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
4620                 /* do not issue unused warnings for main */
4621                 if (!is_sym_main(current_function->base.base.symbol)) {
4622                         warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4623                 }
4624         }
4625         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4626                 walk_statements(current_function->statement, check_unused_variables,
4627                                 NULL);
4628         }
4629 }
4630
4631 static int determine_truth(expression_t const* const cond)
4632 {
4633         return
4634                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4635                 fold_constant_to_bool(cond)                         ? 1 :
4636                 -1;
4637 }
4638
4639 static void check_reachable(statement_t *);
4640 static bool reaches_end;
4641
4642 static bool expression_returns(expression_t const *const expr)
4643 {
4644         switch (expr->kind) {
4645                 case EXPR_CALL: {
4646                         expression_t const *const func = expr->call.function;
4647                         type_t       const *const type = skip_typeref(func->base.type);
4648                         if (type->kind == TYPE_POINTER) {
4649                                 type_t const *const points_to
4650                                         = skip_typeref(type->pointer.points_to);
4651                                 if (points_to->kind == TYPE_FUNCTION
4652                                     && points_to->function.modifiers & DM_NORETURN)
4653                                         return false;
4654                         }
4655
4656                         if (!expression_returns(func))
4657                                 return false;
4658
4659                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4660                                 if (!expression_returns(arg->expression))
4661                                         return false;
4662                         }
4663
4664                         return true;
4665                 }
4666
4667                 case EXPR_REFERENCE:
4668                 case EXPR_ENUM_CONSTANT:
4669                 case EXPR_LITERAL_CASES:
4670                 case EXPR_STRING_LITERAL:
4671                 case EXPR_WIDE_STRING_LITERAL:
4672                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4673                 case EXPR_LABEL_ADDRESS:
4674                 case EXPR_CLASSIFY_TYPE:
4675                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4676                 case EXPR_ALIGNOF:
4677                 case EXPR_FUNCNAME:
4678                 case EXPR_BUILTIN_CONSTANT_P:
4679                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4680                 case EXPR_OFFSETOF:
4681                 case EXPR_ERROR:
4682                         return true;
4683
4684                 case EXPR_STATEMENT: {
4685                         bool old_reaches_end = reaches_end;
4686                         reaches_end = false;
4687                         check_reachable(expr->statement.statement);
4688                         bool returns = reaches_end;
4689                         reaches_end = old_reaches_end;
4690                         return returns;
4691                 }
4692
4693                 case EXPR_CONDITIONAL:
4694                         // TODO handle constant expression
4695
4696                         if (!expression_returns(expr->conditional.condition))
4697                                 return false;
4698
4699                         if (expr->conditional.true_expression != NULL
4700                                         && expression_returns(expr->conditional.true_expression))
4701                                 return true;
4702
4703                         return expression_returns(expr->conditional.false_expression);
4704
4705                 case EXPR_SELECT:
4706                         return expression_returns(expr->select.compound);
4707
4708                 case EXPR_ARRAY_ACCESS:
4709                         return
4710                                 expression_returns(expr->array_access.array_ref) &&
4711                                 expression_returns(expr->array_access.index);
4712
4713                 case EXPR_VA_START:
4714                         return expression_returns(expr->va_starte.ap);
4715
4716                 case EXPR_VA_ARG:
4717                         return expression_returns(expr->va_arge.ap);
4718
4719                 case EXPR_VA_COPY:
4720                         return expression_returns(expr->va_copye.src);
4721
4722                 case EXPR_UNARY_CASES_MANDATORY:
4723                         return expression_returns(expr->unary.value);
4724
4725                 case EXPR_UNARY_THROW:
4726                         return false;
4727
4728                 case EXPR_BINARY_CASES:
4729                         // TODO handle constant lhs of && and ||
4730                         return
4731                                 expression_returns(expr->binary.left) &&
4732                                 expression_returns(expr->binary.right);
4733         }
4734
4735         panic("unhandled expression");
4736 }
4737
4738 static bool initializer_returns(initializer_t const *const init)
4739 {
4740         switch (init->kind) {
4741                 case INITIALIZER_VALUE:
4742                         return expression_returns(init->value.value);
4743
4744                 case INITIALIZER_LIST: {
4745                         initializer_t * const*       i       = init->list.initializers;
4746                         initializer_t * const* const end     = i + init->list.len;
4747                         bool                         returns = true;
4748                         for (; i != end; ++i) {
4749                                 if (!initializer_returns(*i))
4750                                         returns = false;
4751                         }
4752                         return returns;
4753                 }
4754
4755                 case INITIALIZER_STRING:
4756                 case INITIALIZER_WIDE_STRING:
4757                 case INITIALIZER_DESIGNATOR: // designators have no payload
4758                         return true;
4759         }
4760         panic("unhandled initializer");
4761 }
4762
4763 static bool noreturn_candidate;
4764
4765 static void check_reachable(statement_t *const stmt)
4766 {
4767         if (stmt->base.reachable)
4768                 return;
4769         if (stmt->kind != STATEMENT_DO_WHILE)
4770                 stmt->base.reachable = true;
4771
4772         statement_t *last = stmt;
4773         statement_t *next;
4774         switch (stmt->kind) {
4775                 case STATEMENT_ERROR:
4776                 case STATEMENT_EMPTY:
4777                 case STATEMENT_ASM:
4778                         next = stmt->base.next;
4779                         break;
4780
4781                 case STATEMENT_DECLARATION: {
4782                         declaration_statement_t const *const decl = &stmt->declaration;
4783                         entity_t                const *      ent  = decl->declarations_begin;
4784                         entity_t                const *const last_decl = decl->declarations_end;
4785                         if (ent != NULL) {
4786                                 for (;; ent = ent->base.next) {
4787                                         if (ent->kind                 == ENTITY_VARIABLE &&
4788                                             ent->variable.initializer != NULL            &&
4789                                             !initializer_returns(ent->variable.initializer)) {
4790                                                 return;
4791                                         }
4792                                         if (ent == last_decl)
4793                                                 break;
4794                                 }
4795                         }
4796                         next = stmt->base.next;
4797                         break;
4798                 }
4799
4800                 case STATEMENT_COMPOUND:
4801                         next = stmt->compound.statements;
4802                         if (next == NULL)
4803                                 next = stmt->base.next;
4804                         break;
4805
4806                 case STATEMENT_RETURN: {
4807                         expression_t const *const val = stmt->returns.value;
4808                         if (val == NULL || expression_returns(val))
4809                                 noreturn_candidate = false;
4810                         return;
4811                 }
4812
4813                 case STATEMENT_IF: {
4814                         if_statement_t const *const ifs  = &stmt->ifs;
4815                         expression_t   const *const cond = ifs->condition;
4816
4817                         if (!expression_returns(cond))
4818                                 return;
4819
4820                         int const val = determine_truth(cond);
4821
4822                         if (val >= 0)
4823                                 check_reachable(ifs->true_statement);
4824
4825                         if (val > 0)
4826                                 return;
4827
4828                         if (ifs->false_statement != NULL) {
4829                                 check_reachable(ifs->false_statement);
4830                                 return;
4831                         }
4832
4833                         next = stmt->base.next;
4834                         break;
4835                 }
4836
4837                 case STATEMENT_SWITCH: {
4838                         switch_statement_t const *const switchs = &stmt->switchs;
4839                         expression_t       const *const expr    = switchs->expression;
4840
4841                         if (!expression_returns(expr))
4842                                 return;
4843
4844                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4845                                 long                    const val      = fold_constant_to_int(expr);
4846                                 case_label_statement_t *      defaults = NULL;
4847                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4848                                         if (i->expression == NULL) {
4849                                                 defaults = i;
4850                                                 continue;
4851                                         }
4852
4853                                         if (i->first_case <= val && val <= i->last_case) {
4854                                                 check_reachable((statement_t*)i);
4855                                                 return;
4856                                         }
4857                                 }
4858
4859                                 if (defaults != NULL) {
4860                                         check_reachable((statement_t*)defaults);
4861                                         return;
4862                                 }
4863                         } else {
4864                                 bool has_default = false;
4865                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4866                                         if (i->expression == NULL)
4867                                                 has_default = true;
4868
4869                                         check_reachable((statement_t*)i);
4870                                 }
4871
4872                                 if (has_default)
4873                                         return;
4874                         }
4875
4876                         next = stmt->base.next;
4877                         break;
4878                 }
4879
4880                 case STATEMENT_EXPRESSION: {
4881                         /* Check for noreturn function call */
4882                         expression_t const *const expr = stmt->expression.expression;
4883                         if (!expression_returns(expr))
4884                                 return;
4885
4886                         next = stmt->base.next;
4887                         break;
4888                 }
4889
4890                 case STATEMENT_CONTINUE:
4891                         for (statement_t *parent = stmt;;) {
4892                                 parent = parent->base.parent;
4893                                 if (parent == NULL) /* continue not within loop */
4894                                         return;
4895
4896                                 next = parent;
4897                                 switch (parent->kind) {
4898                                         case STATEMENT_WHILE:    goto continue_while;
4899                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4900                                         case STATEMENT_FOR:      goto continue_for;
4901
4902                                         default: break;
4903                                 }
4904                         }
4905
4906                 case STATEMENT_BREAK:
4907                         for (statement_t *parent = stmt;;) {
4908                                 parent = parent->base.parent;
4909                                 if (parent == NULL) /* break not within loop/switch */
4910                                         return;
4911
4912                                 switch (parent->kind) {
4913                                         case STATEMENT_SWITCH:
4914                                         case STATEMENT_WHILE:
4915                                         case STATEMENT_DO_WHILE:
4916                                         case STATEMENT_FOR:
4917                                                 last = parent;
4918                                                 next = parent->base.next;
4919                                                 goto found_break_parent;
4920
4921                                         default: break;
4922                                 }
4923                         }
4924 found_break_parent:
4925                         break;
4926
4927                 case STATEMENT_COMPUTED_GOTO: {
4928                         if (!expression_returns(stmt->computed_goto.expression))
4929                                 return;
4930
4931                         statement_t *parent = stmt->base.parent;
4932                         if (parent == NULL) /* top level goto */
4933                                 return;
4934                         next = parent;
4935                         break;
4936                 }
4937
4938                 case STATEMENT_GOTO:
4939                         next = stmt->gotos.label->statement;
4940                         if (next == NULL) /* missing label */
4941                                 return;
4942                         break;
4943
4944                 case STATEMENT_LABEL:
4945                         next = stmt->label.statement;
4946                         break;
4947
4948                 case STATEMENT_CASE_LABEL:
4949                         next = stmt->case_label.statement;
4950                         break;
4951
4952                 case STATEMENT_WHILE: {
4953                         while_statement_t const *const whiles = &stmt->whiles;
4954                         expression_t      const *const cond   = whiles->condition;
4955
4956                         if (!expression_returns(cond))
4957                                 return;
4958
4959                         int const val = determine_truth(cond);
4960
4961                         if (val >= 0)
4962                                 check_reachable(whiles->body);
4963
4964                         if (val > 0)
4965                                 return;
4966
4967                         next = stmt->base.next;
4968                         break;
4969                 }
4970
4971                 case STATEMENT_DO_WHILE:
4972                         next = stmt->do_while.body;
4973                         break;
4974
4975                 case STATEMENT_FOR: {
4976                         for_statement_t *const fors = &stmt->fors;
4977
4978                         if (fors->condition_reachable)
4979                                 return;
4980                         fors->condition_reachable = true;
4981
4982                         expression_t const *const cond = fors->condition;
4983
4984                         int val;
4985                         if (cond == NULL) {
4986                                 val = 1;
4987                         } else if (expression_returns(cond)) {
4988                                 val = determine_truth(cond);
4989                         } else {
4990                                 return;
4991                         }
4992
4993                         if (val >= 0)
4994                                 check_reachable(fors->body);
4995
4996                         if (val > 0)
4997                                 return;
4998
4999                         next = stmt->base.next;
5000                         break;
5001                 }
5002
5003                 case STATEMENT_MS_TRY: {
5004                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5005                         check_reachable(ms_try->try_statement);
5006                         next = ms_try->final_statement;
5007                         break;
5008                 }
5009
5010                 case STATEMENT_LEAVE: {
5011                         statement_t *parent = stmt;
5012                         for (;;) {
5013                                 parent = parent->base.parent;
5014                                 if (parent == NULL) /* __leave not within __try */
5015                                         return;
5016
5017                                 if (parent->kind == STATEMENT_MS_TRY) {
5018                                         last = parent;
5019                                         next = parent->ms_try.final_statement;
5020                                         break;
5021                                 }
5022                         }
5023                         break;
5024                 }
5025
5026                 default:
5027                         panic("invalid statement kind");
5028         }
5029
5030         while (next == NULL) {
5031                 next = last->base.parent;
5032                 if (next == NULL) {
5033                         noreturn_candidate = false;
5034
5035                         type_t *const type = skip_typeref(current_function->base.type);
5036                         assert(is_type_function(type));
5037                         type_t *const ret  = skip_typeref(type->function.return_type);
5038                         if (!is_type_void(ret) &&
5039                             is_type_valid(ret) &&
5040                             !is_sym_main(current_function->base.base.symbol)) {
5041                                 source_position_t const *const pos = &stmt->base.source_position;
5042                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5043                         }
5044                         return;
5045                 }
5046
5047                 switch (next->kind) {
5048                         case STATEMENT_ERROR:
5049                         case STATEMENT_EMPTY:
5050                         case STATEMENT_DECLARATION:
5051                         case STATEMENT_EXPRESSION:
5052                         case STATEMENT_ASM:
5053                         case STATEMENT_RETURN:
5054                         case STATEMENT_CONTINUE:
5055                         case STATEMENT_BREAK:
5056                         case STATEMENT_COMPUTED_GOTO:
5057                         case STATEMENT_GOTO:
5058                         case STATEMENT_LEAVE:
5059                                 panic("invalid control flow in function");
5060
5061                         case STATEMENT_COMPOUND:
5062                                 if (next->compound.stmt_expr) {
5063                                         reaches_end = true;
5064                                         return;
5065                                 }
5066                                 /* FALLTHROUGH */
5067                         case STATEMENT_IF:
5068                         case STATEMENT_SWITCH:
5069                         case STATEMENT_LABEL:
5070                         case STATEMENT_CASE_LABEL:
5071                                 last = next;
5072                                 next = next->base.next;
5073                                 break;
5074
5075                         case STATEMENT_WHILE: {
5076 continue_while:
5077                                 if (next->base.reachable)
5078                                         return;
5079                                 next->base.reachable = true;
5080
5081                                 while_statement_t const *const whiles = &next->whiles;
5082                                 expression_t      const *const cond   = whiles->condition;
5083
5084                                 if (!expression_returns(cond))
5085                                         return;
5086
5087                                 int const val = determine_truth(cond);
5088
5089                                 if (val >= 0)
5090                                         check_reachable(whiles->body);
5091
5092                                 if (val > 0)
5093                                         return;
5094
5095                                 last = next;
5096                                 next = next->base.next;
5097                                 break;
5098                         }
5099
5100                         case STATEMENT_DO_WHILE: {
5101 continue_do_while:
5102                                 if (next->base.reachable)
5103                                         return;
5104                                 next->base.reachable = true;
5105
5106                                 do_while_statement_t const *const dw   = &next->do_while;
5107                                 expression_t         const *const cond = dw->condition;
5108
5109                                 if (!expression_returns(cond))
5110                                         return;
5111
5112                                 int const val = determine_truth(cond);
5113
5114                                 if (val >= 0)
5115                                         check_reachable(dw->body);
5116
5117                                 if (val > 0)
5118                                         return;
5119
5120                                 last = next;
5121                                 next = next->base.next;
5122                                 break;
5123                         }
5124
5125                         case STATEMENT_FOR: {
5126 continue_for:;
5127                                 for_statement_t *const fors = &next->fors;
5128
5129                                 fors->step_reachable = true;
5130
5131                                 if (fors->condition_reachable)
5132                                         return;
5133                                 fors->condition_reachable = true;
5134
5135                                 expression_t const *const cond = fors->condition;
5136
5137                                 int val;
5138                                 if (cond == NULL) {
5139                                         val = 1;
5140                                 } else if (expression_returns(cond)) {
5141                                         val = determine_truth(cond);
5142                                 } else {
5143                                         return;
5144                                 }
5145
5146                                 if (val >= 0)
5147                                         check_reachable(fors->body);
5148
5149                                 if (val > 0)
5150                                         return;
5151
5152                                 last = next;
5153                                 next = next->base.next;
5154                                 break;
5155                         }
5156
5157                         case STATEMENT_MS_TRY:
5158                                 last = next;
5159                                 next = next->ms_try.final_statement;
5160                                 break;
5161                 }
5162         }
5163
5164         check_reachable(next);
5165 }
5166
5167 static void check_unreachable(statement_t* const stmt, void *const env)
5168 {
5169         (void)env;
5170
5171         switch (stmt->kind) {
5172                 case STATEMENT_DO_WHILE:
5173                         if (!stmt->base.reachable) {
5174                                 expression_t const *const cond = stmt->do_while.condition;
5175                                 if (determine_truth(cond) >= 0) {
5176                                         source_position_t const *const pos = &cond->base.source_position;
5177                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5178                                 }
5179                         }
5180                         return;
5181
5182                 case STATEMENT_FOR: {
5183                         for_statement_t const* const fors = &stmt->fors;
5184
5185                         // if init and step are unreachable, cond is unreachable, too
5186                         if (!stmt->base.reachable && !fors->step_reachable) {
5187                                 goto warn_unreachable;
5188                         } else {
5189                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5190                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5191                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5192                                 }
5193
5194                                 if (!fors->condition_reachable && fors->condition != NULL) {
5195                                         source_position_t const *const pos = &fors->condition->base.source_position;
5196                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5197                                 }
5198
5199                                 if (!fors->step_reachable && fors->step != NULL) {
5200                                         source_position_t const *const pos = &fors->step->base.source_position;
5201                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5202                                 }
5203                         }
5204                         return;
5205                 }
5206
5207                 case STATEMENT_COMPOUND:
5208                         if (stmt->compound.statements != NULL)
5209                                 return;
5210                         goto warn_unreachable;
5211
5212                 case STATEMENT_DECLARATION: {
5213                         /* Only warn if there is at least one declarator with an initializer.
