nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T___FUNCDNAME__:             \
 256         case T___FUNCSIG__:               \
 257         case T___PRETTY_FUNCTION__:       \
 258         case T___alignof__:               \
 259         case T___builtin_classify_type:   \
 260         case T___builtin_constant_p:      \
 261         case T___builtin_isgreater:       \
 262         case T___builtin_isgreaterequal:  \
 263         case T___builtin_isless:          \
 264         case T___builtin_islessequal:     \
 265         case T___builtin_islessgreater:   \
 266         case T___builtin_isunordered:     \
 267         case T___builtin_offsetof:        \
 268         case T___builtin_va_arg:          \
 269         case T___builtin_va_copy:         \
 270         case T___builtin_va_start:        \
 271         case T___func__:                  \
 272         case T___noop:                    \
 273         case T__assume:                   \
 274         case T_delete:                    \
 275         case T_false:                     \
 276         case T_sizeof:                    \
 277         case T_throw:                     \
 278         case T_true:
 279
 280 /**
 281  * Returns the size of a statement node.
 282  *
 283  * @param kind  the statement kind
 284  */
 285 static size_t get_statement_struct_size(statement_kind_t kind)
 286 {
 287         static const size_t sizes[] = {
 288                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 289                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 290                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 291                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 292                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 293                 [STATEMENT_IF]            = sizeof(if_statement_t),
 294                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 295                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 296                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 297                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 298                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 299                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 300                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 301                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 302                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 303                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 304                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 305                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 306                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 307                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 308         };
 309         assert((size_t)kind < lengthof(sizes));
 310         assert(sizes[kind] != 0);
 311         return sizes[kind];
 312 }
 313
 314 /**
 315  * Returns the size of an expression node.
 316  *
 317  * @param kind  the expression kind
 318  */
 319 static size_t get_expression_struct_size(expression_kind_t kind)
 320 {
 321         static const size_t sizes[] = {
 322                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 323                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 324                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 325                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 330                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 331                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 332                 [EXPR_CALL]                       = sizeof(call_expression_t),
 333                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 334                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 335                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 336                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 337                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 338                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 339                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 340                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 341                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 342                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 343                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 344                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 345                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 346                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 347                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 348                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 349                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 350         };
 351         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 352                 return sizes[EXPR_UNARY_FIRST];
 353         }
 354         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 355                 return sizes[EXPR_BINARY_FIRST];
 356         }
 357         assert((size_t)kind < lengthof(sizes));
 358         assert(sizes[kind] != 0);
 359         return sizes[kind];
 360 }
 361
 362 /**
 363  * Allocate a statement node of given kind and initialize all
 364  * fields with zero. Sets its source position to the position
 365  * of the current token.
 366  */
 367 static statement_t *allocate_statement_zero(statement_kind_t kind)
 368 {
 369         size_t       size = get_statement_struct_size(kind);
 370         statement_t *res  = allocate_ast_zero(size);
 371
 372         res->base.kind            = kind;
 373         res->base.parent          = current_parent;
 374         res->base.source_position = *HERE;
 375         return res;
 376 }
 377
 378 /**
 379  * Allocate an expression node of given kind and initialize all
 380  * fields with zero.
 381  *
 382  * @param kind  the kind of the expression to allocate
 383  */
 384 static expression_t *allocate_expression_zero(expression_kind_t kind)
 385 {
 386         size_t        size = get_expression_struct_size(kind);
 387         expression_t *res  = allocate_ast_zero(size);
 388
 389         res->base.kind            = kind;
 390         res->base.type            = type_error_type;
 391         res->base.source_position = *HERE;
 392         return res;
 393 }
 394
 395 /**
 396  * Creates a new invalid expression at the source position
 397  * of the current token.
 398  */
 399 static expression_t *create_error_expression(void)
 400 {
 401         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 402         expression->base.type = type_error_type;
 403         return expression;
 404 }
 405
 406 /**
 407  * Creates a new invalid statement.
 408  */
 409 static statement_t *create_error_statement(void)
 410 {
 411         return allocate_statement_zero(STATEMENT_ERROR);
 412 }
 413
 414 /**
 415  * Allocate a new empty statement.
 416  */
 417 static statement_t *create_empty_statement(void)
 418 {
 419         return allocate_statement_zero(STATEMENT_EMPTY);
 420 }
 421
 422 /**
 423  * Returns the size of an initializer node.
 424  *
 425  * @param kind  the initializer kind
 426  */
 427 static size_t get_initializer_size(initializer_kind_t kind)
 428 {
 429         static const size_t sizes[] = {
 430                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 431                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 432                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 433                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 434                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 435         };
 436         assert((size_t)kind < lengthof(sizes));
 437         assert(sizes[kind] != 0);
 438         return sizes[kind];
 439 }
 440
 441 /**
 442  * Allocate an initializer node of given kind and initialize all
 443  * fields with zero.
 444  */
 445 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 446 {
 447         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 448         result->kind          = kind;
 449
 450         return result;
 451 }
 452
 453 /**
 454  * Returns the index of the top element of the environment stack.
 455  */
 456 static size_t environment_top(void)
 457 {
 458         return ARR_LEN(environment_stack);
 459 }
 460
 461 /**
 462  * Returns the index of the top element of the global label stack.
 463  */
 464 static size_t label_top(void)
 465 {
 466         return ARR_LEN(label_stack);
 467 }
 468
 469 /**
 470  * Return the next token.
 471  */
 472 static inline void next_token(void)
 473 {
 474         token                              = lookahead_buffer[lookahead_bufpos];
 475         lookahead_buffer[lookahead_bufpos] = lexer_token;
 476         lexer_next_token();
 477
 478         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 479
 480 #ifdef PRINT_TOKENS
 481         print_token(stderr, &token);
 482         fprintf(stderr, "\n");
 483 #endif
 484 }
 485
 486 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 487
 488 static inline bool next_if(token_kind_t const type)
 489 {
 490         if (token.kind == type) {
 491                 eat(type);
 492                 return true;
 493         } else {
 494                 return false;
 495         }
 496 }
 497
 498 /**
 499  * Return the next token with a given lookahead.
 500  */
 501 static inline const token_t *look_ahead(size_t num)
 502 {
 503         assert(0 < num && num <= MAX_LOOKAHEAD);
 504         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 505         return &lookahead_buffer[pos];
 506 }
 507
 508 /**
 509  * Adds a token type to the token type anchor set (a multi-set).
 510  */
 511 static void add_anchor_token(token_kind_t const token_kind)
 512 {
 513         assert(token_kind < T_LAST_TOKEN);
 514         ++token_anchor_set[token_kind];
 515 }
 516
 517 /**
 518  * Remove a token type from the token type anchor set (a multi-set).
 519  */
 520 static void rem_anchor_token(token_kind_t const token_kind)
 521 {
 522         assert(token_kind < T_LAST_TOKEN);
 523         assert(token_anchor_set[token_kind] != 0);
 524         --token_anchor_set[token_kind];
 525 }
 526
 527 /**
 528  * Eat tokens until a matching token type is found.
 529  */
 530 static void eat_until_matching_token(token_kind_t const type)
 531 {
 532         token_kind_t end_token;
 533         switch (type) {
 534                 case '(': end_token = ')';  break;
 535                 case '{': end_token = '}';  break;
 536                 case '[': end_token = ']';  break;
 537                 default:  end_token = type; break;
 538         }
 539
 540         unsigned parenthesis_count = 0;
 541         unsigned brace_count       = 0;
 542         unsigned bracket_count     = 0;
 543         while (token.kind        != end_token ||
 544                parenthesis_count != 0         ||
 545                brace_count       != 0         ||
 546                bracket_count     != 0) {
 547                 switch (token.kind) {
 548                 case T_EOF: return;
 549                 case '(': ++parenthesis_count; break;
 550                 case '{': ++brace_count;       break;
 551                 case '[': ++bracket_count;     break;
 552
 553                 case ')':
 554                         if (parenthesis_count > 0)
 555                                 --parenthesis_count;
 556                         goto check_stop;
 557
 558                 case '}':
 559                         if (brace_count > 0)
 560                                 --brace_count;
 561                         goto check_stop;
 562
 563                 case ']':
 564                         if (bracket_count > 0)
 565                                 --bracket_count;
 566 check_stop:
 567                         if (token.kind        == end_token &&
 568                             parenthesis_count == 0         &&
 569                             brace_count       == 0         &&
 570                             bracket_count     == 0)
 571                                 return;
 572                         break;
 573
 574                 default:
 575                         break;
 576                 }
 577                 next_token();
 578         }
 579 }
 580
 581 /**
 582  * Eat input tokens until an anchor is found.
 583  */
 584 static void eat_until_anchor(void)
 585 {
 586         while (token_anchor_set[token.kind] == 0) {
 587                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 588                         eat_until_matching_token(token.kind);
 589                 next_token();
 590         }
 591 }
 592
 593 /**
 594  * Eat a whole block from input tokens.
 595  */
 596 static void eat_block(void)
 597 {
 598         eat_until_matching_token('{');
 599         next_if('}');
 600 }
 601
 602 /**
 603  * Report a parse error because an expected token was not found.
 604  */
 605 static
 606 #if defined __GNUC__ && __GNUC__ >= 4
 607 __attribute__((sentinel))
 608 #endif
 609 void parse_error_expected(const char *message, ...)
 610 {
 611         if (message != NULL) {
 612                 errorf(HERE, "%s", message);
 613         }
 614         va_list ap;
 615         va_start(ap, message);
 616         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 617         va_end(ap);
 618 }
 619
 620 /**
 621  * Report an incompatible type.
 622  */
 623 static void type_error_incompatible(const char *msg,
 624                 const source_position_t *source_position, type_t *type1, type_t *type2)
 625 {
 626         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 627                msg, type1, type2);
 628 }
 629
 630 static bool skip_till(token_kind_t const expected, char const *const context)
 631 {
 632         if (UNLIKELY(token.kind != expected)) {
 633                 parse_error_expected(context, expected, NULL);
 634                 add_anchor_token(expected);
 635                 eat_until_anchor();
 636                 rem_anchor_token(expected);
 637                 if (token.kind != expected)
 638                         return false;
 639         }
 640         return true;
 641 }
 642
 643 /**
 644  * Expect the current token is the expected token.
 645  * If not, generate an error and skip until the next anchor.
 646  */
 647 static void expect(token_kind_t const expected)
 648 {
 649         if (skip_till(expected, NULL))
 650                 eat(expected);
 651 }
 652
 653 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 654 {
 655         if (!skip_till(T_IDENTIFIER, context))
 656                 return NULL;
 657         symbol_t *const sym = token.base.symbol;
 658         if (pos)
 659                 *pos = *HERE;
 660         eat(T_IDENTIFIER);
 661         return sym;
 662 }
 663
 664 /**
 665  * Push a given scope on the scope stack and make it the
 666  * current scope
 667  */
 668 static scope_t *scope_push(scope_t *new_scope)
 669 {
 670         if (current_scope != NULL) {
 671                 new_scope->depth = current_scope->depth + 1;
 672         }
 673
 674         scope_t *old_scope = current_scope;
 675         current_scope      = new_scope;
 676         return old_scope;
 677 }
 678
 679 /**
 680  * Pop the current scope from the scope stack.
 681  */
 682 static void scope_pop(scope_t *old_scope)
 683 {
 684         current_scope = old_scope;
 685 }
 686
 687 /**
 688  * Search an entity by its symbol in a given namespace.
 689  */
 690 static entity_t *get_entity(const symbol_t *const symbol,
 691                             namespace_tag_t namespc)
 692 {
 693         entity_t *entity = symbol->entity;
 694         for (; entity != NULL; entity = entity->base.symbol_next) {
 695                 if ((namespace_tag_t)entity->base.namespc == namespc)
 696                         return entity;
 697         }
 698
 699         return NULL;
 700 }
 701
 702 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 703  * possible. */
 704 static entity_t *get_tag(symbol_t const *const symbol,
 705                          entity_kind_tag_t const kind)
 706 {
 707         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 708         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 709                 errorf(HERE,
 710                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 711                                 symbol, &entity->base.source_position);
 712                 entity = NULL;
 713         }
 714         return entity;
 715 }
 716
 717 /**
 718  * pushs an entity on the environment stack and links the corresponding symbol
 719  * it.
 720  */
 721 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 722 {
 723         symbol_t           *symbol  = entity->base.symbol;
 724         entity_namespace_t  namespc = entity->base.namespc;
 725         assert(namespc != 0);
 726
 727         /* replace/add entity into entity list of the symbol */
 728         entity_t **anchor;
 729         entity_t  *iter;
 730         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 731                 iter = *anchor;
 732                 if (iter == NULL)
 733                         break;
 734
 735                 /* replace an entry? */
 736                 if (iter->base.namespc == namespc) {
 737                         entity->base.symbol_next = iter->base.symbol_next;
 738                         break;
 739                 }
 740         }
 741         *anchor = entity;
 742
 743         /* remember old declaration */
 744         stack_entry_t entry;
 745         entry.symbol     = symbol;
 746         entry.old_entity = iter;
 747         entry.namespc    = namespc;
 748         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 749 }
 750
 751 /**
 752  * Push an entity on the environment stack.
 753  */
 754 static void environment_push(entity_t *entity)
 755 {
 756         assert(entity->base.source_position.input_name != NULL);
 757         assert(entity->base.parent_scope != NULL);
 758         stack_push(&environment_stack, entity);
 759 }
 760
 761 /**
 762  * Push a declaration on the global label stack.
 763  *
 764  * @param declaration  the declaration
 765  */
 766 static void label_push(entity_t *label)
 767 {
 768         /* we abuse the parameters scope as parent for the labels */
 769         label->base.parent_scope = &current_function->parameters;
 770         stack_push(&label_stack, label);
 771 }
 772
 773 /**
 774  * pops symbols from the environment stack until @p new_top is the top element
 775  */
 776 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 777 {
 778         stack_entry_t *stack = *stack_ptr;
 779         size_t         top   = ARR_LEN(stack);
 780         size_t         i;
 781
 782         assert(new_top <= top);
 783         if (new_top == top)
 784                 return;
 785
 786         for (i = top; i > new_top; --i) {
 787                 stack_entry_t *entry = &stack[i - 1];
 788
 789                 entity_t           *old_entity = entry->old_entity;
 790                 symbol_t           *symbol     = entry->symbol;
 791                 entity_namespace_t  namespc    = entry->namespc;
 792
 793                 /* replace with old_entity/remove */
 794                 entity_t **anchor;
 795                 entity_t  *iter;
 796                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 797                         iter = *anchor;
 798                         assert(iter != NULL);
 799                         /* replace an entry? */
 800                         if (iter->base.namespc == namespc)
 801                                 break;
 802                 }
 803
 804                 /* restore definition from outer scopes (if there was one) */
 805                 if (old_entity != NULL) {
 806                         old_entity->base.symbol_next = iter->base.symbol_next;
 807                         *anchor                      = old_entity;
 808                 } else {
 809                         /* remove entry from list */
 810                         *anchor = iter->base.symbol_next;
 811                 }
 812         }
 813
 814         ARR_SHRINKLEN(*stack_ptr, new_top);
 815 }
 816
 817 /**
 818  * Pop all entries from the environment stack until the new_top
 819  * is reached.
 820  *
 821  * @param new_top  the new stack top
 822  */
 823 static void environment_pop_to(size_t new_top)
 824 {
 825         stack_pop_to(&environment_stack, new_top);
 826 }
 827
 828 /**
 829  * Pop all entries from the global label stack until the new_top
 830  * is reached.
 831  *
 832  * @param new_top  the new stack top
 833  */
 834 static void label_pop_to(size_t new_top)
 835 {
 836         stack_pop_to(&label_stack, new_top);
 837 }
 838
 839 static atomic_type_kind_t get_akind(const type_t *type)
 840 {
 841         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 842                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 843         return type->atomic.akind;
 844 }
 845
 846 /**
 847  * §6.3.1.1:2  Do integer promotion for a given type.
 848  *
 849  * @param type  the type to promote
 850  * @return the promoted type
 851  */
 852 static type_t *promote_integer(type_t *type)
 853 {
 854         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 855                 type = type_int;
 856
 857         return type;
 858 }
 859
 860 /**
 861  * Check if a given expression represents a null pointer constant.
 862  *
 863  * @param expression  the expression to check
 864  */
 865 static bool is_null_pointer_constant(const expression_t *expression)
 866 {
 867         /* skip void* cast */
 868         if (expression->kind == EXPR_UNARY_CAST) {
 869                 type_t *const type = skip_typeref(expression->base.type);
 870                 if (types_compatible(type, type_void_ptr))
 871                         expression = expression->unary.value;
 872         }
 873
 874         type_t *const type = skip_typeref(expression->base.type);
 875         if (!is_type_integer(type))
 876                 return false;
 877         switch (is_constant_expression(expression)) {
 878                 case EXPR_CLASS_ERROR:    return true;
 879                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 880                 default:                  return false;
 881         }
 882 }
 883
 884 /**
 885  * Create an implicit cast expression.
 886  *
 887  * @param expression  the expression to cast
 888  * @param dest_type   the destination type
 889  */
 890 static expression_t *create_implicit_cast(expression_t *expression,
 891                                           type_t *dest_type)
 892 {
 893         type_t *const source_type = expression->base.type;
 894
 895         if (source_type == dest_type)
 896                 return expression;
 897
 898         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 899         cast->unary.value   = expression;
 900         cast->base.type     = dest_type;
 901         cast->base.implicit = true;
 902
 903         return cast;
 904 }
 905
 906 typedef enum assign_error_t {
 907         ASSIGN_SUCCESS,
 908         ASSIGN_ERROR_INCOMPATIBLE,
 909         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 910         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 911         ASSIGN_WARNING_POINTER_FROM_INT,
 912         ASSIGN_WARNING_INT_FROM_POINTER
 913 } assign_error_t;
 914
 915 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, source_position_t const *const pos)
 916 {
 917         type_t *const orig_type_right = right->base.type;
 918         type_t *const type_left       = skip_typeref(orig_type_left);
 919         type_t *const type_right      = skip_typeref(orig_type_right);
 920
 921         switch (error) {
 922         case ASSIGN_SUCCESS:
 923                 return;
 924         case ASSIGN_ERROR_INCOMPATIBLE:
 925                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 926                 return;
 927
 928         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 929                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 930                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 931
 932                 /* the left type has all qualifiers from the right type */
 933                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 934                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 935                 return;
 936         }
 937
 938         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 939                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 940                 return;
 941
 942         case ASSIGN_WARNING_POINTER_FROM_INT:
 943                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_INT_FROM_POINTER:
 947                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         default:
 951                 panic("invalid error value");
 952         }
 953 }
 954
 955 /** Implements the rules from §6.5.16.1 */
 956 static assign_error_t semantic_assign(type_t *orig_type_left,
 957                                       const expression_t *const right)
 958 {
 959         type_t *const orig_type_right = right->base.type;
 960         type_t *const type_left       = skip_typeref(orig_type_left);
 961         type_t *const type_right      = skip_typeref(orig_type_right);
 962
 963         if (is_type_pointer(type_left)) {
 964                 if (is_null_pointer_constant(right)) {
 965                         return ASSIGN_SUCCESS;
 966                 } else if (is_type_pointer(type_right)) {
 967                         type_t *points_to_left
 968                                 = skip_typeref(type_left->pointer.points_to);
 969                         type_t *points_to_right
 970                                 = skip_typeref(type_right->pointer.points_to);
 971                         assign_error_t res = ASSIGN_SUCCESS;
 972
 973                         /* the left type has all qualifiers from the right type */
 974                         unsigned missing_qualifiers
 975                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 976                         if (missing_qualifiers != 0) {
 977                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 978                         }
 979
 980                         points_to_left  = get_unqualified_type(points_to_left);
 981                         points_to_right = get_unqualified_type(points_to_right);
 982
 983                         if (is_type_void(points_to_left))
 984                                 return res;
 985
 986                         if (is_type_void(points_to_right)) {
 987                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 988                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 989                         }
 990
 991                         if (!types_compatible(points_to_left, points_to_right)) {
 992                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 993                         }
 994
 995                         return res;
 996                 } else if (is_type_integer(type_right)) {
 997                         return ASSIGN_WARNING_POINTER_FROM_INT;
 998                 }
 999         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1000                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1001                                 && is_type_pointer(type_right))) {
1002                 return ASSIGN_SUCCESS;
1003         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1004                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1005                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1006                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1007                         return ASSIGN_SUCCESS;
1008                 }
1009         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1010                 return ASSIGN_WARNING_INT_FROM_POINTER;
1011         }
1012
1013         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1014                 return ASSIGN_SUCCESS;
1015
1016         return ASSIGN_ERROR_INCOMPATIBLE;
1017 }
1018
1019 static expression_t *parse_constant_expression(void)
1020 {
1021         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1022
1023         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1024                 errorf(&result->base.source_position,
1025                        "expression '%E' is not constant", result);
1026         }
1027
1028         return result;
1029 }
1030
1031 static expression_t *parse_assignment_expression(void)
1032 {
1033         return parse_subexpression(PREC_ASSIGNMENT);
1034 }
1035
1036 static void append_string(string_t const *const s)
1037 {
1038         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1039          * possible, because other tokens are grown there alongside. */
1040         obstack_grow(&ast_obstack, s->begin, s->size);
1041 }
1042
1043 static string_t finish_string(void)
1044 {
1045         obstack_1grow(&ast_obstack, '\0');
1046         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1047         char const *const string = obstack_finish(&ast_obstack);
1048         return (string_t){ string, size };
1049 }
1050
1051 static string_t concat_string_literals(string_encoding_t *const out_enc)
1052 {
1053         assert(token.kind == T_STRING_LITERAL);
1054
1055         string_t          result;
1056         string_encoding_t enc = token.string.encoding;
1057         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1058                 append_string(&token.string.string);
1059                 eat(T_STRING_LITERAL);
1060                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1061                 do {
1062                         if (token.string.encoding != STRING_ENCODING_CHAR) {
1063                                 enc = token.string.encoding;
1064                         }
1065                         append_string(&token.string.string);
1066                         eat(T_STRING_LITERAL);
1067                 } while (token.kind == T_STRING_LITERAL);
1068                 result = finish_string();
1069         } else {
1070                 result = token.string.string;
1071                 eat(T_STRING_LITERAL);
1072         }
1073
1074         *out_enc = enc;
1075         return result;
1076 }
1077
1078 static string_t parse_string_literals(char const *const context)
1079 {
1080         if (!skip_till(T_STRING_LITERAL, context))
1081                 return (string_t){ "", 0 };
1082
1083         string_encoding_t       enc;
1084         source_position_t const pos = *HERE;
1085         string_t          const res = concat_string_literals(&enc);
1086
1087         if (enc != STRING_ENCODING_CHAR) {
1088                 errorf(&pos, "expected plain string literal, got wide string literal");
1089         }
1090
1091         return res;
1092 }
1093
1094 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1095 {
1096         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1097         attribute->kind            = kind;
1098         attribute->source_position = *HERE;
1099         return attribute;
1100 }
1101
1102 /**
1103  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1104  *
1105  *  attribute:
1106  *    __attribute__ ( ( attribute-list ) )
1107  *
1108  *  attribute-list:
1109  *    attrib
1110  *    attribute_list , attrib
1111  *
1112  *  attrib:
1113  *    empty
1114  *    any-word
1115  *    any-word ( identifier )
1116  *    any-word ( identifier , nonempty-expr-list )
1117  *    any-word ( expr-list )
1118  *
1119  *  where the "identifier" must not be declared as a type, and
1120  *  "any-word" may be any identifier (including one declared as a
1121  *  type), a reserved word storage class specifier, type specifier or
1122  *  type qualifier.  ??? This still leaves out most reserved keywords
1123  *  (following the old parser), shouldn't we include them, and why not
1124  *  allow identifiers declared as types to start the arguments?
1125  *
1126  *  Matze: this all looks confusing and little systematic, so we're even less
1127  *  strict and parse any list of things which are identifiers or
1128  *  (assignment-)expressions.
1129  */
1130 static attribute_argument_t *parse_attribute_arguments(void)
1131 {
1132         attribute_argument_t  *first  = NULL;
1133         attribute_argument_t **anchor = &first;
1134         if (token.kind != ')') do {
1135                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1136
1137                 /* is it an identifier */
1138                 if (token.kind == T_IDENTIFIER
1139                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1140                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1141                         argument->v.symbol = token.base.symbol;
1142                         eat(T_IDENTIFIER);
1143                 } else {
1144                         /* must be an expression */
1145                         expression_t *expression = parse_assignment_expression();
1146
1147                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1148                         argument->v.expression = expression;
1149                 }
1150
1151                 /* append argument */
1152                 *anchor = argument;
1153                 anchor  = &argument->next;
1154         } while (next_if(','));
1155         expect(')');
1156         return first;
1157 }
1158
1159 static attribute_t *parse_attribute_asm(void)
1160 {
1161         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1162         eat(T_asm);
1163         expect('(');
1164         attribute->a.arguments = parse_attribute_arguments();
1165         return attribute;
1166 }
1167
1168 static attribute_t *parse_attribute_gnu_single(void)
1169 {
1170         /* parse "any-word" */
1171         symbol_t *const symbol = token.base.symbol;
1172         if (symbol == NULL) {
1173                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1174                 return NULL;
1175         }
1176
1177         attribute_kind_t  kind;
1178         char const *const name = symbol->string;
1179         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1180                 if (kind > ATTRIBUTE_GNU_LAST) {
1181                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1182                         /* TODO: we should still save the attribute in the list... */
1183                         kind = ATTRIBUTE_UNKNOWN;
1184                         break;
1185                 }
1186
1187                 const char *attribute_name = get_attribute_name(kind);
1188                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1189                         break;
1190         }
1191
1192         attribute_t *attribute = allocate_attribute_zero(kind);
1193         next_token();
1194
1195         /* parse arguments */
1196         if (next_if('('))
1197                 attribute->a.arguments = parse_attribute_arguments();
1198
1199         return attribute;
1200 }
1201
1202 static attribute_t *parse_attribute_gnu(void)
1203 {
1204         attribute_t  *first  = NULL;
1205         attribute_t **anchor = &first;
1206
1207         eat(T___attribute__);
1208         add_anchor_token(')');
1209         add_anchor_token(',');
1210         expect('(');
1211         expect('(');
1212
1213         if (token.kind != ')') do {
1214                 attribute_t *attribute = parse_attribute_gnu_single();
1215                 if (attribute) {
1216                         *anchor = attribute;
1217                         anchor  = &attribute->next;
1218                 }
1219         } while (next_if(','));
1220         rem_anchor_token(',');
1221         rem_anchor_token(')');
1222
1223         expect(')');
1224         expect(')');
1225         return first;
1226 }
1227
1228 /** Parse attributes. */
1229 static attribute_t *parse_attributes(attribute_t *first)
1230 {
1231         attribute_t **anchor = &first;
1232         for (;;) {
1233                 while (*anchor != NULL)
1234                         anchor = &(*anchor)->next;
1235
1236                 attribute_t *attribute;
1237                 switch (token.kind) {
1238                 case T___attribute__:
1239                         attribute = parse_attribute_gnu();
1240                         if (attribute == NULL)
1241                                 continue;
1242                         break;
1243
1244                 case T_asm:
1245                         attribute = parse_attribute_asm();
1246                         break;
1247
1248                 case T_cdecl:
1249                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1250                         eat(T_cdecl);
1251                         break;
1252
1253                 case T__fastcall:
1254                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1255                         eat(T__fastcall);
1256                         break;
1257
1258                 case T__forceinline:
1259                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1260                         eat(T__forceinline);
1261                         break;
1262
1263                 case T__stdcall:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1265                         eat(T__stdcall);
1266                         break;
1267
1268                 case T___thiscall:
1269                         /* TODO record modifier */
1270                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1271                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1272                         eat(T___thiscall);
1273                         break;
1274
1275                 default:
1276                         return first;
1277                 }
1278
1279                 *anchor = attribute;
1280                 anchor  = &attribute->next;
1281         }
1282 }
1283
1284 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1285
1286 static entity_t *determine_lhs_ent(expression_t *const expr,
1287                                    entity_t *lhs_ent)
1288 {
1289         switch (expr->kind) {
1290                 case EXPR_REFERENCE: {
1291                         entity_t *const entity = expr->reference.entity;
1292                         /* we should only find variables as lvalues... */
1293                         if (entity->base.kind != ENTITY_VARIABLE
1294                                         && entity->base.kind != ENTITY_PARAMETER)
1295                                 return NULL;
1296
1297                         return entity;
1298                 }
1299
1300                 case EXPR_ARRAY_ACCESS: {
1301                         expression_t *const ref = expr->array_access.array_ref;
1302                         entity_t     *      ent = NULL;
1303                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1304                                 ent     = determine_lhs_ent(ref, lhs_ent);
1305                                 lhs_ent = ent;
1306                         } else {
1307                                 mark_vars_read(ref, lhs_ent);
1308                         }
1309                         mark_vars_read(expr->array_access.index, lhs_ent);
1310                         return ent;
1311                 }
1312
1313                 case EXPR_SELECT: {
1314                         mark_vars_read(expr->select.compound, lhs_ent);
1315                         if (is_type_compound(skip_typeref(expr->base.type)))
1316                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1317                         return NULL;
1318                 }
1319
1320                 case EXPR_UNARY_DEREFERENCE: {
1321                         expression_t *const val = expr->unary.value;
1322                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1323                                 /* *&x is a NOP */
1324                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1325                         } else {
1326                                 mark_vars_read(val, NULL);
1327                                 return NULL;
1328                         }
1329                 }
1330
1331                 default:
1332                         mark_vars_read(expr, NULL);
1333                         return NULL;
1334         }
1335 }
1336
1337 #define ENT_ANY ((entity_t*)-1)
1338
1339 /**
1340  * Mark declarations, which are read.  This is used to detect variables, which
1341  * are never read.
1342  * Example:
1343  * x = x + 1;
1344  *   x is not marked as "read", because it is only read to calculate its own new
1345  *   value.
1346  *
1347  * x += y; y += x;
1348  *   x and y are not detected as "not read", because multiple variables are
1349  *   involved.
1350  */
1351 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1352 {
1353         switch (expr->kind) {
1354                 case EXPR_REFERENCE: {
1355                         entity_t *const entity = expr->reference.entity;
1356                         if (entity->kind != ENTITY_VARIABLE
1357                                         && entity->kind != ENTITY_PARAMETER)
1358                                 return;
1359
1360                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1361                                 entity->variable.read = true;
1362                         }
1363                         return;
1364                 }
1365
1366                 case EXPR_CALL:
1367                         // TODO respect pure/const
1368                         mark_vars_read(expr->call.function, NULL);
1369                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1370                                 mark_vars_read(arg->expression, NULL);
1371                         }
1372                         return;
1373
1374                 case EXPR_CONDITIONAL:
1375                         // TODO lhs_decl should depend on whether true/false have an effect
1376                         mark_vars_read(expr->conditional.condition, NULL);
1377                         if (expr->conditional.true_expression != NULL)
1378                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1379                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1380                         return;
1381
1382                 case EXPR_SELECT:
1383                         if (lhs_ent == ENT_ANY
1384                                         && !is_type_compound(skip_typeref(expr->base.type)))
1385                                 lhs_ent = NULL;
1386                         mark_vars_read(expr->select.compound, lhs_ent);
1387                         return;
1388
1389                 case EXPR_ARRAY_ACCESS: {
1390                         mark_vars_read(expr->array_access.index, lhs_ent);
1391                         expression_t *const ref = expr->array_access.array_ref;
1392                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1393                                 if (lhs_ent == ENT_ANY)
1394                                         lhs_ent = NULL;
1395                         }
1396                         mark_vars_read(ref, lhs_ent);
1397                         return;
1398                 }
1399
1400                 case EXPR_VA_ARG:
1401                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1402                         return;
1403
1404                 case EXPR_VA_COPY:
1405                         mark_vars_read(expr->va_copye.src, lhs_ent);
1406                         return;
1407
1408                 case EXPR_UNARY_CAST:
1409                         /* Special case: Use void cast to mark a variable as "read" */
1410                         if (is_type_void(skip_typeref(expr->base.type)))
1411                                 lhs_ent = NULL;
1412                         goto unary;
1413
1414
1415                 case EXPR_UNARY_THROW:
1416                         if (expr->unary.value == NULL)
1417                                 return;
1418                         /* FALLTHROUGH */
1419                 case EXPR_UNARY_DEREFERENCE:
1420                 case EXPR_UNARY_DELETE:
1421                 case EXPR_UNARY_DELETE_ARRAY:
1422                         if (lhs_ent == ENT_ANY)
1423                                 lhs_ent = NULL;
1424                         goto unary;
1425
1426                 case EXPR_UNARY_NEGATE:
1427                 case EXPR_UNARY_PLUS:
1428                 case EXPR_UNARY_BITWISE_NEGATE:
1429                 case EXPR_UNARY_NOT:
1430                 case EXPR_UNARY_TAKE_ADDRESS:
1431                 case EXPR_UNARY_POSTFIX_INCREMENT:
1432                 case EXPR_UNARY_POSTFIX_DECREMENT:
1433                 case EXPR_UNARY_PREFIX_INCREMENT:
1434                 case EXPR_UNARY_PREFIX_DECREMENT:
1435                 case EXPR_UNARY_ASSUME:
1436 unary:
1437                         mark_vars_read(expr->unary.value, lhs_ent);
1438                         return;
1439
1440                 case EXPR_BINARY_ADD:
1441                 case EXPR_BINARY_SUB:
1442                 case EXPR_BINARY_MUL:
1443                 case EXPR_BINARY_DIV:
1444                 case EXPR_BINARY_MOD:
1445                 case EXPR_BINARY_EQUAL:
1446                 case EXPR_BINARY_NOTEQUAL:
1447                 case EXPR_BINARY_LESS:
1448                 case EXPR_BINARY_LESSEQUAL:
1449                 case EXPR_BINARY_GREATER:
1450                 case EXPR_BINARY_GREATEREQUAL:
1451                 case EXPR_BINARY_BITWISE_AND:
1452                 case EXPR_BINARY_BITWISE_OR:
1453                 case EXPR_BINARY_BITWISE_XOR:
1454                 case EXPR_BINARY_LOGICAL_AND:
1455                 case EXPR_BINARY_LOGICAL_OR:
1456                 case EXPR_BINARY_SHIFTLEFT:
1457                 case EXPR_BINARY_SHIFTRIGHT:
1458                 case EXPR_BINARY_COMMA:
1459                 case EXPR_BINARY_ISGREATER:
1460                 case EXPR_BINARY_ISGREATEREQUAL:
1461                 case EXPR_BINARY_ISLESS:
1462                 case EXPR_BINARY_ISLESSEQUAL:
1463                 case EXPR_BINARY_ISLESSGREATER:
1464                 case EXPR_BINARY_ISUNORDERED:
1465                         mark_vars_read(expr->binary.left,  lhs_ent);
1466                         mark_vars_read(expr->binary.right, lhs_ent);
1467                         return;
1468
1469                 case EXPR_BINARY_ASSIGN:
1470                 case EXPR_BINARY_MUL_ASSIGN:
1471                 case EXPR_BINARY_DIV_ASSIGN:
1472                 case EXPR_BINARY_MOD_ASSIGN:
1473                 case EXPR_BINARY_ADD_ASSIGN:
1474                 case EXPR_BINARY_SUB_ASSIGN:
1475                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1476                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1478                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1479                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1480                         if (lhs_ent == ENT_ANY)
1481                                 lhs_ent = NULL;
1482                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1483                         mark_vars_read(expr->binary.right, lhs_ent);
1484                         return;
1485                 }
1486
1487                 case EXPR_VA_START:
1488                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1489                         return;
1490
1491                 case EXPR_LITERAL_CASES:
1492                 case EXPR_ERROR:
1493                 case EXPR_STRING_LITERAL:
1494                 case EXPR_COMPOUND_LITERAL: // TODO init?
1495                 case EXPR_SIZEOF:
1496                 case EXPR_CLASSIFY_TYPE:
1497                 case EXPR_ALIGNOF:
1498                 case EXPR_FUNCNAME:
1499                 case EXPR_BUILTIN_CONSTANT_P:
1500                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1501                 case EXPR_OFFSETOF:
1502                 case EXPR_STATEMENT: // TODO
1503                 case EXPR_LABEL_ADDRESS:
1504                 case EXPR_ENUM_CONSTANT:
1505                         return;
1506         }
1507
1508         panic("unhandled expression");
1509 }
1510
1511 static designator_t *parse_designation(void)
1512 {
1513         designator_t  *result = NULL;
1514         designator_t **anchor = &result;
1515
1516         for (;;) {
1517                 designator_t *designator;
1518                 switch (token.kind) {
1519                 case '[':
1520                         designator = allocate_ast_zero(sizeof(designator[0]));
1521                         designator->source_position = *HERE;
1522                         eat('[');
1523                         add_anchor_token(']');
1524                         designator->array_index = parse_constant_expression();
1525                         rem_anchor_token(']');
1526                         expect(']');
1527                         break;
1528                 case '.':
1529                         designator = allocate_ast_zero(sizeof(designator[0]));
1530                         designator->source_position = *HERE;
1531                         eat('.');
1532                         designator->symbol = expect_identifier("while parsing designator", NULL);
1533                         if (!designator->symbol)
1534                                 return NULL;
1535                         break;
1536                 default:
1537                         expect('=');
1538                         return result;
1539                 }
1540
1541                 assert(designator != NULL);
1542                 *anchor = designator;
1543                 anchor  = &designator->next;
1544         }
1545 }
1546
1547 static initializer_t *initializer_from_string(array_type_t *const type,
1548                                               const string_t *const string)
1549 {
1550         /* TODO: check len vs. size of array type */
1551         (void) type;
1552
1553         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1554         initializer->string.string = *string;
1555
1556         return initializer;
1557 }
1558
1559 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1560                                                    const string_t *const string)
1561 {
1562         /* TODO: check len vs. size of array type */
1563         (void) type;
1564
1565         initializer_t *const initializer =
1566                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1567         initializer->wide_string.string = *string;
1568
1569         return initializer;
1570 }
1571
1572 /**
1573  * Build an initializer from a given expression.
