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_PARENT(stmt) \
 113         statement_t *const new_parent = (stmt); \
 114         statement_t *const old_parent = current_parent; \
 115         ((void)(current_parent = new_parent))
 116 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 117
 118 #define PUSH_SCOPE(scope) \
 119         size_t   const top       = environment_top(); \
 120         scope_t *const new_scope = (scope); \
 121         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 122 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 123 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 124
 125 #define PUSH_EXTENSION() \
 126         (void)0; \
 127         bool const old_gcc_extension = in_gcc_extension; \
 128         while (next_if(T___extension__)) { \
 129                 in_gcc_extension = true; \
 130         } \
 131         do {} while (0)
 132 #define POP_EXTENSION() \
 133         ((void)(in_gcc_extension = old_gcc_extension))
 134
 135 /** special symbol used for anonymous entities. */
 136 static symbol_t *sym_anonymous = NULL;
 137
 138 /** The token anchor set */
 139 static unsigned short token_anchor_set[T_LAST_TOKEN];
 140
 141 /** The current source position. */
 142 #define HERE (&token.base.source_position)
 143
 144 /** true if we are in GCC mode. */
 145 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 146
 147 static statement_t *parse_compound_statement(bool inside_expression_statement);
 148 static statement_t *parse_statement(void);
 149
 150 static expression_t *parse_subexpression(precedence_t);
 151 static expression_t *parse_expression(void);
 152 static type_t       *parse_typename(void);
 153 static void          parse_externals(void);
 154 static void          parse_external(void);
 155
 156 static void parse_compound_type_entries(compound_t *compound_declaration);
 157
 158 static void check_call_argument(type_t          *expected_type,
 159                                                                 call_argument_t *argument, unsigned pos);
 160
 161 typedef enum declarator_flags_t {
 162         DECL_FLAGS_NONE             = 0,
 163         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 164         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 165         DECL_IS_PARAMETER           = 1U << 2
 166 } declarator_flags_t;
 167
 168 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 169                                   declarator_flags_t flags);
 170
 171 static void semantic_comparison(binary_expression_t *expression);
 172
 173 #define STORAGE_CLASSES       \
 174         STORAGE_CLASSES_NO_EXTERN \
 175         case T_extern:
 176
 177 #define STORAGE_CLASSES_NO_EXTERN \
 178         case T_typedef:         \
 179         case T_static:          \
 180         case T_auto:            \
 181         case T_register:        \
 182         case T___thread:
 183
 184 #define TYPE_QUALIFIERS     \
 185         case T_const:           \
 186         case T_restrict:        \
 187         case T_volatile:        \
 188         case T_inline:          \
 189         case T__forceinline:    \
 190         case T___attribute__:
 191
 192 #define COMPLEX_SPECIFIERS  \
 193         case T__Complex:
 194 #define IMAGINARY_SPECIFIERS \
 195         case T__Imaginary:
 196
 197 #define TYPE_SPECIFIERS       \
 198         case T__Bool:             \
 199         case T___builtin_va_list: \
 200         case T___typeof__:        \
 201         case T__declspec:         \
 202         case T_bool:              \
 203         case T_char:              \
 204         case T_double:            \
 205         case T_enum:              \
 206         case T_float:             \
 207         case T_int:               \
 208         case T_long:              \
 209         case T_short:             \
 210         case T_signed:            \
 211         case T_struct:            \
 212         case T_union:             \
 213         case T_unsigned:          \
 214         case T_void:              \
 215         case T_wchar_t:           \
 216         case T__int8:             \
 217         case T__int16:            \
 218         case T__int32:            \
 219         case T__int64:            \
 220         case T__int128:           \
 221         COMPLEX_SPECIFIERS        \
 222         IMAGINARY_SPECIFIERS
 223
 224 #define DECLARATION_START   \
 225         STORAGE_CLASSES         \
 226         TYPE_QUALIFIERS         \
 227         TYPE_SPECIFIERS
 228
 229 #define DECLARATION_START_NO_EXTERN \
 230         STORAGE_CLASSES_NO_EXTERN       \
 231         TYPE_QUALIFIERS                 \
 232         TYPE_SPECIFIERS
 233
 234 #define EXPRESSION_START              \
 235         case '!':                         \
 236         case '&':                         \
 237         case '(':                         \
 238         case '*':                         \
 239         case '+':                         \
 240         case '-':                         \
 241         case '~':                         \
 242         case T_ANDAND:                    \
 243         case T_CHARACTER_CONSTANT:        \
 244         case T_FLOATINGPOINT:             \
 245         case T_FLOATINGPOINT_HEXADECIMAL: \
 246         case T_INTEGER:                   \
 247         case T_INTEGER_HEXADECIMAL:       \
 248         case T_INTEGER_OCTAL:             \
 249         case T_MINUSMINUS:                \
 250         case T_PLUSPLUS:                  \
 251         case T_STRING_LITERAL:            \
 252         case T_WIDE_CHARACTER_CONSTANT:   \
 253         case T_WIDE_STRING_LITERAL:       \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___FUNCTION__:              \
 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_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 331                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 332                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 333                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 334                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 335                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 336                 [EXPR_CALL]                       = sizeof(call_expression_t),
 337                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 338                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 339                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 340                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 341                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 342                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 343                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 344                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 345                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 346                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 347                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 348                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 349                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 350                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 351                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 352                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 353                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 354         };
 355         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 356                 return sizes[EXPR_UNARY_FIRST];
 357         }
 358         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 359                 return sizes[EXPR_BINARY_FIRST];
 360         }
 361         assert((size_t)kind < lengthof(sizes));
 362         assert(sizes[kind] != 0);
 363         return sizes[kind];
 364 }
 365
 366 /**
 367  * Allocate a statement node of given kind and initialize all
 368  * fields with zero. Sets its source position to the position
 369  * of the current token.
 370  */
 371 static statement_t *allocate_statement_zero(statement_kind_t kind)
 372 {
 373         size_t       size = get_statement_struct_size(kind);
 374         statement_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.parent          = current_parent;
 378         res->base.source_position = token.base.source_position;
 379         return res;
 380 }
 381
 382 /**
 383  * Allocate an expression node of given kind and initialize all
 384  * fields with zero.
 385  *
 386  * @param kind  the kind of the expression to allocate
 387  */
 388 static expression_t *allocate_expression_zero(expression_kind_t kind)
 389 {
 390         size_t        size = get_expression_struct_size(kind);
 391         expression_t *res  = allocate_ast_zero(size);
 392
 393         res->base.kind            = kind;
 394         res->base.type            = type_error_type;
 395         res->base.source_position = token.base.source_position;
 396         return res;
 397 }
 398
 399 /**
 400  * Creates a new invalid expression at the source position
 401  * of the current token.
 402  */
 403 static expression_t *create_error_expression(void)
 404 {
 405         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 406         expression->base.type = type_error_type;
 407         return expression;
 408 }
 409
 410 /**
 411  * Creates a new invalid statement.
 412  */
 413 static statement_t *create_error_statement(void)
 414 {
 415         return allocate_statement_zero(STATEMENT_ERROR);
 416 }
 417
 418 /**
 419  * Allocate a new empty statement.
 420  */
 421 static statement_t *create_empty_statement(void)
 422 {
 423         return allocate_statement_zero(STATEMENT_EMPTY);
 424 }
 425
 426 /**
 427  * Returns the size of an initializer node.
 428  *
 429  * @param kind  the initializer kind
 430  */
 431 static size_t get_initializer_size(initializer_kind_t kind)
 432 {
 433         static const size_t sizes[] = {
 434                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 435                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 436                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 437                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 438                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 439         };
 440         assert((size_t)kind < lengthof(sizes));
 441         assert(sizes[kind] != 0);
 442         return sizes[kind];
 443 }
 444
 445 /**
 446  * Allocate an initializer node of given kind and initialize all
 447  * fields with zero.
 448  */
 449 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 450 {
 451         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 452         result->kind          = kind;
 453
 454         return result;
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the environment stack.
 459  */
 460 static size_t environment_top(void)
 461 {
 462         return ARR_LEN(environment_stack);
 463 }
 464
 465 /**
 466  * Returns the index of the top element of the global label stack.
 467  */
 468 static size_t label_top(void)
 469 {
 470         return ARR_LEN(label_stack);
 471 }
 472
 473 /**
 474  * Return the next token.
 475  */
 476 static inline void next_token(void)
 477 {
 478         token                              = lookahead_buffer[lookahead_bufpos];
 479         lookahead_buffer[lookahead_bufpos] = lexer_token;
 480         lexer_next_token();
 481
 482         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 483
 484 #ifdef PRINT_TOKENS
 485         print_token(stderr, &token);
 486         fprintf(stderr, "\n");
 487 #endif
 488 }
 489
 490 static inline bool next_if(token_kind_t const type)
 491 {
 492         if (token.kind == type) {
 493                 next_token();
 494                 return true;
 495         } else {
 496                 return false;
 497         }
 498 }
 499
 500 /**
 501  * Return the next token with a given lookahead.
 502  */
 503 static inline const token_t *look_ahead(size_t num)
 504 {
 505         assert(0 < num && num <= MAX_LOOKAHEAD);
 506         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 507         return &lookahead_buffer[pos];
 508 }
 509
 510 /**
 511  * Adds a token type to the token type anchor set (a multi-set).
 512  */
 513 static void add_anchor_token(token_kind_t const token_kind)
 514 {
 515         assert(token_kind < T_LAST_TOKEN);
 516         ++token_anchor_set[token_kind];
 517 }
 518
 519 /**
 520  * Remove a token type from the token type anchor set (a multi-set).
 521  */
 522 static void rem_anchor_token(token_kind_t const token_kind)
 523 {
 524         assert(token_kind < T_LAST_TOKEN);
 525         assert(token_anchor_set[token_kind] != 0);
 526         --token_anchor_set[token_kind];
 527 }
 528
 529 /**
 530  * Eat tokens until a matching token type is found.
 531  */
 532 static void eat_until_matching_token(token_kind_t const type)
 533 {
 534         token_kind_t end_token;
 535         switch (type) {
 536                 case '(': end_token = ')';  break;
 537                 case '{': end_token = '}';  break;
 538                 case '[': end_token = ']';  break;
 539                 default:  end_token = type; break;
 540         }
 541
 542         unsigned parenthesis_count = 0;
 543         unsigned brace_count       = 0;
 544         unsigned bracket_count     = 0;
 545         while (token.kind        != end_token ||
 546                parenthesis_count != 0         ||
 547                brace_count       != 0         ||
 548                bracket_count     != 0) {
 549                 switch (token.kind) {
 550                 case T_EOF: return;
 551                 case '(': ++parenthesis_count; break;
 552                 case '{': ++brace_count;       break;
 553                 case '[': ++bracket_count;     break;
 554
 555                 case ')':
 556                         if (parenthesis_count > 0)
 557                                 --parenthesis_count;
 558                         goto check_stop;
 559
 560                 case '}':
 561                         if (brace_count > 0)
 562                                 --brace_count;
 563                         goto check_stop;
 564
 565                 case ']':
 566                         if (bracket_count > 0)
 567                                 --bracket_count;
 568 check_stop:
 569                         if (token.kind        == end_token &&
 570                             parenthesis_count == 0         &&
 571                             brace_count       == 0         &&
 572                             bracket_count     == 0)
 573                                 return;
 574                         break;
 575
 576                 default:
 577                         break;
 578                 }
 579                 next_token();
 580         }
 581 }
 582
 583 /**
 584  * Eat input tokens until an anchor is found.
 585  */
 586 static void eat_until_anchor(void)
 587 {
 588         while (token_anchor_set[token.kind] == 0) {
 589                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 590                         eat_until_matching_token(token.kind);
 591                 next_token();
 592         }
 593 }
 594
 595 /**
 596  * Eat a whole block from input tokens.
 597  */
 598 static void eat_block(void)
 599 {
 600         eat_until_matching_token('{');
 601         next_if('}');
 602 }
 603
 604 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 605
 606 /**
 607  * Report a parse error because an expected token was not found.
 608  */
 609 static
 610 #if defined __GNUC__ && __GNUC__ >= 4
 611 __attribute__((sentinel))
 612 #endif
 613 void parse_error_expected(const char *message, ...)
 614 {
 615         if (message != NULL) {
 616                 errorf(HERE, "%s", message);
 617         }
 618         va_list ap;
 619         va_start(ap, message);
 620         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 621         va_end(ap);
 622 }
 623
 624 /**
 625  * Report an incompatible type.
 626  */
 627 static void type_error_incompatible(const char *msg,
 628                 const source_position_t *source_position, type_t *type1, type_t *type2)
 629 {
 630         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 631                msg, type1, type2);
 632 }
 633
 634 /**
 635  * Expect the current token is the expected token.
 636  * If not, generate an error and skip until the next anchor.
 637  */
 638 static void expect(token_kind_t const expected)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(NULL, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return;
 647         }
 648         eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (token.kind != T_IDENTIFIER) {
 654                 parse_error_expected(context, T_IDENTIFIER, NULL);
 655                 add_anchor_token(T_IDENTIFIER);
 656                 eat_until_anchor();
 657                 rem_anchor_token(T_IDENTIFIER);
 658                 if (token.kind != T_IDENTIFIER)
 659                         return NULL;
 660         }
 661         symbol_t *const sym = token.identifier.symbol;
 662         if (pos)
 663                 *pos = *HERE;
 664         eat(T_IDENTIFIER);
 665         return sym;
 666 }
 667
 668 /**
 669  * Push a given scope on the scope stack and make it the
 670  * current scope
 671  */
 672 static scope_t *scope_push(scope_t *new_scope)
 673 {
 674         if (current_scope != NULL) {
 675                 new_scope->depth = current_scope->depth + 1;
 676         }
 677
 678         scope_t *old_scope = current_scope;
 679         current_scope      = new_scope;
 680         return old_scope;
 681 }
 682
 683 /**
 684  * Pop the current scope from the scope stack.
 685  */
 686 static void scope_pop(scope_t *old_scope)
 687 {
 688         current_scope = old_scope;
 689 }
 690
 691 /**
 692  * Search an entity by its symbol in a given namespace.
 693  */
 694 static entity_t *get_entity(const symbol_t *const symbol,
 695                             namespace_tag_t namespc)
 696 {
 697         entity_t *entity = symbol->entity;
 698         for (; entity != NULL; entity = entity->base.symbol_next) {
 699                 if ((namespace_tag_t)entity->base.namespc == namespc)
 700                         return entity;
 701         }
 702
 703         return NULL;
 704 }
 705
 706 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 707  * possible. */
 708 static entity_t *get_tag(symbol_t const *const symbol,
 709                          entity_kind_tag_t const kind)
 710 {
 711         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 712         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 713                 errorf(HERE,
 714                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 715                                 symbol, &entity->base.source_position);
 716                 entity = NULL;
 717         }
 718         return entity;
 719 }
 720
 721 /**
 722  * pushs an entity on the environment stack and links the corresponding symbol
 723  * it.
 724  */
 725 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 726 {
 727         symbol_t           *symbol  = entity->base.symbol;
 728         entity_namespace_t  namespc = entity->base.namespc;
 729         assert(namespc != 0);
 730
 731         /* replace/add entity into entity list of the symbol */
 732         entity_t **anchor;
 733         entity_t  *iter;
 734         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 735                 iter = *anchor;
 736                 if (iter == NULL)
 737                         break;
 738
 739                 /* replace an entry? */
 740                 if (iter->base.namespc == namespc) {
 741                         entity->base.symbol_next = iter->base.symbol_next;
 742                         break;
 743                 }
 744         }
 745         *anchor = entity;
 746
 747         /* remember old declaration */
 748         stack_entry_t entry;
 749         entry.symbol     = symbol;
 750         entry.old_entity = iter;
 751         entry.namespc    = namespc;
 752         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 753 }
 754
 755 /**
 756  * Push an entity on the environment stack.
 757  */
 758 static void environment_push(entity_t *entity)
 759 {
 760         assert(entity->base.source_position.input_name != NULL);
 761         assert(entity->base.parent_scope != NULL);
 762         stack_push(&environment_stack, entity);
 763 }
 764
 765 /**
 766  * Push a declaration on the global label stack.
 767  *
 768  * @param declaration  the declaration
 769  */
 770 static void label_push(entity_t *label)
 771 {
 772         /* we abuse the parameters scope as parent for the labels */
 773         label->base.parent_scope = &current_function->parameters;
 774         stack_push(&label_stack, label);
 775 }
 776
 777 /**
 778  * pops symbols from the environment stack until @p new_top is the top element
 779  */
 780 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 781 {
 782         stack_entry_t *stack = *stack_ptr;
 783         size_t         top   = ARR_LEN(stack);
 784         size_t         i;
 785
 786         assert(new_top <= top);
 787         if (new_top == top)
 788                 return;
 789
 790         for (i = top; i > new_top; --i) {
 791                 stack_entry_t *entry = &stack[i - 1];
 792
 793                 entity_t           *old_entity = entry->old_entity;
 794                 symbol_t           *symbol     = entry->symbol;
 795                 entity_namespace_t  namespc    = entry->namespc;
 796
 797                 /* replace with old_entity/remove */
 798                 entity_t **anchor;
 799                 entity_t  *iter;
 800                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 801                         iter = *anchor;
 802                         assert(iter != NULL);
 803                         /* replace an entry? */
 804                         if (iter->base.namespc == namespc)
 805                                 break;
 806                 }
 807
 808                 /* restore definition from outer scopes (if there was one) */
 809                 if (old_entity != NULL) {
 810                         old_entity->base.symbol_next = iter->base.symbol_next;
 811                         *anchor                      = old_entity;
 812                 } else {
 813                         /* remove entry from list */
 814                         *anchor = iter->base.symbol_next;
 815                 }
 816         }
 817
 818         ARR_SHRINKLEN(*stack_ptr, new_top);
 819 }
 820
 821 /**
 822  * Pop all entries from the environment stack until the new_top
 823  * is reached.
 824  *
 825  * @param new_top  the new stack top
 826  */
 827 static void environment_pop_to(size_t new_top)
 828 {
 829         stack_pop_to(&environment_stack, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the global label stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void label_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&label_stack, new_top);
 841 }
 842
 843 static atomic_type_kind_t get_akind(const type_t *type)
 844 {
 845         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 846                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 847         return type->atomic.akind;
 848 }
 849
 850 /**
 851  * §6.3.1.1:2  Do integer promotion for a given type.
 852  *
 853  * @param type  the type to promote
 854  * @return the promoted type
 855  */
 856 static type_t *promote_integer(type_t *type)
 857 {
 858         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 859                 type = type_int;
 860
 861         return type;
 862 }
 863
 864 /**
 865  * Check if a given expression represents a null pointer constant.
 866  *
 867  * @param expression  the expression to check
 868  */
 869 static bool is_null_pointer_constant(const expression_t *expression)
 870 {
 871         /* skip void* cast */
 872         if (expression->kind == EXPR_UNARY_CAST) {
 873                 type_t *const type = skip_typeref(expression->base.type);
 874                 if (types_compatible(type, type_void_ptr))
 875                         expression = expression->unary.value;
 876         }
 877
 878         type_t *const type = skip_typeref(expression->base.type);
 879         if (!is_type_integer(type))
 880                 return false;
 881         switch (is_constant_expression(expression)) {
 882                 case EXPR_CLASS_ERROR:    return true;
 883                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 884                 default:                  return false;
 885         }
 886 }
 887
 888 /**
 889  * Create an implicit cast expression.
 890  *
 891  * @param expression  the expression to cast
 892  * @param dest_type   the destination type
 893  */
 894 static expression_t *create_implicit_cast(expression_t *expression,
 895                                           type_t *dest_type)
 896 {
 897         type_t *const source_type = expression->base.type;
 898
 899         if (source_type == dest_type)
 900                 return expression;
 901
 902         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 903         cast->unary.value   = expression;
 904         cast->base.type     = dest_type;
 905         cast->base.implicit = true;
 906
 907         return cast;
 908 }
 909
 910 typedef enum assign_error_t {
 911         ASSIGN_SUCCESS,
 912         ASSIGN_ERROR_INCOMPATIBLE,
 913         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 914         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 915         ASSIGN_WARNING_POINTER_FROM_INT,
 916         ASSIGN_WARNING_INT_FROM_POINTER
 917 } assign_error_t;
 918
 919 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)
 920 {
 921         type_t *const orig_type_right = right->base.type;
 922         type_t *const type_left       = skip_typeref(orig_type_left);
 923         type_t *const type_right      = skip_typeref(orig_type_right);
 924
 925         switch (error) {
 926         case ASSIGN_SUCCESS:
 927                 return;
 928         case ASSIGN_ERROR_INCOMPATIBLE:
 929                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 930                 return;
 931
 932         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 933                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 934                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 935
 936                 /* the left type has all qualifiers from the right type */
 937                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 938                 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);
 939                 return;
 940         }
 941
 942         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 943                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_POINTER_FROM_INT:
 947                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         case ASSIGN_WARNING_INT_FROM_POINTER:
 951                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 952                 return;
 953
 954         default:
 955                 panic("invalid error value");
 956         }
 957 }
 958
 959 /** Implements the rules from §6.5.16.1 */
 960 static assign_error_t semantic_assign(type_t *orig_type_left,
 961                                       const expression_t *const right)
 962 {
 963         type_t *const orig_type_right = right->base.type;
 964         type_t *const type_left       = skip_typeref(orig_type_left);
 965         type_t *const type_right      = skip_typeref(orig_type_right);
 966
 967         if (is_type_pointer(type_left)) {
 968                 if (is_null_pointer_constant(right)) {
 969                         return ASSIGN_SUCCESS;
 970                 } else if (is_type_pointer(type_right)) {
 971                         type_t *points_to_left
 972                                 = skip_typeref(type_left->pointer.points_to);
 973                         type_t *points_to_right
 974                                 = skip_typeref(type_right->pointer.points_to);
 975                         assign_error_t res = ASSIGN_SUCCESS;
 976
 977                         /* the left type has all qualifiers from the right type */
 978                         unsigned missing_qualifiers
 979                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 980                         if (missing_qualifiers != 0) {
 981                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 982                         }
 983
 984                         points_to_left  = get_unqualified_type(points_to_left);
 985                         points_to_right = get_unqualified_type(points_to_right);
 986
 987                         if (is_type_void(points_to_left))
 988                                 return res;
 989
 990                         if (is_type_void(points_to_right)) {
 991                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 992                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 993                         }
 994
 995                         if (!types_compatible(points_to_left, points_to_right)) {
 996                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 997                         }
 998
 999                         return res;
1000                 } else if (is_type_integer(type_right)) {
1001                         return ASSIGN_WARNING_POINTER_FROM_INT;
1002                 }
1003         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1004                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1005                                 && is_type_pointer(type_right))) {
1006                 return ASSIGN_SUCCESS;
1007         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1008                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1009                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1010                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1011                         return ASSIGN_SUCCESS;
1012                 }
1013         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1014                 return ASSIGN_WARNING_INT_FROM_POINTER;
1015         }
1016
1017         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1018                 return ASSIGN_SUCCESS;
1019
1020         return ASSIGN_ERROR_INCOMPATIBLE;
1021 }
1022
1023 static expression_t *parse_constant_expression(void)
1024 {
1025         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1026
1027         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1028                 errorf(&result->base.source_position,
1029                        "expression '%E' is not constant", result);
1030         }
1031
1032         return result;
1033 }
1034
1035 static expression_t *parse_assignment_expression(void)
1036 {
1037         return parse_subexpression(PREC_ASSIGNMENT);
1038 }
1039
1040 static void warn_string_concat(const source_position_t *pos)
1041 {
1042         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1043 }
1044
1045 static string_t parse_string_literals(void)
1046 {
1047         assert(token.kind == T_STRING_LITERAL);
1048         string_t result = token.string.string;
1049
1050         next_token();
1051
1052         while (token.kind == T_STRING_LITERAL) {
1053                 warn_string_concat(&token.base.source_position);
1054                 result = concat_strings(&result, &token.string.string);
1055                 next_token();
1056         }
1057
1058         return result;
1059 }
1060
1061 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1062 {
1063         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1064         attribute->kind            = kind;
1065         attribute->source_position = *HERE;
1066         return attribute;
1067 }
1068
1069 /**
1070  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1071  *
1072  *  attribute:
1073  *    __attribute__ ( ( attribute-list ) )
1074  *
1075  *  attribute-list:
1076  *    attrib
1077  *    attribute_list , attrib
1078  *
1079  *  attrib:
1080  *    empty
1081  *    any-word
1082  *    any-word ( identifier )
1083  *    any-word ( identifier , nonempty-expr-list )
1084  *    any-word ( expr-list )
1085  *
1086  *  where the "identifier" must not be declared as a type, and
1087  *  "any-word" may be any identifier (including one declared as a
1088  *  type), a reserved word storage class specifier, type specifier or
1089  *  type qualifier.  ??? This still leaves out most reserved keywords
1090  *  (following the old parser), shouldn't we include them, and why not
1091  *  allow identifiers declared as types to start the arguments?
1092  *
1093  *  Matze: this all looks confusing and little systematic, so we're even less
1094  *  strict and parse any list of things which are identifiers or
1095  *  (assignment-)expressions.
1096  */
1097 static attribute_argument_t *parse_attribute_arguments(void)
1098 {
1099         attribute_argument_t  *first  = NULL;
1100         attribute_argument_t **anchor = &first;
1101         if (token.kind != ')') do {
1102                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1103
1104                 /* is it an identifier */
1105                 if (token.kind == T_IDENTIFIER
1106                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1107                         symbol_t *symbol   = token.identifier.symbol;
1108                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1109                         argument->v.symbol = symbol;
1110                         next_token();
1111                 } else {
1112                         /* must be an expression */
1113                         expression_t *expression = parse_assignment_expression();
1114
1115                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1116                         argument->v.expression = expression;
1117                 }
1118
1119                 /* append argument */
1120                 *anchor = argument;
1121                 anchor  = &argument->next;
1122         } while (next_if(','));
1123         expect(')');
1124         return first;
1125 }
1126
1127 static attribute_t *parse_attribute_asm(void)
1128 {
1129         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1130         eat(T_asm);
1131         expect('(');
1132         attribute->a.arguments = parse_attribute_arguments();
1133         return attribute;
1134 }
1135
1136 static symbol_t *get_symbol_from_token(void)
1137 {
1138         switch(token.kind) {
1139         case T_CHARACTER_CONSTANT:
1140         case T_EOF:
1141         case T_FLOATINGPOINT:
1142         case T_FLOATINGPOINT_HEXADECIMAL:
1143         case T_INTEGER:
1144         case T_INTEGER_HEXADECIMAL:
1145         case T_INTEGER_OCTAL:
1146         case T_STRING_LITERAL:
1147         case T_WIDE_CHARACTER_CONSTANT:
1148         case T_WIDE_STRING_LITERAL:
1149                 return NULL;
1150
1151         default:
1152                 return token.identifier.symbol;
1153         }
1154 }
1155
1156 static attribute_t *parse_attribute_gnu_single(void)
1157 {
1158         /* parse "any-word" */
1159         symbol_t *symbol = get_symbol_from_token();
1160         if (symbol == NULL) {
1161                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1162                 return NULL;
1163         }
1164
1165         attribute_kind_t  kind;
1166         char const *const name = symbol->string;
1167         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1168                 if (kind > ATTRIBUTE_GNU_LAST) {
1169                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1170                         /* TODO: we should still save the attribute in the list... */
1171                         kind = ATTRIBUTE_UNKNOWN;
1172                         break;
1173                 }
1174
1175                 const char *attribute_name = get_attribute_name(kind);
1176                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1177                         break;
1178         }
1179
1180         attribute_t *attribute = allocate_attribute_zero(kind);
1181         next_token();
1182
1183         /* parse arguments */
1184         if (next_if('('))
1185                 attribute->a.arguments = parse_attribute_arguments();
1186
1187         return attribute;
1188 }
1189
1190 static attribute_t *parse_attribute_gnu(void)
1191 {
1192         attribute_t  *first  = NULL;
1193         attribute_t **anchor = &first;
1194
1195         eat(T___attribute__);
1196         expect('(');
1197         expect('(');
1198
1199         add_anchor_token(')');
1200         add_anchor_token(',');
1201         if (token.kind != ')') do {
1202                 attribute_t *attribute = parse_attribute_gnu_single();
1203                 if (attribute) {
1204                         *anchor = attribute;
1205                         anchor  = &attribute->next;
1206                 }
1207         } while (next_if(','));
1208         rem_anchor_token(',');
1209         rem_anchor_token(')');
1210
1211         expect(')');
1212         expect(')');
1213         return first;
1214 }
1215
1216 /** Parse attributes. */
1217 static attribute_t *parse_attributes(attribute_t *first)
1218 {
1219         attribute_t **anchor = &first;
1220         for (;;) {
1221                 while (*anchor != NULL)
1222                         anchor = &(*anchor)->next;
1223
1224                 attribute_t *attribute;
1225                 switch (token.kind) {
1226                 case T___attribute__:
1227                         attribute = parse_attribute_gnu();
1228                         if (attribute == NULL)
1229                                 continue;
1230                         break;
1231
1232                 case T_asm:
1233                         attribute = parse_attribute_asm();
1234                         break;
1235
1236                 case T_cdecl:
1237                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1238                         eat(T_cdecl);
1239                         break;
1240
1241                 case T__fastcall:
1242                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1243                         eat(T__fastcall);
1244                         break;
1245
1246                 case T__forceinline:
1247                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1248                         eat(T__forceinline);
1249                         break;
1250
1251                 case T__stdcall:
1252                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1253                         eat(T__stdcall);
1254                         break;
1255
1256                 case T___thiscall:
1257                         /* TODO record modifier */
1258                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1259                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1260                         eat(T___thiscall);
1261                         break;
1262
1263                 default:
1264                         return first;
1265                 }
1266
1267                 *anchor = attribute;
1268                 anchor  = &attribute->next;
1269         }
1270 }
1271
1272 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1273
1274 static entity_t *determine_lhs_ent(expression_t *const expr,
1275                                    entity_t *lhs_ent)
1276 {
1277         switch (expr->kind) {
1278                 case EXPR_REFERENCE: {
1279                         entity_t *const entity = expr->reference.entity;
1280                         /* we should only find variables as lvalues... */
1281                         if (entity->base.kind != ENTITY_VARIABLE
1282                                         && entity->base.kind != ENTITY_PARAMETER)
1283                                 return NULL;
1284
1285                         return entity;
1286                 }
1287
1288                 case EXPR_ARRAY_ACCESS: {
1289                         expression_t *const ref = expr->array_access.array_ref;
1290                         entity_t     *      ent = NULL;
1291                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1292                                 ent     = determine_lhs_ent(ref, lhs_ent);
1293                                 lhs_ent = ent;
1294                         } else {
1295                                 mark_vars_read(ref, lhs_ent);
1296                         }
1297                         mark_vars_read(expr->array_access.index, lhs_ent);
1298                         return ent;
1299                 }
1300
1301                 case EXPR_SELECT: {
1302                         mark_vars_read(expr->select.compound, lhs_ent);
1303                         if (is_type_compound(skip_typeref(expr->base.type)))
1304                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1305                         return NULL;
1306                 }
1307
1308                 case EXPR_UNARY_DEREFERENCE: {
1309                         expression_t *const val = expr->unary.value;
1310                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1311                                 /* *&x is a NOP */
1312                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1313                         } else {
1314                                 mark_vars_read(val, NULL);
1315                                 return NULL;
1316                         }
1317                 }
1318
1319                 default:
1320                         mark_vars_read(expr, NULL);
1321                         return NULL;
1322         }
1323 }
1324
1325 #define ENT_ANY ((entity_t*)-1)
1326
1327 /**
1328  * Mark declarations, which are read.  This is used to detect variables, which
1329  * are never read.
1330  * Example:
1331  * x = x + 1;
1332  *   x is not marked as "read", because it is only read to calculate its own new
1333  *   value.
1334  *
1335  * x += y; y += x;
1336  *   x and y are not detected as "not read", because multiple variables are
1337  *   involved.
1338  */
1339 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1340 {
1341         switch (expr->kind) {
1342                 case EXPR_REFERENCE: {
1343                         entity_t *const entity = expr->reference.entity;
1344                         if (entity->kind != ENTITY_VARIABLE
1345                                         && entity->kind != ENTITY_PARAMETER)
1346                                 return;
1347
1348                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1349                                 if (entity->kind == ENTITY_VARIABLE) {
1350                                         entity->variable.read = true;
1351                                 } else {
1352                                         entity->parameter.read = true;
1353                                 }
1354                         }
1355                         return;
1356                 }
1357
1358                 case EXPR_CALL:
1359                         // TODO respect pure/const
1360                         mark_vars_read(expr->call.function, NULL);
1361                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1362                                 mark_vars_read(arg->expression, NULL);
1363                         }
1364                         return;
1365
1366                 case EXPR_CONDITIONAL:
1367                         // TODO lhs_decl should depend on whether true/false have an effect
1368                         mark_vars_read(expr->conditional.condition, NULL);
1369                         if (expr->conditional.true_expression != NULL)
1370                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1371                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1372                         return;
1373
1374                 case EXPR_SELECT:
1375                         if (lhs_ent == ENT_ANY
1376                                         && !is_type_compound(skip_typeref(expr->base.type)))
1377                                 lhs_ent = NULL;
1378                         mark_vars_read(expr->select.compound, lhs_ent);
1379                         return;
1380
1381                 case EXPR_ARRAY_ACCESS: {
1382                         mark_vars_read(expr->array_access.index, lhs_ent);
1383                         expression_t *const ref = expr->array_access.array_ref;
1384                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1385                                 if (lhs_ent == ENT_ANY)
1386                                         lhs_ent = NULL;
1387                         }
1388                         mark_vars_read(ref, lhs_ent);
1389                         return;
1390                 }
1391
1392                 case EXPR_VA_ARG:
1393                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1394                         return;
1395
1396                 case EXPR_VA_COPY:
1397                         mark_vars_read(expr->va_copye.src, lhs_ent);
1398                         return;
1399
1400                 case EXPR_UNARY_CAST:
1401                         /* Special case: Use void cast to mark a variable as "read" */
1402                         if (is_type_void(skip_typeref(expr->base.type)))
1403                                 lhs_ent = NULL;
1404                         goto unary;
1405
1406
1407                 case EXPR_UNARY_THROW:
1408                         if (expr->unary.value == NULL)
1409                                 return;
1410                         /* FALLTHROUGH */
1411                 case EXPR_UNARY_DEREFERENCE:
1412                 case EXPR_UNARY_DELETE:
1413                 case EXPR_UNARY_DELETE_ARRAY:
1414                         if (lhs_ent == ENT_ANY)
1415                                 lhs_ent = NULL;
1416                         goto unary;
1417
1418                 case EXPR_UNARY_NEGATE:
1419                 case EXPR_UNARY_PLUS:
1420                 case EXPR_UNARY_BITWISE_NEGATE:
1421                 case EXPR_UNARY_NOT:
1422                 case EXPR_UNARY_TAKE_ADDRESS:
1423                 case EXPR_UNARY_POSTFIX_INCREMENT:
1424                 case EXPR_UNARY_POSTFIX_DECREMENT:
1425                 case EXPR_UNARY_PREFIX_INCREMENT:
1426                 case EXPR_UNARY_PREFIX_DECREMENT:
1427                 case EXPR_UNARY_ASSUME:
1428 unary:
1429                         mark_vars_read(expr->unary.value, lhs_ent);
1430                         return;
1431
1432                 case EXPR_BINARY_ADD:
1433                 case EXPR_BINARY_SUB:
1434                 case EXPR_BINARY_MUL:
1435                 case EXPR_BINARY_DIV:
1436                 case EXPR_BINARY_MOD:
1437                 case EXPR_BINARY_EQUAL:
1438                 case EXPR_BINARY_NOTEQUAL:
1439                 case EXPR_BINARY_LESS:
1440                 case EXPR_BINARY_LESSEQUAL:
1441                 case EXPR_BINARY_GREATER:
1442                 case EXPR_BINARY_GREATEREQUAL:
1443                 case EXPR_BINARY_BITWISE_AND:
1444                 case EXPR_BINARY_BITWISE_OR:
1445                 case EXPR_BINARY_BITWISE_XOR:
1446                 case EXPR_BINARY_LOGICAL_AND:
1447                 case EXPR_BINARY_LOGICAL_OR:
1448                 case EXPR_BINARY_SHIFTLEFT:
1449                 case EXPR_BINARY_SHIFTRIGHT:
1450                 case EXPR_BINARY_COMMA:
1451                 case EXPR_BINARY_ISGREATER:
1452                 case EXPR_BINARY_ISGREATEREQUAL:
1453                 case EXPR_BINARY_ISLESS:
1454                 case EXPR_BINARY_ISLESSEQUAL:
1455                 case EXPR_BINARY_ISLESSGREATER:
1456                 case EXPR_BINARY_ISUNORDERED:
1457                         mark_vars_read(expr->binary.left,  lhs_ent);
1458                         mark_vars_read(expr->binary.right, lhs_ent);
1459                         return;
1460
1461                 case EXPR_BINARY_ASSIGN:
1462                 case EXPR_BINARY_MUL_ASSIGN:
1463                 case EXPR_BINARY_DIV_ASSIGN:
1464                 case EXPR_BINARY_MOD_ASSIGN:
1465                 case EXPR_BINARY_ADD_ASSIGN:
1466                 case EXPR_BINARY_SUB_ASSIGN:
1467                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1468                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1469                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1470                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1471                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1472                         if (lhs_ent == ENT_ANY)
1473                                 lhs_ent = NULL;
1474                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1475                         mark_vars_read(expr->binary.right, lhs_ent);
1476                         return;
1477                 }
1478
1479                 case EXPR_VA_START:
1480                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1481                         return;
1482
1483                 case EXPR_LITERAL_CASES:
1484                 case EXPR_ERROR:
1485                 case EXPR_STRING_LITERAL:
1486                 case EXPR_WIDE_STRING_LITERAL:
1487                 case EXPR_COMPOUND_LITERAL: // TODO init?
