;
8612         asm_argument_t **anchor = &result;
8613
8614         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8615                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8616
8617                 if (next_if('[')) {
8618                         add_anchor_token(']');
8619                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8620                         rem_anchor_token(']');
8621                         expect(']');
8622                         if (!argument->symbol)
8623                                 return NULL;
8624                 }
8625
8626                 argument->constraints = parse_string_literals("asm argument");
8627                 add_anchor_token(')');
8628                 expect('(');
8629                 expression_t *expression = parse_expression();
8630                 rem_anchor_token(')');
8631                 if (is_out) {
8632                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8633                          * change size or type representation (e.g. int -> long is ok, but
8634                          * int -> float is not) */
8635                         if (expression->kind == EXPR_UNARY_CAST) {
8636                                 type_t      *const type = expression->base.type;
8637                                 type_kind_t  const kind = type->kind;
8638                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8639                                         unsigned flags;
8640                                         unsigned size;
8641                                         if (kind == TYPE_ATOMIC) {
8642                                                 atomic_type_kind_t const akind = type->atomic.akind;
8643                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8644                                                 size  = get_atomic_type_size(akind);
8645                                         } else {
8646                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8647                                                 size  = get_type_size(type_void_ptr);
8648                                         }
8649
8650                                         do {
8651                                                 expression_t *const value      = expression->unary.value;
8652                                                 type_t       *const value_type = value->base.type;
8653                                                 type_kind_t   const value_kind = value_type->kind;
8654
8655                                                 unsigned value_flags;
8656                                                 unsigned value_size;
8657                                                 if (value_kind == TYPE_ATOMIC) {
8658                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8659                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8660                                                         value_size  = get_atomic_type_size(value_akind);
8661                                                 } else if (value_kind == TYPE_POINTER) {
8662                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8663                                                         value_size  = get_type_size(type_void_ptr);
8664                                                 } else {
8665                                                         break;
8666                                                 }
8667
8668                                                 if (value_flags != flags || value_size != size)
8669                                                         break;
8670
8671                                                 expression = value;
8672                                         } while (expression->kind == EXPR_UNARY_CAST);
8673                                 }
8674                         }
8675
8676                         if (!is_lvalue(expression)) {
8677                                 errorf(&expression->base.source_position,
8678                                        "asm output argument is not an lvalue");
8679                         }
8680
8681                         if (argument->constraints.begin[0] == '=')
8682                                 determine_lhs_ent(expression, NULL);
8683                         else
8684                                 mark_vars_read(expression, NULL);
8685                 } else {
8686                         mark_vars_read(expression, NULL);
8687                 }
8688                 argument->expression = expression;
8689                 expect(')');
8690
8691                 set_address_taken(expression, true);
8692
8693                 *anchor = argument;
8694                 anchor  = &argument->next;
8695
8696                 if (!next_if(','))
8697                         break;
8698         }
8699
8700         return result;
8701 }
8702
8703 /**
8704  * Parse a asm statement clobber specification.
8705  */
8706 static asm_clobber_t *parse_asm_clobbers(void)
8707 {
8708         asm_clobber_t *result  = NULL;
8709         asm_clobber_t **anchor = &result;
8710
8711         while (token.kind == T_STRING_LITERAL) {
8712                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8713                 clobber->clobber       = parse_string_literals(NULL);
8714
8715                 *anchor = clobber;
8716                 anchor  = &clobber->next;
8717
8718                 if (!next_if(','))
8719                         break;
8720         }
8721
8722         return result;
8723 }
8724
8725 /**
8726  * Parse an asm statement.
8727  */
8728 static statement_t *parse_asm_statement(void)
8729 {
8730         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8731         asm_statement_t *asm_statement = &statement->asms;
8732
8733         eat(T_asm);
8734         add_anchor_token(')');
8735         add_anchor_token(':');
8736         add_anchor_token(T_STRING_LITERAL);
8737
8738         if (next_if(T_volatile))
8739                 asm_statement->is_volatile = true;
8740
8741         expect('(');
8742         rem_anchor_token(T_STRING_LITERAL);
8743         asm_statement->asm_text = parse_string_literals("asm statement");
8744
8745         if (next_if(':'))
8746                 asm_statement->outputs = parse_asm_arguments(true);
8747
8748         if (next_if(':'))
8749                 asm_statement->inputs = parse_asm_arguments(false);
8750
8751         rem_anchor_token(':');
8752         if (next_if(':'))
8753                 asm_statement->clobbers = parse_asm_clobbers();
8754
8755         rem_anchor_token(')');
8756         expect(')');
8757         expect(';');
8758
8759         if (asm_statement->outputs == NULL) {
8760                 /* GCC: An 'asm' instruction without any output operands will be treated
8761                  * identically to a volatile 'asm' instruction. */
8762                 asm_statement->is_volatile = true;
8763         }
8764
8765         return statement;
8766 }
8767
8768 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8769 {
8770         statement_t *inner_stmt;
8771         switch (token.kind) {
8772                 case '}':
8773                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8774                         inner_stmt = create_error_statement();
8775                         break;
8776
8777                 case ';':
8778                         if (label->kind == STATEMENT_LABEL) {
8779                                 /* Eat an empty statement here, to avoid the warning about an empty
8780                                  * statement after a label.  label:; is commonly used to have a label
8781                                  * before a closing brace. */
8782                                 inner_stmt = create_empty_statement();
8783                                 eat(';');
8784                                 break;
8785                         }
8786                         /* FALLTHROUGH */
8787
8788                 default:
8789                         inner_stmt = parse_statement();
8790                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8791                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8792                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8793                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8794                         }
8795                         break;
8796         }
8797         return inner_stmt;
8798 }
8799
8800 /**
8801  * Parse a case statement.
