nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "preprocessor.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "ast2firm.h"
  45 #include "adt/bitfiddle.h"
  46 #include "adt/error.h"
  47 #include "adt/array.h"
  48
  49 //#define PRINT_TOKENS
  50 #define MAX_LOOKAHEAD 1
  51
  52 typedef struct {
  53         entity_t           *old_entity;
  54         symbol_t           *symbol;
  55         entity_namespace_t  namespc;
  56 } stack_entry_t;
  57
  58 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  59 struct declaration_specifiers_t {
  60         position_t      pos;
  61         storage_class_t storage_class;
  62         unsigned char   alignment;         /**< Alignment, 0 if not set. */
  63         bool            is_inline    : 1;
  64         bool            thread_local : 1;
  65         attribute_t    *attributes;        /**< list of attributes */
  66         type_t         *type;
  67 };
  68
  69 /**
  70  * An environment for parsing initializers (and compound literals).
  71  */
  72 typedef struct parse_initializer_env_t {
  73         type_t     *type;   /**< the type of the initializer. In case of an
  74                                  array type with unspecified size this gets
  75                                  adjusted to the actual size. */
  76         entity_t   *entity; /**< the variable that is initialized if any */
  77         bool        must_be_constant;
  78 } parse_initializer_env_t;
  79
  80 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  81
  82 /** The current token. */
  83 static token_t              token;
  84 /** The lookahead ring-buffer. */
  85 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  86 /** Position of the next token in the lookahead buffer. */
  87 static size_t               lookahead_bufpos;
  88 static stack_entry_t       *environment_stack = NULL;
  89 static stack_entry_t       *label_stack       = NULL;
  90 static scope_t             *file_scope        = NULL;
  91 static scope_t             *current_scope     = NULL;
  92 /** Point to the current function declaration if inside a function. */
  93 static function_t          *current_function  = NULL;
  94 static entity_t            *current_entity    = NULL;
  95 static switch_statement_t  *current_switch    = NULL;
  96 static statement_t         *current_loop      = NULL;
  97 static statement_t         *current_parent    = NULL;
  98 static ms_try_statement_t  *current_try       = NULL;
  99 static linkage_kind_t       current_linkage;
 100 static goto_statement_t    *goto_first        = NULL;
 101 static goto_statement_t   **goto_anchor       = NULL;
 102 static label_statement_t   *label_first       = NULL;
 103 static label_statement_t  **label_anchor      = NULL;
 104 /** current translation unit. */
 105 static translation_unit_t  *unit              = NULL;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_CURRENT_ENTITY(entity) \
 115         entity_t *const new_current_entity = (entity); \
 116         entity_t *const old_current_entity = current_entity; \
 117         ((void)(current_entity = new_current_entity))
 118 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 119
 120 #define PUSH_PARENT(stmt) \
 121         statement_t *const new_parent = (stmt); \
 122         statement_t *const old_parent = current_parent; \
 123         ((void)(current_parent = new_parent))
 124 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 125
 126 #define PUSH_SCOPE(scope) \
 127         size_t   const top       = environment_top(); \
 128         scope_t *const new_scope = (scope); \
 129         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 130 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 131 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 132
 133 #define PUSH_EXTENSION() \
 134         (void)0; \
 135         bool const old_gcc_extension = in_gcc_extension; \
 136         while (accept(T___extension__)) { \
 137                 in_gcc_extension = true; \
 138         } \
 139         do {} while (0)
 140 #define POP_EXTENSION() \
 141         ((void)(in_gcc_extension = old_gcc_extension))
 142
 143 /** The token anchor set */
 144 static unsigned short token_anchor_set[T_LAST_TOKEN];
 145
 146 /** The current source position. */
 147 #define HERE (&token.base.pos)
 148
 149 /** true if we are in GCC mode. */
 150 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 151
 152 static statement_t *parse_compound_statement(bool inside_expression_statement);
 153 static statement_t *parse_statement(void);
 154
 155 static expression_t *parse_subexpression(precedence_t);
 156 static expression_t *parse_expression(void);
 157 static type_t       *parse_typename(void);
 158 static void          parse_externals(void);
 159 static void          parse_external(void);
 160
 161 static void parse_compound_type_entries(compound_t *compound_declaration);
 162
 163 static void check_call_argument(type_t          *expected_type,
 164                                                                 call_argument_t *argument, unsigned pos);
 165
 166 typedef enum declarator_flags_t {
 167         DECL_FLAGS_NONE             = 0,
 168         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 169         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 170         DECL_IS_PARAMETER           = 1U << 2
 171 } declarator_flags_t;
 172
 173 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 174                                   declarator_flags_t flags);
 175
 176 static void semantic_comparison(binary_expression_t *expression);
 177
 178 #define STORAGE_CLASSES       \
 179         STORAGE_CLASSES_NO_EXTERN \
 180         case T_extern:
 181
 182 #define STORAGE_CLASSES_NO_EXTERN \
 183         case T_typedef:         \
 184         case T_static:          \
 185         case T_auto:            \
 186         case T_register:        \
 187         case T__Thread_local:
 188
 189 #define TYPE_QUALIFIERS     \
 190         case T_const:           \
 191         case T_restrict:        \
 192         case T_volatile:        \
 193         case T_inline:          \
 194         case T__forceinline:    \
 195         case T___attribute__:
 196
 197 #define COMPLEX_SPECIFIERS  \
 198         case T__Complex:
 199 #define IMAGINARY_SPECIFIERS \
 200         case T__Imaginary:
 201
 202 #define TYPE_SPECIFIERS       \
 203         case T__Bool:             \
 204         case T___builtin_va_list: \
 205         case T___typeof__:        \
 206         case T__declspec:         \
 207         case T_bool:              \
 208         case T_char:              \
 209         case T_double:            \
 210         case T_enum:              \
 211         case T_float:             \
 212         case T_int:               \
 213         case T_long:              \
 214         case T_short:             \
 215         case T_signed:            \
 216         case T_struct:            \
 217         case T_union:             \
 218         case T_unsigned:          \
 219         case T_void:              \
 220         case T_wchar_t:           \
 221         case T__int8:             \
 222         case T__int16:            \
 223         case T__int32:            \
 224         case T__int64:            \
 225         case T__int128:           \
 226         COMPLEX_SPECIFIERS        \
 227         IMAGINARY_SPECIFIERS
 228
 229 #define DECLARATION_START   \
 230         STORAGE_CLASSES         \
 231         TYPE_QUALIFIERS         \
 232         TYPE_SPECIFIERS
 233
 234 #define DECLARATION_START_NO_EXTERN \
 235         STORAGE_CLASSES_NO_EXTERN       \
 236         TYPE_QUALIFIERS                 \
 237         TYPE_SPECIFIERS
 238
 239 #define EXPRESSION_START              \
 240         case '!':                         \
 241         case '&':                         \
 242         case '(':                         \
 243         case '*':                         \
 244         case '+':                         \
 245         case '-':                         \
 246         case '~':                         \
 247         case T_ANDAND:                    \
 248         case T_CHARACTER_CONSTANT:        \
 249         case T_NUMBER:                    \
 250         case T_MINUSMINUS:                \
 251         case T_PLUSPLUS:                  \
 252         case T_STRING_LITERAL:            \
 253         case T__Alignof:                  \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___PRETTY_FUNCTION__:       \
 257         case T___builtin_classify_type:   \
 258         case T___builtin_constant_p:      \
 259         case T___builtin_isgreater:       \
 260         case T___builtin_isgreaterequal:  \
 261         case T___builtin_isless:          \
 262         case T___builtin_islessequal:     \
 263         case T___builtin_islessgreater:   \
 264         case T___builtin_isunordered:     \
 265         case T___builtin_offsetof:        \
 266         case T___builtin_va_arg:          \
 267         case T___builtin_va_copy:         \
 268         case T___builtin_va_start:        \
 269         case T___func__:                  \
 270         case T___noop:                    \
 271         case T__assume:                   \
 272         case T_delete:                    \
 273         case T_false:                     \
 274         case T_sizeof:                    \
 275         case T_throw:                     \
 276         case T_true:                      \
 277         case T___imag__:                  \
 278         case T___real__:
 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_DO_WHILE]      = sizeof(do_while_statement_t),
 303                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 304                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 305                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 306                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 307         };
 308         assert((size_t)kind < lengthof(sizes));
 309         assert(sizes[kind] != 0);
 310         return sizes[kind];
 311 }
 312
 313 /**
 314  * Returns the size of an expression node.
 315  *
 316  * @param kind  the expression kind
 317  */
 318 static size_t get_expression_struct_size(expression_kind_t kind)
 319 {
 320         static const size_t sizes[] = {
 321                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 322                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 323                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 324                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 328                 [EXPR_LITERAL_MS_NOOP]            = sizeof(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.pos    = *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.pos  = *HERE;
 391         return res;
 392 }
 393
 394 /**
 395  * Creates a new invalid expression at the source position
 396  * of the current token.
 397  */
 398 static expression_t *create_error_expression(void)
 399 {
 400         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 401         expression->base.type = type_error_type;
 402         return expression;
 403 }
 404
 405 /**
 406  * Creates a new invalid statement.
 407  */
 408 static statement_t *create_error_statement(void)
 409 {
 410         return allocate_statement_zero(STATEMENT_ERROR);
 411 }
 412
 413 /**
 414  * Allocate a new empty statement.
 415  */
 416 static statement_t *create_empty_statement(void)
 417 {
 418         return allocate_statement_zero(STATEMENT_EMPTY);
 419 }
 420
 421 /**
 422  * Returns the size of an initializer node.
 423  *
 424  * @param kind  the initializer kind
 425  */
 426 static size_t get_initializer_size(initializer_kind_t kind)
 427 {
 428         static const size_t sizes[] = {
 429                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 430                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert((size_t)kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = pp_token;
 474         next_preprocessing_token();
 475
 476         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 477
 478 #ifdef PRINT_TOKENS
 479         print_token(stderr, &token);
 480         fprintf(stderr, "\n");
 481 #endif
 482 }
 483
 484 static inline void eat(token_kind_t const kind)
 485 {
 486         assert(token.kind == kind);
 487         (void)kind;
 488         next_token();
 489 }
 490
 491 /**
 492  * Consume the current token, if it is of the expected kind.
 493  *
 494  * @param  kind  The kind of token to consume.
 495  * @return Whether the token was consumed.
 496  */
 497 static inline bool accept(token_kind_t const kind)
 498 {
 499         if (token.kind == kind) {
 500                 eat(kind);
 501                 return true;
 502         } else {
 503                 return false;
 504         }
 505 }
 506
 507 /**
 508  * Return the next token with a given lookahead.
 509  */
 510 static inline const token_t *look_ahead(size_t num)
 511 {
 512         assert(0 < num && num <= MAX_LOOKAHEAD);
 513         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 514         return &lookahead_buffer[pos];
 515 }
 516
 517 /**
 518  * Adds a token type to the token type anchor set (a multi-set).
 519  */
 520 static void add_anchor_token(token_kind_t const token_kind)
 521 {
 522         assert(token_kind < T_LAST_TOKEN);
 523         ++token_anchor_set[token_kind];
 524 }
 525
 526 /**
 527  * Remove a token type from the token type anchor set (a multi-set).
 528  */
 529 static void rem_anchor_token(token_kind_t const token_kind)
 530 {
 531         assert(token_kind < T_LAST_TOKEN);
 532         assert(token_anchor_set[token_kind] != 0);
 533         --token_anchor_set[token_kind];
 534 }
 535
 536 /**
 537  * Eat tokens until a matching token type is found.
 538  */
 539 static void eat_until_matching_token(token_kind_t const type)
 540 {
 541         token_kind_t end_token;
 542         switch (type) {
 543                 case '(': end_token = ')';  break;
 544                 case '{': end_token = '}';  break;
 545                 case '[': end_token = ']';  break;
 546                 default:  end_token = type; break;
 547         }
 548
 549         unsigned parenthesis_count = 0;
 550         unsigned brace_count       = 0;
 551         unsigned bracket_count     = 0;
 552         while (token.kind        != end_token ||
 553                parenthesis_count != 0         ||
 554                brace_count       != 0         ||
 555                bracket_count     != 0) {
 556                 switch (token.kind) {
 557                 case T_EOF: return;
 558                 case '(': ++parenthesis_count; break;
 559                 case '{': ++brace_count;       break;
 560                 case '[': ++bracket_count;     break;
 561
 562                 case ')':
 563                         if (parenthesis_count > 0)
 564                                 --parenthesis_count;
 565                         goto check_stop;
 566
 567                 case '}':
 568                         if (brace_count > 0)
 569                                 --brace_count;
 570                         goto check_stop;
 571
 572                 case ']':
 573                         if (bracket_count > 0)
 574                                 --bracket_count;
 575 check_stop:
 576                         if (token.kind        == end_token &&
 577                             parenthesis_count == 0         &&
 578                             brace_count       == 0         &&
 579                             bracket_count     == 0)
 580                                 return;
 581                         break;
 582
 583                 default:
 584                         break;
 585                 }
 586                 next_token();
 587         }
 588 }
 589
 590 /**
 591  * Eat input tokens until an anchor is found.
 592  */
 593 static void eat_until_anchor(void)
 594 {
 595         while (token_anchor_set[token.kind] == 0) {
 596                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 597                         eat_until_matching_token(token.kind);
 598                 next_token();
 599         }
 600 }
 601
 602 /**
 603  * Eat a whole block from input tokens.
 604  */
 605 static void eat_block(void)
 606 {
 607         eat_until_matching_token('{');
 608         accept('}');
 609 }
 610
 611 /**
 612  * Report a parse error because an expected token was not found.
 613  */
 614 static
 615 #if defined __GNUC__ && __GNUC__ >= 4
 616 __attribute__((sentinel))
 617 #endif
 618 void parse_error_expected(const char *message, ...)
 619 {
 620         if (message != NULL) {
 621                 errorf(HERE, "%s", message);
 622         }
 623         va_list ap;
 624         va_start(ap, message);
 625         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 626         va_end(ap);
 627 }
 628
 629 /**
 630  * Report an incompatible type.
 631  */
 632 static void type_error_incompatible(const char *msg,
 633                 const position_t *pos, type_t *type1, type_t *type2)
 634 {
 635         errorf(pos, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 636 }
 637
 638 static bool skip_till(token_kind_t const expected, char const *const context)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(context, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return false;
 647         }
 648         return true;
 649 }
 650
 651 /**
 652  * Expect the current token is the expected token.
 653  * If not, generate an error and skip until the next anchor.
 654  */
 655 static void expect(token_kind_t const expected)
 656 {
 657         if (skip_till(expected, NULL))
 658                 eat(expected);
 659 }
 660
 661 static symbol_t *expect_identifier(char const *const context,
 662                                    position_t *const pos)
 663 {
 664         if (!skip_till(T_IDENTIFIER, context))
 665                 return NULL;
 666         symbol_t *const sym = token.base.symbol;
 667         if (pos)
 668                 *pos = *HERE;
 669         eat(T_IDENTIFIER);
 670         return sym;
 671 }
 672
 673 /**
 674  * Push a given scope on the scope stack and make it the
 675  * current scope
 676  */
 677 static scope_t *scope_push(scope_t *new_scope)
 678 {
 679         if (current_scope != NULL) {
 680                 new_scope->depth = current_scope->depth + 1;
 681         }
 682
 683         scope_t *old_scope = current_scope;
 684         current_scope      = new_scope;
 685         return old_scope;
 686 }
 687
 688 /**
 689  * Pop the current scope from the scope stack.
 690  */
 691 static void scope_pop(scope_t *old_scope)
 692 {
 693         current_scope = old_scope;
 694 }
 695
 696 /**
 697  * Search an entity by its symbol in a given namespace.
 698  */
 699 static entity_t *get_entity(const symbol_t *const symbol,
 700                             namespace_tag_t namespc)
 701 {
 702         entity_t *entity = symbol->entity;
 703         for (; entity != NULL; entity = entity->base.symbol_next) {
 704                 if ((namespace_tag_t)entity->base.namespc == namespc)
 705                         return entity;
 706         }
 707
 708         return NULL;
 709 }
 710
 711 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 712  * possible. */
 713 static entity_t *get_tag(symbol_t const *const symbol,
 714                          entity_kind_tag_t const kind)
 715 {
 716         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 717         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 718                 errorf(HERE,
 719                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 720                                 symbol, &entity->base.pos);
 721                 entity = NULL;
 722         }
 723         return entity;
 724 }
 725
 726 /**
 727  * pushs an entity on the environment stack and links the corresponding symbol
 728  * it.
 729  */
 730 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 731 {
 732         symbol_t           *symbol  = entity->base.symbol;
 733         entity_namespace_t  namespc = entity->base.namespc;
 734         assert(namespc != 0);
 735
 736         /* replace/add entity into entity list of the symbol */
 737         entity_t **anchor;
 738         entity_t  *iter;
 739         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 740                 iter = *anchor;
 741                 if (iter == NULL)
 742                         break;
 743
 744                 /* replace an entry? */
 745                 if (iter->base.namespc == namespc) {
 746                         entity->base.symbol_next = iter->base.symbol_next;
 747                         break;
 748                 }
 749         }
 750         *anchor = entity;
 751
 752         /* remember old declaration */
 753         stack_entry_t entry;
 754         entry.symbol     = symbol;
 755         entry.old_entity = iter;
 756         entry.namespc    = namespc;
 757         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 758 }
 759
 760 /**
 761  * Push an entity on the environment stack.
 762  */
 763 static void environment_push(entity_t *entity)
 764 {
 765         assert(entity->base.pos.input_name != NULL);
 766         assert(entity->base.parent_scope != NULL);
 767         stack_push(&environment_stack, entity);
 768 }
 769
 770 /**
 771  * Push a declaration on the global label stack.
 772  *
 773  * @param declaration  the declaration
 774  */
 775 static void label_push(entity_t *label)
 776 {
 777         /* we abuse the parameters scope as parent for the labels */
 778         label->base.parent_scope = &current_function->parameters;
 779         stack_push(&label_stack, label);
 780 }
 781
 782 /**
 783  * pops symbols from the environment stack until @p new_top is the top element
 784  */
 785 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 786 {
 787         stack_entry_t *stack = *stack_ptr;
 788         size_t         top   = ARR_LEN(stack);
 789         size_t         i;
 790
 791         assert(new_top <= top);
 792         if (new_top == top)
 793                 return;
 794
 795         for (i = top; i > new_top; --i) {
 796                 stack_entry_t *entry = &stack[i - 1];
 797
 798                 entity_t           *old_entity = entry->old_entity;
 799                 symbol_t           *symbol     = entry->symbol;
 800                 entity_namespace_t  namespc    = entry->namespc;
 801
 802                 /* replace with old_entity/remove */
 803                 entity_t **anchor;
 804                 entity_t  *iter;
 805                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 806                         iter = *anchor;
 807                         assert(iter != NULL);
 808                         /* replace an entry? */
 809                         if (iter->base.namespc == namespc)
 810                                 break;
 811                 }
 812
 813                 /* restore definition from outer scopes (if there was one) */
 814                 if (old_entity != NULL) {
 815                         old_entity->base.symbol_next = iter->base.symbol_next;
 816                         *anchor                      = old_entity;
 817                 } else {
 818                         /* remove entry from list */
 819                         *anchor = iter->base.symbol_next;
 820                 }
 821         }
 822
 823         ARR_SHRINKLEN(*stack_ptr, new_top);
 824 }
 825
 826 /**
 827  * Pop all entries from the environment stack until the new_top
 828  * is reached.
 829  *
 830  * @param new_top  the new stack top
 831  */
 832 static void environment_pop_to(size_t new_top)
 833 {
 834         stack_pop_to(&environment_stack, new_top);
 835 }
 836
 837 /**
 838  * Pop all entries from the global label stack until the new_top
 839  * is reached.
 840  *
 841  * @param new_top  the new stack top
 842  */
 843 static void label_pop_to(size_t new_top)
 844 {
 845         stack_pop_to(&label_stack, new_top);
 846 }
 847
 848 /**
 849  * §6.3.1.1:2  Do integer promotion for a given type.
 850  *
 851  * @param type  the type to promote
 852  * @return the promoted type
 853  */
 854 static type_t *promote_integer(type_t *type)
 855 {
 856         atomic_type_kind_t akind = get_arithmetic_akind(type);
 857         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT))
 858                 type = type_int;
 859
 860         return type;
 861 }
 862
 863 /**
 864  * Check if a given expression represents a null pointer constant.
 865  *
 866  * @param expression  the expression to check
 867  */
 868 static bool is_null_pointer_constant(const expression_t *expression)
 869 {
 870         /* skip void* cast */
 871         if (expression->kind == EXPR_UNARY_CAST) {
 872                 type_t *const type = skip_typeref(expression->base.type);
 873                 if (types_compatible(type, type_void_ptr))
 874                         expression = expression->unary.value;
 875         }
 876
 877         type_t *const type = skip_typeref(expression->base.type);
 878         if (!is_type_integer(type))
 879                 return false;
 880         switch (is_constant_expression(expression)) {
 881                 case EXPR_CLASS_ERROR:    return true;
 882                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 883                 default:                  return false;
 884         }
 885 }
 886
 887 /**
 888  * Create an implicit cast expression.
 889  *
 890  * @param expression  the expression to cast
 891  * @param dest_type   the destination type
 892  */
 893 static expression_t *create_implicit_cast(expression_t *expression,
 894                                           type_t *dest_type)
 895 {
 896         type_t *const source_type = skip_typeref(expression->base.type);
 897         if (source_type == skip_typeref(dest_type))
 898                 return expression;
 899
 900         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 901         cast->unary.value   = expression;
 902         cast->base.type     = dest_type;
 903         cast->base.implicit = true;
 904
 905         return cast;
 906 }
 907
 908 typedef enum assign_error_t {
 909         ASSIGN_SUCCESS,
 910         ASSIGN_ERROR_INCOMPATIBLE,
 911         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 912         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 913         ASSIGN_WARNING_POINTER_FROM_INT,
 914         ASSIGN_WARNING_INT_FROM_POINTER
 915 } assign_error_t;
 916
 917 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, position_t const *const pos)
 918 {
 919         type_t *const orig_type_right = right->base.type;
 920         type_t *const type_left       = skip_typeref(orig_type_left);
 921         type_t *const type_right      = skip_typeref(orig_type_right);
 922
 923         switch (error) {
 924         case ASSIGN_SUCCESS:
 925                 return;
 926         case ASSIGN_ERROR_INCOMPATIBLE:
 927                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 928                 return;
 929
 930         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 931                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 932                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 933
 934                 /* the left type has all qualifiers from the right type */
 935                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 936                 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);
 937                 return;
 938         }
 939
 940         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 941                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 942                 return;
 943
 944         case ASSIGN_WARNING_POINTER_FROM_INT:
 945                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 946                 return;
 947
 948         case ASSIGN_WARNING_INT_FROM_POINTER:
 949                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 950                 return;
 951
 952         default:
 953                 panic("invalid error value");
 954         }
 955 }
 956
 957 /** Implements the rules from §6.5.16.1 */
 958 static assign_error_t semantic_assign(type_t *orig_type_left,
 959                                       const expression_t *const right)
 960 {
 961         type_t *const orig_type_right = right->base.type;
 962         type_t *const type_left       = skip_typeref(orig_type_left);
 963         type_t *const type_right      = skip_typeref(orig_type_right);
 964
 965         if (is_type_pointer(type_left)) {
 966                 if (is_null_pointer_constant(right)) {
 967                         return ASSIGN_SUCCESS;
 968                 } else if (is_type_pointer(type_right)) {
 969                         type_t *points_to_left
 970                                 = skip_typeref(type_left->pointer.points_to);
 971                         type_t *points_to_right
 972                                 = skip_typeref(type_right->pointer.points_to);
 973                         assign_error_t res = ASSIGN_SUCCESS;
 974
 975                         /* the left type has all qualifiers from the right type */
 976                         unsigned missing_qualifiers
 977                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 978                         if (missing_qualifiers != 0) {
 979                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 980                         }
 981
 982                         points_to_left  = get_unqualified_type(points_to_left);
 983                         points_to_right = get_unqualified_type(points_to_right);
 984
 985                         if (is_type_void(points_to_left))
 986                                 return res;
 987
 988                         if (is_type_void(points_to_right)) {
 989                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 990                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 991                         }
 992
 993                         if (!types_compatible(points_to_left, points_to_right)) {
 994                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 995                         }
 996
 997                         return res;
 998                 } else if (is_type_integer(type_right)) {
 999                         return ASSIGN_WARNING_POINTER_FROM_INT;
1000                 }
1001         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1002                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1003                                 && is_type_pointer(type_right))) {
1004                 return ASSIGN_SUCCESS;
1005         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1006                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1007                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1008                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1009                         return ASSIGN_SUCCESS;
1010                 }
1011         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1012                 return ASSIGN_WARNING_INT_FROM_POINTER;
1013         }
1014
1015         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1016                 return ASSIGN_SUCCESS;
1017
1018         return ASSIGN_ERROR_INCOMPATIBLE;
1019 }
1020
1021 static expression_t *parse_constant_expression(void)
1022 {
1023         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1024
1025         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1026                 errorf(&result->base.pos, "expression '%E' is not constant", result);
1027         }
1028
1029         return result;
1030 }
1031
1032 static expression_t *parse_assignment_expression(void)
1033 {
1034         return parse_subexpression(PREC_ASSIGNMENT);
1035 }
1036
1037 static void append_string(string_t const *const s)
1038 {
1039         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1040          * possible, because other tokens are grown there alongside. */
1041         obstack_grow(&ast_obstack, s->begin, s->size);
1042 }
1043
1044 static string_t finish_string(string_encoding_t const enc)
1045 {
1046         obstack_1grow(&ast_obstack, '\0');
1047         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1048         char const *const string = obstack_finish(&ast_obstack);
1049         return (string_t){ string, size, enc };
1050 }
1051
1052 static string_t concat_string_literals(void)
1053 {
1054         assert(token.kind == T_STRING_LITERAL);
1055
1056         string_t result;
1057         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1058                 append_string(&token.literal.string);
1059                 eat(T_STRING_LITERAL);
1060                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1061                 string_encoding_t enc = token.literal.string.encoding;
1062                 do {
1063                         string_encoding_t const new_enc = token.literal.string.encoding;
1064                         if (new_enc != enc && new_enc != STRING_ENCODING_CHAR) {
1065                                 if (enc == STRING_ENCODING_CHAR) {
1066                                         enc = new_enc;
1067                                 } else {
1068                                         errorf(HERE, "concatenating string literals with encodings %s and %s", get_string_encoding_prefix(enc), get_string_encoding_prefix(new_enc));
1069                                 }
1070                         }
1071                         append_string(&token.literal.string);
1072                         eat(T_STRING_LITERAL);
1073                 } while (token.kind == T_STRING_LITERAL);
1074                 result = finish_string(enc);
1075         } else {
1076                 result = token.literal.string;
1077                 eat(T_STRING_LITERAL);
1078         }
1079
1080         return result;
1081 }
1082
1083 static string_t parse_string_literals(char const *const context)
1084 {
1085         if (!skip_till(T_STRING_LITERAL, context))
1086                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1087
1088         position_t const pos = *HERE;
1089         string_t   const res = concat_string_literals();
1090
1091         if (res.encoding != STRING_ENCODING_CHAR) {
1092                 errorf(&pos, "expected plain string literal, got %s string literal", get_string_encoding_prefix(res.encoding));
1093         }
1094
1095         return res;
1096 }
1097
1098 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1099 {
1100         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1101         attribute->kind = kind;
1102         attribute->pos  = *HERE;
1103         return attribute;
1104 }
1105
1106 /**
1107  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1108  *
1109  *  attribute:
1110  *    __attribute__ ( ( attribute-list ) )
1111  *
1112  *  attribute-list:
1113  *    attrib
1114  *    attribute_list , attrib
1115  *
1116  *  attrib:
1117  *    empty
1118  *    any-word
1119  *    any-word ( identifier )
1120  *    any-word ( identifier , nonempty-expr-list )
1121  *    any-word ( expr-list )
1122  *
1123  *  where the "identifier" must not be declared as a type, and
1124  *  "any-word" may be any identifier (including one declared as a
1125  *  type), a reserved word storage class specifier, type specifier or
1126  *  type qualifier.  ??? This still leaves out most reserved keywords
1127  *  (following the old parser), shouldn't we include them, and why not
1128  *  allow identifiers declared as types to start the arguments?
1129  *
1130  *  Matze: this all looks confusing and little systematic, so we're even less
1131  *  strict and parse any list of things which are identifiers or
1132  *  (assignment-)expressions.
1133  */
1134 static attribute_argument_t *parse_attribute_arguments(void)
1135 {
1136         attribute_argument_t  *first  = NULL;
1137         attribute_argument_t **anchor = &first;
1138         if (token.kind != ')') do {
1139                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1140
1141                 /* is it an identifier */
1142                 if (token.kind == T_IDENTIFIER
1143                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1144                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1145                         argument->v.symbol = token.base.symbol;
1146                         eat(T_IDENTIFIER);
1147                 } else {
1148                         /* must be an expression */
1149                         expression_t *expression = parse_assignment_expression();
1150
1151                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1152                         argument->v.expression = expression;
1153                 }
1154
1155                 /* append argument */
1156                 *anchor = argument;
1157                 anchor  = &argument->next;
1158         } while (accept(','));
1159         expect(')');
1160         return first;
1161 }
1162
1163 static attribute_t *parse_attribute_asm(void)
1164 {
1165         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1166         eat(T_asm);
1167         expect('(');
1168         attribute->a.arguments = parse_attribute_arguments();
1169         return attribute;
1170 }
1171
1172 static attribute_t *parse_attribute_gnu_single(void)
1173 {
1174         /* parse "any-word" */
1175         symbol_t *const symbol = token.base.symbol;
1176         if (symbol == NULL) {
1177                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1178                 return NULL;
1179         }
1180
1181         attribute_kind_t  kind;
1182         char const *const name = symbol->string;
1183         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1184                 if (kind > ATTRIBUTE_GNU_LAST) {
1185                         /* special case for "__const" */
1186                         if (token.kind == T_const) {
1187                                 kind = ATTRIBUTE_GNU_CONST;
1188                                 break;
1189                         }
1190
1191                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1192                         /* TODO: we should still save the attribute in the list... */
1193                         kind = ATTRIBUTE_UNKNOWN;
1194                         break;
1195                 }
1196
1197                 const char *attribute_name = get_attribute_name(kind);
1198                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1199                         break;
1200         }
1201
1202         attribute_t *attribute = allocate_attribute_zero(kind);
1203         next_token();
1204
1205         /* parse arguments */
1206         if (accept('('))
1207                 attribute->a.arguments = parse_attribute_arguments();
1208
1209         return attribute;
1210 }
1211
1212 static attribute_t *parse_attribute_gnu(void)
1213 {
1214         attribute_t  *first  = NULL;
1215         attribute_t **anchor = &first;
1216
1217         eat(T___attribute__);
1218         add_anchor_token(')');
1219         add_anchor_token(',');
1220         expect('(');
1221         expect('(');
1222
1223         if (token.kind != ')') do {
1224                 attribute_t *attribute = parse_attribute_gnu_single();
1225                 if (attribute) {
1226                         *anchor = attribute;
1227                         anchor  = &attribute->next;
1228                 }
1229         } while (accept(','));
1230         rem_anchor_token(',');
1231         rem_anchor_token(')');
1232
1233         expect(')');
1234         expect(')');
1235         return first;
1236 }
1237
1238 /** Parse attributes. */
1239 static attribute_t *parse_attributes(attribute_t *first)
1240 {
1241         attribute_t **anchor = &first;
1242         for (;;) {
1243                 while (*anchor != NULL)
1244                         anchor = &(*anchor)->next;
1245
1246                 attribute_t *attribute;
1247                 switch (token.kind) {
1248                 case T___attribute__:
1249                         attribute = parse_attribute_gnu();
1250                         if (attribute == NULL)
1251                                 continue;
1252                         break;
1253
1254                 case T_asm:
1255                         attribute = parse_attribute_asm();
1256                         break;
1257
1258                 case T_cdecl:
1259                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1260                         eat(T_cdecl);
1261                         break;
1262
1263                 case T__fastcall:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1265                         eat(T__fastcall);
1266                         break;
1267
1268                 case T__forceinline:
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1270                         eat(T__forceinline);
1271                         break;
1272
1273                 case T__stdcall:
1274                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1275                         eat(T__stdcall);
1276                         break;
1277
1278                 case T___thiscall:
1279                         /* TODO record modifier */
1280                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1281                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1282                         eat(T___thiscall);
1283                         break;
1284
1285                 default:
1286                         return first;
1287                 }
1288
1289                 *anchor = attribute;
1290                 anchor  = &attribute->next;
1291         }
1292 }
1293
1294 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1295
1296 static entity_t *determine_lhs_ent(expression_t *const expr,
1297                                    entity_t *lhs_ent)
1298 {
1299         switch (expr->kind) {
1300                 case EXPR_REFERENCE: {
1301                         entity_t *const entity = expr->reference.entity;
1302                         /* we should only find variables as lvalues... */
1303                         if (entity->base.kind != ENTITY_VARIABLE
1304                                         && entity->base.kind != ENTITY_PARAMETER)
1305                                 return NULL;
1306
1307                         return entity;
1308                 }
1309
1310                 case EXPR_ARRAY_ACCESS: {
1311                         expression_t *const ref = expr->array_access.array_ref;
1312                         entity_t     *      ent = NULL;
1313                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1314                                 ent     = determine_lhs_ent(ref, lhs_ent);
1315                                 lhs_ent = ent;
1316                         } else {
1317                                 mark_vars_read(ref, lhs_ent);
1318                         }
1319                         mark_vars_read(expr->array_access.index, lhs_ent);
1320                         return ent;
1321                 }
1322
1323                 case EXPR_SELECT: {
1324                         mark_vars_read(expr->select.compound, lhs_ent);
1325                         if (is_type_compound(skip_typeref(expr->base.type)))
1326                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1327                         return NULL;
1328                 }
1329
1330                 case EXPR_UNARY_DEREFERENCE: {
1331                         expression_t *const val = expr->unary.value;
1332                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1333                                 /* *&x is a NOP */
1334                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1335                         } else {
1336                                 mark_vars_read(val, NULL);
1337                                 return NULL;
1338                         }
1339                 }
1340
1341                 default:
1342                         mark_vars_read(expr, NULL);
1343                         return NULL;
1344         }
1345 }
1346
1347 #define ENT_ANY ((entity_t*)-1)
1348
1349 /**
1350  * Mark declarations, which are read.  This is used to detect variables, which
1351  * are never read.
1352  * Example:
1353  * x = x + 1;
1354  *   x is not marked as "read", because it is only read to calculate its own new
1355  *   value.
1356  *
1357  * x += y; y += x;
1358  *   x and y are not detected as "not read", because multiple variables are
1359  *   involved.
1360  */
1361 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1362 {
1363         switch (expr->kind) {
1364                 case EXPR_REFERENCE: {
1365                         entity_t *const entity = expr->reference.entity;
1366                         if (entity->kind != ENTITY_VARIABLE
1367                                         && entity->kind != ENTITY_PARAMETER)
1368                                 return;
1369
1370                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1371                                 entity->variable.read = true;
1372                         }
1373                         return;
1374                 }
1375
1376                 case EXPR_CALL:
1377                         // TODO respect pure/const
1378                         mark_vars_read(expr->call.function, NULL);
1379                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1380                                 mark_vars_read(arg->expression, NULL);
1381                         }
1382                         return;
1383
1384                 case EXPR_CONDITIONAL:
1385                         // TODO lhs_decl should depend on whether true/false have an effect
1386                         mark_vars_read(expr->conditional.condition, NULL);
1387                         if (expr->conditional.true_expression != NULL)
1388                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1389                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1390                         return;
1391
1392                 case EXPR_SELECT:
1393                         if (lhs_ent == ENT_ANY
1394                                         && !is_type_compound(skip_typeref(expr->base.type)))
1395                                 lhs_ent = NULL;
1396                         mark_vars_read(expr->select.compound, lhs_ent);
1397                         return;
1398
1399                 case EXPR_ARRAY_ACCESS: {
1400                         mark_vars_read(expr->array_access.index, lhs_ent);
1401                         expression_t *const ref = expr->array_access.array_ref;
1402                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1403                                 if (lhs_ent == ENT_ANY)
1404                                         lhs_ent = NULL;
1405                         }
1406                         mark_vars_read(ref, lhs_ent);
1407                         return;
1408                 }
1409
1410                 case EXPR_VA_ARG:
1411                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1412                         return;
1413
1414                 case EXPR_VA_COPY:
1415                         mark_vars_read(expr->va_copye.src, lhs_ent);
1416                         return;
1417
1418                 case EXPR_UNARY_CAST:
1419                         /* Special case: Use void cast to mark a variable as "read" */
1420                         if (is_type_void(skip_typeref(expr->base.type)))
1421                                 lhs_ent = NULL;
1422                         goto unary;
1423
1424
1425                 case EXPR_UNARY_THROW:
1426                         if (expr->unary.value == NULL)
1427                                 return;
1428                         /* FALLTHROUGH */
1429                 case EXPR_UNARY_DEREFERENCE:
1430                 case EXPR_UNARY_DELETE:
1431                 case EXPR_UNARY_DELETE_ARRAY:
1432                         if (lhs_ent == ENT_ANY)
1433                                 lhs_ent = NULL;
1434                         goto unary;
1435
1436                 case EXPR_UNARY_NEGATE:
1437                 case EXPR_UNARY_PLUS:
1438                 case EXPR_UNARY_COMPLEMENT:
1439                 case EXPR_UNARY_NOT:
1440                 case EXPR_UNARY_TAKE_ADDRESS:
1441                 case EXPR_UNARY_POSTFIX_INCREMENT:
1442                 case EXPR_UNARY_POSTFIX_DECREMENT:
1443                 case EXPR_UNARY_PREFIX_INCREMENT:
1444                 case EXPR_UNARY_PREFIX_DECREMENT:
1445                 case EXPR_UNARY_ASSUME:
1446                 case EXPR_UNARY_IMAG:
1447                 case EXPR_UNARY_REAL:
1448 unary:
1449                         mark_vars_read(expr->unary.value, lhs_ent);
1450                         return;
1451
1452                 case EXPR_BINARY_ADD:
1453                 case EXPR_BINARY_SUB:
1454                 case EXPR_BINARY_MUL:
1455                 case EXPR_BINARY_DIV:
1456                 case EXPR_BINARY_MOD:
1457                 case EXPR_BINARY_EQUAL:
1458                 case EXPR_BINARY_NOTEQUAL:
1459                 case EXPR_BINARY_LESS:
1460                 case EXPR_BINARY_LESSEQUAL:
1461                 case EXPR_BINARY_GREATER:
1462                 case EXPR_BINARY_GREATEREQUAL:
1463                 case EXPR_BINARY_BITWISE_AND:
1464                 case EXPR_BINARY_BITWISE_OR:
1465                 case EXPR_BINARY_BITWISE_XOR:
1466                 case EXPR_BINARY_LOGICAL_AND:
1467                 case EXPR_BINARY_LOGICAL_OR:
1468                 case EXPR_BINARY_SHIFTLEFT:
1469                 case EXPR_BINARY_SHIFTRIGHT:
1470                 case EXPR_BINARY_COMMA:
1471                 case EXPR_BINARY_ISGREATER:
1472                 case EXPR_BINARY_ISGREATEREQUAL:
1473                 case EXPR_BINARY_ISLESS:
1474                 case EXPR_BINARY_ISLESSEQUAL:
1475                 case EXPR_BINARY_ISLESSGREATER:
1476                 case EXPR_BINARY_ISUNORDERED:
1477                         mark_vars_read(expr->binary.left,  lhs_ent);
1478                         mark_vars_read(expr->binary.right, lhs_ent);
1479                         return;
1480
1481                 case EXPR_BINARY_ASSIGN:
1482                 case EXPR_BINARY_MUL_ASSIGN:
1483                 case EXPR_BINARY_DIV_ASSIGN:
1484                 case EXPR_BINARY_MOD_ASSIGN:
1485                 case EXPR_BINARY_ADD_ASSIGN:
1486                 case EXPR_BINARY_SUB_ASSIGN:
1487                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1488                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1489                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1490                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1491                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1492                         if (lhs_ent == ENT_ANY)
1493                                 lhs_ent = NULL;
1494                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1495                         mark_vars_read(expr->binary.right, lhs_ent);
1496                         return;
1497                 }
1498
1499                 case EXPR_VA_START:
1500                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1501                         return;
1502
1503                 case EXPR_LITERAL_CASES:
1504                 case EXPR_LITERAL_CHARACTER:
1505                 case EXPR_ERROR:
1506                 case EXPR_STRING_LITERAL:
1507                 case EXPR_COMPOUND_LITERAL: // TODO init?