5214                          * This typically occurs in switch statements. */
5215                         declaration_statement_t const *const decl = &stmt->declaration;
5216                         entity_t                const *      ent  = decl->declarations_begin;
5217                         entity_t                const *const last = decl->declarations_end;
5218                         if (ent != NULL) {
5219                                 for (;; ent = ent->base.next) {
5220                                         if (ent->kind                 == ENTITY_VARIABLE &&
5221                                                         ent->variable.initializer != NULL) {
5222                                                 goto warn_unreachable;
5223                                         }
5224                                         if (ent == last)
5225                                                 return;
5226                                 }
5227                         }
5228                 }
5229
5230                 default:
5231 warn_unreachable:
5232                         if (!stmt->base.reachable) {
5233                                 source_position_t const *const pos = &stmt->base.source_position;
5234                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5235                         }
5236                         return;
5237         }
5238 }
5239
5240 static bool is_main(entity_t *entity)
5241 {
5242         static symbol_t *sym_main = NULL;
5243         if (sym_main == NULL) {
5244                 sym_main = symbol_table_insert("main");
5245         }
5246
5247         if (entity->base.symbol != sym_main)
5248                 return false;
5249         /* must be in outermost scope */
5250         if (entity->base.parent_scope != file_scope)
5251                 return false;
5252
5253         return true;
5254 }
5255
5256 static void parse_external_declaration(void)
5257 {
5258         /* function-definitions and declarations both start with declaration
5259          * specifiers */
5260         add_anchor_token(';');
5261         declaration_specifiers_t specifiers;
5262         parse_declaration_specifiers(&specifiers);
5263         rem_anchor_token(';');
5264
5265         /* must be a declaration */
5266         if (token.kind == ';') {
5267                 parse_anonymous_declaration_rest(&specifiers);
5268                 return;
5269         }
5270
5271         add_anchor_token(',');
5272         add_anchor_token('=');
5273         add_anchor_token(';');
5274         add_anchor_token('{');
5275
5276         /* declarator is common to both function-definitions and declarations */
5277         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5278
5279         rem_anchor_token('{');
5280         rem_anchor_token(';');
5281         rem_anchor_token('=');
5282         rem_anchor_token(',');
5283
5284         /* must be a declaration */
5285         switch (token.kind) {
5286                 case ',':
5287                 case ';':
5288                 case '=':
5289                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5290                                         DECL_FLAGS_NONE);
5291                         return;
5292         }
5293
5294         /* must be a function definition */
5295         parse_kr_declaration_list(ndeclaration);
5296
5297         if (token.kind != '{') {
5298                 parse_error_expected("while parsing function definition", '{', NULL);
5299                 eat_until_matching_token(';');
5300                 return;
5301         }
5302
5303         assert(is_declaration(ndeclaration));
5304         type_t *const orig_type = ndeclaration->declaration.type;
5305         type_t *      type      = skip_typeref(orig_type);
5306
5307         if (!is_type_function(type)) {
5308                 if (is_type_valid(type)) {
5309                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5310                 }
5311                 eat_block();
5312                 return;
5313         }
5314
5315         source_position_t const *const pos = &ndeclaration->base.source_position;
5316         if (is_typeref(orig_type)) {
5317                 /* §6.9.1:2 */
5318                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5319         }
5320
5321         if (is_type_compound(skip_typeref(type->function.return_type))) {
5322                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5323         }
5324         if (type->function.unspecified_parameters) {
5325                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5326         } else {
5327                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5328         }
5329
5330         /* §6.7.5.3:14 a function definition with () means no
5331          * parameters (and not unspecified parameters) */
5332         if (type->function.unspecified_parameters &&
5333                         type->function.parameters == NULL) {
5334                 type_t *copy                          = duplicate_type(type);
5335                 copy->function.unspecified_parameters = false;
5336                 type                                  = identify_new_type(copy);
5337
5338                 ndeclaration->declaration.type = type;
5339         }
5340
5341         entity_t *const entity = record_entity(ndeclaration, true);
5342         assert(entity->kind == ENTITY_FUNCTION);
5343         assert(ndeclaration->kind == ENTITY_FUNCTION);
5344
5345         function_t *const function = &entity->function;
5346         if (ndeclaration != entity) {
5347                 function->parameters = ndeclaration->function.parameters;
5348         }
5349         assert(is_declaration(entity));
5350         type = skip_typeref(entity->declaration.type);
5351
5352         PUSH_SCOPE(&function->parameters);
5353
5354         entity_t *parameter = function->parameters.entities;
5355         for (; parameter != NULL; parameter = parameter->base.next) {
5356                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5357                         parameter->base.parent_scope = current_scope;
5358                 }
5359                 assert(parameter->base.parent_scope == NULL
5360                                 || parameter->base.parent_scope == current_scope);
5361                 parameter->base.parent_scope = current_scope;
5362                 if (parameter->base.symbol == NULL) {
5363                         errorf(&parameter->base.source_position, "parameter name omitted");
5364                         continue;
5365                 }
5366                 environment_push(parameter);
5367         }
5368
5369         if (function->statement != NULL) {
5370                 parser_error_multiple_definition(entity, HERE);
5371                 eat_block();
5372         } else {
5373                 /* parse function body */
5374                 int         label_stack_top      = label_top();
5375                 function_t *old_current_function = current_function;
5376                 entity_t   *old_current_entity   = current_entity;
5377                 current_function                 = function;
5378                 current_entity                   = entity;
5379                 PUSH_PARENT(NULL);
5380
5381                 goto_first   = NULL;
5382                 goto_anchor  = &goto_first;
5383                 label_first  = NULL;
5384                 label_anchor = &label_first;
5385
5386                 statement_t *const body = parse_compound_statement(false);
5387                 function->statement = body;
5388                 first_err = true;
5389                 check_labels();
5390                 check_declarations();
5391                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5392                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5393                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5394                         noreturn_candidate = true;
5395                         check_reachable(body);
5396                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5397                                 walk_statements(body, check_unreachable, NULL);
5398                         if (noreturn_candidate &&
5399                             !(function->base.modifiers & DM_NORETURN)) {
5400                                 source_position_t const *const pos = &body->base.source_position;
5401                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5402                         }
5403                 }
5404
5405                 if (is_main(entity) && enable_main_collect2_hack)
5406                         prepare_main_collect2(entity);
5407
5408                 POP_PARENT();
5409                 assert(current_function == function);
5410                 assert(current_entity   == entity);
5411                 current_entity   = old_current_entity;
5412                 current_function = old_current_function;
5413                 label_pop_to(label_stack_top);
5414         }
5415
5416         POP_SCOPE();
5417 }
5418
5419 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5420 {
5421         entity_t *iter = compound->members.entities;
5422         for (; iter != NULL; iter = iter->base.next) {
5423                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5424                         continue;
5425
5426                 if (iter->base.symbol == symbol) {
5427                         return iter;
5428                 } else if (iter->base.symbol == NULL) {
5429                         /* search in anonymous structs and unions */
5430                         type_t *type = skip_typeref(iter->declaration.type);
5431                         if (is_type_compound(type)) {
5432                                 if (find_compound_entry(type->compound.compound, symbol)
5433                                                 != NULL)
5434                                         return iter;
5435                         }
5436                         continue;
5437                 }
5438         }
5439
5440         return NULL;
5441 }
5442
5443 static void check_deprecated(const source_position_t *source_position,
5444                              const entity_t *entity)
5445 {
5446         if (!is_declaration(entity))
5447                 return;
5448         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5449                 return;
5450
5451         source_position_t const *const epos = &entity->base.source_position;
5452         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5453         if (msg != NULL) {
5454                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5455         } else {
5456                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5457         }
5458 }
5459
5460
5461 static expression_t *create_select(const source_position_t *pos,
5462                                    expression_t *addr,
5463                                    type_qualifiers_t qualifiers,
5464                                                                    entity_t *entry)
5465 {
5466         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5467
5468         check_deprecated(pos, entry);
5469
5470         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5471         select->select.compound       = addr;
5472         select->select.compound_entry = entry;
5473
5474         type_t *entry_type = entry->declaration.type;
5475         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5476
5477         /* bitfields need special treatment */
5478         if (entry->compound_member.bitfield) {
5479                 unsigned bit_size = entry->compound_member.bit_size;
5480                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5481                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5482                         res_type = type_int;
5483                 }
5484         }
5485
5486         /* we always do the auto-type conversions; the & and sizeof parser contains
5487          * code to revert this! */
5488         select->base.type = automatic_type_conversion(res_type);
5489
5490
5491         return select;
5492 }
5493
5494 /**
5495  * Find entry with symbol in compound. Search anonymous structs and unions and
5496  * creates implicit select expressions for them.
5497  * Returns the adress for the innermost compound.
5498  */
5499 static expression_t *find_create_select(const source_position_t *pos,
5500                                         expression_t *addr,
5501                                         type_qualifiers_t qualifiers,
5502                                         compound_t *compound, symbol_t *symbol)
5503 {
5504         entity_t *iter = compound->members.entities;
5505         for (; iter != NULL; iter = iter->base.next) {
5506                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5507                         continue;
5508
5509                 symbol_t *iter_symbol = iter->base.symbol;
5510                 if (iter_symbol == NULL) {
5511                         type_t *type = iter->declaration.type;
5512                         if (type->kind != TYPE_COMPOUND_STRUCT
5513                                         && type->kind != TYPE_COMPOUND_UNION)
5514                                 continue;
5515
5516                         compound_t *sub_compound = type->compound.compound;
5517
5518                         if (find_compound_entry(sub_compound, symbol) == NULL)
5519                                 continue;
5520
5521                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5522                         sub_addr->base.source_position = *pos;
5523                         sub_addr->base.implicit        = true;
5524                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5525                                                   symbol);
5526                 }
5527
5528                 if (iter_symbol == symbol) {
5529                         return create_select(pos, addr, qualifiers, iter);
5530                 }
5531         }
5532
5533         return NULL;
5534 }
5535
5536 static void parse_bitfield_member(entity_t *entity)
5537 {
5538         eat(':');
5539
5540         expression_t *size = parse_constant_expression();
5541         long          size_long;
5542
5543         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5544         type_t *type = entity->declaration.type;
5545         if (!is_type_integer(skip_typeref(type))) {
5546                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5547                            type);
5548         }
5549
5550         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5551                 /* error already reported by parse_constant_expression */
5552                 size_long = get_type_size(type) * 8;
5553         } else {
5554                 size_long = fold_constant_to_int(size);
5555
5556                 const symbol_t *symbol = entity->base.symbol;
5557                 const symbol_t *user_symbol
5558                         = symbol == NULL ? sym_anonymous : symbol;
5559                 unsigned bit_size = get_type_size(type) * 8;
5560                 if (size_long < 0) {
5561                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5562                 } else if (size_long == 0 && symbol != NULL) {
5563                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5564                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5565                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5566                                    user_symbol);
5567                 } else {
5568                         /* hope that people don't invent crazy types with more bits
5569                          * than our struct can hold */
5570                         assert(size_long <
5571                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5572                 }
5573         }
5574
5575         entity->compound_member.bitfield = true;
5576         entity->compound_member.bit_size = (unsigned char)size_long;
5577 }
5578
5579 static void parse_compound_declarators(compound_t *compound,
5580                 const declaration_specifiers_t *specifiers)
5581 {
5582         add_anchor_token(';');
5583         add_anchor_token(',');
5584         do {
5585                 entity_t *entity;
5586
5587                 if (token.kind == ':') {
5588                         /* anonymous bitfield */
5589                         type_t *type = specifiers->type;
5590                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5591                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5592                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5593                         entity->declaration.type                   = type;
5594
5595                         parse_bitfield_member(entity);
5596
5597                         attribute_t  *attributes = parse_attributes(NULL);
5598                         attribute_t **anchor     = &attributes;
5599                         while (*anchor != NULL)
5600                                 anchor = &(*anchor)->next;
5601                         *anchor = specifiers->attributes;
5602                         if (attributes != NULL) {
5603                                 handle_entity_attributes(attributes, entity);
5604                         }
5605                         entity->declaration.attributes = attributes;
5606
5607                         append_entity(&compound->members, entity);
5608                 } else {
5609                         entity = parse_declarator(specifiers,
5610                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5611                         source_position_t const *const pos = &entity->base.source_position;
5612                         if (entity->kind == ENTITY_TYPEDEF) {
5613                                 errorf(pos, "typedef not allowed as compound member");
5614                         } else {
5615                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5616
5617                                 /* make sure we don't define a symbol multiple times */
5618                                 symbol_t *symbol = entity->base.symbol;
5619                                 if (symbol != NULL) {
5620                                         entity_t *prev = find_compound_entry(compound, symbol);
5621                                         if (prev != NULL) {
5622                                                 source_position_t const *const ppos = &prev->base.source_position;
5623                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5624                                         }
5625                                 }
5626
5627                                 if (token.kind == ':') {
5628                                         parse_bitfield_member(entity);
5629
5630                                         attribute_t *attributes = parse_attributes(NULL);
5631                                         handle_entity_attributes(attributes, entity);
5632                                 } else {
5633                                         type_t *orig_type = entity->declaration.type;
5634                                         type_t *type      = skip_typeref(orig_type);
5635                                         if (is_type_function(type)) {
5636                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5637                                         } else if (is_type_incomplete(type)) {
5638                                                 /* §6.7.2.1:16 flexible array member */
5639                                                 if (!is_type_array(type)       ||
5640                                                                 token.kind          != ';' ||
5641                                                                 look_ahead(1)->kind != '}') {
5642                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5643                                                 } else if (compound->members.entities == NULL) {
5644                                                         errorf(pos, "flexible array member in otherwise empty struct");
5645                                                 }
5646                                         }
5647                                 }
5648
5649                                 append_entity(&compound->members, entity);
5650                         }
5651                 }
5652         } while (next_if(','));
5653         rem_anchor_token(',');
5654         rem_anchor_token(';');
5655         expect(';');
5656
5657         anonymous_entity = NULL;
5658 }
5659
5660 static void parse_compound_type_entries(compound_t *compound)
5661 {
5662         eat('{');
5663         add_anchor_token('}');
5664
5665         for (;;) {
5666                 switch (token.kind) {
5667                         DECLARATION_START
5668                         case T___extension__:
5669                         case T_IDENTIFIER: {
5670                                 PUSH_EXTENSION();
5671                                 declaration_specifiers_t specifiers;
5672                                 parse_declaration_specifiers(&specifiers);
5673                                 parse_compound_declarators(compound, &specifiers);
5674                                 POP_EXTENSION();
5675                                 break;
5676                         }
5677
5678                         default:
5679                                 rem_anchor_token('}');
5680                                 expect('}');
5681                                 /* §6.7.2.1:7 */
5682                                 compound->complete = true;
5683                                 return;
5684                 }
5685         }
5686 }
5687
5688 static type_t *parse_typename(void)
5689 {
5690         declaration_specifiers_t specifiers;
5691         parse_declaration_specifiers(&specifiers);
5692         if (specifiers.storage_class != STORAGE_CLASS_NONE
5693                         || specifiers.thread_local) {
5694                 /* TODO: improve error message, user does probably not know what a
5695                  * storage class is...
5696                  */
5697                 errorf(&specifiers.source_position, "typename must not have a storage class");
5698         }
5699
5700         type_t *result = parse_abstract_declarator(specifiers.type);
5701
5702         return result;
5703 }
5704
5705
5706
5707
5708 typedef expression_t* (*parse_expression_function)(void);
5709 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5710
5711 typedef struct expression_parser_function_t expression_parser_function_t;
5712 struct expression_parser_function_t {
5713         parse_expression_function        parser;
5714         precedence_t                     infix_precedence;
5715         parse_expression_infix_function  infix_parser;
5716 };
5717
5718 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5719
5720 static type_t *get_string_type(void)
5721 {
5722         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5723 }
5724
5725 static type_t *get_wide_string_type(void)
5726 {
5727         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5728 }
5729
5730 /**
5731  * Parse a string constant.
5732  */
5733 static expression_t *parse_string_literal(void)
5734 {
5735         source_position_t begin   = token.base.source_position;
5736         string_t          res     = token.string.string;
5737         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5738
5739         next_token();
5740         while (token.kind == T_STRING_LITERAL
5741                         || token.kind == T_WIDE_STRING_LITERAL) {
5742                 warn_string_concat(&token.base.source_position);
5743                 res = concat_strings(&res, &token.string.string);
5744                 next_token();
5745                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5746         }
5747
5748         expression_t *literal;
5749         if (is_wide) {
5750                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5751                 literal->base.type = get_wide_string_type();
5752         } else {
5753                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5754                 literal->base.type = get_string_type();
5755         }
5756         literal->base.source_position = begin;
5757         literal->literal.value        = res;
5758
5759         return literal;
5760 }
5761
5762 /**
5763  * Parse a boolean constant.
5764  */
5765 static expression_t *parse_boolean_literal(bool value)
5766 {
5767         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5768         literal->base.type           = type_bool;
5769         literal->literal.value.begin = value ? "true" : "false";
5770         literal->literal.value.size  = value ? 4 : 5;
5771
5772         next_token();
5773         return literal;
5774 }
5775
5776 static void warn_traditional_suffix(void)
5777 {
5778         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5779                  &token.number.suffix);
5780 }
5781
5782 static void check_integer_suffix(void)
5783 {
5784         const string_t *suffix = &token.number.suffix;
5785         if (suffix->size == 0)
5786                 return;
5787
5788         bool not_traditional = false;
5789         const char *c = suffix->begin;
5790         if (*c == 'l' || *c == 'L') {
5791                 ++c;
5792                 if (*c == *(c-1)) {
5793                         not_traditional = true;
5794                         ++c;
5795                         if (*c == 'u' || *c == 'U') {
5796                                 ++c;
5797                         }
5798                 } else if (*c == 'u' || *c == 'U') {
5799                         not_traditional = true;
5800                         ++c;
5801                 }
5802         } else if (*c == 'u' || *c == 'U') {
5803                 not_traditional = true;
5804                 ++c;
5805                 if (*c == 'l' || *c == 'L') {
5806                         ++c;
5807                         if (*c == *(c-1)) {
5808                                 ++c;
5809                         }
5810                 }
5811         }
5812         if (*c != '\0') {
5813                 errorf(&token.base.source_position,
5814                        "invalid suffix '%S' on integer constant", suffix);
5815         } else if (not_traditional) {
5816                 warn_traditional_suffix();
5817         }
5818 }
5819
5820 static type_t *check_floatingpoint_suffix(void)
5821 {
5822         const string_t *suffix = &token.number.suffix;
5823         type_t         *type   = type_double;
5824         if (suffix->size == 0)
5825                 return type;
5826
5827         bool not_traditional = false;
5828         const char *c = suffix->begin;
5829         if (*c == 'f' || *c == 'F') {
5830                 ++c;
5831                 type = type_float;
5832         } else if (*c == 'l' || *c == 'L') {
5833                 ++c;
5834                 type = type_long_double;
5835         }
5836         if (*c != '\0') {
5837                 errorf(&token.base.source_position,
5838                        "invalid suffix '%S' on floatingpoint constant", suffix);
5839         } else if (not_traditional) {
5840                 warn_traditional_suffix();
5841         }
5842
5843         return type;
5844 }
5845
5846 /**
5847  * Parse an integer constant.
5848  */
5849 static expression_t *parse_number_literal(void)
5850 {
5851         expression_kind_t  kind;
5852         type_t            *type;
5853
5854         switch (token.kind) {
5855         case T_INTEGER:
5856                 kind = EXPR_LITERAL_INTEGER;
5857                 check_integer_suffix();
5858                 type = type_int;
5859                 break;
5860         case T_INTEGER_OCTAL:
5861                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5862                 check_integer_suffix();
5863                 type = type_int;
5864                 break;
5865         case T_INTEGER_HEXADECIMAL:
5866                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5867                 check_integer_suffix();
5868                 type = type_int;
5869                 break;
5870         case T_FLOATINGPOINT:
5871                 kind = EXPR_LITERAL_FLOATINGPOINT;
5872                 type = check_floatingpoint_suffix();
5873                 break;
5874         case T_FLOATINGPOINT_HEXADECIMAL:
5875                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5876                 type = check_floatingpoint_suffix();
5877                 break;
5878         default:
5879                 panic("unexpected token type in parse_number_literal");
5880         }
5881
5882         expression_t *literal = allocate_expression_zero(kind);
5883         literal->base.type      = type;
5884         literal->literal.value  = token.number.number;
5885         literal->literal.suffix = token.number.suffix;
5886         next_token();
5887
5888         /* integer type depends on the size of the number and the size
5889          * representable by the types. The backend/codegeneration has to determine
5890          * that
5891          */
5892         determine_literal_type(&literal->literal);
5893         return literal;
5894 }
5895
5896 /**
5897  * Parse a character constant.
5898  */
5899 static expression_t *parse_character_constant(void)
5900 {
5901         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5902         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5903         literal->literal.value = token.string.string;
5904
5905         size_t len = literal->literal.value.size;
5906         if (len > 1) {
5907                 if (!GNU_MODE && !(c_mode & _C99)) {
5908                         errorf(HERE, "more than 1 character in character constant");
5909                 } else {
5910                         literal->base.type = type_int;
5911                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5912                 }
5913         }
5914
5915         next_token();
5916         return literal;
5917 }
5918
5919 /**
5920  * Parse a wide character constant.
5921  */
5922 static expression_t *parse_wide_character_constant(void)
5923 {
5924         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5925         literal->base.type     = type_int;
5926         literal->literal.value = token.string.string;
5927
5928         size_t len = wstrlen(&literal->literal.value);
5929         if (len > 1) {
5930                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5931         }
5932
5933         next_token();
5934         return literal;
5935 }
5936
5937 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5938 {
5939         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5940         ntype->function.return_type            = type_int;
5941         ntype->function.unspecified_parameters = true;
5942         ntype->function.linkage                = LINKAGE_C;
5943         type_t *type                           = identify_new_type(ntype);
5944
5945         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5946         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5947         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5948         entity->declaration.type                   = type;
5949         entity->declaration.implicit               = true;
5950
5951         if (current_scope != NULL)
5952                 record_entity(entity, false);
5953
5954         return entity;
5955 }
5956
5957 /**
5958  * Performs automatic type cast as described in §6.3.2.1.
5959  *
5960  * @param orig_type  the original type
5961  */
5962 static type_t *automatic_type_conversion(type_t *orig_type)
5963 {
5964         type_t *type = skip_typeref(orig_type);
5965         if (is_type_array(type)) {
5966                 array_type_t *array_type   = &type->array;
5967                 type_t       *element_type = array_type->element_type;
5968                 unsigned      qualifiers   = array_type->base.qualifiers;
5969
5970                 return make_pointer_type(element_type, qualifiers);
5971         }
5972
5973         if (is_type_function(type)) {
5974                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5975         }
5976
5977         return orig_type;
5978 }
5979
5980 /**
5981  * reverts the automatic casts of array to pointer types and function
5982  * to function-pointer types as defined §6.3.2.1
5983  */
5984 type_t *revert_automatic_type_conversion(const expression_t *expression)
5985 {
5986         switch (expression->kind) {
5987         case EXPR_REFERENCE: {
5988                 entity_t *entity = expression->reference.entity;
5989                 if (is_declaration(entity)) {
5990                         return entity->declaration.type;
5991                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5992                         return entity->enum_value.enum_type;
5993                 } else {
5994                         panic("no declaration or enum in reference");
5995                 }
5996         }
5997
5998         case EXPR_SELECT: {
5999                 entity_t *entity = expression->select.compound_entry;
6000                 assert(is_declaration(entity));
6001                 type_t   *type   = entity->declaration.type;
6002                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6003         }
6004
6005         case EXPR_UNARY_DEREFERENCE: {
6006                 const expression_t *const value = expression->unary.value;
6007                 type_t             *const type  = skip_typeref(value->base.type);
6008                 if (!is_type_pointer(type))
6009                         return type_error_type;
6010                 return type->pointer.points_to;
6011         }
6012
6013         case EXPR_ARRAY_ACCESS: {
6014                 const expression_t *array_ref = expression->array_access.array_ref;
6015                 type_t             *type_left = skip_typeref(array_ref->base.type);
6016                 if (!is_type_pointer(type_left))
6017                         return type_error_type;
6018                 return type_left->pointer.points_to;
6019         }
6020
6021         case EXPR_STRING_LITERAL: {
6022                 size_t size = expression->string_literal.value.size;
6023                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6024         }
6025
6026         case EXPR_WIDE_STRING_LITERAL: {
6027                 size_t size = wstrlen(&expression->string_literal.value);
6028                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6029         }
6030
6031         case EXPR_COMPOUND_LITERAL:
6032                 return expression->compound_literal.type;
6033
6034         default:
6035                 break;
6036         }
6037         return expression->base.type;
6038 }
6039
6040 /**
6041  * Find an entity matching a symbol in a scope.