1574  */
1575 static initializer_t *initializer_from_expression(type_t *orig_type,
1576                                                   expression_t *expression)
1577 {
1578         /* TODO check that expression is a constant expression */
1579
1580         /* §6.7.8.14/15 char array may be initialized by string literals */
1581         type_t *type           = skip_typeref(orig_type);
1582         type_t *expr_type_orig = expression->base.type;
1583         type_t *expr_type      = skip_typeref(expr_type_orig);
1584
1585         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1586                 array_type_t *const array_type   = &type->array;
1587                 type_t       *const element_type = skip_typeref(array_type->element_type);
1588
1589                 if (element_type->kind == TYPE_ATOMIC && expression->kind == EXPR_STRING_LITERAL) {
1590                         switch (expression->string_literal.encoding) {
1591                         case STRING_ENCODING_CHAR: {
1592                                 atomic_type_kind_t const akind = element_type->atomic.akind;
1593                                 if (akind == ATOMIC_TYPE_CHAR
1594                                                 || akind == ATOMIC_TYPE_SCHAR
1595                                                 || akind == ATOMIC_TYPE_UCHAR) {
1596                                         return initializer_from_string(array_type,
1597                                                         &expression->string_literal.value);
1598                                 }
1599                                 break;
1600                         }
1601
1602                         case STRING_ENCODING_WIDE: {
1603                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1604                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1605                                         return initializer_from_wide_string(array_type,
1606                                                         &expression->string_literal.value);
1607                                 }
1608                                 break;
1609                         }
1610                         }
1611                 }
1612         }
1613
1614         assign_error_t error = semantic_assign(type, expression);
1615         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1616                 return NULL;
1617         report_assign_error(error, type, expression, "initializer",
1618                             &expression->base.source_position);
1619
1620         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1621         result->value.value = create_implicit_cast(expression, type);
1622
1623         return result;
1624 }
1625
1626 /**
1627  * Parses an scalar initializer.
1628  *
1629  * §6.7.8.11; eat {} without warning
1630  */
1631 static initializer_t *parse_scalar_initializer(type_t *type,
1632                                                bool must_be_constant)
1633 {
1634         /* there might be extra {} hierarchies */
1635         int braces = 0;
1636         if (token.kind == '{') {
1637                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1638                 do {
1639                         eat('{');
1640                         ++braces;
1641                 } while (token.kind == '{');
1642         }
1643
1644         expression_t *expression = parse_assignment_expression();
1645         mark_vars_read(expression, NULL);
1646         if (must_be_constant && !is_linker_constant(expression)) {
1647                 errorf(&expression->base.source_position,
1648                        "initialisation expression '%E' is not constant",
1649                        expression);
1650         }
1651
1652         initializer_t *initializer = initializer_from_expression(type, expression);
1653
1654         if (initializer == NULL) {
1655                 errorf(&expression->base.source_position,
1656                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1657                        expression, expression->base.type, type);
1658                 /* TODO */
1659                 return NULL;
1660         }
1661
1662         bool additional_warning_displayed = false;
1663         while (braces > 0) {
1664                 next_if(',');
1665                 if (token.kind != '}') {
1666                         if (!additional_warning_displayed) {
1667                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1668                                 additional_warning_displayed = true;
1669                         }
1670                 }
1671                 eat_block();
1672                 braces--;
1673         }
1674
1675         return initializer;
1676 }
1677
1678 /**
1679  * An entry in the type path.
1680  */
1681 typedef struct type_path_entry_t type_path_entry_t;
1682 struct type_path_entry_t {
1683         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1684         union {
1685                 size_t         index;          /**< For array types: the current index. */
1686                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1687         } v;
1688 };
1689
1690 /**
1691  * A type path expression a position inside compound or array types.
1692  */
1693 typedef struct type_path_t type_path_t;
1694 struct type_path_t {
1695         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1696         type_t            *top_type;     /**< type of the element the path points */
1697         size_t             max_index;    /**< largest index in outermost array */
1698 };
1699
1700 /**
1701  * Prints a type path for debugging.
1702  */
1703 static __attribute__((unused)) void debug_print_type_path(
1704                 const type_path_t *path)
1705 {
1706         size_t len = ARR_LEN(path->path);
1707
1708         for (size_t i = 0; i < len; ++i) {
1709                 const type_path_entry_t *entry = & path->path[i];
1710
1711                 type_t *type = skip_typeref(entry->type);
1712                 if (is_type_compound(type)) {
1713                         /* in gcc mode structs can have no members */
1714                         if (entry->v.compound_entry == NULL) {
1715                                 assert(i == len-1);
1716                                 continue;
1717                         }
1718                         fprintf(stderr, ".%s",
1719                                 entry->v.compound_entry->base.symbol->string);
1720                 } else if (is_type_array(type)) {
1721                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1722                 } else {
1723                         fprintf(stderr, "-INVALID-");
1724                 }
1725         }
1726         if (path->top_type != NULL) {
1727                 fprintf(stderr, "  (");
1728                 print_type(path->top_type);
1729                 fprintf(stderr, ")");
1730         }
1731 }
1732
1733 /**
1734  * Return the top type path entry, ie. in a path
1735  * (type).a.b returns the b.
1736  */
1737 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1738 {
1739         size_t len = ARR_LEN(path->path);
1740         assert(len > 0);
1741         return &path->path[len-1];
1742 }
1743
1744 /**
1745  * Enlarge the type path by an (empty) element.
1746  */
1747 static type_path_entry_t *append_to_type_path(type_path_t *path)
1748 {
1749         size_t len = ARR_LEN(path->path);
1750         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1751
1752         type_path_entry_t *result = & path->path[len];
1753         memset(result, 0, sizeof(result[0]));
1754         return result;
1755 }
1756
1757 /**
1758  * Descending into a sub-type. Enter the scope of the current top_type.
1759  */
1760 static void descend_into_subtype(type_path_t *path)
1761 {
1762         type_t *orig_top_type = path->top_type;
1763         type_t *top_type      = skip_typeref(orig_top_type);
1764
1765         type_path_entry_t *top = append_to_type_path(path);
1766         top->type              = top_type;
1767
1768         if (is_type_compound(top_type)) {
1769                 compound_t *const compound = top_type->compound.compound;
1770                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1771
1772                 if (entry != NULL) {
1773                         top->v.compound_entry = &entry->declaration;
1774                         path->top_type = entry->declaration.type;
1775                 } else {
1776                         path->top_type = NULL;
1777                 }
1778         } else if (is_type_array(top_type)) {
1779                 top->v.index   = 0;
1780                 path->top_type = top_type->array.element_type;
1781         } else {
1782                 assert(!is_type_valid(top_type));
1783         }
1784 }
1785
1786 /**
1787  * Pop an entry from the given type path, ie. returning from
1788  * (type).a.b to (type).a
1789  */
1790 static void ascend_from_subtype(type_path_t *path)
1791 {
1792         type_path_entry_t *top = get_type_path_top(path);
1793
1794         path->top_type = top->type;
1795
1796         size_t len = ARR_LEN(path->path);
1797         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1798 }
1799
1800 /**
1801  * Pop entries from the given type path until the given
1802  * path level is reached.
1803  */
1804 static void ascend_to(type_path_t *path, size_t top_path_level)
1805 {
1806         size_t len = ARR_LEN(path->path);
1807
1808         while (len > top_path_level) {
1809                 ascend_from_subtype(path);
1810                 len = ARR_LEN(path->path);
1811         }
1812 }
1813
1814 static bool walk_designator(type_path_t *path, const designator_t *designator,
1815                             bool used_in_offsetof)
1816 {
1817         for (; designator != NULL; designator = designator->next) {
1818                 type_path_entry_t *top       = get_type_path_top(path);
1819                 type_t            *orig_type = top->type;
1820
1821                 type_t *type = skip_typeref(orig_type);
1822
1823                 if (designator->symbol != NULL) {
1824                         symbol_t *symbol = designator->symbol;
1825                         if (!is_type_compound(type)) {
1826                                 if (is_type_valid(type)) {
1827                                         errorf(&designator->source_position,
1828                                                "'.%Y' designator used for non-compound type '%T'",
1829                                                symbol, orig_type);
1830                                 }
1831
1832                                 top->type             = type_error_type;
1833                                 top->v.compound_entry = NULL;
1834                                 orig_type             = type_error_type;
1835                         } else {
1836                                 compound_t *compound = type->compound.compound;
1837                                 entity_t   *iter     = compound->members.entities;
1838                                 for (; iter != NULL; iter = iter->base.next) {
1839                                         if (iter->base.symbol == symbol) {
1840                                                 break;
1841                                         }
1842                                 }
1843                                 if (iter == NULL) {
1844                                         errorf(&designator->source_position,
1845                                                "'%T' has no member named '%Y'", orig_type, symbol);
1846                                         return false;
1847                                 }
1848                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1849                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1850                                         errorf(&designator->source_position,
1851                                                    "offsetof designator '%Y' must not specify bitfield",
1852                                                    symbol);
1853                                         return false;
1854                                 }
1855
1856                                 top->type             = orig_type;
1857                                 top->v.compound_entry = &iter->declaration;
1858                                 orig_type             = iter->declaration.type;
1859                         }
1860                 } else {
1861                         expression_t *array_index = designator->array_index;
1862                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1863                                 return true;
1864
1865                         if (!is_type_array(type)) {
1866                                 if (is_type_valid(type)) {
1867                                         errorf(&designator->source_position,
1868                                                "[%E] designator used for non-array type '%T'",
1869                                                array_index, orig_type);
1870                                 }
1871                                 return false;
1872                         }
1873
1874                         long index = fold_constant_to_int(array_index);
1875                         if (!used_in_offsetof) {
1876                                 if (index < 0) {
1877                                         errorf(&designator->source_position,
1878                                                "array index [%E] must be positive", array_index);
1879                                 } else if (type->array.size_constant) {
1880                                         long array_size = type->array.size;
1881                                         if (index >= array_size) {
1882                                                 errorf(&designator->source_position,
1883                                                        "designator [%E] (%d) exceeds array size %d",
1884                                                        array_index, index, array_size);
1885                                         }
1886                                 }
1887                         }
1888
1889                         top->type    = orig_type;
1890                         top->v.index = (size_t) index;
1891                         orig_type    = type->array.element_type;
1892                 }
1893                 path->top_type = orig_type;
1894
1895                 if (designator->next != NULL) {
1896                         descend_into_subtype(path);
1897                 }
1898         }
1899         return true;
1900 }
1901
1902 static void advance_current_object(type_path_t *path, size_t top_path_level)
1903 {
1904         type_path_entry_t *top = get_type_path_top(path);
1905
1906         type_t *type = skip_typeref(top->type);
1907         if (is_type_union(type)) {
1908                 /* in unions only the first element is initialized */
1909                 top->v.compound_entry = NULL;
1910         } else if (is_type_struct(type)) {
1911                 declaration_t *entry = top->v.compound_entry;
1912
1913                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1914                 if (next_entity != NULL) {
1915                         assert(is_declaration(next_entity));
1916                         entry = &next_entity->declaration;
1917                 } else {
1918                         entry = NULL;
1919                 }
1920
1921                 top->v.compound_entry = entry;
1922                 if (entry != NULL) {
1923                         path->top_type = entry->type;
1924                         return;
1925                 }
1926         } else if (is_type_array(type)) {
1927                 assert(is_type_array(type));
1928
1929                 top->v.index++;
1930
1931                 if (!type->array.size_constant || top->v.index < type->array.size) {
1932                         return;
1933                 }
1934         } else {
1935                 assert(!is_type_valid(type));
1936                 return;
1937         }
1938
1939         /* we're past the last member of the current sub-aggregate, try if we
1940          * can ascend in the type hierarchy and continue with another subobject */
1941         size_t len = ARR_LEN(path->path);
1942
1943         if (len > top_path_level) {
1944                 ascend_from_subtype(path);
1945                 advance_current_object(path, top_path_level);
1946         } else {
1947                 path->top_type = NULL;
1948         }
1949 }
1950
1951 /**
1952  * skip any {...} blocks until a closing bracket is reached.
1953  */
1954 static void skip_initializers(void)
1955 {
1956         next_if('{');
1957
1958         while (token.kind != '}') {
1959                 if (token.kind == T_EOF)
1960                         return;
1961                 if (token.kind == '{') {
1962                         eat_block();
1963                         continue;
1964                 }
1965                 next_token();
1966         }
1967 }
1968
1969 static initializer_t *create_empty_initializer(void)
1970 {
1971         static initializer_t empty_initializer
1972                 = { .list = { { INITIALIZER_LIST }, 0 } };
1973         return &empty_initializer;
1974 }
1975
1976 /**
1977  * Parse a part of an initialiser for a struct or union,
1978  */
1979 static initializer_t *parse_sub_initializer(type_path_t *path,
1980                 type_t *outer_type, size_t top_path_level,
1981                 parse_initializer_env_t *env)
1982 {
1983         if (token.kind == '}') {
1984                 /* empty initializer */
1985                 return create_empty_initializer();
1986         }
1987
1988         type_t *orig_type = path->top_type;
1989         type_t *type      = NULL;
1990
1991         if (orig_type == NULL) {
1992                 /* We are initializing an empty compound. */
1993         } else {
1994                 type = skip_typeref(orig_type);
1995         }
1996
1997         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1998
1999         while (true) {
2000                 designator_t *designator = NULL;
2001                 if (token.kind == '.' || token.kind == '[') {
2002                         designator = parse_designation();
2003                         goto finish_designator;
2004                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2005                         /* GNU-style designator ("identifier: value") */
2006                         designator = allocate_ast_zero(sizeof(designator[0]));
2007                         designator->source_position = *HERE;
2008                         designator->symbol          = token.base.symbol;
2009                         eat(T_IDENTIFIER);
2010                         eat(':');
2011
2012 finish_designator:
2013                         /* reset path to toplevel, evaluate designator from there */
2014                         ascend_to(path, top_path_level);
2015                         if (!walk_designator(path, designator, false)) {
2016                                 /* can't continue after designation error */
2017                                 goto end_error;
2018                         }
2019
2020                         initializer_t *designator_initializer
2021                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2022                         designator_initializer->designator.designator = designator;
2023                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2024
2025                         orig_type = path->top_type;
2026                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2027                 }
2028
2029                 initializer_t *sub;
2030
2031                 if (token.kind == '{') {
2032                         if (type != NULL && is_type_scalar(type)) {
2033                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2034                         } else {
2035                                 if (type == NULL) {
2036                                         if (env->entity != NULL) {
2037                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2038                                         } else {
2039                                                 errorf(HERE, "extra brace group at end of initializer");
2040                                         }
2041                                         eat('{');
2042                                 } else {
2043                                         eat('{');
2044                                         descend_into_subtype(path);
2045                                 }
2046
2047                                 add_anchor_token('}');
2048                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2049                                                             env);
2050                                 rem_anchor_token('}');
2051
2052                                 expect('}');
2053
2054                                 if (!type)
2055                                         goto error_parse_next;
2056
2057                                 ascend_from_subtype(path);
2058                         }
2059                 } else {
2060                         /* must be an expression */
2061                         expression_t *expression = parse_assignment_expression();
2062                         mark_vars_read(expression, NULL);
2063
2064                         if (env->must_be_constant && !is_linker_constant(expression)) {
2065                                 errorf(&expression->base.source_position,
2066                                        "Initialisation expression '%E' is not constant",
2067                                        expression);
2068                         }
2069
2070                         if (type == NULL) {
2071                                 /* we are already outside, ... */
2072                                 if (outer_type == NULL)
2073                                         goto error_parse_next;
2074                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2075                                 if (is_type_compound(outer_type_skip) &&
2076                                                 !outer_type_skip->compound.compound->complete) {
2077                                         goto error_parse_next;
2078                                 }
2079
2080                                 source_position_t const* const pos = &expression->base.source_position;
2081                                 if (env->entity != NULL) {
2082                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2083                                 } else {
2084                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2085                                 }
2086                                 goto error_parse_next;
2087                         }
2088
2089                         /* handle { "string" } special case */
2090                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2091                                 sub = initializer_from_expression(outer_type, expression);
2092                                 if (sub != NULL) {
2093                                         next_if(',');
2094                                         if (token.kind != '}') {
2095                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2096                                         }
2097                                         /* TODO: eat , ... */
2098                                         return sub;
2099                                 }
2100                         }
2101
2102                         /* descend into subtypes until expression matches type */
2103                         while (true) {
2104                                 orig_type = path->top_type;
2105                                 type      = skip_typeref(orig_type);
2106
2107                                 sub = initializer_from_expression(orig_type, expression);
2108                                 if (sub != NULL) {
2109                                         break;
2110                                 }
2111                                 if (!is_type_valid(type)) {
2112                                         goto end_error;
2113                                 }
2114                                 if (is_type_scalar(type)) {
2115                                         errorf(&expression->base.source_position,
2116                                                         "expression '%E' doesn't match expected type '%T'",
2117                                                         expression, orig_type);
2118                                         goto end_error;
2119                                 }
2120
2121                                 descend_into_subtype(path);
2122                         }
2123                 }
2124
2125                 /* update largest index of top array */
2126                 const type_path_entry_t *first      = &path->path[0];
2127                 type_t                  *first_type = first->type;
2128                 first_type                          = skip_typeref(first_type);
2129                 if (is_type_array(first_type)) {
2130                         size_t index = first->v.index;
2131                         if (index > path->max_index)
2132                                 path->max_index = index;
2133                 }
2134
2135                 /* append to initializers list */
2136                 ARR_APP1(initializer_t*, initializers, sub);
2137
2138 error_parse_next:
2139                 if (token.kind == '}') {
2140                         break;
2141                 }
2142                 add_anchor_token('}');
2143                 expect(',');
2144                 rem_anchor_token('}');
2145                 if (token.kind == '}') {
2146                         break;
2147                 }
2148
2149                 if (type != NULL) {
2150                         /* advance to the next declaration if we are not at the end */
2151                         advance_current_object(path, top_path_level);
2152                         orig_type = path->top_type;
2153                         if (orig_type != NULL)
2154                                 type = skip_typeref(orig_type);
2155                         else
2156                                 type = NULL;
2157                 }
2158         }
2159
2160         size_t len  = ARR_LEN(initializers);
2161         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2162         initializer_t *result = allocate_ast_zero(size);
2163         result->kind          = INITIALIZER_LIST;
2164         result->list.len      = len;
2165         memcpy(&result->list.initializers, initializers,
2166                len * sizeof(initializers[0]));
2167
2168         DEL_ARR_F(initializers);
2169         ascend_to(path, top_path_level+1);
2170
2171         return result;
2172
2173 end_error:
2174         skip_initializers();
2175         DEL_ARR_F(initializers);
2176         ascend_to(path, top_path_level+1);
2177         return NULL;
2178 }
2179
2180 static expression_t *make_size_literal(size_t value)
2181 {
2182         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2183         literal->base.type    = type_size_t;
2184
2185         char buf[128];
2186         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2187         literal->literal.value = make_string(buf);
2188
2189         return literal;
2190 }
2191
2192 /**
2193  * Parses an initializer. Parsers either a compound literal
2194  * (env->declaration == NULL) or an initializer of a declaration.
2195  */
2196 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2197 {
2198         type_t        *type      = skip_typeref(env->type);
2199         size_t         max_index = 0;
2200         initializer_t *result;
2201
2202         if (is_type_scalar(type)) {
2203                 result = parse_scalar_initializer(type, env->must_be_constant);
2204         } else if (token.kind == '{') {
2205                 eat('{');
2206
2207                 type_path_t path;
2208                 memset(&path, 0, sizeof(path));
2209                 path.top_type = env->type;
2210                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2211
2212                 descend_into_subtype(&path);
2213
2214                 add_anchor_token('}');
2215                 result = parse_sub_initializer(&path, env->type, 1, env);
2216                 rem_anchor_token('}');
2217
2218                 max_index = path.max_index;
2219                 DEL_ARR_F(path.path);
2220
2221                 expect('}');
2222         } else {
2223                 /* parse_scalar_initializer() also works in this case: we simply
2224                  * have an expression without {} around it */
2225                 result = parse_scalar_initializer(type, env->must_be_constant);
2226         }
2227
2228         /* §6.7.8:22 array initializers for arrays with unknown size determine
2229          * the array type size */
2230         if (is_type_array(type) && type->array.size_expression == NULL
2231                         && result != NULL) {
2232                 size_t size;
2233                 switch (result->kind) {
2234                 case INITIALIZER_LIST:
2235                         assert(max_index != 0xdeadbeaf);
2236                         size = max_index + 1;
2237                         break;
2238
2239                 case INITIALIZER_STRING:
2240                         size = result->string.string.size + 1;
2241                         break;
2242
2243                 case INITIALIZER_WIDE_STRING:
2244                         size = result->wide_string.string.size;
2245                         break;
2246
2247                 case INITIALIZER_DESIGNATOR:
2248                 case INITIALIZER_VALUE:
2249                         /* can happen for parse errors */
2250                         size = 0;
2251                         break;
2252
2253                 default:
2254                         internal_errorf(HERE, "invalid initializer type");
2255                 }
2256
2257                 type_t *new_type = duplicate_type(type);
2258
2259                 new_type->array.size_expression   = make_size_literal(size);
2260                 new_type->array.size_constant     = true;
2261                 new_type->array.has_implicit_size = true;
2262                 new_type->array.size              = size;
2263                 env->type = new_type;
2264         }
2265
2266         return result;
2267 }
2268
2269 static void append_entity(scope_t *scope, entity_t *entity)
2270 {
2271         if (scope->last_entity != NULL) {
2272                 scope->last_entity->base.next = entity;
2273         } else {
2274                 scope->entities = entity;
2275         }
2276         entity->base.parent_entity = current_entity;
2277         scope->last_entity         = entity;
2278 }
2279
2280
2281 static compound_t *parse_compound_type_specifier(bool is_struct)
2282 {
2283         source_position_t const pos = *HERE;
2284         eat(is_struct ? T_struct : T_union);
2285
2286         symbol_t    *symbol     = NULL;
2287         entity_t    *entity     = NULL;
2288         attribute_t *attributes = NULL;
2289
2290         if (token.kind == T___attribute__) {
2291                 attributes = parse_attributes(NULL);
2292         }
2293
2294         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2295         if (token.kind == T_IDENTIFIER) {
2296                 /* the compound has a name, check if we have seen it already */
2297                 symbol = token.base.symbol;
2298                 entity = get_tag(symbol, kind);
2299                 eat(T_IDENTIFIER);
2300
2301                 if (entity != NULL) {
2302                         if (entity->base.parent_scope != current_scope &&
2303                             (token.kind == '{' || token.kind == ';')) {
2304                                 /* we're in an inner scope and have a definition. Shadow
2305                                  * existing definition in outer scope */
2306                                 entity = NULL;
2307                         } else if (entity->compound.complete && token.kind == '{') {
2308                                 source_position_t const *const ppos = &entity->base.source_position;
2309                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2310                                 /* clear members in the hope to avoid further errors */
2311                                 entity->compound.members.entities = NULL;
2312                         }
2313                 }
2314         } else if (token.kind != '{') {
2315                 char const *const msg =
2316                         is_struct ? "while parsing struct type specifier" :
2317                                     "while parsing union type specifier";
2318                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2319
2320                 return NULL;
2321         }
2322
2323         if (entity == NULL) {
2324                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2325                 entity->compound.alignment = 1;
2326                 entity->base.parent_scope  = current_scope;
2327                 if (symbol != NULL) {
2328                         environment_push(entity);
2329                 }
2330                 append_entity(current_scope, entity);
2331         }
2332
2333         if (token.kind == '{') {
2334                 parse_compound_type_entries(&entity->compound);
2335
2336                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2337                 if (symbol == NULL) {
2338                         assert(anonymous_entity == NULL);
2339                         anonymous_entity = entity;
2340                 }
2341         }
2342
2343         if (attributes != NULL) {
2344                 handle_entity_attributes(attributes, entity);
2345         }
2346
2347         return &entity->compound;
2348 }
2349
2350 static void parse_enum_entries(type_t *const enum_type)
2351 {
2352         eat('{');
2353
2354         if (token.kind == '}') {
2355                 errorf(HERE, "empty enum not allowed");
2356                 eat('}');
2357                 return;
2358         }
2359
2360         add_anchor_token('}');
2361         add_anchor_token(',');
2362         do {
2363                 add_anchor_token('=');
2364                 source_position_t pos;
2365                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2366                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2367                 entity->enum_value.enum_type = enum_type;
2368                 rem_anchor_token('=');
2369
2370                 if (next_if('=')) {
2371                         expression_t *value = parse_constant_expression();
2372
2373                         value = create_implicit_cast(value, enum_type);
2374                         entity->enum_value.value = value;
2375
2376                         /* TODO semantic */
2377                 }
2378
2379                 record_entity(entity, false);
2380         } while (next_if(',') && token.kind != '}');
2381         rem_anchor_token(',');
2382         rem_anchor_token('}');
2383
2384         expect('}');
2385 }
2386
2387 static type_t *parse_enum_specifier(void)
2388 {
2389         source_position_t const pos = *HERE;
2390         entity_t               *entity;
2391         symbol_t               *symbol;
2392
2393         eat(T_enum);
2394         switch (token.kind) {
2395                 case T_IDENTIFIER:
2396                         symbol = token.base.symbol;
2397                         entity = get_tag(symbol, ENTITY_ENUM);
2398                         eat(T_IDENTIFIER);
2399
2400                         if (entity != NULL) {
2401                                 if (entity->base.parent_scope != current_scope &&
2402                                                 (token.kind == '{' || token.kind == ';')) {
2403                                         /* we're in an inner scope and have a definition. Shadow
2404                                          * existing definition in outer scope */
2405                                         entity = NULL;
2406                                 } else if (entity->enume.complete && token.kind == '{') {
2407                                         source_position_t const *const ppos = &entity->base.source_position;
2408                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2409                                 }
2410                         }
2411                         break;
2412
2413                 case '{':
2414                         entity = NULL;
2415                         symbol = NULL;
2416                         break;
2417
2418                 default:
2419                         parse_error_expected("while parsing enum type specifier",
2420                                         T_IDENTIFIER, '{', NULL);
2421                         return NULL;
2422         }
2423
2424         if (entity == NULL) {
2425                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2426                 entity->base.parent_scope = current_scope;
2427         }
2428
2429         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2430         type->enumt.enume      = &entity->enume;
2431         type->enumt.base.akind = ATOMIC_TYPE_INT;
2432
2433         if (token.kind == '{') {
2434                 if (symbol != NULL) {
2435                         environment_push(entity);
2436                 }
2437                 append_entity(current_scope, entity);
2438                 entity->enume.complete = true;
2439
2440                 parse_enum_entries(type);
2441                 parse_attributes(NULL);
2442
2443                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2444                 if (symbol == NULL) {
2445                         assert(anonymous_entity == NULL);
2446                         anonymous_entity = entity;
2447                 }
2448         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2449                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2450         }
2451
2452         return type;
2453 }
2454
2455 /**
2456  * if a symbol is a typedef to another type, return true
2457  */
2458 static bool is_typedef_symbol(symbol_t *symbol)
2459 {
2460         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2461         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2462 }
2463
2464 static type_t *parse_typeof(void)
2465 {
2466         eat(T___typeof__);
2467
2468         type_t *type;
2469
2470         add_anchor_token(')');
2471         expect('(');
2472
2473         expression_t *expression  = NULL;
2474
2475         switch (token.kind) {
2476         case T_IDENTIFIER:
2477                 if (is_typedef_symbol(token.base.symbol)) {
2478         DECLARATION_START
2479                         type = parse_typename();
2480                 } else {
2481         default:
2482                         expression = parse_expression();
2483                         type       = revert_automatic_type_conversion(expression);
2484                 }
2485                 break;
2486         }
2487
2488         rem_anchor_token(')');
2489         expect(')');
2490
2491         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2492         typeof_type->typeoft.expression  = expression;
2493         typeof_type->typeoft.typeof_type = type;
2494
2495         return typeof_type;
2496 }
2497
2498 typedef enum specifiers_t {
2499         SPECIFIER_SIGNED    = 1 << 0,
2500         SPECIFIER_UNSIGNED  = 1 << 1,
2501         SPECIFIER_LONG      = 1 << 2,
2502         SPECIFIER_INT       = 1 << 3,
2503         SPECIFIER_DOUBLE    = 1 << 4,
2504         SPECIFIER_CHAR      = 1 << 5,
2505         SPECIFIER_WCHAR_T   = 1 << 6,
2506         SPECIFIER_SHORT     = 1 << 7,
2507         SPECIFIER_LONG_LONG = 1 << 8,
2508         SPECIFIER_FLOAT     = 1 << 9,
2509         SPECIFIER_BOOL      = 1 << 10,
2510         SPECIFIER_VOID      = 1 << 11,
2511         SPECIFIER_INT8      = 1 << 12,
2512         SPECIFIER_INT16     = 1 << 13,
2513         SPECIFIER_INT32     = 1 << 14,
2514         SPECIFIER_INT64     = 1 << 15,
2515         SPECIFIER_INT128    = 1 << 16,
2516         SPECIFIER_COMPLEX   = 1 << 17,
2517         SPECIFIER_IMAGINARY = 1 << 18,
2518 } specifiers_t;
2519
2520 static type_t *get_typedef_type(symbol_t *symbol)
2521 {
2522         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2523         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2524                 return NULL;
2525
2526         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2527         type->typedeft.typedefe = &entity->typedefe;
2528
2529         return type;
2530 }
2531
2532 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2533 {
2534         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2535
2536         add_anchor_token(')');
2537         add_anchor_token(',');
2538         expect('(');
2539
2540         do {
2541                 add_anchor_token('=');
2542                 source_position_t pos;
2543                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2544                 rem_anchor_token('=');
2545
2546                 symbol_t **prop = NULL;
2547                 if (prop_sym) {
2548                         if (streq(prop_sym->string, "put")) {
2549                                 prop = &property->put_symbol;
2550                         } else if (streq(prop_sym->string, "get")) {
2551                                 prop = &property->get_symbol;
2552                         } else {
2553                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2554                         }
2555                 }
2556
2557                 add_anchor_token(T_IDENTIFIER);
2558                 expect('=');
2559                 rem_anchor_token(T_IDENTIFIER);
2560
2561                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2562                 if (prop != NULL)
2563                         *prop = sym ? sym : sym_anonymous;
2564         } while (next_if(','));
2565         rem_anchor_token(',');
2566         rem_anchor_token(')');
2567
2568         attribute->a.property = property;
2569
2570         expect(')');
2571         return attribute;
2572 }
2573
2574 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2575 {
2576         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2577         if (next_if(T_restrict)) {
2578                 kind = ATTRIBUTE_MS_RESTRICT;
2579         } else if (token.kind == T_IDENTIFIER) {
2580                 char const *const name = token.base.symbol->string;
2581                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2582                      ++k) {
2583                         const char *attribute_name = get_attribute_name(k);
2584                         if (attribute_name != NULL && streq(attribute_name, name)) {
2585                                 kind = k;
2586                                 break;
2587                         }
2588                 }
2589
2590                 if (kind == ATTRIBUTE_UNKNOWN) {
2591                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2592                 }
2593         } else {
2594                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2595                 return NULL;
2596         }
2597
2598         attribute_t *attribute = allocate_attribute_zero(kind);
2599         eat(T_IDENTIFIER);
2600
2601         if (kind == ATTRIBUTE_MS_PROPERTY) {
2602                 return parse_attribute_ms_property(attribute);
2603         }
2604
2605         /* parse arguments */
2606         if (next_if('('))
2607                 attribute->a.arguments = parse_attribute_arguments();
2608
2609         return attribute;
2610 }
2611
2612 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2613 {
2614         eat(T__declspec);
2615
2616         add_anchor_token(')');
2617         expect('(');
2618         if (token.kind != ')') {
2619                 attribute_t **anchor = &first;
2620                 do {
2621                         while (*anchor != NULL)
2622                                 anchor = &(*anchor)->next;
2623
2624                         attribute_t *attribute
2625                                 = parse_microsoft_extended_decl_modifier_single();
2626                         if (attribute == NULL)
2627                                 break;
2628
2629                         *anchor = attribute;
2630                         anchor  = &attribute->next;
2631                 } while (next_if(','));
2632         }
2633         rem_anchor_token(')');
2634         expect(')');
2635         return first;
2636 }
2637
2638 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2639 {
2640         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2641         if (is_declaration(entity)) {
2642                 entity->declaration.type     = type_error_type;
2643                 entity->declaration.implicit = true;
2644         } else if (kind == ENTITY_TYPEDEF) {
2645                 entity->typedefe.type    = type_error_type;
2646                 entity->typedefe.builtin = true;
2647         }
2648         if (kind != ENTITY_COMPOUND_MEMBER)
2649                 record_entity(entity, false);
2650         return entity;
2651 }
2652
2653 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2654 {
2655         type_t            *type            = NULL;
2656         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2657         unsigned           type_specifiers = 0;
2658         bool               newtype         = false;
2659         bool               saw_error       = false;
2660
2661         memset(specifiers, 0, sizeof(*specifiers));
2662         specifiers->source_position = *HERE;
2663
2664         while (true) {
2665                 specifiers->attributes = parse_attributes(specifiers->attributes);
2666
2667                 switch (token.kind) {
2668                 /* storage class */
2669 #define MATCH_STORAGE_CLASS(token, class)                                  \
2670                 case token:                                                        \
2671                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2672                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2673                         }                                                              \
2674                         specifiers->storage_class = class;                             \
2675                         if (specifiers->thread_local)                                  \
2676                                 goto check_thread_storage_class;                           \
2677                         eat(token); \
2678                         break;
2679
2680                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2681                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2682                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2683                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2684                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2685
2686                 case T__declspec:
2687                         specifiers->attributes
2688                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2689                         break;
2690
2691                 case T___thread:
2692                         if (specifiers->thread_local) {
2693                                 errorf(HERE, "duplicate '__thread'");
2694                         } else {
2695                                 specifiers->thread_local = true;
2696 check_thread_storage_class:
2697                                 switch (specifiers->storage_class) {
2698                                         case STORAGE_CLASS_EXTERN:
2699                                         case STORAGE_CLASS_NONE:
2700                                         case STORAGE_CLASS_STATIC:
2701                                                 break;
2702
2703                                                 char const* wrong;
2704                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2705                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2706                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2707 wrong_thread_storage_class:
2708                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2709                                                 break;
2710                                 }
2711                         }
2712                         next_token();
2713                         break;
2714
2715                 /* type qualifiers */
2716 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2717                 case token:                                                     \
2718                         qualifiers |= qualifier;                                    \
2719                         eat(token); \
2720                         break
2721
2722                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2723                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2724                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2725                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2726                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2727                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2728                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2729                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2730
2731                 /* type specifiers */
2732 #define MATCH_SPECIFIER(token, specifier, name)                         \
2733                 case token:                                                     \
2734                         if (type_specifiers & specifier) {                           \
2735                                 errorf(HERE, "multiple " name " type specifiers given"); \
2736                         } else {                                                    \
2737                                 type_specifiers |= specifier;                           \
2738                         }                                                           \
2739                         eat(token); \
2740                         break
2741
2742                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2743                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2744                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2745                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2746                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2747                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2748                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2749                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2750                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2751                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2752                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2753                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2754                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2755                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2756                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2757                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2758                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2759                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2760
2761                 case T_inline:
2762                         eat(T_inline);
2763                         specifiers->is_inline = true;
2764                         break;
2765
2766 #if 0
2767                 case T__forceinline:
2768                         eat(T__forceinline);
2769                         specifiers->modifiers |= DM_FORCEINLINE;
2770                         break;
2771 #endif
2772
2773                 case T_long:
2774                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2775                                 errorf(HERE, "too many long type specifiers given");
2776                         } else if (type_specifiers & SPECIFIER_LONG) {