1508                 case EXPR_SIZEOF:
1509                 case EXPR_CLASSIFY_TYPE:
1510                 case EXPR_ALIGNOF:
1511                 case EXPR_FUNCNAME:
1512                 case EXPR_BUILTIN_CONSTANT_P:
1513                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1514                 case EXPR_OFFSETOF:
1515                 case EXPR_STATEMENT: // TODO
1516                 case EXPR_LABEL_ADDRESS:
1517                 case EXPR_ENUM_CONSTANT:
1518                         return;
1519         }
1520
1521         panic("unhandled expression");
1522 }
1523
1524 static designator_t *parse_designation(void)
1525 {
1526         designator_t  *result = NULL;
1527         designator_t **anchor = &result;
1528
1529         for (;;) {
1530                 designator_t *designator;
1531                 switch (token.kind) {
1532                 case '[':
1533                         designator      = allocate_ast_zero(sizeof(designator[0]));
1534                         designator->pos = *HERE;
1535                         eat('[');
1536                         add_anchor_token(']');
1537                         designator->array_index = parse_constant_expression();
1538                         rem_anchor_token(']');
1539                         expect(']');
1540                         break;
1541                 case '.':
1542                         designator      = allocate_ast_zero(sizeof(designator[0]));
1543                         designator->pos = *HERE;
1544                         eat('.');
1545                         designator->symbol = expect_identifier("while parsing designator", NULL);
1546                         if (!designator->symbol)
1547                                 return NULL;
1548                         break;
1549                 default:
1550                         expect('=');
1551                         return result;
1552                 }
1553
1554                 assert(designator != NULL);
1555                 *anchor = designator;
1556                 anchor  = &designator->next;
1557         }
1558 }
1559
1560 /**
1561  * Build an initializer from a given expression.
1562  */
1563 static initializer_t *initializer_from_expression(type_t *orig_type,
1564                                                   expression_t *expression)
1565 {
1566         /* TODO check that expression is a constant expression */
1567
1568         type_t *const type = skip_typeref(orig_type);
1569
1570         /* §6.7.8.14/15 char array may be initialized by string literals */
1571         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1572                 array_type_t *const array_type   = &type->array;
1573                 type_t       *const element_type = skip_typeref(array_type->element_type);
1574                 switch (expression->string_literal.value.encoding) {
1575                 case STRING_ENCODING_CHAR:
1576                 case STRING_ENCODING_UTF8: {
1577                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1578                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1579                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1580                                 goto make_string_init;
1581                         }
1582                         break;
1583                 }
1584
1585                 case STRING_ENCODING_CHAR16:
1586                 case STRING_ENCODING_CHAR32:
1587                 case STRING_ENCODING_WIDE: {
1588                         assert(is_type_pointer(expression->base.type));
1589                         type_t *const init_type = get_unqualified_type(expression->base.type->pointer.points_to);
1590                         if (types_compatible(get_unqualified_type(element_type), init_type)) {
1591 make_string_init:;
1592                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1593                                 init->value.value = expression;
1594                                 return init;
1595                         }
1596                         break;
1597                 }
1598                 }
1599         }
1600
1601         assign_error_t error = semantic_assign(type, expression);
1602         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1603                 return NULL;
1604         report_assign_error(error, type, expression, "initializer",
1605                             &expression->base.pos);
1606
1607         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1608         result->value.value = create_implicit_cast(expression, type);
1609
1610         return result;
1611 }
1612
1613 /**
1614  * Parses an scalar initializer.
1615  *
1616  * §6.7.8.11; eat {} without warning
1617  */
1618 static initializer_t *parse_scalar_initializer(type_t *type,
1619                                                bool must_be_constant)
1620 {
1621         /* there might be extra {} hierarchies */
1622         int braces = 0;
1623         if (token.kind == '{') {
1624                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1625                 do {
1626                         eat('{');
1627                         ++braces;
1628                 } while (token.kind == '{');
1629         }
1630
1631         expression_t *expression = parse_assignment_expression();
1632         mark_vars_read(expression, NULL);
1633         if (must_be_constant && !is_linker_constant(expression)) {
1634                 errorf(&expression->base.pos,
1635                        "initialisation expression '%E' is not constant",
1636                        expression);
1637         }
1638
1639         initializer_t *initializer = initializer_from_expression(type, expression);
1640
1641         if (initializer == NULL) {
1642                 errorf(&expression->base.pos,
1643                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1644                        expression, expression->base.type, type);
1645                 /* TODO */
1646                 return NULL;
1647         }
1648
1649         bool additional_warning_displayed = false;
1650         while (braces > 0) {
1651                 accept(',');
1652                 if (token.kind != '}') {
1653                         if (!additional_warning_displayed) {
1654                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1655                                 additional_warning_displayed = true;
1656                         }
1657                 }
1658                 eat_block();
1659                 braces--;
1660         }
1661
1662         return initializer;
1663 }
1664
1665 /**
1666  * An entry in the type path.
1667  */
1668 typedef struct type_path_entry_t type_path_entry_t;
1669 struct type_path_entry_t {
1670         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1671         union {
1672                 size_t         index;          /**< For array types: the current index. */
1673                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1674         } v;
1675 };
1676
1677 /**
1678  * A type path expression a position inside compound or array types.
1679  */
1680 typedef struct type_path_t type_path_t;
1681 struct type_path_t {
1682         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1683         type_t            *top_type;     /**< type of the element the path points */
1684         size_t             max_index;    /**< largest index in outermost array */
1685 };
1686
1687 /**
1688  * Prints a type path for debugging.
1689  */
1690 static __attribute__((unused)) void debug_print_type_path(
1691                 const type_path_t *path)
1692 {
1693         size_t len = ARR_LEN(path->path);
1694
1695         for (size_t i = 0; i < len; ++i) {
1696                 const type_path_entry_t *entry = & path->path[i];
1697
1698                 type_t *type = skip_typeref(entry->type);
1699                 if (is_type_compound(type)) {
1700                         /* in gcc mode structs can have no members */
1701                         if (entry->v.compound_entry == NULL) {
1702                                 assert(i == len-1);
1703                                 continue;
1704                         }
1705                         fprintf(stderr, ".%s",
1706                                 entry->v.compound_entry->base.symbol->string);
1707                 } else if (is_type_array(type)) {
1708                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1709                 } else {
1710                         fprintf(stderr, "-INVALID-");
1711                 }
1712         }
1713         if (path->top_type != NULL) {
1714                 fprintf(stderr, "  (");
1715                 print_type(path->top_type);
1716                 fprintf(stderr, ")");
1717         }
1718 }
1719
1720 /**
1721  * Return the top type path entry, i.e. in a path
1722  * (type).a.b returns the b.
1723  */
1724 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1725 {
1726         size_t len = ARR_LEN(path->path);
1727         assert(len > 0);
1728         return &path->path[len-1];
1729 }
1730
1731 /**
1732  * Enlarge the type path by an (empty) element.
1733  */
1734 static type_path_entry_t *append_to_type_path(type_path_t *path)
1735 {
1736         size_t len = ARR_LEN(path->path);
1737         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1738
1739         type_path_entry_t *result = & path->path[len];
1740         memset(result, 0, sizeof(result[0]));
1741         return result;
1742 }
1743
1744 /**
1745  * Descending into a sub-type. Enter the scope of the current top_type.
1746  */
1747 static void descend_into_subtype(type_path_t *path)
1748 {
1749         type_t *orig_top_type = path->top_type;
1750         type_t *top_type      = skip_typeref(orig_top_type);
1751
1752         type_path_entry_t *top = append_to_type_path(path);
1753         top->type              = top_type;
1754
1755         if (is_type_compound(top_type)) {
1756                 compound_t *const compound = top_type->compound.compound;
1757                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1758
1759                 if (entry != NULL) {
1760                         top->v.compound_entry = &entry->declaration;
1761                         path->top_type = entry->declaration.type;
1762                 } else {
1763                         path->top_type = NULL;
1764                 }
1765         } else if (is_type_array(top_type)) {
1766                 top->v.index   = 0;
1767                 path->top_type = top_type->array.element_type;
1768         } else {
1769                 assert(!is_type_valid(top_type));
1770         }
1771 }
1772
1773 /**
1774  * Pop an entry from the given type path, i.e. returning from
1775  * (type).a.b to (type).a
1776  */
1777 static void ascend_from_subtype(type_path_t *path)
1778 {
1779         type_path_entry_t *top = get_type_path_top(path);
1780
1781         path->top_type = top->type;
1782
1783         size_t len = ARR_LEN(path->path);
1784         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1785 }
1786
1787 /**
1788  * Pop entries from the given type path until the given
1789  * path level is reached.
1790  */
1791 static void ascend_to(type_path_t *path, size_t top_path_level)
1792 {
1793         size_t len = ARR_LEN(path->path);
1794
1795         while (len > top_path_level) {
1796                 ascend_from_subtype(path);
1797                 len = ARR_LEN(path->path);
1798         }
1799 }
1800
1801 static bool walk_designator(type_path_t *path, const designator_t *designator,
1802                             bool used_in_offsetof)
1803 {
1804         for (; designator != NULL; designator = designator->next) {
1805                 type_path_entry_t *top       = get_type_path_top(path);
1806                 type_t            *orig_type = top->type;
1807
1808                 type_t *type = skip_typeref(orig_type);
1809
1810                 if (designator->symbol != NULL) {
1811                         symbol_t *symbol = designator->symbol;
1812                         if (!is_type_compound(type)) {
1813                                 if (is_type_valid(type)) {
1814                                         errorf(&designator->pos,
1815                                                "'.%Y' designator used for non-compound type '%T'",
1816                                                symbol, orig_type);
1817                                 }
1818
1819                                 top->type             = type_error_type;
1820                                 top->v.compound_entry = NULL;
1821                                 orig_type             = type_error_type;
1822                         } else {
1823                                 compound_t *compound = type->compound.compound;
1824                                 entity_t   *iter     = compound->members.entities;
1825                                 for (; iter != NULL; iter = iter->base.next) {
1826                                         if (iter->base.symbol == symbol) {
1827                                                 break;
1828                                         }
1829                                 }
1830                                 if (iter == NULL) {
1831                                         errorf(&designator->pos,
1832                                                "'%T' has no member named '%Y'", orig_type, symbol);
1833                                         return false;
1834                                 }
1835                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1836                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1837                                         errorf(&designator->pos,
1838                                                    "offsetof designator '%Y' must not specify bitfield",
1839                                                    symbol);
1840                                         return false;
1841                                 }
1842
1843                                 top->type             = orig_type;
1844                                 top->v.compound_entry = &iter->declaration;
1845                                 orig_type             = iter->declaration.type;
1846                         }
1847                 } else {
1848                         expression_t *array_index = designator->array_index;
1849                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1850                                 return true;
1851
1852                         if (!is_type_array(type)) {
1853                                 if (is_type_valid(type)) {
1854                                         errorf(&designator->pos,
1855                                                "[%E] designator used for non-array type '%T'",
1856                                                array_index, orig_type);
1857                                 }
1858                                 return false;
1859                         }
1860
1861                         long index = fold_constant_to_int(array_index);
1862                         if (!used_in_offsetof) {
1863                                 if (index < 0) {
1864                                         errorf(&designator->pos,
1865                                                "array index [%E] must be positive", array_index);
1866                                 } else if (type->array.size_constant) {
1867                                         long array_size = type->array.size;
1868                                         if (index >= array_size) {
1869                                                 errorf(&designator->pos,
1870                                                        "designator [%E] (%d) exceeds array size %d",
1871                                                        array_index, index, array_size);
1872                                         }
1873                                 }
1874                         }
1875
1876                         top->type    = orig_type;
1877                         top->v.index = (size_t) index;
1878                         orig_type    = type->array.element_type;
1879                 }
1880                 path->top_type = orig_type;
1881
1882                 if (designator->next != NULL) {
1883                         descend_into_subtype(path);
1884                 }
1885         }
1886         return true;
1887 }
1888
1889 static void advance_current_object(type_path_t *path, size_t top_path_level)
1890 {
1891         type_path_entry_t *top = get_type_path_top(path);
1892
1893         type_t *type = skip_typeref(top->type);
1894         if (is_type_union(type)) {
1895                 /* in unions only the first element is initialized */
1896                 top->v.compound_entry = NULL;
1897         } else if (is_type_struct(type)) {
1898                 declaration_t *entry = top->v.compound_entry;
1899
1900                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1901                 if (next_entity != NULL) {
1902                         assert(is_declaration(next_entity));
1903                         entry = &next_entity->declaration;
1904                 } else {
1905                         entry = NULL;
1906                 }
1907
1908                 top->v.compound_entry = entry;
1909                 if (entry != NULL) {
1910                         path->top_type = entry->type;
1911                         return;
1912                 }
1913         } else if (is_type_array(type)) {
1914                 assert(is_type_array(type));
1915
1916                 top->v.index++;
1917
1918                 if (!type->array.size_constant || top->v.index < type->array.size) {
1919                         return;
1920                 }
1921         } else {
1922                 assert(!is_type_valid(type));
1923                 return;
1924         }
1925
1926         /* we're past the last member of the current sub-aggregate, try if we
1927          * can ascend in the type hierarchy and continue with another subobject */
1928         size_t len = ARR_LEN(path->path);
1929
1930         if (len > top_path_level) {
1931                 ascend_from_subtype(path);
1932                 advance_current_object(path, top_path_level);
1933         } else {
1934                 path->top_type = NULL;
1935         }
1936 }
1937
1938 /**
1939  * skip any {...} blocks until a closing bracket is reached.
1940  */
1941 static void skip_initializers(void)
1942 {
1943         accept('{');
1944
1945         while (token.kind != '}') {
1946                 if (token.kind == T_EOF)
1947                         return;
1948                 if (token.kind == '{') {
1949                         eat_block();
1950                         continue;
1951                 }
1952                 next_token();
1953         }
1954 }
1955
1956 static initializer_t *create_empty_initializer(void)
1957 {
1958         static initializer_t empty_initializer
1959                 = { .list = { { INITIALIZER_LIST }, 0 } };
1960         return &empty_initializer;
1961 }
1962
1963 /**
1964  * Parse a part of an initialiser for a struct or union,
1965  */
1966 static initializer_t *parse_sub_initializer(type_path_t *path,
1967                 type_t *outer_type, size_t top_path_level,
1968                 parse_initializer_env_t *env)
1969 {
1970         if (token.kind == '}') {
1971                 /* empty initializer */
1972                 return create_empty_initializer();
1973         }
1974
1975         initializer_t *result = NULL;
1976
1977         type_t *orig_type = path->top_type;
1978         type_t *type      = NULL;
1979
1980         if (orig_type == NULL) {
1981                 /* We are initializing an empty compound. */
1982         } else {
1983                 type = skip_typeref(orig_type);
1984         }
1985
1986         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1987
1988         while (true) {
1989                 designator_t *designator = NULL;
1990                 if (token.kind == '.' || token.kind == '[') {
1991                         designator = parse_designation();
1992                         goto finish_designator;
1993                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1994                         /* GNU-style designator ("identifier: value") */
1995                         designator         = allocate_ast_zero(sizeof(designator[0]));
1996                         designator->pos    = *HERE;
1997                         designator->symbol = token.base.symbol;
1998                         eat(T_IDENTIFIER);
1999                         eat(':');
2000
2001 finish_designator:
2002                         /* reset path to toplevel, evaluate designator from there */
2003                         ascend_to(path, top_path_level);
2004                         if (!walk_designator(path, designator, false)) {
2005                                 /* can't continue after designation error */
2006                                 goto end_error;
2007                         }
2008
2009                         initializer_t *designator_initializer
2010                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2011                         designator_initializer->designator.designator = designator;
2012                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2013
2014                         orig_type = path->top_type;
2015                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2016                 }
2017
2018                 initializer_t *sub;
2019
2020                 if (token.kind == '{') {
2021                         if (type != NULL && is_type_scalar(type)) {
2022                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2023                         } else {
2024                                 if (type == NULL) {
2025                                         if (env->entity != NULL) {
2026                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2027                                         } else {
2028                                                 errorf(HERE, "extra brace group at end of initializer");
2029                                         }
2030                                         eat('{');
2031                                 } else {
2032                                         eat('{');
2033                                         descend_into_subtype(path);
2034                                 }
2035
2036                                 add_anchor_token('}');
2037                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2038                                                             env);
2039                                 rem_anchor_token('}');
2040
2041                                 expect('}');
2042
2043                                 if (!type)
2044                                         goto error_parse_next;
2045
2046                                 ascend_from_subtype(path);
2047                         }
2048                 } else {
2049                         /* must be an expression */
2050                         expression_t *expression = parse_assignment_expression();
2051                         mark_vars_read(expression, NULL);
2052
2053                         if (env->must_be_constant && !is_linker_constant(expression)) {
2054                                 errorf(&expression->base.pos,
2055                                        "Initialisation expression '%E' is not constant",
2056                                        expression);
2057                         }
2058
2059                         if (type == NULL) {
2060                                 /* we are already outside, ... */
2061                                 if (outer_type == NULL)
2062                                         goto error_parse_next;
2063                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2064                                 if (is_type_compound(outer_type_skip) &&
2065                                                 !outer_type_skip->compound.compound->complete) {
2066                                         goto error_parse_next;
2067                                 }
2068
2069                                 position_t const* const pos = &expression->base.pos;
2070                                 if (env->entity != NULL) {
2071                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2072                                 } else {
2073                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2074                                 }
2075                                 goto error_parse_next;
2076                         }
2077
2078                         /* handle { "string" } special case */
2079                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2080                                 result = initializer_from_expression(outer_type, expression);
2081                                 if (result != NULL) {
2082                                         accept(',');
2083                                         if (token.kind != '}') {
2084                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2085                                         }
2086                                         /* TODO: eat , ... */
2087                                         goto out;
2088                                 }
2089                         }
2090
2091                         /* descend into subtypes until expression matches type */
2092                         while (true) {
2093                                 orig_type = path->top_type;
2094                                 type      = skip_typeref(orig_type);
2095
2096                                 sub = initializer_from_expression(orig_type, expression);
2097                                 if (sub != NULL) {
2098                                         break;
2099                                 }
2100                                 if (!is_type_valid(type)) {
2101                                         goto end_error;
2102                                 }
2103                                 if (is_type_scalar(type)) {
2104                                         errorf(&expression->base.pos,
2105                                                         "expression '%E' doesn't match expected type '%T'",
2106                                                         expression, orig_type);
2107                                         goto end_error;
2108                                 }
2109
2110                                 descend_into_subtype(path);
2111                         }
2112                 }
2113
2114                 /* update largest index of top array */
2115                 const type_path_entry_t *first      = &path->path[0];
2116                 type_t                  *first_type = first->type;
2117                 first_type                          = skip_typeref(first_type);
2118                 if (is_type_array(first_type)) {
2119                         size_t index = first->v.index;
2120                         if (index > path->max_index)
2121                                 path->max_index = index;
2122                 }
2123
2124                 /* append to initializers list */
2125                 ARR_APP1(initializer_t*, initializers, sub);
2126
2127 error_parse_next:
2128                 if (!accept(','))
2129                         break;
2130                 if (token.kind == '}') {
2131                         break;
2132                 }
2133
2134                 if (type != NULL) {
2135                         /* advance to the next declaration if we are not at the end */
2136                         advance_current_object(path, top_path_level);
2137                         orig_type = path->top_type;
2138                         if (orig_type != NULL)
2139                                 type = skip_typeref(orig_type);
2140                         else
2141                                 type = NULL;
2142                 }
2143         }
2144
2145         size_t len  = ARR_LEN(initializers);
2146         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2147         result = allocate_ast_zero(size);
2148         result->kind     = INITIALIZER_LIST;
2149         result->list.len = len;
2150         memcpy(&result->list.initializers, initializers,
2151                len * sizeof(initializers[0]));
2152         goto out;
2153
2154 end_error:
2155         skip_initializers();
2156 out:
2157         DEL_ARR_F(initializers);
2158         ascend_to(path, top_path_level+1);
2159         return result;
2160 }
2161
2162 static expression_t *make_size_literal(size_t value)
2163 {
2164         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2165         literal->base.type    = type_size_t;
2166
2167         char buf[128];
2168         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2169         literal->literal.value = make_string(buf);
2170
2171         return literal;
2172 }
2173
2174 /**
2175  * Parses an initializer. Parsers either a compound literal
2176  * (env->declaration == NULL) or an initializer of a declaration.
2177  */
2178 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2179 {
2180         type_t        *type      = skip_typeref(env->type);
2181         size_t         max_index = 0;
2182         initializer_t *result;
2183
2184         if (is_type_scalar(type)) {
2185                 result = parse_scalar_initializer(type, env->must_be_constant);
2186         } else if (token.kind == '{') {
2187                 eat('{');
2188
2189                 type_path_t path;
2190                 memset(&path, 0, sizeof(path));
2191                 path.top_type = env->type;
2192                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2193
2194                 descend_into_subtype(&path);
2195
2196                 add_anchor_token('}');
2197                 result = parse_sub_initializer(&path, env->type, 1, env);
2198                 rem_anchor_token('}');
2199
2200                 max_index = path.max_index;
2201                 DEL_ARR_F(path.path);
2202
2203                 expect('}');
2204         } else {
2205                 /* parse_scalar_initializer() also works in this case: we simply
2206                  * have an expression without {} around it */
2207                 result = parse_scalar_initializer(type, env->must_be_constant);
2208         }
2209
2210         /* §6.7.8:22 array initializers for arrays with unknown size determine
2211          * the array type size */
2212         if (is_type_array(type) && type->array.size_expression == NULL
2213                         && result != NULL) {
2214                 size_t size;
2215                 switch (result->kind) {
2216                 case INITIALIZER_LIST:
2217                         assert(max_index != 0xdeadbeaf);
2218                         size = max_index + 1;
2219                         break;
2220
2221                 case INITIALIZER_STRING: {
2222                         size = get_string_len(&get_init_string(result)->value) + 1;
2223                         break;
2224                 }
2225
2226                 case INITIALIZER_DESIGNATOR:
2227                 case INITIALIZER_VALUE:
2228                         /* can happen for parse errors */
2229                         size = 0;
2230                         break;
2231
2232                 default:
2233                         internal_errorf(HERE, "invalid initializer type");
2234                 }
2235
2236                 type_t *new_type = duplicate_type(type);
2237
2238                 new_type->array.size_expression   = make_size_literal(size);
2239                 new_type->array.size_constant     = true;
2240                 new_type->array.has_implicit_size = true;
2241                 new_type->array.size              = size;
2242                 env->type = new_type;
2243         }
2244
2245         return result;
2246 }
2247
2248 static void append_entity(scope_t *scope, entity_t *entity)
2249 {
2250         if (scope->last_entity != NULL) {
2251                 scope->last_entity->base.next = entity;
2252         } else {
2253                 scope->entities = entity;
2254         }
2255         entity->base.parent_entity = current_entity;
2256         scope->last_entity         = entity;
2257 }
2258
2259
2260 static compound_t *parse_compound_type_specifier(bool is_struct)
2261 {
2262         position_t const pos = *HERE;
2263         eat(is_struct ? T_struct : T_union);
2264
2265         symbol_t    *symbol     = NULL;
2266         entity_t    *entity     = NULL;
2267         attribute_t *attributes = NULL;
2268
2269         if (token.kind == T___attribute__) {
2270                 attributes = parse_attributes(NULL);
2271         }
2272
2273         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2274         if (token.kind == T_IDENTIFIER) {
2275                 /* the compound has a name, check if we have seen it already */
2276                 symbol = token.base.symbol;
2277                 entity = get_tag(symbol, kind);
2278                 eat(T_IDENTIFIER);
2279
2280                 if (entity != NULL) {
2281                         if (entity->base.parent_scope != current_scope &&
2282                             (token.kind == '{' || token.kind == ';')) {
2283                                 /* we're in an inner scope and have a definition. Shadow
2284                                  * existing definition in outer scope */
2285                                 entity = NULL;
2286                         } else if (entity->compound.complete && token.kind == '{') {
2287                                 position_t const *const ppos = &entity->base.pos;
2288                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2289                                 /* clear members in the hope to avoid further errors */
2290                                 entity->compound.members.entities = NULL;
2291                         }
2292                 }
2293         } else if (token.kind != '{') {
2294                 char const *const msg =
2295                         is_struct ? "while parsing struct type specifier" :
2296                                     "while parsing union type specifier";
2297                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2298
2299                 return NULL;
2300         }
2301
2302         if (entity == NULL) {
2303                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2304                 entity->compound.alignment = 1;
2305                 entity->base.parent_scope  = current_scope;
2306                 if (symbol != NULL) {
2307                         environment_push(entity);
2308                 }
2309                 append_entity(current_scope, entity);
2310         }
2311
2312         if (token.kind == '{') {
2313                 parse_compound_type_entries(&entity->compound);
2314
2315                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2316                 if (symbol == NULL) {
2317                         assert(anonymous_entity == NULL);
2318                         anonymous_entity = entity;
2319                 }
2320         }
2321
2322         if (attributes != NULL) {
2323                 entity->compound.attributes = attributes;
2324                 handle_entity_attributes(attributes, entity);
2325         }
2326
2327         return &entity->compound;
2328 }
2329
2330 static void parse_enum_entries(type_t *const enum_type)
2331 {
2332         eat('{');
2333
2334         if (token.kind == '}') {
2335                 errorf(HERE, "empty enum not allowed");
2336                 eat('}');
2337                 return;
2338         }
2339
2340         add_anchor_token('}');
2341         add_anchor_token(',');
2342         do {
2343                 add_anchor_token('=');
2344                 position_t pos;
2345                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2346                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2347                 entity->enum_value.enum_type = enum_type;
2348                 rem_anchor_token('=');
2349
2350                 if (accept('=')) {
2351                         expression_t *value = parse_constant_expression();
2352
2353                         value = create_implicit_cast(value, enum_type);
2354                         entity->enum_value.value = value;
2355
2356                         /* TODO semantic */
2357                 }
2358
2359                 record_entity(entity, false);
2360         } while (accept(',') && token.kind != '}');
2361         rem_anchor_token(',');
2362         rem_anchor_token('}');
2363
2364         expect('}');
2365 }
2366
2367 static type_t *parse_enum_specifier(void)
2368 {
2369         position_t const pos = *HERE;
2370         entity_t        *entity;
2371         symbol_t        *symbol;
2372
2373         eat(T_enum);
2374         switch (token.kind) {
2375                 case T_IDENTIFIER:
2376                         symbol = token.base.symbol;
2377                         entity = get_tag(symbol, ENTITY_ENUM);
2378                         eat(T_IDENTIFIER);
2379
2380                         if (entity != NULL) {
2381                                 if (entity->base.parent_scope != current_scope &&
2382                                                 (token.kind == '{' || token.kind == ';')) {
2383                                         /* we're in an inner scope and have a definition. Shadow
2384                                          * existing definition in outer scope */
2385                                         entity = NULL;
2386                                 } else if (entity->enume.complete && token.kind == '{') {
2387                                         position_t const *const ppos = &entity->base.pos;
2388                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2389                                 }
2390                         }
2391                         break;
2392
2393                 case '{':
2394                         entity = NULL;
2395                         symbol = NULL;
2396                         break;
2397
2398                 default:
2399                         parse_error_expected("while parsing enum type specifier",
2400                                         T_IDENTIFIER, '{', NULL);
2401                         return NULL;
2402         }
2403
2404         if (entity == NULL) {
2405                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2406                 entity->base.parent_scope = current_scope;
2407         }
2408
2409         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2410         type->enumt.enume      = &entity->enume;
2411         type->enumt.base.akind = ATOMIC_TYPE_INT;
2412
2413         if (token.kind == '{') {
2414                 if (symbol != NULL) {
2415                         environment_push(entity);
2416                 }
2417                 append_entity(current_scope, entity);
2418                 entity->enume.complete = true;
2419
2420                 parse_enum_entries(type);
2421                 parse_attributes(NULL);
2422
2423                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2424                 if (symbol == NULL) {
2425                         assert(anonymous_entity == NULL);
2426                         anonymous_entity = entity;
2427                 }
2428         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2429                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2430         }
2431
2432         return type;
2433 }
2434
2435 /**
2436  * if a symbol is a typedef to another type, return true
2437  */
2438 static bool is_typedef_symbol(symbol_t *symbol)
2439 {
2440         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2441         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2442 }
2443
2444 static type_t *parse_typeof(void)
2445 {
2446         eat(T___typeof__);
2447
2448         type_t *type;
2449
2450         add_anchor_token(')');
2451         expect('(');
2452
2453         expression_t *expression  = NULL;
2454
2455         switch (token.kind) {
2456         case T_IDENTIFIER:
2457                 if (is_typedef_symbol(token.base.symbol)) {
2458         DECLARATION_START
2459                         type = parse_typename();
2460                 } else {
2461         default:
2462                         expression = parse_expression();
2463                         type       = revert_automatic_type_conversion(expression);
2464                 }
2465                 break;
2466         }
2467
2468         rem_anchor_token(')');
2469         expect(')');
2470
2471         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2472         typeof_type->typeoft.expression  = expression;
2473         typeof_type->typeoft.typeof_type = type;
2474
2475         return typeof_type;
2476 }
2477
2478 typedef enum specifiers_t {
2479         SPECIFIER_NONE      = 0,
2480         SPECIFIER_SIGNED    = 1 << 0,
2481         SPECIFIER_UNSIGNED  = 1 << 1,
2482         SPECIFIER_LONG      = 1 << 2,
2483         SPECIFIER_INT       = 1 << 3,
2484         SPECIFIER_DOUBLE    = 1 << 4,
2485         SPECIFIER_CHAR      = 1 << 5,
2486         SPECIFIER_WCHAR_T   = 1 << 6,
2487         SPECIFIER_SHORT     = 1 << 7,
2488         SPECIFIER_LONG_LONG = 1 << 8,
2489         SPECIFIER_FLOAT     = 1 << 9,
2490         SPECIFIER_BOOL      = 1 << 10,
2491         SPECIFIER_VOID      = 1 << 11,
2492         SPECIFIER_INT8      = 1 << 12,
2493         SPECIFIER_INT16     = 1 << 13,
2494         SPECIFIER_INT32     = 1 << 14,
2495         SPECIFIER_INT64     = 1 << 15,
2496         SPECIFIER_INT128    = 1 << 16,
2497         SPECIFIER_COMPLEX   = 1 << 17,
2498         SPECIFIER_IMAGINARY = 1 << 18,
2499 } specifiers_t;
2500
2501 static type_t *get_typedef_type(symbol_t *symbol)
2502 {
2503         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2504         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2505                 return NULL;
2506
2507         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2508         type->typedeft.typedefe = &entity->typedefe;
2509
2510         return type;
2511 }
2512
2513 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2514 {
2515         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2516
2517         add_anchor_token(')');
2518         add_anchor_token(',');
2519         expect('(');
2520
2521         do {
2522                 add_anchor_token('=');
2523                 position_t pos;
2524                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2525                 rem_anchor_token('=');
2526
2527                 symbol_t **prop = NULL;
2528                 if (prop_sym) {
2529                         if (streq(prop_sym->string, "put")) {
2530                                 prop = &property->put_symbol;
2531                         } else if (streq(prop_sym->string, "get")) {
2532                                 prop = &property->get_symbol;
2533                         } else {
2534                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2535                         }
2536                 }
2537
2538                 add_anchor_token(T_IDENTIFIER);
2539                 expect('=');
2540                 rem_anchor_token(T_IDENTIFIER);
2541
2542                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2543                 if (prop != NULL)
2544                         *prop = sym ? sym : sym_anonymous;
2545         } while (accept(','));
2546         rem_anchor_token(',');
2547         rem_anchor_token(')');
2548
2549         attribute->a.property = property;
2550
2551         expect(')');
2552         return attribute;
2553 }
2554
2555 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2556 {
2557         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2558         if (accept(T_restrict)) {
2559                 kind = ATTRIBUTE_MS_RESTRICT;
2560         } else if (token.kind == T_IDENTIFIER) {
2561                 char const *const name = token.base.symbol->string;
2562                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2563                      ++k) {
2564                         const char *attribute_name = get_attribute_name(k);
2565                         if (attribute_name != NULL && streq(attribute_name, name)) {
2566                                 kind = k;
2567                                 break;
2568                         }
2569                 }
2570
2571                 if (kind == ATTRIBUTE_UNKNOWN) {
2572                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2573                 }
2574         } else {
2575                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2576                 return NULL;
2577         }
2578
2579         attribute_t *attribute = allocate_attribute_zero(kind);
2580         eat(T_IDENTIFIER);
2581
2582         if (kind == ATTRIBUTE_MS_PROPERTY) {
2583                 return parse_attribute_ms_property(attribute);
2584         }
2585
2586         /* parse arguments */
2587         if (accept('('))
2588                 attribute->a.arguments = parse_attribute_arguments();
2589
2590         return attribute;
2591 }
2592
2593 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2594 {
2595         eat(T__declspec);
2596
2597         add_anchor_token(')');
2598         expect('(');
2599         if (token.kind != ')') {
2600                 attribute_t **anchor = &first;
2601                 do {
2602                         while (*anchor != NULL)
2603                                 anchor = &(*anchor)->next;
2604
2605                         attribute_t *attribute
2606                                 = parse_microsoft_extended_decl_modifier_single();
2607                         if (attribute == NULL)
2608                                 break;
2609
2610                         *anchor = attribute;
2611                         anchor  = &attribute->next;
2612                 } while (accept(','));
2613         }
2614         rem_anchor_token(')');
2615         expect(')');
2616         return first;
2617 }
2618
2619 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2620 {
2621         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2622         if (is_declaration(entity)) {
2623                 entity->declaration.type     = type_error_type;
2624                 entity->declaration.implicit = true;
2625         } else if (kind == ENTITY_TYPEDEF) {
2626                 entity->typedefe.type    = type_error_type;
2627                 entity->typedefe.builtin = true;
2628         }
2629         if (kind != ENTITY_COMPOUND_MEMBER)
2630                 record_entity(entity, false);
2631         return entity;
2632 }
2633
2634 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2635 {
2636         type_t            *type            = NULL;
2637         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2638         unsigned           type_specifiers = 0;
2639         bool               newtype         = false;
2640         bool               saw_error       = false;
2641
2642         memset(specifiers, 0, sizeof(*specifiers));
2643         specifiers->pos = *HERE;
2644
2645         while (true) {
2646                 specifiers->attributes = parse_attributes(specifiers->attributes);
2647
2648                 switch (token.kind) {
2649                 /* storage class */
2650 #define MATCH_STORAGE_CLASS(token, class)                                  \
2651                 case token:                                                        \
2652                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2653                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2654                         }                                                              \
2655                         specifiers->storage_class = class;                             \
2656                         if (specifiers->thread_local)                                  \
2657                                 goto check_thread_storage_class;                           \
2658                         eat(token); \
2659                         break;
2660
2661                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2662                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2663                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2664                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2665                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2666
2667                 case T__declspec:
2668                         specifiers->attributes
2669                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2670                         break;
2671
2672                 case T__Thread_local:
2673                         if (specifiers->thread_local) {
2674                                 errorf(HERE, "duplicate %K", &token);
2675                         } else {
2676                                 specifiers->thread_local = true;
2677 check_thread_storage_class:
2678                                 switch (specifiers->storage_class) {
2679                                         case STORAGE_CLASS_EXTERN:
2680                                         case STORAGE_CLASS_NONE:
2681                                         case STORAGE_CLASS_STATIC:
2682                                                 break;
2683
2684                                                 char const* wrong;
2685                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2686                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2687                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2688 wrong_thread_storage_class:
2689                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2690                                                 break;
2691                                 }
2692                         }
2693                         next_token();
2694                         break;
2695
2696                 /* type qualifiers */
2697 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2698                 case token:                                                     \
2699                         qualifiers |= qualifier;                                    \
2700                         eat(token); \
2701                         break
2702
2703                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2704                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2705                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2706                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2707                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2708                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2709                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2710                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2711
2712                 /* type specifiers */
2713 #define MATCH_SPECIFIER(token, specifier, name)                         \
2714                 case token:                                                     \
2715                         if (type_specifiers & specifier) {                           \
2716                                 errorf(HERE, "multiple " name " type specifiers given"); \
2717                         } else {                                                    \
2718                                 type_specifiers |= specifier;                           \
2719                         }                                                           \
2720                         eat(token); \
2721                         break
2722
2723                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2724                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2725                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2726                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2727                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2728                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2729                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2730                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2731                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2732                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2733                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2734                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2735                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2736                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2737                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2738                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2739                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2740                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2741
2742                 case T_inline:
2743                         eat(T_inline);
2744                         specifiers->is_inline = true;