1488                 case EXPR_SIZEOF:
1489                 case EXPR_CLASSIFY_TYPE:
1490                 case EXPR_ALIGNOF:
1491                 case EXPR_FUNCNAME:
1492                 case EXPR_BUILTIN_CONSTANT_P:
1493                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1494                 case EXPR_OFFSETOF:
1495                 case EXPR_STATEMENT: // TODO
1496                 case EXPR_LABEL_ADDRESS:
1497                 case EXPR_ENUM_CONSTANT:
1498                         return;
1499         }
1500
1501         panic("unhandled expression");
1502 }
1503
1504 static designator_t *parse_designation(void)
1505 {
1506         designator_t  *result = NULL;
1507         designator_t **anchor = &result;
1508
1509         for (;;) {
1510                 designator_t *designator;
1511                 switch (token.kind) {
1512                 case '[':
1513                         designator = allocate_ast_zero(sizeof(designator[0]));
1514                         designator->source_position = token.base.source_position;
1515                         next_token();
1516                         add_anchor_token(']');
1517                         designator->array_index = parse_constant_expression();
1518                         rem_anchor_token(']');
1519                         expect(']');
1520                         break;
1521                 case '.':
1522                         designator = allocate_ast_zero(sizeof(designator[0]));
1523                         designator->source_position = token.base.source_position;
1524                         next_token();
1525                         designator->symbol = expect_identifier("while parsing designator", NULL);
1526                         if (!designator->symbol)
1527                                 return NULL;
1528                         break;
1529                 default:
1530                         expect('=');
1531                         return result;
1532                 }
1533
1534                 assert(designator != NULL);
1535                 *anchor = designator;
1536                 anchor  = &designator->next;
1537         }
1538 }
1539
1540 static initializer_t *initializer_from_string(array_type_t *const type,
1541                                               const string_t *const string)
1542 {
1543         /* TODO: check len vs. size of array type */
1544         (void) type;
1545
1546         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1547         initializer->string.string = *string;
1548
1549         return initializer;
1550 }
1551
1552 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1553                                                    const string_t *const string)
1554 {
1555         /* TODO: check len vs. size of array type */
1556         (void) type;
1557
1558         initializer_t *const initializer =
1559                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1560         initializer->wide_string.string = *string;
1561
1562         return initializer;
1563 }
1564
1565 /**
1566  * Build an initializer from a given expression.
1567  */
1568 static initializer_t *initializer_from_expression(type_t *orig_type,
1569                                                   expression_t *expression)
1570 {
1571         /* TODO check that expression is a constant expression */
1572
1573         /* §6.7.8.14/15 char array may be initialized by string literals */
1574         type_t *type           = skip_typeref(orig_type);
1575         type_t *expr_type_orig = expression->base.type;
1576         type_t *expr_type      = skip_typeref(expr_type_orig);
1577
1578         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1579                 array_type_t *const array_type   = &type->array;
1580                 type_t       *const element_type = skip_typeref(array_type->element_type);
1581
1582                 if (element_type->kind == TYPE_ATOMIC) {
1583                         atomic_type_kind_t akind = element_type->atomic.akind;
1584                         switch (expression->kind) {
1585                         case EXPR_STRING_LITERAL:
1586                                 if (akind == ATOMIC_TYPE_CHAR
1587                                                 || akind == ATOMIC_TYPE_SCHAR
1588                                                 || akind == ATOMIC_TYPE_UCHAR) {
1589                                         return initializer_from_string(array_type,
1590                                                         &expression->string_literal.value);
1591                                 }
1592                                 break;
1593
1594                         case EXPR_WIDE_STRING_LITERAL: {
1595                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1596                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1597                                         return initializer_from_wide_string(array_type,
1598                                                         &expression->string_literal.value);
1599                                 }
1600                                 break;
1601                         }
1602
1603                         default:
1604                                 break;
1605                         }
1606                 }
1607         }
1608
1609         assign_error_t error = semantic_assign(type, expression);
1610         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1611                 return NULL;
1612         report_assign_error(error, type, expression, "initializer",
1613                             &expression->base.source_position);
1614
1615         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1616         result->value.value = create_implicit_cast(expression, type);
1617
1618         return result;
1619 }
1620
1621 /**
1622  * Parses an scalar initializer.
1623  *
1624  * §6.7.8.11; eat {} without warning
1625  */
1626 static initializer_t *parse_scalar_initializer(type_t *type,
1627                                                bool must_be_constant)
1628 {
1629         /* there might be extra {} hierarchies */
1630         int braces = 0;
1631         if (token.kind == '{') {
1632                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1633                 do {
1634                         eat('{');
1635                         ++braces;
1636                 } while (token.kind == '{');
1637         }
1638
1639         expression_t *expression = parse_assignment_expression();
1640         mark_vars_read(expression, NULL);
1641         if (must_be_constant && !is_linker_constant(expression)) {
1642                 errorf(&expression->base.source_position,
1643                        "initialisation expression '%E' is not constant",
1644                        expression);
1645         }
1646
1647         initializer_t *initializer = initializer_from_expression(type, expression);
1648
1649         if (initializer == NULL) {
1650                 errorf(&expression->base.source_position,
1651                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1652                        expression, expression->base.type, type);
1653                 /* TODO */
1654                 return NULL;
1655         }
1656
1657         bool additional_warning_displayed = false;
1658         while (braces > 0) {
1659                 next_if(',');
1660                 if (token.kind != '}') {
1661                         if (!additional_warning_displayed) {
1662                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1663                                 additional_warning_displayed = true;
1664                         }
1665                 }
1666                 eat_block();
1667                 braces--;
1668         }
1669
1670         return initializer;
1671 }
1672
1673 /**
1674  * An entry in the type path.
1675  */
1676 typedef struct type_path_entry_t type_path_entry_t;
1677 struct type_path_entry_t {
1678         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1679         union {
1680                 size_t         index;          /**< For array types: the current index. */
1681                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1682         } v;
1683 };
1684
1685 /**
1686  * A type path expression a position inside compound or array types.
1687  */
1688 typedef struct type_path_t type_path_t;
1689 struct type_path_t {
1690         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1691         type_t            *top_type;     /**< type of the element the path points */
1692         size_t             max_index;    /**< largest index in outermost array */
1693 };
1694
1695 /**
1696  * Prints a type path for debugging.
1697  */
1698 static __attribute__((unused)) void debug_print_type_path(
1699                 const type_path_t *path)
1700 {
1701         size_t len = ARR_LEN(path->path);
1702
1703         for (size_t i = 0; i < len; ++i) {
1704                 const type_path_entry_t *entry = & path->path[i];
1705
1706                 type_t *type = skip_typeref(entry->type);
1707                 if (is_type_compound(type)) {
1708                         /* in gcc mode structs can have no members */
1709                         if (entry->v.compound_entry == NULL) {
1710                                 assert(i == len-1);
1711                                 continue;
1712                         }
1713                         fprintf(stderr, ".%s",
1714                                 entry->v.compound_entry->base.symbol->string);
1715                 } else if (is_type_array(type)) {
1716                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1717                 } else {
1718                         fprintf(stderr, "-INVALID-");
1719                 }
1720         }
1721         if (path->top_type != NULL) {
1722                 fprintf(stderr, "  (");
1723                 print_type(path->top_type);
1724                 fprintf(stderr, ")");
1725         }
1726 }
1727
1728 /**
1729  * Return the top type path entry, ie. in a path
1730  * (type).a.b returns the b.
1731  */
1732 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1733 {
1734         size_t len = ARR_LEN(path->path);
1735         assert(len > 0);
1736         return &path->path[len-1];
1737 }
1738
1739 /**
1740  * Enlarge the type path by an (empty) element.
1741  */
1742 static type_path_entry_t *append_to_type_path(type_path_t *path)
1743 {
1744         size_t len = ARR_LEN(path->path);
1745         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1746
1747         type_path_entry_t *result = & path->path[len];
1748         memset(result, 0, sizeof(result[0]));
1749         return result;
1750 }
1751
1752 /**
1753  * Descending into a sub-type. Enter the scope of the current top_type.
1754  */
1755 static void descend_into_subtype(type_path_t *path)
1756 {
1757         type_t *orig_top_type = path->top_type;
1758         type_t *top_type      = skip_typeref(orig_top_type);
1759
1760         type_path_entry_t *top = append_to_type_path(path);
1761         top->type              = top_type;
1762
1763         if (is_type_compound(top_type)) {
1764                 compound_t *const compound = top_type->compound.compound;
1765                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1766
1767                 if (entry != NULL) {
1768                         top->v.compound_entry = &entry->declaration;
1769                         path->top_type = entry->declaration.type;
1770                 } else {
1771                         path->top_type = NULL;
1772                 }
1773         } else if (is_type_array(top_type)) {
1774                 top->v.index   = 0;
1775                 path->top_type = top_type->array.element_type;
1776         } else {
1777                 assert(!is_type_valid(top_type));
1778         }
1779 }
1780
1781 /**
1782  * Pop an entry from the given type path, ie. returning from
1783  * (type).a.b to (type).a
1784  */
1785 static void ascend_from_subtype(type_path_t *path)
1786 {
1787         type_path_entry_t *top = get_type_path_top(path);
1788
1789         path->top_type = top->type;
1790
1791         size_t len = ARR_LEN(path->path);
1792         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1793 }
1794
1795 /**
1796  * Pop entries from the given type path until the given
1797  * path level is reached.
1798  */
1799 static void ascend_to(type_path_t *path, size_t top_path_level)
1800 {
1801         size_t len = ARR_LEN(path->path);
1802
1803         while (len > top_path_level) {
1804                 ascend_from_subtype(path);
1805                 len = ARR_LEN(path->path);
1806         }
1807 }
1808
1809 static bool walk_designator(type_path_t *path, const designator_t *designator,
1810                             bool used_in_offsetof)
1811 {
1812         for (; designator != NULL; designator = designator->next) {
1813                 type_path_entry_t *top       = get_type_path_top(path);
1814                 type_t            *orig_type = top->type;
1815
1816                 type_t *type = skip_typeref(orig_type);
1817
1818                 if (designator->symbol != NULL) {
1819                         symbol_t *symbol = designator->symbol;
1820                         if (!is_type_compound(type)) {
1821                                 if (is_type_valid(type)) {
1822                                         errorf(&designator->source_position,
1823                                                "'.%Y' designator used for non-compound type '%T'",
1824                                                symbol, orig_type);
1825                                 }
1826
1827                                 top->type             = type_error_type;
1828                                 top->v.compound_entry = NULL;
1829                                 orig_type             = type_error_type;
1830                         } else {
1831                                 compound_t *compound = type->compound.compound;
1832                                 entity_t   *iter     = compound->members.entities;
1833                                 for (; iter != NULL; iter = iter->base.next) {
1834                                         if (iter->base.symbol == symbol) {
1835                                                 break;
1836                                         }
1837                                 }
1838                                 if (iter == NULL) {
1839                                         errorf(&designator->source_position,
1840                                                "'%T' has no member named '%Y'", orig_type, symbol);
1841                                         return false;
1842                                 }
1843                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1844                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1845                                         errorf(&designator->source_position,
1846                                                    "offsetof designator '%Y' must not specify bitfield",
1847                                                    symbol);
1848                                         return false;
1849                                 }
1850
1851                                 top->type             = orig_type;
1852                                 top->v.compound_entry = &iter->declaration;
1853                                 orig_type             = iter->declaration.type;
1854                         }
1855                 } else {
1856                         expression_t *array_index = designator->array_index;
1857                         assert(designator->array_index != NULL);
1858
1859                         if (!is_type_array(type)) {
1860                                 if (is_type_valid(type)) {
1861                                         errorf(&designator->source_position,
1862                                                "[%E] designator used for non-array type '%T'",
1863                                                array_index, orig_type);
1864                                 }
1865                                 return false;
1866                         }
1867
1868                         long index = fold_constant_to_int(array_index);
1869                         if (!used_in_offsetof) {
1870                                 if (index < 0) {
1871                                         errorf(&designator->source_position,
1872                                                "array index [%E] must be positive", array_index);
1873                                 } else if (type->array.size_constant) {
1874                                         long array_size = type->array.size;
1875                                         if (index >= array_size) {
1876                                                 errorf(&designator->source_position,
1877                                                        "designator [%E] (%d) exceeds array size %d",
1878                                                        array_index, index, array_size);
1879                                         }
1880                                 }
1881                         }
1882
1883                         top->type    = orig_type;
1884                         top->v.index = (size_t) index;
1885                         orig_type    = type->array.element_type;
1886                 }
1887                 path->top_type = orig_type;
1888
1889                 if (designator->next != NULL) {
1890                         descend_into_subtype(path);
1891                 }
1892         }
1893         return true;
1894 }
1895
1896 static void advance_current_object(type_path_t *path, size_t top_path_level)
1897 {
1898         type_path_entry_t *top = get_type_path_top(path);
1899
1900         type_t *type = skip_typeref(top->type);
1901         if (is_type_union(type)) {
1902                 /* in unions only the first element is initialized */
1903                 top->v.compound_entry = NULL;
1904         } else if (is_type_struct(type)) {
1905                 declaration_t *entry = top->v.compound_entry;
1906
1907                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1908                 if (next_entity != NULL) {
1909                         assert(is_declaration(next_entity));
1910                         entry = &next_entity->declaration;
1911                 } else {
1912                         entry = NULL;
1913                 }
1914
1915                 top->v.compound_entry = entry;
1916                 if (entry != NULL) {
1917                         path->top_type = entry->type;
1918                         return;
1919                 }
1920         } else if (is_type_array(type)) {
1921                 assert(is_type_array(type));
1922
1923                 top->v.index++;
1924
1925                 if (!type->array.size_constant || top->v.index < type->array.size) {
1926                         return;
1927                 }
1928         } else {
1929                 assert(!is_type_valid(type));
1930                 return;
1931         }
1932
1933         /* we're past the last member of the current sub-aggregate, try if we
1934          * can ascend in the type hierarchy and continue with another subobject */
1935         size_t len = ARR_LEN(path->path);
1936
1937         if (len > top_path_level) {
1938                 ascend_from_subtype(path);
1939                 advance_current_object(path, top_path_level);
1940         } else {
1941                 path->top_type = NULL;
1942         }
1943 }
1944
1945 /**
1946  * skip any {...} blocks until a closing bracket is reached.
1947  */
1948 static void skip_initializers(void)
1949 {
1950         next_if('{');
1951
1952         while (token.kind != '}') {
1953                 if (token.kind == T_EOF)
1954                         return;
1955                 if (token.kind == '{') {
1956                         eat_block();
1957                         continue;
1958                 }
1959                 next_token();
1960         }
1961 }
1962
1963 static initializer_t *create_empty_initializer(void)
1964 {
1965         static initializer_t empty_initializer
1966                 = { .list = { { INITIALIZER_LIST }, 0 } };
1967         return &empty_initializer;
1968 }
1969
1970 /**
1971  * Parse a part of an initialiser for a struct or union,
1972  */
1973 static initializer_t *parse_sub_initializer(type_path_t *path,
1974                 type_t *outer_type, size_t top_path_level,
1975                 parse_initializer_env_t *env)
1976 {
1977         if (token.kind == '}') {
1978                 /* empty initializer */
1979                 return create_empty_initializer();
1980         }
1981
1982         type_t *orig_type = path->top_type;
1983         type_t *type      = NULL;
1984
1985         if (orig_type == NULL) {
1986                 /* We are initializing an empty compound. */
1987         } else {
1988                 type = skip_typeref(orig_type);
1989         }
1990
1991         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1992
1993         while (true) {
1994                 designator_t *designator = NULL;
1995                 if (token.kind == '.' || token.kind == '[') {
1996                         designator = parse_designation();
1997                         goto finish_designator;
1998                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1999                         /* GNU-style designator ("identifier: value") */
2000                         designator = allocate_ast_zero(sizeof(designator[0]));
2001                         designator->source_position = token.base.source_position;
2002                         designator->symbol          = token.identifier.symbol;
2003                         eat(T_IDENTIFIER);
2004                         eat(':');
2005
2006 finish_designator:
2007                         /* reset path to toplevel, evaluate designator from there */
2008                         ascend_to(path, top_path_level);
2009                         if (!walk_designator(path, designator, false)) {
2010                                 /* can't continue after designation error */
2011                                 goto end_error;
2012                         }
2013
2014                         initializer_t *designator_initializer
2015                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2016                         designator_initializer->designator.designator = designator;
2017                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2018
2019                         orig_type = path->top_type;
2020                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2021                 }
2022
2023                 initializer_t *sub;
2024
2025                 if (token.kind == '{') {
2026                         if (type != NULL && is_type_scalar(type)) {
2027                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2028                         } else {
2029                                 if (type == NULL) {
2030                                         if (env->entity != NULL) {
2031                                                 errorf(HERE,
2032                                                      "extra brace group at end of initializer for '%Y'",
2033                                                      env->entity->base.symbol);
2034                                         } else {
2035                                                 errorf(HERE, "extra brace group at end of initializer");
2036                                         }
2037                                         eat('{');
2038                                 } else {
2039                                         eat('{');
2040                                         descend_into_subtype(path);
2041                                 }
2042
2043                                 add_anchor_token('}');
2044                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2045                                                             env);
2046                                 rem_anchor_token('}');
2047
2048                                 expect('}');
2049
2050                                 if (!type)
2051                                         goto error_parse_next;
2052
2053                                 ascend_from_subtype(path);
2054                         }
2055                 } else {
2056                         /* must be an expression */
2057                         expression_t *expression = parse_assignment_expression();
2058                         mark_vars_read(expression, NULL);
2059
2060                         if (env->must_be_constant && !is_linker_constant(expression)) {
2061                                 errorf(&expression->base.source_position,
2062                                        "Initialisation expression '%E' is not constant",
2063                                        expression);
2064                         }
2065
2066                         if (type == NULL) {
2067                                 /* we are already outside, ... */
2068                                 if (outer_type == NULL)
2069                                         goto error_parse_next;
2070                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2071                                 if (is_type_compound(outer_type_skip) &&
2072                                                 !outer_type_skip->compound.compound->complete) {
2073                                         goto error_parse_next;
2074                                 }
2075
2076                                 source_position_t const* const pos = &expression->base.source_position;
2077                                 if (env->entity != NULL) {
2078                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2079                                 } else {
2080                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2081                                 }
2082                                 goto error_parse_next;
2083                         }
2084
2085                         /* handle { "string" } special case */
2086                         if ((expression->kind == EXPR_STRING_LITERAL
2087                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2088                                         && outer_type != NULL) {
2089                                 sub = initializer_from_expression(outer_type, expression);
2090                                 if (sub != NULL) {
2091                                         next_if(',');
2092                                         if (token.kind != '}') {
2093                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2094                                         }
2095                                         /* TODO: eat , ... */
2096                                         return sub;
2097                                 }
2098                         }
2099
2100                         /* descend into subtypes until expression matches type */
2101                         while (true) {
2102                                 orig_type = path->top_type;
2103                                 type      = skip_typeref(orig_type);
2104
2105                                 sub = initializer_from_expression(orig_type, expression);
2106                                 if (sub != NULL) {
2107                                         break;
2108                                 }
2109                                 if (!is_type_valid(type)) {
2110                                         goto end_error;
2111                                 }
2112                                 if (is_type_scalar(type)) {
2113                                         errorf(&expression->base.source_position,
2114                                                         "expression '%E' doesn't match expected type '%T'",
2115                                                         expression, orig_type);
2116                                         goto end_error;
2117                                 }
2118
2119                                 descend_into_subtype(path);
2120                         }
2121                 }
2122
2123                 /* update largest index of top array */
2124                 const type_path_entry_t *first      = &path->path[0];
2125                 type_t                  *first_type = first->type;
2126                 first_type                          = skip_typeref(first_type);
2127                 if (is_type_array(first_type)) {
2128                         size_t index = first->v.index;
2129                         if (index > path->max_index)
2130                                 path->max_index = index;
2131                 }
2132
2133                 /* append to initializers list */
2134                 ARR_APP1(initializer_t*, initializers, sub);
2135
2136 error_parse_next:
2137                 if (token.kind == '}') {
2138                         break;
2139                 }
2140                 add_anchor_token('}');
2141                 expect(',');
2142                 rem_anchor_token('}');
2143                 if (token.kind == '}') {
2144                         break;
2145                 }
2146
2147                 if (type != NULL) {
2148                         /* advance to the next declaration if we are not at the end */
2149                         advance_current_object(path, top_path_level);
2150                         orig_type = path->top_type;
2151                         if (orig_type != NULL)
2152                                 type = skip_typeref(orig_type);
2153                         else
2154                                 type = NULL;
2155                 }
2156         }
2157
2158         size_t len  = ARR_LEN(initializers);
2159         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2160         initializer_t *result = allocate_ast_zero(size);
2161         result->kind          = INITIALIZER_LIST;
2162         result->list.len      = len;
2163         memcpy(&result->list.initializers, initializers,
2164                len * sizeof(initializers[0]));
2165
2166         DEL_ARR_F(initializers);
2167         ascend_to(path, top_path_level+1);
2168
2169         return result;
2170
2171 end_error:
2172         skip_initializers();
2173         DEL_ARR_F(initializers);
2174         ascend_to(path, top_path_level+1);
2175         return NULL;
2176 }
2177
2178 static expression_t *make_size_literal(size_t value)
2179 {
2180         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2181         literal->base.type    = type_size_t;
2182
2183         char buf[128];
2184         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2185         literal->literal.value = make_string(buf);
2186
2187         return literal;
2188 }
2189
2190 /**
2191  * Parses an initializer. Parsers either a compound literal
2192  * (env->declaration == NULL) or an initializer of a declaration.
2193  */
2194 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2195 {
2196         type_t        *type      = skip_typeref(env->type);
2197         size_t         max_index = 0;
2198         initializer_t *result;
2199
2200         if (is_type_scalar(type)) {
2201                 result = parse_scalar_initializer(type, env->must_be_constant);
2202         } else if (token.kind == '{') {
2203                 eat('{');
2204
2205                 type_path_t path;
2206                 memset(&path, 0, sizeof(path));
2207                 path.top_type = env->type;
2208                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2209
2210                 descend_into_subtype(&path);
2211
2212                 add_anchor_token('}');
2213                 result = parse_sub_initializer(&path, env->type, 1, env);
2214                 rem_anchor_token('}');
2215
2216                 max_index = path.max_index;
2217                 DEL_ARR_F(path.path);
2218
2219                 expect('}');
2220         } else {
2221                 /* parse_scalar_initializer() also works in this case: we simply
2222                  * have an expression without {} around it */
2223                 result = parse_scalar_initializer(type, env->must_be_constant);
2224         }
2225
2226         /* §6.7.8:22 array initializers for arrays with unknown size determine
2227          * the array type size */
2228         if (is_type_array(type) && type->array.size_expression == NULL
2229                         && result != NULL) {
2230                 size_t size;
2231                 switch (result->kind) {
2232                 case INITIALIZER_LIST:
2233                         assert(max_index != 0xdeadbeaf);
2234                         size = max_index + 1;
2235                         break;
2236
2237                 case INITIALIZER_STRING:
2238                         size = result->string.string.size;
2239                         break;
2240
2241                 case INITIALIZER_WIDE_STRING:
2242                         size = result->wide_string.string.size;
2243                         break;
2244
2245                 case INITIALIZER_DESIGNATOR:
2246                 case INITIALIZER_VALUE:
2247                         /* can happen for parse errors */
2248                         size = 0;
2249                         break;
2250
2251                 default:
2252                         internal_errorf(HERE, "invalid initializer type");
2253                 }
2254
2255                 type_t *new_type = duplicate_type(type);
2256
2257                 new_type->array.size_expression   = make_size_literal(size);
2258                 new_type->array.size_constant     = true;
2259                 new_type->array.has_implicit_size = true;
2260                 new_type->array.size              = size;
2261                 env->type = new_type;
2262         }
2263
2264         return result;
2265 }
2266
2267 static void append_entity(scope_t *scope, entity_t *entity)
2268 {
2269         if (scope->last_entity != NULL) {
2270                 scope->last_entity->base.next = entity;
2271         } else {
2272                 scope->entities = entity;
2273         }
2274         entity->base.parent_entity = current_entity;
2275         scope->last_entity         = entity;
2276 }
2277
2278
2279 static compound_t *parse_compound_type_specifier(bool is_struct)
2280 {
2281         source_position_t const pos = *HERE;
2282         eat(is_struct ? T_struct : T_union);
2283
2284         symbol_t    *symbol     = NULL;
2285         entity_t    *entity     = NULL;
2286         attribute_t *attributes = NULL;
2287
2288         if (token.kind == T___attribute__) {
2289                 attributes = parse_attributes(NULL);
2290         }
2291
2292         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2293         if (token.kind == T_IDENTIFIER) {
2294                 /* the compound has a name, check if we have seen it already */
2295                 symbol = token.identifier.symbol;
2296                 entity = get_tag(symbol, kind);
2297                 next_token();
2298
2299                 if (entity != NULL) {
2300                         if (entity->base.parent_scope != current_scope &&
2301                             (token.kind == '{' || token.kind == ';')) {
2302                                 /* we're in an inner scope and have a definition. Shadow
2303                                  * existing definition in outer scope */
2304                                 entity = NULL;
2305                         } else if (entity->compound.complete && token.kind == '{') {
2306                                 source_position_t const *const ppos = &entity->base.source_position;
2307                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2308                                 /* clear members in the hope to avoid further errors */
2309                                 entity->compound.members.entities = NULL;
2310                         }
2311                 }
2312         } else if (token.kind != '{') {
2313                 char const *const msg =
2314                         is_struct ? "while parsing struct type specifier" :
2315                                     "while parsing union type specifier";
2316                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2317
2318                 return NULL;
2319         }
2320
2321         if (entity == NULL) {
2322                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2323                 entity->compound.alignment = 1;
2324                 entity->base.parent_scope  = current_scope;
2325                 if (symbol != NULL) {
2326                         environment_push(entity);
2327                 }
2328                 append_entity(current_scope, entity);
2329         }
2330
2331         if (token.kind == '{') {
2332                 parse_compound_type_entries(&entity->compound);
2333
2334                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2335                 if (symbol == NULL) {
2336                         assert(anonymous_entity == NULL);
2337                         anonymous_entity = entity;
2338                 }
2339         }
2340
2341         if (attributes != NULL) {
2342                 handle_entity_attributes(attributes, entity);
2343         }
2344
2345         return &entity->compound;
2346 }
2347
2348 static void parse_enum_entries(type_t *const enum_type)
2349 {
2350         eat('{');
2351
2352         if (token.kind == '}') {
2353                 errorf(HERE, "empty enum not allowed");
2354                 next_token();
2355                 return;
2356         }
2357
2358         add_anchor_token('}');
2359         add_anchor_token(',');
2360         do {
2361                 add_anchor_token('=');
2362                 source_position_t pos;
2363                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2364                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2365                 entity->enum_value.enum_type = enum_type;
2366                 rem_anchor_token('=');
2367
2368                 if (next_if('=')) {
2369                         expression_t *value = parse_constant_expression();
2370
2371                         value = create_implicit_cast(value, enum_type);
2372                         entity->enum_value.value = value;
2373
2374                         /* TODO semantic */
2375                 }
2376
2377                 record_entity(entity, false);
2378         } while (next_if(',') && token.kind != '}');
2379         rem_anchor_token(',');
2380         rem_anchor_token('}');
2381
2382         expect('}');
2383 }
2384
2385 static type_t *parse_enum_specifier(void)
2386 {
2387         source_position_t const pos = *HERE;
2388         entity_t               *entity;
2389         symbol_t               *symbol;
2390
2391         eat(T_enum);
2392         switch (token.kind) {
2393                 case T_IDENTIFIER:
2394                         symbol = token.identifier.symbol;
2395                         entity = get_tag(symbol, ENTITY_ENUM);
2396                         next_token();
2397
2398                         if (entity != NULL) {
2399                                 if (entity->base.parent_scope != current_scope &&
2400                                                 (token.kind == '{' || token.kind == ';')) {
2401                                         /* we're in an inner scope and have a definition. Shadow
2402                                          * existing definition in outer scope */
2403                                         entity = NULL;
2404                                 } else if (entity->enume.complete && token.kind == '{') {
2405                                         source_position_t const *const ppos = &entity->base.source_position;
2406                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2407                                 }
2408                         }
2409                         break;
2410
2411                 case '{':
2412                         entity = NULL;
2413                         symbol = NULL;
2414                         break;
2415
2416                 default:
2417                         parse_error_expected("while parsing enum type specifier",
2418                                         T_IDENTIFIER, '{', NULL);
2419                         return NULL;
2420         }
2421
2422         if (entity == NULL) {
2423                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2424                 entity->base.parent_scope = current_scope;
2425         }
2426
2427         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2428         type->enumt.enume      = &entity->enume;
2429         type->enumt.base.akind = ATOMIC_TYPE_INT;
2430
2431         if (token.kind == '{') {
2432                 if (symbol != NULL) {
2433                         environment_push(entity);
2434                 }
2435                 append_entity(current_scope, entity);
2436                 entity->enume.complete = true;
2437
2438                 parse_enum_entries(type);
2439                 parse_attributes(NULL);
2440
2441                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2442                 if (symbol == NULL) {
2443                         assert(anonymous_entity == NULL);
2444                         anonymous_entity = entity;
2445                 }
2446         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2447                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2448         }
2449
2450         return type;
2451 }
2452
2453 /**
2454  * if a symbol is a typedef to another type, return true
2455  */
2456 static bool is_typedef_symbol(symbol_t *symbol)
2457 {
2458         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2459         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2460 }
2461
2462 static type_t *parse_typeof(void)
2463 {
2464         eat(T___typeof__);
2465
2466         type_t *type;
2467
2468         expect('(');
2469         add_anchor_token(')');
2470
2471         expression_t *expression  = NULL;
2472
2473         switch (token.kind) {
2474         case T_IDENTIFIER:
2475                 if (is_typedef_symbol(token.identifier.symbol)) {
2476         DECLARATION_START
2477                         type = parse_typename();
2478                 } else {
2479         default:
2480                         expression = parse_expression();
2481                         type       = revert_automatic_type_conversion(expression);
2482                 }
2483                 break;
2484         }
2485
2486         rem_anchor_token(')');
2487         expect(')');
2488
2489         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2490         typeof_type->typeoft.expression  = expression;
2491         typeof_type->typeoft.typeof_type = type;
2492
2493         return typeof_type;
2494 }
2495
2496 typedef enum specifiers_t {
2497         SPECIFIER_SIGNED    = 1 << 0,
2498         SPECIFIER_UNSIGNED  = 1 << 1,
2499         SPECIFIER_LONG      = 1 << 2,
2500         SPECIFIER_INT       = 1 << 3,
2501         SPECIFIER_DOUBLE    = 1 << 4,
2502         SPECIFIER_CHAR      = 1 << 5,
2503         SPECIFIER_WCHAR_T   = 1 << 6,
2504         SPECIFIER_SHORT     = 1 << 7,
2505         SPECIFIER_LONG_LONG = 1 << 8,
2506         SPECIFIER_FLOAT     = 1 << 9,
2507         SPECIFIER_BOOL      = 1 << 10,
2508         SPECIFIER_VOID      = 1 << 11,
2509         SPECIFIER_INT8      = 1 << 12,
2510         SPECIFIER_INT16     = 1 << 13,
2511         SPECIFIER_INT32     = 1 << 14,
2512         SPECIFIER_INT64     = 1 << 15,
2513         SPECIFIER_INT128    = 1 << 16,
2514         SPECIFIER_COMPLEX   = 1 << 17,
2515         SPECIFIER_IMAGINARY = 1 << 18,
2516 } specifiers_t;
2517
2518 static type_t *get_typedef_type(symbol_t *symbol)
2519 {
2520         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2521         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2522                 return NULL;
2523
2524         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2525         type->typedeft.typedefe = &entity->typedefe;
2526
2527         return type;
2528 }
2529
2530 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2531 {
2532         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2533
2534         expect('(');
2535
2536         add_anchor_token(')');
2537         add_anchor_token(',');
2538         do {
2539                 add_anchor_token('=');
2540                 source_position_t pos;
2541                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2542                 rem_anchor_token('=');
2543
2544                 symbol_t **prop = NULL;
2545                 if (prop_sym) {
2546                         if (streq(prop_sym->string, "put")) {
2547                                 prop = &property->put_symbol;
2548                         } else if (streq(prop_sym->string, "get")) {
2549                                 prop = &property->get_symbol;
2550                         } else {
2551                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2552                         }
2553                 }
2554
2555                 add_anchor_token(T_IDENTIFIER);
2556                 expect('=');
2557                 rem_anchor_token(T_IDENTIFIER);
2558
2559                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2560                 if (prop != NULL)
2561                         *prop = sym ? sym : sym_anonymous;
2562         } while (next_if(','));
2563         rem_anchor_token(',');
2564         rem_anchor_token(')');
2565
2566         attribute->a.property = property;
2567
2568         expect(')');
2569         return attribute;
2570 }
2571
2572 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2573 {
2574         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2575         if (next_if(T_restrict)) {
2576                 kind = ATTRIBUTE_MS_RESTRICT;
2577         } else if (token.kind == T_IDENTIFIER) {
2578                 const char *name = token.identifier.symbol->string;
2579                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2580                      ++k) {
2581                         const char *attribute_name = get_attribute_name(k);
2582                         if (attribute_name != NULL && streq(attribute_name, name)) {
2583                                 kind = k;
2584                                 break;
2585                         }
2586                 }
2587
2588                 if (kind == ATTRIBUTE_UNKNOWN) {
2589                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2590                 }
2591         } else {
2592                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2593                 return NULL;
2594         }
2595
2596         attribute_t *attribute = allocate_attribute_zero(kind);
2597         eat(T_IDENTIFIER);
2598
2599         if (kind == ATTRIBUTE_MS_PROPERTY) {
2600                 return parse_attribute_ms_property(attribute);
2601         }
2602
2603         /* parse arguments */
2604         if (next_if('('))
2605                 attribute->a.arguments = parse_attribute_arguments();
2606
2607         return attribute;
2608 }
2609
2610 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2611 {
2612         eat(T__declspec);
2613
2614         expect('(');
2615         if (token.kind != ')') {
2616                 add_anchor_token(')');
2617
2618                 attribute_t **anchor = &first;
2619                 do {
2620                         while (*anchor != NULL)
2621                                 anchor = &(*anchor)->next;
2622
2623                         attribute_t *attribute
2624                                 = parse_microsoft_extended_decl_modifier_single();
2625                         if (attribute == NULL)
2626                                 break;
2627
2628                         *anchor = attribute;
2629                         anchor  = &attribute->next;
2630                 } while (next_if(','));
2631
2632                 rem_anchor_token(')');
2633         }
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 = token.base.source_position;
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                         next_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                         next_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                         next_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                         next_token();
2763                         specifiers->is_inline = true;
2764                         break;
2765
2766 #if 0
2767                 case T__forceinline:
2768                         next_token();
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                         next_token();
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                         next_token();
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                                                 next_token();
2831                                                 continue;
2832
2833                                         default:
2834                                                 goto finish_specifiers;
2835                                 }
2836                         }
2837