6042  * Uses current scope if scope is NULL
6043  */
6044 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6045                                namespace_tag_t namespc)
6046 {
6047         if (scope == NULL) {
6048                 return get_entity(symbol, namespc);
6049         }
6050
6051         /* we should optimize here, if scope grows above a certain size we should
6052            construct a hashmap here... */
6053         entity_t *entity = scope->entities;
6054         for ( ; entity != NULL; entity = entity->base.next) {
6055                 if (entity->base.symbol == symbol
6056                     && (namespace_tag_t)entity->base.namespc == namespc)
6057                         break;
6058         }
6059
6060         return entity;
6061 }
6062
6063 static entity_t *parse_qualified_identifier(void)
6064 {
6065         /* namespace containing the symbol */
6066         symbol_t          *symbol;
6067         source_position_t  pos;
6068         const scope_t     *lookup_scope = NULL;
6069
6070         if (next_if(T_COLONCOLON))
6071                 lookup_scope = &unit->scope;
6072
6073         entity_t *entity;
6074         while (true) {
6075                 symbol = expect_identifier("while parsing identifier", &pos);
6076                 if (!symbol)
6077                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6078
6079                 /* lookup entity */
6080                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6081
6082                 if (!next_if(T_COLONCOLON))
6083                         break;
6084
6085                 switch (entity->kind) {
6086                 case ENTITY_NAMESPACE:
6087                         lookup_scope = &entity->namespacee.members;
6088                         break;
6089                 case ENTITY_STRUCT:
6090                 case ENTITY_UNION:
6091                 case ENTITY_CLASS:
6092                         lookup_scope = &entity->compound.members;
6093                         break;
6094                 default:
6095                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6096                                symbol, get_entity_kind_name(entity->kind));
6097
6098                         /* skip further qualifications */
6099                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6100
6101                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6102                 }
6103         }
6104
6105         if (entity == NULL) {
6106                 if (!strict_mode && token.kind == '(') {
6107                         /* an implicitly declared function */
6108                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6109                                  "implicit declaration of function '%Y'", symbol);
6110                         entity = create_implicit_function(symbol, &pos);
6111                 } else {
6112                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6113                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6114                 }
6115         }
6116
6117         return entity;
6118 }
6119
6120 static expression_t *parse_reference(void)
6121 {
6122         source_position_t const pos    = token.base.source_position;
6123         entity_t         *const entity = parse_qualified_identifier();
6124
6125         type_t *orig_type;
6126         if (is_declaration(entity)) {
6127                 orig_type = entity->declaration.type;
6128         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6129                 orig_type = entity->enum_value.enum_type;
6130         } else {
6131                 panic("expected declaration or enum value in reference");
6132         }
6133
6134         /* we always do the auto-type conversions; the & and sizeof parser contains
6135          * code to revert this! */
6136         type_t *type = automatic_type_conversion(orig_type);
6137
6138         expression_kind_t kind = EXPR_REFERENCE;
6139         if (entity->kind == ENTITY_ENUM_VALUE)
6140                 kind = EXPR_ENUM_CONSTANT;
6141
6142         expression_t *expression         = allocate_expression_zero(kind);
6143         expression->base.source_position = pos;
6144         expression->base.type            = type;
6145         expression->reference.entity     = entity;
6146
6147         /* this declaration is used */
6148         if (is_declaration(entity)) {
6149                 entity->declaration.used = true;
6150         }
6151
6152         if (entity->base.parent_scope != file_scope
6153                 && (current_function != NULL
6154                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6155                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6156                 if (entity->kind == ENTITY_VARIABLE) {
6157                         /* access of a variable from an outer function */
6158                         entity->variable.address_taken = true;
6159                 } else if (entity->kind == ENTITY_PARAMETER) {
6160                         entity->parameter.address_taken = true;
6161                 }
6162                 current_function->need_closure = true;
6163         }
6164
6165         check_deprecated(&pos, entity);
6166
6167         return expression;
6168 }
6169
6170 static bool semantic_cast(expression_t *cast)
6171 {
6172         expression_t            *expression      = cast->unary.value;
6173         type_t                  *orig_dest_type  = cast->base.type;
6174         type_t                  *orig_type_right = expression->base.type;
6175         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6176         type_t            const *src_type        = skip_typeref(orig_type_right);
6177         source_position_t const *pos             = &cast->base.source_position;
6178
6179         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6180         if (is_type_void(dst_type))
6181                 return true;
6182
6183         /* only integer and pointer can be casted to pointer */
6184         if (is_type_pointer(dst_type)  &&
6185             !is_type_pointer(src_type) &&
6186             !is_type_integer(src_type) &&
6187             is_type_valid(src_type)) {
6188                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6189                 return false;
6190         }
6191
6192         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6193                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6194                 return false;
6195         }
6196
6197         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6198                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6199                 return false;
6200         }
6201
6202         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6203                 type_t *src = skip_typeref(src_type->pointer.points_to);
6204                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6205                 unsigned missing_qualifiers =
6206                         src->base.qualifiers & ~dst->base.qualifiers;
6207                 if (missing_qualifiers != 0) {
6208                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6209                 }
6210         }
6211         return true;
6212 }
6213
6214 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6215 {
6216         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6217         expression->base.source_position = *pos;
6218
6219         parse_initializer_env_t env;
6220         env.type             = type;
6221         env.entity           = NULL;
6222         env.must_be_constant = false;
6223         initializer_t *initializer = parse_initializer(&env);
6224         type = env.type;
6225
6226         expression->compound_literal.initializer = initializer;
6227         expression->compound_literal.type        = type;
6228         expression->base.type                    = automatic_type_conversion(type);
6229
6230         return expression;
6231 }
6232
6233 /**
6234  * Parse a cast expression.
6235  */
6236 static expression_t *parse_cast(void)
6237 {
6238         source_position_t const pos = *HERE;
6239
6240         eat('(');
6241         add_anchor_token(')');
6242
6243         type_t *type = parse_typename();
6244
6245         rem_anchor_token(')');
6246         expect(')');
6247
6248         if (token.kind == '{') {
6249                 return parse_compound_literal(&pos, type);
6250         }
6251
6252         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6253         cast->base.source_position = pos;
6254
6255         expression_t *value = parse_subexpression(PREC_CAST);
6256         cast->base.type   = type;
6257         cast->unary.value = value;
6258
6259         if (! semantic_cast(cast)) {
6260                 /* TODO: record the error in the AST. else it is impossible to detect it */
6261         }
6262
6263         return cast;
6264 }
6265
6266 /**
6267  * Parse a statement expression.
6268  */
6269 static expression_t *parse_statement_expression(void)
6270 {
6271         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6272
6273         eat('(');
6274         add_anchor_token(')');
6275
6276         statement_t *statement          = parse_compound_statement(true);
6277         statement->compound.stmt_expr   = true;
6278         expression->statement.statement = statement;
6279
6280         /* find last statement and use its type */
6281         type_t *type = type_void;
6282         const statement_t *stmt = statement->compound.statements;
6283         if (stmt != NULL) {
6284                 while (stmt->base.next != NULL)
6285                         stmt = stmt->base.next;
6286
6287                 if (stmt->kind == STATEMENT_EXPRESSION) {
6288                         type = stmt->expression.expression->base.type;
6289                 }
6290         } else {
6291                 source_position_t const *const pos = &expression->base.source_position;
6292                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6293         }
6294         expression->base.type = type;
6295
6296         rem_anchor_token(')');
6297         expect(')');
6298         return expression;
6299 }
6300
6301 /**
6302  * Parse a parenthesized expression.
6303  */
6304 static expression_t *parse_parenthesized_expression(void)
6305 {
6306         token_t const* const la1 = look_ahead(1);
6307         switch (la1->kind) {
6308         case '{':
6309                 /* gcc extension: a statement expression */
6310                 return parse_statement_expression();
6311
6312         case T_IDENTIFIER:
6313                 if (is_typedef_symbol(la1->identifier.symbol)) {
6314         DECLARATION_START
6315                         return parse_cast();
6316                 }
6317         }
6318
6319         eat('(');
6320         add_anchor_token(')');
6321         expression_t *result = parse_expression();
6322         result->base.parenthesized = true;
6323         rem_anchor_token(')');
6324         expect(')');
6325
6326         return result;
6327 }
6328
6329 static expression_t *parse_function_keyword(void)
6330 {
6331         /* TODO */
6332
6333         if (current_function == NULL) {
6334                 errorf(HERE, "'__func__' used outside of a function");
6335         }
6336
6337         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6338         expression->base.type     = type_char_ptr;
6339         expression->funcname.kind = FUNCNAME_FUNCTION;
6340
6341         next_token();
6342
6343         return expression;
6344 }
6345
6346 static expression_t *parse_pretty_function_keyword(void)
6347 {
6348         if (current_function == NULL) {
6349                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6350         }
6351
6352         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6353         expression->base.type     = type_char_ptr;
6354         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6355
6356         eat(T___PRETTY_FUNCTION__);
6357
6358         return expression;
6359 }
6360
6361 static expression_t *parse_funcsig_keyword(void)
6362 {
6363         if (current_function == NULL) {
6364                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6365         }
6366
6367         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6368         expression->base.type     = type_char_ptr;
6369         expression->funcname.kind = FUNCNAME_FUNCSIG;
6370
6371         eat(T___FUNCSIG__);
6372
6373         return expression;
6374 }
6375
6376 static expression_t *parse_funcdname_keyword(void)
6377 {
6378         if (current_function == NULL) {
6379                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6380         }
6381
6382         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6383         expression->base.type     = type_char_ptr;
6384         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6385
6386         eat(T___FUNCDNAME__);
6387
6388         return expression;
6389 }
6390
6391 static designator_t *parse_designator(void)
6392 {
6393         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6394         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6395         if (!result->symbol)
6396                 return NULL;
6397
6398         designator_t *last_designator = result;
6399         while (true) {
6400                 if (next_if('.')) {
6401                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6402                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6403                         if (!designator->symbol)
6404                                 return NULL;
6405
6406                         last_designator->next = designator;
6407                         last_designator       = designator;
6408                         continue;
6409                 }
6410                 if (next_if('[')) {
6411                         add_anchor_token(']');
6412                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6413                         designator->source_position = *HERE;
6414                         designator->array_index     = parse_expression();
6415                         rem_anchor_token(']');
6416                         expect(']');
6417                         if (designator->array_index == NULL) {
6418                                 return NULL;
6419                         }
6420
6421                         last_designator->next = designator;
6422                         last_designator       = designator;
6423                         continue;
6424                 }
6425                 break;
6426         }
6427
6428         return result;
6429 }
6430
6431 /**
6432  * Parse the __builtin_offsetof() expression.
6433  */
6434 static expression_t *parse_offsetof(void)
6435 {
6436         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6437         expression->base.type    = type_size_t;
6438
6439         eat(T___builtin_offsetof);
6440
6441         expect('(');
6442         add_anchor_token(')');
6443         add_anchor_token(',');
6444         type_t *type = parse_typename();
6445         rem_anchor_token(',');
6446         expect(',');
6447         designator_t *designator = parse_designator();
6448         rem_anchor_token(')');
6449         expect(')');
6450
6451         expression->offsetofe.type       = type;
6452         expression->offsetofe.designator = designator;
6453
6454         type_path_t path;
6455         memset(&path, 0, sizeof(path));
6456         path.top_type = type;
6457         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6458
6459         descend_into_subtype(&path);
6460
6461         if (!walk_designator(&path, designator, true)) {
6462                 return create_error_expression();
6463         }
6464
6465         DEL_ARR_F(path.path);
6466
6467         return expression;
6468 }
6469
6470 /**
6471  * Parses a _builtin_va_start() expression.
6472  */
6473 static expression_t *parse_va_start(void)
6474 {
6475         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6476
6477         eat(T___builtin_va_start);
6478
6479         expect('(');
6480         add_anchor_token(')');
6481         add_anchor_token(',');
6482         expression->va_starte.ap = parse_assignment_expression();
6483         rem_anchor_token(',');
6484         expect(',');
6485         expression_t *const expr = parse_assignment_expression();
6486         if (expr->kind == EXPR_REFERENCE) {
6487                 entity_t *const entity = expr->reference.entity;
6488                 if (!current_function->base.type->function.variadic) {
6489                         errorf(&expr->base.source_position,
6490                                         "'va_start' used in non-variadic function");
6491                 } else if (entity->base.parent_scope != &current_function->parameters ||
6492                                 entity->base.next != NULL ||
6493                                 entity->kind != ENTITY_PARAMETER) {
6494                         errorf(&expr->base.source_position,
6495                                "second argument of 'va_start' must be last parameter of the current function");
6496                 } else {
6497                         expression->va_starte.parameter = &entity->variable;
6498                 }
6499         } else {
6500                 expression = create_error_expression();
6501         }
6502         rem_anchor_token(')');
6503         expect(')');
6504         return expression;
6505 }
6506
6507 /**
6508  * Parses a __builtin_va_arg() expression.
6509  */
6510 static expression_t *parse_va_arg(void)
6511 {
6512         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6513
6514         eat(T___builtin_va_arg);
6515
6516         expect('(');
6517         add_anchor_token(')');
6518         add_anchor_token(',');
6519         call_argument_t ap;
6520         ap.expression = parse_assignment_expression();
6521         expression->va_arge.ap = ap.expression;
6522         check_call_argument(type_valist, &ap, 1);
6523
6524         rem_anchor_token(',');
6525         expect(',');
6526         expression->base.type = parse_typename();
6527         rem_anchor_token(')');
6528         expect(')');
6529
6530         return expression;
6531 }
6532
6533 /**
6534  * Parses a __builtin_va_copy() expression.
6535  */
6536 static expression_t *parse_va_copy(void)
6537 {
6538         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6539
6540         eat(T___builtin_va_copy);
6541
6542         expect('(');
6543         add_anchor_token(')');
6544         add_anchor_token(',');
6545         expression_t *dst = parse_assignment_expression();
6546         assign_error_t error = semantic_assign(type_valist, dst);
6547         report_assign_error(error, type_valist, dst, "call argument 1",
6548                             &dst->base.source_position);
6549         expression->va_copye.dst = dst;
6550
6551         rem_anchor_token(',');
6552         expect(',');
6553
6554         call_argument_t src;
6555         src.expression = parse_assignment_expression();
6556         check_call_argument(type_valist, &src, 2);
6557         expression->va_copye.src = src.expression;
6558         rem_anchor_token(')');
6559         expect(')');
6560
6561         return expression;
6562 }
6563
6564 /**
6565  * Parses a __builtin_constant_p() expression.
6566  */
6567 static expression_t *parse_builtin_constant(void)
6568 {
6569         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6570
6571         eat(T___builtin_constant_p);
6572
6573         expect('(');
6574         add_anchor_token(')');
6575         expression->builtin_constant.value = parse_assignment_expression();
6576         rem_anchor_token(')');
6577         expect(')');
6578         expression->base.type = type_int;
6579
6580         return expression;
6581 }
6582
6583 /**
6584  * Parses a __builtin_types_compatible_p() expression.
6585  */
6586 static expression_t *parse_builtin_types_compatible(void)
6587 {
6588         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6589
6590         eat(T___builtin_types_compatible_p);
6591
6592         expect('(');
6593         add_anchor_token(')');
6594         add_anchor_token(',');
6595         expression->builtin_types_compatible.left = parse_typename();
6596         rem_anchor_token(',');
6597         expect(',');
6598         expression->builtin_types_compatible.right = parse_typename();
6599         rem_anchor_token(')');
6600         expect(')');
6601         expression->base.type = type_int;
6602
6603         return expression;
6604 }
6605
6606 /**
6607  * Parses a __builtin_is_*() compare expression.
6608  */
6609 static expression_t *parse_compare_builtin(void)
6610 {
6611         expression_t *expression;
6612
6613         switch (token.kind) {
6614         case T___builtin_isgreater:
6615                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6616                 break;
6617         case T___builtin_isgreaterequal:
6618                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6619                 break;
6620         case T___builtin_isless:
6621                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6622                 break;
6623         case T___builtin_islessequal:
6624                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6625                 break;
6626         case T___builtin_islessgreater:
6627                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6628                 break;
6629         case T___builtin_isunordered:
6630                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6631                 break;
6632         default:
6633                 internal_errorf(HERE, "invalid compare builtin found");
6634         }
6635         expression->base.source_position = *HERE;
6636         next_token();
6637
6638         expect('(');
6639         add_anchor_token(')');
6640         add_anchor_token(',');
6641         expression->binary.left = parse_assignment_expression();
6642         rem_anchor_token(',');
6643         expect(',');
6644         expression->binary.right = parse_assignment_expression();
6645         rem_anchor_token(')');
6646         expect(')');
6647
6648         type_t *const orig_type_left  = expression->binary.left->base.type;
6649         type_t *const orig_type_right = expression->binary.right->base.type;
6650
6651         type_t *const type_left  = skip_typeref(orig_type_left);
6652         type_t *const type_right = skip_typeref(orig_type_right);
6653         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6654                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6655                         type_error_incompatible("invalid operands in comparison",
6656                                 &expression->base.source_position, orig_type_left, orig_type_right);
6657                 }
6658         } else {
6659                 semantic_comparison(&expression->binary);
6660         }
6661
6662         return expression;
6663 }
6664
6665 /**
6666  * Parses a MS assume() expression.
6667  */
6668 static expression_t *parse_assume(void)
6669 {
6670         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6671
6672         eat(T__assume);
6673
6674         expect('(');
6675         add_anchor_token(')');
6676         expression->unary.value = parse_assignment_expression();
6677         rem_anchor_token(')');
6678         expect(')');
6679
6680         expression->base.type = type_void;
6681         return expression;
6682 }
6683
6684 /**
6685  * Return the label for the current symbol or create a new one.
6686  */
6687 static label_t *get_label(void)
6688 {
6689         assert(token.kind == T_IDENTIFIER);
6690         assert(current_function != NULL);
6691
6692         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6693         /* If we find a local label, we already created the declaration. */
6694         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6695                 if (label->base.parent_scope != current_scope) {
6696                         assert(label->base.parent_scope->depth < current_scope->depth);
6697                         current_function->goto_to_outer = true;
6698                 }
6699         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6700                 /* There is no matching label in the same function, so create a new one. */
6701                 source_position_t const nowhere = { NULL, 0, 0, false };
6702                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol, &nowhere);
6703                 label_push(label);
6704         }
6705
6706         eat(T_IDENTIFIER);
6707         return &label->label;
6708 }
6709
6710 /**
6711  * Parses a GNU && label address expression.
6712  */
6713 static expression_t *parse_label_address(void)
6714 {
6715         source_position_t source_position = token.base.source_position;
6716         eat(T_ANDAND);
6717         if (token.kind != T_IDENTIFIER) {
6718                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6719                 return create_error_expression();
6720         }
6721
6722         label_t *const label = get_label();
6723         label->used          = true;
6724         label->address_taken = true;
6725
6726         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6727         expression->base.source_position = source_position;
6728
6729         /* label address is treated as a void pointer */
6730         expression->base.type           = type_void_ptr;
6731         expression->label_address.label = label;
6732         return expression;
6733 }
6734
6735 /**
6736  * Parse a microsoft __noop expression.
6737  */
6738 static expression_t *parse_noop_expression(void)
6739 {
6740         /* the result is a (int)0 */
6741         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6742         literal->base.type           = type_int;
6743         literal->literal.value.begin = "__noop";
6744         literal->literal.value.size  = 6;
6745
6746         eat(T___noop);
6747
6748         if (token.kind == '(') {
6749                 /* parse arguments */
6750                 eat('(');
6751                 add_anchor_token(')');
6752                 add_anchor_token(',');
6753
6754                 if (token.kind != ')') do {
6755                         (void)parse_assignment_expression();
6756                 } while (next_if(','));
6757
6758                 rem_anchor_token(',');
6759                 rem_anchor_token(')');
6760         }
6761         expect(')');
6762
6763         return literal;
6764 }
6765
6766 /**
6767  * Parses a primary expression.