2745                         break;
2746
2747 #if 0
2748                 case T__forceinline:
2749                         eat(T__forceinline);
2750                         specifiers->modifiers |= DM_FORCEINLINE;
2751                         break;
2752 #endif
2753
2754                 case T_long:
2755                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2756                                 errorf(HERE, "too many long type specifiers given");
2757                         } else if (type_specifiers & SPECIFIER_LONG) {
2758                                 type_specifiers |= SPECIFIER_LONG_LONG;
2759                         } else {
2760                                 type_specifiers |= SPECIFIER_LONG;
2761                         }
2762                         eat(T_long);
2763                         break;
2764
2765 #define CHECK_DOUBLE_TYPE() \
2766         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2767
2768                 case T_struct:
2769                         CHECK_DOUBLE_TYPE();
2770                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2771
2772                         type->compound.compound = parse_compound_type_specifier(true);
2773                         break;
2774                 case T_union:
2775                         CHECK_DOUBLE_TYPE();
2776                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2777                         type->compound.compound = parse_compound_type_specifier(false);
2778                         break;
2779                 case T_enum:
2780                         CHECK_DOUBLE_TYPE();
2781                         type = parse_enum_specifier();
2782                         break;
2783                 case T___typeof__:
2784                         CHECK_DOUBLE_TYPE();
2785                         type = parse_typeof();
2786                         break;
2787                 case T___builtin_va_list:
2788                         CHECK_DOUBLE_TYPE();
2789                         type = duplicate_type(type_valist);
2790                         eat(T___builtin_va_list);
2791                         break;
2792
2793                 case T_IDENTIFIER: {
2794                         /* only parse identifier if we haven't found a type yet */
2795                         if (type != NULL || type_specifiers != 0) {
2796                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2797                                  * declaration, so it doesn't generate errors about expecting '(' or
2798                                  * '{' later on. */
2799                                 switch (look_ahead(1)->kind) {
2800                                         STORAGE_CLASSES
2801                                         TYPE_SPECIFIERS
2802                                         case T_const:
2803                                         case T_restrict:
2804                                         case T_volatile:
2805                                         case T_inline:
2806                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2807                                         case T_IDENTIFIER:
2808                                         case '&':
2809                                         case '*':
2810                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2811                                                 eat(T_IDENTIFIER);
2812                                                 continue;
2813
2814                                         default:
2815                                                 goto finish_specifiers;
2816                                 }
2817                         }
2818
2819                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2820                         if (typedef_type == NULL) {
2821                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2822                                  * declaration, so it doesn't generate 'implicit int' followed by more
2823                                  * errors later on. */
2824                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2825                                 switch (la1_type) {
2826                                         DECLARATION_START
2827                                         case T_IDENTIFIER:
2828                                         case '&':
2829                                         case '*': {
2830                                                 errorf(HERE, "%K does not name a type", &token);
2831
2832                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2833
2834                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2835                                                 type->typedeft.typedefe = &entity->typedefe;
2836
2837                                                 eat(T_IDENTIFIER);
2838                                                 saw_error = true;
2839                                                 continue;
2840                                         }
2841
2842                                         default:
2843                                                 goto finish_specifiers;
2844                                 }
2845                         }
2846
2847                         eat(T_IDENTIFIER);
2848                         type = typedef_type;
2849                         break;
2850                 }
2851
2852                 /* function specifier */
2853                 default:
2854                         goto finish_specifiers;
2855                 }
2856         }
2857
2858 finish_specifiers:
2859         specifiers->attributes = parse_attributes(specifiers->attributes);
2860
2861         if (type == NULL || (saw_error && type_specifiers != 0)) {
2862                 position_t const* const pos = &specifiers->pos;
2863                 atomic_type_kind_t atomic_type;
2864
2865                 /* match valid basic types */
2866                 switch (type_specifiers & ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2867                 case SPECIFIER_VOID:
2868                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2869                                 if (type_specifiers & SPECIFIER_COMPLEX)
2870                                         errorf(pos, "_Complex specifier is invalid for void");
2871                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2872                                         errorf(pos, "_Imaginary specifier is invalid for void");
2873                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2874                         }
2875                         atomic_type = ATOMIC_TYPE_VOID;
2876                         break;
2877                 case SPECIFIER_WCHAR_T:
2878                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2879                         break;
2880                 case SPECIFIER_CHAR:
2881                         atomic_type = ATOMIC_TYPE_CHAR;
2882                         break;
2883                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2884                         atomic_type = ATOMIC_TYPE_SCHAR;
2885                         break;
2886                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2887                         atomic_type = ATOMIC_TYPE_UCHAR;
2888                         break;
2889                 case SPECIFIER_SHORT:
2890                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2891                 case SPECIFIER_SHORT | SPECIFIER_INT:
2892                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2893                         atomic_type = ATOMIC_TYPE_SHORT;
2894                         break;
2895                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2896                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2897                         atomic_type = ATOMIC_TYPE_USHORT;
2898                         break;
2899                 case SPECIFIER_INT:
2900                 case SPECIFIER_SIGNED:
2901                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2902                         atomic_type = ATOMIC_TYPE_INT;
2903                         break;
2904                 case SPECIFIER_UNSIGNED:
2905                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2906                         atomic_type = ATOMIC_TYPE_UINT;
2907                         break;
2908                 case SPECIFIER_LONG:
2909                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2910                 case SPECIFIER_LONG | SPECIFIER_INT:
2911                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2912                         atomic_type = ATOMIC_TYPE_LONG;
2913                         break;
2914                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2915                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2916                         atomic_type = ATOMIC_TYPE_ULONG;
2917                         break;
2918
2919                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2920                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2921                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2922                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2923                         | SPECIFIER_INT:
2924                         atomic_type = ATOMIC_TYPE_LONGLONG;
2925                         goto warn_about_long_long;
2926
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2929                         | SPECIFIER_INT:
2930                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2931 warn_about_long_long:
2932                         warningf(WARN_LONG_LONG, &specifiers->pos, "ISO C90 does not support 'long long'");
2933                         break;
2934
2935                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2936                         atomic_type = unsigned_int8_type_kind;
2937                         break;
2938
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2940                         atomic_type = unsigned_int16_type_kind;
2941                         break;
2942
2943                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2944                         atomic_type = unsigned_int32_type_kind;
2945                         break;
2946
2947                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2948                         atomic_type = unsigned_int64_type_kind;
2949                         break;
2950
2951                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2952                         atomic_type = unsigned_int128_type_kind;
2953                         break;
2954
2955                 case SPECIFIER_INT8:
2956                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2957                         atomic_type = int8_type_kind;
2958                         break;
2959
2960                 case SPECIFIER_INT16:
2961                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2962                         atomic_type = int16_type_kind;
2963                         break;
2964
2965                 case SPECIFIER_INT32:
2966                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2967                         atomic_type = int32_type_kind;
2968                         break;
2969
2970                 case SPECIFIER_INT64:
2971                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2972                         atomic_type = int64_type_kind;
2973                         break;
2974
2975                 case SPECIFIER_INT128:
2976                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2977                         atomic_type = int128_type_kind;
2978                         break;
2979
2980                 case SPECIFIER_FLOAT:
2981                         atomic_type = ATOMIC_TYPE_FLOAT;
2982                         break;
2983                 case SPECIFIER_DOUBLE:
2984                         atomic_type = ATOMIC_TYPE_DOUBLE;
2985                         break;
2986                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2987                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2988                         break;
2989                 case SPECIFIER_BOOL:
2990                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2991                                 if (type_specifiers & SPECIFIER_COMPLEX)
2992                                         errorf(pos, "_Complex specifier is invalid for _Bool");
2993                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2994                                         errorf(pos, "_Imaginary specifier is invalid for _Bool");
2995                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2996                         }
2997                         atomic_type = ATOMIC_TYPE_BOOL;
2998                         break;
2999                 default: {
3000                         /* invalid specifier combination, give an error message */
3001                         if (type_specifiers == 0) {
3002                                 if (!saw_error) {
3003                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3004                                         if (!(c_mode & _CXX) && !strict_mode) {
3005                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3006                                                 atomic_type = ATOMIC_TYPE_INT;
3007                                                 break;
3008                                         } else {
3009                                                 errorf(pos, "no type specifiers given in declaration");
3010                                         }
3011                                 }
3012                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3013                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3014                                 errorf(pos, "signed and unsigned specifiers given");
3015                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3016                                 errorf(pos, "only integer types can be signed or unsigned");
3017                         } else {
3018                                 errorf(pos, "multiple datatypes in declaration");
3019                         }
3020                         specifiers->type = type_error_type;
3021                         return;
3022                 }
3023                 }
3024
3025                 if (type_specifiers & SPECIFIER_COMPLEX) {
3026                         type = allocate_type_zero(TYPE_COMPLEX);
3027                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3028                         type = allocate_type_zero(TYPE_IMAGINARY);
3029                 } else {
3030                         type = allocate_type_zero(TYPE_ATOMIC);
3031                 }
3032                 type->atomic.akind = atomic_type;
3033                 newtype = true;
3034         } else if (type_specifiers != 0) {
3035                 errorf(&specifiers->pos, "multiple datatypes in declaration");
3036         }
3037
3038         /* FIXME: check type qualifiers here */
3039         type->base.qualifiers = qualifiers;
3040
3041         if (newtype) {
3042                 type = identify_new_type(type);
3043         } else {
3044                 type = typehash_insert(type);
3045         }
3046
3047         if (specifiers->attributes != NULL)
3048                 type = handle_type_attributes(specifiers->attributes, type);
3049         specifiers->type = type;
3050 }
3051
3052 static type_qualifiers_t parse_type_qualifiers(void)
3053 {
3054         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3055
3056         while (true) {
3057                 switch (token.kind) {
3058                 /* type qualifiers */
3059                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3060                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3061                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3062                 /* microsoft extended type modifiers */
3063                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3064                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3065                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3066                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3067                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3068
3069                 default:
3070                         return qualifiers;
3071                 }
3072         }
3073 }
3074
3075 /**
3076  * Parses an K&R identifier list
3077  */
3078 static void parse_identifier_list(scope_t *scope)
3079 {
3080         assert(token.kind == T_IDENTIFIER);
3081         do {
3082                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3083                 /* a K&R parameter has no type, yet */
3084                 eat(T_IDENTIFIER);
3085
3086                 if (scope != NULL)
3087                         append_entity(scope, entity);
3088         } while (accept(',') && token.kind == T_IDENTIFIER);
3089 }
3090
3091 static entity_t *parse_parameter(void)
3092 {
3093         declaration_specifiers_t specifiers;
3094         parse_declaration_specifiers(&specifiers);
3095
3096         entity_t *entity = parse_declarator(&specifiers,
3097                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3098         anonymous_entity = NULL;
3099         return entity;
3100 }
3101
3102 static void semantic_parameter_incomplete(const entity_t *entity)
3103 {
3104         assert(entity->kind == ENTITY_PARAMETER);
3105
3106         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3107          *             list in a function declarator that is part of a
3108          *             definition of that function shall not have
3109          *             incomplete type. */
3110         type_t *type = skip_typeref(entity->declaration.type);
3111         if (is_type_incomplete(type)) {
3112                 errorf(&entity->base.pos, "'%N' has incomplete type", entity);
3113         }
3114 }
3115
3116 static bool has_parameters(void)
3117 {
3118         /* func(void) is not a parameter */
3119         if (look_ahead(1)->kind != ')')
3120                 return true;
3121         if (token.kind == T_IDENTIFIER) {
3122                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3123                 if (entity == NULL)
3124                         return true;
3125                 if (entity->kind != ENTITY_TYPEDEF)
3126                         return true;
3127                 type_t const *const type = skip_typeref(entity->typedefe.type);
3128                 if (!is_type_void(type))
3129                         return true;
3130                 if (c_mode & _CXX) {
3131                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3132                          * is not allowed. */
3133                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3134                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3135                         /* §6.7.5.3:10  Qualification is not allowed here. */
3136                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3137                 }
3138         } else if (token.kind != T_void) {
3139                 return true;
3140         }
3141         next_token();
3142         return false;
3143 }
3144
3145 /**
3146  * Parses function type parameters (and optionally creates variable_t entities
3147  * for them in a scope)
3148  */
3149 static void parse_parameters(function_type_t *type, scope_t *scope)
3150 {
3151         add_anchor_token(')');
3152         eat('(');
3153
3154         if (token.kind == T_IDENTIFIER            &&
3155             !is_typedef_symbol(token.base.symbol) &&
3156             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3157                 type->kr_style_parameters = true;
3158                 parse_identifier_list(scope);
3159         } else if (token.kind == ')') {
3160                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3161                 if (!(c_mode & _CXX))
3162                         type->unspecified_parameters = true;
3163         } else if (has_parameters()) {
3164                 function_parameter_t **anchor = &type->parameters;
3165                 add_anchor_token(',');
3166                 do {
3167                         switch (token.kind) {
3168                         case T_DOTDOTDOT:
3169                                 eat(T_DOTDOTDOT);
3170                                 type->variadic = true;
3171                                 goto parameters_finished;
3172
3173                         case T_IDENTIFIER:
3174                         DECLARATION_START
3175                         {
3176                                 entity_t *entity = parse_parameter();
3177                                 if (entity->kind == ENTITY_TYPEDEF) {
3178                                         errorf(&entity->base.pos,
3179                                                         "typedef not allowed as function parameter");
3180                                         break;
3181                                 }
3182                                 assert(is_declaration(entity));
3183
3184                                 semantic_parameter_incomplete(entity);
3185
3186                                 function_parameter_t *const parameter =
3187                                         allocate_parameter(entity->declaration.type);
3188
3189                                 if (scope != NULL) {
3190                                         append_entity(scope, entity);
3191                                 }
3192
3193                                 *anchor = parameter;
3194                                 anchor  = &parameter->next;
3195                                 break;
3196                         }
3197
3198                         default:
3199                                 goto parameters_finished;
3200                         }
3201                 } while (accept(','));
3202 parameters_finished:
3203                 rem_anchor_token(',');
3204         }
3205
3206         rem_anchor_token(')');
3207         expect(')');
3208 }
3209
3210 typedef enum construct_type_kind_t {
3211         CONSTRUCT_POINTER = 1,
3212         CONSTRUCT_REFERENCE,
3213         CONSTRUCT_FUNCTION,
3214         CONSTRUCT_ARRAY
3215 } construct_type_kind_t;
3216
3217 typedef union construct_type_t construct_type_t;
3218
3219 typedef struct construct_type_base_t {
3220         construct_type_kind_t kind;
3221         position_t            pos;
3222         construct_type_t     *next;
3223 } construct_type_base_t;
3224
3225 typedef struct parsed_pointer_t {
3226         construct_type_base_t  base;
3227         type_qualifiers_t      type_qualifiers;
3228         variable_t            *base_variable;  /**< MS __based extension. */
3229 } parsed_pointer_t;
3230
3231 typedef struct parsed_reference_t {
3232         construct_type_base_t base;
3233 } parsed_reference_t;
3234
3235 typedef struct construct_function_type_t {
3236         construct_type_base_t  base;
3237         type_t                *function_type;
3238 } construct_function_type_t;
3239
3240 typedef struct parsed_array_t {
3241         construct_type_base_t  base;
3242         type_qualifiers_t      type_qualifiers;
3243         bool                   is_static;
3244         bool                   is_variable;
3245         expression_t          *size;
3246 } parsed_array_t;
3247
3248 union construct_type_t {
3249         construct_type_kind_t     kind;
3250         construct_type_base_t     base;
3251         parsed_pointer_t          pointer;
3252         parsed_reference_t        reference;
3253         construct_function_type_t function;
3254         parsed_array_t            array;
3255 };
3256
3257 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3258 {
3259         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3260         memset(cons, 0, size);
3261         cons->kind     = kind;
3262         cons->base.pos = *HERE;
3263         return cons;
3264 }
3265
3266 /* §6.7.5.1 */
3267 static construct_type_t *parse_pointer_declarator(void)
3268 {
3269         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3270         eat('*');
3271         cons->pointer.type_qualifiers = parse_type_qualifiers();
3272         //cons->pointer.base_variable   = base_variable;
3273
3274         return cons;
3275 }
3276
3277 /* ISO/IEC 14882:1998(E) §8.3.2 */
3278 static construct_type_t *parse_reference_declarator(void)
3279 {
3280         if (!(c_mode & _CXX))
3281                 errorf(HERE, "references are only available for C++");
3282
3283         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3284         eat('&');
3285
3286         return cons;
3287 }
3288
3289 /* §6.7.5.2 */
3290 static construct_type_t *parse_array_declarator(void)
3291 {
3292         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3293         parsed_array_t   *const array = &cons->array;
3294
3295         eat('[');
3296         add_anchor_token(']');
3297
3298         bool is_static = accept(T_static);
3299
3300         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3301
3302         if (!is_static)
3303                 is_static = accept(T_static);
3304
3305         array->type_qualifiers = type_qualifiers;
3306         array->is_static       = is_static;
3307
3308         expression_t *size = NULL;
3309         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3310                 array->is_variable = true;
3311                 eat('*');
3312         } else if (token.kind != ']') {
3313                 size = parse_assignment_expression();
3314
3315                 /* §6.7.5.2:1  Array size must have integer type */
3316                 type_t *const orig_type = size->base.type;
3317                 type_t *const type      = skip_typeref(orig_type);
3318                 if (!is_type_integer(type) && is_type_valid(type)) {
3319                         errorf(&size->base.pos,
3320                                "array size '%E' must have integer type but has type '%T'",
3321                                size, orig_type);
3322                 }
3323
3324                 array->size = size;
3325                 mark_vars_read(size, NULL);
3326         }
3327
3328         if (is_static && size == NULL)
3329                 errorf(&array->base.pos, "static array parameters require a size");
3330
3331         rem_anchor_token(']');
3332         expect(']');
3333         return cons;
3334 }
3335
3336 /* §6.7.5.3 */
3337 static construct_type_t *parse_function_declarator(scope_t *scope)
3338 {
3339         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3340
3341         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3342         function_type_t *ftype = &type->function;
3343
3344         ftype->linkage            = current_linkage;
3345         ftype->calling_convention = CC_DEFAULT;
3346
3347         parse_parameters(ftype, scope);
3348
3349         cons->function.function_type = type;
3350
3351         return cons;
3352 }
3353
3354 typedef struct parse_declarator_env_t {
3355         bool              may_be_abstract : 1;
3356         bool              must_be_abstract : 1;
3357         decl_modifiers_t  modifiers;
3358         symbol_t         *symbol;
3359         position_t        pos;
3360         scope_t           parameters;
3361         attribute_t      *attributes;
3362 } parse_declarator_env_t;
3363
3364 /* §6.7.5 */
3365 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3366 {
3367         /* construct a single linked list of construct_type_t's which describe
3368          * how to construct the final declarator type */
3369         construct_type_t  *first      = NULL;
3370         construct_type_t **anchor     = &first;
3371
3372         env->attributes = parse_attributes(env->attributes);
3373
3374         for (;;) {
3375                 construct_type_t *type;
3376                 //variable_t       *based = NULL; /* MS __based extension */
3377                 switch (token.kind) {
3378                         case '&':
3379                                 type = parse_reference_declarator();
3380                                 break;
3381
3382                         case T__based: {
3383                                 panic("based not supported anymore");
3384                                 /* FALLTHROUGH */
3385                         }
3386
3387                         case '*':
3388                                 type = parse_pointer_declarator();
3389                                 break;
3390
3391                         default:
3392                                 goto ptr_operator_end;
3393                 }
3394
3395                 *anchor = type;
3396                 anchor  = &type->base.next;
3397
3398                 /* TODO: find out if this is correct */
3399                 env->attributes = parse_attributes(env->attributes);
3400         }
3401
3402 ptr_operator_end: ;
3403         construct_type_t *inner_types = NULL;
3404
3405         switch (token.kind) {
3406         case T_IDENTIFIER:
3407                 if (env->must_be_abstract) {
3408                         errorf(HERE, "no identifier expected in typename");
3409                 } else {
3410                         env->symbol = token.base.symbol;
3411                         env->pos    = *HERE;
3412                 }
3413                 eat(T_IDENTIFIER);
3414                 break;
3415
3416         case '(': {
3417                 /* Parenthesized declarator or function declarator? */
3418                 token_t const *const la1 = look_ahead(1);
3419                 switch (la1->kind) {
3420                         case T_IDENTIFIER:
3421                                 if (is_typedef_symbol(la1->base.symbol)) {
3422                         case ')':
3423                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3424                                          * interpreted as ``function with no parameter specification'', rather
3425                                          * than redundant parentheses around the omitted identifier. */
3426                         default:
3427                                         /* Function declarator. */
3428                                         if (!env->may_be_abstract) {
3429                                                 errorf(HERE, "function declarator must have a name");
3430                                         }
3431                                 } else {
3432                         case '&':
3433                         case '(':
3434                         case '*':
3435                         case '[':
3436                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3437                                         /* Paranthesized declarator. */
3438                                         eat('(');
3439                                         add_anchor_token(')');
3440                                         inner_types = parse_inner_declarator(env);
3441                                         if (inner_types != NULL) {
3442                                                 /* All later declarators only modify the return type */
3443                                                 env->must_be_abstract = true;
3444                                         }
3445                                         rem_anchor_token(')');
3446                                         expect(')');
3447                                 }
3448                                 break;
3449                 }
3450                 break;
3451         }
3452
3453         default:
3454                 if (env->may_be_abstract)
3455                         break;
3456                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3457                 eat_until_anchor();
3458                 return NULL;
3459         }
3460
3461         construct_type_t **const p = anchor;
3462
3463         for (;;) {
3464                 construct_type_t *type;
3465                 switch (token.kind) {
3466                 case '(': {
3467                         scope_t *scope = NULL;
3468                         if (!env->must_be_abstract) {
3469                                 scope = &env->parameters;
3470                         }
3471
3472                         type = parse_function_declarator(scope);
3473                         break;
3474                 }
3475                 case '[':
3476                         type = parse_array_declarator();
3477                         break;
3478                 default:
3479                         goto declarator_finished;
3480                 }
3481
3482                 /* insert in the middle of the list (at p) */
3483                 type->base.next = *p;
3484                 *p              = type;
3485                 if (anchor == p)
3486                         anchor = &type->base.next;
3487         }
3488
3489 declarator_finished:
3490         /* append inner_types at the end of the list, we don't to set anchor anymore
3491          * as it's not needed anymore */
3492         *anchor = inner_types;
3493
3494         return first;
3495 }
3496
3497 static type_t *construct_declarator_type(construct_type_t *construct_list,
3498                                          type_t *type)
3499 {
3500         construct_type_t *iter = construct_list;
3501         for (; iter != NULL; iter = iter->base.next) {
3502                 position_t const* const pos = &iter->base.pos;
3503                 switch (iter->kind) {
3504                 case CONSTRUCT_FUNCTION: {
3505                         construct_function_type_t *function      = &iter->function;
3506                         type_t                    *function_type = function->function_type;
3507
3508                         function_type->function.return_type = type;
3509
3510                         type_t *skipped_return_type = skip_typeref(type);
3511                         /* §6.7.5.3:1 */
3512                         if (is_type_function(skipped_return_type)) {
3513                                 errorf(pos, "function returning function is not allowed");
3514                         } else if (is_type_array(skipped_return_type)) {
3515                                 errorf(pos, "function returning array is not allowed");
3516                         } else {
3517                                 if (skipped_return_type->base.qualifiers != 0) {
3518                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3519                                 }
3520                         }
3521
3522                         /* The function type was constructed earlier.  Freeing it here will
3523                          * destroy other types. */
3524                         type = typehash_insert(function_type);
3525                         continue;
3526                 }
3527
3528                 case CONSTRUCT_POINTER: {
3529                         if (is_type_reference(skip_typeref(type)))
3530                                 errorf(pos, "cannot declare a pointer to reference");
3531
3532                         parsed_pointer_t *pointer = &iter->pointer;
3533                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3534                         continue;
3535                 }
3536
3537                 case CONSTRUCT_REFERENCE:
3538                         if (is_type_reference(skip_typeref(type)))
3539                                 errorf(pos, "cannot declare a reference to reference");
3540
3541                         type = make_reference_type(type);
3542                         continue;
3543
3544                 case CONSTRUCT_ARRAY: {
3545                         if (is_type_reference(skip_typeref(type)))
3546                                 errorf(pos, "cannot declare an array of references");
3547
3548                         parsed_array_t *array      = &iter->array;
3549                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3550
3551                         expression_t *size_expression = array->size;
3552                         if (size_expression != NULL) {
3553                                 size_expression
3554                                         = create_implicit_cast(size_expression, type_size_t);
3555                         }
3556
3557                         array_type->base.qualifiers       = array->type_qualifiers;
3558                         array_type->array.element_type    = type;
3559                         array_type->array.is_static       = array->is_static;
3560                         array_type->array.is_variable     = array->is_variable;
3561                         array_type->array.size_expression = size_expression;
3562
3563                         if (size_expression != NULL) {
3564                                 switch (is_constant_expression(size_expression)) {
3565                                 case EXPR_CLASS_CONSTANT: {
3566                                         long const size = fold_constant_to_int(size_expression);
3567                                         array_type->array.size          = size;
3568                                         array_type->array.size_constant = true;
3569                                         /* §6.7.5.2:1  If the expression is a constant expression,
3570                                          * it shall have a value greater than zero. */
3571                                         if (size < 0) {
3572                                                 errorf(&size_expression->base.pos,
3573                                                            "size of array must be greater than zero");
3574                                         } else if (size == 0 && !GNU_MODE) {
3575                                                 errorf(&size_expression->base.pos,
3576                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3577                                         }
3578                                         break;
3579                                 }
3580
3581                                 case EXPR_CLASS_VARIABLE:
3582                                         array_type->array.is_vla = true;
3583                                         break;
3584
3585                                 case EXPR_CLASS_ERROR:
3586                                         break;
3587                                 }
3588                         }
3589
3590                         type_t *skipped_type = skip_typeref(type);
3591                         /* §6.7.5.2:1 */
3592                         if (is_type_incomplete(skipped_type)) {
3593                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3594                         } else if (is_type_function(skipped_type)) {
3595                                 errorf(pos, "array of functions is not allowed");
3596                         }
3597                         type = identify_new_type(array_type);
3598                         continue;
3599                 }
3600                 }
3601                 internal_errorf(pos, "invalid type construction found");
3602         }
3603
3604         return type;
3605 }
3606
3607 static type_t *automatic_type_conversion(type_t *orig_type);
3608
3609 static type_t *semantic_parameter(const position_t *pos, type_t *type,
3610                                   const declaration_specifiers_t *specifiers,
3611                                   entity_t const *const param)
3612 {
3613         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3614          *             shall be adjusted to ``qualified pointer to type'',
3615          *             [...]
3616          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3617          *             type'' shall be adjusted to ``pointer to function
3618          *             returning type'', as in 6.3.2.1. */
3619         type = automatic_type_conversion(type);
3620
3621         if (specifiers->is_inline && is_type_valid(type)) {
3622                 errorf(pos, "'%N' declared 'inline'", param);
3623         }
3624
3625         /* §6.9.1:6  The declarations in the declaration list shall contain
3626          *           no storage-class specifier other than register and no
3627          *           initializations. */
3628         if (specifiers->thread_local || (
3629                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3630                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3631            ) {
3632                 errorf(pos, "invalid storage class for '%N'", param);
3633         }
3634
3635         /* delay test for incomplete type, because we might have (void)
3636          * which is legal but incomplete... */
3637
3638         return type;
3639 }
3640
3641 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3642                                   declarator_flags_t flags)
3643 {
3644         parse_declarator_env_t env;
3645         memset(&env, 0, sizeof(env));
3646         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3647
3648         construct_type_t *construct_type = parse_inner_declarator(&env);
3649         type_t           *orig_type      =
3650                 construct_declarator_type(construct_type, specifiers->type);
3651         type_t           *type           = skip_typeref(orig_type);
3652
3653         if (construct_type != NULL) {
3654                 obstack_free(&temp_obst, construct_type);
3655         }
3656
3657         attribute_t *attributes = parse_attributes(env.attributes);
3658         /* append (shared) specifier attribute behind attributes of this
3659          * declarator */
3660         attribute_t **anchor = &attributes;
3661         while (*anchor != NULL)
3662                 anchor = &(*anchor)->next;
3663         *anchor = specifiers->attributes;
3664
3665         entity_t *entity;
3666         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3667                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.pos);
3668                 entity->typedefe.type = orig_type;
3669
3670                 if (anonymous_entity != NULL) {
3671                         if (is_type_compound(type)) {
3672                                 assert(anonymous_entity->compound.alias == NULL);
3673                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3674                                        anonymous_entity->kind == ENTITY_UNION);
3675                                 anonymous_entity->compound.alias = entity;
3676                                 anonymous_entity = NULL;
3677                         } else if (is_type_enum(type)) {
3678                                 assert(anonymous_entity->enume.alias == NULL);
3679                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3680                                 anonymous_entity->enume.alias = entity;
3681                                 anonymous_entity = NULL;
3682                         }
3683                 }
3684         } else {
3685                 /* create a declaration type entity */
3686                 position_t const *const pos = env.symbol ? &env.pos : &specifiers->pos;
3687                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3688                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3689
3690                         if (env.symbol != NULL) {
3691                                 if (specifiers->is_inline && is_type_valid(type)) {
3692                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3693                                 }
3694
3695                                 if (specifiers->thread_local ||
3696                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3697                                         errorf(&env.pos, "'%N' must have no storage class", entity);
3698                                 }
3699                         }
3700                 } else if (flags & DECL_IS_PARAMETER) {
3701                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3702                         orig_type = semantic_parameter(&env.pos, orig_type, specifiers, entity);
3703                 } else if (is_type_function(type)) {
3704                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3705                         entity->function.is_inline      = specifiers->is_inline;
3706                         entity->function.elf_visibility = default_visibility;
3707                         entity->function.parameters     = env.parameters;
3708
3709                         if (env.symbol != NULL) {
3710                                 /* this needs fixes for C++ */
3711                                 bool in_function_scope = current_function != NULL;
3712
3713                                 if (specifiers->thread_local || (
3714                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3715                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3716                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3717                                                 )) {
3718                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3719                                 }
3720                         }
3721                 } else {
3722                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3723                         entity->variable.elf_visibility = default_visibility;
3724                         entity->variable.thread_local   = specifiers->thread_local;
3725
3726                         if (env.symbol != NULL) {
3727                                 if (specifiers->is_inline && is_type_valid(type)) {
3728                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3729                                 }
3730
3731                                 bool invalid_storage_class = false;
3732                                 if (current_scope == file_scope) {
3733                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3734                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3735                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3736                                                 invalid_storage_class = true;
3737                                         }
3738                                 } else {
3739                                         if (specifiers->thread_local &&
3740                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3741                                                 invalid_storage_class = true;
3742                                         }
3743                                 }
3744                                 if (invalid_storage_class) {
3745                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3746                                 }
3747                         }
3748                 }
3749
3750                 entity->declaration.type       = orig_type;
3751                 entity->declaration.alignment  = get_type_alignment(orig_type);
3752                 entity->declaration.modifiers  = env.modifiers;
3753                 entity->declaration.attributes = attributes;
3754
3755                 storage_class_t storage_class = specifiers->storage_class;
3756                 entity->declaration.declared_storage_class = storage_class;
3757
3758                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3759                         storage_class = STORAGE_CLASS_AUTO;
3760                 entity->declaration.storage_class = storage_class;
3761         }
3762
3763         if (attributes != NULL) {
3764                 handle_entity_attributes(attributes, entity);
3765         }
3766
3767         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3768                 adapt_special_functions(&entity->function);
3769         }
3770
3771         return entity;
3772 }
3773
3774 static type_t *parse_abstract_declarator(type_t *base_type)
3775 {
3776         parse_declarator_env_t env;
3777         memset(&env, 0, sizeof(env));
3778         env.may_be_abstract = true;
3779         env.must_be_abstract = true;
3780
3781         construct_type_t *construct_type = parse_inner_declarator(&env);
3782
3783         type_t *result = construct_declarator_type(construct_type, base_type);
3784         if (construct_type != NULL) {
3785                 obstack_free(&temp_obst, construct_type);
3786         }
3787         result = handle_type_attributes(env.attributes, result);
3788
3789         return result;
3790 }
3791
3792 /**
3793  * Check if the declaration of main is suspicious.  main should be a
3794  * function with external linkage, returning int, taking either zero
3795  * arguments, two, or three arguments of appropriate types, ie.
3796  *
3797  * int main([ int argc, char **argv [, char **env ] ]).
3798  *
3799  * @param decl    the declaration to check
3800  * @param type    the function type of the declaration
3801  */
3802 static void check_main(const entity_t *entity)
3803 {
3804         const position_t *pos = &entity->base.pos;
3805         if (entity->kind != ENTITY_FUNCTION) {
3806                 warningf(WARN_MAIN, pos, "'main' is not a function");
3807                 return;
3808         }
3809
3810         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3811                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3812         }
3813
3814         type_t *type = skip_typeref(entity->declaration.type);
3815         assert(is_type_function(type));
3816
3817         function_type_t const *const func_type = &type->function;
3818         type_t                *const ret_type  = func_type->return_type;
3819         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3820                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3821         }
3822         const function_parameter_t *parm = func_type->parameters;
3823         if (parm != NULL) {
3824                 type_t *const first_type        = skip_typeref(parm->type);
3825                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3826                 if (!types_compatible(first_type_unqual, type_int)) {
3827                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3828                 }
3829                 parm = parm->next;
3830                 if (parm != NULL) {
3831                         type_t *const second_type = skip_typeref(parm->type);
3832                         type_t *const second_type_unqual
3833                                 = get_unqualified_type(second_type);
3834                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3835                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3836                         }
3837                         parm = parm->next;
3838                         if (parm != NULL) {
3839                                 type_t *const third_type = skip_typeref(parm->type);
3840                                 type_t *const third_type_unqual
3841                                         = get_unqualified_type(third_type);
3842                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3843                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3844                                 }
3845                                 parm = parm->next;
3846                                 if (parm != NULL)
3847                                         goto warn_arg_count;
3848                         }
3849                 } else {
3850 warn_arg_count:
3851                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3852                 }
3853         }
3854 }
3855
3856 static void error_redefined_as_different_kind(const position_t *pos,
3857                 const entity_t *old, entity_kind_t new_kind)
3858 {
3859         char       const *const what = get_entity_kind_name(new_kind);
3860         position_t const *const ppos = &old->base.pos;
3861         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3862 }
3863
3864 static bool is_entity_valid(entity_t *const ent)
3865 {
3866         if (is_declaration(ent)) {
3867                 return is_type_valid(skip_typeref(ent->declaration.type));
3868         } else if (ent->kind == ENTITY_TYPEDEF) {
3869                 return is_type_valid(skip_typeref(ent->typedefe.type));
3870         }
3871         return true;
3872 }
3873
3874 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3875 {
3876         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3877                 if (attributes_equal(tattr, attr))
3878                         return true;
3879         }
3880         return false;
3881 }
3882
3883 /**
3884  * Tests whether new_list contains any attributes not included in old_list
3885  */
3886 static bool has_new_attributes(const attribute_t *old_list,
3887                                const attribute_t *new_list)
3888 {
3889         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3890                 if (!contains_attribute(old_list, attr))
3891                         return true;
3892         }
3893         return false;
3894 }
3895
3896 /**
3897  * Merge in attributes from an attribute list (probably from a previous
3898  * declaration with the same name). Warning: destroys the old structure
3899  * of the attribute list - don't reuse attributes after this call.