2777                                 type_specifiers |= SPECIFIER_LONG_LONG;
2778                         } else {
2779                                 type_specifiers |= SPECIFIER_LONG;
2780                         }
2781                         eat(T_long);
2782                         break;
2783
2784 #define CHECK_DOUBLE_TYPE() \
2785         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2786
2787                 case T_struct:
2788                         CHECK_DOUBLE_TYPE();
2789                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2790
2791                         type->compound.compound = parse_compound_type_specifier(true);
2792                         break;
2793                 case T_union:
2794                         CHECK_DOUBLE_TYPE();
2795                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2796                         type->compound.compound = parse_compound_type_specifier(false);
2797                         break;
2798                 case T_enum:
2799                         CHECK_DOUBLE_TYPE();
2800                         type = parse_enum_specifier();
2801                         break;
2802                 case T___typeof__:
2803                         CHECK_DOUBLE_TYPE();
2804                         type = parse_typeof();
2805                         break;
2806                 case T___builtin_va_list:
2807                         CHECK_DOUBLE_TYPE();
2808                         type = duplicate_type(type_valist);
2809                         eat(T___builtin_va_list);
2810                         break;
2811
2812                 case T_IDENTIFIER: {
2813                         /* only parse identifier if we haven't found a type yet */
2814                         if (type != NULL || type_specifiers != 0) {
2815                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2816                                  * declaration, so it doesn't generate errors about expecting '(' or
2817                                  * '{' later on. */
2818                                 switch (look_ahead(1)->kind) {
2819                                         STORAGE_CLASSES
2820                                         TYPE_SPECIFIERS
2821                                         case T_const:
2822                                         case T_restrict:
2823                                         case T_volatile:
2824                                         case T_inline:
2825                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2826                                         case T_IDENTIFIER:
2827                                         case '&':
2828                                         case '*':
2829                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2830                                                 eat(T_IDENTIFIER);
2831                                                 continue;
2832
2833                                         default:
2834                                                 goto finish_specifiers;
2835                                 }
2836                         }
2837
2838                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2839                         if (typedef_type == NULL) {
2840                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2841                                  * declaration, so it doesn't generate 'implicit int' followed by more
2842                                  * errors later on. */
2843                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2844                                 switch (la1_type) {
2845                                         DECLARATION_START
2846                                         case T_IDENTIFIER:
2847                                         case '&':
2848                                         case '*': {
2849                                                 errorf(HERE, "%K does not name a type", &token);
2850
2851                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2852
2853                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2854                                                 type->typedeft.typedefe = &entity->typedefe;
2855
2856                                                 eat(T_IDENTIFIER);
2857                                                 saw_error = true;
2858                                                 continue;
2859                                         }
2860
2861                                         default:
2862                                                 goto finish_specifiers;
2863                                 }
2864                         }
2865
2866                         eat(T_IDENTIFIER);
2867                         type = typedef_type;
2868                         break;
2869                 }
2870
2871                 /* function specifier */
2872                 default:
2873                         goto finish_specifiers;
2874                 }
2875         }
2876
2877 finish_specifiers:
2878         specifiers->attributes = parse_attributes(specifiers->attributes);
2879
2880         if (type == NULL || (saw_error && type_specifiers != 0)) {
2881                 atomic_type_kind_t atomic_type;
2882
2883                 /* match valid basic types */
2884                 switch (type_specifiers) {
2885                 case SPECIFIER_VOID:
2886                         atomic_type = ATOMIC_TYPE_VOID;
2887                         break;
2888                 case SPECIFIER_WCHAR_T:
2889                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2890                         break;
2891                 case SPECIFIER_CHAR:
2892                         atomic_type = ATOMIC_TYPE_CHAR;
2893                         break;
2894                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2895                         atomic_type = ATOMIC_TYPE_SCHAR;
2896                         break;
2897                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2898                         atomic_type = ATOMIC_TYPE_UCHAR;
2899                         break;
2900                 case SPECIFIER_SHORT:
2901                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2902                 case SPECIFIER_SHORT | SPECIFIER_INT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2904                         atomic_type = ATOMIC_TYPE_SHORT;
2905                         break;
2906                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2908                         atomic_type = ATOMIC_TYPE_USHORT;
2909                         break;
2910                 case SPECIFIER_INT:
2911                 case SPECIFIER_SIGNED:
2912                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2913                         atomic_type = ATOMIC_TYPE_INT;
2914                         break;
2915                 case SPECIFIER_UNSIGNED:
2916                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2917                         atomic_type = ATOMIC_TYPE_UINT;
2918                         break;
2919                 case SPECIFIER_LONG:
2920                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2921                 case SPECIFIER_LONG | SPECIFIER_INT:
2922                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2923                         atomic_type = ATOMIC_TYPE_LONG;
2924                         break;
2925                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2926                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2927                         atomic_type = ATOMIC_TYPE_ULONG;
2928                         break;
2929
2930                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2931                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2932                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2933                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2934                         | SPECIFIER_INT:
2935                         atomic_type = ATOMIC_TYPE_LONGLONG;
2936                         goto warn_about_long_long;
2937
2938                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2940                         | SPECIFIER_INT:
2941                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2942 warn_about_long_long:
2943                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2944                         break;
2945
2946                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2947                         atomic_type = unsigned_int8_type_kind;
2948                         break;
2949
2950                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2951                         atomic_type = unsigned_int16_type_kind;
2952                         break;
2953
2954                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2955                         atomic_type = unsigned_int32_type_kind;
2956                         break;
2957
2958                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2959                         atomic_type = unsigned_int64_type_kind;
2960                         break;
2961
2962                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2963                         atomic_type = unsigned_int128_type_kind;
2964                         break;
2965
2966                 case SPECIFIER_INT8:
2967                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2968                         atomic_type = int8_type_kind;
2969                         break;
2970
2971                 case SPECIFIER_INT16:
2972                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2973                         atomic_type = int16_type_kind;
2974                         break;
2975
2976                 case SPECIFIER_INT32:
2977                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2978                         atomic_type = int32_type_kind;
2979                         break;
2980
2981                 case SPECIFIER_INT64:
2982                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2983                         atomic_type = int64_type_kind;
2984                         break;
2985
2986                 case SPECIFIER_INT128:
2987                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2988                         atomic_type = int128_type_kind;
2989                         break;
2990
2991                 case SPECIFIER_FLOAT:
2992                         atomic_type = ATOMIC_TYPE_FLOAT;
2993                         break;
2994                 case SPECIFIER_DOUBLE:
2995                         atomic_type = ATOMIC_TYPE_DOUBLE;
2996                         break;
2997                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2998                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2999                         break;
3000                 case SPECIFIER_BOOL:
3001                         atomic_type = ATOMIC_TYPE_BOOL;
3002                         break;
3003                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3004                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3005                         atomic_type = ATOMIC_TYPE_FLOAT;
3006                         break;
3007                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3008                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3009                         atomic_type = ATOMIC_TYPE_DOUBLE;
3010                         break;
3011                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3012                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3013                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3014                         break;
3015                 default: {
3016                         /* invalid specifier combination, give an error message */
3017                         source_position_t const* const pos = &specifiers->source_position;
3018                         if (type_specifiers == 0) {
3019                                 if (!saw_error) {
3020                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3021                                         if (!(c_mode & _CXX) && !strict_mode) {
3022                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3023                                                 atomic_type = ATOMIC_TYPE_INT;
3024                                                 break;
3025                                         } else {
3026                                                 errorf(pos, "no type specifiers given in declaration");
3027                                         }
3028                                 }
3029                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3030                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3031                                 errorf(pos, "signed and unsigned specifiers given");
3032                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3033                                 errorf(pos, "only integer types can be signed or unsigned");
3034                         } else {
3035                                 errorf(pos, "multiple datatypes in declaration");
3036                         }
3037                         goto end_error;
3038                 }
3039                 }
3040
3041                 if (type_specifiers & SPECIFIER_COMPLEX) {
3042                         type = allocate_type_zero(TYPE_COMPLEX);
3043                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3044                         type = allocate_type_zero(TYPE_IMAGINARY);
3045                 } else {
3046                         type = allocate_type_zero(TYPE_ATOMIC);
3047                 }
3048                 type->atomic.akind = atomic_type;
3049                 newtype = true;
3050         } else if (type_specifiers != 0) {
3051                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3052         }
3053
3054         /* FIXME: check type qualifiers here */
3055         type->base.qualifiers = qualifiers;
3056
3057         if (newtype) {
3058                 type = identify_new_type(type);
3059         } else {
3060                 type = typehash_insert(type);
3061         }
3062
3063         if (specifiers->attributes != NULL)
3064                 type = handle_type_attributes(specifiers->attributes, type);
3065         specifiers->type = type;
3066         return;
3067
3068 end_error:
3069         specifiers->type = type_error_type;
3070 }
3071
3072 static type_qualifiers_t parse_type_qualifiers(void)
3073 {
3074         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3075
3076         while (true) {
3077                 switch (token.kind) {
3078                 /* type qualifiers */
3079                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3080                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3081                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3082                 /* microsoft extended type modifiers */
3083                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3084                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3085                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3086                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3087                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3088
3089                 default:
3090                         return qualifiers;
3091                 }
3092         }
3093 }
3094
3095 /**
3096  * Parses an K&R identifier list
3097  */
3098 static void parse_identifier_list(scope_t *scope)
3099 {
3100         assert(token.kind == T_IDENTIFIER);
3101         do {
3102                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3103                 /* a K&R parameter has no type, yet */
3104                 eat(T_IDENTIFIER);
3105
3106                 if (scope != NULL)
3107                         append_entity(scope, entity);
3108         } while (next_if(',') && token.kind == T_IDENTIFIER);
3109 }
3110
3111 static entity_t *parse_parameter(void)
3112 {
3113         declaration_specifiers_t specifiers;
3114         parse_declaration_specifiers(&specifiers);
3115
3116         entity_t *entity = parse_declarator(&specifiers,
3117                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3118         anonymous_entity = NULL;
3119         return entity;
3120 }
3121
3122 static void semantic_parameter_incomplete(const entity_t *entity)
3123 {
3124         assert(entity->kind == ENTITY_PARAMETER);
3125
3126         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3127          *             list in a function declarator that is part of a
3128          *             definition of that function shall not have
3129          *             incomplete type. */
3130         type_t *type = skip_typeref(entity->declaration.type);
3131         if (is_type_incomplete(type)) {
3132                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3133         }
3134 }
3135
3136 static bool has_parameters(void)
3137 {
3138         /* func(void) is not a parameter */
3139         if (look_ahead(1)->kind != ')')
3140                 return true;
3141         if (token.kind == T_IDENTIFIER) {
3142                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3143                 if (entity == NULL)
3144                         return true;
3145                 if (entity->kind != ENTITY_TYPEDEF)
3146                         return true;
3147                 type_t const *const type = skip_typeref(entity->typedefe.type);
3148                 if (!is_type_void(type))
3149                         return true;
3150                 if (c_mode & _CXX) {
3151                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3152                          * is not allowed. */
3153                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3154                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3155                         /* §6.7.5.3:10  Qualification is not allowed here. */
3156                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3157                 }
3158         } else if (token.kind != T_void) {
3159                 return true;
3160         }
3161         next_token();
3162         return false;
3163 }
3164
3165 /**
3166  * Parses function type parameters (and optionally creates variable_t entities
3167  * for them in a scope)
3168  */
3169 static void parse_parameters(function_type_t *type, scope_t *scope)
3170 {
3171         add_anchor_token(')');
3172         eat('(');
3173
3174         if (token.kind == T_IDENTIFIER            &&
3175             !is_typedef_symbol(token.base.symbol) &&
3176             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3177                 type->kr_style_parameters = true;
3178                 parse_identifier_list(scope);
3179         } else if (token.kind == ')') {
3180                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3181                 if (!(c_mode & _CXX))
3182                         type->unspecified_parameters = true;
3183         } else if (has_parameters()) {
3184                 function_parameter_t **anchor = &type->parameters;
3185                 add_anchor_token(',');
3186                 do {
3187                         switch (token.kind) {
3188                         case T_DOTDOTDOT:
3189                                 eat(T_DOTDOTDOT);
3190                                 type->variadic = true;
3191                                 goto parameters_finished;
3192
3193                         case T_IDENTIFIER:
3194                         DECLARATION_START
3195                         {
3196                                 entity_t *entity = parse_parameter();
3197                                 if (entity->kind == ENTITY_TYPEDEF) {
3198                                         errorf(&entity->base.source_position,
3199                                                         "typedef not allowed as function parameter");
3200                                         break;
3201                                 }
3202                                 assert(is_declaration(entity));
3203
3204                                 semantic_parameter_incomplete(entity);
3205
3206                                 function_parameter_t *const parameter =
3207                                         allocate_parameter(entity->declaration.type);
3208
3209                                 if (scope != NULL) {
3210                                         append_entity(scope, entity);
3211                                 }
3212
3213                                 *anchor = parameter;
3214                                 anchor  = &parameter->next;
3215                                 break;
3216                         }
3217
3218                         default:
3219                                 goto parameters_finished;
3220                         }
3221                 } while (next_if(','));
3222 parameters_finished:
3223                 rem_anchor_token(',');
3224         }
3225
3226         rem_anchor_token(')');
3227         expect(')');
3228 }
3229
3230 typedef enum construct_type_kind_t {
3231         CONSTRUCT_POINTER = 1,
3232         CONSTRUCT_REFERENCE,
3233         CONSTRUCT_FUNCTION,
3234         CONSTRUCT_ARRAY
3235 } construct_type_kind_t;
3236
3237 typedef union construct_type_t construct_type_t;
3238
3239 typedef struct construct_type_base_t {
3240         construct_type_kind_t  kind;
3241         source_position_t      pos;
3242         construct_type_t      *next;
3243 } construct_type_base_t;
3244
3245 typedef struct parsed_pointer_t {
3246         construct_type_base_t  base;
3247         type_qualifiers_t      type_qualifiers;
3248         variable_t            *base_variable;  /**< MS __based extension. */
3249 } parsed_pointer_t;
3250
3251 typedef struct parsed_reference_t {
3252         construct_type_base_t base;
3253 } parsed_reference_t;
3254
3255 typedef struct construct_function_type_t {
3256         construct_type_base_t  base;
3257         type_t                *function_type;
3258 } construct_function_type_t;
3259
3260 typedef struct parsed_array_t {
3261         construct_type_base_t  base;
3262         type_qualifiers_t      type_qualifiers;
3263         bool                   is_static;
3264         bool                   is_variable;
3265         expression_t          *size;
3266 } parsed_array_t;
3267
3268 union construct_type_t {
3269         construct_type_kind_t     kind;
3270         construct_type_base_t     base;
3271         parsed_pointer_t          pointer;
3272         parsed_reference_t        reference;
3273         construct_function_type_t function;
3274         parsed_array_t            array;
3275 };
3276
3277 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3278 {
3279         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3280         memset(cons, 0, size);
3281         cons->kind     = kind;
3282         cons->base.pos = *HERE;
3283         return cons;
3284 }
3285
3286 /* §6.7.5.1 */
3287 static construct_type_t *parse_pointer_declarator(void)
3288 {
3289         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3290         eat('*');
3291         cons->pointer.type_qualifiers = parse_type_qualifiers();
3292         //cons->pointer.base_variable   = base_variable;
3293
3294         return cons;
3295 }
3296
3297 /* ISO/IEC 14882:1998(E) §8.3.2 */
3298 static construct_type_t *parse_reference_declarator(void)
3299 {
3300         if (!(c_mode & _CXX))
3301                 errorf(HERE, "references are only available for C++");
3302
3303         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3304         eat('&');
3305
3306         return cons;
3307 }
3308
3309 /* §6.7.5.2 */
3310 static construct_type_t *parse_array_declarator(void)
3311 {
3312         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3313         parsed_array_t   *const array = &cons->array;
3314
3315         eat('[');
3316         add_anchor_token(']');
3317
3318         bool is_static = next_if(T_static);
3319
3320         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3321
3322         if (!is_static)
3323                 is_static = next_if(T_static);
3324
3325         array->type_qualifiers = type_qualifiers;
3326         array->is_static       = is_static;
3327
3328         expression_t *size = NULL;
3329         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3330                 array->is_variable = true;
3331                 eat('*');
3332         } else if (token.kind != ']') {
3333                 size = parse_assignment_expression();
3334
3335                 /* §6.7.5.2:1  Array size must have integer type */
3336                 type_t *const orig_type = size->base.type;
3337                 type_t *const type      = skip_typeref(orig_type);
3338                 if (!is_type_integer(type) && is_type_valid(type)) {
3339                         errorf(&size->base.source_position,
3340                                "array size '%E' must have integer type but has type '%T'",
3341                                size, orig_type);
3342                 }
3343
3344                 array->size = size;
3345                 mark_vars_read(size, NULL);
3346         }
3347
3348         if (is_static && size == NULL)
3349                 errorf(&array->base.pos, "static array parameters require a size");
3350
3351         rem_anchor_token(']');
3352         expect(']');
3353         return cons;
3354 }
3355
3356 /* §6.7.5.3 */
3357 static construct_type_t *parse_function_declarator(scope_t *scope)
3358 {
3359         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3360
3361         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3362         function_type_t *ftype = &type->function;
3363
3364         ftype->linkage            = current_linkage;
3365         ftype->calling_convention = CC_DEFAULT;
3366
3367         parse_parameters(ftype, scope);
3368
3369         cons->function.function_type = type;
3370
3371         return cons;
3372 }
3373
3374 typedef struct parse_declarator_env_t {
3375         bool               may_be_abstract : 1;
3376         bool               must_be_abstract : 1;
3377         decl_modifiers_t   modifiers;
3378         symbol_t          *symbol;
3379         source_position_t  source_position;
3380         scope_t            parameters;
3381         attribute_t       *attributes;
3382 } parse_declarator_env_t;
3383
3384 /* §6.7.5 */
3385 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3386 {
3387         /* construct a single linked list of construct_type_t's which describe
3388          * how to construct the final declarator type */
3389         construct_type_t  *first      = NULL;
3390         construct_type_t **anchor     = &first;
3391
3392         env->attributes = parse_attributes(env->attributes);
3393
3394         for (;;) {
3395                 construct_type_t *type;
3396                 //variable_t       *based = NULL; /* MS __based extension */
3397                 switch (token.kind) {
3398                         case '&':
3399                                 type = parse_reference_declarator();
3400                                 break;
3401
3402                         case T__based: {
3403                                 panic("based not supported anymore");
3404                                 /* FALLTHROUGH */
3405                         }
3406
3407                         case '*':
3408                                 type = parse_pointer_declarator();
3409                                 break;
3410
3411                         default:
3412                                 goto ptr_operator_end;
3413                 }
3414
3415                 *anchor = type;
3416                 anchor  = &type->base.next;
3417
3418                 /* TODO: find out if this is correct */
3419                 env->attributes = parse_attributes(env->attributes);
3420         }
3421
3422 ptr_operator_end: ;
3423         construct_type_t *inner_types = NULL;
3424
3425         switch (token.kind) {
3426         case T_IDENTIFIER:
3427                 if (env->must_be_abstract) {
3428                         errorf(HERE, "no identifier expected in typename");
3429                 } else {
3430                         env->symbol          = token.base.symbol;
3431                         env->source_position = *HERE;
3432                 }
3433                 eat(T_IDENTIFIER);
3434                 break;
3435
3436         case '(': {
3437                 /* Parenthesized declarator or function declarator? */
3438                 token_t const *const la1 = look_ahead(1);
3439                 switch (la1->kind) {
3440                         case T_IDENTIFIER:
3441                                 if (is_typedef_symbol(la1->base.symbol)) {
3442                         case ')':
3443                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3444                                          * interpreted as ``function with no parameter specification'', rather
3445                                          * than redundant parentheses around the omitted identifier. */
3446                         default:
3447                                         /* Function declarator. */
3448                                         if (!env->may_be_abstract) {
3449                                                 errorf(HERE, "function declarator must have a name");
3450                                         }
3451                                 } else {
3452                         case '&':
3453                         case '(':
3454                         case '*':
3455                         case '[':
3456                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3457                                         /* Paranthesized declarator. */
3458                                         eat('(');
3459                                         add_anchor_token(')');
3460                                         inner_types = parse_inner_declarator(env);
3461                                         if (inner_types != NULL) {
3462                                                 /* All later declarators only modify the return type */
3463                                                 env->must_be_abstract = true;
3464                                         }
3465                                         rem_anchor_token(')');
3466                                         expect(')');
3467                                 }
3468                                 break;
3469                 }
3470                 break;
3471         }
3472
3473         default:
3474                 if (env->may_be_abstract)
3475                         break;
3476                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3477                 eat_until_anchor();
3478                 return NULL;
3479         }
3480
3481         construct_type_t **const p = anchor;
3482
3483         for (;;) {
3484                 construct_type_t *type;
3485                 switch (token.kind) {
3486                 case '(': {
3487                         scope_t *scope = NULL;
3488                         if (!env->must_be_abstract) {
3489                                 scope = &env->parameters;
3490                         }
3491
3492                         type = parse_function_declarator(scope);
3493                         break;
3494                 }
3495                 case '[':
3496                         type = parse_array_declarator();
3497                         break;
3498                 default:
3499                         goto declarator_finished;
3500                 }
3501
3502                 /* insert in the middle of the list (at p) */
3503                 type->base.next = *p;
3504                 *p              = type;
3505                 if (anchor == p)
3506                         anchor = &type->base.next;
3507         }
3508
3509 declarator_finished:
3510         /* append inner_types at the end of the list, we don't to set anchor anymore
3511          * as it's not needed anymore */
3512         *anchor = inner_types;
3513
3514         return first;
3515 }
3516
3517 static type_t *construct_declarator_type(construct_type_t *construct_list,
3518                                          type_t *type)
3519 {
3520         construct_type_t *iter = construct_list;
3521         for (; iter != NULL; iter = iter->base.next) {
3522                 source_position_t const* const pos = &iter->base.pos;
3523                 switch (iter->kind) {
3524                 case CONSTRUCT_FUNCTION: {
3525                         construct_function_type_t *function      = &iter->function;
3526                         type_t                    *function_type = function->function_type;
3527
3528                         function_type->function.return_type = type;
3529
3530                         type_t *skipped_return_type = skip_typeref(type);
3531                         /* §6.7.5.3:1 */
3532                         if (is_type_function(skipped_return_type)) {
3533                                 errorf(pos, "function returning function is not allowed");
3534                         } else if (is_type_array(skipped_return_type)) {
3535                                 errorf(pos, "function returning array is not allowed");
3536                         } else {
3537                                 if (skipped_return_type->base.qualifiers != 0) {
3538                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3539                                 }
3540                         }
3541
3542                         /* The function type was constructed earlier.  Freeing it here will
3543                          * destroy other types. */
3544                         type = typehash_insert(function_type);
3545                         continue;
3546                 }
3547
3548                 case CONSTRUCT_POINTER: {
3549                         if (is_type_reference(skip_typeref(type)))
3550                                 errorf(pos, "cannot declare a pointer to reference");
3551
3552                         parsed_pointer_t *pointer = &iter->pointer;
3553                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3554                         continue;
3555                 }
3556
3557                 case CONSTRUCT_REFERENCE:
3558                         if (is_type_reference(skip_typeref(type)))
3559                                 errorf(pos, "cannot declare a reference to reference");
3560
3561                         type = make_reference_type(type);
3562                         continue;
3563
3564                 case CONSTRUCT_ARRAY: {
3565                         if (is_type_reference(skip_typeref(type)))
3566                                 errorf(pos, "cannot declare an array of references");
3567
3568                         parsed_array_t *array      = &iter->array;
3569                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3570
3571                         expression_t *size_expression = array->size;
3572                         if (size_expression != NULL) {
3573                                 size_expression
3574                                         = create_implicit_cast(size_expression, type_size_t);
3575                         }
3576
3577                         array_type->base.qualifiers       = array->type_qualifiers;
3578                         array_type->array.element_type    = type;
3579                         array_type->array.is_static       = array->is_static;
3580                         array_type->array.is_variable     = array->is_variable;
3581                         array_type->array.size_expression = size_expression;
3582
3583                         if (size_expression != NULL) {
3584                                 switch (is_constant_expression(size_expression)) {
3585                                 case EXPR_CLASS_CONSTANT: {
3586                                         long const size = fold_constant_to_int(size_expression);
3587                                         array_type->array.size          = size;
3588                                         array_type->array.size_constant = true;
3589                                         /* §6.7.5.2:1  If the expression is a constant expression,
3590                                          * it shall have a value greater than zero. */
3591                                         if (size < 0) {
3592                                                 errorf(&size_expression->base.source_position,
3593                                                            "size of array must be greater than zero");
3594                                         } else if (size == 0 && !GNU_MODE) {
3595                                                 errorf(&size_expression->base.source_position,
3596                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3597                                         }
3598                                         break;
3599                                 }
3600
3601                                 case EXPR_CLASS_VARIABLE:
3602                                         array_type->array.is_vla = true;
3603                                         break;
3604
3605                                 case EXPR_CLASS_ERROR:
3606                                         break;
3607                                 }
3608                         }
3609
3610                         type_t *skipped_type = skip_typeref(type);
3611                         /* §6.7.5.2:1 */
3612                         if (is_type_incomplete(skipped_type)) {
3613                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3614                         } else if (is_type_function(skipped_type)) {
3615                                 errorf(pos, "array of functions is not allowed");
3616                         }
3617                         type = identify_new_type(array_type);
3618                         continue;
3619                 }
3620                 }
3621                 internal_errorf(pos, "invalid type construction found");
3622         }
3623
3624         return type;
3625 }
3626
3627 static type_t *automatic_type_conversion(type_t *orig_type);
3628
3629 static type_t *semantic_parameter(const source_position_t *pos,
3630                                   type_t *type,
3631                                   const declaration_specifiers_t *specifiers,
3632                                   entity_t const *const param)
3633 {
3634         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3635          *             shall be adjusted to ``qualified pointer to type'',
3636          *             [...]
3637          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3638          *             type'' shall be adjusted to ``pointer to function
3639          *             returning type'', as in 6.3.2.1. */
3640         type = automatic_type_conversion(type);
3641
3642         if (specifiers->is_inline && is_type_valid(type)) {
3643                 errorf(pos, "'%N' declared 'inline'", param);
3644         }
3645
3646         /* §6.9.1:6  The declarations in the declaration list shall contain
3647          *           no storage-class specifier other than register and no
3648          *           initializations. */
3649         if (specifiers->thread_local || (
3650                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3651                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3652            ) {
3653                 errorf(pos, "invalid storage class for '%N'", param);
3654         }
3655
3656         /* delay test for incomplete type, because we might have (void)
3657          * which is legal but incomplete... */
3658
3659         return type;
3660 }
3661
3662 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3663                                   declarator_flags_t flags)
3664 {
3665         parse_declarator_env_t env;
3666         memset(&env, 0, sizeof(env));
3667         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3668
3669         construct_type_t *construct_type = parse_inner_declarator(&env);
3670         type_t           *orig_type      =
3671                 construct_declarator_type(construct_type, specifiers->type);
3672         type_t           *type           = skip_typeref(orig_type);
3673
3674         if (construct_type != NULL) {
3675                 obstack_free(&temp_obst, construct_type);
3676         }
3677
3678         attribute_t *attributes = parse_attributes(env.attributes);
3679         /* append (shared) specifier attribute behind attributes of this
3680          * declarator */
3681         attribute_t **anchor = &attributes;
3682         while (*anchor != NULL)
3683                 anchor = &(*anchor)->next;
3684         *anchor = specifiers->attributes;
3685
3686         entity_t *entity;
3687         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3688                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3689                 entity->typedefe.type = orig_type;
3690
3691                 if (anonymous_entity != NULL) {
3692                         if (is_type_compound(type)) {
3693                                 assert(anonymous_entity->compound.alias == NULL);
3694                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3695                                        anonymous_entity->kind == ENTITY_UNION);
3696                                 anonymous_entity->compound.alias = entity;
3697                                 anonymous_entity = NULL;
3698                         } else if (is_type_enum(type)) {
3699                                 assert(anonymous_entity->enume.alias == NULL);
3700                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3701                                 anonymous_entity->enume.alias = entity;
3702                                 anonymous_entity = NULL;
3703                         }
3704                 }
3705         } else {
3706                 /* create a declaration type entity */
3707                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3708                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3709                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3710
3711                         if (env.symbol != NULL) {
3712                                 if (specifiers->is_inline && is_type_valid(type)) {
3713                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3714                                 }
3715
3716                                 if (specifiers->thread_local ||
3717                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3718                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3719                                 }
3720                         }
3721                 } else if (flags & DECL_IS_PARAMETER) {
3722                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3723                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3724                 } else if (is_type_function(type)) {
3725                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3726                         entity->function.is_inline      = specifiers->is_inline;
3727                         entity->function.elf_visibility = default_visibility;
3728                         entity->function.parameters     = env.parameters;
3729
3730                         if (env.symbol != NULL) {
3731                                 /* this needs fixes for C++ */
3732                                 bool in_function_scope = current_function != NULL;
3733
3734                                 if (specifiers->thread_local || (
3735                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3736                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3737                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3738                                                 )) {
3739                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3740                                 }
3741                         }
3742                 } else {
3743                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3744                         entity->variable.elf_visibility = default_visibility;
3745                         entity->variable.thread_local   = specifiers->thread_local;
3746
3747                         if (env.symbol != NULL) {
3748                                 if (specifiers->is_inline && is_type_valid(type)) {
3749                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3750                                 }
3751
3752                                 bool invalid_storage_class = false;
3753                                 if (current_scope == file_scope) {
3754                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3755                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3756                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3757                                                 invalid_storage_class = true;
3758                                         }
3759                                 } else {
3760                                         if (specifiers->thread_local &&
3761                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3762                                                 invalid_storage_class = true;
3763                                         }
3764                                 }
3765                                 if (invalid_storage_class) {
3766                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3767                                 }
3768                         }
3769                 }
3770
3771                 entity->declaration.type       = orig_type;
3772                 entity->declaration.alignment  = get_type_alignment(orig_type);
3773                 entity->declaration.modifiers  = env.modifiers;
3774                 entity->declaration.attributes = attributes;
3775
3776                 storage_class_t storage_class = specifiers->storage_class;
3777                 entity->declaration.declared_storage_class = storage_class;
3778
3779                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3780                         storage_class = STORAGE_CLASS_AUTO;
3781                 entity->declaration.storage_class = storage_class;
3782         }
3783
3784         if (attributes != NULL) {
3785                 handle_entity_attributes(attributes, entity);
3786         }
3787
3788         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3789                 adapt_special_functions(&entity->function);
3790         }
3791
3792         return entity;
3793 }
3794
3795 static type_t *parse_abstract_declarator(type_t *base_type)
3796 {
3797         parse_declarator_env_t env;
3798         memset(&env, 0, sizeof(env));
3799         env.may_be_abstract = true;
3800         env.must_be_abstract = true;
3801
3802         construct_type_t *construct_type = parse_inner_declarator(&env);
3803
3804         type_t *result = construct_declarator_type(construct_type, base_type);
3805         if (construct_type != NULL) {
3806                 obstack_free(&temp_obst, construct_type);
3807         }
3808         result = handle_type_attributes(env.attributes, result);
3809
3810         return result;
3811 }
3812
3813 /**
3814  * Check if the declaration of main is suspicious.  main should be a
3815  * function with external linkage, returning int, taking either zero
3816  * arguments, two, or three arguments of appropriate types, ie.
3817  *
3818  * int main([ int argc, char **argv [, char **env ] ]).
3819  *
3820  * @param decl    the declaration to check
3821  * @param type    the function type of the declaration
3822  */
3823 static void check_main(const entity_t *entity)
3824 {
3825         const source_position_t *pos = &entity->base.source_position;
3826         if (entity->kind != ENTITY_FUNCTION) {
3827                 warningf(WARN_MAIN, pos, "'main' is not a function");
3828                 return;
3829         }
3830
3831         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3832                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3833         }
3834
3835         type_t *type = skip_typeref(entity->declaration.type);
3836         assert(is_type_function(type));
3837
3838         function_type_t const *const func_type = &type->function;
3839         type_t                *const ret_type  = func_type->return_type;
3840         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3841                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3842         }
3843         const function_parameter_t *parm = func_type->parameters;
3844         if (parm != NULL) {
3845                 type_t *const first_type        = skip_typeref(parm->type);
3846                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3847                 if (!types_compatible(first_type_unqual, type_int)) {
3848                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3849                 }
3850                 parm = parm->next;
3851                 if (parm != NULL) {
3852                         type_t *const second_type = skip_typeref(parm->type);
3853                         type_t *const second_type_unqual
3854                                 = get_unqualified_type(second_type);
3855                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3856                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3857                         }
3858                         parm = parm->next;
3859                         if (parm != NULL) {
3860                                 type_t *const third_type = skip_typeref(parm->type);
3861                                 type_t *const third_type_unqual
3862                                         = get_unqualified_type(third_type);
3863                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3864                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3865                                 }
3866                                 parm = parm->next;
3867                                 if (parm != NULL)
3868                                         goto warn_arg_count;
3869                         }
3870                 } else {
3871 warn_arg_count:
3872                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3873                 }
3874         }
3875 }
3876
3877 static void error_redefined_as_different_kind(const source_position_t *pos,
3878                 const entity_t *old, entity_kind_t new_kind)
3879 {
3880         char              const *const what = get_entity_kind_name(new_kind);
3881         source_position_t const *const ppos = &old->base.source_position;
3882         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3883 }
3884
3885 static bool is_entity_valid(entity_t *const ent)
3886 {
3887         if (is_declaration(ent)) {
3888                 return is_type_valid(skip_typeref(ent->declaration.type));
3889         } else if (ent->kind == ENTITY_TYPEDEF) {
3890                 return is_type_valid(skip_typeref(ent->typedefe.type));
3891         }
3892         return true;
3893 }
3894
3895 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3896 {
3897         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3898                 if (attributes_equal(tattr, attr))
3899                         return true;
3900         }
3901         return false;
3902 }
3903
3904 /**
3905  * test wether new_list contains any attributes not included in old_list
3906  */
3907 static bool has_new_attributes(const attribute_t *old_list,
3908                                const attribute_t *new_list)
3909 {
3910         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3911                 if (!contains_attribute(old_list, attr))
3912                         return true;
3913         }
3914         return false;
3915 }
3916
3917 /**
3918  * Merge in attributes from an attribute list (probably from a previous
3919  * declaration with the same name). Warning: destroys the old structure
3920  * of the attribute list - don't reuse attributes after this call.