2838                         type_t *const typedef_type = get_typedef_type(token.identifier.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                                                 symbol_t *symbol = token.identifier.symbol;
2852                                                 entity_t *entity
2853                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2854
2855                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2856                                                 type->typedeft.typedefe = &entity->typedefe;
2857
2858                                                 next_token();
2859                                                 saw_error = true;
2860                                                 continue;
2861                                         }
2862
2863                                         default:
2864                                                 goto finish_specifiers;
2865                                 }
2866                         }
2867
2868                         next_token();
2869                         type = typedef_type;
2870                         break;
2871                 }
2872
2873                 /* function specifier */
2874                 default:
2875                         goto finish_specifiers;
2876                 }
2877         }
2878
2879 finish_specifiers:
2880         specifiers->attributes = parse_attributes(specifiers->attributes);
2881
2882         if (type == NULL || (saw_error && type_specifiers != 0)) {
2883                 atomic_type_kind_t atomic_type;
2884
2885                 /* match valid basic types */
2886                 switch (type_specifiers) {
2887                 case SPECIFIER_VOID:
2888                         atomic_type = ATOMIC_TYPE_VOID;
2889                         break;
2890                 case SPECIFIER_WCHAR_T:
2891                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2892                         break;
2893                 case SPECIFIER_CHAR:
2894                         atomic_type = ATOMIC_TYPE_CHAR;
2895                         break;
2896                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2897                         atomic_type = ATOMIC_TYPE_SCHAR;
2898                         break;
2899                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2900                         atomic_type = ATOMIC_TYPE_UCHAR;
2901                         break;
2902                 case SPECIFIER_SHORT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2904                 case SPECIFIER_SHORT | SPECIFIER_INT:
2905                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2906                         atomic_type = ATOMIC_TYPE_SHORT;
2907                         break;
2908                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2909                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2910                         atomic_type = ATOMIC_TYPE_USHORT;
2911                         break;
2912                 case SPECIFIER_INT:
2913                 case SPECIFIER_SIGNED:
2914                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2915                         atomic_type = ATOMIC_TYPE_INT;
2916                         break;
2917                 case SPECIFIER_UNSIGNED:
2918                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2919                         atomic_type = ATOMIC_TYPE_UINT;
2920                         break;
2921                 case SPECIFIER_LONG:
2922                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2923                 case SPECIFIER_LONG | SPECIFIER_INT:
2924                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2925                         atomic_type = ATOMIC_TYPE_LONG;
2926                         break;
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2928                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2929                         atomic_type = ATOMIC_TYPE_ULONG;
2930                         break;
2931
2932                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2933                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2934                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2935                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2936                         | SPECIFIER_INT:
2937                         atomic_type = ATOMIC_TYPE_LONGLONG;
2938                         goto warn_about_long_long;
2939
2940                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2941                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2942                         | SPECIFIER_INT:
2943                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2944 warn_about_long_long:
2945                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2946                         break;
2947
2948                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2949                         atomic_type = unsigned_int8_type_kind;
2950                         break;
2951
2952                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2953                         atomic_type = unsigned_int16_type_kind;
2954                         break;
2955
2956                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2957                         atomic_type = unsigned_int32_type_kind;
2958                         break;
2959
2960                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2961                         atomic_type = unsigned_int64_type_kind;
2962                         break;
2963
2964                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2965                         atomic_type = unsigned_int128_type_kind;
2966                         break;
2967
2968                 case SPECIFIER_INT8:
2969                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2970                         atomic_type = int8_type_kind;
2971                         break;
2972
2973                 case SPECIFIER_INT16:
2974                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2975                         atomic_type = int16_type_kind;
2976                         break;
2977
2978                 case SPECIFIER_INT32:
2979                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2980                         atomic_type = int32_type_kind;
2981                         break;
2982
2983                 case SPECIFIER_INT64:
2984                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2985                         atomic_type = int64_type_kind;
2986                         break;
2987
2988                 case SPECIFIER_INT128:
2989                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2990                         atomic_type = int128_type_kind;
2991                         break;
2992
2993                 case SPECIFIER_FLOAT:
2994                         atomic_type = ATOMIC_TYPE_FLOAT;
2995                         break;
2996                 case SPECIFIER_DOUBLE:
2997                         atomic_type = ATOMIC_TYPE_DOUBLE;
2998                         break;
2999                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3000                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3001                         break;
3002                 case SPECIFIER_BOOL:
3003                         atomic_type = ATOMIC_TYPE_BOOL;
3004                         break;
3005                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3006                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3007                         atomic_type = ATOMIC_TYPE_FLOAT;
3008                         break;
3009                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3010                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3011                         atomic_type = ATOMIC_TYPE_DOUBLE;
3012                         break;
3013                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3014                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3015                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3016                         break;
3017                 default: {
3018                         /* invalid specifier combination, give an error message */
3019                         source_position_t const* const pos = &specifiers->source_position;
3020                         if (type_specifiers == 0) {
3021                                 if (!saw_error) {
3022                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3023                                         if (!(c_mode & _CXX) && !strict_mode) {
3024                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3025                                                 atomic_type = ATOMIC_TYPE_INT;
3026                                                 break;
3027                                         } else {
3028                                                 errorf(pos, "no type specifiers given in declaration");
3029                                         }
3030                                 }
3031                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3032                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3033                                 errorf(pos, "signed and unsigned specifiers given");
3034                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3035                                 errorf(pos, "only integer types can be signed or unsigned");
3036                         } else {
3037                                 errorf(pos, "multiple datatypes in declaration");
3038                         }
3039                         goto end_error;
3040                 }
3041                 }
3042
3043                 if (type_specifiers & SPECIFIER_COMPLEX) {
3044                         type = allocate_type_zero(TYPE_COMPLEX);
3045                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3046                         type = allocate_type_zero(TYPE_IMAGINARY);
3047                 } else {
3048                         type = allocate_type_zero(TYPE_ATOMIC);
3049                 }
3050                 type->atomic.akind = atomic_type;
3051                 newtype = true;
3052         } else if (type_specifiers != 0) {
3053                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3054         }
3055
3056         /* FIXME: check type qualifiers here */
3057         type->base.qualifiers = qualifiers;
3058
3059         if (newtype) {
3060                 type = identify_new_type(type);
3061         } else {
3062                 type = typehash_insert(type);
3063         }
3064
3065         if (specifiers->attributes != NULL)
3066                 type = handle_type_attributes(specifiers->attributes, type);
3067         specifiers->type = type;
3068         return;
3069
3070 end_error:
3071         specifiers->type = type_error_type;
3072 }
3073
3074 static type_qualifiers_t parse_type_qualifiers(void)
3075 {
3076         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3077
3078         while (true) {
3079                 switch (token.kind) {
3080                 /* type qualifiers */
3081                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3082                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3083                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3084                 /* microsoft extended type modifiers */
3085                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3086                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3087                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3088                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3089                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3090
3091                 default:
3092                         return qualifiers;
3093                 }
3094         }
3095 }
3096
3097 /**
3098  * Parses an K&R identifier list
3099  */
3100 static void parse_identifier_list(scope_t *scope)
3101 {
3102         assert(token.kind == T_IDENTIFIER);
3103         do {
3104                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol, HERE);
3105                 /* a K&R parameter has no type, yet */
3106                 next_token();
3107
3108                 if (scope != NULL)
3109                         append_entity(scope, entity);
3110         } while (next_if(',') && token.kind == T_IDENTIFIER);
3111 }
3112
3113 static entity_t *parse_parameter(void)
3114 {
3115         declaration_specifiers_t specifiers;
3116         parse_declaration_specifiers(&specifiers);
3117
3118         entity_t *entity = parse_declarator(&specifiers,
3119                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3120         anonymous_entity = NULL;
3121         return entity;
3122 }
3123
3124 static void semantic_parameter_incomplete(const entity_t *entity)
3125 {
3126         assert(entity->kind == ENTITY_PARAMETER);
3127
3128         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3129          *             list in a function declarator that is part of a
3130          *             definition of that function shall not have
3131          *             incomplete type. */
3132         type_t *type = skip_typeref(entity->declaration.type);
3133         if (is_type_incomplete(type)) {
3134                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3135         }
3136 }
3137
3138 static bool has_parameters(void)
3139 {
3140         /* func(void) is not a parameter */
3141         if (look_ahead(1)->kind != ')')
3142                 return true;
3143         if (token.kind == T_IDENTIFIER) {
3144                 entity_t const *const entity
3145                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3146                 if (entity == NULL)
3147                         return true;
3148                 if (entity->kind != ENTITY_TYPEDEF)
3149                         return true;
3150                 type_t const *const type = skip_typeref(entity->typedefe.type);
3151                 if (!is_type_void(type))
3152                         return true;
3153                 if (c_mode & _CXX) {
3154                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3155                          * is not allowed. */
3156                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3157                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3158                         /* §6.7.5.3:10  Qualification is not allowed here. */
3159                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3160                 }
3161         } else if (token.kind != T_void) {
3162                 return true;
3163         }
3164         next_token();
3165         return false;
3166 }
3167
3168 /**
3169  * Parses function type parameters (and optionally creates variable_t entities
3170  * for them in a scope)
3171  */
3172 static void parse_parameters(function_type_t *type, scope_t *scope)
3173 {
3174         eat('(');
3175         add_anchor_token(')');
3176
3177         if (token.kind == T_IDENTIFIER                  &&
3178             !is_typedef_symbol(token.identifier.symbol) &&
3179             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3180                 type->kr_style_parameters = true;
3181                 parse_identifier_list(scope);
3182         } else if (token.kind == ')') {
3183                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3184                 if (!(c_mode & _CXX))
3185                         type->unspecified_parameters = true;
3186         } else if (has_parameters()) {
3187                 function_parameter_t **anchor = &type->parameters;
3188                 add_anchor_token(',');
3189                 do {
3190                         switch (token.kind) {
3191                         case T_DOTDOTDOT:
3192                                 next_token();
3193                                 type->variadic = true;
3194                                 goto parameters_finished;
3195
3196                         case T_IDENTIFIER:
3197                         DECLARATION_START
3198                         {
3199                                 entity_t *entity = parse_parameter();
3200                                 if (entity->kind == ENTITY_TYPEDEF) {
3201                                         errorf(&entity->base.source_position,
3202                                                         "typedef not allowed as function parameter");
3203                                         break;
3204                                 }
3205                                 assert(is_declaration(entity));
3206
3207                                 semantic_parameter_incomplete(entity);
3208
3209                                 function_parameter_t *const parameter =
3210                                         allocate_parameter(entity->declaration.type);
3211
3212                                 if (scope != NULL) {
3213                                         append_entity(scope, entity);
3214                                 }
3215
3216                                 *anchor = parameter;
3217                                 anchor  = &parameter->next;
3218                                 break;
3219                         }
3220
3221                         default:
3222                                 goto parameters_finished;
3223                         }
3224                 } while (next_if(','));
3225 parameters_finished:
3226                 rem_anchor_token(',');
3227         }
3228
3229         rem_anchor_token(')');
3230         expect(')');
3231 }
3232
3233 typedef enum construct_type_kind_t {
3234         CONSTRUCT_POINTER = 1,
3235         CONSTRUCT_REFERENCE,
3236         CONSTRUCT_FUNCTION,
3237         CONSTRUCT_ARRAY
3238 } construct_type_kind_t;
3239
3240 typedef union construct_type_t construct_type_t;
3241
3242 typedef struct construct_type_base_t {
3243         construct_type_kind_t  kind;
3244         source_position_t      pos;
3245         construct_type_t      *next;
3246 } construct_type_base_t;
3247
3248 typedef struct parsed_pointer_t {
3249         construct_type_base_t  base;
3250         type_qualifiers_t      type_qualifiers;
3251         variable_t            *base_variable;  /**< MS __based extension. */
3252 } parsed_pointer_t;
3253
3254 typedef struct parsed_reference_t {
3255         construct_type_base_t base;
3256 } parsed_reference_t;
3257
3258 typedef struct construct_function_type_t {
3259         construct_type_base_t  base;
3260         type_t                *function_type;
3261 } construct_function_type_t;
3262
3263 typedef struct parsed_array_t {
3264         construct_type_base_t  base;
3265         type_qualifiers_t      type_qualifiers;
3266         bool                   is_static;
3267         bool                   is_variable;
3268         expression_t          *size;
3269 } parsed_array_t;
3270
3271 union construct_type_t {
3272         construct_type_kind_t     kind;
3273         construct_type_base_t     base;
3274         parsed_pointer_t          pointer;
3275         parsed_reference_t        reference;
3276         construct_function_type_t function;
3277         parsed_array_t            array;
3278 };
3279
3280 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3281 {
3282         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3283         memset(cons, 0, size);
3284         cons->kind     = kind;
3285         cons->base.pos = *HERE;
3286         return cons;
3287 }
3288
3289 /* §6.7.5.1 */
3290 static construct_type_t *parse_pointer_declarator(void)
3291 {
3292         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3293         eat('*');
3294         cons->pointer.type_qualifiers = parse_type_qualifiers();
3295         //cons->pointer.base_variable   = base_variable;
3296
3297         return cons;
3298 }
3299
3300 /* ISO/IEC 14882:1998(E) §8.3.2 */
3301 static construct_type_t *parse_reference_declarator(void)
3302 {
3303         if (!(c_mode & _CXX))
3304                 errorf(HERE, "references are only available for C++");
3305
3306         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3307         eat('&');
3308
3309         return cons;
3310 }
3311
3312 /* §6.7.5.2 */
3313 static construct_type_t *parse_array_declarator(void)
3314 {
3315         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3316         parsed_array_t   *const array = &cons->array;
3317
3318         eat('[');
3319         add_anchor_token(']');
3320
3321         bool is_static = next_if(T_static);
3322
3323         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3324
3325         if (!is_static)
3326                 is_static = next_if(T_static);
3327
3328         array->type_qualifiers = type_qualifiers;
3329         array->is_static       = is_static;
3330
3331         expression_t *size = NULL;
3332         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3333                 array->is_variable = true;
3334                 next_token();
3335         } else if (token.kind != ']') {
3336                 size = parse_assignment_expression();
3337
3338                 /* §6.7.5.2:1  Array size must have integer type */
3339                 type_t *const orig_type = size->base.type;
3340                 type_t *const type      = skip_typeref(orig_type);
3341                 if (!is_type_integer(type) && is_type_valid(type)) {
3342                         errorf(&size->base.source_position,
3343                                "array size '%E' must have integer type but has type '%T'",
3344                                size, orig_type);
3345                 }
3346
3347                 array->size = size;
3348                 mark_vars_read(size, NULL);
3349         }
3350
3351         if (is_static && size == NULL)
3352                 errorf(&array->base.pos, "static array parameters require a size");
3353
3354         rem_anchor_token(']');
3355         expect(']');
3356         return cons;
3357 }
3358
3359 /* §6.7.5.3 */
3360 static construct_type_t *parse_function_declarator(scope_t *scope)
3361 {
3362         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3363
3364         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3365         function_type_t *ftype = &type->function;
3366
3367         ftype->linkage            = current_linkage;
3368         ftype->calling_convention = CC_DEFAULT;
3369
3370         parse_parameters(ftype, scope);
3371
3372         cons->function.function_type = type;
3373
3374         return cons;
3375 }
3376
3377 typedef struct parse_declarator_env_t {
3378         bool               may_be_abstract : 1;
3379         bool               must_be_abstract : 1;
3380         decl_modifiers_t   modifiers;
3381         symbol_t          *symbol;
3382         source_position_t  source_position;
3383         scope_t            parameters;
3384         attribute_t       *attributes;
3385 } parse_declarator_env_t;
3386
3387 /* §6.7.5 */
3388 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3389 {
3390         /* construct a single linked list of construct_type_t's which describe
3391          * how to construct the final declarator type */
3392         construct_type_t  *first      = NULL;
3393         construct_type_t **anchor     = &first;
3394
3395         env->attributes = parse_attributes(env->attributes);
3396
3397         for (;;) {
3398                 construct_type_t *type;
3399                 //variable_t       *based = NULL; /* MS __based extension */
3400                 switch (token.kind) {
3401                         case '&':
3402                                 type = parse_reference_declarator();
3403                                 break;
3404
3405                         case T__based: {
3406                                 panic("based not supported anymore");
3407                                 /* FALLTHROUGH */
3408                         }
3409
3410                         case '*':
3411                                 type = parse_pointer_declarator();
3412                                 break;
3413
3414                         default:
3415                                 goto ptr_operator_end;
3416                 }
3417
3418                 *anchor = type;
3419                 anchor  = &type->base.next;
3420
3421                 /* TODO: find out if this is correct */
3422                 env->attributes = parse_attributes(env->attributes);
3423         }
3424
3425 ptr_operator_end: ;
3426         construct_type_t *inner_types = NULL;
3427
3428         switch (token.kind) {
3429         case T_IDENTIFIER:
3430                 if (env->must_be_abstract) {
3431                         errorf(HERE, "no identifier expected in typename");
3432                 } else {
3433                         env->symbol          = token.identifier.symbol;
3434                         env->source_position = token.base.source_position;
3435                 }
3436                 next_token();
3437                 break;
3438
3439         case '(': {
3440                 /* Parenthesized declarator or function declarator? */
3441                 token_t const *const la1 = look_ahead(1);
3442                 switch (la1->kind) {
3443                         case T_IDENTIFIER:
3444                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3445                         case ')':
3446                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3447                                          * interpreted as ``function with no parameter specification'', rather
3448                                          * than redundant parentheses around the omitted identifier. */
3449                         default:
3450                                         /* Function declarator. */
3451                                         if (!env->may_be_abstract) {
3452                                                 errorf(HERE, "function declarator must have a name");
3453                                         }
3454                                 } else {
3455                         case '&':
3456                         case '(':
3457                         case '*':
3458                         case '[':
3459                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3460                                         /* Paranthesized declarator. */
3461                                         next_token();
3462                                         add_anchor_token(')');
3463                                         inner_types = parse_inner_declarator(env);
3464                                         if (inner_types != NULL) {
3465                                                 /* All later declarators only modify the return type */
3466                                                 env->must_be_abstract = true;
3467                                         }
3468                                         rem_anchor_token(')');
3469                                         expect(')');
3470                                 }
3471                                 break;
3472                 }
3473                 break;
3474         }
3475
3476         default:
3477                 if (env->may_be_abstract)
3478                         break;
3479                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3480                 eat_until_anchor();
3481                 return NULL;
3482         }
3483
3484         construct_type_t **const p = anchor;
3485
3486         for (;;) {
3487                 construct_type_t *type;
3488                 switch (token.kind) {
3489                 case '(': {
3490                         scope_t *scope = NULL;
3491                         if (!env->must_be_abstract) {
3492                                 scope = &env->parameters;
3493                         }
3494
3495                         type = parse_function_declarator(scope);
3496                         break;
3497                 }
3498                 case '[':
3499                         type = parse_array_declarator();
3500                         break;
3501                 default:
3502                         goto declarator_finished;
3503                 }
3504
3505                 /* insert in the middle of the list (at p) */
3506                 type->base.next = *p;
3507                 *p              = type;
3508                 if (anchor == p)
3509                         anchor = &type->base.next;
3510         }
3511
3512 declarator_finished:
3513         /* append inner_types at the end of the list, we don't to set anchor anymore
3514          * as it's not needed anymore */
3515         *anchor = inner_types;
3516
3517         return first;
3518 }
3519
3520 static type_t *construct_declarator_type(construct_type_t *construct_list,
3521                                          type_t *type)
3522 {
3523         construct_type_t *iter = construct_list;
3524         for (; iter != NULL; iter = iter->base.next) {
3525                 source_position_t const* const pos = &iter->base.pos;
3526                 switch (iter->kind) {
3527                 case CONSTRUCT_FUNCTION: {
3528                         construct_function_type_t *function      = &iter->function;
3529                         type_t                    *function_type = function->function_type;
3530
3531                         function_type->function.return_type = type;
3532
3533                         type_t *skipped_return_type = skip_typeref(type);
3534                         /* §6.7.5.3:1 */
3535                         if (is_type_function(skipped_return_type)) {
3536                                 errorf(pos, "function returning function is not allowed");
3537                         } else if (is_type_array(skipped_return_type)) {
3538                                 errorf(pos, "function returning array is not allowed");
3539                         } else {
3540                                 if (skipped_return_type->base.qualifiers != 0) {
3541                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3542                                 }
3543                         }
3544
3545                         /* The function type was constructed earlier.  Freeing it here will
3546                          * destroy other types. */
3547                         type = typehash_insert(function_type);
3548                         continue;
3549                 }
3550
3551                 case CONSTRUCT_POINTER: {
3552                         if (is_type_reference(skip_typeref(type)))
3553                                 errorf(pos, "cannot declare a pointer to reference");
3554
3555                         parsed_pointer_t *pointer = &iter->pointer;
3556                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3557                         continue;
3558                 }
3559
3560                 case CONSTRUCT_REFERENCE:
3561                         if (is_type_reference(skip_typeref(type)))
3562                                 errorf(pos, "cannot declare a reference to reference");
3563
3564                         type = make_reference_type(type);
3565                         continue;
3566
3567                 case CONSTRUCT_ARRAY: {
3568                         if (is_type_reference(skip_typeref(type)))
3569                                 errorf(pos, "cannot declare an array of references");
3570
3571                         parsed_array_t *array      = &iter->array;
3572                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3573
3574                         expression_t *size_expression = array->size;
3575                         if (size_expression != NULL) {
3576                                 size_expression
3577                                         = create_implicit_cast(size_expression, type_size_t);
3578                         }
3579
3580                         array_type->base.qualifiers       = array->type_qualifiers;
3581                         array_type->array.element_type    = type;
3582                         array_type->array.is_static       = array->is_static;
3583                         array_type->array.is_variable     = array->is_variable;
3584                         array_type->array.size_expression = size_expression;
3585
3586                         if (size_expression != NULL) {
3587                                 switch (is_constant_expression(size_expression)) {
3588                                 case EXPR_CLASS_CONSTANT: {
3589                                         long const size = fold_constant_to_int(size_expression);
3590                                         array_type->array.size          = size;
3591                                         array_type->array.size_constant = true;
3592                                         /* §6.7.5.2:1  If the expression is a constant expression,
3593                                          * it shall have a value greater than zero. */
3594                                         if (size < 0) {
3595                                                 errorf(&size_expression->base.source_position,
3596                                                            "size of array must be greater than zero");
3597                                         } else if (size == 0 && !GNU_MODE) {
3598                                                 errorf(&size_expression->base.source_position,
3599                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3600                                         }
3601                                         break;
3602                                 }
3603
3604                                 case EXPR_CLASS_VARIABLE:
3605                                         array_type->array.is_vla = true;
3606                                         break;
3607
3608                                 case EXPR_CLASS_ERROR:
3609                                         break;
3610                                 }
3611                         }
3612
3613                         type_t *skipped_type = skip_typeref(type);
3614                         /* §6.7.5.2:1 */
3615                         if (is_type_incomplete(skipped_type)) {
3616                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3617                         } else if (is_type_function(skipped_type)) {
3618                                 errorf(pos, "array of functions is not allowed");
3619                         }
3620                         type = identify_new_type(array_type);
3621                         continue;
3622                 }
3623                 }
3624                 internal_errorf(pos, "invalid type construction found");
3625         }
3626
3627         return type;
3628 }
3629
3630 static type_t *automatic_type_conversion(type_t *orig_type);
3631
3632 static type_t *semantic_parameter(const source_position_t *pos,
3633                                   type_t *type,
3634                                   const declaration_specifiers_t *specifiers,
3635                                   entity_t const *const param)
3636 {
3637         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3638          *             shall be adjusted to ``qualified pointer to type'',
3639          *             [...]
3640          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3641          *             type'' shall be adjusted to ``pointer to function
3642          *             returning type'', as in 6.3.2.1. */
3643         type = automatic_type_conversion(type);
3644
3645         if (specifiers->is_inline && is_type_valid(type)) {
3646                 errorf(pos, "'%N' declared 'inline'", param);
3647         }
3648
3649         /* §6.9.1:6  The declarations in the declaration list shall contain
3650          *           no storage-class specifier other than register and no
3651          *           initializations. */
3652         if (specifiers->thread_local || (
3653                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3654                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3655            ) {
3656                 errorf(pos, "invalid storage class for '%N'", param);
3657         }
3658
3659         /* delay test for incomplete type, because we might have (void)
3660          * which is legal but incomplete... */
3661
3662         return type;
3663 }
3664
3665 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3666                                   declarator_flags_t flags)
3667 {
3668         parse_declarator_env_t env;
3669         memset(&env, 0, sizeof(env));
3670         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3671
3672         construct_type_t *construct_type = parse_inner_declarator(&env);
3673         type_t           *orig_type      =
3674                 construct_declarator_type(construct_type, specifiers->type);
3675         type_t           *type           = skip_typeref(orig_type);
3676
3677         if (construct_type != NULL) {
3678                 obstack_free(&temp_obst, construct_type);
3679         }
3680
3681         attribute_t *attributes = parse_attributes(env.attributes);
3682         /* append (shared) specifier attribute behind attributes of this
3683          * declarator */
3684         attribute_t **anchor = &attributes;
3685         while (*anchor != NULL)
3686                 anchor = &(*anchor)->next;
3687         *anchor = specifiers->attributes;
3688
3689         entity_t *entity;
3690         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3691                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3692                 entity->typedefe.type = orig_type;
3693
3694                 if (anonymous_entity != NULL) {
3695                         if (is_type_compound(type)) {
3696                                 assert(anonymous_entity->compound.alias == NULL);
3697                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3698                                        anonymous_entity->kind == ENTITY_UNION);
3699                                 anonymous_entity->compound.alias = entity;
3700                                 anonymous_entity = NULL;
3701                         } else if (is_type_enum(type)) {
3702                                 assert(anonymous_entity->enume.alias == NULL);
3703                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3704                                 anonymous_entity->enume.alias = entity;
3705                                 anonymous_entity = NULL;
3706                         }
3707                 }
3708         } else {
3709                 /* create a declaration type entity */
3710                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3711                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3712                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3713
3714                         if (env.symbol != NULL) {
3715                                 if (specifiers->is_inline && is_type_valid(type)) {
3716                                         errorf(&env.source_position,
3717                                                         "compound member '%Y' declared 'inline'", env.symbol);
3718                                 }
3719
3720                                 if (specifiers->thread_local ||
3721                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3722                                         errorf(&env.source_position,
3723                                                         "compound member '%Y' must have no storage class",
3724                                                         env.symbol);
3725                                 }
3726                         }
3727                 } else if (flags & DECL_IS_PARAMETER) {
3728                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3729                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3730                 } else if (is_type_function(type)) {
3731                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3732                         entity->function.is_inline      = specifiers->is_inline;
3733                         entity->function.elf_visibility = default_visibility;
3734                         entity->function.parameters     = env.parameters;
3735
3736                         if (env.symbol != NULL) {
3737                                 /* this needs fixes for C++ */
3738                                 bool in_function_scope = current_function != NULL;
3739
3740                                 if (specifiers->thread_local || (
3741                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3742                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3743                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3744                                                 )) {
3745                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3746                                 }
3747                         }
3748                 } else {
3749                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3750                         entity->variable.elf_visibility = default_visibility;
3751                         entity->variable.thread_local   = specifiers->thread_local;
3752
3753                         if (env.symbol != NULL) {
3754                                 if (specifiers->is_inline && is_type_valid(type)) {
3755                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3756                                 }
3757
3758                                 bool invalid_storage_class = false;
3759                                 if (current_scope == file_scope) {
3760                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3761                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3762                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3763                                                 invalid_storage_class = true;
3764                                         }
3765                                 } else {
3766                                         if (specifiers->thread_local &&
3767                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3768                                                 invalid_storage_class = true;
3769                                         }
3770                                 }
3771                                 if (invalid_storage_class) {
3772                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3773                                 }
3774                         }
3775                 }
3776
3777                 entity->declaration.type       = orig_type;
3778                 entity->declaration.alignment  = get_type_alignment(orig_type);
3779                 entity->declaration.modifiers  = env.modifiers;
3780                 entity->declaration.attributes = attributes;
3781
3782                 storage_class_t storage_class = specifiers->storage_class;
3783                 entity->declaration.declared_storage_class = storage_class;
3784
3785                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3786                         storage_class = STORAGE_CLASS_AUTO;
3787                 entity->declaration.storage_class = storage_class;
3788         }
3789
3790         if (attributes != NULL) {
3791                 handle_entity_attributes(attributes, entity);
3792         }
3793
3794         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3795                 adapt_special_functions(&entity->function);
3796         }
3797
3798         return entity;
3799 }
3800
3801 static type_t *parse_abstract_declarator(type_t *base_type)
3802 {
3803         parse_declarator_env_t env;
3804         memset(&env, 0, sizeof(env));
3805         env.may_be_abstract = true;
3806         env.must_be_abstract = true;
3807
3808         construct_type_t *construct_type = parse_inner_declarator(&env);
3809
3810         type_t *result = construct_declarator_type(construct_type, base_type);
3811         if (construct_type != NULL) {
3812                 obstack_free(&temp_obst, construct_type);
3813         }
3814         result = handle_type_attributes(env.attributes, result);
3815
3816         return result;
3817 }
3818
3819 /**
3820  * Check if the declaration of main is suspicious.  main should be a
3821  * function with external linkage, returning int, taking either zero
3822  * arguments, two, or three arguments of appropriate types, ie.
3823  *
3824  * int main([ int argc, char **argv [, char **env ] ]).
3825  *
3826  * @param decl    the declaration to check
3827  * @param type    the function type of the declaration
3828  */
3829 static void check_main(const entity_t *entity)
3830 {
3831         const source_position_t *pos = &entity->base.source_position;
3832         if (entity->kind != ENTITY_FUNCTION) {
3833                 warningf(WARN_MAIN, pos, "'main' is not a function");
3834                 return;
3835         }
3836
3837         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3838                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3839         }
3840
3841         type_t *type = skip_typeref(entity->declaration.type);
3842         assert(is_type_function(type));
3843
3844         function_type_t const *const func_type = &type->function;
3845         type_t                *const ret_type  = func_type->return_type;
3846         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3847                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3848         }
3849         const function_parameter_t *parm = func_type->parameters;
3850         if (parm != NULL) {
3851                 type_t *const first_type        = skip_typeref(parm->type);
3852                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3853                 if (!types_compatible(first_type_unqual, type_int)) {
3854                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3855                 }
3856                 parm = parm->next;
3857                 if (parm != NULL) {
3858                         type_t *const second_type = skip_typeref(parm->type);
3859                         type_t *const second_type_unqual
3860                                 = get_unqualified_type(second_type);
3861                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3862                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3863                         }
3864                         parm = parm->next;
3865                         if (parm != NULL) {
3866                                 type_t *const third_type = skip_typeref(parm->type);
3867                                 type_t *const third_type_unqual
3868                                         = get_unqualified_type(third_type);
3869                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3870                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3871                                 }
3872                                 parm = parm->next;
3873                                 if (parm != NULL)
3874                                         goto warn_arg_count;
3875                         }
3876                 } else {
3877 warn_arg_count:
3878                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3879                 }
3880         }
3881 }
3882
3883 /**
3884  * Check if a symbol is the equal to "main".
3885  */
3886 static bool is_sym_main(const symbol_t *const sym)
3887 {
3888         return streq(sym->string, "main");
3889 }
3890
3891 static void error_redefined_as_different_kind(const source_position_t *pos,
3892                 const entity_t *old, entity_kind_t new_kind)
3893 {
3894         char              const *const what = get_entity_kind_name(new_kind);
3895         source_position_t const *const ppos = &old->base.source_position;
3896         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3897 }
3898
3899 static bool is_entity_valid(entity_t *const ent)
3900 {
3901         if (is_declaration(ent)) {
3902                 return is_type_valid(skip_typeref(ent->declaration.type));
3903         } else if (ent->kind == ENTITY_TYPEDEF) {
3904                 return is_type_valid(skip_typeref(ent->typedefe.type));
3905         }
3906         return true;
3907 }
3908
3909 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3910 {
3911         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3912                 if (attributes_equal(tattr, attr))
3913                         return true;
3914         }
3915         return false;
3916 }
3917
3918 /**
3919  * test wether new_list contains any attributes not included in old_list
3920  */
3921 static bool has_new_attributes(const attribute_t *old_list,
3922                                const attribute_t *new_list)
3923 {
3924         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3925                 if (!contains_attribute(old_list, attr))
3926                         return true;
3927         }
3928         return false;
3929 }
3930
3931 /**
3932  * Merge in attributes from an attribute list (probably from a previous
3933  * declaration with the same name). Warning: destroys the old structure
3934  * of the attribute list - don't reuse attributes after this call.