3900  */
3901 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3902 {
3903         attribute_t *next;
3904         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3905                 next = attr->next;
3906                 if (contains_attribute(decl->attributes, attr))
3907                         continue;
3908
3909                 /* move attribute to new declarations attributes list */
3910                 attr->next       = decl->attributes;
3911                 decl->attributes = attr;
3912         }
3913 }
3914
3915 static bool is_main(entity_t*);
3916
3917 /**
3918  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3919  * for various problems that occur for multiple definitions
3920  */
3921 entity_t *record_entity(entity_t *entity, const bool is_definition)
3922 {
3923         const symbol_t *const symbol  = entity->base.symbol;
3924         const namespace_tag_t namespc = (namespace_tag_t)entity->base.namespc;
3925         const position_t     *pos     = &entity->base.pos;
3926
3927         /* can happen in error cases */
3928         if (symbol == NULL)
3929                 return entity;
3930
3931         assert(!entity->base.parent_scope);
3932         assert(current_scope);
3933         entity->base.parent_scope = current_scope;
3934
3935         entity_t *const previous_entity = get_entity(symbol, namespc);
3936         /* pushing the same entity twice will break the stack structure */
3937         assert(previous_entity != entity);
3938
3939         if (entity->kind == ENTITY_FUNCTION) {
3940                 type_t *const orig_type = entity->declaration.type;
3941                 type_t *const type      = skip_typeref(orig_type);
3942
3943                 assert(is_type_function(type));
3944                 if (type->function.unspecified_parameters &&
3945                     previous_entity == NULL               &&
3946                     !entity->declaration.implicit) {
3947                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3948                 }
3949
3950                 if (is_main(entity)) {
3951                         check_main(entity);
3952                 }
3953         }
3954
3955         if (is_declaration(entity)                                    &&
3956             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3957             current_scope != file_scope                               &&
3958             !entity->declaration.implicit) {
3959                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3960         }
3961
3962         if (previous_entity != NULL) {
3963                 position_t const *const ppos = &previous_entity->base.pos;
3964
3965                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3966                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3967                         assert(previous_entity->kind == ENTITY_PARAMETER);
3968                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3969                         goto finish;
3970                 }
3971
3972                 if (previous_entity->base.parent_scope == current_scope) {
3973                         if (previous_entity->kind != entity->kind) {
3974                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3975                                         error_redefined_as_different_kind(pos, previous_entity,
3976                                                         entity->kind);
3977                                 }
3978                                 goto finish;
3979                         }
3980                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3981                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3982                                 goto finish;
3983                         }
3984                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3985                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3986                                 type_t *const prev_type
3987                                         = skip_typeref(previous_entity->typedefe.type);
3988                                 if (c_mode & _CXX) {
3989                                         /* C++ allows double typedef if they are identical
3990                                          * (after skipping typedefs) */
3991                                         if (type == prev_type)
3992                                                 goto finish;
3993                                 } else {
3994                                         /* GCC extension: redef in system headers is allowed */
3995                                         if ((pos->is_system_header || ppos->is_system_header) &&
3996                                             types_compatible(type, prev_type))
3997                                                 goto finish;
3998                                 }
3999                                 errorf(pos, "redefinition of '%N' (declared %P)",
4000                                        entity, ppos);
4001                                 goto finish;
4002                         }
4003
4004                         /* at this point we should have only VARIABLES or FUNCTIONS */
4005                         assert(is_declaration(previous_entity) && is_declaration(entity));
4006
4007                         declaration_t *const prev_decl = &previous_entity->declaration;
4008                         declaration_t *const decl      = &entity->declaration;
4009
4010                         /* can happen for K&R style declarations */
4011                         if (prev_decl->type       == NULL             &&
4012                                         previous_entity->kind == ENTITY_PARAMETER &&
4013                                         entity->kind          == ENTITY_PARAMETER) {
4014                                 prev_decl->type                   = decl->type;
4015                                 prev_decl->storage_class          = decl->storage_class;
4016                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4017                                 prev_decl->modifiers              = decl->modifiers;
4018                                 return previous_entity;
4019                         }
4020
4021                         type_t *const type      = skip_typeref(decl->type);
4022                         type_t *const prev_type = skip_typeref(prev_decl->type);
4023
4024                         if (!types_compatible(type, prev_type)) {
4025                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4026                         } else {
4027                                 unsigned old_storage_class = prev_decl->storage_class;
4028
4029                                 if (is_definition                     &&
4030                                                 !prev_decl->used                  &&
4031                                                 !(prev_decl->modifiers & DM_USED) &&
4032                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4033                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4034                                 }
4035
4036                                 storage_class_t new_storage_class = decl->storage_class;
4037
4038                                 /* pretend no storage class means extern for function
4039                                  * declarations (except if the previous declaration is neither
4040                                  * none nor extern) */
4041                                 if (entity->kind == ENTITY_FUNCTION) {
4042                                         /* the previous declaration could have unspecified parameters or
4043                                          * be a typedef, so use the new type */
4044                                         if (prev_type->function.unspecified_parameters || is_definition)
4045                                                 prev_decl->type = type;
4046
4047                                         switch (old_storage_class) {
4048                                                 case STORAGE_CLASS_NONE:
4049                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4050                                                         /* FALLTHROUGH */
4051
4052                                                 case STORAGE_CLASS_EXTERN:
4053                                                         if (is_definition) {
4054                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4055                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4056                                                                 }
4057                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4058                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4059                                                         }
4060                                                         break;
4061
4062                                                 default:
4063                                                         break;
4064                                         }
4065                                 } else if (is_type_incomplete(prev_type)) {
4066                                         prev_decl->type = type;
4067                                 }
4068
4069                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4070                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4071
4072 warn_redundant_declaration: ;
4073                                         bool has_new_attrs
4074                                                 = has_new_attributes(prev_decl->attributes,
4075                                                                      decl->attributes);
4076                                         if (has_new_attrs) {
4077                                                 merge_in_attributes(decl, prev_decl->attributes);
4078                                         } else if (!is_definition        &&
4079                                                         is_type_valid(prev_type) &&
4080                                                         !pos->is_system_header) {
4081                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4082                                         }
4083                                 } else if (current_function == NULL) {
4084                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4085                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4086                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4087                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4088                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4089                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4090                                         } else {
4091                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4092                                                 if (c_mode & _CXX)
4093                                                         goto error_redeclaration;
4094                                                 goto warn_redundant_declaration;
4095                                         }
4096                                 } else if (is_type_valid(prev_type)) {
4097                                         if (old_storage_class == new_storage_class) {
4098 error_redeclaration:
4099                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4100                                         } else {
4101                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4102                                         }
4103                                 }
4104                         }
4105
4106                         prev_decl->modifiers |= decl->modifiers;
4107                         if (entity->kind == ENTITY_FUNCTION) {
4108                                 previous_entity->function.is_inline |= entity->function.is_inline;
4109                         }
4110                         return previous_entity;
4111                 }
4112
4113                 warning_t why;
4114                 if (is_warn_on(why = WARN_SHADOW) ||
4115                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4116                         char const *const what = get_entity_kind_name(previous_entity->kind);
4117                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4118                 }
4119         }
4120
4121         if (entity->kind == ENTITY_FUNCTION) {
4122                 if (is_definition &&
4123                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4124                                 !is_main(entity)) {
4125                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4126                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4127                         } else {
4128                                 goto warn_missing_declaration;
4129                         }
4130                 }
4131         } else if (entity->kind == ENTITY_VARIABLE) {
4132                 if (current_scope                     == file_scope &&
4133                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4134                                 !entity->declaration.implicit) {
4135 warn_missing_declaration:
4136                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4137                 }
4138         }
4139
4140 finish:
4141         environment_push(entity);
4142         append_entity(current_scope, entity);
4143
4144         return entity;
4145 }
4146
4147 static void parser_error_multiple_definition(entity_t *entity,
4148                                              const position_t *pos)
4149 {
4150         errorf(pos, "redefinition of '%N' (declared %P)", entity, &entity->base.pos);
4151 }
4152
4153 static bool is_declaration_specifier(const token_t *token)
4154 {
4155         switch (token->kind) {
4156                 DECLARATION_START
4157                         return true;
4158                 case T_IDENTIFIER:
4159                         return is_typedef_symbol(token->base.symbol);
4160
4161                 default:
4162                         return false;
4163         }
4164 }
4165
4166 static void parse_init_declarator_rest(entity_t *entity)
4167 {
4168         type_t *orig_type = type_error_type;
4169
4170         if (entity->base.kind == ENTITY_TYPEDEF) {
4171                 position_t const *const pos = &entity->base.pos;
4172                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4173         } else {
4174                 assert(is_declaration(entity));
4175                 orig_type = entity->declaration.type;
4176         }
4177
4178         type_t *type = skip_typeref(orig_type);
4179
4180         if (entity->kind == ENTITY_VARIABLE
4181                         && entity->variable.initializer != NULL) {
4182                 parser_error_multiple_definition(entity, HERE);
4183         }
4184         eat('=');
4185
4186         declaration_t *const declaration = &entity->declaration;
4187         bool must_be_constant = false;
4188         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4189             entity->base.parent_scope  == file_scope) {
4190                 must_be_constant = true;
4191         }
4192
4193         if (is_type_function(type)) {
4194                 position_t const *const pos = &entity->base.pos;
4195                 errorf(pos, "'%N' is initialized like a variable", entity);
4196                 orig_type = type_error_type;
4197         }
4198
4199         parse_initializer_env_t env;
4200         env.type             = orig_type;
4201         env.must_be_constant = must_be_constant;
4202         env.entity           = entity;
4203
4204         initializer_t *initializer = parse_initializer(&env);
4205
4206         if (entity->kind == ENTITY_VARIABLE) {
4207                 /* §6.7.5:22  array initializers for arrays with unknown size
4208                  * determine the array type size */
4209                 declaration->type            = env.type;
4210                 entity->variable.initializer = initializer;
4211         }
4212 }
4213
4214 /* parse rest of a declaration without any declarator */
4215 static void parse_anonymous_declaration_rest(
4216                 const declaration_specifiers_t *specifiers)
4217 {
4218         eat(';');
4219         anonymous_entity = NULL;
4220
4221         position_t const *const pos = &specifiers->pos;
4222         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4223                         specifiers->thread_local) {
4224                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4225         }
4226
4227         type_t *type = specifiers->type;
4228         switch (type->kind) {
4229                 case TYPE_COMPOUND_STRUCT:
4230                 case TYPE_COMPOUND_UNION: {
4231                         if (type->compound.compound->base.symbol == NULL) {
4232                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4233                         }
4234                         break;
4235                 }
4236
4237                 case TYPE_ENUM:
4238                         break;
4239
4240                 default:
4241                         warningf(WARN_OTHER, pos, "empty declaration");
4242                         break;
4243         }
4244 }
4245
4246 static void check_variable_type_complete(entity_t *ent)
4247 {
4248         if (ent->kind != ENTITY_VARIABLE)
4249                 return;
4250
4251         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4252          *         type for the object shall be complete [...] */
4253         declaration_t *decl = &ent->declaration;
4254         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4255                         decl->storage_class == STORAGE_CLASS_STATIC)
4256                 return;
4257
4258         type_t *const type = skip_typeref(decl->type);
4259         if (!is_type_incomplete(type))
4260                 return;
4261
4262         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4263          * are given length one. */
4264         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4265                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4266                 return;
4267         }
4268
4269         errorf(&ent->base.pos, "variable '%#N' has incomplete type", ent);
4270 }
4271
4272
4273 static void parse_declaration_rest(entity_t *ndeclaration,
4274                 const declaration_specifiers_t *specifiers,
4275                 parsed_declaration_func         finished_declaration,
4276                 declarator_flags_t              flags)
4277 {
4278         add_anchor_token(';');
4279         add_anchor_token(',');
4280         while (true) {
4281                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4282
4283                 if (token.kind == '=') {
4284                         parse_init_declarator_rest(entity);
4285                 } else if (entity->kind == ENTITY_VARIABLE) {
4286                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4287                          * [...] where the extern specifier is explicitly used. */
4288                         declaration_t *decl = &entity->declaration;
4289                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4290                             is_type_reference(skip_typeref(decl->type))) {
4291                                 position_t const *const pos = &entity->base.pos;
4292                                 errorf(pos, "reference '%#N' must be initialized", entity);
4293                         }
4294                 }
4295
4296                 check_variable_type_complete(entity);
4297
4298                 if (!accept(','))
4299                         break;
4300
4301                 add_anchor_token('=');
4302                 ndeclaration = parse_declarator(specifiers, flags);
4303                 rem_anchor_token('=');
4304         }
4305         rem_anchor_token(',');
4306         rem_anchor_token(';');
4307         expect(';');
4308
4309         anonymous_entity = NULL;
4310 }
4311
4312 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4313 {
4314         symbol_t *symbol = entity->base.symbol;
4315         if (symbol == NULL)
4316                 return entity;
4317
4318         assert(entity->base.namespc == NAMESPACE_NORMAL);
4319         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4320         if (previous_entity == NULL
4321                         || previous_entity->base.parent_scope != current_scope) {
4322                 errorf(&entity->base.pos, "expected declaration of a function parameter, found '%Y'",
4323                        symbol);
4324                 return entity;
4325         }
4326
4327         if (is_definition) {
4328                 errorf(HERE, "'%N' is initialised", entity);
4329         }
4330
4331         return record_entity(entity, false);
4332 }
4333
4334 static void parse_declaration(parsed_declaration_func finished_declaration,
4335                               declarator_flags_t      flags)
4336 {
4337         add_anchor_token(';');
4338         declaration_specifiers_t specifiers;
4339         parse_declaration_specifiers(&specifiers);
4340         rem_anchor_token(';');
4341
4342         if (token.kind == ';') {
4343                 parse_anonymous_declaration_rest(&specifiers);
4344         } else {
4345                 entity_t *entity = parse_declarator(&specifiers, flags);
4346                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4347         }
4348 }
4349
4350 /* §6.5.2.2:6 */
4351 static type_t *get_default_promoted_type(type_t *orig_type)
4352 {
4353         type_t *result = orig_type;
4354
4355         type_t *type = skip_typeref(orig_type);
4356         if (is_type_integer(type)) {
4357                 result = promote_integer(type);
4358         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4359                 result = type_double;
4360         }
4361
4362         return result;
4363 }
4364
4365 static void parse_kr_declaration_list(entity_t *entity)
4366 {
4367         if (entity->kind != ENTITY_FUNCTION)
4368                 return;
4369
4370         type_t *type = skip_typeref(entity->declaration.type);
4371         assert(is_type_function(type));
4372         if (!type->function.kr_style_parameters)
4373                 return;
4374
4375         add_anchor_token('{');
4376
4377         PUSH_SCOPE(&entity->function.parameters);
4378
4379         entity_t *parameter = entity->function.parameters.entities;
4380         for ( ; parameter != NULL; parameter = parameter->base.next) {
4381                 assert(parameter->base.parent_scope == NULL);
4382                 parameter->base.parent_scope = current_scope;
4383                 environment_push(parameter);
4384         }
4385
4386         /* parse declaration list */
4387         for (;;) {
4388                 switch (token.kind) {
4389                         DECLARATION_START
4390                         /* This covers symbols, which are no type, too, and results in
4391                          * better error messages.  The typical cases are misspelled type
4392                          * names and missing includes. */
4393                         case T_IDENTIFIER:
4394                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4395                                 break;
4396                         default:
4397                                 goto decl_list_end;
4398                 }
4399         }
4400 decl_list_end:
4401
4402         POP_SCOPE();
4403
4404         /* update function type */
4405         type_t *new_type = duplicate_type(type);
4406
4407         function_parameter_t  *parameters = NULL;
4408         function_parameter_t **anchor     = &parameters;
4409
4410         /* did we have an earlier prototype? */
4411         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4412         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4413                 proto_type = NULL;
4414
4415         function_parameter_t *proto_parameter = NULL;
4416         if (proto_type != NULL) {
4417                 type_t *proto_type_type = proto_type->declaration.type;
4418                 proto_parameter         = proto_type_type->function.parameters;
4419                 /* If a K&R function definition has a variadic prototype earlier, then
4420                  * make the function definition variadic, too. This should conform to
4421                  * §6.7.5.3:15 and §6.9.1:8. */
4422                 new_type->function.variadic = proto_type_type->function.variadic;
4423         } else {
4424                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4425                  * prototype */
4426                 new_type->function.unspecified_parameters = true;
4427         }
4428
4429         bool need_incompatible_warning = false;
4430         parameter = entity->function.parameters.entities;
4431         for (; parameter != NULL; parameter = parameter->base.next,
4432                         proto_parameter =
4433                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4434                 if (parameter->kind != ENTITY_PARAMETER)
4435                         continue;
4436
4437                 type_t *parameter_type = parameter->declaration.type;
4438                 if (parameter_type == NULL) {
4439                         position_t const* const pos = &parameter->base.pos;
4440                         if (strict_mode) {
4441                                 errorf(pos, "no type specified for function '%N'", parameter);
4442                                 parameter_type = type_error_type;
4443                         } else {
4444                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4445                                 parameter_type = type_int;
4446                         }
4447                         parameter->declaration.type = parameter_type;
4448                 }
4449
4450                 semantic_parameter_incomplete(parameter);
4451
4452                 /* we need the default promoted types for the function type */
4453                 type_t *not_promoted = parameter_type;
4454                 parameter_type       = get_default_promoted_type(parameter_type);
4455
4456                 /* gcc special: if the type of the prototype matches the unpromoted
4457                  * type don't promote */
4458                 if (!strict_mode && proto_parameter != NULL) {
4459                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4460                         type_t *promo_skip   = skip_typeref(parameter_type);
4461                         type_t *param_skip   = skip_typeref(not_promoted);
4462                         if (!types_compatible(proto_p_type, promo_skip)
4463                                 && types_compatible(proto_p_type, param_skip)) {
4464                                 /* don't promote */
4465                                 need_incompatible_warning = true;
4466                                 parameter_type = not_promoted;
4467                         }
4468                 }
4469                 function_parameter_t *const function_parameter
4470                         = allocate_parameter(parameter_type);
4471
4472                 *anchor = function_parameter;
4473                 anchor  = &function_parameter->next;
4474         }
4475
4476         new_type->function.parameters = parameters;
4477         new_type = identify_new_type(new_type);
4478
4479         if (need_incompatible_warning) {
4480                 symbol_t   const *const sym  = entity->base.symbol;
4481                 position_t const *const pos  = &entity->base.pos;
4482                 position_t const *const ppos = &proto_type->base.pos;
4483                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4484         }
4485         entity->declaration.type = new_type;
4486
4487         rem_anchor_token('{');
4488 }
4489
4490 static bool first_err = true;
4491
4492 /**
4493  * When called with first_err set, prints the name of the current function,
4494  * else does noting.
4495  */
4496 static void print_in_function(void)
4497 {
4498         if (first_err) {
4499                 first_err = false;
4500                 char const *const file = current_function->base.base.pos.input_name;
4501                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4502         }
4503 }
4504
4505 /**
4506  * Check if all labels are defined in the current function.
4507  * Check if all labels are used in the current function.
4508  */
4509 static void check_labels(void)
4510 {
4511         for (const goto_statement_t *goto_statement = goto_first;
4512             goto_statement != NULL;
4513             goto_statement = goto_statement->next) {
4514                 label_t *label = goto_statement->label;
4515                 if (label->base.pos.input_name == NULL) {
4516                         print_in_function();
4517                         position_t const *const pos = &goto_statement->base.pos;
4518                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4519                  }
4520         }
4521
4522         if (is_warn_on(WARN_UNUSED_LABEL)) {
4523                 for (const label_statement_t *label_statement = label_first;
4524                          label_statement != NULL;
4525                          label_statement = label_statement->next) {
4526                         label_t *label = label_statement->label;
4527
4528                         if (! label->used) {
4529                                 print_in_function();
4530                                 position_t const *const pos = &label_statement->base.pos;
4531                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4532                         }
4533                 }
4534         }
4535 }
4536
4537 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4538 {
4539         entity_t const *const end = last != NULL ? last->base.next : NULL;
4540         for (; entity != end; entity = entity->base.next) {
4541                 if (!is_declaration(entity))
4542                         continue;
4543
4544                 declaration_t *declaration = &entity->declaration;
4545                 if (declaration->implicit)
4546                         continue;
4547
4548                 if (!declaration->used) {
4549                         print_in_function();
4550                         warningf(why, &entity->base.pos, "'%N' is unused", entity);
4551                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4552                         print_in_function();
4553                         warningf(why, &entity->base.pos, "'%N' is never read", entity);
4554                 }
4555         }
4556 }
4557
4558 static void check_unused_variables(statement_t *const stmt, void *const env)
4559 {
4560         (void)env;
4561
4562         switch (stmt->kind) {
4563                 case STATEMENT_DECLARATION: {
4564                         declaration_statement_t const *const decls = &stmt->declaration;
4565                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4566                         return;
4567                 }
4568
4569                 case STATEMENT_FOR:
4570                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4571                         return;
4572
4573                 default:
4574                         return;
4575         }
4576 }
4577
4578 /**
4579  * Check declarations of current_function for unused entities.
4580  */
4581 static void check_declarations(void)
4582 {
4583         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4584                 const scope_t *scope = &current_function->parameters;
4585                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4586         }
4587         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4588                 walk_statements(current_function->body, check_unused_variables, NULL);
4589         }
4590 }
4591
4592 static int determine_truth(expression_t const* const cond)
4593 {
4594         return
4595                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4596                 fold_constant_to_bool(cond)                         ? 1 :
4597                 -1;
4598 }
4599
4600 static void check_reachable(statement_t *);
4601 static bool reaches_end;
4602
4603 static bool expression_returns(expression_t const *const expr)
4604 {
4605         switch (expr->kind) {
4606                 case EXPR_CALL: {
4607                         expression_t const *const func = expr->call.function;
4608                         type_t       const *const type = skip_typeref(func->base.type);
4609                         if (type->kind == TYPE_POINTER) {
4610                                 type_t const *const points_to
4611                                         = skip_typeref(type->pointer.points_to);
4612                                 if (points_to->kind == TYPE_FUNCTION
4613                                     && points_to->function.modifiers & DM_NORETURN)
4614                                         return false;
4615                         }
4616
4617                         if (!expression_returns(func))
4618                                 return false;
4619
4620                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4621                                 if (!expression_returns(arg->expression))
4622                                         return false;
4623                         }
4624
4625                         return true;
4626                 }
4627
4628                 case EXPR_REFERENCE:
4629                 case EXPR_ENUM_CONSTANT:
4630                 case EXPR_LITERAL_CASES:
4631                 case EXPR_LITERAL_CHARACTER:
4632                 case EXPR_STRING_LITERAL:
4633                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4634                 case EXPR_LABEL_ADDRESS:
4635                 case EXPR_CLASSIFY_TYPE:
4636                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4637                 case EXPR_ALIGNOF:
4638                 case EXPR_FUNCNAME:
4639                 case EXPR_BUILTIN_CONSTANT_P:
4640                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4641                 case EXPR_OFFSETOF:
4642                 case EXPR_ERROR:
4643                         return true;
4644
4645                 case EXPR_STATEMENT: {
4646                         bool old_reaches_end = reaches_end;
4647                         reaches_end = false;
4648                         check_reachable(expr->statement.statement);
4649                         bool returns = reaches_end;
4650                         reaches_end = old_reaches_end;
4651                         return returns;
4652                 }
4653
4654                 case EXPR_CONDITIONAL:
4655                         // TODO handle constant expression
4656
4657                         if (!expression_returns(expr->conditional.condition))
4658                                 return false;
4659
4660                         if (expr->conditional.true_expression != NULL
4661                                         && expression_returns(expr->conditional.true_expression))
4662                                 return true;
4663
4664                         return expression_returns(expr->conditional.false_expression);
4665
4666                 case EXPR_SELECT:
4667                         return expression_returns(expr->select.compound);
4668
4669                 case EXPR_ARRAY_ACCESS:
4670                         return
4671                                 expression_returns(expr->array_access.array_ref) &&
4672                                 expression_returns(expr->array_access.index);
4673
4674                 case EXPR_VA_START:
4675                         return expression_returns(expr->va_starte.ap);
4676
4677                 case EXPR_VA_ARG:
4678                         return expression_returns(expr->va_arge.ap);
4679
4680                 case EXPR_VA_COPY:
4681                         return expression_returns(expr->va_copye.src);
4682
4683                 case EXPR_UNARY_CASES_MANDATORY:
4684                         return expression_returns(expr->unary.value);
4685
4686                 case EXPR_UNARY_THROW:
4687                         return false;
4688
4689                 case EXPR_BINARY_CASES:
4690                         // TODO handle constant lhs of && and ||
4691                         return
4692                                 expression_returns(expr->binary.left) &&
4693                                 expression_returns(expr->binary.right);
4694         }
4695
4696         panic("unhandled expression");
4697 }
4698
4699 static bool initializer_returns(initializer_t const *const init)
4700 {
4701         switch (init->kind) {
4702                 case INITIALIZER_VALUE:
4703                         return expression_returns(init->value.value);
4704
4705                 case INITIALIZER_LIST: {
4706                         initializer_t * const*       i       = init->list.initializers;
4707                         initializer_t * const* const end     = i + init->list.len;
4708                         bool                         returns = true;
4709                         for (; i != end; ++i) {
4710                                 if (!initializer_returns(*i))
4711                                         returns = false;
4712                         }
4713                         return returns;
4714                 }
4715
4716                 case INITIALIZER_STRING:
4717                 case INITIALIZER_DESIGNATOR: // designators have no payload
4718                         return true;
4719         }
4720         panic("unhandled initializer");
4721 }
4722
4723 static bool noreturn_candidate;
4724
4725 static void check_reachable(statement_t *const stmt)
4726 {
4727         if (stmt->base.reachable)
4728                 return;
4729         if (stmt->kind != STATEMENT_DO_WHILE)
4730                 stmt->base.reachable = true;
4731
4732         statement_t *last = stmt;
4733         statement_t *next;
4734         switch (stmt->kind) {
4735                 case STATEMENT_ERROR:
4736                 case STATEMENT_EMPTY:
4737                 case STATEMENT_ASM:
4738                         next = stmt->base.next;
4739                         break;
4740
4741                 case STATEMENT_DECLARATION: {
4742                         declaration_statement_t const *const decl = &stmt->declaration;
4743                         entity_t                const *      ent  = decl->declarations_begin;
4744                         entity_t                const *const last_decl = decl->declarations_end;
4745                         if (ent != NULL) {
4746                                 for (;; ent = ent->base.next) {
4747                                         if (ent->kind                 == ENTITY_VARIABLE &&
4748                                             ent->variable.initializer != NULL            &&
4749                                             !initializer_returns(ent->variable.initializer)) {
4750                                                 return;
4751                                         }
4752                                         if (ent == last_decl)
4753                                                 break;
4754                                 }
4755                         }
4756                         next = stmt->base.next;
4757                         break;
4758                 }
4759
4760                 case STATEMENT_COMPOUND:
4761                         next = stmt->compound.statements;
4762                         if (next == NULL)
4763                                 next = stmt->base.next;
4764                         break;
4765
4766                 case STATEMENT_RETURN: {
4767                         expression_t const *const val = stmt->returns.value;
4768                         if (val == NULL || expression_returns(val))
4769                                 noreturn_candidate = false;
4770                         return;
4771                 }
4772
4773                 case STATEMENT_IF: {
4774                         if_statement_t const *const ifs  = &stmt->ifs;
4775                         expression_t   const *const cond = ifs->condition;
4776
4777                         if (!expression_returns(cond))
4778                                 return;
4779
4780                         int const val = determine_truth(cond);
4781
4782                         if (val >= 0)
4783                                 check_reachable(ifs->true_statement);
4784
4785                         if (val > 0)
4786                                 return;
4787
4788                         if (ifs->false_statement != NULL) {
4789                                 check_reachable(ifs->false_statement);
4790                                 return;
4791                         }
4792
4793                         next = stmt->base.next;
4794                         break;
4795                 }
4796
4797                 case STATEMENT_SWITCH: {
4798                         switch_statement_t const *const switchs = &stmt->switchs;
4799                         expression_t       const *const expr    = switchs->expression;
4800
4801                         if (!expression_returns(expr))
4802                                 return;
4803
4804                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4805                                 ir_tarval              *const val      = fold_constant_to_tarval(expr);
4806                                 case_label_statement_t *      defaults = NULL;
4807                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4808                                         if (i->expression == NULL) {
4809                                                 defaults = i;
4810                                                 continue;
4811                                         }
4812
4813                                         if (i->first_case == val || i->last_case == val ||
4814                                                 ((tarval_cmp(i->first_case, val) & ir_relation_less_equal)
4815                                             && (tarval_cmp(val, i->last_case) & ir_relation_less_equal))) {
4816                                                 check_reachable((statement_t*)i);
4817                                                 return;
4818                                         }
4819                                 }
4820
4821                                 if (defaults != NULL) {
4822                                         check_reachable((statement_t*)defaults);
4823                                         return;
4824                                 }
4825                         } else {
4826                                 bool has_default = false;
4827                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4828                                         if (i->expression == NULL)
4829                                                 has_default = true;
4830
4831                                         check_reachable((statement_t*)i);
4832                                 }
4833
4834                                 if (has_default)
4835                                         return;
4836                         }
4837
4838                         next = stmt->base.next;
4839                         break;
4840                 }
4841
4842                 case STATEMENT_EXPRESSION: {
4843                         /* Check for noreturn function call */
4844                         expression_t const *const expr = stmt->expression.expression;
4845                         if (!expression_returns(expr))
4846                                 return;
4847
4848                         next = stmt->base.next;
4849                         break;
4850                 }
4851
4852                 case STATEMENT_CONTINUE:
4853                         for (statement_t *parent = stmt;;) {
4854                                 parent = parent->base.parent;
4855                                 if (parent == NULL) /* continue not within loop */
4856                                         return;
4857
4858                                 next = parent;
4859                                 switch (parent->kind) {
4860                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4861                                         case STATEMENT_FOR:      goto continue_for;
4862
4863                                         default: break;
4864                                 }
4865                         }
4866
4867                 case STATEMENT_BREAK:
4868                         for (statement_t *parent = stmt;;) {
4869                                 parent = parent->base.parent;
4870                                 if (parent == NULL) /* break not within loop/switch */
4871                                         return;
4872
4873                                 switch (parent->kind) {
4874                                         case STATEMENT_SWITCH:
4875                                         case STATEMENT_DO_WHILE:
4876                                         case STATEMENT_FOR:
4877                                                 last = parent;
4878                                                 next = parent->base.next;
4879                                                 goto found_break_parent;
4880
4881                                         default: break;
4882                                 }
4883                         }
4884 found_break_parent:
4885                         break;
4886
4887                 case STATEMENT_COMPUTED_GOTO: {
4888                         if (!expression_returns(stmt->computed_goto.expression))
4889                                 return;
4890
4891                         statement_t *parent = stmt->base.parent;
4892                         if (parent == NULL) /* top level goto */
4893                                 return;
4894                         next = parent;
4895                         break;
4896                 }
4897
4898                 case STATEMENT_GOTO:
4899                         next = stmt->gotos.label->statement;
4900                         if (next == NULL) /* missing label */
4901                                 return;
4902                         break;
4903
4904                 case STATEMENT_LABEL:
4905                         next = stmt->label.statement;
4906                         break;
4907
4908                 case STATEMENT_CASE_LABEL:
4909                         next = stmt->case_label.statement;
4910                         break;
4911
4912                 case STATEMENT_DO_WHILE:
4913                         next = stmt->do_while.body;
4914                         break;
4915
4916                 case STATEMENT_FOR: {
4917                         for_statement_t *const fors = &stmt->fors;
4918
4919                         if (fors->condition_reachable)
4920                                 return;
4921                         fors->condition_reachable = true;
4922
4923                         expression_t const *const cond = fors->condition;
4924
4925                         int val;
4926                         if (cond == NULL) {
4927                                 val = 1;
4928                         } else if (expression_returns(cond)) {
4929                                 val = determine_truth(cond);
4930                         } else {
4931                                 return;
4932                         }
4933
4934                         if (val >= 0)
4935                                 check_reachable(fors->body);
4936
4937                         if (val > 0)
4938                                 return;
4939
4940                         next = stmt->base.next;
4941                         break;
4942                 }
4943
4944                 case STATEMENT_MS_TRY: {
4945                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4946                         check_reachable(ms_try->try_statement);
4947                         next = ms_try->final_statement;
4948                         break;
4949                 }
4950
4951                 case STATEMENT_LEAVE: {
4952                         statement_t *parent = stmt;
4953                         for (;;) {
4954                                 parent = parent->base.parent;
4955                                 if (parent == NULL) /* __leave not within __try */
4956                                         return;
4957
4958                                 if (parent->kind == STATEMENT_MS_TRY) {
4959                                         last = parent;
4960                                         next = parent->ms_try.final_statement;
4961                                         break;
4962                                 }
4963                         }
4964                         break;
4965                 }
4966
4967                 default:
4968                         panic("invalid statement kind");
4969         }
4970
4971         while (next == NULL) {
4972                 next = last->base.parent;
4973                 if (next == NULL) {
4974                         noreturn_candidate = false;
4975
4976                         type_t *const type = skip_typeref(current_function->base.type);
4977                         assert(is_type_function(type));
4978                         type_t *const ret  = skip_typeref(type->function.return_type);
4979                         if (!is_type_void(ret) &&
4980                             is_type_valid(ret) &&
4981                             !is_main(current_entity)) {
4982                                 position_t const *const pos = &stmt->base.pos;
4983                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4984                         }
4985                         return;
4986                 }
4987
4988                 switch (next->kind) {
4989                         case STATEMENT_ERROR:
4990                         case STATEMENT_EMPTY:
4991                         case STATEMENT_DECLARATION:
4992                         case STATEMENT_EXPRESSION:
4993                         case STATEMENT_ASM:
4994                         case STATEMENT_RETURN:
4995                         case STATEMENT_CONTINUE:
4996                         case STATEMENT_BREAK:
4997                         case STATEMENT_COMPUTED_GOTO:
4998                         case STATEMENT_GOTO:
4999                         case STATEMENT_LEAVE:
5000                                 panic("invalid control flow in function");
5001
5002                         case STATEMENT_COMPOUND:
5003                                 if (next->compound.stmt_expr) {
5004                                         reaches_end = true;
5005                                         return;
5006                                 }
5007                                 /* FALLTHROUGH */
5008                         case STATEMENT_IF:
5009                         case STATEMENT_SWITCH:
5010                         case STATEMENT_LABEL:
5011                         case STATEMENT_CASE_LABEL:
5012                                 last = next;
5013                                 next = next->base.next;
5014                                 break;
5015
5016                         case STATEMENT_DO_WHILE: {
5017 continue_do_while:
5018                                 if (next->base.reachable)
5019                                         return;
5020                                 next->base.reachable = true;
5021
5022                                 do_while_statement_t const *const dw   = &next->do_while;
5023                                 expression_t         const *const cond = dw->condition;
5024
5025                                 if (!expression_returns(cond))
5026                                         return;
5027
5028                                 int const val = determine_truth(cond);
5029
5030                                 if (val >= 0)
5031                                         check_reachable(dw->body);
5032
5033                                 if (val > 0)
5034                                         return;
5035
5036                                 last = next;
5037                                 next = next->base.next;
5038                                 break;
5039                         }
5040
5041                         case STATEMENT_FOR: {
5042 continue_for:;
5043                                 for_statement_t *const fors = &next->fors;
5044
5045                                 fors->step_reachable = true;
5046
5047                                 if (fors->condition_reachable)
5048                                         return;
5049                                 fors->condition_reachable = true;
5050
5051                                 expression_t const *const cond = fors->condition;
5052
5053                                 int val;
5054                                 if (cond == NULL) {
5055                                         val = 1;
5056                                 } else if (expression_returns(cond)) {
5057                                         val = determine_truth(cond);
5058                                 } else {
5059                                         return;
5060                                 }
5061
5062                                 if (val >= 0)
5063                                         check_reachable(fors->body);
5064
5065                                 if (val > 0)
5066                                         return;
5067
5068                                 last = next;
5069                                 next = next->base.next;
5070                                 break;
5071                         }
5072
5073                         case STATEMENT_MS_TRY:
5074                                 last = next;
5075                                 next = next->ms_try.final_statement;
5076                                 break;
5077                 }
5078         }
5079
5080         check_reachable(next);
5081 }
5082
5083 static void check_unreachable(statement_t* const stmt, void *const env)
5084 {
5085         (void)env;
5086
5087         switch (stmt->kind) {
5088                 case STATEMENT_DO_WHILE:
5089                         if (!stmt->base.reachable) {
5090                                 expression_t const *const cond = stmt->do_while.condition;
5091                                 if (determine_truth(cond) >= 0) {
5092                                         position_t const *const pos = &cond->base.pos;
5093                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5094                                 }
5095                         }
5096                         return;
5097
5098                 case STATEMENT_FOR: {
5099                         for_statement_t const* const fors = &stmt->fors;
5100
5101                         // if init and step are unreachable, cond is unreachable, too
5102                         if (!stmt->base.reachable && !fors->step_reachable) {
5103                                 goto warn_unreachable;
5104                         } else {
5105                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5106                                         position_t const *const pos = &fors->initialisation->base.pos;
5107                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5108                                 }
5109
5110                                 if (!fors->condition_reachable && fors->condition != NULL) {
5111                                         position_t const *const pos = &fors->condition->base.pos;
5112                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5113                                 }
5114
5115                                 if (!fors->step_reachable && fors->step != NULL) {
5116                                         position_t const *const pos = &fors->step->base.pos;
5117                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5118                                 }
5119                         }
5120                         return;
5121                 }
5122
5123                 case STATEMENT_COMPOUND:
5124                         if (stmt->compound.statements != NULL)
5125                                 return;
5126                         goto warn_unreachable;
5127
5128                 case STATEMENT_DECLARATION: {
5129                         /* Only warn if there is at least one declarator with an initializer.
5130                          * This typically occurs in switch statements. */
5131                         declaration_statement_t const *const decl = &stmt->declaration;
5132                         entity_t                const *      ent  = decl->declarations_begin;
5133                         entity_t                const *const last = decl->declarations_end;
5134                         if (ent != NULL) {
5135                                 for (;; ent = ent->base.next) {
5136                                         if (ent->kind                 == ENTITY_VARIABLE &&
5137                                                         ent->variable.initializer != NULL) {
5138                                                 goto warn_unreachable;
5139                                         }
5140                                         if (ent == last)
5141                                                 return;
5142                                 }
5143                         }
5144                 }
5145
5146                 default:
5147 warn_unreachable:
5148                         if (!stmt->base.reachable) {
5149                                 position_t const *const pos = &stmt->base.pos;
5150                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5151                         }
5152                         return;
5153         }
5154 }
5155
5156 static bool is_main(entity_t *entity)
5157 {
5158         static symbol_t *sym_main = NULL;
5159         if (sym_main == NULL) {
5160                 sym_main = symbol_table_insert("main");
5161         }
5162
5163         if (entity->base.symbol != sym_main)
5164                 return false;
5165         /* must be in outermost scope */
5166         if (entity->base.parent_scope != file_scope)
5167                 return false;
5168
5169         return true;
5170 }
5171
5172 static void prepare_main_collect2(entity_t*);
5173
5174 static void parse_external_declaration(void)
5175 {
5176         /* function-definitions and declarations both start with declaration
5177          * specifiers */
5178         add_anchor_token(';');
5179         declaration_specifiers_t specifiers;
5180         parse_declaration_specifiers(&specifiers);
5181         rem_anchor_token(';');
5182
5183         /* must be a declaration */
5184         if (token.kind == ';') {
5185                 parse_anonymous_declaration_rest(&specifiers);
5186                 return;
5187         }
5188
5189         add_anchor_token(',');
5190         add_anchor_token('=');
5191         add_anchor_token(';');
5192         add_anchor_token('{');
5193
5194         /* declarator is common to both function-definitions and declarations */
5195         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5196
5197         rem_anchor_token('{');
5198         rem_anchor_token(';');
5199         rem_anchor_token('=');
5200         rem_anchor_token(',');
5201
5202         /* must be a declaration */
5203         switch (token.kind) {
5204                 case ',':
5205                 case ';':
5206                 case '=':
5207                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5208                                         DECL_FLAGS_NONE);
5209                         return;
5210         }
5211
5212         /* must be a function definition */
5213         parse_kr_declaration_list(ndeclaration);
5214
5215         if (token.kind != '{') {
5216                 parse_error_expected("while parsing function definition", '{', NULL);
5217                 eat_until_matching_token(';');
5218                 return;
5219         }
5220
5221         assert(is_declaration(ndeclaration));
5222         type_t *const orig_type = ndeclaration->declaration.type;
5223         type_t *      type      = skip_typeref(orig_type);
5224
5225         if (!is_type_function(type)) {
5226                 if (is_type_valid(type)) {
5227                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5228                 }
5229                 eat_block();
5230                 return;
5231         }
5232
5233         position_t const *const pos = &ndeclaration->base.pos;
5234         if (is_typeref(orig_type)) {
5235                 /* §6.9.1:2 */
5236                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5237         }
5238
5239         if (is_type_compound(skip_typeref(type->function.return_type))) {
5240                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5241         }
5242         if (type->function.unspecified_parameters) {
5243                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5244         } else {
5245                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5246         }
5247
5248         /* §6.7.5.3:14 a function definition with () means no
5249          * parameters (and not unspecified parameters) */
5250         if (type->function.unspecified_parameters &&
5251                         type->function.parameters == NULL) {
5252                 type_t *copy                          = duplicate_type(type);
5253                 copy->function.unspecified_parameters = false;
5254                 type                                  = identify_new_type(copy);
5255
5256                 ndeclaration->declaration.type = type;
5257         }
5258
5259         entity_t *const entity = record_entity(ndeclaration, true);
5260         assert(entity->kind == ENTITY_FUNCTION);
5261         assert(ndeclaration->kind == ENTITY_FUNCTION);
5262
5263         function_t *const function = &entity->function;
5264         if (ndeclaration != entity) {
5265                 function->parameters = ndeclaration->function.parameters;
5266         }
5267
5268         PUSH_SCOPE(&function->parameters);
5269
5270         entity_t *parameter = function->parameters.entities;
5271         for (; parameter != NULL; parameter = parameter->base.next) {
5272                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5273                         parameter->base.parent_scope = current_scope;
5274                 }
5275                 assert(parameter->base.parent_scope == NULL
5276                                 || parameter->base.parent_scope == current_scope);
5277                 parameter->base.parent_scope = current_scope;
5278                 if (parameter->base.symbol == NULL) {
5279                         errorf(&parameter->base.pos, "parameter name omitted");
5280                         continue;
5281                 }
5282                 environment_push(parameter);
5283         }
5284
5285         if (function->body != NULL) {
5286                 parser_error_multiple_definition(entity, HERE);
5287                 eat_block();
5288         } else {
5289                 /* parse function body */
5290                 int         label_stack_top      = label_top();
5291                 function_t *old_current_function = current_function;
5292                 current_function                 = function;
5293                 PUSH_CURRENT_ENTITY(entity);
5294                 PUSH_PARENT(NULL);
5295
5296                 goto_first   = NULL;
5297                 goto_anchor  = &goto_first;
5298                 label_first  = NULL;
5299                 label_anchor = &label_first;
5300
5301                 statement_t *const body = parse_compound_statement(false);
5302                 function->body = body;
5303                 first_err = true;
5304                 check_labels();
5305                 check_declarations();
5306                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5307                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5308                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5309                         noreturn_candidate = true;
5310                         check_reachable(body);
5311                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5312                                 walk_statements(body, check_unreachable, NULL);
5313                         if (noreturn_candidate &&
5314                             !(function->base.modifiers & DM_NORETURN)) {
5315                                 position_t const *const pos = &body->base.pos;
5316                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5317                         }
5318                 }
5319
5320                 if (is_main(entity)) {
5321                         /* Force main to C linkage. */
5322                         type_t *const type = entity->declaration.type;
5323                         assert(is_type_function(type));
5324                         if (type->function.linkage != LINKAGE_C) {
5325                                 type_t *new_type           = duplicate_type(type);
5326                                 new_type->function.linkage = LINKAGE_C;
5327                                 entity->declaration.type   = identify_new_type(new_type);
5328                         }
5329
5330                         if (enable_main_collect2_hack)
5331                                 prepare_main_collect2(entity);
5332                 }
5333
5334                 POP_CURRENT_ENTITY();
5335                 POP_PARENT();
5336                 assert(current_function == function);
5337                 current_function = old_current_function;
5338                 label_pop_to(label_stack_top);
5339         }
5340
5341         POP_SCOPE();
5342 }
5343
5344 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5345 {
5346         entity_t *iter = compound->members.entities;
5347         for (; iter != NULL; iter = iter->base.next) {
5348                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5349                         continue;
5350
5351                 if (iter->base.symbol == symbol) {
5352                         return iter;
5353                 } else if (iter->base.symbol == NULL) {
5354                         /* search in anonymous structs and unions */
5355                         type_t *type = skip_typeref(iter->declaration.type);
5356                         if (is_type_compound(type)) {
5357                                 if (find_compound_entry(type->compound.compound, symbol)
5358                                                 != NULL)
5359                                         return iter;
5360                         }
5361                         continue;
5362                 }
5363         }
5364
5365         return NULL;
5366 }
5367
5368 static void check_deprecated(const position_t *pos, const entity_t *entity)
5369 {
5370         if (!is_declaration(entity))
5371                 return;
5372         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5373                 return;
5374
5375         position_t const *const epos = &entity->base.pos;
5376         char       const *const msg  = get_deprecated_string(entity->declaration.attributes);
5377         if (msg != NULL) {
5378                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5379         } else {
5380                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P)", entity, epos);
5381         }
5382 }
5383
5384
5385 static expression_t *create_select(const position_t *pos, expression_t *addr,
5386                                    type_qualifiers_t qualifiers,
5387                                                                    entity_t *entry)
5388 {
5389         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5390
5391         check_deprecated(pos, entry);
5392
5393         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5394         select->select.compound       = addr;
5395         select->select.compound_entry = entry;
5396
5397         type_t *entry_type = entry->declaration.type;
5398         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5399
5400         /* bitfields need special treatment */
5401         if (entry->compound_member.bitfield) {
5402                 unsigned bit_size = entry->compound_member.bit_size;
5403                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5404                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5405                         res_type = type_int;
5406                 }
5407         }
5408
5409         /* we always do the auto-type conversions; the & and sizeof parser contains
5410          * code to revert this! */
5411         select->base.type = automatic_type_conversion(res_type);
5412
5413
5414         return select;
5415 }
5416
5417 /**
5418  * Find entry with symbol in compound. Search anonymous structs and unions and
5419  * creates implicit select expressions for them.