3921  */
3922 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3923 {
3924         attribute_t *next;
3925         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3926                 next = attr->next;
3927                 if (contains_attribute(decl->attributes, attr))
3928                         continue;
3929
3930                 /* move attribute to new declarations attributes list */
3931                 attr->next       = decl->attributes;
3932                 decl->attributes = attr;
3933         }
3934 }
3935
3936 static bool is_main(entity_t*);
3937
3938 /**
3939  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3940  * for various problems that occur for multiple definitions
3941  */
3942 entity_t *record_entity(entity_t *entity, const bool is_definition)
3943 {
3944         const symbol_t *const    symbol  = entity->base.symbol;
3945         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3946         const source_position_t *pos     = &entity->base.source_position;
3947
3948         /* can happen in error cases */
3949         if (symbol == NULL)
3950                 return entity;
3951
3952         assert(!entity->base.parent_scope);
3953         assert(current_scope);
3954         entity->base.parent_scope = current_scope;
3955
3956         entity_t *const previous_entity = get_entity(symbol, namespc);
3957         /* pushing the same entity twice will break the stack structure */
3958         assert(previous_entity != entity);
3959
3960         if (entity->kind == ENTITY_FUNCTION) {
3961                 type_t *const orig_type = entity->declaration.type;
3962                 type_t *const type      = skip_typeref(orig_type);
3963
3964                 assert(is_type_function(type));
3965                 if (type->function.unspecified_parameters &&
3966                     previous_entity == NULL               &&
3967                     !entity->declaration.implicit) {
3968                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3969                 }
3970
3971                 if (is_main(entity)) {
3972                         check_main(entity);
3973                 }
3974         }
3975
3976         if (is_declaration(entity)                                    &&
3977             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3978             current_scope != file_scope                               &&
3979             !entity->declaration.implicit) {
3980                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3981         }
3982
3983         if (previous_entity != NULL) {
3984                 source_position_t const *const ppos = &previous_entity->base.source_position;
3985
3986                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3987                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3988                         assert(previous_entity->kind == ENTITY_PARAMETER);
3989                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3990                         goto finish;
3991                 }
3992
3993                 if (previous_entity->base.parent_scope == current_scope) {
3994                         if (previous_entity->kind != entity->kind) {
3995                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3996                                         error_redefined_as_different_kind(pos, previous_entity,
3997                                                         entity->kind);
3998                                 }
3999                                 goto finish;
4000                         }
4001                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4002                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4003                                 goto finish;
4004                         }
4005                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4006                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4007                                 type_t *const prev_type
4008                                         = skip_typeref(previous_entity->typedefe.type);
4009                                 if (c_mode & _CXX) {
4010                                         /* C++ allows double typedef if they are identical
4011                                          * (after skipping typedefs) */
4012                                         if (type == prev_type)
4013                                                 goto finish;
4014                                 } else {
4015                                         /* GCC extension: redef in system headers is allowed */
4016                                         if ((pos->is_system_header || ppos->is_system_header) &&
4017                                             types_compatible(type, prev_type))
4018                                                 goto finish;
4019                                 }
4020                                 errorf(pos, "redefinition of '%N' (declared %P)",
4021                                        entity, ppos);
4022                                 goto finish;
4023                         }
4024
4025                         /* at this point we should have only VARIABLES or FUNCTIONS */
4026                         assert(is_declaration(previous_entity) && is_declaration(entity));
4027
4028                         declaration_t *const prev_decl = &previous_entity->declaration;
4029                         declaration_t *const decl      = &entity->declaration;
4030
4031                         /* can happen for K&R style declarations */
4032                         if (prev_decl->type       == NULL             &&
4033                                         previous_entity->kind == ENTITY_PARAMETER &&
4034                                         entity->kind          == ENTITY_PARAMETER) {
4035                                 prev_decl->type                   = decl->type;
4036                                 prev_decl->storage_class          = decl->storage_class;
4037                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4038                                 prev_decl->modifiers              = decl->modifiers;
4039                                 return previous_entity;
4040                         }
4041
4042                         type_t *const type      = skip_typeref(decl->type);
4043                         type_t *const prev_type = skip_typeref(prev_decl->type);
4044
4045                         if (!types_compatible(type, prev_type)) {
4046                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4047                         } else {
4048                                 unsigned old_storage_class = prev_decl->storage_class;
4049
4050                                 if (is_definition                     &&
4051                                                 !prev_decl->used                  &&
4052                                                 !(prev_decl->modifiers & DM_USED) &&
4053                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4054                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4055                                 }
4056
4057                                 storage_class_t new_storage_class = decl->storage_class;
4058
4059                                 /* pretend no storage class means extern for function
4060                                  * declarations (except if the previous declaration is neither
4061                                  * none nor extern) */
4062                                 if (entity->kind == ENTITY_FUNCTION) {
4063                                         /* the previous declaration could have unspecified parameters or
4064                                          * be a typedef, so use the new type */
4065                                         if (prev_type->function.unspecified_parameters || is_definition)
4066                                                 prev_decl->type = type;
4067
4068                                         switch (old_storage_class) {
4069                                                 case STORAGE_CLASS_NONE:
4070                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4071                                                         /* FALLTHROUGH */
4072
4073                                                 case STORAGE_CLASS_EXTERN:
4074                                                         if (is_definition) {
4075                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4076                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4077                                                                 }
4078                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4079                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4080                                                         }
4081                                                         break;
4082
4083                                                 default:
4084                                                         break;
4085                                         }
4086                                 } else if (is_type_incomplete(prev_type)) {
4087                                         prev_decl->type = type;
4088                                 }
4089
4090                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4091                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4092
4093 warn_redundant_declaration: ;
4094                                         bool has_new_attrs
4095                                                 = has_new_attributes(prev_decl->attributes,
4096                                                                      decl->attributes);
4097                                         if (has_new_attrs) {
4098                                                 merge_in_attributes(decl, prev_decl->attributes);
4099                                         } else if (!is_definition        &&
4100                                                         is_type_valid(prev_type) &&
4101                                                         !pos->is_system_header) {
4102                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4103                                         }
4104                                 } else if (current_function == NULL) {
4105                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4106                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4107                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4108                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4109                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4110                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4111                                         } else {
4112                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4113                                                 if (c_mode & _CXX)
4114                                                         goto error_redeclaration;
4115                                                 goto warn_redundant_declaration;
4116                                         }
4117                                 } else if (is_type_valid(prev_type)) {
4118                                         if (old_storage_class == new_storage_class) {
4119 error_redeclaration:
4120                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4121                                         } else {
4122                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4123                                         }
4124                                 }
4125                         }
4126
4127                         prev_decl->modifiers |= decl->modifiers;
4128                         if (entity->kind == ENTITY_FUNCTION) {
4129                                 previous_entity->function.is_inline |= entity->function.is_inline;
4130                         }
4131                         return previous_entity;
4132                 }
4133
4134                 warning_t why;
4135                 if (is_warn_on(why = WARN_SHADOW) ||
4136                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4137                         char const *const what = get_entity_kind_name(previous_entity->kind);
4138                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4139                 }
4140         }
4141
4142         if (entity->kind == ENTITY_FUNCTION) {
4143                 if (is_definition &&
4144                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4145                                 !is_main(entity)) {
4146                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4147                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4148                         } else {
4149                                 goto warn_missing_declaration;
4150                         }
4151                 }
4152         } else if (entity->kind == ENTITY_VARIABLE) {
4153                 if (current_scope                     == file_scope &&
4154                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4155                                 !entity->declaration.implicit) {
4156 warn_missing_declaration:
4157                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4158                 }
4159         }
4160
4161 finish:
4162         environment_push(entity);
4163         append_entity(current_scope, entity);
4164
4165         return entity;
4166 }
4167
4168 static void parser_error_multiple_definition(entity_t *entity,
4169                 const source_position_t *source_position)
4170 {
4171         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4172 }
4173
4174 static bool is_declaration_specifier(const token_t *token)
4175 {
4176         switch (token->kind) {
4177                 DECLARATION_START
4178                         return true;
4179                 case T_IDENTIFIER:
4180                         return is_typedef_symbol(token->base.symbol);
4181
4182                 default:
4183                         return false;
4184         }
4185 }
4186
4187 static void parse_init_declarator_rest(entity_t *entity)
4188 {
4189         type_t *orig_type = type_error_type;
4190
4191         if (entity->base.kind == ENTITY_TYPEDEF) {
4192                 source_position_t const *const pos = &entity->base.source_position;
4193                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4194         } else {
4195                 assert(is_declaration(entity));
4196                 orig_type = entity->declaration.type;
4197         }
4198
4199         type_t *type = skip_typeref(orig_type);
4200
4201         if (entity->kind == ENTITY_VARIABLE
4202                         && entity->variable.initializer != NULL) {
4203                 parser_error_multiple_definition(entity, HERE);
4204         }
4205         eat('=');
4206
4207         declaration_t *const declaration = &entity->declaration;
4208         bool must_be_constant = false;
4209         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4210             entity->base.parent_scope  == file_scope) {
4211                 must_be_constant = true;
4212         }
4213
4214         if (is_type_function(type)) {
4215                 source_position_t const *const pos = &entity->base.source_position;
4216                 errorf(pos, "'%N' is initialized like a variable", entity);
4217                 orig_type = type_error_type;
4218         }
4219
4220         parse_initializer_env_t env;
4221         env.type             = orig_type;
4222         env.must_be_constant = must_be_constant;
4223         env.entity           = entity;
4224
4225         initializer_t *initializer = parse_initializer(&env);
4226
4227         if (entity->kind == ENTITY_VARIABLE) {
4228                 /* §6.7.5:22  array initializers for arrays with unknown size
4229                  * determine the array type size */
4230                 declaration->type            = env.type;
4231                 entity->variable.initializer = initializer;
4232         }
4233 }
4234
4235 /* parse rest of a declaration without any declarator */
4236 static void parse_anonymous_declaration_rest(
4237                 const declaration_specifiers_t *specifiers)
4238 {
4239         eat(';');
4240         anonymous_entity = NULL;
4241
4242         source_position_t const *const pos = &specifiers->source_position;
4243         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4244                         specifiers->thread_local) {
4245                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4246         }
4247
4248         type_t *type = specifiers->type;
4249         switch (type->kind) {
4250                 case TYPE_COMPOUND_STRUCT:
4251                 case TYPE_COMPOUND_UNION: {
4252                         if (type->compound.compound->base.symbol == NULL) {
4253                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4254                         }
4255                         break;
4256                 }
4257
4258                 case TYPE_ENUM:
4259                         break;
4260
4261                 default:
4262                         warningf(WARN_OTHER, pos, "empty declaration");
4263                         break;
4264         }
4265 }
4266
4267 static void check_variable_type_complete(entity_t *ent)
4268 {
4269         if (ent->kind != ENTITY_VARIABLE)
4270                 return;
4271
4272         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4273          *         type for the object shall be complete [...] */
4274         declaration_t *decl = &ent->declaration;
4275         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4276                         decl->storage_class == STORAGE_CLASS_STATIC)
4277                 return;
4278
4279         type_t *const type = skip_typeref(decl->type);
4280         if (!is_type_incomplete(type))
4281                 return;
4282
4283         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4284          * are given length one. */
4285         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4286                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4287                 return;
4288         }
4289
4290         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4291 }
4292
4293
4294 static void parse_declaration_rest(entity_t *ndeclaration,
4295                 const declaration_specifiers_t *specifiers,
4296                 parsed_declaration_func         finished_declaration,
4297                 declarator_flags_t              flags)
4298 {
4299         add_anchor_token(';');
4300         add_anchor_token(',');
4301         while (true) {
4302                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4303
4304                 if (token.kind == '=') {
4305                         parse_init_declarator_rest(entity);
4306                 } else if (entity->kind == ENTITY_VARIABLE) {
4307                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4308                          * [...] where the extern specifier is explicitly used. */
4309                         declaration_t *decl = &entity->declaration;
4310                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4311                             is_type_reference(skip_typeref(decl->type))) {
4312                                 source_position_t const *const pos = &entity->base.source_position;
4313                                 errorf(pos, "reference '%#N' must be initialized", entity);
4314                         }
4315                 }
4316
4317                 check_variable_type_complete(entity);
4318
4319                 if (!next_if(','))
4320                         break;
4321
4322                 add_anchor_token('=');
4323                 ndeclaration = parse_declarator(specifiers, flags);
4324                 rem_anchor_token('=');
4325         }
4326         rem_anchor_token(',');
4327         rem_anchor_token(';');
4328         expect(';');
4329
4330         anonymous_entity = NULL;
4331 }
4332
4333 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4334 {
4335         symbol_t *symbol = entity->base.symbol;
4336         if (symbol == NULL)
4337                 return entity;
4338
4339         assert(entity->base.namespc == NAMESPACE_NORMAL);
4340         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4341         if (previous_entity == NULL
4342                         || previous_entity->base.parent_scope != current_scope) {
4343                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4344                        symbol);
4345                 return entity;
4346         }
4347
4348         if (is_definition) {
4349                 errorf(HERE, "'%N' is initialised", entity);
4350         }
4351
4352         return record_entity(entity, false);
4353 }
4354
4355 static void parse_declaration(parsed_declaration_func finished_declaration,
4356                               declarator_flags_t      flags)
4357 {
4358         add_anchor_token(';');
4359         declaration_specifiers_t specifiers;
4360         parse_declaration_specifiers(&specifiers);
4361         rem_anchor_token(';');
4362
4363         if (token.kind == ';') {
4364                 parse_anonymous_declaration_rest(&specifiers);
4365         } else {
4366                 entity_t *entity = parse_declarator(&specifiers, flags);
4367                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4368         }
4369 }
4370
4371 /* §6.5.2.2:6 */
4372 static type_t *get_default_promoted_type(type_t *orig_type)
4373 {
4374         type_t *result = orig_type;
4375
4376         type_t *type = skip_typeref(orig_type);
4377         if (is_type_integer(type)) {
4378                 result = promote_integer(type);
4379         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4380                 result = type_double;
4381         }
4382
4383         return result;
4384 }
4385
4386 static void parse_kr_declaration_list(entity_t *entity)
4387 {
4388         if (entity->kind != ENTITY_FUNCTION)
4389                 return;
4390
4391         type_t *type = skip_typeref(entity->declaration.type);
4392         assert(is_type_function(type));
4393         if (!type->function.kr_style_parameters)
4394                 return;
4395
4396         add_anchor_token('{');
4397
4398         PUSH_SCOPE(&entity->function.parameters);
4399
4400         entity_t *parameter = entity->function.parameters.entities;
4401         for ( ; parameter != NULL; parameter = parameter->base.next) {
4402                 assert(parameter->base.parent_scope == NULL);
4403                 parameter->base.parent_scope = current_scope;
4404                 environment_push(parameter);
4405         }
4406
4407         /* parse declaration list */
4408         for (;;) {
4409                 switch (token.kind) {
4410                         DECLARATION_START
4411                         /* This covers symbols, which are no type, too, and results in
4412                          * better error messages.  The typical cases are misspelled type
4413                          * names and missing includes. */
4414                         case T_IDENTIFIER:
4415                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4416                                 break;
4417                         default:
4418                                 goto decl_list_end;
4419                 }
4420         }
4421 decl_list_end:
4422
4423         POP_SCOPE();
4424
4425         /* update function type */
4426         type_t *new_type = duplicate_type(type);
4427
4428         function_parameter_t  *parameters = NULL;
4429         function_parameter_t **anchor     = &parameters;
4430
4431         /* did we have an earlier prototype? */
4432         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4433         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4434                 proto_type = NULL;
4435
4436         function_parameter_t *proto_parameter = NULL;
4437         if (proto_type != NULL) {
4438                 type_t *proto_type_type = proto_type->declaration.type;
4439                 proto_parameter         = proto_type_type->function.parameters;
4440                 /* If a K&R function definition has a variadic prototype earlier, then
4441                  * make the function definition variadic, too. This should conform to
4442                  * §6.7.5.3:15 and §6.9.1:8. */
4443                 new_type->function.variadic = proto_type_type->function.variadic;
4444         } else {
4445                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4446                  * prototype */
4447                 new_type->function.unspecified_parameters = true;
4448         }
4449
4450         bool need_incompatible_warning = false;
4451         parameter = entity->function.parameters.entities;
4452         for (; parameter != NULL; parameter = parameter->base.next,
4453                         proto_parameter =
4454                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4455                 if (parameter->kind != ENTITY_PARAMETER)
4456                         continue;
4457
4458                 type_t *parameter_type = parameter->declaration.type;
4459                 if (parameter_type == NULL) {
4460                         source_position_t const* const pos = &parameter->base.source_position;
4461                         if (strict_mode) {
4462                                 errorf(pos, "no type specified for function '%N'", parameter);
4463                                 parameter_type = type_error_type;
4464                         } else {
4465                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4466                                 parameter_type = type_int;
4467                         }
4468                         parameter->declaration.type = parameter_type;
4469                 }
4470
4471                 semantic_parameter_incomplete(parameter);
4472
4473                 /* we need the default promoted types for the function type */
4474                 type_t *not_promoted = parameter_type;
4475                 parameter_type       = get_default_promoted_type(parameter_type);
4476
4477                 /* gcc special: if the type of the prototype matches the unpromoted
4478                  * type don't promote */
4479                 if (!strict_mode && proto_parameter != NULL) {
4480                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4481                         type_t *promo_skip   = skip_typeref(parameter_type);
4482                         type_t *param_skip   = skip_typeref(not_promoted);
4483                         if (!types_compatible(proto_p_type, promo_skip)
4484                                 && types_compatible(proto_p_type, param_skip)) {
4485                                 /* don't promote */
4486                                 need_incompatible_warning = true;
4487                                 parameter_type = not_promoted;
4488                         }
4489                 }
4490                 function_parameter_t *const function_parameter
4491                         = allocate_parameter(parameter_type);
4492
4493                 *anchor = function_parameter;
4494                 anchor  = &function_parameter->next;
4495         }
4496
4497         new_type->function.parameters = parameters;
4498         new_type = identify_new_type(new_type);
4499
4500         if (need_incompatible_warning) {
4501                 symbol_t          const *const sym  = entity->base.symbol;
4502                 source_position_t const *const pos  = &entity->base.source_position;
4503                 source_position_t const *const ppos = &proto_type->base.source_position;
4504                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4505         }
4506         entity->declaration.type = new_type;
4507
4508         rem_anchor_token('{');
4509 }
4510
4511 static bool first_err = true;
4512
4513 /**
4514  * When called with first_err set, prints the name of the current function,
4515  * else does noting.
4516  */
4517 static void print_in_function(void)
4518 {
4519         if (first_err) {
4520                 first_err = false;
4521                 char const *const file = current_function->base.base.source_position.input_name;
4522                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4523         }
4524 }
4525
4526 /**
4527  * Check if all labels are defined in the current function.
4528  * Check if all labels are used in the current function.
4529  */
4530 static void check_labels(void)
4531 {
4532         for (const goto_statement_t *goto_statement = goto_first;
4533             goto_statement != NULL;
4534             goto_statement = goto_statement->next) {
4535                 label_t *label = goto_statement->label;
4536                 if (label->base.source_position.input_name == NULL) {
4537                         print_in_function();
4538                         source_position_t const *const pos = &goto_statement->base.source_position;
4539                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4540                  }
4541         }
4542
4543         if (is_warn_on(WARN_UNUSED_LABEL)) {
4544                 for (const label_statement_t *label_statement = label_first;
4545                          label_statement != NULL;
4546                          label_statement = label_statement->next) {
4547                         label_t *label = label_statement->label;
4548
4549                         if (! label->used) {
4550                                 print_in_function();
4551                                 source_position_t const *const pos = &label_statement->base.source_position;
4552                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4553                         }
4554                 }
4555         }
4556 }
4557
4558 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4559 {
4560         entity_t const *const end = last != NULL ? last->base.next : NULL;
4561         for (; entity != end; entity = entity->base.next) {
4562                 if (!is_declaration(entity))
4563                         continue;
4564
4565                 declaration_t *declaration = &entity->declaration;
4566                 if (declaration->implicit)
4567                         continue;
4568
4569                 if (!declaration->used) {
4570                         print_in_function();
4571                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4572                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4573                         print_in_function();
4574                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4575                 }
4576         }
4577 }
4578
4579 static void check_unused_variables(statement_t *const stmt, void *const env)
4580 {
4581         (void)env;
4582
4583         switch (stmt->kind) {
4584                 case STATEMENT_DECLARATION: {
4585                         declaration_statement_t const *const decls = &stmt->declaration;
4586                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4587                         return;
4588                 }
4589
4590                 case STATEMENT_FOR:
4591                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4592                         return;
4593
4594                 default:
4595                         return;
4596         }
4597 }
4598
4599 /**
4600  * Check declarations of current_function for unused entities.
4601  */
4602 static void check_declarations(void)
4603 {
4604         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4605                 const scope_t *scope = &current_function->parameters;
4606                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4607         }
4608         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4609                 walk_statements(current_function->statement, check_unused_variables,
4610                                 NULL);
4611         }
4612 }
4613
4614 static int determine_truth(expression_t const* const cond)
4615 {
4616         return
4617                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4618                 fold_constant_to_bool(cond)                         ? 1 :
4619                 -1;
4620 }
4621
4622 static void check_reachable(statement_t *);
4623 static bool reaches_end;
4624
4625 static bool expression_returns(expression_t const *const expr)
4626 {
4627         switch (expr->kind) {
4628                 case EXPR_CALL: {
4629                         expression_t const *const func = expr->call.function;
4630                         type_t       const *const type = skip_typeref(func->base.type);
4631                         if (type->kind == TYPE_POINTER) {
4632                                 type_t const *const points_to
4633                                         = skip_typeref(type->pointer.points_to);
4634                                 if (points_to->kind == TYPE_FUNCTION
4635                                     && points_to->function.modifiers & DM_NORETURN)
4636                                         return false;
4637                         }
4638
4639                         if (!expression_returns(func))
4640                                 return false;
4641
4642                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4643                                 if (!expression_returns(arg->expression))
4644                                         return false;
4645                         }
4646
4647                         return true;
4648                 }
4649
4650                 case EXPR_REFERENCE:
4651                 case EXPR_ENUM_CONSTANT:
4652                 case EXPR_LITERAL_CASES:
4653                 case EXPR_STRING_LITERAL:
4654                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4655                 case EXPR_LABEL_ADDRESS:
4656                 case EXPR_CLASSIFY_TYPE:
4657                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4658                 case EXPR_ALIGNOF:
4659                 case EXPR_FUNCNAME:
4660                 case EXPR_BUILTIN_CONSTANT_P:
4661                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4662                 case EXPR_OFFSETOF:
4663                 case EXPR_ERROR:
4664                         return true;
4665
4666                 case EXPR_STATEMENT: {
4667                         bool old_reaches_end = reaches_end;
4668                         reaches_end = false;
4669                         check_reachable(expr->statement.statement);
4670                         bool returns = reaches_end;
4671                         reaches_end = old_reaches_end;
4672                         return returns;
4673                 }
4674
4675                 case EXPR_CONDITIONAL:
4676                         // TODO handle constant expression
4677
4678                         if (!expression_returns(expr->conditional.condition))
4679                                 return false;
4680
4681                         if (expr->conditional.true_expression != NULL
4682                                         && expression_returns(expr->conditional.true_expression))
4683                                 return true;
4684
4685                         return expression_returns(expr->conditional.false_expression);
4686
4687                 case EXPR_SELECT:
4688                         return expression_returns(expr->select.compound);
4689
4690                 case EXPR_ARRAY_ACCESS:
4691                         return
4692                                 expression_returns(expr->array_access.array_ref) &&
4693                                 expression_returns(expr->array_access.index);
4694
4695                 case EXPR_VA_START:
4696                         return expression_returns(expr->va_starte.ap);
4697
4698                 case EXPR_VA_ARG:
4699                         return expression_returns(expr->va_arge.ap);
4700
4701                 case EXPR_VA_COPY:
4702                         return expression_returns(expr->va_copye.src);
4703
4704                 case EXPR_UNARY_CASES_MANDATORY:
4705                         return expression_returns(expr->unary.value);
4706
4707                 case EXPR_UNARY_THROW:
4708                         return false;
4709
4710                 case EXPR_BINARY_CASES:
4711                         // TODO handle constant lhs of && and ||
4712                         return
4713                                 expression_returns(expr->binary.left) &&
4714                                 expression_returns(expr->binary.right);
4715         }
4716
4717         panic("unhandled expression");
4718 }
4719
4720 static bool initializer_returns(initializer_t const *const init)
4721 {
4722         switch (init->kind) {
4723                 case INITIALIZER_VALUE:
4724                         return expression_returns(init->value.value);
4725
4726                 case INITIALIZER_LIST: {
4727                         initializer_t * const*       i       = init->list.initializers;
4728                         initializer_t * const* const end     = i + init->list.len;
4729                         bool                         returns = true;
4730                         for (; i != end; ++i) {
4731                                 if (!initializer_returns(*i))
4732                                         returns = false;
4733                         }
4734                         return returns;
4735                 }
4736
4737                 case INITIALIZER_STRING:
4738                 case INITIALIZER_WIDE_STRING:
4739                 case INITIALIZER_DESIGNATOR: // designators have no payload
4740                         return true;
4741         }
4742         panic("unhandled initializer");
4743 }
4744
4745 static bool noreturn_candidate;
4746
4747 static void check_reachable(statement_t *const stmt)
4748 {
4749         if (stmt->base.reachable)
4750                 return;
4751         if (stmt->kind != STATEMENT_DO_WHILE)
4752                 stmt->base.reachable = true;
4753
4754         statement_t *last = stmt;
4755         statement_t *next;
4756         switch (stmt->kind) {
4757                 case STATEMENT_ERROR:
4758                 case STATEMENT_EMPTY:
4759                 case STATEMENT_ASM:
4760                         next = stmt->base.next;
4761                         break;
4762
4763                 case STATEMENT_DECLARATION: {
4764                         declaration_statement_t const *const decl = &stmt->declaration;
4765                         entity_t                const *      ent  = decl->declarations_begin;
4766                         entity_t                const *const last_decl = decl->declarations_end;
4767                         if (ent != NULL) {
4768                                 for (;; ent = ent->base.next) {
4769                                         if (ent->kind                 == ENTITY_VARIABLE &&
4770                                             ent->variable.initializer != NULL            &&
4771                                             !initializer_returns(ent->variable.initializer)) {
4772                                                 return;
4773                                         }
4774                                         if (ent == last_decl)
4775                                                 break;
4776                                 }
4777                         }
4778                         next = stmt->base.next;
4779                         break;
4780                 }
4781
4782                 case STATEMENT_COMPOUND:
4783                         next = stmt->compound.statements;
4784                         if (next == NULL)
4785                                 next = stmt->base.next;
4786                         break;
4787
4788                 case STATEMENT_RETURN: {
4789                         expression_t const *const val = stmt->returns.value;
4790                         if (val == NULL || expression_returns(val))
4791                                 noreturn_candidate = false;
4792                         return;
4793                 }
4794
4795                 case STATEMENT_IF: {
4796                         if_statement_t const *const ifs  = &stmt->ifs;
4797                         expression_t   const *const cond = ifs->condition;
4798
4799                         if (!expression_returns(cond))
4800                                 return;
4801
4802                         int const val = determine_truth(cond);
4803
4804                         if (val >= 0)
4805                                 check_reachable(ifs->true_statement);
4806
4807                         if (val > 0)
4808                                 return;
4809
4810                         if (ifs->false_statement != NULL) {
4811                                 check_reachable(ifs->false_statement);
4812                                 return;
4813                         }
4814
4815                         next = stmt->base.next;
4816                         break;
4817                 }
4818
4819                 case STATEMENT_SWITCH: {
4820                         switch_statement_t const *const switchs = &stmt->switchs;
4821                         expression_t       const *const expr    = switchs->expression;
4822
4823                         if (!expression_returns(expr))
4824                                 return;
4825
4826                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4827                                 long                    const val      = fold_constant_to_int(expr);
4828                                 case_label_statement_t *      defaults = NULL;
4829                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4830                                         if (i->expression == NULL) {
4831                                                 defaults = i;
4832                                                 continue;
4833                                         }
4834
4835                                         if (i->first_case <= val && val <= i->last_case) {
4836                                                 check_reachable((statement_t*)i);
4837                                                 return;
4838                                         }
4839                                 }
4840
4841                                 if (defaults != NULL) {
4842                                         check_reachable((statement_t*)defaults);
4843                                         return;
4844                                 }
4845                         } else {
4846                                 bool has_default = false;
4847                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4848                                         if (i->expression == NULL)
4849                                                 has_default = true;
4850
4851                                         check_reachable((statement_t*)i);
4852                                 }
4853
4854                                 if (has_default)
4855                                         return;
4856                         }
4857
4858                         next = stmt->base.next;
4859                         break;
4860                 }
4861
4862                 case STATEMENT_EXPRESSION: {
4863                         /* Check for noreturn function call */
4864                         expression_t const *const expr = stmt->expression.expression;
4865                         if (!expression_returns(expr))
4866                                 return;
4867
4868                         next = stmt->base.next;
4869                         break;
4870                 }
4871
4872                 case STATEMENT_CONTINUE:
4873                         for (statement_t *parent = stmt;;) {
4874                                 parent = parent->base.parent;
4875                                 if (parent == NULL) /* continue not within loop */
4876                                         return;
4877
4878                                 next = parent;
4879                                 switch (parent->kind) {
4880                                         case STATEMENT_WHILE:    goto continue_while;
4881                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4882                                         case STATEMENT_FOR:      goto continue_for;
4883
4884                                         default: break;
4885                                 }
4886                         }
4887
4888                 case STATEMENT_BREAK:
4889                         for (statement_t *parent = stmt;;) {
4890                                 parent = parent->base.parent;
4891                                 if (parent == NULL) /* break not within loop/switch */
4892                                         return;
4893
4894                                 switch (parent->kind) {
4895                                         case STATEMENT_SWITCH:
4896                                         case STATEMENT_WHILE:
4897                                         case STATEMENT_DO_WHILE:
4898                                         case STATEMENT_FOR:
4899                                                 last = parent;
4900                                                 next = parent->base.next;
4901                                                 goto found_break_parent;
4902
4903                                         default: break;
4904                                 }
4905                         }
4906 found_break_parent:
4907                         break;
4908
4909                 case STATEMENT_COMPUTED_GOTO: {
4910                         if (!expression_returns(stmt->computed_goto.expression))
4911                                 return;
4912
4913                         statement_t *parent = stmt->base.parent;
4914                         if (parent == NULL) /* top level goto */
4915                                 return;
4916                         next = parent;
4917                         break;
4918                 }
4919
4920                 case STATEMENT_GOTO:
4921                         next = stmt->gotos.label->statement;
4922                         if (next == NULL) /* missing label */
4923                                 return;
4924                         break;
4925
4926                 case STATEMENT_LABEL:
4927                         next = stmt->label.statement;
4928                         break;
4929
4930                 case STATEMENT_CASE_LABEL:
4931                         next = stmt->case_label.statement;
4932                         break;
4933
4934                 case STATEMENT_WHILE: {
4935                         while_statement_t const *const whiles = &stmt->whiles;
4936                         expression_t      const *const cond   = whiles->condition;
4937
4938                         if (!expression_returns(cond))
4939                                 return;
4940
4941                         int const val = determine_truth(cond);
4942
4943                         if (val >= 0)
4944                                 check_reachable(whiles->body);
4945
4946                         if (val > 0)
4947                                 return;
4948
4949                         next = stmt->base.next;
4950                         break;
4951                 }
4952
4953                 case STATEMENT_DO_WHILE:
4954                         next = stmt->do_while.body;
4955                         break;
4956
4957                 case STATEMENT_FOR: {
4958                         for_statement_t *const fors = &stmt->fors;
4959
4960                         if (fors->condition_reachable)
4961                                 return;
4962                         fors->condition_reachable = true;
4963
4964                         expression_t const *const cond = fors->condition;
4965
4966                         int val;
4967                         if (cond == NULL) {
4968                                 val = 1;
4969                         } else if (expression_returns(cond)) {
4970                                 val = determine_truth(cond);
4971                         } else {
4972                                 return;
4973                         }
4974
4975                         if (val >= 0)
4976                                 check_reachable(fors->body);
4977
4978                         if (val > 0)
4979                                 return;
4980
4981                         next = stmt->base.next;
4982                         break;
4983                 }
4984
4985                 case STATEMENT_MS_TRY: {
4986                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4987                         check_reachable(ms_try->try_statement);
4988                         next = ms_try->final_statement;
4989                         break;
4990                 }
4991
4992                 case STATEMENT_LEAVE: {
4993                         statement_t *parent = stmt;
4994                         for (;;) {
4995                                 parent = parent->base.parent;
4996                                 if (parent == NULL) /* __leave not within __try */
4997                                         return;
4998
4999                                 if (parent->kind == STATEMENT_MS_TRY) {
5000                                         last = parent;
5001                                         next = parent->ms_try.final_statement;
5002                                         break;
5003                                 }
5004                         }
5005                         break;
5006                 }
5007
5008                 default:
5009                         panic("invalid statement kind");
5010         }
5011
5012         while (next == NULL) {
5013                 next = last->base.parent;
5014                 if (next == NULL) {
5015                         noreturn_candidate = false;
5016
5017                         type_t *const type = skip_typeref(current_function->base.type);
5018                         assert(is_type_function(type));
5019                         type_t *const ret  = skip_typeref(type->function.return_type);
5020                         if (!is_type_void(ret) &&
5021                             is_type_valid(ret) &&
5022                             !is_main(current_entity)) {
5023                                 source_position_t const *const pos = &stmt->base.source_position;
5024                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5025                         }
5026                         return;
5027                 }
5028
5029                 switch (next->kind) {
5030                         case STATEMENT_ERROR:
5031                         case STATEMENT_EMPTY:
5032                         case STATEMENT_DECLARATION:
5033                         case STATEMENT_EXPRESSION:
5034                         case STATEMENT_ASM:
5035                         case STATEMENT_RETURN:
5036                         case STATEMENT_CONTINUE:
5037                         case STATEMENT_BREAK:
5038                         case STATEMENT_COMPUTED_GOTO:
5039                         case STATEMENT_GOTO:
5040                         case STATEMENT_LEAVE:
5041                                 panic("invalid control flow in function");
5042
5043                         case STATEMENT_COMPOUND:
5044                                 if (next->compound.stmt_expr) {
5045                                         reaches_end = true;
5046                                         return;
5047                                 }
5048                                 /* FALLTHROUGH */
5049                         case STATEMENT_IF:
5050                         case STATEMENT_SWITCH:
5051                         case STATEMENT_LABEL:
5052                         case STATEMENT_CASE_LABEL:
5053                                 last = next;
5054                                 next = next->base.next;
5055                                 break;
5056
5057                         case STATEMENT_WHILE: {
5058 continue_while:
5059                                 if (next->base.reachable)
5060                                         return;
5061                                 next->base.reachable = true;
5062
5063                                 while_statement_t const *const whiles = &next->whiles;
5064                                 expression_t      const *const cond   = whiles->condition;
5065
5066                                 if (!expression_returns(cond))
5067                                         return;
5068
5069                                 int const val = determine_truth(cond);
5070
5071                                 if (val >= 0)
5072                                         check_reachable(whiles->body);
5073
5074                                 if (val > 0)
5075                                         return;
5076
5077                                 last = next;
5078                                 next = next->base.next;
5079                                 break;
5080                         }
5081
5082                         case STATEMENT_DO_WHILE: {
5083 continue_do_while:
5084                                 if (next->base.reachable)
5085                                         return;
5086                                 next->base.reachable = true;
5087
5088                                 do_while_statement_t const *const dw   = &next->do_while;
5089                                 expression_t         const *const cond = dw->condition;
5090
5091                                 if (!expression_returns(cond))
5092                                         return;
5093
5094                                 int const val = determine_truth(cond);
5095
5096                                 if (val >= 0)
5097                                         check_reachable(dw->body);
5098
5099                                 if (val > 0)
5100                                         return;
5101
5102                                 last = next;
5103                                 next = next->base.next;
5104                                 break;
5105                         }
5106
5107                         case STATEMENT_FOR: {
5108 continue_for:;
5109                                 for_statement_t *const fors = &next->fors;
5110
5111                                 fors->step_reachable = true;
5112
5113                                 if (fors->condition_reachable)
5114                                         return;
5115                                 fors->condition_reachable = true;
5116
5117                                 expression_t const *const cond = fors->condition;
5118
5119                                 int val;
5120                                 if (cond == NULL) {
5121                                         val = 1;
5122                                 } else if (expression_returns(cond)) {
5123                                         val = determine_truth(cond);
5124                                 } else {
5125                                         return;
5126                                 }
5127
5128                                 if (val >= 0)
5129                                         check_reachable(fors->body);
5130
5131                                 if (val > 0)
5132                                         return;
5133
5134                                 last = next;
5135                                 next = next->base.next;
5136                                 break;
5137                         }
5138
5139                         case STATEMENT_MS_TRY:
5140                                 last = next;
5141                                 next = next->ms_try.final_statement;
5142                                 break;
5143                 }
5144         }
5145
5146         check_reachable(next);
5147 }
5148
5149 static void check_unreachable(statement_t* const stmt, void *const env)
5150 {
5151         (void)env;
5152
5153         switch (stmt->kind) {
5154                 case STATEMENT_DO_WHILE:
5155                         if (!stmt->base.reachable) {
5156                                 expression_t const *const cond = stmt->do_while.condition;
5157                                 if (determine_truth(cond) >= 0) {
5158                                         source_position_t const *const pos = &cond->base.source_position;
5159                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5160                                 }
5161                         }
5162                         return;
5163
5164                 case STATEMENT_FOR: {
5165                         for_statement_t const* const fors = &stmt->fors;
5166
5167                         // if init and step are unreachable, cond is unreachable, too
5168                         if (!stmt->base.reachable && !fors->step_reachable) {
5169                                 goto warn_unreachable;
5170                         } else {
5171                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5172                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5173                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5174                                 }
5175
5176                                 if (!fors->condition_reachable && fors->condition != NULL) {
5177                                         source_position_t const *const pos = &fors->condition->base.source_position;
5178                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5179                                 }
5180
5181                                 if (!fors->step_reachable && fors->step != NULL) {
5182                                         source_position_t const *const pos = &fors->step->base.source_position;
5183                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5184                                 }
5185                         }
5186                         return;
5187                 }
5188
5189                 case STATEMENT_COMPOUND:
5190                         if (stmt->compound.statements != NULL)
5191                                 return;
5192                         goto warn_unreachable;
5193
5194                 case STATEMENT_DECLARATION: {
5195                         /* Only warn if there is at least one declarator with an initializer.