3935  */
3936 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3937 {
3938         attribute_t *next;
3939         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3940                 next = attr->next;
3941                 if (contains_attribute(decl->attributes, attr))
3942                         continue;
3943
3944                 /* move attribute to new declarations attributes list */
3945                 attr->next       = decl->attributes;
3946                 decl->attributes = attr;
3947         }
3948 }
3949
3950 /**
3951  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3952  * for various problems that occur for multiple definitions
3953  */
3954 entity_t *record_entity(entity_t *entity, const bool is_definition)
3955 {
3956         const symbol_t *const    symbol  = entity->base.symbol;
3957         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3958         const source_position_t *pos     = &entity->base.source_position;
3959
3960         /* can happen in error cases */
3961         if (symbol == NULL)
3962                 return entity;
3963
3964         entity_t *const previous_entity = get_entity(symbol, namespc);
3965         /* pushing the same entity twice will break the stack structure */
3966         assert(previous_entity != entity);
3967
3968         if (entity->kind == ENTITY_FUNCTION) {
3969                 type_t *const orig_type = entity->declaration.type;
3970                 type_t *const type      = skip_typeref(orig_type);
3971
3972                 assert(is_type_function(type));
3973                 if (type->function.unspecified_parameters &&
3974                     previous_entity == NULL               &&
3975                     !entity->declaration.implicit) {
3976                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3977                 }
3978
3979                 if (current_scope == file_scope && is_sym_main(symbol)) {
3980                         check_main(entity);
3981                 }
3982         }
3983
3984         if (is_declaration(entity)                                    &&
3985             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3986             current_scope != file_scope                               &&
3987             !entity->declaration.implicit) {
3988                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3989         }
3990
3991         if (previous_entity != NULL) {
3992                 source_position_t const *const ppos = &previous_entity->base.source_position;
3993
3994                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3995                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3996                         assert(previous_entity->kind == ENTITY_PARAMETER);
3997                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3998                         goto finish;
3999                 }
4000
4001                 if (previous_entity->base.parent_scope == current_scope) {
4002                         if (previous_entity->kind != entity->kind) {
4003                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4004                                         error_redefined_as_different_kind(pos, previous_entity,
4005                                                         entity->kind);
4006                                 }
4007                                 goto finish;
4008                         }
4009                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4010                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4011                                 goto finish;
4012                         }
4013                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4014                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4015                                 type_t *const prev_type
4016                                         = skip_typeref(previous_entity->typedefe.type);
4017                                 if (c_mode & _CXX) {
4018                                         /* C++ allows double typedef if they are identical
4019                                          * (after skipping typedefs) */
4020                                         if (type == prev_type)
4021                                                 goto finish;
4022                                 } else {
4023                                         /* GCC extension: redef in system headers is allowed */
4024                                         if ((pos->is_system_header || ppos->is_system_header) &&
4025                                             types_compatible(type, prev_type))
4026                                                 goto finish;
4027                                 }
4028                                 errorf(pos, "redefinition of '%N' (declared %P)",
4029                                        entity, ppos);
4030                                 goto finish;
4031                         }
4032
4033                         /* at this point we should have only VARIABLES or FUNCTIONS */
4034                         assert(is_declaration(previous_entity) && is_declaration(entity));
4035
4036                         declaration_t *const prev_decl = &previous_entity->declaration;
4037                         declaration_t *const decl      = &entity->declaration;
4038
4039                         /* can happen for K&R style declarations */
4040                         if (prev_decl->type       == NULL             &&
4041                                         previous_entity->kind == ENTITY_PARAMETER &&
4042                                         entity->kind          == ENTITY_PARAMETER) {
4043                                 prev_decl->type                   = decl->type;
4044                                 prev_decl->storage_class          = decl->storage_class;
4045                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4046                                 prev_decl->modifiers              = decl->modifiers;
4047                                 return previous_entity;
4048                         }
4049
4050                         type_t *const type      = skip_typeref(decl->type);
4051                         type_t *const prev_type = skip_typeref(prev_decl->type);
4052
4053                         if (!types_compatible(type, prev_type)) {
4054                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4055                         } else {
4056                                 unsigned old_storage_class = prev_decl->storage_class;
4057
4058                                 if (is_definition                     &&
4059                                                 !prev_decl->used                  &&
4060                                                 !(prev_decl->modifiers & DM_USED) &&
4061                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4062                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4063                                 }
4064
4065                                 storage_class_t new_storage_class = decl->storage_class;
4066
4067                                 /* pretend no storage class means extern for function
4068                                  * declarations (except if the previous declaration is neither
4069                                  * none nor extern) */
4070                                 if (entity->kind == ENTITY_FUNCTION) {
4071                                         /* the previous declaration could have unspecified parameters or
4072                                          * be a typedef, so use the new type */
4073                                         if (prev_type->function.unspecified_parameters || is_definition)
4074                                                 prev_decl->type = type;
4075
4076                                         switch (old_storage_class) {
4077                                                 case STORAGE_CLASS_NONE:
4078                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4079                                                         /* FALLTHROUGH */
4080
4081                                                 case STORAGE_CLASS_EXTERN:
4082                                                         if (is_definition) {
4083                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4084                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4085                                                                 }
4086                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4087                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4088                                                         }
4089                                                         break;
4090
4091                                                 default:
4092                                                         break;
4093                                         }
4094                                 } else if (is_type_incomplete(prev_type)) {
4095                                         prev_decl->type = type;
4096                                 }
4097
4098                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4099                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4100
4101 warn_redundant_declaration: ;
4102                                         bool has_new_attrs
4103                                                 = has_new_attributes(prev_decl->attributes,
4104                                                                      decl->attributes);
4105                                         if (has_new_attrs) {
4106                                                 merge_in_attributes(decl, prev_decl->attributes);
4107                                         } else if (!is_definition        &&
4108                                                         is_type_valid(prev_type) &&
4109                                                         !pos->is_system_header) {
4110                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4111                                         }
4112                                 } else if (current_function == NULL) {
4113                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4114                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4115                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4116                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4117                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4118                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4119                                         } else {
4120                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4121                                                 if (c_mode & _CXX)
4122                                                         goto error_redeclaration;
4123                                                 goto warn_redundant_declaration;
4124                                         }
4125                                 } else if (is_type_valid(prev_type)) {
4126                                         if (old_storage_class == new_storage_class) {
4127 error_redeclaration:
4128                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4129                                         } else {
4130                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4131                                         }
4132                                 }
4133                         }
4134
4135                         prev_decl->modifiers |= decl->modifiers;
4136                         if (entity->kind == ENTITY_FUNCTION) {
4137                                 previous_entity->function.is_inline |= entity->function.is_inline;
4138                         }
4139                         return previous_entity;
4140                 }
4141
4142                 warning_t why;
4143                 if (is_warn_on(why = WARN_SHADOW) ||
4144                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4145                         char const *const what = get_entity_kind_name(previous_entity->kind);
4146                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4147                 }
4148         }
4149
4150         if (entity->kind == ENTITY_FUNCTION) {
4151                 if (is_definition &&
4152                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4153                                 !is_sym_main(symbol)) {
4154                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4155                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4156                         } else {
4157                                 goto warn_missing_declaration;
4158                         }
4159                 }
4160         } else if (entity->kind == ENTITY_VARIABLE) {
4161                 if (current_scope                     == file_scope &&
4162                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4163                                 !entity->declaration.implicit) {
4164 warn_missing_declaration:
4165                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4166                 }
4167         }
4168
4169 finish:
4170         assert(entity->base.parent_scope == NULL);
4171         assert(current_scope != NULL);
4172
4173         entity->base.parent_scope = current_scope;
4174         environment_push(entity);
4175         append_entity(current_scope, entity);
4176
4177         return entity;
4178 }
4179
4180 static void parser_error_multiple_definition(entity_t *entity,
4181                 const source_position_t *source_position)
4182 {
4183         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4184                entity->base.symbol, &entity->base.source_position);
4185 }
4186
4187 static bool is_declaration_specifier(const token_t *token)
4188 {
4189         switch (token->kind) {
4190                 DECLARATION_START
4191                         return true;
4192                 case T_IDENTIFIER:
4193                         return is_typedef_symbol(token->identifier.symbol);
4194
4195                 default:
4196                         return false;
4197         }
4198 }
4199
4200 static void parse_init_declarator_rest(entity_t *entity)
4201 {
4202         type_t *orig_type = type_error_type;
4203
4204         if (entity->base.kind == ENTITY_TYPEDEF) {
4205                 source_position_t const *const pos = &entity->base.source_position;
4206                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4207         } else {
4208                 assert(is_declaration(entity));
4209                 orig_type = entity->declaration.type;
4210         }
4211
4212         type_t *type = skip_typeref(orig_type);
4213
4214         if (entity->kind == ENTITY_VARIABLE
4215                         && entity->variable.initializer != NULL) {
4216                 parser_error_multiple_definition(entity, HERE);
4217         }
4218         eat('=');
4219
4220         declaration_t *const declaration = &entity->declaration;
4221         bool must_be_constant = false;
4222         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4223             entity->base.parent_scope  == file_scope) {
4224                 must_be_constant = true;
4225         }
4226
4227         if (is_type_function(type)) {
4228                 source_position_t const *const pos = &entity->base.source_position;
4229                 errorf(pos, "'%N' is initialized like a variable", entity);
4230                 orig_type = type_error_type;
4231         }
4232
4233         parse_initializer_env_t env;
4234         env.type             = orig_type;
4235         env.must_be_constant = must_be_constant;
4236         env.entity           = entity;
4237
4238         initializer_t *initializer = parse_initializer(&env);
4239
4240         if (entity->kind == ENTITY_VARIABLE) {
4241                 /* §6.7.5:22  array initializers for arrays with unknown size
4242                  * determine the array type size */
4243                 declaration->type            = env.type;
4244                 entity->variable.initializer = initializer;
4245         }
4246 }
4247
4248 /* parse rest of a declaration without any declarator */
4249 static void parse_anonymous_declaration_rest(
4250                 const declaration_specifiers_t *specifiers)
4251 {
4252         eat(';');
4253         anonymous_entity = NULL;
4254
4255         source_position_t const *const pos = &specifiers->source_position;
4256         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4257                         specifiers->thread_local) {
4258                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4259         }
4260
4261         type_t *type = specifiers->type;
4262         switch (type->kind) {
4263                 case TYPE_COMPOUND_STRUCT:
4264                 case TYPE_COMPOUND_UNION: {
4265                         if (type->compound.compound->base.symbol == NULL) {
4266                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4267                         }
4268                         break;
4269                 }
4270
4271                 case TYPE_ENUM:
4272                         break;
4273
4274                 default:
4275                         warningf(WARN_OTHER, pos, "empty declaration");
4276                         break;
4277         }
4278 }
4279
4280 static void check_variable_type_complete(entity_t *ent)
4281 {
4282         if (ent->kind != ENTITY_VARIABLE)
4283                 return;
4284
4285         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4286          *         type for the object shall be complete [...] */
4287         declaration_t *decl = &ent->declaration;
4288         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4289                         decl->storage_class == STORAGE_CLASS_STATIC)
4290                 return;
4291
4292         type_t *const type = skip_typeref(decl->type);
4293         if (!is_type_incomplete(type))
4294                 return;
4295
4296         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4297          * are given length one. */
4298         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4299                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4300                 return;
4301         }
4302
4303         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4304 }
4305
4306
4307 static void parse_declaration_rest(entity_t *ndeclaration,
4308                 const declaration_specifiers_t *specifiers,
4309                 parsed_declaration_func         finished_declaration,
4310                 declarator_flags_t              flags)
4311 {
4312         add_anchor_token(';');
4313         add_anchor_token(',');
4314         while (true) {
4315                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4316
4317                 if (token.kind == '=') {
4318                         parse_init_declarator_rest(entity);
4319                 } else if (entity->kind == ENTITY_VARIABLE) {
4320                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4321                          * [...] where the extern specifier is explicitly used. */
4322                         declaration_t *decl = &entity->declaration;
4323                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4324                             is_type_reference(skip_typeref(decl->type))) {
4325                                 source_position_t const *const pos = &entity->base.source_position;
4326                                 errorf(pos, "reference '%#N' must be initialized", entity);
4327                         }
4328                 }
4329
4330                 check_variable_type_complete(entity);
4331
4332                 if (!next_if(','))
4333                         break;
4334
4335                 add_anchor_token('=');
4336                 ndeclaration = parse_declarator(specifiers, flags);
4337                 rem_anchor_token('=');
4338         }
4339         rem_anchor_token(',');
4340         rem_anchor_token(';');
4341         expect(';');
4342
4343         anonymous_entity = NULL;
4344 }
4345
4346 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4347 {
4348         symbol_t *symbol = entity->base.symbol;
4349         if (symbol == NULL)
4350                 return entity;
4351
4352         assert(entity->base.namespc == NAMESPACE_NORMAL);
4353         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4354         if (previous_entity == NULL
4355                         || previous_entity->base.parent_scope != current_scope) {
4356                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4357                        symbol);
4358                 return entity;
4359         }
4360
4361         if (is_definition) {
4362                 errorf(HERE, "'%N' is initialised", entity);
4363         }
4364
4365         return record_entity(entity, false);
4366 }
4367
4368 static void parse_declaration(parsed_declaration_func finished_declaration,
4369                               declarator_flags_t      flags)
4370 {
4371         add_anchor_token(';');
4372         declaration_specifiers_t specifiers;
4373         parse_declaration_specifiers(&specifiers);
4374         rem_anchor_token(';');
4375
4376         if (token.kind == ';') {
4377                 parse_anonymous_declaration_rest(&specifiers);
4378         } else {
4379                 entity_t *entity = parse_declarator(&specifiers, flags);
4380                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4381         }
4382 }
4383
4384 /* §6.5.2.2:6 */
4385 static type_t *get_default_promoted_type(type_t *orig_type)
4386 {
4387         type_t *result = orig_type;
4388
4389         type_t *type = skip_typeref(orig_type);
4390         if (is_type_integer(type)) {
4391                 result = promote_integer(type);
4392         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4393                 result = type_double;
4394         }
4395
4396         return result;
4397 }
4398
4399 static void parse_kr_declaration_list(entity_t *entity)
4400 {
4401         if (entity->kind != ENTITY_FUNCTION)
4402                 return;
4403
4404         type_t *type = skip_typeref(entity->declaration.type);
4405         assert(is_type_function(type));
4406         if (!type->function.kr_style_parameters)
4407                 return;
4408
4409         add_anchor_token('{');
4410
4411         PUSH_SCOPE(&entity->function.parameters);
4412
4413         entity_t *parameter = entity->function.parameters.entities;
4414         for ( ; parameter != NULL; parameter = parameter->base.next) {
4415                 assert(parameter->base.parent_scope == NULL);
4416                 parameter->base.parent_scope = current_scope;
4417                 environment_push(parameter);
4418         }
4419
4420         /* parse declaration list */
4421         for (;;) {
4422                 switch (token.kind) {
4423                         DECLARATION_START
4424                         /* This covers symbols, which are no type, too, and results in
4425                          * better error messages.  The typical cases are misspelled type
4426                          * names and missing includes. */
4427                         case T_IDENTIFIER:
4428                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4429                                 break;
4430                         default:
4431                                 goto decl_list_end;
4432                 }
4433         }
4434 decl_list_end:
4435
4436         POP_SCOPE();
4437
4438         /* update function type */
4439         type_t *new_type = duplicate_type(type);
4440
4441         function_parameter_t  *parameters = NULL;
4442         function_parameter_t **anchor     = &parameters;
4443
4444         /* did we have an earlier prototype? */
4445         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4446         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4447                 proto_type = NULL;
4448
4449         function_parameter_t *proto_parameter = NULL;
4450         if (proto_type != NULL) {
4451                 type_t *proto_type_type = proto_type->declaration.type;
4452                 proto_parameter         = proto_type_type->function.parameters;
4453                 /* If a K&R function definition has a variadic prototype earlier, then
4454                  * make the function definition variadic, too. This should conform to
4455                  * §6.7.5.3:15 and §6.9.1:8. */
4456                 new_type->function.variadic = proto_type_type->function.variadic;
4457         } else {
4458                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4459                  * prototype */
4460                 new_type->function.unspecified_parameters = true;
4461         }
4462
4463         bool need_incompatible_warning = false;
4464         parameter = entity->function.parameters.entities;
4465         for (; parameter != NULL; parameter = parameter->base.next,
4466                         proto_parameter =
4467                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4468                 if (parameter->kind != ENTITY_PARAMETER)
4469                         continue;
4470
4471                 type_t *parameter_type = parameter->declaration.type;
4472                 if (parameter_type == NULL) {
4473                         source_position_t const* const pos = &parameter->base.source_position;
4474                         if (strict_mode) {
4475                                 errorf(pos, "no type specified for function '%N'", parameter);
4476                                 parameter_type = type_error_type;
4477                         } else {
4478                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4479                                 parameter_type = type_int;
4480                         }
4481                         parameter->declaration.type = parameter_type;
4482                 }
4483
4484                 semantic_parameter_incomplete(parameter);
4485
4486                 /* we need the default promoted types for the function type */
4487                 type_t *not_promoted = parameter_type;
4488                 parameter_type       = get_default_promoted_type(parameter_type);
4489
4490                 /* gcc special: if the type of the prototype matches the unpromoted
4491                  * type don't promote */
4492                 if (!strict_mode && proto_parameter != NULL) {
4493                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4494                         type_t *promo_skip   = skip_typeref(parameter_type);
4495                         type_t *param_skip   = skip_typeref(not_promoted);
4496                         if (!types_compatible(proto_p_type, promo_skip)
4497                                 && types_compatible(proto_p_type, param_skip)) {
4498                                 /* don't promote */
4499                                 need_incompatible_warning = true;
4500                                 parameter_type = not_promoted;
4501                         }
4502                 }
4503                 function_parameter_t *const function_parameter
4504                         = allocate_parameter(parameter_type);
4505
4506                 *anchor = function_parameter;
4507                 anchor  = &function_parameter->next;
4508         }
4509
4510         new_type->function.parameters = parameters;
4511         new_type = identify_new_type(new_type);
4512
4513         if (need_incompatible_warning) {
4514                 symbol_t          const *const sym  = entity->base.symbol;
4515                 source_position_t const *const pos  = &entity->base.source_position;
4516                 source_position_t const *const ppos = &proto_type->base.source_position;
4517                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4518         }
4519         entity->declaration.type = new_type;
4520
4521         rem_anchor_token('{');
4522 }
4523
4524 static bool first_err = true;
4525
4526 /**
4527  * When called with first_err set, prints the name of the current function,
4528  * else does noting.
4529  */
4530 static void print_in_function(void)
4531 {
4532         if (first_err) {
4533                 first_err = false;
4534                 char const *const file = current_function->base.base.source_position.input_name;
4535                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4536         }
4537 }
4538
4539 /**
4540  * Check if all labels are defined in the current function.
4541  * Check if all labels are used in the current function.
4542  */
4543 static void check_labels(void)
4544 {
4545         for (const goto_statement_t *goto_statement = goto_first;
4546             goto_statement != NULL;
4547             goto_statement = goto_statement->next) {
4548                 label_t *label = goto_statement->label;
4549                 if (label->base.source_position.input_name == NULL) {
4550                         print_in_function();
4551                         source_position_t const *const pos = &goto_statement->base.source_position;
4552                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4553                  }
4554         }
4555
4556         if (is_warn_on(WARN_UNUSED_LABEL)) {
4557                 for (const label_statement_t *label_statement = label_first;
4558                          label_statement != NULL;
4559                          label_statement = label_statement->next) {
4560                         label_t *label = label_statement->label;
4561
4562                         if (! label->used) {
4563                                 print_in_function();
4564                                 source_position_t const *const pos = &label_statement->base.source_position;
4565                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4566                         }
4567                 }
4568         }
4569 }
4570
4571 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4572 {
4573         entity_t const *const end = last != NULL ? last->base.next : NULL;
4574         for (; entity != end; entity = entity->base.next) {
4575                 if (!is_declaration(entity))
4576                         continue;
4577
4578                 declaration_t *declaration = &entity->declaration;
4579                 if (declaration->implicit)
4580                         continue;
4581
4582                 if (!declaration->used) {
4583                         print_in_function();
4584                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4585                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4586                         print_in_function();
4587                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4588                 }
4589         }
4590 }
4591
4592 static void check_unused_variables(statement_t *const stmt, void *const env)
4593 {
4594         (void)env;
4595
4596         switch (stmt->kind) {
4597                 case STATEMENT_DECLARATION: {
4598                         declaration_statement_t const *const decls = &stmt->declaration;
4599                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4600                         return;
4601                 }
4602
4603                 case STATEMENT_FOR:
4604                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4605                         return;
4606
4607                 default:
4608                         return;
4609         }
4610 }
4611
4612 /**
4613  * Check declarations of current_function for unused entities.
4614  */
4615 static void check_declarations(void)
4616 {
4617         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4618                 const scope_t *scope = &current_function->parameters;
4619                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4620         }
4621         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4622                 walk_statements(current_function->statement, check_unused_variables,
4623                                 NULL);
4624         }
4625 }
4626
4627 static int determine_truth(expression_t const* const cond)
4628 {
4629         return
4630                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4631                 fold_constant_to_bool(cond)                         ? 1 :
4632                 -1;
4633 }
4634
4635 static void check_reachable(statement_t *);
4636 static bool reaches_end;
4637
4638 static bool expression_returns(expression_t const *const expr)
4639 {
4640         switch (expr->kind) {
4641                 case EXPR_CALL: {
4642                         expression_t const *const func = expr->call.function;
4643                         type_t       const *const type = skip_typeref(func->base.type);
4644                         if (type->kind == TYPE_POINTER) {
4645                                 type_t const *const points_to
4646                                         = skip_typeref(type->pointer.points_to);
4647                                 if (points_to->kind == TYPE_FUNCTION
4648                                     && points_to->function.modifiers & DM_NORETURN)
4649                                         return false;
4650                         }
4651
4652                         if (!expression_returns(func))
4653                                 return false;
4654
4655                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4656                                 if (!expression_returns(arg->expression))
4657                                         return false;
4658                         }
4659
4660                         return true;
4661                 }
4662
4663                 case EXPR_REFERENCE:
4664                 case EXPR_ENUM_CONSTANT:
4665                 case EXPR_LITERAL_CASES:
4666                 case EXPR_STRING_LITERAL:
4667                 case EXPR_WIDE_STRING_LITERAL:
4668                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4669                 case EXPR_LABEL_ADDRESS:
4670                 case EXPR_CLASSIFY_TYPE:
4671                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4672                 case EXPR_ALIGNOF:
4673                 case EXPR_FUNCNAME:
4674                 case EXPR_BUILTIN_CONSTANT_P:
4675                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4676                 case EXPR_OFFSETOF:
4677                 case EXPR_ERROR:
4678                         return true;
4679
4680                 case EXPR_STATEMENT: {
4681                         bool old_reaches_end = reaches_end;
4682                         reaches_end = false;
4683                         check_reachable(expr->statement.statement);
4684                         bool returns = reaches_end;
4685                         reaches_end = old_reaches_end;
4686                         return returns;
4687                 }
4688
4689                 case EXPR_CONDITIONAL:
4690                         // TODO handle constant expression
4691
4692                         if (!expression_returns(expr->conditional.condition))
4693                                 return false;
4694
4695                         if (expr->conditional.true_expression != NULL
4696                                         && expression_returns(expr->conditional.true_expression))
4697                                 return true;
4698
4699                         return expression_returns(expr->conditional.false_expression);
4700
4701                 case EXPR_SELECT:
4702                         return expression_returns(expr->select.compound);
4703
4704                 case EXPR_ARRAY_ACCESS:
4705                         return
4706                                 expression_returns(expr->array_access.array_ref) &&
4707                                 expression_returns(expr->array_access.index);
4708
4709                 case EXPR_VA_START:
4710                         return expression_returns(expr->va_starte.ap);
4711
4712                 case EXPR_VA_ARG:
4713                         return expression_returns(expr->va_arge.ap);
4714
4715                 case EXPR_VA_COPY:
4716                         return expression_returns(expr->va_copye.src);
4717
4718                 case EXPR_UNARY_CASES_MANDATORY:
4719                         return expression_returns(expr->unary.value);
4720
4721                 case EXPR_UNARY_THROW:
4722                         return false;
4723
4724                 case EXPR_BINARY_CASES:
4725                         // TODO handle constant lhs of && and ||
4726                         return
4727                                 expression_returns(expr->binary.left) &&
4728                                 expression_returns(expr->binary.right);
4729         }
4730
4731         panic("unhandled expression");
4732 }
4733
4734 static bool initializer_returns(initializer_t const *const init)
4735 {
4736         switch (init->kind) {
4737                 case INITIALIZER_VALUE:
4738                         return expression_returns(init->value.value);
4739
4740                 case INITIALIZER_LIST: {
4741                         initializer_t * const*       i       = init->list.initializers;
4742                         initializer_t * const* const end     = i + init->list.len;
4743                         bool                         returns = true;
4744                         for (; i != end; ++i) {
4745                                 if (!initializer_returns(*i))
4746                                         returns = false;
4747                         }
4748                         return returns;
4749                 }
4750
4751                 case INITIALIZER_STRING:
4752                 case INITIALIZER_WIDE_STRING:
4753                 case INITIALIZER_DESIGNATOR: // designators have no payload
4754                         return true;
4755         }
4756         panic("unhandled initializer");
4757 }
4758
4759 static bool noreturn_candidate;
4760
4761 static void check_reachable(statement_t *const stmt)
4762 {
4763         if (stmt->base.reachable)
4764                 return;
4765         if (stmt->kind != STATEMENT_DO_WHILE)
4766                 stmt->base.reachable = true;
4767
4768         statement_t *last = stmt;
4769         statement_t *next;
4770         switch (stmt->kind) {
4771                 case STATEMENT_ERROR:
4772                 case STATEMENT_EMPTY:
4773                 case STATEMENT_ASM:
4774                         next = stmt->base.next;
4775                         break;
4776
4777                 case STATEMENT_DECLARATION: {
4778                         declaration_statement_t const *const decl = &stmt->declaration;
4779                         entity_t                const *      ent  = decl->declarations_begin;
4780                         entity_t                const *const last_decl = decl->declarations_end;
4781                         if (ent != NULL) {
4782                                 for (;; ent = ent->base.next) {
4783                                         if (ent->kind                 == ENTITY_VARIABLE &&
4784                                             ent->variable.initializer != NULL            &&
4785                                             !initializer_returns(ent->variable.initializer)) {
4786                                                 return;
4787                                         }
4788                                         if (ent == last_decl)
4789                                                 break;
4790                                 }
4791                         }
4792                         next = stmt->base.next;
4793                         break;
4794                 }
4795
4796                 case STATEMENT_COMPOUND:
4797                         next = stmt->compound.statements;
4798                         if (next == NULL)
4799                                 next = stmt->base.next;
4800                         break;
4801
4802                 case STATEMENT_RETURN: {
4803                         expression_t const *const val = stmt->returns.value;
4804                         if (val == NULL || expression_returns(val))
4805                                 noreturn_candidate = false;
4806                         return;
4807                 }
4808
4809                 case STATEMENT_IF: {
4810                         if_statement_t const *const ifs  = &stmt->ifs;
4811                         expression_t   const *const cond = ifs->condition;
4812
4813                         if (!expression_returns(cond))
4814                                 return;
4815
4816                         int const val = determine_truth(cond);
4817
4818                         if (val >= 0)
4819                                 check_reachable(ifs->true_statement);
4820
4821                         if (val > 0)
4822                                 return;
4823
4824                         if (ifs->false_statement != NULL) {
4825                                 check_reachable(ifs->false_statement);
4826                                 return;
4827                         }
4828
4829                         next = stmt->base.next;
4830                         break;
4831                 }
4832
4833                 case STATEMENT_SWITCH: {
4834                         switch_statement_t const *const switchs = &stmt->switchs;
4835                         expression_t       const *const expr    = switchs->expression;
4836
4837                         if (!expression_returns(expr))
4838                                 return;
4839
4840                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4841                                 long                    const val      = fold_constant_to_int(expr);
4842                                 case_label_statement_t *      defaults = NULL;
4843                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4844                                         if (i->expression == NULL) {
4845                                                 defaults = i;
4846                                                 continue;
4847                                         }
4848
4849                                         if (i->first_case <= val && val <= i->last_case) {
4850                                                 check_reachable((statement_t*)i);
4851                                                 return;
4852                                         }
4853                                 }
4854
4855                                 if (defaults != NULL) {
4856                                         check_reachable((statement_t*)defaults);
4857                                         return;
4858                                 }
4859                         } else {
4860                                 bool has_default = false;
4861                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4862                                         if (i->expression == NULL)
4863                                                 has_default = true;
4864
4865                                         check_reachable((statement_t*)i);
4866                                 }
4867
4868                                 if (has_default)
4869                                         return;
4870                         }
4871
4872                         next = stmt->base.next;
4873                         break;
4874                 }
4875
4876                 case STATEMENT_EXPRESSION: {
4877                         /* Check for noreturn function call */
4878                         expression_t const *const expr = stmt->expression.expression;
4879                         if (!expression_returns(expr))
4880                                 return;
4881
4882                         next = stmt->base.next;
4883                         break;
4884                 }
4885
4886                 case STATEMENT_CONTINUE:
4887                         for (statement_t *parent = stmt;;) {
4888                                 parent = parent->base.parent;
4889                                 if (parent == NULL) /* continue not within loop */
4890                                         return;
4891
4892                                 next = parent;
4893                                 switch (parent->kind) {
4894                                         case STATEMENT_WHILE:    goto continue_while;
4895                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4896                                         case STATEMENT_FOR:      goto continue_for;
4897
4898                                         default: break;
4899                                 }
4900                         }
4901
4902                 case STATEMENT_BREAK:
4903                         for (statement_t *parent = stmt;;) {
4904                                 parent = parent->base.parent;
4905                                 if (parent == NULL) /* break not within loop/switch */
4906                                         return;
4907
4908                                 switch (parent->kind) {
4909                                         case STATEMENT_SWITCH:
4910                                         case STATEMENT_WHILE:
4911                                         case STATEMENT_DO_WHILE:
4912                                         case STATEMENT_FOR:
4913                                                 last = parent;
4914                                                 next = parent->base.next;
4915                                                 goto found_break_parent;
4916
4917                                         default: break;
4918                                 }
4919                         }
4920 found_break_parent:
4921                         break;
4922
4923                 case STATEMENT_COMPUTED_GOTO: {
4924                         if (!expression_returns(stmt->computed_goto.expression))
4925                                 return;
4926
4927                         statement_t *parent = stmt->base.parent;
4928                         if (parent == NULL) /* top level goto */
4929                                 return;
4930                         next = parent;
4931                         break;
4932                 }
4933
4934                 case STATEMENT_GOTO:
4935                         next = stmt->gotos.label->statement;
4936                         if (next == NULL) /* missing label */
4937                                 return;
4938                         break;
4939
4940                 case STATEMENT_LABEL:
4941                         next = stmt->label.statement;
4942                         break;
4943
4944                 case STATEMENT_CASE_LABEL:
4945                         next = stmt->case_label.statement;
4946                         break;
4947
4948                 case STATEMENT_WHILE: {
4949                         while_statement_t const *const whiles = &stmt->whiles;
4950                         expression_t      const *const cond   = whiles->condition;
4951
4952                         if (!expression_returns(cond))
4953                                 return;
4954
4955                         int const val = determine_truth(cond);
4956
4957                         if (val >= 0)
4958                                 check_reachable(whiles->body);
4959
4960                         if (val > 0)
4961                                 return;
4962
4963                         next = stmt->base.next;
4964                         break;
4965                 }
4966
4967                 case STATEMENT_DO_WHILE:
4968                         next = stmt->do_while.body;
4969                         break;
4970
4971                 case STATEMENT_FOR: {
4972                         for_statement_t *const fors = &stmt->fors;
4973
4974                         if (fors->condition_reachable)
4975                                 return;
4976                         fors->condition_reachable = true;
4977
4978                         expression_t const *const cond = fors->condition;
4979
4980                         int val;
4981                         if (cond == NULL) {
4982                                 val = 1;
4983                         } else if (expression_returns(cond)) {
4984                                 val = determine_truth(cond);
4985                         } else {
4986                                 return;
4987                         }
4988
4989                         if (val >= 0)
4990                                 check_reachable(fors->body);
4991
4992                         if (val > 0)
4993                                 return;
4994
4995                         next = stmt->base.next;
4996                         break;
4997                 }
4998
4999                 case STATEMENT_MS_TRY: {
5000                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5001                         check_reachable(ms_try->try_statement);
5002                         next = ms_try->final_statement;
5003                         break;
5004                 }
5005
5006                 case STATEMENT_LEAVE: {
5007                         statement_t *parent = stmt;
5008                         for (;;) {
5009                                 parent = parent->base.parent;
5010                                 if (parent == NULL) /* __leave not within __try */
5011                                         return;
5012
5013                                 if (parent->kind == STATEMENT_MS_TRY) {
5014                                         last = parent;
5015                                         next = parent->ms_try.final_statement;
5016                                         break;
5017                                 }
5018                         }
5019                         break;
5020                 }
5021
5022                 default:
5023                         panic("invalid statement kind");
5024         }
5025
5026         while (next == NULL) {
5027                 next = last->base.parent;
5028                 if (next == NULL) {
5029                         noreturn_candidate = false;
5030
5031                         type_t *const type = skip_typeref(current_function->base.type);
5032                         assert(is_type_function(type));
5033                         type_t *const ret  = skip_typeref(type->function.return_type);
5034                         if (!is_type_void(ret) &&
5035                             is_type_valid(ret) &&
5036                             !is_sym_main(current_function->base.base.symbol)) {
5037                                 source_position_t const *const pos = &stmt->base.source_position;
5038                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5039                         }
5040                         return;
5041                 }
5042
5043                 switch (next->kind) {
5044                         case STATEMENT_ERROR:
5045                         case STATEMENT_EMPTY:
5046                         case STATEMENT_DECLARATION:
5047                         case STATEMENT_EXPRESSION:
5048                         case STATEMENT_ASM:
5049                         case STATEMENT_RETURN:
5050                         case STATEMENT_CONTINUE:
5051                         case STATEMENT_BREAK:
5052                         case STATEMENT_COMPUTED_GOTO:
5053                         case STATEMENT_GOTO:
5054                         case STATEMENT_LEAVE:
5055                                 panic("invalid control flow in function");
5056
5057                         case STATEMENT_COMPOUND:
5058                                 if (next->compound.stmt_expr) {
5059                                         reaches_end = true;
5060                                         return;
5061                                 }
5062                                 /* FALLTHROUGH */
5063                         case STATEMENT_IF:
5064                         case STATEMENT_SWITCH:
5065                         case STATEMENT_LABEL:
5066                         case STATEMENT_CASE_LABEL:
5067                                 last = next;
5068                                 next = next->base.next;
5069                                 break;
5070
5071                         case STATEMENT_WHILE: {
5072 continue_while:
5073                                 if (next->base.reachable)
5074                                         return;
5075                                 next->base.reachable = true;
5076
5077                                 while_statement_t const *const whiles = &next->whiles;
5078                                 expression_t      const *const cond   = whiles->condition;
5079
5080                                 if (!expression_returns(cond))
5081                                         return;
5082
5083                                 int const val = determine_truth(cond);
5084
5085                                 if (val >= 0)
5086                                         check_reachable(whiles->body);
5087
5088                                 if (val > 0)
5089                                         return;
5090
5091                                 last = next;
5092                                 next = next->base.next;
5093                                 break;
5094                         }
5095
5096                         case STATEMENT_DO_WHILE: {
5097 continue_do_while:
5098                                 if (next->base.reachable)
5099                                         return;
5100                                 next->base.reachable = true;
5101
5102                                 do_while_statement_t const *const dw   = &next->do_while;
5103                                 expression_t         const *const cond = dw->condition;
5104
5105                                 if (!expression_returns(cond))
5106                                         return;
5107
5108                                 int const val = determine_truth(cond);
5109
5110                                 if (val >= 0)
5111                                         check_reachable(dw->body);
5112
5113                                 if (val > 0)
5114                                         return;
5115
5116                                 last = next;
5117                                 next = next->base.next;
5118                                 break;
5119                         }
5120
5121                         case STATEMENT_FOR: {
5122 continue_for:;
5123                                 for_statement_t *const fors = &next->fors;
5124
5125                                 fors->step_reachable = true;
5126
5127                                 if (fors->condition_reachable)
5128                                         return;
5129                                 fors->condition_reachable = true;
5130
5131                                 expression_t const *const cond = fors->condition;
5132
5133                                 int val;
5134                                 if (cond == NULL) {
5135                                         val = 1;
5136                                 } else if (expression_returns(cond)) {
5137                                         val = determine_truth(cond);
5138                                 } else {
5139                                         return;
5140                                 }
5141
5142                                 if (val >= 0)
5143                                         check_reachable(fors->body);
5144
5145                                 if (val > 0)
5146                                         return;
5147
5148                                 last = next;
5149                                 next = next->base.next;
5150                                 break;
5151                         }
5152
5153                         case STATEMENT_MS_TRY:
5154                                 last = next;
5155                                 next = next->ms_try.final_statement;
5156                                 break;
5157                 }
5158         }
5159
5160         check_reachable(next);
5161 }
5162
5163 static void check_unreachable(statement_t* const stmt, void *const env)
5164 {
5165         (void)env;
5166
5167         switch (stmt->kind) {
5168                 case STATEMENT_DO_WHILE:
5169                         if (!stmt->base.reachable) {
5170                                 expression_t const *const cond = stmt->do_while.condition;
5171                                 if (determine_truth(cond) >= 0) {
5172                                         source_position_t const *const pos = &cond->base.source_position;
5173                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5174                                 }
5175                         }
5176                         return;
5177
5178                 case STATEMENT_FOR: {
5179                         for_statement_t const* const fors = &stmt->fors;
5180
5181                         // if init and step are unreachable, cond is unreachable, too
5182                         if (!stmt->base.reachable && !fors->step_reachable) {
5183                                 goto warn_unreachable;
5184                         } else {
5185                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5186                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5187                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5188                                 }
5189
5190                                 if (!fors->condition_reachable && fors->condition != NULL) {
5191                                         source_position_t const *const pos = &fors->condition->base.source_position;
5192                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5193                                 }
5194
5195                                 if (!fors->step_reachable && fors->step != NULL) {
5196                                         source_position_t const *const pos = &fors->step->base.source_position;
5197                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5198                                 }
5199                         }
5200                         return;
5201                 }
5202
5203                 case STATEMENT_COMPOUND:
5204                         if (stmt->compound.statements != NULL)
5205                                 return;
5206                         goto warn_unreachable;
5207
5208                 case STATEMENT_DECLARATION: {
5209                         /* Only warn if there is at least one declarator with an initializer.
5210                          * This typically occurs in switch statements. */
5211                         declaration_statement_t const *const decl = &stmt->declaration;
5212                         entity_t                const *      ent  = decl->declarations_begin;
5213                         entity_t                const *const last = decl->declarations_end;
5214                         if (ent != NULL) {
5215                                 for (;; ent = ent->base.next) {
5216                                         if (ent->kind                 == ENTITY_VARIABLE &&
5217                                                         ent->variable.initializer != NULL) {
5218                                                 goto warn_unreachable;
5219                                         }
5220                                         if (ent == last)
5221                                                 return;
5222                                 }
5223                         }
5224                 }
5225
5226                 default:
5227 warn_unreachable:
5228                         if (!stmt->base.reachable) {
5229                                 source_position_t const *const pos = &stmt->base.source_position;
5230                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5231                         }
5232                         return;
5233         }
5234 }
5235
5236 static bool is_main(entity_t *entity)
5237 {
5238         static symbol_t *sym_main = NULL;
5239         if (sym_main == NULL) {
5240                 sym_main = symbol_table_insert("main");
5241         }
5242
5243         if (entity->base.symbol != sym_main)
5244                 return false;
5245         /* must be in outermost scope */
5246         if (entity->base.parent_scope != file_scope)
5247                 return false;
5248
5249         return true;
5250 }
5251
5252 static void prepare_main_collect2(entity_t*);
5253
5254 static void parse_external_declaration(void)
5255 {
5256         /* function-definitions and declarations both start with declaration
5257          * specifiers */
5258         add_anchor_token(';');
5259         declaration_specifiers_t specifiers;
5260         parse_declaration_specifiers(&specifiers);
5261         rem_anchor_token(';');
5262
5263         /* must be a declaration */
5264         if (token.kind == ';') {
5265                 parse_anonymous_declaration_rest(&specifiers);
5266                 return;
5267         }
5268
5269         add_anchor_token(',');
5270         add_anchor_token('=');
5271         add_anchor_token(';');
5272         add_anchor_token('{');
5273
5274         /* declarator is common to both function-definitions and declarations */
5275         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5276
5277         rem_anchor_token('{');
5278         rem_anchor_token(';');
5279         rem_anchor_token('=');
5280         rem_anchor_token(',');
5281
5282         /* must be a declaration */
5283         switch (token.kind) {
5284                 case ',':
5285                 case ';':
5286                 case '=':
5287                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5288                                         DECL_FLAGS_NONE);
5289                         return;
5290         }
5291
5292         /* must be a function definition */
5293         parse_kr_declaration_list(ndeclaration);
5294
5295         if (token.kind != '{') {
5296                 parse_error_expected("while parsing function definition", '{', NULL);
5297                 eat_until_matching_token(';');
5298                 return;
5299         }
5300
5301         assert(is_declaration(ndeclaration));
5302         type_t *const orig_type = ndeclaration->declaration.type;
5303         type_t *      type      = skip_typeref(orig_type);
5304
5305         if (!is_type_function(type)) {
5306                 if (is_type_valid(type)) {
5307                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5308                 }
5309                 eat_block();
5310                 return;
5311         }
5312
5313         source_position_t const *const pos = &ndeclaration->base.source_position;
5314         if (is_typeref(orig_type)) {
5315                 /* §6.9.1:2 */
5316                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5317         }
5318
5319         if (is_type_compound(skip_typeref(type->function.return_type))) {
5320                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5321         }
5322         if (type->function.unspecified_parameters) {
5323                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5324         } else {
5325                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5326         }
5327
5328         /* §6.7.5.3:14 a function definition with () means no
5329          * parameters (and not unspecified parameters) */
5330         if (type->function.unspecified_parameters &&
5331                         type->function.parameters == NULL) {
5332                 type_t *copy                          = duplicate_type(type);
5333                 copy->function.unspecified_parameters = false;
5334                 type                                  = identify_new_type(copy);
5335
5336                 ndeclaration->declaration.type = type;
5337         }
5338
5339         entity_t *const entity = record_entity(ndeclaration, true);
5340         assert(entity->kind == ENTITY_FUNCTION);
5341         assert(ndeclaration->kind == ENTITY_FUNCTION);
5342
5343         function_t *const function = &entity->function;
5344         if (ndeclaration != entity) {
5345                 function->parameters = ndeclaration->function.parameters;
5346         }
5347
5348         PUSH_SCOPE(&function->parameters);
5349
5350         entity_t *parameter = function->parameters.entities;
5351         for (; parameter != NULL; parameter = parameter->base.next) {
5352                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5353                         parameter->base.parent_scope = current_scope;
5354                 }
5355                 assert(parameter->base.parent_scope == NULL
5356                                 || parameter->base.parent_scope == current_scope);
5357                 parameter->base.parent_scope = current_scope;
5358                 if (parameter->base.symbol == NULL) {
5359                         errorf(&parameter->base.source_position, "parameter name omitted");
5360                         continue;
5361                 }
5362                 environment_push(parameter);
5363         }
5364
5365         if (function->statement != NULL) {
5366                 parser_error_multiple_definition(entity, HERE);
5367                 eat_block();
5368         } else {
5369                 /* parse function body */
5370                 int         label_stack_top      = label_top();
5371                 function_t *old_current_function = current_function;
5372                 entity_t   *old_current_entity   = current_entity;
5373                 current_function                 = function;
5374                 current_entity                   = entity;
5375                 PUSH_PARENT(NULL);
5376
5377                 goto_first   = NULL;
5378                 goto_anchor  = &goto_first;
5379                 label_first  = NULL;
5380                 label_anchor = &label_first;
5381
5382                 statement_t *const body = parse_compound_statement(false);
5383                 function->statement = body;
5384                 first_err = true;
5385                 check_labels();
5386                 check_declarations();
5387                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5388                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5389                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5390                         noreturn_candidate = true;
5391                         check_reachable(body);
5392                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5393                                 walk_statements(body, check_unreachable, NULL);
5394                         if (noreturn_candidate &&
5395                             !(function->base.modifiers & DM_NORETURN)) {
5396                                 source_position_t const *const pos = &body->base.source_position;
5397                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5398                         }
5399                 }
5400
5401                 if (is_main(entity) && enable_main_collect2_hack)
5402                         prepare_main_collect2(entity);
5403
5404                 POP_PARENT();
5405                 assert(current_function == function);
5406                 assert(current_entity   == entity);
5407                 current_entity   = old_current_entity;
5408                 current_function = old_current_function;
5409                 label_pop_to(label_stack_top);
5410         }
5411
5412         POP_SCOPE();
5413 }
5414
5415 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5416 {
5417         entity_t *iter = compound->members.entities;
5418         for (; iter != NULL; iter = iter->base.next) {
5419                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5420                         continue;
5421
5422                 if (iter->base.symbol == symbol) {
5423                         return iter;
5424                 } else if (iter->base.symbol == NULL) {
5425                         /* search in anonymous structs and unions */
5426                         type_t *type = skip_typeref(iter->declaration.type);
5427                         if (is_type_compound(type)) {
5428                                 if (find_compound_entry(type->compound.compound, symbol)
5429                                                 != NULL)
5430                                         return iter;
5431                         }
5432                         continue;
5433                 }
5434         }
5435
5436         return NULL;
5437 }
5438
5439 static void check_deprecated(const source_position_t *source_position,
5440                              const entity_t *entity)
5441 {
5442         if (!is_declaration(entity))
5443                 return;
5444         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5445                 return;
5446
5447         source_position_t const *const epos = &entity->base.source_position;
5448         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5449         if (msg != NULL) {
5450                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5451         } else {
5452                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5453         }
5454 }
5455
5456
5457 static expression_t *create_select(const source_position_t *pos,
5458                                    expression_t *addr,
5459                                    type_qualifiers_t qualifiers,
5460                                                                    entity_t *entry)
5461 {
5462         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5463
5464         check_deprecated(pos, entry);
5465
5466         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5467         select->select.compound       = addr;
5468         select->select.compound_entry = entry;
5469
5470         type_t *entry_type = entry->declaration.type;
5471         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5472
5473         /* bitfields need special treatment */
5474         if (entry->compound_member.bitfield) {
5475                 unsigned bit_size = entry->compound_member.bit_size;
5476                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5477                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5478                         res_type = type_int;
5479                 }
5480         }
5481
5482         /* we always do the auto-type conversions; the & and sizeof parser contains
5483          * code to revert this! */
5484         select->base.type = automatic_type_conversion(res_type);
5485
5486
5487         return select;
5488 }
5489
5490 /**
5491  * Find entry with symbol in compound. Search anonymous structs and unions and
5492  * creates implicit select expressions for them.