8802  */
8803 static statement_t *parse_case_statement(void)
8804 {
8805         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8806         source_position_t *const pos       = &statement->base.source_position;
8807
8808         eat(T_case);
8809         add_anchor_token(':');
8810
8811         expression_t *expression = parse_expression();
8812         type_t *expression_type = expression->base.type;
8813         type_t *skipped         = skip_typeref(expression_type);
8814         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8815                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8816                        expression, expression_type);
8817         }
8818
8819         type_t *type = expression_type;
8820         if (current_switch != NULL) {
8821                 type_t *switch_type = current_switch->expression->base.type;
8822                 if (is_type_valid(switch_type)) {
8823                         expression = create_implicit_cast(expression, switch_type);
8824                 }
8825         }
8826
8827         statement->case_label.expression = expression;
8828         expression_classification_t const expr_class = is_constant_expression(expression);
8829         if (expr_class != EXPR_CLASS_CONSTANT) {
8830                 if (expr_class != EXPR_CLASS_ERROR) {
8831                         errorf(pos, "case label does not reduce to an integer constant");
8832                 }
8833                 statement->case_label.is_bad = true;
8834         } else {
8835                 long const val = fold_constant_to_int(expression);
8836                 statement->case_label.first_case = val;
8837                 statement->case_label.last_case  = val;
8838         }
8839
8840         if (GNU_MODE) {
8841                 if (next_if(T_DOTDOTDOT)) {
8842                         expression_t *end_range = parse_expression();
8843                         expression_type = expression->base.type;
8844                         skipped         = skip_typeref(expression_type);
8845                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8846                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8847                                            expression, expression_type);
8848                         }
8849
8850                         end_range = create_implicit_cast(end_range, type);
8851                         statement->case_label.end_range = end_range;
8852                         expression_classification_t const end_class = is_constant_expression(end_range);
8853                         if (end_class != EXPR_CLASS_CONSTANT) {
8854                                 if (end_class != EXPR_CLASS_ERROR) {
8855                                         errorf(pos, "case range does not reduce to an integer constant");
8856                                 }
8857                                 statement->case_label.is_bad = true;
8858                         } else {
8859                                 long const val = fold_constant_to_int(end_range);
8860                                 statement->case_label.last_case = val;
8861
8862                                 if (val < statement->case_label.first_case) {
8863                                         statement->case_label.is_empty_range = true;
8864                                         warningf(WARN_OTHER, pos, "empty range specified");
8865                                 }
8866                         }
8867                 }
8868         }
8869
8870         PUSH_PARENT(statement);
8871
8872         rem_anchor_token(':');
8873         expect(':');
8874
8875         if (current_switch != NULL) {
8876                 if (! statement->case_label.is_bad) {
8877                         /* Check for duplicate case values */
8878                         case_label_statement_t *c = &statement->case_label;
8879                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8880                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8881                                         continue;
8882
8883                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8884                                         continue;
8885
8886                                 errorf(pos, "duplicate case value (previously used %P)",
8887                                        &l->base.source_position);
8888                                 break;
8889                         }
8890                 }
8891                 /* link all cases into the switch statement */
8892                 if (current_switch->last_case == NULL) {
8893                         current_switch->first_case      = &statement->case_label;
8894                 } else {
8895                         current_switch->last_case->next = &statement->case_label;
8896                 }
8897                 current_switch->last_case = &statement->case_label;
8898         } else {
8899                 errorf(pos, "case label not within a switch statement");
8900         }
8901
8902         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8903
8904         POP_PARENT();
8905         return statement;
8906 }
8907
8908 /**
8909  * Parse a default statement.
8910  */
8911 static statement_t *parse_default_statement(void)
8912 {
8913         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8914
8915         eat(T_default);
8916
8917         PUSH_PARENT(statement);
8918
8919         expect(':');
8920
8921         if (current_switch != NULL) {
8922                 const case_label_statement_t *def_label = current_switch->default_label;
8923                 if (def_label != NULL) {
8924                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8925                 } else {
8926                         current_switch->default_label = &statement->case_label;
8927
8928                         /* link all cases into the switch statement */
8929                         if (current_switch->last_case == NULL) {
8930                                 current_switch->first_case      = &statement->case_label;
8931                         } else {
8932                                 current_switch->last_case->next = &statement->case_label;
8933                         }
8934                         current_switch->last_case = &statement->case_label;
8935                 }
8936         } else {
8937                 errorf(&statement->base.source_position,
8938                         "'default' label not within a switch statement");
8939         }
8940
8941         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8942
8943         POP_PARENT();
8944         return statement;
8945 }
8946
8947 /**
8948  * Parse a label statement.
8949  */
8950 static statement_t *parse_label_statement(void)
8951 {
8952         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8953         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8954         statement->label.label = label;
8955
8956         PUSH_PARENT(statement);
8957
8958         /* if statement is already set then the label is defined twice,
8959          * otherwise it was just mentioned in a goto/local label declaration so far
8960          */
8961         source_position_t const* const pos = &statement->base.source_position;
8962         if (label->statement != NULL) {
8963                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8964         } else {
8965                 label->base.source_position = *pos;
8966                 label->statement            = statement;
8967         }
8968
8969         eat(':');
8970
8971         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8972                 parse_attributes(NULL); // TODO process attributes
8973         }
8974
8975         statement->label.statement = parse_label_inner_statement(statement, "label");
8976
8977         /* remember the labels in a list for later checking */
8978         *label_anchor = &statement->label;
8979         label_anchor  = &statement->label.next;
8980
8981         POP_PARENT();
8982         return statement;
8983 }
8984
8985 static statement_t *parse_inner_statement(void)
8986 {
8987         statement_t *const stmt = parse_statement();
8988         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8989         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8990         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8991                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
8992         }
8993         return stmt;
8994 }
8995
8996 /**
8997  * Parse an expression in parentheses and mark its variables as read.
8998  */
8999 static expression_t *parse_condition(void)
9000 {
9001         add_anchor_token(')');
9002         expect('(');
9003         expression_t *const expr = parse_expression();
9004         mark_vars_read(expr, NULL);
9005         rem_anchor_token(')');
9006         expect(')');
9007         return expr;
9008 }
9009
9010 /**
9011  * Parse an if statement.
9012  */
9013 static statement_t *parse_if(void)
9014 {
9015         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9016
9017         eat(T_if);
9018
9019         PUSH_PARENT(statement);
9020         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9021
9022         add_anchor_token(T_else);
9023
9024         expression_t *const expr = parse_condition();
9025         statement->ifs.condition = expr;
9026         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9027          *             scalar type. */
9028         semantic_condition(expr, "condition of 'if'-statment");
9029
9030         statement_t *const true_stmt = parse_inner_statement();
9031         statement->ifs.true_statement = true_stmt;
9032         rem_anchor_token(T_else);
9033
9034         if (true_stmt->kind == STATEMENT_EMPTY) {
9035                 warningf(WARN_EMPTY_BODY, HERE,
9036                         "suggest braces around empty body in an ‘if’ statement");
9037         }
9038
9039         if (next_if(T_else)) {
9040                 statement->ifs.false_statement = parse_inner_statement();
9041
9042                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9043                         warningf(WARN_EMPTY_BODY, HERE,
9044                                         "suggest braces around empty body in an ‘if’ statement");
9045                 }
9046         } else if (true_stmt->kind == STATEMENT_IF &&
9047                         true_stmt->ifs.false_statement != NULL) {
9048                 source_position_t const *const pos = &true_stmt->base.source_position;
9049                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9050         }
9051
9052         POP_SCOPE();
9053         POP_PARENT();
9054         return statement;
9055 }
9056
9057 /**
9058  * Check that all enums are handled in a switch.