6768  */
6769 static expression_t *parse_primary_expression(void)
6770 {
6771         switch (token.kind) {
6772         case T_false:                        return parse_boolean_literal(false);
6773         case T_true:                         return parse_boolean_literal(true);
6774         case T_INTEGER:
6775         case T_INTEGER_OCTAL:
6776         case T_INTEGER_HEXADECIMAL:
6777         case T_FLOATINGPOINT:
6778         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6779         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6780         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6781         case T_STRING_LITERAL:
6782         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6783         case T___FUNCTION__:
6784         case T___func__:                     return parse_function_keyword();
6785         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6786         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6787         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6788         case T___builtin_offsetof:           return parse_offsetof();
6789         case T___builtin_va_start:           return parse_va_start();
6790         case T___builtin_va_arg:             return parse_va_arg();
6791         case T___builtin_va_copy:            return parse_va_copy();
6792         case T___builtin_isgreater:
6793         case T___builtin_isgreaterequal:
6794         case T___builtin_isless:
6795         case T___builtin_islessequal:
6796         case T___builtin_islessgreater:
6797         case T___builtin_isunordered:        return parse_compare_builtin();
6798         case T___builtin_constant_p:         return parse_builtin_constant();
6799         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6800         case T__assume:                      return parse_assume();
6801         case T_ANDAND:
6802                 if (GNU_MODE)
6803                         return parse_label_address();
6804                 break;
6805
6806         case '(':                            return parse_parenthesized_expression();
6807         case T___noop:                       return parse_noop_expression();
6808
6809         /* Gracefully handle type names while parsing expressions. */
6810         case T_COLONCOLON:
6811                 return parse_reference();
6812         case T_IDENTIFIER:
6813                 if (!is_typedef_symbol(token.identifier.symbol)) {
6814                         return parse_reference();
6815                 }
6816                 /* FALLTHROUGH */
6817         DECLARATION_START {
6818                 source_position_t const  pos = *HERE;
6819                 declaration_specifiers_t specifiers;
6820                 parse_declaration_specifiers(&specifiers);
6821                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6822                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6823                 return create_error_expression();
6824         }
6825         }
6826
6827         errorf(HERE, "unexpected token %K, expected an expression", &token);
6828         eat_until_anchor();
6829         return create_error_expression();
6830 }
6831
6832 static expression_t *parse_array_expression(expression_t *left)
6833 {
6834         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6835         array_access_expression_t *const arr  = &expr->array_access;
6836
6837         eat('[');
6838         add_anchor_token(']');
6839
6840         expression_t *const inside = parse_expression();
6841
6842         type_t *const orig_type_left   = left->base.type;
6843         type_t *const orig_type_inside = inside->base.type;
6844
6845         type_t *const type_left   = skip_typeref(orig_type_left);
6846         type_t *const type_inside = skip_typeref(orig_type_inside);
6847
6848         expression_t *ref;
6849         expression_t *idx;
6850         type_t       *idx_type;
6851         type_t       *res_type;
6852         if (is_type_pointer(type_left)) {
6853                 ref      = left;
6854                 idx      = inside;
6855                 idx_type = type_inside;
6856                 res_type = type_left->pointer.points_to;
6857                 goto check_idx;
6858         } else if (is_type_pointer(type_inside)) {
6859                 arr->flipped = true;
6860                 ref      = inside;
6861                 idx      = left;
6862                 idx_type = type_left;
6863                 res_type = type_inside->pointer.points_to;
6864 check_idx:
6865                 res_type = automatic_type_conversion(res_type);
6866                 if (!is_type_integer(idx_type)) {
6867                         errorf(&idx->base.source_position, "array subscript must have integer type");
6868                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6869                         source_position_t const *const pos = &idx->base.source_position;
6870                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6871                 }
6872         } else {
6873                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6874                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6875                 }
6876                 res_type = type_error_type;
6877                 ref      = left;
6878                 idx      = inside;
6879         }
6880
6881         arr->array_ref = ref;
6882         arr->index     = idx;
6883         arr->base.type = res_type;
6884
6885         rem_anchor_token(']');
6886         expect(']');
6887         return expr;
6888 }
6889
6890 static bool is_bitfield(const expression_t *expression)
6891 {
6892         return expression->kind == EXPR_SELECT
6893                 && expression->select.compound_entry->compound_member.bitfield;
6894 }
6895
6896 static expression_t *parse_typeprop(expression_kind_t const kind)
6897 {
6898         expression_t  *tp_expression = allocate_expression_zero(kind);
6899         tp_expression->base.type     = type_size_t;
6900
6901         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6902
6903         type_t       *orig_type;
6904         expression_t *expression;
6905         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6906                 source_position_t const pos = *HERE;
6907                 next_token();
6908                 add_anchor_token(')');
6909                 orig_type = parse_typename();
6910                 rem_anchor_token(')');
6911                 expect(')');
6912
6913                 if (token.kind == '{') {
6914                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6915                          * starting with a compound literal */
6916                         expression = parse_compound_literal(&pos, orig_type);
6917                         goto typeprop_expression;
6918                 }
6919         } else {
6920                 expression = parse_subexpression(PREC_UNARY);
6921
6922 typeprop_expression:
6923                 if (is_bitfield(expression)) {
6924                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6925                         errorf(&tp_expression->base.source_position,
6926                                    "operand of %s expression must not be a bitfield", what);
6927                 }
6928
6929                 tp_expression->typeprop.tp_expression = expression;
6930
6931                 orig_type = revert_automatic_type_conversion(expression);
6932                 expression->base.type = orig_type;
6933         }
6934
6935         tp_expression->typeprop.type   = orig_type;
6936         type_t const* const type       = skip_typeref(orig_type);
6937         char   const*       wrong_type = NULL;
6938         if (is_type_incomplete(type)) {
6939                 if (!is_type_void(type) || !GNU_MODE)
6940                         wrong_type = "incomplete";
6941         } else if (type->kind == TYPE_FUNCTION) {
6942                 if (GNU_MODE) {
6943                         /* function types are allowed (and return 1) */
6944                         source_position_t const *const pos  = &tp_expression->base.source_position;
6945                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6946                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6947                 } else {
6948                         wrong_type = "function";
6949                 }
6950         }
6951
6952         if (wrong_type != NULL) {
6953                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6954                 errorf(&tp_expression->base.source_position,
6955                                 "operand of %s expression must not be of %s type '%T'",
6956                                 what, wrong_type, orig_type);
6957         }
6958
6959         return tp_expression;
6960 }
6961
6962 static expression_t *parse_sizeof(void)
6963 {
6964         return parse_typeprop(EXPR_SIZEOF);
6965 }
6966
6967 static expression_t *parse_alignof(void)
6968 {
6969         return parse_typeprop(EXPR_ALIGNOF);
6970 }
6971
6972 static expression_t *parse_select_expression(expression_t *addr)
6973 {
6974         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6975         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6976         source_position_t const pos = *HERE;
6977         next_token();
6978
6979         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6980         if (!symbol)
6981                 return create_error_expression();
6982
6983         type_t *const orig_type = addr->base.type;
6984         type_t *const type      = skip_typeref(orig_type);
6985
6986         type_t *type_left;
6987         bool    saw_error = false;
6988         if (is_type_pointer(type)) {
6989                 if (!select_left_arrow) {
6990                         errorf(&pos,
6991                                "request for member '%Y' in something not a struct or union, but '%T'",
6992                                symbol, orig_type);
6993                         saw_error = true;
6994                 }
6995                 type_left = skip_typeref(type->pointer.points_to);
6996         } else {
6997                 if (select_left_arrow && is_type_valid(type)) {
6998                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6999                         saw_error = true;
7000                 }
7001                 type_left = type;
7002         }
7003
7004         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7005             type_left->kind != TYPE_COMPOUND_UNION) {
7006
7007                 if (is_type_valid(type_left) && !saw_error) {
7008                         errorf(&pos,
7009                                "request for member '%Y' in something not a struct or union, but '%T'",
7010                                symbol, type_left);
7011                 }
7012                 return create_error_expression();
7013         }
7014
7015         compound_t *compound = type_left->compound.compound;
7016         if (!compound->complete) {
7017                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7018                        symbol, type_left);
7019                 return create_error_expression();
7020         }
7021
7022         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7023         expression_t      *result     =
7024                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7025
7026         if (result == NULL) {
7027                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7028                 return create_error_expression();
7029         }
7030
7031         return result;
7032 }
7033
7034 static void check_call_argument(type_t          *expected_type,
7035                                 call_argument_t *argument, unsigned pos)
7036 {
7037         type_t         *expected_type_skip = skip_typeref(expected_type);
7038         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7039         expression_t   *arg_expr           = argument->expression;
7040         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7041
7042         /* handle transparent union gnu extension */
7043         if (is_type_union(expected_type_skip)
7044                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7045                 compound_t *union_decl  = expected_type_skip->compound.compound;
7046                 type_t     *best_type   = NULL;
7047                 entity_t   *entry       = union_decl->members.entities;
7048                 for ( ; entry != NULL; entry = entry->base.next) {
7049                         assert(is_declaration(entry));
7050                         type_t *decl_type = entry->declaration.type;
7051                         error = semantic_assign(decl_type, arg_expr);
7052                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7053                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7054                                 continue;
7055
7056                         if (error == ASSIGN_SUCCESS) {
7057                                 best_type = decl_type;
7058                         } else if (best_type == NULL) {
7059                                 best_type = decl_type;
7060                         }
7061                 }
7062
7063                 if (best_type != NULL) {
7064                         expected_type = best_type;
7065                 }
7066         }
7067
7068         error                = semantic_assign(expected_type, arg_expr);
7069         argument->expression = create_implicit_cast(arg_expr, expected_type);
7070
7071         if (error != ASSIGN_SUCCESS) {
7072                 /* report exact scope in error messages (like "in argument 3") */
7073                 char buf[64];
7074                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7075                 report_assign_error(error, expected_type, arg_expr, buf,
7076                                     &arg_expr->base.source_position);
7077         } else {
7078                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7079                 if (!types_compatible(expected_type_skip, promoted_type) &&
7080                     !types_compatible(expected_type_skip, type_void_ptr) &&
7081                     !types_compatible(type_void_ptr,      promoted_type)) {
7082                         /* Deliberately show the skipped types in this warning */
7083                         source_position_t const *const apos = &arg_expr->base.source_position;
7084                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7085                 }
7086         }
7087 }
7088
7089 /**
7090  * Handle the semantic restrictions of builtin calls
7091  */
7092 static void handle_builtin_argument_restrictions(call_expression_t *call)
7093 {
7094         entity_t *entity = call->function->reference.entity;
7095         switch (entity->function.btk) {
7096         case BUILTIN_FIRM:
7097                 switch (entity->function.b.firm_builtin_kind) {
7098                 case ir_bk_return_address:
7099                 case ir_bk_frame_address: {
7100                         /* argument must be constant */
7101                         call_argument_t *argument = call->arguments;
7102
7103                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7104                                 errorf(&call->base.source_position,
7105                                            "argument of '%Y' must be a constant expression",
7106                                            call->function->reference.entity->base.symbol);
7107                         }
7108                         break;
7109                 }
7110                 case ir_bk_prefetch:
7111                         /* second and third argument must be constant if existent */
7112                         if (call->arguments == NULL)
7113                                 break;
7114                         call_argument_t *rw = call->arguments->next;
7115                         call_argument_t *locality = NULL;
7116
7117                         if (rw != NULL) {
7118                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7119                                         errorf(&call->base.source_position,
7120                                                    "second argument of '%Y' must be a constant expression",
7121                                                    call->function->reference.entity->base.symbol);
7122                                 }
7123                                 locality = rw->next;
7124                         }
7125                         if (locality != NULL) {
7126                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7127                                         errorf(&call->base.source_position,
7128                                                    "third argument of '%Y' must be a constant expression",
7129                                                    call->function->reference.entity->base.symbol);
7130                                 }
7131                                 locality = rw->next;
7132                         }
7133                         break;
7134                 default:
7135                         break;
7136                 }
7137
7138         case BUILTIN_OBJECT_SIZE:
7139                 if (call->arguments == NULL)
7140                         break;
7141
7142                 call_argument_t *arg = call->arguments->next;
7143                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7144                         errorf(&call->base.source_position,
7145                                    "second argument of '%Y' must be a constant expression",
7146                                    call->function->reference.entity->base.symbol);
7147                 }
7148                 break;
7149         default:
7150                 break;
7151         }
7152 }
7153
7154 /**
7155  * Parse a call expression, ie. expression '( ... )'.
7156  *
7157  * @param expression  the function address
7158  */
7159 static expression_t *parse_call_expression(expression_t *expression)
7160 {
7161         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7162         call_expression_t *call   = &result->call;
7163         call->function            = expression;
7164
7165         type_t *const orig_type = expression->base.type;
7166         type_t *const type      = skip_typeref(orig_type);
7167
7168         function_type_t *function_type = NULL;
7169         if (is_type_pointer(type)) {
7170                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7171
7172                 if (is_type_function(to_type)) {
7173                         function_type   = &to_type->function;
7174                         call->base.type = function_type->return_type;
7175                 }
7176         }
7177
7178         if (function_type == NULL && is_type_valid(type)) {
7179                 errorf(HERE,
7180                        "called object '%E' (type '%T') is not a pointer to a function",
7181                        expression, orig_type);
7182         }
7183
7184         /* parse arguments */
7185         eat('(');
7186         add_anchor_token(')');
7187         add_anchor_token(',');
7188
7189         if (token.kind != ')') {
7190                 call_argument_t **anchor = &call->arguments;
7191                 do {
7192                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7193                         argument->expression = parse_assignment_expression();
7194
7195                         *anchor = argument;
7196                         anchor  = &argument->next;
7197                 } while (next_if(','));
7198         }
7199         rem_anchor_token(',');
7200         rem_anchor_token(')');
7201         expect(')');
7202
7203         if (function_type == NULL)
7204                 return result;
7205
7206         /* check type and count of call arguments */
7207         function_parameter_t *parameter = function_type->parameters;
7208         call_argument_t      *argument  = call->arguments;
7209         if (!function_type->unspecified_parameters) {
7210                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7211                                 parameter = parameter->next, argument = argument->next) {
7212                         check_call_argument(parameter->type, argument, ++pos);
7213                 }
7214
7215                 if (parameter != NULL) {
7216                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7217                 } else if (argument != NULL && !function_type->variadic) {
7218                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7219                 }
7220         }
7221
7222         /* do default promotion for other arguments */
7223         for (; argument != NULL; argument = argument->next) {
7224                 type_t *argument_type = argument->expression->base.type;
7225                 if (!is_type_object(skip_typeref(argument_type))) {
7226                         errorf(&argument->expression->base.source_position,
7227                                "call argument '%E' must not be void", argument->expression);
7228                 }
7229
7230                 argument_type = get_default_promoted_type(argument_type);
7231
7232                 argument->expression
7233                         = create_implicit_cast(argument->expression, argument_type);
7234         }
7235
7236         check_format(call);
7237
7238         if (is_type_compound(skip_typeref(function_type->return_type))) {
7239                 source_position_t const *const pos = &expression->base.source_position;
7240                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7241         }
7242
7243         if (expression->kind == EXPR_REFERENCE) {
7244                 reference_expression_t *reference = &expression->reference;
7245                 if (reference->entity->kind == ENTITY_FUNCTION &&
7246                     reference->entity->function.btk != BUILTIN_NONE)
7247                         handle_builtin_argument_restrictions(call);
7248         }
7249
7250         return result;
7251 }
7252
7253 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7254
7255 static bool same_compound_type(const type_t *type1, const type_t *type2)
7256 {
7257         return
7258                 is_type_compound(type1) &&
7259                 type1->kind == type2->kind &&
7260                 type1->compound.compound == type2->compound.compound;
7261 }
7262
7263 static expression_t const *get_reference_address(expression_t const *expr)
7264 {
7265         bool regular_take_address = true;
7266         for (;;) {
7267                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7268                         expr = expr->unary.value;
7269                 } else {
7270                         regular_take_address = false;
7271                 }
7272
7273                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7274                         break;
7275
7276                 expr = expr->unary.value;
7277         }
7278
7279         if (expr->kind != EXPR_REFERENCE)
7280                 return NULL;
7281
7282         /* special case for functions which are automatically converted to a
7283          * pointer to function without an extra TAKE_ADDRESS operation */
7284         if (!regular_take_address &&
7285                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7286                 return NULL;
7287         }
7288
7289         return expr;
7290 }
7291
7292 static void warn_reference_address_as_bool(expression_t const* expr)
7293 {
7294         expr = get_reference_address(expr);
7295         if (expr != NULL) {
7296                 source_position_t const *const pos = &expr->base.source_position;
7297                 entity_t          const *const ent = expr->reference.entity;
7298                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7299         }
7300 }
7301
7302 static void warn_assignment_in_condition(const expression_t *const expr)
7303 {
7304         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7305                 return;
7306         if (expr->base.parenthesized)
7307                 return;
7308         source_position_t const *const pos = &expr->base.source_position;
7309         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7310 }
7311
7312 static void semantic_condition(expression_t const *const expr,
7313                                char const *const context)
7314 {
7315         type_t *const type = skip_typeref(expr->base.type);
7316         if (is_type_scalar(type)) {
7317                 warn_reference_address_as_bool(expr);
7318                 warn_assignment_in_condition(expr);
7319         } else if (is_type_valid(type)) {
7320                 errorf(&expr->base.source_position,
7321                                 "%s must have scalar type", context);
7322         }
7323 }
7324
7325 /**
7326  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7327  *
7328  * @param expression  the conditional expression
7329  */
7330 static expression_t *parse_conditional_expression(expression_t *expression)
7331 {
7332         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7333
7334         conditional_expression_t *conditional = &result->conditional;
7335         conditional->condition                = expression;
7336
7337         eat('?');
7338         add_anchor_token(':');
7339
7340         /* §6.5.15:2  The first operand shall have scalar type. */
7341         semantic_condition(expression, "condition of conditional operator");
7342
7343         expression_t *true_expression = expression;
7344         bool          gnu_cond = false;
7345         if (GNU_MODE && token.kind == ':') {
7346                 gnu_cond = true;
7347         } else {
7348                 true_expression = parse_expression();
7349         }
7350         rem_anchor_token(':');
7351         expect(':');
7352         expression_t *false_expression =
7353                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7354
7355         type_t *const orig_true_type  = true_expression->base.type;
7356         type_t *const orig_false_type = false_expression->base.type;
7357         type_t *const true_type       = skip_typeref(orig_true_type);
7358         type_t *const false_type      = skip_typeref(orig_false_type);
7359
7360         /* 6.5.15.3 */
7361         source_position_t const *const pos = &conditional->base.source_position;
7362         type_t                        *result_type;
7363         if (is_type_void(true_type) || is_type_void(false_type)) {
7364                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7365                 if (true_expression->kind == EXPR_UNARY_THROW) {
7366                         result_type = false_type;
7367                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7368                         result_type = true_type;
7369                 } else {
7370                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7371                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7372                         }
7373                         result_type = type_void;
7374                 }
7375         } else if (is_type_arithmetic(true_type)
7376                    && is_type_arithmetic(false_type)) {
7377                 result_type = semantic_arithmetic(true_type, false_type);
7378         } else if (same_compound_type(true_type, false_type)) {
7379                 /* just take 1 of the 2 types */
7380                 result_type = true_type;
7381         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7382                 type_t *pointer_type;
7383                 type_t *other_type;
7384                 expression_t *other_expression;
7385                 if (is_type_pointer(true_type) &&
7386                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7387                         pointer_type     = true_type;
7388                         other_type       = false_type;
7389                         other_expression = false_expression;
7390                 } else {
7391                         pointer_type     = false_type;
7392                         other_type       = true_type;
7393                         other_expression = true_expression;
7394                 }
7395
7396                 if (is_null_pointer_constant(other_expression)) {
7397                         result_type = pointer_type;
7398                 } else if (is_type_pointer(other_type)) {
7399                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7400                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7401
7402                         type_t *to;
7403                         if (is_type_void(to1) || is_type_void(to2)) {
7404                                 to = type_void;
7405                         } else if (types_compatible(get_unqualified_type(to1),
7406                                                     get_unqualified_type(to2))) {
7407                                 to = to1;
7408                         } else {
7409                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7410                                 to = type_void;
7411                         }
7412
7413                         type_t *const type =
7414                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7415                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7416                 } else if (is_type_integer(other_type)) {
7417                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7418                         result_type = pointer_type;
7419                 } else {
7420                         goto types_incompatible;
7421                 }
7422         } else {
7423 types_incompatible:
7424                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7425                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7426                 }
7427                 result_type = type_error_type;
7428         }
7429
7430         conditional->true_expression
7431                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7432         conditional->false_expression
7433                 = create_implicit_cast(false_expression, result_type);
7434         conditional->base.type = result_type;
7435         return result;
7436 }
7437
7438 /**
7439  * Parse an extension expression.
7440  */
7441 static expression_t *parse_extension(void)
7442 {
7443         PUSH_EXTENSION();
7444         expression_t *expression = parse_subexpression(PREC_UNARY);
7445         POP_EXTENSION();
7446         return expression;
7447 }
7448
7449 /**
7450  * Parse a __builtin_classify_type() expression.
7451  */
7452 static expression_t *parse_builtin_classify_type(void)
7453 {
7454         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7455         result->base.type    = type_int;
7456
7457         eat(T___builtin_classify_type);
7458
7459         expect('(');
7460         add_anchor_token(')');
7461         expression_t *expression = parse_expression();
7462         rem_anchor_token(')');
7463         expect(')');
7464         result->classify_type.type_expression = expression;
7465
7466         return result;
7467 }
7468
7469 /**
7470  * Parse a delete expression
7471  * ISO/IEC 14882:1998(E) §5.3.5
7472  */
7473 static expression_t *parse_delete(void)
7474 {
7475         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7476         result->base.type          = type_void;
7477
7478         eat(T_delete);
7479
7480         if (next_if('[')) {
7481                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7482                 expect(']');
7483         }
7484
7485         expression_t *const value = parse_subexpression(PREC_CAST);
7486         result->unary.value = value;
7487
7488         type_t *const type = skip_typeref(value->base.type);
7489         if (!is_type_pointer(type)) {
7490                 if (is_type_valid(type)) {
7491                         errorf(&value->base.source_position,
7492                                         "operand of delete must have pointer type");
7493                 }
7494         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7495                 source_position_t const *const pos = &value->base.source_position;
7496                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7497         }
7498
7499         return result;
7500 }
7501
7502 /**
7503  * Parse a throw expression
7504  * ISO/IEC 14882:1998(E) §15:1
7505  */
7506 static expression_t *parse_throw(void)
7507 {
7508         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7509         result->base.type          = type_void;
7510
7511         eat(T_throw);
7512
7513         expression_t *value = NULL;
7514         switch (token.kind) {
7515                 EXPRESSION_START {
7516                         value = parse_assignment_expression();
7517                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7518                         type_t *const orig_type = value->base.type;
7519                         type_t *const type      = skip_typeref(orig_type);
7520                         if (is_type_incomplete(type)) {
7521                                 errorf(&value->base.source_position,
7522                                                 "cannot throw object of incomplete type '%T'", orig_type);
7523                         } else if (is_type_pointer(type)) {
7524                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7525                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7526                                         errorf(&value->base.source_position,
7527                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7528                                 }
7529                         }
7530                 }
7531
7532                 default:
7533                         break;
7534         }
7535         result->unary.value = value;
7536
7537         return result;
7538 }
7539
7540 static bool check_pointer_arithmetic(const source_position_t *source_position,
7541                                      type_t *pointer_type,
7542                                      type_t *orig_pointer_type)
7543 {
7544         type_t *points_to = pointer_type->pointer.points_to;
7545         points_to = skip_typeref(points_to);
7546
7547         if (is_type_incomplete(points_to)) {
7548                 if (!GNU_MODE || !is_type_void(points_to)) {
7549                         errorf(source_position,
7550                                "arithmetic with pointer to incomplete type '%T' not allowed",
7551                                orig_pointer_type);
7552                         return false;
7553                 } else {
7554                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7555                 }
7556         } else if (is_type_function(points_to)) {
7557                 if (!GNU_MODE) {
7558                         errorf(source_position,
7559                                "arithmetic with pointer to function type '%T' not allowed",
7560                                orig_pointer_type);
7561                         return false;
7562                 } else {
7563                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7564                 }
7565         }
7566         return true;
7567 }
7568
7569 static bool is_lvalue(const expression_t *expression)
7570 {
7571         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7572         switch (expression->kind) {
7573         case EXPR_ARRAY_ACCESS:
7574         case EXPR_COMPOUND_LITERAL:
7575         case EXPR_REFERENCE:
7576         case EXPR_SELECT:
7577         case EXPR_UNARY_DEREFERENCE:
7578                 return true;
7579
7580         default: {
7581                 type_t *type = skip_typeref(expression->base.type);
7582                 return
7583                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7584                         is_type_reference(type) ||
7585                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7586                          * error before, which maybe prevented properly recognizing it as
7587                          * lvalue. */
7588                         !is_type_valid(type);
7589         }
7590         }
7591 }
7592
7593 static void semantic_incdec(unary_expression_t *expression)
7594 {
7595         type_t *const orig_type = expression->value->base.type;
7596         type_t *const type      = skip_typeref(orig_type);
7597         if (is_type_pointer(type)) {
7598                 if (!check_pointer_arithmetic(&expression->base.source_position,
7599                                               type, orig_type)) {
7600                         return;
7601                 }
7602         } else if (!is_type_real(type) && is_type_valid(type)) {
7603                 /* TODO: improve error message */
7604                 errorf(&expression->base.source_position,
7605                        "operation needs an arithmetic or pointer type");
7606                 return;
7607         }
7608         if (!is_lvalue(expression->value)) {
7609                 /* TODO: improve error message */
7610                 errorf(&expression->base.source_position, "lvalue required as operand");
7611         }
7612         expression->base.type = orig_type;
7613 }
7614
7615 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7616 {
7617         type_t *const res_type = promote_integer(type);
7618         expr->base.type = res_type;
7619         expr->value     = create_implicit_cast(expr->value, res_type);
7620 }
7621
7622 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7623 {
7624         type_t *const orig_type = expression->value->base.type;
7625         type_t *const type      = skip_typeref(orig_type);
7626         if (!is_type_arithmetic(type)) {
7627                 if (is_type_valid(type)) {
7628                         /* TODO: improve error message */
7629                         errorf(&expression->base.source_position,
7630                                 "operation needs an arithmetic type");
7631                 }
7632                 return;
7633         } else if (is_type_integer(type)) {
7634                 promote_unary_int_expr(expression, type);
7635         } else {
7636                 expression->base.type = orig_type;
7637         }
7638 }
7639
7640 static void semantic_unexpr_plus(unary_expression_t *expression)
7641 {
7642         semantic_unexpr_arithmetic(expression);
7643         source_position_t const *const pos = &expression->base.source_position;
7644         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7645 }
7646
7647 static void semantic_not(unary_expression_t *expression)
7648 {
7649         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7650         semantic_condition(expression->value, "operand of !");
7651         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7652 }
7653
7654 static void semantic_unexpr_integer(unary_expression_t *expression)
7655 {
7656         type_t *const orig_type = expression->value->base.type;
7657         type_t *const type      = skip_typeref(orig_type);
7658         if (!is_type_integer(type)) {
7659                 if (is_type_valid(type)) {
7660                         errorf(&expression->base.source_position,
7661                                "operand of ~ must be of integer type");
7662                 }
7663                 return;
7664         }
7665
7666         promote_unary_int_expr(expression, type);
7667 }
7668
7669 static void semantic_dereference(unary_expression_t *expression)
7670 {
7671         type_t *const orig_type = expression->value->base.type;
7672         type_t *const type      = skip_typeref(orig_type);
7673         if (!is_type_pointer(type)) {
7674                 if (is_type_valid(type)) {
7675                         errorf(&expression->base.source_position,
7676                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7677                 }
7678                 return;
7679         }
7680
7681         type_t *result_type   = type->pointer.points_to;
7682         result_type           = automatic_type_conversion(result_type);
7683         expression->base.type = result_type;
7684 }
7685
7686 /**
7687  * Record that an address is taken (expression represents an lvalue).