5493  * Returns the adress for the innermost compound.
5494  */
5495 static expression_t *find_create_select(const source_position_t *pos,
5496                                         expression_t *addr,
5497                                         type_qualifiers_t qualifiers,
5498                                         compound_t *compound, symbol_t *symbol)
5499 {
5500         entity_t *iter = compound->members.entities;
5501         for (; iter != NULL; iter = iter->base.next) {
5502                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5503                         continue;
5504
5505                 symbol_t *iter_symbol = iter->base.symbol;
5506                 if (iter_symbol == NULL) {
5507                         type_t *type = iter->declaration.type;
5508                         if (type->kind != TYPE_COMPOUND_STRUCT
5509                                         && type->kind != TYPE_COMPOUND_UNION)
5510                                 continue;
5511
5512                         compound_t *sub_compound = type->compound.compound;
5513
5514                         if (find_compound_entry(sub_compound, symbol) == NULL)
5515                                 continue;
5516
5517                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5518                         sub_addr->base.source_position = *pos;
5519                         sub_addr->base.implicit        = true;
5520                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5521                                                   symbol);
5522                 }
5523
5524                 if (iter_symbol == symbol) {
5525                         return create_select(pos, addr, qualifiers, iter);
5526                 }
5527         }
5528
5529         return NULL;
5530 }
5531
5532 static void parse_bitfield_member(entity_t *entity)
5533 {
5534         eat(':');
5535
5536         expression_t *size = parse_constant_expression();
5537         long          size_long;
5538
5539         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5540         type_t *type = entity->declaration.type;
5541         if (!is_type_integer(skip_typeref(type))) {
5542                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5543                            type);
5544         }
5545
5546         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5547                 /* error already reported by parse_constant_expression */
5548                 size_long = get_type_size(type) * 8;
5549         } else {
5550                 size_long = fold_constant_to_int(size);
5551
5552                 const symbol_t *symbol = entity->base.symbol;
5553                 const symbol_t *user_symbol
5554                         = symbol == NULL ? sym_anonymous : symbol;
5555                 unsigned bit_size = get_type_size(type) * 8;
5556                 if (size_long < 0) {
5557                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5558                 } else if (size_long == 0 && symbol != NULL) {
5559                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5560                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5561                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5562                                    user_symbol);
5563                 } else {
5564                         /* hope that people don't invent crazy types with more bits
5565                          * than our struct can hold */
5566                         assert(size_long <
5567                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5568                 }
5569         }
5570
5571         entity->compound_member.bitfield = true;
5572         entity->compound_member.bit_size = (unsigned char)size_long;
5573 }
5574
5575 static void parse_compound_declarators(compound_t *compound,
5576                 const declaration_specifiers_t *specifiers)
5577 {
5578         add_anchor_token(';');
5579         add_anchor_token(',');
5580         do {
5581                 entity_t *entity;
5582
5583                 if (token.kind == ':') {
5584                         /* anonymous bitfield */
5585                         type_t *type = specifiers->type;
5586                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5587                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5588                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5589                         entity->declaration.type                   = type;
5590
5591                         parse_bitfield_member(entity);
5592
5593                         attribute_t  *attributes = parse_attributes(NULL);
5594                         attribute_t **anchor     = &attributes;
5595                         while (*anchor != NULL)
5596                                 anchor = &(*anchor)->next;
5597                         *anchor = specifiers->attributes;
5598                         if (attributes != NULL) {
5599                                 handle_entity_attributes(attributes, entity);
5600                         }
5601                         entity->declaration.attributes = attributes;
5602
5603                         append_entity(&compound->members, entity);
5604                 } else {
5605                         entity = parse_declarator(specifiers,
5606                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5607                         source_position_t const *const pos = &entity->base.source_position;
5608                         if (entity->kind == ENTITY_TYPEDEF) {
5609                                 errorf(pos, "typedef not allowed as compound member");
5610                         } else {
5611                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5612
5613                                 /* make sure we don't define a symbol multiple times */
5614                                 symbol_t *symbol = entity->base.symbol;
5615                                 if (symbol != NULL) {
5616                                         entity_t *prev = find_compound_entry(compound, symbol);
5617                                         if (prev != NULL) {
5618                                                 source_position_t const *const ppos = &prev->base.source_position;
5619                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5620                                         }
5621                                 }
5622
5623                                 if (token.kind == ':') {
5624                                         parse_bitfield_member(entity);
5625
5626                                         attribute_t *attributes = parse_attributes(NULL);
5627                                         handle_entity_attributes(attributes, entity);
5628                                 } else {
5629                                         type_t *orig_type = entity->declaration.type;
5630                                         type_t *type      = skip_typeref(orig_type);
5631                                         if (is_type_function(type)) {
5632                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5633                                         } else if (is_type_incomplete(type)) {
5634                                                 /* §6.7.2.1:16 flexible array member */
5635                                                 if (!is_type_array(type)       ||
5636                                                                 token.kind          != ';' ||
5637                                                                 look_ahead(1)->kind != '}') {
5638                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5639                                                 } else if (compound->members.entities == NULL) {
5640                                                         errorf(pos, "flexible array member in otherwise empty struct");
5641                                                 }
5642                                         }
5643                                 }
5644
5645                                 append_entity(&compound->members, entity);
5646                         }
5647                 }
5648         } while (next_if(','));
5649         rem_anchor_token(',');
5650         rem_anchor_token(';');
5651         expect(';');
5652
5653         anonymous_entity = NULL;
5654 }
5655
5656 static void parse_compound_type_entries(compound_t *compound)
5657 {
5658         eat('{');
5659         add_anchor_token('}');
5660
5661         for (;;) {
5662                 switch (token.kind) {
5663                         DECLARATION_START
5664                         case T___extension__:
5665                         case T_IDENTIFIER: {
5666                                 PUSH_EXTENSION();
5667                                 declaration_specifiers_t specifiers;
5668                                 parse_declaration_specifiers(&specifiers);
5669                                 parse_compound_declarators(compound, &specifiers);
5670                                 POP_EXTENSION();
5671                                 break;
5672                         }
5673
5674                         default:
5675                                 rem_anchor_token('}');
5676                                 expect('}');
5677                                 /* §6.7.2.1:7 */
5678                                 compound->complete = true;
5679                                 return;
5680                 }
5681         }
5682 }
5683
5684 static type_t *parse_typename(void)
5685 {
5686         declaration_specifiers_t specifiers;
5687         parse_declaration_specifiers(&specifiers);
5688         if (specifiers.storage_class != STORAGE_CLASS_NONE
5689                         || specifiers.thread_local) {
5690                 /* TODO: improve error message, user does probably not know what a
5691                  * storage class is...
5692                  */
5693                 errorf(&specifiers.source_position, "typename must not have a storage class");
5694         }
5695
5696         type_t *result = parse_abstract_declarator(specifiers.type);
5697
5698         return result;
5699 }
5700
5701
5702
5703
5704 typedef expression_t* (*parse_expression_function)(void);
5705 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5706
5707 typedef struct expression_parser_function_t expression_parser_function_t;
5708 struct expression_parser_function_t {
5709         parse_expression_function        parser;
5710         precedence_t                     infix_precedence;
5711         parse_expression_infix_function  infix_parser;
5712 };
5713
5714 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5715
5716 static type_t *get_string_type(void)
5717 {
5718         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5719 }
5720
5721 static type_t *get_wide_string_type(void)
5722 {
5723         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5724 }
5725
5726 /**
5727  * Parse a string constant.
5728  */
5729 static expression_t *parse_string_literal(void)
5730 {
5731         source_position_t begin   = token.base.source_position;
5732         string_t          res     = token.string.string;
5733         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5734
5735         next_token();
5736         while (token.kind == T_STRING_LITERAL
5737                         || token.kind == T_WIDE_STRING_LITERAL) {
5738                 warn_string_concat(&token.base.source_position);
5739                 res = concat_strings(&res, &token.string.string);
5740                 next_token();
5741                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5742         }
5743
5744         expression_t *literal;
5745         if (is_wide) {
5746                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5747                 literal->base.type = get_wide_string_type();
5748         } else {
5749                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5750                 literal->base.type = get_string_type();
5751         }
5752         literal->base.source_position = begin;
5753         literal->literal.value        = res;
5754
5755         return literal;
5756 }
5757
5758 /**
5759  * Parse a boolean constant.
5760  */
5761 static expression_t *parse_boolean_literal(bool value)
5762 {
5763         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5764         literal->base.type           = type_bool;
5765         literal->literal.value.begin = value ? "true" : "false";
5766         literal->literal.value.size  = value ? 4 : 5;
5767
5768         next_token();
5769         return literal;
5770 }
5771
5772 static void warn_traditional_suffix(void)
5773 {
5774         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5775                  &token.number.suffix);
5776 }
5777
5778 static void check_integer_suffix(void)
5779 {
5780         const string_t *suffix = &token.number.suffix;
5781         if (suffix->size == 0)
5782                 return;
5783
5784         bool not_traditional = false;
5785         const char *c = suffix->begin;
5786         if (*c == 'l' || *c == 'L') {
5787                 ++c;
5788                 if (*c == *(c-1)) {
5789                         not_traditional = true;
5790                         ++c;
5791                         if (*c == 'u' || *c == 'U') {
5792                                 ++c;
5793                         }
5794                 } else if (*c == 'u' || *c == 'U') {
5795                         not_traditional = true;
5796                         ++c;
5797                 }
5798         } else if (*c == 'u' || *c == 'U') {
5799                 not_traditional = true;
5800                 ++c;
5801                 if (*c == 'l' || *c == 'L') {
5802                         ++c;
5803                         if (*c == *(c-1)) {
5804                                 ++c;
5805                         }
5806                 }
5807         }
5808         if (*c != '\0') {
5809                 errorf(&token.base.source_position,
5810                        "invalid suffix '%S' on integer constant", suffix);
5811         } else if (not_traditional) {
5812                 warn_traditional_suffix();
5813         }
5814 }
5815
5816 static type_t *check_floatingpoint_suffix(void)
5817 {
5818         const string_t *suffix = &token.number.suffix;
5819         type_t         *type   = type_double;
5820         if (suffix->size == 0)
5821                 return type;
5822
5823         bool not_traditional = false;
5824         const char *c = suffix->begin;
5825         if (*c == 'f' || *c == 'F') {
5826                 ++c;
5827                 type = type_float;
5828         } else if (*c == 'l' || *c == 'L') {
5829                 ++c;
5830                 type = type_long_double;
5831         }
5832         if (*c != '\0') {
5833                 errorf(&token.base.source_position,
5834                        "invalid suffix '%S' on floatingpoint constant", suffix);
5835         } else if (not_traditional) {
5836                 warn_traditional_suffix();
5837         }
5838
5839         return type;
5840 }
5841
5842 /**
5843  * Parse an integer constant.
5844  */
5845 static expression_t *parse_number_literal(void)
5846 {
5847         expression_kind_t  kind;
5848         type_t            *type;
5849
5850         switch (token.kind) {
5851         case T_INTEGER:
5852                 kind = EXPR_LITERAL_INTEGER;
5853                 check_integer_suffix();
5854                 type = type_int;
5855                 break;
5856         case T_INTEGER_OCTAL:
5857                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5858                 check_integer_suffix();
5859                 type = type_int;
5860                 break;
5861         case T_INTEGER_HEXADECIMAL:
5862                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5863                 check_integer_suffix();
5864                 type = type_int;
5865                 break;
5866         case T_FLOATINGPOINT:
5867                 kind = EXPR_LITERAL_FLOATINGPOINT;
5868                 type = check_floatingpoint_suffix();
5869                 break;
5870         case T_FLOATINGPOINT_HEXADECIMAL:
5871                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5872                 type = check_floatingpoint_suffix();
5873                 break;
5874         default:
5875                 panic("unexpected token type in parse_number_literal");
5876         }
5877
5878         expression_t *literal = allocate_expression_zero(kind);
5879         literal->base.type      = type;
5880         literal->literal.value  = token.number.number;
5881         literal->literal.suffix = token.number.suffix;
5882         next_token();
5883
5884         /* integer type depends on the size of the number and the size
5885          * representable by the types. The backend/codegeneration has to determine
5886          * that
5887          */
5888         determine_literal_type(&literal->literal);
5889         return literal;
5890 }
5891
5892 /**
5893  * Parse a character constant.
5894  */
5895 static expression_t *parse_character_constant(void)
5896 {
5897         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5898         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5899         literal->literal.value = token.string.string;
5900
5901         size_t len = literal->literal.value.size;
5902         if (len > 1) {
5903                 if (!GNU_MODE && !(c_mode & _C99)) {
5904                         errorf(HERE, "more than 1 character in character constant");
5905                 } else {
5906                         literal->base.type = type_int;
5907                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5908                 }
5909         }
5910
5911         next_token();
5912         return literal;
5913 }
5914
5915 /**
5916  * Parse a wide character constant.
5917  */
5918 static expression_t *parse_wide_character_constant(void)
5919 {
5920         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5921         literal->base.type     = type_int;
5922         literal->literal.value = token.string.string;
5923
5924         size_t len = wstrlen(&literal->literal.value);
5925         if (len > 1) {
5926                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5927         }
5928
5929         next_token();
5930         return literal;
5931 }
5932
5933 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5934 {
5935         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5936         ntype->function.return_type            = type_int;
5937         ntype->function.unspecified_parameters = true;
5938         ntype->function.linkage                = LINKAGE_C;
5939         type_t *type                           = identify_new_type(ntype);
5940
5941         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5942         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5943         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5944         entity->declaration.type                   = type;
5945         entity->declaration.implicit               = true;
5946
5947         if (current_scope != NULL)
5948                 record_entity(entity, false);
5949
5950         return entity;
5951 }
5952
5953 /**
5954  * Performs automatic type cast as described in §6.3.2.1.
5955  *
5956  * @param orig_type  the original type
5957  */
5958 static type_t *automatic_type_conversion(type_t *orig_type)
5959 {
5960         type_t *type = skip_typeref(orig_type);
5961         if (is_type_array(type)) {
5962                 array_type_t *array_type   = &type->array;
5963                 type_t       *element_type = array_type->element_type;
5964                 unsigned      qualifiers   = array_type->base.qualifiers;
5965
5966                 return make_pointer_type(element_type, qualifiers);
5967         }
5968
5969         if (is_type_function(type)) {
5970                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5971         }
5972
5973         return orig_type;
5974 }
5975
5976 /**
5977  * reverts the automatic casts of array to pointer types and function
5978  * to function-pointer types as defined §6.3.2.1
5979  */
5980 type_t *revert_automatic_type_conversion(const expression_t *expression)
5981 {
5982         switch (expression->kind) {
5983         case EXPR_REFERENCE: {
5984                 entity_t *entity = expression->reference.entity;
5985                 if (is_declaration(entity)) {
5986                         return entity->declaration.type;
5987                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5988                         return entity->enum_value.enum_type;
5989                 } else {
5990                         panic("no declaration or enum in reference");
5991                 }
5992         }
5993
5994         case EXPR_SELECT: {
5995                 entity_t *entity = expression->select.compound_entry;
5996                 assert(is_declaration(entity));
5997                 type_t   *type   = entity->declaration.type;
5998                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5999         }
6000
6001         case EXPR_UNARY_DEREFERENCE: {
6002                 const expression_t *const value = expression->unary.value;
6003                 type_t             *const type  = skip_typeref(value->base.type);
6004                 if (!is_type_pointer(type))
6005                         return type_error_type;
6006                 return type->pointer.points_to;
6007         }
6008
6009         case EXPR_ARRAY_ACCESS: {
6010                 const expression_t *array_ref = expression->array_access.array_ref;
6011                 type_t             *type_left = skip_typeref(array_ref->base.type);
6012                 if (!is_type_pointer(type_left))
6013                         return type_error_type;
6014                 return type_left->pointer.points_to;
6015         }
6016
6017         case EXPR_STRING_LITERAL: {
6018                 size_t size = expression->string_literal.value.size;
6019                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6020         }
6021
6022         case EXPR_WIDE_STRING_LITERAL: {
6023                 size_t size = wstrlen(&expression->string_literal.value);
6024                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6025         }
6026
6027         case EXPR_COMPOUND_LITERAL:
6028                 return expression->compound_literal.type;
6029
6030         default:
6031                 break;
6032         }
6033         return expression->base.type;
6034 }
6035
6036 /**
6037  * Find an entity matching a symbol in a scope.
6038  * Uses current scope if scope is NULL
6039  */
6040 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6041                                namespace_tag_t namespc)
6042 {
6043         if (scope == NULL) {
6044                 return get_entity(symbol, namespc);
6045         }
6046
6047         /* we should optimize here, if scope grows above a certain size we should
6048            construct a hashmap here... */
6049         entity_t *entity = scope->entities;
6050         for ( ; entity != NULL; entity = entity->base.next) {
6051                 if (entity->base.symbol == symbol
6052                     && (namespace_tag_t)entity->base.namespc == namespc)
6053                         break;
6054         }
6055
6056         return entity;
6057 }
6058
6059 static entity_t *parse_qualified_identifier(void)
6060 {
6061         /* namespace containing the symbol */
6062         symbol_t          *symbol;
6063         source_position_t  pos;
6064         const scope_t     *lookup_scope = NULL;
6065
6066         if (next_if(T_COLONCOLON))
6067                 lookup_scope = &unit->scope;
6068
6069         entity_t *entity;
6070         while (true) {
6071                 symbol = expect_identifier("while parsing identifier", &pos);
6072                 if (!symbol)
6073                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6074
6075                 /* lookup entity */
6076                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6077
6078                 if (!next_if(T_COLONCOLON))
6079                         break;
6080
6081                 switch (entity->kind) {
6082                 case ENTITY_NAMESPACE:
6083                         lookup_scope = &entity->namespacee.members;
6084                         break;
6085                 case ENTITY_STRUCT:
6086                 case ENTITY_UNION:
6087                 case ENTITY_CLASS:
6088                         lookup_scope = &entity->compound.members;
6089                         break;
6090                 default:
6091                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6092                                symbol, get_entity_kind_name(entity->kind));
6093
6094                         /* skip further qualifications */
6095                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6096
6097                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6098                 }
6099         }
6100
6101         if (entity == NULL) {
6102                 if (!strict_mode && token.kind == '(') {
6103                         /* an implicitly declared function */
6104                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6105                                  "implicit declaration of function '%Y'", symbol);
6106                         entity = create_implicit_function(symbol, &pos);
6107                 } else {
6108                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6109                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6110                 }
6111         }
6112
6113         return entity;
6114 }
6115
6116 static expression_t *parse_reference(void)
6117 {
6118         source_position_t const pos    = token.base.source_position;
6119         entity_t         *const entity = parse_qualified_identifier();
6120
6121         type_t *orig_type;
6122         if (is_declaration(entity)) {
6123                 orig_type = entity->declaration.type;
6124         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6125                 orig_type = entity->enum_value.enum_type;
6126         } else {
6127                 panic("expected declaration or enum value in reference");
6128         }
6129
6130         /* we always do the auto-type conversions; the & and sizeof parser contains
6131          * code to revert this! */
6132         type_t *type = automatic_type_conversion(orig_type);
6133
6134         expression_kind_t kind = EXPR_REFERENCE;
6135         if (entity->kind == ENTITY_ENUM_VALUE)
6136                 kind = EXPR_ENUM_CONSTANT;
6137
6138         expression_t *expression         = allocate_expression_zero(kind);
6139         expression->base.source_position = pos;
6140         expression->base.type            = type;
6141         expression->reference.entity     = entity;
6142
6143         /* this declaration is used */
6144         if (is_declaration(entity)) {
6145                 entity->declaration.used = true;
6146         }
6147
6148         if (entity->base.parent_scope != file_scope
6149                 && (current_function != NULL
6150                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6151                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6152                 if (entity->kind == ENTITY_VARIABLE) {
6153                         /* access of a variable from an outer function */
6154                         entity->variable.address_taken = true;
6155                 } else if (entity->kind == ENTITY_PARAMETER) {
6156                         entity->parameter.address_taken = true;
6157                 }
6158                 current_function->need_closure = true;
6159         }
6160
6161         check_deprecated(&pos, entity);
6162
6163         return expression;
6164 }
6165
6166 static bool semantic_cast(expression_t *cast)
6167 {
6168         expression_t            *expression      = cast->unary.value;
6169         type_t                  *orig_dest_type  = cast->base.type;
6170         type_t                  *orig_type_right = expression->base.type;
6171         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6172         type_t            const *src_type        = skip_typeref(orig_type_right);
6173         source_position_t const *pos             = &cast->base.source_position;
6174
6175         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6176         if (is_type_void(dst_type))
6177                 return true;
6178
6179         /* only integer and pointer can be casted to pointer */
6180         if (is_type_pointer(dst_type)  &&
6181             !is_type_pointer(src_type) &&
6182             !is_type_integer(src_type) &&
6183             is_type_valid(src_type)) {
6184                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6185                 return false;
6186         }
6187
6188         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6189                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6190                 return false;
6191         }
6192
6193         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6194                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6195                 return false;
6196         }
6197
6198         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6199                 type_t *src = skip_typeref(src_type->pointer.points_to);
6200                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6201                 unsigned missing_qualifiers =
6202                         src->base.qualifiers & ~dst->base.qualifiers;
6203                 if (missing_qualifiers != 0) {
6204                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6205                 }
6206         }
6207         return true;
6208 }
6209
6210 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6211 {
6212         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6213         expression->base.source_position = *pos;
6214
6215         parse_initializer_env_t env;
6216         env.type             = type;
6217         env.entity           = NULL;
6218         env.must_be_constant = false;
6219         initializer_t *initializer = parse_initializer(&env);
6220         type = env.type;
6221
6222         expression->compound_literal.initializer = initializer;
6223         expression->compound_literal.type        = type;
6224         expression->base.type                    = automatic_type_conversion(type);
6225
6226         return expression;
6227 }
6228
6229 /**
6230  * Parse a cast expression.
6231  */
6232 static expression_t *parse_cast(void)
6233 {
6234         source_position_t const pos = *HERE;
6235
6236         eat('(');
6237         add_anchor_token(')');
6238
6239         type_t *type = parse_typename();
6240
6241         rem_anchor_token(')');
6242         expect(')');
6243
6244         if (token.kind == '{') {
6245                 return parse_compound_literal(&pos, type);
6246         }
6247
6248         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6249         cast->base.source_position = pos;
6250
6251         expression_t *value = parse_subexpression(PREC_CAST);
6252         cast->base.type   = type;
6253         cast->unary.value = value;
6254
6255         if (! semantic_cast(cast)) {
6256                 /* TODO: record the error in the AST. else it is impossible to detect it */
6257         }
6258
6259         return cast;
6260 }
6261
6262 /**
6263  * Parse a statement expression.
6264  */
6265 static expression_t *parse_statement_expression(void)
6266 {
6267         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6268
6269         eat('(');
6270         add_anchor_token(')');
6271
6272         statement_t *statement          = parse_compound_statement(true);
6273         statement->compound.stmt_expr   = true;
6274         expression->statement.statement = statement;
6275
6276         /* find last statement and use its type */
6277         type_t *type = type_void;
6278         const statement_t *stmt = statement->compound.statements;
6279         if (stmt != NULL) {
6280                 while (stmt->base.next != NULL)
6281                         stmt = stmt->base.next;
6282
6283                 if (stmt->kind == STATEMENT_EXPRESSION) {
6284                         type = stmt->expression.expression->base.type;
6285                 }
6286         } else {
6287                 source_position_t const *const pos = &expression->base.source_position;
6288                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6289         }
6290         expression->base.type = type;
6291
6292         rem_anchor_token(')');
6293         expect(')');
6294         return expression;
6295 }
6296
6297 /**
6298  * Parse a parenthesized expression.
6299  */
6300 static expression_t *parse_parenthesized_expression(void)
6301 {
6302         token_t const* const la1 = look_ahead(1);
6303         switch (la1->kind) {
6304         case '{':
6305                 /* gcc extension: a statement expression */
6306                 return parse_statement_expression();
6307
6308         case T_IDENTIFIER:
6309                 if (is_typedef_symbol(la1->identifier.symbol)) {
6310         DECLARATION_START
6311                         return parse_cast();
6312                 }
6313         }
6314
6315         eat('(');
6316         add_anchor_token(')');
6317         expression_t *result = parse_expression();
6318         result->base.parenthesized = true;
6319         rem_anchor_token(')');
6320         expect(')');
6321
6322         return result;
6323 }
6324
6325 static expression_t *parse_function_keyword(void)
6326 {
6327         /* TODO */
6328
6329         if (current_function == NULL) {
6330                 errorf(HERE, "'__func__' used outside of a function");
6331         }
6332
6333         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6334         expression->base.type     = type_char_ptr;
6335         expression->funcname.kind = FUNCNAME_FUNCTION;
6336
6337         next_token();
6338
6339         return expression;
6340 }
6341
6342 static expression_t *parse_pretty_function_keyword(void)
6343 {
6344         if (current_function == NULL) {
6345                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6346         }
6347
6348         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6349         expression->base.type     = type_char_ptr;
6350         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6351
6352         eat(T___PRETTY_FUNCTION__);
6353
6354         return expression;
6355 }
6356
6357 static expression_t *parse_funcsig_keyword(void)
6358 {
6359         if (current_function == NULL) {
6360                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6361         }
6362
6363         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6364         expression->base.type     = type_char_ptr;
6365         expression->funcname.kind = FUNCNAME_FUNCSIG;
6366
6367         eat(T___FUNCSIG__);
6368
6369         return expression;
6370 }
6371
6372 static expression_t *parse_funcdname_keyword(void)
6373 {
6374         if (current_function == NULL) {
6375                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6376         }
6377
6378         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6379         expression->base.type     = type_char_ptr;
6380         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6381
6382         eat(T___FUNCDNAME__);
6383
6384         return expression;
6385 }
6386
6387 static designator_t *parse_designator(void)
6388 {
6389         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6390         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6391         if (!result->symbol)
6392                 return NULL;
6393
6394         designator_t *last_designator = result;
6395         while (true) {
6396                 if (next_if('.')) {
6397                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6398                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6399                         if (!designator->symbol)
6400                                 return NULL;
6401
6402                         last_designator->next = designator;
6403                         last_designator       = designator;
6404                         continue;
6405                 }
6406                 if (next_if('[')) {
6407                         add_anchor_token(']');
6408                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6409                         designator->source_position = *HERE;
6410                         designator->array_index     = parse_expression();
6411                         rem_anchor_token(']');
6412                         expect(']');
6413                         if (designator->array_index == NULL) {
6414                                 return NULL;
6415                         }
6416
6417                         last_designator->next = designator;
6418                         last_designator       = designator;
6419                         continue;
6420                 }
6421                 break;
6422         }
6423
6424         return result;
6425 }
6426
6427 /**
6428  * Parse the __builtin_offsetof() expression.
6429  */
6430 static expression_t *parse_offsetof(void)
6431 {
6432         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6433         expression->base.type    = type_size_t;
6434
6435         eat(T___builtin_offsetof);
6436
6437         expect('(');
6438         add_anchor_token(')');
6439         add_anchor_token(',');
6440         type_t *type = parse_typename();
6441         rem_anchor_token(',');
6442         expect(',');
6443         designator_t *designator = parse_designator();
6444         rem_anchor_token(')');
6445         expect(')');
6446
6447         expression->offsetofe.type       = type;
6448         expression->offsetofe.designator = designator;
6449
6450         type_path_t path;
6451         memset(&path, 0, sizeof(path));
6452         path.top_type = type;
6453         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6454
6455         descend_into_subtype(&path);
6456
6457         if (!walk_designator(&path, designator, true)) {
6458                 return create_error_expression();
6459         }
6460
6461         DEL_ARR_F(path.path);
6462
6463         return expression;
6464 }
6465
6466 /**
6467  * Parses a _builtin_va_start() expression.
6468  */
6469 static expression_t *parse_va_start(void)
6470 {
6471         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6472
6473         eat(T___builtin_va_start);
6474
6475         expect('(');
6476         add_anchor_token(')');
6477         add_anchor_token(',');
6478         expression->va_starte.ap = parse_assignment_expression();
6479         rem_anchor_token(',');
6480         expect(',');
6481         expression_t *const expr = parse_assignment_expression();
6482         if (expr->kind == EXPR_REFERENCE) {
6483                 entity_t *const entity = expr->reference.entity;
6484                 if (!current_function->base.type->function.variadic) {
6485                         errorf(&expr->base.source_position,
6486                                         "'va_start' used in non-variadic function");
6487                 } else if (entity->base.parent_scope != &current_function->parameters ||
6488                                 entity->base.next != NULL ||
6489                                 entity->kind != ENTITY_PARAMETER) {
6490                         errorf(&expr->base.source_position,
6491                                "second argument of 'va_start' must be last parameter of the current function");
6492                 } else {
6493                         expression->va_starte.parameter = &entity->variable;
6494                 }
6495         } else {
6496                 expression = create_error_expression();
6497         }
6498         rem_anchor_token(')');
6499         expect(')');
6500         return expression;
6501 }
6502
6503 /**
6504  * Parses a __builtin_va_arg() expression.
6505  */
6506 static expression_t *parse_va_arg(void)
6507 {
6508         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6509
6510         eat(T___builtin_va_arg);
6511
6512         expect('(');
6513         add_anchor_token(')');
6514         add_anchor_token(',');
6515         call_argument_t ap;
6516         ap.expression = parse_assignment_expression();
6517         expression->va_arge.ap = ap.expression;
6518         check_call_argument(type_valist, &ap, 1);
6519
6520         rem_anchor_token(',');
6521         expect(',');
6522         expression->base.type = parse_typename();
6523         rem_anchor_token(')');
6524         expect(')');
6525
6526         return expression;
6527 }
6528
6529 /**
6530  * Parses a __builtin_va_copy() expression.
6531  */
6532 static expression_t *parse_va_copy(void)
6533 {
6534         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6535
6536         eat(T___builtin_va_copy);
6537
6538         expect('(');
6539         add_anchor_token(')');
6540         add_anchor_token(',');
6541         expression_t *dst = parse_assignment_expression();
6542         assign_error_t error = semantic_assign(type_valist, dst);
6543         report_assign_error(error, type_valist, dst, "call argument 1",
6544                             &dst->base.source_position);
6545         expression->va_copye.dst = dst;
6546
6547         rem_anchor_token(',');
6548         expect(',');
6549
6550         call_argument_t src;
6551         src.expression = parse_assignment_expression();
6552         check_call_argument(type_valist, &src, 2);
6553         expression->va_copye.src = src.expression;
6554         rem_anchor_token(')');
6555         expect(')');
6556
6557         return expression;
6558 }
6559
6560 /**
6561  * Parses a __builtin_constant_p() expression.
6562  */
6563 static expression_t *parse_builtin_constant(void)
6564 {
6565         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6566
6567         eat(T___builtin_constant_p);
6568
6569         expect('(');
6570         add_anchor_token(')');
6571         expression->builtin_constant.value = parse_assignment_expression();
6572         rem_anchor_token(')');
6573         expect(')');
6574         expression->base.type = type_int;
6575
6576         return expression;
6577 }
6578
6579 /**
6580  * Parses a __builtin_types_compatible_p() expression.
6581  */
6582 static expression_t *parse_builtin_types_compatible(void)
6583 {
6584         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6585
6586         eat(T___builtin_types_compatible_p);
6587
6588         expect('(');
6589         add_anchor_token(')');
6590         add_anchor_token(',');
6591         expression->builtin_types_compatible.left = parse_typename();
6592         rem_anchor_token(',');
6593         expect(',');
6594         expression->builtin_types_compatible.right = parse_typename();
6595         rem_anchor_token(')');
6596         expect(')');
6597         expression->base.type = type_int;
6598
6599         return expression;
6600 }
6601
6602 /**
6603  * Parses a __builtin_is_*() compare expression.
6604  */
6605 static expression_t *parse_compare_builtin(void)
6606 {
6607         expression_t *expression;
6608
6609         switch (token.kind) {
6610         case T___builtin_isgreater:
6611                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6612                 break;
6613         case T___builtin_isgreaterequal:
6614                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6615                 break;
6616         case T___builtin_isless:
6617                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6618                 break;
6619         case T___builtin_islessequal:
6620                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6621                 break;
6622         case T___builtin_islessgreater:
6623                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6624                 break;
6625         case T___builtin_isunordered:
6626                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6627                 break;
6628         default:
6629                 internal_errorf(HERE, "invalid compare builtin found");
6630         }
6631         expression->base.source_position = *HERE;
6632         next_token();
6633
6634         expect('(');
6635         add_anchor_token(')');
6636         add_anchor_token(',');
6637         expression->binary.left = parse_assignment_expression();
6638         rem_anchor_token(',');
6639         expect(',');
6640         expression->binary.right = parse_assignment_expression();
6641         rem_anchor_token(')');
6642         expect(')');
6643
6644         type_t *const orig_type_left  = expression->binary.left->base.type;
6645         type_t *const orig_type_right = expression->binary.right->base.type;
6646
6647         type_t *const type_left  = skip_typeref(orig_type_left);
6648         type_t *const type_right = skip_typeref(orig_type_right);
6649         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6650                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6651                         type_error_incompatible("invalid operands in comparison",
6652                                 &expression->base.source_position, orig_type_left, orig_type_right);
6653                 }
6654         } else {
6655                 semantic_comparison(&expression->binary);
6656         }
6657
6658         return expression;
6659 }
6660
6661 /**
6662  * Parses a MS assume() expression.
6663  */
6664 static expression_t *parse_assume(void)
6665 {
6666         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6667
6668         eat(T__assume);
6669
6670         expect('(');
6671         add_anchor_token(')');
6672         expression->unary.value = parse_assignment_expression();
6673         rem_anchor_token(')');
6674         expect(')');
6675
6676         expression->base.type = type_void;
6677         return expression;
6678 }
6679
6680 /**
6681  * Return the label for the current symbol or create a new one.
6682  */
6683 static label_t *get_label(void)
6684 {
6685         assert(token.kind == T_IDENTIFIER);
6686         assert(current_function != NULL);
6687
6688         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6689         /* If we find a local label, we already created the declaration. */
6690         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6691                 if (label->base.parent_scope != current_scope) {
6692                         assert(label->base.parent_scope->depth < current_scope->depth);
6693                         current_function->goto_to_outer = true;
6694                 }
6695         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6696                 /* There is no matching label in the same function, so create a new one. */
6697                 source_position_t const nowhere = { NULL, 0, 0, false };
6698                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol, &nowhere);
6699                 label_push(label);
6700         }
6701
6702         eat(T_IDENTIFIER);
6703         return &label->label;
6704 }
6705
6706 /**
6707  * Parses a GNU && label address expression.
6708  */
6709 static expression_t *parse_label_address(void)
6710 {
6711         source_position_t source_position = token.base.source_position;
6712         eat(T_ANDAND);
6713         if (token.kind != T_IDENTIFIER) {
6714                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6715                 return create_error_expression();
6716         }
6717
6718         label_t *const label = get_label();
6719         label->used          = true;
6720         label->address_taken = true;
6721
6722         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6723         expression->base.source_position = source_position;
6724
6725         /* label address is treated as a void pointer */
6726         expression->base.type           = type_void_ptr;
6727         expression->label_address.label = label;
6728         return expression;
6729 }
6730
6731 /**
6732  * Parse a microsoft __noop expression.