9059  *
9060  * @param statement  the switch statement to check
9061  */
9062 static void check_enum_cases(const switch_statement_t *statement)
9063 {
9064         if (!is_warn_on(WARN_SWITCH_ENUM))
9065                 return;
9066         const type_t *type = skip_typeref(statement->expression->base.type);
9067         if (! is_type_enum(type))
9068                 return;
9069         const enum_type_t *enumt = &type->enumt;
9070
9071         /* if we have a default, no warnings */
9072         if (statement->default_label != NULL)
9073                 return;
9074
9075         /* FIXME: calculation of value should be done while parsing */
9076         /* TODO: quadratic algorithm here. Change to an n log n one */
9077         long            last_value = -1;
9078         const entity_t *entry      = enumt->enume->base.next;
9079         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9080              entry = entry->base.next) {
9081                 const expression_t *expression = entry->enum_value.value;
9082                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9083                 bool                found      = false;
9084                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9085                         if (l->expression == NULL)
9086                                 continue;
9087                         if (l->first_case <= value && value <= l->last_case) {
9088                                 found = true;
9089                                 break;
9090                         }
9091                 }
9092                 if (!found) {
9093                         source_position_t const *const pos = &statement->base.source_position;
9094                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9095                 }
9096                 last_value = value;
9097         }
9098 }
9099
9100 /**
9101  * Parse a switch statement.
9102  */
9103 static statement_t *parse_switch(void)
9104 {
9105         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9106
9107         eat(T_switch);
9108
9109         PUSH_PARENT(statement);
9110         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9111
9112         expression_t *const expr = parse_condition();
9113         type_t       *      type = skip_typeref(expr->base.type);
9114         if (is_type_integer(type)) {
9115                 type = promote_integer(type);
9116                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9117                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9118                 }
9119         } else if (is_type_valid(type)) {
9120                 errorf(&expr->base.source_position,
9121                        "switch quantity is not an integer, but '%T'", type);
9122                 type = type_error_type;
9123         }
9124         statement->switchs.expression = create_implicit_cast(expr, type);
9125
9126         switch_statement_t *rem = current_switch;
9127         current_switch          = &statement->switchs;
9128         statement->switchs.body = parse_inner_statement();
9129         current_switch          = rem;
9130
9131         if (statement->switchs.default_label == NULL) {
9132                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9133         }
9134         check_enum_cases(&statement->switchs);
9135
9136         POP_SCOPE();
9137         POP_PARENT();
9138         return statement;
9139 }
9140
9141 static statement_t *parse_loop_body(statement_t *const loop)
9142 {
9143         statement_t *const rem = current_loop;
9144         current_loop = loop;
9145
9146         statement_t *const body = parse_inner_statement();
9147
9148         current_loop = rem;
9149         return body;
9150 }
9151
9152 /**
9153  * Parse a while statement.
9154  */
9155 static statement_t *parse_while(void)
9156 {
9157         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9158
9159         eat(T_while);
9160
9161         PUSH_PARENT(statement);
9162         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9163
9164         expression_t *const cond = parse_condition();
9165         statement->whiles.condition = cond;
9166         /* §6.8.5:2    The controlling expression of an iteration statement shall
9167          *             have scalar type. */
9168         semantic_condition(cond, "condition of 'while'-statement");
9169
9170         statement->whiles.body = parse_loop_body(statement);
9171
9172         POP_SCOPE();
9173         POP_PARENT();
9174         return statement;
9175 }
9176
9177 /**
9178  * Parse a do statement.
9179  */
9180 static statement_t *parse_do(void)
9181 {
9182         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9183
9184         eat(T_do);
9185
9186         PUSH_PARENT(statement);
9187         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9188
9189         add_anchor_token(T_while);
9190         statement->do_while.body = parse_loop_body(statement);
9191         rem_anchor_token(T_while);
9192
9193         expect(T_while);
9194         expression_t *const cond = parse_condition();
9195         statement->do_while.condition = cond;
9196         /* §6.8.5:2    The controlling expression of an iteration statement shall
9197          *             have scalar type. */
9198         semantic_condition(cond, "condition of 'do-while'-statement");
9199         expect(';');
9200
9201         POP_SCOPE();
9202         POP_PARENT();
9203         return statement;
9204 }
9205
9206 /**
9207  * Parse a for statement.
9208  */
9209 static statement_t *parse_for(void)
9210 {
9211         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9212
9213         eat(T_for);
9214
9215         PUSH_PARENT(statement);
9216         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9217
9218         add_anchor_token(')');
9219         expect('(');
9220
9221         PUSH_EXTENSION();
9222
9223         if (next_if(';')) {
9224         } else if (is_declaration_specifier(&token)) {
9225                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9226         } else {
9227                 add_anchor_token(';');
9228                 expression_t *const init = parse_expression();
9229                 statement->fors.initialisation = init;
9230                 mark_vars_read(init, ENT_ANY);
9231                 if (!expression_has_effect(init)) {
9232                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9233                 }
9234                 rem_anchor_token(';');
9235                 expect(';');
9236         }
9237
9238         POP_EXTENSION();
9239
9240         if (token.kind != ';') {
9241                 add_anchor_token(';');
9242                 expression_t *const cond = parse_expression();
9243                 statement->fors.condition = cond;
9244                 /* §6.8.5:2    The controlling expression of an iteration statement
9245                  *             shall have scalar type. */
9246                 semantic_condition(cond, "condition of 'for'-statement");
9247                 mark_vars_read(cond, NULL);
9248                 rem_anchor_token(';');
9249         }
9250         expect(';');
9251         if (token.kind != ')') {
9252                 expression_t *const step = parse_expression();
9253                 statement->fors.step = step;
9254                 mark_vars_read(step, ENT_ANY);
9255                 if (!expression_has_effect(step)) {
9256                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9257                 }
9258         }
9259         rem_anchor_token(')');
9260         expect(')');
9261         statement->fors.body = parse_loop_body(statement);
9262
9263         POP_SCOPE();
9264         POP_PARENT();
9265         return statement;
9266 }
9267
9268 /**
9269  * Parse a goto statement.