7688  *
7689  * @param expression       the expression
7690  * @param may_be_register  if true, the expression might be an register
7691  */
7692 static void set_address_taken(expression_t *expression, bool may_be_register)
7693 {
7694         if (expression->kind != EXPR_REFERENCE)
7695                 return;
7696
7697         entity_t *const entity = expression->reference.entity;
7698
7699         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7700                 return;
7701
7702         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7703                         && !may_be_register) {
7704                 source_position_t const *const pos = &expression->base.source_position;
7705                 errorf(pos, "address of register '%N' requested", entity);
7706         }
7707
7708         if (entity->kind == ENTITY_VARIABLE) {
7709                 entity->variable.address_taken = true;
7710         } else {
7711                 assert(entity->kind == ENTITY_PARAMETER);
7712                 entity->parameter.address_taken = true;
7713         }
7714 }
7715
7716 /**
7717  * Check the semantic of the address taken expression.
7718  */
7719 static void semantic_take_addr(unary_expression_t *expression)
7720 {
7721         expression_t *value = expression->value;
7722         value->base.type    = revert_automatic_type_conversion(value);
7723
7724         type_t *orig_type = value->base.type;
7725         type_t *type      = skip_typeref(orig_type);
7726         if (!is_type_valid(type))
7727                 return;
7728
7729         /* §6.5.3.2 */
7730         if (!is_lvalue(value)) {
7731                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7732         }
7733         if (is_bitfield(value)) {
7734                 errorf(&expression->base.source_position,
7735                        "'&' not allowed on bitfield");
7736         }
7737
7738         set_address_taken(value, false);
7739
7740         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7741 }
7742
7743 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7744 static expression_t *parse_##unexpression_type(void)                         \
7745 {                                                                            \
7746         expression_t *unary_expression                                           \
7747                 = allocate_expression_zero(unexpression_type);                       \
7748         eat(token_kind);                                                         \
7749         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7750                                                                                  \
7751         sfunc(&unary_expression->unary);                                         \
7752                                                                                  \
7753         return unary_expression;                                                 \
7754 }
7755
7756 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7757                                semantic_unexpr_arithmetic)
7758 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7759                                semantic_unexpr_plus)
7760 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7761                                semantic_not)
7762 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7763                                semantic_dereference)
7764 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7765                                semantic_take_addr)
7766 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7767                                semantic_unexpr_integer)
7768 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7769                                semantic_incdec)
7770 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7771                                semantic_incdec)
7772
7773 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7774                                                sfunc)                         \
7775 static expression_t *parse_##unexpression_type(expression_t *left)            \
7776 {                                                                             \
7777         expression_t *unary_expression                                            \
7778                 = allocate_expression_zero(unexpression_type);                        \
7779         eat(token_kind);                                                          \
7780         unary_expression->unary.value = left;                                     \
7781                                                                                   \
7782         sfunc(&unary_expression->unary);                                          \
7783                                                                               \
7784         return unary_expression;                                                  \
7785 }
7786
7787 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7788                                        EXPR_UNARY_POSTFIX_INCREMENT,
7789                                        semantic_incdec)
7790 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7791                                        EXPR_UNARY_POSTFIX_DECREMENT,
7792                                        semantic_incdec)
7793
7794 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7795 {
7796         /* TODO: handle complex + imaginary types */
7797
7798         type_left  = get_unqualified_type(type_left);
7799         type_right = get_unqualified_type(type_right);
7800
7801         /* §6.3.1.8 Usual arithmetic conversions */
7802         if (type_left == type_long_double || type_right == type_long_double) {
7803                 return type_long_double;
7804         } else if (type_left == type_double || type_right == type_double) {
7805                 return type_double;
7806         } else if (type_left == type_float || type_right == type_float) {
7807                 return type_float;
7808         }
7809
7810         type_left  = promote_integer(type_left);
7811         type_right = promote_integer(type_right);
7812
7813         if (type_left == type_right)
7814                 return type_left;
7815
7816         bool     const signed_left  = is_type_signed(type_left);
7817         bool     const signed_right = is_type_signed(type_right);
7818         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7819         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7820
7821         if (signed_left == signed_right)
7822                 return rank_left >= rank_right ? type_left : type_right;
7823
7824         unsigned           s_rank;
7825         unsigned           u_rank;
7826         atomic_type_kind_t s_akind;
7827         atomic_type_kind_t u_akind;
7828         type_t *s_type;
7829         type_t *u_type;
7830         if (signed_left) {
7831                 s_type = type_left;
7832                 u_type = type_right;
7833         } else {
7834                 s_type = type_right;
7835                 u_type = type_left;
7836         }
7837         s_akind = get_akind(s_type);
7838         u_akind = get_akind(u_type);
7839         s_rank  = get_akind_rank(s_akind);
7840         u_rank  = get_akind_rank(u_akind);
7841
7842         if (u_rank >= s_rank)
7843                 return u_type;
7844
7845         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7846                 return s_type;
7847
7848         switch (s_akind) {
7849         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7850         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7851         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7852
7853         default: panic("invalid atomic type");
7854         }
7855 }
7856
7857 /**
7858  * Check the semantic restrictions for a binary expression.
7859  */
7860 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7861 {
7862         expression_t *const left            = expression->left;
7863         expression_t *const right           = expression->right;
7864         type_t       *const orig_type_left  = left->base.type;
7865         type_t       *const orig_type_right = right->base.type;
7866         type_t       *const type_left       = skip_typeref(orig_type_left);
7867         type_t       *const type_right      = skip_typeref(orig_type_right);
7868
7869         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7870                 /* TODO: improve error message */
7871                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7872                         errorf(&expression->base.source_position,
7873                                "operation needs arithmetic types");
7874                 }
7875                 return;
7876         }
7877
7878         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7879         expression->left      = create_implicit_cast(left, arithmetic_type);
7880         expression->right     = create_implicit_cast(right, arithmetic_type);
7881         expression->base.type = arithmetic_type;
7882 }
7883
7884 static void semantic_binexpr_integer(binary_expression_t *const expression)
7885 {
7886         expression_t *const left            = expression->left;
7887         expression_t *const right           = expression->right;
7888         type_t       *const orig_type_left  = left->base.type;
7889         type_t       *const orig_type_right = right->base.type;
7890         type_t       *const type_left       = skip_typeref(orig_type_left);
7891         type_t       *const type_right      = skip_typeref(orig_type_right);
7892
7893         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7894                 /* TODO: improve error message */
7895                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7896                         errorf(&expression->base.source_position,
7897                                "operation needs integer types");
7898                 }
7899                 return;
7900         }
7901
7902         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7903         expression->left      = create_implicit_cast(left, result_type);
7904         expression->right     = create_implicit_cast(right, result_type);
7905         expression->base.type = result_type;
7906 }
7907
7908 static void warn_div_by_zero(binary_expression_t const *const expression)
7909 {
7910         if (!is_type_integer(expression->base.type))
7911                 return;
7912
7913         expression_t const *const right = expression->right;
7914         /* The type of the right operand can be different for /= */
7915         if (is_type_integer(right->base.type)                    &&
7916             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7917             !fold_constant_to_bool(right)) {
7918                 source_position_t const *const pos = &expression->base.source_position;
7919                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7920         }
7921 }
7922
7923 /**
7924  * Check the semantic restrictions for a div/mod expression.
7925  */
7926 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7927 {
7928         semantic_binexpr_arithmetic(expression);
7929         warn_div_by_zero(expression);
7930 }
7931
7932 static void warn_addsub_in_shift(const expression_t *const expr)
7933 {
7934         if (expr->base.parenthesized)
7935                 return;
7936
7937         char op;
7938         switch (expr->kind) {
7939                 case EXPR_BINARY_ADD: op = '+'; break;
7940                 case EXPR_BINARY_SUB: op = '-'; break;
7941                 default:              return;
7942         }
7943
7944         source_position_t const *const pos = &expr->base.source_position;
7945         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7946 }
7947
7948 static bool semantic_shift(binary_expression_t *expression)
7949 {
7950         expression_t *const left            = expression->left;
7951         expression_t *const right           = expression->right;
7952         type_t       *const orig_type_left  = left->base.type;
7953         type_t       *const orig_type_right = right->base.type;
7954         type_t       *      type_left       = skip_typeref(orig_type_left);
7955         type_t       *      type_right      = skip_typeref(orig_type_right);
7956
7957         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7958                 /* TODO: improve error message */
7959                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7960                         errorf(&expression->base.source_position,
7961                                "operands of shift operation must have integer types");
7962                 }
7963                 return false;
7964         }
7965
7966         type_left = promote_integer(type_left);
7967
7968         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7969                 source_position_t const *const pos   = &right->base.source_position;
7970                 long                     const count = fold_constant_to_int(right);
7971                 if (count < 0) {
7972                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7973                 } else if ((unsigned long)count >=
7974                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7975                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7976                 }
7977         }
7978
7979         type_right        = promote_integer(type_right);
7980         expression->right = create_implicit_cast(right, type_right);
7981
7982         return true;
7983 }
7984
7985 static void semantic_shift_op(binary_expression_t *expression)
7986 {
7987         expression_t *const left  = expression->left;
7988         expression_t *const right = expression->right;
7989
7990         if (!semantic_shift(expression))
7991                 return;
7992
7993         warn_addsub_in_shift(left);
7994         warn_addsub_in_shift(right);
7995
7996         type_t *const orig_type_left = left->base.type;
7997         type_t *      type_left      = skip_typeref(orig_type_left);
7998
7999         type_left             = promote_integer(type_left);
8000         expression->left      = create_implicit_cast(left, type_left);
8001         expression->base.type = type_left;
8002 }
8003
8004 static void semantic_add(binary_expression_t *expression)
8005 {
8006         expression_t *const left            = expression->left;
8007         expression_t *const right           = expression->right;
8008         type_t       *const orig_type_left  = left->base.type;
8009         type_t       *const orig_type_right = right->base.type;
8010         type_t       *const type_left       = skip_typeref(orig_type_left);
8011         type_t       *const type_right      = skip_typeref(orig_type_right);
8012
8013         /* §6.5.6 */
8014         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8015                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8016                 expression->left  = create_implicit_cast(left, arithmetic_type);
8017                 expression->right = create_implicit_cast(right, arithmetic_type);
8018                 expression->base.type = arithmetic_type;
8019         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8020                 check_pointer_arithmetic(&expression->base.source_position,
8021                                          type_left, orig_type_left);
8022                 expression->base.type = type_left;
8023         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8024                 check_pointer_arithmetic(&expression->base.source_position,
8025                                          type_right, orig_type_right);
8026                 expression->base.type = type_right;
8027         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8028                 errorf(&expression->base.source_position,
8029                        "invalid operands to binary + ('%T', '%T')",
8030                        orig_type_left, orig_type_right);
8031         }
8032 }
8033
8034 static void semantic_sub(binary_expression_t *expression)
8035 {
8036         expression_t            *const left            = expression->left;
8037         expression_t            *const right           = expression->right;
8038         type_t                  *const orig_type_left  = left->base.type;
8039         type_t                  *const orig_type_right = right->base.type;
8040         type_t                  *const type_left       = skip_typeref(orig_type_left);
8041         type_t                  *const type_right      = skip_typeref(orig_type_right);
8042         source_position_t const *const pos             = &expression->base.source_position;
8043
8044         /* §5.6.5 */
8045         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8046                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8047                 expression->left        = create_implicit_cast(left, arithmetic_type);
8048                 expression->right       = create_implicit_cast(right, arithmetic_type);
8049                 expression->base.type =  arithmetic_type;
8050         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8051                 check_pointer_arithmetic(&expression->base.source_position,
8052                                          type_left, orig_type_left);
8053                 expression->base.type = type_left;
8054         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8055                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8056                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8057                 if (!types_compatible(unqual_left, unqual_right)) {
8058                         errorf(pos,
8059                                "subtracting pointers to incompatible types '%T' and '%T'",
8060                                orig_type_left, orig_type_right);
8061                 } else if (!is_type_object(unqual_left)) {
8062                         if (!is_type_void(unqual_left)) {
8063                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8064                                        orig_type_left);
8065                         } else {
8066                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8067                         }
8068                 }
8069                 expression->base.type = type_ptrdiff_t;
8070         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8071                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8072                        orig_type_left, orig_type_right);
8073         }
8074 }
8075
8076 static void warn_string_literal_address(expression_t const* expr)
8077 {
8078         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8079                 expr = expr->unary.value;
8080                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8081                         return;
8082                 expr = expr->unary.value;
8083         }
8084
8085         if (expr->kind == EXPR_STRING_LITERAL
8086                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8087                 source_position_t const *const pos = &expr->base.source_position;
8088                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8089         }
8090 }
8091
8092 static bool maybe_negative(expression_t const *const expr)
8093 {
8094         switch (is_constant_expression(expr)) {
8095                 case EXPR_CLASS_ERROR:    return false;
8096                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8097                 default:                  return true;
8098         }
8099 }
8100
8101 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8102 {
8103         warn_string_literal_address(expr);
8104
8105         expression_t const* const ref = get_reference_address(expr);
8106         if (ref != NULL && is_null_pointer_constant(other)) {
8107                 entity_t const *const ent = ref->reference.entity;
8108                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8109         }
8110
8111         if (!expr->base.parenthesized) {
8112                 switch (expr->base.kind) {
8113                         case EXPR_BINARY_LESS:
8114                         case EXPR_BINARY_GREATER:
8115                         case EXPR_BINARY_LESSEQUAL:
8116                         case EXPR_BINARY_GREATEREQUAL:
8117                         case EXPR_BINARY_NOTEQUAL:
8118                         case EXPR_BINARY_EQUAL:
8119                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8120                                 break;
8121                         default:
8122                                 break;
8123                 }
8124         }
8125 }
8126
8127 /**
8128  * Check the semantics of comparison expressions.
8129  *
8130  * @param expression   The expression to check.
8131  */
8132 static void semantic_comparison(binary_expression_t *expression)
8133 {
8134         source_position_t const *const pos   = &expression->base.source_position;
8135         expression_t            *const left  = expression->left;
8136         expression_t            *const right = expression->right;
8137
8138         warn_comparison(pos, left, right);
8139         warn_comparison(pos, right, left);
8140
8141         type_t *orig_type_left  = left->base.type;
8142         type_t *orig_type_right = right->base.type;
8143         type_t *type_left       = skip_typeref(orig_type_left);
8144         type_t *type_right      = skip_typeref(orig_type_right);
8145
8146         /* TODO non-arithmetic types */
8147         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8148                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8149
8150                 /* test for signed vs unsigned compares */
8151                 if (is_type_integer(arithmetic_type)) {
8152                         bool const signed_left  = is_type_signed(type_left);
8153                         bool const signed_right = is_type_signed(type_right);
8154                         if (signed_left != signed_right) {
8155                                 /* FIXME long long needs better const folding magic */
8156                                 /* TODO check whether constant value can be represented by other type */
8157                                 if ((signed_left  && maybe_negative(left)) ||
8158                                                 (signed_right && maybe_negative(right))) {
8159                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8160                                 }
8161                         }
8162                 }
8163
8164                 expression->left        = create_implicit_cast(left, arithmetic_type);
8165                 expression->right       = create_implicit_cast(right, arithmetic_type);
8166                 expression->base.type   = arithmetic_type;
8167                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8168                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8169                     is_type_float(arithmetic_type)) {
8170                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8171                 }
8172         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8173                 /* TODO check compatibility */
8174         } else if (is_type_pointer(type_left)) {
8175                 expression->right = create_implicit_cast(right, type_left);
8176         } else if (is_type_pointer(type_right)) {
8177                 expression->left = create_implicit_cast(left, type_right);
8178         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8179                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8180         }
8181         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8182 }
8183
8184 /**
8185  * Checks if a compound type has constant fields.
8186  */
8187 static bool has_const_fields(const compound_type_t *type)
8188 {
8189         compound_t *compound = type->compound;
8190         entity_t   *entry    = compound->members.entities;
8191
8192         for (; entry != NULL; entry = entry->base.next) {
8193                 if (!is_declaration(entry))
8194                         continue;
8195
8196                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8197                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8198                         return true;
8199         }
8200
8201         return false;
8202 }
8203
8204 static bool is_valid_assignment_lhs(expression_t const* const left)
8205 {
8206         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8207         type_t *const type_left      = skip_typeref(orig_type_left);
8208
8209         if (!is_lvalue(left)) {
8210                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8211                        left);
8212                 return false;
8213         }
8214
8215         if (left->kind == EXPR_REFERENCE
8216                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8217                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8218                 return false;
8219         }
8220
8221         if (is_type_array(type_left)) {
8222                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8223                 return false;
8224         }
8225         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8226                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8227                        orig_type_left);
8228                 return false;
8229         }
8230         if (is_type_incomplete(type_left)) {
8231                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8232                        left, orig_type_left);
8233                 return false;
8234         }
8235         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8236                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8237                        left, orig_type_left);
8238                 return false;
8239         }
8240
8241         return true;
8242 }
8243
8244 static void semantic_arithmetic_assign(binary_expression_t *expression)
8245 {
8246         expression_t *left            = expression->left;
8247         expression_t *right           = expression->right;
8248         type_t       *orig_type_left  = left->base.type;
8249         type_t       *orig_type_right = right->base.type;
8250
8251         if (!is_valid_assignment_lhs(left))
8252                 return;
8253
8254         type_t *type_left  = skip_typeref(orig_type_left);
8255         type_t *type_right = skip_typeref(orig_type_right);
8256
8257         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8258                 /* TODO: improve error message */
8259                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8260                         errorf(&expression->base.source_position,
8261                                "operation needs arithmetic types");
8262                 }
8263                 return;
8264         }
8265
8266         /* combined instructions are tricky. We can't create an implicit cast on
8267          * the left side, because we need the uncasted form for the store.
8268          * The ast2firm pass has to know that left_type must be right_type
8269          * for the arithmetic operation and create a cast by itself */
8270         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8271         expression->right       = create_implicit_cast(right, arithmetic_type);
8272         expression->base.type   = type_left;
8273 }
8274
8275 static void semantic_divmod_assign(binary_expression_t *expression)
8276 {
8277         semantic_arithmetic_assign(expression);
8278         warn_div_by_zero(expression);
8279 }
8280
8281 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8282 {
8283         expression_t *const left            = expression->left;
8284         expression_t *const right           = expression->right;
8285         type_t       *const orig_type_left  = left->base.type;
8286         type_t       *const orig_type_right = right->base.type;
8287         type_t       *const type_left       = skip_typeref(orig_type_left);
8288         type_t       *const type_right      = skip_typeref(orig_type_right);
8289
8290         if (!is_valid_assignment_lhs(left))
8291                 return;
8292
8293         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8294                 /* combined instructions are tricky. We can't create an implicit cast on
8295                  * the left side, because we need the uncasted form for the store.