6733  */
6734 static expression_t *parse_noop_expression(void)
6735 {
6736         /* the result is a (int)0 */
6737         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6738         literal->base.type           = type_int;
6739         literal->literal.value.begin = "__noop";
6740         literal->literal.value.size  = 6;
6741
6742         eat(T___noop);
6743
6744         if (token.kind == '(') {
6745                 /* parse arguments */
6746                 eat('(');
6747                 add_anchor_token(')');
6748                 add_anchor_token(',');
6749
6750                 if (token.kind != ')') do {
6751                         (void)parse_assignment_expression();
6752                 } while (next_if(','));
6753
6754                 rem_anchor_token(',');
6755                 rem_anchor_token(')');
6756         }
6757         expect(')');
6758
6759         return literal;
6760 }
6761
6762 /**
6763  * Parses a primary expression.
6764  */
6765 static expression_t *parse_primary_expression(void)
6766 {
6767         switch (token.kind) {
6768         case T_false:                        return parse_boolean_literal(false);
6769         case T_true:                         return parse_boolean_literal(true);
6770         case T_INTEGER:
6771         case T_INTEGER_OCTAL:
6772         case T_INTEGER_HEXADECIMAL:
6773         case T_FLOATINGPOINT:
6774         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6775         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6776         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6777         case T_STRING_LITERAL:
6778         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6779         case T___FUNCTION__:
6780         case T___func__:                     return parse_function_keyword();
6781         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6782         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6783         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6784         case T___builtin_offsetof:           return parse_offsetof();
6785         case T___builtin_va_start:           return parse_va_start();
6786         case T___builtin_va_arg:             return parse_va_arg();
6787         case T___builtin_va_copy:            return parse_va_copy();
6788         case T___builtin_isgreater:
6789         case T___builtin_isgreaterequal:
6790         case T___builtin_isless:
6791         case T___builtin_islessequal:
6792         case T___builtin_islessgreater:
6793         case T___builtin_isunordered:        return parse_compare_builtin();
6794         case T___builtin_constant_p:         return parse_builtin_constant();
6795         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6796         case T__assume:                      return parse_assume();
6797         case T_ANDAND:
6798                 if (GNU_MODE)
6799                         return parse_label_address();
6800                 break;
6801
6802         case '(':                            return parse_parenthesized_expression();
6803         case T___noop:                       return parse_noop_expression();
6804
6805         /* Gracefully handle type names while parsing expressions. */
6806         case T_COLONCOLON:
6807                 return parse_reference();
6808         case T_IDENTIFIER:
6809                 if (!is_typedef_symbol(token.identifier.symbol)) {
6810                         return parse_reference();
6811                 }
6812                 /* FALLTHROUGH */
6813         DECLARATION_START {
6814                 source_position_t const  pos = *HERE;
6815                 declaration_specifiers_t specifiers;
6816                 parse_declaration_specifiers(&specifiers);
6817                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6818                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6819                 return create_error_expression();
6820         }
6821         }
6822
6823         errorf(HERE, "unexpected token %K, expected an expression", &token);
6824         eat_until_anchor();
6825         return create_error_expression();
6826 }
6827
6828 static expression_t *parse_array_expression(expression_t *left)
6829 {
6830         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6831         array_access_expression_t *const arr  = &expr->array_access;
6832
6833         eat('[');
6834         add_anchor_token(']');
6835
6836         expression_t *const inside = parse_expression();
6837
6838         type_t *const orig_type_left   = left->base.type;
6839         type_t *const orig_type_inside = inside->base.type;
6840
6841         type_t *const type_left   = skip_typeref(orig_type_left);
6842         type_t *const type_inside = skip_typeref(orig_type_inside);
6843
6844         expression_t *ref;
6845         expression_t *idx;
6846         type_t       *idx_type;
6847         type_t       *res_type;
6848         if (is_type_pointer(type_left)) {
6849                 ref      = left;
6850                 idx      = inside;
6851                 idx_type = type_inside;
6852                 res_type = type_left->pointer.points_to;
6853                 goto check_idx;
6854         } else if (is_type_pointer(type_inside)) {
6855                 arr->flipped = true;
6856                 ref      = inside;
6857                 idx      = left;
6858                 idx_type = type_left;
6859                 res_type = type_inside->pointer.points_to;
6860 check_idx:
6861                 res_type = automatic_type_conversion(res_type);
6862                 if (!is_type_integer(idx_type)) {
6863                         errorf(&idx->base.source_position, "array subscript must have integer type");
6864                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6865                         source_position_t const *const pos = &idx->base.source_position;
6866                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6867                 }
6868         } else {
6869                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6870                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6871                 }
6872                 res_type = type_error_type;
6873                 ref      = left;
6874                 idx      = inside;
6875         }
6876
6877         arr->array_ref = ref;
6878         arr->index     = idx;
6879         arr->base.type = res_type;
6880
6881         rem_anchor_token(']');
6882         expect(']');
6883         return expr;
6884 }
6885
6886 static bool is_bitfield(const expression_t *expression)
6887 {
6888         return expression->kind == EXPR_SELECT
6889                 && expression->select.compound_entry->compound_member.bitfield;
6890 }
6891
6892 static expression_t *parse_typeprop(expression_kind_t const kind)
6893 {
6894         expression_t  *tp_expression = allocate_expression_zero(kind);
6895         tp_expression->base.type     = type_size_t;
6896
6897         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6898
6899         type_t       *orig_type;
6900         expression_t *expression;
6901         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6902                 source_position_t const pos = *HERE;
6903                 next_token();
6904                 add_anchor_token(')');
6905                 orig_type = parse_typename();
6906                 rem_anchor_token(')');
6907                 expect(')');
6908
6909                 if (token.kind == '{') {
6910                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6911                          * starting with a compound literal */
6912                         expression = parse_compound_literal(&pos, orig_type);
6913                         goto typeprop_expression;
6914                 }
6915         } else {
6916                 expression = parse_subexpression(PREC_UNARY);
6917
6918 typeprop_expression:
6919                 if (is_bitfield(expression)) {
6920                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6921                         errorf(&tp_expression->base.source_position,
6922                                    "operand of %s expression must not be a bitfield", what);
6923                 }
6924
6925                 tp_expression->typeprop.tp_expression = expression;
6926
6927                 orig_type = revert_automatic_type_conversion(expression);
6928                 expression->base.type = orig_type;
6929         }
6930
6931         tp_expression->typeprop.type   = orig_type;
6932         type_t const* const type       = skip_typeref(orig_type);
6933         char   const*       wrong_type = NULL;
6934         if (is_type_incomplete(type)) {
6935                 if (!is_type_void(type) || !GNU_MODE)
6936                         wrong_type = "incomplete";
6937         } else if (type->kind == TYPE_FUNCTION) {
6938                 if (GNU_MODE) {
6939                         /* function types are allowed (and return 1) */
6940                         source_position_t const *const pos  = &tp_expression->base.source_position;
6941                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6942                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6943                 } else {
6944                         wrong_type = "function";
6945                 }
6946         }
6947
6948         if (wrong_type != NULL) {
6949                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6950                 errorf(&tp_expression->base.source_position,
6951                                 "operand of %s expression must not be of %s type '%T'",
6952                                 what, wrong_type, orig_type);
6953         }
6954
6955         return tp_expression;
6956 }
6957
6958 static expression_t *parse_sizeof(void)
6959 {
6960         return parse_typeprop(EXPR_SIZEOF);
6961 }
6962
6963 static expression_t *parse_alignof(void)
6964 {
6965         return parse_typeprop(EXPR_ALIGNOF);
6966 }
6967
6968 static expression_t *parse_select_expression(expression_t *addr)
6969 {
6970         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6971         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6972         source_position_t const pos = *HERE;
6973         next_token();
6974
6975         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6976         if (!symbol)
6977                 return create_error_expression();
6978
6979         type_t *const orig_type = addr->base.type;
6980         type_t *const type      = skip_typeref(orig_type);
6981
6982         type_t *type_left;
6983         bool    saw_error = false;
6984         if (is_type_pointer(type)) {
6985                 if (!select_left_arrow) {
6986                         errorf(&pos,
6987                                "request for member '%Y' in something not a struct or union, but '%T'",
6988                                symbol, orig_type);
6989                         saw_error = true;
6990                 }
6991                 type_left = skip_typeref(type->pointer.points_to);
6992         } else {
6993                 if (select_left_arrow && is_type_valid(type)) {
6994                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6995                         saw_error = true;
6996                 }
6997                 type_left = type;
6998         }
6999
7000         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7001             type_left->kind != TYPE_COMPOUND_UNION) {
7002
7003                 if (is_type_valid(type_left) && !saw_error) {
7004                         errorf(&pos,
7005                                "request for member '%Y' in something not a struct or union, but '%T'",
7006                                symbol, type_left);
7007                 }
7008                 return create_error_expression();
7009         }
7010
7011         compound_t *compound = type_left->compound.compound;
7012         if (!compound->complete) {
7013                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7014                        symbol, type_left);
7015                 return create_error_expression();
7016         }
7017
7018         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7019         expression_t      *result     =
7020                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7021
7022         if (result == NULL) {
7023                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7024                 return create_error_expression();
7025         }
7026
7027         return result;
7028 }
7029
7030 static void check_call_argument(type_t          *expected_type,
7031                                 call_argument_t *argument, unsigned pos)
7032 {
7033         type_t         *expected_type_skip = skip_typeref(expected_type);
7034         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7035         expression_t   *arg_expr           = argument->expression;
7036         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7037
7038         /* handle transparent union gnu extension */
7039         if (is_type_union(expected_type_skip)
7040                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7041                 compound_t *union_decl  = expected_type_skip->compound.compound;
7042                 type_t     *best_type   = NULL;
7043                 entity_t   *entry       = union_decl->members.entities;
7044                 for ( ; entry != NULL; entry = entry->base.next) {
7045                         assert(is_declaration(entry));
7046                         type_t *decl_type = entry->declaration.type;
7047                         error = semantic_assign(decl_type, arg_expr);
7048                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7049                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7050                                 continue;
7051
7052                         if (error == ASSIGN_SUCCESS) {
7053                                 best_type = decl_type;
7054                         } else if (best_type == NULL) {
7055                                 best_type = decl_type;
7056                         }
7057                 }
7058
7059                 if (best_type != NULL) {
7060                         expected_type = best_type;
7061                 }
7062         }
7063
7064         error                = semantic_assign(expected_type, arg_expr);
7065         argument->expression = create_implicit_cast(arg_expr, expected_type);
7066
7067         if (error != ASSIGN_SUCCESS) {
7068                 /* report exact scope in error messages (like "in argument 3") */
7069                 char buf[64];
7070                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7071                 report_assign_error(error, expected_type, arg_expr, buf,
7072                                     &arg_expr->base.source_position);
7073         } else {
7074                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7075                 if (!types_compatible(expected_type_skip, promoted_type) &&
7076                     !types_compatible(expected_type_skip, type_void_ptr) &&
7077                     !types_compatible(type_void_ptr,      promoted_type)) {
7078                         /* Deliberately show the skipped types in this warning */
7079                         source_position_t const *const apos = &arg_expr->base.source_position;
7080                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7081                 }
7082         }
7083 }
7084
7085 /**
7086  * Handle the semantic restrictions of builtin calls
7087  */
7088 static void handle_builtin_argument_restrictions(call_expression_t *call)
7089 {
7090         entity_t *entity = call->function->reference.entity;
7091         switch (entity->function.btk) {
7092         case BUILTIN_FIRM:
7093                 switch (entity->function.b.firm_builtin_kind) {
7094                 case ir_bk_return_address:
7095                 case ir_bk_frame_address: {
7096                         /* argument must be constant */
7097                         call_argument_t *argument = call->arguments;
7098
7099                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7100                                 errorf(&call->base.source_position,
7101                                            "argument of '%Y' must be a constant expression",
7102                                            call->function->reference.entity->base.symbol);
7103                         }
7104                         break;
7105                 }
7106                 case ir_bk_prefetch:
7107                         /* second and third argument must be constant if existent */
7108                         if (call->arguments == NULL)
7109                                 break;
7110                         call_argument_t *rw = call->arguments->next;
7111                         call_argument_t *locality = NULL;
7112
7113                         if (rw != NULL) {
7114                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7115                                         errorf(&call->base.source_position,
7116                                                    "second argument of '%Y' must be a constant expression",
7117                                                    call->function->reference.entity->base.symbol);
7118                                 }
7119                                 locality = rw->next;
7120                         }
7121                         if (locality != NULL) {
7122                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7123                                         errorf(&call->base.source_position,
7124                                                    "third argument of '%Y' must be a constant expression",
7125                                                    call->function->reference.entity->base.symbol);
7126                                 }
7127                                 locality = rw->next;
7128                         }
7129                         break;
7130                 default:
7131                         break;
7132                 }
7133
7134         case BUILTIN_OBJECT_SIZE:
7135                 if (call->arguments == NULL)
7136                         break;
7137
7138                 call_argument_t *arg = call->arguments->next;
7139                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7140                         errorf(&call->base.source_position,
7141                                    "second argument of '%Y' must be a constant expression",
7142                                    call->function->reference.entity->base.symbol);
7143                 }
7144                 break;
7145         default:
7146                 break;
7147         }
7148 }
7149
7150 /**
7151  * Parse a call expression, ie. expression '( ... )'.
7152  *
7153  * @param expression  the function address
7154  */
7155 static expression_t *parse_call_expression(expression_t *expression)
7156 {
7157         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7158         call_expression_t *call   = &result->call;
7159         call->function            = expression;
7160
7161         type_t *const orig_type = expression->base.type;
7162         type_t *const type      = skip_typeref(orig_type);
7163
7164         function_type_t *function_type = NULL;
7165         if (is_type_pointer(type)) {
7166                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7167
7168                 if (is_type_function(to_type)) {
7169                         function_type   = &to_type->function;
7170                         call->base.type = function_type->return_type;
7171                 }
7172         }
7173
7174         if (function_type == NULL && is_type_valid(type)) {
7175                 errorf(HERE,
7176                        "called object '%E' (type '%T') is not a pointer to a function",
7177                        expression, orig_type);
7178         }
7179
7180         /* parse arguments */
7181         eat('(');
7182         add_anchor_token(')');
7183         add_anchor_token(',');
7184
7185         if (token.kind != ')') {
7186                 call_argument_t **anchor = &call->arguments;
7187                 do {
7188                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7189                         argument->expression = parse_assignment_expression();
7190
7191                         *anchor = argument;
7192                         anchor  = &argument->next;
7193                 } while (next_if(','));
7194         }
7195         rem_anchor_token(',');
7196         rem_anchor_token(')');
7197         expect(')');
7198
7199         if (function_type == NULL)
7200                 return result;
7201
7202         /* check type and count of call arguments */
7203         function_parameter_t *parameter = function_type->parameters;
7204         call_argument_t      *argument  = call->arguments;
7205         if (!function_type->unspecified_parameters) {
7206                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7207                                 parameter = parameter->next, argument = argument->next) {
7208                         check_call_argument(parameter->type, argument, ++pos);
7209                 }
7210
7211                 if (parameter != NULL) {
7212                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7213                 } else if (argument != NULL && !function_type->variadic) {
7214                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7215                 }
7216         }
7217
7218         /* do default promotion for other arguments */
7219         for (; argument != NULL; argument = argument->next) {
7220                 type_t *argument_type = argument->expression->base.type;
7221                 if (!is_type_object(skip_typeref(argument_type))) {
7222                         errorf(&argument->expression->base.source_position,
7223                                "call argument '%E' must not be void", argument->expression);
7224                 }
7225
7226                 argument_type = get_default_promoted_type(argument_type);
7227
7228                 argument->expression
7229                         = create_implicit_cast(argument->expression, argument_type);
7230         }
7231
7232         check_format(call);
7233
7234         if (is_type_compound(skip_typeref(function_type->return_type))) {
7235                 source_position_t const *const pos = &expression->base.source_position;
7236                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7237         }
7238
7239         if (expression->kind == EXPR_REFERENCE) {
7240                 reference_expression_t *reference = &expression->reference;
7241                 if (reference->entity->kind == ENTITY_FUNCTION &&
7242                     reference->entity->function.btk != BUILTIN_NONE)
7243                         handle_builtin_argument_restrictions(call);
7244         }
7245
7246         return result;
7247 }
7248
7249 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7250
7251 static bool same_compound_type(const type_t *type1, const type_t *type2)
7252 {
7253         return
7254                 is_type_compound(type1) &&
7255                 type1->kind == type2->kind &&
7256                 type1->compound.compound == type2->compound.compound;
7257 }
7258
7259 static expression_t const *get_reference_address(expression_t const *expr)
7260 {
7261         bool regular_take_address = true;
7262         for (;;) {
7263                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7264                         expr = expr->unary.value;
7265                 } else {
7266                         regular_take_address = false;
7267                 }
7268
7269                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7270                         break;
7271
7272                 expr = expr->unary.value;
7273         }
7274
7275         if (expr->kind != EXPR_REFERENCE)
7276                 return NULL;
7277
7278         /* special case for functions which are automatically converted to a
7279          * pointer to function without an extra TAKE_ADDRESS operation */
7280         if (!regular_take_address &&
7281                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7282                 return NULL;
7283         }
7284
7285         return expr;
7286 }
7287
7288 static void warn_reference_address_as_bool(expression_t const* expr)
7289 {
7290         expr = get_reference_address(expr);
7291         if (expr != NULL) {
7292                 source_position_t const *const pos = &expr->base.source_position;
7293                 entity_t          const *const ent = expr->reference.entity;
7294                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7295         }
7296 }
7297
7298 static void warn_assignment_in_condition(const expression_t *const expr)
7299 {
7300         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7301                 return;
7302         if (expr->base.parenthesized)
7303                 return;
7304         source_position_t const *const pos = &expr->base.source_position;
7305         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7306 }
7307
7308 static void semantic_condition(expression_t const *const expr,
7309                                char const *const context)
7310 {
7311         type_t *const type = skip_typeref(expr->base.type);
7312         if (is_type_scalar(type)) {
7313                 warn_reference_address_as_bool(expr);
7314                 warn_assignment_in_condition(expr);
7315         } else if (is_type_valid(type)) {
7316                 errorf(&expr->base.source_position,
7317                                 "%s must have scalar type", context);
7318         }
7319 }
7320
7321 /**
7322  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7323  *
7324  * @param expression  the conditional expression
7325  */
7326 static expression_t *parse_conditional_expression(expression_t *expression)
7327 {
7328         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7329
7330         conditional_expression_t *conditional = &result->conditional;
7331         conditional->condition                = expression;
7332
7333         eat('?');
7334         add_anchor_token(':');
7335
7336         /* §6.5.15:2  The first operand shall have scalar type. */
7337         semantic_condition(expression, "condition of conditional operator");
7338
7339         expression_t *true_expression = expression;
7340         bool          gnu_cond = false;
7341         if (GNU_MODE && token.kind == ':') {
7342                 gnu_cond = true;
7343         } else {
7344                 true_expression = parse_expression();
7345         }
7346         rem_anchor_token(':');
7347         expect(':');
7348         expression_t *false_expression =
7349                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7350
7351         type_t *const orig_true_type  = true_expression->base.type;
7352         type_t *const orig_false_type = false_expression->base.type;
7353         type_t *const true_type       = skip_typeref(orig_true_type);
7354         type_t *const false_type      = skip_typeref(orig_false_type);
7355
7356         /* 6.5.15.3 */
7357         source_position_t const *const pos = &conditional->base.source_position;
7358         type_t                        *result_type;
7359         if (is_type_void(true_type) || is_type_void(false_type)) {
7360                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7361                 if (true_expression->kind == EXPR_UNARY_THROW) {
7362                         result_type = false_type;
7363                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7364                         result_type = true_type;
7365                 } else {
7366                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7367                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7368                         }
7369                         result_type = type_void;
7370                 }
7371         } else if (is_type_arithmetic(true_type)
7372                    && is_type_arithmetic(false_type)) {
7373                 result_type = semantic_arithmetic(true_type, false_type);
7374         } else if (same_compound_type(true_type, false_type)) {
7375                 /* just take 1 of the 2 types */
7376                 result_type = true_type;
7377         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7378                 type_t *pointer_type;
7379                 type_t *other_type;
7380                 expression_t *other_expression;
7381                 if (is_type_pointer(true_type) &&
7382                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7383                         pointer_type     = true_type;
7384                         other_type       = false_type;
7385                         other_expression = false_expression;
7386                 } else {
7387                         pointer_type     = false_type;
7388                         other_type       = true_type;
7389                         other_expression = true_expression;
7390                 }
7391
7392                 if (is_null_pointer_constant(other_expression)) {
7393                         result_type = pointer_type;
7394                 } else if (is_type_pointer(other_type)) {
7395                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7396                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7397
7398                         type_t *to;
7399                         if (is_type_void(to1) || is_type_void(to2)) {
7400                                 to = type_void;
7401                         } else if (types_compatible(get_unqualified_type(to1),
7402                                                     get_unqualified_type(to2))) {
7403                                 to = to1;
7404                         } else {
7405                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7406                                 to = type_void;
7407                         }
7408
7409                         type_t *const type =
7410                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7411                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7412                 } else if (is_type_integer(other_type)) {
7413                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7414                         result_type = pointer_type;
7415                 } else {
7416                         goto types_incompatible;
7417                 }
7418         } else {
7419 types_incompatible:
7420                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7421                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7422                 }
7423                 result_type = type_error_type;
7424         }
7425
7426         conditional->true_expression
7427                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7428         conditional->false_expression
7429                 = create_implicit_cast(false_expression, result_type);
7430         conditional->base.type = result_type;
7431         return result;
7432 }
7433
7434 /**
7435  * Parse an extension expression.
7436  */
7437 static expression_t *parse_extension(void)
7438 {
7439         PUSH_EXTENSION();
7440         expression_t *expression = parse_subexpression(PREC_UNARY);
7441         POP_EXTENSION();
7442         return expression;
7443 }
7444
7445 /**
7446  * Parse a __builtin_classify_type() expression.
7447  */
7448 static expression_t *parse_builtin_classify_type(void)
7449 {
7450         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7451         result->base.type    = type_int;
7452
7453         eat(T___builtin_classify_type);
7454
7455         expect('(');
7456         add_anchor_token(')');
7457         expression_t *expression = parse_expression();
7458         rem_anchor_token(')');
7459         expect(')');
7460         result->classify_type.type_expression = expression;
7461
7462         return result;
7463 }
7464
7465 /**
7466  * Parse a delete expression
7467  * ISO/IEC 14882:1998(E) §5.3.5
7468  */
7469 static expression_t *parse_delete(void)
7470 {
7471         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7472         result->base.type          = type_void;
7473
7474         eat(T_delete);
7475
7476         if (next_if('[')) {
7477                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7478                 expect(']');
7479         }
7480
7481         expression_t *const value = parse_subexpression(PREC_CAST);
7482         result->unary.value = value;
7483
7484         type_t *const type = skip_typeref(value->base.type);
7485         if (!is_type_pointer(type)) {
7486                 if (is_type_valid(type)) {
7487                         errorf(&value->base.source_position,
7488                                         "operand of delete must have pointer type");
7489                 }
7490         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7491                 source_position_t const *const pos = &value->base.source_position;
7492                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7493         }
7494
7495         return result;
7496 }
7497
7498 /**
7499  * Parse a throw expression
7500  * ISO/IEC 14882:1998(E) §15:1
7501  */
7502 static expression_t *parse_throw(void)
7503 {
7504         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7505         result->base.type          = type_void;
7506
7507         eat(T_throw);
7508
7509         expression_t *value = NULL;
7510         switch (token.kind) {
7511                 EXPRESSION_START {
7512                         value = parse_assignment_expression();
7513                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7514                         type_t *const orig_type = value->base.type;
7515                         type_t *const type      = skip_typeref(orig_type);
7516                         if (is_type_incomplete(type)) {
7517                                 errorf(&value->base.source_position,
7518                                                 "cannot throw object of incomplete type '%T'", orig_type);
7519                         } else if (is_type_pointer(type)) {
7520                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7521                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7522                                         errorf(&value->base.source_position,
7523                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7524                                 }
7525                         }
7526                 }
7527
7528                 default:
7529                         break;
7530         }
7531         result->unary.value = value;
7532
7533         return result;
7534 }
7535
7536 static bool check_pointer_arithmetic(const source_position_t *source_position,
7537                                      type_t *pointer_type,
7538                                      type_t *orig_pointer_type)
7539 {
7540         type_t *points_to = pointer_type->pointer.points_to;
7541         points_to = skip_typeref(points_to);
7542
7543         if (is_type_incomplete(points_to)) {
7544                 if (!GNU_MODE || !is_type_void(points_to)) {
7545                         errorf(source_position,
7546                                "arithmetic with pointer to incomplete type '%T' not allowed",
7547                                orig_pointer_type);
7548                         return false;
7549                 } else {
7550                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7551                 }
7552         } else if (is_type_function(points_to)) {
7553                 if (!GNU_MODE) {
7554                         errorf(source_position,
7555                                "arithmetic with pointer to function type '%T' not allowed",
7556                                orig_pointer_type);
7557                         return false;
7558                 } else {
7559                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7560                 }
7561         }
7562         return true;
7563 }
7564
7565 static bool is_lvalue(const expression_t *expression)
7566 {
7567         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7568         switch (expression->kind) {
7569         case EXPR_ARRAY_ACCESS:
7570         case EXPR_COMPOUND_LITERAL:
7571         case EXPR_REFERENCE:
7572         case EXPR_SELECT:
7573         case EXPR_UNARY_DEREFERENCE:
7574                 return true;
7575
7576         default: {
7577                 type_t *type = skip_typeref(expression->base.type);
7578                 return
7579                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7580                         is_type_reference(type) ||
7581                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7582                          * error before, which maybe prevented properly recognizing it as
7583                          * lvalue. */
7584                         !is_type_valid(type);
7585         }
7586         }
7587 }
7588
7589 static void semantic_incdec(unary_expression_t *expression)
7590 {
7591         type_t *const orig_type = expression->value->base.type;
7592         type_t *const type      = skip_typeref(orig_type);
7593         if (is_type_pointer(type)) {
7594                 if (!check_pointer_arithmetic(&expression->base.source_position,
7595                                               type, orig_type)) {
7596                         return;
7597                 }
7598         } else if (!is_type_real(type) && is_type_valid(type)) {
7599                 /* TODO: improve error message */
7600                 errorf(&expression->base.source_position,
7601                        "operation needs an arithmetic or pointer type");
7602                 return;
7603         }
7604         if (!is_lvalue(expression->value)) {
7605                 /* TODO: improve error message */
7606                 errorf(&expression->base.source_position, "lvalue required as operand");
7607         }
7608         expression->base.type = orig_type;
7609 }
7610
7611 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7612 {
7613         type_t *const res_type = promote_integer(type);
7614         expr->base.type = res_type;
7615         expr->value     = create_implicit_cast(expr->value, res_type);
7616 }
7617
7618 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7619 {
7620         type_t *const orig_type = expression->value->base.type;
7621         type_t *const type      = skip_typeref(orig_type);
7622         if (!is_type_arithmetic(type)) {
7623                 if (is_type_valid(type)) {
7624                         /* TODO: improve error message */
7625                         errorf(&expression->base.source_position,
7626                                 "operation needs an arithmetic type");
7627                 }
7628                 return;
7629         } else if (is_type_integer(type)) {
7630                 promote_unary_int_expr(expression, type);
7631         } else {
7632                 expression->base.type = orig_type;
7633         }
7634 }
7635
7636 static void semantic_unexpr_plus(unary_expression_t *expression)
7637 {
7638         semantic_unexpr_arithmetic(expression);
7639         source_position_t const *const pos = &expression->base.source_position;
7640         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7641 }
7642
7643 static void semantic_not(unary_expression_t *expression)
7644 {
7645         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7646         semantic_condition(expression->value, "operand of !");
7647         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7648 }
7649
7650 static void semantic_unexpr_integer(unary_expression_t *expression)
7651 {
7652         type_t *const orig_type = expression->value->base.type;
7653         type_t *const type      = skip_typeref(orig_type);
7654         if (!is_type_integer(type)) {
7655                 if (is_type_valid(type)) {
7656                         errorf(&expression->base.source_position,
7657                                "operand of ~ must be of integer type");
7658                 }
7659                 return;
7660         }
7661
7662         promote_unary_int_expr(expression, type);
7663 }
7664
7665 static void semantic_dereference(unary_expression_t *expression)
7666 {
7667         type_t *const orig_type = expression->value->base.type;
7668         type_t *const type      = skip_typeref(orig_type);
7669         if (!is_type_pointer(type)) {
7670                 if (is_type_valid(type)) {
7671                         errorf(&expression->base.source_position,
7672                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7673                 }
7674                 return;
7675         }
7676
7677         type_t *result_type   = type->pointer.points_to;
7678         result_type           = automatic_type_conversion(result_type);
7679         expression->base.type = result_type;
7680 }
7681
7682 /**
7683  * Record that an address is taken (expression represents an lvalue).
7684  *
7685  * @param expression       the expression
7686  * @param may_be_register  if true, the expression might be an register
7687  */
7688 static void set_address_taken(expression_t *expression, bool may_be_register)
7689 {
7690         if (expression->kind != EXPR_REFERENCE)
7691                 return;
7692
7693         entity_t *const entity = expression->reference.entity;
7694
7695         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7696                 return;
7697
7698         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7699                         && !may_be_register) {
7700                 source_position_t const *const pos = &expression->base.source_position;
7701                 errorf(pos, "address of register '%N' requested", entity);
7702         }
7703
7704         if (entity->kind == ENTITY_VARIABLE) {
7705                 entity->variable.address_taken = true;
7706         } else {
7707                 assert(entity->kind == ENTITY_PARAMETER);
7708                 entity->parameter.address_taken = true;
7709         }
7710 }
7711
7712 /**
7713  * Check the semantic of the address taken expression.
7714  */
7715 static void semantic_take_addr(unary_expression_t *expression)
7716 {
7717         expression_t *value = expression->value;
7718         value->base.type    = revert_automatic_type_conversion(value);
7719
7720         type_t *orig_type = value->base.type;
7721         type_t *type      = skip_typeref(orig_type);
7722         if (!is_type_valid(type))
7723                 return;
7724
7725         /* §6.5.3.2 */
7726         if (!is_lvalue(value)) {
7727                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7728         }
7729         if (is_bitfield(value)) {
7730                 errorf(&expression->base.source_position,
7731                        "'&' not allowed on bitfield");
7732         }
7733
7734         set_address_taken(value, false);
7735
7736         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7737 }
7738
7739 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7740 static expression_t *parse_##unexpression_type(void)                         \
7741 {                                                                            \
7742         expression_t *unary_expression                                           \
7743                 = allocate_expression_zero(unexpression_type);                       \
7744         eat(token_kind);                                                         \
7745         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7746                                                                                  \
7747         sfunc(&unary_expression->unary);                                         \
7748                                                                                  \
7749         return unary_expression;                                                 \
7750 }
7751
7752 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7753                                semantic_unexpr_arithmetic)
7754 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7755                                semantic_unexpr_plus)
7756 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7757                                semantic_not)
7758 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7759                                semantic_dereference)
7760 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7761                                semantic_take_addr)
7762 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7763                                semantic_unexpr_integer)
7764 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7765                                semantic_incdec)
7766 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7767                                semantic_incdec)
7768
7769 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7770                                                sfunc)                         \
7771 static expression_t *parse_##unexpression_type(expression_t *left)            \
7772 {                                                                             \
7773         expression_t *unary_expression                                            \
7774                 = allocate_expression_zero(unexpression_type);                        \
7775         eat(token_kind);                                                          \
7776         unary_expression->unary.value = left;                                     \
7777                                                                                   \
7778         sfunc(&unary_expression->unary);                                          \
7779                                                                               \
7780         return unary_expression;                                                  \
7781 }
7782
7783 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7784                                        EXPR_UNARY_POSTFIX_INCREMENT,
7785                                        semantic_incdec)
7786 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7787                                        EXPR_UNARY_POSTFIX_DECREMENT,
7788                                        semantic_incdec)
7789
7790 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7791 {
7792         /* TODO: handle complex + imaginary types */
7793
7794         type_left  = get_unqualified_type(type_left);
7795         type_right = get_unqualified_type(type_right);
7796
7797         /* §6.3.1.8 Usual arithmetic conversions */
7798         if (type_left == type_long_double || type_right == type_long_double) {
7799                 return type_long_double;
7800         } else if (type_left == type_double || type_right == type_double) {
7801                 return type_double;
7802         } else if (type_left == type_float || type_right == type_float) {
7803                 return type_float;
7804         }
7805
7806         type_left  = promote_integer(type_left);
7807         type_right = promote_integer(type_right);
7808
7809         if (type_left == type_right)
7810                 return type_left;
7811
7812         bool     const signed_left  = is_type_signed(type_left);
7813         bool     const signed_right = is_type_signed(type_right);
7814         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7815         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7816
7817         if (signed_left == signed_right)
7818                 return rank_left >= rank_right ? type_left : type_right;
7819
7820         unsigned           s_rank;
7821         unsigned           u_rank;
7822         atomic_type_kind_t s_akind;
7823         atomic_type_kind_t u_akind;
7824         type_t *s_type;
7825         type_t *u_type;
7826         if (signed_left) {
7827                 s_type = type_left;
7828                 u_type = type_right;
7829         } else {
7830                 s_type = type_right;
7831                 u_type = type_left;
7832         }
7833         s_akind = get_akind(s_type);
7834         u_akind = get_akind(u_type);
7835         s_rank  = get_akind_rank(s_akind);
7836         u_rank  = get_akind_rank(u_akind);
7837
7838         if (u_rank >= s_rank)
7839                 return u_type;
7840
7841         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7842                 return s_type;
7843
7844         switch (s_akind) {
7845         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7846         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7847         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7848
7849         default: panic("invalid atomic type");
7850         }
7851 }
7852
7853 /**
7854  * Check the semantic restrictions for a binary expression.
7855  */
7856 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7857 {
7858         expression_t *const left            = expression->left;
7859         expression_t *const right           = expression->right;
7860         type_t       *const orig_type_left  = left->base.type;
7861         type_t       *const orig_type_right = right->base.type;
7862         type_t       *const type_left       = skip_typeref(orig_type_left);
7863         type_t       *const type_right      = skip_typeref(orig_type_right);
7864
7865         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7866                 /* TODO: improve error message */
7867                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7868                         errorf(&expression->base.source_position,
7869                                "operation needs arithmetic types");
7870                 }
7871                 return;
7872         }
7873
7874         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7875         expression->left      = create_implicit_cast(left, arithmetic_type);
7876         expression->right     = create_implicit_cast(right, arithmetic_type);
7877         expression->base.type = arithmetic_type;
7878 }
7879
7880 static void semantic_binexpr_integer(binary_expression_t *const expression)
7881 {
7882         expression_t *const left            = expression->left;
7883         expression_t *const right           = expression->right;
7884         type_t       *const orig_type_left  = left->base.type;
7885         type_t       *const orig_type_right = right->base.type;
7886         type_t       *const type_left       = skip_typeref(orig_type_left);
7887         type_t       *const type_right      = skip_typeref(orig_type_right);
7888
7889         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7890                 /* TODO: improve error message */
7891                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7892                         errorf(&expression->base.source_position,
7893                                "operation needs integer types");
7894                 }
7895                 return;
7896         }
7897
7898         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7899         expression->left      = create_implicit_cast(left, result_type);
7900         expression->right     = create_implicit_cast(right, result_type);
7901         expression->base.type = result_type;
7902 }
7903
7904 static void warn_div_by_zero(binary_expression_t const *const expression)
7905 {
7906         if (!is_type_integer(expression->base.type))
7907                 return;
7908
7909         expression_t const *const right = expression->right;
7910         /* The type of the right operand can be different for /= */
7911         if (is_type_integer(right->base.type)                    &&
7912             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7913             !fold_constant_to_bool(right)) {
7914                 source_position_t const *const pos = &expression->base.source_position;
7915                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7916         }
7917 }
7918
7919 /**
7920  * Check the semantic restrictions for a div/mod expression.