9270  */
9271 static statement_t *parse_goto(void)
9272 {
9273         statement_t *statement;
9274         if (GNU_MODE && look_ahead(1)->kind == '*') {
9275                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9276                 eat(T_goto);
9277                 eat('*');
9278
9279                 expression_t *expression = parse_expression();
9280                 mark_vars_read(expression, NULL);
9281
9282                 /* Argh: although documentation says the expression must be of type void*,
9283                  * gcc accepts anything that can be casted into void* without error */
9284                 type_t *type = expression->base.type;
9285
9286                 if (type != type_error_type) {
9287                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9288                                 errorf(&expression->base.source_position,
9289                                         "cannot convert to a pointer type");
9290                         } else if (type != type_void_ptr) {
9291                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9292                         }
9293                         expression = create_implicit_cast(expression, type_void_ptr);
9294                 }
9295
9296                 statement->computed_goto.expression = expression;
9297         } else {
9298                 statement = allocate_statement_zero(STATEMENT_GOTO);
9299                 eat(T_goto);
9300
9301                 label_t *const label = get_label("while parsing goto");
9302                 if (label) {
9303                         label->used            = true;
9304                         statement->gotos.label = label;
9305
9306                         /* remember the goto's in a list for later checking */
9307                         *goto_anchor = &statement->gotos;
9308                         goto_anchor  = &statement->gotos.next;
9309                 } else {
9310                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9311                 }
9312         }
9313
9314         expect(';');
9315         return statement;
9316 }
9317
9318 /**
9319  * Parse a continue statement.
9320  */
9321 static statement_t *parse_continue(void)
9322 {
9323         if (current_loop == NULL) {
9324                 errorf(HERE, "continue statement not within loop");
9325         }
9326
9327         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9328
9329         eat(T_continue);
9330         expect(';');
9331         return statement;
9332 }
9333
9334 /**
9335  * Parse a break statement.
9336  */
9337 static statement_t *parse_break(void)
9338 {
9339         if (current_switch == NULL && current_loop == NULL) {
9340                 errorf(HERE, "break statement not within loop or switch");
9341         }
9342
9343         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9344
9345         eat(T_break);
9346         expect(';');
9347         return statement;
9348 }
9349
9350 /**
9351  * Parse a __leave statement.
9352  */
9353 static statement_t *parse_leave_statement(void)
9354 {
9355         if (current_try == NULL) {
9356                 errorf(HERE, "__leave statement not within __try");
9357         }
9358
9359         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9360
9361         eat(T___leave);
9362         expect(';');
9363         return statement;
9364 }
9365
9366 /**
9367  * Check if a given entity represents a local variable.
9368  */
9369 static bool is_local_variable(const entity_t *entity)
9370 {
9371         if (entity->kind != ENTITY_VARIABLE)
9372                 return false;
9373
9374         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9375         case STORAGE_CLASS_AUTO:
9376         case STORAGE_CLASS_REGISTER: {
9377                 const type_t *type = skip_typeref(entity->declaration.type);
9378                 if (is_type_function(type)) {
9379                         return false;
9380                 } else {
9381                         return true;
9382                 }
9383         }
9384         default:
9385                 return false;
9386         }
9387 }
9388
9389 /**
9390  * Check if a given expression represents a local variable.
9391  */
9392 static bool expression_is_local_variable(const expression_t *expression)
9393 {
9394         if (expression->base.kind != EXPR_REFERENCE) {
9395                 return false;
9396         }
9397         const entity_t *entity = expression->reference.entity;
9398         return is_local_variable(entity);
9399 }
9400
9401 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9402 {
9403         if (c_mode & _CXX || strict_mode) {
9404                 errorf(pos, msg);
9405         } else {
9406                 warningf(WARN_OTHER, pos, msg);
9407         }
9408 }
9409
9410 /**
9411  * Parse a return statement.
9412  */
9413 static statement_t *parse_return(void)
9414 {
9415         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9416         eat(T_return);
9417
9418         expression_t *return_value = NULL;
9419         if (token.kind != ';') {
9420                 return_value = parse_expression();
9421                 mark_vars_read(return_value, NULL);
9422         }
9423
9424         const type_t *const func_type = skip_typeref(current_function->base.type);
9425         assert(is_type_function(func_type));
9426         type_t *const return_type = skip_typeref(func_type->function.return_type);
9427
9428         source_position_t const *const pos = &statement->base.source_position;
9429         if (return_value != NULL) {
9430                 type_t *return_value_type = skip_typeref(return_value->base.type);
9431
9432                 if (is_type_void(return_type)) {
9433                         if (!is_type_void(return_value_type)) {
9434                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9435                                 /* Only warn in C mode, because GCC does the same */
9436                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9437                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9438                                 /* Only warn in C mode, because GCC does the same */
9439                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9440                         }
9441                 } else {
9442                         assign_error_t error = semantic_assign(return_type, return_value);
9443                         report_assign_error(error, return_type, return_value, "'return'",
9444                                             pos);
9445                 }
9446                 return_value = create_implicit_cast(return_value, return_type);
9447                 /* check for returning address of a local var */
9448                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9449                         const expression_t *expression = return_value->unary.value;
9450                         if (expression_is_local_variable(expression)) {
9451                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9452                         }
9453                 }
9454         } else if (!is_type_void(return_type)) {
9455                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9456                 err_or_warn(pos, "'return' without value, in function returning non-void");
9457         }
9458         statement->returns.value = return_value;
9459
9460         expect(';');
9461         return statement;
9462 }
9463
9464 /**
9465  * Parse a declaration statement.
9466  */
9467 static statement_t *parse_declaration_statement(void)
9468 {
9469         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9470
9471         entity_t *before = current_scope->last_entity;
9472         if (GNU_MODE) {
9473                 parse_external_declaration();
9474         } else {
9475                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9476         }
9477
9478         declaration_statement_t *const decl  = &statement->declaration;
9479         entity_t                *const begin =
9480                 before != NULL ? before->base.next : current_scope->entities;
9481         decl->declarations_begin = begin;
9482         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9483
9484         return statement;
9485 }
9486
9487 /**
9488  * Parse an expression statement, ie. expr ';'.