5196                          * This typically occurs in switch statements. */
5197                         declaration_statement_t const *const decl = &stmt->declaration;
5198                         entity_t                const *      ent  = decl->declarations_begin;
5199                         entity_t                const *const last = decl->declarations_end;
5200                         if (ent != NULL) {
5201                                 for (;; ent = ent->base.next) {
5202                                         if (ent->kind                 == ENTITY_VARIABLE &&
5203                                                         ent->variable.initializer != NULL) {
5204                                                 goto warn_unreachable;
5205                                         }
5206                                         if (ent == last)
5207                                                 return;
5208                                 }
5209                         }
5210                 }
5211
5212                 default:
5213 warn_unreachable:
5214                         if (!stmt->base.reachable) {
5215                                 source_position_t const *const pos = &stmt->base.source_position;
5216                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5217                         }
5218                         return;
5219         }
5220 }
5221
5222 static bool is_main(entity_t *entity)
5223 {
5224         static symbol_t *sym_main = NULL;
5225         if (sym_main == NULL) {
5226                 sym_main = symbol_table_insert("main");
5227         }
5228
5229         if (entity->base.symbol != sym_main)
5230                 return false;
5231         /* must be in outermost scope */
5232         if (entity->base.parent_scope != file_scope)
5233                 return false;
5234
5235         return true;
5236 }
5237
5238 static void prepare_main_collect2(entity_t*);
5239
5240 static void parse_external_declaration(void)
5241 {
5242         /* function-definitions and declarations both start with declaration
5243          * specifiers */
5244         add_anchor_token(';');
5245         declaration_specifiers_t specifiers;
5246         parse_declaration_specifiers(&specifiers);
5247         rem_anchor_token(';');
5248
5249         /* must be a declaration */
5250         if (token.kind == ';') {
5251                 parse_anonymous_declaration_rest(&specifiers);
5252                 return;
5253         }
5254
5255         add_anchor_token(',');
5256         add_anchor_token('=');
5257         add_anchor_token(';');
5258         add_anchor_token('{');
5259
5260         /* declarator is common to both function-definitions and declarations */
5261         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5262
5263         rem_anchor_token('{');
5264         rem_anchor_token(';');
5265         rem_anchor_token('=');
5266         rem_anchor_token(',');
5267
5268         /* must be a declaration */
5269         switch (token.kind) {
5270                 case ',':
5271                 case ';':
5272                 case '=':
5273                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5274                                         DECL_FLAGS_NONE);
5275                         return;
5276         }
5277
5278         /* must be a function definition */
5279         parse_kr_declaration_list(ndeclaration);
5280
5281         if (token.kind != '{') {
5282                 parse_error_expected("while parsing function definition", '{', NULL);
5283                 eat_until_matching_token(';');
5284                 return;
5285         }
5286
5287         assert(is_declaration(ndeclaration));
5288         type_t *const orig_type = ndeclaration->declaration.type;
5289         type_t *      type      = skip_typeref(orig_type);
5290
5291         if (!is_type_function(type)) {
5292                 if (is_type_valid(type)) {
5293                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5294                 }
5295                 eat_block();
5296                 return;
5297         }
5298
5299         source_position_t const *const pos = &ndeclaration->base.source_position;
5300         if (is_typeref(orig_type)) {
5301                 /* §6.9.1:2 */
5302                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5303         }
5304
5305         if (is_type_compound(skip_typeref(type->function.return_type))) {
5306                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5307         }
5308         if (type->function.unspecified_parameters) {
5309                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5310         } else {
5311                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5312         }
5313
5314         /* §6.7.5.3:14 a function definition with () means no
5315          * parameters (and not unspecified parameters) */
5316         if (type->function.unspecified_parameters &&
5317                         type->function.parameters == NULL) {
5318                 type_t *copy                          = duplicate_type(type);
5319                 copy->function.unspecified_parameters = false;
5320                 type                                  = identify_new_type(copy);
5321
5322                 ndeclaration->declaration.type = type;
5323         }
5324
5325         entity_t *const entity = record_entity(ndeclaration, true);
5326         assert(entity->kind == ENTITY_FUNCTION);
5327         assert(ndeclaration->kind == ENTITY_FUNCTION);
5328
5329         function_t *const function = &entity->function;
5330         if (ndeclaration != entity) {
5331                 function->parameters = ndeclaration->function.parameters;
5332         }
5333
5334         PUSH_SCOPE(&function->parameters);
5335
5336         entity_t *parameter = function->parameters.entities;
5337         for (; parameter != NULL; parameter = parameter->base.next) {
5338                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5339                         parameter->base.parent_scope = current_scope;
5340                 }
5341                 assert(parameter->base.parent_scope == NULL
5342                                 || parameter->base.parent_scope == current_scope);
5343                 parameter->base.parent_scope = current_scope;
5344                 if (parameter->base.symbol == NULL) {
5345                         errorf(&parameter->base.source_position, "parameter name omitted");
5346                         continue;
5347                 }
5348                 environment_push(parameter);
5349         }
5350
5351         if (function->statement != NULL) {
5352                 parser_error_multiple_definition(entity, HERE);
5353                 eat_block();
5354         } else {
5355                 /* parse function body */
5356                 int         label_stack_top      = label_top();
5357                 function_t *old_current_function = current_function;
5358                 current_function                 = function;
5359                 PUSH_CURRENT_ENTITY(entity);
5360                 PUSH_PARENT(NULL);
5361
5362                 goto_first   = NULL;
5363                 goto_anchor  = &goto_first;
5364                 label_first  = NULL;
5365                 label_anchor = &label_first;
5366
5367                 statement_t *const body = parse_compound_statement(false);
5368                 function->statement = body;
5369                 first_err = true;
5370                 check_labels();
5371                 check_declarations();
5372                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5373                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5374                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5375                         noreturn_candidate = true;
5376                         check_reachable(body);
5377                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5378                                 walk_statements(body, check_unreachable, NULL);
5379                         if (noreturn_candidate &&
5380                             !(function->base.modifiers & DM_NORETURN)) {
5381                                 source_position_t const *const pos = &body->base.source_position;
5382                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5383                         }
5384                 }
5385
5386                 if (is_main(entity)) {
5387                         /* Force main to C linkage. */
5388                         type_t *const type = entity->declaration.type;
5389                         assert(is_type_function(type));
5390                         if (type->function.linkage != LINKAGE_C) {
5391                                 type_t *new_type           = duplicate_type(type);
5392                                 new_type->function.linkage = LINKAGE_C;
5393                                 entity->declaration.type   = identify_new_type(new_type);
5394                         }
5395
5396                         if (enable_main_collect2_hack)
5397                                 prepare_main_collect2(entity);
5398                 }
5399
5400                 POP_CURRENT_ENTITY();
5401                 POP_PARENT();
5402                 assert(current_function == function);
5403                 current_function = old_current_function;
5404                 label_pop_to(label_stack_top);
5405         }
5406
5407         POP_SCOPE();
5408 }
5409
5410 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5411 {
5412         entity_t *iter = compound->members.entities;
5413         for (; iter != NULL; iter = iter->base.next) {
5414                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5415                         continue;
5416
5417                 if (iter->base.symbol == symbol) {
5418                         return iter;
5419                 } else if (iter->base.symbol == NULL) {
5420                         /* search in anonymous structs and unions */
5421                         type_t *type = skip_typeref(iter->declaration.type);
5422                         if (is_type_compound(type)) {
5423                                 if (find_compound_entry(type->compound.compound, symbol)
5424                                                 != NULL)
5425                                         return iter;
5426                         }
5427                         continue;
5428                 }
5429         }
5430
5431         return NULL;
5432 }
5433
5434 static void check_deprecated(const source_position_t *source_position,
5435                              const entity_t *entity)
5436 {
5437         if (!is_declaration(entity))
5438                 return;
5439         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5440                 return;
5441
5442         source_position_t const *const epos = &entity->base.source_position;
5443         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5444         if (msg != NULL) {
5445                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5446         } else {
5447                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5448         }
5449 }
5450
5451
5452 static expression_t *create_select(const source_position_t *pos,
5453                                    expression_t *addr,
5454                                    type_qualifiers_t qualifiers,
5455                                                                    entity_t *entry)
5456 {
5457         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5458
5459         check_deprecated(pos, entry);
5460
5461         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5462         select->select.compound       = addr;
5463         select->select.compound_entry = entry;
5464
5465         type_t *entry_type = entry->declaration.type;
5466         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5467
5468         /* bitfields need special treatment */
5469         if (entry->compound_member.bitfield) {
5470                 unsigned bit_size = entry->compound_member.bit_size;
5471                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5472                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5473                         res_type = type_int;
5474                 }
5475         }
5476
5477         /* we always do the auto-type conversions; the & and sizeof parser contains
5478          * code to revert this! */
5479         select->base.type = automatic_type_conversion(res_type);
5480
5481
5482         return select;
5483 }
5484
5485 /**
5486  * Find entry with symbol in compound. Search anonymous structs and unions and
5487  * creates implicit select expressions for them.
5488  * Returns the adress for the innermost compound.
5489  */
5490 static expression_t *find_create_select(const source_position_t *pos,
5491                                         expression_t *addr,
5492                                         type_qualifiers_t qualifiers,
5493                                         compound_t *compound, symbol_t *symbol)
5494 {
5495         entity_t *iter = compound->members.entities;
5496         for (; iter != NULL; iter = iter->base.next) {
5497                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5498                         continue;
5499
5500                 symbol_t *iter_symbol = iter->base.symbol;
5501                 if (iter_symbol == NULL) {
5502                         type_t *type = iter->declaration.type;
5503                         if (type->kind != TYPE_COMPOUND_STRUCT
5504                                         && type->kind != TYPE_COMPOUND_UNION)
5505                                 continue;
5506
5507                         compound_t *sub_compound = type->compound.compound;
5508
5509                         if (find_compound_entry(sub_compound, symbol) == NULL)
5510                                 continue;
5511
5512                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5513                         sub_addr->base.source_position = *pos;
5514                         sub_addr->base.implicit        = true;
5515                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5516                                                   symbol);
5517                 }
5518
5519                 if (iter_symbol == symbol) {
5520                         return create_select(pos, addr, qualifiers, iter);
5521                 }
5522         }
5523
5524         return NULL;
5525 }
5526
5527 static void parse_bitfield_member(entity_t *entity)
5528 {
5529         eat(':');
5530
5531         expression_t *size = parse_constant_expression();
5532         long          size_long;
5533
5534         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5535         type_t *type = entity->declaration.type;
5536         if (!is_type_integer(skip_typeref(type))) {
5537                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5538                            type);
5539         }
5540
5541         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5542                 /* error already reported by parse_constant_expression */
5543                 size_long = get_type_size(type) * 8;
5544         } else {
5545                 size_long = fold_constant_to_int(size);
5546
5547                 const symbol_t *symbol = entity->base.symbol;
5548                 const symbol_t *user_symbol
5549                         = symbol == NULL ? sym_anonymous : symbol;
5550                 unsigned bit_size = get_type_size(type) * 8;
5551                 if (size_long < 0) {
5552                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5553                 } else if (size_long == 0 && symbol != NULL) {
5554                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5555                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5556                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5557                                    user_symbol);
5558                 } else {
5559                         /* hope that people don't invent crazy types with more bits
5560                          * than our struct can hold */
5561                         assert(size_long <
5562                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5563                 }
5564         }
5565
5566         entity->compound_member.bitfield = true;
5567         entity->compound_member.bit_size = (unsigned char)size_long;
5568 }
5569
5570 static void parse_compound_declarators(compound_t *compound,
5571                 const declaration_specifiers_t *specifiers)
5572 {
5573         add_anchor_token(';');
5574         add_anchor_token(',');
5575         do {
5576                 entity_t *entity;
5577
5578                 if (token.kind == ':') {
5579                         /* anonymous bitfield */
5580                         type_t *type = specifiers->type;
5581                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5582                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5583                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5584                         entity->declaration.type                   = type;
5585
5586                         parse_bitfield_member(entity);
5587
5588                         attribute_t  *attributes = parse_attributes(NULL);
5589                         attribute_t **anchor     = &attributes;
5590                         while (*anchor != NULL)
5591                                 anchor = &(*anchor)->next;
5592                         *anchor = specifiers->attributes;
5593                         if (attributes != NULL) {
5594                                 handle_entity_attributes(attributes, entity);
5595                         }
5596                         entity->declaration.attributes = attributes;
5597
5598                         append_entity(&compound->members, entity);
5599                 } else {
5600                         entity = parse_declarator(specifiers,
5601                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5602                         source_position_t const *const pos = &entity->base.source_position;
5603                         if (entity->kind == ENTITY_TYPEDEF) {
5604                                 errorf(pos, "typedef not allowed as compound member");
5605                         } else {
5606                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5607
5608                                 /* make sure we don't define a symbol multiple times */
5609                                 symbol_t *symbol = entity->base.symbol;
5610                                 if (symbol != NULL) {
5611                                         entity_t *prev = find_compound_entry(compound, symbol);
5612                                         if (prev != NULL) {
5613                                                 source_position_t const *const ppos = &prev->base.source_position;
5614                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5615                                         }
5616                                 }
5617
5618                                 if (token.kind == ':') {
5619                                         parse_bitfield_member(entity);
5620
5621                                         attribute_t *attributes = parse_attributes(NULL);
5622                                         handle_entity_attributes(attributes, entity);
5623                                 } else {
5624                                         type_t *orig_type = entity->declaration.type;
5625                                         type_t *type      = skip_typeref(orig_type);
5626                                         if (is_type_function(type)) {
5627                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5628                                         } else if (is_type_incomplete(type)) {
5629                                                 /* §6.7.2.1:16 flexible array member */
5630                                                 if (!is_type_array(type)       ||
5631                                                                 token.kind          != ';' ||
5632                                                                 look_ahead(1)->kind != '}') {
5633                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5634                                                 } else if (compound->members.entities == NULL) {
5635                                                         errorf(pos, "flexible array member in otherwise empty struct");
5636                                                 }
5637                                         }
5638                                 }
5639
5640                                 append_entity(&compound->members, entity);
5641                         }
5642                 }
5643         } while (next_if(','));
5644         rem_anchor_token(',');
5645         rem_anchor_token(';');
5646         expect(';');
5647
5648         anonymous_entity = NULL;
5649 }
5650
5651 static void parse_compound_type_entries(compound_t *compound)
5652 {
5653         eat('{');
5654         add_anchor_token('}');
5655
5656         for (;;) {
5657                 switch (token.kind) {
5658                         DECLARATION_START
5659                         case T___extension__:
5660                         case T_IDENTIFIER: {
5661                                 PUSH_EXTENSION();
5662                                 declaration_specifiers_t specifiers;
5663                                 parse_declaration_specifiers(&specifiers);
5664                                 parse_compound_declarators(compound, &specifiers);
5665                                 POP_EXTENSION();
5666                                 break;
5667                         }
5668
5669                         default:
5670                                 rem_anchor_token('}');
5671                                 expect('}');
5672                                 /* §6.7.2.1:7 */
5673                                 compound->complete = true;
5674                                 return;
5675                 }
5676         }
5677 }
5678
5679 static type_t *parse_typename(void)
5680 {
5681         declaration_specifiers_t specifiers;
5682         parse_declaration_specifiers(&specifiers);
5683         if (specifiers.storage_class != STORAGE_CLASS_NONE
5684                         || specifiers.thread_local) {
5685                 /* TODO: improve error message, user does probably not know what a
5686                  * storage class is...
5687                  */
5688                 errorf(&specifiers.source_position, "typename must not have a storage class");
5689         }
5690
5691         type_t *result = parse_abstract_declarator(specifiers.type);
5692
5693         return result;
5694 }
5695
5696
5697
5698
5699 typedef expression_t* (*parse_expression_function)(void);
5700 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5701
5702 typedef struct expression_parser_function_t expression_parser_function_t;
5703 struct expression_parser_function_t {
5704         parse_expression_function        parser;
5705         precedence_t                     infix_precedence;
5706         parse_expression_infix_function  infix_parser;
5707 };
5708
5709 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5710
5711 static type_t *get_string_type(string_encoding_t const enc)
5712 {
5713         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5714         switch (enc) {
5715         case STRING_ENCODING_CHAR: return warn ? type_const_char_ptr    : type_char_ptr;
5716         case STRING_ENCODING_WIDE: return warn ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5717         }
5718         panic("invalid string encoding");
5719 }
5720
5721 /**
5722  * Parse a string constant.
5723  */
5724 static expression_t *parse_string_literal(void)
5725 {
5726         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5727         expr->string_literal.value = concat_string_literals(&expr->string_literal.encoding);
5728         expr->base.type            = get_string_type(expr->string_literal.encoding);
5729         return expr;
5730 }
5731
5732 /**
5733  * Parse a boolean constant.
5734  */
5735 static expression_t *parse_boolean_literal(bool value)
5736 {
5737         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5738         literal->base.type           = type_bool;
5739         literal->literal.value.begin = value ? "true" : "false";
5740         literal->literal.value.size  = value ? 4 : 5;
5741
5742         eat(value ? T_true : T_false);
5743         return literal;
5744 }
5745
5746 static void warn_traditional_suffix(void)
5747 {
5748         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5749                  &token.number.suffix);
5750 }
5751
5752 static void check_integer_suffix(void)
5753 {
5754         const string_t *suffix = &token.number.suffix;
5755         if (suffix->size == 0)
5756                 return;
5757
5758         bool not_traditional = false;
5759         const char *c = suffix->begin;
5760         if (*c == 'l' || *c == 'L') {
5761                 ++c;
5762                 if (*c == *(c-1)) {
5763                         not_traditional = true;
5764                         ++c;
5765                         if (*c == 'u' || *c == 'U') {
5766                                 ++c;
5767                         }
5768                 } else if (*c == 'u' || *c == 'U') {
5769                         not_traditional = true;
5770                         ++c;
5771                 }
5772         } else if (*c == 'u' || *c == 'U') {
5773                 not_traditional = true;
5774                 ++c;
5775                 if (*c == 'l' || *c == 'L') {
5776                         ++c;
5777                         if (*c == *(c-1)) {
5778                                 ++c;
5779                         }
5780                 }
5781         }
5782         if (*c != '\0') {
5783                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5784         } else if (not_traditional) {
5785                 warn_traditional_suffix();
5786         }
5787 }
5788
5789 static type_t *check_floatingpoint_suffix(void)
5790 {
5791         const string_t *suffix = &token.number.suffix;
5792         type_t         *type   = type_double;
5793         if (suffix->size == 0)
5794                 return type;
5795
5796         bool not_traditional = false;
5797         const char *c = suffix->begin;
5798         if (*c == 'f' || *c == 'F') {
5799                 ++c;
5800                 type = type_float;
5801         } else if (*c == 'l' || *c == 'L') {
5802                 ++c;
5803                 type = type_long_double;
5804         }
5805         if (*c != '\0') {
5806                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5807         } else if (not_traditional) {
5808                 warn_traditional_suffix();
5809         }
5810
5811         return type;
5812 }
5813
5814 /**
5815  * Parse an integer constant.
5816  */
5817 static expression_t *parse_number_literal(void)
5818 {
5819         expression_kind_t  kind;
5820         type_t            *type;
5821
5822         switch (token.kind) {
5823         case T_INTEGER:
5824                 kind = EXPR_LITERAL_INTEGER;
5825                 check_integer_suffix();
5826                 type = type_int;
5827                 break;
5828
5829         case T_FLOATINGPOINT:
5830                 kind = EXPR_LITERAL_FLOATINGPOINT;
5831                 type = check_floatingpoint_suffix();
5832                 break;
5833
5834         default:
5835                 panic("unexpected token type in parse_number_literal");
5836         }
5837
5838         expression_t *literal = allocate_expression_zero(kind);
5839         literal->base.type      = type;
5840         literal->literal.value  = token.number.number;
5841         literal->literal.suffix = token.number.suffix;
5842         next_token();
5843
5844         /* integer type depends on the size of the number and the size
5845          * representable by the types. The backend/codegeneration has to determine
5846          * that
5847          */
5848         determine_literal_type(&literal->literal);
5849         return literal;
5850 }
5851
5852 /**
5853  * Parse a character constant.
5854  */
5855 static expression_t *parse_character_constant(void)
5856 {
5857         expression_t *literal;
5858         switch (token.string.encoding) {
5859         case STRING_ENCODING_CHAR: {
5860                 literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5861                 literal->base.type     = c_mode & _CXX ? type_char : type_int;
5862                 literal->literal.value = token.string.string;
5863
5864                 size_t len = literal->literal.value.size;
5865                 if (len > 1) {
5866                         if (!GNU_MODE && !(c_mode & _C99)) {
5867                                 errorf(HERE, "more than 1 character in character constant");
5868                         } else {
5869                                 literal->base.type = type_int;
5870                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5871                         }
5872                 }
5873                 break;
5874         }
5875
5876         case STRING_ENCODING_WIDE: {
5877                 literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5878                 literal->base.type     = type_int;
5879                 literal->literal.value = token.string.string;
5880
5881                 size_t len = wstrlen(&literal->literal.value);
5882                 if (len > 1) {
5883                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5884                 }
5885                 break;
5886         }
5887         }
5888
5889         eat(T_CHARACTER_CONSTANT);
5890         return literal;
5891 }
5892
5893 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5894 {
5895         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5896         ntype->function.return_type            = type_int;
5897         ntype->function.unspecified_parameters = true;
5898         ntype->function.linkage                = LINKAGE_C;
5899         type_t *type                           = identify_new_type(ntype);
5900
5901         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5902         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5903         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5904         entity->declaration.type                   = type;
5905         entity->declaration.implicit               = true;
5906
5907         if (current_scope != NULL)
5908                 record_entity(entity, false);
5909
5910         return entity;
5911 }
5912
5913 /**
5914  * Performs automatic type cast as described in §6.3.2.1.
5915  *
5916  * @param orig_type  the original type
5917  */
5918 static type_t *automatic_type_conversion(type_t *orig_type)
5919 {
5920         type_t *type = skip_typeref(orig_type);
5921         if (is_type_array(type)) {
5922                 array_type_t *array_type   = &type->array;
5923                 type_t       *element_type = array_type->element_type;
5924                 unsigned      qualifiers   = array_type->base.qualifiers;
5925
5926                 return make_pointer_type(element_type, qualifiers);
5927         }
5928
5929         if (is_type_function(type)) {
5930                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5931         }
5932
5933         return orig_type;
5934 }
5935
5936 /**
5937  * reverts the automatic casts of array to pointer types and function
5938  * to function-pointer types as defined §6.3.2.1
5939  */
5940 type_t *revert_automatic_type_conversion(const expression_t *expression)
5941 {
5942         switch (expression->kind) {
5943         case EXPR_REFERENCE: {
5944                 entity_t *entity = expression->reference.entity;
5945                 if (is_declaration(entity)) {
5946                         return entity->declaration.type;
5947                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5948                         return entity->enum_value.enum_type;
5949                 } else {
5950                         panic("no declaration or enum in reference");
5951                 }
5952         }
5953
5954         case EXPR_SELECT: {
5955                 entity_t *entity = expression->select.compound_entry;
5956                 assert(is_declaration(entity));
5957                 type_t   *type   = entity->declaration.type;
5958                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5959         }
5960
5961         case EXPR_UNARY_DEREFERENCE: {
5962                 const expression_t *const value = expression->unary.value;
5963                 type_t             *const type  = skip_typeref(value->base.type);
5964                 if (!is_type_pointer(type))
5965                         return type_error_type;
5966                 return type->pointer.points_to;
5967         }
5968
5969         case EXPR_ARRAY_ACCESS: {
5970                 const expression_t *array_ref = expression->array_access.array_ref;
5971                 type_t             *type_left = skip_typeref(array_ref->base.type);
5972                 if (!is_type_pointer(type_left))
5973                         return type_error_type;
5974                 return type_left->pointer.points_to;
5975         }
5976
5977         case EXPR_STRING_LITERAL: {
5978                 size_t  const size = expression->string_literal.value.size + 1;
5979                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5980                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5981         }
5982
5983         case EXPR_COMPOUND_LITERAL:
5984                 return expression->compound_literal.type;
5985
5986         default:
5987                 break;
5988         }
5989         return expression->base.type;
5990 }
5991
5992 /**
5993  * Find an entity matching a symbol in a scope.
5994  * Uses current scope if scope is NULL
5995  */
5996 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5997                                namespace_tag_t namespc)
5998 {
5999         if (scope == NULL) {
6000                 return get_entity(symbol, namespc);
6001         }
6002
6003         /* we should optimize here, if scope grows above a certain size we should
6004            construct a hashmap here... */
6005         entity_t *entity = scope->entities;
6006         for ( ; entity != NULL; entity = entity->base.next) {
6007                 if (entity->base.symbol == symbol
6008                     && (namespace_tag_t)entity->base.namespc == namespc)
6009                         break;
6010         }
6011
6012         return entity;
6013 }
6014
6015 static entity_t *parse_qualified_identifier(void)
6016 {
6017         /* namespace containing the symbol */
6018         symbol_t          *symbol;
6019         source_position_t  pos;
6020         const scope_t     *lookup_scope = NULL;
6021
6022         if (next_if(T_COLONCOLON))
6023                 lookup_scope = &unit->scope;
6024
6025         entity_t *entity;
6026         while (true) {
6027                 symbol = expect_identifier("while parsing identifier", &pos);
6028                 if (!symbol)
6029                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6030
6031                 /* lookup entity */
6032                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6033
6034                 if (!next_if(T_COLONCOLON))
6035                         break;
6036
6037                 switch (entity->kind) {
6038                 case ENTITY_NAMESPACE:
6039                         lookup_scope = &entity->namespacee.members;
6040                         break;
6041                 case ENTITY_STRUCT:
6042                 case ENTITY_UNION:
6043                 case ENTITY_CLASS:
6044                         lookup_scope = &entity->compound.members;
6045                         break;
6046                 default:
6047                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6048                                symbol, get_entity_kind_name(entity->kind));
6049
6050                         /* skip further qualifications */
6051                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6052
6053                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6054                 }
6055         }
6056
6057         if (entity == NULL) {
6058                 if (!strict_mode && token.kind == '(') {
6059                         /* an implicitly declared function */
6060                         entity = create_implicit_function(symbol, &pos);
6061                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6062                 } else {
6063                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6064                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6065                 }
6066         }
6067
6068         return entity;
6069 }
6070
6071 static expression_t *parse_reference(void)
6072 {
6073         source_position_t const pos    = *HERE;
6074         entity_t         *const entity = parse_qualified_identifier();
6075
6076         type_t *orig_type;
6077         if (is_declaration(entity)) {
6078                 orig_type = entity->declaration.type;
6079         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6080                 orig_type = entity->enum_value.enum_type;
6081         } else {
6082                 panic("expected declaration or enum value in reference");
6083         }
6084
6085         /* we always do the auto-type conversions; the & and sizeof parser contains
6086          * code to revert this! */
6087         type_t *type = automatic_type_conversion(orig_type);
6088
6089         expression_kind_t kind = EXPR_REFERENCE;
6090         if (entity->kind == ENTITY_ENUM_VALUE)
6091                 kind = EXPR_ENUM_CONSTANT;
6092
6093         expression_t *expression         = allocate_expression_zero(kind);
6094         expression->base.source_position = pos;
6095         expression->base.type            = type;
6096         expression->reference.entity     = entity;
6097
6098         /* this declaration is used */
6099         if (is_declaration(entity)) {
6100                 entity->declaration.used = true;
6101         }
6102
6103         if (entity->base.parent_scope != file_scope
6104                 && (current_function != NULL
6105                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6106                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6107                 /* access of a variable from an outer function */
6108                 entity->variable.address_taken = true;
6109                 current_function->need_closure = true;
6110         }
6111
6112         check_deprecated(&pos, entity);
6113
6114         return expression;
6115 }
6116
6117 static bool semantic_cast(expression_t *cast)
6118 {
6119         expression_t            *expression      = cast->unary.value;
6120         type_t                  *orig_dest_type  = cast->base.type;
6121         type_t                  *orig_type_right = expression->base.type;
6122         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6123         type_t            const *src_type        = skip_typeref(orig_type_right);
6124         source_position_t const *pos             = &cast->base.source_position;
6125
6126         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6127         if (is_type_void(dst_type))
6128                 return true;
6129
6130         /* only integer and pointer can be casted to pointer */
6131         if (is_type_pointer(dst_type)  &&
6132             !is_type_pointer(src_type) &&
6133             !is_type_integer(src_type) &&
6134             is_type_valid(src_type)) {
6135                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6136                 return false;
6137         }
6138
6139         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6140                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6141                 return false;
6142         }
6143
6144         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6145                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6146                 return false;
6147         }
6148
6149         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6150                 type_t *src = skip_typeref(src_type->pointer.points_to);
6151                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6152                 unsigned missing_qualifiers =
6153                         src->base.qualifiers & ~dst->base.qualifiers;
6154                 if (missing_qualifiers != 0) {
6155                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6156                 }
6157         }
6158         return true;
6159 }
6160
6161 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6162 {
6163         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6164         expression->base.source_position = *pos;
6165
6166         parse_initializer_env_t env;
6167         env.type             = type;
6168         env.entity           = NULL;
6169         env.must_be_constant = false;
6170         initializer_t *initializer = parse_initializer(&env);
6171         type = env.type;
6172
6173         expression->compound_literal.initializer = initializer;
6174         expression->compound_literal.type        = type;
6175         expression->base.type                    = automatic_type_conversion(type);
6176
6177         return expression;
6178 }
6179
6180 /**
6181  * Parse a cast expression.
6182  */
6183 static expression_t *parse_cast(void)
6184 {
6185         source_position_t const pos = *HERE;
6186
6187         eat('(');
6188         add_anchor_token(')');
6189
6190         type_t *type = parse_typename();
6191
6192         rem_anchor_token(')');
6193         expect(')');
6194
6195         if (token.kind == '{') {
6196                 return parse_compound_literal(&pos, type);
6197         }
6198
6199         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6200         cast->base.source_position = pos;
6201
6202         expression_t *value = parse_subexpression(PREC_CAST);
6203         cast->base.type   = type;
6204         cast->unary.value = value;
6205
6206         if (! semantic_cast(cast)) {
6207                 /* TODO: record the error in the AST. else it is impossible to detect it */
6208         }
6209
6210         return cast;
6211 }
6212
6213 /**
6214  * Parse a statement expression.
6215  */
6216 static expression_t *parse_statement_expression(void)
6217 {
6218         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6219
6220         eat('(');
6221         add_anchor_token(')');
6222
6223         statement_t *statement          = parse_compound_statement(true);
6224         statement->compound.stmt_expr   = true;
6225         expression->statement.statement = statement;
6226
6227         /* find last statement and use its type */
6228         type_t *type = type_void;
6229         const statement_t *stmt = statement->compound.statements;
6230         if (stmt != NULL) {
6231                 while (stmt->base.next != NULL)
6232                         stmt = stmt->base.next;
6233
6234                 if (stmt->kind == STATEMENT_EXPRESSION) {
6235                         type = stmt->expression.expression->base.type;
6236                 }
6237         } else {
6238                 source_position_t const *const pos = &expression->base.source_position;
6239                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6240         }
6241         expression->base.type = type;
6242
6243         rem_anchor_token(')');
6244         expect(')');
6245         return expression;
6246 }
6247
6248 /**
6249  * Parse a parenthesized expression.
6250  */
6251 static expression_t *parse_parenthesized_expression(void)
6252 {
6253         token_t const* const la1 = look_ahead(1);
6254         switch (la1->kind) {
6255         case '{':
6256                 /* gcc extension: a statement expression */
6257                 return parse_statement_expression();
6258
6259         case T_IDENTIFIER:
6260                 if (is_typedef_symbol(la1->base.symbol)) {
6261         DECLARATION_START
6262                         return parse_cast();
6263                 }
6264         }
6265
6266         eat('(');
6267         add_anchor_token(')');
6268         expression_t *result = parse_expression();
6269         result->base.parenthesized = true;
6270         rem_anchor_token(')');
6271         expect(')');
6272
6273         return result;
6274 }
6275
6276 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6277 {
6278         if (current_function == NULL) {
6279                 errorf(HERE, "'%K' used outside of a function", &token);
6280         }
6281
6282         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6283         expression->base.type     = type_char_ptr;
6284         expression->funcname.kind = kind;
6285
6286         next_token();
6287
6288         return expression;
6289 }
6290
6291 static designator_t *parse_designator(void)
6292 {
6293         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6294         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6295         if (!result->symbol)
6296                 return NULL;
6297
6298         designator_t *last_designator = result;
6299         while (true) {
6300                 if (next_if('.')) {
6301                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6302                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6303                         if (!designator->symbol)
6304                                 return NULL;
6305
6306                         last_designator->next = designator;
6307                         last_designator       = designator;
6308                         continue;
6309                 }
6310                 if (next_if('[')) {
6311                         add_anchor_token(']');
6312                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6313                         designator->source_position = *HERE;
6314                         designator->array_index     = parse_expression();
6315                         rem_anchor_token(']');
6316                         expect(']');
6317                         if (designator->array_index == NULL) {
6318                                 return NULL;
6319                         }
6320
6321                         last_designator->next = designator;
6322                         last_designator       = designator;
6323                         continue;
6324                 }
6325                 break;
6326         }
6327
6328         return result;
6329 }
6330
6331 /**
6332  * Parse the __builtin_offsetof() expression.
6333  */
6334 static expression_t *parse_offsetof(void)
6335 {
6336         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6337         expression->base.type    = type_size_t;
6338
6339         eat(T___builtin_offsetof);
6340
6341         add_anchor_token(')');
6342         add_anchor_token(',');
6343         expect('(');
6344         type_t *type = parse_typename();
6345         rem_anchor_token(',');
6346         expect(',');
6347         designator_t *designator = parse_designator();
6348         rem_anchor_token(')');
6349         expect(')');
6350
6351         expression->offsetofe.type       = type;
6352         expression->offsetofe.designator = designator;
6353
6354         type_path_t path;
6355         memset(&path, 0, sizeof(path));
6356         path.top_type = type;
6357         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6358
6359         descend_into_subtype(&path);
6360
6361         if (!walk_designator(&path, designator, true)) {
6362                 return create_error_expression();
6363         }
6364
6365         DEL_ARR_F(path.path);
6366
6367         return expression;
6368 }
6369
6370 static bool is_last_parameter(expression_t *const param)
6371 {
6372         if (param->kind == EXPR_REFERENCE) {
6373                 entity_t *const entity = param->reference.entity;
6374                 if (entity->kind == ENTITY_PARAMETER &&
6375                     !entity->base.next               &&
6376                     entity->base.parent_scope == &current_function->parameters) {
6377                         return true;
6378                 }
6379         }
6380
6381         if (!is_type_valid(skip_typeref(param->base.type)))
6382                 return true;
6383
6384         return false;
6385 }
6386
6387 /**
6388  * Parses a __builtin_va_start() expression.
6389  */
6390 static expression_t *parse_va_start(void)
6391 {
6392         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6393
6394         eat(T___builtin_va_start);
6395
6396         add_anchor_token(')');
6397         add_anchor_token(',');
6398         expect('(');
6399         expression->va_starte.ap = parse_assignment_expression();
6400         rem_anchor_token(',');
6401         expect(',');
6402         expression_t *const param = parse_assignment_expression();
6403         expression->va_starte.parameter = param;
6404         rem_anchor_token(')');
6405         expect(')');
6406
6407         if (!current_function) {
6408                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6409         } else if (!current_function->base.type->function.variadic) {
6410                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6411         } else if (!is_last_parameter(param)) {
6412                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6413         }
6414
6415         return expression;
6416 }
6417
6418 /**
6419  * Parses a __builtin_va_arg() expression.
6420  */
6421 static expression_t *parse_va_arg(void)
6422 {
6423         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6424
6425         eat(T___builtin_va_arg);
6426
6427         add_anchor_token(')');
6428         add_anchor_token(',');
6429         expect('(');
6430         call_argument_t ap;
6431         ap.expression = parse_assignment_expression();
6432         expression->va_arge.ap = ap.expression;
6433         check_call_argument(type_valist, &ap, 1);
6434
6435         rem_anchor_token(',');
6436         expect(',');
6437         expression->base.type = parse_typename();
6438         rem_anchor_token(')');
6439         expect(')');
6440
6441         return expression;
6442 }
6443
6444 /**
6445  * Parses a __builtin_va_copy() expression.
6446  */
6447 static expression_t *parse_va_copy(void)
6448 {
6449         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6450
6451         eat(T___builtin_va_copy);
6452
6453         add_anchor_token(')');
6454         add_anchor_token(',');
6455         expect('(');
6456         expression_t *dst = parse_assignment_expression();
6457         assign_error_t error = semantic_assign(type_valist, dst);
6458         report_assign_error(error, type_valist, dst, "call argument 1",
6459                             &dst->base.source_position);
6460         expression->va_copye.dst = dst;
6461
6462         rem_anchor_token(',');
6463         expect(',');
6464
6465         call_argument_t src;
6466         src.expression = parse_assignment_expression();
6467         check_call_argument(type_valist, &src, 2);
6468         expression->va_copye.src = src.expression;
6469         rem_anchor_token(')');
6470         expect(')');
6471
6472         return expression;
6473 }
6474
6475 /**
6476  * Parses a __builtin_constant_p() expression.
6477  */
6478 static expression_t *parse_builtin_constant(void)
6479 {
6480         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6481
6482         eat(T___builtin_constant_p);
6483
6484         add_anchor_token(')');
6485         expect('(');
6486         expression->builtin_constant.value = parse_assignment_expression();
6487         rem_anchor_token(')');
6488         expect(')');
6489         expression->base.type = type_int;
6490
6491         return expression;
6492 }
6493
6494 /**
6495  * Parses a __builtin_types_compatible_p() expression.
6496  */
6497 static expression_t *parse_builtin_types_compatible(void)
6498 {
6499         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6500
6501         eat(T___builtin_types_compatible_p);
6502
6503         add_anchor_token(')');
6504         add_anchor_token(',');
6505         expect('(');
6506         expression->builtin_types_compatible.left = parse_typename();
6507         rem_anchor_token(',');
6508         expect(',');
6509         expression->builtin_types_compatible.right = parse_typename();
6510         rem_anchor_token(')');
6511         expect(')');
6512         expression->base.type = type_int;
6513
6514         return expression;
6515 }
6516
6517 /**
6518  * Parses a __builtin_is_*() compare expression.
6519  */
6520 static expression_t *parse_compare_builtin(void)
6521 {
6522         expression_kind_t kind;
6523         switch (token.kind) {
6524         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6525         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6526         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6527         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6528         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6529         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6530         default: internal_errorf(HERE, "invalid compare builtin found");
6531         }
6532         expression_t *const expression = allocate_expression_zero(kind);
6533         next_token();
6534
6535         add_anchor_token(')');
6536         add_anchor_token(',');
6537         expect('(');
6538         expression->binary.left = parse_assignment_expression();
6539         rem_anchor_token(',');
6540         expect(',');
6541         expression->binary.right = parse_assignment_expression();
6542         rem_anchor_token(')');
6543         expect(')');
6544
6545         type_t *const orig_type_left  = expression->binary.left->base.type;
6546         type_t *const orig_type_right = expression->binary.right->base.type;
6547
6548         type_t *const type_left  = skip_typeref(orig_type_left);
6549         type_t *const type_right = skip_typeref(orig_type_right);
6550         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6551                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6552                         type_error_incompatible("invalid operands in comparison",
6553                                 &expression->base.source_position, orig_type_left, orig_type_right);
6554                 }
6555         } else {
6556                 semantic_comparison(&expression->binary);
6557         }
6558
6559         return expression;
6560 }
6561
6562 /**
6563  * Parses a MS assume() expression.
6564  */
6565 static expression_t *parse_assume(void)
6566 {
6567         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6568
6569         eat(T__assume);
6570
6571         add_anchor_token(')');
6572         expect('(');
6573         expression->unary.value = parse_assignment_expression();
6574         rem_anchor_token(')');
6575         expect(')');
6576
6577         expression->base.type = type_void;
6578         return expression;
6579 }
6580
6581 /**
6582  * Return the label for the current symbol or create a new one.
6583  */
6584 static label_t *get_label(char const *const context)
6585 {
6586         assert(current_function != NULL);
6587
6588         symbol_t *const sym = expect_identifier(context, NULL);
6589         if (!sym)
6590                 return NULL;
6591
6592         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6593         /* If we find a local label, we already created the declaration. */
6594         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6595                 if (label->base.parent_scope != current_scope) {
6596                         assert(label->base.parent_scope->depth < current_scope->depth);
6597                         current_function->goto_to_outer = true;
6598                 }
6599         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6600                 /* There is no matching label in the same function, so create a new one. */
6601                 source_position_t const nowhere = { NULL, 0, 0, false };
6602                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6603                 label_push(label);
6604         }
6605
6606         return &label->label;
6607 }
6608
6609 /**
6610  * Parses a GNU && label address expression.