5420  * Returns the adress for the innermost compound.
5421  */
5422 static expression_t *find_create_select(const position_t *pos,
5423                                         expression_t *addr,
5424                                         type_qualifiers_t qualifiers,
5425                                         compound_t *compound, symbol_t *symbol)
5426 {
5427         entity_t *iter = compound->members.entities;
5428         for (; iter != NULL; iter = iter->base.next) {
5429                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5430                         continue;
5431
5432                 symbol_t *iter_symbol = iter->base.symbol;
5433                 if (iter_symbol == NULL) {
5434                         type_t *type = iter->declaration.type;
5435                         if (!is_type_compound(type))
5436                                 continue;
5437
5438                         compound_t *sub_compound = type->compound.compound;
5439
5440                         if (find_compound_entry(sub_compound, symbol) == NULL)
5441                                 continue;
5442
5443                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5444                         sub_addr->base.pos      = *pos;
5445                         sub_addr->base.implicit = true;
5446                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5447                                                   symbol);
5448                 }
5449
5450                 if (iter_symbol == symbol) {
5451                         return create_select(pos, addr, qualifiers, iter);
5452                 }
5453         }
5454
5455         return NULL;
5456 }
5457
5458 static void parse_bitfield_member(entity_t *entity)
5459 {
5460         eat(':');
5461
5462         expression_t *size = parse_constant_expression();
5463         long          size_long;
5464
5465         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5466         type_t *type = entity->declaration.type;
5467         if (!is_type_integer(skip_typeref(type))) {
5468                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5469                            type);
5470         }
5471
5472         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5473                 /* error already reported by parse_constant_expression */
5474                 size_long = get_type_size(type) * 8;
5475         } else {
5476                 size_long = fold_constant_to_int(size);
5477
5478                 const symbol_t *symbol = entity->base.symbol;
5479                 const symbol_t *user_symbol
5480                         = symbol == NULL ? sym_anonymous : symbol;
5481                 unsigned bit_size = get_type_size(type) * 8;
5482                 if (size_long < 0) {
5483                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5484                 } else if (size_long == 0 && symbol != NULL) {
5485                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5486                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5487                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5488                                    user_symbol);
5489                 } else {
5490                         /* hope that people don't invent crazy types with more bits
5491                          * than our struct can hold */
5492                         assert(size_long <
5493                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5494                 }
5495         }
5496
5497         entity->compound_member.bitfield = true;
5498         entity->compound_member.bit_size = (unsigned char)size_long;
5499 }
5500
5501 static void parse_compound_declarators(compound_t *compound,
5502                 const declaration_specifiers_t *specifiers)
5503 {
5504         add_anchor_token(';');
5505         add_anchor_token(',');
5506         do {
5507                 entity_t *entity;
5508
5509                 if (token.kind == ':') {
5510                         /* anonymous bitfield */
5511                         type_t *type = specifiers->type;
5512                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5513                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5514                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5515                         entity->declaration.type                   = type;
5516
5517                         parse_bitfield_member(entity);
5518
5519                         attribute_t  *attributes = parse_attributes(NULL);
5520                         attribute_t **anchor     = &attributes;
5521                         while (*anchor != NULL)
5522                                 anchor = &(*anchor)->next;
5523                         *anchor = specifiers->attributes;
5524                         if (attributes != NULL) {
5525                                 handle_entity_attributes(attributes, entity);
5526                         }
5527                         entity->declaration.attributes = attributes;
5528
5529                         append_entity(&compound->members, entity);
5530                 } else {
5531                         entity = parse_declarator(specifiers,
5532                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5533                         position_t const *const pos = &entity->base.pos;
5534                         if (entity->kind == ENTITY_TYPEDEF) {
5535                                 errorf(pos, "typedef not allowed as compound member");
5536                         } else {
5537                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5538
5539                                 /* make sure we don't define a symbol multiple times */
5540                                 symbol_t *symbol = entity->base.symbol;
5541                                 if (symbol != NULL) {
5542                                         entity_t *prev = find_compound_entry(compound, symbol);
5543                                         if (prev != NULL) {
5544                                                 position_t const *const ppos = &prev->base.pos;
5545                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5546                                         }
5547                                 }
5548
5549                                 if (token.kind == ':') {
5550                                         parse_bitfield_member(entity);
5551
5552                                         attribute_t *attributes = parse_attributes(NULL);
5553                                         handle_entity_attributes(attributes, entity);
5554                                 } else {
5555                                         type_t *orig_type = entity->declaration.type;
5556                                         type_t *type      = skip_typeref(orig_type);
5557                                         if (is_type_function(type)) {
5558                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5559                                         } else if (is_type_incomplete(type)) {
5560                                                 /* §6.7.2.1:16 flexible array member */
5561                                                 if (!is_type_array(type)       ||
5562                                                                 token.kind          != ';' ||
5563                                                                 look_ahead(1)->kind != '}') {
5564                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5565                                                 } else if (compound->members.entities == NULL) {
5566                                                         errorf(pos, "flexible array member in otherwise empty struct");
5567                                                 }
5568                                         }
5569                                 }
5570
5571                                 append_entity(&compound->members, entity);
5572                         }
5573                 }
5574         } while (accept(','));
5575         rem_anchor_token(',');
5576         rem_anchor_token(';');
5577         expect(';');
5578
5579         anonymous_entity = NULL;
5580 }
5581
5582 static void parse_compound_type_entries(compound_t *compound)
5583 {
5584         eat('{');
5585         add_anchor_token('}');
5586
5587         for (;;) {
5588                 switch (token.kind) {
5589                         DECLARATION_START
5590                         case T___extension__:
5591                         case T_IDENTIFIER: {
5592                                 PUSH_EXTENSION();
5593                                 declaration_specifiers_t specifiers;
5594                                 parse_declaration_specifiers(&specifiers);
5595                                 parse_compound_declarators(compound, &specifiers);
5596                                 POP_EXTENSION();
5597                                 break;
5598                         }
5599
5600                         default:
5601                                 rem_anchor_token('}');
5602                                 expect('}');
5603                                 /* §6.7.2.1:7 */
5604                                 compound->complete = true;
5605                                 return;
5606                 }
5607         }
5608 }
5609
5610 static type_t *parse_typename(void)
5611 {
5612         declaration_specifiers_t specifiers;
5613         parse_declaration_specifiers(&specifiers);
5614         if (specifiers.storage_class != STORAGE_CLASS_NONE
5615                         || specifiers.thread_local) {
5616                 /* TODO: improve error message, user does probably not know what a
5617                  * storage class is...
5618                  */
5619                 errorf(&specifiers.pos, "typename must not have a storage class");
5620         }
5621
5622         type_t *result = parse_abstract_declarator(specifiers.type);
5623
5624         return result;
5625 }
5626
5627
5628
5629
5630 typedef expression_t* (*parse_expression_function)(void);
5631 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5632
5633 typedef struct expression_parser_function_t expression_parser_function_t;
5634 struct expression_parser_function_t {
5635         parse_expression_function        parser;
5636         precedence_t                     infix_precedence;
5637         parse_expression_infix_function  infix_parser;
5638 };
5639
5640 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5641
5642 static type_t *get_string_type(string_encoding_t const enc)
5643 {
5644         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5645         switch (enc) {
5646         case STRING_ENCODING_CHAR:
5647         case STRING_ENCODING_UTF8:   return warn ? type_const_char_ptr     : type_char_ptr;
5648         case STRING_ENCODING_CHAR16: return warn ? type_char16_t_const_ptr : type_char16_t_ptr;
5649         case STRING_ENCODING_CHAR32: return warn ? type_char32_t_const_ptr : type_char32_t_ptr;
5650         case STRING_ENCODING_WIDE:   return warn ? type_const_wchar_t_ptr  : type_wchar_t_ptr;
5651         }
5652         panic("invalid string encoding");
5653 }
5654
5655 /**
5656  * Parse a string constant.
5657  */
5658 static expression_t *parse_string_literal(void)
5659 {
5660         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5661         expr->string_literal.value = concat_string_literals();
5662         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5663         return expr;
5664 }
5665
5666 /**
5667  * Parse a boolean constant.
5668  */
5669 static expression_t *parse_boolean_literal(bool value)
5670 {
5671         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5672         literal->base.type           = type_bool;
5673         literal->literal.value.begin = value ? "true" : "false";
5674         literal->literal.value.size  = value ? 4 : 5;
5675
5676         eat(value ? T_true : T_false);
5677         return literal;
5678 }
5679
5680 static void warn_traditional_suffix(char const *const suffix)
5681 {
5682         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5683 }
5684
5685 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5686 {
5687         unsigned     spec = SPECIFIER_NONE;
5688         char const  *c    = suffix;
5689         while (*c != '\0') {
5690                 specifiers_t add;
5691                 switch (*c) {
5692                 case 'L':
5693                 case 'l':
5694                         add = SPECIFIER_LONG;
5695                         if (*c == c[1]) {
5696                                 add |= SPECIFIER_LONG_LONG;
5697                                 ++c;
5698                         }
5699                         break;
5700                 case 'u':
5701                 case 'U':
5702                         add = SPECIFIER_UNSIGNED;
5703                         break;
5704                 case 'i':
5705                 case 'I':
5706                 case 'j':
5707                 case 'J':
5708                         if (!GNU_MODE)
5709                                 goto error;
5710                         add = SPECIFIER_COMPLEX;
5711                         break;
5712
5713                 default:
5714                         goto error;
5715                 }
5716                 ++c;
5717                 if (spec & add)
5718                         goto error;
5719                 spec |= add;
5720         }
5721
5722         if (*c == '\0') {
5723                 type_t *type;
5724                 switch (spec & ~SPECIFIER_COMPLEX) {
5725                 case SPECIFIER_NONE:                                            type = type_int;                break;
5726                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5727                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5728                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5729                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5730                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5731                 default: panic("inconsistent suffix");
5732                 }
5733                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5734                         warn_traditional_suffix(suffix);
5735                 }
5736                 if (spec & SPECIFIER_COMPLEX) {
5737                         assert(type->kind == TYPE_ATOMIC);
5738                         type = make_complex_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
5739                 }
5740                 expr->base.type = type;
5741                 /* Integer type depends on the size of the number and the size
5742                  * representable by the types. The backend/codegeneration has to
5743                  * determine that. */
5744                 determine_literal_type(&expr->literal);
5745         } else {
5746 error:
5747                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5748         }
5749 }
5750
5751 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5752 {
5753         type_t     *type;
5754         char const *c          = suffix;
5755         bool        is_complex = false;
5756 next:
5757         switch (*c) {
5758         case 'F':
5759         case 'f': type = type_float;       ++c; break;
5760         case 'L':
5761         case 'l': type = type_long_double; ++c; break;
5762         case 'i':
5763         case 'I':
5764         case 'j':
5765         case 'J':
5766                 if (!GNU_MODE)
5767                         break;
5768                 is_complex = true;
5769                 ++c;
5770                 goto next;
5771         default:  type = type_double;           break;
5772         }
5773
5774         if (*c == '\0') {
5775                 if (is_complex) {
5776                         assert(type->kind == TYPE_ATOMIC);
5777                         type = make_complex_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
5778                 }
5779
5780                 expr->base.type = type;
5781                 if (suffix[0] != '\0') {
5782                         warn_traditional_suffix(suffix);
5783                 }
5784         } else {
5785                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5786         }
5787 }
5788
5789 static expression_t *parse_number_literal(void)
5790 {
5791         string_t const *const str      = &token.literal.string;
5792         char     const *      i        = str->begin;
5793         unsigned              digits   = 0;
5794         bool                  is_float = false;
5795
5796         /* Parse base prefix. */
5797         unsigned base;
5798         if (*i == '0') {
5799                 switch (*++i) {
5800                 case 'B': case 'b': base =  2; ++i;               break;
5801                 case 'X': case 'x': base = 16; ++i;               break;
5802                 default:            base =  8; digits |= 1U << 0; break;
5803                 }
5804         } else {
5805                 base = 10;
5806         }
5807
5808         /* Parse mantissa. */
5809         for (;; ++i) {
5810                 unsigned digit;
5811                 switch (*i) {
5812                 case '.':
5813                         if (is_float) {
5814                                 errorf(HERE, "multiple decimal points in %K", &token);
5815                                 i = 0;
5816                                 goto done;
5817                         }
5818                         is_float = true;
5819                         if (base == 8)
5820                                 base = 10;
5821                         continue;
5822
5823                 case '0':           digit =  0; break;
5824                 case '1':           digit =  1; break;
5825                 case '2':           digit =  2; break;
5826                 case '3':           digit =  3; break;
5827                 case '4':           digit =  4; break;
5828                 case '5':           digit =  5; break;
5829                 case '6':           digit =  6; break;
5830                 case '7':           digit =  7; break;
5831                 case '8':           digit =  8; break;
5832                 case '9':           digit =  9; break;
5833                 case 'A': case 'a': digit = 10; break;
5834                 case 'B': case 'b': digit = 11; break;
5835                 case 'C': case 'c': digit = 12; break;
5836                 case 'D': case 'd': digit = 13; break;
5837                 case 'E': case 'e': digit = 14; break;
5838                 case 'F': case 'f': digit = 15; break;
5839
5840                 default: goto done_mantissa;
5841                 }
5842
5843                 if (digit >= 10 && base != 16)
5844                         goto done_mantissa;
5845
5846                 digits |= 1U << digit;
5847         }
5848 done_mantissa:
5849
5850         /* Parse exponent. */
5851         switch (base) {
5852         case 2:
5853                 if (is_float)
5854                         errorf(HERE, "binary floating %K not allowed", &token);
5855                 break;
5856
5857         case  8:
5858         case 10:
5859                 if (*i == 'E' || *i == 'e') {
5860                         base = 10;
5861                         goto parse_exponent;
5862                 }
5863                 break;
5864
5865         case 16:
5866                 if (*i == 'P' || *i == 'p') {
5867 parse_exponent:
5868                         ++i;
5869                         is_float = true;
5870
5871                         if (*i == '-' || *i == '+')
5872                                 ++i;
5873
5874                         if (isdigit(*i)) {
5875                                 do {
5876                                         ++i;
5877                                 } while (isdigit(*i));
5878                         } else {
5879                                 errorf(HERE, "exponent of %K has no digits", &token);
5880                         }
5881                 } else if (is_float) {
5882                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5883                         i = 0;
5884                 }
5885                 break;
5886
5887         default:
5888                 panic("invalid base");
5889         }
5890
5891 done:;
5892         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5893         expr->literal.value = *str;
5894
5895         if (i) {
5896                 if (digits == 0) {
5897                         errorf(HERE, "%K has no digits", &token);
5898                 } else if (digits & ~((1U << base) - 1)) {
5899                         errorf(HERE, "invalid digit in %K", &token);
5900                 } else {
5901                         expr->literal.suffix = i;
5902                         if (is_float) {
5903                                 check_floatingpoint_suffix(expr, i);
5904                         } else {
5905                                 check_integer_suffix(expr, i);
5906                         }
5907                 }
5908         }
5909
5910         eat(T_NUMBER);
5911         return expr;
5912 }
5913
5914 /**
5915  * Parse a character constant.
5916  */
5917 static expression_t *parse_character_constant(void)
5918 {
5919         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5920         literal->string_literal.value = token.literal.string;
5921
5922         size_t const size = get_string_len(&token.literal.string);
5923         switch (token.literal.string.encoding) {
5924         case STRING_ENCODING_CHAR:
5925         case STRING_ENCODING_UTF8:
5926                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5927                 if (size > 1) {
5928                         if (!GNU_MODE && !(c_mode & _C99)) {
5929                                 errorf(HERE, "more than 1 character in character constant");
5930                         } else {
5931                                 literal->base.type = type_int;
5932                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5933                         }
5934                 }
5935                 break;
5936
5937         case STRING_ENCODING_CHAR16: literal->base.type = type_char16_t; goto warn_multi;
5938         case STRING_ENCODING_CHAR32: literal->base.type = type_char32_t; goto warn_multi;
5939         case STRING_ENCODING_WIDE:   literal->base.type = type_wchar_t;  goto warn_multi;
5940 warn_multi:
5941                 if (size > 1) {
5942                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5943                 }
5944                 break;
5945         }
5946
5947         eat(T_CHARACTER_CONSTANT);
5948         return literal;
5949 }
5950
5951 static entity_t *create_implicit_function(symbol_t *symbol, position_t const *const pos)
5952 {
5953         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5954         ntype->function.return_type            = type_int;
5955         ntype->function.unspecified_parameters = true;
5956         ntype->function.linkage                = LINKAGE_C;
5957         type_t *type                           = identify_new_type(ntype);
5958
5959         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5960         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5961         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5962         entity->declaration.type                   = type;
5963         entity->declaration.implicit               = true;
5964
5965         if (current_scope != NULL)
5966                 record_entity(entity, false);
5967
5968         return entity;
5969 }
5970
5971 /**
5972  * Performs automatic type cast as described in §6.3.2.1.
5973  *
5974  * @param orig_type  the original type
5975  */
5976 static type_t *automatic_type_conversion(type_t *orig_type)
5977 {
5978         type_t *type = skip_typeref(orig_type);
5979         if (is_type_array(type)) {
5980                 array_type_t *array_type   = &type->array;
5981                 type_t       *element_type = array_type->element_type;
5982                 unsigned      qualifiers   = array_type->base.qualifiers;
5983
5984                 return make_pointer_type(element_type, qualifiers);
5985         }
5986
5987         if (is_type_function(type)) {
5988                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5989         }
5990
5991         return orig_type;
5992 }
5993
5994 /**
5995  * reverts the automatic casts of array to pointer types and function
5996  * to function-pointer types as defined §6.3.2.1
5997  */
5998 type_t *revert_automatic_type_conversion(const expression_t *expression)
5999 {
6000         switch (expression->kind) {
6001         case EXPR_REFERENCE: {
6002                 entity_t *entity = expression->reference.entity;
6003                 if (is_declaration(entity)) {
6004                         return entity->declaration.type;
6005                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6006                         return entity->enum_value.enum_type;
6007                 } else {
6008                         panic("no declaration or enum in reference");
6009                 }
6010         }
6011
6012         case EXPR_SELECT: {
6013                 entity_t *entity = expression->select.compound_entry;
6014                 assert(is_declaration(entity));
6015                 type_t   *type   = entity->declaration.type;
6016                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6017         }
6018
6019         case EXPR_UNARY_DEREFERENCE: {
6020                 const expression_t *const value = expression->unary.value;
6021                 type_t             *const type  = skip_typeref(value->base.type);
6022                 if (!is_type_pointer(type))
6023                         return type_error_type;
6024                 return type->pointer.points_to;
6025         }
6026
6027         case EXPR_ARRAY_ACCESS: {
6028                 const expression_t *array_ref = expression->array_access.array_ref;
6029                 type_t             *type_left = skip_typeref(array_ref->base.type);
6030                 if (!is_type_pointer(type_left))
6031                         return type_error_type;
6032                 return type_left->pointer.points_to;
6033         }
6034
6035         case EXPR_STRING_LITERAL: {
6036                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
6037                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
6038                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
6039         }
6040
6041         case EXPR_COMPOUND_LITERAL:
6042                 return expression->compound_literal.type;
6043
6044         default:
6045                 break;
6046         }
6047         return expression->base.type;
6048 }
6049
6050 /**
6051  * Find an entity matching a symbol in a scope.
6052  * Uses current scope if scope is NULL
6053  */
6054 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6055                                namespace_tag_t namespc)
6056 {
6057         if (scope == NULL) {
6058                 return get_entity(symbol, namespc);
6059         }
6060
6061         /* we should optimize here, if scope grows above a certain size we should
6062            construct a hashmap here... */
6063         entity_t *entity = scope->entities;
6064         for ( ; entity != NULL; entity = entity->base.next) {
6065                 if (entity->base.symbol == symbol
6066                     && (namespace_tag_t)entity->base.namespc == namespc)
6067                         break;
6068         }
6069
6070         return entity;
6071 }
6072
6073 static entity_t *parse_qualified_identifier(void)
6074 {
6075         /* namespace containing the symbol */
6076         symbol_t      *symbol;
6077         position_t     pos;
6078         const scope_t *lookup_scope = NULL;
6079
6080         if (accept(T_COLONCOLON))
6081                 lookup_scope = &unit->scope;
6082
6083         entity_t *entity;
6084         while (true) {
6085                 symbol = expect_identifier("while parsing identifier", &pos);
6086                 if (!symbol)
6087                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6088
6089                 /* lookup entity */
6090                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6091
6092                 if (!accept(T_COLONCOLON))
6093                         break;
6094
6095                 switch (entity->kind) {
6096                 case ENTITY_NAMESPACE:
6097                         lookup_scope = &entity->namespacee.members;
6098                         break;
6099                 case ENTITY_STRUCT:
6100                 case ENTITY_UNION:
6101                 case ENTITY_CLASS:
6102                         lookup_scope = &entity->compound.members;
6103                         break;
6104                 default:
6105                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6106                                symbol, get_entity_kind_name(entity->kind));
6107
6108                         /* skip further qualifications */
6109                         while (accept(T_IDENTIFIER) && accept(T_COLONCOLON)) {}
6110
6111                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6112                 }
6113         }
6114
6115         if (entity == NULL) {
6116                 if (!strict_mode && token.kind == '(') {
6117                         /* an implicitly declared function */
6118                         entity = create_implicit_function(symbol, &pos);
6119                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6120                 } else {
6121                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6122                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6123                 }
6124         }
6125
6126         return entity;
6127 }
6128
6129 static expression_t *parse_reference(void)
6130 {
6131         position_t const pos    = *HERE;
6132         entity_t  *const entity = parse_qualified_identifier();
6133
6134         type_t *orig_type;
6135         if (is_declaration(entity)) {
6136                 orig_type = entity->declaration.type;
6137         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6138                 orig_type = entity->enum_value.enum_type;
6139         } else {
6140                 panic("expected declaration or enum value in reference");
6141         }
6142
6143         /* we always do the auto-type conversions; the & and sizeof parser contains
6144          * code to revert this! */
6145         type_t *type = automatic_type_conversion(orig_type);
6146
6147         expression_kind_t kind = EXPR_REFERENCE;
6148         if (entity->kind == ENTITY_ENUM_VALUE)
6149                 kind = EXPR_ENUM_CONSTANT;
6150
6151         expression_t *expression     = allocate_expression_zero(kind);
6152         expression->base.pos         = pos;
6153         expression->base.type        = type;
6154         expression->reference.entity = entity;
6155
6156         /* this declaration is used */
6157         if (is_declaration(entity)) {
6158                 entity->declaration.used = true;
6159         }
6160
6161         if (entity->base.parent_scope != file_scope
6162                 && (current_function != NULL
6163                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6164                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6165                 /* access of a variable from an outer function */
6166                 entity->variable.address_taken = true;
6167                 current_function->need_closure = true;
6168         }
6169
6170         check_deprecated(&pos, entity);
6171
6172         return expression;
6173 }
6174
6175 static bool semantic_cast(expression_t *cast)
6176 {
6177         expression_t     *expression      = cast->unary.value;
6178         type_t           *orig_dest_type  = cast->base.type;
6179         type_t           *orig_type_right = expression->base.type;
6180         type_t     const *dst_type        = skip_typeref(orig_dest_type);
6181         type_t     const *src_type        = skip_typeref(orig_type_right);
6182         position_t const *pos             = &cast->base.pos;
6183
6184         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation
6185          * than for utility. */
6186         if (is_type_void(dst_type))
6187                 return true;
6188
6189         /* only integer and pointer can be casted to pointer */
6190         if (is_type_pointer(dst_type)  &&
6191             !is_type_pointer(src_type) &&
6192             !is_type_integer(src_type) &&
6193             is_type_valid(src_type)) {
6194                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6195                 return false;
6196         }
6197
6198         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6199                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6200                 return false;
6201         }
6202
6203         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6204                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6205                 return false;
6206         }
6207
6208         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6209                 type_t *src = skip_typeref(src_type->pointer.points_to);
6210                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6211                 unsigned missing_qualifiers =
6212                         src->base.qualifiers & ~dst->base.qualifiers;
6213                 if (missing_qualifiers != 0) {
6214                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6215                 }
6216         }
6217         return true;
6218 }
6219
6220 static void semantic_complex_extract(unary_expression_t *extract)
6221 {
6222         type_t *orig_value_type = extract->value->base.type;
6223         type_t *value_type      = skip_typeref(orig_value_type);
6224         if (!is_type_valid(value_type)) {
6225                 extract->base.type = type_error_type;
6226                 return;
6227         }
6228
6229         type_t *type = value_type;
6230         if (!is_type_complex(type)) {
6231                 if (!is_type_arithmetic(type)) {
6232                         errorf(&extract->base.pos,
6233                                    "%s requires an argument with complex or arithmetic type, got '%T'",
6234                                    extract->base.kind == EXPR_UNARY_IMAG ? "__imag__" : "__real__",
6235                                    orig_value_type);
6236                         extract->base.type = type_error_type;
6237                         return;
6238                 }
6239                 atomic_type_kind_t const akind = get_arithmetic_akind(type);
6240                 type = make_complex_type(akind, TYPE_QUALIFIER_NONE);
6241                 extract->value = create_implicit_cast(extract->value, type);
6242         }
6243         assert(type->kind == TYPE_COMPLEX);
6244         type = make_atomic_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
6245         extract->base.type = type;
6246 }
6247
6248 static expression_t *parse_compound_literal(position_t const *const pos,
6249                                             type_t *type)
6250 {
6251         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6252         expression->base.pos = *pos;
6253         bool global_scope = current_scope == file_scope;
6254
6255         parse_initializer_env_t env;
6256         env.type             = type;
6257         env.entity           = NULL;
6258         env.must_be_constant = global_scope;
6259         initializer_t *initializer = parse_initializer(&env);
6260         type = env.type;
6261
6262         expression->base.type                     = automatic_type_conversion(type);
6263         expression->compound_literal.initializer  = initializer;
6264         expression->compound_literal.type         = type;
6265         expression->compound_literal.global_scope = global_scope;
6266
6267         return expression;
6268 }
6269
6270 /**
6271  * Parse a cast expression.
6272  */
6273 static expression_t *parse_cast(void)
6274 {
6275         position_t const pos = *HERE;
6276
6277         eat('(');
6278         add_anchor_token(')');
6279
6280         type_t *type = parse_typename();
6281
6282         rem_anchor_token(')');
6283         expect(')');
6284
6285         if (token.kind == '{') {
6286                 return parse_compound_literal(&pos, type);
6287         }
6288
6289         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6290         cast->base.pos     = pos;
6291
6292         expression_t *value = parse_subexpression(PREC_CAST);
6293         cast->base.type   = type;
6294         cast->unary.value = value;
6295
6296         if (!semantic_cast(cast)) {
6297                 cast->base.type = type_error_type;
6298         }
6299
6300         return cast;
6301 }
6302
6303 static expression_t *parse_complex_extract_expression(void)
6304 {
6305         expression_kind_t kind;
6306         if (token.kind == T___imag__) {
6307                 kind = EXPR_UNARY_IMAG;
6308         } else {
6309                 assert(token.kind == T___real__);
6310                 kind = EXPR_UNARY_REAL;
6311         }
6312         expression_t *extract = allocate_expression_zero(kind);
6313         extract->base.pos = *HERE;
6314         next_token();
6315
6316         extract->unary.value = parse_subexpression(PREC_CAST);
6317         semantic_complex_extract(&extract->unary);
6318         return extract;
6319 }
6320
6321 /**
6322  * Parse a statement expression.
6323  */
6324 static expression_t *parse_statement_expression(void)
6325 {
6326         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6327
6328         eat('(');
6329         add_anchor_token(')');
6330
6331         statement_t *statement          = parse_compound_statement(true);
6332         statement->compound.stmt_expr   = true;
6333         expression->statement.statement = statement;
6334
6335         /* find last statement and use its type */
6336         type_t *type = type_void;
6337         const statement_t *stmt = statement->compound.statements;
6338         if (stmt != NULL) {
6339                 while (stmt->base.next != NULL)
6340                         stmt = stmt->base.next;
6341
6342                 if (stmt->kind == STATEMENT_EXPRESSION) {
6343                         type = stmt->expression.expression->base.type;
6344                 }
6345         } else {
6346                 position_t const *const pos = &expression->base.pos;
6347                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6348         }
6349         expression->base.type = type;
6350
6351         rem_anchor_token(')');
6352         expect(')');
6353         return expression;
6354 }
6355
6356 /**
6357  * Parse a parenthesized expression.
6358  */
6359 static expression_t *parse_parenthesized_expression(void)
6360 {
6361         token_t const* const la1 = look_ahead(1);
6362         switch (la1->kind) {
6363         case '{':
6364                 /* gcc extension: a statement expression */
6365                 return parse_statement_expression();
6366
6367         case T_IDENTIFIER:
6368                 if (is_typedef_symbol(la1->base.symbol)) {
6369         DECLARATION_START
6370                         return parse_cast();
6371                 }
6372         }
6373
6374         eat('(');
6375         add_anchor_token(')');
6376         expression_t *result = parse_expression();
6377         result->base.parenthesized = true;
6378         rem_anchor_token(')');
6379         expect(')');
6380
6381         return result;
6382 }
6383
6384 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6385 {
6386         if (current_function == NULL) {
6387                 errorf(HERE, "%K used outside of a function", &token);
6388         }
6389
6390         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6391         expression->base.type     = type_char_ptr;
6392         expression->funcname.kind = kind;
6393
6394         next_token();
6395
6396         return expression;
6397 }
6398
6399 static designator_t *parse_designator(void)
6400 {
6401         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6402         result->symbol = expect_identifier("while parsing member designator", &result->pos);
6403         if (!result->symbol)
6404                 return NULL;
6405
6406         designator_t *last_designator = result;
6407         while (true) {
6408                 if (accept('.')) {
6409                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6410                         designator->symbol = expect_identifier("while parsing member designator", &designator->pos);
6411                         if (!designator->symbol)
6412                                 return NULL;
6413
6414                         last_designator->next = designator;
6415                         last_designator       = designator;
6416                         continue;
6417                 }
6418                 if (accept('[')) {
6419                         add_anchor_token(']');
6420                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
6421                         designator->pos          = *HERE;
6422                         designator->array_index  = parse_expression();
6423                         rem_anchor_token(']');
6424                         expect(']');
6425                         if (designator->array_index == NULL) {
6426                                 return NULL;
6427                         }
6428
6429                         last_designator->next = designator;
6430                         last_designator       = designator;
6431                         continue;
6432                 }
6433                 break;
6434         }
6435
6436         return result;
6437 }
6438
6439 /**
6440  * Parse the __builtin_offsetof() expression.
6441  */
6442 static expression_t *parse_offsetof(void)
6443 {
6444         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6445         expression->base.type    = type_size_t;
6446
6447         eat(T___builtin_offsetof);
6448
6449         add_anchor_token(')');
6450         add_anchor_token(',');
6451         expect('(');
6452         type_t *type = parse_typename();
6453         rem_anchor_token(',');
6454         expect(',');
6455         designator_t *designator = parse_designator();
6456         rem_anchor_token(')');
6457         expect(')');
6458
6459         expression->offsetofe.type       = type;
6460         expression->offsetofe.designator = designator;
6461
6462         type_path_t path;
6463         memset(&path, 0, sizeof(path));
6464         path.top_type = type;
6465         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6466
6467         descend_into_subtype(&path);
6468
6469         if (!walk_designator(&path, designator, true)) {
6470                 return create_error_expression();
6471         }
6472
6473         DEL_ARR_F(path.path);
6474
6475         return expression;
6476 }
6477
6478 static bool is_last_parameter(expression_t *const param)
6479 {
6480         if (param->kind == EXPR_REFERENCE) {
6481                 entity_t *const entity = param->reference.entity;
6482                 if (entity->kind == ENTITY_PARAMETER &&
6483                     !entity->base.next               &&
6484                     entity->base.parent_scope == &current_function->parameters) {
6485                         return true;
6486                 }
6487         }
6488
6489         if (!is_type_valid(skip_typeref(param->base.type)))
6490                 return true;
6491
6492         return false;
6493 }
6494
6495 /**
6496  * Parses a __builtin_va_start() expression.
6497  */
6498 static expression_t *parse_va_start(void)
6499 {
6500         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6501
6502         eat(T___builtin_va_start);
6503
6504         add_anchor_token(')');
6505         add_anchor_token(',');
6506         expect('(');
6507         expression->va_starte.ap = parse_assignment_expression();
6508         rem_anchor_token(',');
6509         expect(',');
6510         expression_t *const param = parse_assignment_expression();
6511         expression->va_starte.parameter = param;
6512         rem_anchor_token(')');
6513         expect(')');
6514
6515         if (!current_function) {
6516                 errorf(&expression->base.pos, "'va_start' used outside of function");
6517         } else if (!current_function->base.type->function.variadic) {
6518                 errorf(&expression->base.pos, "'va_start' used in non-variadic function");
6519         } else if (!is_last_parameter(param)) {
6520                 errorf(&param->base.pos, "second argument of 'va_start' must be last parameter of the current function");
6521         }
6522
6523         return expression;
6524 }
6525
6526 /**
6527  * Parses a __builtin_va_arg() expression.
6528  */
6529 static expression_t *parse_va_arg(void)
6530 {
6531         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6532
6533         eat(T___builtin_va_arg);
6534
6535         add_anchor_token(')');
6536         add_anchor_token(',');
6537         expect('(');
6538         call_argument_t ap;
6539         ap.expression = parse_assignment_expression();
6540         expression->va_arge.ap = ap.expression;
6541         check_call_argument(type_valist, &ap, 1);
6542
6543         rem_anchor_token(',');
6544         expect(',');
6545         expression->base.type = parse_typename();
6546         rem_anchor_token(')');
6547         expect(')');
6548
6549         return expression;
6550 }
6551
6552 /**
6553  * Parses a __builtin_va_copy() expression.
6554  */
6555 static expression_t *parse_va_copy(void)
6556 {
6557         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6558
6559         eat(T___builtin_va_copy);
6560
6561         add_anchor_token(')');
6562         add_anchor_token(',');
6563         expect('(');
6564         expression_t *dst = parse_assignment_expression();
6565         assign_error_t error = semantic_assign(type_valist, dst);
6566         report_assign_error(error, type_valist, dst, "call argument 1",
6567                             &dst->base.pos);
6568         expression->va_copye.dst = dst;
6569
6570         rem_anchor_token(',');
6571         expect(',');
6572
6573         call_argument_t src;
6574         src.expression = parse_assignment_expression();
6575         check_call_argument(type_valist, &src, 2);
6576         expression->va_copye.src = src.expression;
6577         rem_anchor_token(')');
6578         expect(')');
6579
6580         return expression;
6581 }
6582
6583 /**
6584  * Parses a __builtin_constant_p() expression.
6585  */
6586 static expression_t *parse_builtin_constant(void)
6587 {
6588         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6589
6590         eat(T___builtin_constant_p);
6591
6592         add_anchor_token(')');
6593         expect('(');
6594         expression->builtin_constant.value = parse_assignment_expression();
6595         rem_anchor_token(')');
6596         expect(')');
6597         expression->base.type = type_int;
6598
6599         return expression;
6600 }
6601
6602 /**
6603  * Parses a __builtin_types_compatible_p() expression.
6604  */
6605 static expression_t *parse_builtin_types_compatible(void)
6606 {
6607         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6608
6609         eat(T___builtin_types_compatible_p);
6610
6611         add_anchor_token(')');
6612         add_anchor_token(',');
6613         expect('(');
6614         expression->builtin_types_compatible.left = parse_typename();
6615         rem_anchor_token(',');
6616         expect(',');
6617         expression->builtin_types_compatible.right = parse_typename();
6618         rem_anchor_token(')');
6619         expect(')');
6620         expression->base.type = type_int;
6621
6622         return expression;
6623 }
6624
6625 /**
6626  * Parses a __builtin_is_*() compare expression.
6627  */
6628 static expression_t *parse_compare_builtin(void)
6629 {
6630         expression_kind_t kind;
6631         switch (token.kind) {
6632         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6633         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6634         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6635         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6636         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6637         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6638         default: internal_errorf(HERE, "invalid compare builtin found");
6639         }
6640         expression_t *const expression = allocate_expression_zero(kind);
6641         next_token();
6642
6643         add_anchor_token(')');
6644         add_anchor_token(',');
6645         expect('(');
6646         expression->binary.left = parse_assignment_expression();
6647         rem_anchor_token(',');
6648         expect(',');
6649         expression->binary.right = parse_assignment_expression();
6650         rem_anchor_token(')');
6651         expect(')');
6652
6653         type_t *const orig_type_left  = expression->binary.left->base.type;
6654         type_t *const orig_type_right = expression->binary.right->base.type;
6655
6656         type_t *const type_left  = skip_typeref(orig_type_left);
6657         type_t *const type_right = skip_typeref(orig_type_right);
6658         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6659                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6660                         type_error_incompatible("invalid operands in comparison",
6661                                 &expression->base.pos, orig_type_left, orig_type_right);
6662                 }
6663         } else {
6664                 semantic_comparison(&expression->binary);
6665         }
6666
6667         return expression;
6668 }
6669
6670 /**
6671  * Parses a MS assume() expression.
6672  */
6673 static expression_t *parse_assume(void)
6674 {
6675         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6676
6677         eat(T__assume);
6678
6679         add_anchor_token(')');
6680         expect('(');
6681         expression->unary.value = parse_assignment_expression();
6682         rem_anchor_token(')');
6683         expect(')');
6684
6685         expression->base.type = type_void;
6686         return expression;
6687 }
6688
6689 /**
6690  * Return the label for the current symbol or create a new one.
6691  */
6692 static label_t *get_label(char const *const context)
6693 {
6694         assert(current_function != NULL);
6695
6696         symbol_t *const sym = expect_identifier(context, NULL);
6697         if (!sym)
6698                 return NULL;
6699
6700         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6701         /* If we find a local label, we already created the declaration. */
6702         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6703                 if (label->base.parent_scope != current_scope) {
6704                         assert(label->base.parent_scope->depth < current_scope->depth);
6705                         current_function->goto_to_outer = true;
6706                 }
6707         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6708                 /* There is no matching label in the same function, so create a new one. */
6709                 position_t const nowhere = { NULL, 0, 0, false };
6710                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6711                 label_push(label);
6712         }
6713
6714         return &label->label;
6715 }
6716
6717 /**
6718  * Parses a GNU && label address expression.