9489  */
9490 static statement_t *parse_expression_statement(void)
9491 {
9492         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9493
9494         expression_t *const expr         = parse_expression();
9495         statement->expression.expression = expr;
9496         mark_vars_read(expr, ENT_ANY);
9497
9498         expect(';');
9499         return statement;
9500 }
9501
9502 /**
9503  * Parse a microsoft __try { } __finally { } or
9504  * __try{ } __except() { }
9505  */
9506 static statement_t *parse_ms_try_statment(void)
9507 {
9508         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9509         eat(T___try);
9510
9511         PUSH_PARENT(statement);
9512
9513         ms_try_statement_t *rem = current_try;
9514         current_try = &statement->ms_try;
9515         statement->ms_try.try_statement = parse_compound_statement(false);
9516         current_try = rem;
9517
9518         POP_PARENT();
9519
9520         if (next_if(T___except)) {
9521                 expression_t *const expr = parse_condition();
9522                 type_t       *      type = skip_typeref(expr->base.type);
9523                 if (is_type_integer(type)) {
9524                         type = promote_integer(type);
9525                 } else if (is_type_valid(type)) {
9526                         errorf(&expr->base.source_position,
9527                                "__expect expression is not an integer, but '%T'", type);
9528                         type = type_error_type;
9529                 }
9530                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9531         } else if (!next_if(T__finally)) {
9532                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9533         }
9534         statement->ms_try.final_statement = parse_compound_statement(false);
9535         return statement;
9536 }
9537
9538 static statement_t *parse_empty_statement(void)
9539 {
9540         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9541         statement_t *const statement = create_empty_statement();
9542         eat(';');
9543         return statement;
9544 }
9545
9546 static statement_t *parse_local_label_declaration(void)
9547 {
9548         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9549
9550         eat(T___label__);
9551
9552         entity_t *begin   = NULL;
9553         entity_t *end     = NULL;
9554         entity_t **anchor = &begin;
9555         add_anchor_token(';');
9556         add_anchor_token(',');
9557         do {
9558                 source_position_t pos;
9559                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9560                 if (symbol) {
9561                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9562                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9563                                 source_position_t const *const ppos = &entity->base.source_position;
9564                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9565                         } else {
9566                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9567                                 entity->base.parent_scope = current_scope;
9568
9569                                 *anchor = entity;
9570                                 anchor  = &entity->base.next;
9571                                 end     = entity;
9572
9573                                 environment_push(entity);
9574                         }
9575                 }
9576         } while (next_if(','));
9577         rem_anchor_token(',');
9578         rem_anchor_token(';');
9579         expect(';');
9580         statement->declaration.declarations_begin = begin;
9581         statement->declaration.declarations_end   = end;
9582         return statement;
9583 }
9584
9585 static void parse_namespace_definition(void)
9586 {
9587         eat(T_namespace);
9588
9589         entity_t *entity = NULL;
9590         symbol_t *symbol = NULL;
9591
9592         if (token.kind == T_IDENTIFIER) {
9593                 symbol = token.base.symbol;
9594                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9595                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9596                         entity = NULL;
9597                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9598                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9599                         }
9600                 }
9601                 eat(T_IDENTIFIER);
9602         }
9603
9604         if (entity == NULL) {
9605                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9606                 entity->base.parent_scope = current_scope;
9607         }
9608
9609         if (token.kind == '=') {
9610                 /* TODO: parse namespace alias */
9611                 panic("namespace alias definition not supported yet");
9612         }
9613
9614         environment_push(entity);
9615         append_entity(current_scope, entity);
9616
9617         PUSH_SCOPE(&entity->namespacee.members);
9618         PUSH_CURRENT_ENTITY(entity);
9619
9620         add_anchor_token('}');
9621         expect('{');
9622         parse_externals();
9623         rem_anchor_token('}');
9624         expect('}');
9625
9626         POP_CURRENT_ENTITY();
9627         POP_SCOPE();
9628 }
9629
9630 /**
9631  * Parse a statement.
9632  * There's also parse_statement() which additionally checks for
9633  * "statement has no effect" warnings
9634  */
9635 static statement_t *intern_parse_statement(void)
9636 {
9637         /* declaration or statement */
9638         statement_t *statement;
9639         switch (token.kind) {
9640         case T_IDENTIFIER: {
9641                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9642                 if (la1_type == ':') {
9643                         statement = parse_label_statement();
9644                 } else if (is_typedef_symbol(token.base.symbol)) {
9645                         statement = parse_declaration_statement();
9646                 } else {
9647                         /* it's an identifier, the grammar says this must be an
9648                          * expression statement. However it is common that users mistype
9649                          * declaration types, so we guess a bit here to improve robustness
9650                          * for incorrect programs */
9651                         switch (la1_type) {
9652                         case '&':
9653                         case '*':
9654                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9655                         default:
9656                                         statement = parse_expression_statement();
9657                                 } else {
9658                         DECLARATION_START
9659                         case T_IDENTIFIER:
9660                                         statement = parse_declaration_statement();
9661                                 }
9662                                 break;
9663                         }
9664                 }
9665                 break;
9666         }
9667
9668         case T___extension__: {
9669                 /* This can be a prefix to a declaration or an expression statement.
9670                  * We simply eat it now and parse the rest with tail recursion. */
9671                 PUSH_EXTENSION();
9672                 statement = intern_parse_statement();
9673                 POP_EXTENSION();
9674                 break;
9675         }
9676
9677         DECLARATION_START
9678                 statement = parse_declaration_statement();
9679                 break;
9680
9681         case T___label__:
9682                 statement = parse_local_label_declaration();
9683                 break;
9684
9685         case ';':         statement = parse_empty_statement();         break;
9686         case '{':         statement = parse_compound_statement(false); break;
9687         case T___leave:   statement = parse_leave_statement();         break;
9688         case T___try:     statement = parse_ms_try_statment();         break;
9689         case T_asm:       statement = parse_asm_statement();           break;
9690         case T_break:     statement = parse_break();                   break;
9691         case T_case:      statement = parse_case_statement();          break;
9692         case T_continue:  statement = parse_continue();                break;
9693         case T_default:   statement = parse_default_statement();       break;
9694         case T_do:        statement = parse_do();                      break;
9695         case T_for:       statement = parse_for();                     break;
9696         case T_goto:      statement = parse_goto();                    break;
9697         case T_if:        statement = parse_if();                      break;
9698         case T_return:    statement = parse_return();                  break;
9699         case T_switch:    statement = parse_switch();                  break;
9700         case T_while:     statement = parse_while();                   break;
9701
9702         EXPRESSION_START
9703                 statement = parse_expression_statement();
9704                 break;
9705
9706         default:
9707                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9708                 statement = create_error_statement();
9709                 eat_until_anchor();
9710                 break;
9711         }
9712
9713         return statement;
9714 }
9715
9716 /**
9717  * parse a statement and emits "statement has no effect" warning if needed
9718  * (This is really a wrapper around intern_parse_statement with check for 1
9719  *  single warning. It is needed, because for statement expressions we have
9720  *  to avoid the warning on the last statement)
9721  */
9722 static statement_t *parse_statement(void)
9723 {
9724         statement_t *statement = intern_parse_statement();
9725
9726         if (statement->kind == STATEMENT_EXPRESSION) {
9727                 expression_t *expression = statement->expression.expression;
9728                 if (!expression_has_effect(expression)) {
9729                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9730                 }
9731         }
9732
9733         return statement;
9734 }
9735
9736 /**
9737  * Parse a compound statement.