6611  */
6612 static expression_t *parse_label_address(void)
6613 {
6614         source_position_t const source_position = *HERE;
6615         eat(T_ANDAND);
6616
6617         label_t *const label = get_label("while parsing label address");
6618         if (!label)
6619                 return create_error_expression();
6620
6621         label->used          = true;
6622         label->address_taken = true;
6623
6624         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6625         expression->base.source_position = source_position;
6626
6627         /* label address is treated as a void pointer */
6628         expression->base.type           = type_void_ptr;
6629         expression->label_address.label = label;
6630         return expression;
6631 }
6632
6633 /**
6634  * Parse a microsoft __noop expression.
6635  */
6636 static expression_t *parse_noop_expression(void)
6637 {
6638         /* the result is a (int)0 */
6639         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6640         literal->base.type           = type_int;
6641         literal->literal.value.begin = "__noop";
6642         literal->literal.value.size  = 6;
6643
6644         eat(T___noop);
6645
6646         if (token.kind == '(') {
6647                 /* parse arguments */
6648                 eat('(');
6649                 add_anchor_token(')');
6650                 add_anchor_token(',');
6651
6652                 if (token.kind != ')') do {
6653                         (void)parse_assignment_expression();
6654                 } while (next_if(','));
6655
6656                 rem_anchor_token(',');
6657                 rem_anchor_token(')');
6658         }
6659         expect(')');
6660
6661         return literal;
6662 }
6663
6664 /**
6665  * Parses a primary expression.
6666  */
6667 static expression_t *parse_primary_expression(void)
6668 {
6669         switch (token.kind) {
6670         case T_false:                        return parse_boolean_literal(false);
6671         case T_true:                         return parse_boolean_literal(true);
6672         case T_INTEGER:
6673         case T_FLOATINGPOINT:                return parse_number_literal();
6674         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6675         case T_STRING_LITERAL:               return parse_string_literal();
6676         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6677         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6678         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6679         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6680         case T___builtin_offsetof:           return parse_offsetof();
6681         case T___builtin_va_start:           return parse_va_start();
6682         case T___builtin_va_arg:             return parse_va_arg();
6683         case T___builtin_va_copy:            return parse_va_copy();
6684         case T___builtin_isgreater:
6685         case T___builtin_isgreaterequal:
6686         case T___builtin_isless:
6687         case T___builtin_islessequal:
6688         case T___builtin_islessgreater:
6689         case T___builtin_isunordered:        return parse_compare_builtin();
6690         case T___builtin_constant_p:         return parse_builtin_constant();
6691         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6692         case T__assume:                      return parse_assume();
6693         case T_ANDAND:
6694                 if (GNU_MODE)
6695                         return parse_label_address();
6696                 break;
6697
6698         case '(':                            return parse_parenthesized_expression();
6699         case T___noop:                       return parse_noop_expression();
6700
6701         /* Gracefully handle type names while parsing expressions. */
6702         case T_COLONCOLON:
6703                 return parse_reference();
6704         case T_IDENTIFIER:
6705                 if (!is_typedef_symbol(token.base.symbol)) {
6706                         return parse_reference();
6707                 }
6708                 /* FALLTHROUGH */
6709         DECLARATION_START {
6710                 source_position_t const  pos = *HERE;
6711                 declaration_specifiers_t specifiers;
6712                 parse_declaration_specifiers(&specifiers);
6713                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6714                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6715                 return create_error_expression();
6716         }
6717         }
6718
6719         errorf(HERE, "unexpected token %K, expected an expression", &token);
6720         eat_until_anchor();
6721         return create_error_expression();
6722 }
6723
6724 static expression_t *parse_array_expression(expression_t *left)
6725 {
6726         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6727         array_access_expression_t *const arr  = &expr->array_access;
6728
6729         eat('[');
6730         add_anchor_token(']');
6731
6732         expression_t *const inside = parse_expression();
6733
6734         type_t *const orig_type_left   = left->base.type;
6735         type_t *const orig_type_inside = inside->base.type;
6736
6737         type_t *const type_left   = skip_typeref(orig_type_left);
6738         type_t *const type_inside = skip_typeref(orig_type_inside);
6739
6740         expression_t *ref;
6741         expression_t *idx;
6742         type_t       *idx_type;
6743         type_t       *res_type;
6744         if (is_type_pointer(type_left)) {
6745                 ref      = left;
6746                 idx      = inside;
6747                 idx_type = type_inside;
6748                 res_type = type_left->pointer.points_to;
6749                 goto check_idx;
6750         } else if (is_type_pointer(type_inside)) {
6751                 arr->flipped = true;
6752                 ref      = inside;
6753                 idx      = left;
6754                 idx_type = type_left;
6755                 res_type = type_inside->pointer.points_to;
6756 check_idx:
6757                 res_type = automatic_type_conversion(res_type);
6758                 if (!is_type_integer(idx_type)) {
6759                         errorf(&idx->base.source_position, "array subscript must have integer type");
6760                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6761                         source_position_t const *const pos = &idx->base.source_position;
6762                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6763                 }
6764         } else {
6765                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6766                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6767                 }
6768                 res_type = type_error_type;
6769                 ref      = left;
6770                 idx      = inside;
6771         }
6772
6773         arr->array_ref = ref;
6774         arr->index     = idx;
6775         arr->base.type = res_type;
6776
6777         rem_anchor_token(']');
6778         expect(']');
6779         return expr;
6780 }
6781
6782 static bool is_bitfield(const expression_t *expression)
6783 {
6784         return expression->kind == EXPR_SELECT
6785                 && expression->select.compound_entry->compound_member.bitfield;
6786 }
6787
6788 static expression_t *parse_typeprop(expression_kind_t const kind)
6789 {
6790         expression_t  *tp_expression = allocate_expression_zero(kind);
6791         tp_expression->base.type     = type_size_t;
6792
6793         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6794
6795         type_t       *orig_type;
6796         expression_t *expression;
6797         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6798                 source_position_t const pos = *HERE;
6799                 eat('(');
6800                 add_anchor_token(')');
6801                 orig_type = parse_typename();
6802                 rem_anchor_token(')');
6803                 expect(')');
6804
6805                 if (token.kind == '{') {
6806                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6807                          * starting with a compound literal */
6808                         expression = parse_compound_literal(&pos, orig_type);
6809                         goto typeprop_expression;
6810                 }
6811         } else {
6812                 expression = parse_subexpression(PREC_UNARY);
6813
6814 typeprop_expression:
6815                 if (is_bitfield(expression)) {
6816                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6817                         errorf(&tp_expression->base.source_position,
6818                                    "operand of %s expression must not be a bitfield", what);
6819                 }
6820
6821                 tp_expression->typeprop.tp_expression = expression;
6822
6823                 orig_type = revert_automatic_type_conversion(expression);
6824                 expression->base.type = orig_type;
6825         }
6826
6827         tp_expression->typeprop.type   = orig_type;
6828         type_t const* const type       = skip_typeref(orig_type);
6829         char   const*       wrong_type = NULL;
6830         if (is_type_incomplete(type)) {
6831                 if (!is_type_void(type) || !GNU_MODE)
6832                         wrong_type = "incomplete";
6833         } else if (type->kind == TYPE_FUNCTION) {
6834                 if (GNU_MODE) {
6835                         /* function types are allowed (and return 1) */
6836                         source_position_t const *const pos  = &tp_expression->base.source_position;
6837                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6838                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6839                 } else {
6840                         wrong_type = "function";
6841                 }
6842         }
6843
6844         if (wrong_type != NULL) {
6845                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6846                 errorf(&tp_expression->base.source_position,
6847                                 "operand of %s expression must not be of %s type '%T'",
6848                                 what, wrong_type, orig_type);
6849         }
6850
6851         return tp_expression;
6852 }
6853
6854 static expression_t *parse_sizeof(void)
6855 {
6856         return parse_typeprop(EXPR_SIZEOF);
6857 }
6858
6859 static expression_t *parse_alignof(void)
6860 {
6861         return parse_typeprop(EXPR_ALIGNOF);
6862 }
6863
6864 static expression_t *parse_select_expression(expression_t *addr)
6865 {
6866         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6867         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6868         source_position_t const pos = *HERE;
6869         next_token();
6870
6871         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6872         if (!symbol)
6873                 return create_error_expression();
6874
6875         type_t *const orig_type = addr->base.type;
6876         type_t *const type      = skip_typeref(orig_type);
6877
6878         type_t *type_left;
6879         bool    saw_error = false;
6880         if (is_type_pointer(type)) {
6881                 if (!select_left_arrow) {
6882                         errorf(&pos,
6883                                "request for member '%Y' in something not a struct or union, but '%T'",
6884                                symbol, orig_type);
6885                         saw_error = true;
6886                 }
6887                 type_left = skip_typeref(type->pointer.points_to);
6888         } else {
6889                 if (select_left_arrow && is_type_valid(type)) {
6890                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6891                         saw_error = true;
6892                 }
6893                 type_left = type;
6894         }
6895
6896         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6897             type_left->kind != TYPE_COMPOUND_UNION) {
6898
6899                 if (is_type_valid(type_left) && !saw_error) {
6900                         errorf(&pos,
6901                                "request for member '%Y' in something not a struct or union, but '%T'",
6902                                symbol, type_left);
6903                 }
6904                 return create_error_expression();
6905         }
6906
6907         compound_t *compound = type_left->compound.compound;
6908         if (!compound->complete) {
6909                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6910                        symbol, type_left);
6911                 return create_error_expression();
6912         }
6913
6914         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6915         expression_t      *result     =
6916                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6917
6918         if (result == NULL) {
6919                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6920                 return create_error_expression();
6921         }
6922
6923         return result;
6924 }
6925
6926 static void check_call_argument(type_t          *expected_type,
6927                                 call_argument_t *argument, unsigned pos)
6928 {
6929         type_t         *expected_type_skip = skip_typeref(expected_type);
6930         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6931         expression_t   *arg_expr           = argument->expression;
6932         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6933
6934         /* handle transparent union gnu extension */
6935         if (is_type_union(expected_type_skip)
6936                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6937                 compound_t *union_decl  = expected_type_skip->compound.compound;
6938                 type_t     *best_type   = NULL;
6939                 entity_t   *entry       = union_decl->members.entities;
6940                 for ( ; entry != NULL; entry = entry->base.next) {
6941                         assert(is_declaration(entry));
6942                         type_t *decl_type = entry->declaration.type;
6943                         error = semantic_assign(decl_type, arg_expr);
6944                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6945                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6946                                 continue;
6947
6948                         if (error == ASSIGN_SUCCESS) {
6949                                 best_type = decl_type;
6950                         } else if (best_type == NULL) {
6951                                 best_type = decl_type;
6952                         }
6953                 }
6954
6955                 if (best_type != NULL) {
6956                         expected_type = best_type;
6957                 }
6958         }
6959
6960         error                = semantic_assign(expected_type, arg_expr);
6961         argument->expression = create_implicit_cast(arg_expr, expected_type);
6962
6963         if (error != ASSIGN_SUCCESS) {
6964                 /* report exact scope in error messages (like "in argument 3") */
6965                 char buf[64];
6966                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6967                 report_assign_error(error, expected_type, arg_expr, buf,
6968                                     &arg_expr->base.source_position);
6969         } else {
6970                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6971                 if (!types_compatible(expected_type_skip, promoted_type) &&
6972                     !types_compatible(expected_type_skip, type_void_ptr) &&
6973                     !types_compatible(type_void_ptr,      promoted_type)) {
6974                         /* Deliberately show the skipped types in this warning */
6975                         source_position_t const *const apos = &arg_expr->base.source_position;
6976                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
6977                 }
6978         }
6979 }
6980
6981 /**
6982  * Handle the semantic restrictions of builtin calls
6983  */
6984 static void handle_builtin_argument_restrictions(call_expression_t *call)
6985 {
6986         entity_t *entity = call->function->reference.entity;
6987         switch (entity->function.btk) {
6988         case BUILTIN_FIRM:
6989                 switch (entity->function.b.firm_builtin_kind) {
6990                 case ir_bk_return_address:
6991                 case ir_bk_frame_address: {
6992                         /* argument must be constant */
6993                         call_argument_t *argument = call->arguments;
6994
6995                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
6996                                 errorf(&call->base.source_position,
6997                                            "argument of '%Y' must be a constant expression",
6998                                            call->function->reference.entity->base.symbol);
6999                         }
7000                         break;
7001                 }
7002                 case ir_bk_prefetch:
7003                         /* second and third argument must be constant if existent */
7004                         if (call->arguments == NULL)
7005                                 break;
7006                         call_argument_t *rw = call->arguments->next;
7007                         call_argument_t *locality = NULL;
7008
7009                         if (rw != NULL) {
7010                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7011                                         errorf(&call->base.source_position,
7012                                                    "second argument of '%Y' must be a constant expression",
7013                                                    call->function->reference.entity->base.symbol);
7014                                 }
7015                                 locality = rw->next;
7016                         }
7017                         if (locality != NULL) {
7018                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7019                                         errorf(&call->base.source_position,
7020                                                    "third argument of '%Y' must be a constant expression",
7021                                                    call->function->reference.entity->base.symbol);
7022                                 }
7023                                 locality = rw->next;
7024                         }
7025                         break;
7026                 default:
7027                         break;
7028                 }
7029
7030         case BUILTIN_OBJECT_SIZE:
7031                 if (call->arguments == NULL)
7032                         break;
7033
7034                 call_argument_t *arg = call->arguments->next;
7035                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7036                         errorf(&call->base.source_position,
7037                                    "second argument of '%Y' must be a constant expression",
7038                                    call->function->reference.entity->base.symbol);
7039                 }
7040                 break;
7041         default:
7042                 break;
7043         }
7044 }
7045
7046 /**
7047  * Parse a call expression, ie. expression '( ... )'.
7048  *
7049  * @param expression  the function address
7050  */
7051 static expression_t *parse_call_expression(expression_t *expression)
7052 {
7053         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7054         call_expression_t *call   = &result->call;
7055         call->function            = expression;
7056
7057         type_t *const orig_type = expression->base.type;
7058         type_t *const type      = skip_typeref(orig_type);
7059
7060         function_type_t *function_type = NULL;
7061         if (is_type_pointer(type)) {
7062                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7063
7064                 if (is_type_function(to_type)) {
7065                         function_type   = &to_type->function;
7066                         call->base.type = function_type->return_type;
7067                 }
7068         }
7069
7070         if (function_type == NULL && is_type_valid(type)) {
7071                 errorf(HERE,
7072                        "called object '%E' (type '%T') is not a pointer to a function",
7073                        expression, orig_type);
7074         }
7075
7076         /* parse arguments */
7077         eat('(');
7078         add_anchor_token(')');
7079         add_anchor_token(',');
7080
7081         if (token.kind != ')') {
7082                 call_argument_t **anchor = &call->arguments;
7083                 do {
7084                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7085                         argument->expression = parse_assignment_expression();
7086
7087                         *anchor = argument;
7088                         anchor  = &argument->next;
7089                 } while (next_if(','));
7090         }
7091         rem_anchor_token(',');
7092         rem_anchor_token(')');
7093         expect(')');
7094
7095         if (function_type == NULL)
7096                 return result;
7097
7098         /* check type and count of call arguments */
7099         function_parameter_t *parameter = function_type->parameters;
7100         call_argument_t      *argument  = call->arguments;
7101         if (!function_type->unspecified_parameters) {
7102                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7103                                 parameter = parameter->next, argument = argument->next) {
7104                         check_call_argument(parameter->type, argument, ++pos);
7105                 }
7106
7107                 if (parameter != NULL) {
7108                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7109                 } else if (argument != NULL && !function_type->variadic) {
7110                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7111                 }
7112         }
7113
7114         /* do default promotion for other arguments */
7115         for (; argument != NULL; argument = argument->next) {
7116                 type_t *argument_type = argument->expression->base.type;
7117                 if (!is_type_object(skip_typeref(argument_type))) {
7118                         errorf(&argument->expression->base.source_position,
7119                                "call argument '%E' must not be void", argument->expression);
7120                 }
7121
7122                 argument_type = get_default_promoted_type(argument_type);
7123
7124                 argument->expression
7125                         = create_implicit_cast(argument->expression, argument_type);
7126         }
7127
7128         check_format(call);
7129
7130         if (is_type_compound(skip_typeref(function_type->return_type))) {
7131                 source_position_t const *const pos = &expression->base.source_position;
7132                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7133         }
7134
7135         if (expression->kind == EXPR_REFERENCE) {
7136                 reference_expression_t *reference = &expression->reference;
7137                 if (reference->entity->kind == ENTITY_FUNCTION &&
7138                     reference->entity->function.btk != BUILTIN_NONE)
7139                         handle_builtin_argument_restrictions(call);
7140         }
7141
7142         return result;
7143 }
7144
7145 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7146
7147 static bool same_compound_type(const type_t *type1, const type_t *type2)
7148 {
7149         return
7150                 is_type_compound(type1) &&
7151                 type1->kind == type2->kind &&
7152                 type1->compound.compound == type2->compound.compound;
7153 }
7154
7155 static expression_t const *get_reference_address(expression_t const *expr)
7156 {
7157         bool regular_take_address = true;
7158         for (;;) {
7159                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7160                         expr = expr->unary.value;
7161                 } else {
7162                         regular_take_address = false;
7163                 }
7164
7165                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7166                         break;
7167
7168                 expr = expr->unary.value;
7169         }
7170
7171         if (expr->kind != EXPR_REFERENCE)
7172                 return NULL;
7173
7174         /* special case for functions which are automatically converted to a
7175          * pointer to function without an extra TAKE_ADDRESS operation */
7176         if (!regular_take_address &&
7177                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7178                 return NULL;
7179         }
7180
7181         return expr;
7182 }
7183
7184 static void warn_reference_address_as_bool(expression_t const* expr)
7185 {
7186         expr = get_reference_address(expr);
7187         if (expr != NULL) {
7188                 source_position_t const *const pos = &expr->base.source_position;
7189                 entity_t          const *const ent = expr->reference.entity;
7190                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7191         }
7192 }
7193
7194 static void warn_assignment_in_condition(const expression_t *const expr)
7195 {
7196         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7197                 return;
7198         if (expr->base.parenthesized)
7199                 return;
7200         source_position_t const *const pos = &expr->base.source_position;
7201         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7202 }
7203
7204 static void semantic_condition(expression_t const *const expr,
7205                                char const *const context)
7206 {
7207         type_t *const type = skip_typeref(expr->base.type);
7208         if (is_type_scalar(type)) {
7209                 warn_reference_address_as_bool(expr);
7210                 warn_assignment_in_condition(expr);
7211         } else if (is_type_valid(type)) {
7212                 errorf(&expr->base.source_position,
7213                                 "%s must have scalar type", context);
7214         }
7215 }
7216
7217 /**
7218  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7219  *
7220  * @param expression  the conditional expression
7221  */
7222 static expression_t *parse_conditional_expression(expression_t *expression)
7223 {
7224         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7225
7226         conditional_expression_t *conditional = &result->conditional;
7227         conditional->condition                = expression;
7228
7229         eat('?');
7230         add_anchor_token(':');
7231
7232         /* §6.5.15:2  The first operand shall have scalar type. */
7233         semantic_condition(expression, "condition of conditional operator");
7234
7235         expression_t *true_expression = expression;
7236         bool          gnu_cond = false;
7237         if (GNU_MODE && token.kind == ':') {
7238                 gnu_cond = true;
7239         } else {
7240                 true_expression = parse_expression();
7241         }
7242         rem_anchor_token(':');
7243         expect(':');
7244         expression_t *false_expression =
7245                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7246
7247         type_t *const orig_true_type  = true_expression->base.type;
7248         type_t *const orig_false_type = false_expression->base.type;
7249         type_t *const true_type       = skip_typeref(orig_true_type);
7250         type_t *const false_type      = skip_typeref(orig_false_type);
7251
7252         /* 6.5.15.3 */
7253         source_position_t const *const pos = &conditional->base.source_position;
7254         type_t                        *result_type;
7255         if (is_type_void(true_type) || is_type_void(false_type)) {
7256                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7257                 if (true_expression->kind == EXPR_UNARY_THROW) {
7258                         result_type = false_type;
7259                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7260                         result_type = true_type;
7261                 } else {
7262                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7263                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7264                         }
7265                         result_type = type_void;
7266                 }
7267         } else if (is_type_arithmetic(true_type)
7268                    && is_type_arithmetic(false_type)) {
7269                 result_type = semantic_arithmetic(true_type, false_type);
7270         } else if (same_compound_type(true_type, false_type)) {
7271                 /* just take 1 of the 2 types */
7272                 result_type = true_type;
7273         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7274                 type_t *pointer_type;
7275                 type_t *other_type;
7276                 expression_t *other_expression;
7277                 if (is_type_pointer(true_type) &&
7278                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7279                         pointer_type     = true_type;
7280                         other_type       = false_type;
7281                         other_expression = false_expression;
7282                 } else {
7283                         pointer_type     = false_type;
7284                         other_type       = true_type;
7285                         other_expression = true_expression;
7286                 }
7287
7288                 if (is_null_pointer_constant(other_expression)) {
7289                         result_type = pointer_type;
7290                 } else if (is_type_pointer(other_type)) {
7291                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7292                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7293
7294                         type_t *to;
7295                         if (is_type_void(to1) || is_type_void(to2)) {
7296                                 to = type_void;
7297                         } else if (types_compatible(get_unqualified_type(to1),
7298                                                     get_unqualified_type(to2))) {
7299                                 to = to1;
7300                         } else {
7301                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7302                                 to = type_void;
7303                         }
7304
7305                         type_t *const type =
7306                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7307                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7308                 } else if (is_type_integer(other_type)) {
7309                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7310                         result_type = pointer_type;
7311                 } else {
7312                         goto types_incompatible;
7313                 }
7314         } else {
7315 types_incompatible:
7316                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7317                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7318                 }
7319                 result_type = type_error_type;
7320         }
7321
7322         conditional->true_expression
7323                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7324         conditional->false_expression
7325                 = create_implicit_cast(false_expression, result_type);
7326         conditional->base.type = result_type;
7327         return result;
7328 }
7329
7330 /**
7331  * Parse an extension expression.
7332  */
7333 static expression_t *parse_extension(void)
7334 {
7335         PUSH_EXTENSION();
7336         expression_t *expression = parse_subexpression(PREC_UNARY);
7337         POP_EXTENSION();
7338         return expression;
7339 }
7340
7341 /**
7342  * Parse a __builtin_classify_type() expression.
7343  */
7344 static expression_t *parse_builtin_classify_type(void)
7345 {
7346         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7347         result->base.type    = type_int;
7348
7349         eat(T___builtin_classify_type);
7350
7351         add_anchor_token(')');
7352         expect('(');
7353         expression_t *expression = parse_expression();
7354         rem_anchor_token(')');
7355         expect(')');
7356         result->classify_type.type_expression = expression;
7357
7358         return result;
7359 }
7360
7361 /**
7362  * Parse a delete expression
7363  * ISO/IEC 14882:1998(E) §5.3.5
7364  */
7365 static expression_t *parse_delete(void)
7366 {
7367         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7368         result->base.type          = type_void;
7369
7370         eat(T_delete);
7371
7372         if (next_if('[')) {
7373                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7374                 expect(']');
7375         }
7376
7377         expression_t *const value = parse_subexpression(PREC_CAST);
7378         result->unary.value = value;
7379
7380         type_t *const type = skip_typeref(value->base.type);
7381         if (!is_type_pointer(type)) {
7382                 if (is_type_valid(type)) {
7383                         errorf(&value->base.source_position,
7384                                         "operand of delete must have pointer type");
7385                 }
7386         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7387                 source_position_t const *const pos = &value->base.source_position;
7388                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7389         }
7390
7391         return result;
7392 }
7393
7394 /**
7395  * Parse a throw expression
7396  * ISO/IEC 14882:1998(E) §15:1
7397  */
7398 static expression_t *parse_throw(void)
7399 {
7400         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7401         result->base.type          = type_void;
7402
7403         eat(T_throw);
7404
7405         expression_t *value = NULL;
7406         switch (token.kind) {
7407                 EXPRESSION_START {
7408                         value = parse_assignment_expression();
7409                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7410                         type_t *const orig_type = value->base.type;
7411                         type_t *const type      = skip_typeref(orig_type);
7412                         if (is_type_incomplete(type)) {
7413                                 errorf(&value->base.source_position,
7414                                                 "cannot throw object of incomplete type '%T'", orig_type);
7415                         } else if (is_type_pointer(type)) {
7416                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7417                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7418                                         errorf(&value->base.source_position,
7419                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7420                                 }
7421                         }
7422                 }
7423
7424                 default:
7425                         break;
7426         }
7427         result->unary.value = value;
7428
7429         return result;
7430 }
7431
7432 static bool check_pointer_arithmetic(const source_position_t *source_position,
7433                                      type_t *pointer_type,
7434                                      type_t *orig_pointer_type)
7435 {
7436         type_t *points_to = pointer_type->pointer.points_to;
7437         points_to = skip_typeref(points_to);
7438
7439         if (is_type_incomplete(points_to)) {
7440                 if (!GNU_MODE || !is_type_void(points_to)) {
7441                         errorf(source_position,
7442                                "arithmetic with pointer to incomplete type '%T' not allowed",
7443                                orig_pointer_type);
7444                         return false;
7445                 } else {
7446                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7447                 }
7448         } else if (is_type_function(points_to)) {
7449                 if (!GNU_MODE) {
7450                         errorf(source_position,
7451                                "arithmetic with pointer to function type '%T' not allowed",
7452                                orig_pointer_type);
7453                         return false;
7454                 } else {
7455                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7456                 }
7457         }
7458         return true;
7459 }
7460
7461 static bool is_lvalue(const expression_t *expression)
7462 {
7463         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7464         switch (expression->kind) {
7465         case EXPR_ARRAY_ACCESS:
7466         case EXPR_COMPOUND_LITERAL:
7467         case EXPR_REFERENCE:
7468         case EXPR_SELECT:
7469         case EXPR_UNARY_DEREFERENCE:
7470                 return true;
7471
7472         default: {
7473                 type_t *type = skip_typeref(expression->base.type);
7474                 return
7475                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7476                         is_type_reference(type) ||
7477                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7478                          * error before, which maybe prevented properly recognizing it as
7479                          * lvalue. */
7480                         !is_type_valid(type);
7481         }
7482         }
7483 }
7484
7485 static void semantic_incdec(unary_expression_t *expression)
7486 {
7487         type_t *const orig_type = expression->value->base.type;
7488         type_t *const type      = skip_typeref(orig_type);
7489         if (is_type_pointer(type)) {
7490                 if (!check_pointer_arithmetic(&expression->base.source_position,
7491                                               type, orig_type)) {
7492                         return;
7493                 }
7494         } else if (!is_type_real(type) && is_type_valid(type)) {
7495                 /* TODO: improve error message */
7496                 errorf(&expression->base.source_position,
7497                        "operation needs an arithmetic or pointer type");
7498                 return;
7499         }
7500         if (!is_lvalue(expression->value)) {
7501                 /* TODO: improve error message */
7502                 errorf(&expression->base.source_position, "lvalue required as operand");
7503         }
7504         expression->base.type = orig_type;
7505 }
7506
7507 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7508 {
7509         type_t *const res_type = promote_integer(type);
7510         expr->base.type = res_type;
7511         expr->value     = create_implicit_cast(expr->value, res_type);
7512 }
7513
7514 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7515 {
7516         type_t *const orig_type = expression->value->base.type;
7517         type_t *const type      = skip_typeref(orig_type);
7518         if (!is_type_arithmetic(type)) {
7519                 if (is_type_valid(type)) {
7520                         /* TODO: improve error message */
7521                         errorf(&expression->base.source_position,
7522                                 "operation needs an arithmetic type");
7523                 }
7524                 return;
7525         } else if (is_type_integer(type)) {
7526                 promote_unary_int_expr(expression, type);
7527         } else {
7528                 expression->base.type = orig_type;
7529         }
7530 }
7531
7532 static void semantic_unexpr_plus(unary_expression_t *expression)
7533 {
7534         semantic_unexpr_arithmetic(expression);
7535         source_position_t const *const pos = &expression->base.source_position;
7536         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7537 }
7538
7539 static void semantic_not(unary_expression_t *expression)
7540 {
7541         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7542         semantic_condition(expression->value, "operand of !");
7543         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7544 }
7545
7546 static void semantic_unexpr_integer(unary_expression_t *expression)
7547 {
7548         type_t *const orig_type = expression->value->base.type;
7549         type_t *const type      = skip_typeref(orig_type);
7550         if (!is_type_integer(type)) {
7551                 if (is_type_valid(type)) {
7552                         errorf(&expression->base.source_position,
7553                                "operand of ~ must be of integer type");
7554                 }
7555                 return;
7556         }
7557
7558         promote_unary_int_expr(expression, type);
7559 }
7560
7561 static void semantic_dereference(unary_expression_t *expression)
7562 {
7563         type_t *const orig_type = expression->value->base.type;
7564         type_t *const type      = skip_typeref(orig_type);
7565         if (!is_type_pointer(type)) {
7566                 if (is_type_valid(type)) {
7567                         errorf(&expression->base.source_position,
7568                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7569                 }
7570                 return;
7571         }
7572
7573         type_t *result_type   = type->pointer.points_to;
7574         result_type           = automatic_type_conversion(result_type);
7575         expression->base.type = result_type;
7576 }
7577
7578 /**
7579  * Record that an address is taken (expression represents an lvalue).
7580  *
7581  * @param expression       the expression
7582  * @param may_be_register  if true, the expression might be an register
7583  */
7584 static void set_address_taken(expression_t *expression, bool may_be_register)
7585 {
7586         if (expression->kind != EXPR_REFERENCE)
7587                 return;
7588
7589         entity_t *const entity = expression->reference.entity;
7590
7591         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7592                 return;
7593
7594         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7595                         && !may_be_register) {
7596                 source_position_t const *const pos = &expression->base.source_position;
7597                 errorf(pos, "address of register '%N' requested", entity);
7598         }
7599
7600         entity->variable.address_taken = true;
7601 }
7602
7603 /**
7604  * Check the semantic of the address taken expression.
7605  */
7606 static void semantic_take_addr(unary_expression_t *expression)
7607 {
7608         expression_t *value = expression->value;
7609         value->base.type    = revert_automatic_type_conversion(value);
7610
7611         type_t *orig_type = value->base.type;
7612         type_t *type      = skip_typeref(orig_type);
7613         if (!is_type_valid(type))
7614                 return;
7615
7616         /* §6.5.3.2 */
7617         if (!is_lvalue(value)) {
7618                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7619         }
7620         if (is_bitfield(value)) {
7621                 errorf(&expression->base.source_position,
7622                        "'&' not allowed on bitfield");
7623         }
7624
7625         set_address_taken(value, false);
7626
7627         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7628 }
7629
7630 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7631 static expression_t *parse_##unexpression_type(void)                         \
7632 {                                                                            \
7633         expression_t *unary_expression                                           \
7634                 = allocate_expression_zero(unexpression_type);                       \
7635         eat(token_kind);                                                         \
7636         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7637                                                                                  \
7638         sfunc(&unary_expression->unary);                                         \
7639                                                                                  \
7640         return unary_expression;                                                 \
7641 }
7642
7643 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7644                                semantic_unexpr_arithmetic)
7645 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7646                                semantic_unexpr_plus)
7647 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7648                                semantic_not)
7649 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7650                                semantic_dereference)
7651 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7652                                semantic_take_addr)
7653 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7654                                semantic_unexpr_integer)
7655 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7656                                semantic_incdec)
7657 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7658                                semantic_incdec)
7659
7660 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7661                                                sfunc)                         \
7662 static expression_t *parse_##unexpression_type(expression_t *left)            \
7663 {                                                                             \
7664         expression_t *unary_expression                                            \
7665                 = allocate_expression_zero(unexpression_type);                        \
7666         eat(token_kind);                                                          \
7667         unary_expression->unary.value = left;                                     \
7668                                                                                   \
7669         sfunc(&unary_expression->unary);                                          \
7670                                                                               \
7671         return unary_expression;                                                  \
7672 }
7673
7674 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7675                                        EXPR_UNARY_POSTFIX_INCREMENT,
7676                                        semantic_incdec)
7677 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7678                                        EXPR_UNARY_POSTFIX_DECREMENT,
7679                                        semantic_incdec)
7680
7681 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7682 {
7683         /* TODO: handle complex + imaginary types */
7684
7685         type_left  = get_unqualified_type(type_left);
7686         type_right = get_unqualified_type(type_right);
7687
7688         /* §6.3.1.8 Usual arithmetic conversions */
7689         if (type_left == type_long_double || type_right == type_long_double) {
7690                 return type_long_double;
7691         } else if (type_left == type_double || type_right == type_double) {
7692                 return type_double;
7693         } else if (type_left == type_float || type_right == type_float) {
7694                 return type_float;
7695         }
7696
7697         type_left  = promote_integer(type_left);
7698         type_right = promote_integer(type_right);
7699
7700         if (type_left == type_right)
7701                 return type_left;
7702
7703         bool     const signed_left  = is_type_signed(type_left);
7704         bool     const signed_right = is_type_signed(type_right);
7705         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7706         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7707
7708         if (signed_left == signed_right)
7709                 return rank_left >= rank_right ? type_left : type_right;
7710
7711         unsigned           s_rank;
7712         unsigned           u_rank;
7713         atomic_type_kind_t s_akind;
7714         atomic_type_kind_t u_akind;
7715         type_t *s_type;
7716         type_t *u_type;
7717         if (signed_left) {
7718                 s_type = type_left;
7719                 u_type = type_right;
7720         } else {
7721                 s_type = type_right;
7722                 u_type = type_left;
7723         }
7724         s_akind = get_akind(s_type);
7725         u_akind = get_akind(u_type);
7726         s_rank  = get_akind_rank(s_akind);
7727         u_rank  = get_akind_rank(u_akind);
7728
7729         if (u_rank >= s_rank)
7730                 return u_type;
7731
7732         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7733                 return s_type;
7734
7735         switch (s_akind) {
7736         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7737         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7738         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7739
7740         default: panic("invalid atomic type");
7741         }
7742 }
7743
7744 /**
7745  * Check the semantic restrictions for a binary expression.
7746  */
7747 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7748 {
7749         expression_t *const left            = expression->left;
7750         expression_t *const right           = expression->right;
7751         type_t       *const orig_type_left  = left->base.type;
7752         type_t       *const orig_type_right = right->base.type;
7753         type_t       *const type_left       = skip_typeref(orig_type_left);
7754         type_t       *const type_right      = skip_typeref(orig_type_right);
7755
7756         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7757                 /* TODO: improve error message */
7758                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7759                         errorf(&expression->base.source_position,
7760                                "operation needs arithmetic types");
7761                 }
7762                 return;
7763         }
7764
7765         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7766         expression->left      = create_implicit_cast(left, arithmetic_type);
7767         expression->right     = create_implicit_cast(right, arithmetic_type);
7768         expression->base.type = arithmetic_type;
7769 }
7770
7771 static void semantic_binexpr_integer(binary_expression_t *const expression)
7772 {
7773         expression_t *const left            = expression->left;
7774         expression_t *const right           = expression->right;
7775         type_t       *const orig_type_left  = left->base.type;
7776         type_t       *const orig_type_right = right->base.type;
7777         type_t       *const type_left       = skip_typeref(orig_type_left);
7778         type_t       *const type_right      = skip_typeref(orig_type_right);
7779
7780         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7781                 /* TODO: improve error message */
7782                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7783                         errorf(&expression->base.source_position,
7784                                "operation needs integer types");
7785                 }
7786                 return;
7787         }
7788
7789         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7790         expression->left      = create_implicit_cast(left, result_type);
7791         expression->right     = create_implicit_cast(right, result_type);
7792         expression->base.type = result_type;
7793 }
7794
7795 static void warn_div_by_zero(binary_expression_t const *const expression)
7796 {
7797         if (!is_type_integer(expression->base.type))
7798                 return;
7799
7800         expression_t const *const right = expression->right;
7801         /* The type of the right operand can be different for /= */
7802         if (is_type_integer(right->base.type)                    &&
7803             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7804             !fold_constant_to_bool(right)) {
7805                 source_position_t const *const pos = &expression->base.source_position;
7806                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7807         }
7808 }
7809
7810 /**
7811  * Check the semantic restrictions for a div/mod expression.