8296                  * The ast2firm pass has to know that left_type must be right_type
8297                  * for the arithmetic operation and create a cast by itself */
8298                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8299                 expression->right     = create_implicit_cast(right, arithmetic_type);
8300                 expression->base.type = type_left;
8301         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8302                 check_pointer_arithmetic(&expression->base.source_position,
8303                                          type_left, orig_type_left);
8304                 expression->base.type = type_left;
8305         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8306                 errorf(&expression->base.source_position,
8307                        "incompatible types '%T' and '%T' in assignment",
8308                        orig_type_left, orig_type_right);
8309         }
8310 }
8311
8312 static void semantic_integer_assign(binary_expression_t *expression)
8313 {
8314         expression_t *left            = expression->left;
8315         expression_t *right           = expression->right;
8316         type_t       *orig_type_left  = left->base.type;
8317         type_t       *orig_type_right = right->base.type;
8318
8319         if (!is_valid_assignment_lhs(left))
8320                 return;
8321
8322         type_t *type_left  = skip_typeref(orig_type_left);
8323         type_t *type_right = skip_typeref(orig_type_right);
8324
8325         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8326                 /* TODO: improve error message */
8327                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8328                         errorf(&expression->base.source_position,
8329                                "operation needs integer types");
8330                 }
8331                 return;
8332         }
8333
8334         /* combined instructions are tricky. We can't create an implicit cast on
8335          * the left side, because we need the uncasted form for the store.
8336          * The ast2firm pass has to know that left_type must be right_type
8337          * for the arithmetic operation and create a cast by itself */
8338         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8339         expression->right       = create_implicit_cast(right, arithmetic_type);
8340         expression->base.type   = type_left;
8341 }
8342
8343 static void semantic_shift_assign(binary_expression_t *expression)
8344 {
8345         expression_t *left           = expression->left;
8346
8347         if (!is_valid_assignment_lhs(left))
8348                 return;
8349
8350         if (!semantic_shift(expression))
8351                 return;
8352
8353         expression->base.type = skip_typeref(left->base.type);
8354 }
8355
8356 static void warn_logical_and_within_or(const expression_t *const expr)
8357 {
8358         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8359                 return;
8360         if (expr->base.parenthesized)
8361                 return;
8362         source_position_t const *const pos = &expr->base.source_position;
8363         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8364 }
8365
8366 /**
8367  * Check the semantic restrictions of a logical expression.
8368  */
8369 static void semantic_logical_op(binary_expression_t *expression)
8370 {
8371         /* §6.5.13:2  Each of the operands shall have scalar type.
8372          * §6.5.14:2  Each of the operands shall have scalar type. */
8373         semantic_condition(expression->left,   "left operand of logical operator");
8374         semantic_condition(expression->right, "right operand of logical operator");
8375         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8376                 warn_logical_and_within_or(expression->left);
8377                 warn_logical_and_within_or(expression->right);
8378         }
8379         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8380 }
8381
8382 /**
8383  * Check the semantic restrictions of a binary assign expression.
8384  */
8385 static void semantic_binexpr_assign(binary_expression_t *expression)
8386 {
8387         expression_t *left           = expression->left;
8388         type_t       *orig_type_left = left->base.type;
8389
8390         if (!is_valid_assignment_lhs(left))
8391                 return;
8392
8393         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8394         report_assign_error(error, orig_type_left, expression->right,
8395                         "assignment", &left->base.source_position);
8396         expression->right = create_implicit_cast(expression->right, orig_type_left);
8397         expression->base.type = orig_type_left;
8398 }
8399
8400 /**
8401  * Determine if the outermost operation (or parts thereof) of the given
8402  * expression has no effect in order to generate a warning about this fact.
8403  * Therefore in some cases this only examines some of the operands of the
8404  * expression (see comments in the function and examples below).
8405  * Examples:
8406  *   f() + 23;    // warning, because + has no effect
8407  *   x || f();    // no warning, because x controls execution of f()
8408  *   x ? y : f(); // warning, because y has no effect
8409  *   (void)x;     // no warning to be able to suppress the warning
8410  * This function can NOT be used for an "expression has definitely no effect"-
8411  * analysis. */
8412 static bool expression_has_effect(const expression_t *const expr)
8413 {
8414         switch (expr->kind) {
8415                 case EXPR_ERROR:                      return true; /* do NOT warn */
8416                 case EXPR_REFERENCE:                  return false;
8417                 case EXPR_ENUM_CONSTANT:              return false;
8418                 case EXPR_LABEL_ADDRESS:              return false;
8419
8420                 /* suppress the warning for microsoft __noop operations */
8421                 case EXPR_LITERAL_MS_NOOP:            return true;
8422                 case EXPR_LITERAL_BOOLEAN:
8423                 case EXPR_LITERAL_CHARACTER:
8424                 case EXPR_LITERAL_WIDE_CHARACTER:
8425                 case EXPR_LITERAL_INTEGER:
8426                 case EXPR_LITERAL_INTEGER_OCTAL:
8427                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8428                 case EXPR_LITERAL_FLOATINGPOINT:
8429                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8430                 case EXPR_STRING_LITERAL:             return false;
8431                 case EXPR_WIDE_STRING_LITERAL:        return false;
8432
8433                 case EXPR_CALL: {
8434                         const call_expression_t *const call = &expr->call;
8435                         if (call->function->kind != EXPR_REFERENCE)
8436                                 return true;
8437
8438                         switch (call->function->reference.entity->function.btk) {
8439                                 /* FIXME: which builtins have no effect? */
8440                                 default:                      return true;
8441                         }
8442                 }
8443
8444                 /* Generate the warning if either the left or right hand side of a
8445                  * conditional expression has no effect */
8446                 case EXPR_CONDITIONAL: {
8447                         conditional_expression_t const *const cond = &expr->conditional;
8448                         expression_t             const *const t    = cond->true_expression;
8449                         return
8450                                 (t == NULL || expression_has_effect(t)) &&
8451                                 expression_has_effect(cond->false_expression);
8452                 }
8453
8454                 case EXPR_SELECT:                     return false;
8455                 case EXPR_ARRAY_ACCESS:               return false;
8456                 case EXPR_SIZEOF:                     return false;
8457                 case EXPR_CLASSIFY_TYPE:              return false;
8458                 case EXPR_ALIGNOF:                    return false;
8459
8460                 case EXPR_FUNCNAME:                   return false;
8461                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8462                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8463                 case EXPR_OFFSETOF:                   return false;
8464                 case EXPR_VA_START:                   return true;
8465                 case EXPR_VA_ARG:                     return true;
8466                 case EXPR_VA_COPY:                    return true;
8467                 case EXPR_STATEMENT:                  return true; // TODO
8468                 case EXPR_COMPOUND_LITERAL:           return false;
8469
8470                 case EXPR_UNARY_NEGATE:               return false;
8471                 case EXPR_UNARY_PLUS:                 return false;
8472                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8473                 case EXPR_UNARY_NOT:                  return false;
8474                 case EXPR_UNARY_DEREFERENCE:          return false;
8475                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8476                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8477                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8478                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8479                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8480
8481                 /* Treat void casts as if they have an effect in order to being able to
8482                  * suppress the warning */
8483                 case EXPR_UNARY_CAST: {
8484                         type_t *const type = skip_typeref(expr->base.type);
8485                         return is_type_void(type);
8486                 }
8487
8488                 case EXPR_UNARY_ASSUME:               return true;
8489                 case EXPR_UNARY_DELETE:               return true;
8490                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8491                 case EXPR_UNARY_THROW:                return true;
8492
8493                 case EXPR_BINARY_ADD:                 return false;
8494                 case EXPR_BINARY_SUB:                 return false;
8495                 case EXPR_BINARY_MUL:                 return false;
8496                 case EXPR_BINARY_DIV:                 return false;
8497                 case EXPR_BINARY_MOD:                 return false;
8498                 case EXPR_BINARY_EQUAL:               return false;
8499                 case EXPR_BINARY_NOTEQUAL:            return false;
8500                 case EXPR_BINARY_LESS:                return false;
8501                 case EXPR_BINARY_LESSEQUAL:           return false;
8502                 case EXPR_BINARY_GREATER:             return false;
8503                 case EXPR_BINARY_GREATEREQUAL:        return false;
8504                 case EXPR_BINARY_BITWISE_AND:         return false;
8505                 case EXPR_BINARY_BITWISE_OR:          return false;
8506                 case EXPR_BINARY_BITWISE_XOR:         return false;
8507                 case EXPR_BINARY_SHIFTLEFT:           return false;
8508                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8509                 case EXPR_BINARY_ASSIGN:              return true;
8510                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8511                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8512                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8513                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8514                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8515                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8516                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8517                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8518                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8519                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8520
8521                 /* Only examine the right hand side of && and ||, because the left hand
8522                  * side already has the effect of controlling the execution of the right
8523                  * hand side */
8524                 case EXPR_BINARY_LOGICAL_AND:
8525                 case EXPR_BINARY_LOGICAL_OR:
8526                 /* Only examine the right hand side of a comma expression, because the left
8527                  * hand side has a separate warning */
8528                 case EXPR_BINARY_COMMA:
8529                         return expression_has_effect(expr->binary.right);
8530
8531                 case EXPR_BINARY_ISGREATER:           return false;
8532                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8533                 case EXPR_BINARY_ISLESS:              return false;
8534                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8535                 case EXPR_BINARY_ISLESSGREATER:       return false;
8536                 case EXPR_BINARY_ISUNORDERED:         return false;
8537         }
8538
8539         internal_errorf(HERE, "unexpected expression");
8540 }
8541
8542 static void semantic_comma(binary_expression_t *expression)
8543 {
8544         const expression_t *const left = expression->left;
8545         if (!expression_has_effect(left)) {
8546                 source_position_t const *const pos = &left->base.source_position;
8547                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8548         }
8549         expression->base.type = expression->right->base.type;
8550 }
8551
8552 /**
8553  * @param prec_r precedence of the right operand
8554  */
8555 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8556 static expression_t *parse_##binexpression_type(expression_t *left)          \
8557 {                                                                            \
8558         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8559         binexpr->binary.left  = left;                                            \
8560         eat(token_kind);                                                         \
8561                                                                              \
8562         expression_t *right = parse_subexpression(prec_r);                       \
8563                                                                              \
8564         binexpr->binary.right = right;                                           \
8565         sfunc(&binexpr->binary);                                                 \
8566                                                                              \
8567         return binexpr;                                                          \
8568 }
8569
8570 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8571 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8572 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8573 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8574 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8575 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8576 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8577 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8578 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8579 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8580 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8581 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8582 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8583 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8584 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8585 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8586 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8587 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8588 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8589 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8590 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8591 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8592 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8593 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8594 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8595 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8596 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8597 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8598 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8599 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8600
8601
8602 static expression_t *parse_subexpression(precedence_t precedence)
8603 {
8604         expression_parser_function_t *parser
8605                 = &expression_parsers[token.kind];
8606         expression_t                 *left;
8607
8608         if (parser->parser != NULL) {
8609                 left = parser->parser();
8610         } else {
8611                 left = parse_primary_expression();
8612         }
8613         assert(left != NULL);
8614
8615         while (true) {
8616                 parser = &expression_parsers[token.kind];
8617                 if (parser->infix_parser == NULL)
8618                         break;
8619                 if (parser->infix_precedence < precedence)
8620                         break;
8621
8622                 left = parser->infix_parser(left);
8623
8624                 assert(left != NULL);
8625         }
8626
8627         return left;
8628 }
8629
8630 /**
8631  * Parse an expression.
8632  */
8633 static expression_t *parse_expression(void)
8634 {
8635         return parse_subexpression(PREC_EXPRESSION);
8636 }
8637
8638 /**
8639  * Register a parser for a prefix-like operator.
8640  *
8641  * @param parser      the parser function
8642  * @param token_kind  the token type of the prefix token
8643  */
8644 static void register_expression_parser(parse_expression_function parser,
8645                                        int token_kind)
8646 {
8647         expression_parser_function_t *entry = &expression_parsers[token_kind];
8648
8649         if (entry->parser != NULL) {
8650                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8651                 panic("trying to register multiple expression parsers for a token");
8652         }
8653         entry->parser = parser;
8654 }
8655
8656 /**
8657  * Register a parser for an infix operator with given precedence.
8658  *
8659  * @param parser      the parser function
8660  * @param token_kind  the token type of the infix operator
8661  * @param precedence  the precedence of the operator
8662  */
8663 static void register_infix_parser(parse_expression_infix_function parser,
8664                                   int token_kind, precedence_t precedence)
8665 {
8666         expression_parser_function_t *entry = &expression_parsers[token_kind];
8667
8668         if (entry->infix_parser != NULL) {
8669                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8670                 panic("trying to register multiple infix expression parsers for a "
8671                       "token");
8672         }
8673         entry->infix_parser     = parser;
8674         entry->infix_precedence = precedence;
8675 }
8676
8677 /**
8678  * Initialize the expression parsers.
8679  */
8680 static void init_expression_parsers(void)
8681 {
8682         memset(&expression_parsers, 0, sizeof(expression_parsers));
8683
8684         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8685         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8686         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8687         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8688         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8689         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8690         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8691         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8692         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8693         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8694         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8695         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8696         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8697         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8698         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8699         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8700         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8701         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8702         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8703         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8704         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8705         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8706         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8707         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8708         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8709         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8710         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8711         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8712         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8713         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8714         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8715         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8716         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8717         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8718         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8719         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8720         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8721
8722         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8723         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8724         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8725         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8726         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8727         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8728         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8729         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8730         register_expression_parser(parse_sizeof,                      T_sizeof);
8731         register_expression_parser(parse_alignof,                     T___alignof__);
8732         register_expression_parser(parse_extension,                   T___extension__);
8733         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8734         register_expression_parser(parse_delete,                      T_delete);
8735         register_expression_parser(parse_throw,                       T_throw);
8736 }
8737
8738 /**
8739  * Parse a asm statement arguments specification.
8740  */
8741 static asm_argument_t *parse_asm_arguments(bool is_out)
8742 {
8743         asm_argument_t  *result = NULL;
8744         asm_argument_t **anchor = &result;
8745
8746         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8747                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8748
8749                 if (next_if('[')) {
8750                         add_anchor_token(']');
8751                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8752                         rem_anchor_token(']');
8753                         expect(']');
8754                         if (!argument->symbol)
8755                                 return NULL;
8756                 }
8757
8758                 argument->constraints = parse_string_literals();
8759                 expect('(');
8760                 add_anchor_token(')');
8761                 expression_t *expression = parse_expression();
8762                 rem_anchor_token(')');
8763                 if (is_out) {
8764                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8765                          * change size or type representation (e.g. int -> long is ok, but
8766                          * int -> float is not) */
8767                         if (expression->kind == EXPR_UNARY_CAST) {
8768                                 type_t      *const type = expression->base.type;
8769                                 type_kind_t  const kind = type->kind;
8770                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8771                                         unsigned flags;
8772                                         unsigned size;
8773                                         if (kind == TYPE_ATOMIC) {
8774                                                 atomic_type_kind_t const akind = type->atomic.akind;
8775                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8776                                                 size  = get_atomic_type_size(akind);
8777                                         } else {
8778                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8779                                                 size  = get_type_size(type_void_ptr);
8780                                         }
8781
8782                                         do {
8783                                                 expression_t *const value      = expression->unary.value;
8784                                                 type_t       *const value_type = value->base.type;
8785                                                 type_kind_t   const value_kind = value_type->kind;
8786
8787                                                 unsigned value_flags;
8788                                                 unsigned value_size;
8789                                                 if (value_kind == TYPE_ATOMIC) {
8790                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8791                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8792                                                         value_size  = get_atomic_type_size(value_akind);
8793                                                 } else if (value_kind == TYPE_POINTER) {
8794                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8795                                                         value_size  = get_type_size(type_void_ptr);
8796                                                 } else {
8797                                                         break;
8798                                                 }
8799
8800                                                 if (value_flags != flags || value_size != size)
8801                                                         break;
8802
8803                                                 expression = value;
8804                                         } while (expression->kind == EXPR_UNARY_CAST);
8805                                 }
8806                         }
8807
8808                         if (!is_lvalue(expression)) {
8809                                 errorf(&expression->base.source_position,
8810                                        "asm output argument is not an lvalue");
8811                         }
8812
8813                         if (argument->constraints.begin[0] == '=')
8814                                 determine_lhs_ent(expression, NULL);
8815                         else
8816                                 mark_vars_read(expression, NULL);
8817                 } else {
8818                         mark_vars_read(expression, NULL);
8819                 }
8820                 argument->expression = expression;
8821                 expect(')');
8822
8823                 set_address_taken(expression, true);
8824
8825                 *anchor = argument;
8826                 anchor  = &argument->next;
8827
8828                 if (!next_if(','))
8829                         break;
8830         }
8831
8832         return result;
8833 }
8834
8835 /**
8836  * Parse a asm statement clobber specification.
8837  */
8838 static asm_clobber_t *parse_asm_clobbers(void)
8839 {
8840         asm_clobber_t *result  = NULL;
8841         asm_clobber_t **anchor = &result;
8842
8843         while (token.kind == T_STRING_LITERAL) {
8844                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8845                 clobber->clobber       = parse_string_literals();
8846
8847                 *anchor = clobber;
8848                 anchor  = &clobber->next;
8849
8850                 if (!next_if(','))
8851                         break;
8852         }
8853
8854         return result;
8855 }
8856
8857 /**
8858  * Parse an asm statement.
8859  */
8860 static statement_t *parse_asm_statement(void)
8861 {
8862         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8863         asm_statement_t *asm_statement = &statement->asms;
8864
8865         eat(T_asm);
8866
8867         if (next_if(T_volatile))
8868                 asm_statement->is_volatile = true;
8869
8870         expect('(');
8871         add_anchor_token(')');
8872         if (token.kind != T_STRING_LITERAL) {
8873                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8874                 goto end_of_asm;
8875         }
8876         asm_statement->asm_text = parse_string_literals();
8877
8878         add_anchor_token(':');
8879         if (!next_if(':')) {
8880                 rem_anchor_token(':');
8881                 goto end_of_asm;
8882         }
8883
8884         asm_statement->outputs = parse_asm_arguments(true);
8885         if (!next_if(':')) {
8886                 rem_anchor_token(':');
8887                 goto end_of_asm;
8888         }
8889
8890         asm_statement->inputs = parse_asm_arguments(false);
8891         if (!next_if(':')) {
8892                 rem_anchor_token(':');
8893                 goto end_of_asm;
8894         }
8895         rem_anchor_token(':');
8896
8897         asm_statement->clobbers = parse_asm_clobbers();
8898
8899 end_of_asm:
8900         rem_anchor_token(')');
8901         expect(')');
8902         expect(';');
8903
8904         if (asm_statement->outputs == NULL) {
8905                 /* GCC: An 'asm' instruction without any output operands will be treated
8906                  * identically to a volatile 'asm' instruction. */
8907                 asm_statement->is_volatile = true;
8908         }
8909
8910         return statement;
8911 }
8912
8913 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8914 {
8915         statement_t *inner_stmt;
8916         switch (token.kind) {
8917                 case '}':
8918                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8919                         inner_stmt = create_error_statement();
8920                         break;
8921
8922                 case ';':
8923                         if (label->kind == STATEMENT_LABEL) {
8924                                 /* Eat an empty statement here, to avoid the warning about an empty
8925                                  * statement after a label.  label:; is commonly used to have a label
8926                                  * before a closing brace. */
8927                                 inner_stmt = create_empty_statement();
8928                                 next_token();
8929                                 break;
8930                         }
8931                         /* FALLTHROUGH */
8932
8933                 default:
8934                         inner_stmt = parse_statement();
8935                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8936                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8937                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8938                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8939                         }
8940                         break;
8941         }
8942         return inner_stmt;
8943 }
8944
8945 /**
8946  * Parse a case statement.
8947  */
8948 static statement_t *parse_case_statement(void)
8949 {
8950         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8951         source_position_t *const pos       = &statement->base.source_position;
8952
8953         eat(T_case);
8954         add_anchor_token(':');
8955
8956         expression_t *expression = parse_expression();
8957         type_t *expression_type = expression->base.type;
8958         type_t *skipped         = skip_typeref(expression_type);
8959         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8960                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8961                        expression, expression_type);
8962         }
8963
8964         type_t *type = expression_type;
8965         if (current_switch != NULL) {
8966                 type_t *switch_type = current_switch->expression->base.type;
8967                 if (is_type_valid(switch_type)) {
8968                         expression = create_implicit_cast(expression, switch_type);
8969                 }
8970         }
8971
8972         statement->case_label.expression = expression;
8973         expression_classification_t const expr_class = is_constant_expression(expression);
8974         if (expr_class != EXPR_CLASS_CONSTANT) {
8975                 if (expr_class != EXPR_CLASS_ERROR) {
8976                         errorf(pos, "case label does not reduce to an integer constant");
8977                 }
8978                 statement->case_label.is_bad = true;
8979         } else {
8980                 long const val = fold_constant_to_int(expression);
8981                 statement->case_label.first_case = val;
8982                 statement->case_label.last_case  = val;
8983         }
8984
8985         if (GNU_MODE) {
8986                 if (next_if(T_DOTDOTDOT)) {
8987                         expression_t *end_range = parse_expression();
8988                         expression_type = expression->base.type;
8989                         skipped         = skip_typeref(expression_type);
8990                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8991                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8992                                            expression, expression_type);
8993                         }
8994
8995                         end_range = create_implicit_cast(end_range, type);
8996                         statement->case_label.end_range = end_range;
8997                         expression_classification_t const end_class = is_constant_expression(end_range);
8998                         if (end_class != EXPR_CLASS_CONSTANT) {
8999                                 if (end_class != EXPR_CLASS_ERROR) {
9000                                         errorf(pos, "case range does not reduce to an integer constant");
9001                                 }
9002                                 statement->case_label.is_bad = true;
9003                         } else {
9004                                 long const val = fold_constant_to_int(end_range);
9005                                 statement->case_label.last_case = val;
9006
9007                                 if (val < statement->case_label.first_case) {
9008                                         statement->case_label.is_empty_range = true;
9009                                         warningf(WARN_OTHER, pos, "empty range specified");
9010                                 }
9011                         }
9012                 }
9013         }
9014
9015         PUSH_PARENT(statement);
9016
9017         rem_anchor_token(':');
9018         expect(':');
9019
9020         if (current_switch != NULL) {
9021                 if (! statement->case_label.is_bad) {
9022                         /* Check for duplicate case values */
9023                         case_label_statement_t *c = &statement->case_label;
9024                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9025                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9026                                         continue;
9027
9028                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9029                                         continue;
9030
9031                                 errorf(pos, "duplicate case value (previously used %P)",
9032                                        &l->base.source_position);
9033                                 break;
9034                         }
9035                 }
9036                 /* link all cases into the switch statement */
9037                 if (current_switch->last_case == NULL) {
9038                         current_switch->first_case      = &statement->case_label;
9039                 } else {
9040                         current_switch->last_case->next = &statement->case_label;
9041                 }
9042                 current_switch->last_case = &statement->case_label;
9043         } else {
9044                 errorf(pos, "case label not within a switch statement");
9045         }
9046
9047         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9048
9049         POP_PARENT();
9050         return statement;
9051 }
9052
9053 /**
9054  * Parse a default statement.