7921  */
7922 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7923 {
7924         semantic_binexpr_arithmetic(expression);
7925         warn_div_by_zero(expression);
7926 }
7927
7928 static void warn_addsub_in_shift(const expression_t *const expr)
7929 {
7930         if (expr->base.parenthesized)
7931                 return;
7932
7933         char op;
7934         switch (expr->kind) {
7935                 case EXPR_BINARY_ADD: op = '+'; break;
7936                 case EXPR_BINARY_SUB: op = '-'; break;
7937                 default:              return;
7938         }
7939
7940         source_position_t const *const pos = &expr->base.source_position;
7941         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7942 }
7943
7944 static bool semantic_shift(binary_expression_t *expression)
7945 {
7946         expression_t *const left            = expression->left;
7947         expression_t *const right           = expression->right;
7948         type_t       *const orig_type_left  = left->base.type;
7949         type_t       *const orig_type_right = right->base.type;
7950         type_t       *      type_left       = skip_typeref(orig_type_left);
7951         type_t       *      type_right      = skip_typeref(orig_type_right);
7952
7953         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7954                 /* TODO: improve error message */
7955                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7956                         errorf(&expression->base.source_position,
7957                                "operands of shift operation must have integer types");
7958                 }
7959                 return false;
7960         }
7961
7962         type_left = promote_integer(type_left);
7963
7964         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7965                 source_position_t const *const pos   = &right->base.source_position;
7966                 long                     const count = fold_constant_to_int(right);
7967                 if (count < 0) {
7968                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7969                 } else if ((unsigned long)count >=
7970                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7971                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7972                 }
7973         }
7974
7975         type_right        = promote_integer(type_right);
7976         expression->right = create_implicit_cast(right, type_right);
7977
7978         return true;
7979 }
7980
7981 static void semantic_shift_op(binary_expression_t *expression)
7982 {
7983         expression_t *const left  = expression->left;
7984         expression_t *const right = expression->right;
7985
7986         if (!semantic_shift(expression))
7987                 return;
7988
7989         warn_addsub_in_shift(left);
7990         warn_addsub_in_shift(right);
7991
7992         type_t *const orig_type_left = left->base.type;
7993         type_t *      type_left      = skip_typeref(orig_type_left);
7994
7995         type_left             = promote_integer(type_left);
7996         expression->left      = create_implicit_cast(left, type_left);
7997         expression->base.type = type_left;
7998 }
7999
8000 static void semantic_add(binary_expression_t *expression)
8001 {
8002         expression_t *const left            = expression->left;
8003         expression_t *const right           = expression->right;
8004         type_t       *const orig_type_left  = left->base.type;
8005         type_t       *const orig_type_right = right->base.type;
8006         type_t       *const type_left       = skip_typeref(orig_type_left);
8007         type_t       *const type_right      = skip_typeref(orig_type_right);
8008
8009         /* §6.5.6 */
8010         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8011                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8012                 expression->left  = create_implicit_cast(left, arithmetic_type);
8013                 expression->right = create_implicit_cast(right, arithmetic_type);
8014                 expression->base.type = arithmetic_type;
8015         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8016                 check_pointer_arithmetic(&expression->base.source_position,
8017                                          type_left, orig_type_left);
8018                 expression->base.type = type_left;
8019         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8020                 check_pointer_arithmetic(&expression->base.source_position,
8021                                          type_right, orig_type_right);
8022                 expression->base.type = type_right;
8023         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8024                 errorf(&expression->base.source_position,
8025                        "invalid operands to binary + ('%T', '%T')",
8026                        orig_type_left, orig_type_right);
8027         }
8028 }
8029
8030 static void semantic_sub(binary_expression_t *expression)
8031 {
8032         expression_t            *const left            = expression->left;
8033         expression_t            *const right           = expression->right;
8034         type_t                  *const orig_type_left  = left->base.type;
8035         type_t                  *const orig_type_right = right->base.type;
8036         type_t                  *const type_left       = skip_typeref(orig_type_left);
8037         type_t                  *const type_right      = skip_typeref(orig_type_right);
8038         source_position_t const *const pos             = &expression->base.source_position;
8039
8040         /* §5.6.5 */
8041         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8042                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8043                 expression->left        = create_implicit_cast(left, arithmetic_type);
8044                 expression->right       = create_implicit_cast(right, arithmetic_type);
8045                 expression->base.type =  arithmetic_type;
8046         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8047                 check_pointer_arithmetic(&expression->base.source_position,
8048                                          type_left, orig_type_left);
8049                 expression->base.type = type_left;
8050         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8051                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8052                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8053                 if (!types_compatible(unqual_left, unqual_right)) {
8054                         errorf(pos,
8055                                "subtracting pointers to incompatible types '%T' and '%T'",
8056                                orig_type_left, orig_type_right);
8057                 } else if (!is_type_object(unqual_left)) {
8058                         if (!is_type_void(unqual_left)) {
8059                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8060                                        orig_type_left);
8061                         } else {
8062                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8063                         }
8064                 }
8065                 expression->base.type = type_ptrdiff_t;
8066         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8067                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8068                        orig_type_left, orig_type_right);
8069         }
8070 }
8071
8072 static void warn_string_literal_address(expression_t const* expr)
8073 {
8074         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8075                 expr = expr->unary.value;
8076                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8077                         return;
8078                 expr = expr->unary.value;
8079         }
8080
8081         if (expr->kind == EXPR_STRING_LITERAL
8082                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8083                 source_position_t const *const pos = &expr->base.source_position;
8084                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8085         }
8086 }
8087
8088 static bool maybe_negative(expression_t const *const expr)
8089 {
8090         switch (is_constant_expression(expr)) {
8091                 case EXPR_CLASS_ERROR:    return false;
8092                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8093                 default:                  return true;
8094         }
8095 }
8096
8097 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8098 {
8099         warn_string_literal_address(expr);
8100
8101         expression_t const* const ref = get_reference_address(expr);
8102         if (ref != NULL && is_null_pointer_constant(other)) {
8103                 entity_t const *const ent = ref->reference.entity;
8104                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8105         }
8106
8107         if (!expr->base.parenthesized) {
8108                 switch (expr->base.kind) {
8109                         case EXPR_BINARY_LESS:
8110                         case EXPR_BINARY_GREATER:
8111                         case EXPR_BINARY_LESSEQUAL:
8112                         case EXPR_BINARY_GREATEREQUAL:
8113                         case EXPR_BINARY_NOTEQUAL:
8114                         case EXPR_BINARY_EQUAL:
8115                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8116                                 break;
8117                         default:
8118                                 break;
8119                 }
8120         }
8121 }
8122
8123 /**
8124  * Check the semantics of comparison expressions.
8125  *
8126  * @param expression   The expression to check.
8127  */
8128 static void semantic_comparison(binary_expression_t *expression)
8129 {
8130         source_position_t const *const pos   = &expression->base.source_position;
8131         expression_t            *const left  = expression->left;
8132         expression_t            *const right = expression->right;
8133
8134         warn_comparison(pos, left, right);
8135         warn_comparison(pos, right, left);
8136
8137         type_t *orig_type_left  = left->base.type;
8138         type_t *orig_type_right = right->base.type;
8139         type_t *type_left       = skip_typeref(orig_type_left);
8140         type_t *type_right      = skip_typeref(orig_type_right);
8141
8142         /* TODO non-arithmetic types */
8143         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8144                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8145
8146                 /* test for signed vs unsigned compares */
8147                 if (is_type_integer(arithmetic_type)) {
8148                         bool const signed_left  = is_type_signed(type_left);
8149                         bool const signed_right = is_type_signed(type_right);
8150                         if (signed_left != signed_right) {
8151                                 /* FIXME long long needs better const folding magic */
8152                                 /* TODO check whether constant value can be represented by other type */
8153                                 if ((signed_left  && maybe_negative(left)) ||
8154                                                 (signed_right && maybe_negative(right))) {
8155                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8156                                 }
8157                         }
8158                 }
8159
8160                 expression->left        = create_implicit_cast(left, arithmetic_type);
8161                 expression->right       = create_implicit_cast(right, arithmetic_type);
8162                 expression->base.type   = arithmetic_type;
8163                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8164                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8165                     is_type_float(arithmetic_type)) {
8166                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8167                 }
8168         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8169                 /* TODO check compatibility */
8170         } else if (is_type_pointer(type_left)) {
8171                 expression->right = create_implicit_cast(right, type_left);
8172         } else if (is_type_pointer(type_right)) {
8173                 expression->left = create_implicit_cast(left, type_right);
8174         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8175                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8176         }
8177         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8178 }
8179
8180 /**
8181  * Checks if a compound type has constant fields.
8182  */
8183 static bool has_const_fields(const compound_type_t *type)
8184 {
8185         compound_t *compound = type->compound;
8186         entity_t   *entry    = compound->members.entities;
8187
8188         for (; entry != NULL; entry = entry->base.next) {
8189                 if (!is_declaration(entry))
8190                         continue;
8191
8192                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8193                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8194                         return true;
8195         }
8196
8197         return false;
8198 }
8199
8200 static bool is_valid_assignment_lhs(expression_t const* const left)
8201 {
8202         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8203         type_t *const type_left      = skip_typeref(orig_type_left);
8204
8205         if (!is_lvalue(left)) {
8206                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8207                        left);
8208                 return false;
8209         }
8210
8211         if (left->kind == EXPR_REFERENCE
8212                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8213                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8214                 return false;
8215         }
8216
8217         if (is_type_array(type_left)) {
8218                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8219                 return false;
8220         }
8221         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8222                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8223                        orig_type_left);
8224                 return false;
8225         }
8226         if (is_type_incomplete(type_left)) {
8227                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8228                        left, orig_type_left);
8229                 return false;
8230         }
8231         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8232                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8233                        left, orig_type_left);
8234                 return false;
8235         }
8236
8237         return true;
8238 }
8239
8240 static void semantic_arithmetic_assign(binary_expression_t *expression)
8241 {
8242         expression_t *left            = expression->left;
8243         expression_t *right           = expression->right;
8244         type_t       *orig_type_left  = left->base.type;
8245         type_t       *orig_type_right = right->base.type;
8246
8247         if (!is_valid_assignment_lhs(left))
8248                 return;
8249
8250         type_t *type_left  = skip_typeref(orig_type_left);
8251         type_t *type_right = skip_typeref(orig_type_right);
8252
8253         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8254                 /* TODO: improve error message */
8255                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8256                         errorf(&expression->base.source_position,
8257                                "operation needs arithmetic types");
8258                 }
8259                 return;
8260         }
8261
8262         /* combined instructions are tricky. We can't create an implicit cast on
8263          * the left side, because we need the uncasted form for the store.
8264          * The ast2firm pass has to know that left_type must be right_type
8265          * for the arithmetic operation and create a cast by itself */
8266         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8267         expression->right       = create_implicit_cast(right, arithmetic_type);
8268         expression->base.type   = type_left;
8269 }
8270
8271 static void semantic_divmod_assign(binary_expression_t *expression)
8272 {
8273         semantic_arithmetic_assign(expression);
8274         warn_div_by_zero(expression);
8275 }
8276
8277 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8278 {
8279         expression_t *const left            = expression->left;
8280         expression_t *const right           = expression->right;
8281         type_t       *const orig_type_left  = left->base.type;
8282         type_t       *const orig_type_right = right->base.type;
8283         type_t       *const type_left       = skip_typeref(orig_type_left);
8284         type_t       *const type_right      = skip_typeref(orig_type_right);
8285
8286         if (!is_valid_assignment_lhs(left))
8287                 return;
8288
8289         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8290                 /* combined instructions are tricky. We can't create an implicit cast on
8291                  * the left side, because we need the uncasted form for the store.
8292                  * The ast2firm pass has to know that left_type must be right_type
8293                  * for the arithmetic operation and create a cast by itself */
8294                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8295                 expression->right     = create_implicit_cast(right, arithmetic_type);
8296                 expression->base.type = type_left;
8297         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8298                 check_pointer_arithmetic(&expression->base.source_position,
8299                                          type_left, orig_type_left);
8300                 expression->base.type = type_left;
8301         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8302                 errorf(&expression->base.source_position,
8303                        "incompatible types '%T' and '%T' in assignment",
8304                        orig_type_left, orig_type_right);
8305         }
8306 }
8307
8308 static void semantic_integer_assign(binary_expression_t *expression)
8309 {
8310         expression_t *left            = expression->left;
8311         expression_t *right           = expression->right;
8312         type_t       *orig_type_left  = left->base.type;
8313         type_t       *orig_type_right = right->base.type;
8314
8315         if (!is_valid_assignment_lhs(left))
8316                 return;
8317
8318         type_t *type_left  = skip_typeref(orig_type_left);
8319         type_t *type_right = skip_typeref(orig_type_right);
8320
8321         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8322                 /* TODO: improve error message */
8323                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8324                         errorf(&expression->base.source_position,
8325                                "operation needs integer types");
8326                 }
8327                 return;
8328         }
8329
8330         /* combined instructions are tricky. We can't create an implicit cast on
8331          * the left side, because we need the uncasted form for the store.
8332          * The ast2firm pass has to know that left_type must be right_type
8333          * for the arithmetic operation and create a cast by itself */
8334         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8335         expression->right       = create_implicit_cast(right, arithmetic_type);
8336         expression->base.type   = type_left;
8337 }
8338
8339 static void semantic_shift_assign(binary_expression_t *expression)
8340 {
8341         expression_t *left           = expression->left;
8342
8343         if (!is_valid_assignment_lhs(left))
8344                 return;
8345
8346         if (!semantic_shift(expression))
8347                 return;
8348
8349         expression->base.type = skip_typeref(left->base.type);
8350 }
8351
8352 static void warn_logical_and_within_or(const expression_t *const expr)
8353 {
8354         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8355                 return;
8356         if (expr->base.parenthesized)
8357                 return;
8358         source_position_t const *const pos = &expr->base.source_position;
8359         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8360 }
8361
8362 /**
8363  * Check the semantic restrictions of a logical expression.
8364  */
8365 static void semantic_logical_op(binary_expression_t *expression)
8366 {
8367         /* §6.5.13:2  Each of the operands shall have scalar type.
8368          * §6.5.14:2  Each of the operands shall have scalar type. */
8369         semantic_condition(expression->left,   "left operand of logical operator");
8370         semantic_condition(expression->right, "right operand of logical operator");
8371         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8372                 warn_logical_and_within_or(expression->left);
8373                 warn_logical_and_within_or(expression->right);
8374         }
8375         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8376 }
8377
8378 /**
8379  * Check the semantic restrictions of a binary assign expression.
8380  */
8381 static void semantic_binexpr_assign(binary_expression_t *expression)
8382 {
8383         expression_t *left           = expression->left;
8384         type_t       *orig_type_left = left->base.type;
8385
8386         if (!is_valid_assignment_lhs(left))
8387                 return;
8388
8389         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8390         report_assign_error(error, orig_type_left, expression->right,
8391                         "assignment", &left->base.source_position);
8392         expression->right = create_implicit_cast(expression->right, orig_type_left);
8393         expression->base.type = orig_type_left;
8394 }
8395
8396 /**
8397  * Determine if the outermost operation (or parts thereof) of the given
8398  * expression has no effect in order to generate a warning about this fact.
8399  * Therefore in some cases this only examines some of the operands of the
8400  * expression (see comments in the function and examples below).
8401  * Examples:
8402  *   f() + 23;    // warning, because + has no effect
8403  *   x || f();    // no warning, because x controls execution of f()
8404  *   x ? y : f(); // warning, because y has no effect
8405  *   (void)x;     // no warning to be able to suppress the warning
8406  * This function can NOT be used for an "expression has definitely no effect"-
8407  * analysis. */
8408 static bool expression_has_effect(const expression_t *const expr)
8409 {
8410         switch (expr->kind) {
8411                 case EXPR_ERROR:                      return true; /* do NOT warn */
8412                 case EXPR_REFERENCE:                  return false;
8413                 case EXPR_ENUM_CONSTANT:              return false;
8414                 case EXPR_LABEL_ADDRESS:              return false;
8415
8416                 /* suppress the warning for microsoft __noop operations */
8417                 case EXPR_LITERAL_MS_NOOP:            return true;
8418                 case EXPR_LITERAL_BOOLEAN:
8419                 case EXPR_LITERAL_CHARACTER:
8420                 case EXPR_LITERAL_WIDE_CHARACTER:
8421                 case EXPR_LITERAL_INTEGER:
8422                 case EXPR_LITERAL_INTEGER_OCTAL:
8423                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8424                 case EXPR_LITERAL_FLOATINGPOINT:
8425                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8426                 case EXPR_STRING_LITERAL:             return false;
8427                 case EXPR_WIDE_STRING_LITERAL:        return false;
8428
8429                 case EXPR_CALL: {
8430                         const call_expression_t *const call = &expr->call;
8431                         if (call->function->kind != EXPR_REFERENCE)
8432                                 return true;
8433
8434                         switch (call->function->reference.entity->function.btk) {
8435                                 /* FIXME: which builtins have no effect? */
8436                                 default:                      return true;
8437                         }
8438                 }
8439
8440                 /* Generate the warning if either the left or right hand side of a
8441                  * conditional expression has no effect */
8442                 case EXPR_CONDITIONAL: {
8443                         conditional_expression_t const *const cond = &expr->conditional;
8444                         expression_t             const *const t    = cond->true_expression;
8445                         return
8446                                 (t == NULL || expression_has_effect(t)) &&
8447                                 expression_has_effect(cond->false_expression);
8448                 }
8449
8450                 case EXPR_SELECT:                     return false;
8451                 case EXPR_ARRAY_ACCESS:               return false;
8452                 case EXPR_SIZEOF:                     return false;
8453                 case EXPR_CLASSIFY_TYPE:              return false;
8454                 case EXPR_ALIGNOF:                    return false;
8455
8456                 case EXPR_FUNCNAME:                   return false;
8457                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8458                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8459                 case EXPR_OFFSETOF:                   return false;
8460                 case EXPR_VA_START:                   return true;
8461                 case EXPR_VA_ARG:                     return true;
8462                 case EXPR_VA_COPY:                    return true;
8463                 case EXPR_STATEMENT:                  return true; // TODO
8464                 case EXPR_COMPOUND_LITERAL:           return false;
8465
8466                 case EXPR_UNARY_NEGATE:               return false;
8467                 case EXPR_UNARY_PLUS:                 return false;
8468                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8469                 case EXPR_UNARY_NOT:                  return false;
8470                 case EXPR_UNARY_DEREFERENCE:          return false;
8471                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8472                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8473                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8474                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8475                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8476
8477                 /* Treat void casts as if they have an effect in order to being able to
8478                  * suppress the warning */
8479                 case EXPR_UNARY_CAST: {
8480                         type_t *const type = skip_typeref(expr->base.type);
8481                         return is_type_void(type);
8482                 }
8483
8484                 case EXPR_UNARY_ASSUME:               return true;
8485                 case EXPR_UNARY_DELETE:               return true;
8486                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8487                 case EXPR_UNARY_THROW:                return true;
8488
8489                 case EXPR_BINARY_ADD:                 return false;
8490                 case EXPR_BINARY_SUB:                 return false;
8491                 case EXPR_BINARY_MUL:                 return false;
8492                 case EXPR_BINARY_DIV:                 return false;
8493                 case EXPR_BINARY_MOD:                 return false;
8494                 case EXPR_BINARY_EQUAL:               return false;
8495                 case EXPR_BINARY_NOTEQUAL:            return false;
8496                 case EXPR_BINARY_LESS:                return false;
8497                 case EXPR_BINARY_LESSEQUAL:           return false;
8498                 case EXPR_BINARY_GREATER:             return false;
8499                 case EXPR_BINARY_GREATEREQUAL:        return false;
8500                 case EXPR_BINARY_BITWISE_AND:         return false;
8501                 case EXPR_BINARY_BITWISE_OR:          return false;
8502                 case EXPR_BINARY_BITWISE_XOR:         return false;
8503                 case EXPR_BINARY_SHIFTLEFT:           return false;
8504                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8505                 case EXPR_BINARY_ASSIGN:              return true;
8506                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8507                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8508                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8509                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8510                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8511                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8512                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8513                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8514                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8515                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8516
8517                 /* Only examine the right hand side of && and ||, because the left hand
8518                  * side already has the effect of controlling the execution of the right
8519                  * hand side */
8520                 case EXPR_BINARY_LOGICAL_AND:
8521                 case EXPR_BINARY_LOGICAL_OR:
8522                 /* Only examine the right hand side of a comma expression, because the left
8523                  * hand side has a separate warning */
8524                 case EXPR_BINARY_COMMA:
8525                         return expression_has_effect(expr->binary.right);
8526
8527                 case EXPR_BINARY_ISGREATER:           return false;
8528                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8529                 case EXPR_BINARY_ISLESS:              return false;
8530                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8531                 case EXPR_BINARY_ISLESSGREATER:       return false;
8532                 case EXPR_BINARY_ISUNORDERED:         return false;
8533         }
8534
8535         internal_errorf(HERE, "unexpected expression");
8536 }
8537
8538 static void semantic_comma(binary_expression_t *expression)
8539 {
8540         const expression_t *const left = expression->left;
8541         if (!expression_has_effect(left)) {
8542                 source_position_t const *const pos = &left->base.source_position;
8543                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8544         }
8545         expression->base.type = expression->right->base.type;
8546 }
8547
8548 /**
8549  * @param prec_r precedence of the right operand
8550  */
8551 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8552 static expression_t *parse_##binexpression_type(expression_t *left)          \
8553 {                                                                            \
8554         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8555         binexpr->binary.left  = left;                                            \
8556         eat(token_kind);                                                         \
8557                                                                              \
8558         expression_t *right = parse_subexpression(prec_r);                       \
8559                                                                              \
8560         binexpr->binary.right = right;                                           \
8561         sfunc(&binexpr->binary);                                                 \
8562                                                                              \
8563         return binexpr;                                                          \
8564 }
8565
8566 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8567 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8568 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8569 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8570 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8571 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8572 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8573 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8574 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8575 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8576 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8577 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8578 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8579 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8580 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8581 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8582 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8583 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8584 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8585 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8586 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8587 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8588 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8589 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8590 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8591 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8592 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8593 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8594 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8595 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8596
8597
8598 static expression_t *parse_subexpression(precedence_t precedence)
8599 {
8600         expression_parser_function_t *parser
8601                 = &expression_parsers[token.kind];
8602         expression_t                 *left;
8603
8604         if (parser->parser != NULL) {
8605                 left = parser->parser();
8606         } else {
8607                 left = parse_primary_expression();
8608         }
8609         assert(left != NULL);
8610
8611         while (true) {
8612                 parser = &expression_parsers[token.kind];
8613                 if (parser->infix_parser == NULL)
8614                         break;
8615                 if (parser->infix_precedence < precedence)
8616                         break;
8617
8618                 left = parser->infix_parser(left);
8619
8620                 assert(left != NULL);
8621         }
8622
8623         return left;
8624 }
8625
8626 /**
8627  * Parse an expression.
8628  */
8629 static expression_t *parse_expression(void)
8630 {
8631         return parse_subexpression(PREC_EXPRESSION);
8632 }
8633
8634 /**
8635  * Register a parser for a prefix-like operator.
8636  *
8637  * @param parser      the parser function
8638  * @param token_kind  the token type of the prefix token
8639  */
8640 static void register_expression_parser(parse_expression_function parser,
8641                                        int token_kind)
8642 {
8643         expression_parser_function_t *entry = &expression_parsers[token_kind];
8644
8645         if (entry->parser != NULL) {
8646                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8647                 panic("trying to register multiple expression parsers for a token");
8648         }
8649         entry->parser = parser;
8650 }
8651
8652 /**
8653  * Register a parser for an infix operator with given precedence.
8654  *
8655  * @param parser      the parser function
8656  * @param token_kind  the token type of the infix operator
8657  * @param precedence  the precedence of the operator
8658  */
8659 static void register_infix_parser(parse_expression_infix_function parser,
8660                                   int token_kind, precedence_t precedence)
8661 {
8662         expression_parser_function_t *entry = &expression_parsers[token_kind];
8663
8664         if (entry->infix_parser != NULL) {
8665                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8666                 panic("trying to register multiple infix expression parsers for a "
8667                       "token");
8668         }
8669         entry->infix_parser     = parser;
8670         entry->infix_precedence = precedence;
8671 }
8672
8673 /**
8674  * Initialize the expression parsers.
8675  */
8676 static void init_expression_parsers(void)
8677 {
8678         memset(&expression_parsers, 0, sizeof(expression_parsers));
8679
8680         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8681         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8682         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8683         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8684         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8685         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8686         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8687         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8688         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8689         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8690         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8691         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8692         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8693         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8694         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8695         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8696         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8697         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8698         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8699         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8700         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8701         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8702         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8703         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8704         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8705         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8706         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8707         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8708         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8709         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8710         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8711         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8712         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8713         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8714         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8715         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8716         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8717
8718         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8719         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8720         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8721         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8722         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8723         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8724         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8725         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8726         register_expression_parser(parse_sizeof,                      T_sizeof);
8727         register_expression_parser(parse_alignof,                     T___alignof__);
8728         register_expression_parser(parse_extension,                   T___extension__);
8729         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8730         register_expression_parser(parse_delete,                      T_delete);
8731         register_expression_parser(parse_throw,                       T_throw);
8732 }
8733
8734 /**
8735  * Parse a asm statement arguments specification.
8736  */
8737 static asm_argument_t *parse_asm_arguments(bool is_out)
8738 {
8739         asm_argument_t  *result = NULL;
8740         asm_argument_t **anchor = &result;
8741
8742         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8743                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8744
8745                 if (next_if('[')) {
8746                         add_anchor_token(']');
8747                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8748                         rem_anchor_token(']');
8749                         expect(']');
8750                         if (!argument->symbol)
8751                                 return NULL;
8752                 }
8753
8754                 argument->constraints = parse_string_literals();
8755                 expect('(');
8756                 add_anchor_token(')');
8757                 expression_t *expression = parse_expression();
8758                 rem_anchor_token(')');
8759                 if (is_out) {
8760                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8761                          * change size or type representation (e.g. int -> long is ok, but
8762                          * int -> float is not) */
8763                         if (expression->kind == EXPR_UNARY_CAST) {
8764                                 type_t      *const type = expression->base.type;
8765                                 type_kind_t  const kind = type->kind;
8766                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8767                                         unsigned flags;
8768                                         unsigned size;
8769                                         if (kind == TYPE_ATOMIC) {
8770                                                 atomic_type_kind_t const akind = type->atomic.akind;
8771                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8772                                                 size  = get_atomic_type_size(akind);
8773                                         } else {
8774                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8775                                                 size  = get_type_size(type_void_ptr);
8776                                         }
8777
8778                                         do {
8779                                                 expression_t *const value      = expression->unary.value;
8780                                                 type_t       *const value_type = value->base.type;
8781                                                 type_kind_t   const value_kind = value_type->kind;
8782
8783                                                 unsigned value_flags;
8784                                                 unsigned value_size;
8785                                                 if (value_kind == TYPE_ATOMIC) {
8786                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8787                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8788                                                         value_size  = get_atomic_type_size(value_akind);
8789                                                 } else if (value_kind == TYPE_POINTER) {
8790                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8791                                                         value_size  = get_type_size(type_void_ptr);
8792                                                 } else {
8793                                                         break;
8794                                                 }
8795
8796                                                 if (value_flags != flags || value_size != size)
8797                                                         break;
8798
8799                                                 expression = value;
8800                                         } while (expression->kind == EXPR_UNARY_CAST);
8801                                 }
8802                         }
8803
8804                         if (!is_lvalue(expression)) {
8805                                 errorf(&expression->base.source_position,
8806                                        "asm output argument is not an lvalue");
8807                         }
8808
8809                         if (argument->constraints.begin[0] == '=')
8810                                 determine_lhs_ent(expression, NULL);
8811                         else
8812                                 mark_vars_read(expression, NULL);
8813                 } else {
8814                         mark_vars_read(expression, NULL);
8815                 }
8816                 argument->expression = expression;
8817                 expect(')');
8818
8819                 set_address_taken(expression, true);
8820
8821                 *anchor = argument;
8822                 anchor  = &argument->next;
8823
8824                 if (!next_if(','))
8825                         break;
8826         }
8827
8828         return result;
8829 }
8830
8831 /**
8832  * Parse a asm statement clobber specification.
8833  */
8834 static asm_clobber_t *parse_asm_clobbers(void)
8835 {
8836         asm_clobber_t *result  = NULL;
8837         asm_clobber_t **anchor = &result;
8838
8839         while (token.kind == T_STRING_LITERAL) {
8840                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8841                 clobber->clobber       = parse_string_literals();
8842
8843                 *anchor = clobber;
8844                 anchor  = &clobber->next;
8845
8846                 if (!next_if(','))
8847                         break;
8848         }
8849
8850         return result;
8851 }
8852
8853 /**
8854  * Parse an asm statement.
8855  */
8856 static statement_t *parse_asm_statement(void)
8857 {
8858         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8859         asm_statement_t *asm_statement = &statement->asms;
8860
8861         eat(T_asm);
8862
8863         if (next_if(T_volatile))
8864                 asm_statement->is_volatile = true;
8865
8866         expect('(');
8867         add_anchor_token(')');
8868         if (token.kind != T_STRING_LITERAL) {
8869                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8870                 goto end_of_asm;
8871         }
8872         asm_statement->asm_text = parse_string_literals();
8873
8874         add_anchor_token(':');
8875         if (!next_if(':')) {
8876                 rem_anchor_token(':');
8877                 goto end_of_asm;
8878         }
8879
8880         asm_statement->outputs = parse_asm_arguments(true);
8881         if (!next_if(':')) {
8882                 rem_anchor_token(':');
8883                 goto end_of_asm;
8884         }
8885
8886         asm_statement->inputs = parse_asm_arguments(false);
8887         if (!next_if(':')) {
8888                 rem_anchor_token(':');
8889                 goto end_of_asm;
8890         }
8891         rem_anchor_token(':');
8892
8893         asm_statement->clobbers = parse_asm_clobbers();
8894
8895 end_of_asm:
8896         rem_anchor_token(')');
8897         expect(')');
8898         expect(';');
8899
8900         if (asm_statement->outputs == NULL) {
8901                 /* GCC: An 'asm' instruction without any output operands will be treated
8902                  * identically to a volatile 'asm' instruction. */
8903                 asm_statement->is_volatile = true;
8904         }
8905
8906         return statement;
8907 }
8908
8909 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8910 {
8911         statement_t *inner_stmt;
8912         switch (token.kind) {
8913                 case '}':
8914                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8915                         inner_stmt = create_error_statement();
8916                         break;
8917
8918                 case ';':
8919                         if (label->kind == STATEMENT_LABEL) {
8920                                 /* Eat an empty statement here, to avoid the warning about an empty
8921                                  * statement after a label.  label:; is commonly used to have a label
8922                                  * before a closing brace. */
8923                                 inner_stmt = create_empty_statement();
8924                                 next_token();
8925                                 break;
8926                         }
8927                         /* FALLTHROUGH */
8928
8929                 default:
8930                         inner_stmt = parse_statement();
8931                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8932                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8933                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8934                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8935                         }
8936                         break;
8937         }
8938         return inner_stmt;
8939 }
8940
8941 /**
8942  * Parse a case statement.
8943  */
8944 static statement_t *parse_case_statement(void)
8945 {
8946         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8947         source_position_t *const pos       = &statement->base.source_position;
8948
8949         eat(T_case);
8950         add_anchor_token(':');
8951
8952         expression_t *expression = parse_expression();
8953         type_t *expression_type = expression->base.type;
8954         type_t *skipped         = skip_typeref(expression_type);
8955         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8956                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8957                        expression, expression_type);
8958         }
8959
8960         type_t *type = expression_type;
8961         if (current_switch != NULL) {
8962                 type_t *switch_type = current_switch->expression->base.type;
8963                 if (is_type_valid(switch_type)) {
8964                         expression = create_implicit_cast(expression, switch_type);
8965                 }
8966         }
8967
8968         statement->case_label.expression = expression;
8969         expression_classification_t const expr_class = is_constant_expression(expression);
8970         if (expr_class != EXPR_CLASS_CONSTANT) {
8971                 if (expr_class != EXPR_CLASS_ERROR) {
8972                         errorf(pos, "case label does not reduce to an integer constant");
8973                 }
8974                 statement->case_label.is_bad = true;
8975         } else {
8976                 long const val = fold_constant_to_int(expression);
8977                 statement->case_label.first_case = val;
8978                 statement->case_label.last_case  = val;
8979         }
8980
8981         if (GNU_MODE) {
8982                 if (next_if(T_DOTDOTDOT)) {
8983                         expression_t *end_range = parse_expression();
8984                         expression_type = expression->base.type;
8985                         skipped         = skip_typeref(expression_type);
8986                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8987                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8988                                            expression, expression_type);
8989                         }
8990
8991                         end_range = create_implicit_cast(end_range, type);
8992                         statement->case_label.end_range = end_range;
8993                         expression_classification_t const end_class = is_constant_expression(end_range);
8994                         if (end_class != EXPR_CLASS_CONSTANT) {
8995                                 if (end_class != EXPR_CLASS_ERROR) {
8996                                         errorf(pos, "case range does not reduce to an integer constant");
8997                                 }
8998                                 statement->case_label.is_bad = true;
8999                         } else {
9000                                 long const val = fold_constant_to_int(end_range);
9001                                 statement->case_label.last_case = val;
9002
9003                                 if (val < statement->case_label.first_case) {
9004                                         statement->case_label.is_empty_range = true;
9005                                         warningf(WARN_OTHER, pos, "empty range specified");
9006                                 }
9007                         }
9008                 }
9009         }
9010
9011         PUSH_PARENT(statement);
9012
9013         rem_anchor_token(':');
9014         expect(':');
9015
9016         if (current_switch != NULL) {
9017                 if (! statement->case_label.is_bad) {
9018                         /* Check for duplicate case values */
9019                         case_label_statement_t *c = &statement->case_label;
9020                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9021                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9022                                         continue;
9023
9024                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9025                                         continue;
9026
9027                                 errorf(pos, "duplicate case value (previously used %P)",
9028                                        &l->base.source_position);
9029                                 break;
9030                         }
9031                 }
9032                 /* link all cases into the switch statement */
9033                 if (current_switch->last_case == NULL) {
9034                         current_switch->first_case      = &statement->case_label;
9035                 } else {
9036                         current_switch->last_case->next = &statement->case_label;
9037                 }
9038                 current_switch->last_case = &statement->case_label;
9039         } else {
9040                 errorf(pos, "case label not within a switch statement");
9041         }
9042
9043         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9044
9045         POP_PARENT();
9046         return statement;
9047 }
9048
9049 /**
9050  * Parse a default statement.
9051  */
9052 static statement_t *parse_default_statement(void)
9053 {
9054         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9055
9056         eat(T_default);
9057
9058         PUSH_PARENT(statement);
9059
9060         expect(':');
9061
9062         if (current_switch != NULL) {
9063                 const case_label_statement_t *def_label = current_switch->default_label;
9064                 if (def_label != NULL) {
9065                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9066                 } else {
9067                         current_switch->default_label = &statement->case_label;
9068
9069                         /* link all cases into the switch statement */
9070                         if (current_switch->last_case == NULL) {
9071                                 current_switch->first_case      = &statement->case_label;
9072                         } else {
9073                                 current_switch->last_case->next = &statement->case_label;
9074                         }
9075                         current_switch->last_case = &statement->case_label;
9076                 }
9077         } else {
9078                 errorf(&statement->base.source_position,
9079                         "'default' label not within a switch statement");
9080         }
9081
9082         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9083
9084         POP_PARENT();
9085         return statement;
9086 }
9087
9088 /**
9089  * Parse a label statement.
9090  */
9091 static statement_t *parse_label_statement(void)
9092 {
9093         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9094         label_t     *const label     = get_label();
9095         statement->label.label = label;
9096
9097         PUSH_PARENT(statement);
9098
9099         /* if statement is already set then the label is defined twice,
9100          * otherwise it was just mentioned in a goto/local label declaration so far
9101          */
9102         source_position_t const* const pos = &statement->base.source_position;
9103         if (label->statement != NULL) {
9104                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9105         } else {
9106                 label->base.source_position = *pos;
9107                 label->statement            = statement;
9108         }
9109
9110         eat(':');
9111
9112         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9113                 parse_attributes(NULL); // TODO process attributes
9114         }
9115
9116         statement->label.statement = parse_label_inner_statement(statement, "label");
9117
9118         /* remember the labels in a list for later checking */
9119         *label_anchor = &statement->label;
9120         label_anchor  = &statement->label.next;
9121
9122         POP_PARENT();
9123         return statement;
9124 }
9125
9126 static statement_t *parse_inner_statement(void)
9127 {
9128         statement_t *const stmt = parse_statement();
9129         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9130         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9131         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9132                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9133         }
9134         return stmt;
9135 }
9136
9137 /**
9138  * Parse an expression in parentheses and mark its variables as read.
9139  */
9140 static expression_t *parse_condition(void)
9141 {
9142         expect('(');
9143         add_anchor_token(')');
9144         expression_t *const expr = parse_expression();
9145         mark_vars_read(expr, NULL);
9146         rem_anchor_token(')');
9147         expect(')');
9148         return expr;
9149 }
9150
9151 /**
9152  * Parse an if statement.
9153  */
9154 static statement_t *parse_if(void)
9155 {
9156         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9157
9158         eat(T_if);
9159
9160         PUSH_PARENT(statement);
9161         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9162
9163         add_anchor_token(T_else);
9164
9165         expression_t *const expr = parse_condition();
9166         statement->ifs.condition = expr;
9167         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9168          *             scalar type. */
9169         semantic_condition(expr, "condition of 'if'-statment");
9170
9171         statement_t *const true_stmt = parse_inner_statement();
9172         statement->ifs.true_statement = true_stmt;
9173         rem_anchor_token(T_else);
9174
9175         if (true_stmt->kind == STATEMENT_EMPTY) {
9176                 warningf(WARN_EMPTY_BODY, HERE,
9177                         "suggest braces around empty body in an ‘if’ statement");
9178         }
9179
9180         if (next_if(T_else)) {
9181                 statement->ifs.false_statement = parse_inner_statement();
9182
9183                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9184                         warningf(WARN_EMPTY_BODY, HERE,
9185                                         "suggest braces around empty body in an ‘if’ statement");
9186                 }
9187         } else if (true_stmt->kind == STATEMENT_IF &&
9188                         true_stmt->ifs.false_statement != NULL) {
9189                 source_position_t const *const pos = &true_stmt->base.source_position;
9190                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9191         }
9192
9193         POP_SCOPE();
9194         POP_PARENT();
9195         return statement;
9196 }
9197
9198 /**
9199  * Check that all enums are handled in a switch.
9200  *
9201  * @param statement  the switch statement to check
9202  */
9203 static void check_enum_cases(const switch_statement_t *statement)
9204 {
9205         if (!is_warn_on(WARN_SWITCH_ENUM))
9206                 return;
9207         const type_t *type = skip_typeref(statement->expression->base.type);
9208         if (! is_type_enum(type))
9209                 return;
9210         const enum_type_t *enumt = &type->enumt;
9211
9212         /* if we have a default, no warnings */
9213         if (statement->default_label != NULL)
9214                 return;
9215
9216         /* FIXME: calculation of value should be done while parsing */
9217         /* TODO: quadratic algorithm here. Change to an n log n one */
9218         long            last_value = -1;
9219         const entity_t *entry      = enumt->enume->base.next;
9220         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9221              entry = entry->base.next) {
9222                 const expression_t *expression = entry->enum_value.value;
9223                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9224                 bool                found      = false;
9225                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9226                         if (l->expression == NULL)
9227                                 continue;
9228                         if (l->first_case <= value && value <= l->last_case) {
9229                                 found = true;
9230                                 break;
9231                         }
9232                 }
9233                 if (!found) {
9234                         source_position_t const *const pos = &statement->base.source_position;
9235                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9236                 }
9237                 last_value = value;
9238         }
9239 }
9240
9241 /**
9242  * Parse a switch statement.