7812  */
7813 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7814 {
7815         semantic_binexpr_arithmetic(expression);
7816         warn_div_by_zero(expression);
7817 }
7818
7819 static void warn_addsub_in_shift(const expression_t *const expr)
7820 {
7821         if (expr->base.parenthesized)
7822                 return;
7823
7824         char op;
7825         switch (expr->kind) {
7826                 case EXPR_BINARY_ADD: op = '+'; break;
7827                 case EXPR_BINARY_SUB: op = '-'; break;
7828                 default:              return;
7829         }
7830
7831         source_position_t const *const pos = &expr->base.source_position;
7832         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7833 }
7834
7835 static bool semantic_shift(binary_expression_t *expression)
7836 {
7837         expression_t *const left            = expression->left;
7838         expression_t *const right           = expression->right;
7839         type_t       *const orig_type_left  = left->base.type;
7840         type_t       *const orig_type_right = right->base.type;
7841         type_t       *      type_left       = skip_typeref(orig_type_left);
7842         type_t       *      type_right      = skip_typeref(orig_type_right);
7843
7844         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7845                 /* TODO: improve error message */
7846                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7847                         errorf(&expression->base.source_position,
7848                                "operands of shift operation must have integer types");
7849                 }
7850                 return false;
7851         }
7852
7853         type_left = promote_integer(type_left);
7854
7855         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7856                 source_position_t const *const pos   = &right->base.source_position;
7857                 long                     const count = fold_constant_to_int(right);
7858                 if (count < 0) {
7859                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7860                 } else if ((unsigned long)count >=
7861                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7862                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7863                 }
7864         }
7865
7866         type_right        = promote_integer(type_right);
7867         expression->right = create_implicit_cast(right, type_right);
7868
7869         return true;
7870 }
7871
7872 static void semantic_shift_op(binary_expression_t *expression)
7873 {
7874         expression_t *const left  = expression->left;
7875         expression_t *const right = expression->right;
7876
7877         if (!semantic_shift(expression))
7878                 return;
7879
7880         warn_addsub_in_shift(left);
7881         warn_addsub_in_shift(right);
7882
7883         type_t *const orig_type_left = left->base.type;
7884         type_t *      type_left      = skip_typeref(orig_type_left);
7885
7886         type_left             = promote_integer(type_left);
7887         expression->left      = create_implicit_cast(left, type_left);
7888         expression->base.type = type_left;
7889 }
7890
7891 static void semantic_add(binary_expression_t *expression)
7892 {
7893         expression_t *const left            = expression->left;
7894         expression_t *const right           = expression->right;
7895         type_t       *const orig_type_left  = left->base.type;
7896         type_t       *const orig_type_right = right->base.type;
7897         type_t       *const type_left       = skip_typeref(orig_type_left);
7898         type_t       *const type_right      = skip_typeref(orig_type_right);
7899
7900         /* §6.5.6 */
7901         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7902                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7903                 expression->left  = create_implicit_cast(left, arithmetic_type);
7904                 expression->right = create_implicit_cast(right, arithmetic_type);
7905                 expression->base.type = arithmetic_type;
7906         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7907                 check_pointer_arithmetic(&expression->base.source_position,
7908                                          type_left, orig_type_left);
7909                 expression->base.type = type_left;
7910         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7911                 check_pointer_arithmetic(&expression->base.source_position,
7912                                          type_right, orig_type_right);
7913                 expression->base.type = type_right;
7914         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7915                 errorf(&expression->base.source_position,
7916                        "invalid operands to binary + ('%T', '%T')",
7917                        orig_type_left, orig_type_right);
7918         }
7919 }
7920
7921 static void semantic_sub(binary_expression_t *expression)
7922 {
7923         expression_t            *const left            = expression->left;
7924         expression_t            *const right           = expression->right;
7925         type_t                  *const orig_type_left  = left->base.type;
7926         type_t                  *const orig_type_right = right->base.type;
7927         type_t                  *const type_left       = skip_typeref(orig_type_left);
7928         type_t                  *const type_right      = skip_typeref(orig_type_right);
7929         source_position_t const *const pos             = &expression->base.source_position;
7930
7931         /* §5.6.5 */
7932         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7933                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7934                 expression->left        = create_implicit_cast(left, arithmetic_type);
7935                 expression->right       = create_implicit_cast(right, arithmetic_type);
7936                 expression->base.type =  arithmetic_type;
7937         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7938                 check_pointer_arithmetic(&expression->base.source_position,
7939                                          type_left, orig_type_left);
7940                 expression->base.type = type_left;
7941         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7942                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7943                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7944                 if (!types_compatible(unqual_left, unqual_right)) {
7945                         errorf(pos,
7946                                "subtracting pointers to incompatible types '%T' and '%T'",
7947                                orig_type_left, orig_type_right);
7948                 } else if (!is_type_object(unqual_left)) {
7949                         if (!is_type_void(unqual_left)) {
7950                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7951                                        orig_type_left);
7952                         } else {
7953                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7954                         }
7955                 }
7956                 expression->base.type = type_ptrdiff_t;
7957         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7958                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7959                        orig_type_left, orig_type_right);
7960         }
7961 }
7962
7963 static void warn_string_literal_address(expression_t const* expr)
7964 {
7965         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7966                 expr = expr->unary.value;
7967                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7968                         return;
7969                 expr = expr->unary.value;
7970         }
7971
7972         if (expr->kind == EXPR_STRING_LITERAL) {
7973                 source_position_t const *const pos = &expr->base.source_position;
7974                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
7975         }
7976 }
7977
7978 static bool maybe_negative(expression_t const *const expr)
7979 {
7980         switch (is_constant_expression(expr)) {
7981                 case EXPR_CLASS_ERROR:    return false;
7982                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
7983                 default:                  return true;
7984         }
7985 }
7986
7987 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
7988 {
7989         warn_string_literal_address(expr);
7990
7991         expression_t const* const ref = get_reference_address(expr);
7992         if (ref != NULL && is_null_pointer_constant(other)) {
7993                 entity_t const *const ent = ref->reference.entity;
7994                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
7995         }
7996
7997         if (!expr->base.parenthesized) {
7998                 switch (expr->base.kind) {
7999                         case EXPR_BINARY_LESS:
8000                         case EXPR_BINARY_GREATER:
8001                         case EXPR_BINARY_LESSEQUAL:
8002                         case EXPR_BINARY_GREATEREQUAL:
8003                         case EXPR_BINARY_NOTEQUAL:
8004                         case EXPR_BINARY_EQUAL:
8005                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8006                                 break;
8007                         default:
8008                                 break;
8009                 }
8010         }
8011 }
8012
8013 /**
8014  * Check the semantics of comparison expressions.
8015  *
8016  * @param expression   The expression to check.
8017  */
8018 static void semantic_comparison(binary_expression_t *expression)
8019 {
8020         source_position_t const *const pos   = &expression->base.source_position;
8021         expression_t            *const left  = expression->left;
8022         expression_t            *const right = expression->right;
8023
8024         warn_comparison(pos, left, right);
8025         warn_comparison(pos, right, left);
8026
8027         type_t *orig_type_left  = left->base.type;
8028         type_t *orig_type_right = right->base.type;
8029         type_t *type_left       = skip_typeref(orig_type_left);
8030         type_t *type_right      = skip_typeref(orig_type_right);
8031
8032         /* TODO non-arithmetic types */
8033         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8034                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8035
8036                 /* test for signed vs unsigned compares */
8037                 if (is_type_integer(arithmetic_type)) {
8038                         bool const signed_left  = is_type_signed(type_left);
8039                         bool const signed_right = is_type_signed(type_right);
8040                         if (signed_left != signed_right) {
8041                                 /* FIXME long long needs better const folding magic */
8042                                 /* TODO check whether constant value can be represented by other type */
8043                                 if ((signed_left  && maybe_negative(left)) ||
8044                                                 (signed_right && maybe_negative(right))) {
8045                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8046                                 }
8047                         }
8048                 }
8049
8050                 expression->left        = create_implicit_cast(left, arithmetic_type);
8051                 expression->right       = create_implicit_cast(right, arithmetic_type);
8052                 expression->base.type   = arithmetic_type;
8053                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8054                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8055                     is_type_float(arithmetic_type)) {
8056                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8057                 }
8058         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8059                 /* TODO check compatibility */
8060         } else if (is_type_pointer(type_left)) {
8061                 expression->right = create_implicit_cast(right, type_left);
8062         } else if (is_type_pointer(type_right)) {
8063                 expression->left = create_implicit_cast(left, type_right);
8064         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8065                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8066         }
8067         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8068 }
8069
8070 /**
8071  * Checks if a compound type has constant fields.
8072  */
8073 static bool has_const_fields(const compound_type_t *type)
8074 {
8075         compound_t *compound = type->compound;
8076         entity_t   *entry    = compound->members.entities;
8077
8078         for (; entry != NULL; entry = entry->base.next) {
8079                 if (!is_declaration(entry))
8080                         continue;
8081
8082                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8083                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8084                         return true;
8085         }
8086
8087         return false;
8088 }
8089
8090 static bool is_valid_assignment_lhs(expression_t const* const left)
8091 {
8092         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8093         type_t *const type_left      = skip_typeref(orig_type_left);
8094
8095         if (!is_lvalue(left)) {
8096                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8097                        left);
8098                 return false;
8099         }
8100
8101         if (left->kind == EXPR_REFERENCE
8102                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8103                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8104                 return false;
8105         }
8106
8107         if (is_type_array(type_left)) {
8108                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8109                 return false;
8110         }
8111         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8112                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8113                        orig_type_left);
8114                 return false;
8115         }
8116         if (is_type_incomplete(type_left)) {
8117                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8118                        left, orig_type_left);
8119                 return false;
8120         }
8121         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8122                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8123                        left, orig_type_left);
8124                 return false;
8125         }
8126
8127         return true;
8128 }
8129
8130 static void semantic_arithmetic_assign(binary_expression_t *expression)
8131 {
8132         expression_t *left            = expression->left;
8133         expression_t *right           = expression->right;
8134         type_t       *orig_type_left  = left->base.type;
8135         type_t       *orig_type_right = right->base.type;
8136
8137         if (!is_valid_assignment_lhs(left))
8138                 return;
8139
8140         type_t *type_left  = skip_typeref(orig_type_left);
8141         type_t *type_right = skip_typeref(orig_type_right);
8142
8143         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8144                 /* TODO: improve error message */
8145                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8146                         errorf(&expression->base.source_position,
8147                                "operation needs arithmetic types");
8148                 }
8149                 return;
8150         }
8151
8152         /* combined instructions are tricky. We can't create an implicit cast on
8153          * the left side, because we need the uncasted form for the store.
8154          * The ast2firm pass has to know that left_type must be right_type
8155          * for the arithmetic operation and create a cast by itself */
8156         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8157         expression->right       = create_implicit_cast(right, arithmetic_type);
8158         expression->base.type   = type_left;
8159 }
8160
8161 static void semantic_divmod_assign(binary_expression_t *expression)
8162 {
8163         semantic_arithmetic_assign(expression);
8164         warn_div_by_zero(expression);
8165 }
8166
8167 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8168 {
8169         expression_t *const left            = expression->left;
8170         expression_t *const right           = expression->right;
8171         type_t       *const orig_type_left  = left->base.type;
8172         type_t       *const orig_type_right = right->base.type;
8173         type_t       *const type_left       = skip_typeref(orig_type_left);
8174         type_t       *const type_right      = skip_typeref(orig_type_right);
8175
8176         if (!is_valid_assignment_lhs(left))
8177                 return;
8178
8179         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8180                 /* combined instructions are tricky. We can't create an implicit cast on
8181                  * the left side, because we need the uncasted form for the store.
8182                  * The ast2firm pass has to know that left_type must be right_type
8183                  * for the arithmetic operation and create a cast by itself */
8184                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8185                 expression->right     = create_implicit_cast(right, arithmetic_type);
8186                 expression->base.type = type_left;
8187         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8188                 check_pointer_arithmetic(&expression->base.source_position,
8189                                          type_left, orig_type_left);
8190                 expression->base.type = type_left;
8191         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8192                 errorf(&expression->base.source_position,
8193                        "incompatible types '%T' and '%T' in assignment",
8194                        orig_type_left, orig_type_right);
8195         }
8196 }
8197
8198 static void semantic_integer_assign(binary_expression_t *expression)
8199 {
8200         expression_t *left            = expression->left;
8201         expression_t *right           = expression->right;
8202         type_t       *orig_type_left  = left->base.type;
8203         type_t       *orig_type_right = right->base.type;
8204
8205         if (!is_valid_assignment_lhs(left))
8206                 return;
8207
8208         type_t *type_left  = skip_typeref(orig_type_left);
8209         type_t *type_right = skip_typeref(orig_type_right);
8210
8211         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8212                 /* TODO: improve error message */
8213                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8214                         errorf(&expression->base.source_position,
8215                                "operation needs integer types");
8216                 }
8217                 return;
8218         }
8219
8220         /* combined instructions are tricky. We can't create an implicit cast on
8221          * the left side, because we need the uncasted form for the store.
8222          * The ast2firm pass has to know that left_type must be right_type
8223          * for the arithmetic operation and create a cast by itself */
8224         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8225         expression->right       = create_implicit_cast(right, arithmetic_type);
8226         expression->base.type   = type_left;
8227 }
8228
8229 static void semantic_shift_assign(binary_expression_t *expression)
8230 {
8231         expression_t *left           = expression->left;
8232
8233         if (!is_valid_assignment_lhs(left))
8234                 return;
8235
8236         if (!semantic_shift(expression))
8237                 return;
8238
8239         expression->base.type = skip_typeref(left->base.type);
8240 }
8241
8242 static void warn_logical_and_within_or(const expression_t *const expr)
8243 {
8244         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8245                 return;
8246         if (expr->base.parenthesized)
8247                 return;
8248         source_position_t const *const pos = &expr->base.source_position;
8249         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8250 }
8251
8252 /**
8253  * Check the semantic restrictions of a logical expression.
8254  */
8255 static void semantic_logical_op(binary_expression_t *expression)
8256 {
8257         /* §6.5.13:2  Each of the operands shall have scalar type.
8258          * §6.5.14:2  Each of the operands shall have scalar type. */
8259         semantic_condition(expression->left,   "left operand of logical operator");
8260         semantic_condition(expression->right, "right operand of logical operator");
8261         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8262                 warn_logical_and_within_or(expression->left);
8263                 warn_logical_and_within_or(expression->right);
8264         }
8265         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8266 }
8267
8268 /**
8269  * Check the semantic restrictions of a binary assign expression.
8270  */
8271 static void semantic_binexpr_assign(binary_expression_t *expression)
8272 {
8273         expression_t *left           = expression->left;
8274         type_t       *orig_type_left = left->base.type;
8275
8276         if (!is_valid_assignment_lhs(left))
8277                 return;
8278
8279         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8280         report_assign_error(error, orig_type_left, expression->right,
8281                         "assignment", &left->base.source_position);
8282         expression->right = create_implicit_cast(expression->right, orig_type_left);
8283         expression->base.type = orig_type_left;
8284 }
8285
8286 /**
8287  * Determine if the outermost operation (or parts thereof) of the given
8288  * expression has no effect in order to generate a warning about this fact.
8289  * Therefore in some cases this only examines some of the operands of the
8290  * expression (see comments in the function and examples below).
8291  * Examples:
8292  *   f() + 23;    // warning, because + has no effect
8293  *   x || f();    // no warning, because x controls execution of f()
8294  *   x ? y : f(); // warning, because y has no effect
8295  *   (void)x;     // no warning to be able to suppress the warning
8296  * This function can NOT be used for an "expression has definitely no effect"-
8297  * analysis. */
8298 static bool expression_has_effect(const expression_t *const expr)
8299 {
8300         switch (expr->kind) {
8301                 case EXPR_ERROR:                      return true; /* do NOT warn */
8302                 case EXPR_REFERENCE:                  return false;
8303                 case EXPR_ENUM_CONSTANT:              return false;
8304                 case EXPR_LABEL_ADDRESS:              return false;
8305
8306                 /* suppress the warning for microsoft __noop operations */
8307                 case EXPR_LITERAL_MS_NOOP:            return true;
8308                 case EXPR_LITERAL_BOOLEAN:
8309                 case EXPR_LITERAL_CHARACTER:
8310                 case EXPR_LITERAL_WIDE_CHARACTER:
8311                 case EXPR_LITERAL_INTEGER:
8312                 case EXPR_LITERAL_FLOATINGPOINT:
8313                 case EXPR_STRING_LITERAL:             return false;
8314
8315                 case EXPR_CALL: {
8316                         const call_expression_t *const call = &expr->call;
8317                         if (call->function->kind != EXPR_REFERENCE)
8318                                 return true;
8319
8320                         switch (call->function->reference.entity->function.btk) {
8321                                 /* FIXME: which builtins have no effect? */
8322                                 default:                      return true;
8323                         }
8324                 }
8325
8326                 /* Generate the warning if either the left or right hand side of a
8327                  * conditional expression has no effect */
8328                 case EXPR_CONDITIONAL: {
8329                         conditional_expression_t const *const cond = &expr->conditional;
8330                         expression_t             const *const t    = cond->true_expression;
8331                         return
8332                                 (t == NULL || expression_has_effect(t)) &&
8333                                 expression_has_effect(cond->false_expression);
8334                 }
8335
8336                 case EXPR_SELECT:                     return false;
8337                 case EXPR_ARRAY_ACCESS:               return false;
8338                 case EXPR_SIZEOF:                     return false;
8339                 case EXPR_CLASSIFY_TYPE:              return false;
8340                 case EXPR_ALIGNOF:                    return false;
8341
8342                 case EXPR_FUNCNAME:                   return false;
8343                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8344                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8345                 case EXPR_OFFSETOF:                   return false;
8346                 case EXPR_VA_START:                   return true;
8347                 case EXPR_VA_ARG:                     return true;
8348                 case EXPR_VA_COPY:                    return true;
8349                 case EXPR_STATEMENT:                  return true; // TODO
8350                 case EXPR_COMPOUND_LITERAL:           return false;
8351
8352                 case EXPR_UNARY_NEGATE:               return false;
8353                 case EXPR_UNARY_PLUS:                 return false;
8354                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8355                 case EXPR_UNARY_NOT:                  return false;
8356                 case EXPR_UNARY_DEREFERENCE:          return false;
8357                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8358                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8359                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8360                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8361                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8362
8363                 /* Treat void casts as if they have an effect in order to being able to
8364                  * suppress the warning */
8365                 case EXPR_UNARY_CAST: {
8366                         type_t *const type = skip_typeref(expr->base.type);
8367                         return is_type_void(type);
8368                 }
8369
8370                 case EXPR_UNARY_ASSUME:               return true;
8371                 case EXPR_UNARY_DELETE:               return true;
8372                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8373                 case EXPR_UNARY_THROW:                return true;
8374
8375                 case EXPR_BINARY_ADD:                 return false;
8376                 case EXPR_BINARY_SUB:                 return false;
8377                 case EXPR_BINARY_MUL:                 return false;
8378                 case EXPR_BINARY_DIV:                 return false;
8379                 case EXPR_BINARY_MOD:                 return false;
8380                 case EXPR_BINARY_EQUAL:               return false;
8381                 case EXPR_BINARY_NOTEQUAL:            return false;
8382                 case EXPR_BINARY_LESS:                return false;
8383                 case EXPR_BINARY_LESSEQUAL:           return false;
8384                 case EXPR_BINARY_GREATER:             return false;
8385                 case EXPR_BINARY_GREATEREQUAL:        return false;
8386                 case EXPR_BINARY_BITWISE_AND:         return false;
8387                 case EXPR_BINARY_BITWISE_OR:          return false;
8388                 case EXPR_BINARY_BITWISE_XOR:         return false;
8389                 case EXPR_BINARY_SHIFTLEFT:           return false;
8390                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8391                 case EXPR_BINARY_ASSIGN:              return true;
8392                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8393                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8394                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8395                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8396                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8397                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8398                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8399                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8400                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8401                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8402
8403                 /* Only examine the right hand side of && and ||, because the left hand
8404                  * side already has the effect of controlling the execution of the right
8405                  * hand side */
8406                 case EXPR_BINARY_LOGICAL_AND:
8407                 case EXPR_BINARY_LOGICAL_OR:
8408                 /* Only examine the right hand side of a comma expression, because the left
8409                  * hand side has a separate warning */
8410                 case EXPR_BINARY_COMMA:
8411                         return expression_has_effect(expr->binary.right);
8412
8413                 case EXPR_BINARY_ISGREATER:           return false;
8414                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8415                 case EXPR_BINARY_ISLESS:              return false;
8416                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8417                 case EXPR_BINARY_ISLESSGREATER:       return false;
8418                 case EXPR_BINARY_ISUNORDERED:         return false;
8419         }
8420
8421         internal_errorf(HERE, "unexpected expression");
8422 }
8423
8424 static void semantic_comma(binary_expression_t *expression)
8425 {
8426         const expression_t *const left = expression->left;
8427         if (!expression_has_effect(left)) {
8428                 source_position_t const *const pos = &left->base.source_position;
8429                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8430         }
8431         expression->base.type = expression->right->base.type;
8432 }
8433
8434 /**
8435  * @param prec_r precedence of the right operand
8436  */
8437 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8438 static expression_t *parse_##binexpression_type(expression_t *left)          \
8439 {                                                                            \
8440         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8441         binexpr->binary.left  = left;                                            \
8442         eat(token_kind);                                                         \
8443                                                                              \
8444         expression_t *right = parse_subexpression(prec_r);                       \
8445                                                                              \
8446         binexpr->binary.right = right;                                           \
8447         sfunc(&binexpr->binary);                                                 \
8448                                                                              \
8449         return binexpr;                                                          \
8450 }
8451
8452 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8453 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8454 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8455 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8456 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8457 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8458 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8459 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8460 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8461 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8462 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8463 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8464 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8465 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8466 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8467 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8468 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8469 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8470 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8471 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8472 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8473 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8474 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8475 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8476 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8477 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8478 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8479 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8480 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8481 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8482
8483
8484 static expression_t *parse_subexpression(precedence_t precedence)
8485 {
8486         expression_parser_function_t *parser
8487                 = &expression_parsers[token.kind];
8488         expression_t                 *left;
8489
8490         if (parser->parser != NULL) {
8491                 left = parser->parser();
8492         } else {
8493                 left = parse_primary_expression();
8494         }
8495         assert(left != NULL);
8496
8497         while (true) {
8498                 parser = &expression_parsers[token.kind];
8499                 if (parser->infix_parser == NULL)
8500                         break;
8501                 if (parser->infix_precedence < precedence)
8502                         break;
8503
8504                 left = parser->infix_parser(left);
8505
8506                 assert(left != NULL);
8507         }
8508
8509         return left;
8510 }
8511
8512 /**
8513  * Parse an expression.
8514  */
8515 static expression_t *parse_expression(void)
8516 {
8517         return parse_subexpression(PREC_EXPRESSION);
8518 }
8519
8520 /**
8521  * Register a parser for a prefix-like operator.
8522  *
8523  * @param parser      the parser function
8524  * @param token_kind  the token type of the prefix token
8525  */
8526 static void register_expression_parser(parse_expression_function parser,
8527                                        int token_kind)
8528 {
8529         expression_parser_function_t *entry = &expression_parsers[token_kind];
8530
8531         if (entry->parser != NULL) {
8532                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8533                 panic("trying to register multiple expression parsers for a token");
8534         }
8535         entry->parser = parser;
8536 }
8537
8538 /**
8539  * Register a parser for an infix operator with given precedence.
8540  *
8541  * @param parser      the parser function
8542  * @param token_kind  the token type of the infix operator
8543  * @param precedence  the precedence of the operator
8544  */
8545 static void register_infix_parser(parse_expression_infix_function parser,
8546                                   int token_kind, precedence_t precedence)
8547 {
8548         expression_parser_function_t *entry = &expression_parsers[token_kind];
8549
8550         if (entry->infix_parser != NULL) {
8551                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8552                 panic("trying to register multiple infix expression parsers for a "
8553                       "token");
8554         }
8555         entry->infix_parser     = parser;
8556         entry->infix_precedence = precedence;
8557 }
8558
8559 /**
8560  * Initialize the expression parsers.
8561  */
8562 static void init_expression_parsers(void)
8563 {
8564         memset(&expression_parsers, 0, sizeof(expression_parsers));
8565
8566         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8567         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8568         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8569         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8570         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8571         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8572         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8573         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8574         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8575         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8576         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8577         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8578         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8579         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8580         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8581         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8582         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8583         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8584         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8585         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8586         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8587         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8588         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8589         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8590         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8591         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8592         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8593         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8594         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8595         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8596         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8597         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8598         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8599         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8600         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8601         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8602         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8603
8604         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8605         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8606         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8607         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8608         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8609         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8610         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8611         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8612         register_expression_parser(parse_sizeof,                      T_sizeof);
8613         register_expression_parser(parse_alignof,                     T___alignof__);
8614         register_expression_parser(parse_extension,                   T___extension__);
8615         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8616         register_expression_parser(parse_delete,                      T_delete);
8617         register_expression_parser(parse_throw,                       T_throw);
8618 }
8619
8620 /**
8621  * Parse a asm statement arguments specification.
8622  */
8623 static asm_argument_t *parse_asm_arguments(bool is_out)
8624 {
8625         asm_argument_t  *result = NULL;
8626         asm_argument_t **anchor = &result;
8627
8628         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8629                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8630
8631                 if (next_if('[')) {
8632                         add_anchor_token(']');
8633                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8634                         rem_anchor_token(']');
8635                         expect(']');
8636                         if (!argument->symbol)
8637                                 return NULL;
8638                 }
8639
8640                 argument->constraints = parse_string_literals("asm argument");
8641                 add_anchor_token(')');
8642                 expect('(');
8643                 expression_t *expression = parse_expression();
8644                 rem_anchor_token(')');
8645                 if (is_out) {
8646                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8647                          * change size or type representation (e.g. int -> long is ok, but
8648                          * int -> float is not) */
8649                         if (expression->kind == EXPR_UNARY_CAST) {
8650                                 type_t      *const type = expression->base.type;
8651                                 type_kind_t  const kind = type->kind;
8652                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8653                                         unsigned flags;
8654                                         unsigned size;
8655                                         if (kind == TYPE_ATOMIC) {
8656                                                 atomic_type_kind_t const akind = type->atomic.akind;
8657                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8658                                                 size  = get_atomic_type_size(akind);
8659                                         } else {
8660                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8661                                                 size  = get_type_size(type_void_ptr);
8662                                         }
8663
8664                                         do {
8665                                                 expression_t *const value      = expression->unary.value;
8666                                                 type_t       *const value_type = value->base.type;
8667                                                 type_kind_t   const value_kind = value_type->kind;
8668
8669                                                 unsigned value_flags;
8670                                                 unsigned value_size;
8671                                                 if (value_kind == TYPE_ATOMIC) {
8672                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8673                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8674                                                         value_size  = get_atomic_type_size(value_akind);
8675                                                 } else if (value_kind == TYPE_POINTER) {
8676                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8677                                                         value_size  = get_type_size(type_void_ptr);
8678                                                 } else {
8679                                                         break;
8680                                                 }
8681
8682                                                 if (value_flags != flags || value_size != size)
8683                                                         break;
8684
8685                                                 expression = value;
8686                                         } while (expression->kind == EXPR_UNARY_CAST);
8687                                 }
8688                         }
8689
8690                         if (!is_lvalue(expression)) {
8691                                 errorf(&expression->base.source_position,
8692                                        "asm output argument is not an lvalue");
8693                         }
8694
8695                         if (argument->constraints.begin[0] == '=')
8696                                 determine_lhs_ent(expression, NULL);
8697                         else
8698                                 mark_vars_read(expression, NULL);
8699                 } else {
8700                         mark_vars_read(expression, NULL);
8701                 }
8702                 argument->expression = expression;
8703                 expect(')');
8704
8705                 set_address_taken(expression, true);
8706
8707                 *anchor = argument;
8708                 anchor  = &argument->next;
8709
8710                 if (!next_if(','))
8711                         break;
8712         }
8713
8714         return result;
8715 }
8716
8717 /**
8718  * Parse a asm statement clobber specification.
8719  */
8720 static asm_clobber_t *parse_asm_clobbers(void)
8721 {
8722         asm_clobber_t *result  = NULL;
8723         asm_clobber_t **anchor = &result;
8724
8725         while (token.kind == T_STRING_LITERAL) {
8726                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8727                 clobber->clobber       = parse_string_literals(NULL);
8728
8729                 *anchor = clobber;
8730                 anchor  = &clobber->next;
8731
8732                 if (!next_if(','))
8733                         break;
8734         }
8735
8736         return result;
8737 }
8738
8739 /**
8740  * Parse an asm statement.
8741  */
8742 static statement_t *parse_asm_statement(void)
8743 {
8744         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8745         asm_statement_t *asm_statement = &statement->asms;
8746
8747         eat(T_asm);
8748         add_anchor_token(')');
8749         add_anchor_token(':');
8750         add_anchor_token(T_STRING_LITERAL);
8751
8752         if (next_if(T_volatile))
8753                 asm_statement->is_volatile = true;
8754
8755         expect('(');
8756         rem_anchor_token(T_STRING_LITERAL);
8757         asm_statement->asm_text = parse_string_literals("asm statement");
8758
8759         if (next_if(':'))
8760                 asm_statement->outputs = parse_asm_arguments(true);
8761
8762         if (next_if(':'))
8763                 asm_statement->inputs = parse_asm_arguments(false);
8764
8765         rem_anchor_token(':');
8766         if (next_if(':'))
8767                 asm_statement->clobbers = parse_asm_clobbers();
8768
8769         rem_anchor_token(')');
8770         expect(')');
8771         expect(';');
8772
8773         if (asm_statement->outputs == NULL) {
8774                 /* GCC: An 'asm' instruction without any output operands will be treated
8775                  * identically to a volatile 'asm' instruction. */
8776                 asm_statement->is_volatile = true;
8777         }
8778
8779         return statement;
8780 }
8781
8782 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8783 {
8784         statement_t *inner_stmt;
8785         switch (token.kind) {
8786                 case '}':
8787                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8788                         inner_stmt = create_error_statement();
8789                         break;
8790
8791                 case ';':
8792                         if (label->kind == STATEMENT_LABEL) {
8793                                 /* Eat an empty statement here, to avoid the warning about an empty
8794                                  * statement after a label.  label:; is commonly used to have a label
8795                                  * before a closing brace. */
8796                                 inner_stmt = create_empty_statement();
8797                                 eat(';');
8798                                 break;
8799                         }
8800                         /* FALLTHROUGH */
8801
8802                 default:
8803                         inner_stmt = parse_statement();
8804                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8805                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8806                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8807                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8808                         }
8809                         break;
8810         }
8811         return inner_stmt;
8812 }
8813
8814 /**
8815  * Parse a case statement.
8816  */
8817 static statement_t *parse_case_statement(void)
8818 {
8819         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8820         source_position_t *const pos       = &statement->base.source_position;
8821
8822         eat(T_case);
8823         add_anchor_token(':');
8824
8825         expression_t *expression = parse_expression();
8826         type_t *expression_type = expression->base.type;
8827         type_t *skipped         = skip_typeref(expression_type);
8828         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8829                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8830                        expression, expression_type);
8831         }
8832
8833         type_t *type = expression_type;
8834         if (current_switch != NULL) {
8835                 type_t *switch_type = current_switch->expression->base.type;
8836                 if (is_type_valid(switch_type)) {
8837                         expression = create_implicit_cast(expression, switch_type);
8838                 }
8839         }
8840
8841         statement->case_label.expression = expression;
8842         expression_classification_t const expr_class = is_constant_expression(expression);
8843         if (expr_class != EXPR_CLASS_CONSTANT) {
8844                 if (expr_class != EXPR_CLASS_ERROR) {
8845                         errorf(pos, "case label does not reduce to an integer constant");
8846                 }
8847                 statement->case_label.is_bad = true;
8848         } else {
8849                 long const val = fold_constant_to_int(expression);
8850                 statement->case_label.first_case = val;
8851                 statement->case_label.last_case  = val;
8852         }
8853
8854         if (GNU_MODE) {
8855                 if (next_if(T_DOTDOTDOT)) {
8856                         expression_t *end_range = parse_expression();
8857                         expression_type = expression->base.type;
8858                         skipped         = skip_typeref(expression_type);
8859                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8860                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8861                                            expression, expression_type);
8862                         }
8863
8864                         end_range = create_implicit_cast(end_range, type);
8865                         statement->case_label.end_range = end_range;
8866                         expression_classification_t const end_class = is_constant_expression(end_range);
8867                         if (end_class != EXPR_CLASS_CONSTANT) {
8868                                 if (end_class != EXPR_CLASS_ERROR) {
8869                                         errorf(pos, "case range does not reduce to an integer constant");
8870                                 }
8871                                 statement->case_label.is_bad = true;
8872                         } else {
8873                                 long const val = fold_constant_to_int(end_range);
8874                                 statement->case_label.last_case = val;
8875
8876                                 if (val < statement->case_label.first_case) {
8877                                         statement->case_label.is_empty_range = true;
8878                                         warningf(WARN_OTHER, pos, "empty range specified");
8879                                 }
8880                         }
8881                 }
8882         }
8883
8884         PUSH_PARENT(statement);
8885
8886         rem_anchor_token(':');
8887         expect(':');
8888
8889         if (current_switch != NULL) {
8890                 if (! statement->case_label.is_bad) {
8891                         /* Check for duplicate case values */
8892                         case_label_statement_t *c = &statement->case_label;
8893                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8894                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8895                                         continue;
8896
8897                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8898                                         continue;
8899
8900                                 errorf(pos, "duplicate case value (previously used %P)",
8901                                        &l->base.source_position);
8902                                 break;
8903                         }
8904                 }
8905                 /* link all cases into the switch statement */
8906                 if (current_switch->last_case == NULL) {
8907                         current_switch->first_case      = &statement->case_label;
8908                 } else {
8909                         current_switch->last_case->next = &statement->case_label;
8910                 }
8911                 current_switch->last_case = &statement->case_label;
8912         } else {
8913                 errorf(pos, "case label not within a switch statement");
8914         }
8915
8916         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8917
8918         POP_PARENT();
8919         return statement;
8920 }
8921
8922 /**
8923  * Parse a default statement.
8924  */
8925 static statement_t *parse_default_statement(void)
8926 {
8927         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8928
8929         eat(T_default);
8930
8931         PUSH_PARENT(statement);
8932
8933         expect(':');
8934
8935         if (current_switch != NULL) {
8936                 const case_label_statement_t *def_label = current_switch->default_label;
8937                 if (def_label != NULL) {
8938                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
8939                 } else {
8940                         current_switch->default_label = &statement->case_label;
8941
8942                         /* link all cases into the switch statement */
8943                         if (current_switch->last_case == NULL) {
8944                                 current_switch->first_case      = &statement->case_label;
8945                         } else {
8946                                 current_switch->last_case->next = &statement->case_label;
8947                         }
8948                         current_switch->last_case = &statement->case_label;
8949                 }
8950         } else {
8951                 errorf(&statement->base.source_position,
8952                         "'default' label not within a switch statement");
8953         }
8954
8955         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8956
8957         POP_PARENT();
8958         return statement;
8959 }
8960
8961 /**
8962  * Parse a label statement.
8963  */
8964 static statement_t *parse_label_statement(void)
8965 {
8966         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
8967         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
8968         statement->label.label = label;
8969
8970         PUSH_PARENT(statement);
8971
8972         /* if statement is already set then the label is defined twice,
8973          * otherwise it was just mentioned in a goto/local label declaration so far
8974          */
8975         source_position_t const* const pos = &statement->base.source_position;
8976         if (label->statement != NULL) {
8977                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
8978         } else {
8979                 label->base.source_position = *pos;
8980                 label->statement            = statement;
8981         }
8982
8983         eat(':');
8984
8985         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
8986                 parse_attributes(NULL); // TODO process attributes
8987         }
8988
8989         statement->label.statement = parse_label_inner_statement(statement, "label");
8990
8991         /* remember the labels in a list for later checking */
8992         *label_anchor = &statement->label;
8993         label_anchor  = &statement->label.next;
8994
8995         POP_PARENT();
8996         return statement;
8997 }
8998
8999 static statement_t *parse_inner_statement(void)
9000 {
9001         statement_t *const stmt = parse_statement();
9002         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9003         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9004         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9005                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9006         }
9007         return stmt;
9008 }
9009
9010 /**
9011  * Parse an expression in parentheses and mark its variables as read.
9012  */
9013 static expression_t *parse_condition(void)
9014 {
9015         add_anchor_token(')');
9016         expect('(');
9017         expression_t *const expr = parse_expression();
9018         mark_vars_read(expr, NULL);
9019         rem_anchor_token(')');
9020         expect(')');
9021         return expr;
9022 }
9023
9024 /**
9025  * Parse an if statement.
9026  */
9027 static statement_t *parse_if(void)
9028 {
9029         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9030
9031         eat(T_if);
9032
9033         PUSH_PARENT(statement);
9034         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9035
9036         add_anchor_token(T_else);
9037
9038         expression_t *const expr = parse_condition();
9039         statement->ifs.condition = expr;
9040         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9041          *             scalar type. */
9042         semantic_condition(expr, "condition of 'if'-statment");
9043
9044         statement_t *const true_stmt = parse_inner_statement();
9045         statement->ifs.true_statement = true_stmt;
9046         rem_anchor_token(T_else);
9047
9048         if (true_stmt->kind == STATEMENT_EMPTY) {
9049                 warningf(WARN_EMPTY_BODY, HERE,
9050                         "suggest braces around empty body in an ‘if’ statement");
9051         }
9052
9053         if (next_if(T_else)) {
9054                 statement->ifs.false_statement = parse_inner_statement();
9055
9056                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9057                         warningf(WARN_EMPTY_BODY, HERE,
9058                                         "suggest braces around empty body in an ‘if’ statement");
9059                 }
9060         } else if (true_stmt->kind == STATEMENT_IF &&
9061                         true_stmt->ifs.false_statement != NULL) {
9062                 source_position_t const *const pos = &true_stmt->base.source_position;
9063                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9064         }
9065
9066         POP_SCOPE();
9067         POP_PARENT();
9068         return statement;
9069 }
9070
9071 /**
9072  * Check that all enums are handled in a switch.