6719  */
6720 static expression_t *parse_label_address(void)
6721 {
6722         position_t const pos = *HERE;
6723         eat(T_ANDAND);
6724
6725         label_t *const label = get_label("while parsing label address");
6726         if (!label)
6727                 return create_error_expression();
6728
6729         label->used          = true;
6730         label->address_taken = true;
6731
6732         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6733         expression->base.pos     = pos;
6734
6735         /* label address is treated as a void pointer */
6736         expression->base.type           = type_void_ptr;
6737         expression->label_address.label = label;
6738         return expression;
6739 }
6740
6741 /**
6742  * Parse a microsoft __noop expression.
6743  */
6744 static expression_t *parse_noop_expression(void)
6745 {
6746         /* the result is a (int)0 */
6747         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6748         literal->base.type           = type_int;
6749         literal->literal.value.begin = "__noop";
6750         literal->literal.value.size  = 6;
6751
6752         eat(T___noop);
6753
6754         if (token.kind == '(') {
6755                 /* parse arguments */
6756                 eat('(');
6757                 add_anchor_token(')');
6758                 add_anchor_token(',');
6759
6760                 if (token.kind != ')') do {
6761                         (void)parse_assignment_expression();
6762                 } while (accept(','));
6763
6764                 rem_anchor_token(',');
6765                 rem_anchor_token(')');
6766         }
6767         expect(')');
6768
6769         return literal;
6770 }
6771
6772 /**
6773  * Parses a primary expression.
6774  */
6775 static expression_t *parse_primary_expression(void)
6776 {
6777         switch (token.kind) {
6778         case T_false:                        return parse_boolean_literal(false);
6779         case T_true:                         return parse_boolean_literal(true);
6780         case T_NUMBER:                       return parse_number_literal();
6781         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6782         case T_STRING_LITERAL:               return parse_string_literal();
6783         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6784         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6785         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6786         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6787         case T___builtin_offsetof:           return parse_offsetof();
6788         case T___builtin_va_start:           return parse_va_start();
6789         case T___builtin_va_arg:             return parse_va_arg();
6790         case T___builtin_va_copy:            return parse_va_copy();
6791         case T___builtin_isgreater:
6792         case T___builtin_isgreaterequal:
6793         case T___builtin_isless:
6794         case T___builtin_islessequal:
6795         case T___builtin_islessgreater:
6796         case T___builtin_isunordered:        return parse_compare_builtin();
6797         case T___builtin_constant_p:         return parse_builtin_constant();
6798         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6799         case T__assume:                      return parse_assume();
6800         case T_ANDAND:
6801                 if (GNU_MODE)
6802                         return parse_label_address();
6803                 break;
6804
6805         case '(':                            return parse_parenthesized_expression();
6806         case T___noop:                       return parse_noop_expression();
6807         case T___real__:
6808         case T___imag__:                     return parse_complex_extract_expression();
6809
6810         /* Gracefully handle type names while parsing expressions. */
6811         case T_COLONCOLON:
6812                 return parse_reference();
6813         case T_IDENTIFIER:
6814                 if (!is_typedef_symbol(token.base.symbol)) {
6815                         return parse_reference();
6816                 }
6817                 /* FALLTHROUGH */
6818         DECLARATION_START {
6819                 position_t const pos = *HERE;
6820                 declaration_specifiers_t specifiers;
6821                 parse_declaration_specifiers(&specifiers);
6822                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6823                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6824                 return create_error_expression();
6825         }
6826         }
6827
6828         errorf(HERE, "unexpected token %K, expected an expression", &token);
6829         eat_until_anchor();
6830         return create_error_expression();
6831 }
6832
6833 static expression_t *parse_array_expression(expression_t *left)
6834 {
6835         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6836         array_access_expression_t *const arr  = &expr->array_access;
6837
6838         eat('[');
6839         add_anchor_token(']');
6840
6841         expression_t *const inside = parse_expression();
6842
6843         type_t *const orig_type_left   = left->base.type;
6844         type_t *const orig_type_inside = inside->base.type;
6845
6846         type_t *const type_left   = skip_typeref(orig_type_left);
6847         type_t *const type_inside = skip_typeref(orig_type_inside);
6848
6849         expression_t *ref;
6850         expression_t *idx;
6851         type_t       *idx_type;
6852         type_t       *res_type;
6853         if (is_type_pointer(type_left)) {
6854                 ref      = left;
6855                 idx      = inside;
6856                 idx_type = type_inside;
6857                 res_type = type_left->pointer.points_to;
6858                 goto check_idx;
6859         } else if (is_type_pointer(type_inside)) {
6860                 arr->flipped = true;
6861                 ref      = inside;
6862                 idx      = left;
6863                 idx_type = type_left;
6864                 res_type = type_inside->pointer.points_to;
6865 check_idx:
6866                 res_type = automatic_type_conversion(res_type);
6867                 if (!is_type_integer(idx_type)) {
6868                         if (is_type_valid(idx_type))
6869                                 errorf(&idx->base.pos, "array subscript must have integer type");
6870                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6871                         position_t const *const pos = &idx->base.pos;
6872                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6873                 }
6874         } else {
6875                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6876                         errorf(&expr->base.pos, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6877                 }
6878                 res_type = type_error_type;
6879                 ref      = left;
6880                 idx      = inside;
6881         }
6882
6883         arr->array_ref = ref;
6884         arr->index     = idx;
6885         arr->base.type = res_type;
6886
6887         rem_anchor_token(']');
6888         expect(']');
6889         return expr;
6890 }
6891
6892 static bool is_bitfield(const expression_t *expression)
6893 {
6894         return expression->kind == EXPR_SELECT
6895                 && expression->select.compound_entry->compound_member.bitfield;
6896 }
6897
6898 static expression_t *parse_typeprop(expression_kind_t const kind)
6899 {
6900         expression_t  *tp_expression = allocate_expression_zero(kind);
6901         tp_expression->base.type     = type_size_t;
6902
6903         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6904
6905         type_t       *orig_type;
6906         expression_t *expression;
6907         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6908                 position_t const pos = *HERE;
6909                 eat('(');
6910                 add_anchor_token(')');
6911                 orig_type = parse_typename();
6912                 rem_anchor_token(')');
6913                 expect(')');
6914
6915                 if (token.kind == '{') {
6916                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6917                          * starting with a compound literal */
6918                         expression = parse_compound_literal(&pos, orig_type);
6919                         goto typeprop_expression;
6920                 }
6921         } else {
6922                 expression = parse_subexpression(PREC_UNARY);
6923
6924 typeprop_expression:
6925                 if (is_bitfield(expression)) {
6926                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6927                         errorf(&tp_expression->base.pos,
6928                                    "operand of %s expression must not be a bitfield", what);
6929                 }
6930
6931                 tp_expression->typeprop.tp_expression = expression;
6932
6933                 orig_type = revert_automatic_type_conversion(expression);
6934                 expression->base.type = orig_type;
6935         }
6936
6937         tp_expression->typeprop.type   = orig_type;
6938         type_t const* const type       = skip_typeref(orig_type);
6939         char   const*       wrong_type = NULL;
6940         if (is_type_incomplete(type)) {
6941                 if (!is_type_void(type) || !GNU_MODE)
6942                         wrong_type = "incomplete";
6943         } else if (type->kind == TYPE_FUNCTION) {
6944                 if (GNU_MODE) {
6945                         /* function types are allowed (and return 1) */
6946                         position_t const *const pos  = &tp_expression->base.pos;
6947                         char       const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6948                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6949                 } else {
6950                         wrong_type = "function";
6951                 }
6952         }
6953
6954         if (wrong_type != NULL) {
6955                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6956                 errorf(&tp_expression->base.pos,
6957                                 "operand of %s expression must not be of %s type '%T'",
6958                                 what, wrong_type, orig_type);
6959         }
6960
6961         return tp_expression;
6962 }
6963
6964 static expression_t *parse_sizeof(void)
6965 {
6966         return parse_typeprop(EXPR_SIZEOF);
6967 }
6968
6969 static expression_t *parse_alignof(void)
6970 {
6971         return parse_typeprop(EXPR_ALIGNOF);
6972 }
6973
6974 static expression_t *parse_select_expression(expression_t *addr)
6975 {
6976         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6977         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6978         position_t const pos = *HERE;
6979         next_token();
6980
6981         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6982         if (!symbol)
6983                 return create_error_expression();
6984
6985         type_t *const orig_type = addr->base.type;
6986         type_t *const type      = skip_typeref(orig_type);
6987
6988         type_t *type_left;
6989         bool    saw_error = false;
6990         if (is_type_pointer(type)) {
6991                 if (!select_left_arrow) {
6992                         errorf(&pos,
6993                                "request for member '%Y' in something not a struct or union, but '%T'",
6994                                symbol, orig_type);
6995                         saw_error = true;
6996                 }
6997                 type_left = skip_typeref(type->pointer.points_to);
6998         } else {
6999                 if (select_left_arrow && is_type_valid(type)) {
7000                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7001                         saw_error = true;
7002                 }
7003                 type_left = type;
7004         }
7005
7006         if (!is_type_compound(type_left)) {
7007                 if (is_type_valid(type_left) && !saw_error) {
7008                         errorf(&pos,
7009                                "request for member '%Y' in something not a struct or union, but '%T'",
7010                                symbol, type_left);
7011                 }
7012                 return create_error_expression();
7013         }
7014
7015         compound_t *compound = type_left->compound.compound;
7016         if (!compound->complete) {
7017                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7018                        symbol, type_left);
7019                 return create_error_expression();
7020         }
7021
7022         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7023         expression_t      *result     =
7024                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7025
7026         if (result == NULL) {
7027                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7028                 return create_error_expression();
7029         }
7030
7031         return result;
7032 }
7033
7034 static void check_call_argument(type_t          *expected_type,
7035                                 call_argument_t *argument, unsigned pos)
7036 {
7037         type_t         *expected_type_skip = skip_typeref(expected_type);
7038         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7039         expression_t   *arg_expr           = argument->expression;
7040         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7041
7042         /* handle transparent union gnu extension */
7043         if (is_type_union(expected_type_skip)
7044                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7045                 compound_t *union_decl  = expected_type_skip->compound.compound;
7046                 type_t     *best_type   = NULL;
7047                 entity_t   *entry       = union_decl->members.entities;
7048                 for ( ; entry != NULL; entry = entry->base.next) {
7049                         assert(is_declaration(entry));
7050                         type_t *decl_type = entry->declaration.type;
7051                         error = semantic_assign(decl_type, arg_expr);
7052                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7053                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7054                                 continue;
7055
7056                         if (error == ASSIGN_SUCCESS) {
7057                                 best_type = decl_type;
7058                         } else if (best_type == NULL) {
7059                                 best_type = decl_type;
7060                         }
7061                 }
7062
7063                 if (best_type != NULL) {
7064                         expected_type = best_type;
7065                 }
7066         }
7067
7068         error                = semantic_assign(expected_type, arg_expr);
7069         argument->expression = create_implicit_cast(arg_expr, expected_type);
7070
7071         if (error != ASSIGN_SUCCESS) {
7072                 /* report exact scope in error messages (like "in argument 3") */
7073                 char buf[64];
7074                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7075                 report_assign_error(error, expected_type, arg_expr, buf,
7076                                     &arg_expr->base.pos);
7077         } else {
7078                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7079                 if (!types_compatible(expected_type_skip, promoted_type) &&
7080                     !types_compatible(expected_type_skip, type_void_ptr) &&
7081                     !types_compatible(type_void_ptr,      promoted_type)) {
7082                         /* Deliberately show the skipped types in this warning */
7083                         position_t const *const apos = &arg_expr->base.pos;
7084                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7085                 }
7086         }
7087 }
7088
7089 /**
7090  * Handle the semantic restrictions of builtin calls
7091  */
7092 static void handle_builtin_argument_restrictions(call_expression_t *call)
7093 {
7094         entity_t *entity = call->function->reference.entity;
7095         switch (entity->function.btk) {
7096         case BUILTIN_FIRM:
7097                 switch (entity->function.b.firm_builtin_kind) {
7098                 case ir_bk_return_address:
7099                 case ir_bk_frame_address: {
7100                         /* argument must be constant */
7101                         call_argument_t *argument = call->arguments;
7102
7103                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7104                                 errorf(&call->base.pos,
7105                                            "argument of '%Y' must be a constant expression",
7106                                            call->function->reference.entity->base.symbol);
7107                         }
7108                         break;
7109                 }
7110                 case ir_bk_prefetch:
7111                         /* second and third argument must be constant if existent */
7112                         if (call->arguments == NULL)
7113                                 break;
7114                         call_argument_t *rw = call->arguments->next;
7115                         call_argument_t *locality = NULL;
7116
7117                         if (rw != NULL) {
7118                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7119                                         errorf(&call->base.pos,
7120                                                    "second argument of '%Y' must be a constant expression",
7121                                                    call->function->reference.entity->base.symbol);
7122                                 }
7123                                 locality = rw->next;
7124                         }
7125                         if (locality != NULL) {
7126                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7127                                         errorf(&call->base.pos,
7128                                                    "third argument of '%Y' must be a constant expression",
7129                                                    call->function->reference.entity->base.symbol);
7130                                 }
7131                         }
7132                         break;
7133                 default:
7134                         break;
7135                 }
7136
7137         case BUILTIN_OBJECT_SIZE:
7138                 if (call->arguments == NULL)
7139                         break;
7140
7141                 call_argument_t *arg = call->arguments->next;
7142                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7143                         errorf(&call->base.pos,
7144                                    "second argument of '%Y' must be a constant expression",
7145                                    call->function->reference.entity->base.symbol);
7146                 }
7147                 break;
7148         default:
7149                 break;
7150         }
7151 }
7152
7153 /**
7154  * Parse a call expression, i.e. expression '( ... )'.
7155  *
7156  * @param expression  the function address
7157  */
7158 static expression_t *parse_call_expression(expression_t *expression)
7159 {
7160         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7161         call_expression_t *call   = &result->call;
7162         call->function            = expression;
7163
7164         type_t *const orig_type = expression->base.type;
7165         type_t *const type      = skip_typeref(orig_type);
7166
7167         function_type_t *function_type = NULL;
7168         if (is_type_pointer(type)) {
7169                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7170
7171                 if (is_type_function(to_type)) {
7172                         function_type   = &to_type->function;
7173                         call->base.type = function_type->return_type;
7174                 }
7175         }
7176
7177         if (function_type == NULL && is_type_valid(type)) {
7178                 errorf(HERE,
7179                        "called object '%E' (type '%T') is not a pointer to a function",
7180                        expression, orig_type);
7181         }
7182
7183         /* parse arguments */
7184         eat('(');
7185         add_anchor_token(')');
7186         add_anchor_token(',');
7187
7188         if (token.kind != ')') {
7189                 call_argument_t **anchor = &call->arguments;
7190                 do {
7191                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7192                         argument->expression = parse_assignment_expression();
7193
7194                         *anchor = argument;
7195                         anchor  = &argument->next;
7196                 } while (accept(','));
7197         }
7198         rem_anchor_token(',');
7199         rem_anchor_token(')');
7200         expect(')');
7201
7202         if (function_type == NULL)
7203                 return result;
7204
7205         /* check type and count of call arguments */
7206         function_parameter_t *parameter = function_type->parameters;
7207         call_argument_t      *argument  = call->arguments;
7208         if (!function_type->unspecified_parameters) {
7209                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7210                                 parameter = parameter->next, argument = argument->next) {
7211                         check_call_argument(parameter->type, argument, ++pos);
7212                 }
7213
7214                 if (parameter != NULL) {
7215                         errorf(&expression->base.pos, "too few arguments to function '%E'",
7216                                expression);
7217                 } else if (argument != NULL && !function_type->variadic) {
7218                         errorf(&argument->expression->base.pos,
7219                                "too many arguments to function '%E'", expression);
7220                 }
7221         }
7222
7223         /* do default promotion for other arguments */
7224         for (; argument != NULL; argument = argument->next) {
7225                 type_t *argument_type = argument->expression->base.type;
7226                 if (!is_type_object(skip_typeref(argument_type))) {
7227                         errorf(&argument->expression->base.pos,
7228                                "call argument '%E' must not be void", argument->expression);
7229                 }
7230
7231                 argument_type = get_default_promoted_type(argument_type);
7232
7233                 argument->expression
7234                         = create_implicit_cast(argument->expression, argument_type);
7235         }
7236
7237         check_format(call);
7238
7239         if (is_type_compound(skip_typeref(function_type->return_type))) {
7240                 position_t const *const pos = &expression->base.pos;
7241                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7242         }
7243
7244         if (expression->kind == EXPR_REFERENCE) {
7245                 reference_expression_t *reference = &expression->reference;
7246                 if (reference->entity->kind == ENTITY_FUNCTION &&
7247                     reference->entity->function.btk != BUILTIN_NONE)
7248                         handle_builtin_argument_restrictions(call);
7249         }
7250
7251         return result;
7252 }
7253
7254 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7255
7256 static bool same_compound_type(const type_t *type1, const type_t *type2)
7257 {
7258         return
7259                 is_type_compound(type1) &&
7260                 type1->kind == type2->kind &&
7261                 type1->compound.compound == type2->compound.compound;
7262 }
7263
7264 static expression_t const *get_reference_address(expression_t const *expr)
7265 {
7266         bool regular_take_address = true;
7267         for (;;) {
7268                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7269                         expr = expr->unary.value;
7270                 } else {
7271                         regular_take_address = false;
7272                 }
7273
7274                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7275                         break;
7276
7277                 expr = expr->unary.value;
7278         }
7279
7280         if (expr->kind != EXPR_REFERENCE)
7281                 return NULL;
7282
7283         /* special case for functions which are automatically converted to a
7284          * pointer to function without an extra TAKE_ADDRESS operation */
7285         if (!regular_take_address &&
7286                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7287                 return NULL;
7288         }
7289
7290         return expr;
7291 }
7292
7293 static void warn_reference_address_as_bool(expression_t const* expr)
7294 {
7295         expr = get_reference_address(expr);
7296         if (expr != NULL) {
7297                 position_t const *const pos = &expr->base.pos;
7298                 entity_t   const *const ent = expr->reference.entity;
7299                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7300         }
7301 }
7302
7303 static void warn_assignment_in_condition(const expression_t *const expr)
7304 {
7305         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7306                 return;
7307         if (expr->base.parenthesized)
7308                 return;
7309         position_t const *const pos = &expr->base.pos;
7310         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7311 }
7312
7313 static void semantic_condition(expression_t const *const expr,
7314                                char const *const context)
7315 {
7316         type_t *const type = skip_typeref(expr->base.type);
7317         if (is_type_scalar(type)) {
7318                 warn_reference_address_as_bool(expr);
7319                 warn_assignment_in_condition(expr);
7320         } else if (is_type_valid(type)) {
7321                 errorf(&expr->base.pos, "%s must have scalar type", context);
7322         }
7323 }
7324
7325 /**
7326  * Parse a conditional expression, i.e. 'expression ? ... : ...'.
7327  *
7328  * @param expression  the conditional expression
7329  */
7330 static expression_t *parse_conditional_expression(expression_t *expression)
7331 {
7332         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7333
7334         conditional_expression_t *conditional = &result->conditional;
7335         conditional->condition                = expression;
7336
7337         eat('?');
7338         add_anchor_token(':');
7339
7340         /* §6.5.15:2  The first operand shall have scalar type. */
7341         semantic_condition(expression, "condition of conditional operator");
7342
7343         expression_t *true_expression = expression;
7344         bool          gnu_cond = false;
7345         if (GNU_MODE && token.kind == ':') {
7346                 gnu_cond = true;
7347         } else {
7348                 true_expression = parse_expression();
7349         }
7350         rem_anchor_token(':');
7351         expect(':');
7352         expression_t *false_expression =
7353                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7354
7355         type_t *const orig_true_type  = true_expression->base.type;
7356         type_t *const orig_false_type = false_expression->base.type;
7357         type_t *const true_type       = skip_typeref(orig_true_type);
7358         type_t *const false_type      = skip_typeref(orig_false_type);
7359
7360         /* 6.5.15.3 */
7361         position_t const *const pos = &conditional->base.pos;
7362         type_t                 *result_type;
7363         if (is_type_void(true_type) || is_type_void(false_type)) {
7364                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7365                 if (true_expression->kind == EXPR_UNARY_THROW) {
7366                         result_type = false_type;
7367                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7368                         result_type = true_type;
7369                 } else {
7370                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7371                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7372                         }
7373                         result_type = type_void;
7374                 }
7375         } else if (is_type_arithmetic(true_type)
7376                    && is_type_arithmetic(false_type)) {
7377                 result_type = semantic_arithmetic(true_type, false_type);
7378         } else if (same_compound_type(true_type, false_type)) {
7379                 /* just take 1 of the 2 types */
7380                 result_type = true_type;
7381         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7382                 type_t *pointer_type;
7383                 type_t *other_type;
7384                 expression_t *other_expression;
7385                 if (is_type_pointer(true_type) &&
7386                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7387                         pointer_type     = true_type;
7388                         other_type       = false_type;
7389                         other_expression = false_expression;
7390                 } else {
7391                         pointer_type     = false_type;
7392                         other_type       = true_type;
7393                         other_expression = true_expression;
7394                 }
7395
7396                 if (is_null_pointer_constant(other_expression)) {
7397                         result_type = pointer_type;
7398                 } else if (is_type_pointer(other_type)) {
7399                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7400                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7401
7402                         type_t *to;
7403                         if (is_type_void(to1) || is_type_void(to2)) {
7404                                 to = type_void;
7405                         } else if (types_compatible(get_unqualified_type(to1),
7406                                                     get_unqualified_type(to2))) {
7407                                 to = to1;
7408                         } else {
7409                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7410                                 to = type_void;
7411                         }
7412
7413                         type_t *const type =
7414                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7415                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7416                 } else if (is_type_integer(other_type)) {
7417                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7418                         result_type = pointer_type;
7419                 } else {
7420                         goto types_incompatible;
7421                 }
7422         } else {
7423 types_incompatible:
7424                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7425                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7426                 }
7427                 result_type = type_error_type;
7428         }
7429
7430         conditional->true_expression
7431                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7432         conditional->false_expression
7433                 = create_implicit_cast(false_expression, result_type);
7434         conditional->base.type = result_type;
7435         return result;
7436 }
7437
7438 /**
7439  * Parse an extension expression.
7440  */
7441 static expression_t *parse_extension(void)
7442 {
7443         PUSH_EXTENSION();
7444         expression_t *expression = parse_subexpression(PREC_UNARY);
7445         POP_EXTENSION();
7446         return expression;
7447 }
7448
7449 /**
7450  * Parse a __builtin_classify_type() expression.
7451  */
7452 static expression_t *parse_builtin_classify_type(void)
7453 {
7454         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7455         result->base.type    = type_int;
7456
7457         eat(T___builtin_classify_type);
7458
7459         add_anchor_token(')');
7460         expect('(');
7461         expression_t *expression = parse_expression();
7462         rem_anchor_token(')');
7463         expect(')');
7464         result->classify_type.type_expression = expression;
7465
7466         return result;
7467 }
7468
7469 /**
7470  * Parse a delete expression
7471  * ISO/IEC 14882:1998(E) §5.3.5
7472  */
7473 static expression_t *parse_delete(void)
7474 {
7475         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7476         result->base.type          = type_void;
7477
7478         eat(T_delete);
7479
7480         if (accept('[')) {
7481                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7482                 expect(']');
7483         }
7484
7485         expression_t *const value = parse_subexpression(PREC_CAST);
7486         result->unary.value = value;
7487
7488         type_t *const type = skip_typeref(value->base.type);
7489         if (!is_type_pointer(type)) {
7490                 if (is_type_valid(type)) {
7491                         errorf(&value->base.pos,
7492                                         "operand of delete must have pointer type");
7493                 }
7494         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7495                 position_t const *const pos = &value->base.pos;
7496                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7497         }
7498
7499         return result;
7500 }
7501
7502 /**
7503  * Parse a throw expression
7504  * ISO/IEC 14882:1998(E) §15:1
7505  */
7506 static expression_t *parse_throw(void)
7507 {
7508         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7509         result->base.type          = type_void;
7510
7511         eat(T_throw);
7512
7513         expression_t *value = NULL;
7514         switch (token.kind) {
7515                 EXPRESSION_START {
7516                         value = parse_assignment_expression();
7517                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7518                         type_t *const orig_type = value->base.type;
7519                         type_t *const type      = skip_typeref(orig_type);
7520                         if (is_type_incomplete(type)) {
7521                                 errorf(&value->base.pos,
7522                                                 "cannot throw object of incomplete type '%T'", orig_type);
7523                         } else if (is_type_pointer(type)) {
7524                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7525                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7526                                         errorf(&value->base.pos,
7527                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7528                                 }
7529                         }
7530                 }
7531
7532                 default:
7533                         break;
7534         }
7535         result->unary.value = value;
7536
7537         return result;
7538 }
7539
7540 static bool check_pointer_arithmetic(const position_t *pos,
7541                                      type_t *pointer_type,
7542                                      type_t *orig_pointer_type)
7543 {
7544         type_t *points_to = pointer_type->pointer.points_to;
7545         points_to = skip_typeref(points_to);
7546
7547         if (is_type_incomplete(points_to)) {
7548                 if (!GNU_MODE || !is_type_void(points_to)) {
7549                         errorf(pos,
7550                                "arithmetic with pointer to incomplete type '%T' not allowed",
7551                                orig_pointer_type);
7552                         return false;
7553                 } else {
7554                         warningf(WARN_POINTER_ARITH, pos, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7555                 }
7556         } else if (is_type_function(points_to)) {
7557                 if (!GNU_MODE) {
7558                         errorf(pos,
7559                                "arithmetic with pointer to function type '%T' not allowed",
7560                                orig_pointer_type);
7561                         return false;
7562                 } else {
7563                         warningf(WARN_POINTER_ARITH, pos,
7564                                  "pointer to a function '%T' used in arithmetic",
7565                                  orig_pointer_type);
7566                 }
7567         }
7568         return true;
7569 }
7570
7571 static bool is_lvalue(const expression_t *expression)
7572 {
7573         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7574         switch (expression->kind) {
7575         case EXPR_ARRAY_ACCESS:
7576         case EXPR_COMPOUND_LITERAL:
7577         case EXPR_REFERENCE:
7578         case EXPR_SELECT:
7579         case EXPR_UNARY_DEREFERENCE:
7580                 return true;
7581
7582         default: {
7583                 type_t *type = skip_typeref(expression->base.type);
7584                 return
7585                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7586                         is_type_reference(type) ||
7587                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7588                          * error before, which maybe prevented properly recognizing it as
7589                          * lvalue. */
7590                         !is_type_valid(type);
7591         }
7592         }
7593 }
7594
7595 static void semantic_incdec(unary_expression_t *expression)
7596 {
7597         type_t *orig_type = expression->value->base.type;
7598         type_t *type      = skip_typeref(orig_type);
7599         if (is_type_pointer(type)) {
7600                 if (!check_pointer_arithmetic(&expression->base.pos, type, orig_type)) {
7601                         return;
7602                 }
7603         } else if (!is_type_real(type) &&
7604                    (!GNU_MODE || !is_type_complex(type)) && is_type_valid(type)) {
7605                 /* TODO: improve error message */
7606                 errorf(&expression->base.pos,
7607                        "operation needs an arithmetic or pointer type");
7608                 orig_type = type = type_error_type;
7609         }
7610         if (!is_lvalue(expression->value)) {
7611                 /* TODO: improve error message */
7612                 errorf(&expression->base.pos, "lvalue required as operand");
7613         }
7614         expression->base.type = orig_type;
7615 }
7616
7617 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7618 {
7619         atomic_type_kind_t akind = get_arithmetic_akind(type);
7620         type_t *res_type;
7621         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT)) {
7622                 if (type->kind == TYPE_COMPLEX)
7623                         res_type = make_complex_type(ATOMIC_TYPE_INT, TYPE_QUALIFIER_NONE);
7624                 else
7625                         res_type = type_int;
7626         } else {
7627                 res_type = type;
7628         }
7629         expr->base.type = res_type;
7630         expr->value     = create_implicit_cast(expr->value, res_type);
7631 }
7632
7633 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7634 {
7635         type_t *const orig_type = expression->value->base.type;
7636         type_t *const type      = skip_typeref(orig_type);
7637         if (!is_type_arithmetic(type)) {
7638                 if (is_type_valid(type)) {
7639                         position_t const *const pos = &expression->base.pos;
7640                         errorf(pos, "operand of unary expression must have arithmetic type, but is '%T'", orig_type);
7641                 }
7642                 return;
7643         } else if (is_type_integer(type)) {
7644                 promote_unary_int_expr(expression, type);
7645         } else {
7646                 expression->base.type = orig_type;
7647         }
7648 }
7649
7650 static void semantic_unexpr_plus(unary_expression_t *expression)
7651 {
7652         semantic_unexpr_arithmetic(expression);
7653         position_t const *const pos = &expression->base.pos;
7654         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7655 }
7656
7657 static void semantic_not(unary_expression_t *expression)
7658 {
7659         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7660         semantic_condition(expression->value, "operand of !");
7661         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7662 }
7663
7664 static void semantic_complement(unary_expression_t *expression)
7665 {
7666         type_t *const orig_type = expression->value->base.type;
7667         type_t *const type      = skip_typeref(orig_type);
7668         if (!is_type_integer(type) && (!GNU_MODE || !is_type_complex(type))) {
7669                 if (is_type_valid(type)) {
7670                         errorf(&expression->base.pos, "operand of ~ must be of integer type");
7671                 }
7672                 return;
7673         }
7674
7675         if (is_type_integer(type)) {
7676                 promote_unary_int_expr(expression, type);
7677         } else {
7678                 expression->base.type = orig_type;
7679         }
7680 }
7681
7682 static void semantic_dereference(unary_expression_t *expression)
7683 {
7684         type_t *const orig_type = expression->value->base.type;
7685         type_t *const type      = skip_typeref(orig_type);
7686         if (!is_type_pointer(type)) {
7687                 if (is_type_valid(type)) {
7688                         errorf(&expression->base.pos,
7689                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7690                 }
7691                 return;
7692         }
7693
7694         type_t *result_type   = type->pointer.points_to;
7695         result_type           = automatic_type_conversion(result_type);
7696         expression->base.type = result_type;
7697 }
7698
7699 /**
7700  * Record that an address is taken (expression represents an lvalue).
7701  *
7702  * @param expression       the expression
7703  * @param may_be_register  if true, the expression might be an register
7704  */
7705 static void set_address_taken(expression_t *expression, bool may_be_register)
7706 {
7707         if (expression->kind != EXPR_REFERENCE)
7708                 return;
7709
7710         entity_t *const entity = expression->reference.entity;
7711
7712         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7713                 return;
7714
7715         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7716                         && !may_be_register) {
7717                 position_t const *const pos = &expression->base.pos;
7718                 errorf(pos, "address of register '%N' requested", entity);
7719         }
7720
7721         entity->variable.address_taken = true;
7722 }
7723
7724 /**
7725  * Check the semantic of the address taken expression.
7726  */
7727 static void semantic_take_addr(unary_expression_t *expression)
7728 {
7729         expression_t *value = expression->value;
7730         value->base.type    = revert_automatic_type_conversion(value);
7731
7732         type_t *orig_type = value->base.type;
7733         type_t *type      = skip_typeref(orig_type);
7734         if (!is_type_valid(type))
7735                 return;
7736
7737         /* §6.5.3.2 */
7738         if (!is_lvalue(value)) {
7739                 errorf(&expression->base.pos, "'&' requires an lvalue");
7740         }
7741         if (is_bitfield(value)) {
7742                 errorf(&expression->base.pos, "'&' not allowed on bitfield");
7743         }
7744
7745         set_address_taken(value, false);
7746
7747         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7748 }
7749
7750 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7751 static expression_t *parse_##unexpression_type(void)                         \
7752 {                                                                            \
7753         expression_t *unary_expression                                           \
7754                 = allocate_expression_zero(unexpression_type);                       \
7755         eat(token_kind);                                                         \
7756         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7757                                                                                  \
7758         sfunc(&unary_expression->unary);                                         \
7759                                                                                  \
7760         return unary_expression;                                                 \
7761 }
7762
7763 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7764                                semantic_unexpr_arithmetic)
7765 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7766                                semantic_unexpr_plus)
7767 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7768                                semantic_not)
7769 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7770                                semantic_dereference)
7771 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7772                                semantic_take_addr)
7773 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_COMPLEMENT,
7774                                semantic_complement)
7775 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7776                                semantic_incdec)
7777 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7778                                semantic_incdec)
7779
7780 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7781                                                sfunc)                         \
7782 static expression_t *parse_##unexpression_type(expression_t *left)            \
7783 {                                                                             \
7784         expression_t *unary_expression                                            \
7785                 = allocate_expression_zero(unexpression_type);                        \
7786         eat(token_kind);                                                          \
7787         unary_expression->unary.value = left;                                     \
7788                                                                                   \
7789         sfunc(&unary_expression->unary);                                          \
7790                                                                               \
7791         return unary_expression;                                                  \
7792 }
7793
7794 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7795                                        EXPR_UNARY_POSTFIX_INCREMENT,
7796                                        semantic_incdec)
7797 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7798                                        EXPR_UNARY_POSTFIX_DECREMENT,
7799                                        semantic_incdec)
7800
7801 static atomic_type_kind_t semantic_arithmetic_(atomic_type_kind_t kind_left,
7802                                                atomic_type_kind_t kind_right)
7803 {
7804         /* §6.3.1.8 Usual arithmetic conversions */
7805         if (kind_left == ATOMIC_TYPE_LONG_DOUBLE
7806          || kind_right == ATOMIC_TYPE_LONG_DOUBLE) {
7807                 return ATOMIC_TYPE_LONG_DOUBLE;
7808         } else if (kind_left == ATOMIC_TYPE_DOUBLE
7809                 || kind_right == ATOMIC_TYPE_DOUBLE) {
7810             return ATOMIC_TYPE_DOUBLE;
7811         } else if (kind_left == ATOMIC_TYPE_FLOAT
7812                 || kind_right == ATOMIC_TYPE_FLOAT) {
7813                 return ATOMIC_TYPE_FLOAT;
7814         }
7815
7816         unsigned       rank_left  = get_akind_rank(kind_left);
7817         unsigned       rank_right = get_akind_rank(kind_right);
7818         unsigned const rank_int   = get_akind_rank(ATOMIC_TYPE_INT);
7819         if (rank_left < rank_int) {
7820                 kind_left = ATOMIC_TYPE_INT;
7821                 rank_left = rank_int;
7822         }
7823         if (rank_right < rank_int) {
7824                 kind_right = ATOMIC_TYPE_INT;
7825                 rank_right = rank_int;
7826         }
7827         if (kind_left == kind_right)
7828                 return kind_left;
7829
7830         bool const signed_left  = is_akind_signed(kind_left);
7831         bool const signed_right = is_akind_signed(kind_right);
7832         if (signed_left == signed_right)
7833                 return rank_left >= rank_right ? kind_left : kind_right;
7834
7835         unsigned           s_rank;
7836         unsigned           u_rank;
7837         atomic_type_kind_t s_kind;
7838         atomic_type_kind_t u_kind;
7839         if (signed_left) {
7840                 s_kind = kind_left;
7841                 s_rank = rank_left;
7842                 u_kind = kind_right;
7843                 u_rank = rank_right;
7844         } else {
7845                 s_kind = kind_right;
7846                 s_rank = rank_right;
7847                 u_kind = kind_left;
7848                 u_rank = rank_left;
7849         }
7850         if (u_rank >= s_rank)
7851                 return u_kind;
7852         if (get_atomic_type_size(s_kind) > get_atomic_type_size(u_kind))
7853                 return s_kind;
7854
7855         switch (s_kind) {
7856         case ATOMIC_TYPE_INT:      return ATOMIC_TYPE_UINT;
7857         case ATOMIC_TYPE_LONG:     return ATOMIC_TYPE_ULONG;
7858         case ATOMIC_TYPE_LONGLONG: return ATOMIC_TYPE_ULONGLONG;
7859         default: panic("invalid atomic type");
7860         }
7861 }
7862
7863 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7864 {
7865         atomic_type_kind_t kind_left  = get_arithmetic_akind(type_left);
7866         atomic_type_kind_t kind_right = get_arithmetic_akind(type_right);
7867         atomic_type_kind_t kind_res   = semantic_arithmetic_(kind_left, kind_right);
7868
7869         if (type_left->kind == TYPE_COMPLEX || type_right->kind == TYPE_COMPLEX) {
7870                 return make_complex_type(kind_res, TYPE_QUALIFIER_NONE);
7871         }
7872         return make_atomic_type(kind_res, TYPE_QUALIFIER_NONE);
7873 }
7874
7875 /**
7876  * Check the semantic restrictions for a binary expression.
7877  */
7878 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7879 {
7880         expression_t *const left            = expression->left;
7881         expression_t *const right           = expression->right;
7882         type_t       *const orig_type_left  = left->base.type;
7883         type_t       *const orig_type_right = right->base.type;
7884         type_t       *const type_left       = skip_typeref(orig_type_left);
7885         type_t       *const type_right      = skip_typeref(orig_type_right);
7886
7887         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7888                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7889                         position_t const *const pos = &expression->base.pos;
7890                         errorf(pos, "operands of binary expression must have arithmetic types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7891                 }
7892                 return;
7893         }
7894
7895         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7896         expression->left      = create_implicit_cast(left, arithmetic_type);
7897         expression->right     = create_implicit_cast(right, arithmetic_type);
7898         expression->base.type = arithmetic_type;
7899 }
7900
7901 static void semantic_binexpr_integer(binary_expression_t *const expression)
7902 {
7903         expression_t *const left            = expression->left;
7904         expression_t *const right           = expression->right;
7905         type_t       *const orig_type_left  = left->base.type;
7906         type_t       *const orig_type_right = right->base.type;
7907         type_t       *const type_left       = skip_typeref(orig_type_left);
7908         type_t       *const type_right      = skip_typeref(orig_type_right);
7909
7910         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7911                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7912                         position_t const *const pos = &expression->base.pos;
7913                         errorf(pos, "operands of binary expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7914                 }
7915                 return;
7916         }
7917
7918         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7919         expression->left      = create_implicit_cast(left, result_type);
7920         expression->right     = create_implicit_cast(right, result_type);
7921         expression->base.type = result_type;
7922 }
7923
7924 static void warn_div_by_zero(binary_expression_t const *const expression)
7925 {
7926         if (!is_type_integer(expression->base.type))
7927                 return;
7928
7929         expression_t const *const right = expression->right;
7930         /* The type of the right operand can be different for /= */
7931         if (is_type_integer(skip_typeref(right->base.type))      &&
7932             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7933             !fold_constant_to_bool(right)) {
7934                 position_t const *const pos = &expression->base.pos;
7935                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7936         }
7937 }
7938
7939 /**
7940  * Check the semantic restrictions for a div expression.
7941  */
7942 static void semantic_div(binary_expression_t *expression)
7943 {
7944         semantic_binexpr_arithmetic(expression);
7945         warn_div_by_zero(expression);
7946 }
7947
7948 /**
7949  * Check the semantic restrictions for a mod expression.