9243  */
9244 static statement_t *parse_switch(void)
9245 {
9246         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9247
9248         eat(T_switch);
9249
9250         PUSH_PARENT(statement);
9251         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9252
9253         expression_t *const expr = parse_condition();
9254         type_t       *      type = skip_typeref(expr->base.type);
9255         if (is_type_integer(type)) {
9256                 type = promote_integer(type);
9257                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9258                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9259                 }
9260         } else if (is_type_valid(type)) {
9261                 errorf(&expr->base.source_position,
9262                        "switch quantity is not an integer, but '%T'", type);
9263                 type = type_error_type;
9264         }
9265         statement->switchs.expression = create_implicit_cast(expr, type);
9266
9267         switch_statement_t *rem = current_switch;
9268         current_switch          = &statement->switchs;
9269         statement->switchs.body = parse_inner_statement();
9270         current_switch          = rem;
9271
9272         if (statement->switchs.default_label == NULL) {
9273                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9274         }
9275         check_enum_cases(&statement->switchs);
9276
9277         POP_SCOPE();
9278         POP_PARENT();
9279         return statement;
9280 }
9281
9282 static statement_t *parse_loop_body(statement_t *const loop)
9283 {
9284         statement_t *const rem = current_loop;
9285         current_loop = loop;
9286
9287         statement_t *const body = parse_inner_statement();
9288
9289         current_loop = rem;
9290         return body;
9291 }
9292
9293 /**
9294  * Parse a while statement.
9295  */
9296 static statement_t *parse_while(void)
9297 {
9298         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9299
9300         eat(T_while);
9301
9302         PUSH_PARENT(statement);
9303         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9304
9305         expression_t *const cond = parse_condition();
9306         statement->whiles.condition = cond;
9307         /* §6.8.5:2    The controlling expression of an iteration statement shall
9308          *             have scalar type. */
9309         semantic_condition(cond, "condition of 'while'-statement");
9310
9311         statement->whiles.body = parse_loop_body(statement);
9312
9313         POP_SCOPE();
9314         POP_PARENT();
9315         return statement;
9316 }
9317
9318 /**
9319  * Parse a do statement.
9320  */
9321 static statement_t *parse_do(void)
9322 {
9323         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9324
9325         eat(T_do);
9326
9327         PUSH_PARENT(statement);
9328         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9329
9330         add_anchor_token(T_while);
9331         statement->do_while.body = parse_loop_body(statement);
9332         rem_anchor_token(T_while);
9333
9334         expect(T_while);
9335         expression_t *const cond = parse_condition();
9336         statement->do_while.condition = cond;
9337         /* §6.8.5:2    The controlling expression of an iteration statement shall
9338          *             have scalar type. */
9339         semantic_condition(cond, "condition of 'do-while'-statement");
9340         expect(';');
9341
9342         POP_SCOPE();
9343         POP_PARENT();
9344         return statement;
9345 }
9346
9347 /**
9348  * Parse a for statement.
9349  */
9350 static statement_t *parse_for(void)
9351 {
9352         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9353
9354         eat(T_for);
9355
9356         PUSH_PARENT(statement);
9357         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9358
9359         expect('(');
9360         add_anchor_token(')');
9361
9362         PUSH_EXTENSION();
9363
9364         if (next_if(';')) {
9365         } else if (is_declaration_specifier(&token)) {
9366                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9367         } else {
9368                 add_anchor_token(';');
9369                 expression_t *const init = parse_expression();
9370                 statement->fors.initialisation = init;
9371                 mark_vars_read(init, ENT_ANY);
9372                 if (!expression_has_effect(init)) {
9373                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9374                 }
9375                 rem_anchor_token(';');
9376                 expect(';');
9377         }
9378
9379         POP_EXTENSION();
9380
9381         if (token.kind != ';') {
9382                 add_anchor_token(';');
9383                 expression_t *const cond = parse_expression();
9384                 statement->fors.condition = cond;
9385                 /* §6.8.5:2    The controlling expression of an iteration statement
9386                  *             shall have scalar type. */
9387                 semantic_condition(cond, "condition of 'for'-statement");
9388                 mark_vars_read(cond, NULL);
9389                 rem_anchor_token(';');
9390         }
9391         expect(';');
9392         if (token.kind != ')') {
9393                 expression_t *const step = parse_expression();
9394                 statement->fors.step = step;
9395                 mark_vars_read(step, ENT_ANY);
9396                 if (!expression_has_effect(step)) {
9397                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9398                 }
9399         }
9400         rem_anchor_token(')');
9401         expect(')');
9402         statement->fors.body = parse_loop_body(statement);
9403
9404         POP_SCOPE();
9405         POP_PARENT();
9406         return statement;
9407 }
9408
9409 /**
9410  * Parse a goto statement.
9411  */
9412 static statement_t *parse_goto(void)
9413 {
9414         statement_t *statement;
9415         if (GNU_MODE && look_ahead(1)->kind == '*') {
9416                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9417                 eat(T_goto);
9418                 eat('*');
9419
9420                 expression_t *expression = parse_expression();
9421                 mark_vars_read(expression, NULL);
9422
9423                 /* Argh: although documentation says the expression must be of type void*,
9424                  * gcc accepts anything that can be casted into void* without error */
9425                 type_t *type = expression->base.type;
9426
9427                 if (type != type_error_type) {
9428                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9429                                 errorf(&expression->base.source_position,
9430                                         "cannot convert to a pointer type");
9431                         } else if (type != type_void_ptr) {
9432                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9433                         }
9434                         expression = create_implicit_cast(expression, type_void_ptr);
9435                 }
9436
9437                 statement->computed_goto.expression = expression;
9438         } else {
9439                 statement = allocate_statement_zero(STATEMENT_GOTO);
9440                 eat(T_goto);
9441                 if (token.kind == T_IDENTIFIER) {
9442                         label_t *const label = get_label();
9443                         label->used            = true;
9444                         statement->gotos.label = label;
9445
9446                         /* remember the goto's in a list for later checking */
9447                         *goto_anchor = &statement->gotos;
9448                         goto_anchor  = &statement->gotos.next;
9449                 } else {
9450                         if (GNU_MODE)
9451                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9452                         else
9453                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9454                         eat_until_anchor();
9455                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9456                 }
9457         }
9458
9459         expect(';');
9460         return statement;
9461 }
9462
9463 /**
9464  * Parse a continue statement.
9465  */
9466 static statement_t *parse_continue(void)
9467 {
9468         if (current_loop == NULL) {
9469                 errorf(HERE, "continue statement not within loop");
9470         }
9471
9472         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9473
9474         eat(T_continue);
9475         expect(';');
9476         return statement;
9477 }
9478
9479 /**
9480  * Parse a break statement.
9481  */
9482 static statement_t *parse_break(void)
9483 {
9484         if (current_switch == NULL && current_loop == NULL) {
9485                 errorf(HERE, "break statement not within loop or switch");
9486         }
9487
9488         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9489
9490         eat(T_break);
9491         expect(';');
9492         return statement;
9493 }
9494
9495 /**
9496  * Parse a __leave statement.
9497  */
9498 static statement_t *parse_leave_statement(void)
9499 {
9500         if (current_try == NULL) {
9501                 errorf(HERE, "__leave statement not within __try");
9502         }
9503
9504         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9505
9506         eat(T___leave);
9507         expect(';');
9508         return statement;
9509 }
9510
9511 /**
9512  * Check if a given entity represents a local variable.
9513  */
9514 static bool is_local_variable(const entity_t *entity)
9515 {
9516         if (entity->kind != ENTITY_VARIABLE)
9517                 return false;
9518
9519         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9520         case STORAGE_CLASS_AUTO:
9521         case STORAGE_CLASS_REGISTER: {
9522                 const type_t *type = skip_typeref(entity->declaration.type);
9523                 if (is_type_function(type)) {
9524                         return false;
9525                 } else {
9526                         return true;
9527                 }
9528         }
9529         default:
9530                 return false;
9531         }
9532 }
9533
9534 /**
9535  * Check if a given expression represents a local variable.
9536  */
9537 static bool expression_is_local_variable(const expression_t *expression)
9538 {
9539         if (expression->base.kind != EXPR_REFERENCE) {
9540                 return false;
9541         }
9542         const entity_t *entity = expression->reference.entity;
9543         return is_local_variable(entity);
9544 }
9545
9546 /**
9547  * Check if a given expression represents a local variable and
9548  * return its declaration then, else return NULL.
9549  */
9550 entity_t *expression_is_variable(const expression_t *expression)
9551 {
9552         if (expression->base.kind != EXPR_REFERENCE) {
9553                 return NULL;
9554         }
9555         entity_t *entity = expression->reference.entity;
9556         if (entity->kind != ENTITY_VARIABLE)
9557                 return NULL;
9558
9559         return entity;
9560 }
9561
9562 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9563 {
9564         if (c_mode & _CXX || strict_mode) {
9565                 errorf(pos, msg);
9566         } else {
9567                 warningf(WARN_OTHER, pos, msg);
9568         }
9569 }
9570
9571 /**
9572  * Parse a return statement.
9573  */
9574 static statement_t *parse_return(void)
9575 {
9576         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9577         eat(T_return);
9578
9579         expression_t *return_value = NULL;
9580         if (token.kind != ';') {
9581                 return_value = parse_expression();
9582                 mark_vars_read(return_value, NULL);
9583         }
9584
9585         const type_t *const func_type = skip_typeref(current_function->base.type);
9586         assert(is_type_function(func_type));
9587         type_t *const return_type = skip_typeref(func_type->function.return_type);
9588
9589         source_position_t const *const pos = &statement->base.source_position;
9590         if (return_value != NULL) {
9591                 type_t *return_value_type = skip_typeref(return_value->base.type);
9592
9593                 if (is_type_void(return_type)) {
9594                         if (!is_type_void(return_value_type)) {
9595                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9596                                 /* Only warn in C mode, because GCC does the same */
9597                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9598                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9599                                 /* Only warn in C mode, because GCC does the same */
9600                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9601                         }
9602                 } else {
9603                         assign_error_t error = semantic_assign(return_type, return_value);
9604                         report_assign_error(error, return_type, return_value, "'return'",
9605                                             pos);
9606                 }
9607                 return_value = create_implicit_cast(return_value, return_type);
9608                 /* check for returning address of a local var */
9609                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9610                         const expression_t *expression = return_value->unary.value;
9611                         if (expression_is_local_variable(expression)) {
9612                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9613                         }
9614                 }
9615         } else if (!is_type_void(return_type)) {
9616                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9617                 err_or_warn(pos, "'return' without value, in function returning non-void");
9618         }
9619         statement->returns.value = return_value;
9620
9621         expect(';');
9622         return statement;
9623 }
9624
9625 /**
9626  * Parse a declaration statement.
9627  */
9628 static statement_t *parse_declaration_statement(void)
9629 {
9630         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9631
9632         entity_t *before = current_scope->last_entity;
9633         if (GNU_MODE) {
9634                 parse_external_declaration();
9635         } else {
9636                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9637         }
9638
9639         declaration_statement_t *const decl  = &statement->declaration;
9640         entity_t                *const begin =
9641                 before != NULL ? before->base.next : current_scope->entities;
9642         decl->declarations_begin = begin;
9643         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9644
9645         return statement;
9646 }
9647
9648 /**
9649  * Parse an expression statement, ie. expr ';'.
9650  */
9651 static statement_t *parse_expression_statement(void)
9652 {
9653         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9654
9655         expression_t *const expr         = parse_expression();
9656         statement->expression.expression = expr;
9657         mark_vars_read(expr, ENT_ANY);
9658
9659         expect(';');
9660         return statement;
9661 }
9662
9663 /**
9664  * Parse a microsoft __try { } __finally { } or
9665  * __try{ } __except() { }
9666  */
9667 static statement_t *parse_ms_try_statment(void)
9668 {
9669         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9670         eat(T___try);
9671
9672         PUSH_PARENT(statement);
9673
9674         ms_try_statement_t *rem = current_try;
9675         current_try = &statement->ms_try;
9676         statement->ms_try.try_statement = parse_compound_statement(false);
9677         current_try = rem;
9678
9679         POP_PARENT();
9680
9681         if (next_if(T___except)) {
9682                 expression_t *const expr = parse_condition();
9683                 type_t       *      type = skip_typeref(expr->base.type);
9684                 if (is_type_integer(type)) {
9685                         type = promote_integer(type);
9686                 } else if (is_type_valid(type)) {
9687                         errorf(&expr->base.source_position,
9688                                "__expect expression is not an integer, but '%T'", type);
9689                         type = type_error_type;
9690                 }
9691                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9692         } else if (!next_if(T__finally)) {
9693                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9694         }
9695         statement->ms_try.final_statement = parse_compound_statement(false);
9696         return statement;
9697 }
9698
9699 static statement_t *parse_empty_statement(void)
9700 {
9701         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9702         statement_t *const statement = create_empty_statement();
9703         eat(';');
9704         return statement;
9705 }
9706
9707 static statement_t *parse_local_label_declaration(void)
9708 {
9709         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9710
9711         eat(T___label__);
9712
9713         entity_t *begin   = NULL;
9714         entity_t *end     = NULL;
9715         entity_t **anchor = &begin;
9716         do {
9717                 source_position_t pos;
9718                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9719                 if (!symbol)
9720                         goto end_error;
9721
9722                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9723                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9724                         source_position_t const *const ppos = &entity->base.source_position;
9725                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9726                 } else {
9727                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9728                         entity->base.parent_scope = current_scope;
9729
9730                         *anchor = entity;
9731                         anchor  = &entity->base.next;
9732                         end     = entity;
9733
9734                         environment_push(entity);
9735                 }
9736         } while (next_if(','));
9737         expect(';');
9738 end_error:
9739         statement->declaration.declarations_begin = begin;
9740         statement->declaration.declarations_end   = end;
9741         return statement;
9742 }
9743
9744 static void parse_namespace_definition(void)
9745 {
9746         eat(T_namespace);
9747
9748         entity_t *entity = NULL;
9749         symbol_t *symbol = NULL;
9750
9751         if (token.kind == T_IDENTIFIER) {
9752                 symbol = token.identifier.symbol;
9753                 next_token();
9754
9755                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9756                 if (entity != NULL
9757                                 && entity->kind != ENTITY_NAMESPACE
9758                                 && entity->base.parent_scope == current_scope) {
9759                         if (is_entity_valid(entity)) {
9760                                 error_redefined_as_different_kind(&token.base.source_position,
9761                                                 entity, ENTITY_NAMESPACE);
9762                         }
9763                         entity = NULL;
9764                 }
9765         }
9766
9767         if (entity == NULL) {
9768                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9769                 entity->base.parent_scope = current_scope;
9770         }
9771
9772         if (token.kind == '=') {
9773                 /* TODO: parse namespace alias */
9774                 panic("namespace alias definition not supported yet");
9775         }
9776
9777         environment_push(entity);
9778         append_entity(current_scope, entity);
9779
9780         PUSH_SCOPE(&entity->namespacee.members);
9781
9782         entity_t     *old_current_entity = current_entity;
9783         current_entity = entity;
9784
9785         add_anchor_token('}');
9786         expect('{');
9787         parse_externals();
9788         rem_anchor_token('}');
9789         expect('}');
9790
9791         assert(current_entity == entity);
9792         current_entity = old_current_entity;
9793         POP_SCOPE();
9794 }
9795
9796 /**
9797  * Parse a statement.
9798  * There's also parse_statement() which additionally checks for
9799  * "statement has no effect" warnings
9800  */
9801 static statement_t *intern_parse_statement(void)
9802 {
9803         /* declaration or statement */
9804         statement_t *statement;
9805         switch (token.kind) {
9806         case T_IDENTIFIER: {
9807                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9808                 if (la1_type == ':') {
9809                         statement = parse_label_statement();
9810                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9811                         statement = parse_declaration_statement();
9812                 } else {
9813                         /* it's an identifier, the grammar says this must be an
9814                          * expression statement. However it is common that users mistype
9815                          * declaration types, so we guess a bit here to improve robustness
9816                          * for incorrect programs */
9817                         switch (la1_type) {
9818                         case '&':
9819                         case '*':
9820                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9821                         default:
9822                                         statement = parse_expression_statement();
9823                                 } else {
9824                         DECLARATION_START
9825                         case T_IDENTIFIER:
9826                                         statement = parse_declaration_statement();
9827                                 }
9828                                 break;
9829                         }
9830                 }
9831                 break;
9832         }
9833
9834         case T___extension__: {
9835                 /* This can be a prefix to a declaration or an expression statement.
9836                  * We simply eat it now and parse the rest with tail recursion. */
9837                 PUSH_EXTENSION();
9838                 statement = intern_parse_statement();
9839                 POP_EXTENSION();
9840                 break;
9841         }
9842
9843         DECLARATION_START
9844                 statement = parse_declaration_statement();
9845                 break;
9846
9847         case T___label__:
9848                 statement = parse_local_label_declaration();
9849                 break;
9850
9851         case ';':         statement = parse_empty_statement();         break;
9852         case '{':         statement = parse_compound_statement(false); break;
9853         case T___leave:   statement = parse_leave_statement();         break;
9854         case T___try:     statement = parse_ms_try_statment();         break;
9855         case T_asm:       statement = parse_asm_statement();           break;
9856         case T_break:     statement = parse_break();                   break;
9857         case T_case:      statement = parse_case_statement();          break;
9858         case T_continue:  statement = parse_continue();                break;
9859         case T_default:   statement = parse_default_statement();       break;
9860         case T_do:        statement = parse_do();                      break;
9861         case T_for:       statement = parse_for();                     break;
9862         case T_goto:      statement = parse_goto();                    break;
9863         case T_if:        statement = parse_if();                      break;
9864         case T_return:    statement = parse_return();                  break;
9865         case T_switch:    statement = parse_switch();                  break;
9866         case T_while:     statement = parse_while();                   break;
9867
9868         EXPRESSION_START
9869                 statement = parse_expression_statement();
9870                 break;
9871
9872         default:
9873                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9874                 statement = create_error_statement();
9875                 eat_until_anchor();
9876                 break;
9877         }
9878
9879         return statement;
9880 }
9881
9882 /**
9883  * parse a statement and emits "statement has no effect" warning if needed
9884  * (This is really a wrapper around intern_parse_statement with check for 1
9885  *  single warning. It is needed, because for statement expressions we have
9886  *  to avoid the warning on the last statement)
9887  */
9888 static statement_t *parse_statement(void)
9889 {
9890         statement_t *statement = intern_parse_statement();
9891
9892         if (statement->kind == STATEMENT_EXPRESSION) {
9893                 expression_t *expression = statement->expression.expression;
9894                 if (!expression_has_effect(expression)) {
9895                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9896                 }
9897         }
9898
9899         return statement;
9900 }
9901
9902 /**
9903  * Parse a compound statement.
9904  */
9905 static statement_t *parse_compound_statement(bool inside_expression_statement)
9906 {
9907         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9908
9909         PUSH_PARENT(statement);
9910         PUSH_SCOPE(&statement->compound.scope);
9911
9912         eat('{');
9913         add_anchor_token('}');
9914         /* tokens, which can start a statement */
9915         /* TODO MS, __builtin_FOO */
9916         add_anchor_token('!');
9917         add_anchor_token('&');
9918         add_anchor_token('(');
9919         add_anchor_token('*');
9920         add_anchor_token('+');
9921         add_anchor_token('-');
9922         add_anchor_token(';');
9923         add_anchor_token('{');
9924         add_anchor_token('~');
9925         add_anchor_token(T_CHARACTER_CONSTANT);
9926         add_anchor_token(T_COLONCOLON);
9927         add_anchor_token(T_FLOATINGPOINT);
9928         add_anchor_token(T_IDENTIFIER);
9929         add_anchor_token(T_INTEGER);
9930         add_anchor_token(T_MINUSMINUS);
9931         add_anchor_token(T_PLUSPLUS);
9932         add_anchor_token(T_STRING_LITERAL);
9933         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9934         add_anchor_token(T_WIDE_STRING_LITERAL);
9935         add_anchor_token(T__Bool);
9936         add_anchor_token(T__Complex);
9937         add_anchor_token(T__Imaginary);
9938         add_anchor_token(T___FUNCTION__);
9939         add_anchor_token(T___PRETTY_FUNCTION__);
9940         add_anchor_token(T___alignof__);
9941         add_anchor_token(T___attribute__);
9942         add_anchor_token(T___builtin_va_start);
9943         add_anchor_token(T___extension__);
9944         add_anchor_token(T___func__);
9945         add_anchor_token(T___imag__);
9946         add_anchor_token(T___label__);
9947         add_anchor_token(T___real__);
9948         add_anchor_token(T___thread);
9949         add_anchor_token(T_asm);
9950         add_anchor_token(T_auto);
9951         add_anchor_token(T_bool);
9952         add_anchor_token(T_break);
9953         add_anchor_token(T_case);
9954         add_anchor_token(T_char);
9955         add_anchor_token(T_class);
9956         add_anchor_token(T_const);
9957         add_anchor_token(T_const_cast);
9958         add_anchor_token(T_continue);
9959         add_anchor_token(T_default);
9960         add_anchor_token(T_delete);
9961         add_anchor_token(T_double);
9962         add_anchor_token(T_do);
9963         add_anchor_token(T_dynamic_cast);
9964         add_anchor_token(T_enum);
9965         add_anchor_token(T_extern);
9966         add_anchor_token(T_false);
9967         add_anchor_token(T_float);
9968         add_anchor_token(T_for);
9969         add_anchor_token(T_goto);
9970         add_anchor_token(T_if);
9971         add_anchor_token(T_inline);
9972         add_anchor_token(T_int);
9973         add_anchor_token(T_long);
9974         add_anchor_token(T_new);
9975         add_anchor_token(T_operator);
9976         add_anchor_token(T_register);
9977         add_anchor_token(T_reinterpret_cast);
9978         add_anchor_token(T_restrict);
9979         add_anchor_token(T_return);
9980         add_anchor_token(T_short);
9981         add_anchor_token(T_signed);
9982         add_anchor_token(T_sizeof);
9983         add_anchor_token(T_static);
9984         add_anchor_token(T_static_cast);
9985         add_anchor_token(T_struct);
9986         add_anchor_token(T_switch);
9987         add_anchor_token(T_template);
9988         add_anchor_token(T_this);
9989         add_anchor_token(T_throw);
9990         add_anchor_token(T_true);
9991         add_anchor_token(T_try);
9992         add_anchor_token(T_typedef);
9993         add_anchor_token(T_typeid);
9994         add_anchor_token(T_typename);
9995         add_anchor_token(T_typeof);
9996         add_anchor_token(T_union);
9997         add_anchor_token(T_unsigned);
9998         add_anchor_token(T_using);
9999         add_anchor_token(T_void);
10000         add_anchor_token(T_volatile);
10001         add_anchor_token(T_wchar_t);
10002         add_anchor_token(T_while);
10003
10004         statement_t **anchor            = &statement->compound.statements;
10005         bool          only_decls_so_far = true;
10006         while (token.kind != '}' && token.kind != T_EOF) {
10007                 statement_t *sub_statement = intern_parse_statement();
10008                 if (sub_statement->kind == STATEMENT_ERROR) {
10009                         break;
10010                 }
10011
10012                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10013                         only_decls_so_far = false;
10014                 } else if (!only_decls_so_far) {
10015                         source_position_t const *const pos = &sub_statement->base.source_position;
10016                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10017                 }
10018
10019                 *anchor = sub_statement;
10020                 anchor  = &sub_statement->base.next;
10021         }
10022         expect('}');
10023
10024         /* look over all statements again to produce no effect warnings */
10025         if (is_warn_on(WARN_UNUSED_VALUE)) {
10026                 statement_t *sub_statement = statement->compound.statements;
10027                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10028                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10029                                 continue;
10030                         /* don't emit a warning for the last expression in an expression
10031                          * statement as it has always an effect */
10032                         if (inside_expression_statement && sub_statement->base.next == NULL)
10033                                 continue;
10034
10035                         expression_t *expression = sub_statement->expression.expression;
10036                         if (!expression_has_effect(expression)) {
10037                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10038                         }
10039                 }
10040         }
10041
10042         rem_anchor_token(T_while);
10043         rem_anchor_token(T_wchar_t);
10044         rem_anchor_token(T_volatile);
10045         rem_anchor_token(T_void);
10046         rem_anchor_token(T_using);
10047         rem_anchor_token(T_unsigned);
10048         rem_anchor_token(T_union);
10049         rem_anchor_token(T_typeof);
10050         rem_anchor_token(T_typename);
10051         rem_anchor_token(T_typeid);
10052         rem_anchor_token(T_typedef);
10053         rem_anchor_token(T_try);
10054         rem_anchor_token(T_true);
10055         rem_anchor_token(T_throw);
10056         rem_anchor_token(T_this);
10057         rem_anchor_token(T_template);
10058         rem_anchor_token(T_switch);
10059         rem_anchor_token(T_struct);
10060         rem_anchor_token(T_static_cast);
10061         rem_anchor_token(T_static);
10062         rem_anchor_token(T_sizeof);
10063         rem_anchor_token(T_signed);
10064         rem_anchor_token(T_short);
10065         rem_anchor_token(T_return);
10066         rem_anchor_token(T_restrict);
10067         rem_anchor_token(T_reinterpret_cast);
10068         rem_anchor_token(T_register);
10069         rem_anchor_token(T_operator);
10070         rem_anchor_token(T_new);
10071         rem_anchor_token(T_long);
10072         rem_anchor_token(T_int);
10073         rem_anchor_token(T_inline);
10074         rem_anchor_token(T_if);
10075         rem_anchor_token(T_goto);
10076         rem_anchor_token(T_for);
10077         rem_anchor_token(T_float);
10078         rem_anchor_token(T_false);
10079         rem_anchor_token(T_extern);
10080         rem_anchor_token(T_enum);
10081         rem_anchor_token(T_dynamic_cast);
10082         rem_anchor_token(T_do);
10083         rem_anchor_token(T_double);
10084         rem_anchor_token(T_delete);
10085         rem_anchor_token(T_default);
10086         rem_anchor_token(T_continue);
10087         rem_anchor_token(T_const_cast);
10088         rem_anchor_token(T_const);
10089         rem_anchor_token(T_class);
10090         rem_anchor_token(T_char);
10091         rem_anchor_token(T_case);
10092         rem_anchor_token(T_break);
10093         rem_anchor_token(T_bool);
10094         rem_anchor_token(T_auto);
10095         rem_anchor_token(T_asm);
10096         rem_anchor_token(T___thread);
10097         rem_anchor_token(T___real__);
10098         rem_anchor_token(T___label__);
10099         rem_anchor_token(T___imag__);
10100         rem_anchor_token(T___func__);
10101         rem_anchor_token(T___extension__);
10102         rem_anchor_token(T___builtin_va_start);
10103         rem_anchor_token(T___attribute__);
10104         rem_anchor_token(T___alignof__);
10105         rem_anchor_token(T___PRETTY_FUNCTION__);
10106         rem_anchor_token(T___FUNCTION__);
10107         rem_anchor_token(T__Imaginary);
10108         rem_anchor_token(T__Complex);
10109         rem_anchor_token(T__Bool);
10110         rem_anchor_token(T_WIDE_STRING_LITERAL);
10111         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10112         rem_anchor_token(T_STRING_LITERAL);
10113         rem_anchor_token(T_PLUSPLUS);
10114         rem_anchor_token(T_MINUSMINUS);
10115         rem_anchor_token(T_INTEGER);
10116         rem_anchor_token(T_IDENTIFIER);
10117         rem_anchor_token(T_FLOATINGPOINT);
10118         rem_anchor_token(T_COLONCOLON);
10119         rem_anchor_token(T_CHARACTER_CONSTANT);
10120         rem_anchor_token('~');
10121         rem_anchor_token('{');
10122         rem_anchor_token(';');
10123         rem_anchor_token('-');
10124         rem_anchor_token('+');
10125         rem_anchor_token('*');
10126         rem_anchor_token('(');
10127         rem_anchor_token('&');
10128         rem_anchor_token('!');
10129         rem_anchor_token('}');
10130
10131         POP_SCOPE();
10132         POP_PARENT();
10133         return statement;
10134 }
10135
10136 /**
10137  * Check for unused global static functions and variables
10138  */
10139 static void check_unused_globals(void)
10140 {
10141         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10142                 return;
10143
10144         for (const entity_t *entity = file_scope->entities; entity != NULL;
10145              entity = entity->base.next) {
10146                 if (!is_declaration(entity))
10147                         continue;
10148
10149                 const declaration_t *declaration = &entity->declaration;
10150                 if (declaration->used                  ||
10151                     declaration->modifiers & DM_UNUSED ||
10152                     declaration->modifiers & DM_USED   ||
10153                     declaration->storage_class != STORAGE_CLASS_STATIC)
10154                         continue;
10155
10156                 warning_t   why;
10157                 char const *s;
10158                 if (entity->kind == ENTITY_FUNCTION) {
10159                         /* inhibit warning for static inline functions */
10160                         if (entity->function.is_inline)
10161                                 continue;
10162
10163                         why = WARN_UNUSED_FUNCTION;
10164                         s   = entity->function.statement != NULL ? "defined" : "declared";
10165                 } else {
10166                         why = WARN_UNUSED_VARIABLE;
10167                         s   = "defined";
10168                 }
10169
10170                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10171         }
10172 }
10173
10174 static void parse_global_asm(void)
10175 {
10176         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10177
10178         eat(T_asm);
10179         add_anchor_token(';');
10180         add_anchor_token(')');
10181         add_anchor_token(T_STRING_LITERAL);
10182         expect('(');
10183
10184         rem_anchor_token(T_STRING_LITERAL);
10185         statement->asms.asm_text = parse_string_literals();
10186         statement->base.next     = unit->global_asm;
10187         unit->global_asm         = statement;
10188
10189         rem_anchor_token(')');
10190         expect(')');
10191         rem_anchor_token(';');
10192         expect(';');
10193 }
10194
10195 static void parse_linkage_specification(void)
10196 {
10197         eat(T_extern);
10198
10199         source_position_t const pos     = *HERE;
10200         char const       *const linkage = parse_string_literals().begin;
10201
10202         linkage_kind_t old_linkage = current_linkage;
10203         linkage_kind_t new_linkage;
10204         if (streq(linkage, "C")) {
10205                 new_linkage = LINKAGE_C;
10206         } else if (streq(linkage, "C++")) {
10207                 new_linkage = LINKAGE_CXX;
10208         } else {
10209                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10210                 new_linkage = LINKAGE_C;
10211         }
10212         current_linkage = new_linkage;
10213
10214         if (next_if('{')) {
10215                 parse_externals();
10216                 expect('}');
10217         } else {
10218                 parse_external();
10219         }
10220
10221         assert(current_linkage == new_linkage);
10222         current_linkage = old_linkage;
10223 }
10224
10225 static void parse_external(void)
10226 {
10227         switch (token.kind) {
10228                 case T_extern:
10229                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10230                                 parse_linkage_specification();
10231                         } else {
10232                 DECLARATION_START_NO_EXTERN
10233                 case T_IDENTIFIER:
10234                 case T___extension__:
10235                 /* tokens below are for implicit int */
10236                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10237                               implicit int) */
10238                 case '*':  /* * x; -> int* x; */
10239                 case '(':  /* (x); -> int (x); */
10240                                 PUSH_EXTENSION();
10241                                 parse_external_declaration();
10242                                 POP_EXTENSION();
10243                         }
10244                         return;
10245
10246                 case T_asm:
10247                         parse_global_asm();
10248                         return;
10249
10250                 case T_namespace:
10251                         parse_namespace_definition();
10252                         return;
10253
10254                 case ';':
10255                         if (!strict_mode) {
10256                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10257                                 next_token();
10258                                 return;
10259                         }
10260                         /* FALLTHROUGH */
10261
10262                 default:
10263                         errorf(HERE, "stray %K outside of function", &token);
10264                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10265                                 eat_until_matching_token(token.kind);
10266                         next_token();
10267                         return;
10268         }
10269 }
10270
10271 static void parse_externals(void)
10272 {
10273         add_anchor_token('}');
10274         add_anchor_token(T_EOF);
10275
10276 #ifndef NDEBUG
10277         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10278         unsigned short token_anchor_copy[T_LAST_TOKEN];
10279         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10280 #endif
10281
10282         while (token.kind != T_EOF && token.kind != '}') {
10283 #ifndef NDEBUG
10284                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10285                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10286                         if (count != 0) {
10287                                 /* the anchor set and its copy differs */
10288                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10289                         }
10290                 }
10291                 if (in_gcc_extension) {
10292                         /* an gcc extension scope was not closed */
10293                         internal_errorf(HERE, "Leaked __extension__");
10294                 }
10295 #endif
10296
10297                 parse_external();
10298         }
10299
10300         rem_anchor_token(T_EOF);
10301         rem_anchor_token('}');
10302 }
10303
10304 /**
10305  * Parse a translation unit.
10306  */
10307 static void parse_translation_unit(void)
10308 {
10309         add_anchor_token(T_EOF);
10310
10311         while (true) {
10312                 parse_externals();
10313
10314                 if (token.kind == T_EOF)
10315                         break;
10316
10317                 errorf(HERE, "stray %K outside of function", &token);
10318                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10319                         eat_until_matching_token(token.kind);
10320                 next_token();
10321         }
10322 }
10323
10324 void set_default_visibility(elf_visibility_tag_t visibility)
10325 {
10326         default_visibility = visibility;
10327 }
10328
10329 /**
10330  * Parse the input.
10331  *
10332  * @return  the translation unit or NULL if errors occurred.
10333  */
10334 void start_parsing(void)
10335 {
10336         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10337         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10338         diagnostic_count  = 0;
10339         error_count       = 0;
10340         warning_count     = 0;
10341
10342         print_to_file(stderr);
10343
10344         assert(unit == NULL);
10345         unit = allocate_ast_zero(sizeof(unit[0]));
10346
10347         assert(file_scope == NULL);
10348         file_scope = &unit->scope;
10349
10350         assert(current_scope == NULL);
10351         scope_push(&unit->scope);
10352
10353         create_gnu_builtins();
10354         if (c_mode & _MS)
10355                 create_microsoft_intrinsics();
10356 }
10357
10358 translation_unit_t *finish_parsing(void)
10359 {
10360         assert(current_scope == &unit->scope);
10361         scope_pop(NULL);
10362
10363         assert(file_scope == &unit->scope);
10364         check_unused_globals();
10365         file_scope = NULL;
10366
10367         DEL_ARR_F(environment_stack);
10368         DEL_ARR_F(label_stack);
10369
10370         translation_unit_t *result = unit;
10371         unit = NULL;
10372         return result;
10373 }
10374
10375 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10376  * are given length one. */
10377 static void complete_incomplete_arrays(void)
10378 {
10379         size_t n = ARR_LEN(incomplete_arrays);
10380         for (size_t i = 0; i != n; ++i) {
10381                 declaration_t *const decl = incomplete_arrays[i];
10382                 type_t        *const type = skip_typeref(decl->type);
10383
10384                 if (!is_type_incomplete(type))
10385                         continue;
10386
10387                 source_position_t const *const pos = &decl->base.source_position;
10388                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10389
10390                 type_t *const new_type = duplicate_type(type);
10391                 new_type->array.size_constant     = true;
10392                 new_type->array.has_implicit_size = true;
10393                 new_type->array.size              = 1;
10394
10395                 type_t *const result = identify_new_type(new_type);
10396
10397                 decl->type = result;
10398         }
10399 }
10400
10401 static void prepare_main_collect2(entity_t *const entity)
10402 {
10403         PUSH_SCOPE(&entity->function.statement->compound.scope);
10404
10405         // create call to __main
10406         symbol_t *symbol         = symbol_table_insert("__main");
10407         entity_t *subsubmain_ent
10408                 = create_implicit_function(symbol, &builtin_source_position);
10409
10410         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10411         type_t       *ftype       = subsubmain_ent->declaration.type;
10412         ref->base.source_position = builtin_source_position;
10413         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10414         ref->reference.entity     = subsubmain_ent;
10415
10416         expression_t *call = allocate_expression_zero(EXPR_CALL);
10417         call->base.source_position = builtin_source_position;
10418         call->base.type            = type_void;
10419         call->call.function        = ref;
10420
10421         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10422         expr_statement->base.source_position  = builtin_source_position;
10423         expr_statement->expression.expression = call;
10424
10425         statement_t *statement = entity->function.statement;
10426         assert(statement->kind == STATEMENT_COMPOUND);
10427         compound_statement_t *compounds = &statement->compound;
10428
10429         expr_statement->base.next = compounds->statements;
10430         compounds->statements     = expr_statement;
10431
10432         POP_SCOPE();
10433 }
10434
10435 void parse(void)
10436 {
10437         lookahead_bufpos = 0;
10438         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10439                 next_token();
10440         }
10441         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10442         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10443         parse_translation_unit();
10444         complete_incomplete_arrays();
10445         DEL_ARR_F(incomplete_arrays);
10446         incomplete_arrays = NULL;
10447 }
10448
10449 /**
10450  * Initialize the parser.
10451  */
10452 void init_parser(void)
10453 {
10454         sym_anonymous = symbol_table_insert("<anonymous>");
10455
10456         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10457
10458         init_expression_parsers();
10459         obstack_init(&temp_obst);
10460 }
10461
10462 /**
10463  * Terminate the parser.
10464  */
10465 void exit_parser(void)
10466 {
10467         obstack_free(&temp_obst, NULL);
10468 }