9073  *
9074  * @param statement  the switch statement to check
9075  */
9076 static void check_enum_cases(const switch_statement_t *statement)
9077 {
9078         if (!is_warn_on(WARN_SWITCH_ENUM))
9079                 return;
9080         const type_t *type = skip_typeref(statement->expression->base.type);
9081         if (! is_type_enum(type))
9082                 return;
9083         const enum_type_t *enumt = &type->enumt;
9084
9085         /* if we have a default, no warnings */
9086         if (statement->default_label != NULL)
9087                 return;
9088
9089         /* FIXME: calculation of value should be done while parsing */
9090         /* TODO: quadratic algorithm here. Change to an n log n one */
9091         long            last_value = -1;
9092         const entity_t *entry      = enumt->enume->base.next;
9093         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9094              entry = entry->base.next) {
9095                 const expression_t *expression = entry->enum_value.value;
9096                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9097                 bool                found      = false;
9098                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9099                         if (l->expression == NULL)
9100                                 continue;
9101                         if (l->first_case <= value && value <= l->last_case) {
9102                                 found = true;
9103                                 break;
9104                         }
9105                 }
9106                 if (!found) {
9107                         source_position_t const *const pos = &statement->base.source_position;
9108                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9109                 }
9110                 last_value = value;
9111         }
9112 }
9113
9114 /**
9115  * Parse a switch statement.
9116  */
9117 static statement_t *parse_switch(void)
9118 {
9119         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9120
9121         eat(T_switch);
9122
9123         PUSH_PARENT(statement);
9124         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9125
9126         expression_t *const expr = parse_condition();
9127         type_t       *      type = skip_typeref(expr->base.type);
9128         if (is_type_integer(type)) {
9129                 type = promote_integer(type);
9130                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9131                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9132                 }
9133         } else if (is_type_valid(type)) {
9134                 errorf(&expr->base.source_position,
9135                        "switch quantity is not an integer, but '%T'", type);
9136                 type = type_error_type;
9137         }
9138         statement->switchs.expression = create_implicit_cast(expr, type);
9139
9140         switch_statement_t *rem = current_switch;
9141         current_switch          = &statement->switchs;
9142         statement->switchs.body = parse_inner_statement();
9143         current_switch          = rem;
9144
9145         if (statement->switchs.default_label == NULL) {
9146                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9147         }
9148         check_enum_cases(&statement->switchs);
9149
9150         POP_SCOPE();
9151         POP_PARENT();
9152         return statement;
9153 }
9154
9155 static statement_t *parse_loop_body(statement_t *const loop)
9156 {
9157         statement_t *const rem = current_loop;
9158         current_loop = loop;
9159
9160         statement_t *const body = parse_inner_statement();
9161
9162         current_loop = rem;
9163         return body;
9164 }
9165
9166 /**
9167  * Parse a while statement.
9168  */
9169 static statement_t *parse_while(void)
9170 {
9171         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9172
9173         eat(T_while);
9174
9175         PUSH_PARENT(statement);
9176         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9177
9178         expression_t *const cond = parse_condition();
9179         statement->whiles.condition = cond;
9180         /* §6.8.5:2    The controlling expression of an iteration statement shall
9181          *             have scalar type. */
9182         semantic_condition(cond, "condition of 'while'-statement");
9183
9184         statement->whiles.body = parse_loop_body(statement);
9185
9186         POP_SCOPE();
9187         POP_PARENT();
9188         return statement;
9189 }
9190
9191 /**
9192  * Parse a do statement.
9193  */
9194 static statement_t *parse_do(void)
9195 {
9196         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9197
9198         eat(T_do);
9199
9200         PUSH_PARENT(statement);
9201         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9202
9203         add_anchor_token(T_while);
9204         statement->do_while.body = parse_loop_body(statement);
9205         rem_anchor_token(T_while);
9206
9207         expect(T_while);
9208         expression_t *const cond = parse_condition();
9209         statement->do_while.condition = cond;
9210         /* §6.8.5:2    The controlling expression of an iteration statement shall
9211          *             have scalar type. */
9212         semantic_condition(cond, "condition of 'do-while'-statement");
9213         expect(';');
9214
9215         POP_SCOPE();
9216         POP_PARENT();
9217         return statement;
9218 }
9219
9220 /**
9221  * Parse a for statement.
9222  */
9223 static statement_t *parse_for(void)
9224 {
9225         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9226
9227         eat(T_for);
9228
9229         PUSH_PARENT(statement);
9230         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9231
9232         add_anchor_token(')');
9233         expect('(');
9234
9235         PUSH_EXTENSION();
9236
9237         if (next_if(';')) {
9238         } else if (is_declaration_specifier(&token)) {
9239                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9240         } else {
9241                 add_anchor_token(';');
9242                 expression_t *const init = parse_expression();
9243                 statement->fors.initialisation = init;
9244                 mark_vars_read(init, ENT_ANY);
9245                 if (!expression_has_effect(init)) {
9246                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9247                 }
9248                 rem_anchor_token(';');
9249                 expect(';');
9250         }
9251
9252         POP_EXTENSION();
9253
9254         if (token.kind != ';') {
9255                 add_anchor_token(';');
9256                 expression_t *const cond = parse_expression();
9257                 statement->fors.condition = cond;
9258                 /* §6.8.5:2    The controlling expression of an iteration statement
9259                  *             shall have scalar type. */
9260                 semantic_condition(cond, "condition of 'for'-statement");
9261                 mark_vars_read(cond, NULL);
9262                 rem_anchor_token(';');
9263         }
9264         expect(';');
9265         if (token.kind != ')') {
9266                 expression_t *const step = parse_expression();
9267                 statement->fors.step = step;
9268                 mark_vars_read(step, ENT_ANY);
9269                 if (!expression_has_effect(step)) {
9270                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9271                 }
9272         }
9273         rem_anchor_token(')');
9274         expect(')');
9275         statement->fors.body = parse_loop_body(statement);
9276
9277         POP_SCOPE();
9278         POP_PARENT();
9279         return statement;
9280 }
9281
9282 /**
9283  * Parse a goto statement.
9284  */
9285 static statement_t *parse_goto(void)
9286 {
9287         statement_t *statement;
9288         if (GNU_MODE && look_ahead(1)->kind == '*') {
9289                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9290                 eat(T_goto);
9291                 eat('*');
9292
9293                 expression_t *expression = parse_expression();
9294                 mark_vars_read(expression, NULL);
9295
9296                 /* Argh: although documentation says the expression must be of type void*,
9297                  * gcc accepts anything that can be casted into void* without error */
9298                 type_t *type = expression->base.type;
9299
9300                 if (type != type_error_type) {
9301                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9302                                 errorf(&expression->base.source_position,
9303                                         "cannot convert to a pointer type");
9304                         } else if (type != type_void_ptr) {
9305                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9306                         }
9307                         expression = create_implicit_cast(expression, type_void_ptr);
9308                 }
9309
9310                 statement->computed_goto.expression = expression;
9311         } else {
9312                 statement = allocate_statement_zero(STATEMENT_GOTO);
9313                 eat(T_goto);
9314
9315                 label_t *const label = get_label("while parsing goto");
9316                 if (label) {
9317                         label->used            = true;
9318                         statement->gotos.label = label;
9319
9320                         /* remember the goto's in a list for later checking */
9321                         *goto_anchor = &statement->gotos;
9322                         goto_anchor  = &statement->gotos.next;
9323                 } else {
9324                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9325                 }
9326         }
9327
9328         expect(';');
9329         return statement;
9330 }
9331
9332 /**
9333  * Parse a continue statement.
9334  */
9335 static statement_t *parse_continue(void)
9336 {
9337         if (current_loop == NULL) {
9338                 errorf(HERE, "continue statement not within loop");
9339         }
9340
9341         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9342
9343         eat(T_continue);
9344         expect(';');
9345         return statement;
9346 }
9347
9348 /**
9349  * Parse a break statement.
9350  */
9351 static statement_t *parse_break(void)
9352 {
9353         if (current_switch == NULL && current_loop == NULL) {
9354                 errorf(HERE, "break statement not within loop or switch");
9355         }
9356
9357         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9358
9359         eat(T_break);
9360         expect(';');
9361         return statement;
9362 }
9363
9364 /**
9365  * Parse a __leave statement.
9366  */
9367 static statement_t *parse_leave_statement(void)
9368 {
9369         if (current_try == NULL) {
9370                 errorf(HERE, "__leave statement not within __try");
9371         }
9372
9373         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9374
9375         eat(T___leave);
9376         expect(';');
9377         return statement;
9378 }
9379
9380 /**
9381  * Check if a given entity represents a local variable.
9382  */
9383 static bool is_local_variable(const entity_t *entity)
9384 {
9385         if (entity->kind != ENTITY_VARIABLE)
9386                 return false;
9387
9388         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9389         case STORAGE_CLASS_AUTO:
9390         case STORAGE_CLASS_REGISTER: {
9391                 const type_t *type = skip_typeref(entity->declaration.type);
9392                 if (is_type_function(type)) {
9393                         return false;
9394                 } else {
9395                         return true;
9396                 }
9397         }
9398         default:
9399                 return false;
9400         }
9401 }
9402
9403 /**
9404  * Check if a given expression represents a local variable.
9405  */
9406 static bool expression_is_local_variable(const expression_t *expression)
9407 {
9408         if (expression->base.kind != EXPR_REFERENCE) {
9409                 return false;
9410         }
9411         const entity_t *entity = expression->reference.entity;
9412         return is_local_variable(entity);
9413 }
9414
9415 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9416 {
9417         if (c_mode & _CXX || strict_mode) {
9418                 errorf(pos, msg);
9419         } else {
9420                 warningf(WARN_OTHER, pos, msg);
9421         }
9422 }
9423
9424 /**
9425  * Parse a return statement.
9426  */
9427 static statement_t *parse_return(void)
9428 {
9429         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9430         eat(T_return);
9431
9432         expression_t *return_value = NULL;
9433         if (token.kind != ';') {
9434                 return_value = parse_expression();
9435                 mark_vars_read(return_value, NULL);
9436         }
9437
9438         const type_t *const func_type = skip_typeref(current_function->base.type);
9439         assert(is_type_function(func_type));
9440         type_t *const return_type = skip_typeref(func_type->function.return_type);
9441
9442         source_position_t const *const pos = &statement->base.source_position;
9443         if (return_value != NULL) {
9444                 type_t *return_value_type = skip_typeref(return_value->base.type);
9445
9446                 if (is_type_void(return_type)) {
9447                         if (!is_type_void(return_value_type)) {
9448                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9449                                 /* Only warn in C mode, because GCC does the same */
9450                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9451                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9452                                 /* Only warn in C mode, because GCC does the same */
9453                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9454                         }
9455                 } else {
9456                         assign_error_t error = semantic_assign(return_type, return_value);
9457                         report_assign_error(error, return_type, return_value, "'return'",
9458                                             pos);
9459                 }
9460                 return_value = create_implicit_cast(return_value, return_type);
9461                 /* check for returning address of a local var */
9462                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9463                         const expression_t *expression = return_value->unary.value;
9464                         if (expression_is_local_variable(expression)) {
9465                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9466                         }
9467                 }
9468         } else if (!is_type_void(return_type)) {
9469                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9470                 err_or_warn(pos, "'return' without value, in function returning non-void");
9471         }
9472         statement->returns.value = return_value;
9473
9474         expect(';');
9475         return statement;
9476 }
9477
9478 /**
9479  * Parse a declaration statement.
9480  */
9481 static statement_t *parse_declaration_statement(void)
9482 {
9483         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9484
9485         entity_t *before = current_scope->last_entity;
9486         if (GNU_MODE) {
9487                 parse_external_declaration();
9488         } else {
9489                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9490         }
9491
9492         declaration_statement_t *const decl  = &statement->declaration;
9493         entity_t                *const begin =
9494                 before != NULL ? before->base.next : current_scope->entities;
9495         decl->declarations_begin = begin;
9496         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9497
9498         return statement;
9499 }
9500
9501 /**
9502  * Parse an expression statement, ie. expr ';'.
9503  */
9504 static statement_t *parse_expression_statement(void)
9505 {
9506         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9507
9508         expression_t *const expr         = parse_expression();
9509         statement->expression.expression = expr;
9510         mark_vars_read(expr, ENT_ANY);
9511
9512         expect(';');
9513         return statement;
9514 }
9515
9516 /**
9517  * Parse a microsoft __try { } __finally { } or
9518  * __try{ } __except() { }
9519  */
9520 static statement_t *parse_ms_try_statment(void)
9521 {
9522         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9523         eat(T___try);
9524
9525         PUSH_PARENT(statement);
9526
9527         ms_try_statement_t *rem = current_try;
9528         current_try = &statement->ms_try;
9529         statement->ms_try.try_statement = parse_compound_statement(false);
9530         current_try = rem;
9531
9532         POP_PARENT();
9533
9534         if (next_if(T___except)) {
9535                 expression_t *const expr = parse_condition();
9536                 type_t       *      type = skip_typeref(expr->base.type);
9537                 if (is_type_integer(type)) {
9538                         type = promote_integer(type);
9539                 } else if (is_type_valid(type)) {
9540                         errorf(&expr->base.source_position,
9541                                "__expect expression is not an integer, but '%T'", type);
9542                         type = type_error_type;
9543                 }
9544                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9545         } else if (!next_if(T__finally)) {
9546                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9547         }
9548         statement->ms_try.final_statement = parse_compound_statement(false);
9549         return statement;
9550 }
9551
9552 static statement_t *parse_empty_statement(void)
9553 {
9554         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9555         statement_t *const statement = create_empty_statement();
9556         eat(';');
9557         return statement;
9558 }
9559
9560 static statement_t *parse_local_label_declaration(void)
9561 {
9562         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9563
9564         eat(T___label__);
9565
9566         entity_t *begin   = NULL;
9567         entity_t *end     = NULL;
9568         entity_t **anchor = &begin;
9569         add_anchor_token(';');
9570         add_anchor_token(',');
9571         do {
9572                 source_position_t pos;
9573                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9574                 if (symbol) {
9575                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9576                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9577                                 source_position_t const *const ppos = &entity->base.source_position;
9578                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9579                         } else {
9580                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9581                                 entity->base.parent_scope = current_scope;
9582
9583                                 *anchor = entity;
9584                                 anchor  = &entity->base.next;
9585                                 end     = entity;
9586
9587                                 environment_push(entity);
9588                         }
9589                 }
9590         } while (next_if(','));
9591         rem_anchor_token(',');
9592         rem_anchor_token(';');
9593         expect(';');
9594         statement->declaration.declarations_begin = begin;
9595         statement->declaration.declarations_end   = end;
9596         return statement;
9597 }
9598
9599 static void parse_namespace_definition(void)
9600 {
9601         eat(T_namespace);
9602
9603         entity_t *entity = NULL;
9604         symbol_t *symbol = NULL;
9605
9606         if (token.kind == T_IDENTIFIER) {
9607                 symbol = token.base.symbol;
9608                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9609                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9610                         entity = NULL;
9611                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9612                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9613                         }
9614                 }
9615                 eat(T_IDENTIFIER);
9616         }
9617
9618         if (entity == NULL) {
9619                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9620                 entity->base.parent_scope = current_scope;
9621         }
9622
9623         if (token.kind == '=') {
9624                 /* TODO: parse namespace alias */
9625                 panic("namespace alias definition not supported yet");
9626         }
9627
9628         environment_push(entity);
9629         append_entity(current_scope, entity);
9630
9631         PUSH_SCOPE(&entity->namespacee.members);
9632         PUSH_CURRENT_ENTITY(entity);
9633
9634         add_anchor_token('}');
9635         expect('{');
9636         parse_externals();
9637         rem_anchor_token('}');
9638         expect('}');
9639
9640         POP_CURRENT_ENTITY();
9641         POP_SCOPE();
9642 }
9643
9644 /**
9645  * Parse a statement.
9646  * There's also parse_statement() which additionally checks for
9647  * "statement has no effect" warnings
9648  */
9649 static statement_t *intern_parse_statement(void)
9650 {
9651         /* declaration or statement */
9652         statement_t *statement;
9653         switch (token.kind) {
9654         case T_IDENTIFIER: {
9655                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9656                 if (la1_type == ':') {
9657                         statement = parse_label_statement();
9658                 } else if (is_typedef_symbol(token.base.symbol)) {
9659                         statement = parse_declaration_statement();
9660                 } else {
9661                         /* it's an identifier, the grammar says this must be an
9662                          * expression statement. However it is common that users mistype
9663                          * declaration types, so we guess a bit here to improve robustness
9664                          * for incorrect programs */
9665                         switch (la1_type) {
9666                         case '&':
9667                         case '*':
9668                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9669                         default:
9670                                         statement = parse_expression_statement();
9671                                 } else {
9672                         DECLARATION_START
9673                         case T_IDENTIFIER:
9674                                         statement = parse_declaration_statement();
9675                                 }
9676                                 break;
9677                         }
9678                 }
9679                 break;
9680         }
9681
9682         case T___extension__: {
9683                 /* This can be a prefix to a declaration or an expression statement.
9684                  * We simply eat it now and parse the rest with tail recursion. */
9685                 PUSH_EXTENSION();
9686                 statement = intern_parse_statement();
9687                 POP_EXTENSION();
9688                 break;
9689         }
9690
9691         DECLARATION_START
9692                 statement = parse_declaration_statement();
9693                 break;
9694
9695         case T___label__:
9696                 statement = parse_local_label_declaration();
9697                 break;
9698
9699         case ';':         statement = parse_empty_statement();         break;
9700         case '{':         statement = parse_compound_statement(false); break;
9701         case T___leave:   statement = parse_leave_statement();         break;
9702         case T___try:     statement = parse_ms_try_statment();         break;
9703         case T_asm:       statement = parse_asm_statement();           break;
9704         case T_break:     statement = parse_break();                   break;
9705         case T_case:      statement = parse_case_statement();          break;
9706         case T_continue:  statement = parse_continue();                break;
9707         case T_default:   statement = parse_default_statement();       break;
9708         case T_do:        statement = parse_do();                      break;
9709         case T_for:       statement = parse_for();                     break;
9710         case T_goto:      statement = parse_goto();                    break;
9711         case T_if:        statement = parse_if();                      break;
9712         case T_return:    statement = parse_return();                  break;
9713         case T_switch:    statement = parse_switch();                  break;
9714         case T_while:     statement = parse_while();                   break;
9715
9716         EXPRESSION_START
9717                 statement = parse_expression_statement();
9718                 break;
9719
9720         default:
9721                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9722                 statement = create_error_statement();
9723                 eat_until_anchor();
9724                 break;
9725         }
9726
9727         return statement;
9728 }
9729
9730 /**
9731  * parse a statement and emits "statement has no effect" warning if needed
9732  * (This is really a wrapper around intern_parse_statement with check for 1
9733  *  single warning. It is needed, because for statement expressions we have
9734  *  to avoid the warning on the last statement)
9735  */
9736 static statement_t *parse_statement(void)
9737 {
9738         statement_t *statement = intern_parse_statement();
9739
9740         if (statement->kind == STATEMENT_EXPRESSION) {
9741                 expression_t *expression = statement->expression.expression;
9742                 if (!expression_has_effect(expression)) {
9743                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9744                 }
9745         }
9746
9747         return statement;
9748 }
9749
9750 /**
9751  * Parse a compound statement.
9752  */
9753 static statement_t *parse_compound_statement(bool inside_expression_statement)
9754 {
9755         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9756
9757         PUSH_PARENT(statement);
9758         PUSH_SCOPE(&statement->compound.scope);
9759
9760         eat('{');
9761         add_anchor_token('}');
9762         /* tokens, which can start a statement */
9763         /* TODO MS, __builtin_FOO */
9764         add_anchor_token('!');
9765         add_anchor_token('&');
9766         add_anchor_token('(');
9767         add_anchor_token('*');
9768         add_anchor_token('+');
9769         add_anchor_token('-');
9770         add_anchor_token(';');
9771         add_anchor_token('{');
9772         add_anchor_token('~');
9773         add_anchor_token(T_CHARACTER_CONSTANT);
9774         add_anchor_token(T_COLONCOLON);
9775         add_anchor_token(T_FLOATINGPOINT);
9776         add_anchor_token(T_IDENTIFIER);
9777         add_anchor_token(T_INTEGER);
9778         add_anchor_token(T_MINUSMINUS);
9779         add_anchor_token(T_PLUSPLUS);
9780         add_anchor_token(T_STRING_LITERAL);
9781         add_anchor_token(T__Bool);
9782         add_anchor_token(T__Complex);
9783         add_anchor_token(T__Imaginary);
9784         add_anchor_token(T___PRETTY_FUNCTION__);
9785         add_anchor_token(T___alignof__);
9786         add_anchor_token(T___attribute__);
9787         add_anchor_token(T___builtin_va_start);
9788         add_anchor_token(T___extension__);
9789         add_anchor_token(T___func__);
9790         add_anchor_token(T___imag__);
9791         add_anchor_token(T___label__);
9792         add_anchor_token(T___real__);
9793         add_anchor_token(T___thread);
9794         add_anchor_token(T_asm);
9795         add_anchor_token(T_auto);
9796         add_anchor_token(T_bool);
9797         add_anchor_token(T_break);
9798         add_anchor_token(T_case);
9799         add_anchor_token(T_char);
9800         add_anchor_token(T_class);
9801         add_anchor_token(T_const);
9802         add_anchor_token(T_const_cast);
9803         add_anchor_token(T_continue);
9804         add_anchor_token(T_default);
9805         add_anchor_token(T_delete);
9806         add_anchor_token(T_double);
9807         add_anchor_token(T_do);
9808         add_anchor_token(T_dynamic_cast);
9809         add_anchor_token(T_enum);
9810         add_anchor_token(T_extern);
9811         add_anchor_token(T_false);
9812         add_anchor_token(T_float);
9813         add_anchor_token(T_for);
9814         add_anchor_token(T_goto);
9815         add_anchor_token(T_if);
9816         add_anchor_token(T_inline);
9817         add_anchor_token(T_int);
9818         add_anchor_token(T_long);
9819         add_anchor_token(T_new);
9820         add_anchor_token(T_operator);
9821         add_anchor_token(T_register);
9822         add_anchor_token(T_reinterpret_cast);
9823         add_anchor_token(T_restrict);
9824         add_anchor_token(T_return);
9825         add_anchor_token(T_short);
9826         add_anchor_token(T_signed);
9827         add_anchor_token(T_sizeof);
9828         add_anchor_token(T_static);
9829         add_anchor_token(T_static_cast);
9830         add_anchor_token(T_struct);
9831         add_anchor_token(T_switch);
9832         add_anchor_token(T_template);
9833         add_anchor_token(T_this);
9834         add_anchor_token(T_throw);
9835         add_anchor_token(T_true);
9836         add_anchor_token(T_try);
9837         add_anchor_token(T_typedef);
9838         add_anchor_token(T_typeid);
9839         add_anchor_token(T_typename);
9840         add_anchor_token(T_typeof);
9841         add_anchor_token(T_union);
9842         add_anchor_token(T_unsigned);
9843         add_anchor_token(T_using);
9844         add_anchor_token(T_void);
9845         add_anchor_token(T_volatile);
9846         add_anchor_token(T_wchar_t);
9847         add_anchor_token(T_while);
9848
9849         statement_t **anchor            = &statement->compound.statements;
9850         bool          only_decls_so_far = true;
9851         while (token.kind != '}' && token.kind != T_EOF) {
9852                 statement_t *sub_statement = intern_parse_statement();
9853                 if (sub_statement->kind == STATEMENT_ERROR) {
9854                         break;
9855                 }
9856
9857                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9858                         only_decls_so_far = false;
9859                 } else if (!only_decls_so_far) {
9860                         source_position_t const *const pos = &sub_statement->base.source_position;
9861                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9862                 }
9863
9864                 *anchor = sub_statement;
9865                 anchor  = &sub_statement->base.next;
9866         }
9867         expect('}');
9868
9869         /* look over all statements again to produce no effect warnings */
9870         if (is_warn_on(WARN_UNUSED_VALUE)) {
9871                 statement_t *sub_statement = statement->compound.statements;
9872                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9873                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9874                                 continue;
9875                         /* don't emit a warning for the last expression in an expression
9876                          * statement as it has always an effect */
9877                         if (inside_expression_statement && sub_statement->base.next == NULL)
9878                                 continue;
9879
9880                         expression_t *expression = sub_statement->expression.expression;
9881                         if (!expression_has_effect(expression)) {
9882                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9883                         }
9884                 }
9885         }
9886
9887         rem_anchor_token(T_while);
9888         rem_anchor_token(T_wchar_t);
9889         rem_anchor_token(T_volatile);
9890         rem_anchor_token(T_void);
9891         rem_anchor_token(T_using);
9892         rem_anchor_token(T_unsigned);
9893         rem_anchor_token(T_union);
9894         rem_anchor_token(T_typeof);
9895         rem_anchor_token(T_typename);
9896         rem_anchor_token(T_typeid);
9897         rem_anchor_token(T_typedef);
9898         rem_anchor_token(T_try);
9899         rem_anchor_token(T_true);
9900         rem_anchor_token(T_throw);
9901         rem_anchor_token(T_this);
9902         rem_anchor_token(T_template);
9903         rem_anchor_token(T_switch);
9904         rem_anchor_token(T_struct);
9905         rem_anchor_token(T_static_cast);
9906         rem_anchor_token(T_static);
9907         rem_anchor_token(T_sizeof);
9908         rem_anchor_token(T_signed);
9909         rem_anchor_token(T_short);
9910         rem_anchor_token(T_return);
9911         rem_anchor_token(T_restrict);
9912         rem_anchor_token(T_reinterpret_cast);
9913         rem_anchor_token(T_register);
9914         rem_anchor_token(T_operator);
9915         rem_anchor_token(T_new);
9916         rem_anchor_token(T_long);
9917         rem_anchor_token(T_int);
9918         rem_anchor_token(T_inline);
9919         rem_anchor_token(T_if);
9920         rem_anchor_token(T_goto);
9921         rem_anchor_token(T_for);
9922         rem_anchor_token(T_float);
9923         rem_anchor_token(T_false);
9924         rem_anchor_token(T_extern);
9925         rem_anchor_token(T_enum);
9926         rem_anchor_token(T_dynamic_cast);
9927         rem_anchor_token(T_do);
9928         rem_anchor_token(T_double);
9929         rem_anchor_token(T_delete);
9930         rem_anchor_token(T_default);
9931         rem_anchor_token(T_continue);
9932         rem_anchor_token(T_const_cast);
9933         rem_anchor_token(T_const);
9934         rem_anchor_token(T_class);
9935         rem_anchor_token(T_char);
9936         rem_anchor_token(T_case);
9937         rem_anchor_token(T_break);
9938         rem_anchor_token(T_bool);
9939         rem_anchor_token(T_auto);
9940         rem_anchor_token(T_asm);
9941         rem_anchor_token(T___thread);
9942         rem_anchor_token(T___real__);
9943         rem_anchor_token(T___label__);
9944         rem_anchor_token(T___imag__);
9945         rem_anchor_token(T___func__);
9946         rem_anchor_token(T___extension__);
9947         rem_anchor_token(T___builtin_va_start);
9948         rem_anchor_token(T___attribute__);
9949         rem_anchor_token(T___alignof__);
9950         rem_anchor_token(T___PRETTY_FUNCTION__);
9951         rem_anchor_token(T__Imaginary);
9952         rem_anchor_token(T__Complex);
9953         rem_anchor_token(T__Bool);
9954         rem_anchor_token(T_STRING_LITERAL);
9955         rem_anchor_token(T_PLUSPLUS);
9956         rem_anchor_token(T_MINUSMINUS);
9957         rem_anchor_token(T_INTEGER);
9958         rem_anchor_token(T_IDENTIFIER);
9959         rem_anchor_token(T_FLOATINGPOINT);
9960         rem_anchor_token(T_COLONCOLON);
9961         rem_anchor_token(T_CHARACTER_CONSTANT);
9962         rem_anchor_token('~');
9963         rem_anchor_token('{');
9964         rem_anchor_token(';');
9965         rem_anchor_token('-');
9966         rem_anchor_token('+');
9967         rem_anchor_token('*');
9968         rem_anchor_token('(');
9969         rem_anchor_token('&');
9970         rem_anchor_token('!');
9971         rem_anchor_token('}');
9972
9973         POP_SCOPE();
9974         POP_PARENT();
9975         return statement;
9976 }
9977
9978 /**
9979  * Check for unused global static functions and variables
9980  */
9981 static void check_unused_globals(void)
9982 {
9983         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
9984                 return;
9985
9986         for (const entity_t *entity = file_scope->entities; entity != NULL;
9987              entity = entity->base.next) {
9988                 if (!is_declaration(entity))
9989                         continue;
9990
9991                 const declaration_t *declaration = &entity->declaration;
9992                 if (declaration->used                  ||
9993                     declaration->modifiers & DM_UNUSED ||
9994                     declaration->modifiers & DM_USED   ||
9995                     declaration->storage_class != STORAGE_CLASS_STATIC)
9996                         continue;
9997
9998                 warning_t   why;
9999                 char const *s;
10000                 if (entity->kind == ENTITY_FUNCTION) {
10001                         /* inhibit warning for static inline functions */
10002                         if (entity->function.is_inline)
10003                                 continue;
10004
10005                         why = WARN_UNUSED_FUNCTION;
10006                         s   = entity->function.statement != NULL ? "defined" : "declared";
10007                 } else {
10008                         why = WARN_UNUSED_VARIABLE;
10009                         s   = "defined";
10010                 }
10011
10012                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10013         }
10014 }
10015
10016 static void parse_global_asm(void)
10017 {
10018         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10019
10020         eat(T_asm);
10021         add_anchor_token(';');
10022         add_anchor_token(')');
10023         add_anchor_token(T_STRING_LITERAL);
10024         expect('(');
10025
10026         rem_anchor_token(T_STRING_LITERAL);
10027         statement->asms.asm_text = parse_string_literals("global asm");
10028         statement->base.next     = unit->global_asm;
10029         unit->global_asm         = statement;
10030
10031         rem_anchor_token(')');
10032         expect(')');
10033         rem_anchor_token(';');
10034         expect(';');
10035 }
10036
10037 static void parse_linkage_specification(void)
10038 {
10039         eat(T_extern);
10040
10041         source_position_t const pos     = *HERE;
10042         char const       *const linkage = parse_string_literals(NULL).begin;
10043
10044         linkage_kind_t old_linkage = current_linkage;
10045         linkage_kind_t new_linkage;
10046         if (streq(linkage, "C")) {
10047                 new_linkage = LINKAGE_C;
10048         } else if (streq(linkage, "C++")) {
10049                 new_linkage = LINKAGE_CXX;
10050         } else {
10051                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10052                 new_linkage = LINKAGE_C;
10053         }
10054         current_linkage = new_linkage;
10055
10056         if (next_if('{')) {
10057                 parse_externals();
10058                 expect('}');
10059         } else {
10060                 parse_external();
10061         }
10062
10063         assert(current_linkage == new_linkage);
10064         current_linkage = old_linkage;
10065 }
10066
10067 static void parse_external(void)
10068 {
10069         switch (token.kind) {
10070                 case T_extern:
10071                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10072                                 parse_linkage_specification();
10073                         } else {
10074                 DECLARATION_START_NO_EXTERN
10075                 case T_IDENTIFIER:
10076                 case T___extension__:
10077                 /* tokens below are for implicit int */
10078                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10079                               implicit int) */
10080                 case '*':  /* * x; -> int* x; */
10081                 case '(':  /* (x); -> int (x); */
10082                                 PUSH_EXTENSION();
10083                                 parse_external_declaration();
10084                                 POP_EXTENSION();
10085                         }
10086                         return;
10087
10088                 case T_asm:
10089                         parse_global_asm();
10090                         return;
10091
10092                 case T_namespace:
10093                         parse_namespace_definition();
10094                         return;
10095
10096                 case ';':
10097                         if (!strict_mode) {
10098                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10099                                 eat(';');
10100                                 return;
10101                         }
10102                         /* FALLTHROUGH */
10103
10104                 default:
10105                         errorf(HERE, "stray %K outside of function", &token);
10106                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10107                                 eat_until_matching_token(token.kind);
10108                         next_token();
10109                         return;
10110         }
10111 }
10112
10113 static void parse_externals(void)
10114 {
10115         add_anchor_token('}');
10116         add_anchor_token(T_EOF);
10117
10118 #ifndef NDEBUG
10119         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10120         unsigned short token_anchor_copy[T_LAST_TOKEN];
10121         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10122 #endif
10123
10124         while (token.kind != T_EOF && token.kind != '}') {
10125 #ifndef NDEBUG
10126                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10127                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10128                         if (count != 0) {
10129                                 /* the anchor set and its copy differs */
10130                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10131                         }
10132                 }
10133                 if (in_gcc_extension) {
10134                         /* an gcc extension scope was not closed */
10135                         internal_errorf(HERE, "Leaked __extension__");
10136                 }
10137 #endif
10138
10139                 parse_external();
10140         }
10141
10142         rem_anchor_token(T_EOF);
10143         rem_anchor_token('}');
10144 }
10145
10146 /**
10147  * Parse a translation unit.
10148  */
10149 static void parse_translation_unit(void)
10150 {
10151         add_anchor_token(T_EOF);
10152
10153         while (true) {
10154                 parse_externals();
10155
10156                 if (token.kind == T_EOF)
10157                         break;
10158
10159                 errorf(HERE, "stray %K outside of function", &token);
10160                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10161                         eat_until_matching_token(token.kind);
10162                 next_token();
10163         }
10164 }
10165
10166 void set_default_visibility(elf_visibility_tag_t visibility)
10167 {
10168         default_visibility = visibility;
10169 }
10170
10171 /**
10172  * Parse the input.
10173  *
10174  * @return  the translation unit or NULL if errors occurred.
10175  */
10176 void start_parsing(void)
10177 {
10178         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10179         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10180         diagnostic_count  = 0;
10181         error_count       = 0;
10182         warning_count     = 0;
10183
10184         print_to_file(stderr);
10185
10186         assert(unit == NULL);
10187         unit = allocate_ast_zero(sizeof(unit[0]));
10188
10189         assert(file_scope == NULL);
10190         file_scope = &unit->scope;
10191
10192         assert(current_scope == NULL);
10193         scope_push(&unit->scope);
10194
10195         create_gnu_builtins();
10196         if (c_mode & _MS)
10197                 create_microsoft_intrinsics();
10198 }
10199
10200 translation_unit_t *finish_parsing(void)
10201 {
10202         assert(current_scope == &unit->scope);
10203         scope_pop(NULL);
10204
10205         assert(file_scope == &unit->scope);
10206         check_unused_globals();
10207         file_scope = NULL;
10208
10209         DEL_ARR_F(environment_stack);
10210         DEL_ARR_F(label_stack);
10211
10212         translation_unit_t *result = unit;
10213         unit = NULL;
10214         return result;
10215 }
10216
10217 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10218  * are given length one. */
10219 static void complete_incomplete_arrays(void)
10220 {
10221         size_t n = ARR_LEN(incomplete_arrays);
10222         for (size_t i = 0; i != n; ++i) {
10223                 declaration_t *const decl = incomplete_arrays[i];
10224                 type_t        *const type = skip_typeref(decl->type);
10225
10226                 if (!is_type_incomplete(type))
10227                         continue;
10228
10229                 source_position_t const *const pos = &decl->base.source_position;
10230                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10231
10232                 type_t *const new_type = duplicate_type(type);
10233                 new_type->array.size_constant     = true;
10234                 new_type->array.has_implicit_size = true;
10235                 new_type->array.size              = 1;
10236
10237                 type_t *const result = identify_new_type(new_type);
10238
10239                 decl->type = result;
10240         }
10241 }
10242
10243 static void prepare_main_collect2(entity_t *const entity)
10244 {
10245         PUSH_SCOPE(&entity->function.statement->compound.scope);
10246
10247         // create call to __main
10248         symbol_t *symbol         = symbol_table_insert("__main");
10249         entity_t *subsubmain_ent
10250                 = create_implicit_function(symbol, &builtin_source_position);
10251
10252         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10253         type_t       *ftype       = subsubmain_ent->declaration.type;
10254         ref->base.source_position = builtin_source_position;
10255         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10256         ref->reference.entity     = subsubmain_ent;
10257
10258         expression_t *call = allocate_expression_zero(EXPR_CALL);
10259         call->base.source_position = builtin_source_position;
10260         call->base.type            = type_void;
10261         call->call.function        = ref;
10262
10263         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10264         expr_statement->base.source_position  = builtin_source_position;
10265         expr_statement->expression.expression = call;
10266
10267         statement_t *statement = entity->function.statement;
10268         assert(statement->kind == STATEMENT_COMPOUND);
10269         compound_statement_t *compounds = &statement->compound;
10270
10271         expr_statement->base.next = compounds->statements;
10272         compounds->statements     = expr_statement;
10273
10274         POP_SCOPE();
10275 }
10276
10277 void parse(void)
10278 {
10279         lookahead_bufpos = 0;
10280         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10281                 next_token();
10282         }
10283         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10284         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10285         parse_translation_unit();
10286         complete_incomplete_arrays();
10287         DEL_ARR_F(incomplete_arrays);
10288         incomplete_arrays = NULL;
10289 }
10290
10291 /**
10292  * Initialize the parser.
10293  */
10294 void init_parser(void)
10295 {
10296         sym_anonymous = symbol_table_insert("<anonymous>");
10297
10298         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10299
10300         init_expression_parsers();
10301         obstack_init(&temp_obst);
10302 }
10303
10304 /**
10305  * Terminate the parser.
10306  */
10307 void exit_parser(void)
10308 {
10309         obstack_free(&temp_obst, NULL);
10310 }