7950  */
7951 static void semantic_mod(binary_expression_t *expression)
7952 {
7953         semantic_binexpr_integer(expression);
7954         warn_div_by_zero(expression);
7955 }
7956
7957 static void warn_addsub_in_shift(const expression_t *const expr)
7958 {
7959         if (expr->base.parenthesized)
7960                 return;
7961
7962         char op;
7963         switch (expr->kind) {
7964                 case EXPR_BINARY_ADD: op = '+'; break;
7965                 case EXPR_BINARY_SUB: op = '-'; break;
7966                 default:              return;
7967         }
7968
7969         position_t const *const pos = &expr->base.pos;
7970         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7971 }
7972
7973 static bool semantic_shift(binary_expression_t *expression)
7974 {
7975         expression_t *const left            = expression->left;
7976         expression_t *const right           = expression->right;
7977         type_t       *const orig_type_left  = left->base.type;
7978         type_t       *const orig_type_right = right->base.type;
7979         type_t       *      type_left       = skip_typeref(orig_type_left);
7980         type_t       *      type_right      = skip_typeref(orig_type_right);
7981
7982         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7983                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7984                         position_t const *const pos = &expression->base.pos;
7985                         errorf(pos, "operands of shift expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7986                 }
7987                 return false;
7988         }
7989
7990         type_left = promote_integer(type_left);
7991
7992         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7993                 position_t const *const pos   = &right->base.pos;
7994                 long              const count = fold_constant_to_int(right);
7995                 if (count < 0) {
7996                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7997                 } else if ((unsigned long)count >=
7998                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7999                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8000                 }
8001         }
8002
8003         type_right        = promote_integer(type_right);
8004         expression->right = create_implicit_cast(right, type_right);
8005
8006         return true;
8007 }
8008
8009 static void semantic_shift_op(binary_expression_t *expression)
8010 {
8011         expression_t *const left  = expression->left;
8012         expression_t *const right = expression->right;
8013
8014         if (!semantic_shift(expression))
8015                 return;
8016
8017         warn_addsub_in_shift(left);
8018         warn_addsub_in_shift(right);
8019
8020         type_t *const orig_type_left = left->base.type;
8021         type_t *      type_left      = skip_typeref(orig_type_left);
8022
8023         type_left             = promote_integer(type_left);
8024         expression->left      = create_implicit_cast(left, type_left);
8025         expression->base.type = type_left;
8026 }
8027
8028 static void semantic_add(binary_expression_t *expression)
8029 {
8030         expression_t *const left            = expression->left;
8031         expression_t *const right           = expression->right;
8032         type_t       *const orig_type_left  = left->base.type;
8033         type_t       *const orig_type_right = right->base.type;
8034         type_t       *const type_left       = skip_typeref(orig_type_left);
8035         type_t       *const type_right      = skip_typeref(orig_type_right);
8036
8037         /* §6.5.6 */
8038         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8039                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8040                 expression->left  = create_implicit_cast(left, arithmetic_type);
8041                 expression->right = create_implicit_cast(right, arithmetic_type);
8042                 expression->base.type = arithmetic_type;
8043         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8044                 check_pointer_arithmetic(&expression->base.pos, type_left,
8045                                          orig_type_left);
8046                 expression->base.type = type_left;
8047         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8048                 check_pointer_arithmetic(&expression->base.pos, type_right,
8049                                          orig_type_right);
8050                 expression->base.type = type_right;
8051         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8052                 errorf(&expression->base.pos,
8053                        "invalid operands to binary + ('%T', '%T')",
8054                        orig_type_left, orig_type_right);
8055         }
8056 }
8057
8058 static void semantic_sub(binary_expression_t *expression)
8059 {
8060         expression_t     *const left            = expression->left;
8061         expression_t     *const right           = expression->right;
8062         type_t           *const orig_type_left  = left->base.type;
8063         type_t           *const orig_type_right = right->base.type;
8064         type_t           *const type_left       = skip_typeref(orig_type_left);
8065         type_t           *const type_right      = skip_typeref(orig_type_right);
8066         position_t const *const pos             = &expression->base.pos;
8067
8068         /* §5.6.5 */
8069         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8070                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8071                 expression->left        = create_implicit_cast(left, arithmetic_type);
8072                 expression->right       = create_implicit_cast(right, arithmetic_type);
8073                 expression->base.type =  arithmetic_type;
8074         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8075                 check_pointer_arithmetic(&expression->base.pos, type_left,
8076                                          orig_type_left);
8077                 expression->base.type = type_left;
8078         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8079                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8080                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8081                 if (!types_compatible(unqual_left, unqual_right)) {
8082                         errorf(pos,
8083                                "subtracting pointers to incompatible types '%T' and '%T'",
8084                                orig_type_left, orig_type_right);
8085                 } else if (!is_type_object(unqual_left)) {
8086                         if (!is_type_void(unqual_left)) {
8087                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8088                                        orig_type_left);
8089                         } else {
8090                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8091                         }
8092                 }
8093                 expression->base.type = type_ptrdiff_t;
8094         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8095                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8096                        orig_type_left, orig_type_right);
8097         }
8098 }
8099
8100 static void warn_string_literal_address(expression_t const* expr)
8101 {
8102         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8103                 expr = expr->unary.value;
8104                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8105                         return;
8106                 expr = expr->unary.value;
8107         }
8108
8109         if (expr->kind == EXPR_STRING_LITERAL) {
8110                 position_t const *const pos = &expr->base.pos;
8111                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8112         }
8113 }
8114
8115 static bool maybe_negative(expression_t const *const expr)
8116 {
8117         switch (is_constant_expression(expr)) {
8118                 case EXPR_CLASS_ERROR:    return false;
8119                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8120                 default:                  return true;
8121         }
8122 }
8123
8124 static void warn_comparison(position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8125 {
8126         warn_string_literal_address(expr);
8127
8128         expression_t const* const ref = get_reference_address(expr);
8129         if (ref != NULL && is_null_pointer_constant(other)) {
8130                 entity_t const *const ent = ref->reference.entity;
8131                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8132         }
8133
8134         if (!expr->base.parenthesized) {
8135                 switch (expr->base.kind) {
8136                         case EXPR_BINARY_LESS:
8137                         case EXPR_BINARY_GREATER:
8138                         case EXPR_BINARY_LESSEQUAL:
8139                         case EXPR_BINARY_GREATEREQUAL:
8140                         case EXPR_BINARY_NOTEQUAL:
8141                         case EXPR_BINARY_EQUAL:
8142                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8143                                 break;
8144                         default:
8145                                 break;
8146                 }
8147         }
8148 }
8149
8150 /**
8151  * Check the semantics of comparison expressions.
8152  *
8153  * @param expression   The expression to check.
8154  */
8155 static void semantic_comparison(binary_expression_t *expression)
8156 {
8157         position_t const *const pos   = &expression->base.pos;
8158         expression_t     *const left  = expression->left;
8159         expression_t     *const right = expression->right;
8160
8161         warn_comparison(pos, left, right);
8162         warn_comparison(pos, right, left);
8163
8164         type_t *orig_type_left  = left->base.type;
8165         type_t *orig_type_right = right->base.type;
8166         type_t *type_left       = skip_typeref(orig_type_left);
8167         type_t *type_right      = skip_typeref(orig_type_right);
8168
8169         /* TODO non-arithmetic types */
8170         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8171                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8172
8173                 /* test for signed vs unsigned compares */
8174                 if (is_type_integer(arithmetic_type)) {
8175                         bool const signed_left  = is_type_signed(type_left);
8176                         bool const signed_right = is_type_signed(type_right);
8177                         if (signed_left != signed_right) {
8178                                 /* FIXME long long needs better const folding magic */
8179                                 /* TODO check whether constant value can be represented by other type */
8180                                 if ((signed_left  && maybe_negative(left)) ||
8181                                                 (signed_right && maybe_negative(right))) {
8182                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8183                                 }
8184                         }
8185                 }
8186
8187                 expression->left        = create_implicit_cast(left, arithmetic_type);
8188                 expression->right       = create_implicit_cast(right, arithmetic_type);
8189                 expression->base.type   = arithmetic_type;
8190                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8191                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8192                     is_type_float(arithmetic_type)) {
8193                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8194                 }
8195         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8196                 /* TODO check compatibility */
8197         } else if (is_type_pointer(type_left)) {
8198                 expression->right = create_implicit_cast(right, type_left);
8199         } else if (is_type_pointer(type_right)) {
8200                 expression->left = create_implicit_cast(left, type_right);
8201         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8202                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8203         }
8204         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8205 }
8206
8207 /**
8208  * Checks if a compound type has constant fields.
8209  */
8210 static bool has_const_fields(const compound_type_t *type)
8211 {
8212         compound_t *compound = type->compound;
8213         entity_t   *entry    = compound->members.entities;
8214
8215         for (; entry != NULL; entry = entry->base.next) {
8216                 if (!is_declaration(entry))
8217                         continue;
8218
8219                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8220                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8221                         return true;
8222         }
8223
8224         return false;
8225 }
8226
8227 static bool is_valid_assignment_lhs(expression_t const* const left)
8228 {
8229         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8230         type_t *const type_left      = skip_typeref(orig_type_left);
8231
8232         if (!is_lvalue(left)) {
8233                 errorf(&left->base.pos,
8234                        "left hand side '%E' of assignment is not an lvalue", left);
8235                 return false;
8236         }
8237
8238         if (left->kind == EXPR_REFERENCE
8239                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8240                 errorf(&left->base.pos, "cannot assign to function '%E'", left);
8241                 return false;
8242         }
8243
8244         if (is_type_array(type_left)) {
8245                 errorf(&left->base.pos, "cannot assign to array '%E'", left);
8246                 return false;
8247         }
8248         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8249                 errorf(&left->base.pos,
8250                        "assignment to read-only location '%E' (type '%T')", left,
8251                        orig_type_left);
8252                 return false;
8253         }
8254         if (is_type_incomplete(type_left)) {
8255                 errorf(&left->base.pos, "left-hand side '%E' of assignment has incomplete type '%T'",
8256                        left, orig_type_left);
8257                 return false;
8258         }
8259         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8260                 errorf(&left->base.pos, "cannot assign to '%E' because compound type '%T' has read-only fields",
8261                        left, orig_type_left);
8262                 return false;
8263         }
8264
8265         return true;
8266 }
8267
8268 static void semantic_arithmetic_assign(binary_expression_t *expression)
8269 {
8270         expression_t *left            = expression->left;
8271         expression_t *right           = expression->right;
8272         type_t       *orig_type_left  = left->base.type;
8273         type_t       *orig_type_right = right->base.type;
8274
8275         if (!is_valid_assignment_lhs(left))
8276                 return;
8277
8278         type_t *type_left  = skip_typeref(orig_type_left);
8279         type_t *type_right = skip_typeref(orig_type_right);
8280
8281         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8282                 /* TODO: improve error message */
8283                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8284                         errorf(&expression->base.pos, "operation needs arithmetic types");
8285                 }
8286                 return;
8287         }
8288
8289         /* combined instructions are tricky. We can't create an implicit cast on
8290          * the left side, because we need the uncasted form for the store.
8291          * The ast2firm pass has to know that left_type must be right_type
8292          * for the arithmetic operation and create a cast by itself */
8293         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8294         expression->right       = create_implicit_cast(right, arithmetic_type);
8295         expression->base.type   = type_left;
8296 }
8297
8298 static void semantic_divmod_assign(binary_expression_t *expression)
8299 {
8300         semantic_arithmetic_assign(expression);
8301         warn_div_by_zero(expression);
8302 }
8303
8304 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8305 {
8306         expression_t *const left            = expression->left;
8307         expression_t *const right           = expression->right;
8308         type_t       *const orig_type_left  = left->base.type;
8309         type_t       *const orig_type_right = right->base.type;
8310         type_t       *const type_left       = skip_typeref(orig_type_left);
8311         type_t       *const type_right      = skip_typeref(orig_type_right);
8312
8313         if (!is_valid_assignment_lhs(left))
8314                 return;
8315
8316         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8317                 /* combined instructions are tricky. We can't create an implicit cast on
8318                  * the left side, because we need the uncasted form for the store.
8319                  * The ast2firm pass has to know that left_type must be right_type
8320                  * for the arithmetic operation and create a cast by itself */
8321                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8322                 expression->right     = create_implicit_cast(right, arithmetic_type);
8323                 expression->base.type = type_left;
8324         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8325                 check_pointer_arithmetic(&expression->base.pos, type_left,
8326                                          orig_type_left);
8327                 expression->base.type = type_left;
8328         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8329                 errorf(&expression->base.pos,
8330                        "incompatible types '%T' and '%T' in assignment",
8331                        orig_type_left, orig_type_right);
8332         }
8333 }
8334
8335 static void semantic_integer_assign(binary_expression_t *expression)
8336 {
8337         expression_t *left            = expression->left;
8338         expression_t *right           = expression->right;
8339         type_t       *orig_type_left  = left->base.type;
8340         type_t       *orig_type_right = right->base.type;
8341
8342         if (!is_valid_assignment_lhs(left))
8343                 return;
8344
8345         type_t *type_left  = skip_typeref(orig_type_left);
8346         type_t *type_right = skip_typeref(orig_type_right);
8347
8348         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8349                 /* TODO: improve error message */
8350                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8351                         errorf(&expression->base.pos, "operation needs integer types");
8352                 }
8353                 return;
8354         }
8355
8356         /* combined instructions are tricky. We can't create an implicit cast on
8357          * the left side, because we need the uncasted form for the store.
8358          * The ast2firm pass has to know that left_type must be right_type
8359          * for the arithmetic operation and create a cast by itself */
8360         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8361         expression->right       = create_implicit_cast(right, arithmetic_type);
8362         expression->base.type   = type_left;
8363 }
8364
8365 static void semantic_shift_assign(binary_expression_t *expression)
8366 {
8367         expression_t *left           = expression->left;
8368
8369         if (!is_valid_assignment_lhs(left))
8370                 return;
8371
8372         if (!semantic_shift(expression))
8373                 return;
8374
8375         expression->base.type = skip_typeref(left->base.type);
8376 }
8377
8378 static void warn_logical_and_within_or(const expression_t *const expr)
8379 {
8380         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8381                 return;
8382         if (expr->base.parenthesized)
8383                 return;
8384         position_t const *const pos = &expr->base.pos;
8385         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8386 }
8387
8388 /**
8389  * Check the semantic restrictions of a logical expression.
8390  */
8391 static void semantic_logical_op(binary_expression_t *expression)
8392 {
8393         /* §6.5.13:2  Each of the operands shall have scalar type.
8394          * §6.5.14:2  Each of the operands shall have scalar type. */
8395         semantic_condition(expression->left,   "left operand of logical operator");
8396         semantic_condition(expression->right, "right operand of logical operator");
8397         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8398                 warn_logical_and_within_or(expression->left);
8399                 warn_logical_and_within_or(expression->right);
8400         }
8401         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8402 }
8403
8404 /**
8405  * Check the semantic restrictions of a binary assign expression.
8406  */
8407 static void semantic_binexpr_assign(binary_expression_t *expression)
8408 {
8409         expression_t *left           = expression->left;
8410         type_t       *orig_type_left = left->base.type;
8411
8412         if (!is_valid_assignment_lhs(left))
8413                 return;
8414
8415         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8416         report_assign_error(error, orig_type_left, expression->right,
8417                             "assignment", &left->base.pos);
8418         expression->right = create_implicit_cast(expression->right, orig_type_left);
8419         expression->base.type = orig_type_left;
8420 }
8421
8422 /**
8423  * Determine if the outermost operation (or parts thereof) of the given
8424  * expression has no effect in order to generate a warning about this fact.
8425  * Therefore in some cases this only examines some of the operands of the
8426  * expression (see comments in the function and examples below).
8427  * Examples:
8428  *   f() + 23;    // warning, because + has no effect
8429  *   x || f();    // no warning, because x controls execution of f()
8430  *   x ? y : f(); // warning, because y has no effect
8431  *   (void)x;     // no warning to be able to suppress the warning
8432  * This function can NOT be used for an "expression has definitely no effect"-
8433  * analysis. */
8434 static bool expression_has_effect(const expression_t *const expr)
8435 {
8436         switch (expr->kind) {
8437                 case EXPR_ERROR:                      return true; /* do NOT warn */
8438                 case EXPR_REFERENCE:                  return false;
8439                 case EXPR_ENUM_CONSTANT:              return false;
8440                 case EXPR_LABEL_ADDRESS:              return false;
8441
8442                 /* suppress the warning for microsoft __noop operations */
8443                 case EXPR_LITERAL_MS_NOOP:            return true;
8444                 case EXPR_LITERAL_BOOLEAN:
8445                 case EXPR_LITERAL_CHARACTER:
8446                 case EXPR_LITERAL_INTEGER:
8447                 case EXPR_LITERAL_FLOATINGPOINT:
8448                 case EXPR_STRING_LITERAL:             return false;
8449
8450                 case EXPR_CALL: {
8451                         const call_expression_t *const call = &expr->call;
8452                         if (call->function->kind != EXPR_REFERENCE)
8453                                 return true;
8454
8455                         switch (call->function->reference.entity->function.btk) {
8456                                 /* FIXME: which builtins have no effect? */
8457                                 default:                      return true;
8458                         }
8459                 }
8460
8461                 /* Generate the warning if either the left or right hand side of a
8462                  * conditional expression has no effect */
8463                 case EXPR_CONDITIONAL: {
8464                         conditional_expression_t const *const cond = &expr->conditional;
8465                         expression_t             const *const t    = cond->true_expression;
8466                         return
8467                                 (t == NULL || expression_has_effect(t)) &&
8468                                 expression_has_effect(cond->false_expression);
8469                 }
8470
8471                 case EXPR_SELECT:                     return false;
8472                 case EXPR_ARRAY_ACCESS:               return false;
8473                 case EXPR_SIZEOF:                     return false;
8474                 case EXPR_CLASSIFY_TYPE:              return false;
8475                 case EXPR_ALIGNOF:                    return false;
8476
8477                 case EXPR_FUNCNAME:                   return false;
8478                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8479                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8480                 case EXPR_OFFSETOF:                   return false;
8481                 case EXPR_VA_START:                   return true;
8482                 case EXPR_VA_ARG:                     return true;
8483                 case EXPR_VA_COPY:                    return true;
8484                 case EXPR_STATEMENT:                  return true; // TODO
8485                 case EXPR_COMPOUND_LITERAL:           return false;
8486
8487                 case EXPR_UNARY_NEGATE:               return false;
8488                 case EXPR_UNARY_PLUS:                 return false;
8489                 case EXPR_UNARY_COMPLEMENT:           return false;
8490                 case EXPR_UNARY_NOT:                  return false;
8491                 case EXPR_UNARY_DEREFERENCE:          return false;
8492                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8493                 case EXPR_UNARY_REAL:                 return false;
8494                 case EXPR_UNARY_IMAG:                 return false;
8495                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8496                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8497                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8498                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8499
8500                 /* Treat void casts as if they have an effect in order to being able to
8501                  * suppress the warning */
8502                 case EXPR_UNARY_CAST: {
8503                         type_t *const type = skip_typeref(expr->base.type);
8504                         return is_type_void(type);
8505                 }
8506
8507                 case EXPR_UNARY_ASSUME:               return true;
8508                 case EXPR_UNARY_DELETE:               return true;
8509                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8510                 case EXPR_UNARY_THROW:                return true;
8511
8512                 case EXPR_BINARY_ADD:                 return false;
8513                 case EXPR_BINARY_SUB:                 return false;
8514                 case EXPR_BINARY_MUL:                 return false;
8515                 case EXPR_BINARY_DIV:                 return false;
8516                 case EXPR_BINARY_MOD:                 return false;
8517                 case EXPR_BINARY_EQUAL:               return false;
8518                 case EXPR_BINARY_NOTEQUAL:            return false;
8519                 case EXPR_BINARY_LESS:                return false;
8520                 case EXPR_BINARY_LESSEQUAL:           return false;
8521                 case EXPR_BINARY_GREATER:             return false;
8522                 case EXPR_BINARY_GREATEREQUAL:        return false;
8523                 case EXPR_BINARY_BITWISE_AND:         return false;
8524                 case EXPR_BINARY_BITWISE_OR:          return false;
8525                 case EXPR_BINARY_BITWISE_XOR:         return false;
8526                 case EXPR_BINARY_SHIFTLEFT:           return false;
8527                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8528                 case EXPR_BINARY_ASSIGN:              return true;
8529                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8530                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8531                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8532                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8533                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8534                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8535                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8536                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8537                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8538                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8539
8540                 /* Only examine the right hand side of && and ||, because the left hand
8541                  * side already has the effect of controlling the execution of the right
8542                  * hand side */
8543                 case EXPR_BINARY_LOGICAL_AND:
8544                 case EXPR_BINARY_LOGICAL_OR:
8545                 /* Only examine the right hand side of a comma expression, because the left
8546                  * hand side has a separate warning */
8547                 case EXPR_BINARY_COMMA:
8548                         return expression_has_effect(expr->binary.right);
8549
8550                 case EXPR_BINARY_ISGREATER:           return false;
8551                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8552                 case EXPR_BINARY_ISLESS:              return false;
8553                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8554                 case EXPR_BINARY_ISLESSGREATER:       return false;
8555                 case EXPR_BINARY_ISUNORDERED:         return false;
8556         }
8557
8558         internal_errorf(HERE, "unexpected expression");
8559 }
8560
8561 static void semantic_comma(binary_expression_t *expression)
8562 {
8563         const expression_t *const left = expression->left;
8564         if (!expression_has_effect(left)) {
8565                 position_t const *const pos = &left->base.pos;
8566                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8567         }
8568         expression->base.type = expression->right->base.type;
8569 }
8570
8571 /**
8572  * @param prec_r precedence of the right operand
8573  */
8574 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8575 static expression_t *parse_##binexpression_type(expression_t *left)          \
8576 {                                                                            \
8577         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8578         binexpr->binary.left  = left;                                            \
8579         eat(token_kind);                                                         \
8580                                                                              \
8581         expression_t *right = parse_subexpression(prec_r);                       \
8582                                                                              \
8583         binexpr->binary.right = right;                                           \
8584         sfunc(&binexpr->binary);                                                 \
8585                                                                              \
8586         return binexpr;                                                          \
8587 }
8588
8589 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8590 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_div)
8591 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_mod)
8592 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8593 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8594 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8595 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8596 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8597 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8598 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8599 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8600 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8601 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8602 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8603 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8604 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8605 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8606 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8607 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8608 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8609 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8610 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8611 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8612 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8613 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8614 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8615 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8616 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8617 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8618 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8619
8620
8621 static expression_t *parse_subexpression(precedence_t precedence)
8622 {
8623         expression_parser_function_t *parser
8624                 = &expression_parsers[token.kind];
8625         expression_t                 *left;
8626
8627         if (parser->parser != NULL) {
8628                 left = parser->parser();
8629         } else {
8630                 left = parse_primary_expression();
8631         }
8632         assert(left != NULL);
8633
8634         while (true) {
8635                 parser = &expression_parsers[token.kind];
8636                 if (parser->infix_parser == NULL)
8637                         break;
8638                 if (parser->infix_precedence < precedence)
8639                         break;
8640
8641                 left = parser->infix_parser(left);
8642
8643                 assert(left != NULL);
8644         }
8645
8646         return left;
8647 }
8648
8649 /**
8650  * Parse an expression.
8651  */
8652 static expression_t *parse_expression(void)
8653 {
8654         return parse_subexpression(PREC_EXPRESSION);
8655 }
8656
8657 /**
8658  * Register a parser for a prefix-like operator.
8659  *
8660  * @param parser      the parser function
8661  * @param token_kind  the token type of the prefix token
8662  */
8663 static void register_expression_parser(parse_expression_function parser,
8664                                        int token_kind)
8665 {
8666         expression_parser_function_t *entry = &expression_parsers[token_kind];
8667
8668         assert(!entry->parser);
8669         entry->parser = parser;
8670 }
8671
8672 /**
8673  * Register a parser for an infix operator with given precedence.
8674  *
8675  * @param parser      the parser function
8676  * @param token_kind  the token type of the infix operator
8677  * @param precedence  the precedence of the operator
8678  */
8679 static void register_infix_parser(parse_expression_infix_function parser,
8680                                   int token_kind, precedence_t precedence)
8681 {
8682         expression_parser_function_t *entry = &expression_parsers[token_kind];
8683
8684         assert(!entry->infix_parser);
8685         entry->infix_parser     = parser;
8686         entry->infix_precedence = precedence;
8687 }
8688
8689 /**
8690  * Initialize the expression parsers.
8691  */
8692 static void init_expression_parsers(void)
8693 {
8694         memset(&expression_parsers, 0, sizeof(expression_parsers));
8695
8696         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8697         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8698         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8699         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8700         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8701         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8702         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8703         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8704         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8705         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8706         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8707         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8708         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8709         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8710         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8711         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8712         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8713         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8714         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8715         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8716         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8717         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8718         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8719         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8720         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8721         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8722         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8723         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8724         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8725         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8726         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8727         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8728         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8729         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8730         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8731         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8732         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8733
8734         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8735         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8736         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8737         register_expression_parser(parse_EXPR_UNARY_COMPLEMENT,       '~');
8738         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8739         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8740         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8741         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8742         register_expression_parser(parse_sizeof,                      T_sizeof);
8743         register_expression_parser(parse_alignof,                     T__Alignof);
8744         register_expression_parser(parse_extension,                   T___extension__);
8745         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8746         register_expression_parser(parse_delete,                      T_delete);
8747         register_expression_parser(parse_throw,                       T_throw);
8748 }
8749
8750 /**
8751  * Parse a asm statement arguments specification.
8752  */
8753 static void parse_asm_arguments(asm_argument_t **anchor, bool const is_out)
8754 {
8755         if (token.kind == T_STRING_LITERAL || token.kind == '[') {
8756                 add_anchor_token(',');
8757                 do {
8758                         asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8759
8760                         add_anchor_token(')');
8761                         add_anchor_token('(');
8762                         add_anchor_token(T_STRING_LITERAL);
8763
8764                         if (accept('[')) {
8765                                 add_anchor_token(']');
8766                                 argument->symbol = expect_identifier("while parsing asm argument", NULL);
8767                                 rem_anchor_token(']');
8768                                 expect(']');
8769                         }
8770
8771                         rem_anchor_token(T_STRING_LITERAL);
8772                         argument->constraints = parse_string_literals("asm argument");
8773                         rem_anchor_token('(');
8774                         expect('(');
8775                         expression_t *expression = parse_expression();
8776                         if (is_out) {
8777                                 /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8778                                  * change size or type representation (e.g. int -> long is ok, but
8779                                  * int -> float is not) */
8780                                 if (expression->kind == EXPR_UNARY_CAST) {
8781                                         type_t      *const type = expression->base.type;
8782                                         type_kind_t  const kind = type->kind;
8783                                         if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8784                                                 unsigned flags;
8785                                                 unsigned size;
8786                                                 if (kind == TYPE_ATOMIC) {
8787                                                         atomic_type_kind_t const akind = type->atomic.akind;
8788                                                         flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8789                                                         size  = get_atomic_type_size(akind);
8790                                                 } else {
8791                                                         flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8792                                                         size  = get_type_size(type_void_ptr);
8793                                                 }
8794
8795                                                 do {
8796                                                         expression_t *const value      = expression->unary.value;
8797                                                         type_t       *const value_type = value->base.type;
8798                                                         type_kind_t   const value_kind = value_type->kind;
8799
8800                                                         unsigned value_flags;
8801                                                         unsigned value_size;
8802                                                         if (value_kind == TYPE_ATOMIC) {
8803                                                                 atomic_type_kind_t const value_akind = value_type->atomic.akind;
8804                                                                 value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8805                                                                 value_size  = get_atomic_type_size(value_akind);
8806                                                         } else if (value_kind == TYPE_POINTER) {
8807                                                                 value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8808                                                                 value_size  = get_type_size(type_void_ptr);
8809                                                         } else {
8810                                                                 break;
8811                                                         }
8812
8813                                                         if (value_flags != flags || value_size != size)
8814                                                                 break;
8815
8816                                                         expression = value;
8817                                                 } while (expression->kind == EXPR_UNARY_CAST);
8818                                         }
8819                                 }
8820
8821                                 if (!is_lvalue(expression))
8822                                         errorf(&expression->base.pos,
8823                                                "asm output argument is not an lvalue");
8824
8825                                 if (argument->constraints.begin[0] == '=')
8826                                         determine_lhs_ent(expression, NULL);
8827                                 else
8828                                         mark_vars_read(expression, NULL);
8829                         } else {
8830                                 mark_vars_read(expression, NULL);
8831                         }
8832                         argument->expression = expression;
8833                         rem_anchor_token(')');
8834                         expect(')');
8835
8836                         set_address_taken(expression, true);
8837
8838                         *anchor = argument;
8839                         anchor  = &argument->next;
8840                 } while (accept(','));
8841                 rem_anchor_token(',');
8842         }
8843 }
8844
8845 /**
8846  * Parse a asm statement clobber specification.
8847  */
8848 static void parse_asm_clobbers(asm_clobber_t **anchor)
8849 {
8850         if (token.kind == T_STRING_LITERAL) {
8851                 add_anchor_token(',');
8852                 do {
8853                         asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8854                         clobber->clobber       = parse_string_literals(NULL);
8855
8856                         *anchor = clobber;
8857                         anchor  = &clobber->next;
8858                 } while (accept(','));
8859                 rem_anchor_token(',');
8860         }
8861 }
8862
8863 static void parse_asm_labels(asm_label_t **anchor)
8864 {
8865         if (token.kind == T_IDENTIFIER) {
8866                 add_anchor_token(',');
8867                 do {
8868                         label_t *const label = get_label("while parsing 'asm goto' labels");
8869                         if (label) {
8870                                 asm_label_t *const asm_label = allocate_ast_zero(sizeof(*asm_label));
8871                                 asm_label->label = label;
8872
8873                                 *anchor = asm_label;
8874                                 anchor  = &asm_label->next;
8875                         }
8876                 } while (accept(','));
8877                 rem_anchor_token(',');
8878         }
8879 }
8880
8881 /**
8882  * Parse an asm statement.
8883  */
8884 static statement_t *parse_asm_statement(void)
8885 {
8886         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8887         asm_statement_t *asm_statement = &statement->asms;
8888
8889         eat(T_asm);
8890         add_anchor_token(')');
8891         add_anchor_token(':');
8892         add_anchor_token(T_STRING_LITERAL);
8893
8894         if (accept(T_volatile))
8895                 asm_statement->is_volatile = true;
8896
8897         bool const asm_goto = accept(T_goto);
8898
8899         expect('(');
8900         rem_anchor_token(T_STRING_LITERAL);
8901         asm_statement->asm_text = parse_string_literals("asm statement");
8902
8903         if (accept(':')) parse_asm_arguments(&asm_statement->outputs, true);
8904         if (accept(':')) parse_asm_arguments(&asm_statement->inputs, false);
8905         if (accept(':')) parse_asm_clobbers( &asm_statement->clobbers);
8906
8907         rem_anchor_token(':');
8908         if (accept(':')) {
8909                 if (!asm_goto)
8910                         warningf(WARN_OTHER, &statement->base.pos, "assembler statement with labels should be 'asm goto'");
8911                 parse_asm_labels(&asm_statement->labels);
8912                 if (asm_statement->labels)
8913                         errorf(&statement->base.pos, "'asm goto' not supported");
8914         } else {
8915                 if (asm_goto)
8916                         warningf(WARN_OTHER, &statement->base.pos, "'asm goto' without labels");
8917         }
8918
8919         rem_anchor_token(')');
8920         expect(')');
8921         expect(';');
8922
8923         if (asm_statement->outputs == NULL) {
8924                 /* GCC: An 'asm' instruction without any output operands will be treated
8925                  * identically to a volatile 'asm' instruction. */
8926                 asm_statement->is_volatile = true;
8927         }
8928
8929         return statement;
8930 }
8931
8932 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8933 {
8934         statement_t *inner_stmt;
8935         switch (token.kind) {
8936                 case '}':
8937                         errorf(&label->base.pos, "%s at end of compound statement", label_kind);
8938                         inner_stmt = create_error_statement();
8939                         break;
8940
8941                 case ';':
8942                         if (label->kind == STATEMENT_LABEL) {
8943                                 /* Eat an empty statement here, to avoid the warning about an empty
8944                                  * statement after a label.  label:; is commonly used to have a label
8945                                  * before a closing brace. */
8946                                 inner_stmt = create_empty_statement();
8947                                 eat(';');
8948                                 break;
8949                         }
8950                         /* FALLTHROUGH */
8951
8952                 default:
8953                         inner_stmt = parse_statement();
8954                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8955                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8956                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8957                                 errorf(&inner_stmt->base.pos, "declaration after %s", label_kind);
8958                         }
8959                         break;
8960         }
8961         return inner_stmt;
8962 }
8963
8964 /**
8965  * Parse a case statement.
8966  */
8967 static statement_t *parse_case_statement(void)
8968 {
8969         statement_t *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8970         position_t  *const pos       = &statement->base.pos;
8971
8972         eat(T_case);
8973         add_anchor_token(':');
8974
8975         expression_t *expression = parse_expression();
8976         type_t *expression_type = expression->base.type;
8977         type_t *skipped         = skip_typeref(expression_type);
8978         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8979                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8980                        expression, expression_type);
8981         }
8982
8983         type_t *type = expression_type;
8984         if (current_switch != NULL) {
8985                 type_t *switch_type = current_switch->expression->base.type;
8986                 if (is_type_valid(skip_typeref(switch_type))) {
8987                         expression = create_implicit_cast(expression, switch_type);
8988                 }
8989         }
8990
8991         statement->case_label.expression = expression;
8992         expression_classification_t const expr_class = is_constant_expression(expression);
8993         if (expr_class != EXPR_CLASS_CONSTANT) {
8994                 if (expr_class != EXPR_CLASS_ERROR) {
8995                         errorf(pos, "case label does not reduce to an integer constant");
8996                 }
8997                 statement->case_label.is_bad = true;
8998         } else {
8999                 ir_tarval *val = fold_constant_to_tarval(expression);
9000                 statement->case_label.first_case = val;
9001                 statement->case_label.last_case  = val;
9002         }
9003
9004         if (GNU_MODE) {
9005                 if (accept(T_DOTDOTDOT)) {
9006                         expression_t *end_range = parse_expression();
9007                         expression_type = expression->base.type;
9008                         skipped         = skip_typeref(expression_type);
9009                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9010                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9011                                            expression, expression_type);
9012                         }
9013
9014                         end_range = create_implicit_cast(end_range, type);
9015                         statement->case_label.end_range = end_range;
9016                         expression_classification_t const end_class = is_constant_expression(end_range);
9017                         if (end_class != EXPR_CLASS_CONSTANT) {
9018                                 if (end_class != EXPR_CLASS_ERROR) {
9019                                         errorf(pos, "case range does not reduce to an integer constant");
9020                                 }
9021                                 statement->case_label.is_bad = true;
9022                         } else {
9023                                 ir_tarval *val = fold_constant_to_tarval(end_range);
9024                                 statement->case_label.last_case = val;
9025
9026                                 if (tarval_cmp(val, statement->case_label.first_case)
9027                                     == ir_relation_less) {
9028                                         statement->case_label.is_empty_range = true;
9029                                         warningf(WARN_OTHER, pos, "empty range specified");
9030                                 }
9031                         }
9032                 }
9033         }
9034
9035         PUSH_PARENT(statement);
9036
9037         rem_anchor_token(':');
9038         expect(':');
9039
9040         if (current_switch != NULL) {
9041                 if (! statement->case_label.is_bad) {
9042                         /* Check for duplicate case values */
9043                         case_label_statement_t *c = &statement->case_label;
9044                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9045                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9046                                         continue;
9047
9048                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9049                                         continue;
9050
9051                                 errorf(pos, "duplicate case value (previously used %P)",
9052                                        &l->base.pos);
9053                                 break;
9054                         }
9055                 }
9056                 /* link all cases into the switch statement */
9057                 if (current_switch->last_case == NULL) {
9058                         current_switch->first_case      = &statement->case_label;
9059                 } else {
9060                         current_switch->last_case->next = &statement->case_label;
9061                 }
9062                 current_switch->last_case = &statement->case_label;
9063         } else {
9064                 errorf(pos, "case label not within a switch statement");
9065         }
9066
9067         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9068
9069         POP_PARENT();
9070         return statement;
9071 }
9072
9073 /**
9074  * Parse a default statement.
9075  */
9076 static statement_t *parse_default_statement(void)
9077 {
9078         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9079
9080         eat(T_default);
9081
9082         PUSH_PARENT(statement);
9083
9084         expect(':');
9085
9086         if (current_switch != NULL) {
9087                 const case_label_statement_t *def_label = current_switch->default_label;
9088                 if (def_label != NULL) {
9089                         errorf(&statement->base.pos, "multiple default labels in one switch (previous declared %P)", &def_label->base.pos);
9090                 } else {
9091                         current_switch->default_label = &statement->case_label;
9092
9093                         /* link all cases into the switch statement */
9094                         if (current_switch->last_case == NULL) {
9095                                 current_switch->first_case      = &statement->case_label;
9096                         } else {
9097                                 current_switch->last_case->next = &statement->case_label;
9098                         }
9099                         current_switch->last_case = &statement->case_label;
9100                 }
9101         } else {
9102                 errorf(&statement->base.pos,
9103                        "'default' label not within a switch statement");
9104         }
9105
9106         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9107
9108         POP_PARENT();
9109         return statement;
9110 }
9111
9112 /**
9113  * Parse a label statement.
9114  */
9115 static statement_t *parse_label_statement(void)
9116 {
9117         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9118         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9119         statement->label.label = label;
9120
9121         PUSH_PARENT(statement);
9122
9123         /* if statement is already set then the label is defined twice,
9124          * otherwise it was just mentioned in a goto/local label declaration so far
9125          */
9126         position_t const* const pos = &statement->base.pos;
9127         if (label->statement != NULL) {
9128                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.pos);
9129         } else {
9130                 label->base.pos  = *pos;
9131                 label->statement = statement;
9132                 label->n_users  += 1;
9133         }
9134
9135         eat(':');
9136
9137         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9138                 parse_attributes(NULL); // TODO process attributes
9139         }
9140
9141         statement->label.statement = parse_label_inner_statement(statement, "label");
9142
9143         /* remember the labels in a list for later checking */
9144         *label_anchor = &statement->label;
9145         label_anchor  = &statement->label.next;
9146
9147         POP_PARENT();
9148         return statement;
9149 }
9150
9151 static statement_t *parse_inner_statement(void)
9152 {
9153         statement_t *const stmt = parse_statement();
9154         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9155         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9156         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9157                 errorf(&stmt->base.pos, "declaration as inner statement, use {}");
9158         }
9159         return stmt;
9160 }
9161
9162 /**
9163  * Parse an expression in parentheses and mark its variables as read.
9164  */
9165 static expression_t *parse_condition(void)
9166 {
9167         add_anchor_token(')');
9168         expect('(');
9169         expression_t *const expr = parse_expression();
9170         mark_vars_read(expr, NULL);
9171         rem_anchor_token(')');
9172         expect(')');
9173         return expr;
9174 }
9175
9176 /**
9177  * Parse an if statement.