9738  */
9739 static statement_t *parse_compound_statement(bool inside_expression_statement)
9740 {
9741         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9742
9743         PUSH_PARENT(statement);
9744         PUSH_SCOPE(&statement->compound.scope);
9745
9746         eat('{');
9747         add_anchor_token('}');
9748         /* tokens, which can start a statement */
9749         /* TODO MS, __builtin_FOO */
9750         add_anchor_token('!');
9751         add_anchor_token('&');
9752         add_anchor_token('(');
9753         add_anchor_token('*');
9754         add_anchor_token('+');
9755         add_anchor_token('-');
9756         add_anchor_token(';');
9757         add_anchor_token('{');
9758         add_anchor_token('~');
9759         add_anchor_token(T_CHARACTER_CONSTANT);
9760         add_anchor_token(T_COLONCOLON);
9761         add_anchor_token(T_FLOATINGPOINT);
9762         add_anchor_token(T_IDENTIFIER);
9763         add_anchor_token(T_INTEGER);
9764         add_anchor_token(T_MINUSMINUS);
9765         add_anchor_token(T_PLUSPLUS);
9766         add_anchor_token(T_STRING_LITERAL);
9767         add_anchor_token(T__Bool);
9768         add_anchor_token(T__Complex);
9769         add_anchor_token(T__Imaginary);
9770         add_anchor_token(T___PRETTY_FUNCTION__);
9771         add_anchor_token(T___alignof__);
9772         add_anchor_token(T___attribute__);
9773         add_anchor_token(T___builtin_va_start);
9774         add_anchor_token(T___extension__);
9775         add_anchor_token(T___func__);
9776         add_anchor_token(T___imag__);
9777         add_anchor_token(T___label__);
9778         add_anchor_token(T___real__);
9779         add_anchor_token(T___thread);
9780         add_anchor_token(T_asm);
9781         add_anchor_token(T_auto);
9782         add_anchor_token(T_bool);
9783         add_anchor_token(T_break);
9784         add_anchor_token(T_case);
9785         add_anchor_token(T_char);
9786         add_anchor_token(T_class);
9787         add_anchor_token(T_const);
9788         add_anchor_token(T_const_cast);
9789         add_anchor_token(T_continue);
9790         add_anchor_token(T_default);
9791         add_anchor_token(T_delete);
9792         add_anchor_token(T_double);
9793         add_anchor_token(T_do);
9794         add_anchor_token(T_dynamic_cast);
9795         add_anchor_token(T_enum);
9796         add_anchor_token(T_extern);
9797         add_anchor_token(T_false);
9798         add_anchor_token(T_float);
9799         add_anchor_token(T_for);
9800         add_anchor_token(T_goto);
9801         add_anchor_token(T_if);
9802         add_anchor_token(T_inline);
9803         add_anchor_token(T_int);
9804         add_anchor_token(T_long);
9805         add_anchor_token(T_new);
9806         add_anchor_token(T_operator);
9807         add_anchor_token(T_register);
9808         add_anchor_token(T_reinterpret_cast);
9809         add_anchor_token(T_restrict);
9810         add_anchor_token(T_return);
9811         add_anchor_token(T_short);
9812         add_anchor_token(T_signed);
9813         add_anchor_token(T_sizeof);
9814         add_anchor_token(T_static);
9815         add_anchor_token(T_static_cast);
9816         add_anchor_token(T_struct);
9817         add_anchor_token(T_switch);
9818         add_anchor_token(T_template);
9819         add_anchor_token(T_this);
9820         add_anchor_token(T_throw);
9821         add_anchor_token(T_true);
9822         add_anchor_token(T_try);
9823         add_anchor_token(T_typedef);
9824         add_anchor_token(T_typeid);
9825         add_anchor_token(T_typename);
9826         add_anchor_token(T_typeof);
9827         add_anchor_token(T_union);
9828         add_anchor_token(T_unsigned);
9829         add_anchor_token(T_using);
9830         add_anchor_token(T_void);
9831         add_anchor_token(T_volatile);
9832         add_anchor_token(T_wchar_t);
9833         add_anchor_token(T_while);
9834
9835         statement_t **anchor            = &statement->compound.statements;
9836         bool          only_decls_so_far = true;
9837         while (token.kind != '}' && token.kind != T_EOF) {
9838                 statement_t *sub_statement = intern_parse_statement();
9839                 if (sub_statement->kind == STATEMENT_ERROR) {
9840                         break;
9841                 }
9842
9843                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9844                         only_decls_so_far = false;
9845                 } else if (!only_decls_so_far) {
9846                         source_position_t const *const pos = &sub_statement->base.source_position;
9847                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9848                 }
9849
9850                 *anchor = sub_statement;
9851                 anchor  = &sub_statement->base.next;
9852         }
9853         expect('}');
9854
9855         /* look over all statements again to produce no effect warnings */
9856         if (is_warn_on(WARN_UNUSED_VALUE)) {
9857                 statement_t *sub_statement = statement->compound.statements;
9858                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9859                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9860                                 continue;
9861                         /* don't emit a warning for the last expression in an expression
9862                          * statement as it has always an effect */
9863                         if (inside_expression_statement && sub_statement->base.next == NULL)
9864                                 continue;
9865
9866                         expression_t *expression = sub_statement->expression.expression;
9867                         if (!expression_has_effect(expression)) {
9868                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9869                         }
9870                 }
9871         }
9872
9873         rem_anchor_token(T_while);
9874         rem_anchor_token(T_wchar_t);
9875         rem_anchor_token(T_volatile);
9876         rem_anchor_token(T_void);
9877         rem_anchor_token(T_using);
9878         rem_anchor_token(T_unsigned);
9879         rem_anchor_token(T_union);
9880         rem_anchor_token(T_typeof);
9881         rem_anchor_token(T_typename);
9882         rem_anchor_token(T_typeid);
9883         rem_anchor_token(T_typedef);
9884         rem_anchor_token(T_try);
9885         rem_anchor_token(T_true);
9886         rem_anchor_token(T_throw);
9887         rem_anchor_token(T_this);
9888         rem_anchor_token(T_template);
9889         rem_anchor_token(T_switch);
9890         rem_anchor_token(T_struct);
9891         rem_anchor_token(T_static_cast);
9892         rem_anchor_token(T_static);
9893         rem_anchor_token(T_sizeof);
9894         rem_anchor_token(T_signed);
9895         rem_anchor_token(T_short);
9896         rem_anchor_token(T_return);
9897         rem_anchor_token(T_restrict);
9898         rem_anchor_token(T_reinterpret_cast);
9899         rem_anchor_token(T_register);
9900         rem_anchor_token(T_operator);
9901         rem_anchor_token(T_new);
9902         rem_anchor_token(T_long);
9903         rem_anchor_token(T_int);
9904         rem_anchor_token(T_inline);
9905         rem_anchor_token(T_if);
9906         rem_anchor_token(T_goto);
9907         rem_anchor_token(T_for);
9908         rem_anchor_token(T_float);
9909         rem_anchor_token(T_false);
9910         rem_anchor_token(T_extern);
9911         rem_anchor_token(T_enum);
9912         rem_anchor_token(T_dynamic_cast);
9913         rem_anchor_token(T_do);
9914         rem_anchor_token(T_double);
9915         rem_anchor_token(T_delete);
9916         rem_anchor_token(T_default);
9917         rem_anchor_token(T_continue);
9918         rem_anchor_token(T_const_cast);
9919         rem_anchor_token(T_const);
9920         rem_anchor_token(T_class);
9921         rem_anchor_token(T_char);
9922         rem_anchor_token(T_case);
9923         rem_anchor_token(T_break);
9924         rem_anchor_token(T_bool);
9925         rem_anchor_token(T_auto);