9055  */
9056 static statement_t *parse_default_statement(void)
9057 {
9058         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9059
9060         eat(T_default);
9061
9062         PUSH_PARENT(statement);
9063
9064         expect(':');
9065
9066         if (current_switch != NULL) {
9067                 const case_label_statement_t *def_label = current_switch->default_label;
9068                 if (def_label != NULL) {
9069                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9070                 } else {
9071                         current_switch->default_label = &statement->case_label;
9072
9073                         /* link all cases into the switch statement */
9074                         if (current_switch->last_case == NULL) {
9075                                 current_switch->first_case      = &statement->case_label;
9076                         } else {
9077                                 current_switch->last_case->next = &statement->case_label;
9078                         }
9079                         current_switch->last_case = &statement->case_label;
9080                 }
9081         } else {
9082                 errorf(&statement->base.source_position,
9083                         "'default' label not within a switch statement");
9084         }
9085
9086         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9087
9088         POP_PARENT();
9089         return statement;
9090 }
9091
9092 /**
9093  * Parse a label statement.
9094  */
9095 static statement_t *parse_label_statement(void)
9096 {
9097         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9098         label_t     *const label     = get_label();
9099         statement->label.label = label;
9100
9101         PUSH_PARENT(statement);
9102
9103         /* if statement is already set then the label is defined twice,
9104          * otherwise it was just mentioned in a goto/local label declaration so far
9105          */
9106         source_position_t const* const pos = &statement->base.source_position;
9107         if (label->statement != NULL) {
9108                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9109         } else {
9110                 label->base.source_position = *pos;
9111                 label->statement            = statement;
9112         }
9113
9114         eat(':');
9115
9116         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9117                 parse_attributes(NULL); // TODO process attributes
9118         }
9119
9120         statement->label.statement = parse_label_inner_statement(statement, "label");
9121
9122         /* remember the labels in a list for later checking */
9123         *label_anchor = &statement->label;
9124         label_anchor  = &statement->label.next;
9125
9126         POP_PARENT();
9127         return statement;
9128 }
9129
9130 static statement_t *parse_inner_statement(void)
9131 {
9132         statement_t *const stmt = parse_statement();
9133         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9134         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9135         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9136                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9137         }
9138         return stmt;
9139 }
9140
9141 /**
9142  * Parse an expression in parentheses and mark its variables as read.
9143  */
9144 static expression_t *parse_condition(void)
9145 {
9146         expect('(');
9147         add_anchor_token(')');
9148         expression_t *const expr = parse_expression();
9149         mark_vars_read(expr, NULL);
9150         rem_anchor_token(')');
9151         expect(')');
9152         return expr;
9153 }
9154
9155 /**
9156  * Parse an if statement.
9157  */
9158 static statement_t *parse_if(void)
9159 {
9160         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9161
9162         eat(T_if);
9163
9164         PUSH_PARENT(statement);
9165         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9166
9167         add_anchor_token(T_else);
9168
9169         expression_t *const expr = parse_condition();
9170         statement->ifs.condition = expr;
9171         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9172          *             scalar type. */
9173         semantic_condition(expr, "condition of 'if'-statment");
9174
9175         statement_t *const true_stmt = parse_inner_statement();
9176         statement->ifs.true_statement = true_stmt;
9177         rem_anchor_token(T_else);
9178
9179         if (true_stmt->kind == STATEMENT_EMPTY) {
9180                 warningf(WARN_EMPTY_BODY, HERE,
9181                         "suggest braces around empty body in an ‘if’ statement");
9182         }
9183
9184         if (next_if(T_else)) {
9185                 statement->ifs.false_statement = parse_inner_statement();
9186
9187                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9188                         warningf(WARN_EMPTY_BODY, HERE,
9189                                         "suggest braces around empty body in an ‘if’ statement");
9190                 }
9191         } else if (true_stmt->kind == STATEMENT_IF &&
9192                         true_stmt->ifs.false_statement != NULL) {
9193                 source_position_t const *const pos = &true_stmt->base.source_position;
9194                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9195         }
9196
9197         POP_SCOPE();
9198         POP_PARENT();
9199         return statement;
9200 }
9201
9202 /**
9203  * Check that all enums are handled in a switch.
9204  *
9205  * @param statement  the switch statement to check
9206  */
9207 static void check_enum_cases(const switch_statement_t *statement)
9208 {
9209         if (!is_warn_on(WARN_SWITCH_ENUM))
9210                 return;
9211         const type_t *type = skip_typeref(statement->expression->base.type);
9212         if (! is_type_enum(type))
9213                 return;
9214         const enum_type_t *enumt = &type->enumt;
9215
9216         /* if we have a default, no warnings */
9217         if (statement->default_label != NULL)
9218                 return;
9219
9220         /* FIXME: calculation of value should be done while parsing */
9221         /* TODO: quadratic algorithm here. Change to an n log n one */
9222         long            last_value = -1;
9223         const entity_t *entry      = enumt->enume->base.next;
9224         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9225              entry = entry->base.next) {
9226                 const expression_t *expression = entry->enum_value.value;
9227                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9228                 bool                found      = false;
9229                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9230                         if (l->expression == NULL)
9231                                 continue;
9232                         if (l->first_case <= value && value <= l->last_case) {
9233                                 found = true;
9234                                 break;
9235                         }
9236                 }
9237                 if (!found) {
9238                         source_position_t const *const pos = &statement->base.source_position;
9239                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9240                 }
9241                 last_value = value;
9242         }
9243 }
9244
9245 /**
9246  * Parse a switch statement.
9247  */
9248 static statement_t *parse_switch(void)
9249 {
9250         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9251
9252         eat(T_switch);
9253
9254         PUSH_PARENT(statement);
9255         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9256
9257         expression_t *const expr = parse_condition();
9258         type_t       *      type = skip_typeref(expr->base.type);
9259         if (is_type_integer(type)) {
9260                 type = promote_integer(type);
9261                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9262                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9263                 }
9264         } else if (is_type_valid(type)) {
9265                 errorf(&expr->base.source_position,
9266                        "switch quantity is not an integer, but '%T'", type);
9267                 type = type_error_type;
9268         }
9269         statement->switchs.expression = create_implicit_cast(expr, type);
9270
9271         switch_statement_t *rem = current_switch;
9272         current_switch          = &statement->switchs;
9273         statement->switchs.body = parse_inner_statement();
9274         current_switch          = rem;
9275
9276         if (statement->switchs.default_label == NULL) {
9277                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9278         }
9279         check_enum_cases(&statement->switchs);
9280
9281         POP_SCOPE();
9282         POP_PARENT();
9283         return statement;
9284 }
9285
9286 static statement_t *parse_loop_body(statement_t *const loop)
9287 {
9288         statement_t *const rem = current_loop;
9289         current_loop = loop;
9290
9291         statement_t *const body = parse_inner_statement();
9292
9293         current_loop = rem;
9294         return body;
9295 }
9296
9297 /**
9298  * Parse a while statement.
9299  */
9300 static statement_t *parse_while(void)
9301 {
9302         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9303
9304         eat(T_while);
9305
9306         PUSH_PARENT(statement);
9307         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9308
9309         expression_t *const cond = parse_condition();
9310         statement->whiles.condition = cond;
9311         /* §6.8.5:2    The controlling expression of an iteration statement shall
9312          *             have scalar type. */
9313         semantic_condition(cond, "condition of 'while'-statement");
9314
9315         statement->whiles.body = parse_loop_body(statement);
9316
9317         POP_SCOPE();
9318         POP_PARENT();
9319         return statement;
9320 }
9321
9322 /**
9323  * Parse a do statement.
9324  */
9325 static statement_t *parse_do(void)
9326 {
9327         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9328
9329         eat(T_do);
9330
9331         PUSH_PARENT(statement);
9332         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9333
9334         add_anchor_token(T_while);
9335         statement->do_while.body = parse_loop_body(statement);
9336         rem_anchor_token(T_while);
9337
9338         expect(T_while);
9339         expression_t *const cond = parse_condition();
9340         statement->do_while.condition = cond;
9341         /* §6.8.5:2    The controlling expression of an iteration statement shall
9342          *             have scalar type. */
9343         semantic_condition(cond, "condition of 'do-while'-statement");
9344         expect(';');
9345
9346         POP_SCOPE();
9347         POP_PARENT();
9348         return statement;
9349 }
9350
9351 /**
9352  * Parse a for statement.
9353  */
9354 static statement_t *parse_for(void)
9355 {
9356         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9357
9358         eat(T_for);
9359
9360         PUSH_PARENT(statement);
9361         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9362
9363         expect('(');
9364         add_anchor_token(')');
9365
9366         PUSH_EXTENSION();
9367
9368         if (next_if(';')) {
9369         } else if (is_declaration_specifier(&token)) {
9370                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9371         } else {
9372                 add_anchor_token(';');
9373                 expression_t *const init = parse_expression();
9374                 statement->fors.initialisation = init;
9375                 mark_vars_read(init, ENT_ANY);
9376                 if (!expression_has_effect(init)) {
9377                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9378                 }
9379                 rem_anchor_token(';');
9380                 expect(';');
9381         }
9382
9383         POP_EXTENSION();
9384
9385         if (token.kind != ';') {
9386                 add_anchor_token(';');
9387                 expression_t *const cond = parse_expression();
9388                 statement->fors.condition = cond;
9389                 /* §6.8.5:2    The controlling expression of an iteration statement
9390                  *             shall have scalar type. */
9391                 semantic_condition(cond, "condition of 'for'-statement");
9392                 mark_vars_read(cond, NULL);
9393                 rem_anchor_token(';');
9394         }
9395         expect(';');
9396         if (token.kind != ')') {
9397                 expression_t *const step = parse_expression();
9398                 statement->fors.step = step;
9399                 mark_vars_read(step, ENT_ANY);
9400                 if (!expression_has_effect(step)) {
9401                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9402                 }
9403         }
9404         rem_anchor_token(')');
9405         expect(')');
9406         statement->fors.body = parse_loop_body(statement);
9407
9408         POP_SCOPE();
9409         POP_PARENT();
9410         return statement;
9411 }
9412
9413 /**
9414  * Parse a goto statement.
9415  */
9416 static statement_t *parse_goto(void)
9417 {
9418         statement_t *statement;
9419         if (GNU_MODE && look_ahead(1)->kind == '*') {
9420                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9421                 eat(T_goto);
9422                 eat('*');
9423
9424                 expression_t *expression = parse_expression();
9425                 mark_vars_read(expression, NULL);
9426
9427                 /* Argh: although documentation says the expression must be of type void*,
9428                  * gcc accepts anything that can be casted into void* without error */
9429                 type_t *type = expression->base.type;
9430
9431                 if (type != type_error_type) {
9432                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9433                                 errorf(&expression->base.source_position,
9434                                         "cannot convert to a pointer type");
9435                         } else if (type != type_void_ptr) {
9436                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9437                         }
9438                         expression = create_implicit_cast(expression, type_void_ptr);
9439                 }
9440
9441                 statement->computed_goto.expression = expression;
9442         } else {
9443                 statement = allocate_statement_zero(STATEMENT_GOTO);
9444                 eat(T_goto);
9445                 if (token.kind == T_IDENTIFIER) {
9446                         label_t *const label = get_label();
9447                         label->used            = true;
9448                         statement->gotos.label = label;
9449
9450                         /* remember the goto's in a list for later checking */
9451                         *goto_anchor = &statement->gotos;
9452                         goto_anchor  = &statement->gotos.next;
9453                 } else {
9454                         if (GNU_MODE)
9455                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9456                         else
9457                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9458                         eat_until_anchor();
9459                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9460                 }
9461         }
9462
9463         expect(';');
9464         return statement;
9465 }
9466
9467 /**
9468  * Parse a continue statement.
9469  */
9470 static statement_t *parse_continue(void)
9471 {
9472         if (current_loop == NULL) {
9473                 errorf(HERE, "continue statement not within loop");
9474         }
9475
9476         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9477
9478         eat(T_continue);
9479         expect(';');
9480         return statement;
9481 }
9482
9483 /**
9484  * Parse a break statement.
9485  */
9486 static statement_t *parse_break(void)
9487 {
9488         if (current_switch == NULL && current_loop == NULL) {
9489                 errorf(HERE, "break statement not within loop or switch");
9490         }
9491
9492         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9493
9494         eat(T_break);
9495         expect(';');
9496         return statement;
9497 }
9498
9499 /**
9500  * Parse a __leave statement.
9501  */
9502 static statement_t *parse_leave_statement(void)
9503 {
9504         if (current_try == NULL) {
9505                 errorf(HERE, "__leave statement not within __try");
9506         }
9507
9508         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9509
9510         eat(T___leave);
9511         expect(';');
9512         return statement;
9513 }
9514
9515 /**
9516  * Check if a given entity represents a local variable.
9517  */
9518 static bool is_local_variable(const entity_t *entity)
9519 {
9520         if (entity->kind != ENTITY_VARIABLE)
9521                 return false;
9522
9523         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9524         case STORAGE_CLASS_AUTO:
9525         case STORAGE_CLASS_REGISTER: {
9526                 const type_t *type = skip_typeref(entity->declaration.type);
9527                 if (is_type_function(type)) {
9528                         return false;
9529                 } else {
9530                         return true;
9531                 }
9532         }
9533         default:
9534                 return false;
9535         }
9536 }
9537
9538 /**
9539  * Check if a given expression represents a local variable.
9540  */
9541 static bool expression_is_local_variable(const expression_t *expression)
9542 {
9543         if (expression->base.kind != EXPR_REFERENCE) {
9544                 return false;
9545         }
9546         const entity_t *entity = expression->reference.entity;
9547         return is_local_variable(entity);
9548 }
9549
9550 /**
9551  * Check if a given expression represents a local variable and
9552  * return its declaration then, else return NULL.
9553  */
9554 entity_t *expression_is_variable(const expression_t *expression)
9555 {
9556         if (expression->base.kind != EXPR_REFERENCE) {
9557                 return NULL;
9558         }
9559         entity_t *entity = expression->reference.entity;
9560         if (entity->kind != ENTITY_VARIABLE)
9561                 return NULL;
9562
9563         return entity;
9564 }
9565
9566 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9567 {
9568         if (c_mode & _CXX || strict_mode) {
9569                 errorf(pos, msg);
9570         } else {
9571                 warningf(WARN_OTHER, pos, msg);
9572         }
9573 }
9574
9575 /**
9576  * Parse a return statement.
9577  */
9578 static statement_t *parse_return(void)
9579 {
9580         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9581         eat(T_return);
9582
9583         expression_t *return_value = NULL;
9584         if (token.kind != ';') {
9585                 return_value = parse_expression();
9586                 mark_vars_read(return_value, NULL);
9587         }
9588
9589         const type_t *const func_type = skip_typeref(current_function->base.type);
9590         assert(is_type_function(func_type));
9591         type_t *const return_type = skip_typeref(func_type->function.return_type);
9592
9593         source_position_t const *const pos = &statement->base.source_position;
9594         if (return_value != NULL) {
9595                 type_t *return_value_type = skip_typeref(return_value->base.type);
9596
9597                 if (is_type_void(return_type)) {
9598                         if (!is_type_void(return_value_type)) {
9599                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9600                                 /* Only warn in C mode, because GCC does the same */
9601                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9602                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9603                                 /* Only warn in C mode, because GCC does the same */
9604                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9605                         }
9606                 } else {
9607                         assign_error_t error = semantic_assign(return_type, return_value);
9608                         report_assign_error(error, return_type, return_value, "'return'",
9609                                             pos);
9610                 }
9611                 return_value = create_implicit_cast(return_value, return_type);
9612                 /* check for returning address of a local var */
9613                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9614                         const expression_t *expression = return_value->unary.value;
9615                         if (expression_is_local_variable(expression)) {
9616                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9617                         }
9618                 }
9619         } else if (!is_type_void(return_type)) {
9620                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9621                 err_or_warn(pos, "'return' without value, in function returning non-void");
9622         }
9623         statement->returns.value = return_value;
9624
9625         expect(';');
9626         return statement;
9627 }
9628
9629 /**
9630  * Parse a declaration statement.
9631  */
9632 static statement_t *parse_declaration_statement(void)
9633 {
9634         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9635
9636         entity_t *before = current_scope->last_entity;
9637         if (GNU_MODE) {
9638                 parse_external_declaration();
9639         } else {
9640                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9641         }
9642
9643         declaration_statement_t *const decl  = &statement->declaration;
9644         entity_t                *const begin =
9645                 before != NULL ? before->base.next : current_scope->entities;
9646         decl->declarations_begin = begin;
9647         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9648
9649         return statement;
9650 }
9651
9652 /**
9653  * Parse an expression statement, ie. expr ';'.
9654  */
9655 static statement_t *parse_expression_statement(void)
9656 {
9657         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9658
9659         expression_t *const expr         = parse_expression();
9660         statement->expression.expression = expr;
9661         mark_vars_read(expr, ENT_ANY);
9662
9663         expect(';');
9664         return statement;
9665 }
9666
9667 /**
9668  * Parse a microsoft __try { } __finally { } or
9669  * __try{ } __except() { }
9670  */
9671 static statement_t *parse_ms_try_statment(void)
9672 {
9673         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9674         eat(T___try);
9675
9676         PUSH_PARENT(statement);
9677
9678         ms_try_statement_t *rem = current_try;
9679         current_try = &statement->ms_try;
9680         statement->ms_try.try_statement = parse_compound_statement(false);
9681         current_try = rem;
9682
9683         POP_PARENT();
9684
9685         if (next_if(T___except)) {
9686                 expression_t *const expr = parse_condition();
9687                 type_t       *      type = skip_typeref(expr->base.type);
9688                 if (is_type_integer(type)) {
9689                         type = promote_integer(type);
9690                 } else if (is_type_valid(type)) {
9691                         errorf(&expr->base.source_position,
9692                                "__expect expression is not an integer, but '%T'", type);
9693                         type = type_error_type;
9694                 }
9695                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9696         } else if (!next_if(T__finally)) {
9697                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9698         }
9699         statement->ms_try.final_statement = parse_compound_statement(false);
9700         return statement;
9701 }
9702
9703 static statement_t *parse_empty_statement(void)
9704 {
9705         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9706         statement_t *const statement = create_empty_statement();
9707         eat(';');
9708         return statement;
9709 }
9710
9711 static statement_t *parse_local_label_declaration(void)
9712 {
9713         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9714
9715         eat(T___label__);
9716
9717         entity_t *begin   = NULL;
9718         entity_t *end     = NULL;
9719         entity_t **anchor = &begin;
9720         do {
9721                 source_position_t pos;
9722                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9723                 if (!symbol)
9724                         goto end_error;
9725
9726                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9727                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9728                         source_position_t const *const ppos = &entity->base.source_position;
9729                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9730                 } else {
9731                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9732                         entity->base.parent_scope = current_scope;
9733
9734                         *anchor = entity;
9735                         anchor  = &entity->base.next;
9736                         end     = entity;
9737
9738                         environment_push(entity);
9739                 }
9740         } while (next_if(','));
9741         expect(';');
9742 end_error:
9743         statement->declaration.declarations_begin = begin;
9744         statement->declaration.declarations_end   = end;
9745         return statement;
9746 }
9747
9748 static void parse_namespace_definition(void)
9749 {
9750         eat(T_namespace);
9751
9752         entity_t *entity = NULL;
9753         symbol_t *symbol = NULL;
9754
9755         if (token.kind == T_IDENTIFIER) {
9756                 symbol = token.identifier.symbol;
9757                 next_token();
9758
9759                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9760                 if (entity != NULL
9761                                 && entity->kind != ENTITY_NAMESPACE
9762                                 && entity->base.parent_scope == current_scope) {
9763                         if (is_entity_valid(entity)) {
9764                                 error_redefined_as_different_kind(&token.base.source_position,
9765                                                 entity, ENTITY_NAMESPACE);
9766                         }
9767                         entity = NULL;
9768                 }
9769         }
9770
9771         if (entity == NULL) {
9772                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9773                 entity->base.parent_scope = current_scope;
9774         }
9775
9776         if (token.kind == '=') {
9777                 /* TODO: parse namespace alias */
9778                 panic("namespace alias definition not supported yet");
9779         }
9780
9781         environment_push(entity);
9782         append_entity(current_scope, entity);
9783
9784         PUSH_SCOPE(&entity->namespacee.members);
9785
9786         entity_t     *old_current_entity = current_entity;
9787         current_entity = entity;
9788
9789         add_anchor_token('}');
9790         expect('{');
9791         parse_externals();
9792         rem_anchor_token('}');
9793         expect('}');
9794
9795         assert(current_entity == entity);
9796         current_entity = old_current_entity;
9797         POP_SCOPE();
9798 }
9799
9800 /**
9801  * Parse a statement.