9178  */
9179 static statement_t *parse_if(void)
9180 {
9181         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9182
9183         eat(T_if);
9184
9185         PUSH_PARENT(statement);
9186         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9187
9188         add_anchor_token(T_else);
9189
9190         expression_t *const expr = parse_condition();
9191         statement->ifs.condition = expr;
9192         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9193          *             scalar type. */
9194         semantic_condition(expr, "condition of 'if'-statment");
9195
9196         statement_t *const true_stmt = parse_inner_statement();
9197         statement->ifs.true_statement = true_stmt;
9198         rem_anchor_token(T_else);
9199
9200         if (true_stmt->kind == STATEMENT_EMPTY) {
9201                 warningf(WARN_EMPTY_BODY, HERE,
9202                         "suggest braces around empty body in an ‘if’ statement");
9203         }
9204
9205         if (accept(T_else)) {
9206                 statement->ifs.false_statement = parse_inner_statement();
9207
9208                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9209                         warningf(WARN_EMPTY_BODY, HERE,
9210                                         "suggest braces around empty body in an ‘if’ statement");
9211                 }
9212         } else if (true_stmt->kind == STATEMENT_IF &&
9213                         true_stmt->ifs.false_statement != NULL) {
9214                 position_t const *const pos = &true_stmt->base.pos;
9215                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9216         }
9217
9218         POP_SCOPE();
9219         POP_PARENT();
9220         return statement;
9221 }
9222
9223 /**
9224  * Check that all enums are handled in a switch.
9225  *
9226  * @param statement  the switch statement to check
9227  */
9228 static void check_enum_cases(const switch_statement_t *statement)
9229 {
9230         if (!is_warn_on(WARN_SWITCH_ENUM))
9231                 return;
9232         type_t *type = skip_typeref(statement->expression->base.type);
9233         if (! is_type_enum(type))
9234                 return;
9235         enum_type_t *enumt = &type->enumt;
9236
9237         /* if we have a default, no warnings */
9238         if (statement->default_label != NULL)
9239                 return;
9240
9241         determine_enum_values(enumt);
9242
9243         /* FIXME: calculation of value should be done while parsing */
9244         /* TODO: quadratic algorithm here. Change to an n log n one */
9245         const entity_t *entry = enumt->enume->base.next;
9246         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9247              entry = entry->base.next) {
9248                 ir_tarval *value = entry->enum_value.tv;
9249                 bool       found = false;
9250                 for (const case_label_statement_t *l = statement->first_case; l != NULL;
9251                      l = l->next) {
9252                         if (l->expression == NULL)
9253                                 continue;
9254                         if (l->first_case == l->last_case && l->first_case != value)
9255                                 continue;
9256                         if ((tarval_cmp(l->first_case, value) & ir_relation_less_equal)
9257                          && (tarval_cmp(value, l->last_case) & ir_relation_less_equal)) {
9258                                 found = true;
9259                                 break;
9260                         }
9261                 }
9262                 if (!found) {
9263                         position_t const *const pos = &statement->base.pos;
9264                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9265                 }
9266         }
9267 }
9268
9269 /**
9270  * Parse a switch statement.
9271  */
9272 static statement_t *parse_switch(void)
9273 {
9274         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9275
9276         eat(T_switch);
9277
9278         PUSH_PARENT(statement);
9279         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9280
9281         expression_t *const expr = parse_condition();
9282         type_t       *      type = skip_typeref(expr->base.type);
9283         if (is_type_integer(type)) {
9284                 type = promote_integer(type);
9285                 if (get_akind_rank(get_arithmetic_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9286                         warningf(WARN_TRADITIONAL, &expr->base.pos,
9287                                  "'%T' switch expression not converted to '%T' in ISO C",
9288                                  type, type_int);
9289                 }
9290         } else if (is_type_valid(type)) {
9291                 errorf(&expr->base.pos, "switch quantity is not an integer, but '%T'",
9292                        type);
9293                 type = type_error_type;
9294         }
9295         statement->switchs.expression = create_implicit_cast(expr, type);
9296
9297         switch_statement_t *rem = current_switch;
9298         current_switch          = &statement->switchs;
9299         statement->switchs.body = parse_inner_statement();
9300         current_switch          = rem;
9301
9302         if (statement->switchs.default_label == NULL) {
9303                 warningf(WARN_SWITCH_DEFAULT, &statement->base.pos, "switch has no default case");
9304         }
9305         check_enum_cases(&statement->switchs);
9306
9307         POP_SCOPE();
9308         POP_PARENT();
9309         return statement;
9310 }
9311
9312 static statement_t *parse_loop_body(statement_t *const loop)
9313 {
9314         statement_t *const rem = current_loop;
9315         current_loop = loop;
9316
9317         statement_t *const body = parse_inner_statement();
9318
9319         current_loop = rem;
9320         return body;
9321 }
9322
9323 /**
9324  * Parse a while statement.
9325  */
9326 static statement_t *parse_while(void)
9327 {
9328         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9329
9330         eat(T_while);
9331
9332         PUSH_PARENT(statement);
9333         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9334
9335         expression_t *const cond = parse_condition();
9336         statement->fors.condition = cond;
9337         /* §6.8.5:2    The controlling expression of an iteration statement shall
9338          *             have scalar type. */
9339         semantic_condition(cond, "condition of 'while'-statement");
9340
9341         statement->fors.body = parse_loop_body(statement);
9342
9343         POP_SCOPE();
9344         POP_PARENT();
9345         return statement;
9346 }
9347
9348 /**
9349  * Parse a do statement.
9350  */
9351 static statement_t *parse_do(void)
9352 {
9353         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9354
9355         eat(T_do);
9356
9357         PUSH_PARENT(statement);
9358         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9359
9360         add_anchor_token(T_while);
9361         statement->do_while.body = parse_loop_body(statement);
9362         rem_anchor_token(T_while);
9363
9364         expect(T_while);
9365         expression_t *const cond = parse_condition();
9366         statement->do_while.condition = cond;
9367         /* §6.8.5:2    The controlling expression of an iteration statement shall
9368          *             have scalar type. */
9369         semantic_condition(cond, "condition of 'do-while'-statement");
9370         expect(';');
9371
9372         POP_SCOPE();
9373         POP_PARENT();
9374         return statement;
9375 }
9376
9377 /**
9378  * Parse a for statement.
9379  */
9380 static statement_t *parse_for(void)
9381 {
9382         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9383
9384         eat(T_for);
9385
9386         PUSH_PARENT(statement);
9387         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9388
9389         add_anchor_token(')');
9390         expect('(');
9391
9392         PUSH_EXTENSION();
9393
9394         if (accept(';')) {
9395         } else if (is_declaration_specifier(&token)) {
9396                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9397         } else {
9398                 add_anchor_token(';');
9399                 expression_t *const init = parse_expression();
9400                 statement->fors.initialisation = init;
9401                 mark_vars_read(init, ENT_ANY);
9402                 if (!expression_has_effect(init)) {
9403                         warningf(WARN_UNUSED_VALUE, &init->base.pos, "initialisation of 'for'-statement has no effect");
9404                 }
9405                 rem_anchor_token(';');
9406                 expect(';');
9407         }
9408
9409         POP_EXTENSION();
9410
9411         if (token.kind != ';') {
9412                 add_anchor_token(';');
9413                 expression_t *const cond = parse_expression();
9414                 statement->fors.condition = cond;
9415                 /* §6.8.5:2    The controlling expression of an iteration statement
9416                  *             shall have scalar type. */
9417                 semantic_condition(cond, "condition of 'for'-statement");
9418                 mark_vars_read(cond, NULL);
9419                 rem_anchor_token(';');
9420         }
9421         expect(';');
9422         if (token.kind != ')') {
9423                 expression_t *const step = parse_expression();
9424                 statement->fors.step = step;
9425                 mark_vars_read(step, ENT_ANY);
9426                 if (!expression_has_effect(step)) {
9427                         warningf(WARN_UNUSED_VALUE, &step->base.pos, "step of 'for'-statement has no effect");
9428                 }
9429         }
9430         rem_anchor_token(')');
9431         expect(')');
9432         statement->fors.body = parse_loop_body(statement);
9433
9434         POP_SCOPE();
9435         POP_PARENT();
9436         return statement;
9437 }
9438
9439 /**
9440  * Parse a goto statement.
9441  */
9442 static statement_t *parse_goto(void)
9443 {
9444         statement_t *statement;
9445         if (GNU_MODE && look_ahead(1)->kind == '*') {
9446                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9447                 eat(T_goto);
9448                 eat('*');
9449
9450                 expression_t *expression = parse_expression();
9451                 mark_vars_read(expression, NULL);
9452
9453                 /* Argh: although documentation says the expression must be of type void*,
9454                  * gcc accepts anything that can be casted into void* without error */
9455                 type_t *type = expression->base.type;
9456
9457                 if (type != type_error_type) {
9458                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9459                                 errorf(&expression->base.pos, "cannot convert to a pointer type");
9460                         } else if (type != type_void_ptr) {
9461                                 warningf(WARN_OTHER, &expression->base.pos, "type of computed goto expression should be 'void*' not '%T'", type);
9462                         }
9463                         expression = create_implicit_cast(expression, type_void_ptr);
9464                 }
9465
9466                 statement->computed_goto.expression = expression;
9467         } else {
9468                 statement = allocate_statement_zero(STATEMENT_GOTO);
9469                 eat(T_goto);
9470
9471                 label_t *const label = get_label("while parsing goto");
9472                 if (label) {
9473                         label->n_users        += 1;
9474                         label->used            = true;
9475                         statement->gotos.label = label;
9476
9477                         /* remember the goto's in a list for later checking */
9478                         *goto_anchor = &statement->gotos;
9479                         goto_anchor  = &statement->gotos.next;
9480                 } else {
9481                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_position)->label;
9482                 }
9483         }
9484
9485         expect(';');
9486         return statement;
9487 }
9488
9489 /**
9490  * Parse a continue statement.
9491  */
9492 static statement_t *parse_continue(void)
9493 {
9494         if (current_loop == NULL) {
9495                 errorf(HERE, "continue statement not within loop");
9496         }
9497
9498         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9499
9500         eat(T_continue);
9501         expect(';');
9502         return statement;
9503 }
9504
9505 /**
9506  * Parse a break statement.
9507  */
9508 static statement_t *parse_break(void)
9509 {
9510         if (current_switch == NULL && current_loop == NULL) {
9511                 errorf(HERE, "break statement not within loop or switch");
9512         }
9513
9514         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9515
9516         eat(T_break);
9517         expect(';');
9518         return statement;
9519 }
9520
9521 /**
9522  * Parse a __leave statement.
9523  */
9524 static statement_t *parse_leave_statement(void)
9525 {
9526         if (current_try == NULL) {
9527                 errorf(HERE, "__leave statement not within __try");
9528         }
9529
9530         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9531
9532         eat(T___leave);
9533         expect(';');
9534         return statement;
9535 }
9536
9537 /**
9538  * Check if a given entity represents a local variable.
9539  */
9540 static bool is_local_variable(const entity_t *entity)
9541 {
9542         if (entity->kind != ENTITY_VARIABLE)
9543                 return false;
9544
9545         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9546         case STORAGE_CLASS_AUTO:
9547         case STORAGE_CLASS_REGISTER: {
9548                 const type_t *type = skip_typeref(entity->declaration.type);
9549                 if (is_type_function(type)) {
9550                         return false;
9551                 } else {
9552                         return true;
9553                 }
9554         }
9555         default:
9556                 return false;
9557         }
9558 }
9559
9560 /**
9561  * Check if a given expression represents a local variable.
9562  */
9563 static bool expression_is_local_variable(const expression_t *expression)
9564 {
9565         if (expression->base.kind != EXPR_REFERENCE) {
9566                 return false;
9567         }
9568         const entity_t *entity = expression->reference.entity;
9569         return is_local_variable(entity);
9570 }
9571
9572 static void err_or_warn(position_t const *const pos, char const *const msg)
9573 {
9574         if (c_mode & _CXX || strict_mode) {
9575                 errorf(pos, msg);
9576         } else {
9577                 warningf(WARN_OTHER, pos, msg);
9578         }
9579 }
9580
9581 /**
9582  * Parse a return statement.
9583  */
9584 static statement_t *parse_return(void)
9585 {
9586         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9587         eat(T_return);
9588
9589         expression_t *return_value = NULL;
9590         if (token.kind != ';') {
9591                 return_value = parse_expression();
9592                 mark_vars_read(return_value, NULL);
9593         }
9594
9595         const type_t *const func_type = skip_typeref(current_function->base.type);
9596         assert(is_type_function(func_type));
9597         type_t *const return_type = skip_typeref(func_type->function.return_type);
9598
9599         position_t const *const pos = &statement->base.pos;
9600         if (return_value != NULL) {
9601                 type_t *return_value_type = skip_typeref(return_value->base.type);
9602
9603                 if (is_type_void(return_type)) {
9604                         if (!is_type_void(return_value_type)) {
9605                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9606                                 /* Only warn in C mode, because GCC does the same */
9607                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9608                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9609                                 /* Only warn in C mode, because GCC does the same */
9610                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9611                         }
9612                 } else {
9613                         assign_error_t error = semantic_assign(return_type, return_value);
9614                         report_assign_error(error, return_type, return_value, "'return'",
9615                                             pos);
9616                 }
9617                 return_value = create_implicit_cast(return_value, return_type);
9618                 /* check for returning address of a local var */
9619                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9620                         const expression_t *expression = return_value->unary.value;
9621                         if (expression_is_local_variable(expression)) {
9622                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9623                         }
9624                 }
9625         } else if (!is_type_void(return_type)) {
9626                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9627                 err_or_warn(pos, "'return' without value, in function returning non-void");
9628         }
9629         statement->returns.value = return_value;
9630
9631         expect(';');
9632         return statement;
9633 }
9634
9635 /**
9636  * Parse a declaration statement.
9637  */
9638 static statement_t *parse_declaration_statement(void)
9639 {
9640         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9641
9642         entity_t *before = current_scope->last_entity;
9643         if (GNU_MODE) {
9644                 parse_external_declaration();
9645         } else {
9646                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9647         }
9648
9649         declaration_statement_t *const decl  = &statement->declaration;
9650         entity_t                *const begin =
9651                 before != NULL ? before->base.next : current_scope->entities;
9652         decl->declarations_begin = begin;
9653         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9654
9655         return statement;
9656 }
9657
9658 /**
9659  * Parse an expression statement, i.e. expr ';'.
9660  */
9661 static statement_t *parse_expression_statement(void)
9662 {
9663         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9664
9665         expression_t *const expr         = parse_expression();
9666         statement->expression.expression = expr;
9667         mark_vars_read(expr, ENT_ANY);
9668
9669         expect(';');
9670         return statement;
9671 }
9672
9673 /**
9674  * Parse a microsoft __try { } __finally { } or
9675  * __try{ } __except() { }
9676  */
9677 static statement_t *parse_ms_try_statment(void)
9678 {
9679         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9680         eat(T___try);
9681
9682         PUSH_PARENT(statement);
9683
9684         ms_try_statement_t *rem = current_try;
9685         current_try = &statement->ms_try;
9686         statement->ms_try.try_statement = parse_compound_statement(false);
9687         current_try = rem;
9688
9689         POP_PARENT();
9690
9691         if (accept(T___except)) {
9692                 expression_t *const expr = parse_condition();
9693                 type_t       *      type = skip_typeref(expr->base.type);
9694                 if (is_type_integer(type)) {
9695                         type = promote_integer(type);
9696                 } else if (is_type_valid(type)) {
9697                         errorf(&expr->base.pos,
9698                                "__expect expression is not an integer, but '%T'", type);
9699                         type = type_error_type;
9700                 }
9701                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9702         } else if (!accept(T__finally)) {
9703                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9704         }
9705         statement->ms_try.final_statement = parse_compound_statement(false);
9706         return statement;
9707 }
9708
9709 static statement_t *parse_empty_statement(void)
9710 {
9711         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9712         statement_t *const statement = create_empty_statement();
9713         eat(';');
9714         return statement;
9715 }
9716
9717 static statement_t *parse_local_label_declaration(void)
9718 {
9719         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9720
9721         eat(T___label__);
9722
9723         entity_t *begin   = NULL;
9724         entity_t *end     = NULL;
9725         entity_t **anchor = &begin;
9726         add_anchor_token(';');
9727         add_anchor_token(',');
9728         do {
9729                 position_t pos;
9730                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9731                 if (symbol) {
9732                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9733                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9734                                 position_t const *const ppos = &entity->base.pos;
9735                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9736                         } else {
9737                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9738                                 entity->base.parent_scope = current_scope;
9739
9740                                 *anchor = entity;
9741                                 anchor  = &entity->base.next;
9742                                 end     = entity;
9743
9744                                 environment_push(entity);
9745                         }
9746                 }
9747         } while (accept(','));
9748         rem_anchor_token(',');
9749         rem_anchor_token(';');
9750         expect(';');
9751         statement->declaration.declarations_begin = begin;
9752         statement->declaration.declarations_end   = end;
9753         return statement;
9754 }
9755
9756 static void parse_namespace_definition(void)
9757 {
9758         eat(T_namespace);
9759
9760         entity_t *entity = NULL;
9761         symbol_t *symbol = NULL;
9762
9763         if (token.kind == T_IDENTIFIER) {
9764                 symbol = token.base.symbol;
9765                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9766                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9767                         entity = NULL;
9768                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9769                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9770                         }
9771                 }
9772                 eat(T_IDENTIFIER);
9773         }
9774
9775         if (entity == NULL) {
9776                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9777                 entity->base.parent_scope = current_scope;
9778         }
9779
9780         if (token.kind == '=') {
9781                 /* TODO: parse namespace alias */
9782                 panic("namespace alias definition not supported yet");
9783         }
9784
9785         environment_push(entity);
9786         append_entity(current_scope, entity);
9787
9788         PUSH_SCOPE(&entity->namespacee.members);
9789         PUSH_CURRENT_ENTITY(entity);
9790
9791         add_anchor_token('}');
9792         expect('{');
9793         parse_externals();
9794         rem_anchor_token('}');
9795         expect('}');
9796
9797         POP_CURRENT_ENTITY();
9798         POP_SCOPE();
9799 }
9800
9801 /**
9802  * Parse a statement.
9803  * There's also parse_statement() which additionally checks for
9804  * "statement has no effect" warnings
9805  */
9806 static statement_t *intern_parse_statement(void)
9807 {
9808         /* declaration or statement */
9809         statement_t *statement;
9810         switch (token.kind) {
9811         case T_IDENTIFIER: {
9812                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9813                 if (la1_type == ':') {
9814                         statement = parse_label_statement();
9815                 } else if (is_typedef_symbol(token.base.symbol)) {
9816                         statement = parse_declaration_statement();
9817                 } else {
9818                         /* it's an identifier, the grammar says this must be an
9819                          * expression statement. However it is common that users mistype
9820                          * declaration types, so we guess a bit here to improve robustness
9821                          * for incorrect programs */
9822                         switch (la1_type) {
9823                         case '&':
9824                         case '*':
9825                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9826                         default:
9827                                         statement = parse_expression_statement();
9828                                 } else {
9829                         DECLARATION_START
9830                         case T_IDENTIFIER:
9831                                         statement = parse_declaration_statement();
9832                                 }
9833                                 break;
9834                         }
9835                 }
9836                 break;
9837         }
9838
9839         case T___extension__: {
9840                 /* This can be a prefix to a declaration or an expression statement.
9841                  * We simply eat it now and parse the rest with tail recursion. */
9842                 PUSH_EXTENSION();
9843                 statement = intern_parse_statement();
9844                 POP_EXTENSION();
9845                 break;
9846         }
9847
9848         DECLARATION_START
9849                 statement = parse_declaration_statement();
9850                 break;
9851
9852         case T___label__:
9853                 statement = parse_local_label_declaration();
9854                 break;
9855
9856         case ';':         statement = parse_empty_statement();         break;
9857         case '{':         statement = parse_compound_statement(false); break;
9858         case T___leave:   statement = parse_leave_statement();         break;
9859         case T___try:     statement = parse_ms_try_statment();         break;
9860         case T_asm:       statement = parse_asm_statement();           break;
9861         case T_break:     statement = parse_break();                   break;
9862         case T_case:      statement = parse_case_statement();          break;
9863         case T_continue:  statement = parse_continue();                break;
9864         case T_default:   statement = parse_default_statement();       break;
9865         case T_do:        statement = parse_do();                      break;
9866         case T_for:       statement = parse_for();                     break;
9867         case T_goto:      statement = parse_goto();                    break;
9868         case T_if:        statement = parse_if();                      break;
9869         case T_return:    statement = parse_return();                  break;
9870         case T_switch:    statement = parse_switch();                  break;
9871         case T_while:     statement = parse_while();                   break;
9872
9873         EXPRESSION_START
9874                 statement = parse_expression_statement();
9875                 break;
9876
9877         default:
9878                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9879                 statement = create_error_statement();
9880                 eat_until_anchor();
9881                 break;
9882         }
9883
9884         return statement;
9885 }
9886
9887 /**
9888  * parse a statement and emits "statement has no effect" warning if needed
9889  * (This is really a wrapper around intern_parse_statement with check for 1
9890  *  single warning. It is needed, because for statement expressions we have
9891  *  to avoid the warning on the last statement)
9892  */
9893 static statement_t *parse_statement(void)
9894 {
9895         statement_t *statement = intern_parse_statement();
9896
9897         if (statement->kind == STATEMENT_EXPRESSION) {
9898                 expression_t *expression = statement->expression.expression;
9899                 if (!expression_has_effect(expression)) {
9900                         warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9901                                  "statement has no effect");
9902                 }
9903         }
9904
9905         return statement;
9906 }
9907
9908 /**
9909  * Parse a compound statement.
9910  */
9911 static statement_t *parse_compound_statement(bool inside_expression_statement)
9912 {
9913         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9914
9915         PUSH_PARENT(statement);
9916         PUSH_SCOPE(&statement->compound.scope);
9917
9918         eat('{');
9919         add_anchor_token('}');
9920         /* tokens, which can start a statement */
9921         /* TODO MS, __builtin_FOO */
9922         add_anchor_token('!');
9923         add_anchor_token('&');
9924         add_anchor_token('(');
9925         add_anchor_token('*');
9926         add_anchor_token('+');
9927         add_anchor_token('-');
9928         add_anchor_token(';');
9929         add_anchor_token('{');
9930         add_anchor_token('~');
9931         add_anchor_token(T_CHARACTER_CONSTANT);
9932         add_anchor_token(T_COLONCOLON);
9933         add_anchor_token(T_IDENTIFIER);
9934         add_anchor_token(T_MINUSMINUS);
9935         add_anchor_token(T_NUMBER);
9936         add_anchor_token(T_PLUSPLUS);
9937         add_anchor_token(T_STRING_LITERAL);
9938         add_anchor_token(T__Alignof);
9939         add_anchor_token(T__Bool);
9940         add_anchor_token(T__Complex);
9941         add_anchor_token(T__Imaginary);
9942         add_anchor_token(T__Thread_local);
9943         add_anchor_token(T___PRETTY_FUNCTION__);
9944         add_anchor_token(T___attribute__);
9945         add_anchor_token(T___builtin_va_start);
9946         add_anchor_token(T___extension__);
9947         add_anchor_token(T___func__);
9948         add_anchor_token(T___imag__);
9949         add_anchor_token(T___label__);
9950         add_anchor_token(T___real__);
9951         add_anchor_token(T_asm);
9952         add_anchor_token(T_auto);
9953         add_anchor_token(T_bool);
9954         add_anchor_token(T_break);
9955         add_anchor_token(T_case);
9956         add_anchor_token(T_char);
9957         add_anchor_token(T_class);
9958         add_anchor_token(T_const);
9959         add_anchor_token(T_const_cast);
9960         add_anchor_token(T_continue);
9961         add_anchor_token(T_default);
9962         add_anchor_token(T_delete);
9963         add_anchor_token(T_double);
9964         add_anchor_token(T_do);
9965         add_anchor_token(T_dynamic_cast);
9966         add_anchor_token(T_enum);
9967         add_anchor_token(T_extern);
9968         add_anchor_token(T_false);
9969         add_anchor_token(T_float);
9970         add_anchor_token(T_for);
9971         add_anchor_token(T_goto);
9972         add_anchor_token(T_if);
9973         add_anchor_token(T_inline);
9974         add_anchor_token(T_int);
9975         add_anchor_token(T_long);
9976         add_anchor_token(T_new);
9977         add_anchor_token(T_operator);
9978         add_anchor_token(T_register);
9979         add_anchor_token(T_reinterpret_cast);
9980         add_anchor_token(T_restrict);
9981         add_anchor_token(T_return);
9982         add_anchor_token(T_short);
9983         add_anchor_token(T_signed);
9984         add_anchor_token(T_sizeof);
9985         add_anchor_token(T_static);
9986         add_anchor_token(T_static_cast);
9987         add_anchor_token(T_struct);
9988         add_anchor_token(T_switch);
9989         add_anchor_token(T_template);
9990         add_anchor_token(T_this);
9991         add_anchor_token(T_throw);
9992         add_anchor_token(T_true);
9993         add_anchor_token(T_try);
9994         add_anchor_token(T_typedef);
9995         add_anchor_token(T_typeid);
9996         add_anchor_token(T_typename);
9997         add_anchor_token(T_typeof);
9998         add_anchor_token(T_union);
9999         add_anchor_token(T_unsigned);
10000         add_anchor_token(T_using);
10001         add_anchor_token(T_void);
10002         add_anchor_token(T_volatile);
10003         add_anchor_token(T_wchar_t);
10004         add_anchor_token(T_while);
10005
10006         statement_t **anchor            = &statement->compound.statements;
10007         bool          only_decls_so_far = true;
10008         while (token.kind != '}' && token.kind != T_EOF) {
10009                 statement_t *sub_statement = intern_parse_statement();
10010                 if (sub_statement->kind == STATEMENT_ERROR) {
10011                         break;
10012                 }
10013
10014                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10015                         only_decls_so_far = false;
10016                 } else if (!only_decls_so_far) {
10017                         position_t const *const pos = &sub_statement->base.pos;
10018                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10019                 }
10020
10021                 *anchor = sub_statement;
10022                 anchor  = &sub_statement->base.next;
10023         }
10024         expect('}');
10025
10026         /* look over all statements again to produce no effect warnings */
10027         if (is_warn_on(WARN_UNUSED_VALUE)) {
10028                 statement_t *sub_statement = statement->compound.statements;
10029                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10030                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10031                                 continue;
10032                         /* don't emit a warning for the last expression in an expression
10033                          * statement as it has always an effect */
10034                         if (inside_expression_statement && sub_statement->base.next == NULL)
10035                                 continue;
10036
10037                         expression_t *expression = sub_statement->expression.expression;
10038                         if (!expression_has_effect(expression)) {
10039                                 warningf(WARN_UNUSED_VALUE, &expression->base.pos,
10040                                          "statement has no effect");
10041                         }
10042                 }
10043         }
10044
10045         rem_anchor_token(T_while);
10046         rem_anchor_token(T_wchar_t);
10047         rem_anchor_token(T_volatile);
10048         rem_anchor_token(T_void);
10049         rem_anchor_token(T_using);
10050         rem_anchor_token(T_unsigned);
10051         rem_anchor_token(T_union);
10052         rem_anchor_token(T_typeof);
10053         rem_anchor_token(T_typename);
10054         rem_anchor_token(T_typeid);
10055         rem_anchor_token(T_typedef);
10056         rem_anchor_token(T_try);
10057         rem_anchor_token(T_true);
10058         rem_anchor_token(T_throw);
10059         rem_anchor_token(T_this);
10060         rem_anchor_token(T_template);
10061         rem_anchor_token(T_switch);
10062         rem_anchor_token(T_struct);
10063         rem_anchor_token(T_static_cast);
10064         rem_anchor_token(T_static);
10065         rem_anchor_token(T_sizeof);
10066         rem_anchor_token(T_signed);
10067         rem_anchor_token(T_short);
10068         rem_anchor_token(T_return);
10069         rem_anchor_token(T_restrict);
10070         rem_anchor_token(T_reinterpret_cast);
10071         rem_anchor_token(T_register);
10072         rem_anchor_token(T_operator);
10073         rem_anchor_token(T_new);
10074         rem_anchor_token(T_long);
10075         rem_anchor_token(T_int);
10076         rem_anchor_token(T_inline);
10077         rem_anchor_token(T_if);
10078         rem_anchor_token(T_goto);
10079         rem_anchor_token(T_for);
10080         rem_anchor_token(T_float);
10081         rem_anchor_token(T_false);
10082         rem_anchor_token(T_extern);
10083         rem_anchor_token(T_enum);
10084         rem_anchor_token(T_dynamic_cast);
10085         rem_anchor_token(T_do);
10086         rem_anchor_token(T_double);
10087         rem_anchor_token(T_delete);
10088         rem_anchor_token(T_default);
10089         rem_anchor_token(T_continue);
10090         rem_anchor_token(T_const_cast);
10091         rem_anchor_token(T_const);
10092         rem_anchor_token(T_class);
10093         rem_anchor_token(T_char);
10094         rem_anchor_token(T_case);
10095         rem_anchor_token(T_break);
10096         rem_anchor_token(T_bool);
10097         rem_anchor_token(T_auto);
10098         rem_anchor_token(T_asm);
10099         rem_anchor_token(T___real__);
10100         rem_anchor_token(T___label__);
10101         rem_anchor_token(T___imag__);
10102         rem_anchor_token(T___func__);
10103         rem_anchor_token(T___extension__);
10104         rem_anchor_token(T___builtin_va_start);
10105         rem_anchor_token(T___attribute__);
10106         rem_anchor_token(T___PRETTY_FUNCTION__);
10107         rem_anchor_token(T__Thread_local);
10108         rem_anchor_token(T__Imaginary);
10109         rem_anchor_token(T__Complex);
10110         rem_anchor_token(T__Bool);
10111         rem_anchor_token(T__Alignof);
10112         rem_anchor_token(T_STRING_LITERAL);
10113         rem_anchor_token(T_PLUSPLUS);
10114         rem_anchor_token(T_NUMBER);
10115         rem_anchor_token(T_MINUSMINUS);
10116         rem_anchor_token(T_IDENTIFIER);
10117         rem_anchor_token(T_COLONCOLON);
10118         rem_anchor_token(T_CHARACTER_CONSTANT);
10119         rem_anchor_token('~');
10120         rem_anchor_token('{');
10121         rem_anchor_token(';');
10122         rem_anchor_token('-');
10123         rem_anchor_token('+');
10124         rem_anchor_token('*');
10125         rem_anchor_token('(');
10126         rem_anchor_token('&');
10127         rem_anchor_token('!');
10128         rem_anchor_token('}');
10129
10130         POP_SCOPE();
10131         POP_PARENT();
10132         return statement;
10133 }
10134
10135 /**
10136  * Check for unused global static functions and variables
10137  */
10138 static void check_unused_globals(void)
10139 {
10140         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10141                 return;
10142
10143         for (const entity_t *entity = file_scope->entities; entity != NULL;
10144              entity = entity->base.next) {
10145                 if (!is_declaration(entity))
10146                         continue;
10147
10148                 const declaration_t *declaration = &entity->declaration;
10149                 if (declaration->used                  ||
10150                     declaration->modifiers & DM_UNUSED ||
10151                     declaration->modifiers & DM_USED   ||
10152                     declaration->storage_class != STORAGE_CLASS_STATIC)
10153                         continue;
10154
10155                 warning_t   why;
10156                 char const *s;
10157                 if (entity->kind == ENTITY_FUNCTION) {
10158                         /* inhibit warning for static inline functions */
10159                         if (entity->function.is_inline)
10160                                 continue;
10161
10162                         why = WARN_UNUSED_FUNCTION;
10163                         s   = entity->function.body != NULL ? "defined" : "declared";
10164                 } else {
10165                         why = WARN_UNUSED_VARIABLE;
10166                         s   = "defined";
10167                 }
10168
10169                 warningf(why, &declaration->base.pos, "'%#N' %s but not used", entity, s);
10170         }
10171 }
10172
10173 static void parse_global_asm(void)
10174 {
10175         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10176
10177         eat(T_asm);
10178         add_anchor_token(';');
10179         add_anchor_token(')');
10180         add_anchor_token(T_STRING_LITERAL);
10181         expect('(');
10182
10183         rem_anchor_token(T_STRING_LITERAL);
10184         statement->asms.asm_text = parse_string_literals("global asm");
10185         statement->base.next     = unit->global_asm;
10186         unit->global_asm         = statement;
10187
10188         rem_anchor_token(')');
10189         expect(')');
10190         rem_anchor_token(';');
10191         expect(';');
10192 }
10193
10194 static void parse_linkage_specification(void)
10195 {
10196         eat(T_extern);
10197
10198         position_t  const pos     = *HERE;
10199         char const *const linkage = parse_string_literals(NULL).begin;
10200
10201         linkage_kind_t old_linkage = current_linkage;
10202         linkage_kind_t new_linkage;
10203         if (streq(linkage, "C")) {
10204                 new_linkage = LINKAGE_C;
10205         } else if (streq(linkage, "C++")) {
10206                 new_linkage = LINKAGE_CXX;
10207         } else {
10208                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10209                 new_linkage = LINKAGE_C;
10210         }
10211         current_linkage = new_linkage;
10212
10213         if (accept('{')) {
10214                 parse_externals();
10215                 expect('}');
10216         } else {
10217                 parse_external();
10218         }
10219
10220         assert(current_linkage == new_linkage);
10221         current_linkage = old_linkage;
10222 }
10223
10224 static void parse_external(void)
10225 {
10226         switch (token.kind) {
10227                 case T_extern:
10228                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10229                                 parse_linkage_specification();
10230                         } else {
10231                 DECLARATION_START_NO_EXTERN
10232                 case T_IDENTIFIER:
10233                 case T___extension__:
10234                 /* tokens below are for implicit int */
10235                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10236                               implicit int) */
10237                 case '*':  /* * x; -> int* x; */
10238                 case '(':  /* (x); -> int (x); */
10239                                 PUSH_EXTENSION();
10240                                 parse_external_declaration();
10241                                 POP_EXTENSION();
10242                         }
10243                         return;
10244
10245                 case T_asm:
10246                         parse_global_asm();
10247                         return;
10248
10249                 case T_namespace:
10250                         parse_namespace_definition();
10251                         return;
10252
10253                 case ';':
10254                         if (!strict_mode) {
10255                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10256                                 eat(';');
10257                                 return;
10258                         }
10259                         /* FALLTHROUGH */
10260
10261                 default:
10262                         errorf(HERE, "stray %K outside of function", &token);
10263                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10264                                 eat_until_matching_token(token.kind);
10265                         next_token();
10266                         return;
10267         }
10268 }
10269
10270 static void parse_externals(void)
10271 {
10272         add_anchor_token('}');
10273         add_anchor_token(T_EOF);
10274
10275 #ifndef NDEBUG
10276         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10277         unsigned short token_anchor_copy[T_LAST_TOKEN];
10278         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10279 #endif
10280
10281         while (token.kind != T_EOF && token.kind != '}') {
10282 #ifndef NDEBUG
10283                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10284                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10285                         if (count != 0) {
10286                                 /* the anchor set and its copy differs */
10287                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10288                         }
10289                 }
10290                 if (in_gcc_extension) {
10291                         /* an gcc extension scope was not closed */
10292                         internal_errorf(HERE, "Leaked __extension__");
10293                 }
10294 #endif
10295
10296                 parse_external();
10297         }
10298
10299         rem_anchor_token(T_EOF);
10300         rem_anchor_token('}');
10301 }
10302
10303 /**
10304  * Parse a translation unit.
10305  */
10306 static void parse_translation_unit(void)
10307 {
10308         add_anchor_token(T_EOF);
10309
10310         while (true) {
10311                 parse_externals();
10312
10313                 if (token.kind == T_EOF)
10314                         break;
10315
10316                 errorf(HERE, "stray %K outside of function", &token);
10317                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10318                         eat_until_matching_token(token.kind);
10319                 next_token();
10320         }
10321 }
10322
10323 void set_default_visibility(elf_visibility_tag_t visibility)
10324 {
10325         default_visibility = visibility;
10326 }
10327
10328 /**
10329  * Parse the input.
10330  *
10331  * @return  the translation unit or NULL if errors occurred.
10332  */
10333 void start_parsing(void)
10334 {
10335         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10336         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10337
10338         print_to_file(stderr);
10339
10340         assert(unit == NULL);
10341         unit = allocate_ast_zero(sizeof(unit[0]));
10342
10343         assert(file_scope == NULL);
10344         file_scope = &unit->scope;
10345
10346         assert(current_scope == NULL);
10347         scope_push(&unit->scope);
10348
10349         create_gnu_builtins();
10350         if (c_mode & _MS)
10351                 create_microsoft_intrinsics();
10352 }
10353
10354 translation_unit_t *finish_parsing(void)
10355 {
10356         assert(current_scope == &unit->scope);
10357         scope_pop(NULL);
10358
10359         assert(file_scope == &unit->scope);
10360         check_unused_globals();
10361         file_scope = NULL;
10362
10363         DEL_ARR_F(environment_stack);
10364         DEL_ARR_F(label_stack);
10365
10366         translation_unit_t *result = unit;
10367         unit = NULL;
10368         return result;
10369 }
10370
10371 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10372  * are given length one. */
10373 static void complete_incomplete_arrays(void)
10374 {
10375         size_t n = ARR_LEN(incomplete_arrays);
10376         for (size_t i = 0; i != n; ++i) {
10377                 declaration_t *const decl = incomplete_arrays[i];
10378                 type_t        *const type = skip_typeref(decl->type);
10379
10380                 if (!is_type_incomplete(type))
10381                         continue;
10382
10383                 position_t const *const pos = &decl->base.pos;
10384                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10385
10386                 type_t *const new_type = duplicate_type(type);
10387                 new_type->array.size_constant     = true;
10388                 new_type->array.has_implicit_size = true;
10389                 new_type->array.size              = 1;
10390
10391                 type_t *const result = identify_new_type(new_type);
10392
10393                 decl->type = result;
10394         }
10395 }
10396
10397 static void prepare_main_collect2(entity_t *const entity)
10398 {
10399         PUSH_SCOPE(&entity->function.body->compound.scope);
10400
10401         // create call to __main
10402         symbol_t *symbol         = symbol_table_insert("__main");
10403         entity_t *subsubmain_ent
10404                 = create_implicit_function(symbol, &builtin_position);
10405
10406         expression_t *ref     = allocate_expression_zero(EXPR_REFERENCE);
10407         type_t       *ftype   = subsubmain_ent->declaration.type;
10408         ref->base.pos         = builtin_position;
10409         ref->base.type        = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10410         ref->reference.entity = subsubmain_ent;
10411
10412         expression_t *call  = allocate_expression_zero(EXPR_CALL);
10413         call->base.pos      = builtin_position;
10414         call->base.type     = type_void;
10415         call->call.function = ref;
10416
10417         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10418         expr_statement->base.pos              = builtin_position;
10419         expr_statement->expression.expression = call;
10420
10421         statement_t *const body = entity->function.body;
10422         assert(body->kind == STATEMENT_COMPOUND);
10423         compound_statement_t *compounds = &body->compound;
10424
10425         expr_statement->base.next = compounds->statements;
10426         compounds->statements     = expr_statement;
10427
10428         POP_SCOPE();
10429 }
10430
10431 void parse(void)
10432 {
10433         lookahead_bufpos = 0;
10434         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10435                 next_token();
10436         }
10437         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10438         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10439         parse_translation_unit();
10440         complete_incomplete_arrays();
10441         DEL_ARR_F(incomplete_arrays);
10442         incomplete_arrays = NULL;
10443 }
10444
10445 /**
10446  * Initialize the parser.
10447  */
10448 void init_parser(void)
10449 {
10450         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10451
10452         init_expression_parsers();
10453         obstack_init(&temp_obst);
10454 }
10455
10456 /**
10457  * Terminate the parser.
10458  */
10459 void exit_parser(void)
10460 {
10461         obstack_free(&temp_obst, NULL);
10462 }