9926         rem_anchor_token(T_asm);
9927         rem_anchor_token(T___thread);
9928         rem_anchor_token(T___real__);
9929         rem_anchor_token(T___label__);
9930         rem_anchor_token(T___imag__);
9931         rem_anchor_token(T___func__);
9932         rem_anchor_token(T___extension__);
9933         rem_anchor_token(T___builtin_va_start);
9934         rem_anchor_token(T___attribute__);
9935         rem_anchor_token(T___alignof__);
9936         rem_anchor_token(T___PRETTY_FUNCTION__);
9937         rem_anchor_token(T__Imaginary);
9938         rem_anchor_token(T__Complex);
9939         rem_anchor_token(T__Bool);
9940         rem_anchor_token(T_STRING_LITERAL);
9941         rem_anchor_token(T_PLUSPLUS);
9942         rem_anchor_token(T_MINUSMINUS);
9943         rem_anchor_token(T_INTEGER);
9944         rem_anchor_token(T_IDENTIFIER);
9945         rem_anchor_token(T_FLOATINGPOINT);
9946         rem_anchor_token(T_COLONCOLON);
9947         rem_anchor_token(T_CHARACTER_CONSTANT);
9948         rem_anchor_token('~');
9949         rem_anchor_token('{');
9950         rem_anchor_token(';');
9951         rem_anchor_token('-');
9952         rem_anchor_token('+');
9953         rem_anchor_token('*');
9954         rem_anchor_token('(');
9955         rem_anchor_token('&');
9956         rem_anchor_token('!');
9957         rem_anchor_token('}');
9958
9959         POP_SCOPE();
9960         POP_PARENT();
9961         return statement;
9962 }
9963
9964 /**
9965  * Check for unused global static functions and variables
9966  */
9967 static void check_unused_globals(void)
9968 {
9969         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9970                 return;
9971
9972         for (const entity_t *entity = file_scope->entities; entity != NULL;
9973              entity = entity->base.next) {
9974                 if (!is_declaration(entity))
9975                         continue;
9976
9977                 const declaration_t *declaration = &entity->declaration;
9978                 if (declaration->used                  ||
9979                     declaration->modifiers & DM_UNUSED ||
9980                     declaration->modifiers & DM_USED   ||
9981                     declaration->storage_class != STORAGE_CLASS_STATIC)
9982                         continue;
9983
9984                 warning_t   why;
9985                 char const *s;
9986                 if (entity->kind == ENTITY_FUNCTION) {
9987                         /* inhibit warning for static inline functions */
9988                         if (entity->function.is_inline)
9989                                 continue;
9990
9991                         why = WARN_UNUSED_FUNCTION;
9992                         s   = entity->function.statement != NULL ? "defined" : "declared";
9993                 } else {
9994                         why = WARN_UNUSED_VARIABLE;
9995                         s   = "defined";
9996                 }
9997
9998                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
9999         }
10000 }
10001
10002 static void parse_global_asm(void)
10003 {
10004         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10005
10006         eat(T_asm);
10007         add_anchor_token(';');
10008         add_anchor_token(')');
10009         add_anchor_token(T_STRING_LITERAL);
10010         expect('(');
10011
10012         rem_anchor_token(T_STRING_LITERAL);
10013         statement->asms.asm_text = parse_string_literals("global asm");
10014         statement->base.next     = unit->global_asm;
10015         unit->global_asm         = statement;
10016
10017         rem_anchor_token(')');
10018         expect(')');
10019         rem_anchor_token(';');
10020         expect(';');
10021 }
10022
10023 static void parse_linkage_specification(void)
10024 {
10025         eat(T_extern);
10026
10027         source_position_t const pos     = *HERE;
10028         char const       *const linkage = parse_string_literals(NULL).begin;
10029
10030         linkage_kind_t old_linkage = current_linkage;
10031         linkage_kind_t new_linkage;
10032         if (streq(linkage, "C")) {
10033                 new_linkage = LINKAGE_C;
10034         } else if (streq(linkage, "C++")) {
10035                 new_linkage = LINKAGE_CXX;
10036         } else {
10037                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10038                 new_linkage = LINKAGE_C;
10039         }
10040         current_linkage = new_linkage;
10041
10042         if (next_if('{')) {
10043                 parse_externals();
10044                 expect('}');
10045         } else {
10046                 parse_external();
10047         }
10048
10049         assert(current_linkage == new_linkage);
10050         current_linkage = old_linkage;
10051 }
10052
10053 static void parse_external(void)
10054 {
10055         switch (token.kind) {
10056                 case T_extern:
10057                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10058                                 parse_linkage_specification();
10059                         } else {
10060                 DECLARATION_START_NO_EXTERN
10061                 case T_IDENTIFIER:
10062                 case T___extension__:
10063                 /* tokens below are for implicit int */
10064                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10065                               implicit int) */
10066                 case '*':  /* * x; -> int* x; */
10067                 case '(':  /* (x); -> int (x); */
10068                                 PUSH_EXTENSION();
10069                                 parse_external_declaration();
10070                                 POP_EXTENSION();
10071                         }
10072                         return;
10073
10074                 case T_asm:
10075                         parse_global_asm();
10076                         return;
10077
10078                 case T_namespace:
10079                         parse_namespace_definition();
10080                         return;
10081
10082                 case ';':
10083                         if (!strict_mode) {
10084                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10085                                 eat(';');
10086                                 return;
10087                         }
10088                         /* FALLTHROUGH */
10089
10090                 default:
10091                         errorf(HERE, "stray %K outside of function", &token);
10092                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10093                                 eat_until_matching_token(token.kind);
10094                         next_token();
10095                         return;
10096         }
10097 }
10098
10099 static void parse_externals(void)
10100 {
10101         add_anchor_token('}');
10102         add_anchor_token(T_EOF);
10103
10104 #ifndef NDEBUG
10105         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10106         unsigned short token_anchor_copy[T_LAST_TOKEN];
10107         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10108 #endif
10109
10110         while (token.kind != T_EOF && token.kind != '}') {
10111 #ifndef NDEBUG
10112                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10113                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10114                         if (count != 0) {
10115                                 /* the anchor set and its copy differs */
10116                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10117                         }
10118                 }
10119                 if (in_gcc_extension) {
10120                         /* an gcc extension scope was not closed */
10121                         internal_errorf(HERE, "Leaked __extension__");
10122                 }
10123 #endif
10124
10125                 parse_external();
10126         }
10127
10128         rem_anchor_token(T_EOF);
10129         rem_anchor_token('}');
10130 }
10131
10132 /**
10133  * Parse a translation unit.