9802  * There's also parse_statement() which additionally checks for
9803  * "statement has no effect" warnings
9804  */
9805 static statement_t *intern_parse_statement(void)
9806 {
9807         /* declaration or statement */
9808         statement_t *statement;
9809         switch (token.kind) {
9810         case T_IDENTIFIER: {
9811                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9812                 if (la1_type == ':') {
9813                         statement = parse_label_statement();
9814                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9815                         statement = parse_declaration_statement();
9816                 } else {
9817                         /* it's an identifier, the grammar says this must be an
9818                          * expression statement. However it is common that users mistype
9819                          * declaration types, so we guess a bit here to improve robustness
9820                          * for incorrect programs */
9821                         switch (la1_type) {
9822                         case '&':
9823                         case '*':
9824                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9825                         default:
9826                                         statement = parse_expression_statement();
9827                                 } else {
9828                         DECLARATION_START
9829                         case T_IDENTIFIER:
9830                                         statement = parse_declaration_statement();
9831                                 }
9832                                 break;
9833                         }
9834                 }
9835                 break;
9836         }
9837
9838         case T___extension__: {
9839                 /* This can be a prefix to a declaration or an expression statement.
9840                  * We simply eat it now and parse the rest with tail recursion. */
9841                 PUSH_EXTENSION();
9842                 statement = intern_parse_statement();
9843                 POP_EXTENSION();
9844                 break;
9845         }
9846
9847         DECLARATION_START
9848                 statement = parse_declaration_statement();
9849                 break;
9850
9851         case T___label__:
9852                 statement = parse_local_label_declaration();
9853                 break;
9854
9855         case ';':         statement = parse_empty_statement();         break;
9856         case '{':         statement = parse_compound_statement(false); break;
9857         case T___leave:   statement = parse_leave_statement();         break;
9858         case T___try:     statement = parse_ms_try_statment();         break;
9859         case T_asm:       statement = parse_asm_statement();           break;
9860         case T_break:     statement = parse_break();                   break;
9861         case T_case:      statement = parse_case_statement();          break;
9862         case T_continue:  statement = parse_continue();                break;
9863         case T_default:   statement = parse_default_statement();       break;
9864         case T_do:        statement = parse_do();                      break;
9865         case T_for:       statement = parse_for();                     break;
9866         case T_goto:      statement = parse_goto();                    break;
9867         case T_if:        statement = parse_if();                      break;
9868         case T_return:    statement = parse_return();                  break;
9869         case T_switch:    statement = parse_switch();                  break;
9870         case T_while:     statement = parse_while();                   break;
9871
9872         EXPRESSION_START
9873                 statement = parse_expression_statement();
9874                 break;
9875
9876         default:
9877                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9878                 statement = create_error_statement();
9879                 eat_until_anchor();
9880                 break;
9881         }
9882
9883         return statement;
9884 }
9885
9886 /**
9887  * parse a statement and emits "statement has no effect" warning if needed
9888  * (This is really a wrapper around intern_parse_statement with check for 1
9889  *  single warning. It is needed, because for statement expressions we have
9890  *  to avoid the warning on the last statement)
9891  */
9892 static statement_t *parse_statement(void)
9893 {
9894         statement_t *statement = intern_parse_statement();
9895
9896         if (statement->kind == STATEMENT_EXPRESSION) {
9897                 expression_t *expression = statement->expression.expression;
9898                 if (!expression_has_effect(expression)) {
9899                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9900                 }
9901         }
9902
9903         return statement;
9904 }
9905
9906 /**
9907  * Parse a compound statement.
9908  */
9909 static statement_t *parse_compound_statement(bool inside_expression_statement)
9910 {
9911         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9912
9913         PUSH_PARENT(statement);
9914         PUSH_SCOPE(&statement->compound.scope);
9915
9916         eat('{');
9917         add_anchor_token('}');
9918         /* tokens, which can start a statement */
9919         /* TODO MS, __builtin_FOO */
9920         add_anchor_token('!');
9921         add_anchor_token('&');
9922         add_anchor_token('(');
9923         add_anchor_token('*');
9924         add_anchor_token('+');
9925         add_anchor_token('-');
9926         add_anchor_token(';');
9927         add_anchor_token('{');
9928         add_anchor_token('~');
9929         add_anchor_token(T_CHARACTER_CONSTANT);
9930         add_anchor_token(T_COLONCOLON);
9931         add_anchor_token(T_FLOATINGPOINT);
9932         add_anchor_token(T_IDENTIFIER);
9933         add_anchor_token(T_INTEGER);
9934         add_anchor_token(T_MINUSMINUS);
9935         add_anchor_token(T_PLUSPLUS);
9936         add_anchor_token(T_STRING_LITERAL);
9937         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9938         add_anchor_token(T_WIDE_STRING_LITERAL);
9939         add_anchor_token(T__Bool);
9940         add_anchor_token(T__Complex);
9941         add_anchor_token(T__Imaginary);
9942         add_anchor_token(T___FUNCTION__);
9943         add_anchor_token(T___PRETTY_FUNCTION__);
9944         add_anchor_token(T___alignof__);
9945         add_anchor_token(T___attribute__);
9946         add_anchor_token(T___builtin_va_start);
9947         add_anchor_token(T___extension__);
9948         add_anchor_token(T___func__);
9949         add_anchor_token(T___imag__);
9950         add_anchor_token(T___label__);
9951         add_anchor_token(T___real__);
9952         add_anchor_token(T___thread);
9953         add_anchor_token(T_asm);
9954         add_anchor_token(T_auto);
9955         add_anchor_token(T_bool);
9956         add_anchor_token(T_break);
9957         add_anchor_token(T_case);
9958         add_anchor_token(T_char);
9959         add_anchor_token(T_class);
9960         add_anchor_token(T_const);
9961         add_anchor_token(T_const_cast);
9962         add_anchor_token(T_continue);
9963         add_anchor_token(T_default);
9964         add_anchor_token(T_delete);
9965         add_anchor_token(T_double);
9966         add_anchor_token(T_do);
9967         add_anchor_token(T_dynamic_cast);
9968         add_anchor_token(T_enum);
9969         add_anchor_token(T_extern);
9970         add_anchor_token(T_false);
9971         add_anchor_token(T_float);
9972         add_anchor_token(T_for);
9973         add_anchor_token(T_goto);
9974         add_anchor_token(T_if);
9975         add_anchor_token(T_inline);
9976         add_anchor_token(T_int);
9977         add_anchor_token(T_long);
9978         add_anchor_token(T_new);
9979         add_anchor_token(T_operator);
9980         add_anchor_token(T_register);
9981         add_anchor_token(T_reinterpret_cast);
9982         add_anchor_token(T_restrict);
9983         add_anchor_token(T_return);
9984         add_anchor_token(T_short);
9985         add_anchor_token(T_signed);
9986         add_anchor_token(T_sizeof);
9987         add_anchor_token(T_static);
9988         add_anchor_token(T_static_cast);
9989         add_anchor_token(T_struct);
9990         add_anchor_token(T_switch);
9991         add_anchor_token(T_template);
9992         add_anchor_token(T_this);
9993         add_anchor_token(T_throw);
9994         add_anchor_token(T_true);
9995         add_anchor_token(T_try);
9996         add_anchor_token(T_typedef);
9997         add_anchor_token(T_typeid);
9998         add_anchor_token(T_typename);
9999         add_anchor_token(T_typeof);
10000         add_anchor_token(T_union);
10001         add_anchor_token(T_unsigned);
10002         add_anchor_token(T_using);
10003         add_anchor_token(T_void);
10004         add_anchor_token(T_volatile);
10005         add_anchor_token(T_wchar_t);
10006         add_anchor_token(T_while);
10007
10008         statement_t **anchor            = &statement->compound.statements;
10009         bool          only_decls_so_far = true;
10010         while (token.kind != '}' && token.kind != T_EOF) {
10011                 statement_t *sub_statement = intern_parse_statement();
10012                 if (sub_statement->kind == STATEMENT_ERROR) {
10013                         break;
10014                 }
10015
10016                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10017                         only_decls_so_far = false;
10018                 } else if (!only_decls_so_far) {
10019                         source_position_t const *const pos = &sub_statement->base.source_position;
10020                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10021                 }
10022
10023                 *anchor = sub_statement;
10024                 anchor  = &sub_statement->base.next;
10025         }
10026         expect('}');
10027
10028         /* look over all statements again to produce no effect warnings */
10029         if (is_warn_on(WARN_UNUSED_VALUE)) {
10030                 statement_t *sub_statement = statement->compound.statements;
10031                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10032                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10033                                 continue;
10034                         /* don't emit a warning for the last expression in an expression
10035                          * statement as it has always an effect */
10036                         if (inside_expression_statement && sub_statement->base.next == NULL)
10037                                 continue;
10038
10039                         expression_t *expression = sub_statement->expression.expression;
10040                         if (!expression_has_effect(expression)) {
10041                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10042                         }
10043                 }
10044         }
10045
10046         rem_anchor_token(T_while);
10047         rem_anchor_token(T_wchar_t);
10048         rem_anchor_token(T_volatile);
10049         rem_anchor_token(T_void);
10050         rem_anchor_token(T_using);
10051         rem_anchor_token(T_unsigned);
10052         rem_anchor_token(T_union);
10053         rem_anchor_token(T_typeof);
10054         rem_anchor_token(T_typename);
10055         rem_anchor_token(T_typeid);
10056         rem_anchor_token(T_typedef);
10057         rem_anchor_token(T_try);
10058         rem_anchor_token(T_true);
10059         rem_anchor_token(T_throw);
10060         rem_anchor_token(T_this);
10061         rem_anchor_token(T_template);
10062         rem_anchor_token(T_switch);
10063         rem_anchor_token(T_struct);
10064         rem_anchor_token(T_static_cast);
10065         rem_anchor_token(T_static);
10066         rem_anchor_token(T_sizeof);
10067         rem_anchor_token(T_signed);
10068         rem_anchor_token(T_short);
10069         rem_anchor_token(T_return);
10070         rem_anchor_token(T_restrict);
10071         rem_anchor_token(T_reinterpret_cast);
10072         rem_anchor_token(T_register);
10073         rem_anchor_token(T_operator);
10074         rem_anchor_token(T_new);
10075         rem_anchor_token(T_long);
10076         rem_anchor_token(T_int);
10077         rem_anchor_token(T_inline);
10078         rem_anchor_token(T_if);
10079         rem_anchor_token(T_goto);
10080         rem_anchor_token(T_for);
10081         rem_anchor_token(T_float);
10082         rem_anchor_token(T_false);
10083         rem_anchor_token(T_extern);
10084         rem_anchor_token(T_enum);
10085         rem_anchor_token(T_dynamic_cast);
10086         rem_anchor_token(T_do);
10087         rem_anchor_token(T_double);
10088         rem_anchor_token(T_delete);
10089         rem_anchor_token(T_default);
10090         rem_anchor_token(T_continue);
10091         rem_anchor_token(T_const_cast);
10092         rem_anchor_token(T_const);
10093         rem_anchor_token(T_class);
10094         rem_anchor_token(T_char);
10095         rem_anchor_token(T_case);
10096         rem_anchor_token(T_break);
10097         rem_anchor_token(T_bool);
10098         rem_anchor_token(T_auto);
10099         rem_anchor_token(T_asm);
10100         rem_anchor_token(T___thread);
10101         rem_anchor_token(T___real__);
10102         rem_anchor_token(T___label__);
10103         rem_anchor_token(T___imag__);
10104         rem_anchor_token(T___func__);
10105         rem_anchor_token(T___extension__);
10106         rem_anchor_token(T___builtin_va_start);
10107         rem_anchor_token(T___attribute__);
10108         rem_anchor_token(T___alignof__);
10109         rem_anchor_token(T___PRETTY_FUNCTION__);
10110         rem_anchor_token(T___FUNCTION__);
10111         rem_anchor_token(T__Imaginary);
10112         rem_anchor_token(T__Complex);
10113         rem_anchor_token(T__Bool);
10114         rem_anchor_token(T_WIDE_STRING_LITERAL);
10115         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10116         rem_anchor_token(T_STRING_LITERAL);
10117         rem_anchor_token(T_PLUSPLUS);
10118         rem_anchor_token(T_MINUSMINUS);
10119         rem_anchor_token(T_INTEGER);
10120         rem_anchor_token(T_IDENTIFIER);
10121         rem_anchor_token(T_FLOATINGPOINT);
10122         rem_anchor_token(T_COLONCOLON);
10123         rem_anchor_token(T_CHARACTER_CONSTANT);
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         rem_anchor_token('(');
10131         rem_anchor_token('&');
10132         rem_anchor_token('!');
10133         rem_anchor_token('}');
10134
10135         POP_SCOPE();
10136         POP_PARENT();
10137         return statement;
10138 }
10139
10140 /**
10141  * Check for unused global static functions and variables
10142  */
10143 static void check_unused_globals(void)
10144 {
10145         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10146                 return;
10147
10148         for (const entity_t *entity = file_scope->entities; entity != NULL;
10149              entity = entity->base.next) {
10150                 if (!is_declaration(entity))
10151                         continue;
10152
10153                 const declaration_t *declaration = &entity->declaration;
10154                 if (declaration->used                  ||
10155                     declaration->modifiers & DM_UNUSED ||
10156                     declaration->modifiers & DM_USED   ||
10157                     declaration->storage_class != STORAGE_CLASS_STATIC)
10158                         continue;
10159
10160                 warning_t   why;
10161                 char const *s;
10162                 if (entity->kind == ENTITY_FUNCTION) {
10163                         /* inhibit warning for static inline functions */
10164                         if (entity->function.is_inline)
10165                                 continue;
10166
10167                         why = WARN_UNUSED_FUNCTION;
10168                         s   = entity->function.statement != NULL ? "defined" : "declared";
10169                 } else {
10170                         why = WARN_UNUSED_VARIABLE;
10171                         s   = "defined";
10172                 }
10173
10174                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10175         }
10176 }
10177
10178 static void parse_global_asm(void)
10179 {
10180         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10181
10182         eat(T_asm);
10183         add_anchor_token(';');
10184         add_anchor_token(')');
10185         add_anchor_token(T_STRING_LITERAL);
10186         expect('(');
10187
10188         rem_anchor_token(T_STRING_LITERAL);
10189         statement->asms.asm_text = parse_string_literals();
10190         statement->base.next     = unit->global_asm;
10191         unit->global_asm         = statement;
10192
10193         rem_anchor_token(')');
10194         expect(')');
10195         rem_anchor_token(';');
10196         expect(';');
10197 }
10198
10199 static void parse_linkage_specification(void)
10200 {
10201         eat(T_extern);
10202
10203         source_position_t const pos     = *HERE;
10204         char const       *const linkage = parse_string_literals().begin;
10205
10206         linkage_kind_t old_linkage = current_linkage;
10207         linkage_kind_t new_linkage;
10208         if (streq(linkage, "C")) {
10209                 new_linkage = LINKAGE_C;
10210         } else if (streq(linkage, "C++")) {
10211                 new_linkage = LINKAGE_CXX;
10212         } else {
10213                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10214                 new_linkage = LINKAGE_C;
10215         }
10216         current_linkage = new_linkage;
10217
10218         if (next_if('{')) {
10219                 parse_externals();
10220                 expect('}');
10221         } else {
10222                 parse_external();
10223         }
10224
10225         assert(current_linkage == new_linkage);
10226         current_linkage = old_linkage;
10227 }
10228
10229 static void parse_external(void)
10230 {
10231         switch (token.kind) {
10232                 case T_extern:
10233                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10234                                 parse_linkage_specification();
10235                         } else {
10236                 DECLARATION_START_NO_EXTERN
10237                 case T_IDENTIFIER:
10238                 case T___extension__:
10239                 /* tokens below are for implicit int */
10240                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10241                               implicit int) */
10242                 case '*':  /* * x; -> int* x; */
10243                 case '(':  /* (x); -> int (x); */
10244                                 PUSH_EXTENSION();
10245                                 parse_external_declaration();
10246                                 POP_EXTENSION();
10247                         }
10248                         return;
10249
10250                 case T_asm:
10251                         parse_global_asm();
10252                         return;
10253
10254                 case T_namespace:
10255                         parse_namespace_definition();
10256                         return;
10257
10258                 case ';':
10259                         if (!strict_mode) {
10260                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10261                                 next_token();
10262                                 return;
10263                         }
10264                         /* FALLTHROUGH */
10265
10266                 default:
10267                         errorf(HERE, "stray %K outside of function", &token);
10268                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10269                                 eat_until_matching_token(token.kind);
10270                         next_token();
10271                         return;
10272         }
10273 }
10274
10275 static void parse_externals(void)
10276 {
10277         add_anchor_token('}');
10278         add_anchor_token(T_EOF);
10279
10280 #ifndef NDEBUG
10281         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10282         unsigned short token_anchor_copy[T_LAST_TOKEN];
10283         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10284 #endif
10285
10286         while (token.kind != T_EOF && token.kind != '}') {
10287 #ifndef NDEBUG
10288                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10289                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10290                         if (count != 0) {
10291                                 /* the anchor set and its copy differs */
10292                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10293                         }
10294                 }
10295                 if (in_gcc_extension) {
10296                         /* an gcc extension scope was not closed */
10297                         internal_errorf(HERE, "Leaked __extension__");
10298                 }
10299 #endif
10300
10301                 parse_external();
10302         }
10303
10304         rem_anchor_token(T_EOF);
10305         rem_anchor_token('}');
10306 }
10307
10308 /**
10309  * Parse a translation unit.
10310  */
10311 static void parse_translation_unit(void)
10312 {
10313         add_anchor_token(T_EOF);
10314
10315         while (true) {
10316                 parse_externals();
10317
10318                 if (token.kind == T_EOF)
10319                         break;
10320
10321                 errorf(HERE, "stray %K outside of function", &token);
10322                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10323                         eat_until_matching_token(token.kind);
10324                 next_token();
10325         }
10326 }
10327
10328 void set_default_visibility(elf_visibility_tag_t visibility)
10329 {
10330         default_visibility = visibility;
10331 }
10332
10333 /**
10334  * Parse the input.
10335  *
10336  * @return  the translation unit or NULL if errors occurred.
10337  */
10338 void start_parsing(void)
10339 {
10340         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10341         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10342         diagnostic_count  = 0;
10343         error_count       = 0;
10344         warning_count     = 0;
10345
10346         print_to_file(stderr);
10347
10348         assert(unit == NULL);
10349         unit = allocate_ast_zero(sizeof(unit[0]));
10350
10351         assert(file_scope == NULL);
10352         file_scope = &unit->scope;
10353
10354         assert(current_scope == NULL);
10355         scope_push(&unit->scope);
10356
10357         create_gnu_builtins();
10358         if (c_mode & _MS)
10359                 create_microsoft_intrinsics();
10360 }
10361
10362 translation_unit_t *finish_parsing(void)
10363 {
10364         assert(current_scope == &unit->scope);
10365         scope_pop(NULL);
10366
10367         assert(file_scope == &unit->scope);
10368         check_unused_globals();
10369         file_scope = NULL;
10370
10371         DEL_ARR_F(environment_stack);
10372         DEL_ARR_F(label_stack);
10373
10374         translation_unit_t *result = unit;
10375         unit = NULL;
10376         return result;
10377 }
10378
10379 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10380  * are given length one. */
10381 static void complete_incomplete_arrays(void)
10382 {
10383         size_t n = ARR_LEN(incomplete_arrays);
10384         for (size_t i = 0; i != n; ++i) {
10385                 declaration_t *const decl = incomplete_arrays[i];
10386                 type_t        *const type = skip_typeref(decl->type);
10387
10388                 if (!is_type_incomplete(type))
10389                         continue;
10390
10391                 source_position_t const *const pos = &decl->base.source_position;
10392                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10393
10394                 type_t *const new_type = duplicate_type(type);
10395                 new_type->array.size_constant     = true;
10396                 new_type->array.has_implicit_size = true;
10397                 new_type->array.size              = 1;
10398
10399                 type_t *const result = identify_new_type(new_type);
10400
10401                 decl->type = result;
10402         }
10403 }
10404
10405 void prepare_main_collect2(entity_t *entity)
10406 {
10407         PUSH_SCOPE(&entity->function.statement->compound.scope);
10408
10409         // create call to __main
10410         symbol_t *symbol         = symbol_table_insert("__main");
10411         entity_t *subsubmain_ent
10412                 = create_implicit_function(symbol, &builtin_source_position);
10413
10414         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10415         type_t       *ftype       = subsubmain_ent->declaration.type;
10416         ref->base.source_position = builtin_source_position;
10417         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10418         ref->reference.entity     = subsubmain_ent;
10419
10420         expression_t *call = allocate_expression_zero(EXPR_CALL);
10421         call->base.source_position = builtin_source_position;
10422         call->base.type            = type_void;
10423         call->call.function        = ref;
10424
10425         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10426         expr_statement->base.source_position  = builtin_source_position;
10427         expr_statement->expression.expression = call;
10428
10429         statement_t *statement = entity->function.statement;
10430         assert(statement->kind == STATEMENT_COMPOUND);
10431         compound_statement_t *compounds = &statement->compound;
10432
10433         expr_statement->base.next = compounds->statements;
10434         compounds->statements     = expr_statement;
10435
10436         POP_SCOPE();
10437 }
10438
10439 void parse(void)
10440 {
10441         lookahead_bufpos = 0;
10442         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10443                 next_token();
10444         }
10445         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10446         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10447         parse_translation_unit();
10448         complete_incomplete_arrays();
10449         DEL_ARR_F(incomplete_arrays);
10450         incomplete_arrays = NULL;
10451 }
10452
10453 /**
10454  * Initialize the parser.
10455  */
10456 void init_parser(void)
10457 {
10458         sym_anonymous = symbol_table_insert("<anonymous>");
10459
10460         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10461
10462         init_expression_parsers();
10463         obstack_init(&temp_obst);
10464 }
10465
10466 /**
10467  * Terminate the parser.
10468  */
10469 void exit_parser(void)
10470 {
10471         obstack_free(&temp_obst, NULL);
10472 }