10134  */
10135 static void parse_translation_unit(void)
10136 {
10137         add_anchor_token(T_EOF);
10138
10139         while (true) {
10140                 parse_externals();
10141
10142                 if (token.kind == T_EOF)
10143                         break;
10144
10145                 errorf(HERE, "stray %K outside of function", &token);
10146                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10147                         eat_until_matching_token(token.kind);
10148                 next_token();
10149         }
10150 }
10151
10152 void set_default_visibility(elf_visibility_tag_t visibility)
10153 {
10154         default_visibility = visibility;
10155 }
10156
10157 /**
10158  * Parse the input.
10159  *
10160  * @return  the translation unit or NULL if errors occurred.
10161  */
10162 void start_parsing(void)
10163 {
10164         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10165         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10166         error_count       = 0;
10167         warning_count     = 0;
10168
10169         print_to_file(stderr);
10170
10171         assert(unit == NULL);
10172         unit = allocate_ast_zero(sizeof(unit[0]));
10173
10174         assert(file_scope == NULL);
10175         file_scope = &unit->scope;
10176
10177         assert(current_scope == NULL);
10178         scope_push(&unit->scope);
10179
10180         create_gnu_builtins();
10181         if (c_mode & _MS)
10182                 create_microsoft_intrinsics();
10183 }
10184
10185 translation_unit_t *finish_parsing(void)
10186 {
10187         assert(current_scope == &unit->scope);
10188         scope_pop(NULL);
10189
10190         assert(file_scope == &unit->scope);
10191         check_unused_globals();
10192         file_scope = NULL;
10193
10194         DEL_ARR_F(environment_stack);
10195         DEL_ARR_F(label_stack);
10196
10197         translation_unit_t *result = unit;
10198         unit = NULL;
10199         return result;
10200 }
10201
10202 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10203  * are given length one. */
10204 static void complete_incomplete_arrays(void)
10205 {
10206         size_t n = ARR_LEN(incomplete_arrays);
10207         for (size_t i = 0; i != n; ++i) {
10208                 declaration_t *const decl = incomplete_arrays[i];
10209                 type_t        *const type = skip_typeref(decl->type);
10210
10211                 if (!is_type_incomplete(type))
10212                         continue;
10213
10214                 source_position_t const *const pos = &decl->base.source_position;
10215                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10216
10217                 type_t *const new_type = duplicate_type(type);
10218                 new_type->array.size_constant     = true;
10219                 new_type->array.has_implicit_size = true;
10220                 new_type->array.size              = 1;
10221
10222                 type_t *const result = identify_new_type(new_type);
10223
10224                 decl->type = result;
10225         }
10226 }
10227
10228 static void prepare_main_collect2(entity_t *const entity)
10229 {
10230         PUSH_SCOPE(&entity->function.statement->compound.scope);
10231
10232         // create call to __main
10233         symbol_t *symbol         = symbol_table_insert("__main");
10234         entity_t *subsubmain_ent
10235                 = create_implicit_function(symbol, &builtin_source_position);
10236
10237         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10238         type_t       *ftype       = subsubmain_ent->declaration.type;
10239         ref->base.source_position = builtin_source_position;
10240         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10241         ref->reference.entity     = subsubmain_ent;
10242
10243         expression_t *call = allocate_expression_zero(EXPR_CALL);
10244         call->base.source_position = builtin_source_position;
10245         call->base.type            = type_void;
10246         call->call.function        = ref;
10247
10248         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10249         expr_statement->base.source_position  = builtin_source_position;
10250         expr_statement->expression.expression = call;
10251
10252         statement_t *statement = entity->function.statement;
10253         assert(statement->kind == STATEMENT_COMPOUND);
10254         compound_statement_t *compounds = &statement->compound;
10255
10256         expr_statement->base.next = compounds->statements;
10257         compounds->statements     = expr_statement;
10258
10259         POP_SCOPE();
10260 }
10261
10262 void parse(void)
10263 {
10264         lookahead_bufpos = 0;
10265         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10266                 next_token();
10267         }
10268         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10269         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10270         parse_translation_unit();
10271         complete_incomplete_arrays();
10272         DEL_ARR_F(incomplete_arrays);
10273         incomplete_arrays = NULL;
10274 }
10275
10276 /**
10277  * Initialize the parser.
10278  */
10279 void init_parser(void)
10280 {
10281         sym_anonymous = symbol_table_insert("<anonymous>");
10282
10283         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10284
10285         init_expression_parsers();
10286         obstack_init(&temp_obst);
10287 }
10288
10289 /**
10290  * Terminate the parser.
10291  */
10292 void exit_parser(void)
10293 {
10294         obstack_free(&temp_obst, NULL);
10295 }